Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/kern/uipc_sockbuf.c
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1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1988, 1990, 1993 5 * The Regents of the University of California. 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 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)uipc_socket2.c 8.1 (Berkeley) 6/10/93 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD: releng/12.0/sys/kern/uipc_sockbuf.c 337328 2018-08-04 20:26:54Z markj $"); 36 37 #include "opt_param.h" 38 39 #include <sys/param.h> 40 #include <sys/aio.h> /* for aio_swake proto */ 41 #include <sys/kernel.h> 42 #include <sys/lock.h> 43 #include <sys/malloc.h> 44 #include <sys/mbuf.h> 45 #include <sys/mutex.h> 46 #include <sys/proc.h> 47 #include <sys/protosw.h> 48 #include <sys/resourcevar.h> 49 #include <sys/signalvar.h> 50 #include <sys/socket.h> 51 #include <sys/socketvar.h> 52 #include <sys/sx.h> 53 #include <sys/sysctl.h> 54 55 /* 56 * Function pointer set by the AIO routines so that the socket buffer code 57 * can call back into the AIO module if it is loaded. 58 */ 59 void (*aio_swake)(struct socket *, struct sockbuf *); 60 61 /* 62 * Primitive routines for operating on socket buffers 63 */ 64 65 u_long sb_max = SB_MAX; 66 u_long sb_max_adj = 67 (quad_t)SB_MAX * MCLBYTES / (MSIZE + MCLBYTES); /* adjusted sb_max */ 68 69 static u_long sb_efficiency = 8; /* parameter for sbreserve() */ 70 71 static struct mbuf *sbcut_internal(struct sockbuf *sb, int len); 72 static void sbflush_internal(struct sockbuf *sb); 73 74 /* 75 * Our own version of m_clrprotoflags(), that can preserve M_NOTREADY. 76 */ 77 static void 78 sbm_clrprotoflags(struct mbuf *m, int flags) 79 { 80 int mask; 81 82 mask = ~M_PROTOFLAGS; 83 if (flags & PRUS_NOTREADY) 84 mask |= M_NOTREADY; 85 while (m) { 86 m->m_flags &= mask; 87 m = m->m_next; 88 } 89 } 90 91 /* 92 * Mark ready "count" mbufs starting with "m". 93 */ 94 int 95 sbready(struct sockbuf *sb, struct mbuf *m, int count) 96 { 97 u_int blocker; 98 99 SOCKBUF_LOCK_ASSERT(sb); 100 KASSERT(sb->sb_fnrdy != NULL, ("%s: sb %p NULL fnrdy", __func__, sb)); 101 102 blocker = (sb->sb_fnrdy == m) ? M_BLOCKED : 0; 103 104 for (int i = 0; i < count; i++, m = m->m_next) { 105 KASSERT(m->m_flags & M_NOTREADY, 106 ("%s: m %p !M_NOTREADY", __func__, m)); 107 m->m_flags &= ~(M_NOTREADY | blocker); 108 if (blocker) 109 sb->sb_acc += m->m_len; 110 } 111 112 if (!blocker) 113 return (EINPROGRESS); 114 115 /* This one was blocking all the queue. */ 116 for (; m && (m->m_flags & M_NOTREADY) == 0; m = m->m_next) { 117 KASSERT(m->m_flags & M_BLOCKED, 118 ("%s: m %p !M_BLOCKED", __func__, m)); 119 m->m_flags &= ~M_BLOCKED; 120 sb->sb_acc += m->m_len; 121 } 122 123 sb->sb_fnrdy = m; 124 125 return (0); 126 } 127 128 /* 129 * Adjust sockbuf state reflecting allocation of m. 130 */ 131 void 132 sballoc(struct sockbuf *sb, struct mbuf *m) 133 { 134 135 SOCKBUF_LOCK_ASSERT(sb); 136 137 sb->sb_ccc += m->m_len; 138 139 if (sb->sb_fnrdy == NULL) { 140 if (m->m_flags & M_NOTREADY) 141 sb->sb_fnrdy = m; 142 else 143 sb->sb_acc += m->m_len; 144 } else 145 m->m_flags |= M_BLOCKED; 146 147 if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA) 148 sb->sb_ctl += m->m_len; 149 150 sb->sb_mbcnt += MSIZE; 151 sb->sb_mcnt += 1; 152 153 if (m->m_flags & M_EXT) { 154 sb->sb_mbcnt += m->m_ext.ext_size; 155 sb->sb_ccnt += 1; 156 } 157 } 158 159 /* 160 * Adjust sockbuf state reflecting freeing of m. 161 */ 162 void 163 sbfree(struct sockbuf *sb, struct mbuf *m) 164 { 165 166 #if 0 /* XXX: not yet: soclose() call path comes here w/o lock. */ 167 SOCKBUF_LOCK_ASSERT(sb); 168 #endif 169 170 sb->sb_ccc -= m->m_len; 171 172 if (!(m->m_flags & M_NOTAVAIL)) 173 sb->sb_acc -= m->m_len; 174 175 if (m == sb->sb_fnrdy) { 176 struct mbuf *n; 177 178 KASSERT(m->m_flags & M_NOTREADY, 179 ("%s: m %p !M_NOTREADY", __func__, m)); 180 181 n = m->m_next; 182 while (n != NULL && !(n->m_flags & M_NOTREADY)) { 183 n->m_flags &= ~M_BLOCKED; 184 sb->sb_acc += n->m_len; 185 n = n->m_next; 186 } 187 sb->sb_fnrdy = n; 188 } 189 190 if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA) 191 sb->sb_ctl -= m->m_len; 192 193 sb->sb_mbcnt -= MSIZE; 194 sb->sb_mcnt -= 1; 195 if (m->m_flags & M_EXT) { 196 sb->sb_mbcnt -= m->m_ext.ext_size; 197 sb->sb_ccnt -= 1; 198 } 199 200 if (sb->sb_sndptr == m) { 201 sb->sb_sndptr = NULL; 202 sb->sb_sndptroff = 0; 203 } 204 if (sb->sb_sndptroff != 0) 205 sb->sb_sndptroff -= m->m_len; 206 } 207 208 /* 209 * Socantsendmore indicates that no more data will be sent on the socket; it 210 * would normally be applied to a socket when the user informs the system 211 * that no more data is to be sent, by the protocol code (in case 212 * PRU_SHUTDOWN). Socantrcvmore indicates that no more data will be 213 * received, and will normally be applied to the