1 /* 2 * Copyright (c) 2003-2004 Jeffrey Hsu. All rights reserved. 3 * Copyright (c) 1982, 1986, 1993, 1994, 1995 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by the University of 17 * California, Berkeley and its contributors. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)tcp_var.h 8.4 (Berkeley) 5/24/95 35 * $FreeBSD: src/sys/netinet/tcp_var.h,v 1.56.2.13 2003/02/03 02:34:07 hsu Exp $ 36 * $DragonFly: src/sys/netinet/tcp_var.h,v 1.17 2004/04/10 00:10:42 hsu Exp $ 37 */ 38 39 #ifndef _NETINET_TCP_VAR_H_ 40 #define _NETINET_TCP_VAR_H_ 41 42 #include <netinet/in_pcb.h> /* needed for in_conninfo, inp_gen_t */ 43 44 #ifndef _NETINET_TCP_STATS_H_ 45 #include <netinet/tcp_stats.h> 46 #endif 47 48 /* 49 * Kernel variables for tcp. 50 */ 51 extern int tcp_do_rfc1323; 52 extern int tcp_do_rfc1644; 53 54 /* TCP segment queue entry */ 55 struct tseg_qent { 56 LIST_ENTRY(tseg_qent) tqe_q; 57 int tqe_len; /* TCP segment data length */ 58 struct tcphdr *tqe_th; /* a pointer to tcp header */ 59 struct mbuf *tqe_m; /* mbuf contains packet */ 60 }; 61 LIST_HEAD(tsegqe_head, tseg_qent); 62 extern int tcp_reass_maxseg; 63 extern int tcp_reass_qsize; 64 #ifdef MALLOC_DECLARE 65 MALLOC_DECLARE(M_TSEGQ); 66 #endif 67 68 struct tcptemp { 69 u_char tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */ 70 struct tcphdr tt_t; 71 }; 72 73 #define tcp6cb tcpcb /* for KAME src sync over BSD*'s */ 74 75 /* 76 * Tcp control block, one per tcp; fields: 77 * Organized for 16 byte cacheline efficiency. 78 */ 79 struct tcpcb { 80 struct tsegqe_head t_segq; 81 int t_dupacks; /* consecutive dup acks recd */ 82 struct tcptemp *unused; /* unused */ 83 84 struct callout *tt_rexmt; /* retransmit timer */ 85 struct callout *tt_persist; /* retransmit persistence */ 86 struct callout *tt_keep; /* keepalive */ 87 struct callout *tt_2msl; /* 2*msl TIME_WAIT timer */ 88 struct callout *tt_delack; /* delayed ACK timer */ 89 90 struct inpcb *t_inpcb; /* back pointer to internet pcb */ 91 int t_state; /* state of this connection */ 92 u_int t_flags; 93 #define TF_ACKNOW 0x00000001 /* ack peer immediately */ 94 #define TF_DELACK 0x00000002 /* ack, but try to delay it */ 95 #define TF_NODELAY 0x00000004 /* don't delay packets to coalesce */ 96 #define TF_NOOPT 0x00000008 /* don't use tcp options */ 97 #define TF_SENTFIN 0x00000010 /* have sent FIN */ 98 #define TF_REQ_SCALE 0x00000020 /* have/will request window scaling */ 99 #define TF_RCVD_SCALE 0x00000040 /* other side has requested scaling */ 100 #define TF_REQ_TSTMP 0x00000080 /* have/will request timestamps */ 101 #define TF_RCVD_TSTMP 0x00000100 /* a timestamp was received in SYN */ 102 #define TF_SACK_PERMIT 0x00000200 /* other side said I could SACK */ 103 #define TF_NEEDSYN 0x00000400 /* send SYN (implicit state) */ 104 #define TF_NEEDFIN 0x00000800 /* send FIN (implicit state) */ 105 #define TF_NOPUSH 0x00001000 /* don't push */ 106 #define TF_REQ_CC 0x00002000 /* have/will request CC */ 107 #define TF_RCVD_CC 0x00004000 /* a CC was received in SYN */ 108 #define TF_SENDCCNEW 0x00008000 /* send CCnew instead of CC in SYN */ 109 #define TF_MORETOCOME 0x00010000 /* More data to be appended to sock */ 110 #define TF_LQ_OVERFLOW 