net: ipv4: Fix multipath selection with vrf

fib_select_path does not call fib_select_multipath if oif is set in the
flow struct. For VRF use cases oif is always set, so multipath route
selection is bypassed. Use the FLOWI_FLAG_SKIP_NH_OIF to skip the oif
check similar to what is done in fib_table_lookup.

Add saddr and proto to the flow struct for the fib lookup done by the
VRF driver to better match hash computation for a flow.

Fixes: b8ceeef2ca2c ("net: Use VRF device index for lookups on TX")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 23dfb0eac0981704f2770bc3abe9bb32a80e3fc9..0a067708aa39ab578b6a90d70b0fa7cab520eef2 100644 (file)
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -263,7 +263,9 @@ static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
                .flowi4_iif = LOOPBACK_IFINDEX,
                .flowi4_tos = RT_TOS(ip4h->tos),
                .flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_SKIP_NH_OIF,
+               .flowi4_proto = ip4h->protocol,
                .daddr = ip4h->daddr,
+               .saddr = ip4h->saddr,
        };
        struct net *net = dev_net(vrf_dev);
        struct rtable *rt;

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 7a5b4c7d9a87b18051a94aa2e16e6b85c8d85aa6..eba1546b5031e6e280a558118e55b13befc4c8ea 100644 (file)
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -1618,8 +1618,13 @@ void fib_select_multipath(struct fib_result *res, int hash)
 void fib_select_path(struct net *net, struct fib_result *res,
                     struct flowi4 *fl4, int mp_hash)
 {
+       bool oif_check;
+
+       oif_check = (fl4->flowi4_oif == 0 ||
+                    fl4->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF);
+
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
-       if (res->fi->fib_nhs > 1 && fl4->flowi4_oif == 0) {
+       if (res->fi->fib_nhs > 1 && oif_check) {
                if (mp_hash < 0)
                        mp_hash = get_hash_from_flowi4(fl4) >> 1;
 
@@ -1629,7 +1634,7 @@ void fib_select_path(struct net *net, struct fib_result *res,
 #endif
        if (!res->prefixlen &&
            res->table->tb_num_default > 1 &&
-           res->type == RTN_UNICAST && !fl4->flowi4_oif)
+           res->type == RTN_UNICAST && oif_check)
                fib_select_default(fl4, res);
 
        if (!fl4->saddr)