diff options
| -rw-r--r-- | include/linux/tcp.h | 9 | ||||
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 5 | ||||
| -rw-r--r-- | net/ipv4/tcp_minisocks.c | 7 | ||||
| -rw-r--r-- | net/ipv4/tcp_output.c | 14 | ||||
| -rw-r--r-- | net/ipv6/tcp_ipv6.c | 5 |
5 files changed, 17 insertions, 23 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h index f88f4649ba6f..cfc2d9506ce8 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -445,4 +445,13 @@ static inline void tcp_saved_syn_free(struct tcp_sock *tp) struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk); +static inline u16 tcp_mss_clamp(const struct tcp_sock *tp, u16 mss) +{ + /* We use READ_ONCE() here because socket might not be locked. + * This happens for listeners. + */ + u16 user_mss = READ_ONCE(tp->rx_opt.user_mss); + + return (user_mss && user_mss < mss) ? user_mss : mss; +} #endif /* _LINUX_TCP_H */ diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 8c9e9aa17d66..8c124d4ef4b7 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1324,10 +1324,7 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, tcp_ca_openreq_child(newsk, dst); tcp_sync_mss(newsk, dst_mtu(dst)); - newtp->advmss = dst_metric_advmss(dst); - if (tcp_sk(sk)->rx_opt.user_mss && - tcp_sk(sk)->rx_opt.user_mss < newtp->advmss) - newtp->advmss = tcp_sk(sk)->rx_opt.user_mss; + newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst)); tcp_initialize_rcv_mss(newsk); diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index bdb443471c39..dff7d2aaf861 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -360,15 +360,12 @@ void tcp_openreq_init_rwin(struct request_sock *req, { struct inet_request_sock *ireq = inet_rsk(req); const struct tcp_sock *tp = tcp_sk(sk_listener); - u16 user_mss = READ_ONCE(tp->rx_opt.user_mss); int full_space = tcp_full_space(sk_listener); - int mss = dst_metric_advmss(dst); u32 window_clamp; __u8 rcv_wscale; + int mss; - if (user_mss && user_mss < mss) - mss = user_mss; - + mss = tcp_mss_clamp(tp, dst_metric_advmss(dst)); window_clamp = READ_ONCE(tp->window_clamp); /* Set this up on the first call only */ req->rsk_window_clamp = window_clamp ? : dst_metric(dst, RTAX_WINDOW); diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 6d5bab8a3ea6..956bea9a5394 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3062,7 +3062,6 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, struct sk_buff *skb; int tcp_header_size; struct tcphdr *th; - u16 user_mss; int mss; skb = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC); @@ -3092,10 +3091,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, } skb_dst_set(skb, dst); - mss = dst_metric_advmss(dst); - user_mss = READ_ONCE(tp->rx_opt.user_mss); - if (user_mss && user_mss < mss) - mss = user_mss; + mss = tcp_mss_clamp(tp, dst_metric_advmss(dst)); memset(&opts, 0, sizeof(opts)); #ifdef CONFIG_SYN_COOKIES @@ -3201,9 +3197,7 @@ static void tcp_connect_init(struct sock *sk) if (!tp->window_clamp) tp->window_clamp = dst_metric(dst, RTAX_WINDOW); - tp->advmss = dst_metric_advmss(dst); - if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < tp->advmss) - tp->advmss = tp->rx_opt.user_mss; + tp->advmss = tcp_mss_clamp(tp, dst_metric_advmss(dst)); tcp_initialize_rcv_mss(sk); @@ -3280,8 +3274,8 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn) * user-MSS. Reserve maximum option space for middleboxes that add * private TCP options. The cost is reduced data space in SYN :( */ - if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < tp->rx_opt.mss_clamp) - tp->rx_opt.mss_clamp = tp->rx_opt.user_mss; + tp->rx_opt.mss_clamp = tcp_mss_clamp(tp, tp->rx_opt.mss_clamp); + space = __tcp_mtu_to_mss(sk, inet_csk(sk)->icsk_pmtu_cookie) - MAX_TCP_OPTION_SPACE; diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 64834ec5ab73..6b9fc63fd4d2 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1147,10 +1147,7 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff * tcp_ca_openreq_child(newsk, dst); tcp_sync_mss(newsk, dst_mtu(dst)); - newtp->advmss = dst_metric_advmss(dst); - if (tcp_sk(sk)->rx_opt.user_mss && - tcp_sk(sk)->rx_opt.user_mss < newtp->advmss) - newtp->advmss = tcp_sk(sk)->rx_opt.user_mss; + newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst)); tcp_initialize_rcv_mss(newsk); |