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1da177e4 LT |
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> | |
cfb6eeb4 | 22 | #include <linux/socket.h> |
1da177e4 LT |
23 | |
24 | struct tcphdr { | |
46a97324 AV |
25 | __be16 source; |
26 | __be16 dest; | |
27 | __be32 seq; | |
28 | __be32 ack_seq; | |
1da177e4 LT |
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 | |
46a97324 | 54 | __be16 window; |
9981a0e3 | 55 | __sum16 check; |
46a97324 | 56 | __be16 urg_ptr; |
1da177e4 LT |
57 | }; |
58 | ||
1da177e4 LT |
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 | */ | |
64 | union tcp_word_hdr { | |
65 | struct tcphdr hdr; | |
46a97324 | 66 | __be32 words[5]; |
1da177e4 LT |
67 | }; |
68 | ||
69 | #define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3]) | |
70 | ||
71 | enum { | |
f3a7c66b HH |
72 | TCP_FLAG_CWR = __cpu_to_be32(0x00800000), |
73 | TCP_FLAG_ECE = __cpu_to_be32(0x00400000), | |
74 | TCP_FLAG_URG = __cpu_to_be32(0x00200000), | |
75 | TCP_FLAG_ACK = __cpu_to_be32(0x00100000), | |
76 | TCP_FLAG_PSH = __cpu_to_be32(0x00080000), | |
77 | TCP_FLAG_RST = __cpu_to_be32(0x00040000), | |
78 | TCP_FLAG_SYN = __cpu_to_be32(0x00020000), | |
79 | TCP_FLAG_FIN = __cpu_to_be32(0x00010000), | |
80 | TCP_RESERVED_BITS = __cpu_to_be32(0x0F000000), | |
81 | TCP_DATA_OFFSET = __cpu_to_be32(0xF0000000) | |
1da177e4 LT |
82 | }; |
83 | ||
84 | /* TCP socket options */ | |
85 | #define TCP_NODELAY 1 /* Turn off Nagle's algorithm. */ | |
86 | #define TCP_MAXSEG 2 /* Limit MSS */ | |
87 | #define TCP_CORK 3 /* Never send partially complete segments */ | |
88 | #define TCP_KEEPIDLE 4 /* Start keeplives after this period */ | |
89 | #define TCP_KEEPINTVL 5 /* Interval between keepalives */ | |
90 | #define TCP_KEEPCNT 6 /* Number of keepalives before death */ | |
91 | #define TCP_SYNCNT 7 /* Number of SYN retransmits */ | |
92 | #define TCP_LINGER2 8 /* Life time of orphaned FIN-WAIT-2 state */ | |
93 | #define TCP_DEFER_ACCEPT 9 /* Wake up listener only when data arrive */ | |
94 | #define TCP_WINDOW_CLAMP 10 /* Bound advertised window */ | |
95 | #define TCP_INFO 11 /* Information about this connection. */ | |
96 | #define TCP_QUICKACK 12 /* Block/reenable quick acks */ | |
5f8ef48d | 97 | #define TCP_CONGESTION 13 /* Congestion control algorithm */ |
cfb6eeb4 | 98 | #define TCP_MD5SIG 14 /* TCP MD5 Signature (RFC2385) */ |
1da177e4 LT |
99 | |
100 | #define TCPI_OPT_TIMESTAMPS 1 | |
101 | #define TCPI_OPT_SACK 2 | |
102 | #define TCPI_OPT_WSCALE 4 | |
103 | #define TCPI_OPT_ECN 8 | |
104 | ||
d94d9fee | 105 | enum tcp_ca_state { |
1da177e4 LT |
106 | TCP_CA_Open = 0, |
107 | #define TCPF_CA_Open (1<<TCP_CA_Open) | |
108 | TCP_CA_Disorder = 1, | |
109 | #define TCPF_CA_Disorder (1<<TCP_CA_Disorder) | |
110 | TCP_CA_CWR = 2, | |
111 | #define TCPF_CA_CWR (1<<TCP_CA_CWR) | |
112 | TCP_CA_Recovery = 3, | |
113 | #define TCPF_CA_Recovery (1<<TCP_CA_Recovery) | |
114 | TCP_CA_Loss = 4 | |
115 | #define TCPF_CA_Loss (1<<TCP_CA_Loss) | |
116 | }; | |
117 | ||
d94d9fee | 118 | struct tcp_info { |
1da177e4 LT |
119 | __u8 tcpi_state; |
120 | __u8 tcpi_ca_state; | |
121 | __u8 tcpi_retransmits; | |
122 | __u8 tcpi_probes; | |
