Two inter-related bugs.

- If we send EXACTLY the size left in the send buffer
    and then send again, we end up with exactly 0 bytes and
    don't hit the pre-block code to wait for more space.
  - If we fall into the loop with our max_len == 0 (the bug
    above) we then call in to copy out the data, setup the length
    of the waiting to transmit data to 0 and call the mbuf copy routine
    which 0 indicates copy all the data to the mbuf chain.. which it
    does. This then leaves a "stuck" message on the stream queue with
    its size exactly 0 bytes but all the data there and thus nothing
    left in the uio structure. We then reach a stuck forever state
    never being able to send data.
This commit is contained in:
Randall Stewart 2008-10-27 14:01:23 +00:00
parent a4c651183e
commit 35e4161b1f

View File

@ -11682,7 +11682,12 @@ sctp_copy_it_in(struct sctp_tcb *stcb,
sp->put_last_out = 0;
resv_in_first = sizeof(struct sctp_data_chunk);
sp->data = sp->tail_mbuf = NULL;
if (sp->length == 0) {
*error = 0;
goto skip_copy;
}
*error = sctp_copy_one(sp, uio, resv_in_first);
skip_copy:
if (*error) {
sctp_free_a_strmoq(stcb, sp);
sp = NULL;
@ -12443,7 +12448,8 @@ sctp_lower_sosend(struct socket *so,
goto skip_preblock;
}
if (((max_len <= local_add_more) &&
(SCTP_SB_LIMIT_SND(so) > local_add_more)) ||
(SCTP_SB_LIMIT_SND(so) >= local_add_more)) ||
(max_len == 0) ||
((stcb->asoc.chunks_on_out_queue + stcb->asoc.stream_queue_cnt) >= SCTP_BASE_SYSCTL(sctp_max_chunks_on_queue))) { /* if */
/* No room right now ! */
SOCKBUF_LOCK(&so->so_snd);
@ -13058,7 +13064,7 @@ sctp_lower_sosend(struct socket *so,
(void)sctp_med_chunk_output(inp, stcb, &stcb->asoc, &num_out,
&reason, 1, &cwnd_full, 1, &now, &now_filled, frag_point, SCTP_SO_LOCKED);
}
SCTPDBG(SCTP_DEBUG_OUTPUT1, "USR Send complete qo:%d prw:%d unsent:%d tf:%d cooq:%d toqs:%d err:%d",
SCTPDBG(SCTP_DEBUG_OUTPUT1, "USR Send complete qo:%d prw:%d unsent:%d tf:%d cooq:%d toqs:%d err:%d\n",
queue_only, stcb->asoc.peers_rwnd, un_sent,
stcb->asoc.total_flight, stcb->asoc.chunks_on_out_queue,
stcb->asoc.total_output_queue_size, error);