/* * * Connection Manager * * Copyright (C) 2007-2010 Intel Corporation. All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * 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, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * */ #ifdef HAVE_CONFIG_H #include #endif #include #include #include #include #include #include #include #include #include #define CONNMAN_API_SUBJECT_TO_CHANGE #include #include #include #include #include #include #if __BYTE_ORDER == __LITTLE_ENDIAN struct domain_hdr { uint16_t id; uint8_t rd:1; uint8_t tc:1; uint8_t aa:1; uint8_t opcode:4; uint8_t qr:1; uint8_t rcode:4; uint8_t z:3; uint8_t ra:1; uint16_t qdcount; uint16_t ancount; uint16_t nscount; uint16_t arcount; } __attribute__ ((packed)); #elif __BYTE_ORDER == __BIG_ENDIAN struct domain_hdr { uint16_t id; uint8_t qr:1; uint8_t opcode:4; uint8_t aa:1; uint8_t tc:1; uint8_t rd:1; uint8_t ra:1; uint8_t z:3; uint8_t rcode:4; uint16_t qdcount; uint16_t ancount; uint16_t nscount; uint16_t arcount; } __attribute__ ((packed)); #else #error "Unknown byte order" #endif struct partial_reply { uint16_t len; uint16_t received; unsigned char buf[]; }; struct server_data { char *interface; GList *domains; char *server; int protocol; GIOChannel *channel; guint watch; guint timeout; gboolean enabled; gboolean connected; struct partial_reply *incoming_reply; }; struct request_data { union { struct sockaddr_in6 __sin6; /* Only for the length */ struct sockaddr sa; }; socklen_t sa_len; int client_sk; int protocol; guint16 srcid; guint16 dstid; guint16 altid; guint timeout; guint watch; guint numserv; guint numresp; gpointer request; gsize request_len; gpointer name; gpointer resp; gsize resplen; }; static GSList *server_list = NULL; static GSList *request_list = NULL; static GSList *request_pending_list = NULL; static guint16 request_id = 0x0000; static GIOChannel *udp_listener_channel = NULL; static guint udp_listener_watch = 0; static GIOChannel *tcp_listener_channel = NULL; static guint tcp_listener_watch = 0; static int protocol_offset(int protocol) { switch (protocol) { case IPPROTO_UDP: return 0; case IPPROTO_TCP: return 2; default: return -EINVAL; } } static struct request_data *find_request(guint16 id) { GSList *list; for (list = request_list; list; list = list->next) { struct request_data *req = list->data; if (req->dstid == id || req->altid == id) return req; } return NULL; } static struct server_data *find_server(const char *interface, const char *server, int protocol) { GSList *list; DBG("interface %s server %s", interface, server); for (list = server_list; list; list = list->next) { struct server_data *data = list->data; if (data->interface == NULL || data->server == NULL) continue; if (g_str_equal(data->interface, interface) == TRUE && g_str_equal(data->server, server) == TRUE && data->protocol == protocol) return data; } return NULL; } static void send_response(int sk, unsigned char *buf, int len, const struct sockaddr *to, socklen_t tolen, int protocol) { struct domain_hdr *hdr; int err, offset = protocol_offset(protocol); DBG(""); if (offset < 0) return; if (len < 12) return; hdr = (void*) (buf + offset); DBG("id 0x%04x qr %d opcode %d", hdr->id, hdr->qr, hdr->opcode); hdr->qr = 1; hdr->rcode = 2; hdr->ancount = 0; hdr->nscount = 0; hdr->arcount = 0; err = sendto(sk, buf, len, 0, to, tolen); } static gboolean request_timeout(gpointer user_data) { struct request_data *req = user_data; DBG("id 0x%04x", req->srcid); if (req == NULL) return FALSE; request_list = g_slist_remove(request_list, req); req->numserv--; if (req->resplen > 0 && req->resp != NULL) { int sk, err; sk = g_io_channel_unix_get_fd(udp_listener_channel); err = sendto(sk, req->resp, req->resplen, 0, &req->sa, req->sa_len); } else if (req->request && req->numserv == 0) { struct domain_hdr *hdr; if (req->protocol == IPPROTO_TCP) { hdr = (void *) (req->request + 2); hdr->id = req->srcid; send_response(req->client_sk, req->request, req->request_len, NULL, 0, IPPROTO_TCP); } else if (req->protocol == IPPROTO_UDP) { int sk; hdr = (void *) (req->request); hdr->id = req->srcid; sk = g_io_channel_unix_get_fd(udp_listener_channel); send_response(sk, req->request, req->request_len, &req->sa, req->sa_len, IPPROTO_UDP); } } g_free(req->resp); g_free(req); return FALSE; } static int append_query(unsigned char *buf, unsigned int size, const char *query, const char *domain) { unsigned char *ptr = buf; char *offset; DBG("query %s domain %s", query, domain); offset = (char *) query; while (offset != NULL) { char *tmp; tmp = strchr(offset, '.'); if (tmp == NULL) { if (strlen(offset) == 0) break; *ptr = strlen(offset); memcpy(ptr + 1, offset, strlen(offset)); ptr += strlen(offset) + 1; break; } *ptr = tmp - offset; memcpy(ptr + 1, offset, tmp - offset); ptr += tmp - offset + 1; offset = tmp + 1; } offset = (char *) domain; while (offset != NULL) { char *tmp; tmp = strchr(offset, '.'); if (tmp == NULL) { if (strlen(offset) == 0) break; *ptr = strlen(offset); memcpy(ptr + 1, offset, strlen(offset)); ptr += strlen(offset) + 1; break; } *ptr = tmp - offset; memcpy(ptr + 1, offset, tmp - offset); ptr += tmp - offset + 1; offset = tmp + 1; } *ptr++ = 0x00; return ptr - buf; } static int ns_resolv(struct server_data *server, struct request_data *req, gpointer request, gpointer name) { GList *list; int sk, err; sk = g_io_channel_unix_get_fd(server->channel); err = send(sk, request, req->request_len, 0); req->numserv++; for (list = server->domains; list; list = list->next) { char *domain; unsigned char alt[1024]; struct domain_hdr *hdr = (void *) &alt; int altlen, domlen, offset; domain = list->data; if (domain == NULL) continue; offset = protocol_offset(server->protocol); if (offset < 0) return offset; domlen = strlen(domain) + 1; if (domlen < 5) return -EINVAL; alt[offset] = req->altid & 0xff; alt[offset + 1] = req->altid >> 8; memcpy(alt + offset + 2, request + offset + 2, 10); hdr->qdcount = htons(1); altlen = append_query(alt + offset + 12, sizeof(alt) - 12, name, domain); if (altlen < 0) return -EINVAL; altlen += 12; memcpy(alt + offset + altlen, request + offset + altlen - domlen, req->request_len - altlen + domlen); if (server->protocol == IPPROTO_TCP) { int req_len = req->request_len + domlen - 1; alt[0] = (req_len >> 8) & 0xff; alt[1] = req_len & 0xff; } err = send(sk, alt, req->request_len + domlen + 1, 0); req->numserv++; } return 0; } static int forward_dns_reply(unsigned char *reply, int reply_len, int protocol) { struct domain_hdr *hdr; struct request_data *req; int dns_id, sk, err, offset = protocol_offset(protocol); if (offset < 0) return offset; hdr = (void *)(reply + offset); dns_id = reply[offset] | reply[offset + 1] << 8; DBG("Received %d bytes (id 0x%04x)", reply_len, dns_id); req = find_request(dns_id); if (req == NULL) return -EINVAL; DBG("id 0x%04x rcode %d", hdr->id, hdr->rcode); reply[offset] = req->srcid & 0xff; reply[offset + 1] = req->srcid >> 8; req->numresp++; if (hdr->rcode == 0 || req->resp == NULL) { g_free(req->resp); req->resplen = 0; req->resp = g_try_malloc(reply_len); if (req->resp == NULL) return -ENOMEM; memcpy(req->resp, reply, reply_len); req->resplen = reply_len; } if (hdr->rcode > 0 && req->numresp < req->numserv) return -EINVAL; if (req->timeout > 0) g_source_remove(req->timeout); request_list = g_slist_remove(request_list, req); if (protocol == IPPROTO_UDP) { sk = g_io_channel_unix_get_fd(udp_listener_channel); err = sendto(sk, req->resp, req->resplen, 0, &req->sa, req->sa_len); } else { sk = req->client_sk; err = send(sk, req->resp, req->resplen, 0); close(sk); } g_free(req->resp); g_free(req); return err; } static void destroy_server(struct server_data *server) { GList *list; DBG("interface %s server %s", server->interface, server->server); server_list = g_slist_remove(server_list, server); if (server->watch > 0) g_source_remove(server->watch); if (server->timeout > 0) g_source_remove(server->timeout); g_io_channel_unref(server->channel); if (server->protocol == IPPROTO_UDP) connman_info("Removing DNS server %s", server->server); g_free(server->incoming_reply); g_free(server->server); for (list = server->domains; list; list = list->next) { char *domain = list->data; server->domains = g_list_remove(server->domains, domain); g_free(domain); } g_free(server->interface); g_free(server); } static gboolean udp_server_event(GIOChannel *channel, GIOCondition condition, gpointer user_data) { unsigned char buf[4096]; int sk, err, len; if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) { struct server_data *data = user_data; connman_error("Error with UDP server %s", data->server); data->watch = 0; return FALSE; } sk = g_io_channel_unix_get_fd(channel); len = recv(sk, buf, sizeof(buf), 0); if (len < 12) return TRUE; err = forward_dns_reply(buf, len, IPPROTO_UDP); return TRUE; } static gboolean tcp_server_event(GIOChannel *channel, GIOCondition condition, gpointer user_data) { int sk; struct server_data *server = user_data; sk = g_io_channel_unix_get_fd(channel); if (sk == 0) return FALSE; if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) { GSList *list; hangup: DBG("TCP server channel closed"); /* * Discard any partial response which is buffered; better * to get a proper response from a working server. */ g_free(server->incoming_reply); server->incoming_reply = NULL; for (list = request_list; list; list = list->next) { struct request_data *req = list->data; struct domain_hdr *hdr; if (req->protocol == IPPROTO_UDP) continue; if (req->request == NULL) continue; /* * If we're not waiting for any further response * from another name server, then we send an error * response to the client. */ if (req->numserv && --(req->numserv)) continue; hdr = (void *) (req->request + 2); hdr->id = req->srcid; send_response(req->client_sk, req->request, req->request_len, NULL, 0, IPPROTO_TCP); request_list = g_slist_remove(request_list, req); } destroy_server(server); return FALSE; } if ((condition & G_IO_OUT) && !server->connected) { GSList *list; GList *domains; struct server_data *udp_server; udp_server = find_server(server->interface, server->server, IPPROTO_UDP); if (udp_server != NULL) { for (domains = udp_server->domains; domains; domains = domains->next) { char *dom = domains->data; DBG("Adding domain %s to %s", dom, server->server); server->domains = g_list_append(server->domains, g_strdup(dom)); } } server->connected = TRUE; server_list = g_slist_append(server_list, server); if (server->timeout > 0) { g_source_remove(server->timeout); server->timeout = 0; } for (list = request_list; list; list = list->next) { struct request_data *req = list->data; if (req->protocol == IPPROTO_UDP) continue; DBG("Sending req %s over TCP", (char *)req->name); if (req->timeout > 0) g_source_remove(req->timeout); req->timeout = g_timeout_add_seconds(30, request_timeout, req); ns_resolv(server, req, req->request, req->name); } } else if (condition & G_IO_IN) { struct partial_reply *reply = server->incoming_reply; int bytes_recv; if (!reply) { unsigned char reply_len_buf[2]; uint16_t reply_len; bytes_recv = recv(sk, reply_len_buf, 2, MSG_PEEK); if (!bytes_recv) { goto hangup; } else if (bytes_recv < 0) { if (errno == EAGAIN || errno == EWOULDBLOCK) return TRUE; connman_error("DNS proxy error %s", strerror(errno)); goto hangup; } else if (bytes_recv < 2) return TRUE; reply_len = reply_len_buf[1] | reply_len_buf[0] << 8; reply_len += 2; DBG("TCP reply %d bytes", reply_len); reply = g_try_malloc(sizeof(*reply) + reply_len + 2); if (!reply) return TRUE; reply->len = reply_len; reply->received = 0; server->incoming_reply = reply; } while (reply->received < reply->len) { bytes_recv = recv(sk, reply->buf + reply->received, reply->len - reply->received, 0); if (!bytes_recv) { connman_error("DNS proxy TCP disconnect"); break; } else if (bytes_recv < 0) { if (errno == EAGAIN || errno == EWOULDBLOCK) return TRUE; connman_error("DNS proxy error %s", strerror(errno)); break; } reply->received += bytes_recv; } forward_dns_reply(reply->buf, reply->received, IPPROTO_TCP); g_free(reply); server->incoming_reply = NULL; destroy_server(server); return FALSE; } return TRUE; } static gboolean tcp_idle_timeout(gpointer user_data) { struct server_data *server = user_data; DBG(""); if (server == NULL) return FALSE; destroy_server(server); return FALSE; } static struct server_data *create_server(const char *interface, const char *domain, const char *server, int protocol) { struct addrinfo hints, *rp; struct server_data *data; int sk, ret; DBG("interface %s server %s", interface, server); memset(&hints, 0, sizeof(hints)); switch (protocol) { case IPPROTO_UDP: hints.ai_socktype = SOCK_DGRAM; break; case IPPROTO_TCP: hints.ai_socktype = SOCK_STREAM; break; default: return NULL; } hints.ai_family = AF_UNSPEC; hints.ai_flags = AI_PASSIVE | AI_NUMERICSERV | AI_NUMERICHOST; ret = getaddrinfo(server, "53", &hints, &rp); if (ret) { connman_error("Failed to parse server %s address: %s\n", server, gai_strerror(ret)); return NULL; } /* Do not blindly copy this code elsewhere; it doesn't loop over the results using ->ai_next as it should. That's OK in *this* case because it was a numeric lookup; we *know* there's only one. */ sk = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol); if (sk < 0) { connman_error("Failed to create server %s socket", server); freeaddrinfo(rp); return NULL; } if (interface != NULL) { if (setsockopt(sk, SOL_SOCKET, SO_BINDTODEVICE, interface, strlen(interface) + 1) < 0) { connman_error("Failed to bind server %s " "to interface %s", server, interface); freeaddrinfo(rp); close(sk); return NULL; } } data = g_try_new0(struct server_data, 1); if (data == NULL) { connman_error("Failed to allocate server %s data", server); freeaddrinfo(rp); close(sk); return NULL; } data->channel = g_io_channel_unix_new(sk); if (data->channel == NULL) { connman_error("Failed to create server %s channel", server); freeaddrinfo(rp); close(sk); g_free(data); return NULL; } g_io_channel_set_close_on_unref(data->channel, TRUE); if (protocol == IPPROTO_TCP) { g_io_channel_set_flags(data->channel, G_IO_FLAG_NONBLOCK, NULL); data->watch = g_io_add_watch(data->channel, G_IO_OUT | G_IO_IN | G_IO_HUP | G_IO_NVAL | G_IO_ERR, tcp_server_event, data); data->timeout = g_timeout_add_seconds(30, tcp_idle_timeout, data); } else data->watch = g_io_add_watch(data->channel, G_IO_IN | G_IO_NVAL | G_IO_ERR | G_IO_HUP, udp_server_event, data); data->interface = g_strdup(interface); if (domain) data->domains = g_list_append(data->domains, g_strdup(domain)); data->server = g_strdup(server); data->protocol = protocol; ret = connect(sk, rp->ai_addr, rp->ai_addrlen); freeaddrinfo(rp); if (ret < 0) { if ((protocol == IPPROTO_TCP && errno != EINPROGRESS) || protocol == IPPROTO_UDP) { GList *list; connman_error("Failed to connect to server %s", server); if (data->watch > 0) g_source_remove(data->watch); if (data->timeout > 0) g_source_remove(data->timeout); g_io_channel_unref(data->channel); close(sk); g_free(data->server); g_free(data->interface); for (list = data->domains; list; list = list->next) { char *domain = list->data; data->domains = g_list_remove(data->domains, domain); g_free(domain); } g_free(data); return NULL; } } if (protocol == IPPROTO_UDP) { /* Enable new servers by default */ data->enabled = TRUE; connman_info("Adding DNS server %s", data->server); server_list = g_slist_append(server_list, data); return data; } return NULL; } static gboolean resolv(struct request_data *req, gpointer request, gpointer name) { GSList *list; for (list = server_list; list; list = list->next) { struct server_data *data = list->data; DBG("server %s enabled %d", data->server, data->enabled); if (data->enabled == FALSE) continue; if (data->watch == 0 && data->protocol == IPPROTO_UDP) data->watch = g_io_add_watch(data->channel, G_IO_IN | G_IO_NVAL | G_IO_ERR | G_IO_HUP, udp_server_event, data); if (ns_resolv(data, req, request, name) < 0) continue; } return TRUE; } static void append_domain(const char *interface, const char *domain) { GSList *list; DBG("interface %s domain %s", interface, domain); for (list = server_list; list; list = list->next) { struct server_data *data = list->data; GList *dom_list; char *dom; gboolean dom_found = FALSE; if (data->interface == NULL) continue; if (g_str_equal(data->interface, interface) == FALSE) continue; for (dom_list = data->domains; dom_list; dom_list = dom_list->next) { dom = dom_list->data; if (g_str_equal(dom, domain)) { dom_found = TRUE; break; } } if (dom_found == FALSE) data->domains = g_list_append(data->domains, g_strdup(domain)); } } static int dnsproxy_append(const char *interface, const char *domain, const char *server) { struct server_data *data; DBG("interface %s server %s", interface, server); if (server == NULL && domain == NULL) return -EINVAL; if (server == NULL) { append_domain(interface, domain); return 0; } if (g_str_equal(server, "127.0.0.1") == TRUE) return -ENODEV; data = find_server(interface, server, IPPROTO_UDP); if (data != NULL) { append_domain(interface, domain); return 0; } data = create_server(interface, domain, server, IPPROTO_UDP); if (data == NULL) return -EIO; return 0; } static void remove_server(const char *interface, const char *domain, const char *server, int protocol) { struct server_data *data; data = find_server(interface, server, protocol); if (data == NULL) return; destroy_server(data); } static int dnsproxy_remove(const char *interface, const char *domain, const char *server) { DBG("interface %s server %s", interface, server); if (server == NULL) return -EINVAL; if (g_str_equal(server, "127.0.0.1") == TRUE) return -ENODEV; remove_server(interface, domain, server, IPPROTO_UDP); remove_server(interface, domain, server, IPPROTO_TCP); return 0; } static void dnsproxy_flush(void) { GSList *list; list = request_pending_list; while (list) { struct request_data *req = list->data; list = list->next; request_pending_list = g_slist_remove(request_pending_list, req); resolv(req, req->request, req->name); g_free(req->request); g_free(req->name); } } static struct connman_resolver dnsproxy_resolver = { .name = "dnsproxy", .priority = CONNMAN_RESOLVER_PRIORITY_HIGH, .append = dnsproxy_append, .remove = dnsproxy_remove, .flush = dnsproxy_flush, }; static void dnsproxy_offline_mode(connman_bool_t enabled) { GSList *list; DBG("enabled %d", enabled); for (list = server_list; list; list = list->next) { struct server_data *data = list->data; if (enabled == FALSE) { connman_info("Enabling DNS server %s", data->server); data->enabled = TRUE; } else { connman_info("Disabling DNS server %s", data->server); data->enabled = FALSE; } } } static void dnsproxy_default_changed(struct connman_service *service) { GSList *list; char *interface; DBG("service %p", service); if (service == NULL) { /* When no services are active, then disable