modernize backfire 10.03 so it can be operational again

[openwrt-10.03/.git] / package / quagga / patches-upstream / 300-fix_MRT.patch

diff --git a/package/quagga/patches-upstream/300-fix_MRT.patch b/package/quagga/patches-upstream/300-fix_MRT.patch
new file mode 100644 (file)
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+++ b/package/quagga/patches-upstream/300-fix_MRT.patch
@@ -0,0 +1,100 @@
+From fc1c1cc5e2800431e1ca59c938b1329c2365ad60 Mon Sep 17 00:00:00 2001
+From: Colin Petrie <cpetrie@ripe.net>
+Date: Wed, 11 May 2016 09:56:58 +0000
+Subject: bgpd: fix MRT table dumps for locally-originated routes
+
+I've been working on a small patch to correct an issue in the BGP MRT
+table dump code. It's a quick'n'easy fix initially, and I'd appreciate
+any feedback on making it better :)
+
+Issue:
+
+When the BGP table dump code runs, it generates the peer_index_table.
+This walks the list of peers, and dumps out their IP, ASN, address
+family, etc. It also sets the peer index number in the peer struct.
+
+Then the code walks the RIB, and for each prefix, writes out RIB
+entries, that refer to the peer index number.
+
+However, when it finds prefixes that are locally originated, the
+associated peer is the 'self' peer, which wasn't in the list of peers,
+never gets an index number assigned, but because it is calloc'd, the
+index number is set to 0.
+
+End result: locally-originated routes are associated with whichever peer
+happens to be first in the list of remote peers in the index table :)
+
+Example (from one of our route collectors) - these are two of our
+originated prefixes (bgpdump output):
+TABLE_DUMP2|1457568002|B|12.0.1.63|7018|84.205.80.0/24||IGP|193.0.4.28|0|0||NAG|64512
+10.255.255.255|
+TABLE_DUMP2|1457568006|B|12.0.1.63|7018|2001:7fb:ff00::/48||IGP|::|0|0||NAG||
+
+The prefixes are announced by us (note it has an empty AS PATH (the
+field after the prefix)) but also looks like it was received from AS7018
+(12.0.1.63). In fact, the AS7018 peer just happens to be the first peer
+in the index table.
+
+Fix:
+
+The simplest fix (which is also the method adopted by both OpenBGPd and
+the BIRD mrtdump branch) is to create an empty placeholder 'peer' at the
+start of the peer index table, for all the routes which are locally
+originated to refer to.
+
+I've attached a patch for this.
+Here's a resulting bgpdump output after the patch:
+TABLE_DUMP2|1458828539|B|0.0.0.0|0|93.175.150.0/24||IGP|0.0.0.0|0|0||NAG||
+Now it is more obvious that the prefix is locally originated.
+
+There are more complicated potential ways of fixing it
+1) skip the local routes when dumping the RIB. This leads to questions
+about what an MRT table dump *should* contain :)
+2) include the 'self' peer in the list of peers used to generate the
+index table.
+etc etc.
+
+But I'm quite happy with my 'create a fake peer, and associate local
+routes with it' method :)
+
+Your thoughts and feedback are welcome!
+
+Regards,
+
+Colin Petrie
+Systems Engineer
+RIPE NCC RIS Project
+Tested-by: NetDEF CI System <cisystem@netdef.org>
+---
+--- a/bgpd/bgp_dump.c
++++ b/bgpd/bgp_dump.c
+@@ -226,7 +226,7 @@ bgp_dump_routes_index_table(struct bgp *
+ {
+   struct peer *peer;
+   struct listnode *node;
+-  uint16_t peerno = 0;
++  uint16_t peerno = 1;
+   struct stream *obuf;
+ 
+   obuf = bgp_dump_obuf;
+@@ -250,8 +250,18 @@ bgp_dump_routes_index_table(struct bgp *
+       stream_putw(obuf, 0);
+     }
+ 
+-  /* Peer count */
+-  stream_putw (obuf, listcount(bgp->peer));
++  /* Peer count ( plus one extra internal peer ) */
++  stream_putw (obuf, listcount(bgp->peer) + 1);
++
++  /* Populate fake peer at index 0, for locally originated routes */
++  /* Peer type (IPv4) */
++  stream_putc (obuf, TABLE_DUMP_V2_PEER_INDEX_TABLE_AS4+TABLE_DUMP_V2_PEER_INDEX_TABLE_IP);
++  /* Peer BGP ID (0.0.0.0) */
++  stream_putl (obuf, 0);
++  /* Peer IP address (0.0.0.0) */
++  stream_putl (obuf, 0);
++  /* Peer ASN (0) */
++  stream_putl (obuf, 0);
+ 
+   /* Walk down all peers */
+   for(ALL_LIST_ELEMENTS_RO (bgp->peer, node, peer))