ip_rcv_finish_core(), if it does not drop, sets skb->dst by either early
demux or route lookup. The last step, calling dst_input(skb), is left to
the caller; in the listified case, we split to form sublists with a common
dst, but then ip_sublist_rcv_finish() just calls dst_input(skb) in a loop.
The next step in listification would thus be to add a list_input() method
to struct dst_entry.
Early demux is an indirect call based on iph->protocol; this is another
opportunity for listification which is not taken here (it would require
slicing up ip_rcv_finish_core() to allow splitting on protocol changes).
Signed-off-by: Edward Cree <ec...@solarflare.com>
---
net/ipv4/ip_input.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 48 insertions(+), 6 deletions(-)
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 914240830bdf..24b9b0210aeb 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -307,7 +307,8 @@ static inline bool ip_rcv_options(struct sk_buff *skb)
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);
int (*edemux)(struct sk_buff *skb);
@@ -393,7 +394,7 @@ 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);
@@ -405,6 +406,15 @@ static int ip_rcv_finish(struct net *net, struct sock *sk,
struct sk_buff *skb)
goto 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.
*/
@@ -515,15 +525,47 @@ int ip_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt,
ip_rcv_finish);
}
-static void ip_sublist_rcv(struct list_head *head, struct net_device *dev,
- struct net *net)
+static void ip_sublist_rcv_finish(struct list_head *head)
{
struct sk_buff *skb, *next;
+ list_for_each_entry_safe(skb, next, head, list)
+ dst_input(skb);
+}
+
+static void ip_list_rcv_finish(struct net *net, struct sock *sk,
+ struct list_head *head)
+{
+ struct dst_entry *curr_dst = NULL;
+ struct sk_buff *skb, *next;
+ struct list_head sublist;
+
+ list_for_each_entry_safe(skb, next, head, list) {
+ struct dst_entry *dst;
+
+ if (ip_rcv_finish_core(net, sk, skb) == NET_RX_DROP)
+ continue;
+
+ dst = skb_dst(skb);
+ if (curr_dst != dst) {
+ /* dispatch old sublist */
+ list_cut_before(&sublist, head, &skb->list);
+ if (!list_empty(&sublist))
+ ip_sublist_rcv_finish(&sublist);
+ /* start new sublist */
+ curr_dst = dst;
+ }
+ }
+ /* dispatch final sublist */
+ ip_sublist_rcv_finish(head);
+}
+
+static void ip_sublist_rcv(struct list_head *head, struct net_device *dev,
+ struct net *net)
+{
NF_HOOK_LIST(NFPROTO_IPV4, NF_INET_PRE_ROUTING, net, NULL,
head, dev, NULL, ip_rcv_finish);
- list_for_each_entry_safe(skb, next, head, list)
- ip_rcv_finish(net, NULL, skb);
+ ip_list_rcv_finish(net, NULL, head);
}
/* Receive a list of IP packets */
