/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ /* * INET An implementation of the TCP/IP protocol suite for the LINUX * operating system. INET is implemented using the BSD Socket * interface as the means of communication with the user level. * * Definitions for the TCP protocol. * * Version: @(#)tcp.h 1.0.2 04/28/93 * * Author: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #ifndef _LINUX_TCP_H #define _LINUX_TCP_H #include <linux/types.h> #include <asm/byteorder.h> #include <linux/socket.h> struct tcphdr { __be16 source; __be16 dest; __be32 seq; __be32 ack_seq; #if defined(__LITTLE_ENDIAN_BITFIELD) __u16 res1:4, doff:4, fin:1, syn:1, rst:1, psh:1, ack:1, urg:1, ece:1, cwr:1; #elif defined(__BIG_ENDIAN_BITFIELD) __u16 doff:4, res1:4, cwr:1, ece:1, urg:1, ack:1, psh:1, rst:1, syn:1, fin:1; #else #error "Adjust your <asm/byteorder.h> defines" #endif __be16 window; __sum16 check; __be16 urg_ptr; }; /* * The union cast uses a gcc extension to avoid aliasing problems * (union is compatible to any of its members) * This means this part of the code is -fstrict-aliasing safe now. */ union tcp_word_hdr { struct tcphdr hdr; __be32 words[5]; }; #define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3]) enum { TCP_FLAG_CWR = __constant_cpu_to_be32(0x00800000), TCP_FLAG_ECE = __constant_cpu_to_be32(0x00400000), TCP_FLAG_URG = __constant_cpu_to_be32(0x00200000), TCP_FLAG_ACK = __constant_cpu_to_be32(0x00100000), TCP_FLAG_PSH = __constant_cpu_to_be32(0x00080000), TCP_FLAG_RST = __constant_cpu_to_be32(0x00040000), TCP_FLAG_SYN = __constant_cpu_to_be32(0x00020000), TCP_FLAG_FIN = __constant_cpu_to_be32(0x00010000), TCP_RESERVED_BITS = __constant_cpu_to_be32(0x0F000000), TCP_DATA_OFFSET = __constant_cpu_to_be32(0xF0000000) }; /* * TCP general constants */ #define TCP_MSS_DEFAULT 536U /* IPv4 (RFC1122, RFC2581) */ #define TCP_MSS_DESIRED 1220U /* IPv6 (tunneled), EDNS0 (RFC3226) */ /* TCP socket options */ #define TCP_NODELAY 1 /* Turn off Nagle's algorithm. */ #define TCP_MAXSEG 2 /* Limit MSS */ #define TCP_CORK 3 /* Never send partially complete segments */ #define TCP_KEEPIDLE 4 /* Start keeplives after this period */ #define TCP_KEEPINTVL 5 /* Interval between keepalives */ #define TCP_KEEPCNT 6 /* Number of keepalives before death */ #define TCP_SYNCNT 7 /* Number of SYN retransmits */ #define TCP_LINGER2 8 /* Life time of orphaned FIN-WAIT-2 state */ #define TCP_DEFER_ACCEPT 9 /* Wake up listener only when data arrive */ #define TCP_WINDOW_CLAMP 10 /* Bound advertised window */ #define TCP_INFO 11 /* Information about this connection. */ #define TCP_QUICKACK 12 /* Block/reenable quick acks */ #define TCP_CONGESTION 13 /* Congestion control algorithm */ #define TCP_MD5SIG 14 /* TCP MD5 Signature (RFC2385) */ #define TCP_THIN_LINEAR_TIMEOUTS 16 /* Use linear timeouts for thin streams*/ #define TCP_THIN_DUPACK 17 /* Fast retrans. after 1 dupack */ #define TCP_USER_TIMEOUT 18 /* How long for loss retry before timeout */ #define TCP_REPAIR 19 /* TCP sock is under repair right now */ #define TCP_REPAIR_QUEUE 20 #define TCP_QUEUE_SEQ 21 #define TCP_REPAIR_OPTIONS 22 #define TCP_FASTOPEN 23 /* Enable FastOpen on listeners */ #define TCP_TIMESTAMP 24 #define TCP_NOTSENT_LOWAT 25 /* limit number of unsent bytes in write queue */ #define TCP_CC_INFO 26 /* Get Congestion Control (optional) info */ #define TCP_SAVE_SYN 27 /* Record SYN headers for new connections */ #define TCP_SAVED_SYN 28 /* Get SYN headers recorded for connection */ #define TCP_REPAIR_WINDOW 29 /* Get/set window parameters */ #define TCP_FASTOPEN_CONNECT 30 /* Attempt FastOpen with connect */ #define TCP_ULP 31 /* Attach a ULP to a TCP