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 23struct 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 * The union cast uses a gcc extension to avoid aliasing problems 60 * (union is compatible to any of its members) 61 * This means this part of the code is -fstrict-aliasing safe now. 62 */ 63union tcp_word_hdr { 64 struct tcphdr hdr; 65 __u32 words[5]; 66}; 67 68#define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3]) 69 70enum { 71 TCP_FLAG_CWR = __constant_htonl(0x00800000), 72 TCP_FLAG_ECE = __constant_htonl(0x00400000), 73 TCP_FLAG_URG = __constant_htonl(0x00200000), 74 TCP_FLAG_ACK = __constant_htonl(0x00100000), 75 TCP_FLAG_PSH = __constant_htonl(0x00080000), 76 TCP_FLAG_RST = __constant_htonl(0x00040000), 77 TCP_FLAG_SYN = __constant_htonl(0x00020000), 78 TCP_FLAG_FIN = __constant_htonl(0x00010000), 79 TCP_RESERVED_BITS = __constant_htonl(0x0F000000), 80 TCP_DATA_OFFSET = __constant_htonl(0xF0000000) 81}; 82 83/* TCP socket options */ 84#define TCP_NODELAY 1 /* Turn off Nagle's algorithm. */ 85#define TCP_MAXSEG 2 /* Limit MSS */ 86#define TCP_CORK 3 /* Never send partially complete segments */ 87#define TCP_KEEPIDLE 4 /* Start keeplives after this period */ 88#define TCP_KEEPINTVL 5 /* Interval between keepalives */ 89#define TCP_KEEPCNT 6 /* Number of keepalives before death */ 90#define TCP_SYNCNT 7 /* Number of SYN retransmits */ 91#define TCP_LINGER2 8 /* Life time of orphaned FIN-WAIT-2 state */ 92#define TCP_DEFER_ACCEPT 9 /* Wake up listener only when data arrive */ 93#define TCP_WINDOW_CLAMP 10 /* Bound advertised window */ 94#define TCP_INFO 11 /* Information about this connection. */ 95#define TCP_QUICKACK 12 /* Block/reenable quick acks */ 96#define TCP_CONGESTION 13 /* Congestion control algorithm */ 97 98#define TCPI_OPT_TIMESTAMPS 1 99#define TCPI_OPT_SACK 2 100#define TCPI_OPT_WSCALE 4 101#define TCPI_OPT_ECN 8 102 103enum tcp_ca_state 104{ 105 TCP_CA_Open = 0, 106#define TCPF_CA_Open (1<<TCP_CA_Open) 107 TCP_CA_Disorder = 1, 108#define TCPF_CA_Disorder (1<<TCP_CA_Disorder) 109 TCP_CA_CWR = 2, 110#define TCPF_CA_CWR (1<<TCP_CA_CWR) 111 TCP_CA_Recovery = 3, 112#define TCPF_CA_Recovery (1<<TCP_CA_Recovery) 113 TCP_CA_Loss = 4 114#define TCPF_CA_Loss (1<<TCP_CA_Loss) 115}; 116 117struct tcp_info 118{ 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}; 159 160#ifdef __KERNEL__ 161 162#include <linux/skbuff.h> 163#include <linux/dmaengine.h> 164#include <net/sock.h> 165#include <net/inet_connection_sock.h> 166#include <net/inet_timewait_sock.h> 167 168/* This defines a selective acknowledgement block. */ 169struct tcp_sack_block { 170 __u32 start_seq; 171 __u32 end_seq; 172}; 173 174struct tcp_options_received { 175/* PAWS/RTTM data */ 176 long ts_recent_stamp;/* Time we stored ts_recent (for aging) */ 177 __u32 ts_recent; /* Time stamp to echo next */ 178 __u32 rcv_tsval; /* Time stamp value */ 179 __u32 rcv_tsecr; /* Time stamp echo reply */ 180 __u16 saw_tstamp : 1, /* Saw TIMESTAMP on last packet */ 181 tstamp_ok : 1, /* TIMESTAMP seen on SYN packet */ 182 dsack : 1, /* D-SACK is scheduled */ 183 wscale_ok : 1, /* Wscale seen on SYN packet */ 184 sack_ok : 4, /* SACK seen on SYN packet */ 185 snd_wscale : 4, /* Window scaling received from sender */ 