2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * Definitions for the TCP protocol.
8 * Version: @(#)tcp.h 1.0.2 04/28/93
10 * Author: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
17 #ifndef _UAPI_LINUX_TCP_H
18 #define _UAPI_LINUX_TCP_H
20 #include <linux/types.h>
21 #include <asm/byteorder.h>
22 #include <linux/socket.h>
29 #if defined(__LITTLE_ENDIAN_BITFIELD)
40 #elif defined(__BIG_ENDIAN_BITFIELD)
52 #error "Adjust your <asm/byteorder.h> defines"
60 * The union cast uses a gcc extension to avoid aliasing problems
61 * (union is compatible to any of its members)
62 * This means this part of the code is -fstrict-aliasing safe now.
69 #define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3])
72 TCP_FLAG_CWR = __constant_cpu_to_be32(0x00800000),
73 TCP_FLAG_ECE = __constant_cpu_to_be32(0x00400000),
74 TCP_FLAG_URG = __constant_cpu_to_be32(0x00200000),
75 TCP_FLAG_ACK = __constant_cpu_to_be32(0x00100000),
76 TCP_FLAG_PSH = __constant_cpu_to_be32(0x00080000),
77 TCP_FLAG_RST = __constant_cpu_to_be32(0x00040000),
78 TCP_FLAG_SYN = __constant_cpu_to_be32(0x00020000),
79 TCP_FLAG_FIN = __constant_cpu_to_be32(0x00010000),
80 TCP_RESERVED_BITS = __constant_cpu_to_be32(0x0F000000),
81 TCP_DATA_OFFSET = __constant_cpu_to_be32(0xF0000000)
85 * TCP general constants
87 #define TCP_MSS_DEFAULT 536U /* IPv4 (RFC1122, RFC2581) */
88 #define TCP_MSS_DESIRED 1220U /* IPv6 (tunneled), EDNS0 (RFC3226) */
90 /* TCP socket options */
91 #define TCP_NODELAY 1 /* Turn off Nagle's algorithm. */
92 #define TCP_MAXSEG 2 /* Limit MSS */
93 #define TCP_CORK 3 /* Never send partially complete segments */
94 #define TCP_KEEPIDLE 4 /* Start keeplives after this period */
95 #define TCP_KEEPINTVL 5 /* Interval between keepalives */
96 #define TCP_KEEPCNT 6 /* Number of keepalives before death */
97 #define TCP_SYNCNT 7 /* Number of SYN retransmits */
98 #define TCP_LINGER2 8 /* Life time of orphaned FIN-WAIT-2 state */
99 #define TCP_DEFER_ACCEPT 9 /* Wake up listener only when data arrive */
100 #define TCP_WINDOW_CLAMP 10 /* Bound advertised window */
101 #define TCP_INFO 11 /* Information about this connection. */
102 #define TCP_QUICKACK 12 /* Block/reenable quick acks */
103 #define TCP_CONGESTION 13 /* Congestion control algorithm */
104 #define TCP_MD5SIG 14 /* TCP MD5 Signature (RFC2385) */
105 #define TCP_THIN_LINEAR_TIMEOUTS 16 /* Use linear timeouts for thin streams*/
106 #define TCP_THIN_DUPACK 17 /* Fast retrans. after 1 dupack */
107 #define TCP_USER_TIMEOUT 18 /* How long for loss retry before timeout */
108 #define TCP_REPAIR 19 /* TCP sock is under repair right now */
109 #define TCP_REPAIR_QUEUE 20
110 #define TCP_QUEUE_SEQ 21
111 #define TCP_REPAIR_OPTIONS 22
112 #define TCP_FASTOPEN 23 /* Enable FastOpen on listeners */
113 #define TCP_TIMESTAMP 24
114 #define TCP_NOTSENT_LOWAT 25 /* limit number of unsent bytes in write queue */
