[PATCH net-next 1/3] net/tcp-fastopen: refactor cookie check logic
From: Wei Wang <hidden>
Date: 2017-01-23 19:00:20
Subsystem:
networking [general], networking [tcp], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Neal Cardwell, Linus Torvalds
From: Wei Wang <redacted> Refactor the cookie check logic in tcp_send_syn_data() into a function. This function will be called else where in later changes. Signed-off-by: Wei Wang <redacted> --- include/net/tcp.h | 2 ++ net/ipv4/tcp_fastopen.c | 21 +++++++++++++++++++++ net/ipv4/tcp_output.c | 16 ++-------------- 3 files changed, 25 insertions(+), 14 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index c55d65f74f7f..de67541d7adf 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h@@ -1493,6 +1493,8 @@ struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, struct tcp_fastopen_cookie *foc, struct dst_entry *dst); void tcp_fastopen_init_key_once(bool publish); +bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, + struct tcp_fastopen_cookie *cookie); #define TCP_FASTOPEN_KEY_LENGTH 16 /* Fastopen key context */
diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index f51919535ca7..f90e09e1ff4c 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c@@ -325,3 +325,24 @@ struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, *foc = valid_foc; return NULL; } + +bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, + struct tcp_fastopen_cookie *cookie) +{ + unsigned long last_syn_loss = 0; + int syn_loss = 0; + + tcp_fastopen_cache_get(sk, mss, cookie, &syn_loss, &last_syn_loss); + + /* Recurring FO SYN losses: no cookie or data in SYN */ + if (syn_loss > 1 && + time_before(jiffies, last_syn_loss + (60*HZ << syn_loss))) { + cookie->len = -1; + return false; + } + if (sysctl_tcp_fastopen & TFO_CLIENT_NO_COOKIE) { + cookie->len = -1; + return true; + } + return cookie->len > 0; +}
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 9a1a1494b9dd..671c69535671 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c@@ -3267,23 +3267,11 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn) { struct tcp_sock *tp = tcp_sk(sk); struct tcp_fastopen_request *fo = tp->fastopen_req; - int syn_loss = 0, space, err = 0; - unsigned long last_syn_loss = 0; + int space, err = 0; struct sk_buff *syn_data; tp->rx_opt.mss_clamp = tp->advmss; /* If MSS is not cached */ - tcp_fastopen_cache_get(sk, &tp->rx_opt.mss_clamp, &fo->cookie, - &syn_loss, &last_syn_loss); - /* Recurring FO SYN losses: revert to regular handshake temporarily */ - if (syn_loss > 1 && - time_before(jiffies, last_syn_loss + (60*HZ << syn_loss))) { - fo->cookie.len = -1; - goto fallback; - } - - if (sysctl_tcp_fastopen & TFO_CLIENT_NO_COOKIE) - fo->cookie.len = -1; - else if (fo->cookie.len <= 0) + if (!tcp_fastopen_cookie_check(sk, &tp->rx_opt.mss_clamp, &fo->cookie)) goto fallback; /* MSS for SYN-data is based on cached MSS and bounded by PMTU and
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2.11.0.483.g087da7b7c-goog