1 /* 2 * Copyright (c) 1982, 1986, 1988, 1993 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 * From: @(#)tcp_usrreq.c 8.2 (Berkeley) 1/3/94 34 * $FreeBSD: src/sys/netinet/tcp_usrreq.c,v 1.51.2.17 2002/10/11 11:46:44 ume Exp $ 35 * $DragonFly: src/sys/netinet/tcp_usrreq.c,v 1.11 2004/04/05 17:47:01 dillon Exp $ 36 */ 37 38 #include "opt_ipsec.h" 39 #include "opt_inet6.h" 40 #include "opt_tcpdebug.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 #include <sys/sysctl.h> 46 #include <sys/globaldata.h> 47 #include <sys/thread.h> 48 49 #include <sys/mbuf.h> 50 #ifdef INET6 51 #include <sys/domain.h> 52 #endif /* INET6 */ 53 #include <sys/socket.h> 54 #include <sys/socketvar.h> 55 #include <sys/protosw.h> 56 57 #include <net/if.h> 58 #include <net/route.h> 59 60 #include <netinet/in.h> 61 #include <netinet/in_systm.h> 62 #ifdef INET6 63 #include <netinet/ip6.h> 64 #endif 65 #include <netinet/in_pcb.h> 66 #ifdef INET6 67 #include <netinet6/in6_pcb.h> 68 #endif 69 #include <netinet/in_var.h> 70 #include <netinet/ip_var.h> 71 #ifdef INET6 72 #include <netinet6/ip6_var.h> 73 #endif 74 #include <netinet/tcp.h> 75 #include <netinet/tcp_fsm.h> 76 #include <netinet/tcp_seq.h> 77 #include <netinet/tcp_timer.h> 78 #include <netinet/tcp_var.h> 79 #include <netinet/tcpip.h> 80 #ifdef TCPDEBUG 81 #include <netinet/tcp_debug.h> 82 #endif 83 84 #ifdef IPSEC 85 #include <netinet6/ipsec.h> 86 #endif /*IPSEC*/ 87 88 /* 89 * TCP protocol interface to socket abstraction. 90 */ 91 extern char *tcpstates[]; /* XXX ??? */ 92 93 static int tcp_attach (struct socket *, struct pru_attach_info *); 94 static int tcp_connect (struct tcpcb *, struct sockaddr *, 95 struct thread *); 96 #ifdef INET6 97 static int tcp6_connect (struct tcpcb *, struct sockaddr *, 98 struct thread *); 99 #endif /* INET6 */ 100 static struct tcpcb * 101 tcp_disconnect (struct tcpcb *); 102 static struct tcpcb * 103 tcp_usrclosed (struct tcpcb *); 104 105 #ifdef TCPDEBUG 106 #define TCPDEBUG0 int ostate = 0 107 #define TCPDEBUG1() ostate = tp ? tp->t_state : 0 108 #define TCPDEBUG2(req) if (tp && (so->so_options & SO_DEBUG)) \ 109 tcp_trace(TA_USER, ostate, tp, 0, 0, req) 110 #else 111 #define TCPDEBUG0 112 #define TCPDEBUG1() 113 #define TCPDEBUG2(req) 114 #endif 115 116 /* 117 * TCP attaches to socket via pru_attach(), reserving space, 118 * and an internet control block. 119 */ 120 static int 121 tcp_usr_attach(struct socket *so, int proto, struct pru_attach_info *ai) 122 { 123 int s = splnet(); 124 int error; 125 struct inpcb *inp = sotoinpcb(so); 126 struct tcpcb *tp = 0; 127 TCPDEBUG0; 128 129 TCPDEBUG1(); 130 if (inp) { 131 error = EISCONN; 132 goto out; 133 } 134 135 error = tcp_attach(so, ai); 136 if (error) 137 goto out; 138 139 if ((so->so_options & SO_LINGER) && so->so_linger == 0) 140 so->so_linger = TCP_LINGERTIME; 141 tp = sototcpcb(so); 142 out: 143 TCPDEBUG2(PRU_ATTACH); 144 splx(s); 145 return error; 146 } 147 148 /* 149 * pru_detach() detaches the TCP protocol from the socket. 150 * If the protocol state is non-embryonic, then can't 151 * do this directly: have to initiate a pru_disconnect(), 152 * which may finish later; embryonic TCB's can just 153 * be discarded here. 154 */ 155 static int 156 tcp_usr_detach(struct socket *so) 157 { 158 int s = splnet(); 159 int error = 0; 160 struct inpcb *inp = sotoinpcb(so); 161 struct tcpcb *tp; 162 TCPDEBUG0; 163 164 if (inp == 0) { 165 splx(s); 166 return EINVAL; /* XXX */ 167 } 168 tp = intotcpcb(inp); 169 TCPDEBUG1(); 170 tp = tcp_disconnect(tp); 171 172 TCPDEBUG2(PRU_DETACH); 173 splx(s); 174 return error; 175 } 176 177 #define COMMON_START() TCPDEBUG0; \ 178 do { \ 179 if (inp == 0) { \ 180 splx(s); \ 181 return EINVAL; \ 182 } \ 183 tp = intotcpcb(inp); \ 184 TCPDEBUG1(); \ 185 } while(0) 186 187 #define COMMON_END(req) out: TCPDEBUG2(req); splx(s); return error; goto out 188 189 190 /* 191 * Give the socket an address. 