initial commitupstream/1.6.0rc3upstream/1.5.93

Signed-off-by: Gui Chen <gui.chen@intel.com>

23 files changed, 6846 insertions, 0 deletions

diff --git a/net/Makefile.objs b/net/Makefile.objs
new file mode 100644
index 000000000..4854a14fe
--- /dev/null
+++ b/net/Makefile.objs
@@ -0,0 +1,13 @@
+common-obj-y = net.o queue.o checksum.o util.o hub.o
+common-obj-y += socket.o
+common-obj-y += dump.o
+common-obj-y += eth.o
+common-obj-$(CONFIG_POSIX) += tap.o
+common-obj-$(CONFIG_LINUX) += tap-linux.o
+common-obj-$(CONFIG_WIN32) += tap-win32.o
+common-obj-$(CONFIG_BSD) += tap-bsd.o
+common-obj-$(CONFIG_SOLARIS) += tap-solaris.o
+common-obj-$(CONFIG_AIX) += tap-aix.o
+common-obj-$(CONFIG_HAIKU) += tap-haiku.o
+common-obj-$(CONFIG_SLIRP) += slirp.o
+common-obj-$(CONFIG_VDE) += vde.o
diff --git a/net/checksum.c b/net/checksum.c
new file mode 100644
index 000000000..14c08550e
--- /dev/null
+++ b/net/checksum.c
@@ -0,0 +1,115 @@
+/*
+ *  IP checksumming functions.
+ *  (c) 2008 Gerd Hoffmann <kraxel@redhat.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; under version 2 or later of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu-common.h"
+#include "net/checksum.h"
+
+#define PROTO_TCP  6
+#define PROTO_UDP 17
+
+uint32_t net_checksum_add_cont(int len, uint8_t *buf, int seq)
+{
+    uint32_t sum = 0;
+    int i;
+
+    for (i = seq; i < seq + len; i++) {
+        if (i & 1) {
+            sum += (uint32_t)buf[i - seq];
+        } else {
+            sum += (uint32_t)buf[i - seq] << 8;
+        }
+    }
+    return sum;
+}
+
+uint16_t net_checksum_finish(uint32_t sum)
+{
+    while (sum>>16)
+	sum = (sum & 0xFFFF)+(sum >> 16);
+    return ~sum;
+}
+
+uint16_t net_checksum_tcpudp(uint16_t length, uint16_t proto,
+                             uint8_t *addrs, uint8_t *buf)
+{
+    uint32_t sum = 0;
+
+    sum += net_checksum_add(length, buf);         // payload
+    sum += net_checksum_add(8, addrs);            // src + dst address
+    sum += proto + length;                        // protocol & length
+    return net_checksum_finish(sum);
+}
+
+void net_checksum_calculate(uint8_t *data, int length)
+{
+    int hlen, plen, proto, csum_offset;
+    uint16_t csum;
+
+    if ((data[14] & 0xf0) != 0x40)
+	return; /* not IPv4 */
+    hlen  = (data[14] & 0x0f) * 4;
+    plen  = (data[16] << 8 | data[17]) - hlen;
+    proto = data[23];
+
+    switch (proto) {
+    case PROTO_TCP:
+	csum_offset = 16;
+	break;
+    case PROTO_UDP:
+	csum_offset = 6;
+	break;
+    default:
+	return;
+    }
+
+    if (plen < csum_offset+2)
+	return;
+
+    data[14+hlen+csum_offset]   = 0;
+    data[14+hlen+csum_offset+1] = 0;
+    csum = net_checksum_tcpudp(plen, proto, data+14+12, data+14+hlen);
+    data[14+hlen+csum_offset]   = csum >> 8;
+    data[14+hlen+csum_offset+1] = csum & 0xff;
+}
+
+uint32_t
+net_checksum_add_iov(const struct iovec *iov, const unsigned int iov_cnt,
+                     uint32_t iov_off, uint32_t size)
+{
+    size_t iovec_off, buf_off;
+    unsigned int i;
+    uint32_t res = 0;
+    uint32_t seq = 0;
+
+    iovec_off = 0;
+    buf_off = 0;
+    for (i = 0; i < iov_cnt && size; i++) {
+        if (iov_off < (iovec_off + iov[i].iov_len)) {
+            size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off , size);
+            void *chunk_buf = iov[i].iov_base + (iov_off - iovec_off);
+
+            res += net_checksum_add_cont(len, chunk_buf, seq);
+            seq += len;
+
+            buf_off += len;
+            iov_off += len;
+            size -= len;
+        }
+        iovec_off += iov[i].iov_len;
+    }
+    return res;
+}
diff --git a/net/clients.h b/net/clients.h
new file mode 100644
index 000000000..77932942b
--- /dev/null
+++ b/net/clients.h
@@ -0,0 +1,55 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef QEMU_NET_CLIENTS_H
+#define QEMU_NET_CLIENTS_H
+
+#include "net/net.h"
+#include "qapi-types.h"
+
+int net_init_dump(const NetClientOptions *opts, const char *name,
+                  NetClientState *peer);
+
+#ifdef CONFIG_SLIRP
+int net_init_slirp(const NetClientOptions *opts, const char *name,
+                   NetClientState *peer);
+#endif
+
+int net_init_hubport(const NetClientOptions *opts, const char *name,
+                     NetClientState *peer);
+
+int net_init_socket(const NetClientOptions *opts, const char *name,
+                    NetClientState *peer);
+
+int net_init_tap(const NetClientOptions *opts, const char *name,
+                 NetClientState *peer);
+
+int net_init_bridge(const NetClientOptions *opts, const char *name,
+                    NetClientState *peer);
+
+#ifdef CONFIG_VDE
+int net_init_vde(const NetClientOptions *opts, const char *name,
+                 NetClientState *peer);
+#endif
+
+#endif /* QEMU_NET_CLIENTS_H */
diff --git a/net/dump.c b/net/dump.c
new file mode 100644
index 000000000..411972172
--- /dev/null
+++ b/net/dump.c
@@ -0,0 +1,185 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "clients.h"
+#include "qemu-common.h"
+#include "qemu/error-report.h"
+#include "qemu/log.h"
+#include "qemu/timer.h"
+#include "hub.h"
+
+typedef struct DumpState {
+    NetClientState nc;
+    int64_t start_ts;
+    int fd;
+    int pcap_caplen;
+} DumpState;
+
+#define PCAP_MAGIC 0xa1b2c3d4
+
+struct pcap_file_hdr {
+    uint32_t magic;
+    uint16_t version_major;
+    uint16_t version_minor;
+    int32_t thiszone;
+    uint32_t sigfigs;
+    uint32_t snaplen;
+    uint32_t linktype;
+};
+
+struct pcap_sf_pkthdr {
+    struct {
+        int32_t tv_sec;
+        int32_t tv_usec;
+    } ts;
+    uint32_t caplen;
+    uint32_t len;
+};
+
+static ssize_t dump_receive(NetClientState *nc, const uint8_t *buf, size_t size)
+{
+    DumpState *s = DO_UPCAST(DumpState, nc, nc);
+    struct pcap_sf_pkthdr hdr;
+    int64_t ts;
+    int caplen;
+
+    /* Early return in case of previous error. */
+    if (s->fd < 0) {
+        return size;
+    }
+
+    ts = muldiv64(qemu_get_clock_ns(vm_clock), 1000000, get_ticks_per_sec());
+    caplen = size > s->pcap_caplen ? s->pcap_caplen : size;
+
+    hdr.ts.tv_sec = ts / 1000000 + s->start_ts;
+    hdr.ts.tv_usec = ts % 1000000;
+    hdr.caplen = caplen;
+    hdr.len = size;
+    if (write(s->fd, &hdr, sizeof(hdr)) != sizeof(hdr) ||
+        write(s->fd, buf, caplen) != caplen) {
+        qemu_log("-net dump write error - stop dump\n");
+        close(s->fd);
+        s->fd = -1;
+    }
+
+    return size;
+}
+
+static void dump_cleanup(NetClientState *nc)
+{
+    DumpState *s = DO_UPCAST(DumpState, nc, nc);
+
+    close(s->fd);
+}
+
+static NetClientInfo net_dump_info = {
+    .type = NET_CLIENT_OPTIONS_KIND_DUMP,
+    .size = sizeof(DumpState),
+    .receive = dump_receive,
+    .cleanup = dump_cleanup,
+};
+
+static int net_dump_init(NetClientState *peer, const char *device,
+                         const char *name, const char *filename, int len)
+{
+    struct pcap_file_hdr hdr;
+    NetClientState *nc;
+    DumpState *s;
+    struct tm tm;
+    int fd;
+
+    fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY | O_BINARY, 0644);
+    if (fd < 0) {
+        error_report("-net dump: can't open %s", filename);
+        return -1;
+    }
+
+    hdr.magic = PCAP_MAGIC;
+    hdr.version_major = 2;
+    hdr.version_minor = 4;
+    hdr.thiszone = 0;
+    hdr.sigfigs = 0;
+    hdr.snaplen = len;
+    hdr.linktype = 1;
+
+    if (write(fd, &hdr, sizeof(hdr)) < sizeof(hdr)) {
+        error_report("-net dump write error: %s", strerror(errno));
+        close(fd);
+        return -1;
+    }
+
+    nc = qemu_new_net_client(&net_dump_info, peer, device, name);
+
+    snprintf(nc->info_str, sizeof(nc->info_str),
+             "dump to %s (len=%d)", filename, len);
+
+    s = DO_UPCAST(DumpState, nc, nc);
+
+    s->fd = fd;
+    s->pcap_caplen = len;
+
+    qemu_get_timedate(&tm, 0);
+    s->start_ts = mktime(&tm);
+
+    return 0;
+}
+
+int net_init_dump(const NetClientOptions *opts, const char *name,
+                  NetClientState *peer)
+{
+    int len;
+    const char *file;
+    char def_file[128];
+    const NetdevDumpOptions *dump;
+
+    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_DUMP);
+    dump = opts->dump;
+
+    assert(peer);
+
+    if (dump->has_file) {
+        file = dump->file;
+    } else {
+        int id;
+        int ret;
+
+        ret = net_hub_id_for_client(peer, &id);
+        assert(ret == 0); /* peer must be on a hub */
+
+        snprintf(def_file, sizeof(def_file), "qemu-vlan%d.pcap", id);
+        file = def_file;
+    }
+
+    if (dump->has_len) {
+        if (dump->len > INT_MAX) {
+            error_report("invalid length: %"PRIu64, dump->len);
+            return -1;
+        }
+        len = dump->len;
+    } else {
+        len = 65536;
+    }
+
+    return net_dump_init(peer, "dump", name, file, len);
+}
diff --git a/net/eth.c b/net/eth.c
new file mode 100644
index 000000000..7c61132cb
--- /dev/null
+++ b/net/eth.c
@@ -0,0 +1,217 @@
+/*
+ * QEMU network structures definitions and helper functions
+ *
+ * Copyright (c) 2012 Ravello Systems LTD (http://ravellosystems.com)
+ *
+ * Developed by Daynix Computing LTD (http://www.daynix.com)
+ *
+ * Authors:
+ * Dmitry Fleytman <dmitry@daynix.com>
+ * Tamir Shomer <tamirs@daynix.com>
+ * Yan Vugenfirer <yan@daynix.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "net/eth.h"
+#include "net/checksum.h"
+#include "qemu-common.h"
+#include "net/tap.h"
+
+void eth_setup_vlan_headers(struct eth_header *ehdr, uint16_t vlan_tag,
+    bool *is_new)
+{
+    struct vlan_header *vhdr = PKT_GET_VLAN_HDR(ehdr);
+
+    switch (be16_to_cpu(ehdr->h_proto)) {
+    case ETH_P_VLAN:
+    case ETH_P_DVLAN:
+        /* vlan hdr exists */
+        *is_new = false;
+        break;
+
+    default:
+        /* No VLAN header, put a new one */
+        vhdr->h_proto = ehdr->h_proto;
+        ehdr->h_proto = cpu_to_be16(ETH_P_VLAN);
+        *is_new = true;
+        break;
+    }
+    vhdr->h_tci = cpu_to_be16(vlan_tag);
+}
+
+uint8_t
+eth_get_gso_type(uint16_t l3_proto, uint8_t *l3_hdr, uint8_t l4proto)
+{
+    uint8_t ecn_state = 0;
+
+    if (l3_proto == ETH_P_IP) {
+        struct ip_header *iphdr = (struct ip_header *) l3_hdr;
+
+        if (IP_HEADER_VERSION(iphdr) == IP_HEADER_VERSION_4) {
+            if (IPTOS_ECN(iphdr->ip_tos) == IPTOS_ECN_CE) {
+                ecn_state = VIRTIO_NET_HDR_GSO_ECN;
+            }
+            if (l4proto == IP_PROTO_TCP) {
+                return VIRTIO_NET_HDR_GSO_TCPV4 | ecn_state;
+            } else if (l4proto == IP_PROTO_UDP) {
+                return VIRTIO_NET_HDR_GSO_UDP | ecn_state;
+            }
+        }
+    } else if (l3_proto == ETH_P_IPV6) {
+        struct ip6_header *ip6hdr = (struct ip6_header *) l3_hdr;
+
+        if (IP6_ECN(ip6hdr->ip6_ecn_acc) == IP6_ECN_CE) {
+            ecn_state = VIRTIO_NET_HDR_GSO_ECN;
+        }
+
+        if (l4proto == IP_PROTO_TCP) {
+            return VIRTIO_NET_HDR_GSO_TCPV6 | ecn_state;
+        }
+    }
+
+    /* Unsupported offload */
+    g_assert_not_reached();
+
+    return VIRTIO_NET_HDR_GSO_NONE | ecn_state;
+}
+
+void eth_get_protocols(const uint8_t *headers,
+                       uint32_t hdr_length,
+                       bool *isip4, bool *isip6,
+                       bool *isudp, bool *istcp)
+{
+    int proto;
+    size_t l2hdr_len = eth_get_l2_hdr_length(headers);
+    assert(hdr_length >= eth_get_l2_hdr_length(headers));
+    *isip4 = *isip6 = *isudp = *istcp = false;
+
+    proto = eth_get_l3_proto(headers, l2hdr_len);
+    if (proto == ETH_P_IP) {
+        *isip4 = true;
+
+        struct ip_header *iphdr;
+
+        assert(hdr_length >=
+            eth_get_l2_hdr_length(headers) + sizeof(struct ip_header));
+
+        iphdr = PKT_GET_IP_HDR(headers);
+
+        if (IP_HEADER_VERSION(iphdr) == IP_HEADER_VERSION_4) {
+            if (iphdr->ip_p == IP_PROTO_TCP) {
+                *istcp = true;
+            } else if (iphdr->ip_p == IP_PROTO_UDP) {
+                *isudp = true;
+            }
+        }
+    } else if (proto == ETH_P_IPV6) {
+        uint8_t l4proto;
+        size_t full_ip6hdr_len;
+
+        struct iovec hdr_vec;
+        hdr_vec.iov_base = (void *) headers;
+        hdr_vec.iov_len = hdr_length;
+
+        *isip6 = true;
+        if (eth_parse_ipv6_hdr(&hdr_vec, 1, l2hdr_len,
+                              &l4proto, &full_ip6hdr_len)) {
+            if (l4proto == IP_PROTO_TCP) {
+                *istcp = true;
+            } else if (l4proto == IP_PROTO_UDP) {
+                *isudp = true;
+            }
+        }
+    }
+}
+
+void
+eth_setup_ip4_fragmentation(const void *l2hdr, size_t l2hdr_len,
+                            void *l3hdr, size_t l3hdr_len,
+                            size_t l3payload_len,
+                            size_t frag_offset, bool more_frags)
+{
+    if (eth_get_l3_proto(l2hdr, l2hdr_len) == ETH_P_IP) {
+        uint16_t orig_flags;
+        struct ip_header *iphdr = (struct ip_header *) l3hdr;
+        uint16_t frag_off_units = frag_offset / IP_FRAG_UNIT_SIZE;
+        uint16_t new_ip_off;
+
+        assert(frag_offset % IP_FRAG_UNIT_SIZE == 0);
+        assert((frag_off_units & ~IP_OFFMASK) == 0);
+
+        orig_flags = be16_to_cpu(iphdr->ip_off) & ~(IP_OFFMASK|IP_MF);
+        new_ip_off = frag_off_units | orig_flags  | (more_frags ? IP_MF : 0);
+        iphdr->ip_off = cpu_to_be16(new_ip_off);
+        iphdr->ip_len = cpu_to_be16(l3payload_len + l3hdr_len);
+    }
+}
+
+void
+eth_fix_ip4_checksum(void *l3hdr, size_t l3hdr_len)
+{
+    struct ip_header *iphdr = (struct ip_header *) l3hdr;
+    iphdr->ip_sum = 0;
+    iphdr->ip_sum = cpu_to_be16(net_raw_checksum(l3hdr, l3hdr_len));
+}
+
+uint32_t
+eth_calc_pseudo_hdr_csum(struct ip_header *iphdr, uint16_t csl)
+{
+    struct ip_pseudo_header ipph;
+    ipph.ip_src = iphdr->ip_src;
+    ipph.ip_dst = iphdr->ip_dst;
+    ipph.ip_payload = cpu_to_be16(csl);
+    ipph.ip_proto = iphdr->ip_p;
+    ipph.zeros = 0;
+    return net_checksum_add(sizeof(ipph), (uint8_t *) &ipph);
+}
+
+static bool
+eth_is_ip6_extension_header_type(uint8_t hdr_type)
+{
+    switch (hdr_type) {
+    case IP6_HOP_BY_HOP:
+    case IP6_ROUTING:
+    case IP6_FRAGMENT:
+    case IP6_ESP:
+    case IP6_AUTHENTICATION:
+    case IP6_DESTINATON:
+    case IP6_MOBILITY:
+        return true;
+    default:
+        return false;
+    }
+}
+
+bool eth_parse_ipv6_hdr(struct iovec *pkt, int pkt_frags,
+                        size_t ip6hdr_off, uint8_t *l4proto,
+                        size_t *full_hdr_len)
+{
+    struct ip6_header ip6_hdr;
+    struct ip6_ext_hdr ext_hdr;
+    size_t bytes_read;
+
+    bytes_read = iov_to_buf(pkt, pkt_frags, ip6hdr_off,
+                            &ip6_hdr, sizeof(ip6_hdr));
+    if (bytes_read < sizeof(ip6_hdr)) {
+        return false;
+    }
+
+    *full_hdr_len = sizeof(struct ip6_header);
+
+    if (!eth_is_ip6_extension_header_type(ip6_hdr.ip6_nxt)) {
+        *l4proto = ip6_hdr.ip6_nxt;
+        return true;
+    }
+
+    do {
+        bytes_read = iov_to_buf(pkt, pkt_frags, ip6hdr_off + *full_hdr_len,
+                                &ext_hdr, sizeof(ext_hdr));
+        *full_hdr_len += (ext_hdr.ip6r_len + 1) * IP6_EXT_GRANULARITY;
+    } while (eth_is_ip6_extension_header_type(ext_hdr.ip6r_nxt));
+
+    *l4proto = ext_hdr.ip6r_nxt;
+    return true;
+}
diff --git a/net/hub.c b/net/hub.c
new file mode 100644
index 000000000..df32074de
--- /dev/null
+++ b/net/hub.c
@@ -0,0 +1,354 @@
+/*
+ * Hub net client
+ *
+ * Copyright IBM, Corp. 2012
+ *
+ * Authors:
+ *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
+ *  Zhi Yong Wu       <wuzhy@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#include "monitor/monitor.h"
+#include "net/net.h"
+#include "clients.h"
+#include "hub.h"
+#include "qemu/iov.h"
+
+/*
+ * A hub broadcasts incoming packets to all its ports except the source port.
+ * Hubs can be used to provide independent network segments, also confusingly
+ * named the QEMU 'vlan' feature.
+ */
+
+typedef struct NetHub NetHub;
+
+typedef struct NetHubPort {
+    NetClientState nc;
+    QLIST_ENTRY(NetHubPort) next;
+    NetHub *hub;
+    int id;
+} NetHubPort;
+
+struct NetHub {
+    int id;
+    QLIST_ENTRY(NetHub) next;
+    int num_ports;
+    QLIST_HEAD(, NetHubPort) ports;
+};
+
+static QLIST_HEAD(, NetHub) hubs = QLIST_HEAD_INITIALIZER(&hubs);
+
+static ssize_t net_hub_receive(NetHub *hub, NetHubPort *source_port,
+                               const uint8_t *buf, size_t len)
+{
+    NetHubPort *port;
+
+    QLIST_FOREACH(port, &hub->ports, next) {
+        if (port == source_port) {
+            continue;
+        }
+
+        qemu_send_packet(&port->nc, buf, len);
+    }
+    return len;
+}
+
+static ssize_t net_hub_receive_iov(NetHub *hub, NetHubPort *source_port,
+                                   const struct iovec *iov, int iovcnt)
+{
+    NetHubPort *port;
+    ssize_t len = iov_size(iov, iovcnt);
+
+    QLIST_FOREACH(port, &hub->ports, next) {
+        if (port == source_port) {
+            continue;
+        }
+
+        qemu_sendv_packet(&port->nc, iov, iovcnt);
+    }
+    return len;
+}
+
+static NetHub *net_hub_new(int id)
+{
+    NetHub *hub;
+
+    hub = g_malloc(sizeof(*hub));
+    hub->id = id;
+    hub->num_ports = 0;
+    QLIST_INIT(&hub->ports);
+
+    QLIST_INSERT_HEAD(&hubs, hub, next);
+
+    return hub;
+}
+
+static int net_hub_port_can_receive(NetClientState *nc)
+{
+    NetHubPort *port;
+    NetHubPort *src_port = DO_UPCAST(NetHubPort, nc, nc);
+    NetHub *hub = src_port->hub;
+
+    QLIST_FOREACH(port, &hub->ports, next) {
+        if (port == src_port) {
+            continue;
+        }
+
+        if (qemu_can_send_packet(&port->nc)) {
+            return 1;
+        }
+    }
+
+    return 0;
+}
+
+static ssize_t net_hub_port_receive(NetClientState *nc,
+                                    const uint8_t *buf, size_t len)
+{
+    NetHubPort *port = DO_UPCAST(NetHubPort, nc, nc);
+
+    return net_hub_receive(port->hub, port, buf, len);
+}
+
+static ssize_t net_hub_port_receive_iov(NetClientState *nc,
+                                        const struct iovec *iov, int iovcnt)
+{
+    NetHubPort *port = DO_UPCAST(NetHubPort, nc, nc);
+
+    return net_hub_receive_iov(port->hub, port, iov, iovcnt);
+}
+
+static void net_hub_port_cleanup(NetClientState *nc)
+{
+    NetHubPort *port = DO_UPCAST(NetHubPort, nc, nc);
+
+    QLIST_REMOVE(port, next);
+}
+
+static NetClientInfo net_hub_port_info = {
+    .type = NET_CLIENT_OPTIONS_KIND_HUBPORT,
+    .size = sizeof(NetHubPort),
+    .can_receive = net_hub_port_can_receive,
+    .receive = net_hub_port_receive,
+    .receive_iov = net_hub_port_receive_iov,
+    .cleanup = net_hub_port_cleanup,
+};
+
+static NetHubPort *net_hub_port_new(NetHub *hub, const char *name)
+{
+    NetClientState *nc;
+    NetHubPort *port;
+    int id = hub->num_ports++;
+    char default_name[128];
+
+    if (!name) {
+        snprintf(default_name, sizeof(default_name),
+                 "hub%dport%d", hub->id, id);
+        name = default_name;
+    }
+
+    nc = qemu_new_net_client(&net_hub_port_info, NULL, "hub", name);
+    port = DO_UPCAST(NetHubPort, nc, nc);
+    port->id = id;
+    port->hub = hub;
+
+    QLIST_INSERT_HEAD(&hub->ports, port, next);
+
+    return port;
+}
+
+/**
+ * Create a port on a given hub
+ * @name: Net client name or NULL for default name.
+ *
+ * If there is no existing hub with the given id then a new hub is created.
