4 files changed, 116 insertions, 9 deletions

diff --git a/net/sctp/input.c b/net/sctp/input.c
index 2a570184e5a9..ea2192444ce6 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -440,11 +440,25 @@ void sctp_icmp_proto_unreachable(struct sock *sk,
 {
 	SCTP_DEBUG_PRINTK("%s\n",  __func__);
 
-	sctp_do_sm(SCTP_EVENT_T_OTHER,
-		   SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
-		   asoc->state, asoc->ep, asoc, t,
-		   GFP_ATOMIC);
+	if (sock_owned_by_user(sk)) {
+		if (timer_pending(&t->proto_unreach_timer))
+			return;
+		else {
+			if (!mod_timer(&t->proto_unreach_timer,
+						jiffies + (HZ/20)))
+				sctp_association_hold(asoc);
+		}
+			
+	} else {
+		if (timer_pending(&t->proto_unreach_timer) &&
+		    del_timer(&t->proto_unreach_timer))
+			sctp_association_put(asoc);
 
+		sctp_do_sm(SCTP_EVENT_T_OTHER,
+			   SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
+			   asoc->state, asoc->ep, asoc, t,
+			   GFP_ATOMIC);
+	}
 }
 
 /* Common lookup code for icmp/icmpv6 error handler. */
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 0fd5b4c88358..30c1767186b8 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -108,7 +108,7 @@ static const struct sctp_paramhdr prsctp_param = {
 	cpu_to_be16(sizeof(struct sctp_paramhdr)),
 };
 
-/* A helper to initialize to initialize an op error inside a
+/* A helper to initialize an op error inside a
  * provided chunk, as most cause codes will be embedded inside an
  * abort chunk.
  */
@@ -125,6 +125,29 @@ void  sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
 	chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
 }
 
+/* A helper to initialize an op error inside a
+ * provided chunk, as most cause codes will be embedded inside an
+ * abort chunk.  Differs from sctp_init_cause in that it won't oops
+ * if there isn't enough space in the op error chunk
+ */
+int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
+		      size_t paylen)
+{
+	sctp_errhdr_t err;
+	__u16 len;
+
+	/* Cause code constants are now defined in network order.  */
+	err.cause = cause_code;
+	len = sizeof(sctp_errhdr_t) + paylen;
+	err.length  = htons(len);
+
+	if (skb_tailroom(chunk->skb) >  len)
+		return -ENOSPC;
+	chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk,
+						     sizeof(sctp_errhdr_t),
+						     &err);
+	return 0;
+}
 /* 3.3.2 Initiation (INIT) (1)
  *
  * This chunk is used to initiate a SCTP association between two
@@ -1132,6 +1155,24 @@ nodata:
 	return retval;
 }
 
+/* Create an Operation Error chunk of a fixed size,
+ * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT)
+ * This is a helper function to allocate an error chunk for
+ * for those invalid parameter codes in which we may not want
+ * to report all the errors, if the incomming chunk is large
+ */
+static inline struct sctp_chunk *sctp_make_op_error_fixed(
+	const struct sctp_association *asoc,
+	const struct sctp_chunk *chunk)
+{
+	size_t size = asoc ? asoc->pathmtu : 0;
+
+	if (!size)
+		size = SCTP_DEFAULT_MAXSEGMENT;
+
+	return sctp_make_op_error_space(asoc, chunk, size);
+}
+
 /* Create an Operation Error chunk.  */
 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
 				 const struct sctp_chunk *chunk,
@@ -1374,6 +1415,18 @@ void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
 	return target;
 }
 
+/* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
+ * space in the chunk
+ */
+void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
+			     int len, const void *data)
+{
+	if (skb_tailroom(chunk->skb) > len)
+		return sctp_addto_chunk(chunk, len, data);
+	else
+		return NULL;
+}
+
 /* Append bytes from user space to the end of a chunk.  Will panic if
  * chunk is not big enough.
  * Returns a kernel err value.
@@ -1977,13 +2030,12 @@ static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc,
 		 * returning multiple unknown parameters.
 		 */
 		if (NULL == *errp)
-			*errp = sctp_make_op_error_space(asoc, chunk,
-					ntohs(chunk->chunk_hdr->length));
+			*errp = sctp_make_op_error_fixed(asoc, chunk);
 
 		if (*errp) {
-			sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
+			sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM,
 					WORD_ROUND(ntohs(param.p->length)));
-			sctp_addto_chunk(*errp,
+			sctp_addto_chunk_fixed(*errp,
 					WORD_ROUND(ntohs(param.p->length)),
 					param.v);
 		} else {
diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c
index d5ae450b6f02..eb1f42f45fdd 100644
--- a/net/sctp/sm_sideeffect.c
+++ b/net/sctp/sm_sideeffect.c
@@ -397,6 +397,41 @@ out_unlock:
 	sctp_transport_put(transport);
 }
 
+/* Handle the timeout of the ICMP protocol unreachable timer.  Trigger
+ * the correct state machine transition that will close the association.
+ */
+void sctp_generate_proto_unreach_event(unsigned long data)
+{
+	struct sctp_transport *transport = (struct sctp_transport *) data;
+	struct sctp_association *asoc = transport->asoc;
+	
+	sctp_bh_lock_sock(asoc->base.sk);
+	if (sock_owned_by_user(asoc->base.sk)) {
+		SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
+
+		/* Try again later.  */
+		if (!mod_timer(&transport->proto_unreach_timer,
+				jiffies + (HZ/20)))
+			sctp_association_hold(asoc);
+		goto out_unlock;
+	}
+
+	/* Is this structure just waiting around for us to actually
+	 * get destroyed?
+	 */
+	if (asoc->base.dead)
+		goto out_unlock;
+
+	sctp_do_sm(SCTP_EVENT_T_OTHER,
+		   SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
+		   asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
+
+out_unlock:
+	sctp_bh_unlock_sock(asoc->base.sk);
+	sctp_association_put(asoc);
+}
+
+
 /* Inject a SACK Timeout event into the state machine.  */
 static void sctp_generate_sack_event(unsigned long data)
 {
diff --git a/net/sctp/transport.c b/net/sctp/transport.c
index be4d63d5a5cc..165d54e07fcd 100644
--- a/net/sctp/transport.c
+++ b/net/sctp/transport.c
@@ -108,6 +108,8 @@ static struct sctp_transport *sctp_transport_init(struct sctp_transport *peer,
 			(unsigned long)peer);
 	setup_timer(&peer->hb_timer, sctp_generate_heartbeat_event,
 			(unsigned long)peer);
+	setup_timer(&peer->proto_unreach_timer,
+		    sctp_generate_proto_unreach_event, (unsigned long)peer);
 
 	/* Initialize the 64-bit random nonce sent with heartbeat. */
 	get_random_bytes(&peer->hb_nonce, sizeof(peer->hb_nonce));
@@ -171,6 +173,10 @@ void sctp_transport_free(struct sctp_transport *transport)
 	    del_timer(&transport->T3_rtx_timer))
 		sctp_transport_put(transport);
 
+	/* Delete the ICMP proto unreachable timer if it's active. */
+	if (timer_pending(&transport->proto_unreach_timer) &&
+	    del_timer(&transport->proto_unreach_timer))
+		sctp_association_put(transport->asoc);
 
 	sctp_transport_put(transport);
 }