[openssh.git] / openbsd-compat / port-tun.c

/*
 * 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 <arpa/inet.h>
#include <netinet/ip.h>

#include <errno.h>
#include <fcntl.h>
#include <stdarg.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 */
Commit	Line	Data
e914f53a	1	/*
	2	* Copyright (c) 2005 Reyk Floeter <reyk@openbsd.org>
	3	*
	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.
	7	*
	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.
	15	*/
	16
	17	#include "includes.h"
	18
22bbb3e6	19	#include <sys/types.h>
3e9b2b1b	20	#include <sys/ioctl.h>
5e837c7b	21
f9d5c000	22	#include <netinet/in.h>
5e837c7b	23	#include <arpa/inet.h>
3e9b2b1b	24	#include <netinet/ip.h>
3e9b2b1b	25
fec71b2f	26	#include <errno.h>
22bbb3e6	27	#include <fcntl.h>
f2265d5d	28	#include <stdarg.h>
28cb0a43	29	#include <string.h>
28cb0a43	30	#include <unistd.h>
22bbb3e6	31
e914f53a	32	#include "log.h"
e914f53a	33	#include "misc.h"
693a35d3	34	#include "buffer.h"
00a017bd	35	#include "channels.h"
e914f53a	36
	37	/*
	38	* This is the portable version of the SSH tunnel forwarding, it
	39	* uses some preprocessor definitions for various platform-specific
	40	* settings.
	41	*
	42	* SSH_TUN_LINUX Use the (newer) Linux tun/tap device
e02505e2	43	* SSH_TUN_FREEBSD Use the FreeBSD tun/tap device
e914f53a	44	* SSH_TUN_COMPAT_AF Translate the OpenBSD address family
	45	* SSH_TUN_PREPEND_AF Prepend/remove the address family
	46	*/
	47
	48	/*
	49	* System-specific tunnel open function
	50	*/
	51
	52	#if defined(SSH_TUN_LINUX)
3aef38da	53	#include <linux/if.h>
e914f53a	54	#include <linux/if_tun.h>
	55
	56	int
	57	sys_tun_open(int tun, int mode)
	58	{
	59	struct ifreq ifr;
	60	int fd = -1;
	61	const char *name = NULL;
	62
	63	if ((fd = open("/dev/net/tun", O_RDWR)) == -1) {
	64	debug("%s: failed to open tunnel control interface: %s",
	65	__func__, strerror(errno));
	66	return (-1);
	67	}
	68
	69	bzero(&ifr, sizeof(ifr));
	70
	71	if (mode == SSH_TUNMODE_ETHERNET) {
	72	ifr.ifr_flags = IFF_TAP;
	73	name = "tap%d";
	74	} else {
	75	ifr.ifr_flags = IFF_TUN;
	76	name = "tun%d";
	77	}
	78	ifr.ifr_flags \|= IFF_NO_PI;
	79
	80	if (tun != SSH_TUNID_ANY) {
	81	if (tun > SSH_TUNID_MAX) {
	82	debug("%s: invalid tunnel id %x: %s", __func__,
	83	tun, strerror(errno));
	84	goto failed;
	85	}
	86	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), name, tun);
	87	}
	88
	89	if (ioctl(fd, TUNSETIFF, &ifr) == -1) {
	90	debug("%s: failed to configure tunnel (mode %d): %s", __func__,
	91	mode, strerror(errno));
	92	goto failed;
	93	}
	94
	95	if (tun == SSH_TUNID_ANY)
	96	debug("%s: tunnel mode %d fd %d", __func__, mode, fd);
	97	else
	98	debug("%s: %s mode %d fd %d", __func__, ifr.ifr_name, mode, fd);
	99
	100	return (fd);
	101
	102	failed:
	103	close(fd);
	104	return (-1);
	105	}
	106	#endif /* SSH_TUN_LINUX */
	107
0f6cb079	108	#ifdef SSH_TUN_FREEBSD
	109	#include <sys/socket.h>
	110	#include <net/if.h>
e02505e2	111
e02505e2	112	#ifdef HAVE_NET_IF_TUN_H
0f6cb079	113	#include <net/if_tun.h>
e02505e2	114	#endif
0f6cb079	115
	116	int
	117	sys_tun_open(int tun, int mode)
	118	{
	119	struct ifreq ifr;
	120	char name[100];
	121	int fd = -1, sock, flag;
	122	const char *tunbase = "tun";
	123
	124	if (mode == SSH_TUNMODE_ETHERNET) {
	125	#ifdef SSH_TUN_NO_L2
	126	debug("%s: no layer 2 tunnelling support", __func__);
	127	return (-1);
	128	#else
	129	tunbase = "tap";
	130	#endif
	131	}
	132
	133	/* Open the tunnel device */
