ipv4: fix error handling in icmp_protocol.

Now we handle icmp errors in each transport protocol's err_handler,
for icmp protocols, that is ping_err. Since this handler only care
of those icmp errors triggered by echo request, errors triggered
by echo reply(which sent by kernel) are sliently ignored.

So wrap ping_err() with icmp_err() to deal with those icmp errors.

Signed-off-by: Li Wei <lw@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 25 insertions, 1 deletions

diff --git a/include/net/icmp.h b/include/net/icmp.h
index 9ac2524d1402..081439fd070e 100644
--- a/include/net/icmp.h
+++ b/include/net/icmp.h
@@ -41,6 +41,7 @@ struct net;
 
 extern void     icmp_send(struct sk_buff *skb_in,  int type, int code, __be32 info);
 extern int      icmp_rcv(struct sk_buff *skb);
+extern void     icmp_err(struct sk_buff *, u32 info);
 extern int      icmp_init(void);
 extern void     icmp_out_count(struct net *net, unsigned char type);
 
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 9cbcb94a4c6d..15847e19b7dd 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1577,7 +1577,7 @@ static const struct net_offload udp_offload = {
 
 static const struct net_protocol icmp_protocol = {
         .handler =      icmp_rcv,
-        .err_handler =  ping_err,
+        .err_handler =  icmp_err,
         .no_policy =    1,
         .netns_ok =     1,
 };
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 17ff9fd7cdda..3ac5dff79627 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -934,6 +934,29 @@ error:
         goto drop;
 }
 
+void icmp_err(struct sk_buff *skb, u32 info)
+{
+        struct iphdr *iph = (struct iphdr *)skb->data;
+        struct icmphdr *icmph = (struct icmphdr *)(skb->data+(iph->ihl<<2));
+        int type = icmp_hdr(skb)->type;
+        int code = icmp_hdr(skb)->code;
+        struct net *net = dev_net(skb->dev);
+
+        /*
+         * Use ping_err to handle all icmp errors except those
+         * triggered by ICMP_ECHOREPLY which sent from kernel.
+         */
+        if (icmph->type != ICMP_ECHOREPLY) {
+                ping_err(skb, info);
+                return;
+        }
+
+        if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
+                ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ICMP, 0);
+        else if (type == ICMP_REDIRECT)
+                ipv4_redirect(skb, net, 0, 0, IPPROTO_ICMP, 0);
+}
+
 /*
  *      This table is the definition of how we handle ICMP.
  */