File: /usr/include/linux/tcp.h
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 _LINUX_TCP_H
18 #define _LINUX_TCP_H
19
20 #include <linux/types.h>
21 #include <asm/byteorder.h>
22
23 struct tcphdr {
24 __u16 source;
25 __u16 dest;
26 __u32 seq;
27 __u32 ack_seq;
28 #if defined(__LITTLE_ENDIAN_BITFIELD)
29 __u16 res1:4,
30 doff:4,
31 fin:1,
32 syn:1,
33 rst:1,
34 psh:1,
35 ack:1,
36 urg:1,
37 ece:1,
38 cwr:1;
39 #elif defined(__BIG_ENDIAN_BITFIELD)
40 __u16 doff:4,
41 res1:4,
42 cwr:1,
43 ece:1,
44 urg:1,
45 ack:1,
46 psh:1,
47 rst:1,
48 syn:1,
49 fin:1;
50 #else
51 #error "Adjust your <asm/byteorder.h> defines"
52 #endif
53 __u16 window;
54 __u16 check;
55 __u16 urg_ptr;
56 };
57
58
59 enum {
60 TCP_ESTABLISHED = 1,
61 TCP_SYN_SENT,
62 TCP_SYN_RECV,
63 TCP_FIN_WAIT1,
64 TCP_FIN_WAIT2,
65 TCP_TIME_WAIT,
66 TCP_CLOSE,
67 TCP_CLOSE_WAIT,
68 TCP_LAST_ACK,
69 TCP_LISTEN,
70 TCP_CLOSING, /* now a valid state */
71
72 TCP_MAX_STATES /* Leave at the end! */
73 };
74
75 #define TCP_STATE_MASK 0xF
76 #define TCP_ACTION_FIN (1 << 7)
77
78 enum {
79 TCPF_ESTABLISHED = (1 << 1),
80 TCPF_SYN_SENT = (1 << 2),
81 TCPF_SYN_RECV = (1 << 3),
82 TCPF_FIN_WAIT1 = (1 << 4),
83 TCPF_FIN_WAIT2 = (1 << 5),
84 TCPF_TIME_WAIT = (1 << 6),
85 TCPF_CLOSE = (1 << 7),
86 TCPF_CLOSE_WAIT = (1 << 8),
87 TCPF_LAST_ACK = (1 << 9),
88 TCPF_LISTEN = (1 << 10),
89 TCPF_CLOSING = (1 << 11)
90 };
91
92 /*
93 * The union cast uses a gcc extension to avoid aliasing problems
94 * (union is compatible to any of its members)
95 * This means this part of the code is -fstrict-aliasing safe now.
96 */
97 union tcp_word_hdr {
98 struct tcphdr hdr;
99 __u32 words[5];
100 };
101
102 #define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3])
103
104 enum {
105 TCP_FLAG_CWR = __constant_htonl(0x00800000),
106 TCP_FLAG_ECE = __constant_htonl(0x00400000),
107 TCP_FLAG_URG = __constant_htonl(0x00200000),
108 TCP_FLAG_ACK = __constant_htonl(0x00100000),
109 TCP_FLAG_PSH = __constant_htonl(0x00080000),
110 TCP_FLAG_RST = __constant_htonl(0x00040000),
111 TCP_FLAG_SYN = __constant_htonl(0x00020000),
112 TCP_FLAG_FIN = __constant_htonl(0x00010000),
113 TCP_RESERVED_BITS = __constant_htonl(0x0FC00000),
114 TCP_DATA_OFFSET = __constant_htonl(0xF0000000)
115 };
116
117 /* TCP socket options */
118 #define TCP_NODELAY 1 /* Turn off Nagle's algorithm. */
119 #define TCP_MAXSEG 2 /* Limit MSS */
120 #define TCP_CORK 3 /* Never send partially complete segments */
121 #define TCP_KEEPIDLE 4 /* Start keeplives after this period */
122 #define TCP_KEEPINTVL 5 /* Interval between keepalives */
123 #define TCP_KEEPCNT 6 /* Number of keepalives before death */
124 #define TCP_SYNCNT 7 /* Number of SYN retransmits */
125 #define TCP_LINGER2 8 /* Life time of orphaned FIN-WAIT-2 state */
126 #define TCP_DEFER_ACCEPT 9 /* Wake up listener only when data arrive */
127 #define TCP_WINDOW_CLAMP 10 /* Bound advertised window */
128 #define TCP_INFO 11 /* Information about this connection. */
129 #define TCP_QUICKACK 12 /* Block/reenable quick acks */
130
131 #define TCPI_OPT_TIMESTAMPS 1
132 #define TCPI_OPT_SACK 2
133 #define TCPI_OPT_WSCALE 4
134 #define TCPI_OPT_ECN 8
135
136 enum tcp_ca_state
137 {
138 TCP_CA_Open = 0,
139 #define TCPF_CA_Open (1<<TCP_CA_Open)
140 TCP_CA_Disorder = 1,
141 #define TCPF_CA_Disorder (1<<TCP_CA_Disorder)
142 TCP_CA_CWR = 2,
143 #define TCPF_CA_CWR (1<<TCP_CA_CWR)
144 TCP_CA_Recovery = 3,
145 #define TCPF_CA_Recovery (1<<TCP_CA_Recovery)
146 TCP_CA_Loss = 4
147 #define TCPF_CA_Loss (1<<TCP_CA_Loss)
148 };
149
150 struct tcp_info
151 {
152 __u8 tcpi_state;
153 __u8 tcpi_ca_state;
154 __u8 tcpi_retransmits;
155 __u8 tcpi_probes;
156 __u8 tcpi_backoff;
157 __u8 tcpi_options;
158 __u8 tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;
159
160 __u32 tcpi_rto;
161 __u32 tcpi_ato;
162 __u32 tcpi_snd_mss;
163 __u32 tcpi_rcv_mss;
164
165 __u32 tcpi_unacked;
166 __u32 tcpi_sacked;
167 __u32 tcpi_lost;
168 __u32 tcpi_retrans;
169 __u32 tcpi_fackets;
170
171 /* Times. */
172 __u32 tcpi_last_data_sent;
173 __u32 tcpi_last_ack_sent; /* Not remembered, sorry. */
174 __u32 tcpi_last_data_recv;
175 __u32 tcpi_last_ack_recv;
176
177 /* Metrics. */
178 __u32 tcpi_pmtu;
179 __u32 tcpi_rcv_ssthresh;
180 __u32 tcpi_rtt;
181 __u32 tcpi_rttvar;
182 __u32 tcpi_snd_ssthresh;
183 __u32 tcpi_snd_cwnd;
184 __u32 tcpi_advmss;
185 __u32 tcpi_reordering;
186 };
187
188 #endif /* _LINUX_TCP_H */
189