commit b6475ecb14abab936919894050f9ca47415d0f48
author Juliusz Chroboczek <jch@pps.jussieu.fr> Thu Feb 09 12:29:10 2012 +0100
committer Paul Jakma <paul@quagga.net> Sun Mar 25 17:06:53 2012 +0100
tree 2db873dd6edb2e68ef2c0e37d44acf0ea9068521
parent 53b21956f650df86a76b7a7047cfa85114c99dcc

babeld: Don't use an ifindex when installing IPv4 routes.

Stand-alone babeld installs routes using both a next-hop gateway
and an interface index.  Unfortunately, this doesn't work for IPv4
under Quagga.

We now ignore the ifindex when installing IPv4 routes, which makes
Babel work for IPv4 in prefix-based networks.  Of course this breaks
IPv4 mesh networks, unless you play some tricks with your interfaces'
netmasks.

babeld/kernel_zebra.c

diff --git a/babeld/kernel_zebra.c b/babeld/kernel_zebra.c
index f23403e..1df4217 100644
--- a/babeld/kernel_zebra.c
+++ b/babeld/kernel_zebra.c
@@ -157,7 +157,6 @@
 kernel_route_add_v4(const unsigned char *pref, unsigned short plen,
                     const unsigned char *gate, int ifindex, unsigned int metric)
 {
-    unsigned int tmp_ifindex = ifindex; /* (for typing) */
     struct zapi_ipv4 api;               /* quagga's communication system */
     struct prefix_ipv4 quagga_prefix;   /* quagga's prefix */
     struct in_addr babel_prefix_addr;   /* babeld's prefix addr */
@@ -180,12 +179,17 @@
     api.flags = 0;
     api.message = 0;
     api.safi = SAFI_UNICAST;
+
+    /* Unlike the native Linux and BSD interfaces, Quagga doesn't like
+       there to be both and IPv4 nexthop and an ifindex.  Omit the
+       ifindex, and assume that the connected prefixes be set up
+       correctly. */
+
     SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP);
     api.nexthop_num = 1;
     api.nexthop = &nexthop_pointer;
-    SET_FLAG(api.message, ZAPI_MESSAGE_IFINDEX);
-    api.ifindex_num = 1;
-    api.ifindex = &tmp_ifindex;
+    api.ifindex_num = 0;
+
     SET_FLAG(api.message, ZAPI_MESSAGE_METRIC);
     api.metric = metric;
 
@@ -240,7 +244,6 @@
                        const unsigned char *gate, int ifindex,
                        unsigned int metric)
 {
-    unsigned int tmp_ifindex = ifindex; /* (for typing) */
     struct zapi_ipv4 api;               /* quagga's communication system */
     struct prefix_ipv4 quagga_prefix;   /* quagga's prefix */
     struct in_addr babel_prefix_addr;   /* babeld's prefix addr */
@@ -266,9 +269,7 @@
     SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP);
     api.nexthop_num = 1;
     api.nexthop = &nexthop_pointer;
-    SET_FLAG(api.message, ZAPI_MESSAGE_IFINDEX);
-    api.ifindex_num = 1;
-    api.ifindex = &tmp_ifindex;
+    api.ifindex_num = 0;
     SET_FLAG(api.message, ZAPI_MESSAGE_METRIC);
     api.metric = metric;