+ */
+NetClientState *net_hub_add_port(int hub_id, const char *name)
+{
+    NetHub *hub;
+    NetHubPort *port;
+
+    QLIST_FOREACH(hub, &hubs, next) {
+        if (hub->id == hub_id) {
+            break;
+        }
+    }
+
+    if (!hub) {
+        hub = net_hub_new(hub_id);
+    }
+
+    port = net_hub_port_new(hub, name);
+    return &port->nc;
+}
+
+/**
+ * Find a specific client on a hub
+ */
+NetClientState *net_hub_find_client_by_name(int hub_id, const char *name)
+{
+    NetHub *hub;
+    NetHubPort *port;
+    NetClientState *peer;
+
+    QLIST_FOREACH(hub, &hubs, next) {
+        if (hub->id == hub_id) {
+            QLIST_FOREACH(port, &hub->ports, next) {
+                peer = port->nc.peer;
+
+                if (peer && strcmp(peer->name, name) == 0) {
+                    return peer;
+                }
+            }
+        }
+    }
+    return NULL;
+}
+
+/**
+ * Find a available port on a hub; otherwise create one new port
+ */
+NetClientState *net_hub_port_find(int hub_id)
+{
+    NetHub *hub;
+    NetHubPort *port;
+    NetClientState *nc;
+
+    QLIST_FOREACH(hub, &hubs, next) {
+        if (hub->id == hub_id) {
+            QLIST_FOREACH(port, &hub->ports, next) {
+                nc = port->nc.peer;
+                if (!nc) {
+                    return &(port->nc);
+                }
+            }
+            break;
+        }
+    }
+
+    nc = net_hub_add_port(hub_id, NULL);
+    return nc;
+}
+
+/**
+ * Print hub configuration
+ */
+void net_hub_info(Monitor *mon)
+{
+    NetHub *hub;
+    NetHubPort *port;
+
+    QLIST_FOREACH(hub, &hubs, next) {
+        monitor_printf(mon, "hub %d\n", hub->id);
+        QLIST_FOREACH(port, &hub->ports, next) {
+            if (port->nc.peer) {
+                monitor_printf(mon, " \\ ");
+                print_net_client(mon, port->nc.peer);
+            }
+        }
+    }
+}
+
+/**
+ * Get the hub id that a client is connected to
+ *
+ * @id: Pointer for hub id output, may be NULL
+ */
+int net_hub_id_for_client(NetClientState *nc, int *id)
+{
+    NetHubPort *port;
+
+    if (nc->info->type == NET_CLIENT_OPTIONS_KIND_HUBPORT) {
+        port = DO_UPCAST(NetHubPort, nc, nc);
+    } else if (nc->peer != NULL && nc->peer->info->type ==
+            NET_CLIENT_OPTIONS_KIND_HUBPORT) {
+        port = DO_UPCAST(NetHubPort, nc, nc->peer);
+    } else {
+        return -ENOENT;
+    }
+
+    if (id) {
+        *id = port->hub->id;
+    }
+    return 0;
+}
+
+int net_init_hubport(const NetClientOptions *opts, const char *name,
+                     NetClientState *peer)
+{
+    const NetdevHubPortOptions *hubport;
+
+    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_HUBPORT);
+    hubport = opts->hubport;
+
+    /* Treat hub port like a backend, NIC must be the one to peer */
+    if (peer) {
+        return -EINVAL;
+    }
+
+    net_hub_add_port(hubport->hubid, name);
+    return 0;
+}
+
+/**
+ * Warn if hub configurations are likely wrong
+ */
+void net_hub_check_clients(void)
+{
+    NetHub *hub;
+    NetHubPort *port;
+    NetClientState *peer;
+
+    QLIST_FOREACH(hub, &hubs, next) {
+        int has_nic = 0, has_host_dev = 0;
+
+        QLIST_FOREACH(port, &hub->ports, next) {
+            peer = port->nc.peer;
+            if (!peer) {
+                fprintf(stderr, "Warning: hub port %s has no peer\n",
+                        port->nc.name);
+                continue;
+            }
+
+            switch (peer->info->type) {
+            case NET_CLIENT_OPTIONS_KIND_NIC:
+                has_nic = 1;
+                break;
+            case NET_CLIENT_OPTIONS_KIND_USER:
+            case NET_CLIENT_OPTIONS_KIND_TAP:
+            case NET_CLIENT_OPTIONS_KIND_SOCKET:
+            case NET_CLIENT_OPTIONS_KIND_VDE:
+                has_host_dev = 1;
+                break;
+            default:
+                break;
+            }
+        }
+        if (has_host_dev && !has_nic) {
+            fprintf(stderr, "Warning: vlan %d with no nics\n", hub->id);
+        }
+        if (has_nic && !has_host_dev) {
+            fprintf(stderr,
+                    "Warning: vlan %d is not connected to host network\n",
+                    hub->id);
+        }
+    }
+}
+
+bool net_hub_flush(NetClientState *nc)
+{
+    NetHubPort *port;
+    NetHubPort *source_port = DO_UPCAST(NetHubPort, nc, nc);
+    int ret = 0;
+
+    QLIST_FOREACH(port, &source_port->hub->ports, next) {
+        if (port != source_port) {
+            ret += qemu_net_queue_flush(port->nc.send_queue);
+        }
+    }
+    return ret ? true : false;
+}
diff --git a/net/hub.h b/net/hub.h
new file mode 100644
index 000000000..a625effe0
--- /dev/null
+++ b/net/hub.h
@@ -0,0 +1,26 @@
+/*
+ * Hub net client
+ *
+ * Copyright IBM, Corp. 2012
+ *
+ * Authors:
+ *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
+ *  Zhi Yong Wu       <wuzhy@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#ifndef NET_HUB_H
+#define NET_HUB_H
+
+#include "qemu-common.h"
+
+NetClientState *net_hub_add_port(int hub_id, const char *name);
+NetClientState *net_hub_find_client_by_name(int hub_id, const char *name);
+void net_hub_info(Monitor *mon);
+void net_hub_check_clients(void);
+bool net_hub_flush(NetClientState *nc);
+
+#endif /* NET_HUB_H */
diff --git a/net/net.c b/net/net.c
new file mode 100644
index 000000000..c0d61bf78
--- /dev/null
+++ b/net/net.c
@@ -0,0 +1,1250 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "config-host.h"
+
+#include "net/net.h"
+#include "clients.h"
+#include "hub.h"
+#include "net/slirp.h"
+#include "util.h"
+
+#include "monitor/monitor.h"
+#include "qemu-common.h"
+#include "qemu/sockets.h"
+#include "qemu/config-file.h"
+#include "qmp-commands.h"
+#include "hw/qdev.h"
+#include "qemu/iov.h"
+#include "qapi-visit.h"
+#include "qapi/opts-visitor.h"
+#include "qapi/dealloc-visitor.h"
+
+/* Net bridge is currently not supported for W32. */
+#if !defined(_WIN32)
+# define CONFIG_NET_BRIDGE
+#endif
+
+static QTAILQ_HEAD(, NetClientState) net_clients;
+
+int default_net = 1;
+
+/***********************************************************/
+/* network device redirectors */
+
+#if defined(DEBUG_NET)
+static void hex_dump(FILE *f, const uint8_t *buf, int size)
+{
+    int len, i, j, c;
+
+    for(i=0;i<size;i+=16) {
+        len = size - i;
+        if (len > 16)
+            len = 16;
+        fprintf(f, "%08x ", i);
+        for(j=0;j<16;j++) {
+            if (j < len)
+                fprintf(f, " %02x", buf[i+j]);
+            else
+                fprintf(f, "   ");
+        }
+        fprintf(f, " ");
+        for(j=0;j<len;j++) {
+            c = buf[i+j];
+            if (c < ' ' || c > '~')
+                c = '.';
+            fprintf(f, "%c", c);
+        }
+        fprintf(f, "\n");
+    }
+}
+#endif
+
+static int get_str_sep(char *buf, int buf_size, const char **pp, int sep)
+{
+    const char *p, *p1;
+    int len;
+    p = *pp;
+    p1 = strchr(p, sep);
+    if (!p1)
+        return -1;
+    len = p1 - p;
+    p1++;
+    if (buf_size > 0) {
+        if (len > buf_size - 1)
+            len = buf_size - 1;
+        memcpy(buf, p, len);
+        buf[len] = '\0';
+    }
+    *pp = p1;
+    return 0;
+}
+
+int parse_host_port(struct sockaddr_in *saddr, const char *str)
+{
+    char buf[512];
+    struct hostent *he;
+    const char *p, *r;
+    int port;
+
+    p = str;
+    if (get_str_sep(buf, sizeof(buf), &p, ':') < 0)
+        return -1;
+    saddr->sin_family = AF_INET;
+    if (buf[0] == '\0') {
+        saddr->sin_addr.s_addr = 0;
+    } else {
+        if (qemu_isdigit(buf[0])) {
+            if (!inet_aton(buf, &saddr->sin_addr))
+                return -1;
+        } else {
+            if ((he = gethostbyname(buf)) == NULL)
+                return - 1;
+            saddr->sin_addr = *(struct in_addr *)he->h_addr;
+        }
+    }
+    port = strtol(p, (char **)&r, 0);
+    if (r == p)
+        return -1;
+    saddr->sin_port = htons(port);
+    return 0;
+}
+
+void qemu_format_nic_info_str(NetClientState *nc, uint8_t macaddr[6])
+{
+    snprintf(nc->info_str, sizeof(nc->info_str),
+             "model=%s,macaddr=%02x:%02x:%02x:%02x:%02x:%02x",
+             nc->model,
+             macaddr[0], macaddr[1], macaddr[2],
+             macaddr[3], macaddr[4], macaddr[5]);
+}
+
+void qemu_macaddr_default_if_unset(MACAddr *macaddr)
+{
+    static int index = 0;
+    static const MACAddr zero = { .a = { 0,0,0,0,0,0 } };
+
+    if (memcmp(macaddr, &zero, sizeof(zero)) != 0)
+        return;
+    macaddr->a[0] = 0x52;
+    macaddr->a[1] = 0x54;
+    macaddr->a[2] = 0x00;
+    macaddr->a[3] = 0x12;
+    macaddr->a[4] = 0x34;
+    macaddr->a[5] = 0x56 + index++;
+}
+
+/**
+ * Generate a name for net client
+ *
+ * Only net clients created with the legacy -net option and NICs need this.
+ */
+static char *assign_name(NetClientState *nc1, const char *model)
+{
+    NetClientState *nc;
+    char buf[256];
+    int id = 0;
+
+    QTAILQ_FOREACH(nc, &net_clients, next) {
+        if (nc == nc1) {
+            continue;
+        }
+        if (strcmp(nc->model, model) == 0) {
+            id++;
+        }
+    }
+
+    snprintf(buf, sizeof(buf), "%s.%d", model, id);
+
+    return g_strdup(buf);
+}
+
+static void qemu_net_client_destructor(NetClientState *nc)
+{
+    g_free(nc);
+}
+
+static void qemu_net_client_setup(NetClientState *nc,
+                                  NetClientInfo *info,
+                                  NetClientState *peer,
+                                  const char *model,
+                                  const char *name,
+                                  NetClientDestructor *destructor)
+{
+    nc->info = info;
+    nc->model = g_strdup(model);
+    if (name) {
+        nc->name = g_strdup(name);
+    } else {
+        nc->name = assign_name(nc, model);
+    }
+
+    if (peer) {
+        assert(!peer->peer);
+        nc->peer = peer;
+        peer->peer = nc;
+    }
+    QTAILQ_INSERT_TAIL(&net_clients, nc, next);
+
+    nc->send_queue = qemu_new_net_queue(nc);
+    nc->destructor = destructor;
+}
+
+NetClientState *qemu_new_net_client(NetClientInfo *info,
+                                    NetClientState *peer,
+                                    const char *model,
+                                    const char *name)
+{
+    NetClientState *nc;
+
+    assert(info->size >= sizeof(NetClientState));
+
+    nc = g_malloc0(info->size);
+    qemu_net_client_setup(nc, info, peer, model, name,
+                          qemu_net_client_destructor);
+
+    return nc;
+}
+
+NICState *qemu_new_nic(NetClientInfo *info,
+                       NICConf *conf,
+                       const char *model,
+                       const char *name,
+                       void *opaque)
+{
+    NetClientState **peers = conf->peers.ncs;
+    NICState *nic;
+    int i, queues = MAX(1, conf->queues);
+
+    assert(info->type == NET_CLIENT_OPTIONS_KIND_NIC);
+    assert(info->size >= sizeof(NICState));
+
+    nic = g_malloc0(info->size + sizeof(NetClientState) * queues);
+    nic->ncs = (void *)nic + info->size;
+    nic->conf = conf;
+    nic->opaque = opaque;
+
+    for (i = 0; i < queues; i++) {
+        qemu_net_client_setup(&nic->ncs[i], info, peers[i], model, name,
+                              NULL);
+        nic->ncs[i].queue_index = i;
+    }
+
+    return nic;
+}
+
+NetClientState *qemu_get_subqueue(NICState *nic, int queue_index)
+{
+    return nic->ncs + queue_index;
+}
+
+NetClientState *qemu_get_queue(NICState *nic)
+{
+    return qemu_get_subqueue(nic, 0);
+}
+
+NICState *qemu_get_nic(NetClientState *nc)
+{
+    NetClientState *nc0 = nc - nc->queue_index;
+
+    return (NICState *)((void *)nc0 - nc->info->size);
+}
+
+void *qemu_get_nic_opaque(NetClientState *nc)
+{
+    NICState *nic = qemu_get_nic(nc);
+
+    return nic->opaque;
+}
+
+static void qemu_cleanup_net_client(NetClientState *nc)
+{
+    QTAILQ_REMOVE(&net_clients, nc, next);
+
+    if (nc->info->cleanup) {
+        nc->info->cleanup(nc);
+    }
+}
+
+static void qemu_free_net_client(NetClientState *nc)
+{
+    if (nc->send_queue) {
+        qemu_del_net_queue(nc->send_queue);
+    }
+    if (nc->peer) {
+        nc->peer->peer = NULL;
+    }
+    g_free(nc->name);
+    g_free(nc->model);
+    if (nc->destructor) {
+        nc->destructor(nc);
+    }
+}
+
+void qemu_del_net_client(NetClientState *nc)
+{
+    NetClientState *ncs[MAX_QUEUE_NUM];
+    int queues, i;
+
+    /* If the NetClientState belongs to a multiqueue backend, we will change all
+     * other NetClientStates also.
+     */
+    queues = qemu_find_net_clients_except(nc->name, ncs,
+                                          NET_CLIENT_OPTIONS_KIND_NIC,
+                                          MAX_QUEUE_NUM);
+    assert(queues != 0);
+
+    /* If there is a peer NIC, delete and cleanup client, but do not free. */
+    if (nc->peer && nc->peer->info->type == NET_CLIENT_OPTIONS_KIND_NIC) {
+        NICState *nic = qemu_get_nic(nc->peer);
+        if (nic->peer_deleted) {
+            return;
+        }
+        nic->peer_deleted = true;
+
+        for (i = 0; i < queues; i++) {
+            ncs[i]->peer->link_down = true;
+        }
+
+        if (nc->peer->info->link_status_changed) {
+            nc->peer->info->link_status_changed(nc->peer);
+        }
+
+        for (i = 0; i < queues; i++) {
+            qemu_cleanup_net_client(ncs[i]);
+        }
+
+        return;
+    }
+
+    assert(nc->info->type != NET_CLIENT_OPTIONS_KIND_NIC);
+
+    for (i = 0; i < queues; i++) {
+        qemu_cleanup_net_client(ncs[i]);
+        qemu_free_net_client(ncs[i]);
+    }
+}
+
+void qemu_del_nic(NICState *nic)
+{
+    int i, queues = MAX(nic->conf->queues, 1);
+
+    /* If this is a peer NIC and peer has already been deleted, free it now. */
+    if (nic->peer_deleted) {
+        for (i = 0; i < queues; i++) {
+            qemu_free_net_client(qemu_get_subqueue(nic, i)->peer);
+        }
+    }
+
+    for (i = queues - 1; i >= 0; i--) {
+        NetClientState *nc = qemu_get_subqueue(nic, i);
+
+        qemu_cleanup_net_client(nc);
+        qemu_free_net_client(nc);
+    }
+
+    g_free(nic);
+}
+
+void qemu_foreach_nic(qemu_nic_foreach func, void *opaque)
+{
+    NetClientState *nc;
+
+    QTAILQ_FOREACH(nc, &net_clients, next) {
+        if (nc->info->type == NET_CLIENT_OPTIONS_KIND_NIC) {
+            if (nc->queue_index == 0) {
+                func(qemu_get_nic(nc), opaque);
+            }
+        }
+    }
+}
+
+int qemu_can_send_packet(NetClientState *sender)
+{
+    if (!sender->peer) {
+        return 1;
+    }
+
+    if (sender->peer->receive_disabled) {
+        return 0;
+    } else if (sender->peer->info->can_receive &&
+               !sender->peer->info->can_receive(sender->peer)) {
+        return 0;
+    }
+    return 1;
+}
+
+ssize_t qemu_deliver_packet(NetClientState *sender,
+                            unsigned flags,
+                            const uint8_t *data,
+                            size_t size,
+                            void *opaque)
+{
+    NetClientState *nc = opaque;
+    ssize_t ret;
+
+    if (nc->link_down) {
+        return size;
+    }
+
+    if (nc->receive_disabled) {
+        return 0;
+    }
+
+    if (flags & QEMU_NET_PACKET_FLAG_RAW && nc->info->receive_raw) {
+        ret = nc->info->receive_raw(nc, data, size);
+    } else {
+        ret = nc->info->receive(nc, data, size);
+    }
+
+    if (ret == 0) {
+        nc->receive_disabled = 1;
+    };
+
+    return ret;
+}
+
+void qemu_purge_queued_packets(NetClientState *nc)
+{
+    if (!nc->peer) {
+        return;
+    }
+
+    qemu_net_queue_purge(nc->peer->send_queue, nc);
+}
+
+void qemu_flush_queued_packets(NetClientState *nc)
+{
+    nc->receive_disabled = 0;
+
+    if (nc->peer && nc->peer->info->type == NET_CLIENT_OPTIONS_KIND_HUBPORT) {
+        if (net_hub_flush(nc->peer)) {
+            qemu_notify_event();
+        }
+        return;
+    }
+    if (qemu_net_queue_flush(nc->send_queue)) {
+        /* We emptied the queue successfully, signal to the IO thread to repoll
+         * the file descriptor (for tap, for example).
