1 /* 2 * Copyright (c) 1990, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from the Stanford/CMU enet packet filter, 6 * (net/enet.c) distributed as part of 4.3BSD, and code contributed 7 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence 8 * Berkeley Laboratory. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)bpf.c 8.2 (Berkeley) 3/28/94 39 * 40 * $FreeBSD: src/sys/net/bpf.c,v 1.59.2.12 2002/04/14 21:41:48 luigi Exp $ 41 * $DragonFly: src/sys/net/bpf.c,v 1.28 2005/07/08 18:19:39 dillon Exp $ 42 */ 43 44 #include "use_bpf.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/conf.h> 49 #include <sys/malloc.h> 50 #include <sys/mbuf.h> 51 #include <sys/time.h> 52 #include <sys/proc.h> 53 #include <sys/signalvar.h> 54 #include <sys/filio.h> 55 #include <sys/sockio.h> 56 #include <sys/ttycom.h> 57 #include <sys/filedesc.h> 58 59 #include <sys/poll.h> 60 61 #include <sys/socket.h> 62 #include <sys/vnode.h> 63 64 #include <sys/thread2.h> 65 66 #include <net/if.h> 67 #include <net/bpf.h> 68 #include <net/bpfdesc.h> 69 70 #include <netinet/in.h> 71 #include <netinet/if_ether.h> 72 #include <sys/kernel.h> 73 #include <sys/sysctl.h> 74 75 MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 76 77 #if NBPF > 0 78 79 /* 80 * The default read buffer size is patchable. 81 */ 82 static int bpf_bufsize = BPF_DEFAULTBUFSIZE; 83 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW, 84 &bpf_bufsize, 0, ""); 85 static int bpf_maxbufsize = BPF_MAXBUFSIZE; 86 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW, 87 &bpf_maxbufsize, 0, ""); 88 89 /* 90 * bpf_iflist is the list of interfaces; each corresponds to an ifnet 91 */ 92 static struct bpf_if *bpf_iflist; 93 94 static int bpf_allocbufs(struct bpf_d *); 95 static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp); 96 static void bpf_detachd(struct bpf_d *d); 97 static void bpf_freed(struct bpf_d *); 98 static void bpf_mcopy(const void *, void *, size_t); 99 static int bpf_movein(struct uio *, int, struct mbuf **, 100 struct sockaddr *, int *); 101 static int bpf_setif(struct bpf_d *, struct ifreq *); 102 static void bpf_timed_out(void *); 103 static void bpf_wakeup(struct bpf_d *); 104 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 105 void (*)(const void *, void *, size_t)); 106 static void reset_d(struct bpf_d *); 107 static int bpf_setf(struct bpf_d *, struct bpf_program *); 108 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 109 static int bpf_setdlt(struct bpf_d *, u_int); 110 static void bpf_drvinit(void *unused); 111 112 static d_open_t bpfopen; 113 static d_close_t bpfclose; 114 static d_read_t bpfread; 115 static d_write_t bpfwrite; 116 static d_ioctl_t bpfioctl; 117 static d_poll_t bpfpoll; 118 119 #define CDEV_MAJOR 23 120 static struct cdevsw bpf_cdevsw = { 121 /* name */ "bpf", 122 /* maj */ CDEV_MAJOR, 123 /* flags */ 0, 124 /* port */ NULL, 125 /* clone */ NULL, 126 127 /* open */ bpfopen, 128 /* close */ bpfclose, 129 /* read */ bpfread, 130 /* write */ bpfwrite, 131 /* ioctl */ bpfioctl, 132 /* poll */ bpfpoll, 133 /* mmap */ nommap, 134 /* strategy */ nostrategy, 135 /* dump */ nodump, 136 /* psize */ nopsize 137 }; 138 139 140 static int 141 bpf_movein(struct uio *uio, int linktype, struct mbuf **mp, 142 struct sockaddr *sockp, int *datlen) 143 { 144 struct mbuf *m; 145 int error; 146 int len; 147 int hlen; 148 149 /* 150 * Build a sockaddr based on the data link layer type. 151 * We do this at this level because the ethernet header 152 * is copied directly into the data field of the sockaddr. 153 * In the case of SLIP, there is no header and the packet 154 * is forwarded as is. 155 * Also, we are careful to leave room at the front of the mbuf 156 * for the link level header. 157 */ 158 switch (linktype) { 159 160 case DLT_SLIP: 161 sockp->sa_family = AF_INET; 162 hlen = 0; 163 break; 164 165 case DLT_EN10MB: 166 sockp->sa_family = AF_UNSPEC; 167 /* XXX Would MAXLINKHDR be better? */ 168 hlen = sizeof(struct ether_header); 169 break; 170 171 case DLT_FDDI: 172 sockp->sa_family = AF_IMPLINK; 173 hlen = 0; 174 break; 175 176 case DLT_RAW: 177 case DLT_NULL: 178 sockp->sa_family = AF_UNSPEC; 179 hlen = 0; 180 break; 181 182 case DLT_ATM_RFC1483: 183 /* 184 * en atm driver requires 4-byte atm pseudo header. 