diff options
| -rw-r--r-- | net/sctp/output.c | 142 |
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; } |
