[mirror_ubuntu-bionic-kernel.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>
#include <linux/socket.h>

struct tcphdr {
	__be16	source;
	__be16	dest;
	__be32	seq;
	__be32	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	
	__be16	window;
	__sum16	check;
	__be16	urg_ptr;
};

/*
 *	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;
	__be32 		  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 TCP_MD5SIG		14	/* TCP MD5 Signature (RFC2385) */

#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;
};

/* for TCP_MD5SIG socket option */
#define TCP_MD5SIG_MAXKEYLEN	80

struct tcp_md5sig {
	struct __kernel_sockaddr_storage tcpm_addr;	/* address associated */
	__u16	__tcpm_pad1;				/* zero */
	__u16	tcpm_keylen;				/* key length */
	__u32	__tcpm_pad2;				/* zero */
	__u8	tcpm_key[TCP_MD5SIG_MAXKEYLEN];		/* key (binary) */
};

#ifdef __KERNEL__

#include <linux/skbuff.h>
#include <linux/dmaengine.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_wire {
	__be32	start_seq;
	__be32	end_seq;
};

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;
#ifdef CONFIG_TCP_MD5SIG
	/* Only used by TCP MD5 Signature so far. */
	struct tcp_request_sock_ops	*af_specific;
#endif
	__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;
	u16	tcp_header_len;	/* Bytes of tcp header to send		*/
	u16	xmit_size_goal;	/* Goal for segmenting output packets	*/

/*
 *	Header prediction flags
 *	0x5?10 << 16 + snd_wnd in net byte order
 */
	__be32	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;
#ifdef CONFIG_NET_DMA
		/* members for async copy */
		struct dma_chan		*dma_chan;
		int			wakeup;
		struct dma_pinned_list	*pinned_list;
		dma_cookie_t		dma_cookie;
#endif
	} 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	mss_cache;	/* Cached effective mss, not including SACKS */

	__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	keepalive_probes; /* num of allowed keep alive probes	*/

/* 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 */

 	__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*/

	struct tcp_sack_block recv_sack_cache[4];

	/* from STCP, retrans queue hinting */
	struct sk_buff* lost_skb_hint;

	struct sk_buff *scoreboard_skb_hint;
	struct sk_buff *retransmit_skb_hint;
	struct sk_buff *forward_skb_hint;
	struct sk_buff *fastpath_skb_hint;

	int     fastpath_cnt_hint;
	int     lost_cnt_hint;
	int     retransmit_cnt_hint;
	int     forward_cnt_hint;

	__u16	advmss;		/* Advertised MSS			*/
	__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		*/
	__u8	ecn_flags;	/* ECN status bits.			*/
	__u32	snd_up;		/* Urgent pointer		*/

	__u32	total_retrans;	/* Total retransmits for entire connection */
	__u32	bytes_acked;	/* Appropriate Byte Counting - RFC3465 */

	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; 

	__u32	tso_deferred;

/* 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;

/* TCP-specific MTU probe information. */
	struct {
		__u32		  probe_seq_start;
		__u32		  probe_seq_end;
	} mtu_probe;

#ifdef CONFIG_TCP_MD5SIG
/* TCP AF-Specific parts; only used by MD5 Signature support so far */
	struct tcp_sock_af_ops	*af_specific;

/* TCP MD5 Signagure Option information */
	struct tcp_md5sig_info	*md5sig_info;
#endif
};

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;
#ifdef CONFIG_TCP_MD5SIG
	__u16			  tw_md5_keylen;
	__u8			  tw_md5_key[TCP_MD5SIG_MAXKEYLEN];
#endif
};

