uipc_socket2.c revision 1.1.1.3
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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)uipc_socket2.c 8.2 (Berkeley) 2/14/95 34 */ 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/proc.h> 39 #include <sys/file.h> 40 #include <sys/buf.h> 41 #include <sys/malloc.h> 42 #include <sys/mbuf.h> 43 #include <sys/protosw.h> 44 #include <sys/socket.h> 45 #include <sys/socketvar.h> 46 47 /* 48 * Primitive routines for operating on sockets and socket buffers 49 */ 50 51 /* strings for sleep message: */ 52 char netio[] = "netio"; 53 char netcon[] = "netcon"; 54 char netcls[] = "netcls"; 55 56 u_long sb_max = SB_MAX; /* patchable */ 57 58 /* 59 * Procedures to manipulate state flags of socket 60 * and do appropriate wakeups. Normal sequence from the 61 * active (originating) side is that soisconnecting() is 62 * called during processing of connect() call, 63 * resulting in an eventual call to soisconnected() if/when the 64 * connection is established. When the connection is torn down 65 * soisdisconnecting() is called during processing of disconnect() call, 66 * and soisdisconnected() is called when the connection to the peer 67 * is totally severed. The semantics of these routines are such that 68 * connectionless protocols can call soisconnected() and soisdisconnected() 69 * only, bypassing the in-progress calls when setting up a ``connection'' 70 * takes no time. 71 * 72 * From the passive side, a socket is created with 73 * two queues of sockets: so_q0 for connections in progress 74 * and so_q for connections already made and awaiting user acceptance. 75 * As a protocol is preparing incoming connections, it creates a socket 76 * structure queued on so_q0 by calling sonewconn(). When the connection 77 * is established, soisconnected() is called, and transfers the 78 * socket structure to so_q, making it available to accept(). 79 * 80 * If a socket is closed with sockets on either 81 * so_q0 or so_q, these sockets are dropped. 82 * 83 * If higher level protocols are implemented in 84 * the kernel, the wakeups done here will sometimes 85 * cause software-interrupt process scheduling. 86 */ 87 88 void 89 soisconnecting(so) 90 register struct socket *so; 91 { 92 93 so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING); 94 so->so_state |= SS_ISCONNECTING; 95 } 96 97 void 98 soisconnected(so) 99 register struct socket *so; 100 { 101 register struct socket *head = so->so_head; 102 103 so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING); 104 so->so_state |= SS_ISCONNECTED; 105 if (head && soqremque(so, 0)) { 106 soqinsque(head, so, 1); 107 sorwakeup(head); 108 wakeup((caddr_t)&head->so_timeo); 109 } else { 110 wakeup((caddr_t)&so->so_timeo); 111 sorwakeup(so); 112 sowwakeup(so); 113 } 114 } 115 116 void 117 soisdisconnecting(so) 118 register struct socket *so; 119 { 120 121 so->so_state &= ~SS_ISCONNECTING; 122 so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE); 123 wakeup((caddr_t)&so->so_timeo); 124 sowwakeup(so); 125 sorwakeup(so); 126 } 127 128 void 129 soisdisconnected(so) 130 register struct socket *so; 131 { 132 133 so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING); 134 so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE); 135 wakeup((caddr_t)&so->so_timeo); 136 sowwakeup(so); 137 sorwakeup(so); 138 } 139 140 /* 141 * When an attempt at a new connection is noted on a socket 142 * which accepts connections, sonewconn is called. If the 143 * connection is possible (subject to space constraints, etc.) 144 * then we allocate a new structure, propoerly linked into the 145 * data structure of the original socket, and return this. 146 * Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED. 147 * 148 * Currently, sonewconn() is defined as sonewconn1() in socketvar.h 149 * to catch calls that are missing the (new) second parameter. 150 */ 151 struct socket * 152 sonewconn1(head, connstatus) 153 register struct socket *head; 154 int connstatus; 155 { 156 register struct socket *so; 157 int soqueue = connstatus ? 1 : 0; 158 159 if (head->so_qlen + head->so_q0len > 3 * head->so_qlimit / 2) 160 return ((struct socket *)0); 161 MALLOC(so, struct socket *, sizeof(*so), M_SOCKET, M_DONTWAIT); 162 if (so == NULL) 163 return ((struct socket *)0); 164 bzero((caddr_t)so, sizeof(*so)); 165 so->so_type = head->so_type; 166 so->so_options = head->so_options &~ SO_ACCEPTCONN; 167 so->so_linger = head->so_linger; 168 so->so_state = head->so_state | SS_NOFDREF; 169 so->so_proto = head->so_proto; 170 so->so_timeo = head->so_timeo; 171 so->so_pgid = head->so_pgid; 172 (void) soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat); 173 soqinsque(head, so, soqueue); 174 if ((*so->so_proto->pr_usrreq)(so, PRU_ATTACH, 175 (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0)) { 176 (void) soqremque(so, soqueue); 177 (void) free((caddr_t)so, M_SOCKET); 178 return ((struct socket *)0); 179 } 180 if (connstatus) { 181 sorwakeup(head); 182 wakeup((caddr_t)&head->so_timeo); 183 so->so_state |= connstatus; 184 } 185 return (so); 186 } 187 188 void 189 soqinsque(head, so, q) 190 register struct socket *head, *so; 191 int q; 192 { 193 194 register struct socket **prev; 195 so->so_head = head; 196 if (q == 0) { 197 head->so_q0len++; 198 so->so_q0 = 0; 199 for (prev = &(head->so_q0); *prev; ) 200 prev = &((*prev)->so_q0); 201 } else { 202 head->so_qlen++; 203 so->so_q = 0; 204 for (prev = &(head->so_q); *prev; ) 205 prev = &((*prev)->so_q); 206 } 207 *prev = so; 208 } 209 210 int 211 soqremque(so, q) 212 register struct socket *so; 213 int q; 214 { 215 register struct socket *head, *prev, *next; 216 217 head = so->so_head; 218 prev = head; 219 for (;;) { 220 next = q ? prev->so_q : prev->so_q0; 221 if (next == so) 222 break; 223 if (next == 0) 224 return (0); 225 prev = next; 226 } 227 if (q == 0) { 228 prev->so_q0 = next->so_q0; 229 head->so_q0len--; 230 } else { 231 prev->so_q = next->so_q; 232 head->so_qlen--; 233 } 234 next->so_q0 = next->so_q = 0; 235 next->so_head = 0; 236 return (1); 237 } 238 239 /* 240 * Socantsendmore indicates that no more data will be sent on the 241 * socket; it would normally be applied to a socket when the user 242 * informs the system that no more data is to be sent, by the protocol 243 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data 244 * will be received, and will normally be applied to the socket by a 245 * protocol when it detects that the peer will send no more data. 246 * Data queued for reading in the socket may yet be read. 247 */ 248 249 void 250 socantsendmore(so) 251 struct socket *so; 252 { 253 254 so->so_state |= SS_CANTSENDMORE; 255 sowwakeup(so); 256 } 257 258 void 259 socantrcvmore(so) 260 struct socket *so; 261 { 262 263 so->so_state |= SS_CANTRCVMORE; 264 sorwakeup(so); 265 } 266 267 /* 268 * Wait for data to arrive at/drain from a socket buffer. 