From: Vadim Fedorenko <[email protected]> IPVS tunnel mode works as simple tunnel (see RFC 3168) copying ECN field to outer header. That's result in packet drops on egress tunnels in case the egress tunnel operates as ECN-capable with Full-functionality option (like ip_tunnel and ip6_tunnel kernel modules), according to RFC 3168 section 9.1.1 recommendation.
This patch implements ECN full-functionality option into ipvs xmit code. Cc: [email protected] Cc: [email protected] Signed-off-by: Vadim Fedorenko <[email protected]> Reviewed-by: Konstantin Khlebnikov <[email protected]> Acked-by: Julian Anastasov <[email protected]> Signed-off-by: Pablo Neira Ayuso <[email protected]> --- net/netfilter/ipvs/ip_vs_xmit.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c index 90d396814798..4527921b1c3a 100644 --- a/net/netfilter/ipvs/ip_vs_xmit.c +++ b/net/netfilter/ipvs/ip_vs_xmit.c @@ -921,6 +921,7 @@ ip_vs_prepare_tunneled_skb(struct sk_buff *skb, int skb_af, { struct sk_buff *new_skb = NULL; struct iphdr *old_iph = NULL; + __u8 old_dsfield; #ifdef CONFIG_IP_VS_IPV6 struct ipv6hdr *old_ipv6h = NULL; #endif @@ -945,7 +946,7 @@ ip_vs_prepare_tunneled_skb(struct sk_buff *skb, int skb_af, *payload_len = ntohs(old_ipv6h->payload_len) + sizeof(*old_ipv6h); - *dsfield = ipv6_get_dsfield(old_ipv6h); + old_dsfield = ipv6_get_dsfield(old_ipv6h); *ttl = old_ipv6h->hop_limit; if (df) *df = 0; @@ -960,12 +961,15 @@ ip_vs_prepare_tunneled_skb(struct sk_buff *skb, int skb_af, /* fix old IP header checksum */ ip_send_check(old_iph); - *dsfield = ipv4_get_dsfield(old_iph); + old_dsfield = ipv4_get_dsfield(old_iph); *ttl = old_iph->ttl; if (payload_len) *payload_len = ntohs(old_iph->tot_len); } + /* Implement full-functionality option for ECN encapsulation */ + *dsfield = INET_ECN_encapsulate(old_dsfield, old_dsfield); + return skb; error: kfree_skb(skb); -- 2.1.4
