1 files changed, 85 insertions, 57 deletions

diff --git a/net/sctp/output.c b/net/sctp/output.c
index 94c110d..e25e2e2 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -61,8 +61,13 @@
 #include <net/sctp/checksum.h>
 
 /* Forward declarations for private helpers. */
-static sctp_xmit_t sctp_packet_append_data(struct sctp_packet *packet,
+static sctp_xmit_t sctp_packet_can_append_data(struct sctp_packet *packet,
 					   struct sctp_chunk *chunk);
+static void sctp_packet_append_data(struct sctp_packet *packet,
+					   struct sctp_chunk *chunk);
+static sctp_xmit_t sctp_packet_will_fit(struct sctp_packet *packet,
+					struct sctp_chunk *chunk,
+					u16 chunk_len);
 
 /* Config a packet.
  * This appears to be a followup set of initializations.
@@ -262,13 +267,20 @@ sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *packet,
 {
 	sctp_xmit_t retval = SCTP_XMIT_OK;
 	__u16 chunk_len = WORD_ROUND(ntohs(chunk->chunk_hdr->length));
-	size_t psize;
-	size_t pmtu;
-	int too_big;
 
 	SCTP_DEBUG_PRINTK("%s: packet:%p chunk:%p\n", __func__, packet,
 			  chunk);
 
+	/* Data chunks are special.  Before seeing what else we can
+	 * bundle into this packet, check to see if we are allowed to
+	 * send this DATA.
+	 */
+	if (sctp_chunk_is_data(chunk)) {
+		retval = sctp_packet_can_append_data(packet, chunk);
+		if (retval != SCTP_XMIT_OK)
+			goto finish;
+	}
+
 	/* Try to bundle AUTH chunk */
 	retval = sctp_packet_bundle_auth(packet, chunk);
 	if (retval != SCTP_XMIT_OK)
@@ -279,51 +291,16 @@ sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *packet,
 	if (retval != SCTP_XMIT_OK)
 		goto finish;
 
-	psize = packet->size;
-	pmtu  = ((packet->transport->asoc) ?
-		 (packet->transport->asoc->pathmtu) :
-		 (packet->transport->pathmtu));
-
-	too_big = (psize + chunk_len > pmtu);
-
-	/* Decide if we need to fragment or resubmit later. */
-	if (too_big) {
-		/* It's OK to fragmet at IP level if any one of the following
-		 * is true:
-		 * 	1. The packet is empty (meaning this chunk is greater
-		 * 	   the MTU)
-		 * 	2. The chunk we are adding is a control chunk
-		 * 	3. The packet doesn't have any data in it yet and data
-		 * 	requires authentication.
-		 */
-		if (sctp_packet_empty(packet) || !sctp_chunk_is_data(chunk) ||
-		    (!packet->has_data && chunk->auth)) {
-			/* We no longer do re-fragmentation.
-			 * Just fragment at the IP layer, if we
-			 * actually hit this condition
-			 */
-			packet->ipfragok = 1;
-			goto append;
-
-		} else {
-			retval = SCTP_XMIT_PMTU_FULL;
-			goto finish;
-		}
-	}
-
-append:
-	/* We believe that this chunk is OK to add to the packet (as
-	 * long as we have the cwnd for it).
-	 */
+	/* Check to see if this chunk will fit into the packet */
+	retval = sctp_packet_will_fit(packet, chunk, chunk_len);
+	if (retval != SCTP_XMIT_OK)
+		goto finish;
 
-	/* DATA is a special case since we must examine both rwnd and cwnd
-	 * before we send DATA.
-	 */
+	/* We believe that this chunk is OK to add to the packet */
 	switch (chunk->chunk_hdr->type) {
 	    case SCTP_CID_DATA:
-		retval = sctp_packet_append_data(packet, chunk);
-		if (SCTP_XMIT_OK != retval)
-			goto finish;
+		/* Account for the data being in the packet */
+		sctp_packet_append_data(packet, chunk);
 		/* Disallow SACK bundling after DATA. */
 		packet->has_sack = 1;
 		/* Disallow AUTH bundling after DATA */
@@ -633,16 +610,15 @@ nomem:
  * 2nd Level Abstractions
  ********************************************************************/
 
-/* This private function handles the specifics of appending DATA chunks.  */
-static sctp_xmit_t sctp_packet_append_data(struct sctp_packet *packet,
+/* This private function check to see if a chunk can be added */
+static sctp_xmit_t sctp_packet_can_append_data(struct sctp_packet *packet,
 					   struct sctp_chunk *chunk)
 {
 	sctp_xmit_t retval = SCTP_XMIT_OK;
-	size_t datasize, rwnd, inflight;
+	size_t datasize, rwnd, inflight, flight_size;
 	struct sctp_transport *transport = packet->transport;
 	__u32 max_burst_bytes;
 	struct sctp_association *asoc = transport->asoc;
-	struct sctp_sock *sp = sctp_sk(asoc->base.sk);
 	struct sctp_outq *q = &asoc->outqueue;
 