269 */ 270 int 271 sbwait(sb) 272 struct sockbuf *sb; 273 { 274 275 sb->sb_flags |= SB_WAIT; 276 return (tsleep((caddr_t)&sb->sb_cc, 277 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, netio, 278 sb->sb_timeo)); 279 } 280 281 /* 282 * Lock a sockbuf already known to be locked; 283 * return any error returned from sleep (EINTR). 284 */ 285 int 286 sb_lock(sb) 287 register struct sockbuf *sb; 288 { 289 int error; 290 291 while (sb->sb_flags & SB_LOCK) { 292 sb->sb_flags |= SB_WANT; 293 if (error = tsleep((caddr_t)&sb->sb_flags, 294 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK|PCATCH, 295 netio, 0)) 296 return (error); 297 } 298 sb->sb_flags |= SB_LOCK; 299 return (0); 300 } 301 302 /* 303 * Wakeup processes waiting on a socket buffer. 304 * Do asynchronous notification via SIGIO 305 * if the socket has the SS_ASYNC flag set. 306 */ 307 void 308 sowakeup(so, sb) 309 register struct socket *so; 310 register struct sockbuf *sb; 311 { 312 struct proc *p; 313 314 selwakeup(&sb->sb_sel); 315 sb->sb_flags &= ~SB_SEL; 316 if (sb->sb_flags & SB_WAIT) { 317 sb->sb_flags &= ~SB_WAIT; 318 wakeup((caddr_t)&sb->sb_cc); 319 } 320 if (so->so_state & SS_ASYNC) { 321 if (so->so_pgid < 0) 322 gsignal(-so->so_pgid, SIGIO); 323 else if (so->so_pgid > 0 && (p = pfind(so->so_pgid)) != 0) 324 psignal(p, SIGIO); 325 } 326 } 327 328 /* 329 * Socket buffer (struct sockbuf) utility routines. 330 * 331 * Each socket contains two socket buffers: one for sending data and 332 * one for receiving data. Each buffer contains a queue of mbufs, 333 * information about the number of mbufs and amount of data in the 334 * queue, and other fields allowing select() statements and notification 335 * on data availability to be implemented. 336 * 337 * Data stored in a socket buffer is maintained as a list of records. 338 * Each record is a list of mbufs chained together with the m_next 339 * field. Records are chained together with the m_nextpkt field. The upper 340 * level routine soreceive() expects the following conventions to be 341 * observed when placing information in the receive buffer: 342 * 343 * 1. If the protocol requires each message be preceded by the sender's 344 * name, then a record containing that name must be present before 345 * any associated data (mbuf's must be of type MT_SONAME). 346 * 2. If the protocol supports the exchange of ``access rights'' (really 347 * just additional data associated with the message), and there are 348 * ``rights'' to be received, then a record containing this data 349 * should be present (mbuf's must be of type MT_RIGHTS). 350 * 3. If a name or rights record exists, then it must be followed by 351 * a data record, perhaps of zero length. 352 * 353 * Before using a new socket structure it is first necessary to reserve 354 * buffer space to the socket, by calling sbreserve(). This should commit 355 * some of the available buffer space in the system buffer pool for the 356 * socket (currently, it does nothing but enforce limits). The space 357 * should be released by calling sbrelease() when the socket is destroyed. 