socket by a protocol when it 214 * detects that the peer will send no more data. Data queued for reading in 215 * the socket may yet be read. 216 */ 217 void 218 socantsendmore_locked(struct socket *so) 219 { 220 221 SOCKBUF_LOCK_ASSERT(&so->so_snd); 222 223 so->so_snd.sb_state |= SBS_CANTSENDMORE; 224 sowwakeup_locked(so); 225 mtx_assert(SOCKBUF_MTX(&so->so_snd), MA_NOTOWNED); 226 } 227 228 void 229 socantsendmore(struct socket *so) 230 { 231 232 SOCKBUF_LOCK(&so->so_snd); 233 socantsendmore_locked(so); 234 mtx_assert(SOCKBUF_MTX(&so->so_snd), MA_NOTOWNED); 235 } 236 237 void 238 socantrcvmore_locked(struct socket *so) 239 { 240 241 SOCKBUF_LOCK_ASSERT(&so->so_rcv); 242 243 so->so_rcv.sb_state |= SBS_CANTRCVMORE; 244 sorwakeup_locked(so); 245 mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED); 246 } 247 248 void 249 socantrcvmore(struct socket *so) 250 { 251 252 SOCKBUF_LOCK(&so->so_rcv); 253 socantrcvmore_locked(so); 254 mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED); 255 } 256 257 /* 258 * Wait for data to arrive at/drain from a socket buffer. 259 */ 260 int 261 sbwait(struct sockbuf *sb) 262 { 263 264 SOCKBUF_LOCK_ASSERT(sb); 265 266 sb->sb_flags |= SB_WAIT; 267 return (msleep_sbt(&sb->sb_acc, &sb->sb_mtx, 268 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, "sbwait", 269 sb->sb_timeo, 0, 0)); 270 } 271 272 int 273 sblock(struct sockbuf *sb, int flags) 274 { 275 276 KASSERT((flags & SBL_VALID) == flags, 277 ("sblock: flags invalid (0x%x)", flags)); 278 279 if (flags & SBL_WAIT) { 280 if ((sb->sb_flags & SB_NOINTR) || 281 (flags & SBL_NOINTR)) { 282 sx_xlock(&sb->sb_sx); 283 return (0); 284 } 285 return (sx_xlock_sig(&sb->sb_sx)); 286 } else { 287 if (sx_try_xlock(&sb->sb_sx) == 0) 288 return (EWOULDBLOCK); 289 return (0); 290 } 291 } 292 293 void 294 sbunlock(struct sockbuf *sb) 295 { 296 297 sx_xunlock(&sb->sb_sx); 298 } 299 300 /* 301 * Wakeup processes waiting on a socket buffer. Do asynchronous notification 302 * via SIGIO if the socket has the SS_ASYNC flag set. 303 * 304 * Called with the socket buffer lock held; will release the lock by the end 305 * of the function. This allows the caller to acquire the socket buffer lock 306 * while testing for the need for various sorts of wakeup and hold it through 307 * to the point where it's no longer required. We currently hold the lock 308 * through calls out to other subsystems (with the exception of kqueue), and 309 * then release it to avoid lock order issues. It's not clear that's 310 * correct. 311 */ 312 void 313 sowakeup(struct socket *so, struct sockbuf *sb) 314 { 315 int ret; 316 317 SOCKBUF_LOCK_ASSERT(sb); 318 319 selwakeuppri(sb->sb_sel, PSOCK); 320 if (!SEL_WAITING(sb->sb_sel)) 321 sb->sb_flags &= ~SB_SEL; 322 if (sb->sb_flags & SB_WAIT) { 323 sb->sb_flags &= ~SB_WAIT; 324 wakeup(&sb->sb_acc); 325 } 326 KNOTE_LOCKED(&sb->sb_sel->si_note, 0); 327 if (sb->sb_upcall != NULL) { 328 ret = sb->sb_upcall(so, sb->sb_upcallarg, M_NOWAIT); 329 if (ret == SU_ISCONNECTED) { 330 KASSERT(sb == &so->so_rcv, 331 ("SO_SND upcall returned SU_ISCONNECTED")); 332 soupcall_clear(so, SO_RCV); 333 } 334 } else 335 ret = SU_OK; 336 if (sb->sb_flags & SB_AIO) 337 sowakeup_aio(so, sb); 338 SOCKBUF_UNLOCK(sb); 339 if (ret == SU_ISCONNECTED) 340 soisconnected(so); 341 if ((so->so_state & SS_ASYNC) && so->so_sigio != NULL) 342 pgsigio(&so->so_sigio, SIGIO, 0); 343 mtx_assert(SOCKBUF_MTX(sb), MA_NOTOWNED); 344 } 345 346 /* 347 * Socket buffer (struct sockbuf) utility routines. 348 * 349 * Each socket contains two socket buffers: one for sending data and one for 350 * receiving data. Each buffer contains a queue of mbufs, information about 351 * the number of mbufs and amount of data in the queue, and other fields 352 * allowing select() statements and notification on data availability to be 353 * implemented. 354 * 355 * Data stored in a socket buffer is maintained as a list of records. Each 356 * record is a list of mbufs chained together with the m_next field. Records 357 * are chained together with the m_nextpkt field. The upper level routine 358 * soreceive() expects the following conventions to be observed when placing 359 * information in the receive buffer: 360 * 361 * 1. If the protocol requires each message be preceded by the sender's name, 362 * then a record containing that name must be present before any 363 * associated data (mbuf's must be of type MT_SONAME). 364 * 2. If the protocol supports the exchange of ``access rights'' (really just 365 * additional data associated with the message), and there are ``rights'' 366 * to be received, then a record containing this data should be present 367 * (mbuf's must be of type MT_RIGHTS). 368 * 3. If a name or rights record exists, then it must be followed by a data 369 * record, perhaps of zero length. 