[net-next-2.6.git] / include / linux / tcp.h

/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		Definitions for the TCP protocol.
 *
 * Version:	@(#)tcp.h	1.0.2	04/28/93
 *
 * Author:	Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 */
#ifndef _LINUX_TCP_H
#define _LINUX_TCP_H

#include <linux/types.h>
#include <asm/byteorder.h>

struct tcphdr {
	__u16	source;
	__u16	dest;
	__u32	seq;
	__u32	ack_seq;
#if defined(__LITTLE_ENDIAN_BITFIELD)
	__u16	res1:4,
		doff:4,
		fin:1,
		syn:1,
		rst:1,
		psh:1,
		ack:1,
		urg:1,
		ece:1,
		cwr:1;
#elif defined(__BIG_ENDIAN_BITFIELD)
	__u16	doff:4,
		res1:4,
		cwr:1,
		ece:1,
		urg:1,
		ack:1,
		psh:1,
		rst:1,
		syn:1,
		fin:1;
#else
#error	"Adjust your <asm/byteorder.h> defines"
#endif	
	__u16	window;
	__u16	check;
	__u16	urg_ptr;
};

#define TCP_ACTION_FIN	(1 << 7)

enum {
  TCPF_ESTABLISHED = (1 << 1),
  TCPF_SYN_SENT  = (1 << 2),
  TCPF_SYN_RECV  = (1 << 3),
  TCPF_FIN_WAIT1 = (1 << 4),
  TCPF_FIN_WAIT2 = (1 << 5),
  TCPF_TIME_WAIT = (1 << 6),
  TCPF_CLOSE     = (1 << 7),
  TCPF_CLOSE_WAIT = (1 << 8),
  TCPF_LAST_ACK  = (1 << 9),
  TCPF_LISTEN    = (1 << 10),
  TCPF_CLOSING   = (1 << 11) 
};

/*
 *	The union cast uses a gcc extension to avoid aliasing problems
 *  (union is compatible to any of its members)
 *  This means this part of the code is -fstrict-aliasing safe now.
 */
union tcp_word_hdr { 
	struct tcphdr hdr;
	__u32 		  words[5];
}; 

#define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3]) 

enum { 
	TCP_FLAG_CWR = __constant_htonl(0x00800000), 
	TCP_FLAG_ECE = __constant_htonl(0x00400000), 
	TCP_FLAG_URG = __constant_htonl(0x00200000), 
	TCP_FLAG_ACK = __constant_htonl(0x00100000), 
	TCP_FLAG_PSH = __constant_htonl(0x00080000), 
	TCP_FLAG_RST = __constant_htonl(0x00040000), 
	TCP_FLAG_SYN = __constant_htonl(0x00020000), 
	TCP_FLAG_FIN = __constant_htonl(0x00010000),
	TCP_RESERVED_BITS = __constant_htonl(0x0F000000),
	TCP_DATA_OFFSET = __constant_htonl(0xF0000000)
}; 

/* TCP socket options */
#define TCP_NODELAY		1	/* Turn off Nagle's algorithm. */
#define TCP_MAXSEG		2	/* Limit MSS */
#define TCP_CORK		3	/* Never send partially complete segments */
#define TCP_KEEPIDLE		4	/* Start keeplives after this period */
#define TCP_KEEPINTVL		5	/* Interval between keepalives */
#define TCP_KEEPCNT		6	/* Number of keepalives before death */
#define TCP_SYNCNT		7	/* Number of SYN retransmits */
#define TCP_LINGER2		8	/* Life time of orphaned FIN-WAIT-2 state */
#define TCP_DEFER_ACCEPT	9	/* Wake up listener only when data arrive */
#define TCP_WINDOW_CLAMP	10	/* Bound advertised window */
#define TCP_INFO		11	/* Information about this connection. */
#define TCP_QUICKACK		12	/* Block/reenable quick acks */
#define TCP_CONGESTION		13	/* Congestion control algorithm */

