[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/ip.h>

#include <fcntl.h>

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