1 files changed, 55 insertions, 10 deletions

diff --git a/net/sctp/input.c b/net/sctp/input.c
index f9a0c9276e3b..86503e7fa21e 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -911,15 +911,6 @@ static struct sctp_association *__sctp_rcv_init_lookup(struct sk_buff *skb,
 
         ch = (sctp_chunkhdr_t *) skb->data;
 
-        /* If this is INIT/INIT-ACK look inside the chunk too. */
-        switch (ch->type) {
-        case SCTP_CID_INIT:
-        case SCTP_CID_INIT_ACK:
-                break;
-        default:
-                return NULL;
-        }
-
         /* The code below will attempt to walk the chunk and extract
          * parameter information.  Before we do that, we need to verify
          * that the chunk length doesn't cause overflow.  Otherwise, we'll
@@ -964,6 +955,60 @@ static struct sctp_association *__sctp_rcv_init_lookup(struct sk_buff *skb,
         return NULL;
 }
 
+/* SCTP-AUTH, Section 6.3:
+*    If the receiver does not find a STCB for a packet containing an AUTH
+*    chunk as the first chunk and not a COOKIE-ECHO chunk as the second
+*    chunk, it MUST use the chunks after the AUTH chunk to look up an existing
+*    association.
+*
+* This means that any chunks that can help us identify the association need
+* to be looked at to find this assocation.
+*
+* TODO: The only chunk currently defined that can do that is ASCONF, but we
+* don't support that functionality yet.
+*/
+static struct sctp_association *__sctp_rcv_auth_lookup(struct sk_buff *skb,
+                                      const union sctp_addr *paddr,
+                                      const union sctp_addr *laddr,
+                                      struct sctp_transport **transportp)
+{
+        /* XXX - walk through the chunks looking for something that can
+         * help us find the association.  INIT, and INIT-ACK are not permitted.
+         * That leaves ASCONF, but we don't support that yet.
+         */
+        return NULL;
+}
+
+/*
+ * There are circumstances when we need to look inside the SCTP packet
+ * for information to help us find the association.   Examples
+ * include looking inside of INIT/INIT-ACK chunks or after the AUTH
+ * chunks.
+ */
+static struct sctp_association *__sctp_rcv_lookup_harder(struct sk_buff *skb,
+                                      const union sctp_addr *paddr,
+                                      const union sctp_addr *laddr,
+                                      struct sctp_transport **transportp)
+{
+        sctp_chunkhdr_t *ch;
+
+        ch = (sctp_chunkhdr_t *) skb->data;
+
+        /* If this is INIT/INIT-ACK look inside the chunk too. */
+        switch (ch->type) {
+        case SCTP_CID_INIT:
+        case SCTP_CID_INIT_ACK:
+                return __sctp_rcv_init_lookup(skb, laddr, transportp);
+                break;
+
+        case SCTP_CID_AUTH:
+                return __sctp_rcv_auth_lookup(skb, paddr, laddr, transportp);
+                break;
+        }
+
+        return NULL;
+}
+
 /* Lookup an association for an inbound skb. */
 static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb,
                                       const union sctp_addr *paddr,
@@ -979,7 +1024,7 @@ static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb,
          * parameters within the INIT or INIT-ACK.
          */
         if (!asoc)
-                asoc = __sctp_rcv_init_lookup(skb, laddr, transportp);
+                asoc = __sctp_rcv_lookup_harder(skb, paddr, laddr, transportp);
 
         return asoc;
 }