Attachment #196852 for bug #231143




	if (ip->ip_ttl <= IPTTLDEC) {
		icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0, 0);
		return NULL;	/* mbuf already free'd */
	}

	/*
	 * Decrement the TTL and incrementally change the IP header checksum.
	 * Don't bother doing this with hw checksum offloading, it's faster
	 * doing it right here.
	 */
	ip->ip_ttl -= IPTTLDEC;
	if (ip->ip_sum >= (u_int16_t) ~htons(IPTTLDEC << 8))
		ip->ip_sum -= ~htons(IPTTLDEC << 8);
	else
		ip->ip_sum += htons(IPTTLDEC << 8);
#ifdef IPSTEALTH
	}
#endif

	/*
	 * Next hop forced by ipfilter hook?
	 */
	if (m->m_flags & M_IP_NEXTHOP) {
		fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
		/*
		 * Skip outgoing filtering.
		 */
		if (fwd_tag)
			goto reroute;
	}
	/*
	 * Find route to destination.
	 */
	if (ip_findroute(&nh, dest, m) != 0)
		return (NULL);	/* icmp unreach already sent */

	/*
	 * Step 5: outgoing firewall packet processing
	 */
	if (!PFIL_HOOKED(&V_inet_pfil_hook))
		goto passout;

	if (pfil_run_hooks(&V_inet_pfil_hook, &m, nh.nh_ifp, PFIL_OUT, PFIL_FWD,
	    NULL) || m == NULL) {
		goto drop;
	}

	M_ASSERTVALID(m);
	M_ASSERTPKTHDR(m);

	ip = mtod(m, struct ip *);
	dest.s_addr = ip->ip_dst.s_addr;

	/*
	 * Destination address changed?
	 */
	if (m->m_flags & M_IP_NEXTHOP)
		fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
	if (odest.s_addr != dest.s_addr || fwd_tag != NULL) {
		/*
		 * Is it now for a local address on this host?
		 */
		if (m->m_flags & M_FASTFWD_OURS || in_localip(dest)) {
forwardlocal:
			/*
			 * Return packet for processing by ip_input().
			 */
			m->m_flags |= M_FASTFWD_OURS;
			return (m);
		}
	}

reroute:
	if (fwd_tag != NULL) {
		dest.s_addr = ((struct sockaddr_in *)
			    (fwd_tag + 1))->sin_addr.s_addr;
		m_tag_delete(m, fwd_tag);
		m->m_flags &= ~M_IP_NEXTHOP;
	}
	/*
	 * Redo route lookup with new destination address
	 */
	if (odest.s_addr != dest.s_addr || fwd_tag != NULL) {
		if (ip_findroute(&nh, dest, m) != 0)
			return (NULL);	/* icmp unreach already sent */
	}

passout:
	/*
	 * Step 6: send off the packet
	 */
	ip_len = ntohs(ip->ip_len);
	ip_off = ntohs(ip->ip_off);

	bzero(&dst, sizeof(dst));
	dst.sin_family = AF_INET;
	dst.sin_len = sizeof(dst);
	dst.sin_addr = nh.nh_addr;

	/*
	 * Check if packet fits MTU or if hardware will fragment for us
	 */
	if (ip_len <= nh.nh_mtu) {