+         */
+        qemu_notify_event();
+    }
+}
+
+static ssize_t qemu_send_packet_async_with_flags(NetClientState *sender,
+                                                 unsigned flags,
+                                                 const uint8_t *buf, int size,
+                                                 NetPacketSent *sent_cb)
+{
+    NetQueue *queue;
+
+#ifdef DEBUG_NET
+    printf("qemu_send_packet_async:\n");
+    hex_dump(stdout, buf, size);
+#endif
+
+    if (sender->link_down || !sender->peer) {
+        return size;
+    }
+
+    queue = sender->peer->send_queue;
+
+    return qemu_net_queue_send(queue, sender, flags, buf, size, sent_cb);
+}
+
+ssize_t qemu_send_packet_async(NetClientState *sender,
+                               const uint8_t *buf, int size,
+                               NetPacketSent *sent_cb)
+{
+    return qemu_send_packet_async_with_flags(sender, QEMU_NET_PACKET_FLAG_NONE,
+                                             buf, size, sent_cb);
+}
+
+void qemu_send_packet(NetClientState *nc, const uint8_t *buf, int size)
+{
+    qemu_send_packet_async(nc, buf, size, NULL);
+}
+
+ssize_t qemu_send_packet_raw(NetClientState *nc, const uint8_t *buf, int size)
+{
+    return qemu_send_packet_async_with_flags(nc, QEMU_NET_PACKET_FLAG_RAW,
+                                             buf, size, NULL);
+}
+
+static ssize_t nc_sendv_compat(NetClientState *nc, const struct iovec *iov,
+                               int iovcnt)
+{
+    uint8_t buffer[NET_BUFSIZE];
+    size_t offset;
+
+    offset = iov_to_buf(iov, iovcnt, 0, buffer, sizeof(buffer));
+
+    return nc->info->receive(nc, buffer, offset);
+}
+
+ssize_t qemu_deliver_packet_iov(NetClientState *sender,
+                                unsigned flags,
+                                const struct iovec *iov,
+                                int iovcnt,
+                                void *opaque)
+{
+    NetClientState *nc = opaque;
+    int ret;
+
+    if (nc->link_down) {
+        return iov_size(iov, iovcnt);
+    }
+
+    if (nc->receive_disabled) {
+        return 0;
+    }
+
+    if (nc->info->receive_iov) {
+        ret = nc->info->receive_iov(nc, iov, iovcnt);
+    } else {
+        ret = nc_sendv_compat(nc, iov, iovcnt);
+    }
+
+    if (ret == 0) {
+        nc->receive_disabled = 1;
+    }
+
+    return ret;
+}
+
+ssize_t qemu_sendv_packet_async(NetClientState *sender,
+                                const struct iovec *iov, int iovcnt,
+                                NetPacketSent *sent_cb)
+{
+    NetQueue *queue;
+
+    if (sender->link_down || !sender->peer) {
+        return iov_size(iov, iovcnt);
+    }
+
+    queue = sender->peer->send_queue;
+
+    return qemu_net_queue_send_iov(queue, sender,
+                                   QEMU_NET_PACKET_FLAG_NONE,
+                                   iov, iovcnt, sent_cb);
+}
+
+ssize_t
+qemu_sendv_packet(NetClientState *nc, const struct iovec *iov, int iovcnt)
+{
+    return qemu_sendv_packet_async(nc, iov, iovcnt, NULL);
+}
+
+NetClientState *qemu_find_netdev(const char *id)
+{
+    NetClientState *nc;
+
+    QTAILQ_FOREACH(nc, &net_clients, next) {
+        if (nc->info->type == NET_CLIENT_OPTIONS_KIND_NIC)
+            continue;
+        if (!strcmp(nc->name, id)) {
+            return nc;
+        }
+    }
+
+    return NULL;
+}
+
+int qemu_find_net_clients_except(const char *id, NetClientState **ncs,
+                                 NetClientOptionsKind type, int max)
+{
+    NetClientState *nc;
+    int ret = 0;
+
+    QTAILQ_FOREACH(nc, &net_clients, next) {
+        if (nc->info->type == type) {
+            continue;
+        }
+        if (!strcmp(nc->name, id)) {
+            if (ret < max) {
+                ncs[ret] = nc;
+            }
+            ret++;
+        }
+    }
+
+    return ret;
+}
+
+static int nic_get_free_idx(void)
+{
+    int index;
+
+    for (index = 0; index < MAX_NICS; index++)
+        if (!nd_table[index].used)
+            return index;
+    return -1;
+}
+
+int qemu_show_nic_models(const char *arg, const char *const *models)
+{
+    int i;
+
+    if (!arg || !is_help_option(arg)) {
+        return 0;
+    }
+
+    fprintf(stderr, "qemu: Supported NIC models: ");
+    for (i = 0 ; models[i]; i++)
+        fprintf(stderr, "%s%c", models[i], models[i+1] ? ',' : '\n');
+    return 1;
+}
+
+void qemu_check_nic_model(NICInfo *nd, const char *model)
+{
+    const char *models[2];
+
+    models[0] = model;
+    models[1] = NULL;
+
+    if (qemu_show_nic_models(nd->model, models))
+        exit(0);
+    if (qemu_find_nic_model(nd, models, model) < 0)
+        exit(1);
+}
+
+int qemu_find_nic_model(NICInfo *nd, const char * const *models,
+                        const char *default_model)
+{
+    int i;
+
+    if (!nd->model)
+        nd->model = g_strdup(default_model);
+
+    for (i = 0 ; models[i]; i++) {
+        if (strcmp(nd->model, models[i]) == 0)
+            return i;
+    }
+
+    error_report("Unsupported NIC model: %s", nd->model);
+    return -1;
+}
+
+static int net_init_nic(const NetClientOptions *opts, const char *name,
+                        NetClientState *peer)
+{
+    int idx;
+    NICInfo *nd;
+    const NetLegacyNicOptions *nic;
+
+    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_NIC);
+    nic = opts->nic;
+
+    idx = nic_get_free_idx();
+    if (idx == -1 || nb_nics >= MAX_NICS) {
+        error_report("Too Many NICs");
+        return -1;
+    }
+
+    nd = &nd_table[idx];
+
+    memset(nd, 0, sizeof(*nd));
+
+    if (nic->has_netdev) {
+        nd->netdev = qemu_find_netdev(nic->netdev);
+        if (!nd->netdev) {
+            error_report("netdev '%s' not found", nic->netdev);
+            return -1;
+        }
+    } else {
+        assert(peer);
+        nd->netdev = peer;
+    }
+    nd->name = g_strdup(name);
+    if (nic->has_model) {
+        nd->model = g_strdup(nic->model);
+    }
+    if (nic->has_addr) {
+        nd->devaddr = g_strdup(nic->addr);
+    }
+
+    if (nic->has_macaddr &&
+        net_parse_macaddr(nd->macaddr.a, nic->macaddr) < 0) {
+        error_report("invalid syntax for ethernet address");
+        return -1;
+    }
+    qemu_macaddr_default_if_unset(&nd->macaddr);
+
+    if (nic->has_vectors) {
+        if (nic->vectors > 0x7ffffff) {
+            error_report("invalid # of vectors: %"PRIu32, nic->vectors);
+            return -1;
+        }
+        nd->nvectors = nic->vectors;
+    } else {
+        nd->nvectors = DEV_NVECTORS_UNSPECIFIED;
+    }
+
+    nd->used = 1;
+    nb_nics++;
+
+    return idx;
+}
+
+
+static int (* const net_client_init_fun[NET_CLIENT_OPTIONS_KIND_MAX])(
+    const NetClientOptions *opts,
+    const char *name,
+    NetClientState *peer) = {
+        [NET_CLIENT_OPTIONS_KIND_NIC]       = net_init_nic,
+#ifdef CONFIG_SLIRP
+        [NET_CLIENT_OPTIONS_KIND_USER]      = net_init_slirp,
+#endif
+        [NET_CLIENT_OPTIONS_KIND_TAP]       = net_init_tap,
+        [NET_CLIENT_OPTIONS_KIND_SOCKET]    = net_init_socket,
+#ifdef CONFIG_VDE
+        [NET_CLIENT_OPTIONS_KIND_VDE]       = net_init_vde,
+#endif
+        [NET_CLIENT_OPTIONS_KIND_DUMP]      = net_init_dump,
+#ifdef CONFIG_NET_BRIDGE
+        [NET_CLIENT_OPTIONS_KIND_BRIDGE]    = net_init_bridge,
+#endif
+        [NET_CLIENT_OPTIONS_KIND_HUBPORT]   = net_init_hubport,
+};
+
+
+static int net_client_init1(const void *object, int is_netdev, Error **errp)
+{
+    union {
+        const Netdev    *netdev;
+        const NetLegacy *net;
+    } u;
+    const NetClientOptions *opts;
+    const char *name;
+
+    if (is_netdev) {
+        u.netdev = object;
+        opts = u.netdev->opts;
+        name = u.netdev->id;
+
+        switch (opts->kind) {
+#ifdef CONFIG_SLIRP
+        case NET_CLIENT_OPTIONS_KIND_USER:
+#endif
+        case NET_CLIENT_OPTIONS_KIND_TAP:
+        case NET_CLIENT_OPTIONS_KIND_SOCKET:
+#ifdef CONFIG_VDE
+        case NET_CLIENT_OPTIONS_KIND_VDE:
+#endif
+#ifdef CONFIG_NET_BRIDGE
+        case NET_CLIENT_OPTIONS_KIND_BRIDGE:
+#endif
+        case NET_CLIENT_OPTIONS_KIND_HUBPORT:
+            break;
+
+        default:
+            error_set(errp, QERR_INVALID_PARAMETER_VALUE, "type",
+                      "a netdev backend type");
+            return -1;
+        }
+    } else {
+        u.net = object;
+        opts = u.net->opts;
+        /* missing optional values have been initialized to "all bits zero" */
+        name = u.net->has_id ? u.net->id : u.net->name;
+    }
+
+    if (net_client_init_fun[opts->kind]) {
+        NetClientState *peer = NULL;
+
+        /* Do not add to a vlan if it's a -netdev or a nic with a netdev=
+         * parameter. */
+        if (!is_netdev &&
+            (opts->kind != NET_CLIENT_OPTIONS_KIND_NIC ||
+             !opts->nic->has_netdev)) {
+            peer = net_hub_add_port(u.net->has_vlan ? u.net->vlan : 0, NULL);
+        }
+
+        if (net_client_init_fun[opts->kind](opts, name, peer) < 0) {
+            /* TODO push error reporting into init() methods */
+            error_set(errp, QERR_DEVICE_INIT_FAILED,
+                      NetClientOptionsKind_lookup[opts->kind]);
+            return -1;
+        }
+    }
+    return 0;
+}
+
+
+static void net_visit(Visitor *v, int is_netdev, void **object, Error **errp)
+{
+    if (is_netdev) {
+        visit_type_Netdev(v, (Netdev **)object, NULL, errp);
+    } else {
+        visit_type_NetLegacy(v, (NetLegacy **)object, NULL, errp);
+    }
+}
+
+
+int net_client_init(QemuOpts *opts, int is_netdev, Error **errp)
+{
+    void *object = NULL;
+    Error *err = NULL;
+    int ret = -1;
+
+    {
+        OptsVisitor *ov = opts_visitor_new(opts);
+
+        net_visit(opts_get_visitor(ov), is_netdev, &object, &err);
+        opts_visitor_cleanup(ov);
+    }
+
+    if (!err) {
+        ret = net_client_init1(object, is_netdev, &err);
+    }
+
+    if (object) {
+        QapiDeallocVisitor *dv = qapi_dealloc_visitor_new();
+
+        net_visit(qapi_dealloc_get_visitor(dv), is_netdev, &object, NULL);
+        qapi_dealloc_visitor_cleanup(dv);
+    }
+
+    error_propagate(errp, err);
+    return ret;
+}
+
+
+static int net_host_check_device(const char *device)
+{
+    int i;
+    const char *valid_param_list[] = { "tap", "socket", "dump"
+#ifdef CONFIG_NET_BRIDGE
+                                       , "bridge"
+#endif
+#ifdef CONFIG_SLIRP
+                                       ,"user"
+#endif
+#ifdef CONFIG_VDE
+                                       ,"vde"
+#endif
+    };
+    for (i = 0; i < sizeof(valid_param_list) / sizeof(char *); i++) {
+        if (!strncmp(valid_param_list[i], device,
+                     strlen(valid_param_list[i])))
+            return 1;
+    }
+
+    return 0;
+}
+
+void net_host_device_add(Monitor *mon, const QDict *qdict)
+{
+    const char *device = qdict_get_str(qdict, "device");
+    const char *opts_str = qdict_get_try_str(qdict, "opts");
+    Error *local_err = NULL;
+    QemuOpts *opts;
+
+    if (!net_host_check_device(device)) {
+        monitor_printf(mon, "invalid host network device %s\n", device);
+        return;
+    }
+
+    opts = qemu_opts_parse(qemu_find_opts("net"), opts_str ? opts_str : "", 0);
+    if (!opts) {
+        return;
+    }
+
+    qemu_opt_set(opts, "type", device);
+
+    net_client_init(opts, 0, &local_err);
+    if (error_is_set(&local_err)) {
+        qerror_report_err(local_err);
+        error_free(local_err);
+        monitor_printf(mon, "adding host network device %s failed\n", device);
+    }
+}
+
+void net_host_device_remove(Monitor *mon, const QDict *qdict)
+{
+    NetClientState *nc;
+    int vlan_id = qdict_get_int(qdict, "vlan_id");
+    const char *device = qdict_get_str(qdict, "device");
+
+    nc = net_hub_find_client_by_name(vlan_id, device);
+    if (!nc) {
+        return;
+    }
+    if (!net_host_check_device(nc->model)) {
+        monitor_printf(mon, "invalid host network device %s\n", device);
+        return;
+    }
+    qemu_del_net_client(nc);
+}
+
+void netdev_add(QemuOpts *opts, Error **errp)
+{
+    net_client_init(opts, 1, errp);
+}
+
+int qmp_netdev_add(Monitor *mon, const QDict *qdict, QObject **ret)
+{
+    Error *local_err = NULL;
+    QemuOptsList *opts_list;
+    QemuOpts *opts;
+
+    opts_list = qemu_find_opts_err("netdev", &local_err);
+    if (error_is_set(&local_err)) {
+        goto exit_err;
+    }
+
+    opts = qemu_opts_from_qdict(opts_list, qdict, &local_err);
+    if (error_is_set(&local_err)) {
+        goto exit_err;
+    }
+
+    netdev_add(opts, &local_err);
+    if (error_is_set(&local_err)) {
+        qemu_opts_del(opts);
+        goto exit_err;
+    }
+
+    return 0;
+
+exit_err:
+    qerror_report_err(local_err);
+    error_free(local_err);
+    return -1;
+}
+
+void qmp_netdev_del(const char *id, Error **errp)
+{
+    NetClientState *nc;
+    QemuOpts *opts;
+
+    nc = qemu_find_netdev(id);
+    if (!nc) {
+        error_set(errp, QERR_DEVICE_NOT_FOUND, id);
+        return;
+    }
+
+    opts = qemu_opts_find(qemu_find_opts_err("netdev", NULL), id);
+    if (!opts) {
+        error_setg(errp, "Device '%s' is not a netdev", id);
+        return;
+    }
+
+    qemu_del_net_client(nc);
+    qemu_opts_del(opts);
+}
+
+void print_net_client(Monitor *mon, NetClientState *nc)
+{
+    monitor_printf(mon, "%s: index=%d,type=%s,%s\n", nc->name,
+                   nc->queue_index,
+                   NetClientOptionsKind_lookup[nc->info->type],
+                   nc->info_str);
+}
+
+RxFilterInfoList *qmp_query_rx_filter(bool has_name, const char *name,
+                                      Error **errp)
+{
+    NetClientState *nc;
+    RxFilterInfoList *filter_list = NULL, *last_entry = NULL;
+
+    QTAILQ_FOREACH(nc, &net_clients, next) {
+        RxFilterInfoList *entry;
+        RxFilterInfo *info;
+
+        if (has_name && strcmp(nc->name, name) != 0) {
+            continue;
+        }
+
+        /* only query rx-filter information of NIC */
+        if (nc->info->type != NET_CLIENT_OPTIONS_KIND_NIC) {
+            if (has_name) {
+                error_setg(errp, "net client(%s) isn't a NIC", name);
+                break;
+            }
+            continue;
+        }
+
+        if (nc->info->query_rx_filter) {
+            info = nc->info->query_rx_filter(nc);
+            entry = g_malloc0(sizeof(*entry));
+            entry->value = info;
+
+            if (!filter_list) {
+                filter_list = entry;
+            } else {
+                last_entry->next = entry;
+            }
+            last_entry = entry;
+        } else if (has_name) {
+            error_setg(errp, "net client(%s) doesn't support"
+                       " rx-filter querying", name);
+            break;
+        }
+    }
+
+    if (filter_list == NULL && !error_is_set(errp) && has_name) {
+        error_setg(errp, "invalid net client name: %s", name);
+    }
+
+    return filter_list;
+}
+
+void do_info_network(Monitor *mon, const QDict *qdict)
+{
+    NetClientState *nc, *peer;
+    NetClientOptionsKind type;
+
+    net_hub_info(mon);
+
+    QTAILQ_FOREACH(nc, &net_clients, next) {
+        peer = nc->peer;
+        type = nc->info->type;
+
+        /* Skip if already printed in hub info */
+        if (net_hub_id_for_client(nc, NULL) == 0) {
+            continue;
+        }
+
+        if (!peer || type == NET_CLIENT_OPTIONS_KIND_NIC) {
+            print_net_client(mon, nc);
+        } /* else it's a netdev connected to a NIC, printed with the NIC */
+        if (peer && type == NET_CLIENT_OPTIONS_KIND_NIC) {
+            monitor_printf(mon, " \\ ");
+            print_net_client(mon, peer);
+        }
+    }
+}
+
+void qmp_set_link(const char *name, bool up, Error **errp)
+{
+    NetClientState *ncs[MAX_QUEUE_NUM];
+    NetClientState *nc;
+    int queues, i;
+
+    queues = qemu_find_net_clients_except(name, ncs,
+                                          NET_CLIENT_OPTIONS_KIND_MAX,
+                                          MAX_QUEUE_NUM);
+
+    if (queues == 0) {
+        error_set(errp, QERR_DEVICE_NOT_FOUND, name);
+        return;
+    }
+    nc = ncs[0];
+
+    for (i = 0; i < queues; i++) {
+        ncs[i]->link_down = !up;
+    }
+
+    if (nc->info->link_status_changed) {
+        nc->info->link_status_changed(nc);
+    }
+
+    /* Notify peer. Don't update peer link status: this makes it possible to
+     * disconnect from host network without notifying the guest.
+     * FIXME: is disconnected link status change operation useful?
+     *
+     * Current behaviour is compatible with qemu vlans where there could be
+     * multiple clients that can still communicate with each other in
+     * disconnected mode. For now maintain this compatibility. */
+    if (nc->peer && nc->peer->info->link_status_changed) {
+        nc->peer->info->link_status_changed(nc->peer);
+    }
+}
+
+void net_cleanup(void)
+{
+    NetClientState *nc;
+
+    /* We may del multiple entries during qemu_del_net_client(),
+     * so QTAILQ_FOREACH_SAFE() is also not safe here.
+     */
+    while (!QTAILQ_EMPTY(&net_clients)) {
+        nc = QTAILQ_FIRST(&net_clients);
+        if (nc->info->type == NET_CLIENT_OPTIONS_KIND_NIC) {
+            qemu_del_nic(qemu_get_nic(nc));
+        } else {
+            qemu_del_net_client(nc);
+        }
+    }
+}
+
+void net_check_clients(void)
+{
+    NetClientState *nc;
+    int i;
+
+    /* Don't warn about the default network setup that you get if
+     * no command line -net or -netdev options are specified. There
+     * are two cases that we would otherwise complain about:
+     * (1) board doesn't support a NIC but the implicit "-net nic"
+     * requested one
+     * (2) CONFIG_SLIRP not set, in which case the implicit "-net nic"
+     * sets up a nic that isn't connected to anything.
+     */
+    if (default_net) {
+        return;
+    }
+
+    net_hub_check_clients();
+
+    QTAILQ_FOREACH(nc, &net_clients, next) {
+        if (!nc->peer) {
+            fprintf(stderr, "Warning: %s %s has no peer\n",
+                    nc->info->type == NET_CLIENT_OPTIONS_KIND_NIC ?
+                    "nic" : "netdev", nc->name);
+        }
+    }
+
+    /* Check that all NICs requested via -net nic actually got created.
+     * NICs created via -device don't need to be checked here because
+     * they are always instantiated.
+     */
+    for (i = 0; i < MAX_NICS; i++) {
+        NICInfo *nd = &nd_table[i];
+        if (nd->used && !nd->instantiated) {
+            fprintf(stderr, "Warning: requested NIC (%s, model %s) "
+                    "was not created (not supported by this machine?)\n",
+                    nd->name ? nd->name : "anonymous",
+                    nd->model ? nd->model : "unspecified");
+        }
+    }
+}
+
+static int net_init_client(QemuOpts *opts, void *dummy)
+{
+    Error *local_err = NULL;
+
+    net_client_init(opts, 0, &local_err);
+    if (error_is_set(&local_err)) {
+        qerror_report_err(local_err);
+        error_free(local_err);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int net_init_netdev(QemuOpts *opts, void *dummy)
+{
+    Error *local_err = NULL;
+    int ret;
+
+    ret = net_client_init(opts, 1, &local_err);
+    if (error_is_set(&local_err)) {
+        qerror_report_err(local_err);
+        error_free(local_err);
+        return -1;
+    }
+
+    return ret;
+}
+
+int net_init_clients(void)
+{
+    QemuOptsList *net = qemu_find_opts("net");
+
+    if (default_net) {
+        /* if no clients, we use a default config */
+        qemu_opts_set(net, NULL, "type", "nic");
+#ifdef CONFIG_SLIRP
+        qemu_opts_set(net, NULL, "type", "user");
+#endif
+    }
+
+    QTAILQ_INIT(&net_clients);
+
+    if (qemu_opts_foreach(qemu_find_opts("netdev"), net_init_netdev, NULL, 1) == -1)
+        return -1;
+
+    if (qemu_opts_foreach(net, net_init_client, NULL, 1) == -1) {
+        return -1;
+    }
+
+    return 0;
+}
+
+int net_client_parse(QemuOptsList *opts_list, const char *optarg)
+{
+#if defined(CONFIG_SLIRP)
+    int ret;
+    if (net_slirp_parse_legacy(opts_list, optarg, &ret)) {
+        return ret;
+    }
+#endif
+
+    if (!qemu_opts_parse(opts_list, optarg, 1)) {
+        return -1;
+    }
+
+    default_net = 0;
+    return 0;
+}
+
+/* From FreeBSD */
+/* XXX: optimize */
+unsigned compute_mcast_idx(const uint8_t *ep)
+{
+    uint32_t crc;
+    int carry, i, j;
+    uint8_t b;
+
+    crc = 0xffffffff;
+    for (i = 0; i < 6; i++) {
+        b = *ep++;
+        for (j = 0; j < 8; j++) {
+            carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);
+            crc <<= 1;
+            b >>= 1;
+            if (carry) {
+                crc = ((crc ^ POLYNOMIAL) | carry);
+            }
+        }
+    }
+    return crc >> 26;
+}
+
+QemuOptsList qemu_netdev_opts = {
+    .name = "netdev",
+    .implied_opt_name = "type",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_netdev_opts.head),
+    .desc = {
+        /*
+         * no elements => accept any params
+         * validation will happen later
+         */
+        { /* end of list */ }
+    },
+};
+
+QemuOptsList qemu_net_opts = {
+    .name = "net",
+    .implied_opt_name = "type",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_net_opts.head),
+    .desc = {
+        /*
+         * no elements => accept any params
+         * validation will happen later
+         */
+        { /* end of list */ }
+    },
+};
diff --git a/net/queue.c b/net/queue.c
new file mode 100644
index 000000000..859d02a13
--- /dev/null
+++ b/net/queue.c
@@ -0,0 +1,269 @@
+/*
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ * Copyright (c) 2009 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "net/queue.h"
+#include "qemu/queue.h"
+#include "net/net.h"
+
+/* The delivery handler may only return zero if it will call
+ * qemu_net_queue_flush() when it determines that it is once again able
+ * to deliver packets. It must also call qemu_net_queue_purge() in its
+ * cleanup path.
+ *
+ * If a sent callback is provided to send(), the caller must handle a
+ * zero return from the delivery handler by not sending any more packets
+ * until we have invoked the callback. Only in that case will we queue
+ * the packet.
+ *
+ * If a sent callback isn't provided, we just drop the packet to avoid
+ * unbounded queueing.
+ */
+
+struct NetPacket {
+    QTAILQ_ENTRY(NetPacket) entry;
+    NetClientState *sender;
+    unsigned flags;
+    int size;
+    NetPacketSent *sent_cb;
+    uint8_t data[0];
+};
+
+struct NetQueue {
+    void *opaque;
+    uint32_t nq_maxlen;
+    uint32_t nq_count;
+
+    QTAILQ_HEAD(packets, NetPacket) packets;
+
+    unsigned delivering : 1;
+};
+
+NetQueue *qemu_new_net_queue(void *opaque)
+{
+    NetQueue *queue;
+
+    queue = g_malloc0(sizeof(NetQueue));
+
+    queue->opaque = opaque;
+    queue->nq_maxlen = 10000;
+    queue->nq_count = 0;
+
+    QTAILQ_INIT(&queue->packets);
+
+    queue->delivering = 0;
+
+    return queue;
+}
+
+void qemu_del_net_queue(NetQueue *queue)
+{
+    NetPacket *packet, *next;
+
+    QTAILQ_FOREACH_SAFE(packet, &queue->packets, entry, next) {
+        QTAILQ_REMOVE(&queue->packets, packet, entry);
+        g_free(packet);
+    }
+
+    g_free(queue);
+}
+
+static void qemu_net_queue_append(NetQueue *queue,
+                                  NetClientState *sender,
+                                  unsigned flags,
+                                  const uint8_t *buf,
+                                  size_t size,
+                                  NetPacketSent *sent_cb)
+{
+    NetPacket *packet;
+
+    if (queue->nq_count >= queue->nq_maxlen && !sent_cb) {
+        return; /* drop if queue full and no callback */
+    }
+    packet = g_malloc(sizeof(NetPacket) + size);
+    packet->sender = sender;
+    packet->flags = flags;
+    packet->size = size;
+    packet->sent_cb = sent_cb;
+    memcpy(packet->data, buf, size);
+
+    queue->nq_count++;
+    QTAILQ_INSERT_TAIL(&queue->packets, packet, entry);
+}
+
+static void qemu_net_queue_append_iov(NetQueue *queue,
+                                      NetClientState *sender,
+                                      unsigned flags,
+                                      const struct iovec *iov,
+                                      int iovcnt,
+                                      NetPacketSent *sent_cb)
+{
+    NetPacket *packet;
+    size_t max_len = 0;
+    int i;
+
+    if (queue->nq_count >= queue->nq_maxlen && !sent_cb) {
+        return; /* drop if queue full and no callback */
+    }
+    for (i = 0; i < iovcnt; i++) {
+        max_len += iov[i].iov_len;
+    }
+
+    packet = g_malloc(sizeof(NetPacket) + max_len);
+    packet->sender = sender;
+    packet->sent_cb = sent_cb;
+    packet->flags = flags;
+    packet->size = 0;
+
+    for (i = 0; i < iovcnt; i++) {
+        size_t len = iov[i].iov_len;
+
+        memcpy(packet->data + packet->size, iov[i].iov_base, len);
+        packet->size += len;
+    }
+
+    queue->nq_count++;
+    QTAILQ_INSERT_TAIL(&queue->packets, packet, entry);
+}
+
+static ssize_t qemu_net_queue_deliver(NetQueue *queue,
+                                      NetClientState *sender,
+                                      unsigned flags,
+                                      const uint8_t *data,
+                                      size_t size)
+{
+    ssize_t ret = -1;
+
+    queue->delivering = 1;
+    ret = qemu_deliver_packet(sender, flags, data, size, queue->opaque);
+    queue->delivering = 0;
+
+    return ret;
+}
+
+static ssize_t qemu_net_queue_deliver_iov(NetQueue *queue,
+                                          NetClientState *sender,
+                                          unsigned flags,
+                                          const struct iovec *iov,
+                                          int iovcnt)
+{
+    ssize_t ret = -1;
+
+    queue->delivering = 1;
+    ret = qemu_deliver_packet_iov(sender, flags, iov, iovcnt, queue->opaque);
+    queue->delivering = 0;
+
+    return ret;
+}
+
+ssize_t qemu_net_queue_send(NetQueue *queue,
+                            NetClientState *sender,
+                            unsigned flags,
+                            const uint8_t *data,
+                            size_t size,
+                            NetPacketSent *sent_cb)
+{
+    ssize_t ret;
+
+    if (queue->delivering || !qemu_can_send_packet(sender)) {
+        qemu_net_queue_append(queue, sender, flags, data, size, sent_cb);
+        return 0;
+    }
+
+    ret = qemu_net_queue_deliver(queue, sender, flags, data, size);
+    if (ret == 0) {
