1 /* $NetBSD: uipc_socket2.c,v 1.110 2011/12/20 23:56:28 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 /* 30 * Copyright (c) 1982, 1986, 1988, 1990, 1993 31 * The Regents of the University of California. All rights reserved. 32 * 33 * Redistribution and use in source and binary forms, with or without 34 * modification, are permitted provided that the following conditions 35 * are met: 36 * 1. Redistributions of source code must retain the above copyright 37 * notice, this list of conditions and the following disclaimer. 38 * 2. Redistributions in binary form must reproduce the above copyright 39 * notice, this list of conditions and the following disclaimer in the 40 * documentation and/or other materials provided with the distribution. 41 * 3. Neither the name of the University nor the names of its contributors 42 * may be used to endorse or promote products derived from this software 43 * without specific prior written permission. 44 * 45 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 46 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 47 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 48 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 49 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 50 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 51 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 52 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 53 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 54 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 55 * SUCH DAMAGE. 56 * 57 * @(#)uipc_socket2.c 8.2 (Berkeley) 2/14/95 58 */ 59 60 #include <sys/cdefs.h> 61 __KERNEL_RCSID(0, "$NetBSD: uipc_socket2.c,v 1.110 2011/12/20 23:56:28 christos Exp $"); 62 63 #include "opt_mbuftrace.h" 64 #include "opt_sb_max.h" 65 66 #include <sys/param.h> 67 #include <sys/systm.h> 68 #include <sys/proc.h> 69 #include <sys/file.h> 70 #include <sys/buf.h> 71 #include <sys/mbuf.h> 72 #include <sys/protosw.h> 73 #include <sys/domain.h> 74 #include <sys/poll.h> 75 #include <sys/socket.h> 76 #include <sys/socketvar.h> 77 #include <sys/signalvar.h> 78 #include <sys/kauth.h> 79 #include <sys/pool.h> 80 #include <sys/uidinfo.h> 81 82 /* 83 * Primitive routines for operating on sockets and socket buffers. 84 * 85 * Locking rules and assumptions: 86 * 87 * o socket::so_lock can change on the fly. The low level routines used 88 * to lock sockets are aware of this. When so_lock is acquired, the 89 * routine locking must check to see if so_lock still points to the 90 * lock that was acquired. If so_lock has changed in the meantime, the 91 * now irellevant lock that was acquired must be dropped and the lock 92 * operation retried. Although not proven here, this is completely safe 93 * on a multiprocessor system, even with relaxed memory ordering, given 94 * the next two rules: 95 * 96 * o In order to mutate so_lock, the lock pointed to by the current value 97 * of so_lock must be held: i.e., the socket must be held locked by the 98 * changing thread. The thread must issue membar_exit() to prevent 99 * memory accesses being reordered, and can set so_lock to the desired 100 * value. If the lock pointed to by the new value of so_lock is not 101 * held by the changing thread, the socket must then be considered 102 * unlocked. 103 * 104 * o If so_lock is mutated, and the previous lock referred to by so_lock 105 * could still be visible to other threads in the system (e.g. via file 106 * descriptor or protocol-internal reference), then the old lock must 107 * remain valid until the socket and/or protocol control block has been 108 * torn down. 109 * 110 * o If a socket has a non-NULL so_head value (i.e. is in the process of 111 * connecting), then locking the socket must also lock the socket pointed 112 * to by so_head: their lock pointers must match. 113 * 114 * o If a socket has connections in progress (so_q, so_q0 not empty) then 115 * locking the socket must also lock the sockets attached to both queues. 116 * Again, their lock pointers must match. 117 * 118 * o Beyond the initial lock assigment in socreate(), assigning locks to 119 * sockets is the responsibility of the individual protocols / protocol 120 * domains. 121 */ 122 123 static pool_cache_t socket_cache; 124 125 u_long sb_max = SB_MAX; /* maximum socket buffer size */ 126 static u_long sb_max_adj; /* adjusted sb_max */ 127 128 /* 129 * Procedures to manipulate state flags of socket 130 * and do appropriate wakeups. Normal sequence from the 131 * active (originating) side is that soisconnecting() is 132 * called during processing of connect() call, 133 * resulting in an eventual call to soisconnected() if/when the 134 * connection is established. When the connection is torn down 135 * soisdisconnecting() is called during processing of disconnect() call, 136 * and soisdisconnected() is called when the connection to the peer 137 * is totally severed. The semantics of these routines are such that 138 * connectionless protocols can call soisconnected() and soisdisconnected() 139 * only, bypassing the in-progress calls when setting up a ``connection'' 140 * takes no time. 141 * 142 * From the passive side, a socket is created with 143 * two queues of sockets: so_q0 for connections in progress 144 * and so_q for connections already made and awaiting user acceptance. 