Merge branches 'pm-core', 'pm-qos', 'pm-domains' and 'pm-opp'

[linux.git] / net / ipv4 / ip_sockglue.c

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 57e1405e82822543ed6fc788e8b7dc69091f2bb3..900011709e3b8e4807daaa6bf537c3871a7d9306 100644 (file)
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -1225,14 +1225,27 @@ void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
                 * which has interface index (iif) as the first member of the
                 * underlying inet{6}_skb_parm struct. This code then overlays
                 * PKTINFO_SKB_CB and in_pktinfo also has iif as the first
-                * element so the iif is picked up from the prior IPCB
+                * element so the iif is picked up from the prior IPCB. If iif
+                * is the loopback interface, then return the sending interface
+                * (e.g., process binds socket to eth0 for Tx which is
+                * redirected to loopback in the rtable/dst).
                 */
+               if (pktinfo->ipi_ifindex == LOOPBACK_IFINDEX)
+                       pktinfo->ipi_ifindex = inet_iif(skb);
+
                pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);
        } else {
                pktinfo->ipi_ifindex = 0;
                pktinfo->ipi_spec_dst.s_addr = 0;
        }
-       skb_dst_drop(skb);
+       /* We need to keep the dst for __ip_options_echo()
+        * We could restrict the test to opt.ts_needtime || opt.srr,
+        * but the following is good enough as IP options are not often used.
+        */
+       if (unlikely(IPCB(skb)->opt.optlen))
+               skb_dst_force(skb);
+       else
+               skb_dst_drop(skb);
 }
 
 int ip_setsockopt(struct sock *sk, int level,