0x00020000 /* listen queue overflow */ 111 #define TF_LASTIDLE 0x00040000 /* connection was previously idle */ 112 #define TF_RXWIN0SENT 0x00080000 /* sent a receiver win 0 in response */ 113 #define TF_FASTRECOVERY 0x00100000 /* in NewReno Fast Recovery */ 114 #define TF_WASFRECOVERY 0x00200000 /* was in NewReno Fast Recovery */ 115 #define TF_FIRSTACCACK 0x00400000 /* Look for 1st acceptable ACK. */ 116 #define TF_FASTREXMT 0x00800000 /* Did Fast Retransmit. */ 117 #define TF_EARLYREXMT 0x01000000 /* Did Early (Fast) Retransmit. */ 118 int t_force; /* 1 if forcing out a byte */ 119 120 tcp_seq snd_una; /* send unacknowledged */ 121 tcp_seq snd_max; /* highest sequence number sent; 122 * used to recognize retransmits 123 */ 124 tcp_seq snd_nxt; /* send next */ 125 tcp_seq snd_up; /* send urgent pointer */ 126 127 tcp_seq snd_wl1; /* window update seg seq number */ 128 tcp_seq snd_wl2; /* window update seg ack number */ 129 tcp_seq iss; /* initial send sequence number */ 130 tcp_seq irs; /* initial receive sequence number */ 131 132 tcp_seq rcv_nxt; /* receive next */ 133 tcp_seq rcv_adv; /* advertised window */ 134 u_long rcv_wnd; /* receive window */ 135 tcp_seq rcv_up; /* receive urgent pointer */ 136 137 u_long snd_wnd; /* send window */ 138 u_long snd_cwnd; /* congestion-controlled window */ 139 u_long snd_bwnd; /* bandwidth-controlled window */ 140 u_long snd_ssthresh; /* snd_cwnd size threshold for 141 * for slow start exponential to 142 * linear switch 143 */ 144 u_long snd_bandwidth; /* calculated bandwidth or 0 */ 145 tcp_seq snd_recover; /* for use in NewReno fast recovery */ 146 147 u_int t_maxopd; /* mss plus options */ 148 149 u_long t_rcvtime; /* inactivity time */ 150 u_long t_starttime; /* time connection was established */ 151 int t_rtttime; /* round trip time */ 152 tcp_seq t_rtseq; /* sequence number being timed */ 153 154 int t_bw_rtttime; /* used for bandwidth calculation */ 155 tcp_seq t_bw_rtseq; /* used for bandwidth calculation */ 156 157 int t_rxtcur; /* current retransmit value (ticks) */ 158 u_int t_maxseg; /* maximum segment size */ 159 int t_srtt; /* smoothed round-trip time */ 160 int t_rttvar; /* variance in round-trip time */ 161 162 int t_rxtshift; /* log(2) of rexmt exp. backoff */ 163 u_int t_rttmin; /* minimum rtt allowed */ 164 u_int t_rttbest; /* best rtt we've seen */ 165 u_long t_rttupdated; /* number of times rtt sampled */ 166 u_long max_sndwnd; /* largest window peer has offered */ 167 168 int t_softerror; /* possible error not yet reported */ 169 /* out-of-band data */ 170 char t_oobflags; /* have some */ 171 char t_iobc; /* input character */ 172 #define TCPOOB_HAVEDATA 0x01 173 #define TCPOOB_HADDATA 0x02 174 /* RFC 1323 variables */ 175 u_char snd_scale; /* window scaling for send window */ 176 u_char rcv_scale; /* window scaling for recv window */ 177 u_char request_r_scale; /* pending window scaling */ 178 u_char requested_s_scale; 179 u_long ts_recent; /* timestamp echo data */ 180 181 u_long ts_recent_age; /* when last updated */ 182 tcp_seq last_ack_sent; 183 /* RFC 1644 variables */ 184 tcp_cc cc_send; /* send connection count */ 185 tcp_cc cc_recv; /* receive connection count */ 186 /* experimental */ 