uipc_sockbuf.c revision 1541
15483Swollman/* 250476Speter * Copyright (c) 1982, 1986, 1988, 1990, 1993 31638Srgrimes * The Regents of the University of California. All rights reserved. 4106146Sru * 5106146Sru * Redistribution and use in source and binary forms, with or without 6106146Sru * modification, are permitted provided that the following conditions 7106146Sru * are met: 8136910Sru * 1. Redistributions of source code must retain the above copyright 91638Srgrimes * notice, this list of conditions and the following disclaimer. 101638Srgrimes * 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 */ 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: */ 52char netio[] = "netio"; 53char netcon[] = "netcon"; 54char netcls[] = "netcls"; 55 56u_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 88soisconnecting(so) 89 register struct socket *so; 90{ 91 92 so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING); 93 so->so_state |= SS_ISCONNECTING; 94} 95 96soisconnected(so) 97 register struct socket *so; 98{ 99 register struct socket *head = so->so_head; 100 101 so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING); 102 so->so_state |= SS_ISCONNECTED; 103 if (head && soqremque(so, 0)) { 104 soqinsque(head, so, 1); 105 sorwakeup(head); 106 wakeup((caddr_t)&head->so_timeo); 107 } else { 108 wakeup((caddr_t)&so->so_timeo); 109 sorwakeup(so); 110 sowwakeup(so); 111 } 112} 113 114soisdisconnecting(so) 115 register struct socket *so; 116{ 117 118 so->so_state &= ~SS_ISCONNECTING; 119 so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE); 120 wakeup((caddr_t)&so->so_timeo); 121 sowwakeup(so); 122 sorwakeup(so); 123} 124 125soisdisconnected(so) 126 register struct socket *so; 127{ 128 129 so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING); 130 so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE); 131 wakeup((caddr_t)&so->so_timeo); 132 sowwakeup(so); 133 sorwakeup(so); 134} 135 136/* 137 * When an attempt at a new connection is noted on a socket 138 * which accepts connections, sonewconn is called. If the 139 * connection is possible (subject to space constraints, etc.) 140 * then we allocate a new structure, propoerly linked into the 141 * data structure of the original socket, and return this. 142 * Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED. 143 * 144 * Currently, sonewconn() is defined as sonewconn1() in socketvar.h 145 * to catch calls that are missing the (new) second parameter. 146 */ 147struct socket * 148sonewconn1(head, connstatus) 149 register struct socket *head; 150 int connstatus; 151{ 152 register struct socket *so; 153 int soqueue = connstatus ? 1 : 0; 154 155 if (head->so_qlen + head->so_q0len > 3 * head->so_qlimit / 2) 156 return ((struct socket *)0); 157 MALLOC(so, struct socket *, sizeof(*so), M_SOCKET, M_DONTWAIT); 158 if (so == NULL) 159 return ((struct socket *)0); 160 bzero((caddr_t)so, sizeof(*so)); 161 so->so_type = head->so_type; 162 so->so_options = head->so_options &~ SO_ACCEPTCONN; 163 so->so_linger = head->so_linger; 164 so->so_state = head->so_state | SS_NOFDREF; 165 so->so_proto = head->so_proto; 166 so->so_timeo = head->so_timeo; 167 so->so_pgid = head->so_pgid; 168 (void) soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat); 169 soqinsque(head, so, soqueue); 170 if ((*so->so_proto->pr_usrreq)(so, PRU_ATTACH, 171 (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0)) { 172 (void) soqremque(so, soqueue); 173 (void) free((caddr_t)so, M_SOCKET); 174 return ((struct socket *)0); 175 } 176 if (connstatus) { 177 sorwakeup(head); 178 wakeup((caddr_t)&head->so_timeo); 179 so->so_state |= connstatus; 180 } 181 return (so); 182} 