185 * though it isn't standard, vpi:vci needs to be 186 * specified anyway. 187 */ 188 sockp->sa_family = AF_UNSPEC; 189 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 190 break; 191 192 case DLT_PPP: 193 sockp->sa_family = AF_UNSPEC; 194 hlen = 4; /* This should match PPP_HDRLEN */ 195 break; 196 197 default: 198 return(EIO); 199 } 200 201 len = uio->uio_resid; 202 *datlen = len - hlen; 203 if ((unsigned)len > MCLBYTES) 204 return(EIO); 205 206 MGETHDR(m, MB_WAIT, MT_DATA); 207 if (m == NULL) 208 return(ENOBUFS); 209 if (len > MHLEN) { 210 MCLGET(m, MB_WAIT); 211 if (!(m->m_flags & M_EXT)) { 212 error = ENOBUFS; 213 goto bad; 214 } 215 } 216 m->m_pkthdr.len = m->m_len = len; 217 m->m_pkthdr.rcvif = NULL; 218 *mp = m; 219 /* 220 * Make room for link header. 221 */ 222 if (hlen != 0) { 223 m->m_pkthdr.len -= hlen; 224 m->m_len -= hlen; 225 m->m_data += hlen; /* XXX */ 226 error = uiomove(sockp->sa_data, hlen, uio); 227 if (error) 228 goto bad; 229 } 230 error = uiomove(mtod(m, caddr_t), len - hlen, uio); 231 if (!error) 232 return(0); 233 bad: 234 m_freem(m); 235 return(error); 236 } 237 238 /* 239 * Attach file to the bpf interface, i.e. make d listen on bp. 240 * Must be called at splimp. 241 */ 242 static void 243 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 244 { 245 /* 246 * Point d at bp, and add d to the interface's list of listeners. 247 * Finally, point the driver's bpf cookie at the interface so 248 * it will divert packets to bpf. 249 */ 250 d->bd_bif = bp; 251 SLIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 252 *bp->bif_driverp = bp; 253 } 254 255 /* 256 * Detach a file from its interface. 257 */ 258 static void 259 bpf_detachd(struct bpf_d *d) 260 { 261 int error; 262 struct bpf_if *bp; 263 struct ifnet *ifp; 264 265 bp = d->bd_bif; 266 ifp = bp->bif_ifp; 267 268 /* Remove d from the interface's descriptor list. */ 269 SLIST_REMOVE(&bp->bif_dlist, d, bpf_d, bd_next); 270 271 if (SLIST_EMPTY(&bp->bif_dlist)) { 272 /* 273 * Let the driver know that there are no more listeners. 274 */ 275 *bp->bif_driverp = NULL; 276 } 277 d->bd_bif = NULL; 278 /* 279 * Check if this descriptor had requested promiscuous mode. 280 * If so, turn it off. 281 */ 282 if (d->bd_promisc) { 283 d->bd_promisc = 0; 284 error = ifpromisc(ifp, 0); 285 if (error != 0 && error != ENXIO) { 286 /* 287 * ENXIO can happen if a pccard is unplugged, 288 * Something is really wrong if we were able to put 289 * the driver into promiscuous mode, but can't 290 * take it out. 291 */ 292 if_printf(ifp, "bpf_detach: ifpromisc failed(%d)\n", 293 error); 294 } 295 } 296 } 297 298 /* 299 * Open ethernet device. Returns ENXIO for illegal minor device number, 300 * EBUSY if file is open by another process. 301 */ 302 /* ARGSUSED */ 303 static int 304 bpfopen(dev_t dev, int flags, int fmt, struct thread *td) 305 { 306 struct bpf_d *d; 307 struct proc *p = td->td_proc; 308 309 KKASSERT(p != NULL); 310 311 if (p->p_ucred->cr_prison) 312 return(EPERM); 313 314 d = dev->si_drv1; 315 /* 316 * Each minor can be opened by only one process. If the requested 317 * minor is in use, return EBUSY. 318 */ 319 if (d != NULL) 320 return(EBUSY); 321 make_dev(&bpf_cdevsw, minor(dev), 0, 0, 0600, "bpf%d", lminor(dev)); 322 MALLOC(d, struct bpf_d *, sizeof *d, M_BPF, M_WAITOK | M_ZERO); 323 dev->si_drv1 = d; 324 d->bd_bufsize = bpf_bufsize; 325 d->bd_sig = SIGIO; 326 d->bd_seesent = 1; 327 callout_init(&d->bd_callout); 328 return(0); 329 } 330 331 /* 332 * Close the descriptor by detaching it from its interface, 333 * deallocating its buffers, and marking it free. 334 */ 335 /* ARGSUSED */ 336 static int 337 bpfclose(dev_t dev, int flags, int fmt, struct thread *td) 338 { 339 struct bpf_d *d = dev->si_drv1; 340 341 funsetown(d->bd_sigio); 342 crit_enter(); 343 if (d->bd_state == BPF_WAITING) 344 callout_stop(&d->bd_callout); 345 d->bd_state = BPF_IDLE; 346 if (d->bd_bif != NULL) 347 bpf_detachd(d); 348 crit_exit(); 349 bpf_freed(d); 350 dev->si_drv1 = NULL; 351 free(d, M_BPF); 352 353 return(0); 354 } 355 356 /* 357 * Rotate the packet buffers in descriptor d. Move the store buffer 358 * into the hold slot, and the free buffer into the store slot. 359 * Zero the length of the new store buffer. 