Attachment #3020 for bug #2735




 */

#if defined(SSH_TUN_FILTER)
/*
 * The tunnel forwarding protocol prepends the address family of forwarded
 * IP packets using OpenBSD's numbers.
 */
#define OPENBSD_AF_INET		2
#define OPENBSD_AF_INET6	24

int
sys_tun_infilter(struct Channel *c, char *buf, int _len)
{
	int r;
	size_t len;
	struct ip *iph;
#endif
	u_int32_t *af;
	char *ptr = buf;
	int r;

#if defined(SSH_TUN_PREPEND_AF)
	char rbuf[CHAN_RBUF];
	struct ip iph;
#endif
#if defined(SSH_TUN_PREPEND_AF) || defined(SSH_TUN_COMPAT_AF)
	u_int32_t af;
	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

	/* XXX update channel input filter API to use unsigned length */
	if (_len < 0)
		return -1;
	len = _len;

#if defined(SSH_TUN_PREPEND_AF)
	if (len <= sizeof(iph) || len > sizeof(rbuf) - 4)
		return -1;
	/* Determine address family from packet IP header. */
	memcpy(&iph, buf, sizeof(iph));
	af = iph.ip_v == 6 ? OPENBSD_AF_INET6 : OPENBSD_AF_INET;
	/* Prepend address family to packet using OpenBSD constants */
	memcpy(rbuf + 4, buf, len);
	len += 4;
	POKE_U32(rbuf, af);
	ptr = rbuf;
#elif defined(SSH_TUN_COMPAT_AF)
	/* Convert existing address family header to OpenBSD value */
	if (len <= 4)
		return -1;
	af = PEEK_U32(buf);
	/* Put it back */
	POKE_U32(buf, af == AF_INET6 ? OPENBSD_AF_INET6 : OPENBSD_AF_INET);
#endif

	if ((r = sshbuf_put_string(&c->input, ptr, len)) != 0)

sys_tun_outfilter(struct Channel *c, u_char **data, u_int *dlen)
{
	u_char *buf;
	u_int32_t af;
	int r;
	size_t xxx_dlen;


		fatal("%s: buffer error: %s", __func__, ssh_err(r));
	if (dlen != NULL)
		*dlen = xxx_dlen;
	if (*dlen < sizeof(af))
		return (NULL);
	buf = *data;

#if defined(SSH_TUN_PREPEND_AF)
	/* skip address family */
	*dlen -= sizeof(af);
	buf = *data + sizeof(af);
#elif defined(SSH_TUN_COMPAT_AF)
	/* translate address family */
	af = (PEEK_U32(buf) == OPENBSD_AF_INET6) ? AF_INET6 : AF_INET;
	POKE_U32(buf, af);
	else
		*af = htonl(AF_INET);
#endif