192 */ 193 static int 194 tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 195 { 196 int s = splnet(); 197 int error = 0; 198 struct inpcb *inp = sotoinpcb(so); 199 struct tcpcb *tp; 200 struct sockaddr_in *sinp; 201 202 COMMON_START(); 203 204 /* 205 * Must check for multicast addresses and disallow binding 206 * to them. 207 */ 208 sinp = (struct sockaddr_in *)nam; 209 if (sinp->sin_family == AF_INET && 210 IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) { 211 error = EAFNOSUPPORT; 212 goto out; 213 } 214 error = in_pcbbind(inp, nam, td); 215 if (error) 216 goto out; 217 COMMON_END(PRU_BIND); 218 219 } 220 221 #ifdef INET6 222 static int 223 tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 224 { 225 int s = splnet(); 226 int error = 0; 227 struct inpcb *inp = sotoinpcb(so); 228 struct tcpcb *tp; 229 struct sockaddr_in6 *sin6p; 230 231 COMMON_START(); 232 233 /* 234 * Must check for multicast addresses and disallow binding 235 * to them. 236 */ 237 sin6p = (struct sockaddr_in6 *)nam; 238 if (sin6p->sin6_family == AF_INET6 && 239 IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) { 240 error = EAFNOSUPPORT; 241 goto out; 242 } 243 inp->inp_vflag &= ~INP_IPV4; 244 inp->inp_vflag |= INP_IPV6; 245 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) { 246 if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr)) 247 inp->inp_vflag |= INP_IPV4; 248 else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) { 249 struct sockaddr_in sin; 250 251 in6_sin6_2_sin(&sin, sin6p); 252 inp->inp_vflag |= INP_IPV4; 253 inp->inp_vflag &= ~INP_IPV6; 254 error = in_pcbbind(inp, (struct sockaddr *)&sin, td); 255 goto out; 256 } 257 } 258 error = in6_pcbbind(inp, nam, td); 259 if (error) 260 goto out; 261 COMMON_END(PRU_BIND); 262 } 263 #endif /* INET6 */ 264 265 /* 266 * Prepare to accept connections. 267 */ 268 static int 269 tcp_usr_listen(struct socket *so, struct thread *td) 270 { 271 int s = splnet(); 272 int error = 0; 273 struct inpcb *inp = sotoinpcb(so); 274 struct tcpcb *tp; 275 276 COMMON_START(); 277 if (inp->inp_lport == 0) 278 error = in_pcbbind(inp, (struct sockaddr *)0, td); 279 if (error == 0) { 280 tp->t_state = TCPS_LISTEN; 281 in_pcbinswildcardhash(inp); 282 } 283 COMMON_END(PRU_LISTEN); 284 } 285 286 #ifdef INET6 287 static int 288 tcp6_usr_listen(struct socket *so, struct thread *td) 289 { 290 int s = splnet(); 291 int error = 0; 292 struct inpcb *inp = sotoinpcb(so); 293 struct tcpcb *tp; 294 295 COMMON_START(); 296 if (inp->inp_lport == 0) { 297 inp->inp_vflag &= ~INP_IPV4; 298 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) 299 inp->inp_vflag |= INP_IPV4; 300 error = in6_pcbbind(inp, (struct sockaddr *)0, td); 301 } 302 if (error == 0) 303 tp->t_state = TCPS_LISTEN; 304 COMMON_END(PRU_LISTEN); 305 } 306 #endif /* INET6 */ 307 308 /* 309 * Initiate connection to peer. 310 * Create a template for use in transmissions on this connection. 311 * Enter SYN_SENT state, and mark socket as connecting. 312 * Start keep-alive timer, and seed output sequence space. 313 * Send initial segment on connection. 314 */ 315 static int 316 tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 317 { 318 int s = splnet(); 319 int error = 0; 320 struct inpcb *inp = sotoinpcb(so); 321 struct tcpcb *tp; 322 struct sockaddr_in *sinp; 323 324 COMMON_START(); 325 326 /* 327 * Must disallow TCP ``connections'' to multicast addresses. 