183 184soqinsque(head, so, q) 185 register struct socket *head, *so; 186 int q; 187{ 188 189 register struct socket **prev; 190 so->so_head = head; 191 if (q == 0) { 192 head->so_q0len++; 193 so->so_q0 = 0; 194 for (prev = &(head->so_q0); *prev; ) 195 prev = &((*prev)->so_q0); 196 } else { 197 head->so_qlen++; 198 so->so_q = 0; 199 for (prev = &(head->so_q); *prev; ) 200 prev = &((*prev)->so_q); 201 } 202 *prev = so; 203} 204 205soqremque(so, q) 206 register struct socket *so; 207 int q; 208{ 209 register struct socket *head, *prev, *next; 210 211 head = so->so_head; 212 prev = head; 213 for (;;) { 214 next = q ? prev->so_q : prev->so_q0; 215 if (next == so) 216 break; 217 if (next == 0) 218 return (0); 219 prev = next; 220 } 221 if (q == 0) { 222 prev->so_q0 = next->so_q0; 223 head->so_q0len--; 224 } else { 225 prev->so_q = next->so_q; 226 head->so_qlen--; 227 } 228 next->so_q0 = next->so_q = 0; 229 next->so_head = 0; 230 return (1); 231} 232 233/* 234 * Socantsendmore indicates that no more data will be sent on the 235 * socket; it would normally be applied to a socket when the user 236 * informs the system that no more data is to be sent, by the protocol 237 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data 238 * will be received, and will normally be applied to the socket by a 239 * protocol when it detects that the peer will send no more data. 240 * Data queued for reading in the socket may yet be read. 241 */ 242 243socantsendmore(so) 244 struct socket *so; 245{ 246 247 so->so_state |= SS_CANTSENDMORE; 248 sowwakeup(so); 249} 250 251socantrcvmore(so) 252 struct socket *so; 253{ 254 255 so->so_state |= SS_CANTRCVMORE; 256 sorwakeup(so); 257} 258 259/* 260 * Wait for data to arrive at/drain from a socket buffer. 261 */ 262sbwait(sb) 263 struct sockbuf *sb; 264{ 265 266 sb->sb_flags |= SB_WAIT; 267 return (tsleep((caddr_t)&sb->sb_cc, 268 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, netio, 269 sb->sb_timeo)); 270} 271 272/* 273 * Lock a sockbuf already known to be locked; 274 * return any error returned from sleep (EINTR). 275 */ 276sb_lock(sb) 277 register struct sockbuf *sb; 278{ 279 int error; 280 281 while (sb->sb_flags & SB_LOCK) { 282 sb->sb_flags |= SB_WANT; 283 if (error = tsleep((caddr_t)&sb->sb_flags, 284 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK|PCATCH, 285 netio, 0)) 286 return (error); 287 } 288 sb->sb_flags |= SB_LOCK; 289 return (0); 290} 291 292/* 293 * Wakeup processes waiting on a socket buffer. 294 * Do asynchronous notification via SIGIO 295 * if the socket has the SS_ASYNC flag set. 296 */ 297sowakeup(so, sb) 298 register struct socket *so; 299 register struct sockbuf *sb; 300{ 301 struct proc *p; 302 303 selwakeup(&sb->sb_sel); 304 sb->sb_flags &= ~SB_SEL; 305 if (sb->sb_flags & SB_WAIT) { 306 sb->sb_flags &= ~SB_WAIT; 307 wakeup((caddr_t)&sb->sb_cc); 308 } 309 if (so->so_state & SS_ASYNC) { 310 if (so->so_pgid < 0) 311 gsignal(-so->so_pgid, SIGIO); 312 else if (so->so_pgid > 0 && (p = pfind(so->so_pgid)) != 0) 313 psignal(p, SIGIO); 314 } 315} 316 317/* 318 * Socket buffer (struct sockbuf) utility routines. 319 * 320 * Each socket contains two socket buffers: one for sending data and 321 * one for receiving data. Each buffer contains a queue of mbufs, 322 * information about the number of mbufs and amount of data in the 323 * queue, and other fields allowing select() statements and notification 324 * on data availability to be implemented. 325 * 326 * Data stored in a socket buffer is maintained as a list of records. 