Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/x86

[firefly-linux-kernel-4.4.55.git] / net / sctp / input.c

diff --git a/net/sctp/input.c b/net/sctp/input.c
index 47e56017f4ce887716e0dee8a4ba87d3ece37ac9..86503e7fa21e7fa55bcb54f1762dc5840c11cdfe 100644 (file)
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -622,6 +622,14 @@ static int sctp_rcv_ootb(struct sk_buff *skb)
                if (SCTP_CID_SHUTDOWN_COMPLETE == ch->type)
                        goto discard;
 
+               /* RFC 4460, 2.11.2
+                * This will discard packets with INIT chunk bundled as
+                * subsequent chunks in the packet.  When INIT is first,
+                * the normal INIT processing will discard the chunk.
+                */
+               if (SCTP_CID_INIT == ch->type && (void *)ch != skb->data)
+                       goto discard;
+
                /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
                 * or a COOKIE ACK the SCTP Packet should be silently
                 * discarded.
@@ -903,15 +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
@@ -956,6 +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,
@@ -971,7 +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;
 }