186 rcv_wscale : 4; /* Window scaling to send to receiver */ 187/* SACKs data */ 188 __u8 eff_sacks; /* Size of SACK array to send with next packet */ 189 __u8 num_sacks; /* Number of SACK blocks */ 190 __u16 user_mss; /* mss requested by user in ioctl */ 191 __u16 mss_clamp; /* Maximal mss, negotiated at connection setup */ 192}; 193 194struct tcp_request_sock { 195 struct inet_request_sock req; 196 __u32 rcv_isn; 197 __u32 snt_isn; 198}; 199 200static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req) 201{ 202 return (struct tcp_request_sock *)req; 203} 204 205struct tcp_sock { 206 /* inet_connection_sock has to be the first member of tcp_sock */ 207 struct inet_connection_sock inet_conn; 208 int tcp_header_len; /* Bytes of tcp header to send */ 209 210/* 211 * Header prediction flags 212 * 0x5?10 << 16 + snd_wnd in net byte order 213 */ 214 __u32 pred_flags; 215 216/* 217 * RFC793 variables by their proper names. This means you can 218 * read the code and the spec side by side (and laugh ...) 219 * See RFC793 and RFC1122. The RFC writes these in capitals. 220 */ 221 __u32 rcv_nxt; /* What we want to receive next */ 222 __u32 snd_nxt; /* Next sequence we send */ 223 224 __u32 snd_una; /* First byte we want an ack for */ 225 __u32 snd_sml; /* Last byte of the most recently transmitted small packet */ 226 __u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */ 227 __u32 lsndtime; /* timestamp of last sent data packet (for restart window) */ 228 229 /* Data for direct copy to user */ 230 struct { 231 struct sk_buff_head prequeue; 232 struct task_struct *task; 233 struct iovec *iov; 234 int memory; 235 int len; 236#ifdef CONFIG_NET_DMA 237 /* members for async copy */ 238 struct dma_chan *dma_chan; 239 int wakeup; 240 struct dma_pinned_list *pinned_list; 241 dma_cookie_t dma_cookie; 242#endif 243 } ucopy; 244 245 __u32 snd_wl1; /* Sequence for window update */ 246 __u32 snd_wnd; /* The window we expect to receive */ 247 __u32 max_window; /* Maximal window ever seen from peer */ 248 __u32 mss_cache; /* Cached effective mss, not including SACKS */ 249 __u16 xmit_size_goal; /* Goal for segmenting output packets */ 250 /* XXX Two bytes hole, try to pack */ 251 252 __u32 window_clamp; /* Maximal window to advertise */ 253 __u32 rcv_ssthresh; /* Current window clamp */ 254 255 __u32 frto_highmark; /* snd_nxt when RTO occurred */ 256 __u8 reordering; /* Packet reordering metric. */ 257 __u8 frto_counter; /* Number of new acks after RTO */ 258 __u8 nonagle; /* Disable Nagle algorithm? */ 259 __u8 keepalive_probes; /* num of allowed keep alive probes */ 260 261/* RTT measurement */ 262 __u32 srtt; /* smoothed round trip time << 3 */ 263 __u32 mdev; /* medium deviation */ 264 __u32 mdev_max; /* maximal mdev for the last rtt period */ 265 __u32 rttvar; /* smoothed mdev_max */ 266 __u32 rtt_seq; /* sequence number to update rttvar */ 267 268 __u32 packets_out; /* Packets which are "in flight" */ 269 __u32 left_out; /* Packets which leaved network */ 270 __u32 retrans_out; /* Retransmitted packets out */ 271/* 272 * Options received (usually on last packet, some only on SYN packets). 