| /* |
| * Copyright (c) 2005 Reyk Floeter <reyk@openbsd.org> |
| * |
| * 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 "includes.h" |
| |
| #include <sys/types.h> |
| #include <sys/ioctl.h> |
| #include <netinet/in.h> |
| #include <netinet/ip.h> |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <string.h> |
| #include <unistd.h> |
| |
| #include "log.h" |
| #include "misc.h" |
| #include "buffer.h" |
| #include "channels.h" |
| |
| /* |
| * This is the portable version of the SSH tunnel forwarding, it |
| * uses some preprocessor definitions for various platform-specific |
| * settings. |
| * |
| * SSH_TUN_LINUX Use the (newer) Linux tun/tap device |
| * SSH_TUN_FREEBSD Use the FreeBSD tun/tap device |
| * SSH_TUN_COMPAT_AF Translate the OpenBSD address family |
| * SSH_TUN_PREPEND_AF Prepend/remove the address family |
| */ |
| |
| /* |
| * System-specific tunnel open function |
| */ |
| |
| #if defined(SSH_TUN_LINUX) |
| #include <linux/if.h> |
| #include <linux/if_tun.h> |
| |
| int |
| sys_tun_open(int tun, int mode) |
| { |
| struct ifreq ifr; |
| int fd = -1; |
| const char *name = NULL; |
| |
| if ((fd = open("/dev/net/tun", O_RDWR)) == -1) { |
| debug("%s: failed to open tunnel control interface: %s", |
| __func__, strerror(errno)); |
| return (-1); |
| } |
| |
| bzero(&ifr, sizeof(ifr)); |
| |
| if (mode == SSH_TUNMODE_ETHERNET) { |
| ifr.ifr_flags = IFF_TAP; |
| name = "tap%d"; |
| } else { |
| ifr.ifr_flags = IFF_TUN; |
| name = "tun%d"; |
| } |
| ifr.ifr_flags |= IFF_NO_PI; |
| |
| if (tun != SSH_TUNID_ANY) { |
| if (tun > SSH_TUNID_MAX) { |
| debug("%s: invalid tunnel id %x: %s", __func__, |
| tun, strerror(errno)); |
| goto failed; |
| } |
| snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), name, tun); |
| } |
| |
| if (ioctl(fd, TUNSETIFF, &ifr) == -1) { |
| debug("%s: failed to configure tunnel (mode %d): %s", __func__, |
| mode, strerror(errno)); |
| goto failed; |
| } |
| |
| if (tun == SSH_TUNID_ANY) |
| debug("%s: tunnel mode %d fd %d", __func__, mode, fd); |
| else |
| debug("%s: %s mode %d fd %d", __func__, ifr.ifr_name, mode, fd); |
| |
| return (fd); |
| |
| failed: |
| close(fd); |
| return (-1); |
| } |
| #endif /* SSH_TUN_LINUX */ |
| |
| #ifdef SSH_TUN_FREEBSD |
| #include <sys/socket.h> |
| #include <net/if.h> |
| |
| #ifdef HAVE_NET_IF_TUN_H |
| #include <net/if_tun.h> |
| #endif |
| |
| int |
| sys_tun_open(int tun, int mode) |
| { |
| struct ifreq ifr; |
| char name[100]; |
| int fd = -1, sock, flag; |
| const char *tunbase = "tun"; |
| |
| if (mode == SSH_TUNMODE_ETHERNET) { |
| #ifdef SSH_TUN_NO_L2 |
| debug("%s: no layer 2 tunnelling support", __func__); |
| return (-1); |
| #else |
| tunbase = "tap"; |
| #endif |
| } |
| |
| /* Open the tunnel device */ |
| if (tun <= SSH_TUNID_MAX) { |
| snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); |
| fd = open(name, O_RDWR); |
| } else if (tun == SSH_TUNID_ANY) { |
| for (tun = 100; tun >= 0; tun--) { |
| snprintf(name, sizeof(name), "/dev/%s%d", |
