diff options
Diffstat (limited to 'net/ipv4/ip_sockglue.c')
| -rw-r--r-- | net/ipv4/ip_sockglue.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index 57e1405e8282..900011709e3b 100644 --- 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, |