[IPV4]: Move ip options parsing out of ip_rcv_finish()

Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/ip_input.c

@@ -279,37 +279,11 @@ int ip_local_deliver(struct sk_buff *skb)
 		       ip_local_deliver_finish);
 }
 
-static inline int ip_rcv_finish(struct sk_buff *skb)
+static inline int ip_rcv_options(struct sk_buff *skb)
 {
-	struct net_device *dev = skb->dev;
-	struct iphdr *iph = skb->nh.iph;
-	int err;
-
-	/*
-	 *	Initialise the virtual path cache for the packet. It describes
-	 *	how the packet travels inside Linux networking.
-	 */ 
-	if (skb->dst == NULL) {
-		if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) {
-			if (err == -EHOSTUNREACH)
-				IP_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
-			goto drop; 
-		}
-	}
-
-#ifdef CONFIG_NET_CLS_ROUTE
-	if (skb->dst->tclassid) {
-		struct ip_rt_acct *st = ip_rt_acct + 256*smp_processor_id();
-		u32 idx = skb->dst->tclassid;
-		st[idx&0xFF].o_packets++;
-		st[idx&0xFF].o_bytes+=skb->len;
-		st[(idx>>16)&0xFF].i_packets++;
-		st[(idx>>16)&0xFF].i_bytes+=skb->len;
-	}
-#endif
-
-	if (iph->ihl > 5) {
 	struct ip_options *opt;
+	struct iphdr *iph;
+	struct net_device *dev = skb->dev;
 
 	/* It looks as overkill, because not all
 	   IP options require packet mangling.
@@ -318,38 +292,79 @@ static inline int ip_rcv_finish(struct sk_buff *skb)
 	   and running sniffer is extremely rare condition.
 					      --ANK (980813)
 	*/
-
 	if (skb_cow(skb, skb_headroom(skb))) {
 		IP_INC_STATS_BH(IPSTATS_MIB_INDISCARDS);
 		goto drop;
 	}
+
 	iph = skb->nh.iph;
 
-		if (ip_options_compile(NULL, skb))
-			goto inhdr_error;
+	if (ip_options_compile(NULL, skb)) {
+		IP_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+		goto drop;
+	}
 
 	opt = &(IPCB(skb)->opt);
-		if (opt->srr) {
+	if (unlikely(opt->srr)) {
 		struct in_device *in_dev = in_dev_get(dev);
 		if (in_dev) {
 			if (!IN_DEV_SOURCE_ROUTE(in_dev)) {
-					if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
-						printk(KERN_INFO "source route option %u.%u.%u.%u -> %u.%u.%u.%u\n",
-						       NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
+				if (IN_DEV_LOG_MARTIANS(in_dev) &&
+				    net_ratelimit())
+					printk(KERN_INFO "source route option "
+					       "%u.%u.%u.%u -> %u.%u.%u.%u\n",
+					       NIPQUAD(iph->saddr),
+					       NIPQUAD(iph->daddr));
 				in_dev_put(in_dev);
 				goto drop;
 			}
+
 			in_dev_put(in_dev);
 		}
+
 		if (ip_options_rcv_srr(skb))
 			goto drop;
 	}
+
+	return 0;
+drop:
+	return -1;
+}
+
+static inline int ip_rcv_finish(struct sk_buff *skb)
+{
+	struct net_device *dev = skb->dev;
+	struct iphdr *iph = skb->nh.iph;
+	int err;
+
+	/*
+	 *	Initialise the virtual path cache for the packet. It describes
+	 *	how the packet travels inside Linux networking.
+	 */ 
+	if (skb->dst == NULL) {
+		if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) {
+			if (err == -EHOSTUNREACH)
+				IP_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
+			goto drop; 
+		}
+	}
+
+#ifdef CONFIG_NET_CLS_ROUTE
+	if (skb->dst->tclassid) {
+		struct ip_rt_acct *st = ip_rt_acct + 256*smp_processor_id();
+		u32 idx = skb->dst->tclassid;
+		st[idx&0xFF].o_packets++;
+		st[idx&0xFF].o_bytes+=skb->len;
+		st[(idx>>16)&0xFF].i_packets++;
+		st[(idx>>16)&0xFF].i_bytes+=skb->len;
 	}
+#endif
+
+	if (iph->ihl > 5 && ip_rcv_options(skb))
+		goto drop;
 
 	return dst_input(skb);
 
-inhdr_error:
-	IP_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
 drop:
         kfree_skb(skb);
         return NET_RX_DROP;