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

#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>
cfb6eeb4	22	#include <linux/socket.h>
1da177e4 LT	23
1da177e4 LT	24	struct tcphdr {
46a97324 AV	25	__be16 source;
	26	__be16 dest;
	27	__be32 seq;
	28	__be32 ack_seq;
1da177e4 LT	29	#if defined(__LITTLE_ENDIAN_BITFIELD)
	30	__u16 res1:4,
	31	doff:4,
	32	fin:1,
	33	syn:1,
	34	rst:1,
	35	psh:1,
	36	ack:1,
	37	urg:1,
	38	ece:1,
	39	cwr:1;
	40	#elif defined(__BIG_ENDIAN_BITFIELD)
	41	__u16 doff:4,
	42	res1:4,
	43	cwr:1,
	44	ece:1,
	45	urg:1,
	46	ack:1,
	47	psh:1,
	48	rst:1,
	49	syn:1,
	50	fin:1;
	51	#else
	52	#error "Adjust your <asm/byteorder.h> defines"
	53	#endif
46a97324	54	__be16 window;
9981a0e3	55	__sum16 check;
46a97324	56	__be16 urg_ptr;
1da177e4 LT	57	};
1da177e4 LT	58
1da177e4 LT	59	/*
	60	* The union cast uses a gcc extension to avoid aliasing problems
	61	* (union is compatible to any of its members)
	62	* This means this part of the code is -fstrict-aliasing safe now.
	63	*/
	64	union tcp_word_hdr {
	65	struct tcphdr hdr;
46a97324	66	__be32 words[5];
1da177e4 LT	67	};
	68
	69	#define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3])
	70
	71	enum {
	72	TCP_FLAG_CWR = __constant_htonl(0x00800000),
	73	TCP_FLAG_ECE = __constant_htonl(0x00400000),
	74	TCP_FLAG_URG = __constant_htonl(0x00200000),
	75	TCP_FLAG_ACK = __constant_htonl(0x00100000),
	76	TCP_FLAG_PSH = __constant_htonl(0x00080000),
	77	TCP_FLAG_RST = __constant_htonl(0x00040000),
	78	TCP_FLAG_SYN = __constant_htonl(0x00020000),
	79	TCP_FLAG_FIN = __constant_htonl(0x00010000),
	80	TCP_RESERVED_BITS = __constant_htonl(0x0F000000),
	81	TCP_DATA_OFFSET = __constant_htonl(0xF0000000)
	82	};
	83
	84	/* TCP socket options */
	85	#define TCP_NODELAY 1 /* Turn off Nagle's algorithm. */
	86	#define TCP_MAXSEG 2 /* Limit MSS */
	87	#define TCP_CORK 3 /* Never send partially complete segments */
	88	#define TCP_KEEPIDLE 4 /* Start keeplives after this period */
	89	#define TCP_KEEPINTVL 5 /* Interval between keepalives */
	90	#define TCP_KEEPCNT 6 /* Number of keepalives before death */
	91	#define TCP_SYNCNT 7 /* Number of SYN retransmits */
	92	#define TCP_LINGER2 8 /* Life time of orphaned FIN-WAIT-2 state */
	93	#define TCP_DEFER_ACCEPT 9 /* Wake up listener only when data arrive */
	94	#define TCP_WINDOW_CLAMP 10 /* Bound advertised window */
	95	#define TCP_INFO 11 /* Information about this connection. */
	96	#define TCP_QUICKACK 12 /* Block/reenable quick acks */
5f8ef48d	97	#define TCP_CONGESTION 13 /* Congestion control algorithm */
cfb6eeb4	98	#define TCP_MD5SIG 14 /* TCP MD5 Signature (RFC2385) */
1da177e4 LT	99
	100	#define TCPI_OPT_TIMESTAMPS 1
	101	#define TCPI_OPT_SACK 2
	102	#define TCPI_OPT_WSCALE 4
	103	#define TCPI_OPT_ECN 8
	104
	105	enum tcp_ca_state
	106	{
	107	TCP_CA_Open = 0,
	108	#define TCPF_CA_Open (1<<TCP_CA_Open)
	109	TCP_CA_Disorder = 1,
	110	#define TCPF_CA_Disorder (1<<TCP_CA_Disorder)
	111	TCP_CA_CWR = 2,
	112	#define TCPF_CA_CWR (1<<TCP_CA_CWR)
	113	TCP_CA_Recovery = 3,
	114	#define TCPF_CA_Recovery (1<<TCP_CA_Recovery)
	115	TCP_CA_Loss = 4
	116	#define TCPF_CA_Loss (1<<TCP_CA_Loss)
	117	};
	118
	119	struct tcp_info
	120	{
	121	__u8 tcpi_state;
	122	__u8 tcpi_ca_state;
	123	__u8 tcpi_retransmits;
	124	__u8 tcpi_probes;
	125	__u8 tcpi_backoff;
	126	__u8 tcpi_options;
