1 /* $OpenBSD: uipc_socket2.c,v 1.133 2023/01/22 12:05:44 mvs Exp $ */ 2 /* $NetBSD: uipc_socket2.c,v 1.11 1996/02/04 02:17:55 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1988, 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)uipc_socket2.c 8.1 (Berkeley) 6/10/93 33 */ 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/malloc.h> 38 #include <sys/mbuf.h> 39 #include <sys/protosw.h> 40 #include <sys/domain.h> 41 #include <sys/socket.h> 42 #include <sys/socketvar.h> 43 #include <sys/signalvar.h> 44 #include <sys/event.h> 45 #include <sys/pool.h> 46 47 /* 48 * Primitive routines for operating on sockets and socket buffers 49 */ 50 51 u_long sb_max = SB_MAX; /* patchable */ 52 53 extern struct pool mclpools[]; 54 extern struct pool mbpool; 55 56 /* 57 * Procedures to manipulate state flags of socket 58 * and do appropriate wakeups. Normal sequence from the 59 * active (originating) side is that soisconnecting() is 60 * called during processing of connect() call, 61 * resulting in an eventual call to soisconnected() if/when the 62 * connection is established. When the connection is torn down 63 * soisdisconnecting() is called during processing of disconnect() call, 64 * and soisdisconnected() is called when the connection to the peer 65 * is totally severed. The semantics of these routines are such that 66 * connectionless protocols can call soisconnected() and soisdisconnected() 67 * only, bypassing the in-progress calls when setting up a ``connection'' 68 * takes no time. 69 * 70 * From the passive side, a socket is created with 71 * two queues of sockets: so_q0 for connections in progress 72 * and so_q for connections already made and awaiting user acceptance. 73 * As a protocol is preparing incoming connections, it creates a socket 74 * structure queued on so_q0 by calling sonewconn(). When the connection 75 * is established, soisconnected() is called, and transfers the 76 * socket structure to so_q, making it available to accept(). 77 * 78 * If a socket is closed with sockets on either 79 * so_q0 or so_q, these sockets are dropped. 80 * 81 * If higher level protocols are implemented in 82 * the kernel, the wakeups done here will sometimes 83 * cause software-interrupt process scheduling. 84 */ 85 86 void 87 soisconnecting(struct socket *so) 88 { 89 soassertlocked(so); 90 so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING); 91 so->so_state |= SS_ISCONNECTING; 92 } 93 94 void 95 soisconnected(struct socket *so) 96 { 97 struct socket *head = so->so_head; 98 99 soassertlocked(so); 100 so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING); 101 so->so_state |= SS_ISCONNECTED; 102 103 if (head != NULL && so->so_onq == &head->so_q0) { 104 int persocket = solock_persocket(so); 105 106 if (persocket) { 107 soref(so); 108 soref(head); 109 110 sounlock(so); 111 solock(head); 112 solock(so); 113 114 if (so->so_onq != &head->so_q0) { 115 sounlock(head); 116 sorele(head); 117 sorele(so); 118 119 return; 120 } 121 122 sorele(head); 123 sorele(so); 124 } 125 126 soqremque(so, 0); 127 soqinsque(head, so, 1); 128 sorwakeup(head); 129 wakeup_one(&head->so_timeo); 130 131 if (persocket) 132 sounlock(head); 133 } else { 134 wakeup(&so->so_timeo); 135 sorwakeup(so); 136 sowwakeup(so); 137 } 138 } 139 140 void 141 soisdisconnecting(struct socket *so) 142 { 143 soassertlocked(so); 144 so->so_state &= ~SS_ISCONNECTING; 145 so->so_state |= SS_ISDISCONNECTING; 146 so->so_rcv.sb_state |= SS_CANTRCVMORE; 147 so->so_snd.sb_state |= SS_CANTSENDMORE; 148 wakeup(&so->so_timeo); 149 sowwakeup(so); 150 sorwakeup(so); 151 } 152 153 void 154 soisdisconnected(struct socket *so) 155 { 156 soassertlocked(so); 