145 * As a protocol is preparing incoming connections, it creates a socket 146 * structure queued on so_q0 by calling sonewconn(). When the connection 147 * is established, soisconnected() is called, and transfers the 148 * socket structure to so_q, making it available to accept(). 149 * 150 * If a socket is closed with sockets on either 151 * so_q0 or so_q, these sockets are dropped. 152 * 153 * If higher level protocols are implemented in 154 * the kernel, the wakeups done here will sometimes 155 * cause software-interrupt process scheduling. 156 */ 157 158 void 159 soisconnecting(struct socket *so) 160 { 161 162 KASSERT(solocked(so)); 163 164 so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING); 165 so->so_state |= SS_ISCONNECTING; 166 } 167 168 void 169 soisconnected(struct socket *so) 170 { 171 struct socket *head; 172 173 head = so->so_head; 174 175 KASSERT(solocked(so)); 176 KASSERT(head == NULL || solocked2(so, head)); 177 178 so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING); 179 so->so_state |= SS_ISCONNECTED; 180 if (head && so->so_onq == &head->so_q0) { 181 if ((so->so_options & SO_ACCEPTFILTER) == 0) { 182 soqremque(so, 0); 183 soqinsque(head, so, 1); 184 sorwakeup(head); 185 cv_broadcast(&head->so_cv); 186 } else { 187 so->so_upcall = 188 head->so_accf->so_accept_filter->accf_callback; 189 so->so_upcallarg = head->so_accf->so_accept_filter_arg; 190 so->so_rcv.sb_flags |= SB_UPCALL; 191 so->so_options &= ~SO_ACCEPTFILTER; 192 (*so->so_upcall)(so, so->so_upcallarg, 193 POLLIN|POLLRDNORM, M_DONTWAIT); 194 } 195 } else { 196 cv_broadcast(&so->so_cv); 197 sorwakeup(so); 198 sowwakeup(so); 199 } 200 } 201 202 void 203 soisdisconnecting(struct socket *so) 204 { 205 206 KASSERT(solocked(so)); 207 208 so->so_state &= ~SS_ISCONNECTING; 209 so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE); 210 cv_broadcast(&so->so_cv); 211 sowwakeup(so); 212 sorwakeup(so); 213 } 214 215 void 216 soisdisconnected(struct socket *so) 217 { 218 219 KASSERT(solocked(so)); 220 221 so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING); 222 so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED); 223 cv_broadcast(&so->so_cv); 224 sowwakeup(so); 225 sorwakeup(so); 226 } 227 228 void 229 soinit2(void) 230 { 231 232 socket_cache = pool_cache_init(sizeof(struct socket), 0, 0, 0, 233 "socket", NULL, IPL_SOFTNET, NULL, NULL, NULL); 234 } 235 236 /* 237 * When an attempt at a new connection is noted on a socket 238 * which accepts connections, sonewconn is called. If the 239 * connection is possible (subject to space constraints, etc.) 240 * then we allocate a new structure, propoerly linked into the 241 * data structure of the original socket, and return this. 242 * Connstatus may be 0, SS_ISCONFIRMING, or SS_ISCONNECTED. 243 */ 244 struct socket * 245 sonewconn(struct socket *head, int connstatus) 246 { 247 struct socket *so; 248 int soqueue, error; 249 250 KASSERT(connstatus == 0 || connstatus == SS_ISCONFIRMING || 251 connstatus == SS_ISCONNECTED); 252 KASSERT(solocked(head)); 253 254 if ((head->so_options & SO_ACCEPTFILTER) != 0) 255 connstatus = 0; 256 soqueue = connstatus ? 1 : 0; 257 if (head->so_qlen + head->so_q0len > 3 * head->so_qlimit / 2) 258 return NULL; 259 so = soget(false); 260 if (so == NULL) 261 return NULL; 262 mutex_obj_hold(head->so_lock); 263 so->so_lock = head->so_lock; 264 so->so_type = head->so_type; 265 so->so_options = head->so_options &~ SO_ACCEPTCONN; 266 so->so_linger = head->so_linger; 267 so->so_state = head->so_state | SS_NOFDREF; 268 so->so_proto = head->so_proto; 269 so->so_timeo = head->so_timeo; 270 so->so_pgid = head->so_pgid; 271 so->so_send = head->so_send; 272 so->so_receive = head->so_receive; 273 so->so_uidinfo = head->so_uidinfo; 274 so->so_cpid = head->so_cpid; 275 #ifdef MBUFTRACE 276 so->so_mowner = head->so_mowner; 277 so->so_rcv.sb_mowner = head->so_rcv.sb_mowner; 278 so->so_snd.sb_mowner = head->so_snd.sb_mowner; 279 #endif 280 if (soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat) != 0) 281 goto out; 282 so->so_snd.sb_lowat = head->so_snd.sb_lowat; 283 so->so_rcv.sb_lowat = head->so_rcv.sb_lowat; 284 so->so_rcv.sb_timeo = head->so_rcv.sb_timeo; 285 so->so_snd.sb_timeo = head->so_snd.sb_timeo; 286 so->so_rcv.sb_flags |= head->so_rcv.sb_flags & (SB_AUTOSIZE | SB_ASYNC); 287 so->so_snd.sb_flags |= head->so_snd.sb_flags & (SB_AUTOSIZE | SB_ASYNC); 288 soqinsque(head, so, soqueue); 289 error = (*so->so_proto->pr_usrreq)(so, PRU_ATTACH, NULL, NULL, 290 NULL, NULL); 291 KASSERT(solocked(so)); 292 if (error != 0) { 293 (void) soqremque(so, soqueue); 294 out: 295 /* 296 * Remove acccept filter if one is present. 