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>
32 #include "openbsd-compat/sys-queue.h"
40 * This file contains various portability code for network support,
41 * including tun/tap forwarding and routing domains.
44 #if defined(SYS_RDOMAIN_LINUX) || defined(SSH_TUN_LINUX)
48 #if defined(SYS_RDOMAIN_LINUX)
50 sys_get_rdomain(int fd)
52 char dev[IFNAMSIZ + 1];
53 socklen_t len = sizeof(dev) - 1;
55 if (getsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, dev, &len) == -1) {
56 error("%s: cannot determine VRF for fd=%d : %s",
57 __func__, fd, strerror(errno));
65 sys_set_rdomain(int fd, const char *name)
67 if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
68 name, strlen(name)) == -1) {
69 error("%s: setsockopt(%d, SO_BINDTODEVICE, %s): %s",
70 __func__, fd, name, strerror(errno));
77 sys_valid_rdomain(const char *name)
82 * This is a pretty crappy way to test. It would be better to
83 * check whether "name" represents a VRF device, but apparently
84 * that requires an rtnetlink transaction.
86 if ((fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
88 if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
89 name, strlen(name)) == -1) {
96 #elif defined(SYS_RDOMAIN_XXX)
99 sys_get_rdomain(int fd)
105 sys_set_rdomain(int fd, const char *name)
111 valid_rdomain(const char *name)
117 sys_set_process_rdomain(const char *name)
119 fatal("%s: not supported", __func__);
121 #endif /* defined(SYS_RDOMAIN_XXX) */
124 * This is the portable version of the SSH tunnel forwarding, it
125 * uses some preprocessor definitions for various platform-specific
128 * SSH_TUN_LINUX Use the (newer) Linux tun/tap device
129 * SSH_TUN_FREEBSD Use the FreeBSD tun/tap device
130 * SSH_TUN_COMPAT_AF Translate the OpenBSD address family
131 * SSH_TUN_PREPEND_AF Prepend/remove the address family
135 * System-specific tunnel open function
138 #if defined(SSH_TUN_LINUX)
139 #include <linux/if_tun.h>
142 sys_tun_open(int tun, int mode, char **ifname)
146 const char *name = NULL;
151 if ((fd = open("/dev/net/tun", O_RDWR)) == -1) {
152 debug("%s: failed to open tunnel control interface: %s",
153 __func__, strerror(errno));
157 bzero(&ifr, sizeof(ifr));
159 if (mode == SSH_TUNMODE_ETHERNET) {
160 ifr.ifr_flags = IFF_TAP;
163 ifr.ifr_flags = IFF_TUN;
166 ifr.ifr_flags |= IFF_NO_PI;
168 if (tun != SSH_TUNID_ANY) {
169 if (tun > SSH_TUNID_MAX) {
170 debug("%s: invalid tunnel id %x: %s", __func__,
171 tun, strerror(errno));
174 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), name, tun);
177 if (ioctl(fd, TUNSETIFF, &ifr) == -1) {
178 debug("%s: failed to configure tunnel (mode %d): %s", __func__,
179 mode, strerror(errno));
183 if (tun == SSH_TUNID_ANY)
184 debug("%s: tunnel mode %d fd %d", __func__, mode, fd);
186 debug("%s: %s mode %d fd %d", __func__, ifr.ifr_name, mode, fd);
188 if (ifname != NULL && (*ifname = strdup(ifr.ifr_name)) == NULL)
197 #endif /* SSH_TUN_LINUX */
199 #ifdef SSH_TUN_FREEBSD
200 #include <sys/socket.h>
203 #ifdef HAVE_NET_IF_TUN_H
204 #include <net/if_tun.h>
208 sys_tun_open(int tun, int mode, char **ifname)
212 int fd = -1, sock, flag;
213 const char *tunbase = "tun";
218 if (mode == SSH_TUNMODE_ETHERNET) {
220 debug("%s: no layer 2 tunnelling support", __func__);
227 /* Open the tunnel device */
228 if (tun <= SSH_TUNID_MAX) {
229 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun);
230 fd = open(name, O_RDWR);
231 } else if (tun == SSH_TUNID_ANY) {
232 for (tun = 100; tun >= 0; tun--) {
233 snprintf(name, sizeof(name), "/dev/%s%d",
235 if ((fd = open(name, O_RDWR)) >= 0)
239 debug("%s: invalid tunnel %u\n", __func__, tun);
244 debug("%s: %s open failed: %s", __func__, name,
249 /* Turn on tunnel headers */
251 #if defined(TUNSIFHEAD) && !defined(SSH_TUN_PREPEND_AF)
252 if (mode != SSH_TUNMODE_ETHERNET &&
253 ioctl(fd, TUNSIFHEAD, &flag) == -1) {
254 debug("%s: ioctl(%d, TUNSIFHEAD, 1): %s", __func__, fd,
260 debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
262 /* Set the tunnel device operation mode */
263 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun);
264 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
267 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
269 if ((ifr.ifr_flags & IFF_UP) == 0) {
270 ifr.ifr_flags |= IFF_UP;
271 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
275 if (ifname != NULL && (*ifname = strdup(ifr.ifr_name)) == NULL)
286 debug("%s: failed to set %s mode %d: %s", __func__, name,
287 mode, strerror(errno));
290 #endif /* SSH_TUN_FREEBSD */
293 * System-specific channel filters
296 #if defined(SSH_TUN_FILTER)
298 * The tunnel forwarding protocol prepends the address family of forwarded
299 * IP packets using OpenBSD's numbers.
301 #define OPENBSD_AF_INET 2
302 #define OPENBSD_AF_INET6 24
305 sys_tun_infilter(struct ssh *ssh, struct Channel *c, char *buf, int _len)
310 #if defined(SSH_TUN_PREPEND_AF)
311 char rbuf[CHAN_RBUF];
314 #if defined(SSH_TUN_PREPEND_AF) || defined(SSH_TUN_COMPAT_AF)
318 /* XXX update channel input filter API to use unsigned length */
323 #if defined(SSH_TUN_PREPEND_AF)
324 if (len <= sizeof(iph) || len > sizeof(rbuf) - 4)
326 /* Determine address family from packet IP header. */
327 memcpy(&iph, buf, sizeof(iph));
328 af = iph.ip_v == 6 ? OPENBSD_AF_INET6 : OPENBSD_AF_INET;
329 /* Prepend address family to packet using OpenBSD constants */
330 memcpy(rbuf + 4, buf, len);
334 #elif defined(SSH_TUN_COMPAT_AF)
335 /* Convert existing address family header to OpenBSD value */
340 POKE_U32(buf, af == AF_INET6 ? OPENBSD_AF_INET6 : OPENBSD_AF_INET);
343 if ((r = sshbuf_put_string(c->input, ptr, len)) != 0)
344 fatal("%s: buffer error: %s", __func__, ssh_err(r));
349 sys_tun_outfilter(struct ssh *ssh, struct Channel *c,
350 u_char **data, size_t *dlen)
356 /* XXX new API is incompatible with this signature. */
357 if ((r = sshbuf_get_string(c->output, data, dlen)) != 0)
358 fatal("%s: buffer error: %s", __func__, ssh_err(r));
359 if (*dlen < sizeof(af))
363 #if defined(SSH_TUN_PREPEND_AF)
364 /* skip address family */
366 buf = *data + sizeof(af);
367 #elif defined(SSH_TUN_COMPAT_AF)
368 /* translate address family */
369 af = (PEEK_U32(buf) == OPENBSD_AF_INET6) ? AF_INET6 : AF_INET;
374 #endif /* SSH_TUN_FILTER */