4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Paolo Abeni pabeni@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 pabeni@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/udp.c | 49 ++++++++++++++++++++++++++----------------------- 1 file changed, 26 insertions(+), 23 deletions(-)
--- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1730,6 +1730,28 @@ 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. */ @@ -1776,14 +1798,9 @@ 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)) @@ -1791,22 +1808,8 @@ 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;