#define TCPI_OPT_TIMESTAMPS	1
#define TCPI_OPT_SACK		2
#define TCPI_OPT_WSCALE		4
#define TCPI_OPT_ECN		8

enum tcp_ca_state
{
	TCP_CA_Open = 0,
#define TCPF_CA_Open	(1<<TCP_CA_Open)
	TCP_CA_Disorder = 1,
#define TCPF_CA_Disorder (1<<TCP_CA_Disorder)
	TCP_CA_CWR = 2,
#define TCPF_CA_CWR	(1<<TCP_CA_CWR)
	TCP_CA_Recovery = 3,
#define TCPF_CA_Recovery (1<<TCP_CA_Recovery)
	TCP_CA_Loss = 4
#define TCPF_CA_Loss	(1<<TCP_CA_Loss)
};

struct tcp_info
{
	__u8	tcpi_state;
	__u8	tcpi_ca_state;
	__u8	tcpi_retransmits;
	__u8	tcpi_probes;
	__u8	tcpi_backoff;
	__u8	tcpi_options;
	__u8	tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;

	__u32	tcpi_rto;
	__u32	tcpi_ato;
	__u32	tcpi_snd_mss;
	__u32	tcpi_rcv_mss;

	__u32	tcpi_unacked;
	__u32	tcpi_sacked;
	__u32	tcpi_lost;
	__u32	tcpi_retrans;
	__u32	tcpi_fackets;

	/* Times. */
	__u32	tcpi_last_data_sent;
	__u32	tcpi_last_ack_sent;     /* Not remembered, sorry. */
	__u32	tcpi_last_data_recv;
	__u32	tcpi_last_ack_recv;

	/* Metrics. */
	__u32	tcpi_pmtu;
	__u32	tcpi_rcv_ssthresh;
	__u32	tcpi_rtt;
	__u32	tcpi_rttvar;
	__u32	tcpi_snd_ssthresh;
	__u32	tcpi_snd_cwnd;
	__u32	tcpi_advmss;
	__u32	tcpi_reordering;

	__u32	tcpi_rcv_rtt;
	__u32	tcpi_rcv_space;

	__u32	tcpi_total_retrans;
};

#ifdef __KERNEL__

#include <linux/config.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/inet_connection_sock.h>
#include <net/inet_timewait_sock.h>

/* This defines a selective acknowledgement block. */
struct tcp_sack_block {
	__u32	start_seq;
	__u32	end_seq;
};

struct tcp_options_received {
/*	PAWS/RTTM data	*/
	long	ts_recent_stamp;/* Time we stored ts_recent (for aging) */
	__u32	ts_recent;	/* Time stamp to echo next		*/
	__u32	rcv_tsval;	/* Time stamp value             	*/
	__u32	rcv_tsecr;	/* Time stamp echo reply        	*/
	__u16 	saw_tstamp : 1,	/* Saw TIMESTAMP on last packet		*/
		tstamp_ok : 1,	/* TIMESTAMP seen on SYN packet		*/
		dsack : 1,	/* D-SACK is scheduled			*/
		wscale_ok : 1,	/* Wscale seen on SYN packet		*/
		sack_ok : 4,	/* SACK seen on SYN packet		*/
		snd_wscale : 4,	/* Window scaling received from sender	*/
		rcv_wscale : 4;	/* Window scaling to send to receiver	*/
/*	SACKs data	*/
	__u8	eff_sacks;	/* Size of SACK array to send with next packet */
	__u8	num_sacks;	/* Number of SACK blocks		*/
	__u16	user_mss;  	/* mss requested by user in ioctl */
	__u16	mss_clamp;	/* Maximal mss, negotiated at connection setup */
};

struct tcp_request_sock {
	struct inet_request_sock req;
	__u32			 rcv_isn;
	__u32			 snt_isn;
};

static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)
{
	return (struct tcp_request_sock *)req;
}

struct tcp_sock {
	/* inet_connection_sock has to be the first member of tcp_sock */
	struct inet_connection_sock	inet_conn;
	int	tcp_header_len;	/* Bytes of tcp header to send		*/

