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 8.1 (Berkeley) 6/10/93 34 * $Id: uipc_socket2.c,v 1.3 1994/08/02 07:43:08 davidg Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/proc.h> 40 #include <sys/file.h> 41 #include <sys/buf.h> 42 #include <sys/malloc.h> 43 #include <sys/mbuf.h> 44 #include <sys/protosw.h> 45 #include <sys/stat.h> 46 #include <sys/socket.h> 47 #include <sys/socketvar.h> 48 #include <sys/signalvar.h> 49 50 /* 51 * Primitive routines for operating on sockets and socket buffers 52 */ 53 54 /* strings for sleep message: */ 55 char netio[] = "netio"; 56 char netcon[] = "netcon"; 57 char netcls[] = "netcls"; 58 59 u_long sb_max = SB_MAX; /* patchable */ 60 61 /* 62 * Procedures to manipulate state flags of socket 63 * and do appropriate wakeups. Normal sequence from the 64 * active (originating) side is that soisconnecting() is 65 * called during processing of connect() call, 66 * resulting in an eventual call to soisconnected() if/when the 67 * connection is established. When the connection is torn down 68 * soisdisconnecting() is called during processing of disconnect() call, 69 * and soisdisconnected() is called when the connection to the peer 70 * is totally severed. The semantics of these routines are such that 71 * connectionless protocols can call soisconnected() and soisdisconnected() 72 * only, bypassing the in-progress calls when setting up a ``connection'' 73 * takes no time. 74 * 75 * From the passive side, a socket is created with 76 * two queues of sockets: so_q0 for connections in progress 77 * and so_q for connections already made and awaiting user acceptance. 78 * As a protocol is preparing incoming connections, it creates a socket 79 * structure queued on so_q0 by calling sonewconn(). When the connection 80 * is established, soisconnected() is called, and transfers the 81 * socket structure to so_q, making it available to accept(). 82 * 83 * If a socket is closed with sockets on either 84 * so_q0 or so_q, these sockets are dropped. 85 * 86 * If higher level protocols are implemented in 87 * the kernel, the wakeups done here will sometimes 88 * cause software-interrupt process scheduling. 89 */ 90 91 void 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 void 101 soisconnected(so) 102 register struct socket *so; 103 { 104 register struct socket *head = so->so_head; 105 106 so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING); 107 so->so_state |= SS_ISCONNECTED; 108 if (head && soqremque(so, 0)) { 109 soqinsque(head, so, 1); 110 sorwakeup(head); 111 wakeup((caddr_t)&head->so_timeo); 112 } else { 113 wakeup((caddr_t)&so->so_timeo); 114 sorwakeup(so); 115 sowwakeup(so); 116 } 117 } 118 119 void 120 soisdisconnecting(so) 121 register struct socket *so; 122 { 123 124 so->so_state &= ~SS_ISCONNECTING; 125 so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE); 126 wakeup((caddr_t)&so->so_timeo); 127 sowwakeup(so); 128 sorwakeup(so); 129 } 130 131 void 132 soisdisconnected(so) 133 register struct socket *so; 134 { 135 136 so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING); 137 so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE); 138 wakeup((caddr_t)&so->so_timeo); 139 sowwakeup(so); 140 sorwakeup(so); 141 } 142 143 /* 144 * When an attempt at a new connection is noted on a socket 145 * which accepts connections, sonewconn is called. If the 146 * connection is possible (subject to space constraints, etc.) 147 * then we allocate a new structure, propoerly linked into the 148 * data structure of the original socket, and return this. 149 * Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED. 150 * 151 * Currently, sonewconn() is defined as sonewconn1() in socketvar.h 152 * to catch calls that are missing the (new) second parameter. 153 */ 154 struct socket * 155 sonewconn1(head, connstatus) 156 register struct socket *head; 157 int connstatus; 158 { 159 register struct socket *so; 160 int soqueue = connstatus ? 