PERFORCE change 168295 for review

[Andre Oppermann]

http://perforce.freebsd.org/chv.cgi?CH=168295

Change 168295 by andre at andre_t61 on 2009/09/07 19:43:55

	Update TODO list.
	Fix spelling errors and improve comments.
	Save DSACK start and end values.
	Make use of TCP reassembly queue flush timeout.
	tcp_reass_merge gives back overlap size for DSACK.

Affected files ...

.. //depot/projects/tcp_reass/netinet/tcp_reass.c#54 edit

Differences ...

==== //depot/projects/tcp_reass/netinet/tcp_reass.c#54 (text+ko) ====

@@ -95,9 +95,12 @@
  * TODO:
  * - Improve comments and annotate RFC references.
  * - Style improvements.
- * - Acticate timeout on first insert.
+ * - Activate timeout on first insert.
  * - Partial D-SACK support.
+ * - D-SACK when only one SACK slot available?
+ * - Direct pointer to last block in RB-tree.
  * - Return flags should be same minus FIN.
+ * - Remove T/TCP gonk.
  * - Lots of testing.
  */
 
@@ -258,7 +261,7 @@
 
 /*
  * Remove a single block from the reassembly queue
- * and free all its mbufs, if any.
+ * and free all of its mbufs, if any.
  */
 static void
 tcp_reass_free(struct tcpcb *tp, struct tcp_reass_block *trb)
@@ -355,7 +358,8 @@
 
 	/*
 	 * Store TCP header information in local variables as
-	 * we may lose access to it after mbuf compacting.
+	 * we may lose access to it after header dropping and
+	 * mbuf compacting.
 	 */
 	thflags = th->th_flags;
 	th_seq = th->th_seq;
@@ -490,6 +494,8 @@
 		 */
 		if ((len = SEQ_DELTA(trbs.trb_seqs, trbs.trb_seqe)) > 0) {
 			tp->rcv_reass_size -= len;
+			tp->rcv_reass_dsack.start = trbs.trb_seqs;
+			tp->rcv_reass_dsack.end = trbs.trb_seqe;
 			TCPSTAT_INC(tcps_rcvpartduppack);
 			TCPSTAT_ADD(tcps_rcvpartdupbyte, len);
 		}
@@ -521,8 +527,11 @@
 		LIST_INSERT_HEAD(&tp->rcv_reass_sack, trb, trb_sack);
 		tp->rcv_reass_size += SEQ_DELTA(trbs.trb_seqs, trbs.trb_seqe);
 		tp->rcv_reass_blocks++;
-		if (RB_EMPTY(&tp->rcv_reass))
+		if (RB_EMPTY(&tp->rcv_reass)) {
+			KASSERT(tcp_timer_active(tp, TT_REASS) == 0,
+			    ("%s: ", __func__));
 			tcp_timer_activate(tp, TT_REASS, tcp_reass_timeout);
+		}
 		TCPSTAT_INC(tcps_reass_blocks);
 	} else {
 		/* Memory allocation failure. */
@@ -585,7 +594,7 @@
 	 */
 	if (tcp_reass_timeout && !RB_EMPTY(&tp->rcv_reass))
 		tcp_timer_activate(tp, TT_REASS, tcp_reass_timeout);
-	else
+	else if (tcp_timer_active(tp, TT_REASS))
 		tcp_timer_activate(tp, TT_REASS, 0);
 
 	ND6_HINT(tp);
@@ -597,7 +606,7 @@
 }
 
 /*
- * Trim a SACK block.
+ * Trim a reassembly block.
  * A positive value is from head, negative from tail.
  */
 static void
@@ -630,6 +639,7 @@
 tcp_reass_merge(struct tcp_reass_block *trb, struct tcp_reass_block *trbn)
 {
 	int i;
+	tcp_seq s;
 
 	KASSERT(trb != NULL && trbn != NULL,
 	    ("%s: incomplete input", __func__));
@@ -644,6 +654,7 @@
 	    SEQ_GEQ(trbn->trb_seqe, trb->trb_seqe)) {
 
 		i = SEQ_DELTA(trb->trb_seqs, trbn->trb_seqe);
+		s = trb->trb_seqs;
 
 		m_freem(trb->trb_m);
 		trb->trb_seqs = trbn->trb_seqs;
@@ -658,6 +669,7 @@
 		if ((i = SEQ_DELTA(trb->trb_seqs, trbn->trb_seqe)) > 0)
 			tcp_reass_trim(trbn, -i);
 
+		s = trb->trb_seqs;
 		trb->trb_seqs = trbn->trb_seqs;
 		trbn->trb_mt->m_next = trb->trb_m;
 		trb->trb_m = trbn->trb_m;
@@ -672,6 +684,7 @@
 		if ((i = SEQ_DELTA(trb->trb_seqe, trbn->trb_seqs)) > 0)
 			tcp_reass_trim(trbn, i);
 
+		s = trb->trb_seqe;
 		trb->trb_seqe = trbn->trb_seqe;
 		trb->trb_mt->m_next = trbn->trb_m;
 
@@ -684,8 +697,8 @@
 	} else
 		return (NULL);
 
-	trbn->trb_seqs = 0;
-	trbn->trb_seqe = i;
+	trbn->trb_seqs = s;
+	trbn->trb_seqe = trbn->trb_seqs + i;
 	trbn->trb_m = NULL;
 	trbn->trb_mt = NULL;
 	return (trbn);