/*
 *	Header prediction flags
 *	0x5?10 << 16 + snd_wnd in net byte order
 */
	__u32	pred_flags;

/*
 *	RFC793 variables by their proper names. This means you can
 *	read the code and the spec side by side (and laugh ...)
 *	See RFC793 and RFC1122. The RFC writes these in capitals.
 */
 	__u32	rcv_nxt;	/* What we want to receive next 	*/
 	__u32	snd_nxt;	/* Next sequence we send		*/

 	__u32	snd_una;	/* First byte we want an ack for	*/
 	__u32	snd_sml;	/* Last byte of the most recently transmitted small packet */
	__u32	rcv_tstamp;	/* timestamp of last received ACK (for keepalives) */
	__u32	lsndtime;	/* timestamp of last sent data packet (for restart window) */

	/* Data for direct copy to user */
	struct {
		struct sk_buff_head	prequeue;
		struct task_struct	*task;
		struct iovec		*iov;
		int			memory;
		int			len;
	} ucopy;

	__u32	snd_wl1;	/* Sequence for window update		*/
	__u32	snd_wnd;	/* The window we expect to receive	*/
	__u32	max_window;	/* Maximal window ever seen from peer	*/
	__u32	pmtu_cookie;	/* Last pmtu seen by socket		*/
	__u32	mss_cache;	/* Cached effective mss, not including SACKS */
	__u16	xmit_size_goal;	/* Goal for segmenting output packets	*/
	__u16	ext_header_len;	/* Network protocol overhead (IP/IPv6 options) */
	__u8	ca_state;	/* State of fast-retransmit machine 	*/

	__u8	keepalive_probes; /* num of allowed keep alive probes	*/
	__u16	advmss;		/* Advertised MSS			*/
	__u32	window_clamp;	/* Maximal window to advertise		*/
	__u32	rcv_ssthresh;	/* Current window clamp			*/

	__u32	frto_highmark;	/* snd_nxt when RTO occurred */
	__u8	reordering;	/* Packet reordering metric.		*/
	__u8	frto_counter;	/* Number of new acks after RTO */

	__u8	nonagle;	/* Disable Nagle algorithm?             */
	__u8	defer_accept;	/* User waits for some data after accept() */

/* RTT measurement */
	__u32	srtt;		/* smoothed round trip time << 3	*/
	__u32	mdev;		/* medium deviation			*/
	__u32	mdev_max;	/* maximal mdev for the last rtt period	*/
	__u32	rttvar;		/* smoothed mdev_max			*/
	__u32	rtt_seq;	/* sequence number to update rttvar	*/

	__u32	packets_out;	/* Packets which are "in flight"	*/
	__u32	left_out;	/* Packets which leaved network	*/
	__u32	retrans_out;	/* Retransmitted packets out		*/
/*
 *      Options received (usually on last packet, some only on SYN packets).
 */
	struct tcp_options_received rx_opt;

/*
 *	Slow start and congestion control (see also Nagle, and Karn & Partridge)
 */
 	__u32	snd_ssthresh;	/* Slow start size threshold		*/
 	__u32	snd_cwnd;	/* Sending congestion window		*/
 	__u16	snd_cwnd_cnt;	/* Linear increase counter		*/
	__u16	snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */
	__u32	snd_cwnd_used;
	__u32	snd_cwnd_stamp;

	struct sk_buff_head	out_of_order_queue; /* Out of order segments go here */

	struct tcp_func		*af_specific;	/* Operations which are AF_INET{4,6} specific	*/

 	__u32	rcv_wnd;	/* Current receiver window		*/
	__u32	rcv_wup;	/* rcv_nxt on last window update sent	*/
	__u32	write_seq;	/* Tail(+1) of data held in tcp send buffer */
	__u32	pushed_seq;	/* Last pushed seq, required to talk to windows */
	__u32	copied_seq;	/* Head of yet unread data		*/