187 u_long snd_cwnd_prev; /* cwnd prior to retransmit */ 188 u_long snd_ssthresh_prev; /* ssthresh prior to retransmit */ 189 tcp_seq snd_recover_prev; /* snd_recover prior to retransmit */ 190 u_long t_badrxtwin; /* window for retransmit recovery */ 191 u_long t_rexmtTS; /* timestamp of last retransmit */ 192 u_char snd_limited; /* segments limited transmitted */ 193 }; 194 195 #define IN_FASTRECOVERY(tp) (tp->t_flags & TF_FASTRECOVERY) 196 #define ENTER_FASTRECOVERY(tp) tp->t_flags |= TF_FASTRECOVERY 197 #define EXIT_FASTRECOVERY(tp) tp->t_flags &= ~TF_FASTRECOVERY 198 199 /* 200 * Structure to hold TCP options that are only used during segment 201 * processing (in tcp_input), but not held in the tcpcb. 202 * It's basically used to reduce the number of parameters 203 * to tcp_dooptions. 204 */ 205 struct tcpopt { 206 u_long to_flags; /* which options are present */ 207 #define TOF_TS 0x0001 /* timestamp */ 208 #define TOF_CC 0x0002 /* CC and CCnew are exclusive */ 209 #define TOF_CCNEW 0x0004 210 #define TOF_CCECHO 0x0008 211 #define TOF_MSS 0x0010 212 #define TOF_SCALE 0x0020 213 u_int32_t to_tsval; 214 u_int32_t to_tsecr; 215 tcp_cc to_cc; /* holds CC or CCnew */ 216 tcp_cc to_ccecho; 217 u_int16_t to_mss; 218 u_int8_t to_requested_s_scale; 219 u_int8_t to_pad; 220 }; 221 222 struct syncache { 223 inp_gen_t sc_inp_gencnt; /* pointer check */ 224 struct tcpcb *sc_tp; /* tcb for listening socket */ 225 struct mbuf *sc_ipopts; /* source route */ 226 struct in_conninfo sc_inc; /* addresses */ 227 #define sc_route sc_inc.inc_route 228 #define sc_route6 sc_inc.inc6_route 229 u_int32_t sc_tsrecent; 230 tcp_cc sc_cc_send; /* holds CC or CCnew */ 231 tcp_cc sc_cc_recv; 232 tcp_seq sc_irs; /* seq from peer */ 233 tcp_seq sc_iss; /* our ISS */ 234 u_long sc_rxttime; /* retransmit time */ 235 u_int16_t sc_rxtslot; /* retransmit counter */ 236 u_int16_t sc_peer_mss; /* peer's MSS */ 237 u_int16_t sc_wnd; /* advertised window */ 238 u_int8_t sc_requested_s_scale:4, 239 sc_request_r_scale:4; 240 u_int8_t sc_flags; 241 #define SCF_NOOPT 0x01 /* no TCP options */ 242 #define SCF_WINSCALE 0x02 /* negotiated window scaling */ 243 #define SCF_TIMESTAMP 0x04 /* negotiated timestamps */ 244 #define SCF_CC 0x08 /* negotiated CC */ 245 #define SCF_UNREACH 0x10 /* icmp unreachable received */ 246 #define SCF_KEEPROUTE 0x20 /* keep cloned route */ 247 TAILQ_ENTRY(syncache) sc_hash; 248 TAILQ_ENTRY(syncache) sc_timerq; 249 }; 250 251 struct syncache_head { 252 TAILQ_HEAD(, syncache) sch_bucket; 253 u_int sch_length; 254 }; 255 256 /* 257 * The TAO cache entry which is stored in the protocol family specific 258 * portion of the route metrics. 259 */ 260 struct rmxp_tao { 261 tcp_cc tao_cc; /* latest CC in valid SYN */ 262 tcp_cc tao_ccsent; /* latest CC sent to peer */ 263 u_short tao_mssopt; /* peer's cached MSS */ 264 #ifdef notyet 265 u_short tao_flags; /* cache status flags */ 266 #define TAOF_DONT 0x0001 /* peer doesn't understand rfc1644 */ 267 #define TAOF_OK 0x0002 /* peer does understand rfc1644 */ 268 #define TAOF_UNDEF 0 /* we don't know yet */ 269 #endif /* notyet */ 270 }; 271 #define rmx_taop(r) ((struct rmxp_tao *)(r).rmx_filler) 272 273 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 274 #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 275 276 /* 277 * The smoothed round-trip time and estimated variance 278 * are stored as fixed point numbers scaled by the values below. 279 * For convenience, these scales are also used in smoothing the average 280 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed). 281 * With these scales, srtt has 3 bits to the right of the binary point, 282 * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the 283 * binary point, and is smoothed with an ALPHA of 0.75. 284 */ 285 #define TCP_RTT_SCALE 32 /* multiplier for srtt; 3 bits frac. */ 286 #define TCP_RTT_SHIFT 5 /* shift for srtt; 3 bits frac. */ 287 #define TCP_RTTVAR_SCALE 16 /* multiplier for rttvar; 2 bits */ 288 #define TCP_RTTVAR_SHIFT 4 /* shift for rttvar; 2 bits */ 289 #define TCP_DELTA_SHIFT 2 /* see tcp_input.c */ 290 291 /* 292 * The initial retransmission should happen at rtt + 4 * rttvar. 293 * Because of the way we do the smoothing, srtt and rttvar 294 * will each average +1/2 tick of bias. When we compute 295 * the retransmit timer, we want 1/2 tick of rounding and 296 * 1 extra tick because of +-1/2 tick uncertainty in the 297 * firing of the timer. The bias will give us exactly the 298 * 1.5 tick we need. But, because the bias is 299 * statistical, we have to test that we don't drop below 300 * the minimum feasible timer (which is 2 ticks). 301 * This version of the macro adapted from a paper by Lawrence 302 * Brakmo and Larry Peterson which outlines a problem caused 303 * by insufficient precision in the original implementation, 304 * which results in inappropriately large RTO values for very 305 * fast networks. 306 */ 307 #define TCP_REXMTVAL(tp) \ 308 max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT)) \ 309 + (tp)->t_rttvar) >> TCP_DELTA_SHIFT) 310 311 /* 312 * TCB structure exported to user-land via sysctl(3). 313 * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been 314 * included. Not all of our clients do. 315 */ 316 #if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_) 317 struct xtcpcb { 318 size_t xt_len; 319 struct inpcb xt_inp; 320 struct tcpcb xt_tp; 321 struct xsocket xt_socket; 322 u_quad_t xt_alignment_hack; 323 }; 324 #endif 325 326 /* 327 * Names for TCP sysctl objects 328 */ 329 #define TCPCTL_DO_RFC1323 1 /* use RFC-1323 extensions */ 330 #define TCPCTL_DO_RFC1644 2 /* use RFC-1644 extensions */ 331 #define TCPCTL_MSSDFLT 3 /* MSS default */ 332 #define TCPCTL_STATS 4 /* statistics (read-only) */ 333 #define TCPCTL_RTTDFLT 5 /* default RTT estimate */ 334 #define TCPCTL_KEEPIDLE 6 /* keepalive idle timer */ 335 #define TCPCTL_KEEPINTVL 7 /* interval to send keepalives */ 336 #define TCPCTL_SENDSPACE 8 /* send buffer space */ 337 #define TCPCTL_RECVSPACE 9 /* receive buffer space */ 338 #define TCPCTL_KEEPINIT 10 /* timeout for establishing syn */ 339 #define TCPCTL_PCBLIST 11 /* list of all outstanding PCBs */ 340 #define TCPCTL_DELACKTIME 12 /* time before sending delayed ACK */ 341 #define TCPCTL_V6MSSDFLT 13 /* MSS default for IPv6 */ 342 #define TCPCTL_MAXID 14 343 344 #define TCPCTL_NAMES { \ 345 { 0, 0 }, \ 346 { "rfc1323", CTLTYPE_INT }, \ 347 { "rfc1644", CTLTYPE_INT }, \ 348 { "mssdflt", CTLTYPE_INT }, \ 349 { "stats", CTLTYPE_STRUCT }, \ 350 { "rttdflt", CTLTYPE_INT }, \ 351 { "keepidle", CTLTYPE_INT }, \ 352 { "keepintvl", CTLTYPE_INT }, \ 353 { "sendspace", CTLTYPE_INT }, \ 354 { "recvspace", CTLTYPE_INT }, \ 355 { "keepinit", CTLTYPE_INT }, \ 356 { "pcblist", CTLTYPE_STRUCT }, \ 357 { "delacktime", CTLTYPE_INT }, \ 358 { "v6mssdflt", CTLTYPE_INT }, \ 359 } 360 361 #ifdef _KERNEL 362 #ifdef SYSCTL_DECL 363 SYSCTL_DECL(_net_inet_tcp); 364 #endif 365 366 extern struct inpcbinfo tcbinfo[]; 367 extern int tcp_mssdflt; /* XXX */ 368 extern int tcp_delack_enabled; 369 extern int tcp_do_newreno; 370 extern int path_mtu_discovery; 371 extern int ss_fltsz; 372 extern int ss_fltsz_local; 373 374 int tcp_addrcpu(in_addr_t faddr, in_port_t fport, 375 in_addr_t laddr, in_port_t lport); 376 struct lwkt_port * 377 tcp_addrport(in_addr_t faddr, in_port_t fport, 378 in_addr_t laddr, in_port_t lport); 379 void tcp_canceltimers (struct tcpcb *); 380 struct tcpcb * 381 tcp_close (struct tcpcb *); 382 void tcp_ctlinput (int, struct sockaddr *, void *); 383 int tcp_ctloutput (struct socket *, struct sockopt *); 384 struct lwkt_port * 385 tcp_cport(int cpu); 386 struct tcpcb * 387 tcp_drop (struct tcpcb *, int); 388 void tcp_drain (void); 389 void tcp_fasttimo (void); 390 struct rmxp_tao * 391 tcp_gettaocache (struct in_conninfo *); 392 void tcp_init (void); 393 void tcp_thread_init (void); 394 void tcp_input (struct mbuf *, int, int); 395 void tcp_mss (struct tcpcb *, int); 396 int tcp_mssopt (struct tcpcb *); 397 void tcp_drop_syn_sent (struct inpcb *, int); 398 void tcp_mtudisc (struct inpcb *, int); 399 struct tcpcb * 400 tcp_newtcpcb (struct inpcb *); 401 int tcp_output (struct tcpcb *); 402 void tcp_quench (struct inpcb *, int); 403 void tcp_respond (struct tcpcb *, void *, 404 struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int); 405 struct rtentry * 406 tcp_rtlookup (struct in_conninfo *); 407 void tcp_save_congestion_state(struct tcpcb *tp); 408 void tcp_revert_congestion_state(struct tcpcb *tp); 409 void tcp_setpersist (struct tcpcb *); 410 void tcp_slowtimo (void); 411 struct tcptemp * 412 tcp_maketemplate (struct tcpcb *); 413 void tcp_fillheaders (struct tcpcb *, void *, void *); 414 struct lwkt_port * 415 tcp_soport(struct socket *, struct sockaddr *nam); 416 struct tcpcb * 417 tcp_timers (struct tcpcb *, int); 418 void tcp_trace (int, int, struct tcpcb *, void *, struct tcphdr *, 419 int); 420 void tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq); 421 void syncache_init(void); 422 void syncache_unreach(struct in_conninfo *, struct tcphdr *); 423 int syncache_expand(struct in_conninfo *, struct tcphdr *, 424 struct socket **, struct mbuf *); 425 int syncache_add(struct in_conninfo *, struct tcpopt *, 426 struct tcphdr *, struct socket **, struct mbuf *); 427 void syncache_chkrst(struct in_conninfo *, struct tcphdr *); 428 void syncache_badack(struct in_conninfo *); 429 430 extern struct pr_usrreqs tcp_usrreqs; 431 extern u_long tcp_sendspace; 432 extern u_long tcp_recvspace; 433 tcp_seq tcp_new_isn (struct tcpcb *); 434 435 #endif /* _KERNEL */ 436 437 #endif /* _NETINET_TCP_VAR_H_ */ 438