2 * Copyright (c) 2005 Reyk Floeter <reyk@openbsd.org>
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19 #include <sys/types.h>
20 #include <sys/ioctl.h>
22 #include <netinet/in.h>
23 #include <arpa/inet.h>
24 #include <netinet/ip.h>
33 #include "openbsd-compat/sys-queue.h"
41 * This file contains various portability code for network support,
42 * including tun/tap forwarding and routing domains.
45 #if defined(SYS_RDOMAIN_LINUX) || defined(SSH_TUN_LINUX)
49 #if defined(SYS_RDOMAIN_LINUX)
51 sys_get_rdomain(int fd)
53 char dev[IFNAMSIZ + 1];
54 socklen_t len = sizeof(dev) - 1;
56 if (getsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, dev, &len) == -1) {
57 error("%s: cannot determine VRF for fd=%d : %s",
58 __func__, fd, strerror(errno));
66 sys_set_rdomain(int fd, const char *name)
68 if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
69 name, strlen(name)) == -1) {
70 error("%s: setsockopt(%d, SO_BINDTODEVICE, %s): %s",
71 __func__, fd, name, strerror(errno));
78 sys_valid_rdomain(const char *name)
83 * This is a pretty crappy way to test. It would be better to
84 * check whether "name" represents a VRF device, but apparently
85 * that requires an rtnetlink transaction.
87 if ((fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
89 if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
90 name, strlen(name)) == -1) {
97 #elif defined(SYS_RDOMAIN_XXX)
100 sys_get_rdomain(int fd)
106 sys_set_rdomain(int fd, const char *name)
112 valid_rdomain(const char *name)
118 sys_set_process_rdomain(const char *name)
120 fatal("%s: not supported", __func__);
122 #endif /* defined(SYS_RDOMAIN_XXX) */
125 * This is the portable version of the SSH tunnel forwarding, it
126 * uses some preprocessor definitions for various platform-specific
129 * SSH_TUN_LINUX Use the (newer) Linux tun/tap device
130 * SSH_TUN_FREEBSD Use the FreeBSD tun/tap device
131 * SSH_TUN_COMPAT_AF Translate the OpenBSD address family
132 * SSH_TUN_PREPEND_AF Prepend/remove the address family
136 * System-specific tunnel open function
139 #if defined(SSH_TUN_LINUX)
140 #include <linux/if_tun.h>
141 #define TUN_CTRL_DEV "/dev/net/tun"
144 sys_tun_open(int tun, int mode, char **ifname)
148 const char *name = NULL;
152 if ((fd = open(TUN_CTRL_DEV, O_RDWR)) == -1) {
153 debug("%s: failed to open tunnel control device \"%s\": %s",
154 __func__, TUN_CTRL_DEV, strerror(errno));
158 bzero(&ifr, sizeof(ifr));
160 if (mode == SSH_TUNMODE_ETHERNET) {
161 ifr.ifr_flags = IFF_TAP;
164 ifr.ifr_flags = IFF_TUN;
167 ifr.ifr_flags |= IFF_NO_PI;
169 if (tun != SSH_TUNID_ANY) {
170 if (tun > SSH_TUNID_MAX) {
171 debug("%s: invalid tunnel id %x: %s", __func__,
172 tun, strerror(errno));
175 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), name, tun);
178 if (ioctl(fd, TUNSETIFF, &ifr) == -1) {
179 debug("%s: failed to configure tunnel (mode %d): %s", __func__,
180 mode, strerror(errno));
184 if (tun == SSH_TUNID_ANY)
185 debug("%s: tunnel mode %d fd %d", __func__, mode, fd);
187 debug("%s: %s mode %d fd %d", __func__, ifr.ifr_name, mode, fd);
189 if (ifname != NULL && (*ifname = strdup(ifr.ifr_name)) == NULL)
198 #endif /* SSH_TUN_LINUX */
200 #ifdef SSH_TUN_FREEBSD
201 #include <sys/socket.h>
204 #ifdef HAVE_NET_IF_TUN_H
