diff options
Diffstat (limited to 'tools/tap-test.c')
| -rw-r--r-- | tools/tap-test.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/tools/tap-test.c b/tools/tap-test.c new file mode 100644 index 00000000..357d41e9 --- /dev/null +++ b/tools/tap-test.c @@ -0,0 +1,197 @@ +/* + * + * Connection Manager + * + * Copyright (C) 2007-2009 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 <config.h> +#endif + +#include <stdio.h> +#include <errno.h> +#include <fcntl.h> +#include <unistd.h> +#include <string.h> +#include <sys/poll.h> +#include <sys/ioctl.h> + +#include <netinet/in.h> +#include <netinet/ip.h> +#include <net/ethernet.h> +#include <net/if.h> +#include <net/if_arp.h> +#include <linux/if_tun.h> + +static int inet_ifup(const char *ifname) +{ + struct ifreq ifr; + int sk, err; + + sk = socket(PF_INET, SOCK_DGRAM, 0); + if (sk < 0) + return -errno; + + memset(&ifr, 0, sizeof(ifr)); + strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)); + + if (ioctl(sk, SIOCGIFFLAGS, &ifr) < 0) { + err = -errno; + goto done; + } + + if (ifr.ifr_flags & IFF_UP) { + err = -EALREADY; + goto done; + } + + ifr.ifr_flags |= IFF_UP; + + if (ioctl(sk, SIOCSIFFLAGS, &ifr) < 0) { + err = -errno; + goto done; + } + + err = 0; + +done: + close(sk); + + return err; +} + +static int create_tap(const char *ifname) +{ + struct ifreq ifr; + int fd, val; + + fd = open("/dev/net/tun", O_RDWR); + if (fd < 0) { + perror("Failed to open TUN/TAP device"); + return -1; + } + + memset(&ifr, 0, sizeof(ifr)); + ifr.ifr_flags = IFF_TAP | IFF_NO_PI; + strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)); + + if (ioctl(fd, TUNSETIFF, (void *) &ifr) < 0) { + perror("Failed to set TUN/TAP interface"); + close(fd); + return -1; + } + + val = ARPHRD_ETHER; + + if (ioctl(fd, TUNSETLINK, (unsigned long) val) < 0) + perror("Failed to set TUN/TAP link type"); + + return fd; +} + +static void dump_packet(unsigned char *buf, int len) +{ + int i; + + printf("["); + for (i = 0; i < len; i++) { + printf(" %02x", buf[i]); + if ((i + 1) % 16 == 0) + printf("\n "); + else if ((i + 1) % 8 == 0) + printf(" "); + } + printf(" ]\n"); +} + +static void decode_ip(unsigned char *buf, int len) +{ + struct iphdr *ip = (void *) buf; + + printf(" IP proto %d saddr 0x%08x daddr 0x%08x\n", + ip->protocol, ip->saddr, ip->daddr); +} + +static void decode_packet(unsigned char *buf, int len) +{ + struct ether_header *eh = (void *) buf; + char src[18], dst[18]; + uint16_t type; + + snprintf(dst, sizeof(dst), "%02x:%02x:%02x:%02x:%02x:%02x", + eh->ether_dhost[0], eh->ether_dhost[1], + eh->ether_dhost[2], eh->ether_dhost[3], + eh->ether_dhost[4], eh->ether_dhost[5]); + + snprintf(src, sizeof(src), "%02x:%02x:%02x:%02x:%02x:%02x", + eh->ether_shost[0], eh->ether_shost[1], + eh->ether_shost[2], eh->ether_shost[3], + eh->ether_shost[4], eh->ether_shost[5]); + + type = ntohs(eh->ether_type); + + printf("> type 0x%04x src %s dst %s <\n", type, src, dst); + + switch (type) { + case ETHERTYPE_IP: + decode_ip(buf + 14, len - 14); + break; + case ETHERTYPE_LOOPBACK: + dump_packet(buf, len); + break; + } +} + +int main(int argc, char *argv[]) +{ + const char *ifname = "xxx"; + struct pollfd p; + int fd; + + fd = create_tap(ifname); + if (fd < 0) + return 1; + + if (inet_ifup(ifname) < 0) { + close(fd); + return 1; + } + + memset(&p, 0, sizeof(p)); + p.fd = fd; + p.events = POLLHUP | POLLIN; + + while (1) { + unsigned char buf[2048]; + int len; + + len = poll(&p, 1, -1); + if (len < 0) + break; + if (len == 0) + continue; + + len = read(fd, buf, sizeof(buf)); + if (len < 0) + break; + + decode_packet(buf, len); + } + + return 0; +} |