tcp_usrreq.c revision 1.34
1 /* $NetBSD: tcp_usrreq.c,v 1.34 1998/02/19 02:36:44 thorpej Exp $ */ 2 3 /*- 4 * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe and Kevin M. Lahey of the Numerical Aerospace Simulation 9 * Facility, NASA Ames Research Center. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * Copyright (c) 1982, 1986, 1988, 1993, 1995 42 * The Regents of the University of California. All rights reserved. 43 * 44 * Redistribution and use in source and binary forms, with or without 45 * modification, are permitted provided that the following conditions 46 * are met: 47 * 1. Redistributions of source code must retain the above copyright 48 * notice, this list of conditions and the following disclaimer. 49 * 2. Redistributions in binary form must reproduce the above copyright 50 * notice, this list of conditions and the following disclaimer in the 51 * documentation and/or other materials provided with the distribution. 52 * 3. All advertising materials mentioning features or use of this software 53 * must display the following acknowledgement: 54 * This product includes software developed by the University of 55 * California, Berkeley and its contributors. 56 * 4. Neither the name of the University nor the names of its contributors 57 * may be used to endorse or promote products derived from this software 58 * without specific prior written permission. 59 * 60 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 61 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 62 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 63 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 64 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 65 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 66 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 67 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 68 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 69 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 70 * SUCH DAMAGE. 71 * 72 * @(#)tcp_usrreq.c 8.5 (Berkeley) 6/21/95 73 */ 74 75 #include <sys/param.h> 76 #include <sys/systm.h> 77 #include <sys/kernel.h> 78 #include <sys/malloc.h> 79 #include <sys/mbuf.h> 80 #include <sys/socket.h> 81 #include <sys/socketvar.h> 82 #include <sys/protosw.h> 83 #include <sys/errno.h> 84 #include <sys/stat.h> 85 #include <sys/proc.h> 86 #include <sys/ucred.h> 87 88 #include <vm/vm.h> 89 #include <sys/sysctl.h> 90 91 #include <net/if.h> 92 #include <net/route.h> 93 94 #include <netinet/in.h> 95 #include <netinet/in_systm.h> 96 #include <netinet/in_var.h> 97 #include <netinet/ip.h> 98 #include <netinet/in_pcb.h> 99 #include <netinet/ip_var.h> 100 #include <netinet/tcp.h> 101 #include <netinet/tcp_fsm.h> 102 #include <netinet/tcp_seq.h> 103 #include <netinet/tcp_timer.h> 104 #include <netinet/tcp_var.h> 105 #include <netinet/tcpip.h> 106 #include <netinet/tcp_debug.h> 107 108 #include "opt_tcp_recvspace.h" 109 #include "opt_tcp_sendspace.h" 110 111 /* 112 * TCP protocol interface to socket abstraction. 113 */ 114 extern char *tcpstates[]; 115 116 /* 117 * Process a TCP user request for TCP tb. If this is a send request 118 * then m is the mbuf chain of send data. If this is a timer expiration 119 * (called from the software clock routine), then timertype tells which timer. 