123 | __u8 tcpi_backoff; | |
124 | __u8 tcpi_options; | |
125 | __u8 tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4; | |
126 | ||
127 | __u32 tcpi_rto; | |
128 | __u32 tcpi_ato; | |
129 | __u32 tcpi_snd_mss; | |
130 | __u32 tcpi_rcv_mss; | |
131 | ||
132 | __u32 tcpi_unacked; | |
133 | __u32 tcpi_sacked; | |
134 | __u32 tcpi_lost; | |
135 | __u32 tcpi_retrans; | |
136 | __u32 tcpi_fackets; | |
137 | ||
138 | /* Times. */ | |
139 | __u32 tcpi_last_data_sent; | |
140 | __u32 tcpi_last_ack_sent; /* Not remembered, sorry. */ | |
141 | __u32 tcpi_last_data_recv; | |
142 | __u32 tcpi_last_ack_recv; | |
143 | ||
144 | /* Metrics. */ | |
145 | __u32 tcpi_pmtu; | |
146 | __u32 tcpi_rcv_ssthresh; | |
147 | __u32 tcpi_rtt; | |
148 | __u32 tcpi_rttvar; | |
149 | __u32 tcpi_snd_ssthresh; | |
150 | __u32 tcpi_snd_cwnd; | |
151 | __u32 tcpi_advmss; | |
152 | __u32 tcpi_reordering; | |
153 | ||
154 | __u32 tcpi_rcv_rtt; | |
155 | __u32 tcpi_rcv_space; | |
156 | ||
157 | __u32 tcpi_total_retrans; | |
158 | }; | |
159 | ||
cfb6eeb4 YH |
160 | /* for TCP_MD5SIG socket option */ |
161 | #define TCP_MD5SIG_MAXKEYLEN 80 | |
162 | ||
163 | struct tcp_md5sig { | |
164 | struct __kernel_sockaddr_storage tcpm_addr; /* address associated */ | |
165 | __u16 __tcpm_pad1; /* zero */ | |
166 | __u16 tcpm_keylen; /* key length */ | |
167 | __u32 __tcpm_pad2; /* zero */ | |
168 | __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */ | |
169 | }; | |
170 | ||
1da177e4 LT |
171 | #ifdef __KERNEL__ |
172 | ||
1da177e4 | 173 | #include <linux/skbuff.h> |
c8a553ad | 174 | #include <linux/dmaengine.h> |
1da177e4 | 175 | #include <net/sock.h> |
463c84b9 | 176 | #include <net/inet_connection_sock.h> |
8feaf0c0 | 177 | #include <net/inet_timewait_sock.h> |
1da177e4 | 178 | |
aa8223c7 ACM |
179 | static inline struct tcphdr *tcp_hdr(const struct sk_buff *skb) |
180 | { | |
9c70220b | 181 | return (struct tcphdr *)skb_transport_header(skb); |
aa8223c7 ACM |
182 | } |
183 | ||
ab6a5bb6 ACM |
184 | static inline unsigned int tcp_hdrlen(const struct sk_buff *skb) |
185 | { | |
aa8223c7 | 186 | return tcp_hdr(skb)->doff * 4; |
ab6a5bb6 ACM |
187 | } |
188 | ||
189 | static inline unsigned int tcp_optlen(const struct sk_buff *skb) | |
190 | { | |
aa8223c7 | 191 | return (tcp_hdr(skb)->doff - 5) * 4; |
ab6a5bb6 ACM |
192 | } |
193 | ||
1da177e4 | 194 | /* This defines a selective acknowledgement block. */ |
269bd27e AV |
195 | struct tcp_sack_block_wire { |
196 | __be32 start_seq; | |
197 | __be32 end_seq; | |
198 | }; | |
199 | ||
1da177e4 | 200 | struct tcp_sack_block { |
3a137d20 ACM |
201 | u32 start_seq; |
202 | u32 end_seq; | |
1da177e4 LT |
203 | }; |
204 | ||
1da177e4 LT |
205 | struct tcp_options_received { |
206 | /* PAWS/RTTM data */ | |
207 | long ts_recent_stamp;/* Time we stored ts_recent (for aging) */ | |
3a137d20 ACM |
208 | u32 ts_recent; /* Time stamp to echo next */ |
209 | u32 rcv_tsval; /* Time stamp value */ | |
210 | u32 rcv_tsecr; /* Time stamp echo reply */ | |
211 | u16 saw_tstamp : 1, /* Saw TIMESTAMP on last packet */ | |
1da177e4 LT |
212 | tstamp_ok : 1, /* TIMESTAMP seen on SYN packet */ |
213 | dsack : 1, /* D-SACK is scheduled */ | |
