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 1.5 1995/05/30 08:06:22 rgrimes Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/kernel.h> 40 #include <sys/proc.h> 41 #include <sys/file.h> 42 #include <sys/buf.h> 43 #include <sys/malloc.h> 44 #include <sys/mbuf.h> 45 #include <sys/protosw.h> 46 #include <sys/stat.h> 47 #include <sys/socket.h> 48 #include <sys/socketvar.h> 49 #include <sys/signalvar.h> 50 #include <sys/sysctl.h> 51 52 /* 53 * Primitive routines for operating on sockets and socket buffers 54 */ 55 56 /* strings for sleep message: */ 57 char netio[] = "netio"; 58 char netcon[] = "netcon"; 59 char netcls[] = "netcls"; 60 61 u_long sb_max = SB_MAX; /* XXX should be static */ 62 SYSCTL_INT(_kern, KERN_MAXSOCKBUF, maxsockbuf, CTLFLAG_RW, &sb_max, 0, "") 63 64 /* 65 * Procedures to manipulate state flags of socket 66 * and do appropriate wakeups. Normal sequence from the 67 * active (originating) side is that soisconnecting() is 68 * called during processing of connect() call, 69 * resulting in an eventual call to soisconnected() if/when the 70 * connection is established. When the connection is torn down 71 * soisdisconnecting() is called during processing of disconnect() call, 72 * and soisdisconnected() is called when the connection to the peer 73 * is totally severed. The semantics of these routines are such that 74 * connectionless protocols can call soisconnected() and soisdisconnected() 75 * only, bypassing the in-progress calls when setting up a ``connection'' 76 * takes no time. 77 * 78 * From the passive side, a socket is created with 79 * two queues of sockets: so_q0 for connections in progress 80 * and so_q for connections already made and awaiting user acceptance. 81 * As a protocol is preparing incoming connections, it creates a socket 82 * structure queued on so_q0 by calling sonewconn(). When the connection 83 * is established, soisconnected() is called, and transfers the 84 * socket structure to so_q, making it available to accept(). 85 * 86 * If a socket is closed with sockets on either 87 * so_q0 or so_q, these sockets are dropped. 88 * 89 * If higher level protocols are implemented in 90 * the kernel, the wakeups done here will sometimes 91 * cause software-interrupt process scheduling. 92 */ 93 94 void 95 soisconnecting(so) 96 register struct socket *so; 97 { 98 99 so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING); 100 so->so_state |= SS_ISCONNECTING; 101 } 102 103 void 104 soisconnected(so) 105 register struct socket *so; 106 { 107 register struct socket *head = so->so_head; 108 109 so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING); 110 so->so_state |= SS_ISCONNECTED; 111 if (head && soqremque(so, 0)) { 112 soqinsque(head, so, 1); 113 sorwakeup(head); 114 wakeup((caddr_t)&head->so_timeo); 115 } else { 116 wakeup((caddr_t)&so->so_timeo); 117 sorwakeup(so); 118 sowwakeup(so); 119 } 120 } 121 122 void 123 soisdisconnecting(so) 124 register struct socket *so; 125 { 126 127 so->so_state &= ~SS_ISCONNECTING; 128 so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE); 129 wakeup((caddr_t)&so->so_timeo); 130 sowwakeup(so); 131 sorwakeup(so); 132 } 133 134 void 135 soisdisconnected(so) 136 register struct socket *so; 137 { 138 139 so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING); 140 so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE); 141 wakeup((caddr_t)&so->so_timeo); 142 sowwakeup(so); 143 sorwakeup(so); 144 } 145 146 /* 147 * When an attempt at a new connection is noted on a socket 148 * which accepts connections, sonewconn is called. If the 149 * connection is possible (subject to space constraints, etc.) 150 * then we allocate a new structure, propoerly linked into the 151 * data structure of the original socket, and return this. 152 * Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED. 153 * 154 * Currently, sonewconn() is defined as sonewconn1() in socketvar.h 155 * to catch calls that are missing the (new) second parameter. 