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