LXR linux/include/uapi/linux/tcp.h

   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 _UAPI_LINUX_TCP_H
  18#define _UAPI_LINUX_TCP_H
  19
  20#include <linux/types.h>
  21#include <asm/byteorder.h>
  22#include <linux/socket.h>
  23
  24struct tcphdr {
  25        __be16  source;
  26        __be16  dest;
  27        __be32  seq;
  28        __be32  ack_seq;
  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  
  54        __be16  window;
  55        __sum16 check;
  56        __be16  urg_ptr;
  57};
  58
  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 */
  64union tcp_word_hdr { 
  65        struct tcphdr hdr;
  66        __be32            words[5];
  67}; 
  68
  69#define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3]) 
  70
  71enum { 
  72        TCP_FLAG_CWR = __constant_cpu_to_be32(0x00800000),
  73        TCP_FLAG_ECE = __constant_cpu_to_be32(0x00400000),
  74        TCP_FLAG_URG = __constant_cpu_to_be32(0x00200000),
  75        TCP_FLAG_ACK = __constant_cpu_to_be32(0x00100000),
  76        TCP_FLAG_PSH = __constant_cpu_to_be32(0x00080000),
  77        TCP_FLAG_RST = __constant_cpu_to_be32(0x00040000),
  78        TCP_FLAG_SYN = __constant_cpu_to_be32(0x00020000),
  79        TCP_FLAG_FIN = __constant_cpu_to_be32(0x00010000),
  80        TCP_RESERVED_BITS = __constant_cpu_to_be32(0x0F000000),
  81        TCP_DATA_OFFSET = __constant_cpu_to_be32(0xF0000000)
  82}; 
  83
  84/*
  85 * TCP general constants
  86 */
  87#define TCP_MSS_DEFAULT          536U   /* IPv4 (RFC1122, RFC2581) */
  88#define TCP_MSS_DESIRED         1220U   /* IPv6 (tunneled), EDNS0 (RFC3226) */
  89
  90/* TCP socket options */
  91#define TCP_NODELAY             1       /* Turn off Nagle's algorithm. */
  92#define TCP_MAXSEG              2       /* Limit MSS */
  93#define TCP_CORK                3       /* Never send partially complete segments */
  94#define TCP_KEEPIDLE            4       /* Start keeplives after this period */
  95#define TCP_KEEPINTVL           5       /* Interval between keepalives */
  96#define TCP_KEEPCNT             6       /* Number of keepalives before death */
  97#define TCP_SYNCNT              7       /* Number of SYN retransmits */
  98#define TCP_LINGER2             8       /* Life time of orphaned FIN-WAIT-2 state */
  99#define TCP_DEFER_ACCEPT        9       /* Wake up listener only when data arrive */
 100#define TCP_WINDOW_CLAMP        10      /* Bound advertised window */
 101#define TCP_INFO                11      /* Information about this connection. */
 102#define TCP_QUICKACK            12      /* Block/reenable quick acks */
 103#define TCP_CONGESTION          13      /* Congestion control algorithm */
 104#define TCP_MD5SIG              14      /* TCP MD5 Signature (RFC2385) */
 105#define TCP_THIN_LINEAR_TIMEOUTS 16      /* Use linear timeouts for thin streams*/
 106#define TCP_THIN_DUPACK         17      /* Fast retrans. after 1 dupack */
 107#define TCP_USER_TIMEOUT        18      /* How long for loss retry before timeout */
 108#define TCP_REPAIR              19      /* TCP sock is under repair right now */
 109#define TCP_REPAIR_QUEUE        20
 110#define TCP_QUEUE_SEQ           21
