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 1.50 2008/09/23 11:28:49 sephe 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/device.h> 50 #include <sys/malloc.h> 51 #include <sys/mbuf.h> 52 #include <sys/time.h> 53 #include <sys/proc.h> 54 #include <sys/signalvar.h> 55 #include <sys/filio.h> 56 #include <sys/sockio.h> 57 #include <sys/ttycom.h> 58 #include <sys/filedesc.h> 59 60 #include <sys/event.h> 61 62 #include <sys/socket.h> 63 #include <sys/vnode.h> 64 65 #include <sys/thread2.h> 66 #include <sys/mplock2.h> 67 68 #include <net/if.h> 69 #include <net/bpf.h> 70 #include <net/bpfdesc.h> 71 #include <net/netmsg2.h> 72 73 #include <netinet/in.h> 74 #include <netinet/if_ether.h> 75 #include <sys/kernel.h> 76 #include <sys/sysctl.h> 77 78 #include <sys/devfs.h> 79 80 struct netmsg_bpf_output { 81 struct netmsg_base base; 82 struct mbuf *nm_mbuf; 83 struct ifnet *nm_ifp; 84 struct sockaddr *nm_dst; 85 }; 86 87 MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 88 DEVFS_DECLARE_CLONE_BITMAP(bpf); 89 90 #if NBPF <= 1 91 #define BPF_PREALLOCATED_UNITS 4 92 #else 93 #define BPF_PREALLOCATED_UNITS NBPF 94 #endif 95 96 #if NBPF > 0 97 98 /* 99 * The default read buffer size is patchable. 100 */ 101 static int bpf_bufsize = BPF_DEFAULTBUFSIZE; 102 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW, 103 &bpf_bufsize, 0, ""); 104 int bpf_maxbufsize = BPF_MAXBUFSIZE; 105 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW, 106 &bpf_maxbufsize, 0, ""); 107 108 /* 109 * bpf_iflist is the list of interfaces; each corresponds to an ifnet 110 */ 111 static struct bpf_if *bpf_iflist; 112 113 static int bpf_allocbufs(struct bpf_d *); 114 static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp); 115 static void bpf_detachd(struct bpf_d *d); 116 static void bpf_resetd(struct bpf_d *); 117 static void bpf_freed(struct bpf_d *); 118 static void bpf_mcopy(const void *, void *, size_t); 119 static int bpf_movein(struct uio *, int, struct mbuf **, 120 struct sockaddr *, int *, struct bpf_insn *); 121 static int bpf_setif(struct bpf_d *, struct ifreq *); 122 static void bpf_timed_out(void *); 123 static void bpf_wakeup(struct bpf_d *); 124 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 125 void (*)(const void *, void *, size_t), 126 const struct timeval *); 127 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 128 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 129 static int bpf_setdlt(struct bpf_d *, u_int); 130 static void bpf_drvinit(void *unused); 131 static void bpf_filter_detach(struct knote *kn); 132 static int bpf_filter_read(struct knote *kn, long hint); 133 134 static d_open_t bpfopen; 135 static d_clone_t bpfclone; 136 static d_close_t bpfclose; 137 static d_read_t bpfread; 138 static d_write_t bpfwrite; 139 static d_ioctl_t bpfioctl; 140 static d_kqfilter_t bpfkqfilter; 141 142 #define CDEV_MAJOR 23 143 static struct dev_ops bpf_ops = { 144 { "bpf", CDEV_MAJOR, 0 }, 145 .d_open = bpfopen, 146 .d_close = bpfclose, 147 .d_read = bpfread, 148 .d_write = bpfwrite, 149 .d_ioctl = bpfioctl, 150 .d_kqfilter = bpfkqfilter 151 }; 152 153 154 static int 155 bpf_movein(struct uio *uio, int linktype, struct mbuf **mp, 156 struct sockaddr *sockp, int *datlen, struct bpf_insn *wfilter) 157 { 158 struct mbuf *m; 159 int error; 160 int len; 161 int hlen; 162 int slen; 163 164 *datlen = 0; 165 *mp = NULL; 166 167 /* 168 * Build a sockaddr based on the data link layer type. 169 * We do this at this level because the ethernet header 170 * is copied directly into the data field of the sockaddr. 171 * In the case of SLIP, there is no header and the packet 172 * is forwarded as is. 173 * Also, we are careful to leave room at the front of the mbuf 174 * for the link level header. 175 */ 176 switch (linktype) { 177 case DLT_SLIP: 178 sockp->sa_family = AF_INET; 179 hlen = 0; 180 break; 181 182 case DLT_EN10MB: 183 sockp->sa_family = AF_UNSPEC; 184 /* XXX Would MAXLINKHDR be better? */ 185 hlen = sizeof(struct ether_header); 186 break; 187 188 case DLT_RAW: 189 case DLT_NULL: 190 sockp->sa_family = AF_UNSPEC; 191 hlen = 0; 192 break; 193 194 case DLT_ATM_RFC1483: 195 /* 196 * en atm driver requires 4-byte atm pseudo header. 197 * though it isn't standard, vpi:vci needs to be 198 * specified anyway. 199 */ 200 sockp->sa_family = AF_UNSPEC; 201 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 202 break; 203 204 case DLT_PPP: 205 sockp->sa_family = AF_UNSPEC; 206 hlen = 4; /* This should match PPP_HDRLEN */ 207 break; 208 209 default: 210 return(EIO); 211 } 212 213 len = uio->uio_resid; 214 *datlen = len - hlen; 215 if ((unsigned)len > MCLBYTES) 216 return(EIO); 217 218 m = m_getl(len, MB_WAIT, MT_DATA, M_PKTHDR, NULL); 219 if (m == NULL) 220 return(ENOBUFS); 221 m->m_pkthdr.len = m->m_len = len; 222 m->m_pkthdr.rcvif = NULL; 223 *mp = m; 224 225 if (m->m_len < hlen) { 226 error = EPERM; 227 goto bad; 228 } 229 230 error = uiomove(mtod(m, u_char *), len, uio); 231 if (error) 232 goto bad; 233 234 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len); 235 if (slen == 0) { 236 error = EPERM; 237 goto bad; 238 } 239 240 /* 241 * Make room for link header, and copy it to sockaddr. 