diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 61723a7..63ab660 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -96,6 +96,7 @@ enum { #define TCP_QUICKACK 12 /* Block/reenable quick acks */ #define TCP_CONGESTION 13 /* Congestion control algorithm */ #define TCP_MD5SIG 14 /* TCP MD5 Signature (RFC2385) */ +#define TCP_COOKIE_TRANSACTIONS 15 /* TCP Cookie Transactions */ #define TCPI_OPT_TIMESTAMPS 1 #define TCPI_OPT_SACK 2 @@ -170,6 +171,34 @@ struct tcp_md5sig { __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */ }; +/* for TCP_COOKIE_TRANSACTIONS (TCPCT) socket option */ +#define TCP_COOKIE_MAX 16 /* 128-bits */ +#define TCP_COOKIE_MIN 8 /* 64-bits */ +#define TCP_COOKIE_PAIR_SIZE (2*TCP_COOKIE_MAX) + +#define TCP_S_DATA_MAX 64U /* after TCP+IP options */ +#define TCP_S_DATA_MSS_DEFAULT 536U /* default MSS (RFC1122) */ + +/* Flags for both getsockopt and setsockopt */ +#define TCP_COOKIE_IN_ALWAYS (1 << 0) /* Discard SYN without cookie */ +#define TCP_COOKIE_OUT_NEVER (1 << 1) /* Prohibit outgoing cookies, + * supercedes everything else. */ +#define TCP_EXTEND_TIMESTAMP (1 << 4) /* Initiate 64-bit timestamps */ + +/* Flags for getsockopt */ +#define TCP_S_DATA_IN (1 << 2) /* Was data received? */ +#define TCP_S_DATA_OUT (1 << 3) /* Was data sent? */ + +/* TCP_COOKIE_TRANSACTIONS data */ +struct tcp_cookie_transactions { + __u16 tcpct_flags; /* see above */ + __u8 __tcpct_pad1; /* zero */ + __u8 tcpct_cookie_desired; /* bytes */ + __u16 tcpct_s_data_desired; /* bytes of variable data */ + __u16 tcpct_used; /* bytes in value */ + __u8 tcpct_value[TCP_S_DATA_MSS_DEFAULT]; +}; + #ifdef __KERNEL__ #include @@ -431,6 +460,6 @@ static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk) return (struct tcp_timewait_sock *)sk; } -#endif +#endif /* __KERNEL__ */ #endif /* _LINUX_TCP_H */ diff --git a/include/net/tcp.h b/include/net/tcp.h index 28bcaf7..63d17fd 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -237,6 +237,7 @@ extern int sysctl_tcp_base_mss; extern int sysctl_tcp_workaround_signed_windows; extern int sysctl_tcp_slow_start_after_idle; extern int sysctl_tcp_max_ssthresh; +extern int sysctl_tcp_cookie_size; extern atomic_t tcp_memory_allocated; extern struct percpu_counter tcp_sockets_allocated; diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 2dcf04d..3422c54 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -714,6 +714,14 @@ static struct ctl_table ipv4_table[] = { }, { .ctl_name = CTL_UNNUMBERED, + .procname = "tcp_cookie_size", + .data = &sysctl_tcp_cookie_size, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { + .ctl_name = CTL_UNNUMBERED, .procname = "udp_mem", .data = &sysctl_udp_mem, .maxlen = sizeof(sysctl_udp_mem), diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 765d80f..c235196 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -59,6 +59,14 @@ int sysctl_tcp_base_mss __read_mostly = 512; /* By default, RFC2861 behavior. */ int sysctl_tcp_slow_start_after_idle __read_mostly = 1; +#ifdef CONFIG_SYSCTL +/* By default, let the user enable it. */ +int sysctl_tcp_cookie_size __read_mostly = 0; +#else +int sysctl_tcp_cookie_size __read_mostly = TCP_COOKIE_MAX; +#endif + + /* Account for new data that has been sent to the network. */ static void tcp_event_new_data_sent(struct sock *sk, struct sk_buff *skb) { -- 1.6.0.4