417 строки
12 KiB
C
417 строки
12 KiB
C
/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* Definitions for the TCP protocol.
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*
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* Version: @(#)tcp.h 1.0.2 04/28/93
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*
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* Author: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _LINUX_TCP_H
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#define _LINUX_TCP_H
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#include <linux/types.h>
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#include <asm/byteorder.h>
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struct tcphdr {
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__u16 source;
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__u16 dest;
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__u32 seq;
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__u32 ack_seq;
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#if defined(__LITTLE_ENDIAN_BITFIELD)
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__u16 res1:4,
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doff:4,
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fin:1,
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syn:1,
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rst:1,
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psh:1,
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ack:1,
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urg:1,
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ece:1,
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cwr:1;
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#elif defined(__BIG_ENDIAN_BITFIELD)
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__u16 doff:4,
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res1:4,
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cwr:1,
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ece:1,
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urg:1,
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ack:1,
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psh:1,
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rst:1,
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syn:1,
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fin:1;
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#else
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#error "Adjust your <asm/byteorder.h> defines"
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#endif
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__u16 window;
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__u16 check;
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__u16 urg_ptr;
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};
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enum {
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TCP_ESTABLISHED = 1,
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TCP_SYN_SENT,
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TCP_SYN_RECV,
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TCP_FIN_WAIT1,
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TCP_FIN_WAIT2,
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TCP_TIME_WAIT,
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TCP_CLOSE,
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TCP_CLOSE_WAIT,
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TCP_LAST_ACK,
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TCP_LISTEN,
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TCP_CLOSING, /* now a valid state */
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TCP_MAX_STATES /* Leave at the end! */
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};
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#define TCP_STATE_MASK 0xF
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#define TCP_ACTION_FIN (1 << 7)
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enum {
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TCPF_ESTABLISHED = (1 << 1),
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TCPF_SYN_SENT = (1 << 2),
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TCPF_SYN_RECV = (1 << 3),
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TCPF_FIN_WAIT1 = (1 << 4),
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TCPF_FIN_WAIT2 = (1 << 5),
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TCPF_TIME_WAIT = (1 << 6),
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TCPF_CLOSE = (1 << 7),
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TCPF_CLOSE_WAIT = (1 << 8),
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TCPF_LAST_ACK = (1 << 9),
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TCPF_LISTEN = (1 << 10),
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TCPF_CLOSING = (1 << 11)
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};
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/*
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* The union cast uses a gcc extension to avoid aliasing problems
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* (union is compatible to any of its members)
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* This means this part of the code is -fstrict-aliasing safe now.
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*/
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union tcp_word_hdr {
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struct tcphdr hdr;
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__u32 words[5];
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};
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#define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3])
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enum {
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TCP_FLAG_CWR = __constant_htonl(0x00800000),
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TCP_FLAG_ECE = __constant_htonl(0x00400000),
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TCP_FLAG_URG = __constant_htonl(0x00200000),
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TCP_FLAG_ACK = __constant_htonl(0x00100000),
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TCP_FLAG_PSH = __constant_htonl(0x00080000),
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TCP_FLAG_RST = __constant_htonl(0x00040000),
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TCP_FLAG_SYN = __constant_htonl(0x00020000),
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TCP_FLAG_FIN = __constant_htonl(0x00010000),
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TCP_RESERVED_BITS = __constant_htonl(0x0F000000),
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TCP_DATA_OFFSET = __constant_htonl(0xF0000000)
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};
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/* TCP socket options */
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#define TCP_NODELAY 1 /* Turn off Nagle's algorithm. */
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#define TCP_MAXSEG 2 /* Limit MSS */
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#define TCP_CORK 3 /* Never send partially complete segments */
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#define TCP_KEEPIDLE 4 /* Start keeplives after this period */
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#define TCP_KEEPINTVL 5 /* Interval between keepalives */
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#define TCP_KEEPCNT 6 /* Number of keepalives before death */
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#define TCP_SYNCNT 7 /* Number of SYN retransmits */
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#define TCP_LINGER2 8 /* Life time of orphaned FIN-WAIT-2 state */
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#define TCP_DEFER_ACCEPT 9 /* Wake up listener only when data arrive */
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#define TCP_WINDOW_CLAMP 10 /* Bound advertised window */
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#define TCP_INFO 11 /* Information about this connection. */
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#define TCP_QUICKACK 12 /* Block/reenable quick acks */
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#define TCP_CONGESTION 13 /* Congestion control algorithm */
