1 /*- 2 * Copyright (c) 1982, 1986, 1988, 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)uipc_socket2.c 8.1 (Berkeley) 6/10/93 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_param.h" 36 37 #include <sys/param.h> 38 #include <sys/aio.h> /* for aio_swake proto */ 39 #include <sys/kernel.h> 40 #include <sys/lock.h> 41 #include <sys/mbuf.h> 42 #include <sys/mutex.h> 43 #include <sys/proc.h> 44 #include <sys/protosw.h> 45 #include <sys/resourcevar.h> 46 #include <sys/signalvar.h> 47 #include <sys/socket.h> 48 #include <sys/socketvar.h> 49 #include <sys/sx.h> 50 #include <sys/sysctl.h> 51 52 /* 53 * Function pointer set by the AIO routines so that the socket buffer code 54 * can call back into the AIO module if it is loaded. 55 */ 56 void (*aio_swake)(struct socket *, struct sockbuf *); 57 58 /* 59 * Primitive routines for operating on socket buffers 60 */ 61 62 u_long sb_max = SB_MAX; 63 u_long sb_max_adj = 64 SB_MAX * MCLBYTES / (MSIZE + MCLBYTES); /* adjusted sb_max */ 65 66 static u_long sb_efficiency = 8; /* parameter for sbreserve() */ 67 68 static void sbdrop_internal(struct sockbuf *sb, int len); 69 static void sbflush_internal(struct sockbuf *sb); 70 static void sbrelease_internal(struct sockbuf *sb, struct socket *so); 71 72 /* 73 * Socantsendmore indicates that no more data will be sent on the socket; it 74 * would normally be applied to a socket when the user informs the system 75 * that no more data is to be sent, by the protocol code (in case 76 * PRU_SHUTDOWN). Socantrcvmore indicates that no more data will be 77 * received, and will normally be applied to the socket by a protocol when it 78 * detects that the peer will send no more data. Data queued for reading in 79 * the socket may yet be read. 80 */ 81 void 82 socantsendmore_locked(struct socket *so) 83 { 84 85 SOCKBUF_LOCK_ASSERT(&so->so_snd); 86 87 so->so_snd.sb_state |= SBS_CANTSENDMORE; 88 sowwakeup_locked(so); 89 mtx_assert(SOCKBUF_MTX(&so->so_snd), MA_NOTOWNED); 90 } 91 92 void 93 socantsendmore(struct socket *so) 94 { 95 96 SOCKBUF_LOCK(&so->so_snd); 97 socantsendmore_locked(so); 98 mtx_assert(SOCKBUF_MTX(&so->so_snd), MA_NOTOWNED); 99 } 100 101 void 102 socantrcvmore_locked(struct socket *so) 103 { 104 105 SOCKBUF_LOCK_ASSERT(&so->so_rcv); 106 107 so->so_rcv.sb_state |= SBS_CANTRCVMORE; 108 sorwakeup_locked(so); 109 mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED); 110 } 111 112 void 113 socantrcvmore(struct socket *so) 114 { 115 116 SOCKBUF_LOCK(&so->so_rcv); 117 socantrcvmore_locked(so); 118 mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED); 119 } 120 121 /* 122 * Wait for data to arrive at/drain from a socket buffer. 123 */ 124 int 125 sbwait(struct sockbuf *sb) 126 { 127 128 SOCKBUF_LOCK_ASSERT(sb); 129 130 sb->sb_flags |= SB_WAIT; 131 return (msleep(&sb->sb_cc, &sb->sb_mtx, 132 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, "sbwait", 133 sb->sb_timeo)); 134 } 135 136 int 137 sblock(struct sockbuf *sb, int flags) 138 { 139 140 if (flags == M_WAITOK) { 141 if (sb->sb_flags & SB_NOINTR) { 142 sx_xlock(&sb->sb_sx); 143 return (0); 144 } 145 return (sx_xlock_sig(&sb->sb_sx)); 146 } else { 147 if (sx_try_xlock(&sb->sb_sx) == 0) 148 return (EWOULDBLOCK); 149 return (0); 150 } 151 } 152 153 void 154 sbunlock(struct sockbuf *sb) 155 { 156 157 sx_xunlock(&sb->sb_sx); 158 } 159 160 /* 161 * Wakeup processes waiting on a socket buffer. Do asynchronous notification 162 * via SIGIO