370 * 371 * Before using a new socket structure it is first necessary to reserve 372 * buffer space to the socket, by calling sbreserve(). This should commit 373 * some of the available buffer space in the system buffer pool for the 374 * socket (currently, it does nothing but enforce limits). The space should 375 * be released by calling sbrelease() when the socket is destroyed. 376 */ 377 int 378 soreserve(struct socket *so, u_long sndcc, u_long rcvcc) 379 { 380 struct thread *td = curthread; 381 382 SOCKBUF_LOCK(&so->so_snd); 383 SOCKBUF_LOCK(&so->so_rcv); 384 if (sbreserve_locked(&so->so_snd, sndcc, so, td) == 0) 385 goto bad; 386 if (sbreserve_locked(&so->so_rcv, rcvcc, so, td) == 0) 387 goto bad2; 388 if (so->so_rcv.sb_lowat == 0) 389 so->so_rcv.sb_lowat = 1; 390 if (so->so_snd.sb_lowat == 0) 391 so->so_snd.sb_lowat = MCLBYTES; 392 if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat) 393 so->so_snd.sb_lowat = so->so_snd.sb_hiwat; 394 SOCKBUF_UNLOCK(&so->so_rcv); 395 SOCKBUF_UNLOCK(&so->so_snd); 396 return (0); 397 bad2: 398 sbrelease_locked(&so->so_snd, so); 399 bad: 400 SOCKBUF_UNLOCK(&so->so_rcv); 401 SOCKBUF_UNLOCK(&so->so_snd); 402 return (ENOBUFS); 403 } 404 405 static int 406 sysctl_handle_sb_max(SYSCTL_HANDLER_ARGS) 407 { 408 int error = 0; 409 u_long tmp_sb_max = sb_max; 410 411 error = sysctl_handle_long(oidp, &tmp_sb_max, arg2, req); 412 if (error || !req->newptr) 413 return (error); 414 if (tmp_sb_max < MSIZE + MCLBYTES) 415 return (EINVAL); 416 sb_max = tmp_sb_max; 417 sb_max_adj = (u_quad_t)sb_max * MCLBYTES / (MSIZE + MCLBYTES); 418 return (0); 419 } 420 421 /* 422 * Allot mbufs to a sockbuf. Attempt to scale mbmax so that mbcnt doesn't 423 * become limiting if buffering efficiency is near the normal case. 424 */ 425 int 426 sbreserve_locked(struct sockbuf *sb, u_long cc, struct socket *so, 427 struct thread *td) 428 { 429 rlim_t sbsize_limit; 430 431 SOCKBUF_LOCK_ASSERT(sb); 432 433 /* 434 * When a thread is passed, we take into account the thread's socket 435 * buffer size limit. The caller will generally pass curthread, but 436 * in the TCP input path, NULL will be passed to indicate that no 437 * appropriate thread resource limits are available. In that case, 438 * we don't apply a process limit. 439 */ 440 if (cc > sb_max_adj) 441 return (0); 442 if (td != NULL) { 443 sbsize_limit = lim_cur(td, RLIMIT_SBSIZE); 444 } else 445 sbsize_limit = RLIM_INFINITY; 446 if (!chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, cc, 447 sbsize_limit)) 448 return (0); 449 sb->sb_mbmax = min(cc * sb_efficiency, sb_max); 450 if (sb->sb_lowat > sb->sb_hiwat) 451 sb->sb_lowat = sb->sb_hiwat; 452 return (1); 453 } 454 455 int 456 sbsetopt(struct socket *so, int cmd, u_long cc) 457 { 458 struct sockbuf *sb; 459 short *flags; 460 u_int *hiwat, *lowat; 461 int error; 462 463 sb = NULL; 464 SOCK_LOCK(so); 465 if (SOLISTENING(so)) { 466 switch (cmd) { 467 case SO_SNDLOWAT: 468 case SO_SNDBUF: 469 lowat = &so->sol_sbsnd_lowat; 470 hiwat = &so->sol_sbsnd_hiwat; 471 flags = &so->sol_sbsnd_flags; 472 break; 473 case SO_RCVLOWAT: 474 case SO_RCVBUF: 475 lowat = &so->sol_sbrcv_lowat; 476 hiwat = &so->sol_sbrcv_hiwat; 477 flags = &so->sol_sbrcv_flags; 478 break; 479 } 480 } else { 481 switch (cmd) { 482 case SO_SNDLOWAT: 483 case SO_SNDBUF: 484 sb = &so->so_snd; 485 break; 486 case SO_RCVLOWAT: 487 case SO_RCVBUF: 488 sb = &so->so_rcv; 489 break; 490 } 491 flags = &sb->sb_flags; 492 hiwat = &sb->sb_hiwat; 493 lowat = &sb->sb_lowat; 494 SOCKBUF_LOCK(sb); 495 } 496 497 error = 0; 498 switch (cmd) { 499 case SO_SNDBUF: 500 case SO_RCVBUF: 501 if (SOLISTENING(so)) { 502 if (cc > sb_max_adj) { 503 error = ENOBUFS; 504 break; 505 } 506 *hiwat = cc; 507 if (*lowat > *hiwat) 508 *lowat = *hiwat; 509 } else { 510 if (!sbreserve_locked(sb, cc, so, curthread)) 511 error = ENOBUFS; 512 } 513 if (error == 0) 514 *flags &= ~SB_AUTOSIZE; 515 break; 516 case SO_SNDLOWAT: 517 case SO_RCVLOWAT: 518 /* 519 * Make sure the low-water is never greater than the 520 * high-water. 521 */ 522 *lowat = (cc > *hiwat) ? *hiwat : cc; 523 break; 524 } 525 526 if (!SOLISTENING(so)) 527 SOCKBUF_UNLOCK(sb); 528 SOCK_UNLOCK(so); 529 return (error); 530 } 531 532 /* 533 * Free mbufs held by a socket, and reserved mbuf space. 534 */ 535 void 536 sbrelease_internal(struct sockbuf *sb, struct socket *so) 537 { 538 539 sbflush_internal(sb); 540 (void)chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, 0, 541 RLIM_INFINITY); 542 sb->sb_mbmax = 0; 543 } 544 545 void 546 sbrelease_locked(struct sockbuf *sb, struct socket *so) 547 { 548 549 SOCKBUF_LOCK_ASSERT(sb); 550 551 sbrelease_internal(sb, so); 552 } 553 554 void 555 sbrelease(struct sockbuf *sb, struct socket *so) 556 { 557 558 SOCKBUF_LOCK(sb); 559 sbrelease_locked(sb, so); 560 SOCKBUF_UNLOCK(sb); 561 } 562 563 void 564 sbdestroy(struct sockbuf *sb, struct socket *so) 565 { 566 567 sbrelease_internal(sb, so); 568 } 569 570 /* 571 * Routines to add and remove data from an mbuf queue. 