328 */ 329 sinp = (struct sockaddr_in *)nam; 330 if (sinp->sin_family == AF_INET 331 && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) { 332 error = EAFNOSUPPORT; 333 goto out; 334 } 335 336 prison_remote_ip(td, 0, &sinp->sin_addr.s_addr); 337 338 if ((error = tcp_connect(tp, nam, td)) != 0) 339 goto out; 340 error = tcp_output(tp); 341 COMMON_END(PRU_CONNECT); 342 } 343 344 #ifdef INET6 345 static int 346 tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 347 { 348 int s = splnet(); 349 int error = 0; 350 struct inpcb *inp = sotoinpcb(so); 351 struct tcpcb *tp; 352 struct sockaddr_in6 *sin6p; 353 354 COMMON_START(); 355 356 /* 357 * Must disallow TCP ``connections'' to multicast addresses. 358 */ 359 sin6p = (struct sockaddr_in6 *)nam; 360 if (sin6p->sin6_family == AF_INET6 361 && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) { 362 error = EAFNOSUPPORT; 363 goto out; 364 } 365 366 if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) { 367 struct sockaddr_in sin; 368 369 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) { 370 error = EINVAL; 371 goto out; 372 } 373 374 in6_sin6_2_sin(&sin, sin6p); 375 inp->inp_vflag |= INP_IPV4; 376 inp->inp_vflag &= ~INP_IPV6; 377 if ((error = tcp_connect(tp, (struct sockaddr *)&sin, td)) != 0) 378 goto out; 379 error = tcp_output(tp); 380 goto out; 381 } 382 inp->inp_vflag &= ~INP_IPV4; 383 inp->inp_vflag |= INP_IPV6; 384 inp->inp_inc.inc_isipv6 = 1; 385 if ((error = tcp6_connect(tp, nam, td)) != 0) 386 goto out; 387 error = tcp_output(tp); 388 COMMON_END(PRU_CONNECT); 389 } 390 #endif /* INET6 */ 391 392 /* 393 * Initiate disconnect from peer. 394 * If connection never passed embryonic stage, just drop; 395 * else if don't need to let data drain, then can just drop anyways, 396 * else have to begin TCP shutdown process: mark socket disconnecting, 397 * drain unread data, state switch to reflect user close, and 398 * send segment (e.g. FIN) to peer. Socket will be really disconnected 399 * when peer sends FIN and acks ours. 400 * 401 * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB. 402 */ 403 static int 404 tcp_usr_disconnect(struct socket *so) 405 { 406 int s = splnet(); 407 int error = 0; 408 struct inpcb *inp = sotoinpcb(so); 409 struct tcpcb *tp; 410 411 COMMON_START(); 412 tp = tcp_disconnect(tp); 413 COMMON_END(PRU_DISCONNECT); 414 } 415 416 /* 417 * Accept a connection. Essentially all the work is 418 * done at higher levels; just return the address 419 * of the peer, storing through addr. 420 */ 421 static int 422 tcp_usr_accept(struct socket *so, struct sockaddr **nam) 423 { 424 int s = splnet(); 425 int error = 0; 426 struct inpcb *inp = sotoinpcb(so); 427 struct tcpcb *tp = NULL; 428 TCPDEBUG0; 429 430 if (so->so_state & SS_ISDISCONNECTED) { 431 error = ECONNABORTED; 432 goto out; 433 } 434 if (inp == 0) { 435 splx(s); 436 return (EINVAL); 437 } 438 tp = intotcpcb(inp); 439 TCPDEBUG1(); 440 in_setpeeraddr(so, nam); 441 COMMON_END(PRU_ACCEPT); 442 } 443 444 #ifdef INET6 445 static int 446 tcp6_usr_accept(struct socket *so, struct sockaddr **nam) 447 { 448 int s = splnet(); 449 int error = 0; 450 struct inpcb *inp = sotoinpcb(so); 451 struct tcpcb *tp = NULL; 452 TCPDEBUG0; 453 454 if (so->so_state & SS_ISDISCONNECTED) { 455 error = ECONNABORTED; 456 goto out; 457 } 458 if (inp == 0) { 459 splx(s); 460 return (EINVAL); 461 } 462 tp = intotcpcb(inp); 463 TCPDEBUG1(); 464 in6_mapped_peeraddr(so, nam); 465 COMMON_END(PRU_ACCEPT); 466 } 467 #endif /* INET6 */ 468 /* 469 * Mark the connection as being incapable of further output. 