[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 "openbsd-compat/sys-queue.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
c49ce62e	32	#include "openbsd-compat/sys-queue.h"
e914f53a	33	#include "log.h"
e914f53a	34	#include "misc.h"
693a35d3	35	#include "buffer.h"
00a017bd	36	#include "channels.h"
e914f53a	37
	38	/*
	39	* This is the portable version of the SSH tunnel forwarding, it
	40	* uses some preprocessor definitions for various platform-specific
	41	* settings.
	42	*
	43	* SSH_TUN_LINUX Use the (newer) Linux tun/tap device
e02505e2	44	* SSH_TUN_FREEBSD Use the FreeBSD tun/tap device
e914f53a	45	* SSH_TUN_COMPAT_AF Translate the OpenBSD address family
	46	* SSH_TUN_PREPEND_AF Prepend/remove the address family
	47	*/
	48
	49	/*
	50	* System-specific tunnel open function
	51	*/
	52
	53	#if defined(SSH_TUN_LINUX)
3aef38da	54	#include <linux/if.h>
e914f53a	55	#include <linux/if_tun.h>
	56
	57	int
	58	sys_tun_open(int tun, int mode)
	59	{
	60	struct ifreq ifr;
	61	int fd = -1;
	62	const char *name = NULL;
	63
	64	if ((fd = open("/dev/net/tun", O_RDWR)) == -1) {
	65	debug("%s: failed to open tunnel control interface: %s",
	66	__func__, strerror(errno));
	67	return (-1);
	68	}
	69
	70	bzero(&ifr, sizeof(ifr));
	71
	72	if (mode == SSH_TUNMODE_ETHERNET) {
	73	ifr.ifr_flags = IFF_TAP;
	74	name = "tap%d";
	75	} else {
	76	ifr.ifr_flags = IFF_TUN;
	77	name = "tun%d";
	78	}
	79	ifr.ifr_flags \|= IFF_NO_PI;
	80
	81	if (tun != SSH_TUNID_ANY) {
	82	if (tun > SSH_TUNID_MAX) {
	83	debug("%s: invalid tunnel id %x: %s", __func__,
	84	tun, strerror(errno));
	85	goto failed;
	86	}
	87	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), name, tun);
	88	}
	89
	90	if (ioctl(fd, TUNSETIFF, &ifr) == -1) {
	91	debug("%s: failed to configure tunnel (mode %d): %s", __func__,
	92	mode, strerror(errno));
	93	goto failed;
	94	}
	95
	96	if (tun == SSH_TUNID_ANY)
	97	debug("%s: tunnel mode %d fd %d", __func__, mode, fd);
	98	else
	99	debug("%s: %s mode %d fd %d", __func__, ifr.ifr_name, mode, fd);
	100
	101	return (fd);
	102
	103	failed:
	104	close(fd);
	105	return (-1);
	106	}
	107	#endif /* SSH_TUN_LINUX */
	108
0f6cb079	109	#ifdef SSH_TUN_FREEBSD
	110	#include <sys/socket.h>
	111	#include <net/if.h>
e02505e2	112
e02505e2	113	#ifdef HAVE_NET_IF_TUN_H
0f6cb079	114	#include <net/if_tun.h>
e02505e2	115	#endif
0f6cb079	116
	117	int
	118	sys_tun_open(int tun, int mode)
	119	{
	120	struct ifreq ifr;
	121	char name[100];
	122	int fd = -1, sock, flag;
	123	const char *tunbase = "tun";
	124
	125	if (mode == SSH_TUNMODE_ETHERNET) {
	126	#ifdef SSH_TUN_NO_L2
	127	debug("%s: no layer 2 tunnelling support", __func__);
	128	return (-1);
	129	#else
	130	tunbase = "tap";
	131	#endif
	132	}
	133
	134	/* Open the tunnel device */
	135	if (tun <= SSH_TUNID_MAX) {
	136	snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun);
	137	fd = open(name, O_RDWR);
	138	} else if (tun == SSH_TUNID_ANY) {
	139	for (tun = 100; tun >= 0; tun--) {
	140	snprintf(name, sizeof(name), "/dev/%s%d",
	141	tunbase, tun);
	142	if ((fd = open(name, O_RDWR)) >= 0)
	143	break;
	144	}
	145	} else {
