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| author | Eric Dumazet <edumazet@google.com> | 2017-02-02 08:04:56 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-02-03 11:19:34 -0500 |
| commit | 3541f9e8bdebce02458882b66b638d7302c1f616 (patch) | |
| tree | 1049ef01f68f197e66fa77f18768aaf6d219f8b1 /net/ipv4 | |
| parent | ff3edc9b8efc8200c25f3a5adfb1c1de0a882dc5 (diff) | |
| download | linux-stable-3541f9e8bdebce02458882b66b638d7302c1f616.tar.gz linux-stable-3541f9e8bdebce02458882b66b638d7302c1f616.tar.bz2 linux-stable-3541f9e8bdebce02458882b66b638d7302c1f616.zip | |
tcp: add tcp_mss_clamp() helper
Small cleanup factorizing code doing the TCP_MAXSEG clamping.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -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 |
3 files changed, 7 insertions, 19 deletions
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; |