	127	__u8 tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;
	128
	129	__u32 tcpi_rto;
	130	__u32 tcpi_ato;
	131	__u32 tcpi_snd_mss;
	132	__u32 tcpi_rcv_mss;
	133
	134	__u32 tcpi_unacked;
	135	__u32 tcpi_sacked;
	136	__u32 tcpi_lost;
	137	__u32 tcpi_retrans;
	138	__u32 tcpi_fackets;
	139
	140	/* Times. */
	141	__u32 tcpi_last_data_sent;
	142	__u32 tcpi_last_ack_sent; /* Not remembered, sorry. */
	143	__u32 tcpi_last_data_recv;
	144	__u32 tcpi_last_ack_recv;
	145
	146	/* Metrics. */
	147	__u32 tcpi_pmtu;
	148	__u32 tcpi_rcv_ssthresh;
	149	__u32 tcpi_rtt;
	150	__u32 tcpi_rttvar;
	151	__u32 tcpi_snd_ssthresh;
	152	__u32 tcpi_snd_cwnd;
	153	__u32 tcpi_advmss;
	154	__u32 tcpi_reordering;
	155
	156	__u32 tcpi_rcv_rtt;
	157	__u32 tcpi_rcv_space;
	158
	159	__u32 tcpi_total_retrans;
	160	};
	161
cfb6eeb4 YH	162	/* for TCP_MD5SIG socket option */
	163	#define TCP_MD5SIG_MAXKEYLEN 80
	164
	165	struct tcp_md5sig {
	166	struct __kernel_sockaddr_storage tcpm_addr; /* address associated */
	167	__u16 __tcpm_pad1; /* zero */
	168	__u16 tcpm_keylen; /* key length */
	169	__u32 __tcpm_pad2; /* zero */
	170	__u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */
	171	};
	172
1da177e4 LT	173	#ifdef __KERNEL__
1da177e4 LT	174
1da177e4	175	#include <linux/skbuff.h>
c8a553ad	176	#include <linux/dmaengine.h>
1da177e4	177	#include <net/sock.h>
463c84b9	178	#include <net/inet_connection_sock.h>
8feaf0c0	179	#include <net/inet_timewait_sock.h>
1da177e4 LT	180
1da177e4 LT	181	/* This defines a selective acknowledgement block. */
269bd27e AV	182	struct tcp_sack_block_wire {
	183	__be32 start_seq;
	184	__be32 end_seq;
	185	};
	186
1da177e4 LT	187	struct tcp_sack_block {
	188	__u32 start_seq;
	189	__u32 end_seq;
	190	};
	191
1da177e4 LT	192	struct tcp_options_received {
	193	/* PAWS/RTTM data */
	194	long ts_recent_stamp;/* Time we stored ts_recent (for aging) */
	195	__u32 ts_recent; /* Time stamp to echo next */
	196	__u32 rcv_tsval; /* Time stamp value */
	197	__u32 rcv_tsecr; /* Time stamp echo reply */
	198	__u16 saw_tstamp : 1, /* Saw TIMESTAMP on last packet */
	199	tstamp_ok : 1, /* TIMESTAMP seen on SYN packet */
	200	dsack : 1, /* D-SACK is scheduled */
	201	wscale_ok : 1, /* Wscale seen on SYN packet */
	202	sack_ok : 4, /* SACK seen on SYN packet */
	203	snd_wscale : 4, /* Window scaling received from sender */
	204	rcv_wscale : 4; /* Window scaling to send to receiver */
	205	/* SACKs data */
	206	__u8 eff_sacks; /* Size of SACK array to send with next packet */
	207	__u8 num_sacks; /* Number of SACK blocks */
	208	__u16 user_mss; /* mss requested by user in ioctl */
	209	__u16 mss_clamp; /* Maximal mss, negotiated at connection setup */
	210	};
	211
2e6599cb	212	struct tcp_request_sock {
cfb6eeb4 YH	213	struct inet_request_sock req;
	214	#ifdef CONFIG_TCP_MD5SIG
	215	/* Only used by TCP MD5 Signature so far. */
	216	struct tcp_request_sock_ops *af_specific;
	217	#endif
	218	__u32 rcv_isn;
	219	__u32 snt_isn;
2e6599cb ACM	220	};
2e6599cb ACM	221
60236fdd	222	static inline struct tcp_request_sock tcp_rsk(const struct request_sock req)
2e6599cb ACM	223	{
	224	return (struct tcp_request_sock *)req;
	225	}
	226
1da177e4	227	struct tcp_sock {
463c84b9 ACM	228	/* inet_connection_sock has to be the first member of tcp_sock */
463c84b9 ACM	229	struct inet_connection_sock inet_conn;
2ff52f28 ACM	230	u16 tcp_header_len; /* Bytes of tcp header to send */
