[RFC PATCH net-next 8/8] net: ipv4: listify ip_rcv_finish

[Edward Cree]

Signed-off-by: Edward Cree <ec...@solarflare.com>
---
 net/ipv4/ip_input.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 53 insertions(+), 5 deletions(-)

diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index e7d0d85..5bbc409 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -308,7 +308,8 @@ drop:
        return true;
 }
 
-static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
+static int ip_rcv_finish_core(struct net *net, struct sock *sk,
+                             struct sk_buff *skb)
 {
        const struct iphdr *iph = ip_hdr(skb);
        struct rtable *rt;
@@ -385,13 +386,22 @@ static int ip_rcv_finish(struct net *net, struct sock 
*sk, struct sk_buff *skb)
                        goto drop;
        }
 
-       return dst_input(skb);
+       return NET_RX_SUCCESS;
 
 drop:
        kfree_skb(skb);
        return NET_RX_DROP;
 }
 
+static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+       int ret = ip_rcv_finish_core(net, sk, skb);
+
+       if (ret != NET_RX_DROP)
+               ret = dst_input(skb);
+       return ret;
+}
+
 /*
  *     Main IP Receive routine.
  */
@@ -501,16 +511,54 @@ int ip_rcv(struct sk_buff *skb, struct net_device *dev, 
struct packet_type *pt,
                       ip_rcv_finish);
 }
 
+static void ip_sublist_rcv_finish(struct sk_buff_head *list)
+{
+       struct sk_buff *skb;
+
+       while ((skb = __skb_dequeue(list)) != NULL)
+               dst_input(skb);
+}
+
+static void ip_list_rcv_finish(struct net *net, struct sock *sk,
+                              struct sk_buff_head *list)
+{
+       struct dst_entry *curr_dst = NULL;
+       struct sk_buff_head sublist;
+       struct sk_buff *skb;
+
+       __skb_queue_head_init(&sublist);
+
+       while ((skb = __skb_dequeue(list)) != NULL) {
+               struct dst_entry *dst;
+
+               if (ip_rcv_finish_core(net, sk, skb) == NET_RX_DROP)
+                       continue;
+
+               dst = skb_dst(skb);
+               if (skb_queue_empty(&sublist)) {
+                       curr_dst = dst;
+               } else if (curr_dst != dst) {
+                       /* dispatch old sublist */
+                       ip_sublist_rcv_finish(&sublist);
+                       /* start new sublist */
+                       __skb_queue_head_init(&sublist);
+                       curr_dst = dst;
+               }
+               /* add to current sublist */
+               __skb_queue_tail(&sublist, skb);
+       }
+       /* dispatch final sublist */
+       ip_sublist_rcv_finish(&sublist);
+}
+
 static void ip_sublist_rcv(struct sk_buff_head *list, struct net_device *dev,
                           struct net *net)
 {
        struct sk_buff_head sublist;
-       struct sk_buff *skb;
 
        NF_HOOK_LIST(NFPROTO_IPV4, NF_INET_PRE_ROUTING, net, NULL,
                     list, &sublist, dev, NULL, ip_rcv_finish);
-       while ((skb = __skb_dequeue(&sublist)) != NULL)
-               ip_rcv_finish(net, NULL, skb);
+       ip_list_rcv_finish(net, NULL, &sublist);
 }
 
 /* Receive a list of IP packets */