1 : 0; 161 162 if (head->so_qlen + head->so_q0len > 3 * head->so_qlimit / 2) 163 return ((struct socket *)0); 164 MALLOC(so, struct socket *, sizeof(*so), M_SOCKET, M_DONTWAIT); 165 if (so == NULL) 166 return ((struct socket *)0); 167 bzero((caddr_t)so, sizeof(*so)); 168 so->so_type = head->so_type; 169 so->so_options = head->so_options &~ SO_ACCEPTCONN; 170 so->so_linger = head->so_linger; 171 so->so_state = head->so_state | SS_NOFDREF; 172 so->so_proto = head->so_proto; 173 so->so_timeo = head->so_timeo; 174 so->so_pgid = head->so_pgid; 175 (void) soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat); 176 soqinsque(head, so, soqueue); 177 if ((*so->so_proto->pr_usrreq)(so, PRU_ATTACH, 178 (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0)) { 179 (void) soqremque(so, soqueue); 180 (void) free((caddr_t)so, M_SOCKET); 181 return ((struct socket *)0); 182 } 183 if (connstatus) { 184 sorwakeup(head); 185 wakeup((caddr_t)&head->so_timeo); 186 so->so_state |= connstatus; 187 } 188 return (so); 189 } 190 191 void 192 soqinsque(head, so, q) 193 register struct socket *head, *so; 194 int q; 195 { 196 197 register struct socket **prev; 198 so->so_head = head; 199 if (q == 0) { 200 head->so_q0len++; 201 so->so_q0 = 0; 202 for (prev = &(head->so_q0); *prev; ) 203 prev = &((*prev)->so_q0); 204 } else { 205 head->so_qlen++; 206 so->so_q = 0; 207 for (prev = &(head->so_q); *prev; ) 208 prev = &((*prev)->so_q); 209 } 210 *prev = so; 211 } 212 213 int 214 soqremque(so, q) 215 register struct socket *so; 216 int q; 217 { 218 register struct socket *head, *prev, *next; 219 220 head = so->so_head; 221 prev = head; 222 for (;;) { 223 next = q ? prev->so_q : prev->so_q0; 224 if (next == so) 225 break; 226 if (next == 0) 227 return (0); 228 prev = next; 229 } 230 if (q == 0) { 231 prev->so_q0 = next->so_q0; 232 head->so_q0len--; 233 } else { 234 prev->so_q = next->so_q; 235 head->so_qlen--; 236 } 237 next->so_q0 = next->so_q = 0; 238 next->so_head = 0; 239 return (1); 240 } 241 242 /* 243 * Socantsendmore indicates that no more data will be sent on the 244 * socket; it would normally be applied to a socket when the user 245 * informs the system that no more data is to be sent, by the protocol 246 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data 247 * will be received, and will normally be applied to the socket by a 248 * protocol when it detects that the peer will send no more data. 249 * Data queued for reading in the socket may yet be read. 250 */ 251 252 void 253 socantsendmore(so) 254 struct socket *so; 255 { 256 257 so->so_state |= SS_CANTSENDMORE; 258 sowwakeup(so); 259 } 260 261 void 262 socantrcvmore(so) 263 struct socket *so; 264 { 265 266 so->so_state |= SS_CANTRCVMORE; 267 sorwakeup(so); 268 } 269 270 /* 271 * Wait for data to arrive at/drain from a socket buffer. 272 */ 273 int 274 sbwait(sb) 275 struct sockbuf *sb; 276 { 277 278 sb->sb_flags |= SB_WAIT; 279 return (tsleep((caddr_t)&sb->sb_cc, 280 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, netio, 281 sb->sb_timeo)); 282 } 283 284 /* 285 * Lock a sockbuf already known to be locked; 286 * return any error returned from sleep (EINTR). 287 */ 288 int 289 sb_lock(sb) 290 register struct sockbuf *sb; 291 { 292 int error; 293 294 while (sb->sb_flags & SB_LOCK) { 295 sb->sb_flags |= SB_WANT; 296 error = tsleep((caddr_t)&sb->sb_flags, 297 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK|PCATCH, 298 netio, 0); 299 if (error) 300 return (error); 301 } 302 sb->sb_flags |= SB_LOCK; 303 return (0); 304 } 305 306 /* 307 * Wakeup processes waiting on a socket buffer. 