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

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

1 files changed, 54 insertions, 39 deletions

diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 6a06e15694d..48e4ddc1e33 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -279,6 +279,58 @@ int ip_local_deliver(struct sk_buff *skb)
                        ip_local_deliver_finish);
 }
 
+static inline int ip_rcv_options(struct sk_buff *skb)
+{
+        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.
+           But it is the easiest for now, especially taking
+           into account that combination of IP options
+           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)) {
+                IP_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+                goto drop;
+        }
+
+        opt = &(IPCB(skb)->opt);
+        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));
+                                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;
@@ -308,48 +360,11 @@ static inline int ip_rcv_finish(struct sk_buff *skb)
         }
 #endif
 
-        if (iph->ihl > 5) {
-                struct ip_options *opt;
-
-                /* It looks as overkill, because not all
-                   IP options require packet mangling.
-                   But it is the easiest for now, especially taking
-                   into account that combination of IP options
-                   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;
-
-                opt = &(IPCB(skb)->opt);
-                if (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));
-                                        in_dev_put(in_dev);
-                                        goto drop;
-                                }
-                                in_dev_put(in_dev);
-                        }
-                        if (ip_options_rcv_srr(skb))
-                                goto drop;
-                }
-        }
+        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;