+        qemu_net_queue_append(queue, sender, flags, data, size, sent_cb);
+        return 0;
+    }
+
+    qemu_net_queue_flush(queue);
+
+    return ret;
+}
+
+ssize_t qemu_net_queue_send_iov(NetQueue *queue,
+                                NetClientState *sender,
+                                unsigned flags,
+                                const struct iovec *iov,
+                                int iovcnt,
+                                NetPacketSent *sent_cb)
+{
+    ssize_t ret;
+
+    if (queue->delivering || !qemu_can_send_packet(sender)) {
+        qemu_net_queue_append_iov(queue, sender, flags, iov, iovcnt, sent_cb);
+        return 0;
+    }
+
+    ret = qemu_net_queue_deliver_iov(queue, sender, flags, iov, iovcnt);
+    if (ret == 0) {
+        qemu_net_queue_append_iov(queue, sender, flags, iov, iovcnt, sent_cb);
+        return 0;
+    }
+
+    qemu_net_queue_flush(queue);
+
+    return ret;
+}
+
+void qemu_net_queue_purge(NetQueue *queue, NetClientState *from)
+{
+    NetPacket *packet, *next;
+
+    QTAILQ_FOREACH_SAFE(packet, &queue->packets, entry, next) {
+        if (packet->sender == from) {
+            QTAILQ_REMOVE(&queue->packets, packet, entry);
+            queue->nq_count--;
+            g_free(packet);
+        }
+    }
+}
+
+bool qemu_net_queue_flush(NetQueue *queue)
+{
+    while (!QTAILQ_EMPTY(&queue->packets)) {
+        NetPacket *packet;
+        int ret;
+
+        packet = QTAILQ_FIRST(&queue->packets);
+        QTAILQ_REMOVE(&queue->packets, packet, entry);
+        queue->nq_count--;
+
+        ret = qemu_net_queue_deliver(queue,
+                                     packet->sender,
+                                     packet->flags,
+                                     packet->data,
+                                     packet->size);
+        if (ret == 0) {
+            queue->nq_count++;
+            QTAILQ_INSERT_HEAD(&queue->packets, packet, entry);
+            return false;
+        }
+
+        if (packet->sent_cb) {
+            packet->sent_cb(packet->sender, ret);
+        }
+
+        g_free(packet);
+    }
+    return true;
+}
diff --git a/net/slirp.c b/net/slirp.c
new file mode 100644
index 000000000..124e953d9
--- /dev/null
+++ b/net/slirp.c
@@ -0,0 +1,794 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "net/slirp.h"
+
+#include "config-host.h"
+
+#ifndef _WIN32
+#include <pwd.h>
+#include <sys/wait.h>
+#endif
+#include "net/net.h"
+#include "clients.h"
+#include "hub.h"
+#include "monitor/monitor.h"
+#include "qemu/sockets.h"
+#include "slirp/libslirp.h"
+#include "sysemu/char.h"
+
+static int get_str_sep(char *buf, int buf_size, const char **pp, int sep)
+{
+    const char *p, *p1;
+    int len;
+    p = *pp;
+    p1 = strchr(p, sep);
+    if (!p1)
+        return -1;
+    len = p1 - p;
+    p1++;
+    if (buf_size > 0) {
+        if (len > buf_size - 1)
+            len = buf_size - 1;
+        memcpy(buf, p, len);
+        buf[len] = '\0';
+    }
+    *pp = p1;
+    return 0;
+}
+
+/* slirp network adapter */
+
+#define SLIRP_CFG_HOSTFWD 1
+#define SLIRP_CFG_LEGACY  2
+
+struct slirp_config_str {
+    struct slirp_config_str *next;
+    int flags;
+    char str[1024];
+    int legacy_format;
+};
+
+typedef struct SlirpState {
+    NetClientState nc;
+    QTAILQ_ENTRY(SlirpState) entry;
+    Slirp *slirp;
+#ifndef _WIN32
+    char smb_dir[128];
+#endif
+} SlirpState;
+
+static struct slirp_config_str *slirp_configs;
+const char *legacy_tftp_prefix;
+const char *legacy_bootp_filename;
+static QTAILQ_HEAD(slirp_stacks, SlirpState) slirp_stacks =
+    QTAILQ_HEAD_INITIALIZER(slirp_stacks);
+
+static int slirp_hostfwd(SlirpState *s, const char *redir_str,
+                         int legacy_format);
+static int slirp_guestfwd(SlirpState *s, const char *config_str,
+                          int legacy_format);
+
+#ifndef _WIN32
+static const char *legacy_smb_export;
+
+static int slirp_smb(SlirpState *s, const char *exported_dir,
+                     struct in_addr vserver_addr);
+static void slirp_smb_cleanup(SlirpState *s);
+#else
+static inline void slirp_smb_cleanup(SlirpState *s) { }
+#endif
+
+void slirp_output(void *opaque, const uint8_t *pkt, int pkt_len)
+{
+    SlirpState *s = opaque;
+
+    qemu_send_packet(&s->nc, pkt, pkt_len);
+}
+
+static ssize_t net_slirp_receive(NetClientState *nc, const uint8_t *buf, size_t size)
+{
+    SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
+
+    slirp_input(s->slirp, buf, size);
+
+    return size;
+}
+
+static void net_slirp_cleanup(NetClientState *nc)
+{
+    SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
+
+    slirp_cleanup(s->slirp);
+    slirp_smb_cleanup(s);
+    QTAILQ_REMOVE(&slirp_stacks, s, entry);
+}
+
+static NetClientInfo net_slirp_info = {
+    .type = NET_CLIENT_OPTIONS_KIND_USER,
+    .size = sizeof(SlirpState),
+    .receive = net_slirp_receive,
+    .cleanup = net_slirp_cleanup,
+};
+
+static int net_slirp_init(NetClientState *peer, const char *model,
+                          const char *name, int restricted,
+                          const char *vnetwork, const char *vhost,
+                          const char *vhostname, const char *tftp_export,
+                          const char *bootfile, const char *vdhcp_start,
+                          const char *vnameserver, const char *smb_export,
+                          const char *vsmbserver, const char **dnssearch)
+{
+    /* default settings according to historic slirp */
+    struct in_addr net  = { .s_addr = htonl(0x0a000200) }; /* 10.0.2.0 */
+    struct in_addr mask = { .s_addr = htonl(0xffffff00) }; /* 255.255.255.0 */
+    struct in_addr host = { .s_addr = htonl(0x0a000202) }; /* 10.0.2.2 */
+    struct in_addr dhcp = { .s_addr = htonl(0x0a00020f) }; /* 10.0.2.15 */
+    struct in_addr dns  = { .s_addr = htonl(0x0a000203) }; /* 10.0.2.3 */
+#ifndef _WIN32
+    struct in_addr smbsrv = { .s_addr = 0 };
+#endif
+    NetClientState *nc;
+    SlirpState *s;
+    char buf[20];
+    uint32_t addr;
+    int shift;
+    char *end;
+    struct slirp_config_str *config;
+
+    if (!tftp_export) {
+        tftp_export = legacy_tftp_prefix;
+    }
+    if (!bootfile) {
+        bootfile = legacy_bootp_filename;
+    }
+
+    if (vnetwork) {
+        if (get_str_sep(buf, sizeof(buf), &vnetwork, '/') < 0) {
+            if (!inet_aton(vnetwork, &net)) {
+                return -1;
+            }
+            addr = ntohl(net.s_addr);
+            if (!(addr & 0x80000000)) {
+                mask.s_addr = htonl(0xff000000); /* class A */
+            } else if ((addr & 0xfff00000) == 0xac100000) {
+                mask.s_addr = htonl(0xfff00000); /* priv. 172.16.0.0/12 */
+            } else if ((addr & 0xc0000000) == 0x80000000) {
+                mask.s_addr = htonl(0xffff0000); /* class B */
+            } else if ((addr & 0xffff0000) == 0xc0a80000) {
+                mask.s_addr = htonl(0xffff0000); /* priv. 192.168.0.0/16 */
+            } else if ((addr & 0xffff0000) == 0xc6120000) {
+                mask.s_addr = htonl(0xfffe0000); /* tests 198.18.0.0/15 */
+            } else if ((addr & 0xe0000000) == 0xe0000000) {
+                mask.s_addr = htonl(0xffffff00); /* class C */
+            } else {
+                mask.s_addr = htonl(0xfffffff0); /* multicast/reserved */
+            }
+        } else {
+            if (!inet_aton(buf, &net)) {
+                return -1;
+            }
+            shift = strtol(vnetwork, &end, 10);
+            if (*end != '\0') {
+                if (!inet_aton(vnetwork, &mask)) {
+                    return -1;
+                }
+            } else if (shift < 4 || shift > 32) {
+                return -1;
+            } else {
+                mask.s_addr = htonl(0xffffffff << (32 - shift));
+            }
+        }
+        net.s_addr &= mask.s_addr;
+        host.s_addr = net.s_addr | (htonl(0x0202) & ~mask.s_addr);
+        dhcp.s_addr = net.s_addr | (htonl(0x020f) & ~mask.s_addr);
+        dns.s_addr  = net.s_addr | (htonl(0x0203) & ~mask.s_addr);
+    }
+
+    if (vhost && !inet_aton(vhost, &host)) {
+        return -1;
+    }
+    if ((host.s_addr & mask.s_addr) != net.s_addr) {
+        return -1;
+    }
+
+    if (vnameserver && !inet_aton(vnameserver, &dns)) {
+        return -1;
+    }
+    if ((dns.s_addr & mask.s_addr) != net.s_addr ||
+        dns.s_addr == host.s_addr) {
+        return -1;
+    }
+
+    if (vdhcp_start && !inet_aton(vdhcp_start, &dhcp)) {
+        return -1;
+    }
+    if ((dhcp.s_addr & mask.s_addr) != net.s_addr ||
+        dhcp.s_addr == host.s_addr || dhcp.s_addr == dns.s_addr) {
+        return -1;
+    }
+
+#ifndef _WIN32
+    if (vsmbserver && !inet_aton(vsmbserver, &smbsrv)) {
+        return -1;
+    }
+#endif
+
+    nc = qemu_new_net_client(&net_slirp_info, peer, model, name);
+
+    snprintf(nc->info_str, sizeof(nc->info_str),
+             "net=%s,restrict=%s", inet_ntoa(net),
+             restricted ? "on" : "off");
+
+    s = DO_UPCAST(SlirpState, nc, nc);
+
+    s->slirp = slirp_init(restricted, net, mask, host, vhostname,
+                          tftp_export, bootfile, dhcp, dns, dnssearch, s);
+    QTAILQ_INSERT_TAIL(&slirp_stacks, s, entry);
+
+    for (config = slirp_configs; config; config = config->next) {
+        if (config->flags & SLIRP_CFG_HOSTFWD) {
+            if (slirp_hostfwd(s, config->str,
+                              config->flags & SLIRP_CFG_LEGACY) < 0)
+                goto error;
+        } else {
+            if (slirp_guestfwd(s, config->str,
+                               config->flags & SLIRP_CFG_LEGACY) < 0)
+                goto error;
+        }
+    }
+#ifndef _WIN32
+    if (!smb_export) {
+        smb_export = legacy_smb_export;
+    }
+    if (smb_export) {
+        if (slirp_smb(s, smb_export, smbsrv) < 0)
+            goto error;
+    }
+#endif
+
+    return 0;
+
+error:
+    qemu_del_net_client(nc);
+    return -1;
+}
+
+static SlirpState *slirp_lookup(Monitor *mon, const char *vlan,
+                                const char *stack)
+{
+
+    if (vlan) {
+        NetClientState *nc;
+        nc = net_hub_find_client_by_name(strtol(vlan, NULL, 0), stack);
+        if (!nc) {
+            return NULL;
+        }
+        if (strcmp(nc->model, "user")) {
+            monitor_printf(mon, "invalid device specified\n");
+            return NULL;
+        }
+        return DO_UPCAST(SlirpState, nc, nc);
+    } else {
+        if (QTAILQ_EMPTY(&slirp_stacks)) {
+            monitor_printf(mon, "user mode network stack not in use\n");
+            return NULL;
+        }
+        return QTAILQ_FIRST(&slirp_stacks);
+    }
+}
+
+void net_slirp_hostfwd_remove(Monitor *mon, const QDict *qdict)
+{
+    struct in_addr host_addr = { .s_addr = INADDR_ANY };
+    int host_port;
+    char buf[256];
+    const char *src_str, *p;
+    SlirpState *s;
+    int is_udp = 0;
+    int err;
+    const char *arg1 = qdict_get_str(qdict, "arg1");
+    const char *arg2 = qdict_get_try_str(qdict, "arg2");
+    const char *arg3 = qdict_get_try_str(qdict, "arg3");
+
+    if (arg2) {
+        s = slirp_lookup(mon, arg1, arg2);
+        src_str = arg3;
+    } else {
+        s = slirp_lookup(mon, NULL, NULL);
+        src_str = arg1;
+    }
+    if (!s) {
+        return;
+    }
+
+    p = src_str;
+    if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
+        goto fail_syntax;
+    }
+
+    if (!strcmp(buf, "tcp") || buf[0] == '\0') {
+        is_udp = 0;
+    } else if (!strcmp(buf, "udp")) {
+        is_udp = 1;
+    } else {
+        goto fail_syntax;
+    }
+
+    if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
+        goto fail_syntax;
+    }
+    if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
+        goto fail_syntax;
+    }
+
+    host_port = atoi(p);
+
+    err = slirp_remove_hostfwd(QTAILQ_FIRST(&slirp_stacks)->slirp, is_udp,
+                               host_addr, host_port);
+
+    monitor_printf(mon, "host forwarding rule for %s %s\n", src_str,
+                   err ? "not found" : "removed");
+    return;
+
+ fail_syntax:
+    monitor_printf(mon, "invalid format\n");
+}
+
+static int slirp_hostfwd(SlirpState *s, const char *redir_str,
+                         int legacy_format)
+{
+    struct in_addr host_addr = { .s_addr = INADDR_ANY };
+    struct in_addr guest_addr = { .s_addr = 0 };
+    int host_port, guest_port;
+    const char *p;
+    char buf[256];
+    int is_udp;
+    char *end;
+
+    p = redir_str;
+    if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
+        goto fail_syntax;
+    }
+    if (!strcmp(buf, "tcp") || buf[0] == '\0') {
+        is_udp = 0;
+    } else if (!strcmp(buf, "udp")) {
+        is_udp = 1;
+    } else {
+        goto fail_syntax;
+    }
+
+    if (!legacy_format) {
+        if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
+            goto fail_syntax;
+        }
+        if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
+            goto fail_syntax;
+        }
+    }
+
+    if (get_str_sep(buf, sizeof(buf), &p, legacy_format ? ':' : '-') < 0) {
+        goto fail_syntax;
+    }
+    host_port = strtol(buf, &end, 0);
+    if (*end != '\0' || host_port < 1 || host_port > 65535) {
+        goto fail_syntax;
+    }
+
+    if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
+        goto fail_syntax;
+    }
+    if (buf[0] != '\0' && !inet_aton(buf, &guest_addr)) {
+        goto fail_syntax;
+    }
+
+    guest_port = strtol(p, &end, 0);
+    if (*end != '\0' || guest_port < 1 || guest_port > 65535) {
+        goto fail_syntax;
+    }
+
+    if (slirp_add_hostfwd(s->slirp, is_udp, host_addr, host_port, guest_addr,
+                          guest_port) < 0) {
+        error_report("could not set up host forwarding rule '%s'",
+                     redir_str);
+        return -1;
+    }
+    return 0;
+
+ fail_syntax:
+    error_report("invalid host forwarding rule '%s'", redir_str);
+    return -1;
+}
+
+void net_slirp_hostfwd_add(Monitor *mon, const QDict *qdict)
+{
+    const char *redir_str;
+    SlirpState *s;
+    const char *arg1 = qdict_get_str(qdict, "arg1");
+    const char *arg2 = qdict_get_try_str(qdict, "arg2");
+    const char *arg3 = qdict_get_try_str(qdict, "arg3");
+
+    if (arg2) {
+        s = slirp_lookup(mon, arg1, arg2);
+        redir_str = arg3;
+    } else {
+        s = slirp_lookup(mon, NULL, NULL);
+        redir_str = arg1;
+    }
+    if (s) {
+        slirp_hostfwd(s, redir_str, 0);
+    }
+
+}
+
+int net_slirp_redir(const char *redir_str)
+{
+    struct slirp_config_str *config;
+
+    if (QTAILQ_EMPTY(&slirp_stacks)) {
+        config = g_malloc(sizeof(*config));
+        pstrcpy(config->str, sizeof(config->str), redir_str);
+        config->flags = SLIRP_CFG_HOSTFWD | SLIRP_CFG_LEGACY;
+        config->next = slirp_configs;
+        slirp_configs = config;
+        return 0;
+    }
+
+    return slirp_hostfwd(QTAILQ_FIRST(&slirp_stacks), redir_str, 1);
+}
+
+#ifndef _WIN32
+
+/* automatic user mode samba server configuration */
+static void slirp_smb_cleanup(SlirpState *s)
+{
+    char cmd[128];
+    int ret;
+
+    if (s->smb_dir[0] != '\0') {
+        snprintf(cmd, sizeof(cmd), "rm -rf %s", s->smb_dir);
+        ret = system(cmd);
+        if (ret == -1 || !WIFEXITED(ret)) {
+            error_report("'%s' failed.", cmd);
+        } else if (WEXITSTATUS(ret)) {
+            error_report("'%s' failed. Error code: %d",
+                         cmd, WEXITSTATUS(ret));
+        }
+        s->smb_dir[0] = '\0';
+    }
+}
+
+static int slirp_smb(SlirpState* s, const char *exported_dir,
+                     struct in_addr vserver_addr)
+{
+    static int instance;
+    char smb_conf[128];
+    char smb_cmdline[128];
+    struct passwd *passwd;
+    FILE *f;
+
+    passwd = getpwuid(geteuid());
+    if (!passwd) {
+        error_report("failed to retrieve user name");
+        return -1;
+    }
+
+    if (access(CONFIG_SMBD_COMMAND, F_OK)) {
+        error_report("could not find '%s', please install it",
+                     CONFIG_SMBD_COMMAND);
+        return -1;
+    }
+
+    if (access(exported_dir, R_OK | X_OK)) {
+        error_report("error accessing shared directory '%s': %s",
+                     exported_dir, strerror(errno));
+        return -1;
+    }
+
+    snprintf(s->smb_dir, sizeof(s->smb_dir), "/tmp/qemu-smb.%ld-%d",
+             (long)getpid(), instance++);
+    if (mkdir(s->smb_dir, 0700) < 0) {
+        error_report("could not create samba server dir '%s'", s->smb_dir);
+        return -1;
+    }
+    snprintf(smb_conf, sizeof(smb_conf), "%s/%s", s->smb_dir, "smb.conf");
+
+    f = fopen(smb_conf, "w");
+    if (!f) {
+        slirp_smb_cleanup(s);
+        error_report("could not create samba server configuration file '%s'",
+                     smb_conf);
+        return -1;
+    }
+    fprintf(f,
+            "[global]\n"
+            "private dir=%s\n"
+            "socket address=127.0.0.1\n"
+            "pid directory=%s\n"
+            "lock directory=%s\n"
+            "state directory=%s\n"
+            "log file=%s/log.smbd\n"
+            "smb passwd file=%s/smbpasswd\n"
+            "security = share\n"
+            "[qemu]\n"
+            "path=%s\n"
+            "read only=no\n"
+            "guest ok=yes\n"
+            "force user=%s\n",
+            s->smb_dir,
+            s->smb_dir,
+            s->smb_dir,
+            s->smb_dir,
+            s->smb_dir,
+            s->smb_dir,
+            exported_dir,
+            passwd->pw_name
+            );
+    fclose(f);
+
+    snprintf(smb_cmdline, sizeof(smb_cmdline), "%s -s %s",
+             CONFIG_SMBD_COMMAND, smb_conf);
+
+    if (slirp_add_exec(s->slirp, 0, smb_cmdline, &vserver_addr, 139) < 0) {
+        slirp_smb_cleanup(s);
+        error_report("conflicting/invalid smbserver address");
+        return -1;
+    }
+    return 0;
+}
+
+/* automatic user mode samba server configuration (legacy interface) */
+int net_slirp_smb(const char *exported_dir)
+{
+    struct in_addr vserver_addr = { .s_addr = 0 };
+
+    if (legacy_smb_export) {
+        fprintf(stderr, "-smb given twice\n");
+        return -1;
+    }
+    legacy_smb_export = exported_dir;
+    if (!QTAILQ_EMPTY(&slirp_stacks)) {
+        return slirp_smb(QTAILQ_FIRST(&slirp_stacks), exported_dir,
+                         vserver_addr);
+    }
+    return 0;
+}
+
+#endif /* !defined(_WIN32) */
+
+struct GuestFwd {
+    CharDriverState *hd;
+    struct in_addr server;
+    int port;
+    Slirp *slirp;
+};
+
+static int guestfwd_can_read(void *opaque)
+{
+    struct GuestFwd *fwd = opaque;
+    return slirp_socket_can_recv(fwd->slirp, fwd->server, fwd->port);
+}
+
+static void guestfwd_read(void *opaque, const uint8_t *buf, int size)
+{
+    struct GuestFwd *fwd = opaque;
+    slirp_socket_recv(fwd->slirp, fwd->server, fwd->port, buf, size);
+}
+
+static int slirp_guestfwd(SlirpState *s, const char *config_str,
+                          int legacy_format)
+{
+    struct in_addr server = { .s_addr = 0 };
+    struct GuestFwd *fwd;
+    const char *p;
+    char buf[128];
+    char *end;
+    int port;
+
+    p = config_str;
+    if (legacy_format) {
+        if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
+            goto fail_syntax;
+        }
+    } else {
+        if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
+            goto fail_syntax;
+        }
+        if (strcmp(buf, "tcp") && buf[0] != '\0') {
+            goto fail_syntax;
+        }
+        if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
+            goto fail_syntax;
+        }
+        if (buf[0] != '\0' && !inet_aton(buf, &server)) {
+            goto fail_syntax;
+        }
+        if (get_str_sep(buf, sizeof(buf), &p, '-') < 0) {
+            goto fail_syntax;
+        }
+    }
+    port = strtol(buf, &end, 10);
+    if (*end != '\0' || port < 1 || port > 65535) {
+        goto fail_syntax;
+    }
+
+    fwd = g_malloc(sizeof(struct GuestFwd));
+    snprintf(buf, sizeof(buf), "guestfwd.tcp.%d", port);
+
+    if ((strlen(p) > 4) && !strncmp(p, "cmd:", 4)) {
+        if (slirp_add_exec(s->slirp, 0, &p[4], &server, port) < 0) {
+            error_report("conflicting/invalid host:port in guest forwarding "
+                         "rule '%s'", config_str);
+            g_free(fwd);
+            return -1;
+        }
+    } else {
+        fwd->hd = qemu_chr_new(buf, p, NULL);
+        if (!fwd->hd) {
+            error_report("could not open guest forwarding device '%s'", buf);
+            g_free(fwd);
+            return -1;
+        }
+
+        if (slirp_add_exec(s->slirp, 3, fwd->hd, &server, port) < 0) {
+            error_report("conflicting/invalid host:port in guest forwarding "
+                         "rule '%s'", config_str);
+            g_free(fwd);
+            return -1;
+        }
+        fwd->server = server;
+        fwd->port = port;
+        fwd->slirp = s->slirp;
+
+        qemu_chr_fe_claim_no_fail(fwd->hd);
+        qemu_chr_add_handlers(fwd->hd, guestfwd_can_read, guestfwd_read,
+                              NULL, fwd);
+    }
+    return 0;
+
+ fail_syntax:
+    error_report("invalid guest forwarding rule '%s'", config_str);
+    return -1;
+}
+
+void do_info_usernet(Monitor *mon, const QDict *qdict)
+{
+    SlirpState *s;
+
+    QTAILQ_FOREACH(s, &slirp_stacks, entry) {
+        int id;
+        bool got_vlan_id = net_hub_id_for_client(&s->nc, &id) == 0;
+        monitor_printf(mon, "VLAN %d (%s):\n",
+                       got_vlan_id ? id : -1,
+                       s->nc.name);
+        slirp_connection_info(s->slirp, mon);
+    }
+}
+
+static void
+net_init_slirp_configs(const StringList *fwd, int flags)
+{
+    while (fwd) {
+        struct slirp_config_str *config;
+
+        config = g_malloc0(sizeof(*config));
+        pstrcpy(config->str, sizeof(config->str), fwd->value->str);
+        config->flags = flags;
+        config->next = slirp_configs;
+        slirp_configs = config;
+
+        fwd = fwd->next;
+    }
+}
+
+static const char **slirp_dnssearch(const StringList *dnsname)
+{
+    const StringList *c = dnsname;
+    size_t i = 0, num_opts = 0;
+    const char **ret;
+
+    while (c) {
+        num_opts++;
+        c = c->next;
+    }
+
+    if (num_opts == 0) {
+        return NULL;
+    }
+
+    ret = g_malloc((num_opts + 1) * sizeof(*ret));
+    c = dnsname;
+    while (c) {
+        ret[i++] = c->value->str;
+        c = c->next;
+    }
+    ret[i] = NULL;
+    return ret;
+}
+
+int net_init_slirp(const NetClientOptions *opts, const char *name,
+                   NetClientState *peer)
+{
+    struct slirp_config_str *config;
+    char *vnet;
+    int ret;
+    const NetdevUserOptions *user;
+    const char **dnssearch;
+
+    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_USER);
+    user = opts->user;
+
+    vnet = user->has_net ? g_strdup(user->net) :
+           user->has_ip  ? g_strdup_printf("%s/24", user->ip) :
+           NULL;
+
+    dnssearch = slirp_dnssearch(user->dnssearch);
+
+    /* all optional fields are initialized to "all bits zero" */
+
+    net_init_slirp_configs(user->hostfwd, SLIRP_CFG_HOSTFWD);
+    net_init_slirp_configs(user->guestfwd, 0);
+
+    ret = net_slirp_init(peer, "user", name, user->q_restrict, vnet,
+                         user->host, user->hostname, user->tftp,
+                         user->bootfile, user->dhcpstart, user->dns, user->smb,
+                         user->smbserver, dnssearch);
+
+    while (slirp_configs) {
+        config = slirp_configs;
+        slirp_configs = config->next;
+        g_free(config);
+    }
+
+    g_free(vnet);
+    g_free(dnssearch);
+
+    return ret;
+}
+
+int net_slirp_parse_legacy(QemuOptsList *opts_list, const char *optarg, int *ret)
+{
+    if (strcmp(opts_list->name, "net") != 0 ||
+        strncmp(optarg, "channel,", strlen("channel,")) != 0) {
+        return 0;
+    }
+
+    /* handle legacy -net channel,port:chr */
+    optarg += strlen("channel,");
+
+    if (QTAILQ_EMPTY(&slirp_stacks)) {
+        struct slirp_config_str *config;
+
+        config = g_malloc(sizeof(*config));
+        pstrcpy(config->str, sizeof(config->str), optarg);
+        config->flags = SLIRP_CFG_LEGACY;
+        config->next = slirp_configs;
+        slirp_configs = config;
+        *ret = 0;
+    } else {
+        *ret = slirp_guestfwd(QTAILQ_FIRST(&slirp_stacks), optarg, 1);
+    }
+
+    return 1;
+}
+
diff --git a/net/socket.c b/net/socket.c
new file mode 100644
index 000000000..87af1d3d3
--- /dev/null
+++ b/net/socket.c
@@ -0,0 +1,761 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "config-host.h"
+
+#include "net/net.h"
+#include "clients.h"
+#include "monitor/monitor.h"
+#include "qemu-common.h"
+#include "qemu/error-report.h"
+#include "qemu/option.h"
+#include "qemu/sockets.h"
+#include "qemu/iov.h"
+
+typedef struct NetSocketState {
+    NetClientState nc;
+    int listen_fd;
+    int fd;
+    int state; /* 0 = getting length, 1 = getting data */
+    unsigned int index;
+    unsigned int packet_len;
+    unsigned int send_index;      /* number of bytes sent (only SOCK_STREAM) */
+    uint8_t buf[NET_BUFSIZE];
+    struct sockaddr_in dgram_dst; /* contains inet host and port destination iff connectionless (SOCK_DGRAM) */
+    IOHandler *send_fn;           /* differs between SOCK_STREAM/SOCK_DGRAM */
+    bool read_poll;               /* waiting to receive data? */
+    bool write_poll;              /* waiting to transmit data? */
+} NetSocketState;
+
+static void net_socket_accept(void *opaque);
+static void net_socket_writable(void *opaque);
+
+/* Only read packets from socket when peer can receive them */
+static int net_socket_can_send(void *opaque)
+{
+    NetSocketState *s = opaque;
+
+    return qemu_can_send_packet(&s->nc);
+}
+
+static void net_socket_update_fd_handler(NetSocketState *s)
+{
+    qemu_set_fd_handler2(s->fd,
+                         s->read_poll  ? net_socket_can_send : NULL,
+                         s->read_poll  ? s->send_fn : NULL,
+                         s->write_poll ? net_socket_writable : NULL,
+                         s);
+}
+
+static void net_socket_read_poll(NetSocketState *s, bool enable)
+{
+    s->read_poll = enable;
+    net_socket_update_fd_handler(s);
+}
+
+static void net_socket_write_poll(NetSocketState *s, bool enable)
+{
+    s->write_poll = enable;
+    net_socket_update_fd_handler(s);
+}
+
+static void net_socket_writable(void *opaque)
+{
+    NetSocketState *s = opaque;
+
+    net_socket_write_poll(s, false);
