sctp: extract sctp_v4_err_handle function from sctp_v4_err

This patch is to extract sctp_v4_err_handle() from sctp_v4_err() to
only handle the icmp err after the sock lookup, and it also makes
the code clearer.

sctp_v4_err_handle() will be used in sctp over udp's err handling
in the following patch.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sctp/input.c b/net/sctp/input.c
index 9ffdbd6526e95052c88647e5ab1000ba78280dee..83d58d42ea455765f0a435b86fd2552291c7ee0f 100644 (file)
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -556,6 +556,49 @@ void sctp_err_finish(struct sock *sk, struct sctp_transport *t)
        sctp_transport_put(t);
 }
 
+static void sctp_v4_err_handle(struct sctp_transport *t, struct sk_buff *skb,
+                              __u8 type, __u8 code, __u32 info)
+{
+       struct sctp_association *asoc = t->asoc;
+       struct sock *sk = asoc->base.sk;
+       int err = 0;
+
+       switch (type) {
+       case ICMP_PARAMETERPROB:
+               err = EPROTO;
+               break;
+       case ICMP_DEST_UNREACH:
+               if (code > NR_ICMP_UNREACH)
+                       return;
+               if (code == ICMP_FRAG_NEEDED) {
+                       sctp_icmp_frag_needed(sk, asoc, t, SCTP_TRUNC4(info));
+                       return;
+               }
+               if (code == ICMP_PROT_UNREACH) {
+                       sctp_icmp_proto_unreachable(sk, asoc, t);
+                       return;
+               }
+               err = icmp_err_convert[code].errno;
+               break;
+       case ICMP_TIME_EXCEEDED:
+               if (code == ICMP_EXC_FRAGTIME)
+                       return;
+
+               err = EHOSTUNREACH;
+               break;
+       case ICMP_REDIRECT:
+               sctp_icmp_redirect(sk, t, skb);
+       default:
+               return;
+       }
+       if (!sock_owned_by_user(sk) && inet_sk(sk)->recverr) {
+               sk->sk_err = err;
+               sk->sk_error_report(sk);
+       } else {  /* Only an error on timeout */
+               sk->sk_err_soft = err;
+       }
+}
+
 /*
  * This routine is called by the ICMP module when it gets some
  * sort of error condition.  If err < 0 then the socket should
@@ -574,22 +617,19 @@ void sctp_err_finish(struct sock *sk, struct sctp_transport *t)
 int sctp_v4_err(struct sk_buff *skb, __u32 info)
 {
        const struct iphdr *iph = (const struct iphdr *)skb->data;
-       const int ihlen = iph->ihl * 4;
        const int type = icmp_hdr(skb)->type;
        const int code = icmp_hdr(skb)->code;
-       struct sock *sk;
-       struct sctp_association *asoc = NULL;
+       struct net *net = dev_net(skb->dev);
        struct sctp_transport *transport;
-       struct inet_sock *inet;
+       struct sctp_association *asoc;
        __u16 saveip, savesctp;
-       int err;
-       struct net *net = dev_net(skb->dev);
+       struct sock *sk;
 
        /* Fix up skb to look at the embedded net header. */
        saveip = skb->network_header;
        savesctp = skb->transport_header;
        skb_reset_network_header(skb);
-       skb_set_transport_header(skb, ihlen);
+       skb_set_transport_header(skb, iph->ihl * 4);
        sk = sctp_err_lookup(net, AF_INET, skb, sctp_hdr(skb), &asoc, &transport);
        /* Put back, the original values. */
        skb->network_header = saveip;
@@ -598,58 +638,10 @@ int sctp_v4_err(struct sk_buff *skb, __u32 info)
                __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
                return -ENOENT;
        }
-       /* Warning:  The sock lock is held.  Remember to call
-        * sctp_err_finish!
-        */
 
-       switch (type) {
-       case ICMP_PARAMETERPROB:
-               err = EPROTO;
-               break;
-       case ICMP_DEST_UNREACH:
-               if (code > NR_ICMP_UNREACH)
-                       goto out_unlock;
-
-               /* PMTU discovery (RFC1191) */
-               if (ICMP_FRAG_NEEDED == code) {
-                       sctp_icmp_frag_needed(sk, asoc, transport,
-                                             SCTP_TRUNC4(info));
-                       goto out_unlock;
-               } else {
-                       if (ICMP_PROT_UNREACH == code) {
-                               sctp_icmp_proto_unreachable(sk, asoc,
-                                                           transport);
-                               goto out_unlock;
-                       }
-               }
-               err = icmp_err_convert[code].errno;
-               break;
-       case ICMP_TIME_EXCEEDED:
-               /* Ignore any time exceeded errors due to fragment reassembly
-                * timeouts.
-                */
-               if (ICMP_EXC_FRAGTIME == code)
-                       goto out_unlock;
-
-               err = EHOSTUNREACH;
-               break;
-       case ICMP_REDIRECT:
-               sctp_icmp_redirect(sk, transport, skb);
-               /* Fall through to out_unlock. */
-       default:
-               goto out_unlock;
-       }
-
-       inet = inet_sk(sk);
-       if (!sock_owned_by_user(sk) && inet->recverr) {
-               sk->sk_err = err;
-               sk->sk_error_report(sk);
-       } else {  /* Only an error on timeout */
-               sk->sk_err_soft = err;
-       }
-
-out_unlock:
+       sctp_v4_err_handle(transport, skb, type, code, info);
        sctp_err_finish(sk, transport);
+
        return 0;
 }