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 * $FreeBSD: src/sys/kern/uipc_socket2.c,v 1.55.2.17 2002/08/31 19:04:55 dwmalone Exp $ 35 */ 36 37 #include "opt_param.h" 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/domain.h> 41 #include <sys/file.h> /* for maxfiles */ 42 #include <sys/kernel.h> 43 #include <sys/proc.h> 44 #include <sys/malloc.h> 45 #include <sys/mbuf.h> 46 #include <sys/protosw.h> 47 #include <sys/resourcevar.h> 48 #include <sys/stat.h> 49 #include <sys/socket.h> 50 #include <sys/socketvar.h> 51 #include <sys/signalvar.h> 52 #include <sys/sysctl.h> 53 #include <sys/aio.h> /* for aio_swake proto */ 54 #include <sys/event.h> 55 56 int maxsockets; 57 58 /* 59 * Primitive routines for operating on sockets and socket buffers 60 */ 61 62 u_long sb_max = SB_MAX; 63 u_long sb_max_adj = 64 SB_MAX * MCLBYTES / (MSIZE + MCLBYTES); /* adjusted sb_max */ 65 66 static u_long sb_efficiency = 8; /* parameter for sbreserve() */ 67 68 /* 69 * Procedures to manipulate state flags of socket 70 * and do appropriate wakeups. Normal sequence from the 71 * active (originating) side is that soisconnecting() is 72 * called during processing of connect() call, 73 * resulting in an eventual call to soisconnected() if/when the 74 * connection is established. When the connection is torn down 75 * soisdisconnecting() is called during processing of disconnect() call, 76 * and soisdisconnected() is called when the connection to the peer 77 * is totally severed. The semantics of these routines are such that 78 * connectionless protocols can call soisconnected() and soisdisconnected() 79 * only, bypassing the in-progress calls when setting up a ``connection'' 80 * takes no time. 81 * 82 * From the passive side, a socket is created with 83 * two queues of sockets: so_incomp for connections in progress 84 * and so_comp for connections already made and awaiting user acceptance. 85 * As a protocol is preparing incoming connections, it creates a socket 86 * structure queued on so_incomp by calling sonewconn(). When the connection 87 * is established, soisconnected() is called, and transfers the 88 * socket structure to so_comp, making it available to accept(). 89 * 90 * If a socket is closed with sockets on either 91 * so_incomp or so_comp, these sockets are dropped. 92 * 93 * If higher level protocols are implemented in 94 * the kernel, the wakeups done here will sometimes 95 * cause software-interrupt process scheduling. 96 */ 97 98 void 99 soisconnecting(so) 100 register struct socket *so; 101 { 102 103 so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING); 104 so->so_state |= SS_ISCONNECTING; 105 } 106 107 void 108 soisconnected(so) 109 struct socket *so; 110 { 111 struct socket *head = so->so_head; 112 113 so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING); 114 so->so_state |= SS_ISCONNECTED; 115 if (head && (so->so_state & SS_INCOMP)) { 116 if ((so->so_options & SO_ACCEPTFILTER) != 0) { 117 so->so_upcall = head->so_accf->so_accept_filter->accf_callback; 118 so->so_upcallarg = head->so_accf->so_accept_filter_arg; 119 so->so_rcv.sb_flags |= SB_UPCALL; 120 so->so_options &= ~SO_ACCEPTFILTER; 121 so->so_upcall(so, so->so_upcallarg, 0); 122 return; 123 } 124 TAILQ_REMOVE(&head->so_incomp, so, so_list); 125 head->so_incqlen--; 126 so->so_state &= ~SS_INCOMP; 127 