242 */ 243 if (hlen != 0) { 244 bcopy(m->m_data, sockp->sa_data, hlen); 245 m->m_pkthdr.len -= hlen; 246 m->m_len -= hlen; 247 m->m_data += hlen; /* XXX */ 248 } 249 return (0); 250 bad: 251 m_freem(m); 252 return(error); 253 } 254 255 /* 256 * Attach file to the bpf interface, i.e. make d listen on bp. 257 * Must be called at splimp. 258 */ 259 static void 260 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 261 { 262 /* 263 * Point d at bp, and add d to the interface's list of listeners. 264 * Finally, point the driver's bpf cookie at the interface so 265 * it will divert packets to bpf. 266 */ 267 d->bd_bif = bp; 268 SLIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 269 *bp->bif_driverp = bp; 270 271 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 272 } 273 274 /* 275 * Detach a file from its interface. 276 */ 277 static void 278 bpf_detachd(struct bpf_d *d) 279 { 280 int error; 281 struct bpf_if *bp; 282 struct ifnet *ifp; 283 284 bp = d->bd_bif; 285 ifp = bp->bif_ifp; 286 287 /* Remove d from the interface's descriptor list. */ 288 SLIST_REMOVE(&bp->bif_dlist, d, bpf_d, bd_next); 289 290 if (SLIST_EMPTY(&bp->bif_dlist)) { 291 /* 292 * Let the driver know that there are no more listeners. 293 */ 294 *bp->bif_driverp = NULL; 295 } 296 d->bd_bif = NULL; 297 298 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); 299 300 /* 301 * Check if this descriptor had requested promiscuous mode. 302 * If so, turn it off. 303 */ 304 if (d->bd_promisc) { 305 d->bd_promisc = 0; 306 error = ifpromisc(ifp, 0); 307 if (error != 0 && error != ENXIO) { 308 /* 309 * ENXIO can happen if a pccard is unplugged, 310 * Something is really wrong if we were able to put 311 * the driver into promiscuous mode, but can't 312 * take it out. 313 */ 314 if_printf(ifp, "bpf_detach: ifpromisc failed(%d)\n", 315 error); 316 } 317 } 318 } 319 320 /* 321 * Open ethernet device. Returns ENXIO for illegal minor device number, 322 * EBUSY if file is open by another process. 323 */ 324 /* ARGSUSED */ 325 static int 326 bpfopen(struct dev_open_args *ap) 327 { 328 cdev_t dev = ap->a_head.a_dev; 329 struct bpf_d *d; 330 331 if (ap->a_cred->cr_prison) 332 return(EPERM); 333 334 d = dev->si_drv1; 335 /* 336 * Each minor can be opened by only one process. If the requested 337 * minor is in use, return EBUSY. 338 */ 339 if (d != NULL) 340 return(EBUSY); 341 342 MALLOC(d, struct bpf_d *, sizeof *d, M_BPF, M_WAITOK | M_ZERO); 343 dev->si_drv1 = d; 344 d->bd_bufsize = bpf_bufsize; 345 d->bd_sig = SIGIO; 346 d->bd_seesent = 1; 347 callout_init(&d->bd_callout); 348 return(0); 349 } 350 351 static int 352 bpfclone(struct dev_clone_args *ap) 353 { 354 int unit; 355 356 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(bpf), 0); 357 ap->a_dev = make_only_dev(&bpf_ops, unit, 0, 0, 0600, "bpf%d", unit); 358 359 return 0; 360 } 361 362 /* 363 * Close the descriptor by detaching it from its interface, 364 * deallocating its buffers, and marking it free. 365 */ 366 /* ARGSUSED */ 367 static int 368 bpfclose(struct dev_close_args *ap) 369 { 370 cdev_t dev = ap->a_head.a_dev; 371 struct bpf_d *d = dev->si_drv1; 372 373 funsetown(d->bd_sigio); 374 crit_enter(); 375 if (d->bd_state == BPF_WAITING) 376 callout_stop(&d->bd_callout); 377 d->bd_state = BPF_IDLE; 378 if (d->bd_bif != NULL) 379 bpf_detachd(d); 380 crit_exit(); 381 bpf_freed(d); 382 dev->si_drv1 = NULL; 383 if (dev->si_uminor >= BPF_PREALLOCATED_UNITS) { 384 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(bpf), dev->si_uminor); 385 destroy_dev(dev); 386 } 387 kfree(d, M_BPF); 388 return(0); 389 } 390 391 /* 392 * Rotate the packet buffers in descriptor d. Move the store buffer 393 * into the hold slot, and the free buffer into the store slot. 394 * Zero the length of the new store buffer. 395 */ 396 #define ROTATE_BUFFERS(d) \ 397 (d)->bd_hbuf = (d)->bd_sbuf; \ 398 (d)->bd_hlen = (d)->bd_slen; \ 399 (d)->bd_sbuf = (d)->bd_fbuf; \ 400 (d)->bd_slen = 0; \ 401 (d)->bd_fbuf = NULL; 402 /* 403 * bpfread - read next chunk of packets from buffers 404 */ 405 static int 406 bpfread(struct dev_read_args *ap) 407 { 408 cdev_t dev = ap->a_head.a_dev; 409 struct bpf_d *d = dev->si_drv1; 410 int timed_out; 411 int error; 412 413 /* 414 * Restrict application to use a buffer the same size as 415 * as kernel buffers. 