1 /* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * Definitions for the TCP protocol. 8 * 9 * Version: @(#)tcp.h 1.0.2 04/28/93 10 * 11 * Author: Fred N. van Kempen, <waltje (at) uWalt.NL.Mugnet.ORG> 12 * 13 * This program is free software; you can redistribute it and/or 14 * modify it under the terms of the GNU General Public License 15 * as published by the Free Software Foundation; either version 16 * 2 of the License, or (at your option) any later version. 17 */ 18 #ifndef _LINUX_TCP_H 19 #define _LINUX_TCP_H 20 21 #include <linux/types.h> 22 #include <asm/byteorder.h> 23 #include <linux/socket.h> 24 25 struct tcphdr { 26 __be16 source; 27 __be16 dest; 28 __be32 seq; 29 __be32 ack_seq; 30 #if defined(__LITTLE_ENDIAN_BITFIELD) 31 __u16 res1:4, 32 doff:4, 33 fin:1, 34 syn:1, 35 rst:1, 36 psh:1, 37 ack:1, 38 urg:1, 39 ece:1, 40 cwr:1; 41 #elif defined(__BIG_ENDIAN_BITFIELD) 42 __u16 doff:4, 43 res1:4, 44 cwr:1, 45 ece:1, 46 urg:1, 47 ack:1, 48 psh:1, 49 rst:1, 50 syn:1, 51 fin:1; 52 #else 53 #error "Adjust your <asm/byteorder.h> defines" 54 #endif 55 __be16 window; 56 __sum16 check; 57 __be16 urg_ptr; 58 }; 59 60 /* 61 * The union cast uses a gcc extension to avoid aliasing problems 62 * (union is compatible to any of its members) 63 * This means this part of the code is -fstrict-aliasing safe now. 64 */ 65 union tcp_word_hdr { 66 struct tcphdr hdr; 67 __be32 words[5]; 68 }; 69 70 #define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3]) 71 72 enum { 73 TCP_FLAG_CWR = __constant_cpu_to_be32(0x00800000), 74 TCP_FLAG_ECE = __constant_cpu_to_be32(0x00400000), 75 TCP_FLAG_URG = __constant_cpu_to_be32(0x00200000), 76 TCP_FLAG_ACK = __constant_cpu_to_be32(0x00100000), 77 TCP_FLAG_PSH = __constant_cpu_to_be32(0x00080000), 78 TCP_FLAG_RST = __constant_cpu_to_be32(0x00040000), 79 TCP_FLAG_SYN = __constant_cpu_to_be32(0x00020000), 80 TCP_FLAG_FIN = __constant_cpu_to_be32(0x00010000), 81 TCP_RESERVED_BITS = __constant_cpu_to_be32(0x0F000000), 82 TCP_DATA_OFFSET = __constant_cpu_to_be32(0xF0000000) 83 }; 84 85 /* 86 * TCP general constants 87 */ 88 #define TCP_MSS_DEFAULT 536U /* IPv4 (RFC1122, RFC2581) */ 89 #define TCP_MSS_DESIRED 1220U /* IPv6 (tunneled), EDNS0 (RFC3226) */ 90 91 /* TCP socket options */ 92 #define TCP_NODELAY 1 /* Turn off Nagle's algorithm. */ 93 #define TCP_MAXSEG 2 /* Limit MSS */ 94 #define TCP_CORK 3 /* Never send partially complete segments */ 95 #define TCP_KEEPIDLE 4 /* Start keeplives after this period */ 96 #define TCP_KEEPINTVL 5 /* Interval between keepalives */ 97 #define TCP_KEEPCNT 6 /* Number of keepalives before death */ 98 #define TCP_SYNCNT 7 /* Number of SYN retransmits */ 99 #define TCP_LINGER2 8 /* Life time of orphaned FIN-WAIT-2 state */ 100 #define TCP_DEFER_ACCEPT 9 /* Wake up listener only when data arrive */ 101 #define TCP_WINDOW_CLAMP 10 /* Bound advertised window */ 