157 so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING); 158 so->so_state |= SS_ISDISCONNECTED; 159 so->so_rcv.sb_state |= SS_CANTRCVMORE; 160 so->so_snd.sb_state |= SS_CANTSENDMORE; 161 wakeup(&so->so_timeo); 162 sowwakeup(so); 163 sorwakeup(so); 164 } 165 166 /* 167 * When an attempt at a new connection is noted on a socket 168 * which accepts connections, sonewconn is called. If the 169 * connection is possible (subject to space constraints, etc.) 170 * then we allocate a new structure, properly linked into the 171 * data structure of the original socket, and return this. 172 * Connstatus may be 0 or SS_ISCONNECTED. 173 */ 174 struct socket * 175 sonewconn(struct socket *head, int connstatus, int wait) 176 { 177 struct socket *so; 178 int persocket = solock_persocket(head); 179 int error; 180 181 /* 182 * XXXSMP as long as `so' and `head' share the same lock, we 183 * can call soreserve() and pr_attach() below w/o explicitly 184 * locking `so'. 185 */ 186 soassertlocked(head); 187 188 if (m_pool_used() > 95) 189 return (NULL); 190 if (head->so_qlen + head->so_q0len > head->so_qlimit * 3) 191 return (NULL); 192 so = soalloc(wait); 193 if (so == NULL) 194 return (NULL); 195 so->so_type = head->so_type; 196 so->so_options = head->so_options &~ SO_ACCEPTCONN; 197 so->so_linger = head->so_linger; 198 so->so_state = head->so_state | SS_NOFDREF; 199 so->so_proto = head->so_proto; 200 so->so_timeo = head->so_timeo; 201 so->so_euid = head->so_euid; 202 so->so_ruid = head->so_ruid; 203 so->so_egid = head->so_egid; 204 so->so_rgid = head->so_rgid; 205 so->so_cpid = head->so_cpid; 206 207 /* 208 * Lock order will be `head' -> `so' while these sockets are linked. 209 */ 210 if (persocket) 211 solock(so); 212 213 /* 214 * Inherit watermarks but those may get clamped in low mem situations. 215 */ 216 if (soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat)) { 217 if (persocket) 218 sounlock(so); 219 pool_put(&socket_pool, so); 220 return (NULL); 221 } 222 so->so_snd.sb_wat = head->so_snd.sb_wat; 223 so->so_snd.sb_lowat = head->so_snd.sb_lowat; 224 so->so_snd.sb_timeo_nsecs = head->so_snd.sb_timeo_nsecs; 225 so->so_rcv.sb_wat = head->so_rcv.sb_wat; 226 so->so_rcv.sb_lowat = head->so_rcv.sb_lowat; 227 so->so_rcv.sb_timeo_nsecs = head->so_rcv.sb_timeo_nsecs; 228 229 klist_init(&so->so_rcv.sb_sel.si_note, &socket_klistops, so); 230 klist_init(&so->so_snd.sb_sel.si_note, &socket_klistops, so); 231 sigio_init(&so->so_sigio); 232 sigio_copy(&so->so_sigio, &head->so_sigio); 233 234 soqinsque(head, so, 0); 235 236 /* 237 * We need to unlock `head' because PCB layer could release 238 * solock() to enforce desired lock order. 239 */ 240 if (persocket) { 241 head->so_newconn++; 242 sounlock(head); 243 } 244 245 error = pru_attach(so, 0, wait); 246 247 if (persocket) { 248 sounlock(so); 249 solock(head); 250 solock(so); 251 252 if ((head->so_newconn--) == 0) { 253 if ((head->so_state & SS_NEWCONN_WAIT) != 0) { 254 head->so_state &= ~SS_NEWCONN_WAIT; 255 wakeup(&head->so_newconn); 256 } 257 } 258 } 259 260 if (error) { 261 soqremque(so, 0); 262 if (persocket) 263 sounlock(so); 264 sigio_free(&so->so_sigio); 265 klist_free(&so->so_rcv.sb_sel.si_note); 266 klist_free(&so->so_snd.sb_sel.si_note); 267 pool_put(&socket_pool, so); 268 return (NULL); 269 } 270 271 if (connstatus) { 272 so->so_state |= connstatus; 273 soqremque(so, 0); 274 soqinsque(head, so, 1); 275 sorwakeup(head); 276 wakeup(&head->so_timeo); 277 } 278 279 if (persocket) 280 sounlock(so); 281 282 return (so); 283 } 284 285 void 286 soqinsque(struct socket *head, struct socket *so, int q) 287 { 288 soassertlocked(head); 289 soassertlocked(so); 290 