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#define TCPI_OPT_TIMESTAMPS 1
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#define TCPI_OPT_SACK 2
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#define TCPI_OPT_WSCALE 4
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#define TCPI_OPT_ECN 8
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enum tcp_ca_state
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{
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TCP_CA_Open = 0,
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#define TCPF_CA_Open (1<<TCP_CA_Open)
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TCP_CA_Disorder = 1,
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#define TCPF_CA_Disorder (1<<TCP_CA_Disorder)
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TCP_CA_CWR = 2,
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#define TCPF_CA_CWR (1<<TCP_CA_CWR)
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TCP_CA_Recovery = 3,
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#define TCPF_CA_Recovery (1<<TCP_CA_Recovery)
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TCP_CA_Loss = 4
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#define TCPF_CA_Loss (1<<TCP_CA_Loss)
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};
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struct tcp_info
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{
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__u8 tcpi_state;
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__u8 tcpi_ca_state;
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__u8 tcpi_retransmits;
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__u8 tcpi_probes;
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__u8 tcpi_backoff;
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__u8 tcpi_options;
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__u8 tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;
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__u32 tcpi_rto;
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__u32 tcpi_ato;
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__u32 tcpi_snd_mss;
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__u32 tcpi_rcv_mss;
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__u32 tcpi_unacked;
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__u32 tcpi_sacked;
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__u32 tcpi_lost;
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__u32 tcpi_retrans;
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__u32 tcpi_fackets;
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/* Times. */
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__u32 tcpi_last_data_sent;
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__u32 tcpi_last_ack_sent; /* Not remembered, sorry. */
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__u32 tcpi_last_data_recv;
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__u32 tcpi_last_ack_recv;
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/* Metrics. */
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__u32 tcpi_pmtu;
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__u32 tcpi_rcv_ssthresh;
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__u32 tcpi_rtt;
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__u32 tcpi_rttvar;
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__u32 tcpi_snd_ssthresh;
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__u32 tcpi_snd_cwnd;
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__u32 tcpi_advmss;
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__u32 tcpi_reordering;
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__u32 tcpi_rcv_rtt;
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__u32 tcpi_rcv_space;
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__u32 tcpi_total_retrans;
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};
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#ifdef __KERNEL__
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#include <linux/config.h>
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#include <linux/skbuff.h>
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#include <linux/ip.h>
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#include <net/sock.h>
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/* This defines a selective acknowledgement block. */
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struct tcp_sack_block {
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__u32 start_seq;
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__u32 end_seq;
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};
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struct tcp_options_received {
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/* PAWS/RTTM data */
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long ts_recent_stamp;/* Time we stored ts_recent (for aging) */
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__u32 ts_recent; /* Time stamp to echo next */
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__u32 rcv_tsval; /* Time stamp value */
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__u32 rcv_tsecr; /* Time stamp echo reply */
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__u16 saw_tstamp : 1, /* Saw TIMESTAMP on last packet */
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tstamp_ok : 1, /* TIMESTAMP seen on SYN packet */
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dsack : 1, /* D-SACK is scheduled */
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wscale_ok : 1, /* Wscale seen on SYN packet */
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sack_ok : 4, /* SACK seen on SYN packet */
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snd_wscale : 4, /* Window scaling received from sender */
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rcv_wscale : 4; /* Window scaling to send to receiver */
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/* SACKs data */
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__u8 eff_sacks; /* Size of SACK array to send with next packet */
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__u8 num_sacks; /* Number of SACK blocks */
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__u16 user_mss; /* mss requested by user in ioctl */
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__u16 mss_clamp; /* Maximal mss, negotiated at connection setup */
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};
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struct tcp_request_sock {
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struct inet_request_sock req;
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__u32 rcv_isn;
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__u32 snt_isn;
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};
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static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)
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{
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return (struct tcp_request_sock *)req;
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}
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struct tcp_sock {
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/* inet_sock has to be the first member of tcp_sock */
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struct inet_sock inet;
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int tcp_header_len; /* Bytes of tcp header to send */
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/*
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* Header prediction flags
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* 0x5?10 << 16 + snd_wnd in net byte order
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*/
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__u32 pred_flags;
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/*
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* RFC793 variables by their proper names. This means you can
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* read the code and the spec side by side (and laugh ...)
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* See RFC793 and RFC1122. The RFC writes these in capitals.
