uipc_socket2.c revision 1.22
1 /* $NetBSD: uipc_socket2.c,v 1.22 1998/01/07 23:47:09 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1988, 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)uipc_socket2.c 8.1 (Berkeley) 6/10/93 36 */ 37 38 #include <sys/param.h> 39 #include <sys/systm.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/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 const char netio[] = "netio"; 56 const char netcon[] = "netcon"; 57 const 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 (struct proc *)0)) { 180 (void) soqremque(so, soqueue); 181 (void) free((caddr_t)so, M_SOCKET); 182 return ((struct socket *)0); 183 } 184 if (connstatus) { 185 sorwakeup(head); 186 wakeup((caddr_t)&head->so_timeo); 187 so->so_state |= connstatus; 188 } 189 return (so); 190 } 191 192 void 193 soqinsque(head, so, q) 194 register struct socket *head, *so; 195 int q; 196 { 197 198 #ifdef DIAGNOSTIC 199 if (so->so_onq != NULL) 200 panic("soqinsque"); 201 #endif 202 203 so->so_head = head; 204 if (q == 0) { 205 head->so_q0len++; 206 so->so_onq = &head->so_q0; 207 } else { 208 head->so_qlen++; 209 so->so_onq = &head->so_q; 210 } 211 TAILQ_INSERT_TAIL(so->so_onq, so, so_qe); 212 } 213 214 int 215 soqremque(so, q) 216 register struct socket *so; 217 int q; 218 { 219 struct socket *head = so->so_head; 220 221 if (q == 0) { 222 if (so->so_onq != &head->so_q0) 223 return (0); 224 head->so_q0len--; 225 } else { 226 if (so->so_onq != &head->so_q) 227 return (0); 228 head->so_qlen--; 229 } 230 TAILQ_REMOVE(so->so_onq, so, so_qe); 231 so->so_onq = NULL; 232 so->so_head = NULL; 233 return (1); 234 } 235 236 /* 237 * Socantsendmore indicates that no more data will be sent on the 238 * socket; it would normally be applied to a socket when the user 239 * informs the system that no more data is to be sent, by the protocol 240 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data 241 * will be received, and will normally be applied to the socket by a 242 * protocol when it detects that the peer will send no more data. 243 * Data queued for reading in the socket may yet be read. 244 */ 245 246 void 247 socantsendmore(so) 248 struct socket *so; 249 { 250 251 so->so_state |= SS_CANTSENDMORE; 252 sowwakeup(so); 253 } 254 255 void 256 socantrcvmore(so) 257 struct socket *so; 258 { 259 260 so->so_state |= SS_CANTRCVMORE; 261 sorwakeup(so); 262 } 263 264 /* 265 * Wait for data to arrive at/drain from a socket buffer. 266 */ 267 int 268 sbwait(sb) 269 struct sockbuf *sb; 270 { 271 272 sb->sb_flags |= SB_WAIT; 273 return (tsleep((caddr_t)&sb->sb_cc, 274 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, netio, 275 sb->sb_timeo)); 276 } 277 278 /* 279 * Lock a sockbuf already known to be locked; 280 * return any error returned from sleep (EINTR). 281 */ 282 int 283 sb_lock(sb) 284 register struct sockbuf *sb; 285 { 286 int error; 287 288 while (sb->sb_flags & SB_LOCK) { 289 sb->sb_flags |= SB_WANT; 290 error = tsleep((caddr_t)&sb->sb_flags, 291 (sb->sb_flags & SB_NOINTR) ? 292 PSOCK : PSOCK|PCATCH, netio, 0); 293 if (error) 294 return (error); 295 } 296 sb->sb_flags |= SB_LOCK; 297 return (0); 298 } 299 300 /* 301 * Wakeup processes waiting on a socket buffer. 