291 KASSERT(so->so_onq == NULL); 292 293 so->so_head = head; 294 if (q == 0) { 295 head->so_q0len++; 296 so->so_onq = &head->so_q0; 297 } else { 298 head->so_qlen++; 299 so->so_onq = &head->so_q; 300 } 301 TAILQ_INSERT_TAIL(so->so_onq, so, so_qe); 302 } 303 304 int 305 soqremque(struct socket *so, int q) 306 { 307 struct socket *head = so->so_head; 308 309 soassertlocked(so); 310 soassertlocked(head); 311 312 if (q == 0) { 313 if (so->so_onq != &head->so_q0) 314 return (0); 315 head->so_q0len--; 316 } else { 317 if (so->so_onq != &head->so_q) 318 return (0); 319 head->so_qlen--; 320 } 321 TAILQ_REMOVE(so->so_onq, so, so_qe); 322 so->so_onq = NULL; 323 so->so_head = NULL; 324 return (1); 325 } 326 327 /* 328 * Socantsendmore indicates that no more data will be sent on the 329 * socket; it would normally be applied to a socket when the user 330 * informs the system that no more data is to be sent, by the protocol 331 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data 332 * will be received, and will normally be applied to the socket by a 333 * protocol when it detects that the peer will send no more data. 334 * Data queued for reading in the socket may yet be read. 335 */ 336 337 void 338 socantsendmore(struct socket *so) 339 { 340 soassertlocked(so); 341 so->so_snd.sb_state |= SS_CANTSENDMORE; 342 sowwakeup(so); 343 } 344 345 void 346 socantrcvmore(struct socket *so) 347 { 348 soassertlocked(so); 349 so->so_rcv.sb_state |= SS_CANTRCVMORE; 350 sorwakeup(so); 351 } 352 353 void 354 solock(struct socket *so) 355 { 356 switch (so->so_proto->pr_domain->dom_family) { 357 case PF_INET: 358 case PF_INET6: 359 NET_LOCK(); 360 break; 361 default: 362 rw_enter_write(&so->so_lock); 363 break; 364 } 365 } 366 367 void 368 solock_shared(struct socket *so) 369 { 370 switch (so->so_proto->pr_domain->dom_family) { 371 case PF_INET: 372 case PF_INET6: 373 if (so->so_proto->pr_usrreqs->pru_lock != NULL) { 374 NET_LOCK_SHARED(); 375 pru_lock(so); 376 } else 377 NET_LOCK(); 378 break; 379 default: 380 rw_enter_write(&so->so_lock); 381 break; 382 } 383 } 384 385 int 386 solock_persocket(struct socket *so) 387 { 388 switch (so->so_proto->pr_domain->dom_family) { 389 case PF_INET: 390 case PF_INET6: 391 return 0; 392 default: 393 return 1; 394 } 395 } 396 397 void 398 solock_pair(struct socket *so1, struct socket *so2) 399 { 400 KASSERT(so1 != so2); 401 KASSERT(so1->so_type == so2->so_type); 402 KASSERT(solock_persocket(so1)); 403 404 if (so1 < so2) { 405 solock(so1); 406 solock(so2); 407 } else { 408 solock(so2); 409 solock(so1); 410 } 411 } 412 413 void 414 sounlock(struct socket *so) 415 { 416 switch (so->so_proto->pr_domain->dom_family) { 417 case PF_INET: 418 case PF_INET6: 419 NET_UNLOCK(); 420 break; 421 default: 422 rw_exit_write(&so->so_lock); 423 break; 424 } 425 } 426 427 void 428 sounlock_shared(struct socket *so) 429 { 430 switch (so->so_proto->pr_domain->dom_family) { 431 case PF_INET: 432 case PF_INET6: 433 if (so->so_proto->pr_usrreqs->pru_unlock != NULL) { 434 pru_unlock(so); 435 NET_UNLOCK_SHARED(); 436 } else 437 NET_UNLOCK(); 438 break; 439 default: 440 rw_exit_write(&so->so_lock); 441 break; 442 } 443 } 444 445 void 446 soassertlocked(struct socket *so) 447 { 448 switch (so->so_proto->pr_domain->dom_family) { 449 case PF_INET: 450 case PF_INET6: 451 NET_ASSERT_LOCKED(); 452 break; 453 default: 454 rw_assert_wrlock(&so->so_lock); 455 break; 456 } 457 } 458 459 int 460 sosleep_nsec(struct socket *so, void *ident, int prio, const char *wmesg, 461 uint64_t nsecs) 462 { 463 int ret; 464 465 switch (so->so_proto->pr_domain->dom_family) { 466 case PF_INET: 467 case PF_INET6: 468 if (so->so_proto->pr_usrreqs->pru_unlock != NULL && 469 rw_status(&netlock) == RW_READ) { 470 pru_unlock(so); 471 } 472 ret = rwsleep_nsec(ident, &netlock, prio, wmesg, nsecs); 473 if (so->so_proto->pr_usrreqs->pru_lock != NULL && 474 rw_status(&netlock) == RW_READ) { 475 pru_lock(so); 476 } 477 break; 478 default: 479 ret = rwsleep_nsec(ident, &so->so_lock, prio, wmesg, nsecs); 480 break; 481 } 482 483 return ret; 484 } 485 486 /* 487 * Wait for data to arrive at/drain from a socket buffer. 