TAILQ_INSERT_TAIL(&head->so_comp, so, so_list); 128 head->so_qlen++; 129 so->so_state |= SS_COMP; 130 sorwakeup(head); 131 wakeup_one(&head->so_timeo); 132 } else { 133 wakeup(&so->so_timeo); 134 sorwakeup(so); 135 sowwakeup(so); 136 } 137 } 138 139 void 140 soisdisconnecting(so) 141 register struct socket *so; 142 { 143 144 so->so_state &= ~SS_ISCONNECTING; 145 so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE); 146 wakeup((caddr_t)&so->so_timeo); 147 sowwakeup(so); 148 sorwakeup(so); 149 } 150 151 void 152 soisdisconnected(so) 153 register struct socket *so; 154 { 155 156 so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING); 157 so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED); 158 wakeup((caddr_t)&so->so_timeo); 159 sbdrop(&so->so_snd, so->so_snd.sb_cc); 160 sowwakeup(so); 161 sorwakeup(so); 162 } 163 164 /* 165 * When an attempt at a new connection is noted on a socket 166 * which accepts connections, sonewconn is called. If the 167 * connection is possible (subject to space constraints, etc.) 168 * then we allocate a new structure, propoerly linked into the 169 * data structure of the original socket, and return this. 170 * Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED. 171 */ 172 struct socket * 173 sonewconn(head, connstatus) 174 register struct socket *head; 175 int connstatus; 176 { 177 178 return (sonewconn3(head, connstatus, NULL)); 179 } 180 181 struct socket * 182 sonewconn3(head, connstatus, p) 183 register struct socket *head; 184 int connstatus; 185 struct proc *p; 186 { 187 register struct socket *so; 188 189 if (head->so_qlen > 3 * head->so_qlimit / 2) 190 return ((struct socket *)0); 191 so = soalloc(0); 192 if (so == NULL) 193 return ((struct socket *)0); 194 if ((head->so_options & SO_ACCEPTFILTER) != 0) 195 connstatus = 0; 196 so->so_head = head; 197 so->so_type = head->so_type; 198 so->so_options = head->so_options &~ SO_ACCEPTCONN; 199 so->so_linger = head->so_linger; 200 so->so_state = head->so_state | SS_NOFDREF; 201 so->so_proto = head->so_proto; 202 so->so_timeo = head->so_timeo; 203 so->so_cred = p ? p->p_ucred : head->so_cred; 204 crhold(so->so_cred); 205 if (soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat) || 206 (*so->so_proto->pr_usrreqs->pru_attach)(so, 0, NULL)) { 207 sodealloc(so); 208 return ((struct socket *)0); 209 } 210 211 if (connstatus) { 212 TAILQ_INSERT_TAIL(&head->so_comp, so, so_list); 213 so->so_state |= SS_COMP; 214 head->so_qlen++; 215 } else { 216 if (head->so_incqlen > head->so_qlimit) { 217 struct socket *sp; 218 sp = TAILQ_FIRST(&head->so_incomp); 219 (void) soabort(sp); 220 } 221 TAILQ_INSERT_TAIL(&head->so_incomp, so, so_list); 222 so->so_state |= SS_INCOMP; 223 head->so_incqlen++; 224 } 225 if (connstatus) { 226 sorwakeup(head); 227 wakeup((caddr_t)&head->so_timeo); 228 so->so_state |= connstatus; 229 } 230 return (so); 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 */ 242 243 void 244 socantsendmore(so) 245 struct socket *so; 246 { 247 248 so->so_state |= SS_CANTSENDMORE; 249 sowwakeup(so); 250 } 251 252 void 253 socantrcvmore(so) 254 struct socket *so; 255 { 256 257 so->so_state |= SS_CANTRCVMORE; 258 sorwakeup(so); 259 } 260 261 /* 262 * Wait for data to arrive at/drain from a socket buffer. 