102 #define TCP_INFO 11 /* Information about this connection. */ 103 #define TCP_QUICKACK 12 /* Block/reenable quick acks */ 104 #define TCP_CONGESTION 13 /* Congestion control algorithm */ 105 #define TCP_MD5SIG 14 /* TCP MD5 Signature (RFC2385) */ 106 #define TCP_THIN_LINEAR_TIMEOUTS 16 /* Use linear timeouts for thin streams*/ 107 #define TCP_THIN_DUPACK 17 /* Fast retrans. after 1 dupack */ 108 #define TCP_USER_TIMEOUT 18 /* How long for loss retry before timeout */ 109 #define TCP_REPAIR 19 /* TCP sock is under repair right now */ 110 #define TCP_REPAIR_QUEUE 20 111 #define TCP_QUEUE_SEQ 21 112 #define TCP_REPAIR_OPTIONS 22 113 #define TCP_FASTOPEN 23 /* Enable FastOpen on listeners */ 114 #define TCP_TIMESTAMP 24 115 #define TCP_NOTSENT_LOWAT 25 /* limit number of unsent bytes in write queue */ 116 #define TCP_CC_INFO 26 /* Get Congestion Control (optional) info */ 117 #define TCP_SAVE_SYN 27 /* Record SYN headers for new connections */ 118 #define TCP_SAVED_SYN 28 /* Get SYN headers recorded for connection */ 119 #define TCP_REPAIR_WINDOW 29 /* Get/set window parameters */ 120 #define TCP_FASTOPEN_CONNECT 30 /* Attempt FastOpen with connect */ 121 #define TCP_ULP 31 /* Attach a ULP to a TCP connection */ 122 #define TCP_MD5SIG_EXT 32 /* TCP MD5 Signature with extensions */ 123 124 struct tcp_repair_opt { 125 __u32 opt_code; 126 __u32 opt_val; 127 }; 128 129 struct tcp_repair_window { 130 __u32 snd_wl1; 131 __u32 snd_wnd; 132 __u32 max_window; 133 134 __u32 rcv_wnd; 135 __u32 rcv_wup; 136 }; 137 138 enum { 139 TCP_NO_QUEUE, 140 TCP_RECV_QUEUE, 141 TCP_SEND_QUEUE, 142 TCP_QUEUES_NR, 143 }; 144 145 /* for TCP_INFO socket option */ 146 #define TCPI_OPT_TIMESTAMPS 1 147 #define TCPI_OPT_SACK 2 148 #define TCPI_OPT_WSCALE 4 149 #define TCPI_OPT_ECN 8 /* ECN was negociated at TCP session init */ 150 #define TCPI_OPT_ECN_SEEN 16 /* we received at least one packet with ECT */ 151 #define TCPI_OPT_SYN_DATA 32 /* SYN-ACK acked data in SYN sent or rcvd */ 152 153 enum tcp_ca_state { 154 TCP_CA_Open = 0, 155 #define TCPF_CA_Open (1<<TCP_CA_Open) 156 TCP_CA_Disorder = 1, 157 #define TCPF_CA_Disorder (1<<TCP_CA_Disorder) 158 TCP_CA_CWR = 2, 159 #define TCPF_CA_CWR (1<<TCP_CA_CWR) 160 TCP_CA_Recovery = 3, 161 #define TCPF_CA_Recovery (1<<TCP_CA_Recovery) 162 TCP_CA_Loss = 4 163 #define TCPF_CA_Loss (1<<TCP_CA_Loss) 164 }; 165 166 struct tcp_info { 167 __u8 tcpi_state; 168 __u8 tcpi_ca_state; 169 __u8 tcpi_retransmits; 170 __u8 tcpi_probes; 171 __u8 tcpi_backoff; 172 __u8 tcpi_options; 173 __u8 tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4; 174 __u8 tcpi_delivery_rate_app_limited:1; 175 176 __u32 tcpi_rto; 177 __u32 tcpi_ato; 178 __u32 tcpi_snd_mss; 179 __u32 tcpi_rcv_mss; 180 181 __u32 tcpi_unacked; 182 __u32 tcpi_sacked; 183 __u32 tcpi_lost; 184 __u32 tcpi_retrans; 185 __u32 tcpi_fackets; 186 187 /* Times. */ 188 __u32 