488 */ 489 int 490 sbwait(struct socket *so, struct sockbuf *sb) 491 { 492 int prio = (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH; 493 494 soassertlocked(so); 495 496 sb->sb_flags |= SB_WAIT; 497 return sosleep_nsec(so, &sb->sb_cc, prio, "netio", sb->sb_timeo_nsecs); 498 } 499 500 int 501 sblock(struct socket *so, struct sockbuf *sb, int wait) 502 { 503 int error, prio = (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH; 504 505 soassertlocked(so); 506 507 if ((sb->sb_flags & SB_LOCK) == 0) { 508 sb->sb_flags |= SB_LOCK; 509 return (0); 510 } 511 if (wait & M_NOWAIT) 512 return (EWOULDBLOCK); 513 514 while (sb->sb_flags & SB_LOCK) { 515 sb->sb_flags |= SB_WANT; 516 error = sosleep_nsec(so, &sb->sb_flags, prio, "netlck", INFSLP); 517 if (error) 518 return (error); 519 } 520 sb->sb_flags |= SB_LOCK; 521 return (0); 522 } 523 524 void 525 sbunlock(struct socket *so, struct sockbuf *sb) 526 { 527 soassertlocked(so); 528 529 sb->sb_flags &= ~SB_LOCK; 530 if (sb->sb_flags & SB_WANT) { 531 sb->sb_flags &= ~SB_WANT; 532 wakeup(&sb->sb_flags); 533 } 534 } 535 536 /* 537 * Wakeup processes waiting on a socket buffer. 538 * Do asynchronous notification via SIGIO 539 * if the socket buffer has the SB_ASYNC flag set. 540 */ 541 void 542 sowakeup(struct socket *so, struct sockbuf *sb) 543 { 544 soassertlocked(so); 545 546 if (sb->sb_flags & SB_WAIT) { 547 sb->sb_flags &= ~SB_WAIT; 548 wakeup(&sb->sb_cc); 549 } 550 if (sb->sb_flags & SB_ASYNC) 551 pgsigio(&so->so_sigio, SIGIO, 0); 552 KNOTE(&sb->sb_sel.si_note, 0); 553 } 554 555 /* 556 * Socket buffer (struct sockbuf) utility routines. 557 * 558 * Each socket contains two socket buffers: one for sending data and 559 * one for receiving data. Each buffer contains a queue of mbufs, 560 * information about the number of mbufs and amount of data in the 561 * queue, and other fields allowing select() statements and notification 562 * on data availability to be implemented. 563 * 564 * Data stored in a socket buffer is maintained as a list of records. 565 * Each record is a list of mbufs chained together with the m_next 566 * field. Records are chained together with the m_nextpkt field. The upper 567 * level routine soreceive() expects the following conventions to be 568 * observed when placing information in the receive buffer: 569 * 570 * 1. If the protocol requires each message be preceded by the sender's 571 * name, then a record containing that name must be present before 572 * any associated data (mbuf's must be of type MT_SONAME). 573 * 2. If the protocol supports the exchange of ``access rights'' (really 574 * just additional data associated with the message), and there are 575 * ``rights'' to be received, then a record containing this data 576 * should be present (mbuf's must be of type MT_CONTROL). 577 * 3. If a name or rights record exists, then it must be followed by 578 * a data record, perhaps of zero length. 579 * 580 * Before using a new socket structure it is first necessary to reserve 581 * buffer space to the socket, by calling sbreserve(). This should commit 582 * some of the available buffer space in the system buffer pool for the 583 * socket (currently, it does nothing but enforce limits). The space 584 * should be released by calling sbrelease() when the socket is destroyed. 