470 */ 471 static int 472 tcp_usr_shutdown(struct socket *so) 473 { 474 int s = splnet(); 475 int error = 0; 476 struct inpcb *inp = sotoinpcb(so); 477 struct tcpcb *tp; 478 479 COMMON_START(); 480 socantsendmore(so); 481 tp = tcp_usrclosed(tp); 482 if (tp) 483 error = tcp_output(tp); 484 COMMON_END(PRU_SHUTDOWN); 485 } 486 487 /* 488 * After a receive, possibly send window update to peer. 489 */ 490 static int 491 tcp_usr_rcvd(struct socket *so, int flags) 492 { 493 int s = splnet(); 494 int error = 0; 495 struct inpcb *inp = sotoinpcb(so); 496 struct tcpcb *tp; 497 498 COMMON_START(); 499 tcp_output(tp); 500 COMMON_END(PRU_RCVD); 501 } 502 503 /* 504 * Do a send by putting data in output queue and updating urgent 505 * marker if URG set. Possibly send more data. Unlike the other 506 * pru_*() routines, the mbuf chains are our responsibility. We 507 * must either enqueue them or free them. The other pru_* routines 508 * generally are caller-frees. 509 */ 510 static int 511 tcp_usr_send(struct socket *so, int flags, struct mbuf *m, 512 struct sockaddr *nam, struct mbuf *control, struct thread *td) 513 { 514 int s = splnet(); 515 int error = 0; 516 struct inpcb *inp = sotoinpcb(so); 517 struct tcpcb *tp; 518 #ifdef INET6 519 int isipv6; 520 #endif 521 TCPDEBUG0; 522 523 if (inp == NULL) { 524 /* 525 * OOPS! we lost a race, the TCP session got reset after 526 * we checked SS_CANTSENDMORE, eg: while doing uiomove or a 527 * network interrupt in the non-splnet() section of sosend(). 528 */ 529 if (m) 530 m_freem(m); 531 if (control) 532 m_freem(control); 533 error = ECONNRESET; /* XXX EPIPE? */ 534 tp = NULL; 535 TCPDEBUG1(); 536 goto out; 537 } 538 #ifdef INET6 539 isipv6 = nam && nam->sa_family == AF_INET6; 540 #endif /* INET6 */ 541 tp = intotcpcb(inp); 542 TCPDEBUG1(); 543 if (control) { 544 /* TCP doesn't do control messages (rights, creds, etc) */ 545 if (control->m_len) { 546 m_freem(control); 547 if (m) 548 m_freem(m); 549 error = EINVAL; 550 goto out; 551 } 552 m_freem(control); /* empty control, just free it */ 553 } 554 if(!(flags & PRUS_OOB)) { 555 sbappend(&so->so_snd, m); 556 if (nam && tp->t_state < TCPS_SYN_SENT) { 557 /* 558 * Do implied connect if not yet connected, 559 * initialize window to default value, and 560 * initialize maxseg/maxopd using peer's cached 561 * MSS. 562 */ 563 #ifdef INET6 564 if (isipv6) 565 error = tcp6_connect(tp, nam, td); 566 else 567 #endif /* INET6 */ 568 error = tcp_connect(tp, nam, td); 569 if (error) 570 goto out; 571 tp->snd_wnd = TTCP_CLIENT_SND_WND; 572 tcp_mss(tp, -1); 573 } 574 575 if (flags & PRUS_EOF) { 576 /* 577 * Close the send side of the connection after 578 * the data is sent. 579 */ 580 socantsendmore(so); 581 tp = tcp_usrclosed(tp); 582 } 583 if (tp != NULL) { 584 if (flags & PRUS_MORETOCOME) 585 tp->t_flags |= TF_MORETOCOME; 586 error = tcp_output(tp); 587 if (flags & PRUS_MORETOCOME) 588 tp->t_flags &= ~TF_MORETOCOME; 589 } 590 } else { 591 if (sbspace(&so->so_snd) < -512) { 592 m_freem(m); 593 error = ENOBUFS; 594 goto out; 595 } 596 /* 597 * According to RFC961 (Assigned Protocols), 598 * the urgent pointer points to the last octet 599 * of urgent data. We continue, however, 600 * to consider it to indicate the first octet 601 * of data past the urgent section. 602 * Otherwise, snd_up should be one lower. 