tcpi_last_data_sent; 189 __u32 tcpi_last_ack_sent; /* Not remembered, sorry. */ 190 __u32 tcpi_last_data_recv; 191 __u32 tcpi_last_ack_recv; 192 193 /* Metrics. */ 194 __u32 tcpi_pmtu; 195 __u32 tcpi_rcv_ssthresh; 196 __u32 tcpi_rtt; 197 __u32 tcpi_rttvar; 198 __u32 tcpi_snd_ssthresh; 199 __u32 tcpi_snd_cwnd; 200 __u32 tcpi_advmss; 201 __u32 tcpi_reordering; 202 203 __u32 tcpi_rcv_rtt; 204 __u32 tcpi_rcv_space; 205 206 __u32 tcpi_total_retrans; 207 208 __u64 tcpi_pacing_rate; 209 __u64 tcpi_max_pacing_rate; 210 __u64 tcpi_bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked */ 211 __u64 tcpi_bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived */ 212 __u32 tcpi_segs_out; /* RFC4898 tcpEStatsPerfSegsOut */ 213 __u32 tcpi_segs_in; /* RFC4898 tcpEStatsPerfSegsIn */ 214 215 __u32 tcpi_notsent_bytes; 216 __u32 tcpi_min_rtt; 217 __u32 tcpi_data_segs_in; /* RFC4898 tcpEStatsDataSegsIn */ 218 __u32 tcpi_data_segs_out; /* RFC4898 tcpEStatsDataSegsOut */ 219 220 __u64 tcpi_delivery_rate; 221 222 __u64 tcpi_busy_time; /* Time (usec) busy sending data */ 223 __u64 tcpi_rwnd_limited; /* Time (usec) limited by receive window */ 224 __u64 tcpi_sndbuf_limited; /* Time (usec) limited by send buffer */ 225 }; 226 227 /* netlink attributes types for SCM_TIMESTAMPING_OPT_STATS */ 228 enum { 229 TCP_NLA_PAD, 230 TCP_NLA_BUSY, /* Time (usec) busy sending data */ 231 TCP_NLA_RWND_LIMITED, /* Time (usec) limited by receive window */ 232 TCP_NLA_SNDBUF_LIMITED, /* Time (usec) limited by send buffer */ 233 TCP_NLA_DATA_SEGS_OUT, /* Data pkts sent including retransmission */ 234 TCP_NLA_TOTAL_RETRANS, /* Data pkts retransmitted */ 235 TCP_NLA_PACING_RATE, /* Pacing rate in bytes per second */ 236 TCP_NLA_DELIVERY_RATE, /* Delivery rate in bytes per second */ 237 TCP_NLA_SND_CWND, /* Sending congestion window */ 238 TCP_NLA_REORDERING, /* Reordering metric */ 239 TCP_NLA_MIN_RTT, /* minimum RTT */ 240 TCP_NLA_RECUR_RETRANS, /* Recurring retransmits for the current pkt */ 241 TCP_NLA_DELIVERY_RATE_APP_LMT, /* delivery rate application limited ? */ 242 243 }; 244 245 /* for TCP_MD5SIG socket option */ 246 #define TCP_MD5SIG_MAXKEYLEN 80 247 248 /* tcp_md5sig extension flags for TCP_MD5SIG_EXT */ 249 #define TCP_MD5SIG_FLAG_PREFIX 1 /* address prefix length */ 250 251 struct tcp_md5sig { 252 struct __kernel_sockaddr_storage tcpm_addr; /* address associated */ 253 __u8 tcpm_flags; /* extension flags */ 254 __u8 tcpm_prefixlen; /* address prefix */ 255 __u16 tcpm_keylen; /* key length */ 256 __u32 __tcpm_pad; /* zero */ 257 __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */ 258 }; 259 260 /* INET_DIAG_MD5SIG */ 261 struct tcp_diag_md5sig { 262 __u8 tcpm_family; 263 __u8 tcpm_prefixlen; 264 __u16 tcpm_keylen; 265 __be32 tcpm_addr[4]; 266 __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; 267 }; 268 269 #endif /* _LINUX_TCP_H */ 270
