diff options
Diffstat (limited to 'include/net/tcp.h')
| -rw-r--r-- | include/net/tcp.h | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index c826ed7b007b..92faa6a7ea97 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -367,13 +367,6 @@ static inline void tcp_dec_quickack_mode(struct sock *sk, #define TCP_ECN_DEMAND_CWR 4 #define TCP_ECN_SEEN 8 -static __inline__ void -TCP_ECN_create_request(struct request_sock *req, struct tcphdr *th) -{ - if (sysctl_tcp_ecn && th->ece && th->cwr) - inet_rsk(req)->ecn_ok = 1; -} - enum tcp_tw_status { TCP_TW_SUCCESS = 0, TCP_TW_RST = 1, @@ -671,6 +664,22 @@ struct tcp_skb_cb { #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) +/* RFC3168 : 6.1.1 SYN packets must not have ECT/ECN bits set + * + * If we receive a SYN packet with these bits set, it means a network is + * playing bad games with TOS bits. In order to avoid possible false congestion + * notifications, we disable TCP ECN negociation. + */ +static inline void +TCP_ECN_create_request(struct request_sock *req, const struct sk_buff *skb) +{ + const struct tcphdr *th = tcp_hdr(skb); + + if (sysctl_tcp_ecn && th->ece && th->cwr && + INET_ECN_is_not_ect(TCP_SKB_CB(skb)->ip_dsfield)) + inet_rsk(req)->ecn_ok = 1; +} + /* Due to TSO, an SKB can be composed of multiple actual * packets. To keep these tracked properly, we use this. */ |