263 */ 264 int 265 sbwait(sb) 266 struct sockbuf *sb; 267 { 268 269 sb->sb_flags |= SB_WAIT; 270 return (tsleep((caddr_t)&sb->sb_cc, 271 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, "sbwait", 272 sb->sb_timeo)); 273 } 274 275 /* 276 * Lock a sockbuf already known to be locked; 277 * return any error returned from sleep (EINTR). 278 */ 279 int 280 sb_lock(sb) 281 register struct sockbuf *sb; 282 { 283 int error; 284 285 while (sb->sb_flags & SB_LOCK) { 286 sb->sb_flags |= SB_WANT; 287 error = tsleep((caddr_t)&sb->sb_flags, 288 (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK|PCATCH, 289 "sblock", 0); 290 if (error) 291 return (error); 292 } 293 sb->sb_flags |= SB_LOCK; 294 return (0); 295 } 296 297 /* 298 * Wakeup processes waiting on a socket buffer. 299 * Do asynchronous notification via SIGIO 300 * if the socket has the SS_ASYNC flag set. 301 */ 302 void 303 sowakeup(so, sb) 304 register struct socket *so; 305 register struct sockbuf *sb; 306 { 307 selwakeup(&sb->sb_sel); 308 sb->sb_flags &= ~SB_SEL; 309 if (sb->sb_flags & SB_WAIT) { 310 sb->sb_flags &= ~SB_WAIT; 311 wakeup((caddr_t)&sb->sb_cc); 312 } 313 if ((so->so_state & SS_ASYNC) && so->so_sigio != NULL) 314 pgsigio(so->so_sigio, SIGIO, 0); 315 if (sb->sb_flags & SB_UPCALL) 316 (*so->so_upcall)(so, so->so_upcallarg, M_DONTWAIT); 317 if (sb->sb_flags & SB_AIO) 318 aio_swake(so, sb); 319 KNOTE(&sb->sb_sel.si_note, 0); 320 } 321 322 /* 323 * Socket buffer (struct sockbuf) utility routines. 324 * 325 * Each socket contains two socket buffers: one for sending data and 326 * one for receiving data. Each buffer contains a queue of mbufs, 327 * information about the number of mbufs and amount of data in the 328 * queue, and other fields allowing select() statements and notification 329 * on data availability to be implemented. 330 * 331 * Data stored in a socket buffer is maintained as a list of records. 332 * Each record is a list of mbufs chained together with the m_next 333 * field. Records are chained together with the m_nextpkt field. The upper 334 * level routine soreceive() expects the following conventions to be 335 * observed when placing information in the receive buffer: 336 * 337 * 1. If the protocol requires each message be preceded by the sender's 338 * name, then a record containing that name must be present before 339 * any associated data (mbuf's must be of type MT_SONAME). 340 * 2. If the protocol supports the exchange of ``access rights'' (really 341 * just additional data associated with the message), and there are 342 * ``rights'' to be received, then a record containing this data 343 * should be present (mbuf's must be of type MT_RIGHTS). 344 * 3. If a name or rights record exists, then it must be followed by 345 * a data record, perhaps of zero length. 346 * 347 * Before using a new socket structure it is first necessary to reserve 348 * buffer space to the socket, by calling sbreserve(). This should commit 349 * some of the available buffer space in the system buffer pool for the 350 * socket (currently, it does nothing but enforce limits). The space 351 * should be released by calling sbrelease() when the socket is destroyed. 