156 */ 157 struct socket * 158 sonewconn1(head, connstatus) 159 register struct socket *head; 160 int connstatus; 161 { 162 register struct socket *so; 163 int soqueue = connstatus ? 1 : 0; 164 165 if (head->so_qlen + head->so_q0len > 3 * head->so_qlimit / 2) 166 return ((struct socket *)0); 167 MALLOC(so, struct socket *, sizeof(*so), M_SOCKET, M_DONTWAIT); 168 if (so == NULL) 169 return ((struct socket *)0); 170 bzero((caddr_t)so, sizeof(*so)); 171 so->so_type = head->so_type; 172 so->so_options = head->so_options &~ SO_ACCEPTCONN; 173 so->so_linger = head->so_linger; 174 so->so_state = head->so_state | SS_NOFDREF; 175 so->so_proto = head->so_proto; 176 so->so_timeo = head->so_timeo; 177 so->so_pgid = head->so_pgid; 178 (void) soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat); 179 soqinsque(head, so, soqueue); 180 if ((*so->so_proto->pr_usrreq)(so, PRU_ATTACH, 181 (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0)) { 182 (void) soqremque(so, soqueue); 183 (void) free((caddr_t)so, M_SOCKET); 184 return ((struct socket *)0); 185 } 186 if (connstatus) { 187 sorwakeup(head); 188 wakeup((caddr_t)&head->so_timeo); 189 so->so_state |= connstatus; 190 } 191 return (so); 192 } 193 194 void 195 soqinsque(head, so, q) 196 register struct socket *head, *so; 197 int q; 198 { 199 200 register struct socket **prev; 201 so->so_head = head; 202 if (q == 0) { 203 head->so_q0len++; 204 so->so_q0 = 0; 205 for (prev = &(head->so_q0); *prev; ) 206 prev = &((*prev)->so_q0); 207 } else { 208 head->so_qlen++; 209 so->so_q = 0; 210 for (prev = &(head->so_q); *prev; ) 211 prev = &((*prev)->so_q); 212 } 213 *prev = so; 214 } 215 216 int 217 soqremque(so, q) 218 register struct socket *so; 219 int q; 220 { 221 register struct socket *head, *prev, *next; 222 223 head = so->so_head; 224 prev = head; 225 for (;;) { 226 next = q ? prev->so_q : prev->so_q0; 227 if (next == so) 228 break; 229 if (next == 0) 230 return (0); 231 prev = next; 232 } 233 if (q == 0) { 234 prev->so_q0 = next->so_q0; 235 head->so_q0len--; 236 } else { 237 prev->so_q = next->so_q; 238 head->so_qlen--; 239 } 240 next->so_q0 = next->so_q = 0; 241 next->so_head = 0; 242 return (1); 243 } 244 245 /* 246 * Socantsendmore indicates that no more data will be sent on the 247 * socket; it would normally be applied to a socket when the user 248 * informs the system that no more data is to be sent, by the protocol 249 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data 250 * will be received, and will normally be applied to the socket by a 251 * protocol when it detects that the peer will send no more data. 252 * Data queued for reading in the socket may yet be read. 253 */ 254 255 void 256 socantsendmore(so) 257 struct socket *so; 258 { 259 260 so->so_state |= SS_CANTSENDMORE; 261 sowwakeup(so); 262 } 263 264 void 265 socantrcvmore(so) 266 struct socket *so; 267 { 268 269 so->so_state |= SS_CANTRCVMORE; 270 sorwakeup(so); 271 } 272 273 /* 274 * Wait for data to arrive at/drain from a socket buffer. 