360 */ 361 #define ROTATE_BUFFERS(d) \ 362 (d)->bd_hbuf = (d)->bd_sbuf; \ 363 (d)->bd_hlen = (d)->bd_slen; \ 364 (d)->bd_sbuf = (d)->bd_fbuf; \ 365 (d)->bd_slen = 0; \ 366 (d)->bd_fbuf = NULL; 367 /* 368 * bpfread - read next chunk of packets from buffers 369 */ 370 static int 371 bpfread(dev_t dev, struct uio *uio, int ioflag) 372 { 373 struct bpf_d *d = dev->si_drv1; 374 int timed_out; 375 int error; 376 377 /* 378 * Restrict application to use a buffer the same size as 379 * as kernel buffers. 380 */ 381 if (uio->uio_resid != d->bd_bufsize) 382 return(EINVAL); 383 384 crit_enter(); 385 if (d->bd_state == BPF_WAITING) 386 callout_stop(&d->bd_callout); 387 timed_out = (d->bd_state == BPF_TIMED_OUT); 388 d->bd_state = BPF_IDLE; 389 /* 390 * If the hold buffer is empty, then do a timed sleep, which 391 * ends when the timeout expires or when enough packets 392 * have arrived to fill the store buffer. 393 */ 394 while (d->bd_hbuf == NULL) { 395 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { 396 /* 397 * A packet(s) either arrived since the previous 398 * read or arrived while we were asleep. 399 * Rotate the buffers and return what's here. 400 */ 401 ROTATE_BUFFERS(d); 402 break; 403 } 404 405 /* 406 * No data is available, check to see if the bpf device 407 * is still pointed at a real interface. If not, return 408 * ENXIO so that the userland process knows to rebind 409 * it before using it again. 410 */ 411 if (d->bd_bif == NULL) { 412 crit_exit(); 413 return(ENXIO); 414 } 415 416 if (ioflag & IO_NDELAY) { 417 crit_exit(); 418 return(EWOULDBLOCK); 419 } 420 error = tsleep(d, PCATCH, "bpf", d->bd_rtout); 421 if (error == EINTR || error == ERESTART) { 422 crit_exit(); 423 return(error); 424 } 425 if (error == EWOULDBLOCK) { 426 /* 427 * On a timeout, return what's in the buffer, 428 * which may be nothing. If there is something 429 * in the store buffer, we can rotate the buffers. 430 */ 431 if (d->bd_hbuf) 432 /* 433 * We filled up the buffer in between 434 * getting the timeout and arriving 435 * here, so we don't need to rotate. 436 */ 437 break; 438 439 if (d->bd_slen == 0) { 440 crit_exit(); 441 return(0); 442 } 443 ROTATE_BUFFERS(d); 444 break; 445 } 446 } 447 /* 448 * At this point, we know we have something in the hold slot. 449 */ 450 crit_exit(); 451 452 /* 453 * Move data from hold buffer into user space. 454 * We know the entire buffer is transferred since 455 * we checked above that the read buffer is bpf_bufsize bytes. 456 */ 457 error = uiomove(d->bd_hbuf, d->bd_hlen, uio); 458 459 crit_enter(); 460 d->bd_fbuf = d->bd_hbuf; 461 d->bd_hbuf = NULL; 462 d->bd_hlen = 0; 463 crit_exit(); 464 465 return(error); 466 } 467 468 469 /* 470 * If there are processes sleeping on this descriptor, wake them up. 471 */ 472 static void 473 bpf_wakeup(struct bpf_d *d) 474 { 475 if (d->bd_state == BPF_WAITING) { 476 callout_stop(&d->bd_callout); 477 d->bd_state = BPF_IDLE; 478 } 479 wakeup(d); 480 if (d->bd_async && d->bd_sig && d->bd_sigio) 481 pgsigio(d->bd_sigio, d->bd_sig, 0); 482 483 selwakeup(&d->bd_sel); 484 /* XXX */ 485 d->bd_sel.si_pid = 0; 486 } 487 488 static void 489 bpf_timed_out(void *arg) 490 { 491 struct bpf_d *d = (struct bpf_d *)arg; 492 493 crit_enter(); 494 if (d->bd_state == BPF_WAITING) { 495 d->bd_state = BPF_TIMED_OUT; 496 if (d->bd_slen != 0) 497 bpf_wakeup(d); 498 } 499 crit_exit(); 500 } 501 502 static int 503 bpfwrite(dev_t dev, struct uio *uio, int ioflag) 504 { 505 struct bpf_d *d = dev->si_drv1; 506 struct ifnet *ifp; 507 struct mbuf *m; 508 int error; 509 static struct sockaddr dst; 510 int datlen; 511 512 if (d->bd_bif == NULL) 513 return(ENXIO); 514 515 ifp = d->bd_bif->bif_ifp; 516 517 if (uio->uio_resid == 0) 518 return(0); 519 520 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen); 521 if (error) 522 return(error); 523 524 if (datlen > ifp->if_mtu) { 525 m_freem(m); 526 return(EMSGSIZE); 527 } 528 529 if (d->bd_hdrcmplt) 530 dst.sa_family = pseudo_AF_HDRCMPLT; 531 532 crit_enter(); 533 error = (*ifp->if_output)(ifp, m, &dst, (struct rtentry *)NULL); 534 crit_exit(); 535 /* 536 * The driver frees the mbuf. 537 */ 538 return(error); 539 } 540 541 /* 542 * Reset a descriptor by flushing its packet buffer and clearing the 543 * receive and drop counts. Should be called at splimp. 