[PATCH 3.14 12/73] ipv4: Fix incorrect error code when adding an unreachable route

Greg Kroah-Hartman
2014-12-05T23:33:10Z

From: Panu Matilainen <pmatilai@redhat.com>

[ Upstream commit 49dd18ba4615eaa72f15c9087dea1c2ab4744cf5 ]

Trying to add an unreachable route incorrectly returns -ESRCH if
if custom FIB rules are present:

[root@localhost ~]# ip route add 74.125.31.199 dev eth0 via 1.2.3.4
RTNETLINK answers: Network is unreachable
[root@localhost ~]# ip rule add to 55.66.77.88 table 200
[root@localhost ~]# ip route add 74.125.31.199 dev eth0 via 1.2.3.4
RTNETLINK answers: No such process
[root@localhost ~]#

Commit 83886b6b636173b206f475929e58fac75c6f2446 ("[NET]: Change "not found"
return value for rule lookup") changed fib_rules_lookup()
to use -ESRCH as a "not found" code internally, but for user space it
should be translated into -ENETUNREACH. Handle the translation centrally in
ipv4-specific fib_lookup(), leaving the DECnet case alone.

On a related note, commit b7a71b51ee37d919e4098cd961d59a883fd272d8
("ipv4: removed redundant conditional") removed a similar translation from
ip_route_input_slow() prematurely AIUI.

Fixes: b7a71b51ee37 ("ipv4: removed redundant conditional")
Signed-off-by: Panu Matilainen <pmatilai@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ipv4/fib_rules.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/net/ipv4/fib_rules.c
+++ b/net/ipv4/fib_rules.c
@@ -62,6 +62,10 @@ int __fib_lookup(struct net *net, struct
else
res->tclassid = 0;
#endif
+
+ if (err == -ESRCH)
+ err = -ENETUNREACH;
+
return err;
}
EXPORT_SYMBOL_GPL(__fib_lookup);