352 */ 353 354 int 355 soreserve(so, sndcc, rcvcc) 356 register struct socket *so; 357 u_long sndcc, rcvcc; 358 { 359 struct proc *p = curproc; 360 361 if (sbreserve(&so->so_snd, sndcc, so, p) == 0) 362 goto bad; 363 if (sbreserve(&so->so_rcv, rcvcc, so, p) == 0) 364 goto bad2; 365 if (so->so_rcv.sb_lowat == 0) 366 so->so_rcv.sb_lowat = 1; 367 if (so->so_snd.sb_lowat == 0) 368 so->so_snd.sb_lowat = MCLBYTES; 369 if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat) 370 so->so_snd.sb_lowat = so->so_snd.sb_hiwat; 371 return (0); 372 bad2: 373 sbrelease(&so->so_snd, so); 374 bad: 375 return (ENOBUFS); 376 } 377 378 static int 379 sysctl_handle_sb_max(SYSCTL_HANDLER_ARGS) 380 { 381 int error = 0; 382 u_long old_sb_max = sb_max; 383 384 error = SYSCTL_OUT(req, arg1, sizeof(int)); 385 if (error || !req->newptr) 386 return (error); 387 error = SYSCTL_IN(req, arg1, sizeof(int)); 388 if (error) 389 return (error); 390 if (sb_max < MSIZE + MCLBYTES) { 391 sb_max = old_sb_max; 392 return (EINVAL); 393 } 394 sb_max_adj = (u_quad_t)sb_max * MCLBYTES / (MSIZE + MCLBYTES); 395 return (0); 396 } 397 398 /* 399 * Allot mbufs to a sockbuf. 400 * Attempt to scale mbmax so that mbcnt doesn't become limiting 401 * if buffering efficiency is near the normal case. 402 */ 403 int 404 sbreserve(sb, cc, so, p) 405 struct sockbuf *sb; 406 u_long cc; 407 struct socket *so; 408 struct proc *p; 409 { 410 411 /* 412 * p will only be NULL when we're in an interrupt 413 * (e.g. in tcp_input()) 414 */ 415 if (cc > sb_max_adj) 416 return (0); 417 if (!chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, cc, 418 p ? p->p_rlimit[RLIMIT_SBSIZE].rlim_cur : RLIM_INFINITY)) { 419 return (0); 420 } 421 sb->sb_mbmax = min(cc * sb_efficiency, sb_max); 422 if (sb->sb_lowat > sb->sb_hiwat) 423 sb->sb_lowat = sb->sb_hiwat; 424 return (1); 425 } 426 427 /* 428 * Free mbufs held by a socket, and reserved mbuf space. 429 */ 430 void 431 sbrelease(sb, so) 432 struct sockbuf *sb; 433 struct socket *so; 434 { 435 436 sbflush(sb); 437 (void)chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, 0, 438 RLIM_INFINITY); 439 sb->sb_mbmax = 0; 440 } 441 442 /* 443 * Routines to add and remove 444 * data from an mbuf queue. 445 * 446 * The routines sbappend() or sbappendrecord() are normally called to 447 * append new mbufs to a socket buffer, after checking that adequate 448 * space is available, comparing the function sbspace() with the amount 449 * of data to be added. sbappendrecord() differs from sbappend() in 450 * that data supplied is treated as the beginning of a new record. 451 * To place a sender's address, optional access rights, and data in a 452 * socket receive buffer, sbappendaddr() should be used. To place 453 * access rights and data in a socket receive buffer, sbappendrights() 454 * should be used. In either case, the new data begins a new record. 455 * Note that unlike sbappend() and sbappendrecord(), these routines check 456 * for the caller that there will be enough space to store the data. 457 * Each fails if there is not enough space, or if it cannot find mbufs 458 * to store additional information in. 459 * 460 * Reliable protocols may use the socket send buffer to hold data 461 * awaiting acknowledgement. Data is normally copied from a socket 462 * send buffer in a protocol with m_copy for output to a peer, 463 * and then removing the data from the socket buffer with sbdrop() 464 * or sbdroprecord() when the data is acknowledged by the peer. 465 */ 466 467 /* 468 * Append mbuf chain m to the last record in the 469 * socket buffer sb. The additional space associated 470 * the mbuf chain is recorded in sb. Empty mbufs are 471 * discarded and mbufs are compacted where possible. 