275 */ 276 int 277 sbwait(sb) 278 struct sockbuf *sb; 279 { 280 281 sb->sb_flags |= SB_WAIT; 282 return (tsleep((caddr_t)&sb->sb_cc, 283 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, netio, 284 sb->sb_timeo)); 285 } 286 287 /* 288 * Lock a sockbuf already known to be locked; 289 * return any error returned from sleep (EINTR). 290 */ 291 int 292 sb_lock(sb) 293 register struct sockbuf *sb; 294 { 295 int error; 296 297 while (sb->sb_flags & SB_LOCK) { 298 sb->sb_flags |= SB_WANT; 299 error = tsleep((caddr_t)&sb->sb_flags, 300 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK|PCATCH, 301 netio, 0); 302 if (error) 303 return (error); 304 } 305 sb->sb_flags |= SB_LOCK; 306 return (0); 307 } 308 309 /* 310 * Wakeup processes waiting on a socket buffer. 311 * Do asynchronous notification via SIGIO 312 * if the socket has the SS_ASYNC flag set. 313 */ 314 void 315 sowakeup(so, sb) 316 register struct socket *so; 317 register struct sockbuf *sb; 318 { 319 struct proc *p; 320 321 selwakeup(&sb->sb_sel); 322 sb->sb_flags &= ~SB_SEL; 323 if (sb->sb_flags & SB_WAIT) { 324 sb->sb_flags &= ~SB_WAIT; 325 wakeup((caddr_t)&sb->sb_cc); 326 } 327 if (so->so_state & SS_ASYNC) { 328 if (so->so_pgid < 0) 329 gsignal(-so->so_pgid, SIGIO); 330 else if (so->so_pgid > 0 && (p = pfind(so->so_pgid)) != 0) 331 psignal(p, SIGIO); 332 } 333 } 334 335 /* 336 * Socket buffer (struct sockbuf) utility routines. 337 * 338 * Each socket contains two socket buffers: one for sending data and 339 * one for receiving data. Each buffer contains a queue of mbufs, 340 * information about the number of mbufs and amount of data in the 341 * queue, and other fields allowing select() statements and notification 342 * on data availability to be implemented. 343 * 344 * Data stored in a socket buffer is maintained as a list of records. 345 * Each record is a list of mbufs chained together with the m_next 346 * field. Records are chained together with the m_nextpkt field. The upper 347 * level routine soreceive() expects the following conventions to be 348 * observed when placing information in the receive buffer: 349 * 350 * 1. If the protocol requires each message be preceded by the sender's 351 * name, then a record containing that name must be present before 352 * any associated data (mbuf's must be of type MT_SONAME). 353 * 2. If the protocol supports the exchange of ``access rights'' (really 354 * just additional data associated with the message), and there are 355 * ``rights'' to be received, then a record containing this data 356 * should be present (mbuf's must be of type MT_RIGHTS). 357 * 3. If a name or rights record exists, then it must be followed by 358 * a data record, perhaps of zero length. 359 * 360 * Before using a new socket structure it is first necessary to reserve 361 * buffer space to the socket, by calling sbreserve(). This should commit 362 * some of the available buffer space in the system buffer pool for the 363 * socket (currently, it does nothing but enforce limits). The space 364 * should be released by calling sbrelease() when the socket is destroyed. 365 */ 366 367 int 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 int 396 sbreserve(sb, cc) 397 struct sockbuf *sb; 398 u_long cc; 399 { 400 401 if (cc > sb_max * MCLBYTES / (MSIZE + MCLBYTES)) 402 return (0); 403 sb->sb_hiwat = cc; 404 sb->sb_mbmax = min(cc * 2, sb_max); 405 if (sb->sb_lowat > sb->sb_hiwat) 406 sb->sb_lowat = sb->sb_hiwat; 407 return (1); 408 } 409 410 /* 411 * Free mbufs held by a socket, and reserved mbuf space. 