babeld: change the modify route system.
Zebra doesn't set errno to EEXIST if we add a route who was already in
the kernel, so we always returned after just doing "add; delete". This
patch fix the problem by doing "delete; add" always.
diff --git a/babeld/kernel_zebra.c b/babeld/kernel_zebra.c
index 82f03e4..7ddc797 100644
--- a/babeld/kernel_zebra.c
+++ b/babeld/kernel_zebra.c
@@ -142,26 +142,7 @@
if(newmetric == metric && memcmp(newgate, gate, 16) == 0 &&
newifindex == ifindex)
return 0;
- /* It is better to add the new route before removing the old
- one, to avoid losing packets. However, if the old and new
- priorities are equal, this only works if the kernel supports
- ECMP. So we first try the "right" order, and fall back on
- the "wrong" order if it fails with EEXIST. */
- rc = ipv4 ?
- kernel_route_add_v4(pref, plen,
- newgate, newifindex, newmetric,
- NULL, 0, 0):
- kernel_route_add_v6(pref, plen,
- newgate, newifindex, newmetric,
- NULL, 0, 0);
- if(rc < 0) {
- if(errno != EEXIST)
- return rc;
- added = 0;
- } else {
- added = 1;
- }
-
+ debugf(BABEL_DEBUG_ROUTE, "Modify route: delete old; add new.");
if (ipv4) {
kernel_route_delete_v4(pref, plen,
gate, ifindex, metric,
@@ -172,21 +153,19 @@
NULL, 0, 0);
}
- if(!added) {
- rc = ipv4 ?
- kernel_route_add_v4(pref, plen,
- newgate, newifindex, newmetric,
- NULL, 0, 0):
- kernel_route_add_v6(pref, plen,
- newgate, newifindex, newmetric,
- NULL, 0, 0);
- if(rc < 0) {
- if(errno == EEXIST)
- rc = 1;
- /* In principle, we should try to re-install the flushed
- route on failure to preserve. However, this should
- hopefully not matter much in practice. */
- }
+ rc = ipv4 ?
+ kernel_route_add_v4(pref, plen,
+ newgate, newifindex, newmetric,
+ NULL, 0, 0):
+ kernel_route_add_v6(pref, plen,
+ newgate, newifindex, newmetric,
+ NULL, 0, 0);
+ if(rc < 0) {
+ if(errno == EEXIST)
+ rc = 1;
+ /* In principle, we should try to re-install the flushed
+ route on failure to preserve. However, this should
+ hopefully not matter much in practice. */
}
return rc;