327 * Each record is a list of mbufs chained together with the m_next 328 * field. Records are chained together with the m_nextpkt field. The upper 329 * level routine soreceive() expects the following conventions to be 330 * observed when placing information in the receive buffer: 331 * 332 * 1. If the protocol requires each message be preceded by the sender's 333 * name, then a record containing that name must be present before 334 * any associated data (mbuf's must be of type MT_SONAME). 335 * 2. If the protocol supports the exchange of ``access rights'' (really 336 * just additional data associated with the message), and there are 337 * ``rights'' to be received, then a record containing this data 338 * should be present (mbuf's must be of type MT_RIGHTS). 339 * 3. If a name or rights record exists, then it must be followed by 340 * a data record, perhaps of zero length. 341 * 342 * Before using a new socket structure it is first necessary to reserve 343 * buffer space to the socket, by calling sbreserve(). This should commit 344 * some of the available buffer space in the system buffer pool for the 345 * socket (currently, it does nothing but enforce limits). The space 346 * should be released by calling sbrelease() when the socket is destroyed. 347 */ 348 349soreserve(so, sndcc, rcvcc) 350 register struct socket *so; 351 u_long sndcc, rcvcc; 352{ 353 354 if (sbreserve(&so->so_snd, sndcc) == 0) 355 goto bad; 356 if (sbreserve(&so->so_rcv, rcvcc) == 0) 357 goto bad2; 358 if (so->so_rcv.sb_lowat == 0) 359 so->so_rcv.sb_lowat = 1; 360 if (so->so_snd.sb_lowat == 0) 361 so->so_snd.sb_lowat = MCLBYTES; 362 if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat) 363 so->so_snd.sb_lowat = so->so_snd.sb_hiwat; 364 return (0); 365bad2: 366 sbrelease(&so->so_snd); 367bad: 368 return (ENOBUFS); 369} 370 371/* 372 * Allot mbufs to a sockbuf. 373 * Attempt to scale mbmax so that mbcnt doesn't become limiting 374 * if buffering efficiency is near the normal case. 375 */ 376sbreserve(sb, cc) 377 struct sockbuf *sb; 378 u_long cc; 379{ 380 381 if (cc > sb_max * MCLBYTES / (MSIZE + MCLBYTES)) 382 return (0); 383 sb->sb_hiwat = cc; 384 sb->sb_mbmax = min(cc * 2, sb_max); 385 if (sb->sb_lowat > sb->sb_hiwat) 386 sb->sb_lowat = sb->sb_hiwat; 387 return (1); 388} 389 390/* 391 * Free mbufs held by a socket, and reserved mbuf space. 392 */ 393sbrelease(sb) 394 struct sockbuf *sb; 395{ 396 397 sbflush(sb); 398 sb->sb_hiwat = sb->sb_mbmax = 0; 399} 400 401/* 402 * Routines to add and remove 403 * data from an mbuf queue. 404 * 405 * The routines sbappend() or sbappendrecord() are normally called to 406 * append new mbufs to a socket buffer, after checking that adequate 407 * space is available, comparing the function sbspace() with the amount 408 * of data to be added. sbappendrecord() differs from sbappend() in 409 * that data supplied is treated as the beginning of a new record. 410 * To place a sender's address, optional access rights, and data in a 411 * socket receive buffer, sbappendaddr() should be used. To place 412 * access rights and data in a socket receive buffer, sbappendrights() 413 * should be used. In either case, the new data begins a new record. 414 * Note that unlike sbappend() and sbappendrecord(), these routines check 415 * for the caller that there will be enough space to store the data. 416 * Each fails if there is not enough space, or if it cannot find mbufs 417 * to store additional information in. 418 * 419 * Reliable protocols may use the socket send buffer to hold data 420 * awaiting acknowledgement. Data is normally copied from a socket 421 * send buffer in a protocol with m_copy for output to a peer, 422 * and then removing the data from the socket buffer with sbdrop() 423 * or sbdroprecord() when the data is acknowledged by the peer. 424 */ 425 426/* 427 * Append mbuf chain m to the last record in the 428 * socket buffer sb. The additional space associated 429 * the mbuf chain is recorded in sb. Empty mbufs are 430 * discarded and mbufs are compacted where possible. 