358 */ 359 360 int 361 soreserve(so, sndcc, rcvcc) 362 register struct socket *so; 363 u_long sndcc, rcvcc; 364 { 365 366 if (sbreserve(&so->so_snd, sndcc) == 0) 367 goto bad; 368 if (sbreserve(&so->so_rcv, rcvcc) == 0) 369 goto bad2; 370 if (so->so_rcv.sb_lowat == 0) 371 so->so_rcv.sb_lowat = 1; 372 if (so->so_snd.sb_lowat == 0) 373 so->so_snd.sb_lowat = MCLBYTES; 374 if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat) 375 so->so_snd.sb_lowat = so->so_snd.sb_hiwat; 376 return (0); 377 bad2: 378 sbrelease(&so->so_snd); 379 bad: 380 return (ENOBUFS); 381 } 382 383 /* 384 * Allot mbufs to a sockbuf. 385 * Attempt to scale mbmax so that mbcnt doesn't become limiting 386 * if buffering efficiency is near the normal case. 387 */ 388 int 389 sbreserve(sb, cc) 390 struct sockbuf *sb; 391 u_long cc; 392 { 393 394 if (cc > sb_max * MCLBYTES / (MSIZE + MCLBYTES)) 395 return (0); 396 sb->sb_hiwat = cc; 397 sb->sb_mbmax = min(cc * 2, sb_max); 398 if (sb->sb_lowat > sb->sb_hiwat) 399 sb->sb_lowat = sb->sb_hiwat; 400 return (1); 401 } 402 403 /* 404 * Free mbufs held by a socket, and reserved mbuf space. 405 */ 406 void 407 sbrelease(sb) 408 struct sockbuf *sb; 409 { 410 411 sbflush(sb); 412 sb->sb_hiwat = sb->sb_mbmax = 0; 413 } 414 415 /* 416 * Routines to add and remove 417 * data from an mbuf queue. 418 * 419 * The routines sbappend() or sbappendrecord() are normally called to 420 * append new mbufs to a socket buffer, after checking that adequate 421 * space is available, comparing the function sbspace() with the amount 422 * of data to be added. sbappendrecord() differs from sbappend() in 423 * that data supplied is treated as the beginning of a new record. 424 * To place a sender's address, optional access rights, and data in a 425 * socket receive buffer, sbappendaddr() should be used. To place 426 * access rights and data in a socket receive buffer, sbappendrights() 427 * should be used. In either case, the new data begins a new record. 428 * Note that unlike sbappend() and sbappendrecord(), these routines check 429 * for the caller that there will be enough space to store the data. 430 * Each fails if there is not enough space, or if it cannot find mbufs 431 * to store additional information in. 432 * 433 * Reliable protocols may use the socket send buffer to hold data 434 * awaiting acknowledgement. Data is normally copied from a socket 435 * send buffer in a protocol with m_copy for output to a peer, 436 * and then removing the data from the socket buffer with sbdrop() 437 * or sbdroprecord() when the data is acknowledged by the peer. 438 */ 439 440 /* 441 * Append mbuf chain m to the last record in the 442 * socket buffer sb. The additional space associated 443 * the mbuf chain is recorded in sb. Empty mbufs are 444 * discarded and mbufs are compacted where possible. 445 */ 446 void 447 sbappend(sb, m) 448 struct sockbuf *sb; 449 struct mbuf *m; 450 { 451 register struct mbuf *n; 452 453 if (m == 0) 454 return; 455 if (n = sb->sb_mb) { 456 while (n->m_nextpkt) 457 n = n->m_nextpkt; 458 do { 459 if (n->m_flags & M_EOR) { 460 sbappendrecord(sb, m); /* XXXXXX!!!! */ 461 return; 462 } 463 } while (n->m_next && (n = n->m_next)); 464 } 465 sbcompress(sb, m, n); 466 } 467 468 #ifdef SOCKBUF_DEBUG 469 void 470 sbcheck(sb) 471 register struct sockbuf *sb; 472 { 473 register struct mbuf *m; 474 register int len = 0, mbcnt = 0; 475 476 for (m = sb->sb_mb; m; m = m->m_next) { 477 len += m->m_len; 478 mbcnt += MSIZE; 479 if (m->m_flags & M_EXT) 480 mbcnt += m->m_ext.ext_size; 481 if (m->m_nextpkt) 482 panic("sbcheck nextpkt"); 483 } 484 if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) { 485 printf("cc %d != %d || mbcnt %d != %d\n", len, sb->sb_cc, 486 mbcnt, sb->sb_mbcnt); 487 panic("sbcheck"); 488 } 489 } 490 #endif 491 492 /* 493 * As above, except the mbuf chain 494 * begins a new record. 