	134	if (tun <= SSH_TUNID_MAX) {
	135	snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun);
	136	fd = open(name, O_RDWR);
	137	} else if (tun == SSH_TUNID_ANY) {
	138	for (tun = 100; tun >= 0; tun--) {
	139	snprintf(name, sizeof(name), "/dev/%s%d",
	140	tunbase, tun);
	141	if ((fd = open(name, O_RDWR)) >= 0)
	142	break;
	143	}
	144	} else {
	145	debug("%s: invalid tunnel %u\n", __func__, tun);
	146	return (-1);
	147	}
	148
	149	if (fd < 0) {
	150	debug("%s: %s open failed: %s", __func__, name,
	151	strerror(errno));
	152	return (-1);
	153	}
	154
	155	/* Turn on tunnel headers */
	156	flag = 1;
	157	#if defined(TUNSIFHEAD) && !defined(SSH_TUN_PREPEND_AF)
	158	if (mode != SSH_TUNMODE_ETHERNET &&
	159	ioctl(fd, TUNSIFHEAD, &flag) == -1) {
	160	debug("%s: ioctl(%d, TUNSIFHEAD, 1): %s", __func__, fd,
	161	strerror(errno));
	162	close(fd);
	163	}
	164	#endif
	165
	166	debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
	167
	168	/* Set the tunnel device operation mode */
	169	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun);
	170	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
	171	goto failed;
	172
	173	if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
	174	goto failed;
	175	ifr.ifr_flags \|= IFF_UP;
	176	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
	177	goto failed;
	178
179	close(sock);
180	return (fd);
181
182	failed:
183	if (fd >= 0)
184	close(fd);
185	if (sock >= 0)
186	close(sock);
187	debug("%s: failed to set %s mode %d: %s", __func__, name,
188	mode, strerror(errno));
189	return (-1);
190	}
191	#endif /* SSH_TUN_FREEBSD */
192
e914f53a	193	/*
	194	* System-specific channel filters
	195	*/
	196
	197	#if defined(SSH_TUN_FILTER)
	198	#define OPENBSD_AF_INET 2
	199	#define OPENBSD_AF_INET6 24
	200
	201	int
	202	sys_tun_infilter(struct Channel c, char buf, int len)
	203	{
	204	#if defined(SSH_TUN_PREPEND_AF)
	205	char rbuf[CHAN_RBUF];
0f6cb079	206	struct ip *iph;
e914f53a	207	#endif
	208	u_int32_t *af;
	209	char *ptr = buf;
	210
	211	#if defined(SSH_TUN_PREPEND_AF)
0f6cb079	212	if (len <= 0 \|\| len > (int)(sizeof(rbuf) - sizeof(*af)))
e914f53a	213	return (-1);
	214	ptr = (char *)&rbuf[0];
	215	bcopy(buf, ptr + sizeof(u_int32_t), len);
	216	len += sizeof(u_int32_t);
0f6cb079	217	af = (u_int32_t *)ptr;
	218
	219	iph = (struct ip *)(ptr + sizeof(u_int32_t));
	220	switch (iph->ip_v) {
	221	case 6:
	222	*af = AF_INET6;
	223	break;
	224	case 4:
	225	default:
	226	*af = AF_INET;
	227	break;
	228	}
e914f53a	229	#endif
	230
	231	#if defined(SSH_TUN_COMPAT_AF)
	232	if (len < (int)sizeof(u_int32_t))
	233	return (-1);
	234
	235	af = (u_int32_t *)ptr;
	236	if (*af == htonl(AF_INET6))
	237	*af = htonl(OPENBSD_AF_INET6);
	238	else
	239	*af = htonl(OPENBSD_AF_INET);
	240	#endif
0f6cb079	241
e914f53a	242	buffer_put_string(&c->input, ptr, len);
	243	return (0);
	244	}
	245
	246	u_char *
	247	sys_tun_outfilter(struct Channel c, u_char data, u_int dlen)
	248	{
	249	u_char *buf;
	250	u_int32_t *af;
	251
	252	*data = buffer_get_string(&c->output, dlen);
	253	if (dlen < sizeof(af))
	254	return (NULL);
	255	buf = *data;
	256
	257	#if defined(SSH_TUN_PREPEND_AF)
	258	*dlen -= sizeof(u_int32_t);
	259	buf = *data + sizeof(u_int32_t);
	260	#elif defined(SSH_TUN_COMPAT_AF)
	261	af = ntohl((u_int32_t )buf);
	262	if (*af == OPENBSD_AF_INET6)
	263	*af = htonl(AF_INET6);
	264	else
	265	*af = htonl(AF_INET);
	266	#endif
	267
	268	return (buf);
	269	}
	270	#endif /* SSH_TUN_FILTER */