603 */ 604 sbappend(&so->so_snd, m); 605 if (nam && tp->t_state < TCPS_SYN_SENT) { 606 /* 607 * Do implied connect if not yet connected, 608 * initialize window to default value, and 609 * initialize maxseg/maxopd using peer's cached 610 * MSS. 611 */ 612 #ifdef INET6 613 if (isipv6) 614 error = tcp6_connect(tp, nam, td); 615 else 616 #endif /* INET6 */ 617 error = tcp_connect(tp, nam, td); 618 if (error) 619 goto out; 620 tp->snd_wnd = TTCP_CLIENT_SND_WND; 621 tcp_mss(tp, -1); 622 } 623 tp->snd_up = tp->snd_una + so->so_snd.sb_cc; 624 tp->t_force = 1; 625 error = tcp_output(tp); 626 tp->t_force = 0; 627 } 628 COMMON_END((flags & PRUS_OOB) ? PRU_SENDOOB : 629 ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND)); 630 } 631 632 /* 633 * Abort the TCP. 634 */ 635 static int 636 tcp_usr_abort(struct socket *so) 637 { 638 int s = splnet(); 639 int error = 0; 640 struct inpcb *inp = sotoinpcb(so); 641 struct tcpcb *tp; 642 643 COMMON_START(); 644 tp = tcp_drop(tp, ECONNABORTED); 645 COMMON_END(PRU_ABORT); 646 } 647 648 /* 649 * Receive out-of-band data. 650 */ 651 static int 652 tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags) 653 { 654 int s = splnet(); 655 int error = 0; 656 struct inpcb *inp = sotoinpcb(so); 657 struct tcpcb *tp; 658 659 COMMON_START(); 660 if ((so->so_oobmark == 0 && 661 (so->so_state & SS_RCVATMARK) == 0) || 662 so->so_options & SO_OOBINLINE || 663 tp->t_oobflags & TCPOOB_HADDATA) { 664 error = EINVAL; 665 goto out; 666 } 667 if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) { 668 error = EWOULDBLOCK; 669 goto out; 670 } 671 m->m_len = 1; 672 *mtod(m, caddr_t) = tp->t_iobc; 673 if ((flags & MSG_PEEK) == 0) 674 tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA); 675 COMMON_END(PRU_RCVOOB); 676 } 677 678 /* xxx - should be const */ 679 struct pr_usrreqs tcp_usrreqs = { 680 tcp_usr_abort, tcp_usr_accept, tcp_usr_attach, tcp_usr_bind, 681 tcp_usr_connect, pru_connect2_notsupp, in_control, tcp_usr_detach, 682 tcp_usr_disconnect, tcp_usr_listen, in_setpeeraddr, tcp_usr_rcvd, 683 tcp_usr_rcvoob, tcp_usr_send, pru_sense_null, tcp_usr_shutdown, 684 in_setsockaddr, sosend, soreceive, sopoll 685 }; 686 687 #ifdef INET6 688 struct pr_usrreqs tcp6_usrreqs = { 689 tcp_usr_abort, tcp6_usr_accept, tcp_usr_attach, tcp6_usr_bind, 690 tcp6_usr_connect, pru_connect2_notsupp, in6_control, tcp_usr_detach, 691 tcp_usr_disconnect, tcp6_usr_listen, in6_mapped_peeraddr, tcp_usr_rcvd, 692 tcp_usr_rcvoob, tcp_usr_send, pru_sense_null, tcp_usr_shutdown, 693 in6_mapped_sockaddr, sosend, soreceive, sopoll 694 }; 695 #endif /* INET6 */ 696 697 /* 698 * Common subroutine to open a TCP connection to remote host specified 699 * by struct sockaddr_in in mbuf *nam. Call in_pcbbind to assign a local 700 * port number if needed. Call in_pcbladdr to do the routing and to choose 701 * a local host address (interface). If there is an existing incarnation 702 * of the same connection in TIME-WAIT state and if the remote host was 703 * sending CC options and if the connection duration was < MSL, then 704 * truncate the previous TIME-WAIT state and proceed. 705 * Initialize connection parameters and enter SYN-SENT state. 706 */ 707 static int 708 tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td) 709 { 710 struct inpcb *inp = tp->t_inpcb, *oinp; 711 struct socket *so = inp->inp_socket; 712 struct tcpcb *otp; 713 struct sockaddr_in *sin = (struct sockaddr_in *)nam; 714 struct sockaddr_in *if_sin; 715 struct rmxp_tao *taop; 716 struct rmxp_tao tao_noncached; 717 int error; 718 719 if (inp->inp_lport == 0) { 720 error = in_pcbbind(inp, (struct sockaddr *)0, td); 721 if (error) 722 return (error); 723 } 724 725 /* 726 * Cannot simply call in_pcbconnect, because there might be an 727 * earlier incarnation of this same connection still in 728 * TIME_WAIT state, creating an ADDRINUSE error. 