472 */ 473 void 474 sbappend(sb, m) 475 struct sockbuf *sb; 476 struct mbuf *m; 477 { 478 register struct mbuf *n; 479 480 if (m == 0) 481 return; 482 n = sb->sb_mb; 483 if (n) { 484 while (n->m_nextpkt) 485 n = n->m_nextpkt; 486 do { 487 if (n->m_flags & M_EOR) { 488 sbappendrecord(sb, m); /* XXXXXX!!!! */ 489 return; 490 } 491 } while (n->m_next && (n = n->m_next)); 492 } 493 sbcompress(sb, m, n); 494 } 495 496 #ifdef SOCKBUF_DEBUG 497 void 498 sbcheck(sb) 499 register struct sockbuf *sb; 500 { 501 register struct mbuf *m; 502 register struct mbuf *n = 0; 503 register u_long len = 0, mbcnt = 0; 504 505 for (m = sb->sb_mb; m; m = n) { 506 n = m->m_nextpkt; 507 for (; m; m = m->m_next) { 508 len += m->m_len; 509 mbcnt += MSIZE; 510 if (m->m_flags & M_EXT) /*XXX*/ /* pretty sure this is bogus */ 511 mbcnt += m->m_ext.ext_size; 512 } 513 } 514 if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) { 515 printf("cc %ld != %ld || mbcnt %ld != %ld\n", len, sb->sb_cc, 516 mbcnt, sb->sb_mbcnt); 517 panic("sbcheck"); 518 } 519 } 520 #endif 521 522 /* 523 * As above, except the mbuf chain 524 * begins a new record. 525 */ 526 void 527 sbappendrecord(sb, m0) 528 register struct sockbuf *sb; 529 register struct mbuf *m0; 530 { 531 register struct mbuf *m; 532 533 if (m0 == 0) 534 return; 535 m = sb->sb_mb; 536 if (m) 537 while (m->m_nextpkt) 538 m = m->m_nextpkt; 539 /* 540 * Put the first mbuf on the queue. 541 * Note this permits zero length records. 542 */ 543 sballoc(sb, m0); 544 if (m) 545 m->m_nextpkt = m0; 546 else 547 sb->sb_mb = m0; 548 m = m0->m_next; 549 m0->m_next = 0; 550 if (m && (m0->m_flags & M_EOR)) { 551 m0->m_flags &= ~M_EOR; 552 m->m_flags |= M_EOR; 553 } 554 sbcompress(sb, m, m0); 555 } 556 557 /* 558 * As above except that OOB data 559 * is inserted at the beginning of the sockbuf, 560 * but after any other OOB data. 561 */ 562 void 563 sbinsertoob(sb, m0) 564 register struct sockbuf *sb; 565 register struct mbuf *m0; 566 { 567 register struct mbuf *m; 568 register struct mbuf **mp; 569 570 if (m0 == 0) 571 return; 572 for (mp = &sb->sb_mb; *mp ; mp = &((*mp)->m_nextpkt)) { 573 m = *mp; 574 again: 575 switch (m->m_type) { 576 577 case MT_OOBDATA: 578 continue; /* WANT next train */ 579 580 case MT_CONTROL: 581 m = m->m_next; 582 if (m) 583 goto again; /* inspect THIS train further */ 584 } 585 break; 586 } 587 /* 588 * Put the first mbuf on the queue. 589 * Note this permits zero length records. 590 */ 591 sballoc(sb, m0); 592 m0->m_nextpkt = *mp; 593 *mp = m0; 594 m = m0->m_next; 595 m0->m_next = 0; 596 if (m && (m0->m_flags & M_EOR)) { 597 m0->m_flags &= ~M_EOR; 598 m->m_flags |= M_EOR; 599 } 600 sbcompress(sb, m, m0); 601 } 602 603 /* 604 * Append address and data, and optionally, control (ancillary) data 605 * to the receive queue of a socket. If present, 606 * m0 must include a packet header with total length. 607 * Returns 0 if no space in sockbuf or insufficient mbufs. 