412 */ 413 void 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 void 454 sbappend(sb, m) 455 struct sockbuf *sb; 456 struct mbuf *m; 457 { 458 register struct mbuf *n; 459 460 if (m == 0) 461 return; 462 n = sb->sb_mb; 463 if (n) { 464 while (n->m_nextpkt) 465 n = n->m_nextpkt; 466 do { 467 if (n->m_flags & M_EOR) { 468 sbappendrecord(sb, m); /* XXXXXX!!!! */ 469 return; 470 } 471 } while (n->m_next && (n = n->m_next)); 472 } 473 sbcompress(sb, m, n); 474 } 475 476 #ifdef SOCKBUF_DEBUG 477 void 478 sbcheck(sb) 479 register struct sockbuf *sb; 480 { 481 register struct mbuf *m; 482 register int len = 0, mbcnt = 0; 483 484 for (m = sb->sb_mb; m; m = m->m_next) { 485 len += m->m_len; 486 mbcnt += MSIZE; 487 if (m->m_flags & M_EXT) 488 mbcnt += m->m_ext.ext_size; 489 if (m->m_nextpkt) 490 panic("sbcheck nextpkt"); 491 } 492 if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) { 493 printf("cc %d != %d || mbcnt %d != %d\n", len, sb->sb_cc, 494 mbcnt, sb->sb_mbcnt); 495 panic("sbcheck"); 496 } 497 } 498 #endif 499 500 /* 501 * As above, except the mbuf chain 502 * begins a new record. 503 */ 504 void 505 sbappendrecord(sb, m0) 506 register struct sockbuf *sb; 507 register struct mbuf *m0; 508 { 509 register struct mbuf *m; 510 511 if (m0 == 0) 512 return; 513 m = sb->sb_mb; 514 if (m) 515 while (m->m_nextpkt) 516 m = m->m_nextpkt; 517 /* 518 * Put the first mbuf on the queue. 519 * Note this permits zero length records. 520 */ 521 sballoc(sb, m0); 522 if (m) 523 m->m_nextpkt = m0; 524 else 525 sb->sb_mb = m0; 526 m = m0->m_next; 527 m0->m_next = 0; 528 if (m && (m0->m_flags & M_EOR)) { 529 m0->m_flags &= ~M_EOR; 530 m->m_flags |= M_EOR; 531 } 532 sbcompress(sb, m, m0); 533 } 534 535 /* 536 * As above except that OOB data 537 * is inserted at the beginning of the sockbuf, 538 * but after any other OOB data. 539 */ 540 void 541 sbinsertoob(sb, m0) 542 register struct sockbuf *sb; 543 register struct mbuf *m0; 544 { 545 register struct mbuf *m; 546 register struct mbuf **mp; 547 548 if (m0 == 0) 549 return; 550 for (mp = &sb->sb_mb; *mp ; mp = &((*mp)->m_nextpkt)) { 551 m = *mp; 552 again: 553 switch (m->m_type) { 554 555 case MT_OOBDATA: 556 continue; /* WANT next train */ 557 558 case MT_CONTROL: 559 m = m->m_next; 560 if (m) 561 goto again; /* inspect THIS train further */ 562 } 563 break; 564 } 565 /* 566 * Put the first mbuf on the queue. 567 * Note this permits zero length records. 568 */ 569 sballoc(sb, m0); 570 m0->m_nextpkt = *mp; 571 *mp = m0; 572 m = m0->m_next; 573 m0->m_next = 0; 574 if (m && (m0->m_flags & M_EOR)) { 575 m0->m_flags &= ~M_EOR; 576 m->m_flags |= M_EOR; 577 } 578 sbcompress(sb, m, m0); 579 } 580 581 /* 582 * Append address and data, and optionally, control (ancillary) data 583 * to the receive queue of a socket. If present, 584 * m0 must include a packet header with total length. 585 * Returns 0 if no space in sockbuf or insufficient mbufs. 586 */ 587 int 588 sbappendaddr(sb, asa, m0, control) 589 register struct sockbuf *sb; 590 struct sockaddr *asa; 591 struct mbuf *m0, *control; 592 { 593 register struct mbuf *m, *n; 594 int space = asa->sa_len; 595 596 if (m0 && (m0->m_flags & M_PKTHDR) == 0) 597 panic("sbappendaddr"); 598 if (m0) 599 space += m0->m_pkthdr.len; 600 for (n = control; n; n = n->m_next) { 601 space += n->m_len; 602 if (n->m_next == 0) /* keep pointer to last control buf */ 603 break; 604 } 605 if (space > sbspace(sb)) 606 return (0); 607 if (asa->sa_len > MLEN) 608 return (0); 609 MGET(m, M_DONTWAIT, MT_SONAME); 610 if (m == 0) 611 return (0); 612 m->m_len = asa->sa_len; 613 bcopy((caddr_t)asa, mtod(m, caddr_t), asa->sa_len); 614 if (n) 615 n->m_next = m0; /* concatenate data to control */ 616 else 617 control = m0; 