729 */ 730 error = in_pcbladdr(inp, nam, &if_sin); 731 if (error) 732 return (error); 733 oinp = in_pcblookup_hash(inp->inp_pcbinfo, 734 sin->sin_addr, sin->sin_port, 735 inp->inp_laddr.s_addr != INADDR_ANY ? 736 inp->inp_laddr : if_sin->sin_addr, 737 inp->inp_lport, 0, NULL); 738 if (oinp != NULL) { 739 if (oinp != inp && (otp = intotcpcb(oinp)) != NULL && 740 otp->t_state == TCPS_TIME_WAIT && 741 (ticks - otp->t_starttime) < tcp_msl && 742 (otp->t_flags & TF_RCVD_CC)) 743 (void) tcp_close(otp); 744 else 745 return (EADDRINUSE); 746 } 747 if (inp->inp_laddr.s_addr == INADDR_ANY) 748 inp->inp_laddr = if_sin->sin_addr; 749 inp->inp_faddr = sin->sin_addr; 750 inp->inp_fport = sin->sin_port; 751 in_pcbinsconnhash(inp); 752 753 /* Compute window scaling to request. */ 754 while (tp->request_r_scale < TCP_MAX_WINSHIFT && 755 (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat) 756 tp->request_r_scale++; 757 758 soisconnecting(so); 759 tcpstat.tcps_connattempt++; 760 tp->t_state = TCPS_SYN_SENT; 761 callout_reset(tp->tt_keep, tcp_keepinit, tcp_timer_keep, tp); 762 tp->iss = tcp_new_isn(tp); 763 tp->t_bw_rtseq = tp->iss; 764 tcp_sendseqinit(tp); 765 766 /* 767 * Generate a CC value for this connection and 768 * check whether CC or CCnew should be used. 769 */ 770 if ((taop = tcp_gettaocache(&tp->t_inpcb->inp_inc)) == NULL) { 771 taop = &tao_noncached; 772 bzero(taop, sizeof(*taop)); 773 } 774 775 tp->cc_send = CC_INC(tcp_ccgen); 776 if (taop->tao_ccsent != 0 && 777 CC_GEQ(tp->cc_send, taop->tao_ccsent)) { 778 taop->tao_ccsent = tp->cc_send; 779 } else { 780 taop->tao_ccsent = 0; 781 tp->t_flags |= TF_SENDCCNEW; 782 } 783 784 return (0); 785 } 786 787 #ifdef INET6 788 static int 789 tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td) 790 { 791 struct inpcb *inp = tp->t_inpcb, *oinp; 792 struct socket *so = inp->inp_socket; 793 struct tcpcb *otp; 794 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam; 795 struct in6_addr *addr6; 796 struct rmxp_tao *taop; 797 struct rmxp_tao tao_noncached; 798 int error; 799 800 if (inp->inp_lport == 0) { 801 error = in6_pcbbind(inp, (struct sockaddr *)0, td); 802 if (error) 803 return error; 804 } 805 806 /* 807 * Cannot simply call in_pcbconnect, because there might be an 808 * earlier incarnation of this same connection still in 809 * TIME_WAIT state, creating an ADDRINUSE error. 810 */ 811 error = in6_pcbladdr(inp, nam, &addr6); 812 if (error) 813 return error; 814 oinp = in6_pcblookup_hash(inp->inp_pcbinfo, 815 &sin6->sin6_addr, sin6->sin6_port, 816 IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) ? 817 addr6 : &inp->in6p_laddr, 818 inp->inp_lport, 0, NULL); 819 if (oinp) { 820 if (oinp != inp && (otp = intotcpcb(oinp)) != NULL && 821 otp->t_state == TCPS_TIME_WAIT && 822 (ticks - otp->t_starttime) < tcp_msl && 823 (otp->t_flags & TF_RCVD_CC)) 824 otp = tcp_close(otp); 825 else 826 return (EADDRINUSE); 827 } 828 if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) 829 inp->in6p_laddr = *addr6; 830 inp->in6p_faddr = sin6->sin6_addr; 831 inp->inp_fport = sin6->sin6_port; 832 if ((sin6->sin6_flowinfo & IPV6_FLOWINFO_MASK) != NULL) 833 inp->in6p_flowinfo = sin6->sin6_flowinfo; 834 in_pcbinsconnhash(inp); 835 836 /* Compute window scaling to request. */ 837 while (tp->request_r_scale < TCP_MAX_WINSHIFT && 838 (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat) 839 tp->request_r_scale++; 840 841 soisconnecting(so); 842 tcpstat.tcps_connattempt++; 843 tp->t_state = TCPS_SYN_SENT; 844 callout_reset(tp->tt_keep, tcp_keepinit, tcp_timer_keep, tp); 845 tp->iss = tcp_new_isn(tp); 846 tp->t_bw_rtseq = tp->iss; 847 tcp_sendseqinit(tp); 848 849 /* 850 * Generate a CC