544 */ 545 static void 546 reset_d(struct bpf_d *d) 547 { 548 if (d->bd_hbuf) { 549 /* Free the hold buffer. */ 550 d->bd_fbuf = d->bd_hbuf; 551 d->bd_hbuf = NULL; 552 } 553 d->bd_slen = 0; 554 d->bd_hlen = 0; 555 d->bd_rcount = 0; 556 d->bd_dcount = 0; 557 } 558 559 /* 560 * FIONREAD Check for read packet available. 561 * SIOCGIFADDR Get interface address - convenient hook to driver. 562 * BIOCGBLEN Get buffer len [for read()]. 563 * BIOCSETF Set ethernet read filter. 564 * BIOCFLUSH Flush read packet buffer. 565 * BIOCPROMISC Put interface into promiscuous mode. 566 * BIOCGDLT Get link layer type. 567 * BIOCGETIF Get interface name. 568 * BIOCSETIF Set interface. 569 * BIOCSRTIMEOUT Set read timeout. 570 * BIOCGRTIMEOUT Get read timeout. 571 * BIOCGSTATS Get packet stats. 572 * BIOCIMMEDIATE Set immediate mode. 573 * BIOCVERSION Get filter language version. 574 * BIOCGHDRCMPLT Get "header already complete" flag 575 * BIOCSHDRCMPLT Set "header already complete" flag 576 * BIOCGSEESENT Get "see packets sent" flag 577 * BIOCSSEESENT Set "see packets sent" flag 578 */ 579 /* ARGSUSED */ 580 static int 581 bpfioctl(dev_t dev, u_long cmd, caddr_t addr, int flags, struct thread *td) 582 { 583 struct bpf_d *d = dev->si_drv1; 584 int error = 0; 585 586 crit_enter(); 587 if (d->bd_state == BPF_WAITING) 588 callout_stop(&d->bd_callout); 589 d->bd_state = BPF_IDLE; 590 crit_exit(); 591 592 switch (cmd) { 593 594 default: 595 error = EINVAL; 596 break; 597 598 /* 599 * Check for read packet available. 600 */ 601 case FIONREAD: 602 { 603 int n; 604 605 crit_enter(); 606 n = d->bd_slen; 607 if (d->bd_hbuf) 608 n += d->bd_hlen; 609 crit_exit(); 610 611 *(int *)addr = n; 612 break; 613 } 614 615 case SIOCGIFADDR: 616 { 617 struct ifnet *ifp; 618 619 if (d->bd_bif == NULL) 620 error = EINVAL; 621 else { 622 ifp = d->bd_bif->bif_ifp; 623 error = (*ifp->if_ioctl)(ifp, cmd, addr, 624 td->td_proc->p_ucred); 625 } 626 break; 627 } 628 629 /* 630 * Get buffer len [for read()]. 631 */ 632 case BIOCGBLEN: 633 *(u_int *)addr = d->bd_bufsize; 634 break; 635 636 /* 637 * Set buffer length. 638 */ 639 case BIOCSBLEN: 640 if (d->bd_bif != 0) 641 error = EINVAL; 642 else { 643 u_int size = *(u_int *)addr; 644 645 if (size > bpf_maxbufsize) 646 *(u_int *)addr = size = bpf_maxbufsize; 647 else if (size < BPF_MINBUFSIZE) 648 *(u_int *)addr = size = BPF_MINBUFSIZE; 649 d->bd_bufsize = size; 650 } 651 break; 652 653 /* 654 * Set link layer read filter. 655 */ 656 case BIOCSETF: 657 error = bpf_setf(d, (struct bpf_program *)addr); 658 break; 659 660 /* 661 * Flush read packet buffer. 662 */ 663 case BIOCFLUSH: 664 crit_enter(); 665 reset_d(d); 666 crit_exit(); 667 break; 668 669 /* 670 * Put interface into promiscuous mode. 671 */ 672 case BIOCPROMISC: 673 if (d->bd_bif == NULL) { 674 /* 675 * No interface attached yet. 676 */ 677 error = EINVAL; 678 break; 679 } 680 crit_enter(); 681 if (d->bd_promisc == 0) { 682 error = ifpromisc(d->bd_bif->bif_ifp, 1); 683 if (error == 0) 684 d->bd_promisc = 1; 685 } 686 crit_exit(); 687 break; 688 689 /* 690 * Get device parameters. 691 */ 692 case BIOCGDLT: 693 if (d->bd_bif == NULL) 694 error = EINVAL; 695 else 696 *(u_int *)addr = d->bd_bif->bif_dlt; 697 break; 698 699 /* 700 * Get a list of supported data link types. 701 */ 702 case BIOCGDLTLIST: 703 if (d->bd_bif == NULL) 704 error = EINVAL; 705 else 706 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 707 break; 708 709 /* 710 * Set data link type. 711 */ 712 case BIOCSDLT: 713 if (d->bd_bif == NULL) 714 error = EINVAL; 715 else 716 error = bpf_setdlt(d, *(u_int *)addr); 717 break; 718 719 /* 720 * Get interface name. 721 */ 722 case BIOCGETIF: 723 if (d->bd_bif == NULL) { 724 error = EINVAL; 725 } else { 726 struct ifnet *const ifp = d->bd_bif->bif_ifp; 727 struct ifreq *const ifr = (struct ifreq *)addr; 728 729 strlcpy(ifr->ifr_name, ifp->if_xname, 730 sizeof ifr->ifr_name); 731 } 732 break; 733 734 /* 735 * Set interface. 736 */ 737 case BIOCSETIF: 738 error = bpf_setif(d, (struct ifreq *)addr); 739 break; 740 741 /* 742 * Set read timeout. 743 */ 744 case BIOCSRTIMEOUT: 745 { 746 struct timeval *tv = (struct timeval *)addr; 747 748 /* 749 * Subtract 1 tick from tvtohz() since this isn't 750 * a one-shot timer. 