DNS proxying */ dnsproxy_offline_mode(TRUE); return; } interface = connman_service_get_interface(service); if (interface == NULL) return; for (list = server_list; list; list = list->next) { struct server_data *data = list->data; if (g_strcmp0(data->interface, interface) == 0) { connman_info("Enabling DNS server %s", data->server); data->enabled = TRUE; } else { connman_info("Disabling DNS server %s", data->server); data->enabled = FALSE; } } g_free(interface); } static struct connman_notifier dnsproxy_notifier = { .name = "dnsproxy", .default_changed = dnsproxy_default_changed, .offline_mode = dnsproxy_offline_mode, }; static unsigned char opt_edns0_type[2] = { 0x00, 0x29 }; static int parse_request(unsigned char *buf, int len, char *name, unsigned int size) { struct domain_hdr *hdr = (void *) buf; uint16_t qdcount = ntohs(hdr->qdcount); uint16_t arcount = ntohs(hdr->arcount); unsigned char *ptr; char *last_label = NULL; unsigned int remain, used = 0; if (len < 12) return -EINVAL; DBG("id 0x%04x qr %d opcode %d qdcount %d arcount %d", hdr->id, hdr->qr, hdr->opcode, qdcount, arcount); if (hdr->qr != 0 || qdcount != 1) return -EINVAL; memset(name, 0, size); ptr = buf + sizeof(struct domain_hdr); remain = len - sizeof(struct domain_hdr); while (remain > 0) { uint8_t len = *ptr; if (len == 0x00) { last_label = (char *) (ptr + 1); break; } if (used + len + 1 > size) return -ENOBUFS; strncat(name, (char *) (ptr + 1), len); strcat(name, "."); used += len + 1; ptr += len + 1; remain -= len + 1; } if (last_label && arcount && remain >= 9 && last_label[4] == 0 && !memcmp(last_label + 5, opt_edns0_type, 2)) { uint16_t edns0_bufsize; edns0_bufsize = last_label[7] << 8 | last_label[8]; DBG("EDNS0 buffer size %u", edns0_bufsize); /* This is an evil hack until full TCP support has been * implemented. * * Somtimes the EDNS0 request gets send with a too-small * buffer size. Since glibc doesn't seem to crash when it * gets a response biffer then it requested, just bump * the buffer size up to 4KiB. */ if (edns0_bufsize < 0x1000) { last_label[7] = 0x10; last_label[8] = 0x00; } } DBG("query %s", name); return 0; } static gboolean tcp_listener_event(GIOChannel *channel, GIOCondition condition, gpointer user_data) { unsigned char buf[768]; char query[512]; struct request_data *req; struct server_data *server; int sk, client_sk, len, err; struct sockaddr_in6 client_addr; socklen_t client_addr_len = sizeof(client_addr); GSList *list; DBG("condition 0x%x", condition); if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) { if (tcp_listener_watch > 0) g_source_remove(tcp_listener_watch); tcp_listener_watch = 0; connman_error("Error with TCP listener channel"); return FALSE; } sk = g_io_channel_unix_get_fd(channel); client_sk = accept(sk, (void *)&client_addr, &client_addr_len); if (client_sk < 0) { connman_error("Accept failure on TCP listener"); tcp_listener_watch = 0; return FALSE; } len = recv(client_sk, buf, sizeof(buf), 0); if (len < 2) return TRUE; DBG("Received %d bytes (id 0x%04x)", len, buf[2] | buf[3] << 8); err = parse_request(buf + 2, len - 2, query, sizeof(query)); if (err < 0 || (g_slist_length(server_list) == 0 && connman_ondemand_connected())) { send_response(client_sk, buf, len, NULL, 0, IPPROTO_TCP); return TRUE; } req = g_try_new0(struct request_data, 1); if (req == NULL) return TRUE; memcpy(&req->sa, &client_addr, client_addr_len); req->sa_len = client_addr_len; req->client_sk = client_sk; req->protocol = IPPROTO_TCP; request_id += 2; if (request_id == 0x0000 || request_id == 0xffff) request_id += 2; req->srcid = buf[2] | (buf[3] << 8); req->dstid = request_id; req->altid = request_id + 1; req->request_len = len; buf[2] = req->dstid & 0xff; buf[3] = req->dstid >> 8; req->numserv = 0; request_list = g_slist_append(request_list, req); for (list = server_list; list; list = list->next) { struct server_data *data = list->data; GList *domains; if (data->protocol != IPPROTO_UDP || data->enabled == FALSE) continue; server = create_server(data->interface, NULL, data->server, IPPROTO_TCP); /* * If server is NULL, we're not connected yet. * Copy the relevant buffers and continue with * the next nameserver. * The request will actually be sent once we're * properly connected over TCP to this nameserver. */ if (server == NULL) { req->request = g_try_malloc0(req->request_len); if (req->request == NULL) return TRUE; memcpy(req->request, buf, req->request_len); req->name = g_try_malloc0(sizeof(query)); if (req->name == NULL) { g_free(req->request); return TRUE; } memcpy(req->name, query, sizeof(query)); continue; } if (req->timeout > 0) g_source_remove(req->timeout); for (domains = data->domains; domains; domains = domains->next) { char *dom = domains->data; DBG("Adding domain %s to %s", dom, server->server); server->domains = g_list_append(server->domains, g_strdup(dom)); } req->timeout = g_timeout_add_seconds(30, request_timeout, req); ns_resolv(server, req, buf, query); } return TRUE; } static gboolean udp_listener_event(GIOChannel *channel, GIOCondition condition, gpointer user_data) { unsigned char buf[768]; char query[512]; struct request_data *req; struct sockaddr_in6 client_addr; socklen_t client_addr_len = sizeof(client_addr); int sk, err, len; if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) { connman_error("Error with UDP listener channel"); udp_listener_watch = 0; return FALSE; } sk = g_io_channel_unix_get_fd(channel); memset(&client_addr, 0, client_addr_len); len = recvfrom(sk, buf, sizeof(buf), 0, (void *)&client_addr, &client_addr_len); if (len < 2) return TRUE; DBG("Received %d bytes (id 0x%04x)", len, buf[0] | buf[1] << 8); err = parse_request(buf, len, query, sizeof(query)); if (err < 0 || (g_slist_length(server_list) == 0 && connman_ondemand_connected())) { send_response(sk, buf, len, (void *)&client_addr, client_addr_len, IPPROTO_UDP); return TRUE; } req = g_try_new0(struct request_data, 1); if (req == NULL) return TRUE; memcpy(&req->sa, &client_addr, client_addr_len); req->sa_len = client_addr_len; req->client_sk = 0; req->protocol = IPPROTO_UDP; request_id += 2; if (request_id == 0x0000 || request_id == 0xffff) request_id += 2; req->srcid = buf[0] | (buf[1] << 8); req->dstid = request_id; req->altid = request_id + 1; req->request_len = len; buf[0] = req->dstid & 0xff; buf[1] = req->dstid >> 8; if (!connman_ondemand_connected()) { DBG("Starting on demand connection"); /* * We're not connected, let's queue the request and start * an on-demand connection. */ req->request = g_try_malloc0(req->request_len); if (req->request == NULL) return TRUE; memcpy(req->request, buf, req->request_len); req->name = g_try_malloc0(sizeof(query)); if (req->name == NULL) { g_free(req->request); return TRUE; } memcpy(req->name, query, sizeof(query)); request_pending_list = g_slist_append(request_pending_list, req); connman_ondemand_start("", 300); return TRUE; } req->numserv = 0; req->timeout = g_timeout_add_seconds(5, request_timeout, req); request_list = g_slist_append(request_list, req); return resolv(req, buf, query); } static int create_dns_listener(int protocol) { GIOChannel *channel; const char *ifname = "lo", *proto; union { struct sockaddr sa; struct sockaddr_in6 sin6; struct sockaddr_in sin; } s; socklen_t slen; int sk, type, v6only = 0; int family = AF_INET6; DBG(""); switch (protocol) { case IPPROTO_UDP: proto = "UDP"; type = SOCK_DGRAM; break; case IPPROTO_TCP: proto = "TCP"; type = SOCK_STREAM; break; default: return -EINVAL; } sk = socket(family, type, protocol); if (sk < 0 && family == AF_INET6 && errno == EAFNOSUPPORT) { connman_error("No IPv6 support; DNS proxy listening only on Legacy IP"); family = AF_INET; sk = socket(family, type, protocol); } if (sk < 0) { connman_error("Failed to create %s listener socket", proto); return -EIO; } if (setsockopt(sk, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname) + 1) < 0) { connman_error("Failed to bind %s listener interface", proto); close(sk); return -EIO; } /* Ensure it accepts Legacy IP connections too */ if (family == AF_INET6 && setsockopt(sk, SOL_IPV6, IPV6_V6ONLY, &v6only, sizeof(v6only)) < 0) { connman_error("Failed to clear V6ONLY on %s listener socket", proto); close(sk); return -EIO; } if (family == AF_INET) { memset(&s.sin, 0, sizeof(s.sin)); s.sin.sin_family = AF_INET; s.sin.sin_port = htons(53); s.sin.sin_addr.s_addr = htonl(INADDR_ANY); slen = sizeof(s.sin); } else { memset(&s.sin6, 0, sizeof(s.sin6)); s.sin6.sin6_family = AF_INET6; s.sin6.sin6_port = htons(53); s.sin6.sin6_addr = in6addr_any; slen = sizeof(s.sin6); } if (bind(sk, &s.sa, slen) < 0) { connman_error("Failed to bind %s listener socket", proto); close(sk); return -EIO; } if (protocol == IPPROTO_TCP && listen(sk, 10) < 0) { connman_error("Failed to listen on TCP socket"); close(sk); return -EIO; } channel = g_io_channel_unix_new(sk); if (channel == NULL) { connman_error("Failed to create %s listener channel", proto); close(sk); return -EIO; } g_io_channel_set_close_on_unref(channel, TRUE); if (protocol == IPPROTO_TCP) { tcp_listener_channel = channel; tcp_listener_watch = g_io_add_watch(channel, G_IO_IN, tcp_listener_event, NULL); } else { udp_listener_channel = channel; udp_listener_watch = g_io_add_watch(channel, G_IO_IN, udp_listener_event, NULL); } return 0; } static void destroy_udp_listener(void) { DBG(""); if (udp_listener_watch > 0) g_source_remove(udp_listener_watch); g_io_channel_unref(udp_listener_channel); } static void destroy_tcp_listener(void) { DBG(""); if (tcp_listener_watch > 0) g_source_remove(tcp_listener_watch); g_io_channel_unref(tcp_listener_channel); } static int create_listener(void) { int err; err = create_dns_listener(IPPROTO_UDP); if (err < 0) return err; err = create_dns_listener(IPPROTO_TCP); if (err < 0) { destroy_udp_listener(); return err; } connman_resolver_append("lo", NULL, "127.0.0.1"); return 0; } static void destroy_listener(void) { GSList *list; connman_resolver_remove_all("lo"); for (list = request_pending_list; list; list = list->next) { struct request_data *req = list->data; DBG("Dropping pending request (id 0x%04x -> 0x%04x)", req->srcid, req->dstid); g_free(req->resp); g_free(req->request); g_free(req->name); g_free(req); list->data = NULL; } g_slist_free(request_pending_list); request_pending_list = NULL; for (list = request_list; list; list = list->next) { struct request_data *req = list->data; DBG("Dropping request (id 0x%04x -> 0x%04x)", req->srcid, req->dstid); g_free(req->resp); g_free(req->request); g_free(req->name); g_free(req); list->data = NULL; } g_slist_free(request_list); request_list = NULL; destroy_tcp_listener(); destroy_udp_listener(); } static int dnsproxy_init(void) { int err; err = create_listener(); if (err < 0) return err; err = connman_resolver_register(&dnsproxy_resolver); if (err < 0) goto destroy; err = connman_notifier_register(&dnsproxy_notifier); if (err < 0) goto unregister; return 0; unregister: connman_resolver_unregister(&dnsproxy_resolver); destroy: destroy_listener(); return err; } static void dnsproxy_exit(void) { connman_notifier_unregister(&dnsproxy_notifier); connman_resolver_unregister(&dnsproxy_resolver); destroy_listener(); } CONNMAN_PLUGIN_DEFINE(dnsproxy, "DNS proxy resolver plugin", VERSION, CONNMAN_PLUGIN_PRIORITY_DEFAULT, dnsproxy_init, dnsproxy_exit)