495 */ 496 void 497 sbappendrecord(sb, m0) 498 register struct sockbuf *sb; 499 register struct mbuf *m0; 500 { 501 register struct mbuf *m; 502 503 if (m0 == 0) 504 return; 505 if (m = sb->sb_mb) 506 while (m->m_nextpkt) 507 m = m->m_nextpkt; 508 /* 509 * Put the first mbuf on the queue. 510 * Note this permits zero length records. 511 */ 512 sballoc(sb, m0); 513 if (m) 514 m->m_nextpkt = m0; 515 else 516 sb->sb_mb = m0; 517 m = m0->m_next; 518 m0->m_next = 0; 519 if (m && (m0->m_flags & M_EOR)) { 520 m0->m_flags &= ~M_EOR; 521 m->m_flags |= M_EOR; 522 } 523 sbcompress(sb, m, m0); 524 } 525 526 /* 527 * As above except that OOB data 528 * is inserted at the beginning of the sockbuf, 529 * but after any other OOB data. 530 */ 531 void 532 sbinsertoob(sb, m0) 533 register struct sockbuf *sb; 534 register struct mbuf *m0; 535 { 536 register struct mbuf *m; 537 register struct mbuf **mp; 538 539 if (m0 == 0) 540 return; 541 for (mp = &sb->sb_mb; m = *mp; mp = &((*mp)->m_nextpkt)) { 542 again: 543 switch (m->m_type) { 544 545 case MT_OOBDATA: 546 continue; /* WANT next train */ 547 548 case MT_CONTROL: 549 if (m = m->m_next) 550 goto again; /* inspect THIS train further */ 551 } 552 break; 553 } 554 /* 555 * Put the first mbuf on the queue. 556 * Note this permits zero length records. 557 */ 558 sballoc(sb, m0); 559 m0->m_nextpkt = *mp; 560 *mp = m0; 561 m = m0->m_next; 562 m0->m_next = 0; 563 if (m && (m0->m_flags & M_EOR)) { 564 m0->m_flags &= ~M_EOR; 565 m->m_flags |= M_EOR; 566 } 567 sbcompress(sb, m, m0); 568 } 569 570 /* 571 * Append address and data, and optionally, control (ancillary) data 572 * to the receive queue of a socket. If present, 573 * m0 must include a packet header with total length. 574 * Returns 0 if no space in sockbuf or insufficient mbufs. 575 */ 576 int 577 sbappendaddr(sb, asa, m0, control) 578 register struct sockbuf *sb; 579 struct sockaddr *asa; 580 struct mbuf *m0, *control; 581 { 582 register struct mbuf *m, *n; 583 int space = asa->sa_len; 584 585 if (m0 && (m0->m_flags & M_PKTHDR) == 0) 586 panic("sbappendaddr"); 587 if (m0) 588 space += m0->m_pkthdr.len; 589 for (n = control; n; n = n->m_next) { 590 space += n->m_len; 591 if (n->m_next == 0) /* keep pointer to last control buf */ 592 break; 593 } 594 if (space > sbspace(sb)) 595 return (0); 596 if (asa->sa_len > MLEN) 597 return (0); 598 MGET(m, M_DONTWAIT, MT_SONAME); 599 if (m == 0) 600 return (0); 601 m->m_len = asa->sa_len; 602 bcopy((caddr_t)asa, mtod(m, caddr_t), asa->sa_len); 603 if (n) 604 n->m_next = m0; /* concatenate data to control */ 605 else 606 control = m0; 607 m->m_next = control; 608 for (n = m; n; n = n->m_next) 609 sballoc(sb, n); 610 if (n = sb->sb_mb) { 611 while (n->m_nextpkt) 612 n = n->m_nextpkt; 613 n->m_nextpkt = m; 614 } else 615 sb->sb_mb = m; 616 return (1); 617 } 618 619 int 620 