308 * Do asynchronous notification via SIGIO 309 * if the socket has the SS_ASYNC flag set. 310 */ 311 void 312 sowakeup(so, sb) 313 register struct socket *so; 314 register struct sockbuf *sb; 315 { 316 struct proc *p; 317 318 selwakeup(&sb->sb_sel); 319 sb->sb_flags &= ~SB_SEL; 320 if (sb->sb_flags & SB_WAIT) { 321 sb->sb_flags &= ~SB_WAIT; 322 wakeup((caddr_t)&sb->sb_cc); 323 } 324 if (so->so_state & SS_ASYNC) { 325 if (so->so_pgid < 0) 326 gsignal(-so->so_pgid, SIGIO); 327 else if (so->so_pgid > 0 && (p = pfind(so->so_pgid)) != 0) 328 psignal(p, SIGIO); 329 } 330 } 331 332 /* 333 * Socket buffer (struct sockbuf) utility routines. 334 * 335 * Each socket contains two socket buffers: one for sending data and 336 * one for receiving data. Each buffer contains a queue of mbufs, 337 * information about the number of mbufs and amount of data in the 338 * queue, and other fields allowing select() statements and notification 339 * on data availability to be implemented. 340 * 341 * Data stored in a socket buffer is maintained as a list of records. 342 * Each record is a list of mbufs chained together with the m_next 343 * field. Records are chained together with the m_nextpkt field. The upper 344 * level routine soreceive() expects the following conventions to be 345 * observed when placing information in the receive buffer: 346 * 347 * 1. If the protocol requires each message be preceded by the sender's 348 * name, then a record containing that name must be present before 349 * any associated data (mbuf's must be of type MT_SONAME). 350 * 2. If the protocol supports the exchange of ``access rights'' (really 351 * just additional data associated with the message), and there are 352 * ``rights'' to be received, then a record containing this data 353 * should be present (mbuf's must be of type MT_RIGHTS). 354 * 3. If a name or rights record exists, then it must be followed by 355 * a data record, perhaps of zero length. 356 * 357 * Before using a new socket structure it is first necessary to reserve 358 * buffer space to the socket, by calling sbreserve(). This should commit 359 * some of the available buffer space in the system buffer pool for the 360 * socket (currently, it does nothing but enforce limits). The space 361 * should be released by calling sbrelease() when the socket is destroyed. 362 */ 363 364 int 365 soreserve(so, sndcc, rcvcc) 366 register struct socket *so; 367 u_long sndcc, rcvcc; 368 { 369 370 if (sbreserve(&so->so_snd, sndcc) == 0) 371 goto bad; 372 if (sbreserve(&so->so_rcv, rcvcc) == 0) 373 goto bad2; 374 if (so->so_rcv.sb_lowat == 0) 375 so->so_rcv.sb_lowat = 1; 376 if (so->so_snd.sb_lowat == 0) 377 so->so_snd.sb_lowat = MCLBYTES; 378 if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat) 379 so->so_snd.sb_lowat = so->so_snd.sb_hiwat; 380 return (0); 381 bad2: 382 sbrelease(&so->so_snd); 383 bad: 384 return (ENOBUFS); 385 } 386 387 /* 388 * Allot mbufs to a sockbuf. 389 * Attempt to scale mbmax so that mbcnt doesn't become limiting 390 * if buffering efficiency is near the normal case. 391 */ 392 int 393 sbreserve(sb, cc) 394 struct sockbuf *sb; 395 u_long cc; 396 { 397 398 if (cc > sb_max * MCLBYTES / (MSIZE + MCLBYTES)) 399 return (0); 400 sb->sb_hiwat = cc; 401 sb->sb_mbmax = min(cc * 2, sb_max); 402 if (sb->sb_lowat > sb->sb_hiwat) 403 sb->sb_lowat = sb->sb_hiwat; 404 return (1); 405 } 406 407 /* 408 * Free mbufs held by a socket, and reserved mbuf space. 409 */ 410 void 411 sbrelease(sb) 412 struct sockbuf *sb; 413 { 414 415 sbflush(sb); 416 sb->sb_hiwat = sb->sb_mbmax = 0; 417 } 418 419 /* 420 * Routines to add and remove 421 * data from an mbuf queue. 422 * 423 * The routines sbappend() or sbappendrecord() are normally called to 424 * append new mbufs to a socket buffer, after checking that adequate 425 * space is available, comparing the function sbspace() with the amount 426 * of data to be added. sbappendrecord() differs from sbappend() in 427 * that data supplied is treated as the beginning of a new record. 