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/*
* 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;
};
enum {
TCP_ESTABLISHED = 1,
TCP_SYN_SENT,
TCP_SYN_RECV,
TCP_FIN_WAIT1,
TCP_FIN_WAIT2,
TCP_TIME_WAIT,
TCP_CLOSE,
TCP_CLOSE_WAIT,
TCP_LAST_ACK,
TCP_LISTEN,
TCP_CLOSING, /* now a valid state */
TCP_MAX_STATES /* Leave at the end! */
};
#define TCP_STATE_MASK 0xF
#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 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;
};
#ifdef __KERNEL__
#include <linux/config.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <net/sock.h>
/* This defines a selective acknowledgement block. */
struct tcp_sack_block {
__u32 start_seq;
__u32 end_seq;
};
struct tcp_opt {
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) */
struct tcp_bind_bucket *bind_hash;
/* Delayed ACK control data */
struct {
__u8 pending; /* ACK is pending */
__u8 quick; /* Scheduled number of quick acks */
__u8 pingpong; /* The session is interactive */
__u8 blocked; /* Delayed ACK was blocked by socket lock*/
__u32 ato; /* Predicted tick of soft clock */
unsigned long timeout; /* Currently scheduled timeout */
__u32 lrcvtime; /* timestamp of last received data packet*/
__u16 last_seg_size; /* Size of last incoming segment */
__u16 rcv_mss; /* MSS used for delayed ACK decisions */
} ack;
/* 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 mss_cache_std; /* Like mss_cache, but without TSO */
__u16 mss_clamp; /* Maximal mss, negotiated at connection setup */
__u16 ext_header_len; /* Network protocol overhead (IP/IPv6 options) */
__u16 ext2_header_len;/* Options depending on route */
__u8 ca_state; /* State of fast-retransmit machine */
__u8 retransmits; /* Number of unrecovered RTO timeouts. */
__u8 reordering; /* Packet reordering metric. */
__u8 queue_shrunk; /* Write queue has been shrunk recently.*/
__u8 defer_accept; /* User waits for some data after accept() */
/* RTT measurement */
__u8 backoff; /* backoff */
__u32 srtt; /* smothed 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 rto; /* retransmit timeout */
__u32 packets_out; /* Packets which are "in flight" */
__u32 left_out; /* Packets which leaved network */
__u32 retrans_out; /* Retransmitted packets out */
/*
* 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;
/* Two commonly used timers in both sender and receiver paths. */
unsigned long timeout;
struct timer_list retransmit_timer; /* Resend (no ack) */
struct timer_list delack_timer; /* Ack delay */
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 */
struct sk_buff *send_head; /* Front of stuff to transmit */
__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 */
/*
* Options received (usually on last packet, some only on SYN packets).
*/
char tstamp_ok, /* TIMESTAMP seen on SYN packet */
wscale_ok, /* Wscale seen on SYN packet */
sack_ok; /* SACK seen on SYN packet */
char saw_tstamp; /* Saw TIMESTAMP on last packet */
__u8 snd_wscale; /* Window scaling received from sender */
__u8 rcv_wscale; /* Window scaling to send to receiver */
__u8 nonagle; /* Disable Nagle algorithm? */
__u8 keepalive_probes; /* num of allowed keep alive probes */
/* PAWS/RTTM data */
__u32 rcv_tsval; /* Time stamp value */
__u32 rcv_tsecr; /* Time stamp echo reply */
__u32 ts_recent; /* Time stamp to echo next */
long ts_recent_stamp;/* Time we stored ts_recent (for aging) */
/* SACKs data */
__u16 user_mss; /* mss requested by user in ioctl */
__u8 dsack; /* D-SACK is scheduled */
__u8 eff_sacks; /* Size of SACK array to send with next packet */
struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */
struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/
__u32 window_clamp; /* Maximal window to advertise */
__u32 rcv_ssthresh; /* Current window clamp */
__u8 probes_out; /* unanswered 0 window probes */
__u8 num_sacks; /* Number of SACK blocks */
__u16 advmss; /* Advertised MSS */
__u8 syn_retries; /* num of allowed syn retries */
__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 pending; /* Scheduled timer event */
__u8 urg_mode; /* In urgent mode */
__u32 snd_up; /* Urgent pointer */
/* The syn_wait_lock is necessary only to avoid tcp_get_info having
* to grab the main lock sock while browsing the listening hash
* (otherwise it's deadlock prone).
* This lock is acquired in read mode only from tcp_get_info() and
* it's acquired in write mode _only_ from code that is actively
* changing the syn_wait_queue. All readers that are holding
* the master sock lock don't need to grab this lock in read mode
* too as the syn_wait_queue writes are always protected from
* the main sock lock.
*/
rwlock_t syn_wait_lock;
struct tcp_listen_opt *listen_opt;
/* FIFO of established children */
struct open_request *accept_queue;
struct open_request *accept_queue_tail;
int write_pending; /* A write to socket waits to start. */
unsigned int keepalive_time; /* time before keep alive takes place */
unsigned int keepalive_intvl; /* time interval between keep alive probes */
int linger2;
int frto_counter; /* Number of new acks after RTO */
__u32 frto_highmark; /* snd_nxt when RTO occurred */
unsigned long last_synq_overflow;
};
/* WARNING: don't change the layout of the members in tcp_sock! */
struct tcp_sock {
struct sock sk;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
struct ipv6_pinfo *pinet6;
#endif
struct inet_opt inet;
struct tcp_opt tcp;
};
#define tcp_sk(__sk) (&((struct tcp_sock *)__sk)->tcp)
#endif
#endif /* _LINUX_TCP_H */