sbappendcontrol(sb, m0, control) 621 struct sockbuf *sb; 622 struct mbuf *m0, *control; 623 { 624 register struct mbuf *m, *n; 625 int space = 0; 626 627 if (control == 0) 628 panic("sbappendcontrol"); 629 for (m = control; ; m = m->m_next) { 630 space += m->m_len; 631 if (m->m_next == 0) 632 break; 633 } 634 n = m; /* save pointer to last control buffer */ 635 for (m = m0; m; m = m->m_next) 636 space += m->m_len; 637 if (space > sbspace(sb)) 638 return (0); 639 n->m_next = m0; /* concatenate data to control */ 640 for (m = control; m; m = m->m_next) 641 sballoc(sb, m); 642 if (n = sb->sb_mb) { 643 while (n->m_nextpkt) 644 n = n->m_nextpkt; 645 n->m_nextpkt = control; 646 } else 647 sb->sb_mb = control; 648 return (1); 649 } 650 651 /* 652 * Compress mbuf chain m into the socket 653 * buffer sb following mbuf n. If n 654 * is null, the buffer is presumed empty. 655 */ 656 void 657 sbcompress(sb, m, n) 658 register struct sockbuf *sb; 659 register struct mbuf *m, *n; 660 { 661 register int eor = 0; 662 register struct mbuf *o; 663 664 while (m) { 665 eor |= m->m_flags & M_EOR; 666 if (m->m_len == 0 && 667 (eor == 0 || 668 (((o = m->m_next) || (o = n)) && 669 o->m_type == m->m_type))) { 670 m = m_free(m); 671 continue; 672 } 673 if (n && (n->m_flags & (M_EXT | M_EOR)) == 0 && 674 (n->m_data + n->m_len + m->m_len) < &n->m_dat[MLEN] && 675 n->m_type == m->m_type) { 676 bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len, 677 (unsigned)m->m_len); 678 n->m_len += m->m_len; 679 sb->sb_cc += m->m_len; 680 m = m_free(m); 681 continue; 682 } 683 if (n) 684 n->m_next = m; 685 else 686 sb->sb_mb = m; 687 sballoc(sb, m); 688 n = m; 689 m->m_flags &= ~M_EOR; 690 m = m->m_next; 691 n->m_next = 0; 692 } 693 if (eor) { 694 if (n) 695 n->m_flags |= eor; 696 else 697 printf("semi-panic: sbcompress\n"); 698 } 699 } 700 701 /* 702 * Free all mbufs in a sockbuf. 703 * Check that all resources are reclaimed. 704 */ 705 void 706 sbflush(sb) 707 register struct sockbuf *sb; 708 { 709 710 if (sb->sb_flags & SB_LOCK) 711 panic("sbflush"); 712 while (sb->sb_mbcnt) 713 sbdrop(sb, (int)sb->sb_cc); 714 if (sb->sb_cc || sb->sb_mb) 715 panic("sbflush 2"); 716 } 717 718 /* 719 * Drop data from (the front of) a sockbuf. 720 */ 721 void 722 sbdrop(sb, len) 723 register struct sockbuf *sb; 724 register int len; 725 { 726 register struct mbuf *m, *mn; 727 struct mbuf *next; 728 729 next = (m = sb->sb_mb) ? m->m_nextpkt : 0; 730 while (len > 0) { 731 if (m == 0) { 732 if (next == 0) 733 panic("sbdrop"); 734 m = next; 735 next = m->m_nextpkt; 736 continue; 737 } 738 if (m->m_len > len) { 739 m->m_len -= len; 740 m->m_data += len; 741 sb->sb_cc -= len; 742 break; 743 } 744 len -= m->m_len; 745 sbfree(sb, m); 746 MFREE(m, mn); 747 m = mn; 748 } 749 while (m && m->m_len == 0) { 750 sbfree(sb, m); 751 MFREE(m, mn); 752 m = mn; 753 } 754 if (m) { 755 sb->sb_mb = m; 756 m->m_nextpkt = next; 757 } else 758 sb->sb_mb = next; 759 } 760 761 /* 762 * Drop a record off the front of a sockbuf 763 * and move the next record to the front. 764 */ 765 void 766 sbdroprecord(sb) 767 register struct sockbuf *sb; 768 { 769 register struct mbuf *m, *mn; 770 771 m = sb->sb_mb; 772 if (m) { 773 sb->sb_mb = m->m_nextpkt; 774 do { 775 sbfree(sb, m); 776 MFREE(m, mn); 777 } while (m = mn); 778 } 779 } 780
Indexes created Tue Sep 30 20:09:53 GMT 2025