120 */ 121 /*ARGSUSED*/ 122 int 123 tcp_usrreq(so, req, m, nam, control, p) 124 struct socket *so; 125 int req; 126 struct mbuf *m, *nam, *control; 127 struct proc *p; 128 { 129 register struct inpcb *inp; 130 register struct tcpcb *tp = NULL; 131 int s; 132 int error = 0; 133 int ostate; 134 135 if (req == PRU_CONTROL) 136 return (in_control(so, (long)m, (caddr_t)nam, 137 (struct ifnet *)control, p)); 138 139 s = splsoftnet(); 140 inp = sotoinpcb(so); 141 #ifdef DIAGNOSTIC 142 if (req != PRU_SEND && req != PRU_SENDOOB && control) 143 panic("tcp_usrreq: unexpected control mbuf"); 144 #endif 145 /* 146 * When a TCP is attached to a socket, then there will be 147 * a (struct inpcb) pointed at by the socket, and this 148 * structure will point at a subsidary (struct tcpcb). 149 */ 150 if (inp == 0 && req != PRU_ATTACH) { 151 error = EINVAL; 152 goto release; 153 } 154 if (inp) { 155 tp = intotcpcb(inp); 156 /* WHAT IF TP IS 0? */ 157 #ifdef KPROF 158 tcp_acounts[tp->t_state][req]++; 159 #endif 160 ostate = tp->t_state; 161 } else 162 ostate = 0; 163 164 switch (req) { 165 166 /* 167 * TCP attaches to socket via PRU_ATTACH, reserving space, 168 * and an internet control block. 169 */ 170 case PRU_ATTACH: 171 if (inp != 0) { 172 error = EISCONN; 173 break; 174 } 175 error = tcp_attach(so); 176 if (error) 177 break; 178 if ((so->so_options & SO_LINGER) && so->so_linger == 0) 179 so->so_linger = TCP_LINGERTIME; 180 tp = sototcpcb(so); 181 break; 182 183 /* 184 * PRU_DETACH detaches the TCP protocol from the socket. 185 */ 186 case PRU_DETACH: 187 tp = tcp_disconnect(tp); 188 break; 189 190 /* 191 * Give the socket an address. 192 */ 193 case PRU_BIND: 194 error = in_pcbbind(inp, nam, p); 195 break; 196 197 /* 198 * Prepare to accept connections. 199 */ 200 case PRU_LISTEN: 201 if (inp->inp_lport == 0) { 202 error = in_pcbbind(inp, (struct mbuf *)0, 203 (struct proc *)0); 204 if (error) 205 break; 206 } 207 tp->t_state = TCPS_LISTEN; 208 break; 209 210 /* 211 * Initiate connection to peer. 212 * Create a template for use in transmissions on this connection. 213 * Enter SYN_SENT state, and mark socket as connecting. 214 * Start keep-alive timer, and seed output sequence space. 215 * Send initial segment on connection. 216 */ 217 case PRU_CONNECT: 218 if (inp->inp_lport == 0) { 219 error = in_pcbbind(inp, (struct mbuf *)0, 220 (struct proc *)0); 221 if (error) 222 break; 223 } 224 error = in_pcbconnect(inp, nam); 225 if (error) 226 break; 227 tp->t_template = tcp_template(tp); 228 if (tp->t_template == 0) { 229 in_pcbdisconnect(inp); 230 error = ENOBUFS; 231 break; 232 } 233 /* Compute window scaling to request. */ 234 while (tp->request_r_scale < TCP_MAX_WINSHIFT && 235 (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat) 236 tp->request_r_scale++; 237 soisconnecting(so); 238 tcpstat.tcps_connattempt++; 239 tp->t_state = TCPS_SYN_SENT; 240 tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT; 241 tp->iss = tcp_new_iss(tp, sizeof(struct tcpcb), 0); 242 tcp_sendseqinit(tp); 243 error = tcp_output(tp); 244 break; 245 246 /* 247 * Create a TCP connection between two sockets. 