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1/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */2/*3 * INET An implementation of the TCP/IP protocol suite for the LINUX4 * operating system. INET is implemented using the BSD Socket5 * 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 04/28/9310 *11 * Author: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>12 *13 * This program is free software; you can redistribute it and/or14 * modify it under the terms of the GNU General Public License15 * as published by the Free Software Foundation; either version16 * 2 of the License, or (at your option) any later version.17 */18#ifndef _UAPI_LINUX_TCP_H19#define _UAPI_LINUX_TCP_H20 21#include <linux/types.h>22#include <asm/byteorder.h>23#include <linux/socket.h>24 25struct 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#else53#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 problems62 * (union is compatible to any of its members)63 * This means this part of the code is -fstrict-aliasing safe now.64 */65union 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 72enum { 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 constants87 */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 20111#define TCP_QUEUE_SEQ 21112#define TCP_REPAIR_OPTIONS 22113#define TCP_FASTOPEN 23 /* Enable FastOpen on listeners */114#define TCP_TIMESTAMP 24115#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 35126#define TCP_INQ 36 /* Notify bytes available to read as a cmsg on read */127 128#define TCP_CM_INQ TCP_INQ129 130#define TCP_TX_DELAY 37 /* delay outgoing packets by XX usec */131 132 133#define TCP_REPAIR_ON 1134#define TCP_REPAIR_OFF 0135#define TCP_REPAIR_OFF_NO_WP -1 /* Turn off without window probes */136 137struct tcp_repair_opt {138 __u32 opt_code;139 __u32 opt_val;140};141 142struct tcp_repair_window {143 __u32 snd_wl1;144 __u32 snd_wnd;145 __u32 max_window;146 147 __u32 rcv_wnd;148 __u32 rcv_wup;149};150 151enum {152 TCP_NO_QUEUE,153 TCP_RECV_QUEUE,154 TCP_SEND_QUEUE,155 TCP_QUEUES_NR,156};157 158/* why fastopen failed from client perspective */159enum tcp_fastopen_client_fail {160 TFO_STATUS_UNSPEC, /* catch-all */161 TFO_COOKIE_UNAVAILABLE, /* if not in TFO_CLIENT_NO_COOKIE mode */162 TFO_DATA_NOT_ACKED, /* SYN-ACK did not ack SYN data */163 TFO_SYN_RETRANSMITTED, /* SYN-ACK did not ack SYN data after timeout */164};165 166/* for TCP_INFO socket option */167#define TCPI_OPT_TIMESTAMPS 1168#define TCPI_OPT_SACK 2169#define TCPI_OPT_WSCALE 4170#define TCPI_OPT_ECN 8 /* ECN was negociated at TCP session init */171#define TCPI_OPT_ECN_SEEN 16 /* we received at least one packet with ECT */172#define TCPI_OPT_SYN_DATA 32 /* SYN-ACK acked data in SYN sent or rcvd */173 174/*175 * Sender's congestion state indicating normal or abnormal situations176 * in the last round of packets sent. The state is driven by the ACK177 * information and timer events.178 */179enum tcp_ca_state {180 /*181 * Nothing bad has been observed recently.182 * No apparent reordering, packet loss, or ECN marks.183 */184 TCP_CA_Open = 0,185#define TCPF_CA_Open (1<<TCP_CA_Open)186 /*187 * The sender enters disordered state when it has received DUPACKs or188 * SACKs in the last round of packets sent. This could be due to packet189 * loss or reordering but needs further information to confirm packets190 * have been lost.191 */192 TCP_CA_Disorder = 1,193#define TCPF_CA_Disorder (1<<TCP_CA_Disorder)194 /*195 * The sender enters Congestion Window Reduction (CWR) state when it196 * has received ACKs with ECN-ECE marks, or has experienced congestion197 * or packet discard on the sender host (e.g. qdisc).198 */199 TCP_CA_CWR = 2,200#define TCPF_CA_CWR (1<<TCP_CA_CWR)201 /*202 * The sender is in fast recovery and retransmitting lost packets,203 * typically triggered by ACK events.204 */205 TCP_CA_Recovery = 3,206#define TCPF_CA_Recovery (1<<TCP_CA_Recovery)207 /*208 * The sender is in loss recovery triggered by retransmission timeout.209 */210 TCP_CA_Loss = 4211#define TCPF_CA_Loss (1<<TCP_CA_Loss)212};213 214struct tcp_info {215 __u8 tcpi_state;216 __u8 tcpi_ca_state;217 __u8 tcpi_retransmits;218 __u8 tcpi_probes;219 __u8 tcpi_backoff;220 __u8 tcpi_options;221 __u8 tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;222 __u8 tcpi_delivery_rate_app_limited:1, tcpi_fastopen_client_fail:2;223 224 __u32 tcpi_rto;225 __u32 tcpi_ato;226 __u32 tcpi_snd_mss;227 __u32 tcpi_rcv_mss;228 229 __u32 tcpi_unacked;230 __u32 tcpi_sacked;231 __u32 tcpi_lost;232 __u32 tcpi_retrans;233 __u32 tcpi_fackets;234 235 /* Times. */236 __u32 tcpi_last_data_sent;237 __u32 tcpi_last_ack_sent; /* Not remembered, sorry. */238 __u32 tcpi_last_data_recv;239 __u32 tcpi_last_ack_recv;240 241 /* Metrics. */242 __u32 tcpi_pmtu;243 __u32 tcpi_rcv_ssthresh;244 __u32 tcpi_rtt;245 __u32 tcpi_rttvar;246 __u32 tcpi_snd_ssthresh;247 __u32 tcpi_snd_cwnd;248 __u32 tcpi_advmss;249 __u32 tcpi_reordering;250 251 __u32 tcpi_rcv_rtt;252 __u32 tcpi_rcv_space;253 254 __u32 tcpi_total_retrans;255 256 __u64 tcpi_pacing_rate;257 __u64 tcpi_max_pacing_rate;258 __u64 tcpi_bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked */259 __u64 tcpi_bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived */260 __u32 tcpi_segs_out; /* RFC4898 tcpEStatsPerfSegsOut */261 __u32 tcpi_segs_in; /* RFC4898 tcpEStatsPerfSegsIn */262 263 __u32 tcpi_notsent_bytes;264 __u32 tcpi_min_rtt;265 __u32 tcpi_data_segs_in; /* RFC4898 tcpEStatsDataSegsIn */266 __u32 tcpi_data_segs_out; /* RFC4898 tcpEStatsDataSegsOut */267 268 __u64 tcpi_delivery_rate;269 270 __u64 tcpi_busy_time; /* Time (usec) busy sending data */271 __u64 tcpi_rwnd_limited; /* Time (usec) limited by receive window */272 __u64 tcpi_sndbuf_limited; /* Time (usec) limited by send buffer */273 274 __u32 tcpi_delivered;275 __u32 tcpi_delivered_ce;276 277 __u64 tcpi_bytes_sent; /* RFC4898 tcpEStatsPerfHCDataOctetsOut */278 __u64 tcpi_bytes_retrans; /* RFC4898 tcpEStatsPerfOctetsRetrans */279 __u32 tcpi_dsack_dups; /* RFC4898 tcpEStatsStackDSACKDups */280 __u32 tcpi_reord_seen; /* reordering events seen */281 282 __u32 tcpi_rcv_ooopack; /* Out-of-order packets received */283 284 __u32 tcpi_snd_wnd; /* peer's advertised receive window after285 * scaling (bytes)286 */287};288 289/* netlink attributes types for SCM_TIMESTAMPING_OPT_STATS */290enum {291 TCP_NLA_PAD,292 TCP_NLA_BUSY, /* Time (usec) busy sending data */293 TCP_NLA_RWND_LIMITED, /* Time (usec) limited by receive window */294 TCP_NLA_SNDBUF_LIMITED, /* Time (usec) limited by send buffer */295 TCP_NLA_DATA_SEGS_OUT, /* Data pkts sent including retransmission */296 TCP_NLA_TOTAL_RETRANS, /* Data pkts retransmitted */297 TCP_NLA_PACING_RATE, /* Pacing rate in bytes per second */298 TCP_NLA_DELIVERY_RATE, /* Delivery rate in bytes per second */299 TCP_NLA_SND_CWND, /* Sending congestion window */300 TCP_NLA_REORDERING, /* Reordering metric */301 TCP_NLA_MIN_RTT, /* minimum RTT */302 TCP_NLA_RECUR_RETRANS, /* Recurring retransmits for the current pkt */303 TCP_NLA_DELIVERY_RATE_APP_LMT, /* delivery rate application limited ? */304 TCP_NLA_SNDQ_SIZE, /* Data (bytes) pending in send queue */305 TCP_NLA_CA_STATE, /* ca_state of socket */306 TCP_NLA_SND_SSTHRESH, /* Slow start size threshold */307 TCP_NLA_DELIVERED, /* Data pkts delivered incl. out-of-order */308 TCP_NLA_DELIVERED_CE, /* Like above but only ones w/ CE marks */309 TCP_NLA_BYTES_SENT, /* Data bytes sent including retransmission */310 TCP_NLA_BYTES_RETRANS, /* Data bytes retransmitted */311 TCP_NLA_DSACK_DUPS, /* DSACK blocks received */312 TCP_NLA_REORD_SEEN, /* reordering events seen */313 TCP_NLA_SRTT, /* smoothed RTT in usecs */314 TCP_NLA_TIMEOUT_REHASH, /* Timeout-triggered rehash attempts */315 TCP_NLA_BYTES_NOTSENT, /* Bytes in write queue not yet sent */316 TCP_NLA_EDT, /* Earliest departure time (CLOCK_MONOTONIC) */317};318 319/* for TCP_MD5SIG socket option */320#define TCP_MD5SIG_MAXKEYLEN 80321 322/* tcp_md5sig extension flags for TCP_MD5SIG_EXT */323#define TCP_MD5SIG_FLAG_PREFIX 0x1 /* address prefix length */324#define TCP_MD5SIG_FLAG_IFINDEX 0x2 /* ifindex set */325 326struct tcp_md5sig {327 struct __kernel_sockaddr_storage tcpm_addr; /* address associated */328 __u8 tcpm_flags; /* extension flags */329 __u8 tcpm_prefixlen; /* address prefix */330 __u16 tcpm_keylen; /* key length */331 int tcpm_ifindex; /* device index for scope */332 __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */333};334 335/* INET_DIAG_MD5SIG */336struct tcp_diag_md5sig {337 __u8 tcpm_family;338 __u8 tcpm_prefixlen;339 __u16 tcpm_keylen;340 __be32 tcpm_addr[4];341 __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN];342};343 344/* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */345 346#define TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT 0x1347struct tcp_zerocopy_receive {348 __u64 address; /* in: address of mapping */349 __u32 length; /* in/out: number of bytes to map/mapped */350 __u32 recv_skip_hint; /* out: amount of bytes to skip */351 __u32 inq; /* out: amount of bytes in read queue */352 __s32 err; /* out: socket error */353 __u64 copybuf_address; /* in: copybuf address (small reads) */354 __s32 copybuf_len; /* in/out: copybuf bytes avail/used or error */355 __u32 flags; /* in: flags */356};357#endif /* _UAPI_LINUX_TCP_H */358