diff options
Diffstat (limited to 'include/net/tcp.h')
| -rw-r--r-- | include/net/tcp.h | 131 |
1 files changed, 97 insertions, 34 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index 03a49c703377..34f5cc24d903 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -30,6 +30,7 @@ #include <linux/dmaengine.h> #include <linux/crypto.h> #include <linux/cryptohash.h> +#include <linux/kref.h> #include <net/inet_connection_sock.h> #include <net/inet_timewait_sock.h> @@ -62,9 +63,6 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); /* Minimal accepted MSS. It is (60+60+8) - (20+20). */ #define TCP_MIN_MSS 88U -/* Minimal RCV_MSS. */ -#define TCP_MIN_RCVMSS 536U - /* The least MTU to use for probing */ #define TCP_BASE_MSS 512 @@ -167,6 +165,7 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); #define TCPOPT_SACK 5 /* SACK Block */ #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */ +#define TCPOPT_COOKIE 253 /* Cookie extension (experimental) */ /* * TCP option lengths @@ -177,6 +176,10 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); #define TCPOLEN_SACK_PERM 2 #define TCPOLEN_TIMESTAMP 10 #define TCPOLEN_MD5SIG 18 +#define TCPOLEN_COOKIE_BASE 2 /* Cookie-less header extension */ +#define TCPOLEN_COOKIE_PAIR 3 /* Cookie pair header extension */ +#define TCPOLEN_COOKIE_MIN (TCPOLEN_COOKIE_BASE+TCP_COOKIE_MIN) +#define TCPOLEN_COOKIE_MAX (TCPOLEN_COOKIE_BASE+TCP_COOKIE_MAX) /* But this is what stacks really send out. */ #define TCPOLEN_TSTAMP_ALIGNED 12 @@ -237,6 +240,7 @@ 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; @@ -343,11 +347,6 @@ static inline void tcp_dec_quickack_mode(struct sock *sk, extern void tcp_enter_quickack_mode(struct sock *sk); -static inline void tcp_clear_options(struct tcp_options_received *rx_opt) -{ - rx_opt->tstamp_ok = rx_opt->sack_ok = rx_opt->wscale_ok = rx_opt->snd_wscale = 0; -} - #define TCP_ECN_OK 1 #define TCP_ECN_QUEUE_CWR 2 #define TCP_ECN_DEMAND_CWR 4 @@ -359,8 +358,7 @@ TCP_ECN_create_request(struct request_sock *req, struct tcphdr *th) inet_rsk(req)->ecn_ok = 1; } -enum tcp_tw_status -{ +enum tcp_tw_status { TCP_TW_SUCCESS = 0, TCP_TW_RST = 1, TCP_TW_ACK = 2, @@ -409,6 +407,7 @@ extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, extern void tcp_parse_options(struct sk_buff *skb, struct tcp_options_received *opt_rx, + u8 **hvpp, int estab); extern u8 *tcp_parse_md5sig_option(struct tcphdr *th); @@ -443,7 +442,8 @@ extern int tcp_connect(struct sock *sk); extern struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst, - struct request_sock *req); + struct request_sock *req, + struct request_values *rvp); extern int tcp_disconnect(struct sock *sk, int flags); @@ -1228,6 +1228,7 @@ static inline void tcp_write_queue_purge(struct sock *sk) while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) sk_wmem_free_skb(sk, skb); sk_mem_reclaim(sk); + tcp_clear_all_retrans_hints(tcp_sk(sk)); } static inline struct sk_buff *tcp_write_queue_head(struct sock *sk) @@ -1259,29 +1260,6 @@ static inline struct sk_buff *tcp_write_queue_prev(struct sock *sk, struct sk_bu #define tcp_for_write_queue_from_safe(skb, tmp, sk) \ skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp) -/* This function calculates a "timeout" which is equivalent to the timeout of a - * TCP connection after "boundary" unsucessful, exponentially backed-off - * retransmissions with an initial RTO of TCP_RTO_MIN. - */ -static inline bool