	146	debug("%s: invalid tunnel %u\n", __func__, tun);
	147	return (-1);
	148	}
	149
	150	if (fd < 0) {
	151	debug("%s: %s open failed: %s", __func__, name,
	152	strerror(errno));
	153	return (-1);
	154	}
	155
	156	/* Turn on tunnel headers */
	157	flag = 1;
	158	#if defined(TUNSIFHEAD) && !defined(SSH_TUN_PREPEND_AF)
	159	if (mode != SSH_TUNMODE_ETHERNET &&
	160	ioctl(fd, TUNSIFHEAD, &flag) == -1) {
	161	debug("%s: ioctl(%d, TUNSIFHEAD, 1): %s", __func__, fd,
	162	strerror(errno));
	163	close(fd);
	164	}
	165	#endif
	166
	167	debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
	168
	169	/* Set the tunnel device operation mode */
	170	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun);
	171	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
	172	goto failed;
	173
	174	if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
	175	goto failed;
	176	ifr.ifr_flags \|= IFF_UP;
	177	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
	178	goto failed;
	179
180	close(sock);
181	return (fd);
182
183	failed:
184	if (fd >= 0)
185	close(fd);
186	if (sock >= 0)
187	close(sock);
188	debug("%s: failed to set %s mode %d: %s", __func__, name,
189	mode, strerror(errno));
190	return (-1);
191	}
192	#endif /* SSH_TUN_FREEBSD */
193
e914f53a	194	/*
	195	* System-specific channel filters
	196	*/
	197
	198	#if defined(SSH_TUN_FILTER)
	199	#define OPENBSD_AF_INET 2
	200	#define OPENBSD_AF_INET6 24
	201
	202	int
	203	sys_tun_infilter(struct Channel c, char buf, int len)
	204	{
	205	#if defined(SSH_TUN_PREPEND_AF)
	206	char rbuf[CHAN_RBUF];
0f6cb079	207	struct ip *iph;
e914f53a	208	#endif
	209	u_int32_t *af;
	210	char *ptr = buf;
	211
	212	#if defined(SSH_TUN_PREPEND_AF)
0f6cb079	213	if (len <= 0 \|\| len > (int)(sizeof(rbuf) - sizeof(*af)))
e914f53a	214	return (-1);
	215	ptr = (char *)&rbuf[0];
	216	bcopy(buf, ptr + sizeof(u_int32_t), len);
	217	len += sizeof(u_int32_t);
0f6cb079	218	af = (u_int32_t *)ptr;
	219
	220	iph = (struct ip *)(ptr + sizeof(u_int32_t));
	221	switch (iph->ip_v) {
	222	case 6:
	223	*af = AF_INET6;
	224	break;
	225	case 4:
	226	default:
	227	*af = AF_INET;
	228	break;
	229	}
e914f53a	230	#endif
	231
	232	#if defined(SSH_TUN_COMPAT_AF)
	233	if (len < (int)sizeof(u_int32_t))
	234	return (-1);
	235
	236	af = (u_int32_t *)ptr;
	237	if (*af == htonl(AF_INET6))
	238	*af = htonl(OPENBSD_AF_INET6);
	239	else
	240	*af = htonl(OPENBSD_AF_INET);
	241	#endif
0f6cb079	242
e914f53a	243	buffer_put_string(&c->input, ptr, len);
	244	return (0);
	245	}
	246
	247	u_char *
	248	sys_tun_outfilter(struct Channel c, u_char data, u_int dlen)
	249	{
	250	u_char *buf;
	251	u_int32_t *af;
	252
	253	*data = buffer_get_string(&c->output, dlen);
	254	if (dlen < sizeof(af))
	255	return (NULL);
	256	buf = *data;
	257
	258	#if defined(SSH_TUN_PREPEND_AF)
	259	*dlen -= sizeof(u_int32_t);
	260	buf = *data + sizeof(u_int32_t);
	261	#elif defined(SSH_TUN_COMPAT_AF)
	262	af = ntohl((u_int32_t )buf);
	263	if (*af == OPENBSD_AF_INET6)
	264	*af = htonl(AF_INET6);
	265	else
	266	*af = htonl(AF_INET);
	267	#endif
	268
	269	return (buf);
	270	}
	271	#endif /* SSH_TUN_FILTER */