751 */ 752 if ((error = itimerfix(tv)) == 0) 753 d->bd_rtout = tvtohz_low(tv); 754 break; 755 } 756 757 /* 758 * Get read timeout. 759 */ 760 case BIOCGRTIMEOUT: 761 { 762 struct timeval *tv = (struct timeval *)addr; 763 764 tv->tv_sec = d->bd_rtout / hz; 765 tv->tv_usec = (d->bd_rtout % hz) * tick; 766 break; 767 } 768 769 /* 770 * Get packet stats. 771 */ 772 case BIOCGSTATS: 773 { 774 struct bpf_stat *bs = (struct bpf_stat *)addr; 775 776 bs->bs_recv = d->bd_rcount; 777 bs->bs_drop = d->bd_dcount; 778 break; 779 } 780 781 /* 782 * Set immediate mode. 783 */ 784 case BIOCIMMEDIATE: 785 d->bd_immediate = *(u_int *)addr; 786 break; 787 788 case BIOCVERSION: 789 { 790 struct bpf_version *bv = (struct bpf_version *)addr; 791 792 bv->bv_major = BPF_MAJOR_VERSION; 793 bv->bv_minor = BPF_MINOR_VERSION; 794 break; 795 } 796 797 /* 798 * Get "header already complete" flag 799 */ 800 case BIOCGHDRCMPLT: 801 *(u_int *)addr = d->bd_hdrcmplt; 802 break; 803 804 /* 805 * Set "header already complete" flag 806 */ 807 case BIOCSHDRCMPLT: 808 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 809 break; 810 811 /* 812 * Get "see sent packets" flag 813 */ 814 case BIOCGSEESENT: 815 *(u_int *)addr = d->bd_seesent; 816 break; 817 818 /* 819 * Set "see sent packets" flag 820 */ 821 case BIOCSSEESENT: 822 d->bd_seesent = *(u_int *)addr; 823 break; 824 825 case FIONBIO: /* Non-blocking I/O */ 826 break; 827 828 case FIOASYNC: /* Send signal on receive packets */ 829 d->bd_async = *(int *)addr; 830 break; 831 832 case FIOSETOWN: 833 error = fsetown(*(int *)addr, &d->bd_sigio); 834 break; 835 836 case FIOGETOWN: 837 *(int *)addr = fgetown(d->bd_sigio); 838 break; 839 840 /* This is deprecated, FIOSETOWN should be used instead. */ 841 case TIOCSPGRP: 842 error = fsetown(-(*(int *)addr), &d->bd_sigio); 843 break; 844 845 /* This is deprecated, FIOGETOWN should be used instead. */ 846 case TIOCGPGRP: 847 *(int *)addr = -fgetown(d->bd_sigio); 848 break; 849 850 case BIOCSRSIG: /* Set receive signal */ 851 { 852 u_int sig; 853 854 sig = *(u_int *)addr; 855 856 if (sig >= NSIG) 857 error = EINVAL; 858 else 859 d->bd_sig = sig; 860 break; 861 } 862 case BIOCGRSIG: 863 *(u_int *)addr = d->bd_sig; 864 break; 865 } 866 return(error); 867 } 868 869 /* 870 * Set d's packet filter program to fp. If this file already has a filter, 871 * free it and replace it. Returns EINVAL for bogus requests. 872 */ 873 static int 874 bpf_setf(struct bpf_d *d, struct bpf_program *fp) 875 { 876 struct bpf_insn *fcode, *old; 877 u_int flen, size; 878 879 old = d->bd_filter; 880 if (fp->bf_insns == NULL) { 881 if (fp->bf_len != 0) 882 return(EINVAL); 883 crit_enter(); 884 d->bd_filter = NULL; 885 reset_d(d); 886 crit_exit(); 887 if (old != 0) 888 free(old, M_BPF); 889 return(0); 890 } 891 flen = fp->bf_len; 892 if (flen > BPF_MAXINSNS) 893 return(EINVAL); 894 895 size = flen * sizeof *fp->bf_insns; 896 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); 897 if (copyin(fp->bf_insns, fcode, size) == 0 && 898 bpf_validate(fcode, (int)flen)) { 899 crit_enter(); 900 d->bd_filter = fcode; 901 reset_d(d); 902 crit_exit(); 903 if (old != 0) 904 free(old, M_BPF); 905 906 return(0); 907 } 908 free(fcode, M_BPF); 909 return(EINVAL); 910 } 911 912 /* 913 * Detach a file from its current interface (if attached at all) and attach 914 * to the interface indicated by the name stored in ifr. 915 * Return an errno or 0. 916 */ 917 static int 918 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 919 { 920 struct bpf_if *bp; 921 int error; 922 struct ifnet *theywant; 923 924 theywant = ifunit(ifr->ifr_name); 925 if (theywant == NULL) 926 return(ENXIO); 927 928 /* 929 * Look through attached interfaces for the named one. 930 */ 931 for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) { 932 struct ifnet *ifp = bp->bif_ifp; 933 934 if (ifp == NULL || ifp != theywant) 935 continue; 936 /* skip additional entry */ 937 if (bp->bif_driverp != &ifp->if_bpf) 938 continue; 939 /* 940 * We found the requested interface. 941 * If it's not up, return an error. 942 * Allocate the packet buffers if we need to. 943 * If we're already attached to requested interface, 944 * just flush the buffer. 