1 /* 2 * Copyright (c) 1982, 1986, 1993, 1994, 1995 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)tcp_var.h 8.4 (Berkeley) 5/24/95 34 * $FreeBSD$ 35 */ 36 37 #ifndef _NETINET_TCP_VAR_H_ 38 #define _NETINET_TCP_VAR_H_ 39 /* 40 * Kernel variables for tcp. 41 */ 42 43 /* 44 * Tcp control block, one per tcp; fields: 45 * Organized for 16 byte cacheline efficiency. 46 */ 47 struct tcpcb { 48 struct mbuf *t_segq; 49 int t_dupacks; /* consecutive dup acks recd */ 50 struct tcpiphdr *t_template; /* skeletal packet for transmit */ 51 52 int t_timer[TCPT_NTIMERS]; /* tcp timers */ 53 54 struct inpcb *t_inpcb; /* back pointer to internet pcb */ 55 int t_state; /* state of this connection */ 56 u_int t_flags; 57 #define TF_ACKNOW 0x00001 /* ack peer immediately */ 58 #define TF_DELACK 0x00002 /* ack, but try to delay it */ 59 #define TF_NODELAY 0x00004 /* don't delay packets to coalesce */ 60 #define TF_NOOPT 0x00008 /* don't use tcp options */ 61 #define TF_SENTFIN 0x00010 /* have sent FIN */ 62 #define TF_REQ_SCALE 0x00020 /* have/will request window scaling */ 63 #define TF_RCVD_SCALE 0x00040 /* other side has requested scaling */ 64 #define TF_REQ_TSTMP 0x00080 /* have/will request timestamps */ 65 #define TF_RCVD_TSTMP 0x00100 /* a timestamp was received in SYN */ 66 #define TF_SACK_PERMIT 0x00200 /* other side said I could SACK */ 67 #define TF_NEEDSYN 0x00400 /* send SYN (implicit state) */ 68 #define TF_NEEDFIN 0x00800 /* send FIN (implicit state) */ 69 #define TF_NOPUSH 0x01000 /* don't push */ 70 #define TF_REQ_CC 0x02000 /* have/will request CC */ 71 #define TF_RCVD_CC 0x04000 /* a CC was received in SYN */ 72 #define TF_SENDCCNEW 0x08000 /* send CCnew instead of CC in SYN */ 73 #define TF_MORETOCOME 0x10000 /* More data to be appended to sock */ 74 int t_force; /* 1 if forcing out a byte */ 75 76 tcp_seq snd_una; /* send unacknowledged */ 77 tcp_seq snd_max; /* highest sequence number sent; 78 * used to recognize retransmits 79 */ 80 tcp_seq snd_nxt; /* send next */ 81 tcp_seq snd_up; /* send urgent pointer */ 82 83 tcp_seq snd_wl1; /* window update seg seq number */ 84 tcp_seq snd_wl2; /* window update seg ack number */ 85 tcp_seq iss; /* initial send sequence number */ 86 tcp_seq irs; /* initial receive sequence number */ 87 88 tcp_seq rcv_nxt; /* receive next */ 89 tcp_seq rcv_adv; /* advertised window */ 90 u_long rcv_wnd; /* receive window */ 91 tcp_seq rcv_up; /* receive urgent pointer */ 92 93 u_long snd_wnd; /* send window */ 94 u_long snd_cwnd; /* congestion-controlled window */ 95 u_long snd_ssthresh; /* snd_cwnd size threshold for 96 * for slow start exponential to 97 * linear switch 98 */ 99 u_int t_maxopd; /* mss plus options */ 100 101 u_int t_idle; /* inactivity time */ 102 u_long t_duration; /* connection duration */ 103 int t_rtt; /* round trip time */ 104 tcp_seq t_rtseq; /* sequence number being timed */ 105 106 int t_rxtcur; /* current retransmit value */ 107 u_int t_maxseg; /* maximum segment size */ 108 int t_srtt; /* smoothed round-trip time */ 109 int t_rttvar; /* variance in round-trip time */ 110 111 int t_rxtshift; /* log(2) of rexmt exp. backoff */ 112 u_int t_rttmin; /* minimum rtt allowed */ 113 u_long t_rttupdated; /* number of times rtt sampled */ 114 u_long max_sndwnd; /* largest window peer has offered */ 115 116 int t_softerror; /* possible error not yet reported */ 117 /* out-of-band data */ 118 char t_oobflags; /* have some */ 119 char t_iobc; /* input character */ 120 #define TCPOOB_HAVEDATA 0x01 121 #define TCPOOB_HADDATA 0x02 122 /* RFC 1323 variables */ 123 u_char snd_scale; /* window scaling for send window */ 124 u_char rcv_scale; /* window scaling for recv window */ 125 u_char request_r_scale; /* pending window scaling */ 126 u_char requested_s_scale; 127 u_long ts_recent; /* timestamp echo data */ 128 129 u_long ts_recent_age; /* when last updated */ 130 tcp_seq last_ack_sent; 131 /* RFC 1644 variables */ 132 tcp_cc cc_send; /* send connection count */ 133 tcp_cc cc_recv; /* receive connection count */ 134 }; 135 136 /* 137 * Structure to hold TCP options that are only used during segment 138 * processing (in tcp_input), but not held in the tcpcb. 139 * It's basically used to reduce the number of parameters 140 * to tcp_dooptions. 141 */ 142 struct tcpopt { 143 u_long to_flag; /* which options are present */ 144 #define TOF_TS 0x0001 /* timestamp */ 145 #define TOF_CC 0x0002 /* CC and CCnew are exclusive */ 146 #define TOF_CCNEW 0x0004 147 #define TOF_CCECHO 0x0008 148 u_long to_tsval; 149 u_long to_tsecr; 150 tcp_cc to_cc; /* holds CC or CCnew */ 151 tcp_cc to_ccecho; 152 }; 153 154 /* 155 * The TAO cache entry which is stored in the protocol family specific 156 * portion of the route metrics. 157 */ 158 struct rmxp_tao { 159 tcp_cc tao_cc; /* latest CC in valid SYN */ 160 tcp_cc tao_ccsent; /* latest CC sent to peer */ 161 u_short tao_mssopt; /* peer's cached MSS */ 162 #ifdef notyet 163 u_short tao_flags; /* cache status flags */ 164 #define TAOF_DONT 0x0001 /* peer doesn't understand rfc1644 */ 165 #define TAOF_OK 0x0002 /* peer does understand rfc1644 */ 166 #define TAOF_UNDEF 0 /* we don't know yet */ 167 #endif /* notyet */ 168 }; 169 #define rmx_taop(r) ((struct rmxp_tao *)(r).rmx_filler) 170 171 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 172 #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 173 174 /* 175 * The smoothed round-trip time and estimated variance 176 * are stored as fixed point numbers scaled by the values below. 177 * For convenience, these scales are also used in smoothing the average 178 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed). 179 * With these scales, srtt has 3 bits to the right of the binary point, 180 * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the 181 * binary point, and is smoothed with an ALPHA of 0.75. 182 */ 183 #define TCP_RTT_SCALE 32 /* multiplier for srtt; 3 bits frac. */ 184 #define TCP_RTT_SHIFT 5 /* shift for srtt; 3 bits frac. */ 185 #define TCP_RTTVAR_SCALE 16 /* multiplier for rttvar; 2 bits */ 186 #define TCP_RTTVAR_SHIFT 4 /* shift for rttvar; 2 bits */ 187 #define TCP_DELTA_SHIFT 2 /* see tcp_input.c */ 188 189 /* 190 * The initial retransmission should happen at rtt + 4 * rttvar. 191 * Because of the way we do the smoothing, srtt and rttvar 192 * will each average +1/2 tick of bias. When we compute 193 * the retransmit timer, we want 1/2 tick of rounding and 194 * 1 extra tick because of +-1/2 tick uncertainty in the 195 * firing of the timer. The bias will give us exactly the 196 * 1.5 tick we need. But, because the bias is 197 * statistical, we have to test that we don't drop below 198 * the minimum feasible timer (which is 2 ticks). 199 * This version of the macro adapted from a paper by Lawrence 200 * Brakmo and Larry Peterson which outlines a problem caused 201 * by insufficient precision in the original implementation, 202 * which results in inappropriately large RTO values for very 203 * fast networks. 204 */ 205 #define TCP_REXMTVAL(tp) \ 206 max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT)) \ 207 + (tp)->t_rttvar) >> TCP_DELTA_SHIFT) 208 209 /* 210 * TCP statistics. 