From: Ondrej Zajicek (work) <santiago@crfreenet.org>
Date: Wed, 5 Jan 2022 18:25:42 +0000 (+0100)
Subject: Netlink: Do not ignore dead routes from BIRD
X-Git-Tag: v2.0.9~21
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f5c8fb5fba959d356ce1ea0fb5879223f76137f7;p=thirdparty%2Fbird.git

Netlink: Do not ignore dead routes from BIRD

Currently, BIRD ignores dead routes to consider them absent. But it also
ignores its own routes and thus it can not correctly manage such routes
in some cases. This patch makes an exception for routes with proto bird
when ignoring dead routes, so they can be properly updated or removed.

Thanks to Alexander Zubkov for the original patch.
---

diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c
index 1293df4d5..e127052a0 100644
--- a/sysdep/linux/netlink.c
+++ b/sysdep/linux/netlink.c
@@ -681,7 +681,7 @@ nl_add_multipath(struct nlmsghdr *h, uint bufsize, struct nexthop *nh, int af, e
 }
 
 static struct nexthop *
-nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, const net_addr *n, struct rtattr *ra, int af)
+nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, const net_addr *n, struct rtattr *ra, int af, int krt_src)
 {
   struct rtattr *a[BIRD_RTA_MAX];
   struct rtnexthop *nh = RTA_DATA(ra);
@@ -697,7 +697,7 @@ nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, const net_addr
       if ((len < sizeof(*nh)) || (len < nh->rtnh_len))
 	goto err;
 
-      if (nh->rtnh_flags & RTNH_F_DEAD)
+      if ((nh->rtnh_flags & RTNH_F_DEAD) && (krt_src != KRT_SRC_BIRD))
 	goto next;
 
       *last = rv = lp_allocz(s->pool, NEXTHOP_MAX_SIZE);
@@ -1687,7 +1687,7 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
 
       if (a[RTA_MULTIPATH])
         {
-	  struct nexthop *nh = nl_parse_multipath(s, p, n, a[RTA_MULTIPATH], i->rtm_family);
+	  struct nexthop *nh = nl_parse_multipath(s, p, n, a[RTA_MULTIPATH], i->rtm_family, krt_src);
 	  if (!nh)
 	    SKIP("strange RTA_MULTIPATH\n");
 
@@ -1695,7 +1695,7 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
 	  break;
 	}
 
-      if (i->rtm_flags & RTNH_F_DEAD)
+      if ((i->rtm_flags & RTNH_F_DEAD) && (krt_src != KRT_SRC_BIRD))
 	SKIP("ignore RTNH_F_DEAD\n");
 
       ra->nh.iface = if_find_by_index(oif);