945 */ 946 if (!(ifp->if_flags & IFF_UP)) 947 return(ENETDOWN); 948 949 if (d->bd_sbuf == NULL) { 950 error = bpf_allocbufs(d); 951 if (error != 0) 952 return(error); 953 } 954 crit_enter(); 955 if (bp != d->bd_bif) { 956 if (d->bd_bif != NULL) { 957 /* 958 * Detach if attached to something else. 959 */ 960 bpf_detachd(d); 961 } 962 963 bpf_attachd(d, bp); 964 } 965 reset_d(d); 966 crit_exit(); 967 return(0); 968 } 969 970 /* Not found. */ 971 return(ENXIO); 972 } 973 974 /* 975 * Support for select() and poll() system calls 976 * 977 * Return true iff the specific operation will not block indefinitely. 978 * Otherwise, return false but make a note that a selwakeup() must be done. 979 */ 980 int 981 bpfpoll(dev_t dev, int events, struct thread *td) 982 { 983 struct bpf_d *d; 984 int revents; 985 986 d = dev->si_drv1; 987 if (d->bd_bif == NULL) 988 return(ENXIO); 989 990 revents = events & (POLLOUT | POLLWRNORM); 991 crit_enter(); 992 if (events & (POLLIN | POLLRDNORM)) { 993 /* 994 * An imitation of the FIONREAD ioctl code. 995 * XXX not quite. An exact imitation: 996 * if (d->b_slen != 0 || 997 * (d->bd_hbuf != NULL && d->bd_hlen != 0) 998 */ 999 if (d->bd_hlen != 0 || 1000 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1001 d->bd_slen != 0)) 1002 revents |= events & (POLLIN | POLLRDNORM); 1003 else { 1004 selrecord(td, &d->bd_sel); 1005 /* Start the read timeout if necessary. */ 1006 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1007 callout_reset(&d->bd_callout, d->bd_rtout, 1008 bpf_timed_out, d); 1009 d->bd_state = BPF_WAITING; 1010 } 1011 } 1012 } 1013 crit_exit(); 1014 return(revents); 1015 } 1016 1017 /* 1018 * Process the packet pkt of length pktlen. The packet is parsed 1019 * by each listener's filter, and if accepted, stashed into the 1020 * corresponding buffer. 1021 */ 1022 void 1023 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1024 { 1025 struct bpf_d *d; 1026 u_int slen; 1027 1028 /* 1029 * Note that the ipl does not have to be raised at this point. 1030 * The only problem that could arise here is that if two different 1031 * interfaces shared any data. This is not the case. 1032 */ 1033 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1034 ++d->bd_rcount; 1035 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen); 1036 if (slen != 0) 1037 catchpacket(d, pkt, pktlen, slen, ovbcopy); 1038 } 1039 } 1040 1041 /* 1042 * Copy data from an mbuf chain into a buffer. This code is derived 1043 * from m_copydata in sys/uipc_mbuf.c. 1044 */ 1045 static void 1046 bpf_mcopy(const void *src_arg, void *dst_arg, size_t len) 1047 { 1048 const struct mbuf *m; 1049 u_int count; 1050 u_char *dst; 1051 1052 m = src_arg; 1053 dst = dst_arg; 1054 while (len > 0) { 1055 if (m == NULL) 1056 panic("bpf_mcopy"); 1057 count = min(m->m_len, len); 1058 bcopy(mtod(m, void *), dst, count); 1059 m = m->m_next; 1060 dst += count; 1061 len -= count; 1062 } 1063 } 1064 1065 /* 1066 * Process the packet in the mbuf chain m. The packet is parsed by each 1067 * listener's filter, and if accepted, stashed into the corresponding 1068 * buffer. 1069 */ 1070 void 1071 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1072 { 1073 struct bpf_d *d; 1074 u_int pktlen, slen; 1075 struct mbuf *m0; 1076 1077 /* Don't compute pktlen, if no descriptor is attached. */ 1078 if (SLIST_EMPTY(&bp->bif_dlist)) 1079 return; 1080 1081 pktlen = 0; 1082 for (m0 = m; m0 != NULL; m0 = m0->m_next) 1083 pktlen += m0->m_len; 1084 1085 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1086 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1087 continue; 1088 ++d->bd_rcount; 1089 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0); 1090 if (slen != 0) 1091 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy); 1092 } 1093 } 1094 1095 void 1096 bpf_mtap_family(struct bpf_if *bp, struct mbuf *m, sa_family_t family) 1097 { 1098 u_int family4; 1099 1100 KKASSERT(family != AF_UNSPEC); 1101 1102 family4 = (u_int)family; 1103 bpf_ptap(bp, m, &family4, sizeof(family4)); 1104 } 1105 1106 /* 1107 * Process the packet in the mbuf chain m with the header in m prepended. 1108 * The packet is parsed by each listener's filter, and if accepted, 1109 * stashed into the corresponding buffer. 