/*	SACKs data	*/
	struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */
	struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/

	__u8	probes_out;	/* unanswered 0 window probes		*/
	__u8	ecn_flags;	/* ECN status bits.			*/
	__u16	prior_ssthresh; /* ssthresh saved at recovery start	*/
	__u32	lost_out;	/* Lost packets			*/
	__u32	sacked_out;	/* SACK'd packets			*/
	__u32	fackets_out;	/* FACK'd packets			*/
	__u32	high_seq;	/* snd_nxt at onset of congestion	*/

	__u32	retrans_stamp;	/* Timestamp of the last retransmit,
				 * also used in SYN-SENT to remember stamp of
				 * the first SYN. */
	__u32	undo_marker;	/* tracking retrans started here. */
	int	undo_retrans;	/* number of undoable retransmissions. */
	__u32	urg_seq;	/* Seq of received urgent pointer */
	__u16	urg_data;	/* Saved octet of OOB data and control flags */
	__u8	urg_mode;	/* In urgent mode		*/
	/* ONE BYTE HOLE, TRY TO PACK! */
	__u32	snd_up;		/* Urgent pointer		*/

	__u32	total_retrans;	/* Total retransmits for entire connection */

	unsigned int		keepalive_time;	  /* time before keep alive takes place */
	unsigned int		keepalive_intvl;  /* time interval between keep alive probes */
	int			linger2;

	unsigned long last_synq_overflow; 

/* Receiver side RTT estimation */
	struct {
		__u32	rtt;
		__u32	seq;
		__u32	time;
	} rcv_rtt_est;

/* Receiver queue space */
	struct {
		int	space;
		__u32	seq;
		__u32	time;
	} rcvq_space;

	/* Pluggable TCP congestion control hook */
	struct tcp_congestion_ops *ca_ops;
	u32	ca_priv[16];
#define TCP_CA_PRIV_SIZE	(16*sizeof(u32))
};

static inline struct tcp_sock *tcp_sk(const struct sock *sk)
{
	return (struct tcp_sock *)sk;
}

struct tcp_timewait_sock {
	struct inet_timewait_sock tw_sk;
	__u32			  tw_rcv_nxt;
	__u32			  tw_snd_nxt;
	__u32			  tw_rcv_wnd;
	__u32			  tw_ts_recent;
	long			  tw_ts_recent_stamp;
};

static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk)
{
	return (struct tcp_timewait_sock *)sk;
}

static inline void *tcp_ca(const struct tcp_sock *tp)
{
	return (void *) tp->ca_priv;
}