585 */ 586 587 int 588 soreserve(struct socket *so, u_long sndcc, u_long rcvcc) 589 { 590 soassertlocked(so); 591 592 if (sbreserve(so, &so->so_snd, sndcc)) 593 goto bad; 594 if (sbreserve(so, &so->so_rcv, rcvcc)) 595 goto bad2; 596 so->so_snd.sb_wat = sndcc; 597 so->so_rcv.sb_wat = rcvcc; 598 if (so->so_rcv.sb_lowat == 0) 599 so->so_rcv.sb_lowat = 1; 600 if (so->so_snd.sb_lowat == 0) 601 so->so_snd.sb_lowat = MCLBYTES; 602 if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat) 603 so->so_snd.sb_lowat = so->so_snd.sb_hiwat; 604 return (0); 605 bad2: 606 sbrelease(so, &so->so_snd); 607 bad: 608 return (ENOBUFS); 609 } 610 611 /* 612 * Allot mbufs to a sockbuf. 613 * Attempt to scale mbmax so that mbcnt doesn't become limiting 614 * if buffering efficiency is near the normal case. 615 */ 616 int 617 sbreserve(struct socket *so, struct sockbuf *sb, u_long cc) 618 { 619 KASSERT(sb == &so->so_rcv || sb == &so->so_snd); 620 soassertlocked(so); 621 622 if (cc == 0 || cc > sb_max) 623 return (1); 624 sb->sb_hiwat = cc; 625 sb->sb_mbmax = max(3 * MAXMCLBYTES, cc * 8); 626 if (sb->sb_lowat > sb->sb_hiwat) 627 sb->sb_lowat = sb->sb_hiwat; 628 return (0); 629 } 630 631 /* 632 * In low memory situation, do not accept any greater than normal request. 633 */ 634 int 635 sbcheckreserve(u_long cnt, u_long defcnt) 636 { 637 if (cnt > defcnt && sbchecklowmem()) 638 return (ENOBUFS); 639 return (0); 640 } 641 642 int 643 sbchecklowmem(void) 644 { 645 static int sblowmem; 646 unsigned int used = m_pool_used(); 647 648 if (used < 60) 649 sblowmem = 0; 650 else if (used > 80) 651 sblowmem = 1; 652 653 return (sblowmem); 654 } 655 656 /* 657 * Free mbufs held by a socket, and reserved mbuf space. 658 */ 659 void 660 sbrelease(struct socket *so, struct sockbuf *sb) 661 { 662 663 sbflush(so, sb); 664 sb->sb_hiwat = sb->sb_mbmax = 0; 665 } 666 667 /* 668 * Routines to add and remove 669 * data from an mbuf queue. 670 * 671 * The routines sbappend() or sbappendrecord() are normally called to 672 * append new mbufs to a socket buffer, after checking that adequate 673 * space is available, comparing the function sbspace() with the amount 674 * of data to be added. sbappendrecord() differs from sbappend() in 675 * that data supplied is treated as the beginning of a new record. 676 * To place a sender's address, optional access rights, and data in a 677 * socket receive buffer, sbappendaddr() should be used. To place 678 * access rights and data in a socket receive buffer, sbappendrights() 679 * should be used. In either case, the new data begins a new record. 680 * Note that unlike sbappend() and sbappendrecord(), these routines check 681 * for the caller that there will be enough space to store the data. 682 * Each fails if there is not enough space, or if it cannot find mbufs 683 * to store additional information in. 684 * 685 * Reliable protocols may use the socket send buffer to hold data 686 * awaiting acknowledgement. Data is normally copied from a socket 687 * send buffer in a protocol with m_copym for output to a peer, 688 * and then removing the data from the socket buffer with sbdrop() 689 * or sbdroprecord() when the data is acknowledged by the peer. 690 */ 691 692 #ifdef SOCKBUF_DEBUG 693 void 694 sblastrecordchk(struct sockbuf *sb, const char *where) 695 { 696 struct mbuf *m = sb->sb_mb; 697 698 while (m && m->m_nextpkt) 699 m = m->m_nextpkt; 700 701 if (m != sb->sb_lastrecord) { 702 printf("sblastrecordchk: sb_mb %p sb_lastrecord %p last %p\n", 703 sb->sb_mb, sb->sb_lastrecord, m); 704 printf("packet