[NETFILTER]: nf_conntrack_sctp: consolidate sctp_packet() error paths

Consolidate error paths and use proper symbolic return value instead
of magic values.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 20 insertions, 26 deletions

diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c
index fdabef56bf17..e52b6b95b304 100644
--- a/net/netfilter/nf_conntrack_proto_sctp.c
+++ b/net/netfilter/nf_conntrack_proto_sctp.c
@@ -291,7 +291,7 @@ static int new_state(enum ip_conntrack_dir dir,
         return sctp_conntracks[dir][i][cur_state];
 }
 
-/* Returns verdict for packet, or -1 for invalid. */
+/* Returns verdict for packet, or -NF_ACCEPT for invalid. */
 static int sctp_packet(struct nf_conn *ct,
                        const struct sk_buff *skb,
                        unsigned int dataoff,
@@ -308,10 +308,10 @@ static int sctp_packet(struct nf_conn *ct,
 
         sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
         if (sh == NULL)
-                return -1;
+                goto out;
 
         if (do_basic_checks(ct, skb, dataoff, map) != 0)
-                return -1;
+                goto out;
 
         /* Check the verification tag (Sec 8.5) */
         if (!test_bit(SCTP_CID_INIT, map) &&
@@ -321,7 +321,7 @@ static int sctp_packet(struct nf_conn *ct,
             !test_bit(SCTP_CID_SHUTDOWN_ACK, map) &&
             sh->vtag != ct->proto.sctp.vtag[dir]) {
                 pr_debug("Verification tag check failed\n");
-                return -1;
+                goto out;
         }
 
         oldsctpstate = newconntrack = SCTP_CONNTRACK_MAX;
@@ -331,31 +331,23 @@ static int sctp_packet(struct nf_conn *ct,
                 /* Special cases of Verification tag check (Sec 8.5.1) */
                 if (sch->type == SCTP_CID_INIT) {
                         /* Sec 8.5.1 (A) */
-                        if (sh->vtag != 0) {
-                                write_unlock_bh(&sctp_lock);
-                                return -1;
-                        }
+                        if (sh->vtag != 0)
+                                goto out_unlock;
                 } else if (sch->type == SCTP_CID_ABORT) {
                         /* Sec 8.5.1 (B) */
                         if (sh->vtag != ct->proto.sctp.vtag[dir] &&
-                            sh->vtag != ct->proto.sctp.vtag[!dir]) {
-                                write_unlock_bh(&sctp_lock);
-                                return -1;
-                        }
+                            sh->vtag != ct->proto.sctp.vtag[!dir])
+                                goto out_unlock;
                 } else if (sch->type == SCTP_CID_SHUTDOWN_COMPLETE) {
                         /* Sec 8.5.1 (C) */
                         if (sh->vtag != ct->proto.sctp.vtag[dir] &&
                             sh->vtag != ct->proto.sctp.vtag[!dir] &&
-                            (sch->flags & 1)) {
-                                write_unlock_bh(&sctp_lock);
-                                return -1;
-                        }
+                            (sch->flags & 1))
+                                goto out_unlock;
                 } else if (sch->type == SCTP_CID_COOKIE_ECHO) {
                         /* Sec 8.5.1 (D) */
-                        if (sh->vtag != ct->proto.sctp.vtag[dir]) {
-                                write_unlock_bh(&sctp_lock);
-                                return -1;
-                        }
+                        if (sh->vtag != ct->proto.sctp.vtag[dir])
+                                goto out_unlock;
                 }
 
                 oldsctpstate = ct->proto.sctp.state;
@@ -366,8 +358,7 @@ static int sctp_packet(struct nf_conn *ct,
                         pr_debug("nf_conntrack_sctp: Invalid dir=%i ctype=%u "
                                  "conntrack=%u\n",
                                  dir, sch->type, oldsctpstate);
-                        write_unlock_bh(&sctp_lock);
-                        return -1;
+                        goto out_unlock;
                 }
 
                 /* If it is an INIT or an INIT ACK note down the vtag */
@@ -377,10 +368,8 @@ static int sctp_packet(struct nf_conn *ct,
 
                         ih = skb_header_pointer(skb, offset + sizeof(sctp_chunkhdr_t),
                                                 sizeof(_inithdr), &_inithdr);
-                        if (ih == NULL) {
-                                write_unlock_bh(&sctp_lock);
-                                return -1;
-                        }
+                        if (ih == NULL)
+                                goto out_unlock;
                         pr_debug("Setting vtag %x for dir %d\n",
                                  ih->init_tag, !dir);
                         ct->proto.sctp.vtag[!dir] = ih->init_tag;
@@ -403,6 +392,11 @@ static int sctp_packet(struct nf_conn *ct,
         }
 
         return NF_ACCEPT;
+
+out_unlock:
+        write_unlock_bh(&sctp_lock);
+out:
+        return -NF_ACCEPT;
 }
 
 /* Called when a new connection for this protocol found. */