if the socket has the SS_ASYNC flag set. 163 * 164 * Called with the socket buffer lock held; will release the lock by the end 165 * of the function. This allows the caller to acquire the socket buffer lock 166 * while testing for the need for various sorts of wakeup and hold it through 167 * to the point where it's no longer required. We currently hold the lock 168 * through calls out to other subsystems (with the exception of kqueue), and 169 * then release it to avoid lock order issues. It's not clear that's 170 * correct. 171 */ 172 void 173 sowakeup(struct socket *so, struct sockbuf *sb) 174 { 175 176 SOCKBUF_LOCK_ASSERT(sb); 177 178 selwakeuppri(&sb->sb_sel, PSOCK); 179 sb->sb_flags &= ~SB_SEL; 180 if (sb->sb_flags & SB_WAIT) { 181 sb->sb_flags &= ~SB_WAIT; 182 wakeup(&sb->sb_cc); 183 } 184 KNOTE_LOCKED(&sb->sb_sel.si_note, 0); 185 SOCKBUF_UNLOCK(sb); 186 if ((so->so_state & SS_ASYNC) && so->so_sigio != NULL) 187 pgsigio(&so->so_sigio, SIGIO, 0); 188 if (sb->sb_flags & SB_UPCALL) 189 (*so->so_upcall)(so, so->so_upcallarg, M_DONTWAIT); 190 if (sb->sb_flags & SB_AIO) 191 aio_swake(so, sb); 192 mtx_assert(SOCKBUF_MTX(sb), MA_NOTOWNED); 193 } 194 195 /* 196 * Socket buffer (struct sockbuf) utility routines. 197 * 198 * Each socket contains two socket buffers: one for sending data and one for 199 * receiving data. Each buffer contains a queue of mbufs, information about 200 * the number of mbufs and amount of data in the queue, and other fields 201 * allowing select() statements and notification on data availability to be 202 * implemented. 203 * 204 * Data stored in a socket buffer is maintained as a list of records. Each 205 * record is a list of mbufs chained together with the m_next field. Records 206 * are chained together with the m_nextpkt field. The upper level routine 207 * soreceive() expects the following conventions to be observed when placing 208 * information in the receive buffer: 209 * 210 * 1. If the protocol requires each message be preceded by the sender's name, 211 * then a record containing that name must be present before any 212 * associated data (mbuf's must be of type MT_SONAME). 213 * 2. If the protocol supports the exchange of ``access rights'' (really just 214 * additional data associated with the message), and there are ``rights'' 215 * to be received, then a record containing this data should be present 216 * (mbuf's must be of type MT_RIGHTS). 217 * 3. If a name or rights record exists, then it must be followed by a data 218 * record, perhaps of zero length. 219 * 220 * Before using a new socket structure it is first necessary to reserve 221 * buffer space to the socket, by calling sbreserve(). This should commit 222 * some of the available buffer space in the system buffer pool for the 223 * socket (currently, it does nothing but enforce limits). The space should 224 * be released by calling sbrelease() when the socket is destroyed. 225 */ 226 int 227 soreserve(struct socket *so, u_long sndcc, u_long rcvcc) 228 { 229 struct thread *td = curthread; 230 231 SOCKBUF_LOCK(&so->so_snd); 232 SOCKBUF_LOCK(&so->so_rcv); 233 if (sbreserve_locked(&so->so_snd, sndcc, so, td) == 0) 234 goto bad; 235 if (sbreserve_locked(&so->so_rcv, rcvcc, so, td) == 0) 236 goto bad2; 237 if (so->so_rcv.sb_lowat == 0) 238 so->so_rcv.sb_lowat = 1; 239 if (so->so_snd.sb_lowat == 0) 240 so->so_snd.sb_lowat = MCLBYTES; 241 if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat) 