chain:\n"); 705 for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) 706 printf("\t%p\n", m); 707 panic("sblastrecordchk from %s", where); 708 } 709 } 710 711 void 712 sblastmbufchk(struct sockbuf *sb, const char *where) 713 { 714 struct mbuf *m = sb->sb_mb; 715 struct mbuf *n; 716 717 while (m && m->m_nextpkt) 718 m = m->m_nextpkt; 719 720 while (m && m->m_next) 721 m = m->m_next; 722 723 if (m != sb->sb_mbtail) { 724 printf("sblastmbufchk: sb_mb %p sb_mbtail %p last %p\n", 725 sb->sb_mb, sb->sb_mbtail, m); 726 printf("packet tree:\n"); 727 for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) { 728 printf("\t"); 729 for (n = m; n != NULL; n = n->m_next) 730 printf("%p ", n); 731 printf("\n"); 732 } 733 panic("sblastmbufchk from %s", where); 734 } 735 } 736 #endif /* SOCKBUF_DEBUG */ 737 738 #define SBLINKRECORD(sb, m0) \ 739 do { \ 740 if ((sb)->sb_lastrecord != NULL) \ 741 (sb)->sb_lastrecord->m_nextpkt = (m0); \ 742 else \ 743 (sb)->sb_mb = (m0); \ 744 (sb)->sb_lastrecord = (m0); \ 745 } while (/*CONSTCOND*/0) 746 747 /* 748 * Append mbuf chain m to the last record in the 749 * socket buffer sb. The additional space associated 750 * the mbuf chain is recorded in sb. Empty mbufs are 751 * discarded and mbufs are compacted where possible. 752 */ 753 void 754 sbappend(struct socket *so, struct sockbuf *sb, struct mbuf *m) 755 { 756 struct mbuf *n; 757 758 if (m == NULL) 759 return; 760 761 soassertlocked(so); 762 SBLASTRECORDCHK(sb, "sbappend 1"); 763 764 if ((n = sb->sb_lastrecord) != NULL) { 765 /* 766 * XXX Would like to simply use sb_mbtail here, but 767 * XXX I need to verify that I won't miss an EOR that 768 * XXX way. 769 */ 770 do { 771 if (n->m_flags & M_EOR) { 772 sbappendrecord(so, sb, m); /* XXXXXX!!!! */ 773 return; 774 } 775 } while (n->m_next && (n = n->m_next)); 776 } else { 777 /* 778 * If this is the first record in the socket buffer, it's 779 * also the last record. 780 */ 781 sb->sb_lastrecord = m; 782 } 783 sbcompress(so, sb, m, n); 784 SBLASTRECORDCHK(sb, "sbappend 2"); 785 } 786 787 /* 788 * This version of sbappend() should only be used when the caller 789 * absolutely knows that there will never be more than one record 790 * in the socket buffer, that is, a stream protocol (such as TCP). 791 */ 792 void 793 sbappendstream(struct socket *so, struct sockbuf *sb, struct mbuf *m) 794 { 795 KASSERT(sb == &so->so_rcv || sb == &so->so_snd); 796 soassertlocked(so); 797 KDASSERT(m->m_nextpkt == NULL); 798 KASSERT(sb->sb_mb == sb->sb_lastrecord); 799 800 SBLASTMBUFCHK(sb, __func__); 801 802 sbcompress(so, sb, m, sb->sb_mbtail); 803 804 sb->sb_lastrecord = sb->sb_mb; 805 SBLASTRECORDCHK(sb, __func__); 806 } 807 808 #ifdef SOCKBUF_DEBUG 809 void 810 sbcheck(struct socket *so, struct sockbuf *sb) 811 { 812 struct mbuf *m, *n; 813 u_long len = 0, mbcnt = 0; 814 815 for (m = sb->sb_mb; m; m = m->m_nextpkt) { 816 for (n = m; n; n = n->m_next) { 817 len += n->m_len; 818 mbcnt += MSIZE; 819 if (n->m_flags & M_EXT) 820 mbcnt += n->m_ext.ext_size; 821 if (m != n && n->m_nextpkt) 822 panic("sbcheck nextpkt"); 823 } 824 } 825 if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) { 826 printf("cc %lu != %lu || mbcnt %lu != %lu\n", len, sb->sb_cc, 827 mbcnt, sb->sb_mbcnt); 828 panic("sbcheck"); 829 } 830 } 831 #endif 832 833 /* 834 * As above, except the mbuf chain 835 * begins a new record. 836 */ 837 void 838 sbappendrecord(struct socket *so, struct sockbuf *sb, struct mbuf *m0) 839 { 840 struct mbuf *m; 841 842 KASSERT(sb == &so->so_rcv || sb == &so->so_snd); 843 soassertlocked(so); 844 845 if (m0 == NULL) 846 return; 847 848 /* 849 * Put the first mbuf on the queue. 