214 | wscale_ok : 1, /* Wscale seen on SYN packet */ | |
215 | sack_ok : 4, /* SACK seen on SYN packet */ | |
216 | snd_wscale : 4, /* Window scaling received from sender */ | |
217 | rcv_wscale : 4; /* Window scaling to send to receiver */ | |
218 | /* SACKs data */ | |
3a137d20 ACM |
219 | u8 num_sacks; /* Number of SACK blocks */ |
220 | u16 user_mss; /* mss requested by user in ioctl */ | |
221 | u16 mss_clamp; /* Maximal mss, negotiated at connection setup */ | |
1da177e4 LT |
222 | }; |
223 | ||
4389dded AL |
224 | /* This is the max number of SACKS that we'll generate and process. It's safe |
225 | * to increse this, although since: | |
226 | * size = TCPOLEN_SACK_BASE_ALIGNED (4) + n * TCPOLEN_SACK_PERBLOCK (8) | |
227 | * only four options will fit in a standard TCP header */ | |
228 | #define TCP_NUM_SACKS 4 | |
229 | ||
2e6599cb | 230 | struct tcp_request_sock { |
cfb6eeb4 YH |
231 | struct inet_request_sock req; |
232 | #ifdef CONFIG_TCP_MD5SIG | |
233 | /* Only used by TCP MD5 Signature so far. */ | |
b2e4b3de | 234 | const struct tcp_request_sock_ops *af_specific; |
cfb6eeb4 | 235 | #endif |
3a137d20 ACM |
236 | u32 rcv_isn; |
237 | u32 snt_isn; | |
2e6599cb ACM |
238 | }; |
239 | ||
60236fdd | 240 | static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req) |
2e6599cb ACM |
241 | { |
242 | return (struct tcp_request_sock *)req; | |
243 | } | |
244 | ||
1da177e4 | 245 | struct tcp_sock { |
463c84b9 ACM |
246 | /* inet_connection_sock has to be the first member of tcp_sock */ |
247 | struct inet_connection_sock inet_conn; | |
2ff52f28 | 248 | u16 tcp_header_len; /* Bytes of tcp header to send */ |
2a3a041c | 249 | u16 xmit_size_goal_segs; /* Goal for segmenting output packets */ |
1da177e4 LT |
250 | |
251 | /* | |
252 | * Header prediction flags | |
253 | * 0x5?10 << 16 + snd_wnd in net byte order | |
254 | */ | |
dddc93c0 | 255 | __be32 pred_flags; |
1da177e4 LT |
256 | |
257 | /* | |
258 | * RFC793 variables by their proper names. This means you can | |
259 | * read the code and the spec side by side (and laugh ...) | |
260 | * See RFC793 and RFC1122. The RFC writes these in capitals. | |
261 | */ | |
3a137d20 | 262 | u32 rcv_nxt; /* What we want to receive next */ |
54287cc1 ED |
263 | u32 copied_seq; /* Head of yet unread data */ |
264 | u32 rcv_wup; /* rcv_nxt on last window update sent */ | |
3a137d20 | 265 | u32 snd_nxt; /* Next sequence we send */ |
1da177e4 | 266 | |
3a137d20 ACM |
267 | u32 snd_una; /* First byte we want an ack for */ |
268 | u32 snd_sml; /* Last byte of the most recently transmitted small packet */ | |
269 | u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */ | |
270 | u32 lsndtime; /* timestamp of last sent data packet (for restart window) */ | |
1da177e4 LT |
271 | |
272 | /* Data for direct copy to user */ | |
273 | struct { | |
274 | struct sk_buff_head prequeue; | |
275 | struct task_struct *task; | |
276 | struct iovec *iov; | |
277 | int memory; | |
278 | int len; | |
97fc2f08 CL |
279 | #ifdef CONFIG_NET_DMA |
280 | /* members for async copy */ | |
281 | struct dma_chan *dma_chan; | |
282 | int wakeup; | |
283 | struct dma_pinned_list *pinned_list; | |
284 | dma_cookie_t dma_cookie; | |
285 | #endif | |
1da177e4 LT |
