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 1993/06/27 06:02:00 andrew 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 /* 50 * Primitive routines for operating on sockets and socket buffers 51 */ 52 53 /* strings for sleep message: */ 54 char netio[] = "netio"; 55 char netcon[] = "netcon"; 56 char netcls[] = "netcls"; 57 58 u_long sb_max = SB_MAX; /* patchable */ 59 60 /* 61 * Procedures to manipulate state flags of socket 62 * and do appropriate wakeups. Normal sequence from the 63 * active (originating) side is that soisconnecting() is 64 * called during processing of connect() call, 65 * resulting in an eventual call to soisconnected() if/when the 66 * connection is established. When the connection is torn down 67 * soisdisconnecting() is called during processing of disconnect() call, 68 * and soisdisconnected() is called when the connection to the peer 69 * is totally severed. The semantics of these routines are such that 70 * connectionless protocols can call soisconnected() and soisdisconnected() 71 * only, bypassing the in-progress calls when setting up a ``connection'' 72 * takes no time. 73 * 74 * From the passive side, a socket is created with 75 * two queues of sockets: so_q0 for connections in progress 76 * and so_q for connections already made and awaiting user acceptance. 77 * As a protocol is preparing incoming connections, it creates a socket 78 * structure queued on so_q0 by calling sonewconn(). When the connection 79 * is established, soisconnected() is called, and transfers the 80 * socket structure to so_q, making it available to accept(). 81 * 82 * If a socket is closed with sockets on either 83 * so_q0 or so_q, these sockets are dropped. 84 * 85 * If higher level protocols are implemented in 86 * the kernel, the wakeups done here will sometimes 87 * cause software-interrupt process scheduling. 88 */ 89 90 soisconnecting(so) 91 register struct socket *so; 92 { 93 94 so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING); 95 so->so_state |= SS_ISCONNECTING; 96 } 97 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 soisdisconnecting(so) 117 register struct socket *so; 118 { 119 120 so->so_state &= ~SS_ISCONNECTING; 121 so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE); 122 wakeup((caddr_t)&so->so_timeo); 123 sowwakeup(so); 124 sorwakeup(so); 125 } 126 127 soisdisconnected(so) 128 register struct socket *so; 129 { 130 131 so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING); 132 so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE); 133 wakeup((caddr_t)&so->so_timeo); 134 sowwakeup(so); 135 sorwakeup(so); 136 } 137 138 /* 139 * When an attempt at a new connection is noted on a socket 140 * which accepts connections, sonewconn is called. If the 141 * connection is possible (subject to space constraints, etc.) 142 * then we allocate a new structure, propoerly linked into the 143 * data structure of the original socket, and return this. 144 * Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED. 145 * 146 * Currently, sonewconn() is defined as sonewconn1() in socketvar.h 147 * to catch calls that are missing the (new) second parameter. 148 */ 149 struct socket * 150 sonewconn1(head, connstatus) 151 register struct socket *head; 152 int connstatus; 153 { 154 register struct socket *so; 155 int soqueue = connstatus ? 