connection */ #define TCP_MD5SIG_EXT 32 /* TCP MD5 Signature with extensions */ #define TCP_FASTOPEN_KEY 33 /* Set the key for Fast Open (cookie) */ #define TCP_FASTOPEN_NO_COOKIE 34 /* Enable TFO without a TFO cookie */ #define TCP_ZEROCOPY_RECEIVE 35 #define TCP_INQ 36 /* Notify bytes available to read as a cmsg on read */ #define TCP_CM_INQ TCP_INQ #define TCP_TX_DELAY 37 /* delay outgoing packets by XX usec */ #define TCP_REPAIR_ON 1 #define TCP_REPAIR_OFF 0 #define TCP_REPAIR_OFF_NO_WP -1 /* Turn off without window probes */ struct tcp_repair_opt { __u32 opt_code; __u32 opt_val; }; struct tcp_repair_window { __u32 snd_wl1; __u32 snd_wnd; __u32 max_window; __u32 rcv_wnd; __u32 rcv_wup; }; enum { TCP_NO_QUEUE, TCP_RECV_QUEUE, TCP_SEND_QUEUE, TCP_QUEUES_NR, }; /* why fastopen failed from client perspective */ enum tcp_fastopen_client_fail { TFO_STATUS_UNSPEC, /* catch-all */ TFO_COOKIE_UNAVAILABLE, /* if not in TFO_CLIENT_NO_COOKIE mode */ TFO_DATA_NOT_ACKED, /* SYN-ACK did not ack SYN data */ TFO_SYN_RETRANSMITTED, /* SYN-ACK did not ack SYN data after timeout */ }; /* for TCP_INFO socket option */ #define TCPI_OPT_TIMESTAMPS 1 #define TCPI_OPT_SACK 2 #define TCPI_OPT_WSCALE 4 #define TCPI_OPT_ECN 8 /* ECN was negociated at TCP session init */ #define TCPI_OPT_ECN_SEEN 16 /* we received at least one packet with ECT */ #define TCPI_OPT_SYN_DATA 32 /* SYN-ACK acked data in SYN sent or rcvd */ /* * Sender's congestion state indicating normal or abnormal situations * in the last round of packets sent. The state is driven by the ACK * information and timer events. */ enum tcp_ca_state { /* * Nothing bad has been observed recently. * No apparent reordering, packet loss, or ECN marks. */ TCP_CA_Open = 0, #define TCPF_CA_Open (1<<TCP_CA_Open) /* * The sender enters disordered state when it has received DUPACKs or * SACKs in the last round of packets sent. This could be due to packet * loss or reordering but needs further information to confirm packets * have been lost. */ TCP_CA_Disorder = 1, #define TCPF_CA_Disorder (1<<TCP_CA_Disorder) /* * The sender enters Congestion Window Reduction (CWR) state when it * has received ACKs with ECN-ECE marks, or has experienced congestion * or packet discard on the sender host (e.g. qdisc). */ TCP_CA_CWR = 2, #define TCPF_CA_CWR (1<<TCP_CA_CWR) /* * The sender is in fast recovery and retransmitting lost packets, * typically triggered by ACK events. */ TCP_CA_Recovery = 3, #define TCPF_CA_Recovery (1<<TCP_CA_Recovery) /* * The sender is in loss recovery triggered by retransmission timeout. */ TCP_CA_Loss = 4 #define TCPF_CA_Loss (1<<TCP_CA_Loss) }; struct tcp_info { __u8 tcpi_state; __u8 tcpi_ca_state; __u8 tcpi_retransmits; __u8 tcpi_probes; __u8 tcpi_backoff; __u8 tcpi_options; __u8 tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4; __u8 tcpi_delivery_rate_app_limited:1, tcpi_fastopen_client_fail:2; __u32 tcpi_rto; __u32 tcpi_ato; __u32 tcpi_snd_mss; __u32 tcpi_rcv_mss; __u32 tcpi_unacked; __u32 tcpi_sacked; __u32 tcpi_lost; __u32 tcpi_retrans; __u32 tcpi_fackets; /* Times. */ __u32 tcpi_last_data_sent; __u32 tcpi_last_ack_sent; /* Not remembered, sorry. */ __u32 tcpi_last_data_recv; __u32 tcpi_last_ack_recv; /* Metrics. */ __u32 tcpi_pmtu; __u32 tcpi_rcv_ssthresh; __u32 tcpi_rtt; __u32 tcpi_rttvar; __u32 tcpi_snd_ssthresh; __u32 tcpi_snd_cwnd; __u32 tcpi_advmss; __u32 tcpi_reordering; __u32 tcpi_rcv_rtt; __u32 tcpi_rcv_space; __u32 tcpi_total_retrans; __u64 tcpi_pacing_rate; __u64 tcpi_max_pacing_rate; __u64 tcpi_bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked */ __u64 tcpi_bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived */ __u32 