428 * To place a sender's address, optional access rights, and data in a 429 * socket receive buffer, sbappendaddr() should be used. To place 430 * access rights and data in a socket receive buffer, sbappendrights() 431 * should be used. In either case, the new data begins a new record. 432 * Note that unlike sbappend() and sbappendrecord(), these routines check 433 * for the caller that there will be enough space to store the data. 434 * Each fails if there is not enough space, or if it cannot find mbufs 435 * to store additional information in. 436 * 437 * Reliable protocols may use the socket send buffer to hold data 438 * awaiting acknowledgement. Data is normally copied from a socket 439 * send buffer in a protocol with m_copy for output to a peer, 440 * and then removing the data from the socket buffer with sbdrop() 441 * or sbdroprecord() when the data is acknowledged by the peer. 442 */ 443 444 /* 445 * Append mbuf chain m to the last record in the 446 * socket buffer sb. The additional space associated 447 * the mbuf chain is recorded in sb. Empty mbufs are 448 * discarded and mbufs are compacted where possible. 449 */ 450 void 451 sbappend(sb, m) 452 struct sockbuf *sb; 453 struct mbuf *m; 454 { 455 register struct mbuf *n; 456 457 if (m == 0) 458 return; 459 n = sb->sb_mb; 460 if (n) { 461 while (n->m_nextpkt) 462 n = n->m_nextpkt; 463 do { 464 if (n->m_flags & M_EOR) { 465 sbappendrecord(sb, m); /* XXXXXX!!!! */ 466 return; 467 } 468 } while (n->m_next && (n = n->m_next)); 469 } 470 sbcompress(sb, m, n); 471 } 472 473 #ifdef SOCKBUF_DEBUG 474 void 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 void 502 sbappendrecord(sb, m0) 503 register struct sockbuf *sb; 504 register struct mbuf *m0; 505 { 506 register struct mbuf *m; 507 508 if (m0 == 0) 509 return; 510 m = sb->sb_mb; 511 if (m) 512 while (m->m_nextpkt) 513 m = m->m_nextpkt; 514 /* 515 * Put the first mbuf on the queue. 516 * Note this permits zero length records. 517 */ 518 sballoc(sb, m0); 519 if (m) 520 m->m_nextpkt = m0; 521 else 522 sb->sb_mb = m0; 523 m = m0->m_next; 524 m0->m_next = 0; 525 if (m && (m0->m_flags & M_EOR)) { 526 m0->m_flags &= ~M_EOR; 527 m->m_flags |= M_EOR; 528 } 529 sbcompress(sb, m, m0); 530 } 531 532 /* 533 * As above except that OOB data 534 * is inserted at the beginning of the sockbuf, 535 * but after any other OOB data. 536 */ 537 void 538 sbinsertoob(sb, m0) 539 register struct sockbuf *sb; 540 register struct mbuf *m0; 541 { 542 register struct mbuf *m; 543 register struct mbuf **mp; 544 545 if (m0 == 0) 546 return; 547 for (mp = &sb->sb_mb; *mp ; mp = &((*mp)->m_nextpkt)) { 548 m = *mp; 549 again: 550 switch (m->m_type) { 551 552 case MT_OOBDATA: 553 continue; /* WANT next train */ 554 555 case MT_CONTROL: 556 m = m->m_next; 557 if (m) 558 goto again; /* inspect THIS train further */ 559 } 560 break; 561 } 562 /* 563 * Put the first mbuf on the queue. 564 * Note this permits zero length records. 565 */ 566 sballoc(sb, m0); 567 m0->m_nextpkt = *mp; 568 *mp = m0; 569 m = m0->m_next; 570 m0->m_next = 0; 571 if (m && (m0->m_flags & M_EOR)) { 572 m0->m_flags &= ~M_EOR; 573 m->m_flags |= M_EOR; 574 } 575 sbcompress(sb, m, m0); 576 } 577 578 /* 579 * Append address and data, and optionally, control (ancillary) data 580 * to the receive queue of a socket. If present, 581 * m0 must include a packet header with total length. 582 * Returns 0 if no space in sockbuf or insufficient mbufs. 