242 so->so_snd.sb_lowat = so->so_snd.sb_hiwat; 243 SOCKBUF_UNLOCK(&so->so_rcv); 244 SOCKBUF_UNLOCK(&so->so_snd); 245 return (0); 246 bad2: 247 sbrelease_locked(&so->so_snd, so); 248 bad: 249 SOCKBUF_UNLOCK(&so->so_rcv); 250 SOCKBUF_UNLOCK(&so->so_snd); 251 return (ENOBUFS); 252 } 253 254 static int 255 sysctl_handle_sb_max(SYSCTL_HANDLER_ARGS) 256 { 257 int error = 0; 258 u_long tmp_sb_max = sb_max; 259 260 error = sysctl_handle_long(oidp, &tmp_sb_max, arg2, req); 261 if (error || !req->newptr) 262 return (error); 263 if (tmp_sb_max < MSIZE + MCLBYTES) 264 return (EINVAL); 265 sb_max = tmp_sb_max; 266 sb_max_adj = (u_quad_t)sb_max * MCLBYTES / (MSIZE + MCLBYTES); 267 return (0); 268 } 269 270 /* 271 * Allot mbufs to a sockbuf. Attempt to scale mbmax so that mbcnt doesn't 272 * become limiting if buffering efficiency is near the normal case. 273 */ 274 int 275 sbreserve_locked(struct sockbuf *sb, u_long cc, struct socket *so, 276 struct thread *td) 277 { 278 rlim_t sbsize_limit; 279 280 SOCKBUF_LOCK_ASSERT(sb); 281 282 /* 283 * td will only be NULL when we're in an interrupt (e.g. in 284 * tcp_input()). 285 * 286 * XXXRW: This comment needs updating, as might the code. 287 */ 288 if (cc > sb_max_adj) 289 return (0); 290 if (td != NULL) { 291 PROC_LOCK(td->td_proc); 292 sbsize_limit = lim_cur(td->td_proc, RLIMIT_SBSIZE); 293 PROC_UNLOCK(td->td_proc); 294 } else 295 sbsize_limit = RLIM_INFINITY; 296 if (!chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, cc, 297 sbsize_limit)) 298 return (0); 299 sb->sb_mbmax = min(cc * sb_efficiency, sb_max); 300 if (sb->sb_lowat > sb->sb_hiwat) 301 sb->sb_lowat = sb->sb_hiwat; 302 return (1); 303 } 304 305 int 306 sbreserve(struct sockbuf *sb, u_long cc, struct socket *so, 307 struct thread *td) 308 { 309 int error; 310 311 SOCKBUF_LOCK(sb); 312 error = sbreserve_locked(sb, cc, so, td); 313 SOCKBUF_UNLOCK(sb); 314 return (error); 315 } 316 317 /* 318 * Free mbufs held by a socket, and reserved mbuf space. 319 */ 320 static void 321 sbrelease_internal(struct sockbuf *sb, struct socket *so) 322 { 323 324 sbflush_internal(sb); 325 (void)chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, 0, 326 RLIM_INFINITY); 327 sb->sb_mbmax = 0; 328 } 329 330 void 331 sbrelease_locked(struct sockbuf *sb, struct socket *so) 332 { 333 334 SOCKBUF_LOCK_ASSERT(sb); 335 336 sbrelease_internal(sb, so); 337 } 338 339 void 340 sbrelease(struct sockbuf *sb, struct socket *so) 341 { 342 343 SOCKBUF_LOCK(sb); 344 sbrelease_locked(sb, so); 345 SOCKBUF_UNLOCK(sb); 346 } 347 348 void 349 sbdestroy(struct sockbuf *sb, struct socket *so) 350 { 351 352 sbrelease_internal(sb, so); 353 } 354 355 /* 356 * Routines to add and remove data from an mbuf queue. 357 * 358 * The routines sbappend() or sbappendrecord() are normally called to append 359 * new mbufs to a socket buffer, after checking that adequate space is 360 * available, comparing the function sbspace() with the amount of data to be 361 * added. sbappendrecord() differs from sbappend() in that data supplied is 362 * treated as the beginning of a new record. To place a sender's address, 363 * optional access rights, and data in a socket receive buffer, 364 * sbappendaddr() should be used. To place access rights and data in a 365 * socket receive buffer, sbappendrights() should be used. In either case, 366 * the new data begins a new record. Note that unlike sbappend() and 367 * sbappendrecord(), these routines check