diff options
| author | Donald Sharp <sharpd@cumulusnetworks.com> | 2017-09-12 08:14:50 -0400 |
|---|---|---|
| committer | Donald Sharp <sharpd@cumulusnetworks.com> | 2017-09-12 08:33:37 -0400 |
| commit | 1f1d24a8f1f183d6d0a4598b854b459f5b5d7e5c (patch) | |
| tree | 3e532999bac61a2d96f45f4c507ed933f6b7003c | |
| parent | 953d97fc4aef0c7715e8d42d7d52ebc18d873ac6 (diff) | |
zebra: Allow recursively resolved blackhole routes to be installed
So the current code for a blackhole route assumed that you
would never want a recursively resolved blackhole to work.
Suppose you have this setup:
1) ip route 192.0.2.1/32 Null0
2) BGP installed with a route-map that rewrites the
nexthop to 192.0.2.1.
Zebra will end up with a recursive nexthop that resolves
to the blackhole.
The original rib install function assumed that we would never
want the ability to recursively resolve a blackhole route.
Instead just handle the blackhole as part of the nexthop_num = 1
case.
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
| -rw-r--r-- | zebra/rt_netlink.c | 38 |
1 files changed, 21 insertions, 17 deletions
diff --git a/zebra/rt_netlink.c b/zebra/rt_netlink.c index 12b6185395..ef59f26f21 100644 --- a/zebra/rt_netlink.c +++ b/zebra/rt_netlink.c @@ -1321,23 +1321,6 @@ static int netlink_route_multipath(int cmd, struct prefix *p, req.r.rtm_scope = RT_SCOPE_UNIVERSE; req.r.rtm_type = RTN_UNICAST; - if (re->nexthop_num == 1 - && re->nexthop->type == NEXTHOP_TYPE_BLACKHOLE) { - discard = 1; - - switch (re->nexthop->bh_type) { - case BLACKHOLE_ADMINPROHIB: - req.r.rtm_type = RTN_PROHIBIT; - break; - case BLACKHOLE_REJECT: - req.r.rtm_type = RTN_UNREACHABLE; - break; - default: - req.r.rtm_type = RTN_BLACKHOLE; - break; - } - } - addattr_l(&req.n, sizeof req, RTA_DST, &p->u.prefix, bytelen); if (src_p) addattr_l(&req.n, sizeof req, RTA_SRC, &src_p->u.prefix, @@ -1396,6 +1379,27 @@ static int netlink_route_multipath(int cmd, struct prefix *p, if (nexthop_num == 1 || multipath_num == 1) { nexthop_num = 0; for (ALL_NEXTHOPS(re->nexthop, nexthop)) { + /* + * So we want to cover 2 types of blackhole + * routes here: + * 1) A normal blackhole route( ala from a static + * install. + * 2) A recursively resolved blackhole route + */ + if (nexthop->type == NEXTHOP_TYPE_BLACKHOLE) { + switch (nexthop->bh_type) { + case BLACKHOLE_ADMINPROHIB: + req.r.rtm_type = RTN_PROHIBIT; + break; + case BLACKHOLE_REJECT: + req.r.rtm_type = RTN_UNREACHABLE; + break; + default: + req.r.rtm_type = RTN_BLACKHOLE; + break; + } + goto skip; + } if (CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_RECURSIVE)) { if (!setsrc) { |