[gssapi-openssh.git] / openssh / 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 "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_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>
#include <net/if_tun.h>

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
b96a6af6	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
	19	#include "log.h"
	20	#include "misc.h"
	21	#include "bufaux.h"
	22
	23	/*
	24	* This is the portable version of the SSH tunnel forwarding, it
	25	* uses some preprocessor definitions for various platform-specific
	26	* settings.
	27	*
	28	* SSH_TUN_LINUX Use the (newer) Linux tun/tap device
	29	* SSH_TUN_COMPAT_AF Translate the OpenBSD address family
	30	* SSH_TUN_PREPEND_AF Prepend/remove the address family
	31	*/
	32
	33	/*
	34	* System-specific tunnel open function
	35	*/
	36
	37	#if defined(SSH_TUN_LINUX)
	38	#include <linux/if.h>
	39	#include <linux/if_tun.h>
	40
	41	int
	42	sys_tun_open(int tun, int mode)
	43	{
	44	struct ifreq ifr;
	45	int fd = -1;
	46	const char *name = NULL;
	47
	48	if ((fd = open("/dev/net/tun", O_RDWR)) == -1) {
	49	debug("%s: failed to open tunnel control interface: %s",
	50	__func__, strerror(errno));
	51	return (-1);
	52	}
	53
	54	bzero(&ifr, sizeof(ifr));
	55
	56	if (mode == SSH_TUNMODE_ETHERNET) {
	57	ifr.ifr_flags = IFF_TAP;
	58	name = "tap%d";
	59	} else {
	60	ifr.ifr_flags = IFF_TUN;
	61	name = "tun%d";
	62	}
	63	ifr.ifr_flags \|= IFF_NO_PI;
	64
65	if (tun != SSH_TUNID_ANY) {
66	if (tun > SSH_TUNID_MAX) {
67	debug("%s: invalid tunnel id %x: %s", __func__,
68	tun, strerror(errno));
69	goto failed;
70	}
71	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), name, tun);
72	}
73
74	if (ioctl(fd, TUNSETIFF, &ifr) == -1) {
75	debug("%s: failed to configure tunnel (mode %d): %s", __func__,
76	mode, strerror(errno));
77	goto failed;
78	}
79
80	if (tun == SSH_TUNID_ANY)
81	debug("%s: tunnel mode %d fd %d", __func__, mode, fd);
82	else
83	debug("%s: %s mode %d fd %d", __func__, ifr.ifr_name, mode, fd);
84
85	return (fd);
86
87	failed:
88	close(fd);
89	return (-1);
90	}
91	#endif /* SSH_TUN_LINUX */
92
93	#ifdef SSH_TUN_FREEBSD
94	#include <sys/socket.h>
95	#include <net/if.h>
96	#include <net/if_tun.h>
97
98	int
99	sys_tun_open(int tun, int mode)
100	{
101	struct ifreq ifr;
102	char name[100];
103	int fd = -1, sock, flag;
104	const char *tunbase = "tun";
105
106	if (mode == SSH_TUNMODE_ETHERNET) {
107	#ifdef SSH_TUN_NO_L2
108	debug("%s: no layer 2 tunnelling support", __func__);
109	return (-1);
110	#else
111	tunbase = "tap";
112	#endif
113	}
114
115	/* Open the tunnel device */
116	if (tun <= SSH_TUNID_MAX) {
117	snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun);
118	fd = open(name, O_RDWR);
119	} else if (tun == SSH_TUNID_ANY) {
120	for (tun = 100; tun >= 0; tun--) {
121	snprintf(name, sizeof(name), "/dev/%s%d",
122	tunbase, tun);
123	if ((fd = open(name, O_RDWR)) >= 0)
124	break;
125	}
126	} else {
127	debug("%s: invalid tunnel %u\n", __func__, tun);
128	return (-1);
129	}
130
131	if (fd < 0) {
132	debug("%s: %s open failed: %s", __func__, name,
133	strerror(errno));
134	return (-1);
135	}
136
137	/* Turn on tunnel headers */
138	flag = 1;
139	#if defined(TUNSIFHEAD) && !defined(SSH_TUN_PREPEND_AF)
140	if (mode != SSH_TUNMODE_ETHERNET &&
141	ioctl(fd, TUNSIFHEAD, &flag) == -1) {
142	debug("%s: ioctl(%d, TUNSIFHEAD, 1): %s", __func__, fd,
143	strerror(errno));
144	close(fd);
145	}
146	#endif
147
148	debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
149
150	/* Set the tunnel device operation mode */
151	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun);
152	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
153	goto failed;
154
155	if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
156	goto failed;
157	ifr.ifr_flags \|= IFF_UP;
158	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
159	goto failed;
160
161	close(sock);
162	return (fd);
163
164	failed:
165	if (fd >= 0)
166	close(fd);
167	if (sock >= 0)
168	close(sock);
169	debug("%s: failed to set %s mode %d: %s", __func__, name,
170	mode, strerror(errno));
171	return (-1);
172	}
173	#endif /* SSH_TUN_FREEBSD */
174
175	/*
176	* System-specific channel filters
177	*/
178
179	#if defined(SSH_TUN_FILTER)
180	#define OPENBSD_AF_INET 2
181	#define OPENBSD_AF_INET6 24
182
183	int
184	sys_tun_infilter(struct Channel c, char buf, int len)
185	{
186	#if defined(SSH_TUN_PREPEND_AF)
187	char rbuf[CHAN_RBUF];
188	struct ip *iph;
189	#endif
190	u_int32_t *af;
191	char *ptr = buf;
192
193	#if defined(SSH_TUN_PREPEND_AF)
194	if (len <= 0 \|\| len > (int)(sizeof(rbuf) - sizeof(*af)))
195	return (-1);
196	ptr = (char *)&rbuf[0];
197	bcopy(buf, ptr + sizeof(u_int32_t), len);
198	len += sizeof(u_int32_t);
199	af = (u_int32_t *)ptr;
200
201	iph = (struct ip *)(ptr + sizeof(u_int32_t));
202	switch (iph->ip_v) {
203	case 6:
204	*af = AF_INET6;
205	break;
206	case 4:
207	default:
208	*af = AF_INET;
209	break;
210	}
211	#endif
212
213	#if defined(SSH_TUN_COMPAT_AF)
214	if (len < (int)sizeof(u_int32_t))
215	return (-1);
216
217	af = (u_int32_t *)ptr;
218	if (*af == htonl(AF_INET6))
219	*af = htonl(OPENBSD_AF_INET6);
220	else
221	*af = htonl(OPENBSD_AF_INET);
222	#endif
223
224	buffer_put_string(&c->input, ptr, len);
225	return (0);
226	}
227
228	u_char *
229	sys_tun_outfilter(struct Channel c, u_char data, u_int dlen)
230	{
231	u_char *buf;
232	u_int32_t *af;
233
234	*data = buffer_get_string(&c->output, dlen);
235	if (dlen < sizeof(af))
236	return (NULL);
237	buf = *data;
238
239	#if defined(SSH_TUN_PREPEND_AF)
240	*dlen -= sizeof(u_int32_t);
241	buf = *data + sizeof(u_int32_t);
242	#elif defined(SSH_TUN_COMPAT_AF)
243	af = ntohl((u_int32_t )buf);
244	if (*af == OPENBSD_AF_INET6)
245	*af = htonl(AF_INET6);
246	else
247	*af = htonl(AF_INET);
248	#endif
249
250	return (buf);
251	}
252	#endif /* SSH_TUN_FILTER */