for the caller that there will be 368 * enough space to store the data. Each fails if there is not enough space, 369 * or if it cannot find mbufs to store additional information in. 370 * 371 * Reliable protocols may use the socket send buffer to hold data awaiting 372 * acknowledgement. Data is normally copied from a socket send buffer in a 373 * protocol with m_copy for output to a peer, and then removing the data from 374 * the socket buffer with sbdrop() or sbdroprecord() when the data is 375 * acknowledged by the peer. 376 */ 377 #ifdef SOCKBUF_DEBUG 378 void 379 sblastrecordchk(struct sockbuf *sb, const char *file, int line) 380 { 381 struct mbuf *m = sb->sb_mb; 382 383 SOCKBUF_LOCK_ASSERT(sb); 384 385 while (m && m->m_nextpkt) 386 m = m->m_nextpkt; 387 388 if (m != sb->sb_lastrecord) { 389 printf("%s: sb_mb %p sb_lastrecord %p last %p\n", 390 __func__, sb->sb_mb, sb->sb_lastrecord, m); 391 printf("packet chain:\n"); 392 for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) 393 printf("\t%p\n", m); 394 panic("%s from %s:%u", __func__, file, line); 395 } 396 } 397 398 void 399 sblastmbufchk(struct sockbuf *sb, const char *file, int line) 400 { 401 struct mbuf *m = sb->sb_mb; 402 struct mbuf *n; 403 404 SOCKBUF_LOCK_ASSERT(sb); 405 406 while (m && m->m_nextpkt) 407 m = m->m_nextpkt; 408 409 while (m && m->m_next) 410 m = m->m_next; 411 412 if (m != sb->sb_mbtail) { 413 printf("%s: sb_mb %p sb_mbtail %p last %p\n", 414 __func__, sb->sb_mb, sb->sb_mbtail, m); 415 printf("packet tree:\n"); 416 for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) { 417 printf("\t"); 418 for (n = m; n != NULL; n = n->m_next) 419 printf("%p ", n); 420 printf("\n"); 421 } 422 panic("%s from %s:%u", __func__, file, line); 423 } 424 } 425 #endif /* SOCKBUF_DEBUG */ 426 427 #define SBLINKRECORD(sb, m0) do { \ 428 SOCKBUF_LOCK_ASSERT(sb); \ 429 if ((sb)->sb_lastrecord != NULL) \ 430 (sb)->sb_lastrecord->m_nextpkt = (m0); \ 431 else \ 432 (sb)->sb_mb = (m0); \ 433 (sb)->sb_lastrecord = (m0); \ 434 } while (/*CONSTCOND*/0) 435 436 /* 437 * Append mbuf chain m to the last record in the socket buffer sb. The 438 * additional space associated the mbuf chain is recorded in sb. Empty mbufs 439 * are discarded and mbufs are compacted where possible. 440 */ 441 void 442 sbappend_locked(struct sockbuf *sb, struct mbuf *m) 443 { 444 struct mbuf *n; 445 446 SOCKBUF_LOCK_ASSERT(sb); 447 448 if (m == 0) 449 return; 450 451 SBLASTRECORDCHK(sb); 452 n = sb->sb_mb; 453 if (n) { 454 while (n->m_nextpkt) 455 n = n->m_nextpkt; 456 do { 457 if (n->m_flags & M_EOR) { 458 sbappendrecord_locked(sb, m); /* XXXXXX!!!! */ 459 return; 460 } 461 } while (n->m_next && (n = n->m_next)); 462 } else { 463 /* 464 * XXX Would like to simply use sb_mbtail here, but 465 * XXX I need to verify that I won't miss an EOR that 466 * XXX way. 467 */ 468 if ((n = sb->sb_lastrecord) != NULL) { 469 do { 470 if (n->m_flags & M_EOR) { 471 sbappendrecord_locked(sb, m); /* XXXXXX!!!! */ 472 return; 473 } 474 } while (n->m_next && (n = n->m_next)); 475 } else { 476 /* 477 * If this is the first record in the socket buffer, 478 * it's also the last record. 479 */ 480 sb->sb_lastrecord = m; 481 } 482 } 483 sbcompress(sb, m, n); 484 SBLASTRECORDCHK(sb); 485 } 486 487 /* 488 * Append mbuf chain m to the last record in the socket buffer sb. The 489 * additional space associated the mbuf chain is recorded in sb. Empty mbufs 490 * are discarded and mbufs are compacted where possible. 