uipc_socket2.c revision 1.4.4.1
1 /* 2 * Copyright (c) 1982, 1986, 1988, 1990 Regents of the University of California. 3 * 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 * from: @(#)uipc_socket2.c 7.17 (Berkeley) 5/4/91 34 * $Id: uipc_socket2.c,v 1.4.4.1 1993/09/24 08:51:56 mycroft Exp $ 35 */ 36 37 #include "param.h" 38 #include "systm.h" 39 #include "proc.h" 40 #include "file.h" 41 #include "buf.h" 42 #include "malloc.h" 43 #include "select.h" 44 #include "mbuf.h" 45 #include "protosw.h" 46 #include "socket.h" 47 #include "socketvar.h" 48 49 #include "machine/cpu.h" 50 51 /* 52 * Primitive routines for operating on sockets and socket buffers 53 */ 54 55 /* strings for sleep message: */ 56 char netio[] = "netio"; 57 char netcon[] = "netcon"; 58 char netcls[] = "netcls"; 59 60 u_long sb_max = SB_MAX; /* patchable */ 61 62 /* 63 * Procedures to manipulate state flags of socket 64 * and do appropriate wakeups. Normal sequence from the 65 * active (originating) side is that soisconnecting() is 66 * called during processing of connect() call, 67 * resulting in an eventual call to soisconnected() if/when the 68 * connection is established. When the connection is torn down 69 * soisdisconnecting() is called during processing of disconnect() call, 70 * and soisdisconnected() is called when the connection to the peer 71 * is totally severed. The semantics of these routines are such that 72 * connectionless protocols can call soisconnected() and soisdisconnected() 73 * only, bypassing the in-progress calls when setting up a ``connection'' 74 * takes no time. 75 * 76 * From the passive side, a socket is created with 77 * two queues of sockets: so_q0 for connections in progress 78 * and so_q for connections already made and awaiting user acceptance. 79 * As a protocol is preparing incoming connections, it creates a socket 80 * structure queued on so_q0 by calling sonewconn(). When the connection 81 * is established, soisconnected() is called, and transfers the 82 * socket structure to so_q, making it available to accept(). 83 * 84 * If a socket is closed with sockets on either 85 * so_q0 or so_q, these sockets are dropped. 86 * 87 * If higher level protocols are implemented in 88 * the kernel, the wakeups done here will sometimes 89 * cause software-interrupt process scheduling. 90 */ 91 92 soisconnecting(so) 93 register struct socket *so; 94 { 95 96 so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING); 97 so->so_state |= SS_ISCONNECTING; 98 } 99 100 soisconnected(so) 101 register struct socket *so; 102 { 103 register struct socket *head = so->so_head; 104 105 so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING); 106 so->so_state |= SS_ISCONNECTED; 107 if (head && soqremque(so, 0)) { 108 soqinsque(head, so, 1); 109 sorwakeup(head); 110 wakeup((caddr_t)&head->so_timeo); 111 } else { 112 wakeup((caddr_t)&so->so_timeo); 113 sorwakeup(so); 114 sowwakeup(so); 115 } 116 } 117 118 soisdisconnecting(so) 119 register struct socket *so; 120 { 121 122 so->so_state &= ~SS_ISCONNECTING; 123 so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE); 124 wakeup((caddr_t)&so->so_timeo); 125 sowwakeup(so); 126 sorwakeup(so); 127 } 128 129 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 soqinsque(head, so, q) 189 register struct socket *head, *so; 190 int q; 191 { 192 193 register struct socket **prev; 194 so->so_head = head; 195 if (q == 0) { 196 head->so_q0len++; 197 so->so_q0 = 0; 198 for (prev = &(head->so_q0); *prev; ) 199 prev = &((*prev)->so_q0); 200 } else { 201 head->so_qlen++; 202 so->so_q = 0; 203 for (prev = &(head->so_q); *prev; ) 204 prev = &((*prev)->so_q); 205 } 206 *prev = so; 207 } 208 209 soqremque(so, q) 210 register struct socket *so; 211 int q; 212 { 213 register struct socket *head, *prev, *next; 214 215 head = so->so_head; 216 prev = head; 217 for (;;) { 218 next = q ? prev->so_q : prev->so_q0; 219 if (next == so) 220 break; 221 if (next == 0) 222 return (0); 223 prev = next; 224 } 225 if (q == 0) { 226 prev->so_q0 = next->so_q0; 227 head->so_q0len--; 228 } else { 229 prev->so_q = next->so_q; 230 head->so_qlen--; 231 } 232 next->so_q0 = next->so_q = 0; 233 next->so_head = 0; 234 return (1); 235 } 236 237 /* 238 * Socantsendmore indicates that no more data will be sent on the 239 * socket; it would normally be applied to a socket when the user 240 * informs the system that no more data is to be sent, by the protocol 241 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data 242 * will be received, and will normally be applied to the socket by a 243 * protocol when it detects that the peer will send no more data. 244 * Data queued for reading in the socket may yet be read. 245 */ 246 247 void 248 socantsendmore(so) 249 struct socket *so; 250 { 251 252 so->so_state |= SS_CANTSENDMORE; 253 sowwakeup(so); 254 } 255 256 void 257 socantrcvmore(so) 258 struct socket *so; 259 { 260 261 so->so_state |= SS_CANTRCVMORE; 262 sorwakeup(so); 263 } 264 265 /* 266 * Socket select/wakeup routines. 267 */ 268 269 /* 270 * Queue a process for a select on a socket buffer. 271 */ 272 sbselqueue(sb, cp) 273 struct sockbuf *sb; 274 struct proc *cp; 275 { 276 selrecord(cp, &sb->sb_sel); 277 sb->sb_flags |= SB_SEL; 278 } 279 280 /* 281 * Wait for data to arrive at/drain from a socket buffer. 282 */ 283 sbwait(sb) 284 struct sockbuf *sb; 285 { 286 287 sb->sb_flags |= SB_WAIT; 288 return (tsleep((caddr_t)&sb->sb_cc, 289 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, netio, 290 sb->sb_timeo)); 291 } 292 293 /* 294 * Lock a sockbuf already known to be locked; 295 * return any error returned from sleep (EINTR). 296 */ 297 sb_lock(sb) 298 register struct sockbuf *sb; 299 { 300 int error; 301 302 while (sb->sb_flags & SB_LOCK) { 303 sb->sb_flags |= SB_WANT; 304 if (error = tsleep((caddr_t)&sb->sb_flags, 305 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK|PCATCH, 306 netio, 0)) 307 return (error); 308 } 309 sb->sb_flags |= SB_LOCK; 310 return (0); 311 } 312 313 /* 314 * Wakeup processes waiting on a socket buffer. 315 * Do asynchronous notification via SIGIO 316 * if the socket has the SS_ASYNC flag set. 317 */ 318 sowakeup(so, sb) 319 register struct socket *so; 320 register struct sockbuf *sb; 321 { 322 struct proc *p; 323 324 selwakeup(&sb->sb_sel); 325 sb->sb_flags &= ~SB_SEL; 326 if (sb->sb_flags & SB_WAIT) { 327 sb->sb_flags &= ~SB_WAIT; 328 wakeup((caddr_t)&sb->sb_cc); 329 } 330 if (so->so_state & SS_ASYNC) { 331 if (so->so_pgid < 0) 332 gsignal(-so->so_pgid, SIGIO); 333 else if (so->so_pgid > 0 && (p = pfind(so->so_pgid)) != 0) 334 psignal(p, SIGIO); 335 } 336 } 337 338 /* 339 * Socket buffer (struct sockbuf) utility routines. 340 * 341 * Each socket contains two socket buffers: one for sending data and 342 * one for receiving data. Each buffer contains a queue of mbufs, 343 * information about the number of mbufs and amount of data in the 344 * queue, and other fields allowing select() statements and notification 345 * on data availability to be implemented. 