+
+    qemu_flush_queued_packets(&s->nc);
+}
+
+static ssize_t net_socket_receive(NetClientState *nc, const uint8_t *buf, size_t size)
+{
+    NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
+    uint32_t len = htonl(size);
+    struct iovec iov[] = {
+        {
+            .iov_base = &len,
+            .iov_len  = sizeof(len),
+        }, {
+            .iov_base = (void *)buf,
+            .iov_len  = size,
+        },
+    };
+    size_t remaining;
+    ssize_t ret;
+
+    remaining = iov_size(iov, 2) - s->send_index;
+    ret = iov_send(s->fd, iov, 2, s->send_index, remaining);
+
+    if (ret == -1 && errno == EAGAIN) {
+        ret = 0; /* handled further down */
+    }
+    if (ret == -1) {
+        s->send_index = 0;
+        return -errno;
+    }
+    if (ret < (ssize_t)remaining) {
+        s->send_index += ret;
+        net_socket_write_poll(s, true);
+        return 0;
+    }
+    s->send_index = 0;
+    return size;
+}
+
+static ssize_t net_socket_receive_dgram(NetClientState *nc, const uint8_t *buf, size_t size)
+{
+    NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
+    ssize_t ret;
+
+    do {
+        ret = qemu_sendto(s->fd, buf, size, 0,
+                          (struct sockaddr *)&s->dgram_dst,
+                          sizeof(s->dgram_dst));
+    } while (ret == -1 && errno == EINTR);
+
+    if (ret == -1 && errno == EAGAIN) {
+        net_socket_write_poll(s, true);
+        return 0;
+    }
+    return ret;
+}
+
+static void net_socket_send(void *opaque)
+{
+    NetSocketState *s = opaque;
+    int size, err;
+    unsigned l;
+    uint8_t buf1[NET_BUFSIZE];
+    const uint8_t *buf;
+
+    size = qemu_recv(s->fd, buf1, sizeof(buf1), 0);
+    if (size < 0) {
+        err = socket_error();
+        if (err != EWOULDBLOCK)
+            goto eoc;
+    } else if (size == 0) {
+        /* end of connection */
+    eoc:
+        net_socket_read_poll(s, false);
+        net_socket_write_poll(s, false);
+        if (s->listen_fd != -1) {
+            qemu_set_fd_handler(s->listen_fd, net_socket_accept, NULL, s);
+        }
+        closesocket(s->fd);
+
+        s->fd = -1;
+        s->state = 0;
+        s->index = 0;
+        s->packet_len = 0;
+        s->nc.link_down = true;
+        memset(s->buf, 0, sizeof(s->buf));
+        memset(s->nc.info_str, 0, sizeof(s->nc.info_str));
+
+        return;
+    }
+    buf = buf1;
+    while (size > 0) {
+        /* reassemble a packet from the network */
+        switch(s->state) {
+        case 0:
+            l = 4 - s->index;
+            if (l > size)
+                l = size;
+            memcpy(s->buf + s->index, buf, l);
+            buf += l;
+            size -= l;
+            s->index += l;
+            if (s->index == 4) {
+                /* got length */
+                s->packet_len = ntohl(*(uint32_t *)s->buf);
+                s->index = 0;
+                s->state = 1;
+            }
+            break;
+        case 1:
+            l = s->packet_len - s->index;
+            if (l > size)
+                l = size;
+            if (s->index + l <= sizeof(s->buf)) {
+                memcpy(s->buf + s->index, buf, l);
+            } else {
+                fprintf(stderr, "serious error: oversized packet received,"
+                    "connection terminated.\n");
+                s->state = 0;
+                goto eoc;
+            }
+
+            s->index += l;
+            buf += l;
+            size -= l;
+            if (s->index >= s->packet_len) {
+                qemu_send_packet(&s->nc, s->buf, s->packet_len);
+                s->index = 0;
+                s->state = 0;
+            }
+            break;
+        }
+    }
+}
+
+static void net_socket_send_dgram(void *opaque)
+{
+    NetSocketState *s = opaque;
+    int size;
+
+    size = qemu_recv(s->fd, s->buf, sizeof(s->buf), 0);
+    if (size < 0)
+        return;
+    if (size == 0) {
+        /* end of connection */
+        net_socket_read_poll(s, false);
+        net_socket_write_poll(s, false);
+        return;
+    }
+    qemu_send_packet(&s->nc, s->buf, size);
+}
+
+static int net_socket_mcast_create(struct sockaddr_in *mcastaddr, struct in_addr *localaddr)
+{
+    struct ip_mreq imr;
+    int fd;
+    int val, ret;
+#ifdef __OpenBSD__
+    unsigned char loop;
+#else
+    int loop;
+#endif
+
+    if (!IN_MULTICAST(ntohl(mcastaddr->sin_addr.s_addr))) {
+        fprintf(stderr, "qemu: error: specified mcastaddr \"%s\" (0x%08x) "
+                "does not contain a multicast address\n",
+                inet_ntoa(mcastaddr->sin_addr),
+                (int)ntohl(mcastaddr->sin_addr.s_addr));
+        return -1;
+
+    }
+    fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
+    if (fd < 0) {
+        perror("socket(PF_INET, SOCK_DGRAM)");
+        return -1;
+    }
+
+    val = 1;
+    ret = qemu_setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
+    if (ret < 0) {
+        perror("setsockopt(SOL_SOCKET, SO_REUSEADDR)");
+        goto fail;
+    }
+
+    ret = bind(fd, (struct sockaddr *)mcastaddr, sizeof(*mcastaddr));
+    if (ret < 0) {
+        perror("bind");
+        goto fail;
+    }
+
+    /* Add host to multicast group */
+    imr.imr_multiaddr = mcastaddr->sin_addr;
+    if (localaddr) {
+        imr.imr_interface = *localaddr;
+    } else {
+        imr.imr_interface.s_addr = htonl(INADDR_ANY);
+    }
+
+    ret = qemu_setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
+                          &imr, sizeof(struct ip_mreq));
+    if (ret < 0) {
+        perror("setsockopt(IP_ADD_MEMBERSHIP)");
+        goto fail;
+    }
+
+    /* Force mcast msgs to loopback (eg. several QEMUs in same host */
+    loop = 1;
+    ret = qemu_setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
+                          &loop, sizeof(loop));
+    if (ret < 0) {
+        perror("setsockopt(SOL_IP, IP_MULTICAST_LOOP)");
+        goto fail;
+    }
+
+    /* If a bind address is given, only send packets from that address */
+    if (localaddr != NULL) {
+        ret = qemu_setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF,
+                              localaddr, sizeof(*localaddr));
+        if (ret < 0) {
+            perror("setsockopt(IP_MULTICAST_IF)");
+            goto fail;
+        }
+    }
+
+    qemu_set_nonblock(fd);
+    return fd;
+fail:
+    if (fd >= 0)
+        closesocket(fd);
+    return -1;
+}
+
+static void net_socket_cleanup(NetClientState *nc)
+{
+    NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
+    if (s->fd != -1) {
+        net_socket_read_poll(s, false);
+        net_socket_write_poll(s, false);
+        close(s->fd);
+        s->fd = -1;
+    }
+    if (s->listen_fd != -1) {
+        qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
+        closesocket(s->listen_fd);
+        s->listen_fd = -1;
+    }
+}
+
+static NetClientInfo net_dgram_socket_info = {
+    .type = NET_CLIENT_OPTIONS_KIND_SOCKET,
+    .size = sizeof(NetSocketState),
+    .receive = net_socket_receive_dgram,
+    .cleanup = net_socket_cleanup,
+};
+
+static NetSocketState *net_socket_fd_init_dgram(NetClientState *peer,
+                                                const char *model,
+                                                const char *name,
+                                                int fd, int is_connected)
+{
+    struct sockaddr_in saddr;
+    int newfd;
+    socklen_t saddr_len;
+    NetClientState *nc;
+    NetSocketState *s;
+
+    /* fd passed: multicast: "learn" dgram_dst address from bound address and save it
+     * Because this may be "shared" socket from a "master" process, datagrams would be recv()
+     * by ONLY ONE process: we must "clone" this dgram socket --jjo
+     */
+
+    if (is_connected) {
+        if (getsockname(fd, (struct sockaddr *) &saddr, &saddr_len) == 0) {
+            /* must be bound */
+            if (saddr.sin_addr.s_addr == 0) {
+                fprintf(stderr, "qemu: error: init_dgram: fd=%d unbound, "
+                        "cannot setup multicast dst addr\n", fd);
+                goto err;
+            }
+            /* clone dgram socket */
+            newfd = net_socket_mcast_create(&saddr, NULL);
+            if (newfd < 0) {
+                /* error already reported by net_socket_mcast_create() */
+                goto err;
+            }
+            /* clone newfd to fd, close newfd */
+            dup2(newfd, fd);
+            close(newfd);
+
+        } else {
+            fprintf(stderr,
+                    "qemu: error: init_dgram: fd=%d failed getsockname(): %s\n",
+                    fd, strerror(errno));
+            goto err;
+        }
+    }
+
+    nc = qemu_new_net_client(&net_dgram_socket_info, peer, model, name);
+
+    snprintf(nc->info_str, sizeof(nc->info_str),
+            "socket: fd=%d (%s mcast=%s:%d)",
+            fd, is_connected ? "cloned" : "",
+            inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
+
+    s = DO_UPCAST(NetSocketState, nc, nc);
+
+    s->fd = fd;
+    s->listen_fd = -1;
+    s->send_fn = net_socket_send_dgram;
+    net_socket_read_poll(s, true);
+
+    /* mcast: save bound address as dst */
+    if (is_connected) {
+        s->dgram_dst = saddr;
+    }
+
+    return s;
+
+err:
+    closesocket(fd);
+    return NULL;
+}
+
+static void net_socket_connect(void *opaque)
+{
+    NetSocketState *s = opaque;
+    s->send_fn = net_socket_send;
+    net_socket_read_poll(s, true);
+}
+
+static NetClientInfo net_socket_info = {
+    .type = NET_CLIENT_OPTIONS_KIND_SOCKET,
+    .size = sizeof(NetSocketState),
+    .receive = net_socket_receive,
+    .cleanup = net_socket_cleanup,
+};
+
+static NetSocketState *net_socket_fd_init_stream(NetClientState *peer,
+                                                 const char *model,
+                                                 const char *name,
+                                                 int fd, int is_connected)
+{
+    NetClientState *nc;
+    NetSocketState *s;
+
+    nc = qemu_new_net_client(&net_socket_info, peer, model, name);
+
+    snprintf(nc->info_str, sizeof(nc->info_str), "socket: fd=%d", fd);
+
+    s = DO_UPCAST(NetSocketState, nc, nc);
+
+    s->fd = fd;
+    s->listen_fd = -1;
+
+    /* Disable Nagle algorithm on TCP sockets to reduce latency */
+    socket_set_nodelay(fd);
+
+    if (is_connected) {
+        net_socket_connect(s);
+    } else {
+        qemu_set_fd_handler(s->fd, NULL, net_socket_connect, s);
+    }
+    return s;
+}
+
+static NetSocketState *net_socket_fd_init(NetClientState *peer,
+                                          const char *model, const char *name,
+                                          int fd, int is_connected)
+{
+    int so_type = -1, optlen=sizeof(so_type);
+
+    if(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&so_type,
+        (socklen_t *)&optlen)< 0) {
+        fprintf(stderr, "qemu: error: getsockopt(SO_TYPE) for fd=%d failed\n",
+                fd);
+        closesocket(fd);
+        return NULL;
+    }
+    switch(so_type) {
+    case SOCK_DGRAM:
+        return net_socket_fd_init_dgram(peer, model, name, fd, is_connected);
+    case SOCK_STREAM:
+        return net_socket_fd_init_stream(peer, model, name, fd, is_connected);
+    default:
+        /* who knows ... this could be a eg. a pty, do warn and continue as stream */
+        fprintf(stderr, "qemu: warning: socket type=%d for fd=%d is not SOCK_DGRAM or SOCK_STREAM\n", so_type, fd);
+        return net_socket_fd_init_stream(peer, model, name, fd, is_connected);
+    }
+    return NULL;
+}
+
+static void net_socket_accept(void *opaque)
+{
+    NetSocketState *s = opaque;
+    struct sockaddr_in saddr;
+    socklen_t len;
+    int fd;
+
+    for(;;) {
+        len = sizeof(saddr);
+        fd = qemu_accept(s->listen_fd, (struct sockaddr *)&saddr, &len);
+        if (fd < 0 && errno != EINTR) {
+            return;
+        } else if (fd >= 0) {
+            qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
+            break;
+        }
+    }
+
+    s->fd = fd;
+    s->nc.link_down = false;
+    net_socket_connect(s);
+    snprintf(s->nc.info_str, sizeof(s->nc.info_str),
+             "socket: connection from %s:%d",
+             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
+}
+
+static int net_socket_listen_init(NetClientState *peer,
+                                  const char *model,
+                                  const char *name,
+                                  const char *host_str)
+{
+    NetClientState *nc;
+    NetSocketState *s;
+    struct sockaddr_in saddr;
+    int fd, val, ret;
+
+    if (parse_host_port(&saddr, host_str) < 0)
+        return -1;
+
+    fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
+    if (fd < 0) {
+        perror("socket");
+        return -1;
+    }
+    qemu_set_nonblock(fd);
+
+    /* allow fast reuse */
+    val = 1;
+    qemu_setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
+
+    ret = bind(fd, (struct sockaddr *)&saddr, sizeof(saddr));
+    if (ret < 0) {
+        perror("bind");
+        closesocket(fd);
+        return -1;
+    }
+    ret = listen(fd, 0);
+    if (ret < 0) {
+        perror("listen");
+        closesocket(fd);
+        return -1;
+    }
+
+    nc = qemu_new_net_client(&net_socket_info, peer, model, name);
+    s = DO_UPCAST(NetSocketState, nc, nc);
+    s->fd = -1;
+    s->listen_fd = fd;
+    s->nc.link_down = true;
+
+    qemu_set_fd_handler(s->listen_fd, net_socket_accept, NULL, s);
+    return 0;
+}
+
+static int net_socket_connect_init(NetClientState *peer,
+                                   const char *model,
+                                   const char *name,
+                                   const char *host_str)
+{
+    NetSocketState *s;
+    int fd, connected, ret, err;
+    struct sockaddr_in saddr;
+
+    if (parse_host_port(&saddr, host_str) < 0)
+        return -1;
+
+    fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
+    if (fd < 0) {
+        perror("socket");
+        return -1;
+    }
+    qemu_set_nonblock(fd);
+
+    connected = 0;
+    for(;;) {
+        ret = connect(fd, (struct sockaddr *)&saddr, sizeof(saddr));
+        if (ret < 0) {
+            err = socket_error();
+            if (err == EINTR || err == EWOULDBLOCK) {
+            } else if (err == EINPROGRESS) {
+                break;
+#ifdef _WIN32
+            } else if (err == WSAEALREADY || err == WSAEINVAL) {
+                break;
+#endif
+            } else {
+                perror("connect");
+                closesocket(fd);
+                return -1;
+            }
+        } else {
+            connected = 1;
+            break;
+        }
+    }
+    s = net_socket_fd_init(peer, model, name, fd, connected);
+    if (!s)
+        return -1;
+    snprintf(s->nc.info_str, sizeof(s->nc.info_str),
+             "socket: connect to %s:%d",
+             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
+    return 0;
+}
+
+static int net_socket_mcast_init(NetClientState *peer,
+                                 const char *model,
+                                 const char *name,
+                                 const char *host_str,
+                                 const char *localaddr_str)
+{
+    NetSocketState *s;
+    int fd;
+    struct sockaddr_in saddr;
+    struct in_addr localaddr, *param_localaddr;
+
+    if (parse_host_port(&saddr, host_str) < 0)
+        return -1;
+
+    if (localaddr_str != NULL) {
+        if (inet_aton(localaddr_str, &localaddr) == 0)
+            return -1;
+        param_localaddr = &localaddr;
+    } else {
+        param_localaddr = NULL;
+    }
+
+    fd = net_socket_mcast_create(&saddr, param_localaddr);
+    if (fd < 0)
+        return -1;
+
+    s = net_socket_fd_init(peer, model, name, fd, 0);
+    if (!s)
+        return -1;
+
+    s->dgram_dst = saddr;
+
+    snprintf(s->nc.info_str, sizeof(s->nc.info_str),
+             "socket: mcast=%s:%d",
+             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
+    return 0;
+
+}
+
+static int net_socket_udp_init(NetClientState *peer,
+                                 const char *model,
+                                 const char *name,
+                                 const char *rhost,
+                                 const char *lhost)
+{
+    NetSocketState *s;
+    int fd, val, ret;
+    struct sockaddr_in laddr, raddr;
+
+    if (parse_host_port(&laddr, lhost) < 0) {
+        return -1;
+    }
+
+    if (parse_host_port(&raddr, rhost) < 0) {
+        return -1;
+    }
+
+    fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
+    if (fd < 0) {
+        perror("socket(PF_INET, SOCK_DGRAM)");
+        return -1;
+    }
+    val = 1;
+    ret = qemu_setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
+                          &val, sizeof(val));
+    if (ret < 0) {
+        perror("setsockopt(SOL_SOCKET, SO_REUSEADDR)");
+        closesocket(fd);
+        return -1;
+    }
+    ret = bind(fd, (struct sockaddr *)&laddr, sizeof(laddr));
+    if (ret < 0) {
+        perror("bind");
+        closesocket(fd);
+        return -1;
+    }
+    qemu_set_nonblock(fd);
+
+    s = net_socket_fd_init(peer, model, name, fd, 0);
+    if (!s) {
+        return -1;
+    }
+
+    s->dgram_dst = raddr;
+
+    snprintf(s->nc.info_str, sizeof(s->nc.info_str),
+             "socket: udp=%s:%d",
+             inet_ntoa(raddr.sin_addr), ntohs(raddr.sin_port));
+    return 0;
+}
+
+int net_init_socket(const NetClientOptions *opts, const char *name,
+                    NetClientState *peer)
+{
+    const NetdevSocketOptions *sock;
+
+    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_SOCKET);
+    sock = opts->socket;
+
+    if (sock->has_fd + sock->has_listen + sock->has_connect + sock->has_mcast +
+        sock->has_udp != 1) {
+        error_report("exactly one of fd=, listen=, connect=, mcast= or udp="
+                     " is required");
+        return -1;
+    }
+
+    if (sock->has_localaddr && !sock->has_mcast && !sock->has_udp) {
+        error_report("localaddr= is only valid with mcast= or udp=");
+        return -1;
+    }
+
+    if (sock->has_fd) {
+        int fd;
+
+        fd = monitor_handle_fd_param(cur_mon, sock->fd);
+        if (fd == -1) {
+            return -1;
+        }
+        qemu_set_nonblock(fd);
+        if (!net_socket_fd_init(peer, "socket", name, fd, 1)) {
+            return -1;
+        }
+        return 0;
+    }
+
+    if (sock->has_listen) {
+        if (net_socket_listen_init(peer, "socket", name, sock->listen) == -1) {
+            return -1;
+        }
+        return 0;
+    }
+
+    if (sock->has_connect) {
+        if (net_socket_connect_init(peer, "socket", name, sock->connect) ==
+            -1) {
+            return -1;
+        }
+        return 0;
+    }
+
+    if (sock->has_mcast) {
+        /* if sock->localaddr is missing, it has been initialized to "all bits
+         * zero" */
+        if (net_socket_mcast_init(peer, "socket", name, sock->mcast,
+            sock->localaddr) == -1) {
+            return -1;
+        }
+        return 0;
+    }
+
+    assert(sock->has_udp);
+    if (!sock->has_localaddr) {
+        error_report("localaddr= is mandatory with udp=");
+        return -1;
+    }
+    if (net_socket_udp_init(peer, "socket", name, sock->udp, sock->localaddr) ==
+        -1) {
+        return -1;
+    }
+    return 0;
+}
diff --git a/net/tap-aix.c b/net/tap-aix.c
new file mode 100644
index 000000000..804d16448
--- /dev/null
+++ b/net/tap-aix.c
@@ -0,0 +1,78 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "tap_int.h"
+#include <stdio.h>
+
+int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
+             int vnet_hdr_required, int mq_required)
+{
+    fprintf(stderr, "no tap on AIX\n");
+    return -1;
+}
+
+int tap_set_sndbuf(int fd, const NetdevTapOptions *tap)
+{
+    return 0;
+}
+
+int tap_probe_vnet_hdr(int fd)
+{
+    return 0;
+}
+
+int tap_probe_has_ufo(int fd)
+{
+    return 0;
+}
+
+int tap_probe_vnet_hdr_len(int fd, int len)
+{
+    return 0;
+}
+
+void tap_fd_set_vnet_hdr_len(int fd, int len)
+{
+}
+
+void tap_fd_set_offload(int fd, int csum, int tso4,
+                        int tso6, int ecn, int ufo)
+{
+}
+
+int tap_fd_enable(int fd)
+{
+    return -1;
+}
+
+int tap_fd_disable(int fd)
+{
+    return -1;
+}
+
+int tap_fd_get_ifname(int fd, char *ifname)
+{
+    return -1;
+}
+
diff --git a/net/tap-bsd.c b/net/tap-bsd.c
new file mode 100644
index 000000000..f61d58096
--- /dev/null
+++ b/net/tap-bsd.c
@@ -0,0 +1,164 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "tap_int.h"
+#include "qemu-common.h"
+#include "sysemu/sysemu.h"
+#include "qemu/error-report.h"
+
+#ifdef __NetBSD__
+#include <sys/ioctl.h>
+#include <net/if.h>
+#include <net/if_tap.h>
+#endif
+
+int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
+             int vnet_hdr_required, int mq_required)
+{
+    int fd;
+#ifdef TAPGIFNAME
+    struct ifreq ifr;
+#else
+    char *dev;
+    struct stat s;
+#endif
+
+#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || \
+    defined(__OpenBSD__) || defined(__APPLE__)
+    /* if no ifname is given, always start the search from tap0/tun0. */
+    int i;
+    char dname[100];
+
+    for (i = 0; i < 10; i++) {
+        if (*ifname) {
+            snprintf(dname, sizeof dname, "/dev/%s", ifname);
+        } else {
+#if defined(__OpenBSD__)
+            snprintf(dname, sizeof dname, "/dev/tun%d", i);
+#else
+            snprintf(dname, sizeof dname, "/dev/tap%d", i);
+#endif
+        }
+        TFR(fd = open(dname, O_RDWR));
+        if (fd >= 0) {
+            break;
+        }
+        else if (errno == ENXIO || errno == ENOENT) {
+            break;
+        }
+        if (*ifname) {
+            break;
+        }
+    }
+    if (fd < 0) {
+        error_report("warning: could not open %s (%s): no virtual network emulation",
+                   dname, strerror(errno));
+        return -1;
+    }
+#else
+    TFR(fd = open("/dev/tap", O_RDWR));
+    if (fd < 0) {
+        fprintf(stderr,
+            "warning: could not open /dev/tap: no virtual network emulation: %s\n",
+            strerror(errno));
+        return -1;
+    }
+#endif
+
+#ifdef TAPGIFNAME
+    if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) {
+        fprintf(stderr, "warning: could not get tap name: %s\n",
+            strerror(errno));
+        return -1;
+    }
+    pstrcpy(ifname, ifname_size, ifr.ifr_name);
+#else
+    if (fstat(fd, &s) < 0) {
+        fprintf(stderr,
+            "warning: could not stat /dev/tap: no virtual network emulation: %s\n",
+            strerror(errno));
+        return -1;
+    }
+    dev = devname(s.st_rdev, S_IFCHR);
+    pstrcpy(ifname, ifname_size, dev);
+#endif
+
+    if (*vnet_hdr) {
+        /* BSD doesn't have IFF_VNET_HDR */
+        *vnet_hdr = 0;
+
+        if (vnet_hdr_required && !*vnet_hdr) {
+            error_report("vnet_hdr=1 requested, but no kernel "
+                         "support for IFF_VNET_HDR available");
+            close(fd);
+            return -1;
+        }
+    }
+    fcntl(fd, F_SETFL, O_NONBLOCK);
+    return fd;
+}
+
+int tap_set_sndbuf(int fd, const NetdevTapOptions *tap)
+{
+    return 0;
+}
+
+int tap_probe_vnet_hdr(int fd)
+{
+    return 0;
+}
+
+int tap_probe_has_ufo(int fd)
+{
+    return 0;
+}
+
+int tap_probe_vnet_hdr_len(int fd, int len)
+{
+    return 0;
+}
+
+void tap_fd_set_vnet_hdr_len(int fd, int len)
+{
+}
+
+void tap_fd_set_offload(int fd, int csum, int tso4,
+                        int tso6, int ecn, int ufo)
+{
+}
+
+int tap_fd_enable(int fd)
+{
+    return -1;
+}
+
+int tap_fd_disable(int fd)
+{
+    return -1;
+}
+
+int tap_fd_get_ifname(int fd, char *ifname)
+{
+    return -1;
+}
diff --git a/net/tap-haiku.c b/net/tap-haiku.c
new file mode 100644
index 000000000..e5ce436d2
--- /dev/null
+++ b/net/tap-haiku.c
@@ -0,0 +1,77 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "tap_int.h"
+#include <stdio.h>
+
+int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
+             int vnet_hdr_required, int mq_required)
+{
+    fprintf(stderr, "no tap on Haiku\n");
+    return -1;
+}
+
+int tap_set_sndbuf(int fd, const NetdevTapOptions *tap)
+{
+    return 0;
+}
+
+int tap_probe_vnet_hdr(int fd)
+{
+    return 0;
+}
+
+int tap_probe_has_ufo(int fd)
+{
+    return 0;
+}
+
+int tap_probe_vnet_hdr_len(int fd, int len)
+{
+    return 0;
+}
+
+void tap_fd_set_vnet_hdr_len(int fd, int len)
+{
+}
+
+void tap_fd_set_offload(int fd, int csum, int tso4,
+                        int tso6, int ecn, int ufo)
+{
+}
+
+int tap_fd_enable(int fd)
+{
+    return -1;
+}
+
+int tap_fd_disable(int fd)
+{
+    return -1;
+}
+
+int tap_fd_get_ifname(int fd, char *ifname)
+{
+    return -1;
+}
diff --git a/net/tap-linux.c b/net/tap-linux.c
new file mode 100644
index 000000000..36c09e24d
--- /dev/null
+++ b/net/tap-linux.c
@@ -0,0 +1,278 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ * Copyright (c) 2009 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "tap_int.h"
+#include "tap-linux.h"
+#include "net/tap.h"
+
+#include <net/if.h>
+#include <sys/ioctl.h>
+
+#include "sysemu/sysemu.h"
+#include "qemu-common.h"
+#include "qemu/error-report.h"
+
+#define PATH_NET_TUN "/dev/net/tun"
+
+int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
+             int vnet_hdr_required, int mq_required)
+{
+    struct ifreq ifr;
+    int fd, ret;
+    int len = sizeof(struct virtio_net_hdr);
+    unsigned int features;
+
+    TFR(fd = open(PATH_NET_TUN, O_RDWR));
+    if (fd < 0) {
+        error_report("could not open %s: %m", PATH_NET_TUN);
+        return -1;
+    }
+    memset(&ifr, 0, sizeof(ifr));
+    ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+
+    if (ioctl(fd, TUNGETFEATURES, &features) == 0 &&
+        features & IFF_ONE_QUEUE) {
+        ifr.ifr_flags |= IFF_ONE_QUEUE;
+    }
+
+    if (*vnet_hdr) {
+        if (ioctl(fd, TUNGETFEATURES, &features) == 0 &&
+            features & IFF_VNET_HDR) {
+            *vnet_hdr = 1;
+            ifr.ifr_flags |= IFF_VNET_HDR;
+        } else {
+            *vnet_hdr = 0;
+        }
+
+        if (vnet_hdr_required && !*vnet_hdr) {
+            error_report("vnet_hdr=1 requested, but no kernel "
+                         "support for IFF_VNET_HDR available");
+            close(fd);
+            return -1;
+        }
+        /*
+         * Make sure vnet header size has the default value: for a persistent
+         * tap it might have been modified e.g. by another instance of qemu.
