From: "Toke H�iland-J�rgensen" toke@redhat.com
[ Upstream commit eebabcb26ea1e3295704477c6cd4e772c96a9559 ]
WireGuard currently only propagates ECN markings on tunnel decap according to the old RFC3168 specification. However, the spec has since been updated in RFC6040 to recommend slightly different decapsulation semantics. This was implemented in the kernel as a set of common helpers for ECN decapsulation, so let's just switch over WireGuard to using those, so it can benefit from this enhancement and any future tweaks. We do not drop packets with invalid ECN marking combinations, because WireGuard is frequently used to work around broken ISPs, which could be doing that.
Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Reported-by: Olivier Tilmans olivier.tilmans@nokia-bell-labs.com Cc: Dave Taht dave.taht@gmail.com Cc: Rodney W. Grimes ietf@gndrsh.dnsmgr.net Signed-off-by: Toke Høiland-Jørgensen toke@redhat.com Signed-off-by: Jason A. Donenfeld Jason@zx2c4.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/wireguard/receive.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
--- a/drivers/net/wireguard/receive.c +++ b/drivers/net/wireguard/receive.c @@ -393,13 +393,11 @@ static void wg_packet_consume_data_done( len = ntohs(ip_hdr(skb)->tot_len); if (unlikely(len < sizeof(struct iphdr))) goto dishonest_packet_size; - if (INET_ECN_is_ce(PACKET_CB(skb)->ds)) - IP_ECN_set_ce(ip_hdr(skb)); + INET_ECN_decapsulate(skb, PACKET_CB(skb)->ds, ip_hdr(skb)->tos); } else if (skb->protocol == htons(ETH_P_IPV6)) { len = ntohs(ipv6_hdr(skb)->payload_len) + sizeof(struct ipv6hdr); - if (INET_ECN_is_ce(PACKET_CB(skb)->ds)) - IP6_ECN_set_ce(skb, ipv6_hdr(skb)); + INET_ECN_decapsulate(skb, PACKET_CB(skb)->ds, ipv6_get_dsfield(ipv6_hdr(skb))); } else { goto dishonest_packet_type; }