net: ipv6: Compare lwstate in detecting duplicate nexthops
Lennert reported a failure to add different mpls encaps in a multipath
route:
$ ip -6 route add 1234::/16 \
nexthop encap mpls 10 via fe80::1 dev ens3 \
nexthop encap mpls 20 via fe80::1 dev ens3
RTNETLINK answers: File exists
The problem is that the duplicate nexthop detection does not compare
lwtunnel configuration. Add it.
Fixes: 19e42e451506 ("ipv6: support for fib route lwtunnel encap attributes")
Signed-off-by: David Ahern <dsahern@gmail.com>
Reported-by: João Taveira Araújo <joao.taveira@gmail.com>
Reported-by: Lennert Buytenhek <buytenh@wantstofly.org>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Tested-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 0fbf73d..1990569 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -22,6 +22,7 @@
#include <net/flow.h>
#include <net/ip6_fib.h>
#include <net/sock.h>
+#include <net/lwtunnel.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/route.h>
@@ -232,4 +233,11 @@
return daddr;
}
+static inline bool rt6_duplicate_nexthop(struct rt6_info *a, struct rt6_info *b)
+{
+ return a->dst.dev == b->dst.dev &&
+ a->rt6i_idev == b->rt6i_idev &&
+ ipv6_addr_equal(&a->rt6i_gateway, &b->rt6i_gateway) &&
+ !lwtunnel_cmp_encap(a->dst.lwtstate, b->dst.lwtstate);
+}
#endif
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 5477ba7..ebb299c 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -786,10 +786,7 @@
goto next_iter;
}
- if (iter->dst.dev == rt->dst.dev &&
- iter->rt6i_idev == rt->rt6i_idev &&
- ipv6_addr_equal(&iter->rt6i_gateway,
- &rt->rt6i_gateway)) {
+ if (rt6_duplicate_nexthop(iter, rt)) {
if (rt->rt6i_nsiblings)
rt->rt6i_nsiblings = 0;
if (!(iter->rt6i_flags & RTF_EXPIRES))
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 0488a24c..4d30c96 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3036,17 +3036,11 @@
struct rt6_info *rt, struct fib6_config *r_cfg)
{
struct rt6_nh *nh;
- struct rt6_info *rtnh;
int err = -EEXIST;
list_for_each_entry(nh, rt6_nh_list, next) {
/* check if rt6_info already exists */
- rtnh = nh->rt6_info;
-
- if (rtnh->dst.dev == rt->dst.dev &&
- rtnh->rt6i_idev == rt->rt6i_idev &&
- ipv6_addr_equal(&rtnh->rt6i_gateway,
- &rt->rt6i_gateway))
+ if (rt6_duplicate_nexthop(nh->rt6_info, rt))
return err;
}