net: Fix prefsrc lookups

[ Upstream commit e1b8d903c6c3862160d2d5036806a94786c8fc4e ]

A bug report (https://bugzilla.kernel.org/show_bug.cgi?id=107071) noted
that the follwoing ip command is failing with v4.3:

    $ ip route add 10.248.5.0/24 dev bond0.250 table vlan_250 src 10.248.5.154
    RTNETLINK answers: Invalid argument

021dd3b8a142d changed the lookup of the given preferred source address to
use the table id passed in, but this assumes the local entries are in the
given table which is not necessarily true for non-VRF use cases. When
validating the preferred source fallback to the local table on failure.

Fixes: 021dd3b8a142d ("net: Add routes to the table associated with the device")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index e966f8599b4a1df8e504cf307ec7c8707d8af41e..ef5892f5e046a855e0b2c018d89c161d69e01c0d 100644 (file)
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -864,14 +864,21 @@ static bool fib_valid_prefsrc(struct fib_config *cfg, __be32 fib_prefsrc)
        if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst ||
            fib_prefsrc != cfg->fc_dst) {
                u32 tb_id = cfg->fc_table;
+               int rc;
 
                if (tb_id == RT_TABLE_MAIN)
                        tb_id = RT_TABLE_LOCAL;
 
-               if (inet_addr_type_table(cfg->fc_nlinfo.nl_net,
-                                        fib_prefsrc, tb_id) != RTN_LOCAL) {
-                       return false;
+               rc = inet_addr_type_table(cfg->fc_nlinfo.nl_net,
+                                         fib_prefsrc, tb_id);
+
+               if (rc != RTN_LOCAL && tb_id != RT_TABLE_LOCAL) {
+                       rc = inet_addr_type_table(cfg->fc_nlinfo.nl_net,
+                                                 fib_prefsrc, RT_TABLE_LOCAL);
                }
+
+               if (rc != RTN_LOCAL)
+                       return false;
        }
        return true;
 }