Revert "ipv4: Allow configuring subnets as local addresses"

This reverts commit 4465b469008bc03b98a1b8df4e9ae501b6c69d4b.

Conflicts:

	net/ipv4/fib_frontend.c

As reported by Ben Greear, this causes regressions:

> Change 4465b469008bc03b98a1b8df4e9ae501b6c69d4b caused rules
> to stop matching the input device properly because the
> FLOWI_FLAG_MATCH_ANY_IIF is always defined in ip_dev_find().
>
> This breaks rules such as:
>
> ip rule add pref 512 lookup local
> ip rule del pref 0 lookup local
> ip link set eth2 up
> ip -4 addr add 172.16.0.102/24 broadcast 172.16.0.255 dev eth2
> ip rule add to 172.16.0.102 iif eth2 lookup local pref 10
> ip rule add iif eth2 lookup 10001 pref 20
> ip route add 172.16.0.0/24 dev eth2 table 10001
> ip route add unreachable 0/0 table 10001
>
> If you had a second interface 'eth0' that was on a different
> subnet, pinging a system on that interface would fail:
>
>   [root@ct503-60 ~]# ping 192.168.100.1
>   connect: Invalid argument

Reported-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 9 insertions, 4 deletions

diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index 82a4369ae150..a20e5d3bbfa0 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -181,8 +181,7 @@ static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
 {
         int ret = 0;
 
-        if (rule->iifindex && (rule->iifindex != fl->iif) &&
-            !(fl->flags & FLOWI_FLAG_MATCH_ANY_IIF))
+        if (rule->iifindex && (rule->iifindex != fl->iif))
                 goto out;
 
         if (rule->oifindex && (rule->oifindex != fl->oif))
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index eb6f69a8f27a..c19c1f739fba 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -163,13 +163,19 @@ struct net_device *__ip_dev_find(struct net *net, __be32 addr, bool devref)
                                 .daddr = addr
                         }
                 },
-                .flags = FLOWI_FLAG_MATCH_ANY_IIF
         };
         struct fib_result res = { 0 };
         struct net_device *dev = NULL;
+        struct fib_table *local_table;
+
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+        res.r = NULL;
+#endif
 
         rcu_read_lock();
-        if (fib_lookup(net, &fl, &res)) {
+        local_table = fib_get_table(net, RT_TABLE_LOCAL);
+        if (!local_table ||
+            fib_table_lookup(local_table, &fl, &res, FIB_LOOKUP_NOREF)) {
                 rcu_read_unlock();
                 return NULL;
         }