 111#define TCP_REPAIR_OPTIONS      22
 112#define TCP_FASTOPEN            23      /* Enable FastOpen on listeners */
 113#define TCP_TIMESTAMP           24
 114#define TCP_NOTSENT_LOWAT       25      /* limit number of unsent bytes in write queue */
 115
 116struct tcp_repair_opt {
 117        __u32   opt_code;
 118        __u32   opt_val;
 119};
 120
 121enum {
 122        TCP_NO_QUEUE,
 123        TCP_RECV_QUEUE,
 124        TCP_SEND_QUEUE,
 125        TCP_QUEUES_NR,
 126};
 127
 128/* for TCP_INFO socket option */
 129#define TCPI_OPT_TIMESTAMPS     1
 130#define TCPI_OPT_SACK           2
 131#define TCPI_OPT_WSCALE         4
 132#define TCPI_OPT_ECN            8 /* ECN was negociated at TCP session init */
 133#define TCPI_OPT_ECN_SEEN       16 /* we received at least one packet with ECT */
 134#define TCPI_OPT_SYN_DATA       32 /* SYN-ACK acked data in SYN sent or rcvd */
 135
 136enum tcp_ca_state {
 137        TCP_CA_Open = 0,
 138#define TCPF_CA_Open    (1<<TCP_CA_Open)
 139        TCP_CA_Disorder = 1,
 140#define TCPF_CA_Disorder (1<<TCP_CA_Disorder)
 141        TCP_CA_CWR = 2,
 142#define TCPF_CA_CWR     (1<<TCP_CA_CWR)
 143        TCP_CA_Recovery = 3,
 144#define TCPF_CA_Recovery (1<<TCP_CA_Recovery)
 145        TCP_CA_Loss = 4
 146#define TCPF_CA_Loss    (1<<TCP_CA_Loss)
 147};
 148
 149struct tcp_info {
 150        __u8    tcpi_state;
 151        __u8    tcpi_ca_state;
 152        __u8    tcpi_retransmits;
 153        __u8    tcpi_probes;
 154        __u8    tcpi_backoff;
 155        __u8    tcpi_options;
 156        __u8    tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;
 157
 158        __u32   tcpi_rto;
 159        __u32   tcpi_ato;
 160        __u32   tcpi_snd_mss;
 161        __u32   tcpi_rcv_mss;
 162
 163        __u32   tcpi_unacked;
 164        __u32   tcpi_sacked;
 165        __u32   tcpi_lost;
 166        __u32   tcpi_retrans;
 167        __u32   tcpi_fackets;
 168
 169        /* Times. */
 170        __u32   tcpi_last_data_sent;
 171        __u32   tcpi_last_ack_sent;     /* Not remembered, sorry. */
 172        __u32   tcpi_last_data_recv;
 173        __u32   tcpi_last_ack_recv;
 174
 175        /* Metrics. */
 176        __u32   tcpi_pmtu;
 177        __u32   tcpi_rcv_ssthresh;
 178        __u32   tcpi_rtt;
 179        __u32   tcpi_rttvar;
 180        __u32   tcpi_snd_ssthresh;
 181        __u32   tcpi_snd_cwnd;
 182        __u32   tcpi_advmss;
 183        __u32   tcpi_reordering;
 184
 185        __u32   tcpi_rcv_rtt;
 186        __u32   tcpi_rcv_space;
 187
 188        __u32   tcpi_total_retrans;
 189
 190        __u64   tcpi_pacing_rate;
 191        __u64   tcpi_max_pacing_rate;
 192};
 193
 194/* for TCP_MD5SIG socket option */
 195#define TCP_MD5SIG_MAXKEYLEN    80
 196
 197struct tcp_md5sig {
 198        struct __kernel_sockaddr_storage tcpm_addr;     /* address associated */
 199        __u16   __tcpm_pad1;                            /* zero */
 200        __u16   tcpm_keylen;                            /* key length */
 201        __u32   __tcpm_pad2;                            /* zero */
 202        __u8    tcpm_key[TCP_MD5SIG_MAXKEYLEN];         /* key (binary) */
 203};
 204
 205#endif /* _UAPI_LINUX_TCP_H */
 206