346 * 347 * Data stored in a socket buffer is maintained as a list of records. 348 * Each record is a list of mbufs chained together with the m_next 349 * field. Records are chained together with the m_nextpkt field. The upper 350 * level routine soreceive() expects the following conventions to be 351 * observed when placing information in the receive buffer: 352 * 353 * 1. If the protocol requires each message be preceded by the sender's 354 * name, then a record containing that name must be present before 355 * any associated data (mbuf's must be of type MT_SONAME). 356 * 2. If the protocol supports the exchange of ``access rights'' (really 357 * just additional data associated with the message), and there are 358 * ``rights'' to be received, then a record containing this data 359 * should be present (mbuf's must be of type MT_RIGHTS). 360 * 3. If a name or rights record exists, then it must be followed by 361 * a data record, perhaps of zero length. 362 * 363 * Before using a new socket structure it is first necessary to reserve 364 * buffer space to the socket, by calling sbreserve(). This should commit 365 * some of the available buffer space in the system buffer pool for the 366 * socket (currently, it does nothing but enforce limits). The space 367 * should be released by calling sbrelease() when the socket is destroyed. 368 */ 369 370 soreserve(so, sndcc, rcvcc) 371 register struct socket *so; 372 u_long sndcc, rcvcc; 373 { 374 375 if (sbreserve(&so->so_snd, sndcc) == 0) 376 goto bad; 377 if (sbreserve(&so->so_rcv, rcvcc) == 0) 378 goto bad2; 379 if (so->so_rcv.sb_lowat == 0) 380 so->so_rcv.sb_lowat = 1; 381 if (so->so_snd.sb_lowat == 0) 382 so->so_snd.sb_lowat = MCLBYTES; 383 if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat) 384 so->so_snd.sb_lowat = so->so_snd.sb_hiwat; 385 return (0); 386 bad2: 387 sbrelease(&so->so_snd); 388 bad: 389 return (ENOBUFS); 390 } 391 392 /* 393 * Allot mbufs to a sockbuf. 394 * Attempt to scale mbmax so that mbcnt doesn't become limiting 395 * if buffering efficiency is near the normal case. 396 */ 397 sbreserve(sb, cc) 398 struct sockbuf *sb; 399 u_long cc; 400 { 401 402 if (cc > sb_max * MCLBYTES / (MSIZE + MCLBYTES)) 403 return (0); 404 sb->sb_hiwat = cc; 405 sb->sb_mbmax = min(cc * 2, sb_max); 406 if (sb->sb_lowat > sb->sb_hiwat) 407 sb->sb_lowat = sb->sb_hiwat; 408 return (1); 409 } 410 411 /* 412 * Free mbufs held by a socket, and reserved mbuf space. 413 */ 414 sbrelease(sb) 415 struct sockbuf *sb; 416 { 417 418 sbflush(sb); 419 sb->sb_hiwat = sb->sb_mbmax = 0; 420 } 421 422 /* 423 * Routines to add and remove 424 * data from an mbuf queue. 425 * 426 * The routines sbappend() or sbappendrecord() are normally called to 427 * append new mbufs to a socket buffer, after checking that adequate 428 * space is available, comparing the function sbspace() with the amount 429 * of data to be added. sbappendrecord() differs from sbappend() in 430 * that data supplied is treated as the beginning of a new record. 431 * To place a sender's address, optional access rights, and data in a 432 * socket receive buffer, sbappendaddr() should be used. To place 433 * access rights and data in a socket receive buffer, sbappendrights() 434 * should be used. In either case, the new data begins a new record. 