/* * Copyright (c) 2006-2007 Bjorn Andersson , Erik Ekman * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include "tun.h" #define TUN_MAX_TRY 50 char if_name[50]; #ifdef LINUX #include #include #include int open_tun(const char *tun_device) { int i; int tun_fd; struct ifreq ifreq; char *tunnel = "/dev/net/tun"; if ((tun_fd = open(tunnel, O_RDWR)) < 0) { warn("open_tun: %s: %s", tunnel, strerror(errno)); return -1; } memset(&ifreq, 0, sizeof(ifreq)); ifreq.ifr_flags = IFF_TUN; if (tun_device != NULL) { strncpy(ifreq.ifr_name, tun_device, IFNAMSIZ); ifreq.ifr_name[IFNAMSIZ-1] = '\0'; strncpy(if_name, tun_device, sizeof(if_name)); if_name[sizeof(if_name)-1] = '\0'; if (ioctl(tun_fd, TUNSETIFF, (void *) &ifreq) != -1) { printf("Opened %s\n", ifreq.ifr_name); return tun_fd; } if (errno != EBUSY) { warn("open_tun: ioctl[TUNSETIFF]: %s", strerror(errno)); return -1; } } else { for (i = 0; i < TUN_MAX_TRY; i++) { snprintf(ifreq.ifr_name, IFNAMSIZ, "dns%d", i); if (ioctl(tun_fd, TUNSETIFF, (void *) &ifreq) != -1) { printf("Opened %s\n", ifreq.ifr_name); snprintf(if_name, sizeof(if_name), "dns%d", i); return tun_fd; } if (errno != EBUSY) { warn("open_tun: ioctl[TUNSETIFF]: %s", strerror(errno)); return -1; } } warn("open_tun: Couldn't set interface name"); } return -1; } #else /* BSD */ int open_tun(const char *tun_device) { int i; int tun_fd; char tun_name[50]; if (tun_device != NULL) { snprintf(tun_name, sizeof(tun_name), "/dev/%s", tun_device); strncpy(if_name, tun_device, sizeof(if_name)); if_name[sizeof(if_name)-1] = '\0'; if ((tun_fd = open(tun_name, O_RDWR)) < 0) { warn("open_tun: %s: %s", tun_name, strerror(errno)); return -1; } printf("Opened %s\n", tun_name); return tun_fd; } else { for (i = 0; i < TUN_MAX_TRY; i++) { snprintf(tun_name, sizeof(tun_name), "/dev/tun%d", i); if ((tun_fd = open(tun_name, O_RDWR)) >= 0) { printf("Opened %s\n", tun_name); snprintf(if_name, sizeof(if_name), "tun%d", i); return tun_fd; } if (errno == ENOENT) break; } warn("open_tun: Failed to open tunneling device"); } return -1; } #endif /* !LINUX */ void close_tun(int tun_fd) { if (tun_fd >= 0) close(tun_fd); } int write_tun(int tun_fd, char *data, size_t len) { #if defined (FREEBSD) || defined (DARWIN) || defined(NETBSD) data += 4; len -= 4; #else /* !FREEBSD/DARWIN */ #ifdef LINUX data[0] = 0x00; data[1] = 0x00; data[2] = 0x08; data[3] = 0x00; #else /* OPENBSD */ data[0] = 0x00; data[1] = 0x00; data[2] = 0x00; data[3] = 0x02; #endif /* !LINUX */ #endif /* FREEBSD */ if (write(tun_fd, data, len) != len) { warn("write_tun"); return 1; } return 0; } ssize_t read_tun(int tun_fd, char *buf, size_t len) { #if defined (FREEBSD) || defined (DARWIN) || defined(NETBSD) /* FreeBSD/Darwin/NetBSD has no header */ return read(tun_fd, buf + 4, len - 4) + 4; #else /* !FREEBSD */ return read(tun_fd, buf, len); #endif /* !FREEBSD */ } int tun_setip(const char *ip) { char cmdline[512]; #ifndef LINUX int r; #endif if (inet_addr(ip) != INADDR_NONE) { snprintf(cmdline, sizeof(cmdline), "/sbin/ifconfig %s %s %s netmask 255.255.255.0", if_name, ip, ip); printf("Setting IP of %s to %s\n", if_name, ip); #ifndef LINUX r = system(cmdline); if(r != 0) { return r; } else { snprintf(cmdline, sizeof(cmdline), "/sbin/route add %s/24 %s", ip, ip); } printf("Adding route %s/24 to %s\n", ip, ip); #endif return system(cmdline); } else { printf("Invalid IP: %s!\n", ip); } return 1; } int tun_setmtu(const size_t mtu) { char cmdline[512]; if (mtu > 200 && mtu < 1500) { snprintf(cmdline, sizeof(cmdline), "/sbin/ifconfig %s mtu %ld", if_name, mtu); printf("Setting MTU of %s to %ld\n", if_name, mtu); return system(cmdline); } else { warn("MTU out of range: %ld\n", mtu); } return 1; }