Return to bug 231143

Lines 275-362 passin: Link Here

(-)sys/netinet/ip_fastfwd.c (-9 / +24 lines)
275	if (ip->ip_ttl <= IPTTLDEC) {	275	if (ip->ip_ttl <= IPTTLDEC) {
276	icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0, 0);	276	icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0, 0);
277	return NULL; /* mbuf already free'd */	277	return NULL; /* mbuf already free'd */
278	}	278	}
279		279
280	/*	280	/*
281	* Decrement the TTL and incrementally change the IP header checksum.	281	* Decrement the TTL and incrementally change the IP header checksum.
282	* Don't bother doing this with hw checksum offloading, it's faster	282	* Don't bother doing this with hw checksum offloading, it's faster
283	* doing it right here.	283	* doing it right here.
284	*/	284	*/
285	ip->ip_ttl -= IPTTLDEC;	285	ip->ip_ttl -= IPTTLDEC;
286	if (ip->ip_sum >= (u_int16_t) ~htons(IPTTLDEC << 8))	286	if (ip->ip_sum >= (u_int16_t) ~htons(IPTTLDEC << 8))
287	ip->ip_sum -= ~htons(IPTTLDEC << 8);	287	ip->ip_sum -= ~htons(IPTTLDEC << 8);
288	else	288	else
289	ip->ip_sum += htons(IPTTLDEC << 8);	289	ip->ip_sum += htons(IPTTLDEC << 8);
290	#ifdef IPSTEALTH	290	#ifdef IPSTEALTH
291	}	291	}
292	#endif	292	#endif
293		293
294	/*	294	/*
		295	* Next hop forced by ipfilter hook?
		296	*/
		297	if (m->m_flags & M_IP_NEXTHOP) {
		298	fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
		299	/*
		300	* Skip outgoing filtering.
		301	*/
		302	if (fwd_tag)
		303	goto reroute;
		304	}
		305	/*
295	* Find route to destination.	306	* Find route to destination.
296	*/	307	*/
297	if (ip_findroute(&nh, dest, m) != 0)	308	if (ip_findroute(&nh, dest, m) != 0)
298	return (NULL); /* icmp unreach already sent */	309	return (NULL); /* icmp unreach already sent */
299		310
300	/*	311	/*
301	* Step 5: outgoing firewall packet processing	312	* Step 5: outgoing firewall packet processing
302	*/	313	*/
303	if (!PFIL_HOOKED(&V_inet_pfil_hook))	314	if (!PFIL_HOOKED(&V_inet_pfil_hook))
304	goto passout;	315	goto passout;
305		316
306	if (pfil_run_hooks(&V_inet_pfil_hook, &m, nh.nh_ifp, PFIL_OUT, PFIL_FWD,	317	if (pfil_run_hooks(&V_inet_pfil_hook, &m, nh.nh_ifp, PFIL_OUT, PFIL_FWD,
307	NULL) \|\| m == NULL) {	318	NULL) \|\| m == NULL) {
308	goto drop;	319	goto drop;
309	}	320	}
310		321
311	M_ASSERTVALID(m);	322	M_ASSERTVALID(m);
312	M_ASSERTPKTHDR(m);	323	M_ASSERTPKTHDR(m);
313		324
314	ip = mtod(m, struct ip *);	325	ip = mtod(m, struct ip *);
315	dest.s_addr = ip->ip_dst.s_addr;	326	dest.s_addr = ip->ip_dst.s_addr;
316		327
317	/*	328	/*
318	* Destination address changed?	329	* Destination address changed?
319	*/	330	*/
320	if (m->m_flags & M_IP_NEXTHOP)	331	if (m->m_flags & M_IP_NEXTHOP)
321	fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);	332	fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
322	if (odest.s_addr != dest.s_addr \|\| fwd_tag != NULL) {	333	if (odest.s_addr != dest.s_addr \|\| fwd_tag != NULL) {
323	/*	334	/*
324	* Is it now for a local address on this host?	335	* Is it now for a local address on this host?
325	*/	336	*/
326	if (m->m_flags & M_FASTFWD_OURS \|\| in_localip(dest)) {	337	if (m->m_flags & M_FASTFWD_OURS \|\| in_localip(dest)) {
327	forwardlocal:	338	forwardlocal:
328	/*	339	/*
329	* Return packet for processing by ip_input().	340	* Return packet for processing by ip_input().
330	*/	341	*/
331	m->m_flags \|= M_FASTFWD_OURS;	342	m->m_flags \|= M_FASTFWD_OURS;
332	return (m);	343	return (m);
333	}	344	}
334	/*	345	}
335	* Redo route lookup with new destination address	346
336	*/	347	reroute:
337	if (fwd_tag) {	348	if (fwd_tag != NULL) {
338	dest.s_addr = ((struct sockaddr_in *)	349	dest.s_addr = ((struct sockaddr_in *)
339	(fwd_tag + 1))->sin_addr.s_addr;	350	(fwd_tag + 1))->sin_addr.s_addr;
340	m_tag_delete(m, fwd_tag);	351	m_tag_delete(m, fwd_tag);
341	m->m_flags &= ~M_IP_NEXTHOP;	352	m->m_flags &= ~M_IP_NEXTHOP;
342	}	353	}
		354	/*
		355	* Redo route lookup with new destination address
		356	*/
		357	if (odest.s_addr != dest.s_addr \|\| fwd_tag != NULL) {
343	if (ip_findroute(&nh, dest, m) != 0)	358	if (ip_findroute(&nh, dest, m) != 0)
344	return (NULL); /* icmp unreach already sent */	359	return (NULL); /* icmp unreach already sent */
345	}	360	}
346		361
347	passout:	362	passout:
348	/*	363	/*
349	* Step 6: send off the packet	364	* Step 6: send off the packet
350	*/	365	*/
351	ip_len = ntohs(ip->ip_len);	366	ip_len = ntohs(ip->ip_len);
352	ip_off = ntohs(ip->ip_off);	367	ip_off = ntohs(ip->ip_off);
353		368
354	bzero(&dst, sizeof(dst));	369	bzero(&dst, sizeof(dst));
355	dst.sin_family = AF_INET;	370	dst.sin_family = AF_INET;
356	dst.sin_len = sizeof(dst);	371	dst.sin_len = sizeof(dst);
357	dst.sin_addr = nh.nh_addr;	372	dst.sin_addr = nh.nh_addr;
358		373
359	/*	374	/*
360	* Check if packet fits MTU or if hardware will fragment for us	375	* Check if packet fits MTU or if hardware will fragment for us
361	*/	376	*/
362	if (ip_len <= nh.nh_mtu) {	377	if (ip_len <= nh.nh_mtu) {