435 * Note that unlike sbappend() and sbappendrecord(), these routines check 436 * for the caller that there will be enough space to store the data. 437 * Each fails if there is not enough space, or if it cannot find mbufs 438 * to store additional information in. 439 * 440 * Reliable protocols may use the socket send buffer to hold data 441 * awaiting acknowledgement. Data is normally copied from a socket 442 * send buffer in a protocol with m_copy for output to a peer, 443 * and then removing the data from the socket buffer with sbdrop() 444 * or sbdroprecord() when the data is acknowledged by the peer. 445 */ 446 447 /* 448 * Append mbuf chain m to the last record in the 449 * socket buffer sb. The additional space associated 450 * the mbuf chain is recorded in sb. Empty mbufs are 451 * discarded and mbufs are compacted where possible. 452 */ 453 sbappend(sb, m) 454 struct sockbuf *sb; 455 struct mbuf *m; 456 { 457 register struct mbuf *n; 458 459 if (m == 0) 460 return; 461 if (n = sb->sb_mb) { 462 while (n->m_nextpkt) 463 n = n->m_nextpkt; 464 do { 465 if (n->m_flags & M_EOR) { 466 sbappendrecord(sb, m); /* XXXXXX!!!! */ 467 return; 468 } 469 } while (n->m_next && (n = n->m_next)); 470 } 471 sbcompress(sb, m, n); 472 } 473 474 #ifdef SOCKBUF_DEBUG 475 sbcheck(sb) 476 register struct sockbuf *sb; 477 { 478 register struct mbuf *m; 479 register int len = 0, mbcnt = 0; 480 481 for (m = sb->sb_mb; m; m = m->m_next) { 482 len += m->m_len; 483 mbcnt += MSIZE; 484 if (m->m_flags & M_EXT) 485 mbcnt += m->m_ext.ext_size; 486 if (m->m_nextpkt) 487 panic("sbcheck nextpkt"); 488 } 489 if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) { 490 printf("cc %d != %d || mbcnt %d != %d\n", len, sb->sb_cc, 491 mbcnt, sb->sb_mbcnt); 492 panic("sbcheck"); 493 } 494 } 495 #endif 496 497 /* 498 * As above, except the mbuf chain 499 * begins a new record. 500 */ 501 sbappendrecord(sb, m0) 502 register struct sockbuf *sb; 503 register struct mbuf *m0; 504 { 505 register struct mbuf *m; 506 507 if (m0 == 0) 508 return; 509 if (m = sb->sb_mb) 510 while (m->m_nextpkt) 511 m = m->m_nextpkt; 512 /* 513 * Put the first mbuf on the queue. 514 * Note this permits zero length records. 515 */ 516 sballoc(sb, m0); 517 if (m) 518 m->m_nextpkt = m0; 519 else 520 sb->sb_mb = m0; 521 m = m0->m_next; 522 m0->m_next = 0; 523 if (m && (m0->m_flags & M_EOR)) { 524 m0->m_flags &= ~M_EOR; 525 m->m_flags |= M_EOR; 526 } 527 sbcompress(sb, m, m0); 528 } 529 530 /* 531 * As above except that OOB data 532 * is inserted at the beginning of the sockbuf, 533 * but after any other OOB data. 534 */ 535 sbinsertoob(sb, m0) 536 register struct sockbuf *sb; 537 register struct mbuf *m0; 538 { 539 register struct mbuf *m; 540 register struct mbuf **mp; 541 542 if (m0 == 0) 543 return; 544 for (mp = &sb->sb_mb; m = *mp; mp = &((*mp)->m_nextpkt)) { 545 again: 546 switch (m->m_type) { 547 548 case MT_OOBDATA: 549 continue; /* WANT next train */ 550 551 case MT_CONTROL: 552 if (m = m->m_next) 553 goto again; /* inspect THIS train further */ 554 } 555 break; 556 } 557 /* 558 * Put the first mbuf on the queue. 559 * Note this permits zero length records. 560 */ 561 sballoc(sb, m0); 562 m0->m_nextpkt = *mp; 563 *mp = m0; 564 m = m0->m_next; 565 m0->m_next = 0; 566 if (m && (m0->m_flags & M_EOR)) { 567 m0->m_flags &= ~M_EOR; 568 m->m_flags |= M_EOR; 569 } 570 sbcompress(sb, m, m0); 571 } 572 573 /* 574 * Append address and data, and optionally, control (ancillary) data 575 * to the receive queue of a socket. If present, 576 * m0 must include a packet header with total length. 