491 */ 492 void 493 sbappend(struct sockbuf *sb, struct mbuf *m) 494 { 495 496 SOCKBUF_LOCK(sb); 497 sbappend_locked(sb, m); 498 SOCKBUF_UNLOCK(sb); 499 } 500 501 /* 502 * This version of sbappend() should only be used when the caller absolutely 503 * knows that there will never be more than one record in the socket buffer, 504 * that is, a stream protocol (such as TCP). 505 */ 506 void 507 sbappendstream_locked(struct sockbuf *sb, struct mbuf *m) 508 { 509 SOCKBUF_LOCK_ASSERT(sb); 510 511 KASSERT(m->m_nextpkt == NULL,("sbappendstream 0")); 512 KASSERT(sb->sb_mb == sb->sb_lastrecord,("sbappendstream 1")); 513 514 SBLASTMBUFCHK(sb); 515 516 sbcompress(sb, m, sb->sb_mbtail); 517 518 sb->sb_lastrecord = sb->sb_mb; 519 SBLASTRECORDCHK(sb); 520 } 521 522 /* 523 * This version of sbappend() should only be used when the caller absolutely 524 * knows that there will never be more than one record in the socket buffer, 525 * that is, a stream protocol (such as TCP). 526 */ 527 void 528 sbappendstream(struct sockbuf *sb, struct mbuf *m) 529 { 530 531 SOCKBUF_LOCK(sb); 532 sbappendstream_locked(sb, m); 533 SOCKBUF_UNLOCK(sb); 534 } 535 536 #ifdef SOCKBUF_DEBUG 537 void 538 sbcheck(struct sockbuf *sb) 539 { 540 struct mbuf *m; 541 struct mbuf *n = 0; 542 u_long len = 0, mbcnt = 0; 543 544 SOCKBUF_LOCK_ASSERT(sb); 545 546 for (m = sb->sb_mb; m; m = n) { 547 n = m->m_nextpkt; 548 for (; m; m = m->m_next) { 549 len += m->m_len; 550 mbcnt += MSIZE; 551 if (m->m_flags & M_EXT) /*XXX*/ /* pretty sure this is bogus */ 552 mbcnt += m->m_ext.ext_size; 553 } 554 } 555 if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) { 556 printf("cc %ld != %u || mbcnt %ld != %u\n", len, sb->sb_cc, 557 mbcnt, sb->sb_mbcnt); 558 panic("sbcheck"); 559 } 560 } 561 #endif 562 563 /* 564 * As above, except the mbuf chain begins a new record. 565 */ 566 void 567 sbappendrecord_locked(struct sockbuf *sb, struct mbuf *m0) 568 { 569 struct mbuf *m; 570 571 SOCKBUF_LOCK_ASSERT(sb); 572 573 if (m0 == 0) 574 return; 575 m = sb->sb_mb; 576 if (m) 577 while (m->m_nextpkt) 578 m = m->m_nextpkt; 579 /* 580 * Put the first mbuf on the queue. Note this permits zero length 581 * records. 582 */ 583 sballoc(sb, m0); 584 SBLASTRECORDCHK(sb); 585 SBLINKRECORD(sb, m0); 586 if (m) 587 m->m_nextpkt = m0; 588 else 589 sb->sb_mb = m0; 590 m = m0->m_next; 591 m0->m_next = 0; 592 if (m && (m0->m_flags & M_EOR)) { 593 m0->m_flags &= ~M_EOR; 594 m->m_flags |= M_EOR; 595 } 596 sbcompress(sb, m, m0); 597 } 598 599 /* 600 * As above, except the mbuf chain begins a new record. 601 */ 602 void 603 sbappendrecord(struct sockbuf *sb, struct mbuf *m0) 604 { 605 606 SOCKBUF_LOCK(sb); 607 sbappendrecord_locked(sb, m0); 608 SOCKBUF_UNLOCK(sb); 609 } 610 611 /* 612 * Append address and data, and optionally, control (ancillary) data to the 613 * receive queue of a socket. If present, m0 must include a packet header 614 * with total length. Returns 0 if no space in sockbuf or insufficient 615 * mbufs. 