4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Paolo Abeni <pab...@redhat.com>
[ Upstream commit 2b5a921740a55c00223a797d075b9c77c42cb171 ]
commit 2abb7cdc0dc8 ("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: 2abb7cdc0dc8 ("udp: Add support for doing checksum unnecessary
conversion")
Signed-off-by: Paolo Abeni <pab...@redhat.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
net/ipv4/udp.c | 49 ++++++++++++++++++++++++++-----------------------
1 file changed, 26 insertions(+), 23 deletions(-)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2128,6 +2128,28 @@ static inline int udp4_csum_init(struct
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.
*/
@@ -2174,14 +2196,9 @@ int __udp4_lib_rcv(struct sk_buff *skb,
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))
@@ -2189,22 +2206,8 @@ int __udp4_lib_rcv(struct sk_buff *skb,
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;