211 * Many of these should be kept per connection, 212 * but that's inconvenient at the moment. 213 */ 214 struct tcpstat { 215 u_long tcps_connattempt; /* connections initiated */ 216 u_long tcps_accepts; /* connections accepted */ 217 u_long tcps_connects; /* connections established */ 218 u_long tcps_drops; /* connections dropped */ 219 u_long tcps_conndrops; /* embryonic connections dropped */ 220 u_long tcps_closed; /* conn. closed (includes drops) */ 221 u_long tcps_segstimed; /* segs where we tried to get rtt */ 222 u_long tcps_rttupdated; /* times we succeeded */ 223 u_long tcps_delack; /* delayed acks sent */ 224 u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */ 225 u_long tcps_rexmttimeo; /* retransmit timeouts */ 226 u_long tcps_persisttimeo; /* persist timeouts */ 227 u_long tcps_keeptimeo; /* keepalive timeouts */ 228 u_long tcps_keepprobe; /* keepalive probes sent */ 229 u_long tcps_keepdrops; /* connections dropped in keepalive */ 230 231 u_long tcps_sndtotal; /* total packets sent */ 232 u_long tcps_sndpack; /* data packets sent */ 233 u_long tcps_sndbyte; /* data bytes sent */ 234 u_long tcps_sndrexmitpack; /* data packets retransmitted */ 235 u_long tcps_sndrexmitbyte; /* data bytes retransmitted */ 236 u_long tcps_sndacks; /* ack-only packets sent */ 237 u_long tcps_sndprobe; /* window probes sent */ 238 u_long tcps_sndurg; /* packets sent with URG only */ 239 u_long tcps_sndwinup; /* window update-only packets sent */ 240 u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */ 241 242 u_long tcps_rcvtotal; /* total packets received */ 243 u_long tcps_rcvpack; /* packets received in sequence */ 244 u_long tcps_rcvbyte; /* bytes received in sequence */ 245 u_long tcps_rcvbadsum; /* packets received with ccksum errs */ 246 u_long tcps_rcvbadoff; /* packets received with bad offset */ 247 u_long tcps_rcvshort; /* packets received too short */ 248 u_long tcps_rcvduppack; /* duplicate-only packets received */ 249 u_long tcps_rcvdupbyte; /* duplicate-only bytes received */ 250 u_long tcps_rcvpartduppack; /* packets with some duplicate data */ 251 u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */ 252 u_long tcps_rcvoopack; /* out-of-order packets received */ 253 u_long tcps_rcvoobyte; /* out-of-order bytes received */ 254 u_long tcps_rcvpackafterwin; /* packets with data after window */ 255 u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */ 256 u_long tcps_rcvafterclose; /* packets rcvd after "close" */ 257 u_long tcps_rcvwinprobe; /* rcvd window probe packets */ 258 u_long tcps_rcvdupack; /* rcvd duplicate acks */ 259 u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */ 260 u_long tcps_rcvackpack; /* rcvd ack packets */ 261 u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */ 262 u_long tcps_rcvwinupd; /* rcvd window update packets */ 263 u_long tcps_pawsdrop; /* segments dropped due to PAWS */ 264 u_long tcps_predack; /* times hdr predict ok for acks */ 265 u_long tcps_preddat; /* times hdr predict ok for data pkts */ 266 u_long tcps_pcbcachemiss; 267 u_long tcps_cachedrtt; /* times cached RTT in route updated */ 268 u_long tcps_cachedrttvar; /* times cached rttvar updated */ 269 u_long tcps_cachedssthresh; /* times cached ssthresh updated */ 270 u_long tcps_usedrtt; /* times RTT initialized from route */ 271 u_long tcps_usedrttvar; /* times RTTVAR initialized from rt */ 272 u_long tcps_usedssthresh; /* times ssthresh initialized from rt*/ 273 u_long tcps_persistdrop; /* timeout in persist state */ 274 u_long tcps_badsyn; /* bogus SYN, e.g. premature ACK */ 275 u_long tcps_mturesent; /* resends due to MTU discovery */ 276 u_long tcps_listendrop; /* listen queue overflows */ 277 }; 278 279 /* 280 * TCB structure exported to user-land via sysctl(3). 