From 10df8e6152c6c400a563a673e9956320bfce1871 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 23 Oct 2016 18:03:06 -0700 Subject: udp: fix IP_CHECKSUM handling First bug was added in commit ad6f939ab193 ("ip: Add offset parameter to ip_cmsg_recv") : Tom missed that ipv4 udp messages could be received on AF_INET6 socket. ip_cmsg_recv(msg, skb) should have been replaced by ip_cmsg_recv_offset(msg, skb, sizeof(struct udphdr)); Then commit e6afc8ace6dd ("udp: remove headers from UDP packets before queueing") forgot to adjust the offsets now UDP headers are pulled before skb are put in receive queue. Fixes: ad6f939ab193 ("ip: Add offset parameter to ip_cmsg_recv") Fixes: e6afc8ace6dd ("udp: remove headers from UDP packets before queueing") Signed-off-by: Eric Dumazet Cc: Sam Kumar Cc: Willem de Bruijn Tested-by: Willem de Bruijn Signed-off-by: David S. Miller --- net/ipv4/ip_sockglue.c | 11 ++++++----- net/ipv4/udp.c | 2 +- net/ipv6/udp.c | 3 ++- 3 files changed, 9 insertions(+), 7 deletions(-) (limited to 'net') diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index af4919792b6a..b8a2d63d1fb8 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -98,7 +98,7 @@ static void ip_cmsg_recv_retopts(struct msghdr *msg, struct sk_buff *skb) } static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb, - int offset) + int tlen, int offset) { __wsum csum = skb->csum; @@ -106,8 +106,9 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb, return; if (offset != 0) - csum = csum_sub(csum, csum_partial(skb_transport_header(skb), - offset, 0)); + csum = csum_sub(csum, + csum_partial(skb_transport_header(skb) + tlen, + offset, 0)); put_cmsg(msg, SOL_IP, IP_CHECKSUM, sizeof(__wsum), &csum); } @@ -153,7 +154,7 @@ static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb) } void ip_cmsg_recv_offset(struct msghdr *msg, struct sk_buff *skb, - int offset) + int tlen, int offset) { struct inet_sock *inet = inet_sk(skb->sk); unsigned int flags = inet->cmsg_flags; @@ -216,7 +217,7 @@ void ip_cmsg_recv_offset(struct msghdr *msg, struct sk_buff *skb, } if (flags & IP_CMSG_CHECKSUM) - ip_cmsg_recv_checksum(msg, skb, offset); + ip_cmsg_recv_checksum(msg, skb, tlen, offset); } EXPORT_SYMBOL(ip_cmsg_recv_offset); diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 311613e413cb..d123d68f4d1d 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1322,7 +1322,7 @@ try_again: *addr_len = sizeof(*sin); } if (inet->cmsg_flags) - ip_cmsg_recv_offset(msg, skb, sizeof(struct udphdr) + off); + ip_cmsg_recv_offset(msg, skb, sizeof(struct udphdr), off); err = copied; if (flags & MSG_TRUNC) diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 9aa7c1c7a9ce..b2ef061e6836 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -427,7 +427,8 @@ try_again: if (is_udp4) { if (inet->cmsg_flags) - ip_cmsg_recv(msg, skb); + ip_cmsg_recv_offset(msg, skb, + sizeof(struct udphdr), off); } else { if (np->rxopt.all) ip6_datagram_recv_specific_ctl(sk, msg, skb); -- cgit v1.2.3