2ff52f28 ACM	231	u16 xmit_size_goal; /* Goal for segmenting output packets */
1da177e4 LT	232
	233	/*
	234	* Header prediction flags
	235	* 0x5?10 << 16 + snd_wnd in net byte order
	236	*/
dddc93c0	237	__be32 pred_flags;
1da177e4 LT	238
	239	/*
	240	* RFC793 variables by their proper names. This means you can
	241	* read the code and the spec side by side (and laugh ...)
	242	* See RFC793 and RFC1122. The RFC writes these in capitals.
	243	*/
	244	__u32 rcv_nxt; /* What we want to receive next */
	245	__u32 snd_nxt; /* Next sequence we send */
	246
	247	__u32 snd_una; /* First byte we want an ack for */
	248	__u32 snd_sml; /* Last byte of the most recently transmitted small packet */
	249	__u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */
	250	__u32 lsndtime; /* timestamp of last sent data packet (for restart window) */
1da177e4 LT	251
	252	/* Data for direct copy to user */
	253	struct {
	254	struct sk_buff_head prequeue;
	255	struct task_struct *task;
	256	struct iovec *iov;
	257	int memory;
	258	int len;
97fc2f08 CL	259	#ifdef CONFIG_NET_DMA
	260	/* members for async copy */
	261	struct dma_chan *dma_chan;
	262	int wakeup;
	263	struct dma_pinned_list *pinned_list;
	264	dma_cookie_t dma_cookie;
	265	#endif
1da177e4 LT	266	} ucopy;
	267
	268	__u32 snd_wl1; /* Sequence for window update */
	269	__u32 snd_wnd; /* The window we expect to receive */
	270	__u32 max_window; /* Maximal window ever seen from peer */
1da177e4	271	__u32 mss_cache; /* Cached effective mss, not including SACKS */
1da177e4	272
1da177e4 LT	273	__u32 window_clamp; /* Maximal window to advertise */
	274	__u32 rcv_ssthresh; /* Current window clamp */
	275
	276	__u32 frto_highmark; /* snd_nxt when RTO occurred */
	277	__u8 reordering; /* Packet reordering metric. */
	278	__u8 frto_counter; /* Number of new acks after RTO */
463c84b9	279	__u8 nonagle; /* Disable Nagle algorithm? */
6687e988	280	__u8 keepalive_probes; /* num of allowed keep alive probes */
1da177e4 LT	281
	282	/* RTT measurement */
	283	__u32 srtt; /* smoothed round trip time << 3 */
	284	__u32 mdev; /* medium deviation */
	285	__u32 mdev_max; /* maximal mdev for the last rtt period */
	286	__u32 rttvar; /* smoothed mdev_max */
	287	__u32 rtt_seq; /* sequence number to update rttvar */
1da177e4 LT	288
	289	__u32 packets_out; /* Packets which are "in flight" */
	290	__u32 left_out; /* Packets which leaved network */
	291	__u32 retrans_out; /* Retransmitted packets out */
1da177e4 LT	292	/*
	293	* Options received (usually on last packet, some only on SYN packets).
	294	*/
1da177e4 LT	295	struct tcp_options_received rx_opt;
	296
	297	/*
	298	* Slow start and congestion control (see also Nagle, and Karn & Partridge)
	299	*/
	300	__u32 snd_ssthresh; /* Slow start size threshold */
	301	__u32 snd_cwnd; /* Sending congestion window */
	302	__u16 snd_cwnd_cnt; /* Linear increase counter */
	303	__u16 snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */
	304	__u32 snd_cwnd_used;
	305	__u32 snd_cwnd_stamp;
	306
1da177e4 LT	307	struct sk_buff_head out_of_order_queue; /* Out of order segments go here */
1da177e4 LT	308
1da177e4 LT	309	__u32 rcv_wnd; /* Current receiver window */
	310	__u32 rcv_wup; /* rcv_nxt on last window update sent */
	311	__u32 write_seq; /* Tail(+1) of data held in tcp send buffer */
	312	__u32 pushed_seq; /* Last pushed seq, required to talk to windows */