608 */ 609 int 610 sbappendaddr(sb, asa, m0, control) 611 register struct sockbuf *sb; 612 struct sockaddr *asa; 613 struct mbuf *m0, *control; 614 { 615 register struct mbuf *m, *n; 616 int space = asa->sa_len; 617 618 if (m0 && (m0->m_flags & M_PKTHDR) == 0) 619 panic("sbappendaddr"); 620 if (m0) 621 space += m0->m_pkthdr.len; 622 for (n = control; n; n = n->m_next) { 623 space += n->m_len; 624 if (n->m_next == 0) /* keep pointer to last control buf */ 625 break; 626 } 627 if (space > sbspace(sb)) 628 return (0); 629 if (asa->sa_len > MLEN) 630 return (0); 631 MGET(m, M_DONTWAIT, MT_SONAME); 632 if (m == 0) 633 return (0); 634 m->m_len = asa->sa_len; 635 bcopy((caddr_t)asa, mtod(m, caddr_t), asa->sa_len); 636 if (n) 637 n->m_next = m0; /* concatenate data to control */ 638 else 639 control = m0; 640 m->m_next = control; 641 for (n = m; n; n = n->m_next) 642 sballoc(sb, n); 643 n = sb->sb_mb; 644 if (n) { 645 while (n->m_nextpkt) 646 n = n->m_nextpkt; 647 n->m_nextpkt = m; 648 } else 649 sb->sb_mb = m; 650 return (1); 651 } 652 653 int 654 sbappendcontrol(sb, m0, control) 655 struct sockbuf *sb; 656 struct mbuf *control, *m0; 657 { 658 register struct mbuf *m, *n; 659 int space = 0; 660 661 if (control == 0) 662 panic("sbappendcontrol"); 663 for (m = control; ; m = m->m_next) { 664 space += m->m_len; 665 if (m->m_next == 0) 666 break; 667 } 668 n = m; /* save pointer to last control buffer */ 669 for (m = m0; m; m = m->m_next) 670 space += m->m_len; 671 if (space > sbspace(sb)) 672 return (0); 673 n->m_next = m0; /* concatenate data to control */ 674 for (m = control; m; m = m->m_next) 675 sballoc(sb, m); 676 n = sb->sb_mb; 677 if (n) { 678 while (n->m_nextpkt) 679 n = n->m_nextpkt; 680 n->m_nextpkt = control; 681 } else 682 sb->sb_mb = control; 683 return (1); 684 } 685 686 /* 687 * Compress mbuf chain m into the socket 688 * buffer sb following mbuf n. If n 689 * is null, the buffer is presumed empty. 690 */ 691 void 692 sbcompress(sb, m, n) 693 register struct sockbuf *sb; 694 register struct mbuf *m, *n; 695 { 696 register int eor = 0; 697 register struct mbuf *o; 698 699 while (m) { 700 eor |= m->m_flags & M_EOR; 701 if (m->m_len == 0 && 702 (eor == 0 || 703 (((o = m->m_next) || (o = n)) && 704 o->m_type == m->m_type))) { 705 m = m_free(m); 706 continue; 707 } 708 if (n && (n->m_flags & M_EOR) == 0 && 709 M_WRITABLE(n) && 710 m->m_len <= MCLBYTES / 4 && /* XXX: Don't copy too much */ 711 m->m_len <= M_TRAILINGSPACE(n) && 712 n->m_type == m->m_type) { 713 bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len, 714 (unsigned)m->m_len); 715 n->m_len += m->m_len; 716 sb->sb_cc += m->m_len; 717 m = m_free(m); 718 continue; 719 } 720 if (n) 721 n->m_next = m; 722 else 723 sb->sb_mb = m; 724 sballoc(sb, m); 725 n = m; 726 m->m_flags &= ~M_EOR; 727 m = m->m_next; 728 n->m_next = 0; 729 } 730 if (eor) { 731 if (n) 732 n->m_flags |= eor; 733 else 734 printf("semi-panic: sbcompress\n"); 735 } 736 } 737 738 /* 739 * Free all mbufs in a sockbuf. 740 * Check that all resources are reclaimed. 741 */ 742 void 743 sbflush(sb) 744 register struct sockbuf *sb; 745 { 746 747 if (sb->sb_flags & SB_LOCK) 748 panic("sbflush: locked"); 749 while (sb->sb_mbcnt) { 750 /* 751 * Don't call sbdrop(sb, 0) if the leading mbuf is non-empty: 752 * we would loop forever. Panic instead. 753 */ 754 if (!sb->sb_cc && (sb->sb_mb == NULL || sb->sb_mb->m_len)) 755 break; 756 sbdrop(sb, (int)sb->sb_cc); 757 } 758 if (sb->sb_cc || sb->sb_mb || sb->sb_mbcnt) 759 panic("sbflush: cc %ld || mb %p || mbcnt %ld", sb->sb_cc, (void *)sb->sb_mb, sb->sb_mbcnt); 760 } 761 762 /* 763 * Drop data from (the front of) a sockbuf. 