577 * Returns 0 if no space in sockbuf or insufficient mbufs. 578 */ 579 sbappendaddr(sb, asa, m0, control) 580 register struct sockbuf *sb; 581 struct sockaddr *asa; 582 struct mbuf *m0, *control; 583 { 584 register struct mbuf *m, *n; 585 int space = asa->sa_len; 586 587 if (m0 && (m0->m_flags & M_PKTHDR) == 0) 588 panic("sbappendaddr"); 589 if (m0) 590 space += m0->m_pkthdr.len; 591 for (n = control; n; n = n->m_next) { 592 space += n->m_len; 593 if (n->m_next == 0) /* keep pointer to last control buf */ 594 break; 595 } 596 if (space > sbspace(sb)) 597 return (0); 598 if (asa->sa_len > MLEN) 599 return (0); 600 MGET(m, M_DONTWAIT, MT_SONAME); 601 if (m == 0) 602 return (0); 603 m->m_len = asa->sa_len; 604 bcopy((caddr_t)asa, mtod(m, caddr_t), asa->sa_len); 605 if (n) 606 n->m_next = m0; /* concatenate data to control */ 607 else 608 control = m0; 609 m->m_next = control; 610 for (n = m; n; n = n->m_next) 611 sballoc(sb, n); 612 if (n = sb->sb_mb) { 613 while (n->m_nextpkt) 614 n = n->m_nextpkt; 615 n->m_nextpkt = m; 616 } else 617 sb->sb_mb = m; 618 return (1); 619 } 620 621 sbappendcontrol(sb, m0, control) 622 struct sockbuf *sb; 623 struct mbuf *control, *m0; 624 { 625 register struct mbuf *m, *n; 626 int space = 0; 627 628 if (control == 0) 629 panic("sbappendcontrol"); 630 for (m = control; ; m = m->m_next) { 631 space += m->m_len; 632 if (m->m_next == 0) 633 break; 634 } 635 n = m; /* save pointer to last control buffer */ 636 for (m = m0; m; m = m->m_next) 637 space += m->m_len; 638 if (space > sbspace(sb)) 639 return (0); 640 n->m_next = m0; /* concatenate data to control */ 641 for (m = control; m; m = m->m_next) 642 sballoc(sb, m); 643 if (n = sb->sb_mb) { 644 while (n->m_nextpkt) 645 n = n->m_nextpkt; 646 n->m_nextpkt = control; 647 } else 648 sb->sb_mb = control; 649 return (1); 650 } 651 652 /* 653 * Compress mbuf chain m into the socket 654 * buffer sb following mbuf n. If n 655 * is null, the buffer is presumed empty. 656 */ 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 sbflush(sb) 706 register struct sockbuf *sb; 707 { 708 709 if (sb->sb_flags & SB_LOCK) 710 panic("sbflush"); 711 while (sb->sb_mbcnt) 712 sbdrop(sb, (int)sb->sb_cc); 713 if (sb->sb_cc || sb->sb_mb) 714 panic("sbflush 2"); 715 } 716 717 /* 718 * Drop data from (the front of) a sockbuf. 719 */ 720 sbdrop(sb, len) 721 register struct sockbuf *sb; 722 register int len; 723 { 724 register struct mbuf *m, *mn; 725 struct mbuf *next; 726 727 next = (m = sb->sb_mb) ? m->m_nextpkt : 0; 728 while (len > 0) { 729 if (m == 0) { 730 if (next == 0) 731 panic("sbdrop"); 732 m = next; 733 next = m->m_nextpkt; 734 continue; 735 } 736 if (m->m_len > len) { 737 m->m_len -= len; 738 m->m_data += len; 739 sb->sb_cc -= len; 740 break; 741 } 742 len -= m->m_len; 743 sbfree(sb, m); 744 MFREE(m, mn); 745 m = mn; 746 } 747 while (m && m->m_len == 0) { 748 sbfree(sb, m); 749 MFREE(m, mn); 750 m = mn; 751 } 752 if (m) { 753 sb->sb_mb = m; 754 m->m_nextpkt = next; 755 } else 756 sb->sb_mb = next; 757 } 758 759 /* 760 * Drop a record off the front of a sockbuf 761 * and move the next record to the front. 762 */ 763 sbdroprecord(sb) 764 register struct sockbuf *sb; 765 { 766 register struct mbuf *m, *mn; 767 768 m = sb->sb_mb; 769 if (m) { 770 sb->sb_mb = m->m_nextpkt; 771 do { 772 sbfree(sb, m); 773 MFREE(m, mn); 774 } while (m = mn); 775 } 776 } 777
Indexes created Tue Sep 30 20:09:53 GMT 2025