	313	__u32 copied_seq; /* Head of yet unread data */
	314
	315	/* SACKs data */
	316	struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */
	317	struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/
	318
6a438bbe SH	319	struct tcp_sack_block recv_sack_cache[4];
	320
	321	/* from STCP, retrans queue hinting */
	322	struct sk_buff* lost_skb_hint;
	323
	324	struct sk_buff *scoreboard_skb_hint;
	325	struct sk_buff *retransmit_skb_hint;
	326	struct sk_buff *forward_skb_hint;
	327	struct sk_buff *fastpath_skb_hint;
	328
	329	int fastpath_cnt_hint;
	330	int lost_cnt_hint;
	331	int retransmit_cnt_hint;
	332	int forward_cnt_hint;
	333
6687e988	334	__u16 advmss; /* Advertised MSS */
1da177e4 LT	335	__u16 prior_ssthresh; /* ssthresh saved at recovery start */
	336	__u32 lost_out; /* Lost packets */
	337	__u32 sacked_out; /* SACK'd packets */
	338	__u32 fackets_out; /* FACK'd packets */
	339	__u32 high_seq; /* snd_nxt at onset of congestion */
	340
	341	__u32 retrans_stamp; /* Timestamp of the last retransmit,
	342	* also used in SYN-SENT to remember stamp of
	343	* the first SYN. */
	344	__u32 undo_marker; /* tracking retrans started here. */
	345	int undo_retrans; /* number of undoable retransmissions. */
	346	__u32 urg_seq; /* Seq of received urgent pointer */
	347	__u16 urg_data; /* Saved octet of OOB data and control flags */
1da177e4	348	__u8 urg_mode; /* In urgent mode */
6687e988	349	__u8 ecn_flags; /* ECN status bits. */
1da177e4 LT	350	__u32 snd_up; /* Urgent pointer */
	351
	352	__u32 total_retrans; /* Total retransmits for entire connection */
9772efb9	353	__u32 bytes_acked; /* Appropriate Byte Counting - RFC3465 */
1da177e4	354
1da177e4 LT	355	unsigned int keepalive_time; /* time before keep alive takes place */
	356	unsigned int keepalive_intvl; /* time interval between keep alive probes */
	357	int linger2;
	358
	359	unsigned long last_synq_overflow;
	360
ae8064ac JH	361	__u32 tso_deferred;
ae8064ac JH	362
1da177e4 LT	363	/* Receiver side RTT estimation */
	364	struct {
	365	__u32 rtt;
	366	__u32 seq;
	367	__u32 time;
	368	} rcv_rtt_est;
	369
	370	/* Receiver queue space */
	371	struct {
	372	int space;
	373	__u32 seq;
	374	__u32 time;
	375	} rcvq_space;
0e7b1368 JH	376
	377	/* TCP-specific MTU probe information. */
	378	struct {
	379	__u32 probe_seq_start;
	380	__u32 probe_seq_end;
	381	} mtu_probe;
cfb6eeb4 YH	382
	383	#ifdef CONFIG_TCP_MD5SIG
	384	/* TCP AF-Specific parts; only used by MD5 Signature support so far */
	385	struct tcp_sock_af_ops *af_specific;
	386
	387	/* TCP MD5 Signagure Option information */
	388	struct tcp_md5sig_info *md5sig_info;
	389	#endif
1da177e4 LT	390	};
	391
	392	static inline struct tcp_sock tcp_sk(const struct sock sk)
	393	{
	394	return (struct tcp_sock *)sk;
	395	}
	396
8feaf0c0 ACM	397	struct tcp_timewait_sock {
	398	struct inet_timewait_sock tw_sk;
	399	__u32 tw_rcv_nxt;
	400	__u32 tw_snd_nxt;
	401	__u32 tw_rcv_wnd;
	402	__u32 tw_ts_recent;
	403	long tw_ts_recent_stamp;
cfb6eeb4 YH	404	#ifdef CONFIG_TCP_MD5SIG
	405	__u16 tw_md5_keylen;
	406	__u8 tw_md5_key[TCP_MD5SIG_MAXKEYLEN];
	407	#endif
8feaf0c0 ACM	408	};
	409
	410	static inline struct tcp_timewait_sock tcp_twsk(const struct sock sk)
	411	{
	412	return (struct tcp_timewait_sock *)sk;
	413	}
	414
1da177e4 LT	415	#endif
	416
	417	#endif /* _LINUX_TCP_H */