431 */ 432sbappend(sb, m) 433 struct sockbuf *sb; 434 struct mbuf *m; 435{ 436 register struct mbuf *n; 437 438 if (m == 0) 439 return; 440 if (n = sb->sb_mb) { 441 while (n->m_nextpkt) 442 n = n->m_nextpkt; 443 do { 444 if (n->m_flags & M_EOR) { 445 sbappendrecord(sb, m); /* XXXXXX!!!! */ 446 return; 447 } 448 } while (n->m_next && (n = n->m_next)); 449 } 450 sbcompress(sb, m, n); 451} 452 453#ifdef SOCKBUF_DEBUG 454sbcheck(sb) 455 register struct sockbuf *sb; 456{ 457 register struct mbuf *m; 458 register int len = 0, mbcnt = 0; 459 460 for (m = sb->sb_mb; m; m = m->m_next) { 461 len += m->m_len; 462 mbcnt += MSIZE; 463 if (m->m_flags & M_EXT) 464 mbcnt += m->m_ext.ext_size; 465 if (m->m_nextpkt) 466 panic("sbcheck nextpkt"); 467 } 468 if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) { 469 printf("cc %d != %d || mbcnt %d != %d\n", len, sb->sb_cc, 470 mbcnt, sb->sb_mbcnt); 471 panic("sbcheck"); 472 } 473} 474#endif 475 476/* 477 * As above, except the mbuf chain 478 * begins a new record. 479 */ 480sbappendrecord(sb, m0) 481 register struct sockbuf *sb; 482 register struct mbuf *m0; 483{ 484 register struct mbuf *m; 485 486 if (m0 == 0) 487 return; 488 if (m = sb->sb_mb) 489 while (m->m_nextpkt) 490 m = m->m_nextpkt; 491 /* 492 * Put the first mbuf on the queue. 493 * Note this permits zero length records. 494 */ 495 sballoc(sb, m0); 496 if (m) 497 m->m_nextpkt = m0; 498 else 499 sb->sb_mb = m0; 500 m = m0->m_next; 501 m0->m_next = 0; 502 if (m && (m0->m_flags & M_EOR)) { 503 m0->m_flags &= ~M_EOR; 504 m->m_flags |= M_EOR; 505 } 506 sbcompress(sb, m, m0); 507} 508 509/* 510 * As above except that OOB data 511 * is inserted at the beginning of the sockbuf, 512 * but after any other OOB data. 513 */ 514sbinsertoob(sb, m0) 515 register struct sockbuf *sb; 516 register struct mbuf *m0; 517{ 518 register struct mbuf *m; 519 register struct mbuf **mp; 520 521 if (m0 == 0) 522 return; 523 for (mp = &sb->sb_mb; m = *mp; mp = &((*mp)->m_nextpkt)) { 524 again: 525 switch (m->m_type) { 526 527 case MT_OOBDATA: 528 continue; /* WANT next train */ 529 530 case MT_CONTROL: 531 if (m = m->m_next) 532 goto again; /* inspect THIS train further */ 533 } 534 break; 535 } 536 /* 537 * Put the first mbuf on the queue. 538 * Note this permits zero length records. 539 */ 540 sballoc(sb, m0); 541 m0->m_nextpkt = *mp; 542 *mp = m0; 543 m = m0->m_next; 544 m0->m_next = 0; 545 if (m && (m0->m_flags & M_EOR)) { 546 m0->m_flags &= ~M_EOR; 547 m->m_flags |= M_EOR; 548 } 549 sbcompress(sb, m, m0); 550} 551 552/* 553 * Append address and data, and optionally, control (ancillary) data 554 * to the receive queue of a socket. If present, 555 * m0 must include a packet header with total length. 556 * Returns 0 if no space in sockbuf or insufficient mbufs. 557 */ 558sbappendaddr(sb, asa, m0, control) 559 register struct sockbuf *sb; 560 struct sockaddr *asa; 561 struct mbuf *m0, *control; 562{ 563 register struct mbuf *m, *n; 564 int space = asa->sa_len; 565 566if (m0 && (m0->m_flags & M_PKTHDR) == 0) 567panic("sbappendaddr"); 568 if (m0) 569 space += m0->m_pkthdr.len; 570 for (n = control; n; n = n->m_next) { 571 space += n->m_len; 572 if (n->m_next == 0) /* keep pointer to last control buf */ 573 break; 574 } 575 if (space > sbspace(sb)) 576 return (0); 577 if (asa->sa_len > MLEN) 578 return (0); 579 MGET(m, M_DONTWAIT, MT_SONAME); 580 if (m == 0) 581 return (0); 582 m->m_len = asa->sa_len; 583 bcopy((caddr_t)asa, mtod(m, caddr_t), asa->sa_len); 584 if (n) 585 n->m_next = m0; /* concatenate data to control */ 586 else 587 control = m0; 588 m->m_next = control; 589 for (n = m; n; n = n->m_next) 590 sballoc(sb, n); 591 if (n = sb->sb_mb) { 592 while (n->m_nextpkt) 593 n = n->m_nextpkt; 594 n->m_nextpkt = m; 595 } else 596 sb->sb_mb = m; 597 return (1); 598} 599 600sbappendcontrol(sb, m0, control) 601 struct sockbuf *sb; 602 struct mbuf *control, *m0; 603{ 604 register struct mbuf *m, *n; 605 int space = 0; 606 607 if (control == 0) 608 panic("sbappendcontrol"); 609 for (m = control; ; m = m->m_next) { 610 space += m->m_len; 611 if (m->m_next == 0) 612 break; 613 } 614 n = m; /* save pointer to last control buffer */ 615 for (m = m0; m; m = m->m_next) 616 space += m->m_len; 617 if (space > sbspace(sb)) 618 return (0); 619 n->m_next = m0; /* concatenate data to control */ 620 for (m = control; m; m = m->m_next) 621 sballoc(sb, m); 622 if (n = sb->sb_mb) { 623 while (n->m_nextpkt) 624 n = n->m_nextpkt; 625 n->m_nextpkt = control; 626 } else 627 sb->sb_mb = control; 628 return (1); 629} 630 631/* 632 * Compress mbuf chain m into the socket 633 * buffer sb following mbuf n. If n 634 * is null, the buffer is presumed empty. 635 */ 636sbcompress(sb, m, n) 637 register struct sockbuf *sb; 638 register struct mbuf *m, *n; 639{ 640 register int eor = 0; 641 register struct mbuf *o; 642 643 while (m) { 644 eor |= m->m_flags & M_EOR; 645 if (m->m_len == 0 && 646 (eor == 0 || 647 (((o = m->m_next) || (o = n)) && 648 o->m_type == m->m_type))) { 649 m = m_free(m); 650 continue; 651 } 652 if (n && (n->m_flags & (M_EXT | M_EOR)) == 0 && 653 (n->m_data + n->m_len + m->m_len) < &n->m_dat[MLEN] && 654 n->m_type == m->m_type) { 655 bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len, 656 (unsigned)m->m_len); 657 n->m_len += m->m_len; 658 sb->sb_cc += m->m_len; 659 m = m_free(m); 660 continue; 661 } 662 if (n) 663 n->m_next = m; 664 else 665 sb->sb_mb = m; 666 sballoc(sb, m); 667 n = m; 668 m->m_flags &= ~M_EOR; 669 m = m->m_next; 670 n->m_next = 0; 671 } 672 if (eor) { 673 if (n) 674 n->m_flags |= eor; 675 else 676 printf("semi-panic: sbcompress\n"); 677 } 678} 679 680/* 681 * Free all mbufs in a sockbuf. 682 * Check that all resources are reclaimed. 683 */ 684sbflush(sb) 685 register struct sockbuf *sb; 686{ 687 688 if (sb->sb_flags & SB_LOCK) 689 panic("sbflush"); 690 while (sb->sb_mbcnt) 691 sbdrop(sb, (int)sb->sb_cc); 692 if (sb->sb_cc || sb->sb_mb) 693 panic("sbflush 2"); 694} 695 696/* 697 * Drop data from (the front of) a sockbuf. 698 */ 699sbdrop(sb, len) 700 register struct sockbuf *sb; 701 register int len; 702{ 703 register struct mbuf *m, *mn; 704 struct mbuf *next; 705 706 next = (m = sb->sb_mb) ? m->m_nextpkt : 0; 707 while (len > 0) { 708 if (m == 0) { 709 if (next == 0) 710 panic("sbdrop"); 711 m = next; 712 next = m->m_nextpkt; 713 continue; 714 } 715 if (m->m_len > len) { 716 m->m_len -= len; 717 m->m_data += len; 718 sb->sb_cc -= len; 719 break; 720 } 721 len -= m->m_len; 722 sbfree(sb, m); 723 MFREE(m, mn); 724 m = mn; 725 } 726 while (m && m->m_len == 0) { 727 sbfree(sb, m); 728 MFREE(m, mn); 729 m = mn; 730 } 731 if (m) { 732 sb->sb_mb = m; 733 m->m_nextpkt = next; 734 } else 735 sb->sb_mb = next; 736} 737 738/* 739 * Drop a record off the front of a sockbuf 740 * and move the next record to the front. 741 */ 742sbdroprecord(sb) 743 register struct sockbuf *sb; 744{ 745 register struct mbuf *m, *mn; 746 747 m = sb->sb_mb; 748 if (m) { 749 sb->sb_mb = m->m_nextpkt; 750 do { 751 sbfree(sb, m); 752 MFREE(m, mn); 753 } while (m = mn); 754 } 755} 756