416 */ 417 if (ap->a_uio->uio_resid != d->bd_bufsize) 418 return(EINVAL); 419 420 crit_enter(); 421 if (d->bd_state == BPF_WAITING) 422 callout_stop(&d->bd_callout); 423 timed_out = (d->bd_state == BPF_TIMED_OUT); 424 d->bd_state = BPF_IDLE; 425 /* 426 * If the hold buffer is empty, then do a timed sleep, which 427 * ends when the timeout expires or when enough packets 428 * have arrived to fill the store buffer. 429 */ 430 while (d->bd_hbuf == NULL) { 431 if ((d->bd_immediate || (ap->a_ioflag & IO_NDELAY) || timed_out) 432 && d->bd_slen != 0) { 433 /* 434 * A packet(s) either arrived since the previous, 435 * We're in immediate mode, or are reading 436 * in non-blocking mode, and a packet(s) 437 * either arrived since the previous 438 * read or arrived while we were asleep. 439 * Rotate the buffers and return what's here. 440 */ 441 ROTATE_BUFFERS(d); 442 break; 443 } 444 445 /* 446 * No data is available, check to see if the bpf device 447 * is still pointed at a real interface. If not, return 448 * ENXIO so that the userland process knows to rebind 449 * it before using it again. 450 */ 451 if (d->bd_bif == NULL) { 452 crit_exit(); 453 return(ENXIO); 454 } 455 456 if (ap->a_ioflag & IO_NDELAY) { 457 crit_exit(); 458 return(EWOULDBLOCK); 459 } 460 error = tsleep(d, PCATCH, "bpf", d->bd_rtout); 461 if (error == EINTR || error == ERESTART) { 462 crit_exit(); 463 return(error); 464 } 465 if (error == EWOULDBLOCK) { 466 /* 467 * On a timeout, return what's in the buffer, 468 * which may be nothing. If there is something 469 * in the store buffer, we can rotate the buffers. 470 */ 471 if (d->bd_hbuf) 472 /* 473 * We filled up the buffer in between 474 * getting the timeout and arriving 475 * here, so we don't need to rotate. 476 */ 477 break; 478 479 if (d->bd_slen == 0) { 480 crit_exit(); 481 return(0); 482 } 483 ROTATE_BUFFERS(d); 484 break; 485 } 486 } 487 /* 488 * At this point, we know we have something in the hold slot. 489 */ 490 crit_exit(); 491 492 /* 493 * Move data from hold buffer into user space. 494 * We know the entire buffer is transferred since 495 * we checked above that the read buffer is bpf_bufsize bytes. 496 */ 497 error = uiomove(d->bd_hbuf, d->bd_hlen, ap->a_uio); 498 499 crit_enter(); 500 d->bd_fbuf = d->bd_hbuf; 501 d->bd_hbuf = NULL; 502 d->bd_hlen = 0; 503 crit_exit(); 504 505 return(error); 506 } 507 508 509 /* 510 * If there are processes sleeping on this descriptor, wake them up. 511 */ 512 static void 513 bpf_wakeup(struct bpf_d *d) 514 { 515 if (d->bd_state == BPF_WAITING) { 516 callout_stop(&d->bd_callout); 517 d->bd_state = BPF_IDLE; 518 } 519 wakeup(d); 520 if (d->bd_async && d->bd_sig && d->bd_sigio) 521 pgsigio(d->bd_sigio, d->bd_sig, 0); 522 523 get_mplock(); 524 KNOTE(&d->bd_kq.ki_note, 0); 525 rel_mplock(); 526 } 527 528 static void 529 bpf_timed_out(void *arg) 530 { 531 struct bpf_d *d = (struct bpf_d *)arg; 532 533 crit_enter(); 534 if (d->bd_state == BPF_WAITING) { 535 d->bd_state = BPF_TIMED_OUT; 536 if (d->bd_slen != 0) 537 bpf_wakeup(d); 538 } 539 crit_exit(); 540 } 541 542 static void 543 bpf_output_dispatch(netmsg_t msg) 544 { 545 struct netmsg_bpf_output *bmsg = (struct netmsg_bpf_output *)msg; 546 struct ifnet *ifp = bmsg->nm_ifp; 547 int error; 548 549 /* 550 * The driver frees the mbuf. 551 */ 552 error = ifp->if_output(ifp, bmsg->nm_mbuf, bmsg->nm_dst, NULL); 553 lwkt_replymsg(&msg->lmsg, error); 554 } 555 556 static int 557 bpfwrite(struct dev_write_args *ap) 558 { 559 cdev_t dev = ap->a_head.a_dev; 560 struct bpf_d *d = dev->si_drv1; 561 struct ifnet *ifp; 562 struct mbuf *m; 563 int error; 564 struct sockaddr dst; 565 int datlen; 566 struct netmsg_bpf_output bmsg; 567 568 if (d->bd_bif == NULL) 569 return(ENXIO); 570 571 ifp = d->bd_bif->bif_ifp; 572 573 if (ap->a_uio->uio_resid == 0) 574 return(0); 575 576 error = bpf_movein(ap->a_uio, (int)d->bd_bif->bif_dlt, &m, 577 &dst, &datlen, d->bd_wfilter); 578 if (error) 579 return(error); 580 581 if (datlen > ifp->if_mtu) { 582 m_freem(m); 583 return(EMSGSIZE); 584 } 585 586 if (d->bd_hdrcmplt) 587 dst.sa_family = pseudo_AF_HDRCMPLT; 588 589 netmsg_init(&bmsg.base, NULL, &curthread->td_msgport, 590 0, bpf_output_dispatch); 591 bmsg.nm_mbuf = m; 592 bmsg.nm_ifp = ifp; 593 bmsg.nm_dst = &dst; 594 595 return lwkt_domsg(cpu_portfn(0), &bmsg.base.lmsg, 0); 596 } 597 598 /* 599 * Reset a descriptor by flushing its packet buffer and clearing the 600 * receive and drop counts. Should be called at splimp. 601 */ 602 static void 603 bpf_resetd(struct bpf_d *d) 604 { 605 if (d->bd_hbuf) { 606 /* Free the hold buffer. */ 607 d->bd_fbuf = d->bd_hbuf; 608 d->bd_hbuf = NULL; 609 } 610 d->bd_slen = 0; 611 d->bd_hlen = 0; 612 d->bd_rcount = 0; 613 d->bd_dcount = 0; 614 } 615 616 /* 617 * FIONREAD Check for read packet available. 618 * SIOCGIFADDR Get interface address - convenient hook to driver. 