+         * Ignore errors since old kernels do not support this ioctl: in this
+         * case the header size implicitly has the correct value.
+         */
+        ioctl(fd, TUNSETVNETHDRSZ, &len);
+    }
+
+    if (mq_required) {
+        if ((ioctl(fd, TUNGETFEATURES, &features) != 0) ||
+            !(features & IFF_MULTI_QUEUE)) {
+            error_report("multiqueue required, but no kernel "
+                         "support for IFF_MULTI_QUEUE available");
+            close(fd);
+            return -1;
+        } else {
+            ifr.ifr_flags |= IFF_MULTI_QUEUE;
+        }
+    }
+
+    if (ifname[0] != '\0')
+        pstrcpy(ifr.ifr_name, IFNAMSIZ, ifname);
+    else
+        pstrcpy(ifr.ifr_name, IFNAMSIZ, "tap%d");
+    ret = ioctl(fd, TUNSETIFF, (void *) &ifr);
+    if (ret != 0) {
+        if (ifname[0] != '\0') {
+            error_report("could not configure %s (%s): %m", PATH_NET_TUN, ifr.ifr_name);
+        } else {
+            error_report("could not configure %s: %m", PATH_NET_TUN);
+        }
+        close(fd);
+        return -1;
+    }
+    pstrcpy(ifname, ifname_size, ifr.ifr_name);
+    fcntl(fd, F_SETFL, O_NONBLOCK);
+    return fd;
+}
+
+/* sndbuf implements a kind of flow control for tap.
+ * Unfortunately when it's enabled, and packets are sent
+ * to other guests on the same host, the receiver
+ * can lock up the transmitter indefinitely.
+ *
+ * To avoid packet loss, sndbuf should be set to a value lower than the tx
+ * queue capacity of any destination network interface.
+ * Ethernet NICs generally have txqueuelen=1000, so 1Mb is
+ * a good value, given a 1500 byte MTU.
+ */
+#define TAP_DEFAULT_SNDBUF 0
+
+int tap_set_sndbuf(int fd, const NetdevTapOptions *tap)
+{
+    int sndbuf;
+
+    sndbuf = !tap->has_sndbuf       ? TAP_DEFAULT_SNDBUF :
+             tap->sndbuf > INT_MAX  ? INT_MAX :
+             tap->sndbuf;
+
+    if (!sndbuf) {
+        sndbuf = INT_MAX;
+    }
+
+    if (ioctl(fd, TUNSETSNDBUF, &sndbuf) == -1 && tap->has_sndbuf) {
+        error_report("TUNSETSNDBUF ioctl failed: %s", strerror(errno));
+        return -1;
+    }
+    return 0;
+}
+
+int tap_probe_vnet_hdr(int fd)
+{
+    struct ifreq ifr;
+
+    if (ioctl(fd, TUNGETIFF, &ifr) != 0) {
+        error_report("TUNGETIFF ioctl() failed: %s", strerror(errno));
+        return 0;
+    }
+
+    return ifr.ifr_flags & IFF_VNET_HDR;
+}
+
+int tap_probe_has_ufo(int fd)
+{
+    unsigned offload;
+
+    offload = TUN_F_CSUM | TUN_F_UFO;
+
+    if (ioctl(fd, TUNSETOFFLOAD, offload) < 0)
+        return 0;
+
+    return 1;
+}
+
+/* Verify that we can assign given length */
+int tap_probe_vnet_hdr_len(int fd, int len)
+{
+    int orig;
+    if (ioctl(fd, TUNGETVNETHDRSZ, &orig) == -1) {
+        return 0;
+    }
+    if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) {
+        return 0;
+    }
+    /* Restore original length: we can't handle failure. */
+    if (ioctl(fd, TUNSETVNETHDRSZ, &orig) == -1) {
+        fprintf(stderr, "TUNGETVNETHDRSZ ioctl() failed: %s. Exiting.\n",
+                strerror(errno));
+        abort();
+        return -errno;
+    }
+    return 1;
+}
+
+void tap_fd_set_vnet_hdr_len(int fd, int len)
+{
+    if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) {
+        fprintf(stderr, "TUNSETVNETHDRSZ ioctl() failed: %s. Exiting.\n",
+                strerror(errno));
+        abort();
+    }
+}
+
+void tap_fd_set_offload(int fd, int csum, int tso4,
+                        int tso6, int ecn, int ufo)
+{
+    unsigned int offload = 0;
+
+    /* Check if our kernel supports TUNSETOFFLOAD */
+    if (ioctl(fd, TUNSETOFFLOAD, 0) != 0 && errno == EINVAL) {
+        return;
+    }
+
+    if (csum) {
+        offload |= TUN_F_CSUM;
+        if (tso4)
+            offload |= TUN_F_TSO4;
+        if (tso6)
+            offload |= TUN_F_TSO6;
+        if ((tso4 || tso6) && ecn)
+            offload |= TUN_F_TSO_ECN;
+        if (ufo)
+            offload |= TUN_F_UFO;
+    }
+
+    if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) {
+        offload &= ~TUN_F_UFO;
+        if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) {
+            fprintf(stderr, "TUNSETOFFLOAD ioctl() failed: %s\n",
+                    strerror(errno));
+        }
+    }
+}
+
+/* Enable a specific queue of tap. */
+int tap_fd_enable(int fd)
+{
+    struct ifreq ifr;
+    int ret;
+
+    memset(&ifr, 0, sizeof(ifr));
+
+    ifr.ifr_flags = IFF_ATTACH_QUEUE;
+    ret = ioctl(fd, TUNSETQUEUE, (void *) &ifr);
+
+    if (ret != 0) {
+        error_report("could not enable queue");
+    }
+
+    return ret;
+}
+
+/* Disable a specific queue of tap/ */
+int tap_fd_disable(int fd)
+{
+    struct ifreq ifr;
+    int ret;
+
+    memset(&ifr, 0, sizeof(ifr));
+
+    ifr.ifr_flags = IFF_DETACH_QUEUE;
+    ret = ioctl(fd, TUNSETQUEUE, (void *) &ifr);
+
+    if (ret != 0) {
+        error_report("could not disable queue");
+    }
+
+    return ret;
+}
+
+int tap_fd_get_ifname(int fd, char *ifname)
+{
+    struct ifreq ifr;
+
+    if (ioctl(fd, TUNGETIFF, &ifr) != 0) {
+        error_report("TUNGETIFF ioctl() failed: %s",
+                     strerror(errno));
+        return -1;
+    }
+
+    pstrcpy(ifname, sizeof(ifr.ifr_name), ifr.ifr_name);
+    return 0;
+}
diff --git a/net/tap-linux.h b/net/tap-linux.h
new file mode 100644
index 000000000..1cf35d41b
--- /dev/null
+++ b/net/tap-linux.h
@@ -0,0 +1,52 @@
+/*
+ *  Universal TUN/TAP device driver.
+ *  Copyright (C) 1999-2000 Maxim Krasnyansky <max_mk@yahoo.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *  GNU General Public License for more details.
+ */
+
+#ifndef QEMU_TAP_LINUX_H
+#define QEMU_TAP_LINUX_H
+
+#include <stdint.h>
+#ifdef __linux__
+
+#include <linux/ioctl.h>
+
+/* Ioctl defines */
+#define TUNSETIFF     _IOW('T', 202, int)
+#define TUNGETFEATURES _IOR('T', 207, unsigned int)
+#define TUNSETOFFLOAD  _IOW('T', 208, unsigned int)
+#define TUNGETIFF      _IOR('T', 210, unsigned int)
+#define TUNSETSNDBUF   _IOW('T', 212, int)
+#define TUNGETVNETHDRSZ _IOR('T', 215, int)
+#define TUNSETVNETHDRSZ _IOW('T', 216, int)
+#define TUNSETQUEUE  _IOW('T', 217, int)
+
+#endif
+
+/* TUNSETIFF ifr flags */
+#define IFF_TAP          0x0002
+#define IFF_NO_PI        0x1000
+#define IFF_ONE_QUEUE    0x2000
+#define IFF_VNET_HDR     0x4000
+#define IFF_MULTI_QUEUE  0x0100
+#define IFF_ATTACH_QUEUE 0x0200
+#define IFF_DETACH_QUEUE 0x0400
+
+/* Features for GSO (TUNSETOFFLOAD). */
+#define TUN_F_CSUM	0x01	/* You can hand me unchecksummed packets. */
+#define TUN_F_TSO4	0x02	/* I can handle TSO for IPv4 packets */
+#define TUN_F_TSO6	0x04	/* I can handle TSO for IPv6 packets */
+#define TUN_F_TSO_ECN	0x08	/* I can handle TSO with ECN bits. */
+#define TUN_F_UFO	0x10	/* I can handle UFO packets */
+
+#endif /* QEMU_TAP_H */
diff --git a/net/tap-solaris.c b/net/tap-solaris.c
new file mode 100644
index 000000000..9c7278f1b
--- /dev/null
+++ b/net/tap-solaris.c
@@ -0,0 +1,243 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "tap_int.h"
+#include "sysemu/sysemu.h"
+
+#include <sys/stat.h>
+#include <sys/ethernet.h>
+#include <sys/sockio.h>
+#include <netinet/arp.h>
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#include <netinet/ip.h>
+#include <netinet/ip_icmp.h> // must come after ip.h
+#include <netinet/udp.h>
+#include <netinet/tcp.h>
+#include <net/if.h>
+#include <syslog.h>
+#include <stropts.h>
+#include "qemu/error-report.h"
+
+ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen)
+{
+    struct strbuf sbuf;
+    int f = 0;
+
+    sbuf.maxlen = maxlen;
+    sbuf.buf = (char *)buf;
+
+    return getmsg(tapfd, NULL, &sbuf, &f) >= 0 ? sbuf.len : -1;
+}
+
+#define TUNNEWPPA       (('T'<<16) | 0x0001)
+/*
+ * Allocate TAP device, returns opened fd.
+ * Stores dev name in the first arg(must be large enough).
+ */
+static int tap_alloc(char *dev, size_t dev_size)
+{
+    int tap_fd, if_fd, ppa = -1;
+    static int ip_fd = 0;
+    char *ptr;
+
+    static int arp_fd = 0;
+    int ip_muxid, arp_muxid;
+    struct strioctl  strioc_if, strioc_ppa;
+    int link_type = I_PLINK;
+    struct lifreq ifr;
+    char actual_name[32] = "";
+
+    memset(&ifr, 0x0, sizeof(ifr));
+
+    if( *dev ){
+       ptr = dev;
+       while( *ptr && !qemu_isdigit((int)*ptr) ) ptr++;
+       ppa = atoi(ptr);
+    }
+
+    /* Check if IP device was opened */
+    if( ip_fd )
+       close(ip_fd);
+
+    TFR(ip_fd = open("/dev/udp", O_RDWR, 0));
+    if (ip_fd < 0) {
+       syslog(LOG_ERR, "Can't open /dev/ip (actually /dev/udp)");
+       return -1;
+    }
+
+    TFR(tap_fd = open("/dev/tap", O_RDWR, 0));
+    if (tap_fd < 0) {
+       syslog(LOG_ERR, "Can't open /dev/tap");
+       return -1;
+    }
+
+    /* Assign a new PPA and get its unit number. */
+    strioc_ppa.ic_cmd = TUNNEWPPA;
+    strioc_ppa.ic_timout = 0;
+    strioc_ppa.ic_len = sizeof(ppa);
+    strioc_ppa.ic_dp = (char *)&ppa;
+    if ((ppa = ioctl (tap_fd, I_STR, &strioc_ppa)) < 0)
+       syslog (LOG_ERR, "Can't assign new interface");
+
+    TFR(if_fd = open("/dev/tap", O_RDWR, 0));
+    if (if_fd < 0) {
+       syslog(LOG_ERR, "Can't open /dev/tap (2)");
+       return -1;
+    }
+    if(ioctl(if_fd, I_PUSH, "ip") < 0){
+       syslog(LOG_ERR, "Can't push IP module");
+       return -1;
+    }
+
+    if (ioctl(if_fd, SIOCGLIFFLAGS, &ifr) < 0)
+	syslog(LOG_ERR, "Can't get flags\n");
+
+    snprintf (actual_name, 32, "tap%d", ppa);
+    pstrcpy(ifr.lifr_name, sizeof(ifr.lifr_name), actual_name);
+
+    ifr.lifr_ppa = ppa;
+    /* Assign ppa according to the unit number returned by tun device */
+
+    if (ioctl (if_fd, SIOCSLIFNAME, &ifr) < 0)
+        syslog (LOG_ERR, "Can't set PPA %d", ppa);
+    if (ioctl(if_fd, SIOCGLIFFLAGS, &ifr) <0)
+        syslog (LOG_ERR, "Can't get flags\n");
+    /* Push arp module to if_fd */
+    if (ioctl (if_fd, I_PUSH, "arp") < 0)
+        syslog (LOG_ERR, "Can't push ARP module (2)");
+
+    /* Push arp module to ip_fd */
+    if (ioctl (ip_fd, I_POP, NULL) < 0)
+        syslog (LOG_ERR, "I_POP failed\n");
+    if (ioctl (ip_fd, I_PUSH, "arp") < 0)
+        syslog (LOG_ERR, "Can't push ARP module (3)\n");
+    /* Open arp_fd */
+    TFR(arp_fd = open ("/dev/tap", O_RDWR, 0));
+    if (arp_fd < 0)
+       syslog (LOG_ERR, "Can't open %s\n", "/dev/tap");
+
+    /* Set ifname to arp */
+    strioc_if.ic_cmd = SIOCSLIFNAME;
+    strioc_if.ic_timout = 0;
+    strioc_if.ic_len = sizeof(ifr);
+    strioc_if.ic_dp = (char *)&ifr;
+    if (ioctl(arp_fd, I_STR, &strioc_if) < 0){
+        syslog (LOG_ERR, "Can't set ifname to arp\n");
+    }
+
+    if((ip_muxid = ioctl(ip_fd, I_LINK, if_fd)) < 0){
+       syslog(LOG_ERR, "Can't link TAP device to IP");
+       return -1;
+    }
+
+    if ((arp_muxid = ioctl (ip_fd, link_type, arp_fd)) < 0)
+        syslog (LOG_ERR, "Can't link TAP device to ARP");
+
+    close (if_fd);
+
+    memset(&ifr, 0x0, sizeof(ifr));
+    pstrcpy(ifr.lifr_name, sizeof(ifr.lifr_name), actual_name);
+    ifr.lifr_ip_muxid  = ip_muxid;
+    ifr.lifr_arp_muxid = arp_muxid;
+
+    if (ioctl (ip_fd, SIOCSLIFMUXID, &ifr) < 0)
+    {
+      ioctl (ip_fd, I_PUNLINK , arp_muxid);
+      ioctl (ip_fd, I_PUNLINK, ip_muxid);
+      syslog (LOG_ERR, "Can't set multiplexor id");
+    }
+
+    snprintf(dev, dev_size, "tap%d", ppa);
+    return tap_fd;
+}
+
+int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
+             int vnet_hdr_required, int mq_required)
+{
+    char  dev[10]="";
+    int fd;
+    if( (fd = tap_alloc(dev, sizeof(dev))) < 0 ){
+       fprintf(stderr, "Cannot allocate TAP device\n");
+       return -1;
+    }
+    pstrcpy(ifname, ifname_size, dev);
+    if (*vnet_hdr) {
+        /* Solaris doesn't have IFF_VNET_HDR */
+        *vnet_hdr = 0;
+
+        if (vnet_hdr_required && !*vnet_hdr) {
+            error_report("vnet_hdr=1 requested, but no kernel "
+                         "support for IFF_VNET_HDR available");
+            close(fd);
+            return -1;
+        }
+    }
+    fcntl(fd, F_SETFL, O_NONBLOCK);
+    return fd;
+}
+
+int tap_set_sndbuf(int fd, const NetdevTapOptions *tap)
+{
+    return 0;
+}
+
+int tap_probe_vnet_hdr(int fd)
+{
+    return 0;
+}
+
+int tap_probe_has_ufo(int fd)
+{
+    return 0;
+}
+
+int tap_probe_vnet_hdr_len(int fd, int len)
+{
+    return 0;
+}
+
+void tap_fd_set_vnet_hdr_len(int fd, int len)
+{
+}
+
+void tap_fd_set_offload(int fd, int csum, int tso4,
+                        int tso6, int ecn, int ufo)
+{
+}
+
+int tap_fd_enable(int fd)
+{
+    return -1;
+}
+
+int tap_fd_disable(int fd)
+{
+    return -1;
+}
+
+int tap_fd_get_ifname(int fd, char *ifname)
+{
+    return -1;
+}
diff --git a/net/tap-win32.c b/net/tap-win32.c
new file mode 100644
index 000000000..91e9e844a
--- /dev/null
+++ b/net/tap-win32.c
@@ -0,0 +1,776 @@
+/*
+ *  TAP-Win32 -- A kernel driver to provide virtual tap device functionality
+ *               on Windows.  Originally derived from the CIPE-Win32
+ *               project by Damion K. Wilson, with extensive modifications by
+ *               James Yonan.
+ *
+ *  All source code which derives from the CIPE-Win32 project is
+ *  Copyright (C) Damion K. Wilson, 2003, and is released under the
+ *  GPL version 2 (see below).
+ *
+ *  All other source code is Copyright (C) James Yonan, 2003-2004,
+ *  and is released under the GPL version 2 (see below).
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program (see the file COPYING included with this
+ *  distribution); if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "tap_int.h"
+
+#include "qemu-common.h"
+#include "clients.h"            /* net_init_tap */
+#include "net/net.h"
+#include "net/tap.h"            /* tap_has_ufo, ... */
+#include "sysemu/sysemu.h"
+#include "qemu/error-report.h"
+#include <stdio.h>
+#include <windows.h>
+#include <winioctl.h>
+
+//=============
+// TAP IOCTLs
+//=============
+
+#define TAP_CONTROL_CODE(request,method) \
+  CTL_CODE (FILE_DEVICE_UNKNOWN, request, method, FILE_ANY_ACCESS)
+
+#define TAP_IOCTL_GET_MAC               TAP_CONTROL_CODE (1, METHOD_BUFFERED)
+#define TAP_IOCTL_GET_VERSION           TAP_CONTROL_CODE (2, METHOD_BUFFERED)
+#define TAP_IOCTL_GET_MTU               TAP_CONTROL_CODE (3, METHOD_BUFFERED)
+#define TAP_IOCTL_GET_INFO              TAP_CONTROL_CODE (4, METHOD_BUFFERED)
+#define TAP_IOCTL_CONFIG_POINT_TO_POINT TAP_CONTROL_CODE (5, METHOD_BUFFERED)
+#define TAP_IOCTL_SET_MEDIA_STATUS      TAP_CONTROL_CODE (6, METHOD_BUFFERED)
+#define TAP_IOCTL_CONFIG_DHCP_MASQ      TAP_CONTROL_CODE (7, METHOD_BUFFERED)
+#define TAP_IOCTL_GET_LOG_LINE          TAP_CONTROL_CODE (8, METHOD_BUFFERED)
+#define TAP_IOCTL_CONFIG_DHCP_SET_OPT   TAP_CONTROL_CODE (9, METHOD_BUFFERED)
+
+//=================
+// Registry keys
+//=================
+
+#define ADAPTER_KEY "SYSTEM\\CurrentControlSet\\Control\\Class\\{4D36E972-E325-11CE-BFC1-08002BE10318}"
+
+#define NETWORK_CONNECTIONS_KEY "SYSTEM\\CurrentControlSet\\Control\\Network\\{4D36E972-E325-11CE-BFC1-08002BE10318}"
+
+//======================
+// Filesystem prefixes
+//======================
+
+#define USERMODEDEVICEDIR "\\\\.\\Global\\"
+#define TAPSUFFIX         ".tap"
+
+
+//======================
+// Compile time configuration
+//======================
+
+//#define DEBUG_TAP_WIN32
+
+#define TUN_ASYNCHRONOUS_WRITES 1
+
+#define TUN_BUFFER_SIZE 1560
+#define TUN_MAX_BUFFER_COUNT 32
+
+/*
+ * The data member "buffer" must be the first element in the tun_buffer
+ * structure. See the function, tap_win32_free_buffer.
