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