616 */ 617 int 618 sbappendaddr_locked(struct sockbuf *sb, const struct sockaddr *asa, 619 struct mbuf *m0, struct mbuf *control) 620 { 621 struct mbuf *m, *n, *nlast; 622 int space = asa->sa_len; 623 624 SOCKBUF_LOCK_ASSERT(sb); 625 626 if (m0 && (m0->m_flags & M_PKTHDR) == 0) 627 panic("sbappendaddr_locked"); 628 if (m0) 629 space += m0->m_pkthdr.len; 630 space += m_length(control, &n); 631 632 if (space > sbspace(sb)) 633 return (0); 634 #if MSIZE <= 256 635 if (asa->sa_len > MLEN) 636 return (0); 637 #endif 638 MGET(m, M_DONTWAIT, MT_SONAME); 639 if (m == 0) 640 return (0); 641 m->m_len = asa->sa_len; 642 bcopy(asa, mtod(m, caddr_t), asa->sa_len); 643 if (n) 644 n->m_next = m0; /* concatenate data to control */ 645 else 646 control = m0; 647 m->m_next = control; 648 for (n = m; n->m_next != NULL; n = n->m_next) 649 sballoc(sb, n); 650 sballoc(sb, n); 651 nlast = n; 652 SBLINKRECORD(sb, m); 653 654 sb->sb_mbtail = nlast; 655 SBLASTMBUFCHK(sb); 656 657 SBLASTRECORDCHK(sb); 658 return (1); 659 } 660 661 /* 662 * Append address and data, and optionally, control (ancillary) data to the 663 * receive queue of a socket. If present, m0 must include a packet header 664 * with total length. Returns 0 if no space in sockbuf or insufficient 665 * mbufs. 666 */ 667 int 668 sbappendaddr(struct sockbuf *sb, const struct sockaddr *asa, 669 struct mbuf *m0, struct mbuf *control) 670 { 671 int retval; 672 673 SOCKBUF_LOCK(sb); 674 retval = sbappendaddr_locked(sb, asa, m0, control); 675 SOCKBUF_UNLOCK(sb); 676 return (retval); 677 } 678 679 int 680 sbappendcontrol_locked(struct sockbuf *sb, struct mbuf *m0, 681 struct mbuf *control) 682 { 683 struct mbuf *m, *n, *mlast; 684 int space; 685 686 SOCKBUF_LOCK_ASSERT(sb); 687 688 if (control == 0) 689 panic("sbappendcontrol_locked"); 690 space = m_length(control, &n) + m_length(m0, NULL); 691 692 if (space > sbspace(sb)) 693 return (0); 694 n->m_next = m0; /* concatenate data to control */ 695 696 SBLASTRECORDCHK(sb); 697 698 for (m = control; m->m_next; m = m->m_next) 699 sballoc(sb, m); 700 sballoc(sb, m); 701 mlast = m; 702 SBLINKRECORD(sb, control); 703 704 sb->sb_mbtail = mlast; 705 SBLASTMBUFCHK(sb); 706 707 SBLASTRECORDCHK(sb); 708 return (1); 709 } 710 711 int 712 sbappendcontrol(struct sockbuf *sb, struct mbuf *m0, struct mbuf *control) 713 { 714 int retval; 715 716 SOCKBUF_LOCK(sb); 717 retval = sbappendcontrol_locked(sb, m0, control); 718 SOCKBUF_UNLOCK(sb); 719 return (retval); 720 } 721 722 /* 723 * Append the data in mbuf chain (m) into the socket buffer sb following mbuf 724 * (n). If (n) is NULL, the buffer is presumed empty. 725 * 726 * When the data is compressed, mbufs in the chain may be handled in one of 727 * three ways: 728 * 729 * (1) The mbuf may simply be dropped, if it contributes nothing (no data, no 730 * record boundary, and no change in data type). 731 * 732 * (2) The mbuf may be coalesced -- i.e., data in the mbuf may be copied into 733 * an mbuf already in the socket buffer. This can occur if an 734 * appropriate mbuf exists, there is room, and no merging of data types 735 * will occur. 736 * 737 * (3) The mbuf may be appended to the end of the existing mbuf chain. 738 * 739 * If any of the new mbufs is marked as M_EOR, mark the last mbuf appended as 740 * end-of-record. 741 */ 742 void 743 sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n) 744 { 745 int eor = 0; 746 struct mbuf *o; 747 748 SOCKBUF_LOCK_ASSERT(sb); 749 750 while (m) { 751 eor |= m->m_flags & M_EOR; 752 if (m->m_len == 0 && 753 (eor == 0 || 754 (((o = m->m_next) || (o = n)) && 755 o->m_type == m->m_type))) { 756 if (sb->sb_lastrecord == m) 757 sb->sb_lastrecord = m->m_next; 758 m = m_free(m); 759 continue; 760 } 761 if (n && (n->m_flags & M_EOR) == 0 && 762 M_WRITABLE(n) && 763 m->m_len <= MCLBYTES / 4 && /* XXX: Don't copy too much */ 764 m->m_len <= M_TRAILINGSPACE(n) && 765 n->m_type == m->m_type) { 766 bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len, 767 (unsigned)m->m_len); 768 n->m_len += m->m_len; 769 sb->sb_cc += m->m_len; 770 if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA) 771 /* XXX: Probably don't need.