248 */ 249 case PRU_CONNECT2: 250 error = EOPNOTSUPP; 251 break; 252 253 /* 254 * Initiate disconnect from peer. 255 * If connection never passed embryonic stage, just drop; 256 * else if don't need to let data drain, then can just drop anyways, 257 * else have to begin TCP shutdown process: mark socket disconnecting, 258 * drain unread data, state switch to reflect user close, and 259 * send segment (e.g. FIN) to peer. Socket will be really disconnected 260 * when peer sends FIN and acks ours. 261 * 262 * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB. 263 */ 264 case PRU_DISCONNECT: 265 tp = tcp_disconnect(tp); 266 break; 267 268 /* 269 * Accept a connection. Essentially all the work is 270 * done at higher levels; just return the address 271 * of the peer, storing through addr. 272 */ 273 case PRU_ACCEPT: 274 in_setpeeraddr(inp, nam); 275 break; 276 277 /* 278 * Mark the connection as being incapable of further output. 279 */ 280 case PRU_SHUTDOWN: 281 socantsendmore(so); 282 tp = tcp_usrclosed(tp); 283 if (tp) 284 error = tcp_output(tp); 285 break; 286 287 /* 288 * After a receive, possibly send window update to peer. 289 */ 290 case PRU_RCVD: 291 (void) tcp_output(tp); 292 break; 293 294 /* 295 * Do a send by putting data in output queue and updating urgent 296 * marker if URG set. Possibly send more data. 297 */ 298 case PRU_SEND: 299 if (control && control->m_len) { 300 m_freem(control); 301 m_freem(m); 302 error = EINVAL; 303 break; 304 } 305 sbappend(&so->so_snd, m); 306 error = tcp_output(tp); 307 break; 308 309 /* 310 * Abort the TCP. 311 */ 312 case PRU_ABORT: 313 tp = tcp_drop(tp, ECONNABORTED); 314 break; 315 316 case PRU_SENSE: 317 /* 318 * stat: don't bother with a blocksize. 319 */ 320 splx(s); 321 return (0); 322 323 case PRU_RCVOOB: 324 if (control && control->m_len) { 325 m_freem(control); 326 m_freem(m); 327 error = EINVAL; 328 break; 329 } 330 if ((so->so_oobmark == 0 && 331 (so->so_state & SS_RCVATMARK) == 0) || 332 so->so_options & SO_OOBINLINE || 333 tp->t_oobflags & TCPOOB_HADDATA) { 334 error = EINVAL; 335 break; 336 } 337 if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) { 338 error = EWOULDBLOCK; 339 break; 340 } 341 m->m_len = 1; 342 *mtod(m, caddr_t) = tp->t_iobc; 343 if (((long)nam & MSG_PEEK) == 0) 344 tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA); 345 break; 346 347 case PRU_SENDOOB: 348 if (sbspace(&so->so_snd) < -512) { 349 m_freem(m); 350 error = ENOBUFS; 351 break; 352 } 353 /* 354 * According to RFC961 (Assigned Protocols), 355 * the urgent pointer points to the last octet 356 * of urgent data. We continue, however, 357 * to consider it to indicate the first octet 358 * of data past the urgent section. 359 * Otherwise, snd_up should be one lower. 360 */ 361 sbappend(&so->so_snd, m); 362 tp->snd_up = tp->snd_una + so->so_snd.sb_cc; 363 tp->t_force = 1; 364 error = tcp_output(tp); 365 tp->t_force = 0; 366 break; 367 368 case PRU_SOCKADDR: 369 in_setsockaddr(inp, nam); 370 break; 371 372 case PRU_PEERADDR: 373 in_setpeeraddr(inp, nam); 374 break; 375 376 /* 377 * TCP slow timer went off; going through this 378 * routine for tracing's sake. 379 */ 380 case PRU_SLOWTIMO: 381 tp = tcp_timers(tp, (long)nam); 382 req |= (long)nam << 8; /* for debug's sake */ 383 break; 384 385 