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