572 * 573 * The routines sbappend() or sbappendrecord() are normally called to append 574 * new mbufs to a socket buffer, after checking that adequate space is 575 * available, comparing the function sbspace() with the amount of data to be 576 * added. sbappendrecord() differs from sbappend() in that data supplied is 577 * treated as the beginning of a new record. To place a sender's address, 578 * optional access rights, and data in a socket receive buffer, 579 * sbappendaddr() should be used. To place access rights and data in a 580 * socket receive buffer, sbappendrights() should be used. In either case, 581 * the new data begins a new record. Note that unlike sbappend() and 582 * sbappendrecord(), these routines check for the caller that there will be 583 * enough space to store the data. Each fails if there is not enough space, 584 * or if it cannot find mbufs to store additional information in. 585 * 586 * Reliable protocols may use the socket send buffer to hold data awaiting 587 * acknowledgement. Data is normally copied from a socket send buffer in a 588 * protocol with m_copy for output to a peer, and then removing the data from 589 * the socket buffer with sbdrop() or sbdroprecord() when the data is 590 * acknowledged by the peer. 591 */ 592 #ifdef SOCKBUF_DEBUG 593 void 594 sblastrecordchk(struct sockbuf *sb, const char *file, int line) 595 { 596 struct mbuf *m = sb->sb_mb; 597 598 SOCKBUF_LOCK_ASSERT(sb); 599 600 while (m && m->m_nextpkt) 601 m = m->m_nextpkt; 602 603 if (m != sb->sb_lastrecord) { 604 printf("%s: sb_mb %p sb_lastrecord %p last %p\n", 605 __func__, sb->sb_mb, sb->sb_lastrecord, m); 606 printf("packet chain:\n"); 607 for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) 608 printf("\t%p\n", m); 609 panic("%s from %s:%u", __func__, file, line); 610 } 611 } 612 613 void 614 sblastmbufchk(struct sockbuf *sb, const char *file, int line) 615 { 616 struct mbuf *m = sb->sb_mb; 617 struct mbuf *n; 618 619 SOCKBUF_LOCK_ASSERT(sb); 620 621 while (m && m->m_nextpkt) 622 m = m->m_nextpkt; 623 624 while (m && m->m_next) 625 m = m->m_next; 626 627 if (m != sb->sb_mbtail) { 628 printf("%s: sb_mb %p sb_mbtail %p last %p\n", 629 __func__, sb->sb_mb, sb->sb_mbtail, m); 630 printf("packet tree:\n"); 631 for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) { 632 printf("\t"); 633 for (n = m; n != NULL; n = n->m_next) 634 printf("%p ", n); 635 printf("\n"); 636 } 637 panic("%s from %s:%u", __func__, file, line); 638 } 639 } 640 #endif /* SOCKBUF_DEBUG */ 641 642 #define SBLINKRECORD(sb, m0) do { \ 643 SOCKBUF_LOCK_ASSERT(sb); \ 644 if ((sb)->sb_lastrecord != NULL) \ 645 (sb)->sb_lastrecord->m_nextpkt = (m0); \ 646 else \ 647 (sb)->sb_mb = (m0); \ 648 (sb)->sb_lastrecord = (m0); \ 649 } while (/*CONSTCOND*/0) 650 651 /* 652 * Append mbuf chain m to the last record in the socket buffer sb. The 653 * additional space associated the mbuf chain is recorded in sb. Empty mbufs 654 * are discarded and mbufs are compacted where possible. 655 */ 656 void 657 sbappend_locked(struct sockbuf *sb, struct mbuf *m, int flags) 658 { 659 struct mbuf *n; 660 661 SOCKBUF_LOCK_ASSERT(sb); 662 663 if (m == NULL) 664 return; 665 sbm_clrprotoflags(m, flags); 666 SBLASTRECORDCHK(sb); 667 n = sb->sb_mb; 668 if (n) { 669 while (n->m_nextpkt) 670 n = n->m_nextpkt; 671 do { 672 if (n->m_flags & M_EOR) { 673 sbappendrecord_locked(sb, m); /* XXXXXX!!!! */ 674 return; 675 } 676 } while (n->m_next && (n = n->m_next)); 677 } else { 678 /* 679 * XXX Would like to simply use sb_mbtail here, but 680 * XXX I need to verify that I won't miss an EOR that 681 * XXX way. 682 */ 683 if ((n = sb->sb_lastrecord) != NULL) { 684 do { 685 if (n->m_flags & M_EOR) { 686 sbappendrecord_locked(sb, m); /* XXXXXX!!!! */ 687 return; 688 } 689 } while (n->m_next && (n = n->m_next)); 690 } else { 691 /* 692 * If this is the first record in the socket buffer, 693 * it's also the last record. 694 */ 695 sb->sb_lastrecord = m; 696 } 697 } 698 sbcompress(sb, m, n); 699 SBLASTRECORDCHK(sb); 700 } 701 702 /* 703 * Append mbuf chain m to the last record in the socket buffer sb. The 704 * additional space associated the mbuf chain is recorded in sb. Empty mbufs 705 * are discarded and mbufs are compacted where possible. 706 */ 707 void 708 sbappend(struct sockbuf *sb, struct mbuf *m, int flags) 709 { 710 711 SOCKBUF_LOCK(sb); 712 sbappend_locked(sb, m, flags); 713 SOCKBUF_UNLOCK(sb); 714 } 715 716 /* 717 * This version of sbappend() should only be used when the caller absolutely 718 * knows that there will never be more than one record in the socket buffer, 719 * that is, a stream protocol (such as TCP). 