| tunbase, tun); |
| if ((fd = open(name, O_RDWR)) >= 0) |
| break; |
| } |
| } else { |
| debug("%s: invalid tunnel %u\n", __func__, tun); |
| return (-1); |
| } |
| |
| if (fd < 0) { |
| debug("%s: %s open failed: %s", __func__, name, |
| strerror(errno)); |
| return (-1); |
| } |
| |
| /* Turn on tunnel headers */ |
| flag = 1; |
| #if defined(TUNSIFHEAD) && !defined(SSH_TUN_PREPEND_AF) |
| if (mode != SSH_TUNMODE_ETHERNET && |
| ioctl(fd, TUNSIFHEAD, &flag) == -1) { |
| debug("%s: ioctl(%d, TUNSIFHEAD, 1): %s", __func__, fd, |
| strerror(errno)); |
| close(fd); |
| } |
| #endif |
| |
| debug("%s: %s mode %d fd %d", __func__, name, mode, fd); |
| |
| /* Set the tunnel device operation mode */ |
| snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); |
| if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) |
| goto failed; |
| |
| if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) |
| goto failed; |
| ifr.ifr_flags |= IFF_UP; |
| if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) |
| goto failed; |
| |
| close(sock); |
| return (fd); |
| |
| failed: |
| if (fd >= 0) |
| close(fd); |
| if (sock >= 0) |
| close(sock); |
| debug("%s: failed to set %s mode %d: %s", __func__, name, |
| mode, strerror(errno)); |
| return (-1); |
| } |
| #endif /* SSH_TUN_FREEBSD */ |
| |
| /* |
| * System-specific channel filters |
| */ |
| |
| #if defined(SSH_TUN_FILTER) |
| #define OPENBSD_AF_INET 2 |
| #define OPENBSD_AF_INET6 24 |
| |
| int |
| sys_tun_infilter(struct Channel *c, char *buf, int len) |
| { |
| #if defined(SSH_TUN_PREPEND_AF) |
| char rbuf[CHAN_RBUF]; |
| struct ip *iph; |
| #endif |
| u_int32_t *af; |
| char *ptr = buf; |
| |
| #if defined(SSH_TUN_PREPEND_AF) |
| if (len <= 0 || len > (int)(sizeof(rbuf) - sizeof(*af))) |
| return (-1); |
| ptr = (char *)&rbuf[0]; |
| bcopy(buf, ptr + sizeof(u_int32_t), len); |
| len += sizeof(u_int32_t); |
| af = (u_int32_t *)ptr; |
| |
| iph = (struct ip *)(ptr + sizeof(u_int32_t)); |
| switch (iph->ip_v) { |
| case 6: |
| *af = AF_INET6; |
| break; |
| case 4: |
| default: |
| *af = AF_INET; |
| break; |
| } |
| #endif |
| |
| #if defined(SSH_TUN_COMPAT_AF) |
| if (len < (int)sizeof(u_int32_t)) |
| return (-1); |
| |
| af = (u_int32_t *)ptr; |
| if (*af == htonl(AF_INET6)) |
| *af = htonl(OPENBSD_AF_INET6); |
| else |
| *af = htonl(OPENBSD_AF_INET); |
| #endif |
| |
| buffer_put_string(&c->input, ptr, len); |
| return (0); |
| } |
| |
| u_char * |
| sys_tun_outfilter(struct Channel *c, u_char **data, u_int *dlen) |
| { |
| u_char *buf; |
| u_int32_t *af; |
| |
| *data = buffer_get_string(&c->output, dlen); |
| if (*dlen < sizeof(*af)) |
| return (NULL); |
| buf = *data; |
| |
| #if defined(SSH_TUN_PREPEND_AF) |
| *dlen -= sizeof(u_int32_t); |
| buf = *data + sizeof(u_int32_t); |
| #elif defined(SSH_TUN_COMPAT_AF) |
| af = ntohl(*(u_int32_t *)buf); |
| if (*af == OPENBSD_AF_INET6) |
| *af = htonl(AF_INET6); |
| else |
| *af = htonl(AF_INET); |
| #endif |
| |
| return (buf); |
| } |
| #endif /* SSH_TUN_FILTER */ |