BGP: support for addpath TX

Signed-off-by: Daniel Walton <dwalton@cumulusnetworks.com>
Reviewed-by:   Donald Sharp <sharpd@cumulusnetworks.com>
Reviewed-by:   Vivek Venkataraman <vivek@cumulusnetworks.com

Ticket: CM-8014

This implements addpath TX with the first feature to use it
being "neighbor x.x.x.x addpath-tx-all-paths".

One change to show output is 'show ip bgp x.x.x.x'.  If no addpath-tx
features are configured for any peers then everything looks the same
as it is today in that "Advertised to" is at the top and refers to
which peers the bestpath was advertise to.

root@superm-redxp-05[quagga-stash5]# vtysh -c 'show ip bgp 1.1.1.1'
BGP routing table entry for 1.1.1.1/32
Paths: (6 available, best #6, table Default-IP-Routing-Table)
  Advertised to non peer-group peers:
  r1(10.0.0.1) r2(10.0.0.2) r3(10.0.0.3) r4(10.0.0.4) r5(10.0.0.5) r6(10.0.0.6) r8(10.0.0.8)
  Local, (Received from a RR-client)
    12.12.12.12 (metric 20) from r2(10.0.0.2) (10.0.0.2)
      Origin IGP, metric 0, localpref 100, valid, internal
      AddPath ID: RX 0, TX 8
      Last update: Fri Oct 30 18:26:44 2015
[snip]

but once you enable an addpath feature we must display "Advertised to" on a path-by-path basis:

superm-redxp-05# show ip bgp 1.1.1.1/32
BGP routing table entry for 1.1.1.1/32
Paths: (6 available, best #6, table Default-IP-Routing-Table)
  Local, (Received from a RR-client)
    12.12.12.12 (metric 20) from r2(10.0.0.2) (10.0.0.2)
      Origin IGP, metric 0, localpref 100, valid, internal
      AddPath ID: RX 0, TX 8
      Advertised to: r8(10.0.0.8)
      Last update: Fri Oct 30 18:26:44 2015

  Local, (Received from a RR-client)
    34.34.34.34 (metric 20) from r3(10.0.0.3) (10.0.0.3)
      Origin IGP, metric 0, localpref 100, valid, internal
      AddPath ID: RX 0, TX 7
      Advertised to: r8(10.0.0.8)
      Last update: Fri Oct 30 18:26:39 2015

  Local, (Received from a RR-client)
    56.56.56.56 (metric 20) from r6(10.0.0.6) (10.0.0.6)
      Origin IGP, metric 0, localpref 100, valid, internal
      AddPath ID: RX 0, TX 6
      Advertised to: r8(10.0.0.8)
      Last update: Fri Oct 30 18:26:39 2015

  Local, (Received from a RR-client)
    56.56.56.56 (metric 20) from r5(10.0.0.5) (10.0.0.5)
      Origin IGP, metric 0, localpref 100, valid, internal
      AddPath ID: RX 0, TX 5
      Advertised to: r8(10.0.0.8)
      Last update: Fri Oct 30 18:26:39 2015

  Local, (Received from a RR-client)
    34.34.34.34 (metric 20) from r4(10.0.0.4) (10.0.0.4)
      Origin IGP, metric 0, localpref 100, valid, internal
      AddPath ID: RX 0, TX 4
      Advertised to: r8(10.0.0.8)
      Last update: Fri Oct 30 18:26:39 2015

  Local, (Received from a RR-client)
    12.12.12.12 (metric 20) from r1(10.0.0.1) (10.0.0.1)
      Origin IGP, metric 0, localpref 100, valid, internal, best
      AddPath ID: RX 0, TX 3
      Advertised to: r1(10.0.0.1) r2(10.0.0.2) r3(10.0.0.3) r4(10.0.0.4) r5(10.0.0.5) r6(10.0.0.6) r8(10.0.0.8)
      Last update: Fri Oct 30 18:26:34 2015

superm-redxp-05#

1 files changed, 6 insertions, 2 deletions

diff --git a/bgpd/bgp_updgrp.h b/bgpd/bgp_updgrp.h
index 542517f62e..1ca62a0a83 100644
--- a/bgpd/bgp_updgrp.h
+++ b/bgpd/bgp_updgrp.h
@@ -49,6 +49,7 @@
 			      PEER_FLAG_REMOVE_PRIVATE_AS_ALL | \
 			      PEER_FLAG_REMOVE_PRIVATE_AS_REPLACE | \
 			      PEER_FLAG_REMOVE_PRIVATE_AS_ALL_REPLACE | \
+                              PEER_FLAG_ADDPATH_TX_ALL_PATHS | \
 			      PEER_FLAG_AS_OVERRIDE)
 
 #define PEER_UPDGRP_CAP_FLAGS (PEER_CAP_AS4_RCV)
@@ -454,7 +455,8 @@ extern void update_group_announce (struct bgp *bgp);
 extern void update_group_announce_rrclients (struct bgp *bgp);
 extern void peer_af_announce_route (struct peer_af *paf, int combine);
 extern struct bgp_adj_out *bgp_adj_out_alloc (struct update_subgroup *subgrp,
-					      struct bgp_node *rn);
+                                              struct bgp_node *rn,
+                                              u_int32_t addpath_tx_id);
 extern void bgp_adj_out_remove_subgroup (struct bgp_node *rn,
 					 struct bgp_adj_out *adj,
 					 struct update_subgroup *subgrp);
@@ -465,7 +467,8 @@ bgp_adj_out_set_subgroup (struct bgp_node *rn,
 extern void
 bgp_adj_out_unset_subgroup (struct bgp_node *rn,
 			    struct update_subgroup *subgrp,
-                            char withdraw);
+                            char withdraw,
+                            u_int32_t addpath_tx_id);
 void
 subgroup_announce_table (struct update_subgroup *subgrp,
 			 struct bgp_table *table, int rsclient);
@@ -476,6 +479,7 @@ extern int
 update_group_clear_update_dbg (struct update_group *updgrp, void *arg);
 
 extern void update_bgp_group_free(struct bgp *bgp);
+extern int bgp_addpath_encode_tx (struct peer *peer, afi_t afi, safi_t safi);
 
 /*
  * Inline functions