From 200ecef67b8d09d16ec55f91c92751dcc7a38d40 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 7 Nov 2019 11:51:18 -0800 Subject: [PATCH] tcp: Remove one extra ktime_get_ns() from cookie_init_timestamp tcp_make_synack() already uses tcp_clock_ns(), and can pass the value to cookie_init_timestamp() to avoid another call to ktime_get_ns() helper. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/tcp.h | 12 +++++++++--- net/ipv4/syncookies.c | 4 ++-- net/ipv4/tcp_output.c | 2 +- 3 files changed, 12 insertions(+), 6 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index ab4eb5e..36f195f 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -537,7 +537,7 @@ static inline u32 tcp_cookie_time(void) u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, u16 *mssp); __u32 cookie_v4_init_sequence(const struct sk_buff *skb, __u16 *mss); -u64 cookie_init_timestamp(struct request_sock *req); +u64 cookie_init_timestamp(struct request_sock *req, u64 now); bool cookie_timestamp_decode(const struct net *net, struct tcp_options_received *opt); bool cookie_ecn_ok(const struct tcp_options_received *opt, @@ -757,10 +757,16 @@ static inline u32 tcp_time_stamp(const struct tcp_sock *tp) return div_u64(tp->tcp_mstamp, USEC_PER_SEC / TCP_TS_HZ); } +/* Convert a nsec timestamp into TCP TSval timestamp (ms based currently) */ +static inline u32 tcp_ns_to_ts(u64 ns) +{ + return div_u64(ns, NSEC_PER_SEC / TCP_TS_HZ); +} + /* Could use tcp_clock_us() / 1000, but this version uses a single divide */ static inline u32 tcp_time_stamp_raw(void) { - return div_u64(tcp_clock_ns(), NSEC_PER_SEC / TCP_TS_HZ); + return tcp_ns_to_ts(tcp_clock_ns()); } void tcp_mstamp_refresh(struct tcp_sock *tp); @@ -772,7 +778,7 @@ static inline u32 tcp_stamp_us_delta(u64 t1, u64 t0) static inline u32 tcp_skb_timestamp(const struct sk_buff *skb) { - return div_u64(skb->skb_mstamp_ns, NSEC_PER_SEC / TCP_TS_HZ); + return tcp_ns_to_ts(skb->skb_mstamp_ns); } /* provide the departure time in us unit */ diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index 535b693..345b2b0 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -62,10 +62,10 @@ static u32 cookie_hash(__be32 saddr, __be32 daddr, __be16 sport, __be16 dport, * Since subsequent timestamps use the normal tcp_time_stamp value, we * must make sure that the resulting initial timestamp is <= tcp_time_stamp. */ -u64 cookie_init_timestamp(struct request_sock *req) +u64 cookie_init_timestamp(struct request_sock *req, u64 now) { struct inet_request_sock *ireq; - u32 ts, ts_now = tcp_time_stamp_raw(); + u32 ts, ts_now = tcp_ns_to_ts(now); u32 options = 0; ireq = inet_rsk(req); diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 0488607..be6d22b 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3290,7 +3290,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, now = tcp_clock_ns(); #ifdef CONFIG_SYN_COOKIES if (unlikely(req->cookie_ts)) - skb->skb_mstamp_ns = cookie_init_timestamp(req); + skb->skb_mstamp_ns = cookie_init_timestamp(req, now); else #endif { -- 2.7.4