619 * BIOCGBLEN Get buffer len [for read()]. 620 * BIOCSETF Set ethernet read filter. 621 * BIOCSETWF Set ethernet write filter. 622 * BIOCFLUSH Flush read packet buffer. 623 * BIOCPROMISC Put interface into promiscuous mode. 624 * BIOCGDLT Get link layer type. 625 * BIOCGETIF Get interface name. 626 * BIOCSETIF Set interface. 627 * BIOCSRTIMEOUT Set read timeout. 628 * BIOCGRTIMEOUT Get read timeout. 629 * BIOCGSTATS Get packet stats. 630 * BIOCIMMEDIATE Set immediate mode. 631 * BIOCVERSION Get filter language version. 632 * BIOCGHDRCMPLT Get "header already complete" flag 633 * BIOCSHDRCMPLT Set "header already complete" flag 634 * BIOCGSEESENT Get "see packets sent" flag 635 * BIOCSSEESENT Set "see packets sent" flag 636 * BIOCLOCK Set "locked" flag 637 */ 638 /* ARGSUSED */ 639 static int 640 bpfioctl(struct dev_ioctl_args *ap) 641 { 642 cdev_t dev = ap->a_head.a_dev; 643 struct bpf_d *d = dev->si_drv1; 644 int error = 0; 645 646 crit_enter(); 647 if (d->bd_state == BPF_WAITING) 648 callout_stop(&d->bd_callout); 649 d->bd_state = BPF_IDLE; 650 crit_exit(); 651 652 if (d->bd_locked == 1) { 653 switch (ap->a_cmd) { 654 case BIOCGBLEN: 655 case BIOCFLUSH: 656 case BIOCGDLT: 657 case BIOCGDLTLIST: 658 case BIOCGETIF: 659 case BIOCGRTIMEOUT: 660 case BIOCGSTATS: 661 case BIOCVERSION: 662 case BIOCGRSIG: 663 case BIOCGHDRCMPLT: 664 case FIONREAD: 665 case BIOCLOCK: 666 case BIOCSRTIMEOUT: 667 case BIOCIMMEDIATE: 668 case TIOCGPGRP: 669 break; 670 default: 671 return (EPERM); 672 } 673 } 674 switch (ap->a_cmd) { 675 default: 676 error = EINVAL; 677 break; 678 679 /* 680 * Check for read packet available. 681 */ 682 case FIONREAD: 683 { 684 int n; 685 686 crit_enter(); 687 n = d->bd_slen; 688 if (d->bd_hbuf) 689 n += d->bd_hlen; 690 crit_exit(); 691 692 *(int *)ap->a_data = n; 693 break; 694 } 695 696 case SIOCGIFADDR: 697 { 698 struct ifnet *ifp; 699 700 if (d->bd_bif == NULL) { 701 error = EINVAL; 702 } else { 703 ifp = d->bd_bif->bif_ifp; 704 ifnet_serialize_all(ifp); 705 error = ifp->if_ioctl(ifp, ap->a_cmd, 706 ap->a_data, ap->a_cred); 707 ifnet_deserialize_all(ifp); 708 } 709 break; 710 } 711 712 /* 713 * Get buffer len [for read()]. 714 */ 715 case BIOCGBLEN: 716 *(u_int *)ap->a_data = d->bd_bufsize; 717 break; 718 719 /* 720 * Set buffer length. 721 */ 722 case BIOCSBLEN: 723 if (d->bd_bif != NULL) { 724 error = EINVAL; 725 } else { 726 u_int size = *(u_int *)ap->a_data; 727 728 if (size > bpf_maxbufsize) 729 *(u_int *)ap->a_data = size = bpf_maxbufsize; 730 else if (size < BPF_MINBUFSIZE) 731 *(u_int *)ap->a_data = size = BPF_MINBUFSIZE; 732 d->bd_bufsize = size; 733 } 734 break; 735 736 /* 737 * Set link layer read filter. 738 */ 739 case BIOCSETF: 740 case BIOCSETWF: 741 error = bpf_setf(d, (struct bpf_program *)ap->a_data, 742 ap->a_cmd); 743 break; 744 745 /* 746 * Flush read packet buffer. 747 */ 748 case BIOCFLUSH: 749 crit_enter(); 750 bpf_resetd(d); 751 crit_exit(); 752 break; 753 754 /* 755 * Put interface into promiscuous mode. 756 */ 757 case BIOCPROMISC: 758 if (d->bd_bif == NULL) { 759 /* 760 * No interface attached yet. 761 */ 762 error = EINVAL; 763 break; 764 } 765 crit_enter(); 766 if (d->bd_promisc == 0) { 767 error = ifpromisc(d->bd_bif->bif_ifp, 1); 768 if (error == 0) 769 d->bd_promisc = 1; 770 } 771 crit_exit(); 772 break; 773 774 /* 775 * Get device parameters. 776 */ 777 case BIOCGDLT: 778 if (d->bd_bif == NULL) 779 error = EINVAL; 780 else 781 *(u_int *)ap->a_data = d->bd_bif->bif_dlt; 782 break; 783 784 /* 785 * Get a list of supported data link types. 786 */ 787 case BIOCGDLTLIST: 788 if (d->bd_bif == NULL) { 789 error = EINVAL; 790 } else { 791 error = bpf_getdltlist(d, 792 (struct bpf_dltlist *)ap->a_data); 793 } 794 break; 795 796 /* 797 * Set data link type. 798 */ 799 case BIOCSDLT: 800 if (d->bd_bif == NULL) 801 error = EINVAL; 802 else 803 error = bpf_setdlt(d, *(u_int *)ap->a_data); 804 break; 805 806 /* 807 * Get interface name. 808 */ 809 case BIOCGETIF: 810 if (d->bd_bif == NULL) { 811 error = EINVAL; 812 } else { 813 struct ifnet *const ifp = d->bd_bif->bif_ifp; 814 struct ifreq *const ifr = (struct ifreq *)ap->a_data; 815 816 strlcpy(ifr->ifr_name, ifp->if_xname, 817 sizeof ifr->ifr_name); 818 } 819 break; 820 821 /* 822 * Set interface. 823 */ 824 case BIOCSETIF: 825 error = bpf_setif(d, (struct ifreq *)ap->a_data); 826 break; 827 828 /* 829 * Set read timeout. 830 */ 831 case BIOCSRTIMEOUT: 832 { 833 struct timeval *tv = (struct timeval *)ap->a_data; 834 835 /* 836 * Subtract 1 tick from tvtohz() since this isn't 837 * a one-shot timer. 838 */ 839 if ((error = itimerfix(tv)) == 0) 840 d->bd_rtout = tvtohz_low(tv); 841 break; 842 } 843 844 /* 845 * Get read timeout. 