1 : 0; 156 157 if (head->so_qlen + head->so_q0len > 3 * head->so_qlimit / 2) 158 return ((struct socket *)0); 159 MALLOC(so, struct socket *, sizeof(*so), M_SOCKET, M_DONTWAIT); 160 if (so == NULL) 161 return ((struct socket *)0); 162 bzero((caddr_t)so, sizeof(*so)); 163 so->so_type = head->so_type; 164 so->so_options = head->so_options &~ SO_ACCEPTCONN; 165 so->so_linger = head->so_linger; 166 so->so_state = head->so_state | SS_NOFDREF; 167 so->so_proto = head->so_proto; 168 so->so_timeo = head->so_timeo; 169 so->so_pgid = head->so_pgid; 170 (void) soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat); 171 soqinsque(head, so, soqueue); 172 if ((*so->so_proto->pr_usrreq)(so, PRU_ATTACH, 173 (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0)) { 174 (void) soqremque(so, soqueue); 175 (void) free((caddr_t)so, M_SOCKET); 176 return ((struct socket *)0); 177 } 178 if (connstatus) { 179 sorwakeup(head); 180 wakeup((caddr_t)&head->so_timeo); 181 so->so_state |= connstatus; 182 } 183 return (so); 184 } 185 186 soqinsque(head, so, q) 187 register struct socket *head, *so; 188 int q; 189 { 190 191 register struct socket **prev; 192 so->so_head = head; 193 if (q == 0) { 194 head->so_q0len++; 195 so->so_q0 = 0; 196 for (prev = &(head->so_q0); *prev; ) 197 prev = &((*prev)->so_q0); 198 } else { 199 head->so_qlen++; 200 so->so_q = 0; 201 for (prev = &(head->so_q); *prev; ) 202 prev = &((*prev)->so_q); 203 } 204 *prev = so; 205 } 206 207 soqremque(so, q) 208 register struct socket *so; 209 int q; 210 { 211 register struct socket *head, *prev, *next; 212 213 head = so->so_head; 214 prev = head; 215 for (;;) { 216 next = q ? prev->so_q : prev->so_q0; 217 if (next == so) 218 break; 219 if (next == 0) 220 return (0); 221 prev = next; 222 } 223 if (q == 0) { 224 prev->so_q0 = next->so_q0; 225 head->so_q0len--; 226 } else { 227 prev->so_q = next->so_q; 228 head->so_qlen--; 229 } 230 next->so_q0 = next->so_q = 0; 231 next->so_head = 0; 232 return (1); 233 } 234 235 /* 236 * Socantsendmore indicates that no more data will be sent on the 237 * socket; it would normally be applied to a socket when the user 238 * informs the system that no more data is to be sent, by the protocol 239 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data 240 * will be received, and will normally be applied to the socket by a 241 * protocol when it detects that the peer will send no more data. 242 * Data queued for reading in the socket may yet be read. 243 */ 244 245 void 246 socantsendmore(so) 247 struct socket *so; 248 { 249 250 so->so_state |= SS_CANTSENDMORE; 251 sowwakeup(so); 252 } 253 254 void 255 socantrcvmore(so) 256 struct socket *so; 257 { 258 259 so->so_state |= SS_CANTRCVMORE; 260 sorwakeup(so); 261 } 262 263 /* 264 * Socket select/wakeup routines. 265 */ 266 267 /* 268 * Queue a process for a select on a socket buffer. 269 */ 270 sbselqueue(sb, cp) 271 struct sockbuf *sb; 272 struct proc *cp; 273 { 274 selrecord(cp, &sb->sb_sel); 275 sb->sb_flags |= SB_SEL; 276 } 277 278 /* 279 * Wait for data to arrive at/drain from a socket buffer. 280 */ 281 sbwait(sb) 282 struct sockbuf *sb; 283 { 284 285 sb->sb_flags |= SB_WAIT; 286 return (tsleep((caddr_t)&sb->sb_cc, 287 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, netio, 288 sb->sb_timeo)); 289 } 290 291 /* 292 * Lock a sockbuf already known to be locked; 293 * return any error returned from sleep (EINTR). 294 */ 295 sb_lock(sb) 296 register struct sockbuf *sb; 297 { 298 int error; 299 300 while (sb->sb_flags & SB_LOCK) { 301 sb->sb_flags |= SB_WANT; 302 if (error = tsleep((caddr_t)&sb->sb_flags, 303 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK|PCATCH, 304 netio, 0)) 305 return (error); 306 } 307 sb->sb_flags |= SB_LOCK; 308 return (0); 309 } 310 311 /* 312 * Wakeup processes waiting on a socket buffer. 