+ */
+typedef struct tun_buffer_s {
+    unsigned char buffer [TUN_BUFFER_SIZE];
+    unsigned long read_size;
+    struct tun_buffer_s* next;
+} tun_buffer_t;
+
+typedef struct tap_win32_overlapped {
+    HANDLE handle;
+    HANDLE read_event;
+    HANDLE write_event;
+    HANDLE output_queue_semaphore;
+    HANDLE free_list_semaphore;
+    HANDLE tap_semaphore;
+    CRITICAL_SECTION output_queue_cs;
+    CRITICAL_SECTION free_list_cs;
+    OVERLAPPED read_overlapped;
+    OVERLAPPED write_overlapped;
+    tun_buffer_t buffers[TUN_MAX_BUFFER_COUNT];
+    tun_buffer_t* free_list;
+    tun_buffer_t* output_queue_front;
+    tun_buffer_t* output_queue_back;
+} tap_win32_overlapped_t;
+
+static tap_win32_overlapped_t tap_overlapped;
+
+static tun_buffer_t* get_buffer_from_free_list(tap_win32_overlapped_t* const overlapped)
+{
+    tun_buffer_t* buffer = NULL;
+    WaitForSingleObject(overlapped->free_list_semaphore, INFINITE);
+    EnterCriticalSection(&overlapped->free_list_cs);
+    buffer = overlapped->free_list;
+//    assert(buffer != NULL);
+    overlapped->free_list = buffer->next;
+    LeaveCriticalSection(&overlapped->free_list_cs);
+    buffer->next = NULL;
+    return buffer;
+}
+
+static void put_buffer_on_free_list(tap_win32_overlapped_t* const overlapped, tun_buffer_t* const buffer)
+{
+    EnterCriticalSection(&overlapped->free_list_cs);
+    buffer->next = overlapped->free_list;
+    overlapped->free_list = buffer;
+    LeaveCriticalSection(&overlapped->free_list_cs);
+    ReleaseSemaphore(overlapped->free_list_semaphore, 1, NULL);
+}
+
+static tun_buffer_t* get_buffer_from_output_queue(tap_win32_overlapped_t* const overlapped, const int block)
+{
+    tun_buffer_t* buffer = NULL;
+    DWORD result, timeout = block ? INFINITE : 0L;
+
+    // Non-blocking call
+    result = WaitForSingleObject(overlapped->output_queue_semaphore, timeout);
+
+    switch (result)
+    {
+        // The semaphore object was signaled.
+        case WAIT_OBJECT_0:
+            EnterCriticalSection(&overlapped->output_queue_cs);
+
+            buffer = overlapped->output_queue_front;
+            overlapped->output_queue_front = buffer->next;
+
+            if(overlapped->output_queue_front == NULL) {
+                overlapped->output_queue_back = NULL;
+            }
+
+            LeaveCriticalSection(&overlapped->output_queue_cs);
+            break;
+
+        // Semaphore was nonsignaled, so a time-out occurred.
+        case WAIT_TIMEOUT:
+            // Cannot open another window.
+            break;
+    }
+
+    return buffer;
+}
+
+static tun_buffer_t* get_buffer_from_output_queue_immediate (tap_win32_overlapped_t* const overlapped)
+{
+    return get_buffer_from_output_queue(overlapped, 0);
+}
+
+static void put_buffer_on_output_queue(tap_win32_overlapped_t* const overlapped, tun_buffer_t* const buffer)
+{
+    EnterCriticalSection(&overlapped->output_queue_cs);
+
+    if(overlapped->output_queue_front == NULL && overlapped->output_queue_back == NULL) {
+        overlapped->output_queue_front = overlapped->output_queue_back = buffer;
+    } else {
+        buffer->next = NULL;
+        overlapped->output_queue_back->next = buffer;
+        overlapped->output_queue_back = buffer;
+    }
+
+    LeaveCriticalSection(&overlapped->output_queue_cs);
+
+    ReleaseSemaphore(overlapped->output_queue_semaphore, 1, NULL);
+}
+
+
+static int is_tap_win32_dev(const char *guid)
+{
+    HKEY netcard_key;
+    LONG status;
+    DWORD len;
+    int i = 0;
+
+    status = RegOpenKeyEx(
+        HKEY_LOCAL_MACHINE,
+        ADAPTER_KEY,
+        0,
+        KEY_READ,
+        &netcard_key);
+
+    if (status != ERROR_SUCCESS) {
+        return FALSE;
+    }
+
+    for (;;) {
+        char enum_name[256];
+        char unit_string[256];
+        HKEY unit_key;
+        char component_id_string[] = "ComponentId";
+        char component_id[256];
+        char net_cfg_instance_id_string[] = "NetCfgInstanceId";
+        char net_cfg_instance_id[256];
+        DWORD data_type;
+
+        len = sizeof (enum_name);
+        status = RegEnumKeyEx(
+            netcard_key,
+            i,
+            enum_name,
+            &len,
+            NULL,
+            NULL,
+            NULL,
+            NULL);
+
+        if (status == ERROR_NO_MORE_ITEMS)
+            break;
+        else if (status != ERROR_SUCCESS) {
+            return FALSE;
+        }
+
+        snprintf (unit_string, sizeof(unit_string), "%s\\%s",
+                  ADAPTER_KEY, enum_name);
+
+        status = RegOpenKeyEx(
+            HKEY_LOCAL_MACHINE,
+            unit_string,
+            0,
+            KEY_READ,
+            &unit_key);
+
+        if (status != ERROR_SUCCESS) {
+            return FALSE;
+        } else {
+            len = sizeof (component_id);
+            status = RegQueryValueEx(
+                unit_key,
+                component_id_string,
+                NULL,
+                &data_type,
+                (LPBYTE)component_id,
+                &len);
+
+            if (!(status != ERROR_SUCCESS || data_type != REG_SZ)) {
+                len = sizeof (net_cfg_instance_id);
+                status = RegQueryValueEx(
+                    unit_key,
+                    net_cfg_instance_id_string,
+                    NULL,
+                    &data_type,
+                    (LPBYTE)net_cfg_instance_id,
+                    &len);
+
+                if (status == ERROR_SUCCESS && data_type == REG_SZ) {
+                    if (/* !strcmp (component_id, TAP_COMPONENT_ID) &&*/
+                        !strcmp (net_cfg_instance_id, guid)) {
+                        RegCloseKey (unit_key);
+                        RegCloseKey (netcard_key);
+                        return TRUE;
+                    }
+                }
+            }
+            RegCloseKey (unit_key);
+        }
+        ++i;
+    }
+
+    RegCloseKey (netcard_key);
+    return FALSE;
+}
+
+static int get_device_guid(
+    char *name,
+    int name_size,
+    char *actual_name,
+    int actual_name_size)
+{
+    LONG status;
+    HKEY control_net_key;
+    DWORD len;
+    int i = 0;
+    int stop = 0;
+
+    status = RegOpenKeyEx(
+        HKEY_LOCAL_MACHINE,
+        NETWORK_CONNECTIONS_KEY,
+        0,
+        KEY_READ,
+        &control_net_key);
+
+    if (status != ERROR_SUCCESS) {
+        return -1;
+    }
+
+    while (!stop)
+    {
+        char enum_name[256];
+        char connection_string[256];
+        HKEY connection_key;
+        char name_data[256];
+        DWORD name_type;
+        const char name_string[] = "Name";
+
+        len = sizeof (enum_name);
+        status = RegEnumKeyEx(
+            control_net_key,
+            i,
+            enum_name,
+            &len,
+            NULL,
+            NULL,
+            NULL,
+            NULL);
+
+        if (status == ERROR_NO_MORE_ITEMS)
+            break;
+        else if (status != ERROR_SUCCESS) {
+            return -1;
+        }
+
+        snprintf(connection_string,
+             sizeof(connection_string),
+             "%s\\%s\\Connection",
+             NETWORK_CONNECTIONS_KEY, enum_name);
+
+        status = RegOpenKeyEx(
+            HKEY_LOCAL_MACHINE,
+            connection_string,
+            0,
+            KEY_READ,
+            &connection_key);
+
+        if (status == ERROR_SUCCESS) {
+            len = sizeof (name_data);
+            status = RegQueryValueEx(
+                connection_key,
+                name_string,
+                NULL,
+                &name_type,
+                (LPBYTE)name_data,
+                &len);
+
+            if (status != ERROR_SUCCESS || name_type != REG_SZ) {
+                    return -1;
+            }
+            else {
+                if (is_tap_win32_dev(enum_name)) {
+                    snprintf(name, name_size, "%s", enum_name);
+                    if (actual_name) {
+                        if (strcmp(actual_name, "") != 0) {
+                            if (strcmp(name_data, actual_name) != 0) {
+                                RegCloseKey (connection_key);
+                                ++i;
+                                continue;
+                            }
+                        }
+                        else {
+                            snprintf(actual_name, actual_name_size, "%s", name_data);
+                        }
+                    }
+                    stop = 1;
+                }
+            }
+
+            RegCloseKey (connection_key);
+        }
+        ++i;
+    }
+
+    RegCloseKey (control_net_key);
+
+    if (stop == 0)
+        return -1;
+
+    return 0;
+}
+
+static int tap_win32_set_status(HANDLE handle, int status)
+{
+    unsigned long len = 0;
+
+    return DeviceIoControl(handle, TAP_IOCTL_SET_MEDIA_STATUS,
+                &status, sizeof (status),
+                &status, sizeof (status), &len, NULL);
+}
+
+static void tap_win32_overlapped_init(tap_win32_overlapped_t* const overlapped, const HANDLE handle)
+{
+    overlapped->handle = handle;
+
+    overlapped->read_event = CreateEvent(NULL, FALSE, FALSE, NULL);
+    overlapped->write_event = CreateEvent(NULL, FALSE, FALSE, NULL);
+
+    overlapped->read_overlapped.Offset = 0;
+    overlapped->read_overlapped.OffsetHigh = 0;
+    overlapped->read_overlapped.hEvent = overlapped->read_event;
+
+    overlapped->write_overlapped.Offset = 0;
+    overlapped->write_overlapped.OffsetHigh = 0;
+    overlapped->write_overlapped.hEvent = overlapped->write_event;
+
+    InitializeCriticalSection(&overlapped->output_queue_cs);
+    InitializeCriticalSection(&overlapped->free_list_cs);
+
+    overlapped->output_queue_semaphore = CreateSemaphore(
+        NULL,   // default security attributes
+        0,   // initial count
+        TUN_MAX_BUFFER_COUNT,   // maximum count
+        NULL);  // unnamed semaphore
+
+    if(!overlapped->output_queue_semaphore)  {
+        fprintf(stderr, "error creating output queue semaphore!\n");
+    }
+
+    overlapped->free_list_semaphore = CreateSemaphore(
+        NULL,   // default security attributes
+        TUN_MAX_BUFFER_COUNT,   // initial count
+        TUN_MAX_BUFFER_COUNT,   // maximum count
+        NULL);  // unnamed semaphore
+
+    if(!overlapped->free_list_semaphore)  {
+        fprintf(stderr, "error creating free list semaphore!\n");
+    }
+
+    overlapped->free_list = overlapped->output_queue_front = overlapped->output_queue_back = NULL;
+
+    {
+        unsigned index;
+        for(index = 0; index < TUN_MAX_BUFFER_COUNT; index++) {
+            tun_buffer_t* element = &overlapped->buffers[index];
+            element->next = overlapped->free_list;
+            overlapped->free_list = element;
+        }
+    }
+    /* To count buffers, initially no-signal. */
+    overlapped->tap_semaphore = CreateSemaphore(NULL, 0, TUN_MAX_BUFFER_COUNT, NULL);
+    if(!overlapped->tap_semaphore)
+        fprintf(stderr, "error creating tap_semaphore.\n");
+}
+
+static int tap_win32_write(tap_win32_overlapped_t *overlapped,
+                           const void *buffer, unsigned long size)
+{
+    unsigned long write_size;
+    BOOL result;
+    DWORD error;
+
+    result = GetOverlappedResult( overlapped->handle, &overlapped->write_overlapped,
+                                  &write_size, FALSE);
+
+    if (!result && GetLastError() == ERROR_IO_INCOMPLETE)
+        WaitForSingleObject(overlapped->write_event, INFINITE);
+
+    result = WriteFile(overlapped->handle, buffer, size,
+                       &write_size, &overlapped->write_overlapped);
+
+    if (!result) {
+        switch (error = GetLastError())
+        {
+        case ERROR_IO_PENDING:
+#ifndef TUN_ASYNCHRONOUS_WRITES
+            WaitForSingleObject(overlapped->write_event, INFINITE);
+#endif
+            break;
+        default:
+            return -1;
+        }
+    }
+
+    return write_size;
+}
+
+static DWORD WINAPI tap_win32_thread_entry(LPVOID param)
+{
+    tap_win32_overlapped_t *overlapped = (tap_win32_overlapped_t*)param;
+    unsigned long read_size;
+    BOOL result;
+    DWORD dwError;
+    tun_buffer_t* buffer = get_buffer_from_free_list(overlapped);
+
+
+    for (;;) {
+        result = ReadFile(overlapped->handle,
+                          buffer->buffer,
+                          sizeof(buffer->buffer),
+                          &read_size,
+                          &overlapped->read_overlapped);
+        if (!result) {
+            dwError = GetLastError();
+            if (dwError == ERROR_IO_PENDING) {
+                WaitForSingleObject(overlapped->read_event, INFINITE);
+                result = GetOverlappedResult( overlapped->handle, &overlapped->read_overlapped,
+                                              &read_size, FALSE);
+                if (!result) {
+#ifdef DEBUG_TAP_WIN32
+                    LPVOID lpBuffer;
+                    dwError = GetLastError();
+                    FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
+                                   NULL, dwError, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+                                   (LPTSTR) & lpBuffer, 0, NULL );
+                    fprintf(stderr, "Tap-Win32: Error GetOverlappedResult %d - %s\n", dwError, lpBuffer);
+                    LocalFree( lpBuffer );
+#endif
+                }
+            } else {
+#ifdef DEBUG_TAP_WIN32
+                LPVOID lpBuffer;
+                FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
+                               NULL, dwError, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+                               (LPTSTR) & lpBuffer, 0, NULL );
+                fprintf(stderr, "Tap-Win32: Error ReadFile %d - %s\n", dwError, lpBuffer);
+                LocalFree( lpBuffer );
+#endif
+            }
+        }
+
+        if(read_size > 0) {
+            buffer->read_size = read_size;
+            put_buffer_on_output_queue(overlapped, buffer);
+            ReleaseSemaphore(overlapped->tap_semaphore, 1, NULL);
+            buffer = get_buffer_from_free_list(overlapped);
+        }
+    }
+
+    return 0;
+}
+
+static int tap_win32_read(tap_win32_overlapped_t *overlapped,
+                          uint8_t **pbuf, int max_size)
+{
+    int size = 0;
+
+    tun_buffer_t* buffer = get_buffer_from_output_queue_immediate(overlapped);
+
+    if(buffer != NULL) {
+        *pbuf = buffer->buffer;
+        size = (int)buffer->read_size;
+        if(size > max_size) {
+            size = max_size;
+        }
+    }
+
+    return size;
+}
+
+static void tap_win32_free_buffer(tap_win32_overlapped_t *overlapped,
+                                  uint8_t *pbuf)
+{
+    tun_buffer_t* buffer = (tun_buffer_t*)pbuf;
+    put_buffer_on_free_list(overlapped, buffer);
+}
+
+static int tap_win32_open(tap_win32_overlapped_t **phandle,
+                          const char *preferred_name)
+{
+    char device_path[256];
+    char device_guid[0x100];
+    int rc;
+    HANDLE handle;
+    BOOL bret;
+    char name_buffer[0x100] = {0, };
+    struct {
+        unsigned long major;
+        unsigned long minor;
+        unsigned long debug;
+    } version;
+    DWORD version_len;
+    DWORD idThread;
+
+    if (preferred_name != NULL) {
+        snprintf(name_buffer, sizeof(name_buffer), "%s", preferred_name);
+    }
+
+    rc = get_device_guid(device_guid, sizeof(device_guid), name_buffer, sizeof(name_buffer));
+    if (rc)
+        return -1;
+
+    snprintf (device_path, sizeof(device_path), "%s%s%s",
+              USERMODEDEVICEDIR,
+              device_guid,
+              TAPSUFFIX);
+
+    handle = CreateFile (
+        device_path,
+        GENERIC_READ | GENERIC_WRITE,
+        0,
+        0,
+        OPEN_EXISTING,
+        FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED,
+        0 );
+
+    if (handle == INVALID_HANDLE_VALUE) {
+        return -1;
+    }
+
+    bret = DeviceIoControl(handle, TAP_IOCTL_GET_VERSION,
+                           &version, sizeof (version),
+                           &version, sizeof (version), &version_len, NULL);
+
+    if (bret == FALSE) {
+        CloseHandle(handle);
+        return -1;
+    }
+
+    if (!tap_win32_set_status(handle, TRUE)) {
+        return -1;
+    }
+
+    tap_win32_overlapped_init(&tap_overlapped, handle);
+
+    *phandle = &tap_overlapped;
+
+    CreateThread(NULL, 0, tap_win32_thread_entry,
+                 (LPVOID)&tap_overlapped, 0, &idThread);
+    return 0;
+}
+
+/********************************************/
+
+ typedef struct TAPState {
+     NetClientState nc;
+     tap_win32_overlapped_t *handle;
+ } TAPState;
+
+static void tap_cleanup(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    qemu_del_wait_object(s->handle->tap_semaphore, NULL, NULL);
+
+    /* FIXME: need to kill thread and close file handle:
+       tap_win32_close(s);
+    */
+}
+
+static ssize_t tap_receive(NetClientState *nc, const uint8_t *buf, size_t size)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    return tap_win32_write(s->handle, buf, size);
+}
+
+static void tap_win32_send(void *opaque)
+{
+    TAPState *s = opaque;
+    uint8_t *buf;
+    int max_size = 4096;
+    int size;
+
+    size = tap_win32_read(s->handle, &buf, max_size);
+    if (size > 0) {
+        qemu_send_packet(&s->nc, buf, size);
+        tap_win32_free_buffer(s->handle, buf);
+    }
+}
+
+static NetClientInfo net_tap_win32_info = {
+    .type = NET_CLIENT_OPTIONS_KIND_TAP,
+    .size = sizeof(TAPState),
+    .receive = tap_receive,
+    .cleanup = tap_cleanup,
+};
+
+static int tap_win32_init(NetClientState *peer, const char *model,
+                          const char *name, const char *ifname)
+{
+    NetClientState *nc;
+    TAPState *s;
+    tap_win32_overlapped_t *handle;
+
+    if (tap_win32_open(&handle, ifname) < 0) {
+        printf("tap: Could not open '%s'\n", ifname);
+        return -1;
+    }
+
+    nc = qemu_new_net_client(&net_tap_win32_info, peer, model, name);
+
+    s = DO_UPCAST(TAPState, nc, nc);
+
+    snprintf(s->nc.info_str, sizeof(s->nc.info_str),
+             "tap: ifname=%s", ifname);
+
+    s->handle = handle;
+
+    qemu_add_wait_object(s->handle->tap_semaphore, tap_win32_send, s);
+
+    return 0;
+}
+
+int net_init_tap(const NetClientOptions *opts, const char *name,
+                 NetClientState *peer)
+{
+    const NetdevTapOptions *tap;
+
+    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_TAP);
+    tap = opts->tap;
+
+    if (!tap->has_ifname) {
+        error_report("tap: no interface name");
+        return -1;
+    }
+
+    if (tap_win32_init(peer, "tap", name, tap->ifname) == -1) {
+        return -1;
+    }
+
+    return 0;
+}
+
+bool tap_has_ufo(NetClientState *nc)
+{
+    return false;
+}
+
+int tap_has_vnet_hdr(NetClientState *nc)
+{
+    return 0;
+}
+
+int tap_probe_vnet_hdr_len(int fd, int len)
+{
+    return 0;
+}
+
+void tap_fd_set_vnet_hdr_len(int fd, int len)
+{
+}
+
+void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr)
+{
+}
+
+void tap_set_offload(NetClientState *nc, int csum, int tso4,
+                     int tso6, int ecn, int ufo)
+{
+}
+
+struct vhost_net *tap_get_vhost_net(NetClientState *nc)
+{
+    return NULL;
+}
+
+int tap_has_vnet_hdr_len(NetClientState *nc, int len)
+{
+    return 0;
+}
+
+void tap_set_vnet_hdr_len(NetClientState *nc, int len)
+{
+    abort();
+}
+
+int tap_enable(NetClientState *nc)
+{
+    abort();
+}
+
+int tap_disable(NetClientState *nc)
+{
+    abort();
+}
diff --git a/net/tap.c b/net/tap.c
new file mode 100644
index 000000000..39c1cda3e
--- /dev/null
+++ b/net/tap.c
@@ -0,0 +1,870 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ * Copyright (c) 2009 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "tap_int.h"
+
+#include "config-host.h"
+
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <sys/socket.h>
+#include <net/if.h>
+
+#include "net/net.h"
+#include "clients.h"
+#include "monitor/monitor.h"
+#include "sysemu/sysemu.h"
+#include "qemu-common.h"
+#include "qemu/error-report.h"
+
+#include "net/tap.h"
+
+#include "net/vhost_net.h"
+
+typedef struct TAPState {
+    NetClientState nc;
+    int fd;
+    char down_script[1024];
+    char down_script_arg[128];
+    uint8_t buf[NET_BUFSIZE];
+    bool read_poll;
+    bool write_poll;
+    bool using_vnet_hdr;
+    bool has_ufo;
+    bool enabled;
+    VHostNetState *vhost_net;
+    unsigned host_vnet_hdr_len;
+} TAPState;
+
+static int launch_script(const char *setup_script, const char *ifname, int fd);
+
+static int tap_can_send(void *opaque);
+static void tap_send(void *opaque);
+static void tap_writable(void *opaque);
+
+static void tap_update_fd_handler(TAPState *s)
+{
+    qemu_set_fd_handler2(s->fd,
+                         s->read_poll && s->enabled ? tap_can_send : NULL,
+                         s->read_poll && s->enabled ? tap_send     : NULL,
+                         s->write_poll && s->enabled ? tap_writable : NULL,
+                         s);
+}
+
+static void tap_read_poll(TAPState *s, bool enable)
+{
+    s->read_poll = enable;
+    tap_update_fd_handler(s);
+}
+
+static void tap_write_poll(TAPState *s, bool enable)
+{
+    s->write_poll = enable;
+    tap_update_fd_handler(s);
+}
+
+static void tap_writable(void *opaque)
+{
+    TAPState *s = opaque;
+
+    tap_write_poll(s, false);
+
+    qemu_flush_queued_packets(&s->nc);
+}
+
+static ssize_t tap_write_packet(TAPState *s, const struct iovec *iov, int iovcnt)
+{
+    ssize_t len;
+
+    do {
+        len = writev(s->fd, iov, iovcnt);
+    } while (len == -1 && errno == EINTR);
+
+    if (len == -1 && errno == EAGAIN) {
+        tap_write_poll(s, true);
+        return 0;
+    }
+
+    return len;
+}
+
+static ssize_t tap_receive_iov(NetClientState *nc, const struct iovec *iov,
+                               int iovcnt)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    const struct iovec *iovp = iov;
+    struct iovec iov_copy[iovcnt + 1];
+    struct virtio_net_hdr_mrg_rxbuf hdr = { };
+
+    if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
+        iov_copy[0].iov_base = &hdr;
+        iov_copy[0].iov_len =  s->host_vnet_hdr_len;
+        memcpy(&iov_copy[1], iov, iovcnt * sizeof(*iov));
+        iovp = iov_copy;
+        iovcnt++;
+    }
+
+    return tap_write_packet(s, iovp, iovcnt);
+}
+
+static ssize_t tap_receive_raw(NetClientState *nc, const uint8_t *buf, size_t size)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    struct iovec iov[2];
+    int iovcnt = 0;
+    struct virtio_net_hdr_mrg_rxbuf hdr = { };
+
+    if (s->host_vnet_hdr_len) {
+        iov[iovcnt].iov_base = &hdr;
+        iov[iovcnt].iov_len  = s->host_vnet_hdr_len;
+        iovcnt++;
+    }
+
+    iov[iovcnt].iov_base = (char *)buf;
+    iov[iovcnt].iov_len  = size;
+    iovcnt++;
+
+    return tap_write_packet(s, iov, iovcnt);
+}
+
+static ssize_t tap_receive(NetClientState *nc, const uint8_t *buf, size_t size)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    struct iovec iov[1];
+
+    if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
+        return tap_receive_raw(nc, buf, size);
+    }
+
+    iov[0].iov_base = (char *)buf;
+    iov[0].iov_len  = size;
+
+    return tap_write_packet(s, iov, 1);
+}
+
+static int tap_can_send(void *opaque)
+{
+    TAPState *s = opaque;
+
+    return qemu_can_send_packet(&s->nc);
+}
+
+#ifndef __sun__
+ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen)
+{
+    return read(tapfd, buf, maxlen);
+}
+#endif
+
+static void tap_send_completed(NetClientState *nc, ssize_t len)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    tap_read_poll(s, true);
+}
+
+static void tap_send(void *opaque)
+{
+    TAPState *s = opaque;
+    int size;
+
+    do {
+        uint8_t *buf = s->buf;
+
+        size = tap_read_packet(s->fd, s->buf, sizeof(s->buf));
+        if (size <= 0) {
+            break;
+        }
+
+        if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
+            buf  += s->host_vnet_hdr_len;
+            size -= s->host_vnet_hdr_len;
+        }
+
+        size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed);
+        if (size == 0) {
+            tap_read_poll(s, false);
+        }
+    } while (size > 0 && qemu_can_send_packet(&s->nc));
+}
+
+bool tap_has_ufo(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
+
+    return s->has_ufo;
+}
+
+int tap_has_vnet_hdr(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
+
+    return !!s->host_vnet_hdr_len;
+}
+
+int tap_has_vnet_hdr_len(NetClientState *nc, int len)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
+
+    return tap_probe_vnet_hdr_len(s->fd, len);
+}
+
+void tap_set_vnet_hdr_len(NetClientState *nc, int len)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
+    assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) ||
+           len == sizeof(struct virtio_net_hdr));
+
+    tap_fd_set_vnet_hdr_len(s->fd, len);
+    s->host_vnet_hdr_len = len;
+}
+
+void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
+    assert(!!s->host_vnet_hdr_len == using_vnet_hdr);
+
+    s->using_vnet_hdr = using_vnet_hdr;
+}
+
+void tap_set_offload(NetClientState *nc, int csum, int tso4,
+                     int tso6, int ecn, int ufo)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    if (s->fd < 0) {
+        return;
+    }
+
+    tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo);
+}
+
+static void tap_cleanup(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    if (s->vhost_net) {
+        vhost_net_cleanup(s->vhost_net);
+        s->vhost_net = NULL;
+    }
+
+    qemu_purge_queued_packets(nc);
+
+    if (s->down_script[0])
+        launch_script(s->down_script, s->down_script_arg, s->fd);
+
+    tap_read_poll(s, false);
+    tap_write_poll(s, false);
+    close(s->fd);
+    s->fd = -1;
+}
+
+static void tap_poll(NetClientState *nc, bool enable)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    tap_read_poll(s, enable);
+    tap_write_poll(s, enable);
+}
+
+int tap_get_fd(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
+    return s->fd;
+}
+
+/* fd support */
+
+static NetClientInfo net_tap_info = {
+    .type = NET_CLIENT_OPTIONS_KIND_TAP,
+    .size = sizeof(TAPState),
+    .receive = tap_receive,
+    .receive_raw = tap_receive_raw,
+    .receive_iov = tap_receive_iov,
+    .poll = tap_poll,
+    .cleanup = tap_cleanup,
+};
+
+static TAPState *net_tap_fd_init(NetClientState *peer,
+                                 const char *model,
+                                 const char *name,
+                                 int fd,
+                                 int vnet_hdr)
+{
+    NetClientState *nc;
+    TAPState *s;
+
+    nc = qemu_new_net_client(&net_tap_info, peer, model, name);
+
+    s = DO_UPCAST(TAPState, nc, nc);
+
+    s->fd = fd;
+    s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
+    s->using_vnet_hdr = false;
+    s->has_ufo = tap_probe_has_ufo(s->fd);
+    s->enabled = true;
+    tap_set_offload(&s->nc, 0, 0, 0, 0, 0);
+    /*
+     * Make sure host header length is set correctly in tap:
+     * it might have been modified by another instance of qemu.
