X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=net%2Fipv4%2Fip_forward.c;h=8c95cf09f87ac213e81b0a2421d568a4a7a6bd92;hb=40b42f1ebf653cd72c32eb1a1a0b9fea2dfbfd7d;hp=a22d11d2911cd4f7772b2d6428a5d525c5cc2f59;hpb=c4e00fac42f268ed0a547cdd1d12bb8399864040;p=linux-2.6

diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c
index a22d11d291..8c95cf09f8 100644
--- a/net/ipv4/ip_forward.c
+++ b/net/ipv4/ip_forward.c
@@ -4,15 +4,15 @@
  *		interface as the means of communication with the user level.
  *
  *		The IP forwarding functionality.
- *		
+ *
  * Version:	$Id: ip_forward.c,v 1.48 2000/12/13 18:31:48 davem Exp $
  *
  * Authors:	see ip.c
  *
  * Fixes:
- *		Many		:	Split from ip.c , see ip_input.c for 
+ *		Many		:	Split from ip.c , see ip_input.c for
  *					history.
- *		Dave Gregorich	:	NULL ip_rt_put fix for multicast 
+ *		Dave Gregorich	:	NULL ip_rt_put fix for multicast
  *					routing.
  *		Jos Vos		:	Add call_out_firewall before sending,
  *					use output device for accounting.
@@ -23,7 +23,6 @@
 
 #include <linux/types.h>
 #include <linux/mm.h>
-#include <linux/sched.h>
 #include <linux/skbuff.h>
 #include <linux/ip.h>
 #include <linux/icmp.h>
@@ -68,15 +67,15 @@ int ip_forward(struct sk_buff *skb)
 	if (skb->pkt_type != PACKET_HOST)
 		goto drop;
 
-	skb->ip_summed = CHECKSUM_NONE;
-	
+	skb_forward_csum(skb);
+
 	/*
 	 *	According to the RFC, we must first decrease the TTL field. If
 	 *	that reaches zero, we must reply an ICMP control message telling
 	 *	that the packet's lifetime expired.
 	 */
-	if (skb->nh.iph->ttl <= 1)
-                goto too_many_hops;
+	if (ip_hdr(skb)->ttl <= 1)
+		goto too_many_hops;
 
 	if (!xfrm4_route_forward(skb))
 		goto drop;
@@ -86,10 +85,18 @@ int ip_forward(struct sk_buff *skb)
 	if (opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
 		goto sr_failed;
 
+	if (unlikely(skb->len > dst_mtu(&rt->u.dst) &&
+		     (ip_hdr(skb)->frag_off & htons(IP_DF))) && !skb->local_df) {
+		IP_INC_STATS(IPSTATS_MIB_FRAGFAILS);
+		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
+			  htonl(dst_mtu(&rt->u.dst)));
+		goto drop;
+	}
+
 	/* We are about to mangle packet. Copy it! */
 	if (skb_cow(skb, LL_RESERVED_SPACE(rt->u.dst.dev)+rt->u.dst.header_len))
 		goto drop;
-	iph = skb->nh.iph;
+	iph = ip_hdr(skb);
 
 	/* Decrease ttl after skb cow done */
 	ip_decrease_ttl(iph);
@@ -107,16 +114,16 @@ int ip_forward(struct sk_buff *skb)
 		       ip_forward_finish);
 
 sr_failed:
-        /*
+	/*
 	 *	Strict routing permits no gatewaying
 	 */
-         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_SR_FAILED, 0);
-         goto drop;
+	 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_SR_FAILED, 0);
+	 goto drop;
 
 too_many_hops:
-        /* Tell the sender its packet died... */
-        IP_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
-        icmp_send(skb, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL, 0);
+	/* Tell the sender its packet died... */
+	IP_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+	icmp_send(skb, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL, 0);
 drop:
 	kfree_skb(skb);
 	return NET_RX_DROP;