313 * Do asynchronous notification via SIGIO 314 * if the socket has the SS_ASYNC flag set. 315 */ 316 sowakeup(so, sb) 317 register struct socket *so; 318 register struct sockbuf *sb; 319 { 320 struct proc *p; 321 322 selwakeup(&sb->sb_sel); 323 sb->sb_flags &= ~SB_SEL; 324 if (sb->sb_flags & SB_WAIT) { 325 sb->sb_flags &= ~SB_WAIT; 326 wakeup((caddr_t)&sb->sb_cc); 327 } 328 if (so->so_state & SS_ASYNC) { 329 if (so->so_pgid < 0) 330 gsignal(-so->so_pgid, SIGIO); 331 else if (so->so_pgid > 0 && (p = pfind(so->so_pgid)) != 0) 332 psignal(p, SIGIO); 333 } 334 } 335 336 /* 337 * Socket buffer (struct sockbuf) utility routines. 338 * 339 * Each socket contains two socket buffers: one for sending data and 340 * one for receiving data. Each buffer contains a queue of mbufs, 341 * information about the number of mbufs and amount of data in the 342 * queue, and other fields allowing select() statements and notification 343 * on data availability to be implemented. 344 * 345 * Data stored in a socket buffer is maintained as a list of records. 346 * Each record is a list of mbufs chained together with the m_next 347 * field. Records are chained together with the m_nextpkt field. The upper 348 * level routine soreceive() expects the following conventions to be 349 * observed when placing information in the receive buffer: 350 * 351 * 1. If the protocol requires each message be preceded by the sender's 352 * name, then a record containing that name must be present before 353 * any associated data (mbuf's must be of type MT_SONAME). 354 * 2. If the protocol supports the exchange of ``access rights'' (really 355 * just additional data associated with the message), and there are 356 * ``rights'' to be received, then a record containing this data 357 * should be present (mbuf's must be of type MT_RIGHTS). 358 * 3. If a name or rights record exists, then it must be followed by 359 * a data record, perhaps of zero length. 360 * 361 * Before using a new socket structure it is first necessary to reserve 362 * buffer space to the socket, by calling sbreserve(). This should commit 363 * some of the available buffer space in the system buffer pool for the 364 * socket (currently, it does nothing but enforce limits). The space 365 * should be released by calling sbrelease() when the socket is destroyed. 366 */ 367 368 soreserve(so, sndcc, rcvcc) 369 register struct socket *so; 370 u_long sndcc, rcvcc; 371 { 372 373 if (sbreserve(&so->so_snd, sndcc) == 0) 374 goto bad; 375 if (sbreserve(&so->so_rcv, rcvcc) == 0) 376 goto bad2; 377 if (so->so_rcv.sb_lowat == 0) 378 so->so_rcv.sb_lowat = 1; 379 if (so->so_snd.sb_lowat == 0) 380 so->so_snd.sb_lowat = MCLBYTES; 381 if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat) 382 so->so_snd.sb_lowat = so->so_snd.sb_hiwat; 383 return (0); 384 bad2: 385 sbrelease(&so->so_snd); 386 bad: 387 return (ENOBUFS); 388 } 389 390 /* 391 * Allot mbufs to a sockbuf. 392 * Attempt to scale mbmax so that mbcnt doesn't become limiting 393 * if buffering efficiency is near the normal case. 394 */ 395 sbreserve(sb, cc) 396 struct sockbuf *sb; 397 u_long cc; 398 { 399 400 if (cc > sb_max * MCLBYTES / (MSIZE + MCLBYTES)) 401 return (0); 402 sb->sb_hiwat = cc; 403 sb->sb_mbmax = min(cc * 2, sb_max); 404 if (sb->sb_lowat > sb->sb_hiwat) 405 sb->sb_lowat = sb->sb_hiwat; 406 return (1); 407 } 408 409 /* 410 * Free mbufs held by a socket, and reserved mbuf space. 411 */ 412 sbrelease(sb) 413 struct sockbuf *sb; 414 { 415 416 sbflush(sb); 417 sb->sb_hiwat = sb->sb_mbmax = 0; 418 } 419 420 /* 421 * Routines to add and remove 422 * data from an mbuf queue. 423 * 424 * The routines sbappend() or sbappendrecord() are normally called to 425 * append new mbufs to a socket buffer, after checking that adequate 426 * space is available, comparing the function sbspace() with the amount 427 * of data to be added. sbappendrecord() differs from sbappend() in 428 * that data supplied is treated as the beginning of a new record. 