720 */ 721 void 722 sbappendstream_locked(struct sockbuf *sb, struct mbuf *m, int flags) 723 { 724 SOCKBUF_LOCK_ASSERT(sb); 725 726 KASSERT(m->m_nextpkt == NULL,("sbappendstream 0")); 727 KASSERT(sb->sb_mb == sb->sb_lastrecord,("sbappendstream 1")); 728 729 SBLASTMBUFCHK(sb); 730 731 /* Remove all packet headers and mbuf tags to get a pure data chain. */ 732 m_demote(m, 1, flags & PRUS_NOTREADY ? M_NOTREADY : 0); 733 734 sbcompress(sb, m, sb->sb_mbtail); 735 736 sb->sb_lastrecord = sb->sb_mb; 737 SBLASTRECORDCHK(sb); 738 } 739 740 /* 741 * This version of sbappend() should only be used when the caller absolutely 742 * knows that there will never be more than one record in the socket buffer, 743 * that is, a stream protocol (such as TCP). 744 */ 745 void 746 sbappendstream(struct sockbuf *sb, struct mbuf *m, int flags) 747 { 748 749 SOCKBUF_LOCK(sb); 750 sbappendstream_locked(sb, m, flags); 751 SOCKBUF_UNLOCK(sb); 752 } 753 754 #ifdef SOCKBUF_DEBUG 755 void 756 sbcheck(struct sockbuf *sb, const char *file, int line) 757 { 758 struct mbuf *m, *n, *fnrdy; 759 u_long acc, ccc, mbcnt; 760 761 SOCKBUF_LOCK_ASSERT(sb); 762 763 acc = ccc = mbcnt = 0; 764 fnrdy = NULL; 765 766 for (m = sb->sb_mb; m; m = n) { 767 n = m->m_nextpkt; 768 for (; m; m = m->m_next) { 769 if (m->m_len == 0) { 770 printf("sb %p empty mbuf %p\n", sb, m); 771 goto fail; 772 } 773 if ((m->m_flags & M_NOTREADY) && fnrdy == NULL) { 774 if (m != sb->sb_fnrdy) { 775 printf("sb %p: fnrdy %p != m %p\n", 776 sb, sb->sb_fnrdy, m); 777 goto fail; 778 } 779 fnrdy = m; 780 } 781 if (fnrdy) { 782 if (!(m->m_flags & M_NOTAVAIL)) { 783 printf("sb %p: fnrdy %p, m %p is avail\n", 784 sb, sb->sb_fnrdy, m); 785 goto fail; 786 } 787 } else 788 acc += m->m_len; 789 ccc += m->m_len; 790 mbcnt += MSIZE; 791 if (m->m_flags & M_EXT) /*XXX*/ /* pretty sure this is bogus */ 792 mbcnt += m->m_ext.ext_size; 793 } 794 } 795 if (acc != sb->sb_acc || ccc != sb->sb_ccc || mbcnt != sb->sb_mbcnt) { 796 printf("acc %ld/%u ccc %ld/%u mbcnt %ld/%u\n", 797 acc, sb->sb_acc, ccc, sb->sb_ccc, mbcnt, sb->sb_mbcnt); 798 goto fail; 799 } 800 return; 801 fail: 802 panic("%s from %s:%u", __func__, file, line); 803 } 804 #endif 805 806 /* 807 * As above, except the mbuf chain begins a new record. 808 */ 809 void 810 sbappendrecord_locked(struct sockbuf *sb, struct mbuf *m0) 811 { 812 struct mbuf *m; 813 814 SOCKBUF_LOCK_ASSERT(sb); 815 816 if (m0 == NULL) 817 return; 818 m_clrprotoflags(m0); 819 /* 820 * Put the first mbuf on the queue. Note this permits zero length 821 * records. 822 */ 823 sballoc(sb, m0); 824 SBLASTRECORDCHK(sb); 825 SBLINKRECORD(sb, m0); 826 sb->sb_mbtail = m0; 827 m = m0->m_next; 828 m0->m_next = 0; 829 if (m && (m0->m_flags & M_EOR)) { 830 m0->m_flags &= ~M_EOR; 831 m->m_flags |= M_EOR; 832 } 833 /* always call sbcompress() so it can do SBLASTMBUFCHK() */ 834 sbcompress(sb, m, m0); 835 } 836 837 /* 838 * As above, except the mbuf chain begins a new record. 839 */ 840 void 841 sbappendrecord(struct sockbuf *sb, struct mbuf *m0) 842 { 843 844 SOCKBUF_LOCK(sb); 845 sbappendrecord_locked(sb, m0); 846 SOCKBUF_UNLOCK(sb); 847 } 848 849 /* Helper routine that appends data, control, and address to a sockbuf. */ 850 static int 851 sbappendaddr_locked_internal(struct sockbuf *sb, const struct sockaddr *asa, 852 struct mbuf *m0, struct mbuf *control, struct mbuf *ctrl_last) 853 { 854 struct mbuf *m, *n, *nlast; 855 #if MSIZE <= 256 856 if (asa->sa_len > MLEN) 857 return (0); 858 #endif 859 m = m_get(M_NOWAIT, MT_SONAME); 860 if (m == NULL) 861 return (0); 862 m->m_len = asa->sa_len; 863 bcopy(asa, mtod(m, caddr_t), asa->sa_len); 864 if (m0) { 865 m_clrprotoflags(m0); 866 m_tag_delete_chain(m0, NULL); 867 /* 868 * Clear some persistent info from pkthdr. 869 * We don't use m_demote(), because some netgraph consumers 870 * expect M_PKTHDR presence. 871 */ 872 m0->m_pkthdr.rcvif = NULL; 873 m0->m_pkthdr.flowid = 0; 874 m0->m_pkthdr.csum_flags = 0; 875 m0->m_pkthdr.fibnum = 0; 876 m0->m_pkthdr.rsstype = 0; 877 } 878 if (ctrl_last) 879 ctrl_last->m_next = m0; /* concatenate data to control */ 880 else 881 control = m0; 882 m->m_next = control; 883 for (n = m; n->m_next != NULL; n = n->m_next) 884 sballoc(sb, n); 885 sballoc(sb, n); 886 nlast = n; 887 SBLINKRECORD(sb, m); 888 889 sb->sb_mbtail = nlast; 890 SBLASTMBUFCHK(sb); 891 892 SBLASTRECORDCHK(sb); 893 return (1); 894 } 895 896 /* 897 * Append address and data, and optionally, control (ancillary) data to the 898 * receive queue of a socket. If present, m0 must include a packet header 899 * with total length. Returns 0 if no space in sockbuf or insufficient 900 * mbufs. 