281 * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been 282 * included. Not all of our clients do. 283 */ 284 #if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_) 285 struct xtcpcb { 286 size_t xt_len; 287 struct inpcb xt_inp; 288 struct tcpcb xt_tp; 289 struct xsocket xt_socket; 290 u_quad_t xt_alignment_hack; 291 }; 292 #endif 293 294 /* 295 * Names for TCP sysctl objects 296 */ 297 #define TCPCTL_DO_RFC1323 1 /* use RFC-1323 extensions */ 298 #define TCPCTL_DO_RFC1644 2 /* use RFC-1644 extensions */ 299 #define TCPCTL_MSSDFLT 3 /* MSS default */ 300 #define TCPCTL_STATS 4 /* statistics (read-only) */ 301 #define TCPCTL_RTTDFLT 5 /* default RTT estimate */ 302 #define TCPCTL_KEEPIDLE 6 /* keepalive idle timer */ 303 #define TCPCTL_KEEPINTVL 7 /* interval to send keepalives */ 304 #define TCPCTL_SENDSPACE 8 /* send buffer space */ 305 #define TCPCTL_RECVSPACE 9 /* receive buffer space */ 306 #define TCPCTL_KEEPINIT 10 /* receive buffer space */ 307 #define TCPCTL_PCBLIST 11 /* list of all outstanding PCBs */ 308 #define TCPCTL_MAXID 12 309 310 #define TCPCTL_NAMES { \ 311 { 0, 0 }, \ 312 { "rfc1323", CTLTYPE_INT }, \ 313 { "rfc1644", CTLTYPE_INT }, \ 314 { "mssdflt", CTLTYPE_INT }, \ 315 { "stats", CTLTYPE_STRUCT }, \ 316 { "rttdflt", CTLTYPE_INT }, \ 317 { "keepidle", CTLTYPE_INT }, \ 318 { "keepintvl", CTLTYPE_INT }, \ 319 { "sendspace", CTLTYPE_INT }, \ 320 { "recvspace", CTLTYPE_INT }, \ 321 { "keepinit", CTLTYPE_INT }, \ 322 { "pcblist", CTLTYPE_STRUCT }, \ 323 } 324 325 326 #ifdef KERNEL 327 #ifdef SYSCTL_DECL 328 SYSCTL_DECL(_net_inet_tcp); 329 #endif 330 331 extern struct inpcbhead tcb; /* head of queue of active tcpcb's */ 332 extern struct inpcbinfo tcbinfo; 333 extern struct tcpstat tcpstat; /* tcp statistics */ 334 extern int tcp_mssdflt; /* XXX */ 335 extern u_long tcp_now; /* for RFC 1323 timestamps */ 336 extern int tcp_delack_enabled; 337 338 void tcp_canceltimers __P((struct tcpcb *)); 339 struct tcpcb * 340 tcp_close __P((struct tcpcb *)); 341 void tcp_ctlinput __P((int, struct sockaddr *, void *)); 342 int tcp_ctloutput __P((struct socket *, struct sockopt *)); 343 struct tcpcb * 344 tcp_drop __P((struct tcpcb *, int)); 345 void tcp_drain __P((void)); 346 void tcp_fasttimo __P((void)); 347 struct rmxp_tao * 348 tcp_gettaocache __P((struct inpcb *)); 349 void tcp_init __P((void)); 350 void tcp_input __P((struct mbuf *, int)); 351 void tcp_mss __P((struct tcpcb *, int)); 352 int tcp_mssopt __P((struct tcpcb *)); 353 void tcp_mtudisc __P((struct inpcb *, int)); 354 struct tcpcb * 355 tcp_newtcpcb __P((struct inpcb *)); 356 int tcp_output __P((struct tcpcb *)); 357 void tcp_quench __P((struct inpcb *, int)); 358 void tcp_respond __P((struct tcpcb *, 359 struct tcpiphdr *, struct mbuf *, tcp_seq, tcp_seq, int)); 360 struct rtentry * 361 tcp_rtlookup __P((struct inpcb *)); 362 void tcp_setpersist __P((struct tcpcb *)); 363 void tcp_slowtimo __P((void)); 364 struct tcpiphdr * 365 tcp_template __P((struct tcpcb *)); 366 struct tcpcb * 367 tcp_timers __P((struct tcpcb *, int)); 368 void tcp_trace __P((int, int, struct tcpcb *, struct tcpiphdr *, int)); 369 370 extern struct pr_usrreqs tcp_usrreqs; 371 extern u_long tcp_sendspace; 372 extern u_long tcp_recvspace; 373 374 #endif /* KERNEL */ 375 376 #endif /* _NETINET_TCP_VAR_H_ */ 377