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, <[email protected]> 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(0x0F000000), 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 __u32 tcpi_rcv_rtt; 188 __u32 tcpi_rcv_space; 189 190 __u32 tcpi_total_retrans; 191 }; 192 193 #ifdef __KERNEL__ 194 195 #include <linux/config.h> 196 #include <linux/skbuff.h> 197 #include <linux/ip.h> 198 #include <net/sock.h> 199 200 /* This defines a selective acknowledgement block. */ 201 struct tcp_sack_block { 202 __u32 start_seq; 203 __u32 end_seq; 204 }; 205 206 struct tcp_options_received { 207 /* PAWS/RTTM data */ 208 long ts_recent_stamp;/* Time we stored ts_recent (for aging) */ 209 __u32 ts_recent; /* Time stamp to echo next */ 210 __u32 rcv_tsval; /* Time stamp value */ 211 __u32 rcv_tsecr; /* Time stamp echo reply */ 212 __u16 saw_tstamp : 1, /* Saw TIMESTAMP on last packet */ 213 tstamp_ok : 1, /* TIMESTAMP seen on SYN packet */ 214 dsack : 1, /* D-SACK is scheduled */ 215 wscale_ok : 1, /* Wscale seen on SYN packet */ 216 sack_ok : 4, /* SACK seen on SYN packet */ 217 snd_wscale : 4, /* Window scaling received from sender */ 218 rcv_wscale : 4; /* Window scaling to send to receiver */ 219 /* SACKs data */ 220 __u8 eff_sacks; /* Size of SACK array to send with next packet */ 221 __u8 num_sacks; /* Number of SACK blocks */ 222 __u16 user_mss; /* mss requested by user in ioctl */ 223 __u16 mss_clamp; /* Maximal mss, negotiated at connection setup */ 224 }; 225 226 struct tcp_request_sock { 227 struct inet_request_sock req; 228 __u32 rcv_isn; 229 __u32 snt_isn; 230 }; 231 232 static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req) 233 { 234 return (struct tcp_request_sock *)req; 235 } 236 237 struct tcp_sock { 238 /* inet_sock has to be the first member of tcp_sock */ 239 struct inet_sock inet; 240 int tcp_header_len; /* Bytes of tcp header to send */ 241 242 /* 243 * Header prediction flags 244 * 0x5?10 << 16 + snd_wnd in net byte order 245 */ 246 __u32 pred_flags; 247 248 /* 249 * RFC793 variables by their proper names. This means you can 250 * read the code and the spec side by side (and laugh ...) 251 * See RFC793 and RFC1122. The RFC writes these in capitals. 252 */ 253 __u32 rcv_nxt; /* What we want to receive next */ 254 __u32 snd_nxt; /* Next sequence we send */ 255 256 __u32 snd_una; /* First byte we want an ack for */ 257 __u32 snd_sml; /* Last byte of the most recently transmitted small packet */ 258 __u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */ 259 __u32 lsndtime; /* timestamp of last sent data packet (for restart window) */ 260 struct tcp_bind_bucket *bind_hash; 261 /* Delayed ACK control data */ 262 struct { 263 __u8 pending; /* ACK is pending */ 264 __u8 quick; /* Scheduled number of quick acks */ 265 __u8 pingpong; /* The session is interactive */ 266 __u8 blocked; /* Delayed ACK was blocked by socket lock*/ 267 __u32 ato; /* Predicted tick of soft clock */ 268 unsigned long timeout; /* Currently scheduled timeout */ 269 __u32 lrcvtime; /* timestamp of last received data packet*/ 270 __u16 last_seg_size; /* Size of last incoming segment */ 271 __u16 rcv_mss; /* MSS used for delayed ACK decisions */ 272 } ack; 273 274 /* Data for direct copy to user */ 275 struct { 276 struct sk_buff_head prequeue; 277 struct task_struct *task; 278 struct iovec *iov; 279 int memory; 280 int len; 281 } ucopy; 282 283 __u32 snd_wl1; /* Sequence for window update */ 284 __u32 snd_wnd; /* The window we expect to receive */ 285 __u32 max_window; /* Maximal window ever seen from peer */ 286 __u32 pmtu_cookie; /* Last pmtu seen by socket */ 287 __u32 mss_cache; /* Cached effective mss, not including SACKS */ 288 __u16 mss_cache_std; /* Like mss_cache, but without TSO */ 289 __u16 ext_header_len; /* Network protocol overhead (IP/IPv6 options) */ 290 __u8 ca_state; /* State of fast-retransmit machine */ 291 __u8 retransmits; /* Number of unrecovered RTO timeouts. */ 292 293 __u16 advmss; /* Advertised MSS */ 294 __u32 window_clamp; /* Maximal window to advertise */ 295 __u32 rcv_ssthresh; /* Current window clamp */ 296 297 __u32 frto_highmark; /* snd_nxt when RTO occurred */ 298 __u8 reordering; /* Packet reordering metric. */ 299 __u8 frto_counter; /* Number of new acks after RTO */ 300 301 __u8 unused; 302 __u8 defer_accept; /* User waits for some data after accept() */ 303 304 /* RTT measurement */ 305 __u32 srtt; /* smoothed round trip time << 3 */ 306 __u32 mdev; /* medium deviation */ 307 __u32 mdev_max; /* maximal mdev for the last rtt period */ 308 __u32 rttvar; /* smoothed mdev_max */ 309 __u32 rtt_seq; /* sequence number to update rttvar */ 310 __u32 rto; /* retransmit timeout */ 311 312 __u32 packets_out; /* Packets which are "in flight" */ 313 __u32 left_out; /* Packets which leaved network */ 314 __u32 retrans_out; /* Retransmitted packets out */ 315 __u8 backoff; /* backoff */ 316 /* 317 * Options received (usually on last packet, some only on SYN packets). 318 */ 319 __u8 nonagle; /* Disable Nagle algorithm? */ 320 __u8 keepalive_probes; /* num of allowed keep alive probes */ 321 322 __u8 probes_out; /* unanswered 0 window probes */ 323 struct tcp_options_received rx_opt; 324 325 /* 326 * Slow start and congestion control (see also Nagle, and Karn & Partridge) 327 */ 328 __u32 snd_ssthresh; /* Slow start size threshold */ 329 __u32 snd_cwnd; /* Sending congestion window */ 330 __u16 snd_cwnd_cnt; /* Linear increase counter */ 331 __u16 snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */ 332 __u32 snd_cwnd_used; 333 __u32 snd_cwnd_stamp; 334 335 /* Two commonly used timers in both sender and receiver paths. */ 336 unsigned long timeout; 337 struct timer_list retransmit_timer; /* Resend (no ack) */ 338 struct timer_list delack_timer; /* Ack delay */ 339 340 struct sk_buff_head out_of_order_queue; /* Out of order segments go here */ 341 342 struct tcp_func *af_specific; /* Operations which are AF_INET{4,6} specific */ 343 344 __u32 rcv_wnd; /* Current receiver window */ 345 __u32 rcv_wup; /* rcv_nxt on last window update sent */ 346 __u32 write_seq; /* Tail(+1) of data held in tcp send buffer */ 347 __u32 pushed_seq; /* Last pushed seq, required to talk to windows */ 348 __u32 copied_seq; /* Head of yet unread data */ 349 350 /* SACKs data */ 351 struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */ 352 struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/ 353 354 __u8 syn_retries; /* num of allowed syn retries */ 355 __u8 ecn_flags; /* ECN status bits. */ 356 __u16 prior_ssthresh; /* ssthresh saved at recovery start */ 357 __u32 lost_out; /* Lost packets */ 358 __u32 sacked_out; /* SACK'd packets */ 359 __u32 fackets_out; /* FACK'd packets */ 360 __u32 high_seq; /* snd_nxt at onset of congestion */ 361 362 __u32 retrans_stamp; /* Timestamp of the last retransmit, 363 * also used in SYN-SENT to remember stamp of 364 * the first SYN. */ 365 __u32 undo_marker; /* tracking retrans started here. */ 366 int undo_retrans; /* number of undoable retransmissions. */ 367 __u32 urg_seq; /* Seq of received urgent pointer */ 368 __u16 urg_data; /* Saved octet of OOB data and control flags */ 369 __u8 pending; /* Scheduled timer event */ 370 __u8 urg_mode; /* In urgent mode */ 371 __u32 snd_up; /* Urgent pointer */ 372 373 __u32 total_retrans; /* Total retransmits for entire connection */ 374 375 struct request_sock_queue accept_queue; /* FIFO of established children */ 376 377 unsigned int keepalive_time; /* time before keep alive takes place */ 378 unsigned int keepalive_intvl; /* time interval between keep alive probes */ 379 int linger2; 380 381 unsigned long last_synq_overflow; 382 383 /* Receiver side RTT estimation */ 384 struct { 385 __u32 rtt; 386 __u32 seq; 387 __u32 time; 388 } rcv_rtt_est; 389 390 /* Receiver queue space */ 391 struct { 392 int space; 393 __u32 seq; 394 __u32 time; 395 } rcvq_space; 396 397 /* Pluggable TCP congestion control hook */ 398 struct tcp_congestion_ops *ca_ops; 399 u32 ca_priv[16]; 400 #define TCP_CA_PRIV_SIZE (16*sizeof(u32)) 401 }; 402 403 static inline struct tcp_sock *tcp_sk(const struct sock *sk) 404 { 405 return (struct tcp_sock *)sk; 406 } 407 408 static inline void *tcp_ca(const struct tcp_sock *tp) 409 { 410 return (void *) tp->ca_priv; 411 } 412 413 #endif 414 415 #endif /* _LINUX_TCP_H */ 416