297 * XXX Is this really needed? 298 */ 299 if (so->so_accf != NULL) 300 (void)accept_filt_clear(so); 301 soput(so); 302 return NULL; 303 } 304 if (connstatus) { 305 sorwakeup(head); 306 cv_broadcast(&head->so_cv); 307 so->so_state |= connstatus; 308 } 309 return so; 310 } 311 312 struct socket * 313 soget(bool waitok) 314 { 315 struct socket *so; 316 317 so = pool_cache_get(socket_cache, (waitok ? PR_WAITOK : PR_NOWAIT)); 318 if (__predict_false(so == NULL)) 319 return (NULL); 320 memset(so, 0, sizeof(*so)); 321 TAILQ_INIT(&so->so_q0); 322 TAILQ_INIT(&so->so_q); 323 cv_init(&so->so_cv, "socket"); 324 cv_init(&so->so_rcv.sb_cv, "netio"); 325 cv_init(&so->so_snd.sb_cv, "netio"); 326 selinit(&so->so_rcv.sb_sel); 327 selinit(&so->so_snd.sb_sel); 328 so->so_rcv.sb_so = so; 329 so->so_snd.sb_so = so; 330 return so; 331 } 332 333 void 334 soput(struct socket *so) 335 { 336 337 KASSERT(!cv_has_waiters(&so->so_cv)); 338 KASSERT(!cv_has_waiters(&so->so_rcv.sb_cv)); 339 KASSERT(!cv_has_waiters(&so->so_snd.sb_cv)); 340 seldestroy(&so->so_rcv.sb_sel); 341 seldestroy(&so->so_snd.sb_sel); 342 mutex_obj_free(so->so_lock); 343 cv_destroy(&so->so_cv); 344 cv_destroy(&so->so_rcv.sb_cv); 345 cv_destroy(&so->so_snd.sb_cv); 346 pool_cache_put(socket_cache, so); 347 } 348 349 void 350 soqinsque(struct socket *head, struct socket *so, int q) 351 { 352 353 KASSERT(solocked2(head, so)); 354 355 #ifdef DIAGNOSTIC 356 if (so->so_onq != NULL) 357 panic("soqinsque"); 358 #endif 359 360 so->so_head = head; 361 if (q == 0) { 362 head->so_q0len++; 363 so->so_onq = &head->so_q0; 364 } else { 365 head->so_qlen++; 366 so->so_onq = &head->so_q; 367 } 368 TAILQ_INSERT_TAIL(so->so_onq, so, so_qe); 369 } 370 371 int 372 soqremque(struct socket *so, int q) 373 { 374 struct socket *head; 375 376 head = so->so_head; 377 378 KASSERT(solocked(so)); 379 if (q == 0) { 380 if (so->so_onq != &head->so_q0) 381 return (0); 382 head->so_q0len--; 383 } else { 384 if (so->so_onq != &head->so_q) 385 return (0); 386 head->so_qlen--; 387 } 388 KASSERT(solocked2(so, head)); 389 TAILQ_REMOVE(so->so_onq, so, so_qe); 390 so->so_onq = NULL; 391 so->so_head = NULL; 392 return (1); 393 } 394 395 /* 396 * Socantsendmore indicates that no more data will be sent on the 397 * socket; it would normally be applied to a socket when the user 398 * informs the system that no more data is to be sent, by the protocol 399 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data 400 * will be received, and will normally be applied to the socket by a 401 * protocol when it detects that the peer will send no more data. 402 * Data queued for reading in the socket may yet be read. 403 */ 404 405 void 406 socantsendmore(struct socket *so) 407 { 408 409 KASSERT(solocked(so)); 410 411 so->so_state |= SS_CANTSENDMORE; 412 sowwakeup(so); 413 } 414 415 void 416 socantrcvmore(struct socket *so) 417 { 418 419 KASSERT(solocked(so)); 420 421 so->so_state |= SS_CANTRCVMORE; 422 sorwakeup(so); 423 } 424 425 /* 426 * Wait for data to arrive at/drain from a socket buffer. 427 */ 428 int 429 sbwait(struct sockbuf *sb) 430 { 431 struct socket *so; 432 kmutex_t *lock; 433 int error; 434 435 so = sb->sb_so; 436 437 KASSERT(solocked(so)); 438 439 sb->sb_flags |= SB_NOTIFY; 440 lock = so->so_lock; 441 if ((sb->sb_flags & SB_NOINTR) != 0) 442 error = cv_timedwait(&sb->sb_cv, lock, sb->sb_timeo); 443 else 444 error = cv_timedwait_sig(&sb->sb_cv, lock, sb->sb_timeo); 445 if (__predict_false(lock != so->so_lock)) 446 solockretry(so, lock); 447 return error; 448 } 449 450 /* 451 * Wakeup processes waiting on a socket buffer. 452 * Do asynchronous notification via SIGIO 453 * if the socket buffer has the SB_ASYNC flag set. 454 */ 455 void 456 sowakeup(struct socket *so, struct sockbuf *sb, int code) 457 { 458 int band; 459 460 KASSERT(solocked(so)); 461 KASSERT(sb->sb_so == so); 462 463 if (code == POLL_IN) 464 band = POLLIN|POLLRDNORM; 465 else 466 band = POLLOUT|POLLWRNORM; 467 sb->sb_flags &= ~SB_NOTIFY; 468 selnotify(&sb->sb_sel, band, NOTE_SUBMIT); 469 cv_broadcast(&sb->sb_cv); 470 if (sb->sb_flags & SB_ASYNC) 471 fownsignal(so->so_pgid, SIGIO, code, band, so); 472 if (sb->sb_flags & SB_UPCALL) 473 (*so->so_upcall)(so, so->so_upcallarg, band, M_DONTWAIT); 474 } 475 476 /* 477 * Reset a socket's lock pointer. Wake all threads waiting on the 478 * socket's condition variables so that they can restart their waits 479 * using the new lock. The existing lock must be held. 480 */ 481 void 482 solockreset(struct socket *so, kmutex_t *lock) 483 { 484 485 KASSERT(solocked(so)); 486 487 so->so_lock = lock; 488 cv_broadcast(&so->so_snd.sb_cv); 489 cv_broadcast(&so->so_rcv.sb_cv); 490 cv_broadcast(&so->so_cv); 491 } 492 493 /* 494 * Socket buffer (struct sockbuf) utility routines. 