value for this connection and 851 * check whether CC or CCnew should be used. 852 */ 853 if ((taop = tcp_gettaocache(&tp->t_inpcb->inp_inc)) == NULL) { 854 taop = &tao_noncached; 855 bzero(taop, sizeof(*taop)); 856 } 857 858 tp->cc_send = CC_INC(tcp_ccgen); 859 if (taop->tao_ccsent != 0 && 860 CC_GEQ(tp->cc_send, taop->tao_ccsent)) { 861 taop->tao_ccsent = tp->cc_send; 862 } else { 863 taop->tao_ccsent = 0; 864 tp->t_flags |= TF_SENDCCNEW; 865 } 866 867 return (0); 868 } 869 #endif /* INET6 */ 870 871 /* 872 * The new sockopt interface makes it possible for us to block in the 873 * copyin/out step (if we take a page fault). Taking a page fault at 874 * splnet() is probably a Bad Thing. (Since sockets and pcbs both now 875 * use TSM, there probably isn't any need for this function to run at 876 * splnet() any more. This needs more examination.) 877 */ 878 int 879 tcp_ctloutput(so, sopt) 880 struct socket *so; 881 struct sockopt *sopt; 882 { 883 int error, opt, optval, s; 884 struct inpcb *inp; 885 struct tcpcb *tp; 886 887 error = 0; 888 s = splnet(); /* XXX */ 889 inp = sotoinpcb(so); 890 if (inp == NULL) { 891 splx(s); 892 return (ECONNRESET); 893 } 894 if (sopt->sopt_level != IPPROTO_TCP) { 895 #ifdef INET6 896 if (INP_CHECK_SOCKAF(so, AF_INET6)) 897 error = ip6_ctloutput(so, sopt); 898 else 899 #endif /* INET6 */ 900 error = ip_ctloutput(so, sopt); 901 splx(s); 902 return (error); 903 } 904 tp = intotcpcb(inp); 905 906 switch (sopt->sopt_dir) { 907 case SOPT_SET: 908 switch (sopt->sopt_name) { 909 case TCP_NODELAY: 910 case TCP_NOOPT: 911 error = sooptcopyin(sopt, &optval, sizeof optval, 912 sizeof optval); 913 if (error) 914 break; 915 916 switch (sopt->sopt_name) { 917 case TCP_NODELAY: 918 opt = TF_NODELAY; 919 break; 920 case TCP_NOOPT: 921 opt = TF_NOOPT; 922 break; 923 default: 924 opt = 0; /* dead code to fool gcc */ 925 break; 926 } 927 928 if (optval) 929 tp->t_flags |= opt; 930 else 931 tp->t_flags &= ~opt; 932 break; 933 934 case TCP_NOPUSH: 935 error = sooptcopyin(sopt, &optval, sizeof optval, 936 sizeof optval); 937 if (error) 938 break; 939 940 if (optval) 941 tp->t_flags |= TF_NOPUSH; 942 else { 943 tp->t_flags &= ~TF_NOPUSH; 944 error = tcp_output(tp); 945 } 946 break; 947 948 case TCP_MAXSEG: 949 error = sooptcopyin(sopt, &optval, sizeof optval, 950 sizeof optval); 951 if (error) 952 break; 953 954 if (optval > 0 && optval <= tp->t_maxseg) 955 tp->t_maxseg = optval; 956 else 957 error = EINVAL; 958 break; 959 960 default: 961 error = ENOPROTOOPT; 962 break; 963 } 964 break; 965 966 case SOPT_GET: 967 switch (sopt->sopt_name) { 968 case TCP_NODELAY: 969 optval = tp->t_flags & TF_NODELAY; 970 break; 971 case TCP_MAXSEG: 972 optval = tp->t_maxseg; 973 break; 974 case TCP_NOOPT: 975 optval = tp->t_flags & TF_NOOPT; 976 break; 977 case TCP_NOPUSH: 978 optval = tp->t_flags & TF_NOPUSH; 979 break; 980 default: 981 error = ENOPROTOOPT; 982 break; 983 } 984 if (error == 0) 985 error = sooptcopyout(sopt, &optval, sizeof optval); 986 break; 987 } 988 splx(s); 989 return (error); 990 } 991 992 /* 993 * tcp_sendspace and tcp_recvspace are the default send and receive window 994 * sizes, respectively. These are obsolescent (this information should 995 * be set by the route). 996 */ 997 u_long tcp_sendspace = 1024*32; 998 SYSCTL_INT(_net_inet_tcp, TCPCTL_SENDSPACE, sendspace, CTLFLAG_RW, 999 &tcp_sendspace , 0, "Maximum outgoing TCP datagram size"); 1000 u_long tcp_recvspace = 57344; /* largest multiple of PAGE_SIZE < 64k */ 1001 SYSCTL_INT(_net_inet_tcp, TCPCTL_RECVSPACE, recvspace, CTLFLAG_RW, 1002 &tcp_recvspace , 0, "Maximum incoming TCP datagram size"); 1003 1004 /* 1005 * Attach TCP protocol to socket, allocating 1006 * internet protocol control block, tcp control block, 1007 * bufer space, and entering LISTEN state if to accept connections. 