*/ 772 sb->sb_ctl += m->m_len; 773 m = m_free(m); 774 continue; 775 } 776 if (n) 777 n->m_next = m; 778 else 779 sb->sb_mb = m; 780 sb->sb_mbtail = m; 781 sballoc(sb, m); 782 n = m; 783 m->m_flags &= ~M_EOR; 784 m = m->m_next; 785 n->m_next = 0; 786 } 787 if (eor) { 788 KASSERT(n != NULL, ("sbcompress: eor && n == NULL")); 789 n->m_flags |= eor; 790 } 791 SBLASTMBUFCHK(sb); 792 } 793 794 /* 795 * Free all mbufs in a sockbuf. Check that all resources are reclaimed. 796 */ 797 static void 798 sbflush_internal(struct sockbuf *sb) 799 { 800 801 while (sb->sb_mbcnt) { 802 /* 803 * Don't call sbdrop(sb, 0) if the leading mbuf is non-empty: 804 * we would loop forever. Panic instead. 805 */ 806 if (!sb->sb_cc && (sb->sb_mb == NULL || sb->sb_mb->m_len)) 807 break; 808 sbdrop_internal(sb, (int)sb->sb_cc); 809 } 810 if (sb->sb_cc || sb->sb_mb || sb->sb_mbcnt) 811 panic("sbflush_internal: cc %u || mb %p || mbcnt %u", 812 sb->sb_cc, (void *)sb->sb_mb, sb->sb_mbcnt); 813 } 814 815 void 816 sbflush_locked(struct sockbuf *sb) 817 { 818 819 SOCKBUF_LOCK_ASSERT(sb); 820 sbflush_internal(sb); 821 } 822 823 void 824 sbflush(struct sockbuf *sb) 825 { 826 827 SOCKBUF_LOCK(sb); 828 sbflush_locked(sb); 829 SOCKBUF_UNLOCK(sb); 830 } 831 832 /* 833 * Drop data from (the front of) a sockbuf. 834 */ 835 static void 836 sbdrop_internal(struct sockbuf *sb, int len) 837 { 838 struct mbuf *m; 839 struct mbuf *next; 840 841 next = (m = sb->sb_mb) ? m->m_nextpkt : 0; 842 while (len > 0) { 843 if (m == 0) { 844 if (next == 0) 845 panic("sbdrop"); 846 m = next; 847 next = m->m_nextpkt; 848 continue; 849 } 850 if (m->m_len > len) { 851 m->m_len -= len; 852 m->m_data += len; 853 sb->sb_cc -= len; 854 if (sb->sb_sndptroff != 0) 855 sb->sb_sndptroff -= len; 856 if (m->m_type != MT_DATA && m->m_type != MT_OOBDATA) 857 sb->sb_ctl -= len; 858 break; 859 } 860 len -= m->m_len; 861 sbfree(sb, m); 862 m = m_free(m); 863 } 864 while (m && m->m_len == 0) { 865 sbfree(sb, m); 866 m = m_free(m); 867 } 868 if (m) { 869 sb->sb_mb = m; 870 m->m_nextpkt = next; 871 } else 872 sb->sb_mb = next; 873 /* 874 * First part is an inline SB_EMPTY_FIXUP(). Second part makes sure 875 * sb_lastrecord is up-to-date if we dropped part of the last record. 876 */ 877 m = sb->sb_mb; 878 if (m == NULL) { 879 sb->sb_mbtail = NULL; 880 sb->sb_lastrecord = NULL; 881 } else if (m->m_nextpkt == NULL) { 882 sb->sb_lastrecord = m; 883 } 884 } 885 886 /* 887 * Drop data from (the front of) a sockbuf. 888 */ 889 void 890 sbdrop_locked(struct sockbuf *sb, int len) 891 { 892 893 SOCKBUF_LOCK_ASSERT(sb); 894 895 sbdrop_internal(sb, len); 896 } 897 898 void 899 sbdrop(struct sockbuf *sb, int len) 900 { 901 902 SOCKBUF_LOCK(sb); 903 sbdrop_locked(sb, len); 904 SOCKBUF_UNLOCK(sb); 905 } 906 907 /* 908 * Maintain a pointer and offset pair into the socket buffer mbuf chain to 909 * avoid traversal of the entire socket buffer for larger offsets. 910 */ 911 struct mbuf * 912 sbsndptr(struct sockbuf *sb, u_int off, u_int len, u_int *moff) 913 { 914 struct mbuf *m, *ret; 915 916 KASSERT(sb->sb_mb != NULL, ("%s: sb_mb is NULL", __func__)); 917 KASSERT(off + len <= sb->sb_cc, ("%s: beyond sb", __func__)); 918 KASSERT(sb->sb_sndptroff <= sb->sb_cc, ("%s: sndptroff broken", __func__)); 919 920 /* 921 * Is off below stored offset? Happens on retransmits. 