retransmits_timed_out(const struct sock *sk, - unsigned int boundary) -{ - unsigned int timeout, linear_backoff_thresh; - - if (!inet_csk(sk)->icsk_retransmits) - return false; - - linear_backoff_thresh = ilog2(TCP_RTO_MAX/TCP_RTO_MIN); - - if (boundary <= linear_backoff_thresh) - timeout = ((2 << boundary) - 1) * TCP_RTO_MIN; - else - timeout = ((2 << linear_backoff_thresh) - 1) * TCP_RTO_MIN + - (boundary - linear_backoff_thresh) * TCP_RTO_MAX; - - return (tcp_time_stamp - tcp_sk(sk)->retrans_stamp) >= timeout; -} - static inline struct sk_buff *tcp_send_head(struct sock *sk) { return sk->sk_send_head; @@ -1480,6 +1458,91 @@ struct tcp_request_sock_ops { #endif }; +/* Using SHA1 for now, define some constants. + */ +#define COOKIE_DIGEST_WORDS (SHA_DIGEST_WORDS) +#define COOKIE_MESSAGE_WORDS (SHA_MESSAGE_BYTES / 4) +#define COOKIE_WORKSPACE_WORDS (COOKIE_DIGEST_WORDS + COOKIE_MESSAGE_WORDS) + +extern int tcp_cookie_generator(u32 *bakery); + +/** + * struct tcp_cookie_values - each socket needs extra space for the + * cookies, together with (optional) space for any SYN data. + * + * A tcp_sock contains a pointer to the current value, and this is + * cloned to the tcp_timewait_sock. + * + * @cookie_pair: variable data from the option exchange. + * + * @cookie_desired: user specified tcpct_cookie_desired. Zero + * indicates default (sysctl_tcp_cookie_size). + * After cookie sent, remembers size of cookie. + * Range 0, TCP_COOKIE_MIN to TCP_COOKIE_MAX. + * + * @s_data_desired: user specified tcpct_s_data_desired. When the + * constant payload is specified (@s_data_constant), + * holds its length instead. + * Range 0 to TCP_MSS_DESIRED. + * + * @s_data_payload: constant data that is to be included in the + * payload of SYN or SYNACK segments when the + * cookie option is present. + */ +struct tcp_cookie_values { + struct kref kref; + u8 cookie_pair[TCP_COOKIE_PAIR_SIZE]; + u8 cookie_pair_size; + u8 cookie_desired; + u16 s_data_desired:11, + s_data_constant:1, + s_data_in:1, + s_data_out:1, + s_data_unused:2; + u8 s_data_payload[0]; +}; + +static inline void tcp_cookie_values_release(struct kref *kref) +{ + kfree(container_of(kref, struct tcp_cookie_values, kref)); +} + +/* The length of constant payload data. Note that s_data_desired is + * overloaded, depending on s_data_constant: either the length of constant + * data (returned here) or the limit on variable data. + */ +static inline int tcp_s_data_size(const struct tcp_sock *tp) +{ + return (tp->cookie_values != NULL && tp->cookie_values->s_data_constant) + ? tp->cookie_values->s_data_desired + : 0; +} + +/** + * struct tcp_extend_values - tcp_ipv?.c to tcp_output.c workspace. + * + * As tcp_request_sock has already been extended in other places, the + * only remaining method is to pass stack values along as function + * parameters. These parameters are not needed after sending SYNACK. + * + * @cookie_bakery: cryptographic secret and message workspace. + * + * @cookie_plus: bytes in authenticator/cookie option, copied from + * struct tcp_options_received (above). + */ +struct tcp_extend_values { + struct request_values rv; + u32 cookie_bakery[COOKIE_WORKSPACE_WORDS]; + u8 cookie_plus:6, + cookie_out_never:1, + cookie_in_always:1; +}; + +static inline struct tcp_extend_values *tcp_xv(struct request_values *rvp) +{ + return (struct tcp_extend_values *)rvp; +} + extern void tcp_v4_init(void); extern void tcp_init(void); |