1008 */ 1009 static int 1010 tcp_attach(struct socket *so, struct pru_attach_info *ai) 1011 { 1012 struct tcpcb *tp; 1013 struct inpcb *inp; 1014 int error; 1015 int cpu; 1016 #ifdef INET6 1017 int isipv6 = INP_CHECK_SOCKAF(so, AF_INET6) != NULL; 1018 #endif 1019 1020 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 1021 error = soreserve(so, tcp_sendspace, tcp_recvspace, 1022 ai->sb_rlimit); 1023 if (error) 1024 return (error); 1025 } 1026 #ifdef TCP_DISTRIBUTED_TCBINFO 1027 cpu = mycpu->gd_cpuid; 1028 #else 1029 cpu = 0; 1030 #endif 1031 error = in_pcballoc(so, &tcbinfo[cpu]); 1032 if (error) 1033 return (error); 1034 inp = sotoinpcb(so); 1035 #ifdef INET6 1036 if (isipv6) { 1037 inp->inp_vflag |= INP_IPV6; 1038 inp->in6p_hops = -1; /* use kernel default */ 1039 } 1040 else 1041 #endif 1042 inp->inp_vflag |= INP_IPV4; 1043 tp = tcp_newtcpcb(inp); 1044 if (tp == 0) { 1045 int nofd = so->so_state & SS_NOFDREF; /* XXX */ 1046 1047 so->so_state &= ~SS_NOFDREF; /* don't free the socket yet */ 1048 #ifdef INET6 1049 if (isipv6) 1050 in6_pcbdetach(inp); 1051 else 1052 #endif 1053 in_pcbdetach(inp); 1054 so->so_state |= nofd; 1055 return (ENOBUFS); 1056 } 1057 tp->t_state = TCPS_CLOSED; 1058 return (0); 1059 } 1060 1061 /* 1062 * Initiate (or continue) disconnect. 1063 * If embryonic state, just send reset (once). 1064 * If in ``let data drain'' option and linger null, just drop. 1065 * Otherwise (hard), mark socket disconnecting and drop 1066 * current input data; switch states based on user close, and 1067 * send segment to peer (with FIN). 1068 */ 1069 static struct tcpcb * 1070 tcp_disconnect(tp) 1071 struct tcpcb *tp; 1072 { 1073 struct socket *so = tp->t_inpcb->inp_socket; 1074 1075 if (tp->t_state < TCPS_ESTABLISHED) 1076 tp = tcp_close(tp); 1077 else if ((so->so_options & SO_LINGER) && so->so_linger == 0) 1078 tp = tcp_drop(tp, 0); 1079 else { 1080 soisdisconnecting(so); 1081 sbflush(&so->so_rcv); 1082 tp = tcp_usrclosed(tp); 1083 if (tp) 1084 (void) tcp_output(tp); 1085 } 1086 return (tp); 1087 } 1088 1089 /* 1090 * User issued close, and wish to trail through shutdown states: 1091 * if never received SYN, just forget it. If got a SYN from peer, 1092 * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN. 1093 * If already got a FIN from peer, then almost done; go to LAST_ACK 1094 * state. In all other cases, have already sent FIN to peer (e.g. 1095 * after PRU_SHUTDOWN), and just have to play tedious game waiting 1096 * for peer to send FIN or not respond to keep-alives, etc. 1097 * We can let the user exit from the close as soon as the FIN is acked. 1098 */ 1099 static struct tcpcb * 1100 tcp_usrclosed(tp) 1101 struct tcpcb *tp; 1102 { 1103 1104 switch (tp->t_state) { 1105 1106 case TCPS_CLOSED: 1107 case TCPS_LISTEN: 1108 tp->t_state = TCPS_CLOSED; 1109 tp = tcp_close(tp); 1110 break; 1111 1112 case TCPS_SYN_SENT: 1113 case TCPS_SYN_RECEIVED: 1114 tp->t_flags |= TF_NEEDFIN; 1115 break; 1116 1117 case TCPS_ESTABLISHED: 1118 tp->t_state = TCPS_FIN_WAIT_1; 1119 break; 1120 1121 case TCPS_CLOSE_WAIT: 1122 tp->t_state = TCPS_LAST_ACK; 1123 break; 1124 } 1125 if (tp && tp->t_state >= TCPS_FIN_WAIT_2) { 1126 soisdisconnected(tp->t_inpcb->inp_socket); 1127 /* To prevent the connection hanging in FIN_WAIT_2 forever. */ 1128 if (tp->t_state == TCPS_FIN_WAIT_2) 1129 callout_reset(tp->tt_2msl, tcp_maxidle, 1130 tcp_timer_2msl, tp); 1131 } 1132 return (tp); 1133 } 1134 1135