846 */ 847 case BIOCGRTIMEOUT: 848 { 849 struct timeval *tv = (struct timeval *)ap->a_data; 850 851 tv->tv_sec = d->bd_rtout / hz; 852 tv->tv_usec = (d->bd_rtout % hz) * ustick; 853 break; 854 } 855 856 /* 857 * Get packet stats. 858 */ 859 case BIOCGSTATS: 860 { 861 struct bpf_stat *bs = (struct bpf_stat *)ap->a_data; 862 863 bs->bs_recv = d->bd_rcount; 864 bs->bs_drop = d->bd_dcount; 865 break; 866 } 867 868 /* 869 * Set immediate mode. 870 */ 871 case BIOCIMMEDIATE: 872 d->bd_immediate = *(u_int *)ap->a_data; 873 break; 874 875 case BIOCVERSION: 876 { 877 struct bpf_version *bv = (struct bpf_version *)ap->a_data; 878 879 bv->bv_major = BPF_MAJOR_VERSION; 880 bv->bv_minor = BPF_MINOR_VERSION; 881 break; 882 } 883 884 /* 885 * Get "header already complete" flag 886 */ 887 case BIOCGHDRCMPLT: 888 *(u_int *)ap->a_data = d->bd_hdrcmplt; 889 break; 890 891 /* 892 * Set "header already complete" flag 893 */ 894 case BIOCSHDRCMPLT: 895 d->bd_hdrcmplt = *(u_int *)ap->a_data ? 1 : 0; 896 break; 897 898 /* 899 * Get "see sent packets" flag 900 */ 901 case BIOCGSEESENT: 902 *(u_int *)ap->a_data = d->bd_seesent; 903 break; 904 905 /* 906 * Set "see sent packets" flag 907 */ 908 case BIOCSSEESENT: 909 d->bd_seesent = *(u_int *)ap->a_data; 910 break; 911 912 case FIOASYNC: /* Send signal on receive packets */ 913 d->bd_async = *(int *)ap->a_data; 914 break; 915 916 case FIOSETOWN: 917 error = fsetown(*(int *)ap->a_data, &d->bd_sigio); 918 break; 919 920 case FIOGETOWN: 921 *(int *)ap->a_data = fgetown(d->bd_sigio); 922 break; 923 924 /* This is deprecated, FIOSETOWN should be used instead. */ 925 case TIOCSPGRP: 926 error = fsetown(-(*(int *)ap->a_data), &d->bd_sigio); 927 break; 928 929 /* This is deprecated, FIOGETOWN should be used instead. */ 930 case TIOCGPGRP: 931 *(int *)ap->a_data = -fgetown(d->bd_sigio); 932 break; 933 934 case BIOCSRSIG: /* Set receive signal */ 935 { 936 u_int sig; 937 938 sig = *(u_int *)ap->a_data; 939 940 if (sig >= NSIG) 941 error = EINVAL; 942 else 943 d->bd_sig = sig; 944 break; 945 } 946 case BIOCGRSIG: 947 *(u_int *)ap->a_data = d->bd_sig; 948 break; 949 case BIOCLOCK: 950 d->bd_locked = 1; 951 break; 952 } 953 return(error); 954 } 955 956 /* 957 * Set d's packet filter program to fp. If this file already has a filter, 958 * free it and replace it. Returns EINVAL for bogus requests. 959 */ 960 static int 961 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 962 { 963 struct bpf_insn *fcode, *old; 964 u_int wfilter, flen, size; 965 966 if (cmd == BIOCSETWF) { 967 old = d->bd_wfilter; 968 wfilter = 1; 969 } else { 970 wfilter = 0; 971 old = d->bd_rfilter; 972 } 973 if (fp->bf_insns == NULL) { 974 if (fp->bf_len != 0) 975 return(EINVAL); 976 crit_enter(); 977 if (wfilter) 978 d->bd_wfilter = NULL; 979 else 980 d->bd_rfilter = NULL; 981 bpf_resetd(d); 982 crit_exit(); 983 if (old != NULL) 984 kfree(old, M_BPF); 985 return(0); 986 } 987 flen = fp->bf_len; 988 if (flen > BPF_MAXINSNS) 989 return(EINVAL); 990 991 size = flen * sizeof *fp->bf_insns; 992 fcode = (struct bpf_insn *)kmalloc(size, M_BPF, M_WAITOK); 993 if (copyin(fp->bf_insns, fcode, size) == 0 && 994 bpf_validate(fcode, (int)flen)) { 995 crit_enter(); 996 if (wfilter) 997 d->bd_wfilter = fcode; 998 else 999 d->bd_rfilter = fcode; 1000 bpf_resetd(d); 1001 crit_exit(); 1002 if (old != NULL) 1003 kfree(old, M_BPF); 1004 1005 return(0); 1006 } 1007 kfree(fcode, M_BPF); 1008 return(EINVAL); 1009 } 1010 1011 /* 1012 * Detach a file from its current interface (if attached at all) and attach 1013 * to the interface indicated by the name stored in ifr. 1014 * Return an errno or 0. 1015 */ 1016 static int 1017 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 1018 { 1019 struct bpf_if *bp; 1020 int error; 1021 struct ifnet *theywant; 1022 1023 theywant = ifunit(ifr->ifr_name); 1024 if (theywant == NULL) 1025 return(ENXIO); 1026 1027 /* 1028 * Look through attached interfaces for the named one. 1029 */ 1030 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1031 struct ifnet *ifp = bp->bif_ifp; 1032 1033 if (ifp == NULL || ifp != theywant) 1034 continue; 1035 /* skip additional entry */ 1036 if (bp->bif_driverp != &ifp->if_bpf) 1037 continue; 1038 /* 1039 * We found the requested interface. 1040 * Allocate the packet buffers if we need to. 1041 * If we're already attached to requested interface, 1042 * just flush the buffer. 