#endif

#endif	/* _LINUX_TCP_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* INET An implementation of the TCP/IP protocol suite for the LINUX
	3	* operating system. INET is implemented using the BSD Socket
	4	* interface as the means of communication with the user level.
	5	*
	6	* Definitions for the TCP protocol.
	7	*
	8	* Version: @(#)tcp.h 1.0.2 04/28/93
	9	*
	10	* Author: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
	11	*
	12	* This program is free software; you can redistribute it and/or
	13	* modify it under the terms of the GNU General Public License
	14	* as published by the Free Software Foundation; either version
	15	* 2 of the License, or (at your option) any later version.
	16	*/
	17	#ifndef _LINUX_TCP_H
	18	#define _LINUX_TCP_H
	19
	20	#include <linux/types.h>
	21	#include <asm/byteorder.h>
	22
	23	struct tcphdr {
	24	__u16 source;
	25	__u16 dest;
	26	__u32 seq;
	27	__u32 ack_seq;
	28	#if defined(__LITTLE_ENDIAN_BITFIELD)
	29	__u16 res1:4,
	30	doff:4,
	31	fin:1,
	32	syn:1,
	33	rst:1,
	34	psh:1,
	35	ack:1,
	36	urg:1,
	37	ece:1,
	38	cwr:1;
	39	#elif defined(__BIG_ENDIAN_BITFIELD)
	40	__u16 doff:4,
	41	res1:4,
	42	cwr:1,
	43	ece:1,
	44	urg:1,
	45	ack:1,
	46	psh:1,
	47	rst:1,
	48	syn:1,
	49	fin:1;
	50	#else
	51	#error "Adjust your <asm/byteorder.h> defines"
	52	#endif
	53	__u16 window;
	54	__u16 check;
	55	__u16 urg_ptr;
	56	};
	57
1da177e4 LT	58	#define TCP_ACTION_FIN (1 << 7)
	59
	60	enum {
	61	TCPF_ESTABLISHED = (1 << 1),
	62	TCPF_SYN_SENT = (1 << 2),
	63	TCPF_SYN_RECV = (1 << 3),
	64	TCPF_FIN_WAIT1 = (1 << 4),
	65	TCPF_FIN_WAIT2 = (1 << 5),
	66	TCPF_TIME_WAIT = (1 << 6),
	67	TCPF_CLOSE = (1 << 7),
	68	TCPF_CLOSE_WAIT = (1 << 8),
	69	TCPF_LAST_ACK = (1 << 9),
	70	TCPF_LISTEN = (1 << 10),
	71	TCPF_CLOSING = (1 << 11)
	72	};
	73
	74	/*
	75	* The union cast uses a gcc extension to avoid aliasing problems
	76	* (union is compatible to any of its members)
	77	* This means this part of the code is -fstrict-aliasing safe now.
	78	*/
	79	union tcp_word_hdr {
	80	struct tcphdr hdr;
	81	__u32 words[5];
	82	};
	83
	84	#define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3])
	85
	86	enum {
	87	TCP_FLAG_CWR = __constant_htonl(0x00800000),
	88	TCP_FLAG_ECE = __constant_htonl(0x00400000),
	89	TCP_FLAG_URG = __constant_htonl(0x00200000),
	90	TCP_FLAG_ACK = __constant_htonl(0x00100000),
	91	TCP_FLAG_PSH = __constant_htonl(0x00080000),
	92	TCP_FLAG_RST = __constant_htonl(0x00040000),
	93	TCP_FLAG_SYN = __constant_htonl(0x00020000),
	94	TCP_FLAG_FIN = __constant_htonl(0x00010000),
	95	TCP_RESERVED_BITS = __constant_htonl(0x0F000000),
	96	TCP_DATA_OFFSET = __constant_htonl(0xF0000000)
	97	};
	98
	99	/* TCP socket options */
	100	#define TCP_NODELAY 1 /* Turn off Nagle's algorithm. */
	101	#define TCP_MAXSEG 2 /* Limit MSS */
	102	#define TCP_CORK 3 /* Never send partially complete segments */
	103	#define TCP_KEEPIDLE 4 /* Start keeplives after this period */
	104	#define TCP_KEEPINTVL 5 /* Interval between keepalives */
	105	#define TCP_KEEPCNT 6 /* Number of keepalives before death */
	106	#define TCP_SYNCNT 7 /* Number of SYN retransmits */
	107	#define TCP_LINGER2 8 /* Life time of orphaned FIN-WAIT-2 state */
	108	#define TCP_DEFER_ACCEPT 9 /* Wake up listener only when data arrive */
