bgpd: efficient NLRI packing for AFs != ipv4-unicast
ISSUE:
Currently, for non-ipv4-unicast address families where prefixes are
encoded in MP_REACH/MP_UNREACH attributes, BGP ends up sending one
prefix per UPDATE message. This is quite inefficient. The patch
addresses the issue.
PATCH:
We introduce a scratch buffer in the peer structure that stores the
MP_REACH/MP_UNREACH attributes for non-ipv4-unicast families. This
enables us to encode multiple prefixes. In the end, the two buffers
are merged to create the UPDATE packet.
Signed-off-by: Pradosh Mohapatra <pmohapat@cumulusnetworks.com>
Reviewed-by: Daniel Walton <dwalton@cumulusnetworks.com>
[DL: removed no longer existing bgp_packet_withdraw prototype]
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
diff --git a/bgpd/bgpd.h b/bgpd/bgpd.h
index 3d516d3..688f459 100644
--- a/bgpd/bgpd.h
+++ b/bgpd/bgpd.h
@@ -313,6 +313,12 @@
struct stream_fifo *obuf;
struct stream *work;
+ /* We use a separate stream to encode MP_REACH_NLRI for efficient
+ * NLRI packing. peer->work stores all the other attributes. The
+ * actual packet is then constructed by concatenating the two.
+ */
+ struct stream *scratch;
+
/* Status of the peer. */
int status;
int ostatus;