1043 */ 1044 if (d->bd_sbuf == NULL) { 1045 error = bpf_allocbufs(d); 1046 if (error != 0) 1047 return(error); 1048 } 1049 crit_enter(); 1050 if (bp != d->bd_bif) { 1051 if (d->bd_bif != NULL) { 1052 /* 1053 * Detach if attached to something else. 1054 */ 1055 bpf_detachd(d); 1056 } 1057 1058 bpf_attachd(d, bp); 1059 } 1060 bpf_resetd(d); 1061 crit_exit(); 1062 return(0); 1063 } 1064 1065 /* Not found. */ 1066 return(ENXIO); 1067 } 1068 1069 static struct filterops bpf_read_filtops = 1070 { FILTEROP_ISFD, NULL, bpf_filter_detach, bpf_filter_read }; 1071 1072 static int 1073 bpfkqfilter(struct dev_kqfilter_args *ap) 1074 { 1075 cdev_t dev = ap->a_head.a_dev; 1076 struct knote *kn = ap->a_kn; 1077 struct klist *klist; 1078 struct bpf_d *d; 1079 1080 d = dev->si_drv1; 1081 if (d->bd_bif == NULL) { 1082 ap->a_result = 1; 1083 return (0); 1084 } 1085 1086 ap->a_result = 0; 1087 switch (kn->kn_filter) { 1088 case EVFILT_READ: 1089 kn->kn_fop = &bpf_read_filtops; 1090 kn->kn_hook = (caddr_t)d; 1091 break; 1092 default: 1093 ap->a_result = EOPNOTSUPP; 1094 return (0); 1095 } 1096 1097 klist = &d->bd_kq.ki_note; 1098 knote_insert(klist, kn); 1099 1100 return (0); 1101 } 1102 1103 static void 1104 bpf_filter_detach(struct knote *kn) 1105 { 1106 struct klist *klist; 1107 struct bpf_d *d; 1108 1109 d = (struct bpf_d *)kn->kn_hook; 1110 klist = &d->bd_kq.ki_note; 1111 knote_remove(klist, kn); 1112 } 1113 1114 static int 1115 bpf_filter_read(struct knote *kn, long hint) 1116 { 1117 struct bpf_d *d; 1118 int ready = 0; 1119 1120 crit_enter(); 1121 d = (struct bpf_d *)kn->kn_hook; 1122 if (d->bd_hlen != 0 || 1123 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1124 d->bd_slen != 0)) { 1125 ready = 1; 1126 } else { 1127 /* Start the read timeout if necessary. */ 1128 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1129 callout_reset(&d->bd_callout, d->bd_rtout, 1130 bpf_timed_out, d); 1131 d->bd_state = BPF_WAITING; 1132 } 1133 } 1134 crit_exit(); 1135 1136 return (ready); 1137 } 1138 1139 1140 /* 1141 * Process the packet pkt of length pktlen. The packet is parsed 1142 * by each listener's filter, and if accepted, stashed into the 1143 * corresponding buffer. 1144 */ 1145 void 1146 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1147 { 1148 struct bpf_d *d; 1149 struct timeval tv; 1150 int gottime = 0; 1151 u_int slen; 1152 1153 get_mplock(); 1154 1155 /* Re-check */ 1156 if (bp == NULL) { 1157 rel_mplock(); 1158 return; 1159 } 1160 1161 /* 1162 * Note that the ipl does not have to be raised at this point. 1163 * The only problem that could arise here is that if two different 1164 * interfaces shared any data. This is not the case. 1165 */ 1166 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1167 ++d->bd_rcount; 1168 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 1169 if (slen != 0) { 1170 if (!gottime) { 1171 microtime(&tv); 1172 gottime = 1; 1173 } 1174 catchpacket(d, pkt, pktlen, slen, ovbcopy, &tv); 1175 } 1176 } 1177 1178 rel_mplock(); 1179 } 1180 1181 /* 1182 * Copy data from an mbuf chain into a buffer. This code is derived 1183 * from m_copydata in sys/uipc_mbuf.c. 1184 */ 1185 static void 1186 bpf_mcopy(const void *src_arg, void *dst_arg, size_t len) 1187 { 1188 const struct mbuf *m; 1189 u_int count; 1190 u_char *dst; 1191 1192 m = src_arg; 1193 dst = dst_arg; 1194 while (len > 0) { 1195 if (m == NULL) 1196 panic("bpf_mcopy"); 1197 count = min(m->m_len, len); 1198 bcopy(mtod(m, void *), dst, count); 1199 m = m->m_next; 1200 dst += count; 1201 len -= count; 1202 } 1203 } 1204 1205 /* 1206 * Process the packet in the mbuf chain m. The packet is parsed by each 1207 * listener's filter, and if accepted, stashed into the corresponding 1208 * buffer. 1209 */ 1210 void 1211 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1212 { 1213 struct bpf_d *d; 1214 u_int pktlen, slen; 1215 struct timeval tv; 1216 int gottime = 0; 1217 1218 get_mplock(); 1219 1220 /* Re-check */ 1221 if (bp == NULL) { 1222 rel_mplock(); 1223 return; 1224 } 1225 1226 /* Don't compute pktlen, if no descriptor is attached. */ 1227 if (SLIST_EMPTY(&bp->bif_dlist)) { 1228 rel_mplock(); 1229 return; 1230 } 1231 1232 pktlen = m_lengthm(m, NULL); 1233 1234 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1235 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1236 continue; 1237 ++d->bd_rcount; 1238 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 1239 if (slen != 0) { 1240 if (!gottime) { 1241 microtime(&tv); 1242 gottime = 1; 1243 } 1244 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy, 1245 &tv); 1246 } 1247 } 1248 1249 rel_mplock(); 1250 } 1251 1252 /* 1253 * Incoming linkage from device drivers, where we have a mbuf chain 1254 * but need to prepend some arbitrary header from a linear buffer. 1255 * 1256 * Con up a minimal dummy header to pacify bpf. Allocate (only) a 1257 * struct m_hdr on the stack. This is safe as bpf only reads from the 1258 * fields in this header that we initialize, and will not try to free 1259 * it or keep a pointer to it. 1260 */ 1261 void 1262 bpf_mtap_hdr(struct bpf_if *arg, caddr_t data, u_int dlen, struct mbuf *m, u_int direction) 1263 { 1264 struct m_hdr mh; 1265 1266 mh.mh_flags = 0; 1267 mh.mh_next = m; 1268 mh.mh_len = dlen; 1269 mh.mh_data = data; 1270 1271 return bpf_mtap(arg, (struct mbuf *) &mh); 1272 } 1273 1274 void 1275 bpf_mtap_family(struct bpf_if *bp, struct mbuf *m, sa_family_t family) 1276 { 1277 u_int family4; 1278 1279 KKASSERT(family != AF_UNSPEC); 1280 1281 family4 = (u_int)family; 1282 bpf_ptap(bp, m, &family4, sizeof(family4)); 1283 } 1284 1285 /* 1286 * Process the packet in the mbuf chain m with the header in m prepended. 