429 * To place a sender's address, optional access rights, and data in a 430 * socket receive buffer, sbappendaddr() should be used. To place 431 * access rights and data in a socket receive buffer, sbappendrights() 432 * should be used. In either case, the new data begins a new record. 433 * Note that unlike sbappend() and sbappendrecord(), these routines check 434 * for the caller that there will be enough space to store the data. 435 * Each fails if there is not enough space, or if it cannot find mbufs 436 * to store additional information in. 437 * 438 * Reliable protocols may use the socket send buffer to hold data 439 * awaiting acknowledgement. Data is normally copied from a socket 440 * send buffer in a protocol with m_copy for output to a peer, 441 * and then removing the data from the socket buffer with sbdrop() 442 * or sbdroprecord() when the data is acknowledged by the peer. 443 */ 444 445 /* 446 * Append mbuf chain m to the last record in the 447 * socket buffer sb. The additional space associated 448 * the mbuf chain is recorded in sb. Empty mbufs are 449 * discarded and mbufs are compacted where possible. 450 */ 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 if (n = sb->sb_mb) { 460 while (n->m_nextpkt) 461 n = n->m_nextpkt; 462 do { 463 if (n->m_flags & M_EOR) { 464 sbappendrecord(sb, m); /* XXXXXX!!!! */ 465 return; 466 } 467 } while (n->m_next && (n = n->m_next)); 468 } 469 sbcompress(sb, m, n); 470 } 471 472 #ifdef SOCKBUF_DEBUG 473 sbcheck(sb) 474 register struct sockbuf *sb; 475 { 476 register struct mbuf *m; 477 register int len = 0, mbcnt = 0; 478 479 for (m = sb->sb_mb; m; m = m->m_next) { 480 len += m->m_len; 481 mbcnt += MSIZE; 482 if (m->m_flags & M_EXT) 483 mbcnt += m->m_ext.ext_size; 484 if (m->m_nextpkt) 485 panic("sbcheck nextpkt"); 486 } 487 if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) { 488 printf("cc %d != %d || mbcnt %d != %d\n", len, sb->sb_cc, 489 mbcnt, sb->sb_mbcnt); 490 panic("sbcheck"); 491 } 492 } 493 #endif 494 495 /* 496 * As above, except the mbuf chain 497 * begins a new record. 498 */ 499 sbappendrecord(sb, m0) 500 register struct sockbuf *sb; 501 register struct mbuf *m0; 502 { 503 register struct mbuf *m; 504 505 if (m0 == 0) 506 return; 507 if (m = sb->sb_mb) 508 while (m->m_nextpkt) 509 m = m->m_nextpkt; 510 /* 511 * Put the first mbuf on the queue. 512 * Note this permits zero length records. 513 */ 514 sballoc(sb, m0); 515 if (m) 516 m->m_nextpkt = m0; 517 else 518 sb->sb_mb = m0; 519 m = m0->m_next; 520 m0->m_next = 0; 521 if (m && (m0->m_flags & M_EOR)) { 522 m0->m_flags &= ~M_EOR; 523 m->m_flags |= M_EOR; 524 } 525 sbcompress(sb, m, m0); 526 } 527 528 /* 529 * As above except that OOB data 530 * is inserted at the beginning of the sockbuf, 531 * but after any other OOB data. 532 */ 533 sbinsertoob(sb, m0) 534 register struct sockbuf *sb; 535 register struct mbuf *m0; 536 { 537 register struct mbuf *m; 538 register struct mbuf **mp; 539 540 if (m0 == 0) 541 return; 542 for (mp = &sb->sb_mb; m = *mp; mp = &((*mp)->m_nextpkt)) { 543 again: 544 switch (m->m_type) { 545 546 case MT_OOBDATA: 547 continue; /* WANT next train */ 548 549 case MT_CONTROL: 550 if (m = m->m_next) 551 goto again; /* inspect THIS train further */ 552 } 553 break; 554 } 555 /* 556 * Put the first mbuf on the queue. 557 * Note this permits zero length records. 