From f2b53dac4c72811c06779c596c6162b994eb427a Mon Sep 17 00:00:00 2001 From: Christian Franke Date: Wed, 20 Mar 2013 15:28:46 +0000 Subject: ospfd: restore nexthop IP for p2p interfaces commit c81ee5c... "ospfd: Optimize and improve SPF nexthop calculation" subtly changed semantics of routes calculated over pointopoint links by removing the nexthop IP address and instead using an ifindex route. This breaks calculation of AS-Ext routes with a forwarding address since in ospf_ase_complete_direct_routes() this will be hit: if (op->nexthop.s_addr == 0) op->nexthop.s_addr = nexthop.s_addr; thus turning the route unusable by having an invalid nexthop. Fix by restoring the nexthop IP on routes over PtP links. This also allows running multi-access (Ethernet) interfaces in PtP mode again. This bug is a regression against 0.99.21 and only present in 0.99.22. Signed-off-by: Christian Franke [patch description and code comments rewritten] Acked-by: Joakim Tjernlund Acked-by: James Li Signed-off-by: David Lamparter --- ospfd/ospf_spf.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/ospfd/ospf_spf.c b/ospfd/ospf_spf.c index a5242b68..bd9564d9 100644 --- a/ospfd/ospf_spf.c +++ b/ospfd/ospf_spf.c @@ -568,8 +568,22 @@ ospf_nexthop_calculation (struct ospf_area *area, struct vertex *v, */ if (oi->type == OSPF_IFTYPE_POINTOPOINT) { - added = 1; - nexthop.s_addr = 0; /* Nexthop not required */ + /* Having nexthop = 0 is tempting, but NOT acceptable. + It breaks AS-External routes with a forwarding address, + since ospf_ase_complete_direct_routes() will mistakenly + assume we've reached the last hop and should place the + forwarding address as nexthop. + Also, users may configure multi-access links in p2p mode, + so we need the IP to ARP the nexthop. + */ + struct ospf_neighbor *nbr_w; + + nbr_w = ospf_nbr_lookup_by_routerid (oi->nbrs, &l->link_id); + if (nbr_w != NULL) + { + added = 1; + nexthop = nbr_w->src; + } } else if (oi->type == OSPF_IFTYPE_POINTOMULTIPOINT) { -- cgit v1.2.1