495 * 496 * Each socket contains two socket buffers: one for sending data and 497 * one for receiving data. Each buffer contains a queue of mbufs, 498 * information about the number of mbufs and amount of data in the 499 * queue, and other fields allowing poll() statements and notification 500 * on data availability to be implemented. 501 * 502 * Data stored in a socket buffer is maintained as a list of records. 503 * Each record is a list of mbufs chained together with the m_next 504 * field. Records are chained together with the m_nextpkt field. The upper 505 * level routine soreceive() expects the following conventions to be 506 * observed when placing information in the receive buffer: 507 * 508 * 1. If the protocol requires each message be preceded by the sender's 509 * name, then a record containing that name must be present before 510 * any associated data (mbuf's must be of type MT_SONAME). 511 * 2. If the protocol supports the exchange of ``access rights'' (really 512 * just additional data associated with the message), and there are 513 * ``rights'' to be received, then a record containing this data 514 * should be present (mbuf's must be of type MT_CONTROL). 515 * 3. If a name or rights record exists, then it must be followed by 516 * a data record, perhaps of zero length. 517 * 518 * Before using a new socket structure it is first necessary to reserve 519 * buffer space to the socket, by calling sbreserve(). This should commit 520 * some of the available buffer space in the system buffer pool for the 521 * socket (currently, it does nothing but enforce limits). The space 522 * should be released by calling sbrelease() when the socket is destroyed. 523 */ 524 525 int 526 sb_max_set(u_long new_sbmax) 527 { 528 int s; 529 530 if (new_sbmax < (16 * 1024)) 531 return (EINVAL); 532 533 s = splsoftnet(); 534 sb_max = new_sbmax; 535 sb_max_adj = (u_quad_t)new_sbmax * MCLBYTES / (MSIZE + MCLBYTES); 536 splx(s); 537 538 return (0); 539 } 540 541 int 542 soreserve(struct socket *so, u_long sndcc, u_long rcvcc) 543 { 544 545 KASSERT(so->so_lock == NULL || solocked(so)); 546 547 /* 548 * there's at least one application (a configure script of screen) 549 * which expects a fifo is writable even if it has "some" bytes 550 * in its buffer. 551 * so we want to make sure (hiwat - lowat) >= (some bytes). 552 * 553 * PIPE_BUF here is an arbitrary value chosen as (some bytes) above. 554 * we expect it's large enough for such applications. 555 */ 556 u_long lowat = MAX(sock_loan_thresh, MCLBYTES); 557 u_long hiwat = lowat + PIPE_BUF; 558 559 if (sndcc < hiwat) 560 sndcc = hiwat; 561 if (sbreserve(&so->so_snd, sndcc, so) == 0) 562 goto bad; 563 if (sbreserve(&so->so_rcv, rcvcc, so) == 0) 564 goto bad2; 565 if (so->so_rcv.sb_lowat == 0) 566 so->so_rcv.sb_lowat = 1; 567 if (so->so_snd.sb_lowat == 0) 568 so->so_snd.sb_lowat = lowat; 569 if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat) 570 so->so_snd.sb_lowat = so->so_snd.sb_hiwat; 571 return (0); 572 bad2: 573 sbrelease(&so->so_snd, so); 574 bad: 575 return (ENOBUFS); 576 } 577 578 /* 579 * Allot mbufs to a sockbuf. 580 * Attempt to scale mbmax so that mbcnt doesn't become limiting 581 * if buffering efficiency is near the normal case. 582 */ 583 int 584 sbreserve(struct sockbuf *sb, u_long cc, struct socket *so) 585 { 586 struct lwp *l = curlwp; /* XXX */ 587 rlim_t maxcc; 588 struct uidinfo *uidinfo; 589 590 KASSERT(so->so_lock == NULL || solocked(so)); 591 KASSERT(sb->sb_so == so); 592 KASSERT(sb_max_adj != 0); 593 594 if (cc == 0 || cc > sb_max_adj) 595 return (0); 596 597 maxcc = l->l_proc->p_rlimit[RLIMIT_SBSIZE].rlim_cur; 598 599 uidinfo = so->so_uidinfo; 600 if (!chgsbsize(uidinfo, &sb->sb_hiwat, cc, maxcc)) 601 return 0; 602 sb->sb_mbmax = min(cc * 2, sb_max); 603 if (sb->sb_lowat > sb->sb_hiwat) 604 sb->sb_lowat = sb->sb_hiwat; 605 return (1); 606 } 607 608 /* 609 * Free mbufs held by a socket, and reserved mbuf space. We do not assert 610 * that the socket is held locked here: see sorflush(). 611 */ 612 void 613 sbrelease(struct sockbuf *sb, struct socket *so) 614 { 615 616 KASSERT(sb->sb_so == so); 617 618 sbflush(sb); 619 (void)chgsbsize(so->so_uidinfo, &sb->sb_hiwat, 0, RLIM_INFINITY); 620 sb->sb_mbmax = 0; 621 } 622 623 /* 624 * Routines to add and remove 625 * data from an mbuf queue. 626 * 627 * The routines sbappend() or sbappendrecord() are normally called to 628 * append new mbufs to a socket buffer, after checking that adequate 629 * space is available, comparing the function sbspace() with the amount 630 * of data to be added. sbappendrecord() differs from sbappend() in 631 * that data supplied is treated as the beginning of a new record. 632 * To place a sender's address, optional access rights, and data in a 633 * socket receive buffer, sbappendaddr() should be used. To place 634 * access rights and data in a socket receive buffer, sbappendrights() 635 * should be used. In either case, the new data begins a new record. 