tcpi_segs_out; /* RFC4898 tcpEStatsPerfSegsOut */ __u32 tcpi_segs_in; /* RFC4898 tcpEStatsPerfSegsIn */ __u32 tcpi_notsent_bytes; __u32 tcpi_min_rtt; __u32 tcpi_data_segs_in; /* RFC4898 tcpEStatsDataSegsIn */ __u32 tcpi_data_segs_out; /* RFC4898 tcpEStatsDataSegsOut */ __u64 tcpi_delivery_rate; __u64 tcpi_busy_time; /* Time (usec) busy sending data */ __u64 tcpi_rwnd_limited; /* Time (usec) limited by receive window */ __u64 tcpi_sndbuf_limited; /* Time (usec) limited by send buffer */ __u32 tcpi_delivered; __u32 tcpi_delivered_ce; __u64 tcpi_bytes_sent; /* RFC4898 tcpEStatsPerfHCDataOctetsOut */ __u64 tcpi_bytes_retrans; /* RFC4898 tcpEStatsPerfOctetsRetrans */ __u32 tcpi_dsack_dups; /* RFC4898 tcpEStatsStackDSACKDups */ __u32 tcpi_reord_seen; /* reordering events seen */ __u32 tcpi_rcv_ooopack; /* Out-of-order packets received */ __u32 tcpi_snd_wnd; /* peer's advertised receive window after * scaling (bytes) */ }; /* netlink attributes types for SCM_TIMESTAMPING_OPT_STATS */ enum { TCP_NLA_PAD, TCP_NLA_BUSY, /* Time (usec) busy sending data */ TCP_NLA_RWND_LIMITED, /* Time (usec) limited by receive window */ TCP_NLA_SNDBUF_LIMITED, /* Time (usec) limited by send buffer */ TCP_NLA_DATA_SEGS_OUT, /* Data pkts sent including retransmission */ TCP_NLA_TOTAL_RETRANS, /* Data pkts retransmitted */ TCP_NLA_PACING_RATE, /* Pacing rate in bytes per second */ TCP_NLA_DELIVERY_RATE, /* Delivery rate in bytes per second */ TCP_NLA_SND_CWND, /* Sending congestion window */ TCP_NLA_REORDERING, /* Reordering metric */ TCP_NLA_MIN_RTT, /* minimum RTT */ TCP_NLA_RECUR_RETRANS, /* Recurring retransmits for the current pkt */ TCP_NLA_DELIVERY_RATE_APP_LMT, /* delivery rate application limited ? */ TCP_NLA_SNDQ_SIZE, /* Data (bytes) pending in send queue */ TCP_NLA_CA_STATE, /* ca_state of socket */ TCP_NLA_SND_SSTHRESH, /* Slow start size threshold */ TCP_NLA_DELIVERED, /* Data pkts delivered incl. out-of-order */ TCP_NLA_DELIVERED_CE, /* Like above but only ones w/ CE marks */ TCP_NLA_BYTES_SENT, /* Data bytes sent including retransmission */ TCP_NLA_BYTES_RETRANS, /* Data bytes retransmitted */ TCP_NLA_DSACK_DUPS, /* DSACK blocks received */ TCP_NLA_REORD_SEEN, /* reordering events seen */ TCP_NLA_SRTT, /* smoothed RTT in usecs */ TCP_NLA_TIMEOUT_REHASH, /* Timeout-triggered rehash attempts */ TCP_NLA_BYTES_NOTSENT, /* Bytes in write queue not yet sent */ TCP_NLA_EDT, /* Earliest departure time (CLOCK_MONOTONIC) */ }; /* for TCP_MD5SIG socket option */ #define TCP_MD5SIG_MAXKEYLEN 80 /* tcp_md5sig extension flags for TCP_MD5SIG_EXT */ #define TCP_MD5SIG_FLAG_PREFIX 0x1 /* address prefix length */ #define TCP_MD5SIG_FLAG_IFINDEX 0x2 /* ifindex set */ struct tcp_md5sig { struct __kernel_sockaddr_storage tcpm_addr; /* address associated */ __u8 tcpm_flags; /* extension flags */ __u8 tcpm_prefixlen; /* address prefix */ __u16 tcpm_keylen; /* key length */ int tcpm_ifindex; /* device index for scope */ __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */ }; /* INET_DIAG_MD5SIG */ struct tcp_diag_md5sig { __u8 tcpm_family; __u8 tcpm_prefixlen; __u16 tcpm_keylen; __be32 tcpm_addr[4]; __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; }; /* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */ struct tcp_zerocopy_receive { __u64 address; /* in: address of mapping */ __u32 length; /* in/out: number of bytes to map/mapped */ __u32 recv_skip_hint; /* out: amount of bytes to skip */ __u32 inq; /* out: amount of bytes in read queue */ __s32 err; /* out: socket error */ __u64 copybuf_address; /* in: copybuf address (small reads) */ __s32 copybuf_len; /* in/out: copybuf bytes avail/used or error */ }; #endif /* _LINUX_TCP_H */