svn commit: r184340 - head/sys/netinet

[Randall Stewart]

Author: rrs
Date: Mon Oct 27 14:49:12 2008
New Revision: 184340
URL: http://svn.freebsd.org/changeset/base/184340

Log:
  More issues with pre-blocking:
   a) Need for EEOR mode to take the min of the socket buffer size and the
      add more threshold, otherwise if you are so silly as to set a send
      buf size less than the add-more you could block forever in eeor mode.
  
   b) We were incorrectly using the sysctl vs the calculated value. This
      causes us to block forever if the addmore theshold is larger than
      then the socket buffer size.

Modified:
  head/sys/netinet/sctp_output.c

Modified: head/sys/netinet/sctp_output.c
==============================================================================
--- head/sys/netinet/sctp_output.c	Mon Oct 27 14:29:49 2008	(r184339)
+++ head/sys/netinet/sctp_output.c	Mon Oct 27 14:49:12 2008	(r184340)
@@ -12435,7 +12435,7 @@ sctp_lower_sosend(struct socket *so,
 		goto out_unlocked;
 	}
 	if (user_marks_eor) {
-		local_add_more = SCTP_BASE_SYSCTL(sctp_add_more_threshold);
+		local_add_more = min(SCTP_SB_LIMIT_SND(so), SCTP_BASE_SYSCTL(sctp_add_more_threshold));
 	} else {
 		/*-
 		 * For non-eeor the whole message must fit in
@@ -12454,9 +12454,15 @@ sctp_lower_sosend(struct socket *so,
 		/* No room right now ! */
 		SOCKBUF_LOCK(&so->so_snd);
 		inqueue_bytes = stcb->asoc.total_output_queue_size - (stcb->asoc.chunks_on_out_queue * sizeof(struct sctp_data_chunk));
-		while ((SCTP_SB_LIMIT_SND(so) < (inqueue_bytes + SCTP_BASE_SYSCTL(sctp_add_more_threshold))) ||
-		    ((stcb->asoc.stream_queue_cnt + stcb->asoc.chunks_on_out_queue) >= SCTP_BASE_SYSCTL(sctp_max_chunks_on_queue) /* while */ )) {
-
+		while ((SCTP_SB_LIMIT_SND(so) < (inqueue_bytes + local_add_more)) ||
+		    ((stcb->asoc.stream_queue_cnt + stcb->asoc.chunks_on_out_queue) >= SCTP_BASE_SYSCTL(sctp_max_chunks_on_queue)) /* while */ ) {
+			SCTPDBG(SCTP_DEBUG_OUTPUT1, "pre_block limit:%d <(inq:%d + %d) || (%d+%d > %d)\n",
+			    SCTP_SB_LIMIT_SND(so),
+			    inqueue_bytes,
+			    local_add_more,
+			    stcb->asoc.stream_queue_cnt,
+			    stcb->asoc.chunks_on_out_queue,
+			    SCTP_BASE_SYSCTL(sctp_max_chunks_on_queue));
 			if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_BLK_LOGGING_ENABLE) {
 				sctp_log_block(SCTP_BLOCK_LOG_INTO_BLKA,
 				    so, asoc, sndlen);