	109	#define TCP_WINDOW_CLAMP 10 /* Bound advertised window */
	110	#define TCP_INFO 11 /* Information about this connection. */
	111	#define TCP_QUICKACK 12 /* Block/reenable quick acks */
5f8ef48d	112	#define TCP_CONGESTION 13 /* Congestion control algorithm */
1da177e4 LT	113
	114	#define TCPI_OPT_TIMESTAMPS 1
	115	#define TCPI_OPT_SACK 2
	116	#define TCPI_OPT_WSCALE 4
	117	#define TCPI_OPT_ECN 8
	118
	119	enum tcp_ca_state
	120	{
	121	TCP_CA_Open = 0,
	122	#define TCPF_CA_Open (1<<TCP_CA_Open)
	123	TCP_CA_Disorder = 1,
	124	#define TCPF_CA_Disorder (1<<TCP_CA_Disorder)
	125	TCP_CA_CWR = 2,
	126	#define TCPF_CA_CWR (1<<TCP_CA_CWR)
	127	TCP_CA_Recovery = 3,
	128	#define TCPF_CA_Recovery (1<<TCP_CA_Recovery)
	129	TCP_CA_Loss = 4
	130	#define TCPF_CA_Loss (1<<TCP_CA_Loss)
	131	};
	132
	133	struct tcp_info
	134	{
	135	__u8 tcpi_state;
	136	__u8 tcpi_ca_state;
	137	__u8 tcpi_retransmits;
	138	__u8 tcpi_probes;
	139	__u8 tcpi_backoff;
	140	__u8 tcpi_options;
	141	__u8 tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;
	142
	143	__u32 tcpi_rto;
	144	__u32 tcpi_ato;
	145	__u32 tcpi_snd_mss;
	146	__u32 tcpi_rcv_mss;
	147
	148	__u32 tcpi_unacked;
	149	__u32 tcpi_sacked;
	150	__u32 tcpi_lost;
	151	__u32 tcpi_retrans;
	152	__u32 tcpi_fackets;
	153
	154	/* Times. */
	155	__u32 tcpi_last_data_sent;
	156	__u32 tcpi_last_ack_sent; /* Not remembered, sorry. */
	157	__u32 tcpi_last_data_recv;
	158	__u32 tcpi_last_ack_recv;
	159
	160	/* Metrics. */
	161	__u32 tcpi_pmtu;
	162	__u32 tcpi_rcv_ssthresh;
	163	__u32 tcpi_rtt;
	164	__u32 tcpi_rttvar;
	165	__u32 tcpi_snd_ssthresh;
	166	__u32 tcpi_snd_cwnd;
	167	__u32 tcpi_advmss;
	168	__u32 tcpi_reordering;
	169
	170	__u32 tcpi_rcv_rtt;
	171	__u32 tcpi_rcv_space;
	172
	173	__u32 tcpi_total_retrans;
	174	};
	175
	176	#ifdef __KERNEL__
177
178	#include <linux/config.h>
179	#include <linux/skbuff.h>
1da177e4	180	#include <net/sock.h>
463c84b9	181	#include <net/inet_connection_sock.h>
8feaf0c0	182	#include <net/inet_timewait_sock.h>
1da177e4 LT	183
	184	/* This defines a selective acknowledgement block. */
	185	struct tcp_sack_block {
	186	__u32 start_seq;
	187	__u32 end_seq;
	188	};
	189
1da177e4 LT	190	struct tcp_options_received {
	191	/* PAWS/RTTM data */
	192	long ts_recent_stamp;/* Time we stored ts_recent (for aging) */
	193	__u32 ts_recent; /* Time stamp to echo next */
	194	__u32 rcv_tsval; /* Time stamp value */
	195	__u32 rcv_tsecr; /* Time stamp echo reply */
	196	__u16 saw_tstamp : 1, /* Saw TIMESTAMP on last packet */
	197	tstamp_ok : 1, /* TIMESTAMP seen on SYN packet */
	198	dsack : 1, /* D-SACK is scheduled */
	199	wscale_ok : 1, /* Wscale seen on SYN packet */
	200	sack_ok : 4, /* SACK seen on SYN packet */
	201	snd_wscale : 4, /* Window scaling received from sender */
	202	rcv_wscale : 4; /* Window scaling to send to receiver */
	203	/* SACKs data */
	204	__u8 eff_sacks; /* Size of SACK array to send with next packet */
	205	__u8 num_sacks; /* Number of SACK blocks */
	206	__u16 user_mss; /* mss requested by user in ioctl */
	207	__u16 mss_clamp; /* Maximal mss, negotiated at connection setup */
	208	};
	209
2e6599cb ACM	210	struct tcp_request_sock {
	211	struct inet_request_sock req;
	212	__u32 rcv_isn;
