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 <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/tcp.h b/include/net/tcp.h
index a1d2f5d6a430f0a082d8860dc237b4935657466a..5aa6672c6f5bc9732cca6b36225afb82750c9cd1 100644 (file)
--- 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 6595affded202a9ab7d3f3be679f444fe19111e4..6b97b5f6457cf4fb672201162655ae7ff9080e28 100644 (file)
--- 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 2461b3ff9551bd10d7d697b32d15f1a9d2263e45..7606eba83e7b36f803271cd6e21ef5ea81aa0315 100644 (file)
--- 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);
 }