+     */
+    if (tap_probe_vnet_hdr_len(s->fd, s->host_vnet_hdr_len)) {
+        tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len);
+    }
+    tap_read_poll(s, true);
+    s->vhost_net = NULL;
+    return s;
+}
+
+static int launch_script(const char *setup_script, const char *ifname, int fd)
+{
+    int pid, status;
+    char *args[3];
+    char **parg;
+
+    /* try to launch network script */
+    pid = fork();
+    if (pid == 0) {
+        int open_max = sysconf(_SC_OPEN_MAX), i;
+
+        for (i = 0; i < open_max; i++) {
+            if (i != STDIN_FILENO &&
+                i != STDOUT_FILENO &&
+                i != STDERR_FILENO &&
+                i != fd) {
+                close(i);
+            }
+        }
+        parg = args;
+        *parg++ = (char *)setup_script;
+        *parg++ = (char *)ifname;
+        *parg = NULL;
+        execv(setup_script, args);
+        _exit(1);
+    } else if (pid > 0) {
+        while (waitpid(pid, &status, 0) != pid) {
+            /* loop */
+        }
+
+        if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
+            return 0;
+        }
+    }
+    fprintf(stderr, "%s: could not launch network script\n", setup_script);
+    return -1;
+}
+
+static int recv_fd(int c)
+{
+    int fd;
+    uint8_t msgbuf[CMSG_SPACE(sizeof(fd))];
+    struct msghdr msg = {
+        .msg_control = msgbuf,
+        .msg_controllen = sizeof(msgbuf),
+    };
+    struct cmsghdr *cmsg;
+    struct iovec iov;
+    uint8_t req[1];
+    ssize_t len;
+
+    cmsg = CMSG_FIRSTHDR(&msg);
+    cmsg->cmsg_level = SOL_SOCKET;
+    cmsg->cmsg_type = SCM_RIGHTS;
+    cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
+    msg.msg_controllen = cmsg->cmsg_len;
+
+    iov.iov_base = req;
+    iov.iov_len = sizeof(req);
+
+    msg.msg_iov = &iov;
+    msg.msg_iovlen = 1;
+
+    len = recvmsg(c, &msg, 0);
+    if (len > 0) {
+        memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd));
+        return fd;
+    }
+
+    return len;
+}
+
+static int net_bridge_run_helper(const char *helper, const char *bridge)
+{
+    sigset_t oldmask, mask;
+    int pid, status;
+    char *args[5];
+    char **parg;
+    int sv[2];
+
+    sigemptyset(&mask);
+    sigaddset(&mask, SIGCHLD);
+    sigprocmask(SIG_BLOCK, &mask, &oldmask);
+
+    if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) {
+        return -1;
+    }
+
+    /* try to launch bridge helper */
+    pid = fork();
+    if (pid == 0) {
+        int open_max = sysconf(_SC_OPEN_MAX), i;
+        char fd_buf[6+10];
+        char br_buf[6+IFNAMSIZ] = {0};
+        char helper_cmd[PATH_MAX + sizeof(fd_buf) + sizeof(br_buf) + 15];
+
+        for (i = 0; i < open_max; i++) {
+            if (i != STDIN_FILENO &&
+                i != STDOUT_FILENO &&
+                i != STDERR_FILENO &&
+                i != sv[1]) {
+                close(i);
+            }
+        }
+
+        snprintf(fd_buf, sizeof(fd_buf), "%s%d", "--fd=", sv[1]);
+
+        if (strrchr(helper, ' ') || strrchr(helper, '\t')) {
+            /* assume helper is a command */
+
+            if (strstr(helper, "--br=") == NULL) {
+                snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge);
+            }
+
+            snprintf(helper_cmd, sizeof(helper_cmd), "%s %s %s %s",
+                     helper, "--use-vnet", fd_buf, br_buf);
+
+            parg = args;
+            *parg++ = (char *)"sh";
+            *parg++ = (char *)"-c";
+            *parg++ = helper_cmd;
+            *parg++ = NULL;
+
+            execv("/bin/sh", args);
+        } else {
+            /* assume helper is just the executable path name */
+
+            snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge);
+
+            parg = args;
+            *parg++ = (char *)helper;
+            *parg++ = (char *)"--use-vnet";
+            *parg++ = fd_buf;
+            *parg++ = br_buf;
+            *parg++ = NULL;
+
+            execv(helper, args);
+        }
+        _exit(1);
+
+    } else if (pid > 0) {
+        int fd;
+
+        close(sv[1]);
+
+        do {
+            fd = recv_fd(sv[0]);
+        } while (fd == -1 && errno == EINTR);
+
+        close(sv[0]);
+
+        while (waitpid(pid, &status, 0) != pid) {
+            /* loop */
+        }
+        sigprocmask(SIG_SETMASK, &oldmask, NULL);
+        if (fd < 0) {
+            fprintf(stderr, "failed to recv file descriptor\n");
+            return -1;
+        }
+
+        if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
+            return fd;
+        }
+    }
+    fprintf(stderr, "failed to launch bridge helper\n");
+    return -1;
+}
+
+int net_init_bridge(const NetClientOptions *opts, const char *name,
+                    NetClientState *peer)
+{
+    const NetdevBridgeOptions *bridge;
+    const char *helper, *br;
+
+    TAPState *s;
+    int fd, vnet_hdr;
+
+    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_BRIDGE);
+    bridge = opts->bridge;
+
+    helper = bridge->has_helper ? bridge->helper : DEFAULT_BRIDGE_HELPER;
+    br     = bridge->has_br     ? bridge->br     : DEFAULT_BRIDGE_INTERFACE;
+
+    fd = net_bridge_run_helper(helper, br);
+    if (fd == -1) {
+        return -1;
+    }
+
+    fcntl(fd, F_SETFL, O_NONBLOCK);
+
+    vnet_hdr = tap_probe_vnet_hdr(fd);
+
+    s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr);
+    if (!s) {
+        close(fd);
+        return -1;
+    }
+
+    snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s,br=%s", helper,
+             br);
+
+    return 0;
+}
+
+static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr,
+                        const char *setup_script, char *ifname,
+                        size_t ifname_sz, int mq_required)
+{
+    int fd, vnet_hdr_required;
+
+    if (tap->has_vnet_hdr) {
+        *vnet_hdr = tap->vnet_hdr;
+        vnet_hdr_required = *vnet_hdr;
+    } else {
+        *vnet_hdr = 1;
+        vnet_hdr_required = 0;
+    }
+
+    TFR(fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required,
+                      mq_required));
+    if (fd < 0) {
+        return -1;
+    }
+
+    if (setup_script &&
+        setup_script[0] != '\0' &&
+        strcmp(setup_script, "no") != 0 &&
+        launch_script(setup_script, ifname, fd)) {
+        close(fd);
+        return -1;
+    }
+
+    return fd;
+}
+
+#define MAX_TAP_QUEUES 1024
+
+static int net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
+                            const char *model, const char *name,
+                            const char *ifname, const char *script,
+                            const char *downscript, const char *vhostfdname,
+                            int vnet_hdr, int fd)
+{
+    TAPState *s;
+
+    s = net_tap_fd_init(peer, model, name, fd, vnet_hdr);
+    if (!s) {
+        close(fd);
+        return -1;
+    }
+
+    if (tap_set_sndbuf(s->fd, tap) < 0) {
+        return -1;
+    }
+
+    if (tap->has_fd || tap->has_fds) {
+        snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd);
+    } else if (tap->has_helper) {
+        snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s",
+                 tap->helper);
+    } else {
+        snprintf(s->nc.info_str, sizeof(s->nc.info_str),
+                 "ifname=%s,script=%s,downscript=%s", ifname, script,
+                 downscript);
+
+        if (strcmp(downscript, "no") != 0) {
+            snprintf(s->down_script, sizeof(s->down_script), "%s", downscript);
+            snprintf(s->down_script_arg, sizeof(s->down_script_arg),
+                     "%s", ifname);
+        }
+    }
+
+    if (tap->has_vhost ? tap->vhost :
+        vhostfdname || (tap->has_vhostforce && tap->vhostforce)) {
+        int vhostfd;
+
+        if (tap->has_vhostfd || tap->has_vhostfds) {
+            vhostfd = monitor_handle_fd_param(cur_mon, vhostfdname);
+            if (vhostfd == -1) {
+                return -1;
+            }
+        } else {
+            vhostfd = -1;
+        }
+
+        s->vhost_net = vhost_net_init(&s->nc, vhostfd,
+                                      tap->has_vhostforce && tap->vhostforce);
+        if (!s->vhost_net) {
+            error_report("vhost-net requested but could not be initialized");
+            return -1;
+        }
+    } else if (tap->has_vhostfd || tap->has_vhostfds) {
+        error_report("vhostfd= is not valid without vhost");
+        return -1;
+    }
+
+    return 0;
+}
+
+static int get_fds(char *str, char *fds[], int max)
+{
+    char *ptr = str, *this;
+    size_t len = strlen(str);
+    int i = 0;
+
+    while (i < max && ptr < str + len) {
+        this = strchr(ptr, ':');
+
+        if (this == NULL) {
+            fds[i] = g_strdup(ptr);
+        } else {
+            fds[i] = g_strndup(ptr, this - ptr);
+        }
+
+        i++;
+        if (this == NULL) {
+            break;
+        } else {
+            ptr = this + 1;
+        }
+    }
+
+    return i;
+}
+
+int net_init_tap(const NetClientOptions *opts, const char *name,
+                 NetClientState *peer)
+{
+    const NetdevTapOptions *tap;
+    int fd, vnet_hdr = 0, i = 0, queues;
+    /* for the no-fd, no-helper case */
+    const char *script = NULL; /* suppress wrong "uninit'd use" gcc warning */
+    const char *downscript = NULL;
+    const char *vhostfdname;
+    char ifname[128];
+
+    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_TAP);
+    tap = opts->tap;
+    queues = tap->has_queues ? tap->queues : 1;
+    vhostfdname = tap->has_vhostfd ? tap->vhostfd : NULL;
+
+    /* QEMU vlans does not support multiqueue tap, in this case peer is set.
+     * For -netdev, peer is always NULL. */
+    if (peer && (tap->has_queues || tap->has_fds || tap->has_vhostfds)) {
+        error_report("Multiqueue tap cannot be used with QEMU vlans");
+        return -1;
+    }
+
+    if (tap->has_fd) {
+        if (tap->has_ifname || tap->has_script || tap->has_downscript ||
+            tap->has_vnet_hdr || tap->has_helper || tap->has_queues ||
+            tap->has_fds || tap->has_vhostfds) {
+            error_report("ifname=, script=, downscript=, vnet_hdr=, "
+                         "helper=, queues=, fds=, and vhostfds= "
+                         "are invalid with fd=");
+            return -1;
+        }
+
+        fd = monitor_handle_fd_param(cur_mon, tap->fd);
+        if (fd == -1) {
+            return -1;
+        }
+
+        fcntl(fd, F_SETFL, O_NONBLOCK);
+
+        vnet_hdr = tap_probe_vnet_hdr(fd);
+
+        if (net_init_tap_one(tap, peer, "tap", name, NULL,
+                             script, downscript,
+                             vhostfdname, vnet_hdr, fd)) {
+            return -1;
+        }
+    } else if (tap->has_fds) {
+        char *fds[MAX_TAP_QUEUES];
+        char *vhost_fds[MAX_TAP_QUEUES];
+        int nfds, nvhosts;
+
+        if (tap->has_ifname || tap->has_script || tap->has_downscript ||
+            tap->has_vnet_hdr || tap->has_helper || tap->has_queues ||
+            tap->has_vhostfd) {
+            error_report("ifname=, script=, downscript=, vnet_hdr=, "
+                         "helper=, queues=, and vhostfd= "
+                         "are invalid with fds=");
+            return -1;
+        }
+
+        nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES);
+        if (tap->has_vhostfds) {
+            nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES);
+            if (nfds != nvhosts) {
+                error_report("The number of fds passed does not match the "
+                             "number of vhostfds passed");
+                return -1;
+            }
+        }
+
+        for (i = 0; i < nfds; i++) {
+            fd = monitor_handle_fd_param(cur_mon, fds[i]);
+            if (fd == -1) {
+                return -1;
+            }
+
+            fcntl(fd, F_SETFL, O_NONBLOCK);
+
+            if (i == 0) {
+                vnet_hdr = tap_probe_vnet_hdr(fd);
+            } else if (vnet_hdr != tap_probe_vnet_hdr(fd)) {
+                error_report("vnet_hdr not consistent across given tap fds");
+                return -1;
+            }
+
+            if (net_init_tap_one(tap, peer, "tap", name, ifname,
+                                 script, downscript,
+                                 tap->has_vhostfds ? vhost_fds[i] : NULL,
+                                 vnet_hdr, fd)) {
+                return -1;
+            }
+        }
+    } else if (tap->has_helper) {
+        if (tap->has_ifname || tap->has_script || tap->has_downscript ||
+            tap->has_vnet_hdr || tap->has_queues || tap->has_vhostfds) {
+            error_report("ifname=, script=, downscript=, and vnet_hdr= "
+                         "queues=, and vhostfds= are invalid with helper=");
+            return -1;
+        }
+
+        fd = net_bridge_run_helper(tap->helper, DEFAULT_BRIDGE_INTERFACE);
+        if (fd == -1) {
+            return -1;
+        }
+
+        fcntl(fd, F_SETFL, O_NONBLOCK);
+        vnet_hdr = tap_probe_vnet_hdr(fd);
+
+        if (net_init_tap_one(tap, peer, "bridge", name, ifname,
+                             script, downscript, vhostfdname,
+                             vnet_hdr, fd)) {
+            return -1;
+        }
+    } else {
+        if (tap->has_vhostfds) {
+            error_report("vhostfds= is invalid if fds= wasn't specified");
+            return -1;
+        }
+        script = tap->has_script ? tap->script : DEFAULT_NETWORK_SCRIPT;
+        downscript = tap->has_downscript ? tap->downscript :
+            DEFAULT_NETWORK_DOWN_SCRIPT;
+
+        if (tap->has_ifname) {
+            pstrcpy(ifname, sizeof ifname, tap->ifname);
+        } else {
+            ifname[0] = '\0';
+        }
+
+        for (i = 0; i < queues; i++) {
+            fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script,
+                              ifname, sizeof ifname, queues > 1);
+            if (fd == -1) {
+                return -1;
+            }
+
+            if (queues > 1 && i == 0 && !tap->has_ifname) {
+                if (tap_fd_get_ifname(fd, ifname)) {
+                    error_report("Fail to get ifname");
+                    return -1;
+                }
+            }
+
+            if (net_init_tap_one(tap, peer, "tap", name, ifname,
+                                 i >= 1 ? "no" : script,
+                                 i >= 1 ? "no" : downscript,
+                                 vhostfdname, vnet_hdr, fd)) {
+                return -1;
+            }
+        }
+    }
+
+    return 0;
+}
+
+VHostNetState *tap_get_vhost_net(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);
+    return s->vhost_net;
+}
+
+int tap_enable(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    int ret;
+
+    if (s->enabled) {
+        return 0;
+    } else {
+        ret = tap_fd_enable(s->fd);
+        if (ret == 0) {
+            s->enabled = true;
+            tap_update_fd_handler(s);
+        }
+        return ret;
+    }
+}
+
+int tap_disable(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    int ret;
+
+    if (s->enabled == 0) {
+        return 0;
+    } else {
+        ret = tap_fd_disable(s->fd);
+        if (ret == 0) {
+            qemu_purge_queued_packets(nc);
+            s->enabled = false;
+            tap_update_fd_handler(s);
+        }
+        return ret;
+    }
+}
diff --git a/net/tap_int.h b/net/tap_int.h
new file mode 100644
index 000000000..86bb224bc
--- /dev/null
+++ b/net/tap_int.h
@@ -0,0 +1,50 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ * Copyright (c) 2009 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef QEMU_TAP_H
+#define QEMU_TAP_H
+
+#include "qemu-common.h"
+#include "qapi-types.h"
+
+#define DEFAULT_NETWORK_SCRIPT "/etc/qemu-ifup"
+#define DEFAULT_NETWORK_DOWN_SCRIPT "/etc/qemu-ifdown"
+
+int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
+             int vnet_hdr_required, int mq_required);
+
+ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen);
+
+int tap_set_sndbuf(int fd, const NetdevTapOptions *tap);
+int tap_probe_vnet_hdr(int fd);
+int tap_probe_vnet_hdr_len(int fd, int len);
+int tap_probe_has_ufo(int fd);
+void tap_fd_set_offload(int fd, int csum, int tso4, int tso6, int ecn, int ufo);
+void tap_fd_set_vnet_hdr_len(int fd, int len);
+int tap_fd_enable(int fd);
+int tap_fd_disable(int fd);
+int tap_fd_get_ifname(int fd, char *ifname);
+
+#endif /* QEMU_TAP_H */
diff --git a/net/util.c b/net/util.c
new file mode 100644
index 000000000..7e9507679
--- /dev/null
+++ b/net/util.c
@@ -0,0 +1,60 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "util.h"
+#include <errno.h>
+#include <stdlib.h>
+
+int net_parse_macaddr(uint8_t *macaddr, const char *p)
+{
+    int i;
+    char *last_char;
+    long int offset;
+
+    errno = 0;
+    offset = strtol(p, &last_char, 0);
+    if (errno == 0 && *last_char == '\0' &&
+        offset >= 0 && offset <= 0xFFFFFF) {
+        macaddr[3] = (offset & 0xFF0000) >> 16;
+        macaddr[4] = (offset & 0xFF00) >> 8;
+        macaddr[5] = offset & 0xFF;
+        return 0;
+    }
+
+    for (i = 0; i < 6; i++) {
+        macaddr[i] = strtol(p, (char **)&p, 16);
+        if (i == 5) {
+            if (*p != '\0') {
+                return -1;
+            }
+        } else {
+            if (*p != ':' && *p != '-') {
+                return -1;
+            }
+            p++;
+        }
+    }
+
+    return 0;
+}
diff --git a/net/util.h b/net/util.h
new file mode 100644
index 000000000..10c7da95f
--- /dev/null
+++ b/net/util.h
@@ -0,0 +1,32 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef QEMU_NET_UTIL_H
+#define QEMU_NET_UTIL_H
+
+#include <stdint.h>
+
+int net_parse_macaddr(uint8_t *macaddr, const char *p);
+
+#endif /* QEMU_NET_UTIL_H */
diff --git a/net/vde.c b/net/vde.c
new file mode 100644
index 000000000..2a619fbc8
--- /dev/null
+++ b/net/vde.c
@@ -0,0 +1,127 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "config-host.h"
+
+#include <libvdeplug.h>
+
+#include "net/net.h"
+#include "clients.h"
+#include "qemu-common.h"
+#include "qemu/option.h"
+#include "qemu/main-loop.h"
+
+typedef struct VDEState {
+    NetClientState nc;
+    VDECONN *vde;
+} VDEState;
+
+static void vde_to_qemu(void *opaque)
+{
+    VDEState *s = opaque;
+    uint8_t buf[NET_BUFSIZE];
+    int size;
+
+    size = vde_recv(s->vde, (char *)buf, sizeof(buf), 0);
+    if (size > 0) {
+        qemu_send_packet(&s->nc, buf, size);
+    }
+}
+
+static ssize_t vde_receive(NetClientState *nc, const uint8_t *buf, size_t size)
+{
+    VDEState *s = DO_UPCAST(VDEState, nc, nc);
+    ssize_t ret;
+
+    do {
+      ret = vde_send(s->vde, (const char *)buf, size, 0);
+    } while (ret < 0 && errno == EINTR);
+
+    return ret;
+}
+
+static void vde_cleanup(NetClientState *nc)
+{
+    VDEState *s = DO_UPCAST(VDEState, nc, nc);
+    qemu_set_fd_handler(vde_datafd(s->vde), NULL, NULL, NULL);
+    vde_close(s->vde);
+}
+
+static NetClientInfo net_vde_info = {
+    .type = NET_CLIENT_OPTIONS_KIND_VDE,
+    .size = sizeof(VDEState),
+    .receive = vde_receive,
+    .cleanup = vde_cleanup,
+};
+
+static int net_vde_init(NetClientState *peer, const char *model,
+                        const char *name, const char *sock,
+                        int port, const char *group, int mode)
+{
+    NetClientState *nc;
+    VDEState *s;
+    VDECONN *vde;
+    char *init_group = (char *)group;
+    char *init_sock = (char *)sock;
+
+    struct vde_open_args args = {
+        .port = port,
+        .group = init_group,
+        .mode = mode,
+    };
+
+    vde = vde_open(init_sock, (char *)"QEMU", &args);
+    if (!vde){
+        return -1;
+    }
+
+    nc = qemu_new_net_client(&net_vde_info, peer, model, name);
+
+    snprintf(nc->info_str, sizeof(nc->info_str), "sock=%s,fd=%d",
+             sock, vde_datafd(vde));
+
+    s = DO_UPCAST(VDEState, nc, nc);
+
+    s->vde = vde;
+
+    qemu_set_fd_handler(vde_datafd(s->vde), vde_to_qemu, NULL, s);
+
+    return 0;
+}
+
+int net_init_vde(const NetClientOptions *opts, const char *name,
+                 NetClientState *peer)
+{
+    const NetdevVdeOptions *vde;
+
+    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_VDE);
+    vde = opts->vde;
+
+    /* missing optional values have been initialized to "all bits zero" */
+    if (net_vde_init(peer, "vde", name, vde->sock, vde->port, vde->group,
+                     vde->has_mode ? vde->mode : 0700) == -1) {
+        return -1;
+    }
+
+    return 0;
+}