286 | } ucopy; |
287 | ||
3a137d20 ACM |
288 | u32 snd_wl1; /* Sequence for window update */ |
289 | u32 snd_wnd; /* The window we expect to receive */ | |
290 | u32 max_window; /* Maximal window ever seen from peer */ | |
291 | u32 mss_cache; /* Cached effective mss, not including SACKS */ | |
1da177e4 | 292 | |
3a137d20 ACM |
293 | u32 window_clamp; /* Maximal window to advertise */ |
294 | u32 rcv_ssthresh; /* Current window clamp */ | |
1da177e4 | 295 | |
3a137d20 | 296 | u32 frto_highmark; /* snd_nxt when RTO occurred */ |
b79eeeb9 | 297 | u16 advmss; /* Advertised MSS */ |
3a137d20 ACM |
298 | u8 frto_counter; /* Number of new acks after RTO */ |
299 | u8 nonagle; /* Disable Nagle algorithm? */ | |
1da177e4 LT |
300 | |
301 | /* RTT measurement */ | |
3a137d20 ACM |
302 | u32 srtt; /* smoothed round trip time << 3 */ |
303 | u32 mdev; /* medium deviation */ | |
304 | u32 mdev_max; /* maximal mdev for the last rtt period */ | |
305 | u32 rttvar; /* smoothed mdev_max */ | |
306 | u32 rtt_seq; /* sequence number to update rttvar */ | |
307 | ||
308 | u32 packets_out; /* Packets which are "in flight" */ | |
3a137d20 | 309 | u32 retrans_out; /* Retransmitted packets out */ |
b79eeeb9 IJ |
310 | |
311 | u16 urg_data; /* Saved octet of OOB data and control flags */ | |
b79eeeb9 | 312 | u8 ecn_flags; /* ECN status bits. */ |
33f5f57e IJ |
313 | u8 reordering; /* Packet reordering metric. */ |
314 | u32 snd_up; /* Urgent pointer */ | |
315 | ||
316 | u8 keepalive_probes; /* num of allowed keep alive probes */ | |
1da177e4 LT |
317 | /* |
318 | * Options received (usually on last packet, some only on SYN packets). | |
319 | */ | |
1da177e4 LT |
320 | struct tcp_options_received rx_opt; |
321 | ||
322 | /* | |
323 | * Slow start and congestion control (see also Nagle, and Karn & Partridge) | |
324 | */ | |
3a137d20 ACM |
325 | u32 snd_ssthresh; /* Slow start size threshold */ |
326 | u32 snd_cwnd; /* Sending congestion window */ | |
f78a1b38 | 327 | u32 snd_cwnd_cnt; /* Linear increase counter */ |
e0ef57cc | 328 | u32 snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */ |
3a137d20 ACM |
329 | u32 snd_cwnd_used; |
330 | u32 snd_cwnd_stamp; | |
1da177e4 | 331 | |
3a137d20 | 332 | u32 rcv_wnd; /* Current receiver window */ |
3a137d20 ACM |
333 | u32 write_seq; /* Tail(+1) of data held in tcp send buffer */ |
334 | u32 pushed_seq; /* Last pushed seq, required to talk to windows */ | |
b79eeeb9 IJ |
335 | u32 lost_out; /* Lost packets */ |
336 | u32 sacked_out; /* SACK'd packets */ | |
337 | u32 fackets_out; /* FACK'd packets */ | |
338 | u32 tso_deferred; | |
339 | u32 bytes_acked; /* Appropriate Byte Counting - RFC3465 */ | |
1da177e4 | 340 | |
b79eeeb9 IJ |
341 | /* from STCP, retrans queue hinting */ |
342 | struct sk_buff* lost_skb_hint; | |
343 | struct sk_buff *scoreboard_skb_hint; | |
344 | struct sk_buff *retransmit_skb_hint; | |
b79eeeb9 IJ |
345 | |
346 | struct sk_buff_head out_of_order_queue; /* Out of order segments go here */ | |
347 | ||
348 | /* SACKs data, these 2 need to be together (see tcp_build_and_update_options) */ | |
1da177e4 LT |
349 | struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */ |
350 | struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/ | |
351 | ||
fd6dad61 | 352 | struct tcp_sack_block recv_sack_cache[4]; |
6a438bbe | 353 | |
a47e5a98 IJ |
354 | struct sk_buff *highest_sack; /* highest skb with SACK received |
355 | * (validity guaranteed only if | |
356 | * sacked_out > 0) | |
357 | */ | |
d738cd8f | 358 | |
6a438bbe | 359 | int lost_cnt_hint; |
006f582c | 360 | u32 retransmit_high; /* L-bits may be on up to this seqno */ |
6a438bbe | 361 | |
b08d6cb2 IJ |
362 | u32 lost_retrans_low; /* Sent seq after any rxmit (lowest) */ |
363 | ||
4b749440 | 364 | u32 prior_ssthresh; /* ssthresh saved at recovery start */ |
3a137d20 | 365 | u32 high_seq; /* snd_nxt at onset of congestion */ |
1da177e4 | 366 | |
3a137d20 | 367 | u32 retrans_stamp; /* Timestamp of the last retransmit, |
1da177e4 LT |
368 | * also used in SYN-SENT to remember stamp of |
369 | * the first SYN. */ | |
3a137d20 | 370 | u32 undo_marker; /* tracking retrans started here. */ |
1da177e4 | 371 | int undo_retrans; /* number of undoable retransmissions. */ |
b79eeeb9 IJ |
372 | u32 total_retrans; /* Total retransmits for entire connection */ |
373 | ||
3a137d20 | 374 | u32 urg_seq; /* Seq of received urgent pointer */ |
1da177e4 LT |
375 | unsigned int keepalive_time; /* time before keep alive takes place */ |
376 | unsigned int keepalive_intvl; /* time interval between keep alive probes */ | |
1da177e4 | 377 | |
a0f82f64 | 378 | int linger2; |
1da177e4 LT |
379 | |
380 | /* Receiver side RTT estimation */ | |
381 | struct { | |
3a137d20 ACM |
382 | u32 rtt; |
383 | u32 seq; | |
384 | u32 time; | |
1da177e4 LT |
385 | } rcv_rtt_est; |
386 | ||
387 | /* Receiver queue space */ | |
388 | struct { | |
389 | int space; | |
3a137d20 ACM |
390 | u32 seq; |
391 | u32 time; | |
1da177e4 | 392 | } rcvq_space; |
0e7b1368 JH |
393 | |
394 | /* TCP-specific MTU probe information. */ | |
395 | struct { | |
3a137d20 ACM |
396 | u32 probe_seq_start; |
397 | u32 probe_seq_end; | |
0e7b1368 | 398 | } mtu_probe; |
cfb6eeb4 YH |
399 | |
400 | #ifdef CONFIG_TCP_MD5SIG | |
401 | /* TCP AF-Specific parts; only used by MD5 Signature support so far */ | |
b2e4b3de | 402 | const struct tcp_sock_af_ops *af_specific; |
cfb6eeb4 | 403 | |
b2e4b3de | 404 | /* TCP MD5 Signature Option information */ |
cfb6eeb4 YH |
405 | struct tcp_md5sig_info *md5sig_info; |
406 | #endif | |
1da177e4 LT |
407 | }; |
408 | ||
409 | static inline struct tcp_sock *tcp_sk(const struct sock *sk) | |
410 | { | |
411 | return (struct tcp_sock *)sk; | |
412 | } | |
413 | ||
8feaf0c0 ACM |
414 | struct tcp_timewait_sock { |
415 | struct inet_timewait_sock tw_sk; | |
3a137d20 ACM |
416 | u32 tw_rcv_nxt; |
417 | u32 tw_snd_nxt; | |
418 | u32 tw_rcv_wnd; | |
419 | u32 tw_ts_recent; | |
8feaf0c0 | 420 | long tw_ts_recent_stamp; |
cfb6eeb4 | 421 | #ifdef CONFIG_TCP_MD5SIG |
3a137d20 ACM |
422 | u16 tw_md5_keylen; |
423 | u8 tw_md5_key[TCP_MD5SIG_MAXKEYLEN]; | |
cfb6eeb4 | 424 | #endif |
8feaf0c0 ACM |
425 | }; |
426 | ||
427 | static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk) | |
428 | { | |
429 | return (struct tcp_timewait_sock *)sk; | |
430 | } | |
431 | ||
1da177e4 LT |
432 | #endif |
433 | ||
434 | #endif /* _LINUX_TCP_H */ |