273 */ 274 struct tcp_options_received rx_opt; 275 276/* 277 * Slow start and congestion control (see also Nagle, and Karn & Partridge) 278 */ 279 __u32 snd_ssthresh; /* Slow start size threshold */ 280 __u32 snd_cwnd; /* Sending congestion window */ 281 __u16 snd_cwnd_cnt; /* Linear increase counter */ 282 __u16 snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */ 283 __u32 snd_cwnd_used; 284 __u32 snd_cwnd_stamp; 285 286 struct sk_buff_head out_of_order_queue; /* Out of order segments go here */ 287 288 __u32 rcv_wnd; /* Current receiver window */ 289 __u32 rcv_wup; /* rcv_nxt on last window update sent */ 290 __u32 write_seq; /* Tail(+1) of data held in tcp send buffer */ 291 __u32 pushed_seq; /* Last pushed seq, required to talk to windows */ 292 __u32 copied_seq; /* Head of yet unread data */ 293 294/* SACKs data */ 295 struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */ 296 struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/ 297 298 struct tcp_sack_block recv_sack_cache[4]; 299 300 /* from STCP, retrans queue hinting */ 301 struct sk_buff* lost_skb_hint; 302 303 struct sk_buff *scoreboard_skb_hint; 304 struct sk_buff *retransmit_skb_hint; 305 struct sk_buff *forward_skb_hint; 306 struct sk_buff *fastpath_skb_hint; 307 308 int fastpath_cnt_hint; 309 int lost_cnt_hint; 310 int retransmit_cnt_hint; 311 int forward_cnt_hint; 312 313 __u16 advmss; /* Advertised MSS */ 314 __u16 prior_ssthresh; /* ssthresh saved at recovery start */ 315 __u32 lost_out; /* Lost packets */ 316 __u32 sacked_out; /* SACK'd packets */ 317 __u32 fackets_out; /* FACK'd packets */ 318 __u32 high_seq; /* snd_nxt at onset of congestion */ 319 320 __u32 retrans_stamp; /* Timestamp of the last retransmit, 321 * also used in SYN-SENT to remember stamp of 322 * the first SYN. */ 323 __u32 undo_marker; /* tracking retrans started here. */ 324 int undo_retrans; /* number of undoable retransmissions. */ 325 __u32 urg_seq; /* Seq of received urgent pointer */ 326 __u16 urg_data; /* Saved octet of OOB data and control flags */ 327 __u8 urg_mode; /* In urgent mode */ 328 __u8 ecn_flags; /* ECN status bits. */ 329 __u32 snd_up; /* Urgent pointer */ 330 331 __u32 total_retrans; /* Total retransmits for entire connection */ 332 __u32 bytes_acked; /* Appropriate Byte Counting - RFC3465 */ 333 334 unsigned int keepalive_time; /* time before keep alive takes place */ 335 unsigned int keepalive_intvl; /* time interval between keep alive probes */ 336 int linger2; 337 338 unsigned long last_synq_overflow; 339 340/* Receiver side RTT estimation */ 341 struct { 342 __u32 rtt; 343 __u32 seq; 344 __u32 time; 345 } rcv_rtt_est; 346 347/* Receiver queue space */ 348 struct { 349 int space; 350 __u32 seq; 351 __u32 time; 352 } rcvq_space; 353 354/* TCP-specific MTU probe information. */ 355 struct { 356 __u32 probe_seq_start; 357 __u32 probe_seq_end; 358 } mtu_probe; 359}; 360 361static inline struct tcp_sock *tcp_sk(const struct sock *sk) 362{ 363 return (struct tcp_sock *)sk; 364} 365 366struct tcp_timewait_sock { 367 struct inet_timewait_sock tw_sk; 368 __u32 tw_rcv_nxt; 369 __u32 tw_snd_nxt; 370 __u32 tw_rcv_wnd; 371 __u32 tw_ts_recent; 372 long tw_ts_recent_stamp; 373}; 374 375static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk) 376{ 377 return (struct tcp_timewait_sock *)sk; 378} 379 380#endif 381 382#endif /* _LINUX_TCP_H */ 383