From: Ondrej Zajicek (work) <santiago@crfreenet.org>
Date: Fri, 14 Jan 2022 18:07:57 +0000 (+0100)
Subject: Netlink: Explicitly skip received cloned routes
X-Git-Tag: v2.0.9~17
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d0dd1d20cd40e75e417d58569fac3ff0bf1db41a;p=thirdparty%2Fbird.git

Netlink: Explicitly skip received cloned routes

Kernel uses cloned routes to keep route cache entries, but reports them
together with regular routes. They were skipped implicitly as they
do not have rtm_protocol filled. Add explicit check for cloned flag
and skip such routes explicitly.

Also, improve debug logs of skipped routes.
---

diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c
index e127052a0..7cea53220 100644
--- a/sysdep/linux/netlink.c
+++ b/sysdep/linux/netlink.c
@@ -1535,7 +1535,8 @@ nl_parse_end(struct nl_parse_state *s)
 }
 
 
-#define SKIP(ARG...) do { DBG("KRT: Ignoring route - " ARG); return; } while(0)
+#define SKIP0(ARG, ...) do { DBG("KRT: Ignoring route - " ARG, ##__VA_ARGS__); return; } while(0)
+#define SKIP(ARG, ...)  do { DBG("KRT: Ignoring route %N - " ARG, &dst, ##__VA_ARGS__); return; } while(0)
 
 static void
 nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
@@ -1588,10 +1589,10 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
 	return;
 
       if (!a[RTA_DST])
-	SKIP("MPLS route without RTA_DST");
+	SKIP0("MPLS route without RTA_DST\n");
 
       if (rta_get_mpls(a[RTA_DST], rta_mpls_stack) != 1)
-	SKIP("MPLS route with multi-label RTA_DST");
+	SKIP0("MPLS route with multi-label RTA_DST\n");
 
       net_fill_mpls(&dst, rta_mpls_stack[0]);
       break;
@@ -1609,6 +1610,9 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
   else
     table_id = i->rtm_table;
 
+  if (i->rtm_flags & RTM_F_CLONED)
+    SKIP("cloned\n");
+
   /* Do we know this table? */
   p = HASH_FIND(nl_table_map, RTH, i->rtm_family, table_id);
   if (!p)