ip: report the original address of ICMP messages
ICMP messages can trigger ICMP and local errors. In this case
serr->port is 0 and starting from Linux 4.0 we do not return
the original target address to the error queue readers.
Add function to define which errors provide addr_offset.
With this fix my ping command is not silent anymore.
Fixes: c247f0534cc5 ("ip: fix error queue empty skb handling")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 7cfb089..6ddde89 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -432,6 +432,15 @@
kfree_skb(skb);
}
+/* For some errors we have valid addr_offset even with zero payload and
+ * zero port. Also, addr_offset should be supported if port is set.
+ */
+static inline bool ipv4_datagram_support_addr(struct sock_exterr_skb *serr)
+{
+ return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
+ serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
+}
+
/* IPv4 supports cmsg on all imcp errors and some timestamps
*
* Timestamp code paths do not initialize the fields expected by cmsg:
@@ -498,7 +507,7 @@
serr = SKB_EXT_ERR(skb);
- if (sin && serr->port) {
+ if (sin && ipv4_datagram_support_addr(serr)) {
sin->sin_family = AF_INET;
sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
serr->addr_offset);