Commit 2b5a9217 authored by Paolo Abeni's avatar Paolo Abeni Committed by David S. Miller
Browse files

udp4: fix IP_CMSG_CHECKSUM for connected sockets 



commit 2abb7cdc ("udp: Add support for doing checksum
unnecessary conversion") left out the early demux path for
connected sockets. As a result IP_CMSG_CHECKSUM gives wrong
values for such socket when GRO is not enabled/available.

This change addresses the issue by moving the csum conversion to a
common helper and using such helper in both the default and the
early demux rx path.

Fixes: 2abb7cdc ("udp: Add support for doing checksum unnecessary conversion")
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent edf2ef72

net/ipv4/udp.c

+26 −23
Original line number Diff line number Diff line
@@ -2124,6 +2124,28 @@ static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, 
							 inet_compute_pseudo);

}



/* wrapper for udp_queue_rcv_skb tacking care of csum conversion and

 * return code conversion for ip layer consumption

 */

static int udp_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,

			       struct udphdr *uh)

{

	int ret;



	if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))

		skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,

					 inet_compute_pseudo);



	ret = udp_queue_rcv_skb(sk, skb);



	/* a return value > 0 means to resubmit the input, but

	 * it wants the return to be -protocol, or 0

	 */

	if (ret > 0)

		return -ret;

	return 0;

}



/*

 *	All we need to do is get the socket, and then do a checksum.

 */
@@ -2170,14 +2192,9 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 
		if (unlikely(sk->sk_rx_dst != dst))

			udp_sk_rx_dst_set(sk, dst);



		ret = udp_queue_rcv_skb(sk, skb);

		ret = udp_unicast_rcv_skb(sk, skb, uh);

		sock_put(sk);

		/* a return value > 0 means to resubmit the input, but

		 * it wants the return to be -protocol, or 0

		 */

		if (ret > 0)

			return -ret;

		return 0;

		return ret;

	}



	if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
@@ -2185,22 +2202,8 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 
						saddr, daddr, udptable, proto);



	sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);

	if (sk) {

		int ret;



		if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))

			skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,

						 inet_compute_pseudo);



		ret = udp_queue_rcv_skb(sk, skb);



		/* a return value > 0 means to resubmit the input, but

		 * it wants the return to be -protocol, or 0

		 */

		if (ret > 0)

			return -ret;

		return 0;

	}

	if (sk)

		return udp_unicast_rcv_skb(sk, skb, uh);



	if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))

		goto drop;

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