	213	__u32 snt_isn;
	214	};
	215
60236fdd	216	static inline struct tcp_request_sock tcp_rsk(const struct request_sock req)
2e6599cb ACM	217	{
	218	return (struct tcp_request_sock *)req;
	219	}
	220
1da177e4	221	struct tcp_sock {
463c84b9 ACM	222	/* inet_connection_sock has to be the first member of tcp_sock */
463c84b9 ACM	223	struct inet_connection_sock inet_conn;
1da177e4 LT	224	int tcp_header_len; /* Bytes of tcp header to send */
	225
	226	/*
	227	* Header prediction flags
	228	* 0x5?10 << 16 + snd_wnd in net byte order
	229	*/
	230	__u32 pred_flags;
	231
	232	/*
	233	* RFC793 variables by their proper names. This means you can
	234	* read the code and the spec side by side (and laugh ...)
	235	* See RFC793 and RFC1122. The RFC writes these in capitals.
	236	*/
	237	__u32 rcv_nxt; /* What we want to receive next */
	238	__u32 snd_nxt; /* Next sequence we send */
	239
	240	__u32 snd_una; /* First byte we want an ack for */
	241	__u32 snd_sml; /* Last byte of the most recently transmitted small packet */
	242	__u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */
	243	__u32 lsndtime; /* timestamp of last sent data packet (for restart window) */
1da177e4 LT	244
	245	/* Data for direct copy to user */
	246	struct {
	247	struct sk_buff_head prequeue;
	248	struct task_struct *task;
	249	struct iovec *iov;
	250	int memory;
	251	int len;
	252	} ucopy;
	253
	254	__u32 snd_wl1; /* Sequence for window update */
	255	__u32 snd_wnd; /* The window we expect to receive */
	256	__u32 max_window; /* Maximal window ever seen from peer */
	257	__u32 pmtu_cookie; /* Last pmtu seen by socket */
	258	__u32 mss_cache; /* Cached effective mss, not including SACKS */
c1b4a7e6	259	__u16 xmit_size_goal; /* Goal for segmenting output packets */
1da177e4 LT	260	__u16 ext_header_len; /* Network protocol overhead (IP/IPv6 options) */
1da177e4 LT	261	__u8 ca_state; /* State of fast-retransmit machine */
1da177e4	262
463c84b9	263	__u8 keepalive_probes; /* num of allowed keep alive probes */
1da177e4 LT	264	__u16 advmss; /* Advertised MSS */
	265	__u32 window_clamp; /* Maximal window to advertise */
	266	__u32 rcv_ssthresh; /* Current window clamp */
	267
	268	__u32 frto_highmark; /* snd_nxt when RTO occurred */
	269	__u8 reordering; /* Packet reordering metric. */
	270	__u8 frto_counter; /* Number of new acks after RTO */
	271
463c84b9	272	__u8 nonagle; /* Disable Nagle algorithm? */
1da177e4 LT	273	__u8 defer_accept; /* User waits for some data after accept() */
	274
	275	/* RTT measurement */
	276	__u32 srtt; /* smoothed round trip time << 3 */
	277	__u32 mdev; /* medium deviation */
	278	__u32 mdev_max; /* maximal mdev for the last rtt period */
	279	__u32 rttvar; /* smoothed mdev_max */
	280	__u32 rtt_seq; /* sequence number to update rttvar */
1da177e4 LT	281
	282	__u32 packets_out; /* Packets which are "in flight" */
	283	__u32 left_out; /* Packets which leaved network */
	284	__u32 retrans_out; /* Retransmitted packets out */
1da177e4 LT	285	/*
	286	* Options received (usually on last packet, some only on SYN packets).
	287	*/
1da177e4 LT	288	struct tcp_options_received rx_opt;
	289
	290	/*
	291	* Slow start and congestion control (see also Nagle, and Karn & Partridge)
	292	*/