558 */ 559 sballoc(sb, m0); 560 m0->m_nextpkt = *mp; 561 *mp = m0; 562 m = m0->m_next; 563 m0->m_next = 0; 564 if (m && (m0->m_flags & M_EOR)) { 565 m0->m_flags &= ~M_EOR; 566 m->m_flags |= M_EOR; 567 } 568 sbcompress(sb, m, m0); 569 } 570 571 /* 572 * Append address and data, and optionally, control (ancillary) data 573 * to the receive queue of a socket. If present, 574 * m0 must include a packet header with total length. 575 * Returns 0 if no space in sockbuf or insufficient mbufs. 576 */ 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 sbappendcontrol(sb, m0, control) 620 struct sockbuf *sb; 621 struct mbuf *control, *m0; 622 { 623 register struct mbuf *m, *n; 624 int space = 0; 625 626 if (control == 0) 627 panic("sbappendcontrol"); 628 for (m = control; ; m = m->m_next) { 629 space += m->m_len; 630 if (m->m_next == 0) 631 break; 632 } 633 n = m; /* save pointer to last control buffer */ 634 for (m = m0; m; m = m->m_next) 635 space += m->m_len; 636 if (space > sbspace(sb)) 637 return (0); 638 n->m_next = m0; /* concatenate data to control */ 639 for (m = control; m; m = m->m_next) 640 sballoc(sb, m); 641 if (n = sb->sb_mb) { 642 while (n->m_nextpkt) 643 n = n->m_nextpkt; 644 n->m_nextpkt = control; 645 } else 646 sb->sb_mb = control; 647 return (1); 648 } 649 650 /* 651 * Compress mbuf chain m into the socket 652 * buffer sb following mbuf n. If n 653 * is null, the buffer is presumed empty. 654 */ 655 sbcompress(sb, m, n) 656 register struct sockbuf *sb; 657 register struct mbuf *m, *n; 658 { 659 register int eor = 0; 660 register struct mbuf *o; 661 662 while (m) { 663 eor |= m->m_flags & M_EOR; 664 if (m->m_len == 0 && 665 (eor == 0 || 666 (((o = m->m_next) || (o = n)) && 667 o->m_type == m->m_type))) { 668 m = m_free(m); 669 continue; 670 } 671 if (n && (n->m_flags & (M_EXT | M_EOR)) == 0 && 672 (n->m_data + n->m_len + m->m_len) < &n->m_dat[MLEN] && 673 n->m_type == m->m_type) { 674 bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len, 675 (unsigned)m->m_len); 676 n->m_len += m->m_len; 677 sb->sb_cc += m->m_len; 678 m = m_free(m); 679 continue; 680 } 681 if (n) 682 n->m_next = m; 683 else 684 sb->sb_mb = m; 685 sballoc(sb, m); 686 n = m; 687 m->m_flags &= ~M_EOR; 688 m = m->m_next; 689 n->m_next = 0; 690 } 691 if (eor) { 692 if (n) 693 n->m_flags |= eor; 694 else 695 printf("semi-panic: sbcompress\n"); 696 } 697 } 698 699 /* 700 * Free all mbufs in a sockbuf. 701 * Check that all resources are reclaimed. 702 */ 703 sbflush(sb) 704 register struct sockbuf *sb; 705 { 706 707 if (sb->sb_flags & SB_LOCK) 708 panic("sbflush"); 709 while (sb->sb_mbcnt) 710 sbdrop(sb, (int)sb->sb_cc); 711 if (sb->sb_cc || sb->sb_mb) 712 panic("sbflush 2"); 713 } 714 715 /* 716 * Drop data from (the front of) a sockbuf. 717 */ 718 sbdrop(sb, len) 719 register struct sockbuf *sb; 720 register int len; 721 { 722 register struct mbuf *m, *mn; 723 struct mbuf *next; 724 725 next = (m = sb->sb_mb) ? m->m_nextpkt : 0; 726 while (len > 0) { 727 if (m == 0) { 728 if (next == 0) 729 panic("sbdrop"); 730 m = next; 731 next = m->m_nextpkt; 732 continue; 733 } 734 if (m->m_len > len) { 735 m->m_len -= len; 736 m->m_data += len; 737 sb->sb_cc -= len; 738 break; 739 } 740 len -= m->m_len; 741 sbfree(sb, m); 742 MFREE(m, mn); 743 m = mn; 744 } 745 while (m && m->m_len == 0) { 746 sbfree(sb, m); 747 MFREE(m, mn); 748 m = mn; 749 } 750 if (m) { 751 sb->sb_mb = m; 752 m->m_nextpkt = next; 753 } else 754 sb->sb_mb = next; 755 } 756 757 /* 758 * Drop a record off the front of a sockbuf 759 * and move the next record to the front. 760 */ 761 sbdroprecord(sb) 762 register struct sockbuf *sb; 763 { 764 register struct mbuf *m, *mn; 765 766 m = sb->sb_mb; 767 if (m) { 768 sb->sb_mb = m->m_nextpkt; 769 do { 770 sbfree(sb, m); 771 MFREE(m, mn); 772 } while (m = mn); 773 } 774 } 775