901 */ 902 int 903 sbappendaddr_locked(struct sockbuf *sb, const struct sockaddr *asa, 904 struct mbuf *m0, struct mbuf *control) 905 { 906 struct mbuf *ctrl_last; 907 int space = asa->sa_len; 908 909 SOCKBUF_LOCK_ASSERT(sb); 910 911 if (m0 && (m0->m_flags & M_PKTHDR) == 0) 912 panic("sbappendaddr_locked"); 913 if (m0) 914 space += m0->m_pkthdr.len; 915 space += m_length(control, &ctrl_last); 916 917 if (space > sbspace(sb)) 918 return (0); 919 return (sbappendaddr_locked_internal(sb, asa, m0, control, ctrl_last)); 920 } 921 922 /* 923 * Append address and data, and optionally, control (ancillary) data to the 924 * receive queue of a socket. If present, m0 must include a packet header 925 * with total length. Returns 0 if insufficient mbufs. Does not validate space 926 * on the receiving sockbuf. 927 */ 928 int 929 sbappendaddr_nospacecheck_locked(struct sockbuf *sb, const struct sockaddr *asa, 930 struct mbuf *m0, struct mbuf *control) 931 { 932 struct mbuf *ctrl_last; 933 934 SOCKBUF_LOCK_ASSERT(sb); 935 936 ctrl_last = (control == NULL) ? NULL : m_last(control); 937 return (sbappendaddr_locked_internal(sb, asa, m0, control, ctrl_last)); 938 } 939 940 /* 941 * Append address and data, and optionally, control (ancillary) data to the 942 * receive queue of a socket. If present, m0 must include a packet header 943 * with total length. Returns 0 if no space in sockbuf or insufficient 944 * mbufs. 945 */ 946 int 947 sbappendaddr(struct sockbuf *sb, const struct sockaddr *asa, 948 struct mbuf *m0, struct mbuf *control) 949 { 950 int retval; 951 952 SOCKBUF_LOCK(sb); 953 retval = sbappendaddr_locked(sb, asa, m0, control); 954 SOCKBUF_UNLOCK(sb); 955 return (retval); 956 } 957 958 void 959 sbappendcontrol_locked(struct sockbuf *sb, struct mbuf *m0, 960 struct mbuf *control) 961 { 962 struct mbuf *m, *mlast; 963 964 m_clrprotoflags(m0); 965 m_last(control)->m_next = m0; 966 967 SBLASTRECORDCHK(sb); 968 969 for (m = control; m->m_next; m = m->m_next) 970 sballoc(sb, m); 971 sballoc(sb, m); 972 mlast = m; 973 SBLINKRECORD(sb, control); 974 975 sb->sb_mbtail = mlast; 976 SBLASTMBUFCHK(sb); 977 978 SBLASTRECORDCHK(sb); 979 } 980 981 void 982 sbappendcontrol(struct sockbuf *sb, struct mbuf *m0, struct mbuf *control) 983 { 984 985 SOCKBUF_LOCK(sb); 986 sbappendcontrol_locked(sb, m0, control); 987 SOCKBUF_UNLOCK(sb); 988 } 989 990 /* 991 * Append the data in mbuf chain (m) into the socket buffer sb following mbuf 992 * (n). If (n) is NULL, the buffer is presumed empty. 993 * 994 * When the data is compressed, mbufs in the chain may be handled in one of 995 * three ways: 996 * 997 * (1) The mbuf may simply be dropped, if it contributes nothing (no data, no 998 * record boundary, and no change in data type). 999 * 1000 * (2) The mbuf may be coalesced -- i.e., data in the mbuf may be copied into 1001 * an mbuf already in the socket buffer. This can occur if an 1002 * appropriate mbuf exists, there is room, both mbufs are not marked as 1003 * not ready, and no merging of data types will occur. 1004 * 1005 * (3) The mbuf may be appended to the end of the existing mbuf chain. 1006 * 1007 * If any of the new mbufs is marked as M_EOR, mark the last mbuf appended as 1008 * end-of-record. 1009 */ 1010 void 1011 sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n) 1012 { 1013 int eor = 0; 1014 struct mbuf *o; 1015 1016 SOCKBUF_LOCK_ASSERT(sb); 1017 1018 while (m) { 1019 eor |= m->m_flags & M_EOR; 1020 if (m->m_len == 0 && 1021 (eor == 0 || 1022 (((o = m->m_next) || (o = n)) && 1023 o->m_type == m->m_type))) { 1024 if (sb->sb_lastrecord == m) 1025 sb->sb_lastrecord = m->m_next; 1026 m = m_free(m); 1027 continue; 1028 } 1029 if (n && (n->m_flags & M_EOR) == 0 && 1030 M_WRITABLE(n) && 1031 ((sb->sb_flags & SB_NOCOALESCE) == 0) && 1032 !(m->m_flags & M_NOTREADY) && 1033 !(n->m_flags & M_NOTREADY) && 1034 m->m_len <= MCLBYTES / 4 && /* XXX: Don't copy too much */ 1035 m->m_len <= M_TRAILINGSPACE(n) && 1036 n->m_type == m->m_type) { 1037 bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len, 1038 (unsigned)m->m_len); 1039 n->m_len += m->m_len; 1040 sb->sb_ccc += m->m_len; 1041 if (sb->sb_fnrdy == NULL) 1042 sb->sb_acc += m->m_len; 1043 if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA) 1044 /* XXX: Probably don't need.*/ 1045 sb->sb_ctl += m->m_len; 1046 m = m_free(m); 1047 continue; 1048 } 1049 if (n) 1050 n->m_next = m; 1051 else 1052 sb->sb_mb = m; 1053 sb->sb_mbtail = m; 1054 sballoc(sb, m); 1055 n = m; 1056 m->m_flags &= ~M_EOR; 1057 m = m->m_next; 1058 n->m_next = 0; 1059 } 1060 if (eor) { 1061 KASSERT(n != NULL, ("sbcompress: eor && n == NULL")); 1062 n->m_flags |= eor; 1063 } 1064 SBLASTMBUFCHK(sb); 1065 } 1066 1067 /* 1068 * Free all mbufs in a sockbuf. Check that all resources are reclaimed. 1069 */ 1070 static void 1071 sbflush_internal(struct sockbuf *sb) 1072 { 1073 1074 while (sb->sb_mbcnt) { 1075 /* 1076 * Don't call sbcut(sb, 0) if the leading mbuf is non-empty: 1077 * we would loop forever. Panic instead. 