583 */ 584 int 585 sbappendaddr(sb, asa, m0, control) 586 register struct sockbuf *sb; 587 struct sockaddr *asa; 588 struct mbuf *m0, *control; 589 { 590 register struct mbuf *m, *n; 591 int space = asa->sa_len; 592 593 if (m0 && (m0->m_flags & M_PKTHDR) == 0) 594 panic("sbappendaddr"); 595 if (m0) 596 space += m0->m_pkthdr.len; 597 for (n = control; n; n = n->m_next) { 598 space += n->m_len; 599 if (n->m_next == 0) /* keep pointer to last control buf */ 600 break; 601 } 602 if (space > sbspace(sb)) 603 return (0); 604 if (asa->sa_len > MLEN) 605 return (0); 606 MGET(m, M_DONTWAIT, MT_SONAME); 607 if (m == 0) 608 return (0); 609 m->m_len = asa->sa_len; 610 bcopy((caddr_t)asa, mtod(m, caddr_t), asa->sa_len); 611 if (n) 612 n->m_next = m0; /* concatenate data to control */ 613 else 614 control = m0; 615 m->m_next = control; 616 for (n = m; n; n = n->m_next) 617 sballoc(sb, n); 618 n = sb->sb_mb; 619 if (n) { 620 while (n->m_nextpkt) 621 n = n->m_nextpkt; 622 n->m_nextpkt = m; 623 } else 624 sb->sb_mb = m; 625 return (1); 626 } 627 628 int 629 sbappendcontrol(sb, m0, control) 630 struct sockbuf *sb; 631 struct mbuf *control, *m0; 632 { 633 register struct mbuf *m, *n; 634 int space = 0; 635 636 if (control == 0) 637 panic("sbappendcontrol"); 638 for (m = control; ; m = m->m_next) { 639 space += m->m_len; 640 if (m->m_next == 0) 641 break; 642 } 643 n = m; /* save pointer to last control buffer */ 644 for (m = m0; m; m = m->m_next) 645 space += m->m_len; 646 if (space > sbspace(sb)) 647 return (0); 648 n->m_next = m0; /* concatenate data to control */ 649 for (m = control; m; m = m->m_next) 650 sballoc(sb, m); 651 n = sb->sb_mb; 652 if (n) { 653 while (n->m_nextpkt) 654 n = n->m_nextpkt; 655 n->m_nextpkt = control; 656 } else 657 sb->sb_mb = control; 658 return (1); 659 } 660 661 /* 662 * Compress mbuf chain m into the socket 663 * buffer sb following mbuf n. If n 664 * is null, the buffer is presumed empty. 665 */ 666 void 667 sbcompress(sb, m, n) 668 register struct sockbuf *sb; 669 register struct mbuf *m, *n; 670 { 671 register int eor = 0; 672 register struct mbuf *o; 673 674 while (m) { 675 eor |= m->m_flags & M_EOR; 676 if (m->m_len == 0 && 677 (eor == 0 || 678 (((o = m->m_next) || (o = n)) && 679 o->m_type == m->m_type))) { 680 m = m_free(m); 681 continue; 682 } 683 if (n && (n->m_flags & (M_EXT | M_EOR)) == 0 && 684 (n->m_data + n->m_len + m->m_len) < &n->m_dat[MLEN] && 685 n->m_type == m->m_type) { 686 bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len, 687 (unsigned)m->m_len); 688 n->m_len += m->m_len; 689 sb->sb_cc += m->m_len; 690 m = m_free(m); 691 continue; 692 } 693 if (n) 694 n->m_next = m; 695 else 696 sb->sb_mb = m; 697 sballoc(sb, m); 698 n = m; 699 m->m_flags &= ~M_EOR; 700 m = m->m_next; 701 n->m_next = 0; 702 } 703 if (eor) { 704 if (n) 705 n->m_flags |= eor; 706 else 707 printf("semi-panic: sbcompress\n"); 708 } 709 } 710 711 /* 712 * Free all mbufs in a sockbuf. 713 * Check that all resources are reclaimed. 714 */ 715 void 716 sbflush(sb) 717 register struct sockbuf *sb; 718 { 719 720 if (sb->sb_flags & SB_LOCK) 721 panic("sbflush"); 722 while (sb->sb_mbcnt) 723 sbdrop(sb, (int)sb->sb_cc); 724 if (sb->sb_cc || sb->sb_mb) 725 panic("sbflush 2"); 726 } 727 728 /* 729 * Drop data from (the front of) a sockbuf. 730 */ 731 void 732 sbdrop(sb, len) 733 register struct sockbuf *sb; 734 register int len; 735 { 736 register struct mbuf *m, *mn; 737 struct mbuf *next; 738 739 next = (m = sb->sb_mb) ? m->m_nextpkt : 0; 740 while (len > 0) { 741 if (m == 0) { 742 if (next == 0) 743 panic("sbdrop"); 744 m = next; 745 next = m->m_nextpkt; 746 continue; 747 } 748 if (m->m_len > len) { 749 m->m_len -= len; 750 m->m_data += len; 751 sb->sb_cc -= len; 752 break; 753 } 754 len -= m->m_len; 755 sbfree(sb, m); 756 MFREE(m, mn); 757 m = mn; 758 } 759 while (m && m->m_len == 0) { 760 sbfree(sb, m); 761 MFREE(m, mn); 762 m = mn; 763 } 764 if (m) { 765 sb->sb_mb = m; 766 m->m_nextpkt = next; 767 } else 768 sb->sb_mb = next; 769 } 770 771 /* 772 * Drop a record off the front of a sockbuf 773 * and move the next record to the front. 774 */ 775 void 776 sbdroprecord(sb) 777 register struct sockbuf *sb; 778 { 779 register struct mbuf *m, *mn; 780 781 m = sb->sb_mb; 782 if (m) { 783 sb->sb_mb = m->m_nextpkt; 784 do { 785 sbfree(sb, m); 786 MFREE(m, mn); 787 m = mn; 788 } while (m); 789 } 790 } 791