default: 386 panic("tcp_usrreq"); 387 } 388 if (tp && (so->so_options & SO_DEBUG)) 389 tcp_trace(TA_USER, ostate, tp, (struct tcpiphdr *)0, req); 390 391 release: 392 splx(s); 393 return (error); 394 } 395 396 int 397 tcp_ctloutput(op, so, level, optname, mp) 398 int op; 399 struct socket *so; 400 int level, optname; 401 struct mbuf **mp; 402 { 403 int error = 0, s; 404 struct inpcb *inp; 405 register struct tcpcb *tp; 406 register struct mbuf *m; 407 register int i; 408 409 s = splsoftnet(); 410 inp = sotoinpcb(so); 411 if (inp == NULL) { 412 splx(s); 413 if (op == PRCO_SETOPT && *mp) 414 (void) m_free(*mp); 415 return (ECONNRESET); 416 } 417 if (level != IPPROTO_TCP) { 418 error = ip_ctloutput(op, so, level, optname, mp); 419 splx(s); 420 return (error); 421 } 422 tp = intotcpcb(inp); 423 424 switch (op) { 425 426 case PRCO_SETOPT: 427 m = *mp; 428 switch (optname) { 429 430 case TCP_NODELAY: 431 if (m == NULL || m->m_len < sizeof (int)) 432 error = EINVAL; 433 else if (*mtod(m, int *)) 434 tp->t_flags |= TF_NODELAY; 435 else 436 tp->t_flags &= ~TF_NODELAY; 437 break; 438 439 case TCP_MAXSEG: 440 if (m && (i = *mtod(m, int *)) > 0 && 441 i <= tp->t_peermss) 442 tp->t_peermss = i; /* limit on send size */ 443 else 444 error = EINVAL; 445 break; 446 447 default: 448 error = ENOPROTOOPT; 449 break; 450 } 451 if (m) 452 (void) m_free(m); 453 break; 454 455 case PRCO_GETOPT: 456 *mp = m = m_get(M_WAIT, MT_SOOPTS); 457 m->m_len = sizeof(int); 458 459 switch (optname) { 460 case TCP_NODELAY: 461 *mtod(m, int *) = tp->t_flags & TF_NODELAY; 462 break; 463 case TCP_MAXSEG: 464 *mtod(m, int *) = tp->t_peermss; 465 break; 466 default: 467 error = ENOPROTOOPT; 468 break; 469 } 470 break; 471 } 472 splx(s); 473 return (error); 474 } 475 476 #ifndef TCP_SENDSPACE 477 #define TCP_SENDSPACE 1024*16; 478 #endif 479 int tcp_sendspace = TCP_SENDSPACE; 480 #ifndef TCP_RECVSPACE 481 #define TCP_RECVSPACE 1024*16; 482 #endif 483 int tcp_recvspace = TCP_RECVSPACE; 484 485 /* 486 * Attach TCP protocol to socket, allocating 487 * internet protocol control block, tcp control block, 488 * bufer space, and entering LISTEN state if to accept connections. 489 */ 490 int 491 tcp_attach(so) 492 struct socket *so; 493 { 494 register struct tcpcb *tp; 495 struct inpcb *inp; 496 int error; 497 498 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 499 error = soreserve(so, tcp_sendspace, tcp_recvspace); 500 if (error) 501 return (error); 502 } 503 error = in_pcballoc(so, &tcbtable); 504 if (error) 505 return (error); 506 inp = sotoinpcb(so); 507 tp = tcp_newtcpcb(inp); 508 if (tp == 0) { 509 int nofd = so->so_state & SS_NOFDREF; /* XXX */ 510 511 so->so_state &= ~SS_NOFDREF; /* don't free the socket yet */ 512 in_pcbdetach(inp); 513 so->so_state |= nofd; 514 return (ENOBUFS); 515 } 516 tp->t_state = TCPS_CLOSED; 517 return (0); 518 } 519 520 /* 521 * Initiate (or continue) disconnect. 522 * If embryonic state, just send reset (once). 523 * If in ``let data drain'' option and linger null, just drop. 524 * Otherwise (hard), mark socket disconnecting and drop 525 * current input data; switch states based on user close, and 526 * send segment to peer (with FIN). 