636 * Note that unlike sbappend() and sbappendrecord(), these routines check 637 * for the caller that there will be enough space to store the data. 638 * Each fails if there is not enough space, or if it cannot find mbufs 639 * to store additional information in. 640 * 641 * Reliable protocols may use the socket send buffer to hold data 642 * awaiting acknowledgement. Data is normally copied from a socket 643 * send buffer in a protocol with m_copy for output to a peer, 644 * and then removing the data from the socket buffer with sbdrop() 645 * or sbdroprecord() when the data is acknowledged by the peer. 646 */ 647 648 #ifdef SOCKBUF_DEBUG 649 void 650 sblastrecordchk(struct sockbuf *sb, const char *where) 651 { 652 struct mbuf *m = sb->sb_mb; 653 654 KASSERT(solocked(sb->sb_so)); 655 656 while (m && m->m_nextpkt) 657 m = m->m_nextpkt; 658 659 if (m != sb->sb_lastrecord) { 660 printf("sblastrecordchk: sb_mb %p sb_lastrecord %p last %p\n", 661 sb->sb_mb, sb->sb_lastrecord, m); 662 printf("packet chain:\n"); 663 for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) 664 printf("\t%p\n", m); 665 panic("sblastrecordchk from %s", where); 666 } 667 } 668 669 void 670 sblastmbufchk(struct sockbuf *sb, const char *where) 671 { 672 struct mbuf *m = sb->sb_mb; 673 struct mbuf *n; 674 675 KASSERT(solocked(sb->sb_so)); 676 677 while (m && m->m_nextpkt) 678 m = m->m_nextpkt; 679 680 while (m && m->m_next) 681 m = m->m_next; 682 683 if (m != sb->sb_mbtail) { 684 printf("sblastmbufchk: sb_mb %p sb_mbtail %p last %p\n", 685 sb->sb_mb, sb->sb_mbtail, m); 686 printf("packet tree:\n"); 687 for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) { 688 printf("\t"); 689 for (n = m; n != NULL; n = n->m_next) 690 printf("%p ", n); 691 printf("\n"); 692 } 693 panic("sblastmbufchk from %s", where); 694 } 695 } 696 #endif /* SOCKBUF_DEBUG */ 697 698 /* 699 * Link a chain of records onto a socket buffer 700 */ 701 #define SBLINKRECORDCHAIN(sb, m0, mlast) \ 702 do { \ 703 if ((sb)->sb_lastrecord != NULL) \ 704 (sb)->sb_lastrecord->m_nextpkt = (m0); \ 705 else \ 706 (sb)->sb_mb = (m0); \ 707 (sb)->sb_lastrecord = (mlast); \ 708 } while (/*CONSTCOND*/0) 709 710 711 #define SBLINKRECORD(sb, m0) \ 712 SBLINKRECORDCHAIN(sb, m0, m0) 713 714 /* 715 * Append mbuf chain m to the last record in the 716 * socket buffer sb. The additional space associated 717 * the mbuf chain is recorded in sb. Empty mbufs are 718 * discarded and mbufs are compacted where possible. 719 */ 720 void 721 sbappend(struct sockbuf *sb, struct mbuf *m) 722 { 723 struct mbuf *n; 724 725 KASSERT(solocked(sb->sb_so)); 726 727 if (m == 0) 728 return; 729 730 #ifdef MBUFTRACE 731 m_claimm(m, sb->sb_mowner); 732 #endif 733 734 SBLASTRECORDCHK(sb, "sbappend 1"); 735 736 if ((n = sb->sb_lastrecord) != NULL) { 737 /* 738 * XXX Would like to simply use sb_mbtail here, but 739 * XXX I need to verify that I won't miss an EOR that 740 * XXX way. 741 */ 742 do { 743 if (n->m_flags & M_EOR) { 744 sbappendrecord(sb, m); /* XXXXXX!!!! */ 745 return; 746 } 747 } while (n->m_next && (n = n->m_next)); 748 } else { 749 /* 750 * If this is the first record in the socket buffer, it's 751 * also the last record. 752 */ 753 sb->sb_lastrecord = m; 754 } 755 sbcompress(sb, m, n); 756 SBLASTRECORDCHK(sb, "sbappend 2"); 757 } 758 759 /* 760 * This version of sbappend() should only be used when the caller 761 * absolutely knows that there will never be more than one record 762 * in the socket buffer, that is, a stream protocol (such as TCP). 763 */ 764 void 765 sbappendstream(struct sockbuf *sb, struct mbuf *m) 766 { 767 768 KASSERT(solocked(sb->sb_so)); 769 KDASSERT(m->m_nextpkt == NULL); 770 KASSERT(sb->sb_mb == sb->sb_lastrecord); 771 772 SBLASTMBUFCHK(sb, __func__); 773 774 #ifdef MBUFTRACE 775 m_claimm(m, sb->sb_mowner); 776 #endif 777 778 sbcompress(sb, m, sb->sb_mbtail); 779 780 sb->sb_lastrecord = sb->sb_mb; 781 SBLASTRECORDCHK(sb, __func__); 782 } 783 784 #ifdef SOCKBUF_DEBUG 785 void 786 sbcheck(struct sockbuf *sb) 787 { 788 struct mbuf *m, *m2; 789 u_long len, mbcnt; 790 791 KASSERT(solocked(sb->sb_so)); 792 793 len = 0; 794 mbcnt = 0; 795 for (m = sb->sb_mb; m; m = m->m_nextpkt) { 796 for (m2 = m; m2 != NULL; m2 = m2->m_next) { 797 len += m2->m_len; 798 mbcnt += MSIZE; 799 if (m2->m_flags & M_EXT) 800 mbcnt += m2->m_ext.ext_size; 801 if (m2->m_nextpkt != NULL) 802 panic("sbcheck nextpkt"); 803 } 804 } 805 if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) { 806 printf("cc %lu != %lu || mbcnt %lu != %lu\n", len, sb->sb_cc, 807 mbcnt, sb->sb_mbcnt); 808 panic("sbcheck"); 809 } 810 } 811 #endif 812 813 /* 814 * As above, except the mbuf chain 815 * begins a new record. 816 */ 817 void 818 sbappendrecord(struct sockbuf *sb, struct mbuf *m0) 819 { 820 struct mbuf *m; 821 822 KASSERT(solocked(sb->sb_so)); 823 824 if (m0 == 0) 825 return; 826 827 #ifdef MBUFTRACE 828 m_claimm(m0, sb->sb_mowner); 829 #endif 830 /* 831 * Put the first mbuf on the queue. 