 	/* RFC 2960 6.1  Transmission of DATA Chunks
@@ -659,7 +635,8 @@ static sctp_xmit_t sctp_packet_append_data(struct sctp_packet *packet,
 	 */
 
 	rwnd = asoc->peer.rwnd;
-	inflight = asoc->outqueue.outstanding_bytes;
+	inflight = q->outstanding_bytes;
+	flight_size = transport->flight_size;
 
 	datasize = sctp_data_size(chunk);
 
@@ -682,8 +659,8 @@ static sctp_xmit_t sctp_packet_append_data(struct sctp_packet *packet,
 	 *		cwnd = flightsize + Max.Burst * MTU
 	 */
 	max_burst_bytes = asoc->max_burst * asoc->pathmtu;
-	if ((transport->flight_size + max_burst_bytes) < transport->cwnd) {
-		transport->cwnd = transport->flight_size + max_burst_bytes;
+	if ((flight_size + max_burst_bytes) < transport->cwnd) {
+		transport->cwnd = flight_size + max_burst_bytes;
 		SCTP_DEBUG_PRINTK("%s: cwnd limited by max_burst: "
 				  "transport: %p, cwnd: %d, "
 				  "ssthresh: %d, flight_size: %d, "
@@ -708,7 +685,7 @@ static sctp_xmit_t sctp_packet_append_data(struct sctp_packet *packet,
 	 *    ignore the value of cwnd and SHOULD NOT delay retransmission.
 	 */
 	if (chunk->fast_retransmit != SCTP_NEED_FRTX)
-		if (transport->flight_size >= transport->cwnd) {
+		if (flight_size >= transport->cwnd) {
 			retval = SCTP_XMIT_RWND_FULL;
 			goto finish;
 		}
@@ -718,8 +695,8 @@ static sctp_xmit_t sctp_packet_append_data(struct sctp_packet *packet,
 	 * if any previously transmitted data on the connection remains
 	 * unacknowledged.
 	 */
-	if (!sp->nodelay && sctp_packet_empty(packet) &&
-	    q->outstanding_bytes && sctp_state(asoc, ESTABLISHED)) {
+	if (!sctp_sk(asoc->base.sk)->nodelay && sctp_packet_empty(packet) &&
+	    inflight && sctp_state(asoc, ESTABLISHED)) {
 		unsigned len = datasize + q->out_qlen;
 
 		/* Check whether this chunk and all the rest of pending
@@ -732,6 +709,19 @@ static sctp_xmit_t sctp_packet_append_data(struct sctp_packet *packet,
 		}
 	}
 
+finish:
+	return retval;
+}
+
+/* This private function does management things when adding DATA chunk */
+static void sctp_packet_append_data(struct sctp_packet *packet,
+				struct sctp_chunk *chunk)
+{
+	struct sctp_transport *transport = packet->transport;
+	size_t datasize = sctp_data_size(chunk);
+	struct sctp_association *asoc = transport->asoc;
+	u32 rwnd = asoc->peer.rwnd;
+
 	/* Keep track of how many bytes are in flight over this transport. */
 	transport->flight_size += datasize;
 
@@ -754,7 +744,45 @@ static sctp_xmit_t sctp_packet_append_data(struct sctp_packet *packet,
 	/* Has been accepted for transmission. */
 	if (!asoc->peer.prsctp_capable)
 		chunk->msg->can_abandon = 0;
+}
+
+static sctp_xmit_t sctp_packet_will_fit(struct sctp_packet *packet,
+					struct sctp_chunk *chunk,
+					u16 chunk_len)
+{
+	size_t psize;
+	size_t pmtu;
+	int too_big;
+	sctp_xmit_t retval = SCTP_XMIT_OK;
+
+	psize = packet->size;
+	pmtu  = ((packet->transport->asoc) ?
+		(packet->transport->asoc->pathmtu) :
+		(packet->transport->pathmtu));
+
+	too_big = (psize + chunk_len > pmtu);
+
+	/* Decide if we need to fragment or resubmit later. */
+	if (too_big) {
+		/* It's OK to fragmet at IP level if any one of the following
+		 * is true:
+		 * 	1. The packet is empty (meaning this chunk is greater
+		 * 	   the MTU)
+		 * 	2. The chunk we are adding is a control chunk
+		 * 	3. The packet doesn't have any data in it yet and data
+		 * 	requires authentication.
+		 */
+		if (sctp_packet_empty(packet) || !sctp_chunk_is_data(chunk) ||
+		    (!packet->has_data && chunk->auth)) {
+			/* We no longer do re-fragmentation.
+			 * Just fragment at the IP layer, if we
+			 * actually hit this condition
+			 */
+			packet->ipfragok = 1;
+		} else {
+			retval = SCTP_XMIT_PMTU_FULL;
+		}
+	}
 
-finish:
 	return retval;
 }