1110 */ 1111 void 1112 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen) 1113 { 1114 struct mbuf mb; 1115 1116 /* 1117 * Craft on-stack mbuf suitable for passing to bpf_mtap. 1118 * Note that we cut corners here; we only setup what's 1119 * absolutely needed--this mbuf should never go anywhere else. 1120 */ 1121 mb.m_next = m; 1122 mb.m_data = __DECONST(void *, data); /* LINTED */ 1123 mb.m_len = dlen; 1124 1125 bpf_mtap(bp, &mb); 1126 } 1127 1128 /* 1129 * Move the packet data from interface memory (pkt) into the 1130 * store buffer. Return 1 if it's time to wakeup a listener (buffer full), 1131 * otherwise 0. "copy" is the routine called to do the actual data 1132 * transfer. bcopy is passed in to copy contiguous chunks, while 1133 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1134 * pkt is really an mbuf. 1135 */ 1136 static void 1137 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 1138 void (*cpfn)(const void *, void *, size_t)) 1139 { 1140 struct bpf_hdr *hp; 1141 int totlen, curlen; 1142 int hdrlen = d->bd_bif->bif_hdrlen; 1143 /* 1144 * Figure out how many bytes to move. If the packet is 1145 * greater or equal to the snapshot length, transfer that 1146 * much. Otherwise, transfer the whole packet (unless 1147 * we hit the buffer size limit). 1148 */ 1149 totlen = hdrlen + min(snaplen, pktlen); 1150 if (totlen > d->bd_bufsize) 1151 totlen = d->bd_bufsize; 1152 1153 /* 1154 * Round up the end of the previous packet to the next longword. 1155 */ 1156 curlen = BPF_WORDALIGN(d->bd_slen); 1157 if (curlen + totlen > d->bd_bufsize) { 1158 /* 1159 * This packet will overflow the storage buffer. 1160 * Rotate the buffers if we can, then wakeup any 1161 * pending reads. 1162 */ 1163 if (d->bd_fbuf == NULL) { 1164 /* 1165 * We haven't completed the previous read yet, 1166 * so drop the packet. 1167 */ 1168 ++d->bd_dcount; 1169 return; 1170 } 1171 ROTATE_BUFFERS(d); 1172 bpf_wakeup(d); 1173 curlen = 0; 1174 } 1175 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1176 /* 1177 * Immediate mode is set, or the read timeout has 1178 * already expired during a select call. A packet 1179 * arrived, so the reader should be woken up. 1180 */ 1181 bpf_wakeup(d); 1182 1183 /* 1184 * Append the bpf header. 1185 */ 1186 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1187 microtime(&hp->bh_tstamp); 1188 hp->bh_datalen = pktlen; 1189 hp->bh_hdrlen = hdrlen; 1190 /* 1191 * Copy the packet data into the store buffer and update its length. 1192 */ 1193 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1194 d->bd_slen = curlen + totlen; 1195 } 1196 1197 /* 1198 * Initialize all nonzero fields of a descriptor. 1199 */ 1200 static int 1201 bpf_allocbufs(struct bpf_d *d) 1202 { 1203 d->bd_fbuf = malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1204 if (d->bd_fbuf == NULL) 1205 return(ENOBUFS); 1206 1207 d->bd_sbuf = malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1208 if (d->bd_sbuf == NULL) { 1209 free(d->bd_fbuf, M_BPF); 1210 return(ENOBUFS); 1211 } 1212 d->bd_slen = 0; 1213 d->bd_hlen = 0; 1214 return(0); 1215 } 1216 1217 /* 1218 * Free buffers currently in use by a descriptor. 1219 * Called on close. 1220 */ 1221 static void 1222 bpf_freed(struct bpf_d *d) 1223 { 1224 /* 1225 * We don't need to lock out interrupts since this descriptor has 1226 * been detached from its interface and it yet hasn't been marked 1227 * free. 1228 */ 1229 if (d->bd_sbuf != NULL) { 1230 free(d->bd_sbuf, M_BPF); 1231 if (d->bd_hbuf != NULL) 1232 free(d->bd_hbuf, M_BPF); 1233 if (d->bd_fbuf != NULL) 1234 free(d->bd_fbuf, M_BPF); 1235 } 1236 if (d->bd_filter) 1237 free(d->bd_filter, M_BPF); 1238 } 1239 1240 /* 1241 * Attach an interface to bpf. ifp is a pointer to the structure 1242 * defining the interface to be attached, dlt is the link layer type, 1243 * and hdrlen is the fixed size of the link header (variable length 1244 * headers are not yet supported). 