1 files changed, 85 insertions, 57 deletions

diff --git a/net/sctp/output.c b/net/sctp/output.c
index 94c110dcaf1d..e25e2e20b63d 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;
 }