[ospfd] Raise ExchangeDone earlier, avoid often needless round of DD packets
2006-08-03 Paul Jakma <paul.jakma@sun.com>
* ospf_packet.c: (ospf_make_db_desc) Unset the DD More bit
after constructing the packet, if appropriate.
(ospf_db_desc_proc) Speed up Exchange, slave should raise
ExchangeDone earlier, as RFC mandates, by forming its reply
before deciding whether both sides are done, avoids a
needless round of empty DD packet exchanges at the end of
Exchange, hence speeding up ExchangeDone.
(ospf_db_desc) use UNSET_FLAG macro.
diff --git a/ospfd/ChangeLog b/ospfd/ChangeLog
index 094742f..193f0de 100644
--- a/ospfd/ChangeLog
+++ b/ospfd/ChangeLog
@@ -6,6 +6,17 @@
(ospf_lsdb_delete) ditto.
(ospf_lsdb_delete_all) ditto.
+2006-08-03 Paul Jakma <paul.jakma@sun.com>
+
+ * ospf_packet.c: (ospf_make_db_desc) Unset the DD More bit
+ after constructing the packet, if appropriate.
+ (ospf_db_desc_proc) Speed up Exchange, slave should raise
+ ExchangeDone earlier, as RFC mandates, by forming its reply
+ before deciding whether both sides are done, avoids a
+ needless round of empty DD packet exchanges at the end of
+ Exchange, hence speeding up ExchangeDone.
+ (ospf_db_desc) use UNSET_FLAG macro.
+
2006-07-27 Andrew J. Schorr <ajschorr@alumni.princeton.edu>
* ospfd.c: (ospf_router_id_update) Fix and document the algorithm for
diff --git a/ospfd/ospf_packet.c b/ospfd/ospf_packet.c
index 44dca18..74caaa7 100644
--- a/ospfd/ospf_packet.c
+++ b/ospfd/ospf_packet.c
@@ -1055,11 +1055,11 @@
if (IS_SET_DD_MS (nbr->dd_flags))
{
nbr->dd_seqnum++;
- /* Entire DD packet sent. */
+
+ /* Both sides have no More, then we're done with Exchange */
if (!IS_SET_DD_M (dd->flags) && !IS_SET_DD_M (nbr->dd_flags))
OSPF_NSM_EVENT_SCHEDULE (nbr, NSM_ExchangeDone);
else
- /* Send new DD packet. */
ospf_db_desc_send (nbr);
}
/* Slave */
@@ -1067,17 +1067,21 @@
{
nbr->dd_seqnum = ntohl (dd->dd_seqnum);
- /* When master's more flags is not set. */
- if (!IS_SET_DD_M (dd->flags) && ospf_db_summary_isempty (nbr))
- {
- nbr->dd_flags &= ~(OSPF_DD_FLAG_M);
- OSPF_NSM_EVENT_SCHEDULE (nbr, NSM_ExchangeDone);
- }
-
- /* Send DD packet in reply. */
+ /* Send DD packet in reply.
+ *
+ * Must be done to acknowledge the Master's DD, regardless of
+ * whether we have more LSAs ourselves to describe.
+ *
+ * This function will clear the 'More' bit, if after this DD
+ * we have no more LSAs to describe to the master..
+ */
ospf_db_desc_send (nbr);
+
+ /* Slave can raise ExchangeDone now, if master is also done */
+ if (!IS_SET_DD_M (dd->flags) && !IS_SET_DD_M (nbr->dd_flags))
+ OSPF_NSM_EVENT_SCHEDULE (nbr, NSM_ExchangeDone);
}
-
+
/* Save received neighbor values from DD. */
ospf_db_desc_save_current (nbr, dd);
}
@@ -1200,7 +1204,9 @@
zlog_info ("Packet[DD]: Neighbor %s Negotiation done (Slave).",
inet_ntoa(nbr->router_id));
nbr->dd_seqnum = ntohl (dd->dd_seqnum);
- nbr->dd_flags &= ~(OSPF_DD_FLAG_MS|OSPF_DD_FLAG_I); /* Reset I/MS */
+
+ /* Reset I/MS */
+ UNSET_FLAG (nbr->dd_flags, (OSPF_DD_FLAG_MS|OSPF_DD_FLAG_I));
}
else
{
@@ -1217,7 +1223,8 @@
{
zlog_info ("Packet[DD]: Neighbor %s Negotiation done (Master).",
inet_ntoa(nbr->router_id));
- nbr->dd_flags &= ~OSPF_DD_FLAG_I;
+ /* Reset I, leaving MS */
+ UNSET_FLAG (nbr->dd_flags, OSPF_DD_FLAG_I);
}
else
{
@@ -2676,7 +2683,7 @@
#endif /* HAVE_OPAQUE_LSA */
stream_putc (s, options);
- /* Keep pointer to flags. */
+ /* DD flags */
pp = stream_get_endp (s);
stream_putc (s, nbr->dd_flags);
@@ -2685,12 +2692,21 @@
if (ospf_db_summary_isempty (nbr))
{
+ /* Sanity check:
+ *
+ * Must be here either:
+ * - Initial DBD (ospf_nsm.c)
+ * - M must be set
+ * or
+ * - finishing Exchange, and DB-Summary list empty
+ * - from ospf_db_desc_proc()
+ * - M must not be set
+ */
if (nbr->state >= NSM_Exchange)
- {
- nbr->dd_flags &= ~OSPF_DD_FLAG_M;
- /* Set DD flags again */
- stream_putc_at (s, pp, nbr->dd_flags);
- }
+ assert (!IS_SET_DD_M(nbr->dd_flags));
+ else
+ assert (IS_SET_DD_M(nbr->dd_flags));
+
return length;
}
@@ -2744,6 +2760,13 @@
}
}
+ /* Update 'More' bit */
+ if (ospf_db_summary_isempty (nbr))
+ {
+ UNSET_FLAG (nbr->dd_flags, OSPF_DD_FLAG_M);
+ /* Rewrite DD flags */
+ stream_putc_at (s, pp, nbr->dd_flags);
+ }
return length;
}