922 * Just return, we can't help here. 923 */ 924 if (sb->sb_sndptroff > off) { 925 *moff = off; 926 return (sb->sb_mb); 927 } 928 929 /* Return closest mbuf in chain for current offset. */ 930 *moff = off - sb->sb_sndptroff; 931 m = ret = sb->sb_sndptr ? sb->sb_sndptr : sb->sb_mb; 932 933 /* Advance by len to be as close as possible for the next transmit. */ 934 for (off = off - sb->sb_sndptroff + len - 1; 935 off > 0 && off >= m->m_len; 936 m = m->m_next) { 937 sb->sb_sndptroff += m->m_len; 938 off -= m->m_len; 939 } 940 sb->sb_sndptr = m; 941 942 return (ret); 943 } 944 945 /* 946 * Drop a record off the front of a sockbuf and move the next record to the 947 * front. 948 */ 949 void 950 sbdroprecord_locked(struct sockbuf *sb) 951 { 952 struct mbuf *m; 953 954 SOCKBUF_LOCK_ASSERT(sb); 955 956 m = sb->sb_mb; 957 if (m) { 958 sb->sb_mb = m->m_nextpkt; 959 do { 960 sbfree(sb, m); 961 m = m_free(m); 962 } while (m); 963 } 964 SB_EMPTY_FIXUP(sb); 965 } 966 967 /* 968 * Drop a record off the front of a sockbuf and move the next record to the 969 * front. 970 */ 971 void 972 sbdroprecord(struct sockbuf *sb) 973 { 974 975 SOCKBUF_LOCK(sb); 976 sbdroprecord_locked(sb); 977 SOCKBUF_UNLOCK(sb); 978 } 979 980 /* 981 * Create a "control" mbuf containing the specified data with the specified 982 * type for presentation on a socket buffer. 983 */ 984 struct mbuf * 985 sbcreatecontrol(caddr_t p, int size, int type, int level) 986 { 987 struct cmsghdr *cp; 988 struct mbuf *m; 989 990 if (CMSG_SPACE((u_int)size) > MCLBYTES) 991 return ((struct mbuf *) NULL); 992 if (CMSG_SPACE((u_int)size) > MLEN) 993 m = m_getcl(M_DONTWAIT, MT_CONTROL, 0); 994 else 995 m = m_get(M_DONTWAIT, MT_CONTROL); 996 if (m == NULL) 997 return ((struct mbuf *) NULL); 998 cp = mtod(m, struct cmsghdr *); 999 m->m_len = 0; 1000 KASSERT(CMSG_SPACE((u_int)size) <= M_TRAILINGSPACE(m), 1001 ("sbcreatecontrol: short mbuf")); 1002 if (p != NULL) 1003 (void)memcpy(CMSG_DATA(cp), p, size); 1004 m->m_len = CMSG_SPACE(size); 1005 cp->cmsg_len = CMSG_LEN(size); 1006 cp->cmsg_level = level; 1007 cp->cmsg_type = type; 1008 return (m); 1009 } 1010 1011 /* 1012 * This does the same for socket buffers that sotoxsocket does for sockets: 1013 * generate an user-format data structure describing the socket buffer. Note 1014 * that the xsockbuf structure, since it is always embedded in a socket, does 1015 * not include a self pointer nor a length. We make this entry point public 1016 * in case some other mechanism needs it. 1017 */ 1018 void 1019 sbtoxsockbuf(struct sockbuf *sb, struct xsockbuf *xsb) 1020 { 1021 1022 xsb->sb_cc = sb->sb_cc; 1023 xsb->sb_hiwat = sb->sb_hiwat; 1024 xsb->sb_mbcnt = sb->sb_mbcnt; 1025 xsb->sb_mbmax = sb->sb_mbmax; 1026 xsb->sb_lowat = sb->sb_lowat; 1027 xsb->sb_flags = sb->sb_flags; 1028 xsb->sb_timeo = sb->sb_timeo; 1029 } 1030 1031 /* This takes the place of kern.maxsockbuf, which moved to kern.ipc. */ 1032 static int dummy; 1033 SYSCTL_INT(_kern, KERN_DUMMY, dummy, CTLFLAG_RW, &dummy, 0, ""); 1034 SYSCTL_OID(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf, CTLTYPE_ULONG|CTLFLAG_RW, 1035 &sb_max, 0, sysctl_handle_sb_max, "LU", "Maximum socket buffer size"); 1036 SYSCTL_ULONG(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW, 1037 &sb_efficiency, 0, ""); 1038