From 6913cb1b20a76f68f185f4ae65349a358bd4b372 Mon Sep 17 00:00:00 2001 From: Stephen Worley Date: Mon, 9 Sep 2019 17:20:17 -0400 Subject: [PATCH] zebra: Don't resolve to diff interface if given If the nexthop is of type `GATEWAY_IFINDEX` then the nexthop should not resolve to a nexthop that has a different ifindex from the one given. Signed-off-by: Stephen Worley --- zebra/zebra_nhg.c | 33 +++++++++++++++++++++++++++++---- 1 file changed, 29 insertions(+), 4 deletions(-) diff --git a/zebra/zebra_nhg.c b/zebra/zebra_nhg.c index ee2956d3ea..35df02a19a 100644 --- a/zebra/zebra_nhg.c +++ b/zebra/zebra_nhg.c @@ -122,6 +122,33 @@ static void nexthop_set_resolved(afi_t afi, const struct nexthop *newhop, _nexthop_add(&nexthop->resolved, resolved_hop); } +/* Checks if nexthop we are trying to resolve to is valid */ +static bool nexthop_valid_resolve(const struct nexthop *nexthop, + const struct nexthop *resolved) +{ + /* Can't resolve to a recursive nexthop */ + if (CHECK_FLAG(resolved->flags, NEXTHOP_FLAG_RECURSIVE)) + return false; + + switch (nexthop->type) { + case NEXTHOP_TYPE_IPV4_IFINDEX: + case NEXTHOP_TYPE_IPV6_IFINDEX: + /* If the nexthop we are resolving to does not match the + * ifindex for the nexthop the route wanted, its not valid. + */ + if (nexthop->ifindex != resolved->ifindex) + return false; + break; + case NEXTHOP_TYPE_IPV4: + case NEXTHOP_TYPE_IPV6: + case NEXTHOP_TYPE_IFINDEX: + case NEXTHOP_TYPE_BLACKHOLE: + break; + } + + return true; +} + /* * Given a nexthop we need to properly recursively resolve * the route. As such, do a table lookup to find and match @@ -287,8 +314,7 @@ static int nexthop_active(afi_t afi, struct route_entry *re, if (!CHECK_FLAG(match->status, ROUTE_ENTRY_INSTALLED)) continue; - if (CHECK_FLAG(newhop->flags, - NEXTHOP_FLAG_RECURSIVE)) + if (!nexthop_valid_resolve(nexthop, newhop)) continue; SET_FLAG(nexthop->flags, @@ -308,8 +334,7 @@ static int nexthop_active(afi_t afi, struct route_entry *re, if (!CHECK_FLAG(match->status, ROUTE_ENTRY_INSTALLED)) continue; - if (CHECK_FLAG(newhop->flags, - NEXTHOP_FLAG_RECURSIVE)) + if (!nexthop_valid_resolve(nexthop, newhop)) continue; SET_FLAG(nexthop->flags, -- 2.39.5