850 * Note this permits zero length records. 851 */ 852 sballoc(so, sb, m0); 853 SBLASTRECORDCHK(sb, "sbappendrecord 1"); 854 SBLINKRECORD(sb, m0); 855 m = m0->m_next; 856 m0->m_next = NULL; 857 if (m && (m0->m_flags & M_EOR)) { 858 m0->m_flags &= ~M_EOR; 859 m->m_flags |= M_EOR; 860 } 861 sbcompress(so, sb, m, m0); 862 SBLASTRECORDCHK(sb, "sbappendrecord 2"); 863 } 864 865 /* 866 * Append address and data, and optionally, control (ancillary) data 867 * to the receive queue of a socket. If present, 868 * m0 must include a packet header with total length. 869 * Returns 0 if no space in sockbuf or insufficient mbufs. 870 */ 871 int 872 sbappendaddr(struct socket *so, struct sockbuf *sb, const struct sockaddr *asa, 873 struct mbuf *m0, struct mbuf *control) 874 { 875 struct mbuf *m, *n, *nlast; 876 int space = asa->sa_len; 877 878 soassertlocked(so); 879 880 if (m0 && (m0->m_flags & M_PKTHDR) == 0) 881 panic("sbappendaddr"); 882 if (m0) 883 space += m0->m_pkthdr.len; 884 for (n = control; n; n = n->m_next) { 885 space += n->m_len; 886 if (n->m_next == NULL) /* keep pointer to last control buf */ 887 break; 888 } 889 if (space > sbspace(so, sb)) 890 return (0); 891 if (asa->sa_len > MLEN) 892 return (0); 893 MGET(m, M_DONTWAIT, MT_SONAME); 894 if (m == NULL) 895 return (0); 896 m->m_len = asa->sa_len; 897 memcpy(mtod(m, caddr_t), asa, asa->sa_len); 898 if (n) 899 n->m_next = m0; /* concatenate data to control */ 900 else 901 control = m0; 902 m->m_next = control; 903 904 SBLASTRECORDCHK(sb, "sbappendaddr 1"); 905 906 for (n = m; n->m_next != NULL; n = n->m_next) 907 sballoc(so, sb, n); 908 sballoc(so, sb, n); 909 nlast = n; 910 SBLINKRECORD(sb, m); 911 912 sb->sb_mbtail = nlast; 913 SBLASTMBUFCHK(sb, "sbappendaddr"); 914 915 SBLASTRECORDCHK(sb, "sbappendaddr 2"); 916 917 return (1); 918 } 919 920 int 921 sbappendcontrol(struct socket *so, struct sockbuf *sb, struct mbuf *m0, 922 struct mbuf *control) 923 { 924 struct mbuf *m, *mlast, *n; 925 int space = 0; 926 927 if (control == NULL) 928 panic("sbappendcontrol"); 929 for (m = control; ; m = m->m_next) { 930 space += m->m_len; 931 if (m->m_next == NULL) 932 break; 933 } 934 n = m; /* save pointer to last control buffer */ 935 for (m = m0; m; m = m->m_next) 936 space += m->m_len; 937 if (space > sbspace(so, sb)) 938 return (0); 939 n->m_next = m0; /* concatenate data to control */ 940 941 SBLASTRECORDCHK(sb, "sbappendcontrol 1"); 942 943 for (m = control; m->m_next != NULL; m = m->m_next) 944 sballoc(so, sb, m); 945 sballoc(so, sb, m); 946 mlast = m; 947 SBLINKRECORD(sb, control); 948 949 sb->sb_mbtail = mlast; 950 SBLASTMBUFCHK(sb, "sbappendcontrol"); 951 952 SBLASTRECORDCHK(sb, "sbappendcontrol 2"); 953 954 return (1); 955 } 956 957 /* 958 * Compress mbuf chain m into the socket 959 * buffer sb following mbuf n. If n 960 * is null, the buffer is presumed empty. 961 */ 962 void 963 sbcompress(struct socket *so, struct sockbuf *sb, struct mbuf *m, 964 struct mbuf *n) 965 { 966 int eor = 0; 967 struct mbuf *o; 968 969 while (m) { 970 eor |= m->m_flags & M_EOR; 971 if (m->m_len == 0 && 972 (eor == 0 || 973 (((o = m->m_next) || (o = n)) && 974 o->m_type == m->m_type))) { 975 if (sb->sb_lastrecord == m) 976 sb->sb_lastrecord = m->m_next; 977 m = m_free(m); 978 continue; 979 } 980 if (n && (n->m_flags & M_EOR) == 0 && 981 /* m_trailingspace() checks buffer writeability */ 982 m->m_len <= ((n->m_flags & M_EXT)? n->m_ext.ext_size : 983 MCLBYTES) / 4 && /* XXX Don't copy too much */ 984 m->m_len <= m_trailingspace(n) && 985 n->m_type == m->m_type) { 986 memcpy(mtod(n, caddr_t) + n->m_len, mtod(m, caddr_t), 987 m->m_len); 988 n->m_len += m->m_len; 989 sb->sb_cc += m->m_len; 990 if (m->m_type != MT_CONTROL && m->m_type != MT_SONAME) 991 sb->sb_datacc += m->m_len; 992 m = m_free(m); 993 continue; 994 } 995 if (n) 996 n->m_next = m; 997 else 998 sb->sb_mb = m; 999 sb->sb_mbtail = m; 1000 sballoc(so, sb, m); 1001 n = m; 1002 m->m_flags &= ~M_EOR; 1003 m = m->m_next; 1004 n->m_next = NULL; 1005 } 1006 if (eor) { 1007 if (n) 1008 n->m_flags |= eor; 1009 else 1010 printf("semi-panic: sbcompress"); 1011 } 1012 SBLASTMBUFCHK(sb, __func__); 1013 } 1014 1015 /* 1016 * Free all mbufs in a sockbuf. 