1287 * The packet is parsed by each listener's filter, and if accepted, 1288 * stashed into the corresponding buffer. 1289 */ 1290 void 1291 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen) 1292 { 1293 struct mbuf mb; 1294 1295 /* 1296 * Craft on-stack mbuf suitable for passing to bpf_mtap. 1297 * Note that we cut corners here; we only setup what's 1298 * absolutely needed--this mbuf should never go anywhere else. 1299 */ 1300 mb.m_next = m; 1301 mb.m_data = __DECONST(void *, data); /* LINTED */ 1302 mb.m_len = dlen; 1303 mb.m_pkthdr.rcvif = m->m_pkthdr.rcvif; 1304 1305 bpf_mtap(bp, &mb); 1306 } 1307 1308 /* 1309 * Move the packet data from interface memory (pkt) into the 1310 * store buffer. Return 1 if it's time to wakeup a listener (buffer full), 1311 * otherwise 0. "copy" is the routine called to do the actual data 1312 * transfer. bcopy is passed in to copy contiguous chunks, while 1313 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1314 * pkt is really an mbuf. 1315 */ 1316 static void 1317 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 1318 void (*cpfn)(const void *, void *, size_t), 1319 const struct timeval *tv) 1320 { 1321 struct bpf_hdr *hp; 1322 int totlen, curlen; 1323 int hdrlen = d->bd_bif->bif_hdrlen; 1324 int wakeup = 0; 1325 /* 1326 * Figure out how many bytes to move. If the packet is 1327 * greater or equal to the snapshot length, transfer that 1328 * much. Otherwise, transfer the whole packet (unless 1329 * we hit the buffer size limit). 1330 */ 1331 totlen = hdrlen + min(snaplen, pktlen); 1332 if (totlen > d->bd_bufsize) 1333 totlen = d->bd_bufsize; 1334 1335 /* 1336 * Round up the end of the previous packet to the next longword. 1337 */ 1338 curlen = BPF_WORDALIGN(d->bd_slen); 1339 if (curlen + totlen > d->bd_bufsize) { 1340 /* 1341 * This packet will overflow the storage buffer. 1342 * Rotate the buffers if we can, then wakeup any 1343 * pending reads. 1344 */ 1345 if (d->bd_fbuf == NULL) { 1346 /* 1347 * We haven't completed the previous read yet, 1348 * so drop the packet. 1349 */ 1350 ++d->bd_dcount; 1351 return; 1352 } 1353 ROTATE_BUFFERS(d); 1354 wakeup = 1; 1355 curlen = 0; 1356 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) { 1357 /* 1358 * Immediate mode is set, or the read timeout has 1359 * already expired during a select call. A packet 1360 * arrived, so the reader should be woken up. 1361 */ 1362 wakeup = 1; 1363 } 1364 1365 /* 1366 * Append the bpf header. 1367 */ 1368 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1369 hp->bh_tstamp = *tv; 1370 hp->bh_datalen = pktlen; 1371 hp->bh_hdrlen = hdrlen; 1372 /* 1373 * Copy the packet data into the store buffer and update its length. 1374 */ 1375 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1376 d->bd_slen = curlen + totlen; 1377 1378 if (wakeup) 1379 bpf_wakeup(d); 1380 } 1381 1382 /* 1383 * Initialize all nonzero fields of a descriptor. 1384 */ 1385 static int 1386 bpf_allocbufs(struct bpf_d *d) 1387 { 1388 d->bd_fbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK); 1389 d->bd_sbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK); 1390 d->bd_slen = 0; 1391 d->bd_hlen = 0; 1392 return(0); 1393 } 1394 1395 /* 1396 * Free buffers and packet filter program currently in use by a descriptor. 1397 * Called on close. 1398 */ 1399 static void 1400 bpf_freed(struct bpf_d *d) 1401 { 1402 /* 1403 * We don't need to lock out interrupts since this descriptor has 1404 * been detached from its interface and it yet hasn't been marked 1405 * free. 1406 */ 1407 if (d->bd_sbuf != NULL) { 1408 kfree(d->bd_sbuf, M_BPF); 1409 if (d->bd_hbuf != NULL) 1410 kfree(d->bd_hbuf, M_BPF); 1411 if (d->bd_fbuf != NULL) 1412 kfree(d->bd_fbuf, M_BPF); 1413 } 1414 if (d->bd_rfilter) 1415 kfree(d->bd_rfilter, M_BPF); 1416 if (d->bd_wfilter) 1417 kfree(d->bd_wfilter, M_BPF); 1418 } 1419 1420 /* 1421 * Attach an interface to bpf. ifp is a pointer to the structure 1422 * defining the interface to be attached, dlt is the link layer type, 1423 * and hdrlen is the fixed size of the link header (variable length 1424 * headers are not yet supported). 