527 */ 528 struct tcpcb * 529 tcp_disconnect(tp) 530 register struct tcpcb *tp; 531 { 532 struct socket *so = tp->t_inpcb->inp_socket; 533 534 if (TCPS_HAVEESTABLISHED(tp->t_state) == 0) 535 tp = tcp_close(tp); 536 else if ((so->so_options & SO_LINGER) && so->so_linger == 0) 537 tp = tcp_drop(tp, 0); 538 else { 539 soisdisconnecting(so); 540 sbflush(&so->so_rcv); 541 tp = tcp_usrclosed(tp); 542 if (tp) 543 (void) tcp_output(tp); 544 } 545 return (tp); 546 } 547 548 /* 549 * User issued close, and wish to trail through shutdown states: 550 * if never received SYN, just forget it. If got a SYN from peer, 551 * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN. 552 * If already got a FIN from peer, then almost done; go to LAST_ACK 553 * state. In all other cases, have already sent FIN to peer (e.g. 554 * after PRU_SHUTDOWN), and just have to play tedious game waiting 555 * for peer to send FIN or not respond to keep-alives, etc. 556 * We can let the user exit from the close as soon as the FIN is acked. 557 */ 558 struct tcpcb * 559 tcp_usrclosed(tp) 560 register struct tcpcb *tp; 561 { 562 563 switch (tp->t_state) { 564 565 case TCPS_CLOSED: 566 case TCPS_LISTEN: 567 case TCPS_SYN_SENT: 568 tp->t_state = TCPS_CLOSED; 569 tp = tcp_close(tp); 570 break; 571 572 case TCPS_SYN_RECEIVED: 573 case TCPS_ESTABLISHED: 574 tp->t_state = TCPS_FIN_WAIT_1; 575 break; 576 577 case TCPS_CLOSE_WAIT: 578 tp->t_state = TCPS_LAST_ACK; 579 break; 580 } 581 if (tp && tp->t_state >= TCPS_FIN_WAIT_2) { 582 soisdisconnected(tp->t_inpcb->inp_socket); 583 /* 584 * If we are in FIN_WAIT_2, we arrived here because the 585 * application did a shutdown of the send side. Like the 586 * case of a transition from FIN_WAIT_1 to FIN_WAIT_2 after 587 * a full close, we start a timer to make sure sockets are 588 * not left in FIN_WAIT_2 forever. 589 */ 590 if (tp->t_state == TCPS_FIN_WAIT_2) 591 tp->t_timer[TCPT_2MSL] = tcp_maxidle; 592 } 593 return (tp); 594 } 595 596 /* 597 * Sysctl for tcp variables. 598 */ 599 int 600 tcp_sysctl(name, namelen, oldp, oldlenp, newp, newlen) 601 int *name; 602 u_int namelen; 603 void *oldp; 604 size_t *oldlenp; 605 void *newp; 606 size_t newlen; 607 { 608 609 /* All sysctl names at this level are terminal. */ 610 if (namelen != 1) 611 return (ENOTDIR); 612 613 switch (name[0]) { 614 case TCPCTL_RFC1323: 615 return (sysctl_int(oldp, oldlenp, newp, newlen, 616 &tcp_do_rfc1323)); 617 case TCPCTL_SENDSPACE: 618 return (sysctl_int(oldp, oldlenp, newp, newlen, 619 &tcp_sendspace)); 620 case TCPCTL_RECVSPACE: 621 return (sysctl_int(oldp, oldlenp, newp, newlen, 622 &tcp_recvspace)); 623 case TCPCTL_MSSDFLT: 624 return (sysctl_int(oldp, oldlenp, newp, newlen, 625 &tcp_mssdflt)); 626 case TCPCTL_SYN_CACHE_LIMIT: 627 return (sysctl_int(oldp, oldlenp, newp, newlen, 628 &tcp_syn_cache_limit)); 629 case TCPCTL_SYN_BUCKET_LIMIT: 630 return (sysctl_int(oldp, oldlenp, newp, newlen, 631 &tcp_syn_bucket_limit)); 632 case TCPCTL_SYN_CACHE_INTER: 633 return (sysctl_int(oldp, oldlenp, newp, newlen, 634 &tcp_syn_cache_interval)); 635 case TCPCTL_INIT_WIN: 636 return (sysctl_int(oldp, oldlenp, newp, newlen, 637 &tcp_init_win)); 638 default: 639 return (ENOPROTOOPT); 640 } 641 /* NOTREACHED */ 642 } 643
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