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@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 _UAPI_LINUX_TCP_H 19 #define _UAPI_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 #define TCP_FASTOPEN_KEY 33 /* Set the key for Fast Open (cookie) */ 124 #define TCP_FASTOPEN_NO_COOKIE 34 /* Enable TFO without a TFO cookie */ 125 #define TCP_ZEROCOPY_RECEIVE 35 126 #define TCP_INQ 36 /* Notify bytes available to read as a cmsg on read */ 127 128 #define TCP_CM_INQ TCP_INQ 129 130 #define TCP_REPAIR_ON 1 131 #define TCP_REPAIR_OFF 0 132 #define TCP_REPAIR_OFF_NO_WP -1 /* Turn off without window probes */ 133 134 struct tcp_repair_opt { 135 __u32 opt_code; 136 __u32 opt_val; 137 }; 138 139 struct tcp_repair_window { 140 __u32 snd_wl1; 141 __u32 snd_wnd; 142 __u32 max_window; 143 144 __u32 rcv_wnd; 145 __u32 rcv_wup; 146 }; 147 148 enum { 149 TCP_NO_QUEUE, 150 TCP_RECV_QUEUE, 151 TCP_SEND_QUEUE, 152 TCP_QUEUES_NR, 153 }; 154 155 /* for TCP_INFO socket option */ 156 #define TCPI_OPT_TIMESTAMPS 1 157 #define TCPI_OPT_SACK 2 158 #define TCPI_OPT_WSCALE 4 159 #define TCPI_OPT_ECN 8 /* ECN was negociated at TCP session init */ 160 #define TCPI_OPT_ECN_SEEN 16 /* we received at least one packet with ECT */ 161 #define TCPI_OPT_SYN_DATA 32 /* SYN-ACK acked data in SYN sent or rcvd */ 162 163 enum tcp_ca_state { 164 TCP_CA_Open = 0, 165 #define TCPF_CA_Open (1<<TCP_CA_Open) 166 TCP_CA_Disorder = 1, 167 #define TCPF_CA_Disorder (1<<TCP_CA_Disorder) 168 TCP_CA_CWR = 2, 169 #define TCPF_CA_CWR (1<<TCP_CA_CWR) 170 TCP_CA_Recovery = 3, 171 #define TCPF_CA_Recovery (1<<TCP_CA_Recovery) 172 TCP_CA_Loss = 4 173 #define TCPF_CA_Loss (1<<TCP_CA_Loss) 174 }; 175 176 struct tcp_info { 177 __u8 tcpi_state; 178 __u8 tcpi_ca_state; 179 __u8 tcpi_retransmits; 180 __u8 tcpi_probes; 181 __u8 tcpi_backoff; 182 __u8 tcpi_options; 183 __u8 tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4; 184 __u8 tcpi_delivery_rate_app_limited:1; 185 186 __u32 tcpi_rto; 187 __u32 tcpi_ato; 188 __u32 tcpi_snd_mss; 189 __u32 tcpi_rcv_mss; 190 191 __u32 tcpi_unacked; 192 __u32 tcpi_sacked; 193 __u32 tcpi_lost; 194 __u32 tcpi_retrans; 195 __u32 tcpi_fackets; 196 197 /* Times. */ 198 __u32 tcpi_last_data_sent; 199 __u32 tcpi_last_ack_sent; /* Not remembered, sorry. */ 200 __u32 tcpi_last_data_recv; 201 __u32 tcpi_last_ack_recv; 202 203 /* Metrics. */ 204 __u32 tcpi_pmtu; 205 __u32 tcpi_rcv_ssthresh; 206 __u32 tcpi_rtt; 207 __u32 tcpi_rttvar; 208 __u32 tcpi_snd_ssthresh; 209 __u32 tcpi_snd_cwnd; 210 __u32 tcpi_advmss; 211 __u32 tcpi_reordering; 212 213 __u32 tcpi_rcv_rtt; 214 __u32 tcpi_rcv_space; 215 216 __u32 tcpi_total_retrans; 217 218 __u64 tcpi_pacing_rate; 219 __u64 tcpi_max_pacing_rate; 220 __u64 tcpi_bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked */ 221 __u64 tcpi_bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived */ 222 __u32 tcpi_segs_out; /* RFC4898 tcpEStatsPerfSegsOut */ 223 __u32 tcpi_segs_in; /* RFC4898 tcpEStatsPerfSegsIn */ 224 225 __u32 tcpi_notsent_bytes; 226 __u32 tcpi_min_rtt; 227 __u32 tcpi_data_segs_in; /* RFC4898 tcpEStatsDataSegsIn */ 228 __u32 tcpi_data_segs_out; /* RFC4898 tcpEStatsDataSegsOut */ 229 230 __u64 tcpi_delivery_rate; 231 232 __u64 tcpi_busy_time; /* Time (usec) busy sending data */ 233 __u64 tcpi_rwnd_limited; /* Time (usec) limited by receive window */ 234 __u64 tcpi_sndbuf_limited; /* Time (usec) limited by send buffer */ 235 236 __u32 tcpi_delivered; 237 __u32 tcpi_delivered_ce; 238 239 __u64 tcpi_bytes_sent; /* RFC4898 tcpEStatsPerfHCDataOctetsOut */ 240 __u64 tcpi_bytes_retrans; /* RFC4898 tcpEStatsPerfOctetsRetrans */ 241 __u32 tcpi_dsack_dups; /* RFC4898 tcpEStatsStackDSACKDups */ 242 __u32 tcpi_reord_seen; /* reordering events seen */ 243 }; 244 245 /* netlink attributes types for SCM_TIMESTAMPING_OPT_STATS */ 246 enum { 247 TCP_NLA_PAD, 248 TCP_NLA_BUSY, /* Time (usec) busy sending data */ 249 TCP_NLA_RWND_LIMITED, /* Time (usec) limited by receive window */ 250 TCP_NLA_SNDBUF_LIMITED, /* Time (usec) limited by send buffer */ 251 TCP_NLA_DATA_SEGS_OUT, /* Data pkts sent including retransmission */ 252 TCP_NLA_TOTAL_RETRANS, /* Data pkts retransmitted */ 253 TCP_NLA_PACING_RATE, /* Pacing rate in bytes per second */ 254 TCP_NLA_DELIVERY_RATE, /* Delivery rate in bytes per second */ 255 TCP_NLA_SND_CWND, /* Sending congestion window */ 256 TCP_NLA_REORDERING, /* Reordering metric */ 257 TCP_NLA_MIN_RTT, /* minimum RTT */ 258 TCP_NLA_RECUR_RETRANS, /* Recurring retransmits for the current pkt */ 259 TCP_NLA_DELIVERY_RATE_APP_LMT, /* delivery rate application limited ? */ 260 TCP_NLA_SNDQ_SIZE, /* Data (bytes) pending in send queue */ 261 TCP_NLA_CA_STATE, /* ca_state of socket */ 262 TCP_NLA_SND_SSTHRESH, /* Slow start size threshold */ 263 TCP_NLA_DELIVERED, /* Data pkts delivered incl. out-of-order */ 264 TCP_NLA_DELIVERED_CE, /* Like above but only ones w/ CE marks */ 265 TCP_NLA_BYTES_SENT, /* Data bytes sent including retransmission */ 266 TCP_NLA_BYTES_RETRANS, /* Data bytes retransmitted */ 267 TCP_NLA_DSACK_DUPS, /* DSACK blocks received */ 268 TCP_NLA_REORD_SEEN, /* reordering events seen */ 269 }; 270 271 /* for TCP_MD5SIG socket option */ 272 #define TCP_MD5SIG_MAXKEYLEN 80 273 274 /* tcp_md5sig extension flags for TCP_MD5SIG_EXT */ 275 #define TCP_MD5SIG_FLAG_PREFIX 1 /* address prefix length */ 276 277 struct tcp_md5sig { 278 struct __kernel_sockaddr_storage tcpm_addr; /* address associated */ 279 __u8 tcpm_flags; /* extension flags */ 280 __u8 tcpm_prefixlen; /* address prefix */ 281 __u16 tcpm_keylen; /* key length */ 282 __u32 __tcpm_pad; /* zero */ 283 __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */ 284 }; 285 286 /* INET_DIAG_MD5SIG */ 287 struct tcp_diag_md5sig { 288 __u8 tcpm_family; 289 __u8 tcpm_prefixlen; 290 __u16 tcpm_keylen; 291 __be32 tcpm_addr[4]; 292 __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; 293 }; 294 295 /* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */ 296 297 struct tcp_zerocopy_receive { 298 __u64 address; /* in: address of mapping */ 299 __u32 length; /* in/out: number of bytes to map/mapped */ 300 __u32 recv_skip_hint; /* out: amount of bytes to skip */ 301 }; 302 #endif /* _UAPI_LINUX_TCP_H */ 303