618 m->m_next = control; 619 for (n = m; n; n = n->m_next) 620 sballoc(sb, n); 621 n = sb->sb_mb; 622 if (n) { 623 while (n->m_nextpkt) 624 n = n->m_nextpkt; 625 n->m_nextpkt = m; 626 } else 627 sb->sb_mb = m; 628 return (1); 629 } 630 631 int 632 sbappendcontrol(sb, m0, control) 633 struct sockbuf *sb; 634 struct mbuf *control, *m0; 635 { 636 register struct mbuf *m, *n; 637 int space = 0; 638 639 if (control == 0) 640 panic("sbappendcontrol"); 641 for (m = control; ; m = m->m_next) { 642 space += m->m_len; 643 if (m->m_next == 0) 644 break; 645 } 646 n = m; /* save pointer to last control buffer */ 647 for (m = m0; m; m = m->m_next) 648 space += m->m_len; 649 if (space > sbspace(sb)) 650 return (0); 651 n->m_next = m0; /* concatenate data to control */ 652 for (m = control; m; m = m->m_next) 653 sballoc(sb, m); 654 n = sb->sb_mb; 655 if (n) { 656 while (n->m_nextpkt) 657 n = n->m_nextpkt; 658 n->m_nextpkt = control; 659 } else 660 sb->sb_mb = control; 661 return (1); 662 } 663 664 /* 665 * Compress mbuf chain m into the socket 666 * buffer sb following mbuf n. If n 667 * is null, the buffer is presumed empty. 668 */ 669 void 670 sbcompress(sb, m, n) 671 register struct sockbuf *sb; 672 register struct mbuf *m, *n; 673 { 674 register int eor = 0; 675 register struct mbuf *o; 676 677 while (m) { 678 eor |= m->m_flags & M_EOR; 679 if (m->m_len == 0 && 680 (eor == 0 || 681 (((o = m->m_next) || (o = n)) && 682 o->m_type == m->m_type))) { 683 m = m_free(m); 684 continue; 685 } 686 if (n && (n->m_flags & (M_EXT | M_EOR)) == 0 && 687 (n->m_data + n->m_len + m->m_len) < &n->m_dat[MLEN] && 688 n->m_type == m->m_type) { 689 bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len, 690 (unsigned)m->m_len); 691 n->m_len += m->m_len; 692 sb->sb_cc += m->m_len; 693 m = m_free(m); 694 continue; 695 } 696 if (n) 697 n->m_next = m; 698 else 699 sb->sb_mb = m; 700 sballoc(sb, m); 701 n = m; 702 m->m_flags &= ~M_EOR; 703 m = m->m_next; 704 n->m_next = 0; 705 } 706 if (eor) { 707 if (n) 708 n->m_flags |= eor; 709 else 710 printf("semi-panic: sbcompress\n"); 711 } 712 } 713 714 /* 715 * Free all mbufs in a sockbuf. 716 * Check that all resources are reclaimed. 717 */ 718 void 719 sbflush(sb) 720 register struct sockbuf *sb; 721 { 722 723 if (sb->sb_flags & SB_LOCK) 724 panic("sbflush"); 725 while (sb->sb_mbcnt) 726 sbdrop(sb, (int)sb->sb_cc); 727 if (sb->sb_cc || sb->sb_mb) 728 panic("sbflush 2"); 729 } 730 731 /* 732 * Drop data from (the front of) a sockbuf. 733 */ 734 void 735 sbdrop(sb, len) 736 register struct sockbuf *sb; 737 register int len; 738 { 739 register struct mbuf *m, *mn; 740 struct mbuf *next; 741 742 next = (m = sb->sb_mb) ? m->m_nextpkt : 0; 743 while (len > 0) { 744 if (m == 0) { 745 if (next == 0) 746 panic("sbdrop"); 747 m = next; 748 next = m->m_nextpkt; 749 continue; 750 } 751 if (m->m_len > len) { 752 m->m_len -= len; 753 m->m_data += len; 754 sb->sb_cc -= len; 755 break; 756 } 757 len -= m->m_len; 758 sbfree(sb, m); 759 MFREE(m, mn); 760 m = mn; 761 } 762 while (m && m->m_len == 0) { 763 sbfree(sb, m); 764 MFREE(m, mn); 765 m = mn; 766 } 767 if (m) { 768 sb->sb_mb = m; 769 m->m_nextpkt = next; 770 } else 771 sb->sb_mb = next; 772 } 773 774 /* 775 * Drop a record off the front of a sockbuf 776 * and move the next record to the front. 777 */ 778 void 779 sbdroprecord(sb) 780 register struct sockbuf *sb; 781 { 782 register struct mbuf *m, *mn; 783 784 m = sb->sb_mb; 785 if (m) { 786 sb->sb_mb = m->m_nextpkt; 787 do { 788 sbfree(sb, m); 789 MFREE(m, mn); 790 m = mn; 791 } while (m); 792 } 793 } 794