764 */ 765 void 766 sbdrop(sb, len) 767 register struct sockbuf *sb; 768 register int len; 769 { 770 register struct mbuf *m; 771 struct mbuf *next; 772 773 next = (m = sb->sb_mb) ? m->m_nextpkt : 0; 774 while (len > 0) { 775 if (m == 0) { 776 if (next == 0) 777 panic("sbdrop"); 778 m = next; 779 next = m->m_nextpkt; 780 continue; 781 } 782 if (m->m_len > len) { 783 m->m_len -= len; 784 m->m_data += len; 785 sb->sb_cc -= len; 786 break; 787 } 788 len -= m->m_len; 789 sbfree(sb, m); 790 m = m_free(m); 791 } 792 while (m && m->m_len == 0) { 793 sbfree(sb, m); 794 m = m_free(m); 795 } 796 if (m) { 797 sb->sb_mb = m; 798 m->m_nextpkt = next; 799 } else 800 sb->sb_mb = next; 801 } 802 803 /* 804 * Drop a record off the front of a sockbuf 805 * and move the next record to the front. 806 */ 807 void 808 sbdroprecord(sb) 809 register struct sockbuf *sb; 810 { 811 register struct mbuf *m; 812 813 m = sb->sb_mb; 814 if (m) { 815 sb->sb_mb = m->m_nextpkt; 816 do { 817 sbfree(sb, m); 818 m = m_free(m); 819 } while (m); 820 } 821 } 822 823 /* 824 * Create a "control" mbuf containing the specified data 825 * with the specified type for presentation on a socket buffer. 826 */ 827 struct mbuf * 828 sbcreatecontrol(p, size, type, level) 829 caddr_t p; 830 register int size; 831 int type, level; 832 { 833 register struct cmsghdr *cp; 834 struct mbuf *m; 835 836 if (CMSG_SPACE((u_int)size) > MCLBYTES) 837 return ((struct mbuf *) NULL); 838 if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL) 839 return ((struct mbuf *) NULL); 840 if (CMSG_SPACE((u_int)size) > MLEN) { 841 MCLGET(m, M_DONTWAIT); 842 if ((m->m_flags & M_EXT) == 0) { 843 m_free(m); 844 return ((struct mbuf *) NULL); 845 } 846 } 847 cp = mtod(m, struct cmsghdr *); 848 m->m_len = 0; 849 KASSERT(CMSG_SPACE((u_int)size) <= M_TRAILINGSPACE(m), 850 ("sbcreatecontrol: short mbuf")); 851 if (p != NULL) 852 (void)memcpy(CMSG_DATA(cp), p, size); 853 m->m_len = CMSG_SPACE(size); 854 cp->cmsg_len = CMSG_LEN(size); 855 cp->cmsg_level = level; 856 cp->cmsg_type = type; 857 return (m); 858 } 859 860 /* 861 * Some routines that return EOPNOTSUPP for entry points that are not 862 * supported by a protocol. Fill in as needed. 863 */ 864 int 865 pru_accept_notsupp(struct socket *so, struct sockaddr **nam) 866 { 867 return EOPNOTSUPP; 868 } 869 870 int 871 pru_connect_notsupp(struct socket *so, struct sockaddr *nam, struct proc *p) 872 { 873 return EOPNOTSUPP; 874 } 875 876 int 877 pru_connect2_notsupp(struct socket *so1, struct socket *so2) 878 { 879 return EOPNOTSUPP; 880 } 881 882 int 883 pru_control_notsupp(struct socket *so, u_long cmd, caddr_t data, 884 struct ifnet *ifp, struct proc *p) 885 { 886 return EOPNOTSUPP; 887 } 888 889 int 890 pru_listen_notsupp(struct socket *so, struct proc *p) 891 { 892 return EOPNOTSUPP; 893 } 894 895 int 896 pru_rcvd_notsupp(struct socket *so, int flags) 897 { 898 return EOPNOTSUPP; 899 } 900 901 int 902 pru_rcvoob_notsupp(struct socket *so, struct mbuf *m, int flags) 903 { 904 return EOPNOTSUPP; 905 } 906 907 /* 908 * This isn't really a ``null'' operation, but it's the default one 909 * and doesn't do anything destructive. 