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*/
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__u32 rcv_nxt; /* What we want to receive next */
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__u32 snd_nxt; /* Next sequence we send */
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__u32 snd_una; /* First byte we want an ack for */
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__u32 snd_sml; /* Last byte of the most recently transmitted small packet */
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__u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */
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__u32 lsndtime; /* timestamp of last sent data packet (for restart window) */
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struct tcp_bind_bucket *bind_hash;
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/* Delayed ACK control data */
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struct {
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__u8 pending; /* ACK is pending */
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__u8 quick; /* Scheduled number of quick acks */
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__u8 pingpong; /* The session is interactive */
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__u8 blocked; /* Delayed ACK was blocked by socket lock*/
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__u32 ato; /* Predicted tick of soft clock */
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unsigned long timeout; /* Currently scheduled timeout */
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__u32 lrcvtime; /* timestamp of last received data packet*/
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__u16 last_seg_size; /* Size of last incoming segment */
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__u16 rcv_mss; /* MSS used for delayed ACK decisions */
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} ack;
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/* Data for direct copy to user */
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struct {
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struct sk_buff_head prequeue;
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struct task_struct *task;
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struct iovec *iov;
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int memory;
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int len;
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} ucopy;
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__u32 snd_wl1; /* Sequence for window update */
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__u32 snd_wnd; /* The window we expect to receive */
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__u32 max_window; /* Maximal window ever seen from peer */
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__u32 pmtu_cookie; /* Last pmtu seen by socket */
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__u32 mss_cache; /* Cached effective mss, not including SACKS */
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__u16 xmit_size_goal; /* Goal for segmenting output packets */
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__u16 ext_header_len; /* Network protocol overhead (IP/IPv6 options) */
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__u8 ca_state; /* State of fast-retransmit machine */
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__u8 retransmits; /* Number of unrecovered RTO timeouts. */
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__u16 advmss; /* Advertised MSS */
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__u32 window_clamp; /* Maximal window to advertise */
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__u32 rcv_ssthresh; /* Current window clamp */
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__u32 frto_highmark; /* snd_nxt when RTO occurred */
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__u8 reordering; /* Packet reordering metric. */
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__u8 frto_counter; /* Number of new acks after RTO */
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__u8 unused;
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__u8 defer_accept; /* User waits for some data after accept() */
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/* RTT measurement */
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__u32 srtt; /* smoothed round trip time << 3 */
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__u32 mdev; /* medium deviation */
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__u32 mdev_max; /* maximal mdev for the last rtt period */
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__u32 rttvar; /* smoothed mdev_max */
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__u32 rtt_seq; /* sequence number to update rttvar */
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__u32 rto; /* retransmit timeout */
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__u32 packets_out; /* Packets which are "in flight" */
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__u32 left_out; /* Packets which leaved network */
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__u32 retrans_out; /* Retransmitted packets out */
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__u8 backoff; /* backoff */
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/*
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* Options received (usually on last packet, some only on SYN packets).
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*/
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__u8 nonagle; /* Disable Nagle algorithm? */
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__u8 keepalive_probes; /* num of allowed keep alive probes */
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__u8 probes_out; /* unanswered 0 window probes */
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struct tcp_options_received rx_opt;
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/*
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* Slow start and congestion control (see also Nagle, and Karn & Partridge)
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*/
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__u32 snd_ssthresh; /* Slow start size threshold */
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__u32 snd_cwnd; /* Sending congestion window */
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__u16 snd_cwnd_cnt; /* Linear increase counter */
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__u16 snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */
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__u32 snd_cwnd_used;
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__u32 snd_cwnd_stamp;
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/* Two commonly used timers in both sender and receiver paths. */
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unsigned long timeout;
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struct timer_list retransmit_timer; /* Resend (no ack) */
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struct timer_list delack_timer; /* Ack delay */
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struct sk_buff_head out_of_order_queue; /* Out of order segments go here */
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struct tcp_func *af_specific; /* Operations which are AF_INET{4,6} specific */
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__u32 rcv_wnd; /* Current receiver window */
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__u32 rcv_wup; /* rcv_nxt on last window update sent */
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__u32 write_seq; /* Tail(+1) of data held in tcp send buffer */
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__u32 pushed_seq; /* Last pushed seq, required to talk to windows */
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__u32 copied_seq; /* Head of yet unread data */
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/* SACKs data */
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struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */
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struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/
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__u8 syn_retries; /* num of allowed syn retries */
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__u8 ecn_flags; /* ECN status bits. */
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__u16 prior_ssthresh; /* ssthresh saved at recovery start */
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__u32 lost_out; /* Lost packets */
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__u32 sacked_out; /* SACK'd packets */
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__u32 fackets_out; /* FACK'd packets */
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__u32 high_seq; /* snd_nxt at onset of congestion */
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__u32 retrans_stamp; /* Timestamp of the last retransmit,
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* also used in SYN-SENT to remember stamp of
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* the first SYN. */
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__u32 undo_marker; /* tracking retrans started here. */
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int undo_retrans; /* number of undoable retransmissions. */
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__u32 urg_seq; /* Seq of received urgent pointer */
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__u16 urg_data; /* Saved octet of OOB data and control flags */
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__u8 pending; /* Scheduled timer event */
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__u8 urg_mode; /* In urgent mode */
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__u32 snd_up; /* Urgent pointer */
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__u32 total_retrans; /* Total retransmits for entire connection */
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struct request_sock_queue accept_queue; /* FIFO of established children */
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unsigned int keepalive_time; /* time before keep alive takes place */
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unsigned int keepalive_intvl; /* time interval between keep alive probes */
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int linger2;
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unsigned long last_synq_overflow;
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/* Receiver side RTT estimation */
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struct {
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__u32 rtt;
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__u32 seq;
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__u32 time;
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} rcv_rtt_est;
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/* Receiver queue space */
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struct {
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int space;
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__u32 seq;
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__u32 time;
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} rcvq_space;
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/* Pluggable TCP congestion control hook */
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struct tcp_congestion_ops *ca_ops;
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u32 ca_priv[16];
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#define TCP_CA_PRIV_SIZE (16*sizeof(u32))
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};
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static inline struct tcp_sock *tcp_sk(const struct sock *sk)
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{
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return (struct tcp_sock *)sk;
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}
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static inline void *tcp_ca(const struct tcp_sock *tp)
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{
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return (void *) tp->ca_priv;
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}
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#endif
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#endif /* _LINUX_TCP_H */
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