	293	__u32 snd_ssthresh; /* Slow start size threshold */
	294	__u32 snd_cwnd; /* Sending congestion window */
	295	__u16 snd_cwnd_cnt; /* Linear increase counter */
	296	__u16 snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */
	297	__u32 snd_cwnd_used;
	298	__u32 snd_cwnd_stamp;
	299
1da177e4 LT	300	struct sk_buff_head out_of_order_queue; /* Out of order segments go here */
	301
	302	struct tcp_func af_specific; / Operations which are AF_INET{4,6} specific */
	303
	304	__u32 rcv_wnd; /* Current receiver window */
	305	__u32 rcv_wup; /* rcv_nxt on last window update sent */
	306	__u32 write_seq; /* Tail(+1) of data held in tcp send buffer */
	307	__u32 pushed_seq; /* Last pushed seq, required to talk to windows */
	308	__u32 copied_seq; /* Head of yet unread data */
	309
	310	/* SACKs data */
	311	struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */
	312	struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/
	313
463c84b9	314	__u8 probes_out; /* unanswered 0 window probes */
1da177e4 LT	315	__u8 ecn_flags; /* ECN status bits. */
	316	__u16 prior_ssthresh; /* ssthresh saved at recovery start */
	317	__u32 lost_out; /* Lost packets */
	318	__u32 sacked_out; /* SACK'd packets */
	319	__u32 fackets_out; /* FACK'd packets */
	320	__u32 high_seq; /* snd_nxt at onset of congestion */
	321
	322	__u32 retrans_stamp; /* Timestamp of the last retransmit,
	323	* also used in SYN-SENT to remember stamp of
	324	* the first SYN. */
	325	__u32 undo_marker; /* tracking retrans started here. */
	326	int undo_retrans; /* number of undoable retransmissions. */
	327	__u32 urg_seq; /* Seq of received urgent pointer */
	328	__u16 urg_data; /* Saved octet of OOB data and control flags */
1da177e4	329	__u8 urg_mode; /* In urgent mode */
463c84b9	330	/* ONE BYTE HOLE, TRY TO PACK! */
1da177e4 LT	331	__u32 snd_up; /* Urgent pointer */
	332
	333	__u32 total_retrans; /* Total retransmits for entire connection */
	334
1da177e4 LT	335	unsigned int keepalive_time; /* time before keep alive takes place */
	336	unsigned int keepalive_intvl; /* time interval between keep alive probes */
	337	int linger2;
	338
	339	unsigned long last_synq_overflow;
	340
	341	/* Receiver side RTT estimation */
	342	struct {
	343	__u32 rtt;
	344	__u32 seq;
	345	__u32 time;
	346	} rcv_rtt_est;
	347
	348	/* Receiver queue space */
	349	struct {
	350	int space;
	351	__u32 seq;
	352	__u32 time;
	353	} rcvq_space;
	354
317a76f9 SH	355	/* Pluggable TCP congestion control hook */
	356	struct tcp_congestion_ops *ca_ops;
	357	u32 ca_priv[16];
	358	#define TCP_CA_PRIV_SIZE (16*sizeof(u32))
1da177e4 LT	359	};
	360
	361	static inline struct tcp_sock tcp_sk(const struct sock sk)
	362	{
	363	return (struct tcp_sock *)sk;
	364	}
	365
8feaf0c0 ACM	366	struct tcp_timewait_sock {
	367	struct inet_timewait_sock tw_sk;
	368	__u32 tw_rcv_nxt;
	369	__u32 tw_snd_nxt;
	370	__u32 tw_rcv_wnd;
	371	__u32 tw_ts_recent;
	372	long tw_ts_recent_stamp;
	373	};
	374
	375	static inline struct tcp_timewait_sock tcp_twsk(const struct sock sk)
	376	{
	377	return (struct tcp_timewait_sock *)sk;
	378	}
	379
317a76f9 SH	380	static inline void tcp_ca(const struct tcp_sock tp)
	381	{
	382	return (void *) tp->ca_priv;
	383	}
	384
1da177e4 LT	385	#endif
	386
	387	#endif /* _LINUX_TCP_H */