910 */ 911 int 912 pru_sense_null(struct socket *so, struct stat *sb) 913 { 914 sb->st_blksize = so->so_snd.sb_hiwat; 915 return 0; 916 } 917 918 /* 919 * Make a copy of a sockaddr in a malloced buffer of type M_SONAME. 920 */ 921 struct sockaddr * 922 dup_sockaddr(sa, canwait) 923 struct sockaddr *sa; 924 int canwait; 925 { 926 struct sockaddr *sa2; 927 928 MALLOC(sa2, struct sockaddr *, sa->sa_len, M_SONAME, 929 canwait ? M_WAITOK : M_NOWAIT); 930 if (sa2) 931 bcopy(sa, sa2, sa->sa_len); 932 return sa2; 933 } 934 935 /* 936 * Create an external-format (``xsocket'') structure using the information 937 * in the kernel-format socket structure pointed to by so. This is done 938 * to reduce the spew of irrelevant information over this interface, 939 * to isolate user code from changes in the kernel structure, and 940 * potentially to provide information-hiding if we decide that 941 * some of this information should be hidden from users. 942 */ 943 void 944 sotoxsocket(struct socket *so, struct xsocket *xso) 945 { 946 xso->xso_len = sizeof *xso; 947 xso->xso_so = so; 948 xso->so_type = so->so_type; 949 xso->so_options = so->so_options; 950 xso->so_linger = so->so_linger; 951 xso->so_state = so->so_state; 952 xso->so_pcb = so->so_pcb; 953 xso->xso_protocol = so->so_proto->pr_protocol; 954 xso->xso_family = so->so_proto->pr_domain->dom_family; 955 xso->so_qlen = so->so_qlen; 956 xso->so_incqlen = so->so_incqlen; 957 xso->so_qlimit = so->so_qlimit; 958 xso->so_timeo = so->so_timeo; 959 xso->so_error = so->so_error; 960 xso->so_pgid = so->so_sigio ? so->so_sigio->sio_pgid : 0; 961 xso->so_oobmark = so->so_oobmark; 962 sbtoxsockbuf(&so->so_snd, &xso->so_snd); 963 sbtoxsockbuf(&so->so_rcv, &xso->so_rcv); 964 xso->so_uid = so->so_cred->cr_uid; 965 } 966 967 /* 968 * This does the same for sockbufs. Note that the xsockbuf structure, 969 * since it is always embedded in a socket, does not include a self 970 * pointer nor a length. We make this entry point public in case 971 * some other mechanism needs it. 972 */ 973 void 974 sbtoxsockbuf(struct sockbuf *sb, struct xsockbuf *xsb) 975 { 976 xsb->sb_cc = sb->sb_cc; 977 xsb->sb_hiwat = sb->sb_hiwat; 978 xsb->sb_mbcnt = sb->sb_mbcnt; 979 xsb->sb_mbmax = sb->sb_mbmax; 980 xsb->sb_lowat = sb->sb_lowat; 981 xsb->sb_flags = sb->sb_flags; 982 xsb->sb_timeo = sb->sb_timeo; 983 } 984 985 /* 986 * Here is the definition of some of the basic objects in the kern.ipc 987 * branch of the MIB. 988 */ 989 SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW, 0, "IPC"); 990 991 /* This takes the place of kern.maxsockbuf, which moved to kern.ipc. */ 992 static int dummy; 993 SYSCTL_INT(_kern, KERN_DUMMY, dummy, CTLFLAG_RW, &dummy, 0, ""); 994 SYSCTL_OID(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf, CTLTYPE_INT|CTLFLAG_RW, 995 &sb_max, 0, sysctl_handle_sb_max, "I", "Maximum socket buffer size"); 996 SYSCTL_INT(_kern_ipc, OID_AUTO, maxsockets, CTLFLAG_RD, 997 &maxsockets, 0, "Maximum number of sockets avaliable"); 998 SYSCTL_INT(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW, 999 &sb_efficiency, 0, ""); 1000 1001 /* 1002 * Initialise maxsockets 1003 */ 1004 static void init_maxsockets(void *ignored) 1005 { 1006 TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets); 1007 maxsockets = imax(maxsockets, imax(maxfiles, nmbclusters)); 1008 } 1009 SYSINIT(param, SI_SUB_TUNABLES, SI_ORDER_ANY, init_maxsockets, NULL); 1010