302 * Do asynchronous notification via SIGIO 303 * if the socket has the SS_ASYNC flag set. 304 */ 305 void 306 sowakeup(so, sb) 307 register struct socket *so; 308 register struct sockbuf *sb; 309 { 310 struct proc *p; 311 312 selwakeup(&sb->sb_sel); 313 sb->sb_flags &= ~SB_SEL; 314 if (sb->sb_flags & SB_WAIT) { 315 sb->sb_flags &= ~SB_WAIT; 316 wakeup((caddr_t)&sb->sb_cc); 317 } 318 if (so->so_state & SS_ASYNC) { 319 if (so->so_pgid < 0) 320 gsignal(-so->so_pgid, SIGIO); 321 else if (so->so_pgid > 0 && (p = pfind(so->so_pgid)) != 0) 322 psignal(p, SIGIO); 323 } 324 } 325 326 /* 327 * Socket buffer (struct sockbuf) utility routines. 328 * 329 * Each socket contains two socket buffers: one for sending data and 330 * one for receiving data. Each buffer contains a queue of mbufs, 331 * information about the number of mbufs and amount of data in the 332 * queue, and other fields allowing poll() statements and notification 333 * on data availability to be implemented. 334 * 335 * Data stored in a socket buffer is maintained as a list of records. 336 * Each record is a list of mbufs chained together with the m_next 337 * field. Records are chained together with the m_nextpkt field. The upper 338 * level routine soreceive() expects the following conventions to be 339 * observed when placing information in the receive buffer: 340 * 341 * 1. If the protocol requires each message be preceded by the sender's 342 * name, then a record containing that name must be present before 343 * any associated data (mbuf's must be of type MT_SONAME). 344 * 2. If the protocol supports the exchange of ``access rights'' (really 345 * just additional data associated with the message), and there are 346 * ``rights'' to be received, then a record containing this data 347 * should be present (mbuf's must be of type MT_CONTROL). 348 * 3. If a name or rights record exists, then it must be followed by 349 * a data record, perhaps of zero length. 350 * 351 * Before using a new socket structure it is first necessary to reserve 352 * buffer space to the socket, by calling sbreserve(). This should commit 353 * some of the available buffer space in the system buffer pool for the 354 * socket (currently, it does nothing but enforce limits). The space 355 * should be released by calling sbrelease() when the socket is destroyed. 356 */ 357 358 int 359 soreserve(so, sndcc, rcvcc) 360 register struct socket *so; 361 u_long sndcc, rcvcc; 362 { 363 364 if (sbreserve(&so->so_snd, sndcc) == 0) 365 goto bad; 366 if (sbreserve(&so->so_rcv, rcvcc) == 0) 367 goto bad2; 368 if (so->so_rcv.sb_lowat == 0) 369 so->so_rcv.sb_lowat = 1; 370 if (so->so_snd.sb_lowat == 0) 371 so->so_snd.sb_lowat = MCLBYTES; 372 if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat) 373 so->so_snd.sb_lowat = so->so_snd.sb_hiwat; 374 return (0); 375 bad2: 376 sbrelease(&so->so_snd); 377 bad: 378 return (ENOBUFS); 379 } 380 381 /* 382 * Allot mbufs to a sockbuf. 383 * Attempt to scale mbmax so that mbcnt doesn't become limiting 384 * if buffering efficiency is near the normal case. 385 */ 386 int 387 sbreserve(sb, cc) 388 struct sockbuf *sb; 389 u_long cc; 390 { 391 392 if (cc == 0 || cc > sb_max * MCLBYTES / (MSIZE + MCLBYTES)) 393 return (0); 394 sb->sb_hiwat = cc; 395 sb->sb_mbmax = min(cc * 2, sb_max); 396 if (sb->sb_lowat > sb->sb_hiwat) 397 sb->sb_lowat = sb->sb_hiwat; 398 return (1); 399 } 400 401 /* 402 * Free mbufs held by a socket, and reserved mbuf space. 403 */ 404 void 405 sbrelease(sb) 406 struct sockbuf *sb; 407 { 408 409 sbflush(sb); 410 sb->sb_hiwat = sb->sb_mbmax = 0; 411 } 412 413 /* 414 * Routines to add and remove 415 * data from an mbuf queue. 416 * 417 * The routines sbappend() or sbappendrecord() are normally called to 418 * append new mbufs to a socket buffer, after checking that adequate 419 * space is available, comparing the function sbspace() with the amount 420 * of data to be added. sbappendrecord() differs from sbappend() in 421 * that data supplied is treated as the beginning of a new record. 422 * To place a sender's address, optional access rights, and data in a 423 * socket receive buffer, sbappendaddr() should be used. To place 424 * access rights and data in a socket receive buffer, sbappendrights() 425 * should be used. In either case, the new data begins a new record. 426 * Note that unlike sbappend() and sbappendrecord(), these routines check 427 * for the caller that there will be enough space to store the data. 428 * Each fails if there is not enough space, or if it cannot find mbufs 429 * to store additional information in. 430 * 431 * Reliable protocols may use the socket send buffer to hold data 432 * awaiting acknowledgement. Data is normally copied from a socket 433 * send buffer in a protocol with m_copy for output to a peer, 434 * and then removing the data from the socket buffer with sbdrop() 435 * or sbdroprecord() when the data is acknowledged by the peer. 436 */ 437 438 /* 439 * Append mbuf chain m to the last record in the 440 * socket buffer sb. The additional space associated 441 * the mbuf chain is recorded in sb. Empty mbufs are 442 * discarded and mbufs are compacted where possible. 443 */ 444 void 445 sbappend(sb, m) 446 struct sockbuf *sb; 447 struct mbuf *m; 448 { 449 register struct mbuf *n; 450 451 if (m == 0) 452 return; 453 if ((n = sb->sb_mb) != NULL) { 454 while (n->m_nextpkt) 455 n = n->m_nextpkt; 456 do { 457 if (n->m_flags & M_EOR) { 458 sbappendrecord(sb, m); /* XXXXXX!!!! */ 459 return; 460 } 461 } while (n->m_next && (n = n->m_next)); 462 } 463 sbcompress(sb, m, n); 464 } 465 466 #ifdef SOCKBUF_DEBUG 467 void 468 sbcheck(sb) 469 register struct sockbuf *sb; 470 { 471 register struct mbuf *m; 472 register int len = 0, mbcnt = 0; 473 474 for (m = sb->sb_mb; m; m = m->m_next) { 475 len += m->m_len; 476 mbcnt += MSIZE; 477 if (m->m_flags & M_EXT) 478 mbcnt += m->m_ext.ext_size; 479 if (m->m_nextpkt) 480 panic("sbcheck nextpkt"); 481 } 482 if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) { 483 printf("cc %d != %d || mbcnt %d != %d\n", len, sb->sb_cc, 484 mbcnt, sb->sb_mbcnt); 485 panic("sbcheck"); 486 } 487 } 488 #endif 489 490 /* 491 * As above, except the mbuf chain 492 * begins a new record. 493 */ 494 void 495 sbappendrecord(sb, m0) 496 register struct sockbuf *sb; 497 register struct mbuf *m0; 498 { 499 register struct mbuf *m; 500 501 if (m0 == 0) 502 return; 503 if ((m = sb->sb_mb) != NULL) 504 while (m->m_nextpkt) 505 m = m->m_nextpkt; 506 /* 507 * Put the first mbuf on the queue. 508 * Note this permits zero length records. 509 */ 510 sballoc(sb, m0); 511 if (m) 512 m->m_nextpkt = m0; 513 else 514 sb->sb_mb = m0; 515 m = m0->m_next; 516 m0->m_next = 0; 517 if (m && (m0->m_flags & M_EOR)) { 518 m0->m_flags &= ~M_EOR; 519 m->m_flags |= M_EOR; 520 } 521 sbcompress(sb, m, m0); 522 } 523 524 /* 525 * As above except that OOB data 526 * is inserted at the beginning of the sockbuf, 527 * but after any other OOB data. 528 */ 529 void 530 sbinsertoob(sb, m0) 531 register struct sockbuf *sb; 532 register struct mbuf *m0; 533 { 534 register struct mbuf *m; 535 register struct mbuf **mp; 536 537 if (m0 == 0) 538 return; 539 for (mp = &sb->sb_mb; (m = *mp) != NULL; mp = &((*mp)->m_nextpkt)) { 540 again: 541 switch (m->m_type) { 542 543 case MT_OOBDATA: 544 continue; /* WANT next train */ 545 546 case MT_CONTROL: 547 if ((m = m->m_next) != NULL) 548 goto again; /* inspect THIS train further */ 549 } 550 break; 551 } 552 /* 553 * Put the first mbuf on the queue. 554 * Note this permits zero length records. 555 */ 556 sballoc(sb, m0); 557 m0->m_nextpkt = *mp; 558 *mp = m0; 559 m = m0->m_next; 560 m0->m_next = 0; 561 if (m && (m0->m_flags & M_EOR)) { 562 m0->m_flags &= ~M_EOR; 563 m->m_flags |= M_EOR; 564 } 565 sbcompress(sb, m, m0); 566 } 567 568 /* 569 * Append address and data, and optionally, control (ancillary) data 570 * to the receive queue of a socket. If present, 571 * m0 must include a packet header with total length. 572 * Returns 0 if no space in sockbuf or insufficient mbufs. 573 */ 574 int 575 sbappendaddr(sb, asa, m0, control) 576 register struct sockbuf *sb; 577 struct sockaddr *asa; 578 struct mbuf *m0, *control; 579 { 580 register struct mbuf *m, *n; 581 int space = asa->sa_len; 582 583 if (m0 && (m0->m_flags & M_PKTHDR) == 0) 584 panic("sbappendaddr"); 585 if (m0) 586 space += m0->m_pkthdr.len; 587 for (n = control; n; n = n->m_next) { 588 space += n->m_len; 589 if (n->m_next == 0) /* keep pointer to last control buf */ 590 break; 591 } 592 if (space > sbspace(sb)) 593 return (0); 594 MGET(m, M_DONTWAIT, MT_SONAME); 595 if (m == 0) 596 return (0); 597 if (asa->sa_len > MLEN) { 598 MEXTMALLOC(m, asa->sa_len, M_NOWAIT); 599 if ((m->m_flags & M_EXT) == 0) { 600 m_free(m); 601 return (0); 602 } 603 } 604 m->m_len = asa->sa_len; 605 bcopy((caddr_t)asa, mtod(m, caddr_t), asa->sa_len); 606 if (n) 607 n->m_next = m0; /* concatenate data to control */ 608 else 609 control = m0; 610 m->m_next = control; 611 for (n = m; n; n = n->m_next) 612 sballoc(sb, n); 613 if ((n = sb->sb_mb) != NULL) { 614 while (n->m_nextpkt) 615 n = n->m_nextpkt; 616 n->m_nextpkt = m; 617 } else 618 sb->sb_mb = m; 619 return (1); 620 } 621 622 int 623 sbappendcontrol(sb, m0, control) 624 struct sockbuf *sb; 625 struct mbuf *m0, *control; 626 { 627 register struct mbuf *m, *n; 628 int space = 0; 629 630 if (control == 0) 631 panic("sbappendcontrol"); 632 for (m = control; ; m = m->m_next) { 633 space += m->m_len; 634 if (m->m_next == 0) 635 break; 636 } 637 n = m; /* save pointer to last control buffer */ 638 for (m = m0; m; m = m->m_next) 639 space += m->m_len; 640 if (space > sbspace(sb)) 641 return (0); 642 n->m_next = m0; /* concatenate data to control */ 643 for (m = control; m; m = m->m_next) 644 sballoc(sb, m); 645 if ((n = sb->sb_mb) != NULL) { 646 while (n->m_nextpkt) 647 n = n->m_nextpkt; 648 n->m_nextpkt = control; 649 } else 650 sb->sb_mb = control; 651 return (1); 652 } 653 654 /* 655 * Compress mbuf chain m into the socket 656 * buffer sb following mbuf n. If n 657 * is null, the buffer is presumed empty. 658 */ 659 void 660 sbcompress(sb, m, n) 661 register struct sockbuf *sb; 662 register struct mbuf *m, *n; 663 { 664 register int eor = 0; 665 register struct mbuf *o; 666 667 while (m) { 668 eor |= m->m_flags & M_EOR; 669 if (m->m_len == 0 && 670 (eor == 0 || 671 (((o = m->m_next) || (o = n)) && 672 o->m_type == m->m_type))) { 673 m = m_free(m); 674 continue; 675 } 676 if (n && (n->m_flags & (M_EXT | M_EOR)) == 0 && 677 (n->m_data + n->m_len + m->m_len) < &n->m_dat[MLEN] && 678 n->m_type == m->m_type) { 679 bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len, 680 (unsigned)m->m_len); 681 n->m_len += m->m_len; 682 sb->sb_cc += m->m_len; 683 m = m_free(m); 684 continue; 685 } 686 if (n) 687 n->m_next = m; 688 else 689 sb->sb_mb = m; 690 sballoc(sb, m); 691 n = m; 692 m->m_flags &= ~M_EOR; 693 m = m->m_next; 694 n->m_next = 0; 695 } 696 if (eor) { 697 if (n) 698 n->m_flags |= eor; 699 else 700 printf("semi-panic: sbcompress\n"); 701 } 702 } 703 704 /* 705 * Free all mbufs in a sockbuf. 706 * Check that all resources are reclaimed. 707 */ 708 void 709 sbflush(sb) 710 register struct sockbuf *sb; 711 { 712 713 if (sb->sb_flags & SB_LOCK) 714 panic("sbflush"); 715 while (sb->sb_mbcnt) 716 sbdrop(sb, (int)sb->sb_cc); 717 if (sb->sb_cc || sb->sb_mb) 718 panic("sbflush 2"); 719 } 720 721 /* 722 * Drop data from (the front of) a sockbuf. 723 */ 724 void 725 sbdrop(sb, len) 726 register struct sockbuf *sb; 727 register int len; 728 { 729 register struct mbuf *m, *mn; 730 struct mbuf *next; 731 732 next = (m = sb->sb_mb) ? m->m_nextpkt : 0; 733 while (len > 0) { 734 if (m == 0) { 735 if (next == 0) 736 panic("sbdrop"); 737 m = next; 738 next = m->m_nextpkt; 739 continue; 740 } 741 if (m->m_len > len) { 742 m->m_len -= len; 743 m->m_data += len; 744 sb->sb_cc -= len; 745 break; 746 } 747 len -= m->m_len; 748 sbfree(sb, m); 749 MFREE(m, mn); 750 m = mn; 751 } 752 while (m && m->m_len == 0) { 753 sbfree(sb, m); 754 MFREE(m, mn); 755 m = mn; 756 } 757 if (m) { 758 sb->sb_mb = m; 759 m->m_nextpkt = next; 760 } else 761 sb->sb_mb = next; 762 } 763 764 /* 765 * Drop a record off the front of a sockbuf 766 * and move the next record to the front. 767 */ 768 void 769 sbdroprecord(sb) 770 register struct sockbuf *sb; 771 { 772 register struct mbuf *m, *mn; 773 774 m = sb->sb_mb; 775 if (m) { 776 sb->sb_mb = m->m_nextpkt; 777 do { 778 sbfree(sb, m); 779 MFREE(m, mn); 780 } while ((m = mn) != NULL); 781 } 782 } 783 784 /* 785 * Create a "control" mbuf containing the specified data 786 * with the specified type for presentation on a socket buffer. 787 */ 788 struct mbuf * 789 sbcreatecontrol(p, size, type, level) 790 caddr_t p; 791 register int size; 792 int type, level; 793 { 794 register struct cmsghdr *cp; 795 struct mbuf *m; 796 797 if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL) 798 return ((struct mbuf *) NULL); 799 cp = mtod(m, struct cmsghdr *); 800 bcopy(p, CMSG_DATA(cp), size); 801 size += sizeof(*cp); 802 m->m_len = size; 803 cp->cmsg_len = size; 804 cp->cmsg_level = level; 805 cp->cmsg_type = type; 806 return (m); 807 } 808
Indexes created Mon Sep 22 13:09:51 GMT 2025