/* 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)
*/
__u32 tcpi_rcv_wnd; /* local advertised receive window after
* scaling (bytes)
*/
__u32 tcpi_rehash; /* PLB or timeout triggered rehash attempts */
};
/* 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) */
TCP_NLA_TTL, /* TTL or hop limit of a packet received */
TCP_NLA_REHASH, /* PLB and timeout triggered rehash attempts */
};
/* 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, ...) */
#define TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT 0x1
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 */
__u32 flags; /* in: flags */
__u64 msg_control; /* ancillary data */
__u64 msg_controllen;
__u32 msg_flags;
__u32 reserved; /* set to 0 for now */
};
#endif /* _LINUX_TCP_H */