diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_input.c | 29 | ||||
| -rw-r--r-- | net/ipv4/tcp_metrics.c | 13 | ||||
| -rw-r--r-- | net/ipv4/tcp_output.c | 6 | ||||
| -rw-r--r-- | net/ipv4/tcp_timer.c | 2 |
4 files changed, 36 insertions, 14 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 24f1630b2afb..031cf72cd05c 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5378,8 +5378,8 @@ static bool tcp_rcv_fastopen_synack(struct sock *sk, struct sk_buff *synack, { struct tcp_sock *tp = tcp_sk(sk); struct sk_buff *data = tp->syn_data ? tcp_write_queue_head(sk) : NULL; - u16 mss = tp->rx_opt.mss_clamp; - bool syn_drop; + u16 mss = tp->rx_opt.mss_clamp, try_exp = 0; + bool syn_drop = false; if (mss == tp->rx_opt.user_mss) { struct tcp_options_received opt; @@ -5391,16 +5391,25 @@ static bool tcp_rcv_fastopen_synack(struct sock *sk, struct sk_buff *synack, mss = opt.mss_clamp; } - if (!tp->syn_fastopen) /* Ignore an unsolicited cookie */ + if (!tp->syn_fastopen) { + /* Ignore an unsolicited cookie */ cookie->len = -1; + } else if (tp->total_retrans) { + /* SYN timed out and the SYN-ACK neither has a cookie nor + * acknowledges data. Presumably the remote received only + * the retransmitted (regular) SYNs: either the original + * SYN-data or the corresponding SYN-ACK was dropped. + */ + syn_drop = (cookie->len < 0 && data); + } else if (cookie->len < 0 && !tp->syn_data) { + /* We requested a cookie but didn't get it. If we did not use + * the (old) exp opt format then try so next time (try_exp=1). + * Otherwise we go back to use the RFC7413 opt (try_exp=2). + */ + try_exp = tp->syn_fastopen_exp ? 2 : 1; + } - /* The SYN-ACK neither has cookie nor acknowledges the data. Presumably - * the remote receives only the retransmitted (regular) SYNs: either - * the original SYN-data or the corresponding SYN-ACK is lost. - */ - syn_drop = (cookie->len <= 0 && data && tp->total_retrans); - - tcp_fastopen_cache_set(sk, mss, cookie, syn_drop); + tcp_fastopen_cache_set(sk, mss, cookie, syn_drop, try_exp); if (data) { /* Retransmit unacked data in SYN */ tcp_for_write_queue_from(data, sk) { diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c index 78ecc4a01712..a51d63a43e33 100644 --- a/net/ipv4/tcp_metrics.c +++ b/net/ipv4/tcp_metrics.c @@ -28,7 +28,8 @@ static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *s struct tcp_fastopen_metrics { u16 mss; - u16 syn_loss:10; /* Recurring Fast Open SYN losses */ + u16 syn_loss:10, /* Recurring Fast Open SYN losses */ + try_exp:2; /* Request w/ exp. option (once) */ unsigned long last_syn_loss; /* Last Fast Open SYN loss */ struct tcp_fastopen_cookie cookie; }; @@ -131,6 +132,8 @@ static void tcpm_suck_dst(struct tcp_metrics_block *tm, if (fastopen_clear) { tm->tcpm_fastopen.mss = 0; tm->tcpm_fastopen.syn_loss = 0; + tm->tcpm_fastopen.try_exp = 0; + tm->tcpm_fastopen.cookie.exp = false; tm->tcpm_fastopen.cookie.len = 0; } } @@ -713,6 +716,8 @@ void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, if (tfom->mss) *mss = tfom->mss; *cookie = tfom->cookie; + if (cookie->len <= 0 && tfom->try_exp == 1) + cookie->exp = true; *syn_loss = tfom->syn_loss; *last_syn_loss = *syn_loss ? tfom->last_syn_loss : 0; } while (read_seqretry(&fastopen_seqlock, seq)); @@ -721,7 +726,8 @@ void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, } void tcp_fastopen_cache_set(struct sock *sk, u16 mss, - struct tcp_fastopen_cookie *cookie, bool syn_lost) + struct tcp_fastopen_cookie *cookie, bool syn_lost, + u16 try_exp) { struct dst_entry *dst = __sk_dst_get(sk); struct tcp_metrics_block *tm; @@ -738,6 +744,9 @@ void tcp_fastopen_cache_set(struct sock *sk, u16 mss, tfom->mss = mss; if (cookie && cookie->len > 0) tfom->cookie = *cookie; + else if (try_exp > tfom->try_exp && + tfom->cookie.len <= 0 && !tfom->cookie.exp) + tfom->try_exp = try_exp; if (syn_lost) { ++tfom->syn_loss; tfom->last_syn_loss = jiffies; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 464bd8c5de69..e662d85d1635 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -592,13 +592,17 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb, } if (fastopen && fastopen->cookie.len >= 0) { - u32 need = TCPOLEN_EXP_FASTOPEN_BASE + fastopen->cookie.len; + u32 need = fastopen->cookie.len; + + need += fastopen->cookie.exp ? TCPOLEN_EXP_FASTOPEN_BASE : + TCPOLEN_FASTOPEN_BASE; need = (need + 3) & ~3U; /* Align to 32 bits */ if (remaining >= need) { opts->options |= OPTION_FAST_OPEN_COOKIE; opts->fastopen_cookie = &fastopen->cookie; remaining -= need; tp->syn_fastopen = 1; + tp->syn_fastopen_exp = fastopen->cookie.exp ? 1 : 0; } } diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 2568fd282873..8c65dc147d8b 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -167,7 +167,7 @@ static int tcp_write_timeout(struct sock *sk) if (icsk->icsk_retransmits) { dst_negative_advice(sk); if (tp->syn_fastopen || tp->syn_data) - tcp_fastopen_cache_set(sk, 0, NULL, true); + tcp_fastopen_cache_set(sk, 0, NULL, true, 0); if (tp->syn_data) NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFASTOPENACTIVEFAIL); |