Commit 34b99df4 authored by Julian Anastasov's avatar Julian Anastasov Committed by David S. Miller
Browse files

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: c247f053 ("ip: fix error queue empty skb handling")
Signed-off-by: default avatarJulian Anastasov <ja@ssi.bg>
Acked-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a076e6bf

net/ipv4/ip_sockglue.c

+10 −1
Original line number Diff line number Diff line
@@ -432,6 +432,15 @@ void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 inf 
		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 @@ int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len) 


	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);

net/ipv6/datagram.c

+11 −1
Original line number Diff line number Diff line
@@ -325,6 +325,16 @@ void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu) 
	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 ipv6_datagram_support_addr(struct sock_exterr_skb *serr)

{

	return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||

	       serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||

	       serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;

}



/* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.

 *

 * At one point, excluding local errors was a quick test to identify icmp/icmp6
@@ -389,7 +399,7 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len) 


	serr = SKB_EXT_ERR(skb);



	if (sin && serr->port) {

	if (sin && ipv6_datagram_support_addr(serr)) {

		const unsigned char *nh = skb_network_header(skb);

		sin->sin6_family = AF_INET6;

		sin->sin6_flowinfo = 0;

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