From 3f684b4b1f1c86e3a6ac63389d1032e239fddd79 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 29 Sep 2015 07:42:49 -0700 Subject: [PATCH] tcp: cookie_init_sequence() cleanups Some common IPv4/IPv6 code can be factorized. Also constify cookie_init_sequence() socket argument. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/tcp.h | 19 ++++++++++--------- net/ipv4/syncookies.c | 6 +----- net/ipv6/syncookies.c | 5 +---- 3 files changed, 12 insertions(+), 18 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index a1d2f5d..5aa6672 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -491,8 +491,9 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb); /* syncookies: remember time of last synqueue overflow * But do not dirty this field too often (once per second is enough) + * It is racy as we do not hold a lock, but race is very minor. */ -static inline void tcp_synq_overflow(struct sock *sk) +static inline void tcp_synq_overflow(const struct sock *sk) { unsigned long last_overflow = tcp_sk(sk)->rx_opt.ts_recent_stamp; unsigned long now = jiffies; @@ -519,8 +520,7 @@ 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(struct sock *sk, const struct sk_buff *skb, - __u16 *mss); +__u32 cookie_v4_init_sequence(const struct sk_buff *skb, __u16 *mss); __u32 cookie_init_timestamp(struct request_sock *req); bool cookie_timestamp_decode(struct tcp_options_received *opt); bool cookie_ecn_ok(const struct tcp_options_received *opt, @@ -533,8 +533,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, const struct tcphdr *th, u16 *mssp); -__u32 cookie_v6_init_sequence(struct sock *sk, const struct sk_buff *skb, - __u16 *mss); +__u32 cookie_v6_init_sequence(const struct sk_buff *skb, __u16 *mss); #endif /* tcp_output.c */ @@ -1709,7 +1708,7 @@ struct tcp_request_sock_ops { const struct sock *sk_listener, struct sk_buff *skb); #ifdef CONFIG_SYN_COOKIES - __u32 (*cookie_init_seq)(struct sock *sk, const struct sk_buff *skb, + __u32 (*cookie_init_seq)(const struct sk_buff *skb, __u16 *mss); #endif struct dst_entry *(*route_req)(struct sock *sk, struct flowi *fl, @@ -1725,14 +1724,16 @@ struct tcp_request_sock_ops { #ifdef CONFIG_SYN_COOKIES static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, - struct sock *sk, struct sk_buff *skb, + const struct sock *sk, struct sk_buff *skb, __u16 *mss) { - return ops->cookie_init_seq(sk, skb, mss); + tcp_synq_overflow(sk); + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT); + return ops->cookie_init_seq(skb, mss); } #else static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, - struct sock *sk, struct sk_buff *skb, + const struct sock *sk, struct sk_buff *skb, __u16 *mss) { return 0; diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index 6595aff..6b97b5f 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -192,15 +192,11 @@ u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, } EXPORT_SYMBOL_GPL(__cookie_v4_init_sequence); -__u32 cookie_v4_init_sequence(struct sock *sk, const struct sk_buff *skb, - __u16 *mssp) +__u32 cookie_v4_init_sequence(const struct sk_buff *skb, __u16 *mssp) { const struct iphdr *iph = ip_hdr(skb); const struct tcphdr *th = tcp_hdr(skb); - tcp_synq_overflow(sk); - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT); - return __cookie_v4_init_sequence(iph, th, mssp); } diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c index 2461b3f..7606eba 100644 --- a/net/ipv6/syncookies.c +++ b/net/ipv6/syncookies.c @@ -114,14 +114,11 @@ u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, } EXPORT_SYMBOL_GPL(__cookie_v6_init_sequence); -__u32 cookie_v6_init_sequence(struct sock *sk, const struct sk_buff *skb, __u16 *mssp) +__u32 cookie_v6_init_sequence(const struct sk_buff *skb, __u16 *mssp) { const struct ipv6hdr *iph = ipv6_hdr(skb); const struct tcphdr *th = tcp_hdr(skb); - tcp_synq_overflow(sk); - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT); - return __cookie_v6_init_sequence(iph, th, mssp); } -- 2.7.4