1017 * Check that all resources are reclaimed. 1018 */ 1019 void 1020 sbflush(struct socket *so, struct sockbuf *sb) 1021 { 1022 KASSERT(sb == &so->so_rcv || sb == &so->so_snd); 1023 KASSERT((sb->sb_flags & SB_LOCK) == 0); 1024 1025 while (sb->sb_mbcnt) 1026 sbdrop(so, sb, (int)sb->sb_cc); 1027 1028 KASSERT(sb->sb_cc == 0); 1029 KASSERT(sb->sb_datacc == 0); 1030 KASSERT(sb->sb_mb == NULL); 1031 KASSERT(sb->sb_mbtail == NULL); 1032 KASSERT(sb->sb_lastrecord == NULL); 1033 } 1034 1035 /* 1036 * Drop data from (the front of) a sockbuf. 1037 */ 1038 void 1039 sbdrop(struct socket *so, struct sockbuf *sb, int len) 1040 { 1041 struct mbuf *m, *mn; 1042 struct mbuf *next; 1043 1044 KASSERT(sb == &so->so_rcv || sb == &so->so_snd); 1045 soassertlocked(so); 1046 1047 next = (m = sb->sb_mb) ? m->m_nextpkt : NULL; 1048 while (len > 0) { 1049 if (m == NULL) { 1050 if (next == NULL) 1051 panic("sbdrop"); 1052 m = next; 1053 next = m->m_nextpkt; 1054 continue; 1055 } 1056 if (m->m_len > len) { 1057 m->m_len -= len; 1058 m->m_data += len; 1059 sb->sb_cc -= len; 1060 if (m->m_type != MT_CONTROL && m->m_type != MT_SONAME) 1061 sb->sb_datacc -= len; 1062 break; 1063 } 1064 len -= m->m_len; 1065 sbfree(so, sb, m); 1066 mn = m_free(m); 1067 m = mn; 1068 } 1069 while (m && m->m_len == 0) { 1070 sbfree(so, sb, m); 1071 mn = m_free(m); 1072 m = mn; 1073 } 1074 if (m) { 1075 sb->sb_mb = m; 1076 m->m_nextpkt = next; 1077 } else 1078 sb->sb_mb = next; 1079 /* 1080 * First part is an inline SB_EMPTY_FIXUP(). Second part 1081 * makes sure sb_lastrecord is up-to-date if we dropped 1082 * part of the last record. 1083 */ 1084 m = sb->sb_mb; 1085 if (m == NULL) { 1086 sb->sb_mbtail = NULL; 1087 sb->sb_lastrecord = NULL; 1088 } else if (m->m_nextpkt == NULL) 1089 sb->sb_lastrecord = m; 1090 } 1091 1092 /* 1093 * Drop a record off the front of a sockbuf 1094 * and move the next record to the front. 1095 */ 1096 void 1097 sbdroprecord(struct socket *so, struct sockbuf *sb) 1098 { 1099 struct mbuf *m, *mn; 1100 1101 m = sb->sb_mb; 1102 if (m) { 1103 sb->sb_mb = m->m_nextpkt; 1104 do { 1105 sbfree(so, sb, m); 1106 mn = m_free(m); 1107 } while ((m = mn) != NULL); 1108 } 1109 SB_EMPTY_FIXUP(sb); 1110 } 1111 1112 /* 1113 * Create a "control" mbuf containing the specified data 1114 * with the specified type for presentation on a socket buffer. 1115 */ 1116 struct mbuf * 1117 sbcreatecontrol(const void *p, size_t size, int type, int level) 1118 { 1119 struct cmsghdr *cp; 1120 struct mbuf *m; 1121 1122 if (CMSG_SPACE(size) > MCLBYTES) { 1123 printf("sbcreatecontrol: message too large %zu\n", size); 1124 return (NULL); 1125 } 1126 1127 if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL) 1128 return (NULL); 1129 if (CMSG_SPACE(size) > MLEN) { 1130 MCLGET(m, M_DONTWAIT); 1131 if ((m->m_flags & M_EXT) == 0) { 1132 m_free(m); 1133 return NULL; 1134 } 1135 } 1136 cp = mtod(m, struct cmsghdr *); 1137 memset(cp, 0, CMSG_SPACE(size)); 1138 memcpy(CMSG_DATA(cp), p, size); 1139 m->m_len = CMSG_SPACE(size); 1140 cp->cmsg_len = CMSG_LEN(size); 1141 cp->cmsg_level = level; 1142 cp->cmsg_type = type; 1143 return (m); 1144 } 1145