diff options
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/syncookies.c | 31 |
1 files changed, 21 insertions, 10 deletions
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index c3792c0557dd..6de772500ee9 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -241,10 +241,10 @@ static inline struct sock *get_cookie_sock(struct sock *sk, struct sk_buff *skb, * additional tcp options in the timestamp. * This extracts these options from the timestamp echo. * - * return false if we decode an option that should not be. + * return false if we decode a tcp option that is disabled + * on the host. */ -bool cookie_check_timestamp(struct tcp_options_received *tcp_opt, - struct net *net, bool *ecn_ok) +bool cookie_timestamp_decode(struct tcp_options_received *tcp_opt) { /* echoed timestamp, lowest bits contain options */ u32 options = tcp_opt->rcv_tsecr; @@ -258,9 +258,6 @@ bool cookie_check_timestamp(struct tcp_options_received *tcp_opt, return false; tcp_opt->sack_ok = (options & TS_OPT_SACK) ? TCP_SACK_SEEN : 0; - *ecn_ok = options & TS_OPT_ECN; - if (*ecn_ok && !net->ipv4.sysctl_tcp_ecn) - return false; if (tcp_opt->sack_ok && !sysctl_tcp_sack) return false; @@ -273,7 +270,22 @@ bool cookie_check_timestamp(struct tcp_options_received *tcp_opt, return sysctl_tcp_window_scaling != 0; } -EXPORT_SYMBOL(cookie_check_timestamp); +EXPORT_SYMBOL(cookie_timestamp_decode); + +bool cookie_ecn_ok(const struct tcp_options_received *tcp_opt, + const struct net *net) +{ + bool ecn_ok = tcp_opt->rcv_tsecr & TS_OPT_ECN; + + if (!ecn_ok) + return false; + + if (net->ipv4.sysctl_tcp_ecn) + return true; + + return false; +} +EXPORT_SYMBOL(cookie_ecn_ok); struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) { @@ -289,7 +301,6 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) int mss; struct rtable *rt; __u8 rcv_wscale; - bool ecn_ok = false; struct flowi4 fl4; if (!sysctl_tcp_syncookies || !th->ack || th->rst) @@ -310,7 +321,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) memset(&tcp_opt, 0, sizeof(tcp_opt)); tcp_parse_options(skb, &tcp_opt, 0, NULL); - if (!cookie_check_timestamp(&tcp_opt, sock_net(sk), &ecn_ok)) + if (!cookie_timestamp_decode(&tcp_opt)) goto out; ret = NULL; @@ -328,7 +339,6 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) ireq->ir_loc_addr = ip_hdr(skb)->daddr; ireq->ir_rmt_addr = ip_hdr(skb)->saddr; ireq->ir_mark = inet_request_mark(sk, skb); - ireq->ecn_ok = ecn_ok; ireq->snd_wscale = tcp_opt.snd_wscale; ireq->sack_ok = tcp_opt.sack_ok; ireq->wscale_ok = tcp_opt.wscale_ok; @@ -377,6 +387,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) dst_metric(&rt->dst, RTAX_INITRWND)); ireq->rcv_wscale = rcv_wscale; + ireq->ecn_ok = cookie_ecn_ok(&tcp_opt, sock_net(sk)); ret = get_cookie_sock(sk, skb, req, &rt->dst); /* ip_queue_xmit() depends on our flow being setup |