ipv4: Loosen source address check on IPv4 output
ip_route_output() contains a check to make sure that no flows with
non-local source IP addresses are routed. This obviously makes using
such addresses impossible.
This patch introduces a flowi flag which makes omitting this check
possible. The new flag provides a way of handling transparent and
non-transparent connections differently.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index f62187b..a6d7c58 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2361,11 +2361,6 @@
ipv4_is_zeronet(oldflp->fl4_src))
goto out;
- /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
- dev_out = ip_dev_find(net, oldflp->fl4_src);
- if (dev_out == NULL)
- goto out;
-
/* I removed check for oif == dev_out->oif here.
It was wrong for two reasons:
1. ip_dev_find(net, saddr) can return wrong iface, if saddr
@@ -2377,6 +2372,11 @@
if (oldflp->oif == 0
&& (ipv4_is_multicast(oldflp->fl4_dst) ||
oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
+ /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
+ dev_out = ip_dev_find(net, oldflp->fl4_src);
+ if (dev_out == NULL)
+ goto out;
+
/* Special hack: user can direct multicasts
and limited broadcast via necessary interface
without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
@@ -2395,9 +2395,15 @@
fl.oif = dev_out->ifindex;
goto make_route;
}
- if (dev_out)
+
+ if (!(oldflp->flags & FLOWI_FLAG_ANYSRC)) {
+ /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
+ dev_out = ip_dev_find(net, oldflp->fl4_src);
+ if (dev_out == NULL)
+ goto out;
dev_put(dev_out);
- dev_out = NULL;
+ dev_out = NULL;
+ }
}