	return (buf);
}
#endif /* SSH_TUN_FILTER */

Return to bug 2735

Lines 199-247 sys_tun_open(int tun, int mode) Link Here

(-)a/openbsd-compat/port-tun.c (-43 / +42 lines)
199	*/	199	*/
200		200
201	#if defined(SSH_TUN_FILTER)	201	#if defined(SSH_TUN_FILTER)
		202	/*
		203	* The tunnel forwarding protocol prepends the address family of forwarded
		204	* IP packets using OpenBSD's numbers.
		205	*/
202	#define OPENBSD_AF_INET 2	206	#define OPENBSD_AF_INET 2
203	#define OPENBSD_AF_INET6 24	207	#define OPENBSD_AF_INET6 24
204		208
205	int	209	int
206	sys_tun_infilter(struct Channel c, char buf, int len)	210	sys_tun_infilter(struct Channel c, char buf, int _len)
207	{	211	{
208	#if defined(SSH_TUN_PREPEND_AF)	212	int r;
209	char rbuf[CHAN_RBUF];	213	size_t len;
210	struct ip *iph;
211	#endif
212	u_int32_t *af;
213	char *ptr = buf;	214	char *ptr = buf;
214	int r;
215
216	#if defined(SSH_TUN_PREPEND_AF)	215	#if defined(SSH_TUN_PREPEND_AF)
217	if (len <= 0 \|\| len > (int)(sizeof(rbuf) - sizeof(*af)))	216	char rbuf[CHAN_RBUF];
218	return (-1);	217	struct ip iph;
219	ptr = (char *)&rbuf[0];	218	#endif
220	bcopy(buf, ptr + sizeof(u_int32_t), len);	219	#if defined(SSH_TUN_PREPEND_AF) \|\| defined(SSH_TUN_COMPAT_AF)
221	len += sizeof(u_int32_t);	220	u_int32_t af;
222	af = (u_int32_t *)ptr;
223
224	iph = (struct ip *)(ptr + sizeof(u_int32_t));
225	switch (iph->ip_v) {
226	case 6:
227	*af = AF_INET6;
228	break;
229	case 4:
230	default:
231	*af = AF_INET;
232	break;
233	}
234	#endif	221	#endif
235		222
236	#if defined(SSH_TUN_COMPAT_AF)	223	/* XXX update channel input filter API to use unsigned length */
237	if (len < (int)sizeof(u_int32_t))	224	if (_len < 0)
238	return (-1);	225	return -1;
		226	len = _len;
239		227
240	af = (u_int32_t *)ptr;	228	#if defined(SSH_TUN_PREPEND_AF)
241	if (*af == htonl(AF_INET6))	229	if (len <= sizeof(iph) \|\| len > sizeof(rbuf) - 4)
242	*af = htonl(OPENBSD_AF_INET6);	230	return -1;
243	else	231	/* Determine address family from packet IP header. */
244	*af = htonl(OPENBSD_AF_INET);	232	memcpy(&iph, buf, sizeof(iph));
		233	af = iph.ip_v == 6 ? OPENBSD_AF_INET6 : OPENBSD_AF_INET;
		234	/* Prepend address family to packet using OpenBSD constants */
		235	memcpy(rbuf + 4, buf, len);
		236	len += 4;
		237	POKE_U32(rbuf, af);
		238	ptr = rbuf;
		239	#elif defined(SSH_TUN_COMPAT_AF)
		240	/* Convert existing address family header to OpenBSD value */
		241	if (len <= 4)
		242	return -1;
		243	af = PEEK_U32(buf);
		244	/* Put it back */
		245	POKE_U32(buf, af == AF_INET6 ? OPENBSD_AF_INET6 : OPENBSD_AF_INET);
245	#endif	246	#endif
246		247
247	if ((r = sshbuf_put_string(&c->input, ptr, len)) != 0)	248	if ((r = sshbuf_put_string(&c->input, ptr, len)) != 0)
Lines 253-259 u_char * Link Here
253	sys_tun_outfilter(struct Channel c, u_char data, u_int dlen)	254	sys_tun_outfilter(struct Channel c, u_char data, u_int dlen)
254	{	255	{
255	u_char *buf;	256	u_char *buf;
256	u_int32_t *af;	257	u_int32_t af;
257	int r;	258	int r;
258	size_t xxx_dlen;	259	size_t xxx_dlen;
259		260
Lines 262-282 sys_tun_outfilter(struct Channel c, u_char data, u_int dlen) Link Here
262	fatal("%s: buffer error: %s", __func__, ssh_err(r));	263	fatal("%s: buffer error: %s", __func__, ssh_err(r));
263	if (dlen != NULL)	264	if (dlen != NULL)
264	*dlen = xxx_dlen;	265	*dlen = xxx_dlen;
265	if (dlen < sizeof(af))	266	if (*dlen < sizeof(af))
266	return (NULL);	267	return (NULL);
267	buf = *data;	268	buf = *data;
268		269
269	#if defined(SSH_TUN_PREPEND_AF)	270	#if defined(SSH_TUN_PREPEND_AF)
270	*dlen -= sizeof(u_int32_t);	271	/* skip address family */
271	buf = *data + sizeof(u_int32_t);	272	*dlen -= sizeof(af);
		273	buf = *data + sizeof(af);
272	#elif defined(SSH_TUN_COMPAT_AF)	274	#elif defined(SSH_TUN_COMPAT_AF)
273	af = ntohl((u_int32_t )buf);	275	/* translate address family */
274	if (*af == OPENBSD_AF_INET6)	276	af = (PEEK_U32(buf) == OPENBSD_AF_INET6) ? AF_INET6 : AF_INET;
275	*af = htonl(AF_INET6);	277	POKE_U32(buf, af);
276	else
277	*af = htonl(AF_INET);
278	#endif	278	#endif
279
280	return (buf);	279	return (buf);
281	}	280	}
282	#endif /* SSH_TUN_FILTER */	281	#endif /* SSH_TUN_FILTER */