832 * Note this permits zero length records. 833 */ 834 sballoc(sb, m0); 835 SBLASTRECORDCHK(sb, "sbappendrecord 1"); 836 SBLINKRECORD(sb, m0); 837 m = m0->m_next; 838 m0->m_next = 0; 839 if (m && (m0->m_flags & M_EOR)) { 840 m0->m_flags &= ~M_EOR; 841 m->m_flags |= M_EOR; 842 } 843 sbcompress(sb, m, m0); 844 SBLASTRECORDCHK(sb, "sbappendrecord 2"); 845 } 846 847 /* 848 * As above except that OOB data 849 * is inserted at the beginning of the sockbuf, 850 * but after any other OOB data. 851 */ 852 void 853 sbinsertoob(struct sockbuf *sb, struct mbuf *m0) 854 { 855 struct mbuf *m, **mp; 856 857 KASSERT(solocked(sb->sb_so)); 858 859 if (m0 == 0) 860 return; 861 862 SBLASTRECORDCHK(sb, "sbinsertoob 1"); 863 864 for (mp = &sb->sb_mb; (m = *mp) != NULL; mp = &((*mp)->m_nextpkt)) { 865 again: 866 switch (m->m_type) { 867 868 case MT_OOBDATA: 869 continue; /* WANT next train */ 870 871 case MT_CONTROL: 872 if ((m = m->m_next) != NULL) 873 goto again; /* inspect THIS train further */ 874 } 875 break; 876 } 877 /* 878 * Put the first mbuf on the queue. 879 * Note this permits zero length records. 880 */ 881 sballoc(sb, m0); 882 m0->m_nextpkt = *mp; 883 if (*mp == NULL) { 884 /* m0 is actually the new tail */ 885 sb->sb_lastrecord = m0; 886 } 887 *mp = m0; 888 m = m0->m_next; 889 m0->m_next = 0; 890 if (m && (m0->m_flags & M_EOR)) { 891 m0->m_flags &= ~M_EOR; 892 m->m_flags |= M_EOR; 893 } 894 sbcompress(sb, m, m0); 895 SBLASTRECORDCHK(sb, "sbinsertoob 2"); 896 } 897 898 /* 899 * Append address and data, and optionally, control (ancillary) data 900 * to the receive queue of a socket. If present, 901 * m0 must include a packet header with total length. 902 * Returns 0 if no space in sockbuf or insufficient mbufs. 903 */ 904 int 905 sbappendaddr(struct sockbuf *sb, const struct sockaddr *asa, struct mbuf *m0, 906 struct mbuf *control) 907 { 908 struct mbuf *m, *n, *nlast; 909 int space, len; 910 911 KASSERT(solocked(sb->sb_so)); 912 913 space = asa->sa_len; 914 915 if (m0 != NULL) { 916 if ((m0->m_flags & M_PKTHDR) == 0) 917 panic("sbappendaddr"); 918 space += m0->m_pkthdr.len; 919 #ifdef MBUFTRACE 920 m_claimm(m0, sb->sb_mowner); 921 #endif 922 } 923 for (n = control; n; n = n->m_next) { 924 space += n->m_len; 925 MCLAIM(n, sb->sb_mowner); 926 if (n->m_next == 0) /* keep pointer to last control buf */ 927 break; 928 } 929 if (space > sbspace(sb)) 930 return (0); 931 MGET(m, M_DONTWAIT, MT_SONAME); 932 if (m == 0) 933 return (0); 934 MCLAIM(m, sb->sb_mowner); 935 /* 936 * XXX avoid 'comparison always true' warning which isn't easily 937 * avoided. 938 */ 939 len = asa->sa_len; 940 if (len > MLEN) { 941 MEXTMALLOC(m, asa->sa_len, M_NOWAIT); 942 if ((m->m_flags & M_EXT) == 0) { 943 m_free(m); 944 return (0); 945 } 946 } 947 m->m_len = asa->sa_len; 948 memcpy(mtod(m, void *), asa, asa->sa_len); 949 if (n) 950 n->m_next = m0; /* concatenate data to control */ 951 else 952 control = m0; 953 m->m_next = control; 954 955 SBLASTRECORDCHK(sb, "sbappendaddr 1"); 956 957 for (n = m; n->m_next != NULL; n = n->m_next) 958 sballoc(sb, n); 959 sballoc(sb, n); 960 nlast = n; 961 SBLINKRECORD(sb, m); 962 963 sb->sb_mbtail = nlast; 964 SBLASTMBUFCHK(sb, "sbappendaddr"); 965 SBLASTRECORDCHK(sb, "sbappendaddr 2"); 966 967 return (1); 968 } 969 970 /* 971 * Helper for sbappendchainaddr: prepend a struct sockaddr* to 972 * an mbuf chain. 973 */ 974 static inline struct mbuf * 975 m_prepend_sockaddr(struct sockbuf *sb, struct mbuf *m0, 976 const struct sockaddr *asa) 977 { 978 struct mbuf *m; 979 const int salen = asa->sa_len; 980 981 KASSERT(solocked(sb->sb_so)); 982 983 /* only the first in each chain need be a pkthdr */ 984 MGETHDR(m, M_DONTWAIT, MT_SONAME); 985 if (m == 0) 986 return (0); 987 MCLAIM(m, sb->sb_mowner); 988 #ifdef notyet 989 if (salen > MHLEN) { 990 MEXTMALLOC(m, salen, M_NOWAIT); 991 if ((m->m_flags & M_EXT) == 0) { 992 m_free(m); 993 return (0); 994 } 995 } 996 #else 997 KASSERT(salen <= MHLEN); 998 #endif 999 m->m_len = salen; 1000 memcpy(mtod(m, void *), asa, salen); 1001 m->m_next = m0; 1002 m->m_pkthdr.len = salen + m0->m_pkthdr.len; 1003 1004 return m; 1005 } 1006 1007 int 1008 sbappendaddrchain(struct sockbuf *sb, const struct sockaddr *asa, 1009 struct mbuf *m0, int sbprio) 1010 { 1011 int space; 1012 struct mbuf *m, *n, *n0, *nlast; 1013 int error; 1014 1015 KASSERT(solocked(sb->sb_so)); 1016 1017 /* 1018 * XXX sbprio reserved for encoding priority of this* request: 1019 * SB_PRIO_NONE --> honour normal sb limits 1020 * SB_PRIO_ONESHOT_OVERFLOW --> if socket has any space, 1021 * take whole chain. Intended for large requests 1022 * that should be delivered atomically (all, or none). 1023 * SB_PRIO_OVERDRAFT -- allow a small (2*MLEN) overflow 1024 * over normal socket limits, for messages indicating 1025 * buffer overflow in earlier normal/lower-priority messages 1026 * SB_PRIO_BESTEFFORT --> ignore limits entirely. 