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
  24 struct 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  */
  64 union 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
  71 enum {
  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
 115 struct tcp_repair_opt {
 116         __u32   opt_code;
 117         __u32   opt_val;
 118 };
 119
 120 enum {
 121         TCP_NO_QUEUE,
 122         TCP_RECV_QUEUE,
 123         TCP_SEND_QUEUE,
 124         TCP_QUEUES_NR,
 125 };
 126
 127 /* for TCP_INFO socket option */
 128 #define TCPI_OPT_TIMESTAMPS     1
 129 #define TCPI_OPT_SACK           2
 130 #define TCPI_OPT_WSCALE         4
 131 #define TCPI_OPT_ECN            8 /* ECN was negociated at TCP session init */
 132 #define TCPI_OPT_ECN_SEEN       16 /* we received at least one packet with ECT */
 133 #define TCPI_OPT_SYN_DATA       32 /* SYN-ACK acked data in SYN sent or rcvd */
 134
 135 enum tcp_ca_state {
 136         TCP_CA_Open = 0,
 137 #define TCPF_CA_Open    (1<<TCP_CA_Open)
 138         TCP_CA_Disorder = 1,
 139 #define TCPF_CA_Disorder (1<<TCP_CA_Disorder)
 140         TCP_CA_CWR = 2,
 141 #define TCPF_CA_CWR     (1<<TCP_CA_CWR)
 142         TCP_CA_Recovery = 3,
 143 #define TCPF_CA_Recovery (1<<TCP_CA_Recovery)
 144         TCP_CA_Loss = 4
 145 #define TCPF_CA_Loss    (1<<TCP_CA_Loss)
 146 };
 147
 148 struct tcp_info {
 149         __u8    tcpi_state;
 150         __u8    tcpi_ca_state;
 151         __u8    tcpi_retransmits;
 152         __u8    tcpi_probes;
 153         __u8    tcpi_backoff;
 154         __u8    tcpi_options;
 155         __u8    tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;
 156
 157         __u32   tcpi_rto;
 158         __u32   tcpi_ato;
 159         __u32   tcpi_snd_mss;
 160         __u32   tcpi_rcv_mss;
 161
 162         __u32   tcpi_unacked;
 163         __u32   tcpi_sacked;
 164         __u32   tcpi_lost;
 165         __u32   tcpi_retrans;
 166         __u32   tcpi_fackets;
 167
 168         /* Times. */
 169         __u32   tcpi_last_data_sent;
 170         __u32   tcpi_last_ack_sent;     /* Not remembered, sorry. */
 171         __u32   tcpi_last_data_recv;
 172         __u32   tcpi_last_ack_recv;
 173
 174         /* Metrics. */
 175         __u32   tcpi_pmtu;
 176         __u32   tcpi_rcv_ssthresh;
 177         __u32   tcpi_rtt;
 178         __u32   tcpi_rttvar;
 179         __u32   tcpi_snd_ssthresh;
 180         __u32   tcpi_snd_cwnd;
 181         __u32   tcpi_advmss;
 182         __u32   tcpi_reordering;
 183
 184         __u32   tcpi_rcv_rtt;
 185         __u32   tcpi_rcv_space;
 186
 187         __u32   tcpi_total_retrans;
 188 };
 189
 190 /* for TCP_MD5SIG socket option */
 191 #define TCP_MD5SIG_MAXKEYLEN    80
 192
 193 struct tcp_md5sig {
 194         struct __kernel_sockaddr_storage tcpm_addr;     /* address associated */
 195         __u16   __tcpm_pad1;                            /* zero */
 196         __u16   tcpm_keylen;                            /* key length */
 197         __u32   __tcpm_pad2;                            /* zero */
 198         __u8    tcpm_key[TCP_MD5SIG_MAXKEYLEN];         /* key (binary) */
 199 };
 200
 201 #endif /* _UAPI_LINUX_TCP_H */