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1/*
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.
5 *
6 * Definitions for the TCP protocol.
7 *
8 * Version: @(#)tcp.h 1.0.2 04/28/93
9 *
10 * Author: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 *
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.
16 */
17#ifndef _UAPI_LINUX_TCP_H
18#define _UAPI_LINUX_TCP_H
19
20#include <linux/types.h>
21#include <asm/byteorder.h>
22#include <linux/socket.h>
23
24struct tcphdr {
25 __be16 source;
26 __be16 dest;
27 __be32 seq;
28 __be32 ack_seq;
29#if defined(__LITTLE_ENDIAN_BITFIELD)
30 __u16 res1:4,
31 doff:4,
32 fin:1,
33 syn:1,
34 rst:1,
35 psh:1,
36 ack:1,
37 urg:1,
38 ece:1,
39 cwr:1;
40#elif defined(__BIG_ENDIAN_BITFIELD)
41 __u16 doff:4,
42 res1:4,
43 cwr:1,
44 ece:1,
45 urg:1,
46 ack:1,
47 psh:1,
48 rst:1,
49 syn:1,
50 fin:1;
51#else
52#error "Adjust your <asm/byteorder.h> defines"
53#endif
54 __be16 window;
55 __sum16 check;
56 __be16 urg_ptr;
57};
58
59/*
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.
63 */
64union tcp_word_hdr {
65 struct tcphdr hdr;
66 __be32 words[5];
67};
68
69#define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3])
70
71enum {
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)
82};
83
84/*
85 * TCP general constants
86 */
87#define TCP_MSS_DEFAULT 536U /* IPv4 (RFC1122, RFC2581) */
88#define TCP_MSS_DESIRED 1220U /* IPv6 (tunneled), EDNS0 (RFC3226) */
89
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
120struct tcp_repair_opt {
121 __u32 opt_code;
122 __u32 opt_val;
123};
124
125struct tcp_repair_window {
126 __u32 snd_wl1;
127 __u32 snd_wnd;
128 __u32 max_window;
129
130 __u32 rcv_wnd;
131 __u32 rcv_wup;
132};
133
134enum {
135 TCP_NO_QUEUE,
136 TCP_RECV_QUEUE,
137 TCP_SEND_QUEUE,
138 TCP_QUEUES_NR,
139};
140
141/* for TCP_INFO socket option */
142#define TCPI_OPT_TIMESTAMPS 1
143#define TCPI_OPT_SACK 2
144#define TCPI_OPT_WSCALE 4
145#define TCPI_OPT_ECN 8 /* ECN was negociated at TCP session init */
146#define TCPI_OPT_ECN_SEEN 16 /* we received at least one packet with ECT */
147#define TCPI_OPT_SYN_DATA 32 /* SYN-ACK acked data in SYN sent or rcvd */
148
149enum tcp_ca_state {
150 TCP_CA_Open = 0,
151#define TCPF_CA_Open (1<<TCP_CA_Open)
152 TCP_CA_Disorder = 1,
153#define TCPF_CA_Disorder (1<<TCP_CA_Disorder)
154 TCP_CA_CWR = 2,
155#define TCPF_CA_CWR (1<<TCP_CA_CWR)
156 TCP_CA_Recovery = 3,
157#define TCPF_CA_Recovery (1<<TCP_CA_Recovery)
158 TCP_CA_Loss = 4
159#define TCPF_CA_Loss (1<<TCP_CA_Loss)
160};
161
162struct tcp_info {
163 __u8 tcpi_state;
164 __u8 tcpi_ca_state;
165 __u8 tcpi_retransmits;
166 __u8 tcpi_probes;
167 __u8 tcpi_backoff;
168 __u8 tcpi_options;
169 __u8 tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;
170
171 __u32 tcpi_rto;
172 __u32 tcpi_ato;
173 __u32 tcpi_snd_mss;
174 __u32 tcpi_rcv_mss;
175
176 __u32 tcpi_unacked;
177 __u32 tcpi_sacked;
178 __u32 tcpi_lost;
179 __u32 tcpi_retrans;
180 __u32 tcpi_fackets;
181
182 /* Times. */
183 __u32 tcpi_last_data_sent;
184 __u32 tcpi_last_ack_sent; /* Not remembered, sorry. */
185 __u32 tcpi_last_data_recv;
186 __u32 tcpi_last_ack_recv;
187
188 /* Metrics. */
189 __u32 tcpi_pmtu;
190 __u32 tcpi_rcv_ssthresh;
191 __u32 tcpi_rtt;
192 __u32 tcpi_rttvar;
193 __u32 tcpi_snd_ssthresh;
194 __u32 tcpi_snd_cwnd;
195 __u32 tcpi_advmss;
196 __u32 tcpi_reordering;
197
198 __u32 tcpi_rcv_rtt;
199 __u32 tcpi_rcv_space;
200
201 __u32 tcpi_total_retrans;
202
203 __u64 tcpi_pacing_rate;
204 __u64 tcpi_max_pacing_rate;
205 __u64 tcpi_bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked */
206 __u64 tcpi_bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived */
207 __u32 tcpi_segs_out; /* RFC4898 tcpEStatsPerfSegsOut */
208 __u32 tcpi_segs_in; /* RFC4898 tcpEStatsPerfSegsIn */
209
210 __u32 tcpi_notsent_bytes;
211 __u32 tcpi_min_rtt;
212 __u32 tcpi_data_segs_in; /* RFC4898 tcpEStatsDataSegsIn */
213 __u32 tcpi_data_segs_out; /* RFC4898 tcpEStatsDataSegsOut */
214};
215
216/* for TCP_MD5SIG socket option */
217#define TCP_MD5SIG_MAXKEYLEN 80
218
219struct tcp_md5sig {
220 struct __kernel_sockaddr_storage tcpm_addr; /* address associated */
221 __u16 __tcpm_pad1; /* zero */
222 __u16 tcpm_keylen; /* key length */
223 __u32 __tcpm_pad2; /* zero */
224 __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */
225};
226
227#endif /* _UAPI_LINUX_TCP_H */