205 #include <net/if_tun.h>
209 sys_tun_open(int tun, int mode, char **ifname)
214 const char *tunbase = "tun";
215 #if defined(TUNSIFHEAD) && !defined(SSH_TUN_PREPEND_AF)
222 if (mode == SSH_TUNMODE_ETHERNET) {
224 debug("%s: no layer 2 tunnelling support", __func__);
231 /* Open the tunnel device */
232 if (tun <= SSH_TUNID_MAX) {
233 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun);
234 fd = open(name, O_RDWR);
235 } else if (tun == SSH_TUNID_ANY) {
236 for (tun = 100; tun >= 0; tun--) {
237 snprintf(name, sizeof(name), "/dev/%s%d",
239 if ((fd = open(name, O_RDWR)) >= 0)
243 debug("%s: invalid tunnel %u\n", __func__, tun);
248 debug("%s: %s open failed: %s", __func__, name,
253 /* Turn on tunnel headers */
254 #if defined(TUNSIFHEAD) && !defined(SSH_TUN_PREPEND_AF)
256 if (mode != SSH_TUNMODE_ETHERNET &&
257 ioctl(fd, TUNSIFHEAD, &flag) == -1) {
258 debug("%s: ioctl(%d, TUNSIFHEAD, 1): %s", __func__, fd,
264 debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
266 /* Set the tunnel device operation mode */
267 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun);
268 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
271 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
273 if ((ifr.ifr_flags & IFF_UP) == 0) {
274 ifr.ifr_flags |= IFF_UP;
275 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
279 if (ifname != NULL && (*ifname = strdup(ifr.ifr_name)) == NULL)
290 debug("%s: failed to set %s mode %d: %s", __func__, name,
291 mode, strerror(errno));
294 #endif /* SSH_TUN_FREEBSD */
297 * System-specific channel filters
300 #if defined(SSH_TUN_FILTER)
302 * The tunnel forwarding protocol prepends the address family of forwarded
303 * IP packets using OpenBSD's numbers.
305 #define OPENBSD_AF_INET 2
306 #define OPENBSD_AF_INET6 24
309 sys_tun_infilter(struct ssh *ssh, struct Channel *c, char *buf, int _len)
314 #if defined(SSH_TUN_PREPEND_AF)
315 char rbuf[CHAN_RBUF];
318 #if defined(SSH_TUN_PREPEND_AF) || defined(SSH_TUN_COMPAT_AF)
322 /* XXX update channel input filter API to use unsigned length */
327 #if defined(SSH_TUN_PREPEND_AF)
328 if (len <= sizeof(iph) || len > sizeof(rbuf) - 4)
330 /* Determine address family from packet IP header. */
331 memcpy(&iph, buf, sizeof(iph));
332 af = iph.ip_v == 6 ? OPENBSD_AF_INET6 : OPENBSD_AF_INET;
333 /* Prepend address family to packet using OpenBSD constants */
334 memcpy(rbuf + 4, buf, len);
338 #elif defined(SSH_TUN_COMPAT_AF)
339 /* Convert existing address family header to OpenBSD value */
344 POKE_U32(buf, af == AF_INET6 ? OPENBSD_AF_INET6 : OPENBSD_AF_INET);
347 if ((r = sshbuf_put_string(c->input, ptr, len)) != 0)
348 fatal("%s: buffer error: %s", __func__, ssh_err(r));
353 sys_tun_outfilter(struct ssh *ssh, struct Channel *c,
354 u_char **data, size_t *dlen)
360 /* XXX new API is incompatible with this signature. */
361 if ((r = sshbuf_get_string(c->output, data, dlen)) != 0)
362 fatal("%s: buffer error: %s", __func__, ssh_err(r));
363 if (*dlen < sizeof(af))
367 #if defined(SSH_TUN_PREPEND_AF)
368 /* skip address family */
370 buf = *data + sizeof(af);
371 #elif defined(SSH_TUN_COMPAT_AF)
372 /* translate address family */
373 af = (PEEK_U32(buf) == OPENBSD_AF_INET6) ? AF_INET6 : AF_INET;
378 #endif /* SSH_TUN_FILTER */