1245 */ 1246 void 1247 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1248 { 1249 bpfattach_dlt(ifp, dlt, hdrlen, &ifp->if_bpf); 1250 } 1251 1252 void 1253 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1254 { 1255 struct bpf_if *bp; 1256 1257 bp = malloc(sizeof *bp, M_BPF, M_WAITOK | M_ZERO); 1258 1259 SLIST_INIT(&bp->bif_dlist); 1260 bp->bif_ifp = ifp; 1261 bp->bif_dlt = dlt; 1262 bp->bif_driverp = driverp; 1263 *bp->bif_driverp = NULL; 1264 1265 bp->bif_next = bpf_iflist; 1266 bpf_iflist = bp; 1267 1268 /* 1269 * Compute the length of the bpf header. This is not necessarily 1270 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1271 * that the network layer header begins on a longword boundary (for 1272 * performance reasons and to alleviate alignment restrictions). 1273 */ 1274 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1275 1276 if (bootverbose) 1277 if_printf(ifp, "bpf attached\n"); 1278 } 1279 1280 /* 1281 * Detach bpf from an interface. This involves detaching each descriptor 1282 * associated with the interface, and leaving bd_bif NULL. Notify each 1283 * descriptor as it's detached so that any sleepers wake up and get 1284 * ENXIO. 1285 */ 1286 void 1287 bpfdetach(struct ifnet *ifp) 1288 { 1289 struct bpf_if *bp, *bp_prev; 1290 struct bpf_d *d; 1291 1292 crit_enter(); 1293 1294 /* Locate BPF interface information */ 1295 bp_prev = NULL; 1296 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1297 if (ifp == bp->bif_ifp) 1298 break; 1299 bp_prev = bp; 1300 } 1301 1302 /* Interface wasn't attached */ 1303 if (bp->bif_ifp == NULL) { 1304 crit_exit(); 1305 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 1306 return; 1307 } 1308 1309 while ((d = SLIST_FIRST(&bp->bif_dlist)) != NULL) { 1310 bpf_detachd(d); 1311 bpf_wakeup(d); 1312 } 1313 1314 if (bp_prev != NULL) 1315 bp_prev->bif_next = bp->bif_next; 1316 else 1317 bpf_iflist = bp->bif_next; 1318 1319 free(bp, M_BPF); 1320 1321 crit_exit(); 1322 } 1323 1324 /* 1325 * Get a list of available data link type of the interface. 1326 */ 1327 static int 1328 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 1329 { 1330 int n, error; 1331 struct ifnet *ifp; 1332 struct bpf_if *bp; 1333 1334 ifp = d->bd_bif->bif_ifp; 1335 n = 0; 1336 error = 0; 1337 for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) { 1338 if (bp->bif_ifp != ifp) 1339 continue; 1340 if (bfl->bfl_list != NULL) { 1341 if (n >= bfl->bfl_len) { 1342 return (ENOMEM); 1343 } 1344 error = copyout(&bp->bif_dlt, 1345 bfl->bfl_list + n, sizeof(u_int)); 1346 } 1347 n++; 1348 } 1349 bfl->bfl_len = n; 1350 return(error); 1351 } 1352 1353 /* 1354 * Set the data link type of a BPF instance. 1355 */ 1356 static int 1357 bpf_setdlt(struct bpf_d *d, u_int dlt) 1358 { 1359 int error, opromisc; 1360 struct ifnet *ifp; 1361 struct bpf_if *bp; 1362 1363 if (d->bd_bif->bif_dlt == dlt) 1364 return (0); 1365 ifp = d->bd_bif->bif_ifp; 1366 for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) { 1367 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1368 break; 1369 } 1370 if (bp != NULL) { 1371 opromisc = d->bd_promisc; 1372 crit_enter(); 1373 bpf_detachd(d); 1374 bpf_attachd(d, bp); 1375 reset_d(d); 1376 if (opromisc) { 1377 error = ifpromisc(bp->bif_ifp, 1); 1378 if (error) 1379 if_printf(bp->bif_ifp, 1380 "bpf_setdlt: ifpromisc failed (%d)\n", 1381 error); 1382 else 1383 d->bd_promisc = 1; 1384 } 1385 crit_exit(); 1386 } 1387 return(bp == NULL ? EINVAL : 0); 1388 } 1389 1390 static void 1391 bpf_drvinit(void *unused) 1392 { 1393 cdevsw_add(&bpf_cdevsw, 0, 0); 1394 } 1395 1396 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL) 1397 1398 #else /* !BPF */ 1399 /* 1400 * NOP stubs to allow bpf-using drivers to load and function. 1401 * 1402 * A 'better' implementation would allow the core bpf functionality 1403 * to be loaded at runtime. 1404 */ 1405 1406 void 1407 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1408 { 1409 } 1410 1411 void 1412 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1413 { 1414 } 1415 1416 void 1417 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen) 1418 { 1419 } 1420 1421 void 1422 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1423 { 1424 } 1425 1426 void 1427 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1428 { 1429 } 1430 1431 void 1432 bpfdetach(struct ifnet *ifp) 1433 { 1434 } 1435 1436 u_int 1437 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 1438 { 1439 return -1; /* "no filter" behaviour */ 1440 } 1441 1442 #endif /* !BPF */ 1443