115 #define TCP_CC_INFO 26 /* Get Congestion Control (optional) info */
116 #define TCP_SAVE_SYN 27 /* Record SYN headers for new connections */
117 #define TCP_SAVED_SYN 28 /* Get SYN headers recorded for connection */
118 #define TCP_REPAIR_WINDOW 29 /* Get/set window parameters */
119 #define TCP_FASTOPEN_CONNECT 30 /* Attempt FastOpen with connect */
121 struct tcp_repair_opt {
126 struct tcp_repair_window {
142 /* for TCP_INFO socket option */
143 #define TCPI_OPT_TIMESTAMPS 1
144 #define TCPI_OPT_SACK 2
145 #define TCPI_OPT_WSCALE 4
146 #define TCPI_OPT_ECN 8 /* ECN was negociated at TCP session init */
147 #define TCPI_OPT_ECN_SEEN 16 /* we received at least one packet with ECT */
148 #define TCPI_OPT_SYN_DATA 32 /* SYN-ACK acked data in SYN sent or rcvd */
152 #define TCPF_CA_Open (1<<TCP_CA_Open)
154 #define TCPF_CA_Disorder (1<<TCP_CA_Disorder)
156 #define TCPF_CA_CWR (1<<TCP_CA_CWR)
158 #define TCPF_CA_Recovery (1<<TCP_CA_Recovery)
160 #define TCPF_CA_Loss (1<<TCP_CA_Loss)
166 __u8 tcpi_retransmits;
170 __u8 tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;
171 __u8 tcpi_delivery_rate_app_limited:1;
185 __u32 tcpi_last_data_sent;
186 __u32 tcpi_last_ack_sent; /* Not remembered, sorry. */
187 __u32 tcpi_last_data_recv;
188 __u32 tcpi_last_ack_recv;
192 __u32 tcpi_rcv_ssthresh;
195 __u32 tcpi_snd_ssthresh;
198 __u32 tcpi_reordering;
201 __u32 tcpi_rcv_space;
203 __u32 tcpi_total_retrans;
205 __u64 tcpi_pacing_rate;
206 __u64 tcpi_max_pacing_rate;
207 __u64 tcpi_bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked */
208 __u64 tcpi_bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived */
209 __u32 tcpi_segs_out; /* RFC4898 tcpEStatsPerfSegsOut */
210 __u32 tcpi_segs_in; /* RFC4898 tcpEStatsPerfSegsIn */
212 __u32 tcpi_notsent_bytes;
214 __u32 tcpi_data_segs_in; /* RFC4898 tcpEStatsDataSegsIn */
215 __u32 tcpi_data_segs_out; /* RFC4898 tcpEStatsDataSegsOut */
217 __u64 tcpi_delivery_rate;
219 __u64 tcpi_busy_time; /* Time (usec) busy sending data */
220 __u64 tcpi_rwnd_limited; /* Time (usec) limited by receive window */
221 __u64 tcpi_sndbuf_limited; /* Time (usec) limited by send buffer */
224 /* netlink attributes types for SCM_TIMESTAMPING_OPT_STATS */
227 TCP_NLA_BUSY, /* Time (usec) busy sending data */
228 TCP_NLA_RWND_LIMITED, /* Time (usec) limited by receive window */
229 TCP_NLA_SNDBUF_LIMITED, /* Time (usec) limited by send buffer */
230 TCP_NLA_DATA_SEGS_OUT, /* Data pkts sent including retransmission */
231 TCP_NLA_TOTAL_RETRANS, /* Data pkts retransmitted */
234 /* for TCP_MD5SIG socket option */
235 #define TCP_MD5SIG_MAXKEYLEN 80
238 struct __kernel_sockaddr_storage tcpm_addr; /* address associated */
239 __u16 __tcpm_pad1; /* zero */
240 __u16 tcpm_keylen; /* key length */
241 __u32 __tcpm_pad2; /* zero */
242 __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */
245 #endif /* _UAPI_LINUX_TCP_H */