1027 * Intended for kernel-generated messages only. 1028 * Up to generator to avoid total mbuf resource exhaustion. 1029 */ 1030 (void)sbprio; 1031 1032 if (m0 && (m0->m_flags & M_PKTHDR) == 0) 1033 panic("sbappendaddrchain"); 1034 1035 space = sbspace(sb); 1036 1037 #ifdef notyet 1038 /* 1039 * Enforce SB_PRIO_* limits as described above. 1040 */ 1041 #endif 1042 1043 n0 = NULL; 1044 nlast = NULL; 1045 for (m = m0; m; m = m->m_nextpkt) { 1046 struct mbuf *np; 1047 1048 #ifdef MBUFTRACE 1049 m_claimm(m, sb->sb_mowner); 1050 #endif 1051 1052 /* Prepend sockaddr to this record (m) of input chain m0 */ 1053 n = m_prepend_sockaddr(sb, m, asa); 1054 if (n == NULL) { 1055 error = ENOBUFS; 1056 goto bad; 1057 } 1058 1059 /* Append record (asa+m) to end of new chain n0 */ 1060 if (n0 == NULL) { 1061 n0 = n; 1062 } else { 1063 nlast->m_nextpkt = n; 1064 } 1065 /* Keep track of last record on new chain */ 1066 nlast = n; 1067 1068 for (np = n; np; np = np->m_next) 1069 sballoc(sb, np); 1070 } 1071 1072 SBLASTRECORDCHK(sb, "sbappendaddrchain 1"); 1073 1074 /* Drop the entire chain of (asa+m) records onto the socket */ 1075 SBLINKRECORDCHAIN(sb, n0, nlast); 1076 1077 SBLASTRECORDCHK(sb, "sbappendaddrchain 2"); 1078 1079 for (m = nlast; m->m_next; m = m->m_next) 1080 ; 1081 sb->sb_mbtail = m; 1082 SBLASTMBUFCHK(sb, "sbappendaddrchain"); 1083 1084 return (1); 1085 1086 bad: 1087 /* 1088 * On error, free the prepended addreseses. For consistency 1089 * with sbappendaddr(), leave it to our caller to free 1090 * the input record chain passed to us as m0. 1091 */ 1092 while ((n = n0) != NULL) { 1093 struct mbuf *np; 1094 1095 /* Undo the sballoc() of this record */ 1096 for (np = n; np; np = np->m_next) 1097 sbfree(sb, np); 1098 1099 n0 = n->m_nextpkt; /* iterate at next prepended address */ 1100 MFREE(n, np); /* free prepended address (not data) */ 1101 } 1102 return 0; 1103 } 1104 1105 1106 int 1107 sbappendcontrol(struct sockbuf *sb, struct mbuf *m0, struct mbuf *control) 1108 { 1109 struct mbuf *m, *mlast, *n; 1110 int space; 1111 1112 KASSERT(solocked(sb->sb_so)); 1113 1114 space = 0; 1115 if (control == 0) 1116 panic("sbappendcontrol"); 1117 for (m = control; ; m = m->m_next) { 1118 space += m->m_len; 1119 MCLAIM(m, sb->sb_mowner); 1120 if (m->m_next == 0) 1121 break; 1122 } 1123 n = m; /* save pointer to last control buffer */ 1124 for (m = m0; m; m = m->m_next) { 1125 MCLAIM(m, sb->sb_mowner); 1126 space += m->m_len; 1127 } 1128 if (space > sbspace(sb)) 1129 return (0); 1130 n->m_next = m0; /* concatenate data to control */ 1131 1132 SBLASTRECORDCHK(sb, "sbappendcontrol 1"); 1133 1134 for (m = control; m->m_next != NULL; m = m->m_next) 1135 sballoc(sb, m); 1136 sballoc(sb, m); 1137 mlast = m; 1138 SBLINKRECORD(sb, control); 1139 1140 sb->sb_mbtail = mlast; 1141 SBLASTMBUFCHK(sb, "sbappendcontrol"); 1142 SBLASTRECORDCHK(sb, "sbappendcontrol 2"); 1143 1144 return (1); 1145 } 1146 1147 /* 1148 * Compress mbuf chain m into the socket 1149 * buffer sb following mbuf n. If n 1150 * is null, the buffer is presumed empty. 1151 */ 1152 void 1153 sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n) 1154 { 1155 int eor; 1156 struct mbuf *o; 1157 1158 KASSERT(solocked(sb->sb_so)); 1159 1160 eor = 0; 1161 while (m) { 1162 eor |= m->m_flags & M_EOR; 1163 if (m->m_len == 0 && 1164 (eor == 0 || 1165 (((o = m->m_next) || (o = n)) && 1166 o->m_type == m->m_type))) { 1167 if (sb->sb_lastrecord == m) 1168 sb->sb_lastrecord = m->m_next; 1169 m = m_free(m); 1170 continue; 1171 } 1172 if (n && (n->m_flags & M_EOR) == 0 && 1173 /* M_TRAILINGSPACE() checks buffer writeability */ 1174 m->m_len <= MCLBYTES / 4 && /* XXX Don't copy too much */ 1175 m->m_len <= M_TRAILINGSPACE(n) && 1176 n->m_type == m->m_type) { 1177 memcpy(mtod(n, char *) + n->m_len, mtod(m, void *), 1178 (unsigned)m->m_len); 1179 n->m_len += m->m_len; 1180 sb->sb_cc += m->m_len; 1181 m = m_free(m); 1182 continue; 1183 } 1184 if (n) 1185 n->m_next = m; 1186 else 1187 sb->sb_mb = m; 1188 sb->sb_mbtail = m; 1189 sballoc(sb, m); 1190 n = m; 1191 m->m_flags &= ~M_EOR; 1192 m = m->m_next; 1193 n->m_next = 0; 1194 } 1195 if (eor) { 1196 if (n) 1197 n->m_flags |= eor; 1198 else 1199 printf("semi-panic: sbcompress\n"); 1200 } 1201 SBLASTMBUFCHK(sb, __func__); 1202 } 1203 1204 /* 1205 * Free all mbufs in a sockbuf. 1206 * Check that all resources are reclaimed. 1207 */ 1208 void 1209 sbflush(struct sockbuf *sb) 1210 { 1211 1212 KASSERT(solocked(sb->sb_so)); 1213 KASSERT((sb->sb_flags & SB_LOCK) == 0); 1214 1215 while (sb->sb_mbcnt) 1216 sbdrop(sb, (int)sb->sb_cc); 1217 1218 KASSERT(sb->sb_cc == 0); 1219 KASSERT(sb->sb_mb == NULL); 1220 KASSERT(sb->sb_mbtail == NULL); 1221 KASSERT(sb->sb_lastrecord == NULL); 1222 } 1223 1224 /* 1225 * Drop data from (the front of) a sockbuf. 