1425 */ 1426 void 1427 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1428 { 1429 bpfattach_dlt(ifp, dlt, hdrlen, &ifp->if_bpf); 1430 } 1431 1432 void 1433 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1434 { 1435 struct bpf_if *bp; 1436 1437 bp = kmalloc(sizeof *bp, M_BPF, M_WAITOK | M_ZERO); 1438 1439 SLIST_INIT(&bp->bif_dlist); 1440 bp->bif_ifp = ifp; 1441 bp->bif_dlt = dlt; 1442 bp->bif_driverp = driverp; 1443 *bp->bif_driverp = NULL; 1444 1445 bp->bif_next = bpf_iflist; 1446 bpf_iflist = bp; 1447 1448 /* 1449 * Compute the length of the bpf header. This is not necessarily 1450 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1451 * that the network layer header begins on a longword boundary (for 1452 * performance reasons and to alleviate alignment restrictions). 1453 */ 1454 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1455 1456 if (bootverbose) 1457 if_printf(ifp, "bpf attached\n"); 1458 } 1459 1460 /* 1461 * Detach bpf from an interface. This involves detaching each descriptor 1462 * associated with the interface, and leaving bd_bif NULL. Notify each 1463 * descriptor as it's detached so that any sleepers wake up and get 1464 * ENXIO. 1465 */ 1466 void 1467 bpfdetach(struct ifnet *ifp) 1468 { 1469 struct bpf_if *bp, *bp_prev; 1470 struct bpf_d *d; 1471 1472 crit_enter(); 1473 1474 /* Locate BPF interface information */ 1475 bp_prev = NULL; 1476 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1477 if (ifp == bp->bif_ifp) 1478 break; 1479 bp_prev = bp; 1480 } 1481 1482 /* Interface wasn't attached */ 1483 if (bp->bif_ifp == NULL) { 1484 crit_exit(); 1485 kprintf("bpfdetach: %s was not attached\n", ifp->if_xname); 1486 return; 1487 } 1488 1489 while ((d = SLIST_FIRST(&bp->bif_dlist)) != NULL) { 1490 bpf_detachd(d); 1491 bpf_wakeup(d); 1492 } 1493 1494 if (bp_prev != NULL) 1495 bp_prev->bif_next = bp->bif_next; 1496 else 1497 bpf_iflist = bp->bif_next; 1498 1499 kfree(bp, M_BPF); 1500 1501 crit_exit(); 1502 } 1503 1504 /* 1505 * Get a list of available data link type of the interface. 1506 */ 1507 static int 1508 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 1509 { 1510 int n, error; 1511 struct ifnet *ifp; 1512 struct bpf_if *bp; 1513 1514 ifp = d->bd_bif->bif_ifp; 1515 n = 0; 1516 error = 0; 1517 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1518 if (bp->bif_ifp != ifp) 1519 continue; 1520 if (bfl->bfl_list != NULL) { 1521 if (n >= bfl->bfl_len) { 1522 return (ENOMEM); 1523 } 1524 error = copyout(&bp->bif_dlt, 1525 bfl->bfl_list + n, sizeof(u_int)); 1526 } 1527 n++; 1528 } 1529 bfl->bfl_len = n; 1530 return(error); 1531 } 1532 1533 /* 1534 * Set the data link type of a BPF instance. 1535 */ 1536 static int 1537 bpf_setdlt(struct bpf_d *d, u_int dlt) 1538 { 1539 int error, opromisc; 1540 struct ifnet *ifp; 1541 struct bpf_if *bp; 1542 1543 if (d->bd_bif->bif_dlt == dlt) 1544 return (0); 1545 ifp = d->bd_bif->bif_ifp; 1546 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1547 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1548 break; 1549 } 1550 if (bp != NULL) { 1551 opromisc = d->bd_promisc; 1552 crit_enter(); 1553 bpf_detachd(d); 1554 bpf_attachd(d, bp); 1555 bpf_resetd(d); 1556 if (opromisc) { 1557 error = ifpromisc(bp->bif_ifp, 1); 1558 if (error) { 1559 if_printf(bp->bif_ifp, 1560 "bpf_setdlt: ifpromisc failed (%d)\n", 1561 error); 1562 } else { 1563 d->bd_promisc = 1; 1564 } 1565 } 1566 crit_exit(); 1567 } 1568 return(bp == NULL ? EINVAL : 0); 1569 } 1570 1571 static void 1572 bpf_drvinit(void *unused) 1573 { 1574 int i; 1575 1576 make_autoclone_dev(&bpf_ops, &DEVFS_CLONE_BITMAP(bpf), 1577 bpfclone, 0, 0, 0600, "bpf"); 1578 for (i = 0; i < BPF_PREALLOCATED_UNITS; i++) { 1579 make_dev(&bpf_ops, i, 0, 0, 0600, "bpf%d", i); 1580 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(bpf), i); 1581 } 1582 } 1583 1584 static void 1585 bpf_drvuninit(void *unused) 1586 { 1587 devfs_clone_handler_del("bpf"); 1588 dev_ops_remove_all(&bpf_ops); 1589 devfs_clone_bitmap_uninit(&DEVFS_CLONE_BITMAP(bpf)); 1590 } 1591 1592 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL) 1593 SYSUNINIT(bpfdev, SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvuninit, NULL); 1594 1595 #else /* !BPF */ 1596 /* 1597 * NOP stubs to allow bpf-using drivers to load and function. 1598 * 1599 * A 'better' implementation would allow the core bpf functionality 1600 * to be loaded at runtime. 1601 */ 1602 1603 void 1604 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1605 { 1606 } 1607 1608 void 1609 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1610 { 1611 } 1612 1613 void 1614 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen) 1615 { 1616 } 1617 1618 void 1619 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1620 { 1621 } 1622 1623 void 1624 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1625 { 1626 } 1627 1628 void 1629 bpfdetach(struct ifnet *ifp) 1630 { 1631 } 1632 1633 u_int 1634 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 1635 { 1636 return -1; /* "no filter" behaviour */ 1637 } 1638 1639 #endif /* !BPF */ 1640