From 1c19448c9ba6545b80ded18488a64a7f3d8e6998 Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Fri, 23 May 2014 08:47:32 -0700 Subject: net: Make enabling of zero UDP6 csums more restrictive RFC 6935 permits zero checksums to be used in IPv6 however this is recommended only for certain tunnel protocols, it does not make checksums completely optional like they are in IPv4. This patch restricts the use of IPv6 zero checksums that was previously intoduced. no_check6_tx and no_check6_rx have been added to control the use of checksums in UDP6 RX and TX path. The normal sk_no_check_{rx,tx} settings are not used (this avoids ambiguity when dealing with a dual stack socket). A helper function has been added (udp_set_no_check6) which can be called by tunnel impelmentations to all zero checksums (send on the socket, and accept them as valid). Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- net/ipv6/udp.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index b8db453..6032523 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -794,10 +794,10 @@ static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb, dif = inet6_iif(skb); sk = udp_v6_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif); while (sk) { - /* If zero checksum and sk_no_check is not on for + /* If zero checksum and no_check is not on for * the socket then skip it. */ - if (uh->check || sk->sk_no_check_rx) + if (uh->check || udp_sk(sk)->no_check6_rx) stack[count++] = sk; sk = udp_v6_mcast_next(net, sk_nulls_next(sk), uh->dest, daddr, @@ -887,7 +887,7 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, if (sk != NULL) { int ret; - if (!uh->check && !sk->sk_no_check_rx) { + if (!uh->check && !udp_sk(sk)->no_check6_rx) { sock_put(sk); udp6_csum_zero_error(skb); goto csum_error; @@ -1037,7 +1037,7 @@ static int udp_v6_push_pending_frames(struct sock *sk) if (is_udplite) csum = udplite_csum_outgoing(sk, skb); - else if (sk->sk_no_check_tx) { /* UDP csum disabled */ + else if (up->no_check6_tx) { /* UDP csum disabled */ skb->ip_summed = CHECKSUM_NONE; goto send; } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ -- cgit v1.1