1226 */ 1227 void 1228 sbdrop(struct sockbuf *sb, int len) 1229 { 1230 struct mbuf *m, *mn, *next; 1231 1232 KASSERT(solocked(sb->sb_so)); 1233 1234 next = (m = sb->sb_mb) ? m->m_nextpkt : 0; 1235 while (len > 0) { 1236 if (m == 0) { 1237 if (next == 0) 1238 panic("sbdrop"); 1239 m = next; 1240 next = m->m_nextpkt; 1241 continue; 1242 } 1243 if (m->m_len > len) { 1244 m->m_len -= len; 1245 m->m_data += len; 1246 sb->sb_cc -= len; 1247 break; 1248 } 1249 len -= m->m_len; 1250 sbfree(sb, m); 1251 MFREE(m, mn); 1252 m = mn; 1253 } 1254 while (m && m->m_len == 0) { 1255 sbfree(sb, m); 1256 MFREE(m, mn); 1257 m = mn; 1258 } 1259 if (m) { 1260 sb->sb_mb = m; 1261 m->m_nextpkt = next; 1262 } else 1263 sb->sb_mb = next; 1264 /* 1265 * First part is an inline SB_EMPTY_FIXUP(). Second part 1266 * makes sure sb_lastrecord is up-to-date if we dropped 1267 * part of the last record. 1268 */ 1269 m = sb->sb_mb; 1270 if (m == NULL) { 1271 sb->sb_mbtail = NULL; 1272 sb->sb_lastrecord = NULL; 1273 } else if (m->m_nextpkt == NULL) 1274 sb->sb_lastrecord = m; 1275 } 1276 1277 /* 1278 * Drop a record off the front of a sockbuf 1279 * and move the next record to the front. 1280 */ 1281 void 1282 sbdroprecord(struct sockbuf *sb) 1283 { 1284 struct mbuf *m, *mn; 1285 1286 KASSERT(solocked(sb->sb_so)); 1287 1288 m = sb->sb_mb; 1289 if (m) { 1290 sb->sb_mb = m->m_nextpkt; 1291 do { 1292 sbfree(sb, m); 1293 MFREE(m, mn); 1294 } while ((m = mn) != NULL); 1295 } 1296 SB_EMPTY_FIXUP(sb); 1297 } 1298 1299 /* 1300 * Create a "control" mbuf containing the specified data 1301 * with the specified type for presentation on a socket buffer. 1302 */ 1303 struct mbuf * 1304 sbcreatecontrol(void *p, int size, int type, int level) 1305 { 1306 struct cmsghdr *cp; 1307 struct mbuf *m; 1308 1309 if (CMSG_SPACE(size) > MCLBYTES) { 1310 printf("sbcreatecontrol: message too large %d\n", size); 1311 return NULL; 1312 } 1313 1314 if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL) 1315 return (NULL); 1316 if (CMSG_SPACE(size) > MLEN) { 1317 MCLGET(m, M_DONTWAIT); 1318 if ((m->m_flags & M_EXT) == 0) { 1319 m_free(m); 1320 return NULL; 1321 } 1322 } 1323 cp = mtod(m, struct cmsghdr *); 1324 memcpy(CMSG_DATA(cp), p, size); 1325 m->m_len = CMSG_SPACE(size); 1326 cp->cmsg_len = CMSG_LEN(size); 1327 cp->cmsg_level = level; 1328 cp->cmsg_type = type; 1329 return (m); 1330 } 1331 1332 void 1333 solockretry(struct socket *so, kmutex_t *lock) 1334 { 1335 1336 while (lock != so->so_lock) { 1337 mutex_exit(lock); 1338 lock = so->so_lock; 1339 mutex_enter(lock); 1340 } 1341 } 1342 1343 bool 1344 solocked(struct socket *so) 1345 { 1346 1347 return mutex_owned(so->so_lock); 1348 } 1349 1350 bool 1351 solocked2(struct socket *so1, struct socket *so2) 1352 { 1353 kmutex_t *lock; 1354 1355 lock = so1->so_lock; 1356 if (lock != so2->so_lock) 1357 return false; 1358 return mutex_owned(lock); 1359 } 1360 1361 /* 1362 * Assign a default lock to a new socket. For PRU_ATTACH, and done by 1363 * protocols that do not have special locking requirements. 1364 */ 1365 void 1366 sosetlock(struct socket *so) 1367 { 1368 kmutex_t *lock; 1369 1370 if (so->so_lock == NULL) { 1371 lock = softnet_lock; 1372 so->so_lock = lock; 1373 mutex_obj_hold(lock); 1374 mutex_enter(lock); 1375 } 1376 1377 /* In all cases, lock must be held on return from PRU_ATTACH. */ 1378 KASSERT(solocked(so)); 1379 } 1380 1381 /* 1382 * Set lock on sockbuf sb; sleep if lock is already held. 1383 * Unless SB_NOINTR is set on sockbuf, sleep is interruptible. 1384 * Returns error without lock if sleep is interrupted. 1385 */ 1386 int 1387 sblock(struct sockbuf *sb, int wf) 1388 { 1389 struct socket *so; 1390 kmutex_t *lock; 1391 int error; 1392 1393 KASSERT(solocked(sb->sb_so)); 1394 1395 for (;;) { 1396 if (__predict_true((sb->sb_flags & SB_LOCK) == 0)) { 1397 sb->sb_flags |= SB_LOCK; 1398 return 0; 1399 } 1400 if (wf != M_WAITOK) 1401 return EWOULDBLOCK; 1402 so = sb->sb_so; 1403 lock = so->so_lock; 1404 if ((sb->sb_flags & SB_NOINTR) != 0) { 1405 cv_wait(&so->so_cv, lock); 1406 error = 0; 1407 } else 1408 error = cv_wait_sig(&so->so_cv, lock); 1409 if (__predict_false(lock != so->so_lock)) 1410 solockretry(so, lock); 1411 if (error != 0) 1412 return error; 1413 } 1414 } 1415 1416 void 1417 sbunlock(struct sockbuf *sb) 1418 { 1419 struct socket *so; 1420 1421 so = sb->sb_so; 1422 1423 KASSERT(solocked(so)); 1424 KASSERT((sb->sb_flags & SB_LOCK) != 0); 1425 1426 sb->sb_flags &= ~SB_LOCK; 1427 cv_broadcast(&so->so_cv); 1428 } 1429 1430 int 1431 sowait(struct socket *so, bool catch, int timo) 1432 { 1433 kmutex_t *lock; 1434 int error; 1435 1436 KASSERT(solocked(so)); 1437 KASSERT(catch || timo != 0); 1438 1439 lock = so->so_lock; 1440 if (catch) 1441 error = cv_timedwait_sig(&so->so_cv, lock, timo); 1442 else 1443 error = cv_timedwait(&so->so_cv, lock, timo); 1444 if (__predict_false(lock != so->so_lock)) 1445 solockretry(so, lock); 1446 return error; 1447 } 1448