1078 */ 1079 if (sb->sb_ccc == 0 && (sb->sb_mb == NULL || sb->sb_mb->m_len)) 1080 break; 1081 m_freem(sbcut_internal(sb, (int)sb->sb_ccc)); 1082 } 1083 KASSERT(sb->sb_ccc == 0 && sb->sb_mb == 0 && sb->sb_mbcnt == 0, 1084 ("%s: ccc %u mb %p mbcnt %u", __func__, 1085 sb->sb_ccc, (void *)sb->sb_mb, sb->sb_mbcnt)); 1086 } 1087 1088 void 1089 sbflush_locked(struct sockbuf *sb) 1090 { 1091 1092 SOCKBUF_LOCK_ASSERT(sb); 1093 sbflush_internal(sb); 1094 } 1095 1096 void 1097 sbflush(struct sockbuf *sb) 1098 { 1099 1100 SOCKBUF_LOCK(sb); 1101 sbflush_locked(sb); 1102 SOCKBUF_UNLOCK(sb); 1103 } 1104 1105 /* 1106 * Cut data from (the front of) a sockbuf. 1107 */ 1108 static struct mbuf * 1109 sbcut_internal(struct sockbuf *sb, int len) 1110 { 1111 struct mbuf *m, *next, *mfree; 1112 1113 KASSERT(len >= 0, ("%s: len is %d but it is supposed to be >= 0", 1114 __func__, len)); 1115 KASSERT(len <= sb->sb_ccc, ("%s: len: %d is > ccc: %u", 1116 __func__, len, sb->sb_ccc)); 1117 1118 next = (m = sb->sb_mb) ? m->m_nextpkt : 0; 1119 mfree = NULL; 1120 1121 while (len > 0) { 1122 if (m == NULL) { 1123 KASSERT(next, ("%s: no next, len %d", __func__, len)); 1124 m = next; 1125 next = m->m_nextpkt; 1126 } 1127 if (m->m_len > len) { 1128 KASSERT(!(m->m_flags & M_NOTAVAIL), 1129 ("%s: m %p M_NOTAVAIL", __func__, m)); 1130 m->m_len -= len; 1131 m->m_data += len; 1132 sb->sb_ccc -= len; 1133 sb->sb_acc -= len; 1134 if (sb->sb_sndptroff != 0) 1135 sb->sb_sndptroff -= len; 1136 if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA) 1137 sb->sb_ctl -= len; 1138 break; 1139 } 1140 len -= m->m_len; 1141 sbfree(sb, m); 1142 /* 1143 * Do not put M_NOTREADY buffers to the free list, they 1144 * are referenced from outside. 1145 */ 1146 if (m->m_flags & M_NOTREADY) 1147 m = m->m_next; 1148 else { 1149 struct mbuf *n; 1150 1151 n = m->m_next; 1152 m->m_next = mfree; 1153 mfree = m; 1154 m = n; 1155 } 1156 } 1157 /* 1158 * Free any zero-length mbufs from the buffer. 1159 * For SOCK_DGRAM sockets such mbufs represent empty records. 1160 * XXX: For SOCK_STREAM sockets such mbufs can appear in the buffer, 1161 * when sosend_generic() needs to send only control data. 1162 */ 1163 while (m && m->m_len == 0) { 1164 struct mbuf *n; 1165 1166 sbfree(sb, m); 1167 n = m->m_next; 1168 m->m_next = mfree; 1169 mfree = m; 1170 m = n; 1171 } 1172 if (m) { 1173 sb->sb_mb = m; 1174 m->m_nextpkt = next; 1175 } else 1176 sb->sb_mb = next; 1177 /* 1178 * First part is an inline SB_EMPTY_FIXUP(). Second part makes sure 1179 * sb_lastrecord is up-to-date if we dropped part of the last record. 1180 */ 1181 m = sb->sb_mb; 1182 if (m == NULL) { 1183 sb->sb_mbtail = NULL; 1184 sb->sb_lastrecord = NULL; 1185 } else if (m->m_nextpkt == NULL) { 1186 sb->sb_lastrecord = m; 1187 } 1188 1189 return (mfree); 1190 } 1191 1192 /* 1193 * Drop data from (the front of) a sockbuf. 1194 */ 1195 void 1196 sbdrop_locked(struct sockbuf *sb, int len) 1197 { 1198 1199 SOCKBUF_LOCK_ASSERT(sb); 1200 m_freem(sbcut_internal(sb, len)); 1201 } 1202 1203 /* 1204 * Drop data from (the front of) a sockbuf, 1205 * and return it to caller. 1206 */ 1207 struct mbuf * 1208 sbcut_locked(struct sockbuf *sb, int len) 1209 { 1210 1211 SOCKBUF_LOCK_ASSERT(sb); 1212 return (sbcut_internal(sb, len)); 1213 } 1214 1215 void 1216 sbdrop(struct sockbuf *sb, int len) 1217 { 1218 struct mbuf *mfree; 1219 1220 SOCKBUF_LOCK(sb); 1221 mfree = sbcut_internal(sb, len); 1222 SOCKBUF_UNLOCK(sb); 1223 1224 m_freem(mfree); 1225 } 1226 1227 /* 1228 * Maintain a pointer and offset pair into the socket buffer mbuf chain to 1229 * avoid traversal of the entire socket buffer for larger offsets. 1230 */ 1231 struct mbuf * 1232 sbsndptr(struct sockbuf *sb, u_int off, u_int len, u_int *moff) 1233 { 1234 struct mbuf *m, *ret; 1235 1236 KASSERT(sb->sb_mb != NULL, ("%s: sb_mb is NULL", __func__)); 1237 KASSERT(off + len <= sb->sb_acc, ("%s: beyond sb", __func__)); 1238 KASSERT(sb->sb_sndptroff <= sb->sb_acc, ("%s: sndptroff broken", __func__)); 1239 1240 /* 1241 * Is off below stored offset? Happens on retransmits. 1242 * Just return, we can't help here. 1243 */ 1244 if (sb->sb_sndptroff > off) { 1245 *moff = off; 1246 return (sb->sb_mb); 1247 } 1248 1249 /* Return closest mbuf in chain for current offset. */ 1250 *moff = off - sb->sb_sndptroff; 1251 m = ret = sb->sb_sndptr ? sb->sb_sndptr : sb->sb_mb; 1252 if (*moff == m->m_len) { 1253 *moff = 0; 1254 sb->sb_sndptroff += m->m_len; 1255 m = ret = m->m_next; 1256 KASSERT(ret->m_len > 0, 1257 ("mbuf %p in sockbuf %p chain has no valid data", ret, sb)); 1258 } 1259 1260 /* Advance by len to be as close as possible for the next transmit. */ 1261 for (off = off - sb->sb_sndptroff + len - 1; 1262 off > 0 && m != NULL && off >= m->m_len; 1263 m = m->m_next) { 1264 sb->sb_sndptroff += m->m_len; 1265 off -= m->m_len; 1266 } 1267 if (off > 0 && m == NULL) 1268 panic("%s: sockbuf %p and mbuf %p clashing", __func__, sb, ret); 1269 sb->sb_sndptr = m; 1270 1271 return (ret); 1272 } 1273 1274 struct mbuf * 1275 sbsndptr_noadv(struct sockbuf *sb, uint32_t off, uint32_t *moff) 1276 { 1277 struct mbuf *m; 1278 1279 KASSERT(sb->sb_mb != NULL, ("%s: sb_mb is NULL", __func__)); 1280 if (sb->sb_sndptr == NULL || sb->sb_sndptroff > off) { 1281 *moff = off; 1282 if (sb->sb_sndptr == NULL) { 1283 sb->sb_sndptr = sb->sb_mb; 1284 sb->sb_sndptroff = 0; 1285 } 1286 return (sb->sb_mb); 1287 } else { 1288 m = sb->sb_sndptr; 1289 off -= sb->sb_sndptroff; 1290 } 1291 *moff = off; 1292 return (m); 1293 } 1294 1295 void 1296 sbsndptr_adv(struct sockbuf *sb, struct mbuf *mb, uint32_t len) 1297 { 1298 /* 1299 * A small copy was done, advance forward the sb_sbsndptr to cover 1300 * it. 1301 */ 1302 struct mbuf *m; 1303 1304 if (mb != sb->sb_sndptr) { 1305 /* Did not copyout at the same mbuf */ 1306 return; 1307 } 1308 m = mb; 1309 while (m && (len > 0)) { 1310 if (len >= m->m_len) { 1311 len -= m->m_len; 1312 if (m->m_next) { 1313 sb->sb_sndptroff += m->m_len; 1314 sb->sb_sndptr = m->m_next; 1315 } 1316 m = m->m_next; 1317 } else { 1318 len = 0; 1319 } 1320 } 1321 } 1322 1323 /* 1324 * Return the first mbuf and the mbuf data offset for the provided 1325 * send offset without changing the "sb_sndptroff" field. 1326 */ 1327 struct mbuf * 1328 sbsndmbuf(struct sockbuf *sb, u_int off, u_int *moff) 1329 { 1330 struct mbuf *m; 1331 1332 KASSERT(sb->sb_mb != NULL, ("%s: sb_mb is NULL", __func__)); 1333 1334 /* 1335 * If the "off" is below the stored offset, which happens on 1336 * retransmits, just use "sb_mb": 1337 */ 1338 if (sb->sb_sndptr == NULL || sb->sb_sndptroff > off) { 1339 m = sb->sb_mb; 1340 } else { 1341 m = sb->sb_sndptr; 1342 off -= sb->sb_sndptroff; 1343 } 1344 while (off > 0 && m != NULL) { 1345 if (off < m->m_len) 1346 break; 1347 off -= m->m_len; 1348 m = m->m_next; 1349 } 1350 *moff = off; 1351 return (m); 1352 } 1353 1354 /* 1355 * Drop a record off the front of a sockbuf and move the next record to the 1356 * front. 1357 */ 1358 void 1359 sbdroprecord_locked(struct sockbuf *sb) 1360 { 1361 struct mbuf *m; 1362 1363 SOCKBUF_LOCK_ASSERT(sb); 1364 1365 m = sb->sb_mb; 1366 if (m) { 1367 sb->sb_mb = m->m_nextpkt; 1368 do { 1369 sbfree(sb, m); 1370 m = m_free(m); 1371 } while (m); 1372 } 1373 SB_EMPTY_FIXUP(sb); 1374 } 1375 1376 /* 1377 * Drop a record off the front of a sockbuf and move the next record to the 1378 * front. 1379 */ 1380 void 1381 sbdroprecord(struct sockbuf *sb) 1382 { 1383 1384 SOCKBUF_LOCK(sb); 1385 sbdroprecord_locked(sb); 1386 SOCKBUF_UNLOCK(sb); 1387 } 1388 1389 /* 1390 * Create a "control" mbuf containing the specified data with the specified 1391 * type for presentation on a socket buffer. 1392 */ 1393 struct mbuf * 1394 sbcreatecontrol(caddr_t p, int size, int type, int level) 1395 { 1396 struct cmsghdr *cp; 1397 struct mbuf *m; 1398 1399 if (CMSG_SPACE((u_int)size) > MCLBYTES) 1400 return ((struct mbuf *) NULL); 1401 if (CMSG_SPACE((u_int)size) > MLEN) 1402 m = m_getcl(M_NOWAIT, MT_CONTROL, 0); 1403 else 1404 m = m_get(M_NOWAIT, MT_CONTROL); 1405 if (m == NULL) 1406 return ((struct mbuf *) NULL); 1407 cp = mtod(m, struct cmsghdr *); 1408 m->m_len = 0; 1409 KASSERT(CMSG_SPACE((u_int)size) <= M_TRAILINGSPACE(m), 1410 ("sbcreatecontrol: short mbuf")); 1411 /* 1412 * Don't leave the padding between the msg header and the 1413 * cmsg data and the padding after the cmsg data un-initialized. 1414 */ 1415 bzero(cp, CMSG_SPACE((u_int)size)); 1416 if (p != NULL) 1417 (void)memcpy(CMSG_DATA(cp), p, size); 1418 m->m_len = CMSG_SPACE(size); 1419 cp->cmsg_len = CMSG_LEN(size); 1420 cp->cmsg_level = level; 1421 cp->cmsg_type = type; 1422 return (m); 1423 } 1424 1425 /* 1426 * This does the same for socket buffers that sotoxsocket does for sockets: 1427 * generate an user-format data structure describing the socket buffer. Note 1428 * that the xsockbuf structure, since it is always embedded in a socket, does 1429 * not include a self pointer nor a length. We make this entry point public 1430 * in case some other mechanism needs it. 1431 */ 1432 void 1433 sbtoxsockbuf(struct sockbuf *sb, struct xsockbuf *xsb) 1434 { 1435 1436 xsb->sb_cc = sb->sb_ccc; 1437 xsb->sb_hiwat = sb->sb_hiwat; 1438 xsb->sb_mbcnt = sb->sb_mbcnt; 1439 xsb->sb_mcnt = sb->sb_mcnt; 1440 xsb->sb_ccnt = sb->sb_ccnt; 1441 xsb->sb_mbmax = sb->sb_mbmax; 1442 xsb->sb_lowat = sb->sb_lowat; 1443 xsb->sb_flags = sb->sb_flags; 1444 xsb->sb_timeo = sb->sb_timeo; 1445 } 1446 1447 /* This takes the place of kern.maxsockbuf, which moved to kern.ipc. */ 1448 static int dummy; 1449 SYSCTL_INT(_kern, KERN_DUMMY, dummy, CTLFLAG_RW, &dummy, 0, ""); 1450 SYSCTL_OID(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf, CTLTYPE_ULONG|CTLFLAG_RW, 1451 &sb_max, 0, sysctl_handle_sb_max, "LU", "Maximum socket buffer size"); 1452 SYSCTL_ULONG(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW, 1453 &sb_efficiency, 0, "Socket buffer size waste factor");
Cache object: f1b24de0699cae43eb18c13297b4245a
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