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 */ 42 43 #include "use_bpf.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/conf.h> 48 #include <sys/device.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/event.h> 60 61 #include <sys/socket.h> 62 #include <sys/vnode.h> 63 64 #include <sys/thread2.h> 65 #include <sys/mplock2.h> 66 67 #include <net/if.h> 68 #include <net/bpf.h> 69 #include <net/bpfdesc.h> 70 #include <net/netmsg2.h> 71 72 #include <netinet/in.h> 73 #include <netinet/if_ether.h> 74 #include <sys/kernel.h> 75 #include <sys/sysctl.h> 76 77 #include <sys/devfs.h> 78 79 struct netmsg_bpf_output { 80 struct netmsg_base base; 81 struct mbuf *nm_mbuf; 82 struct ifnet *nm_ifp; 83 struct sockaddr *nm_dst; 84 }; 85 86 MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 87 DEVFS_DECLARE_CLONE_BITMAP(bpf); 88 89 #if NBPF <= 1 90 #define BPF_PREALLOCATED_UNITS 4 91 #else 92 #define BPF_PREALLOCATED_UNITS NBPF 93 #endif 94 95 #if NBPF > 0 96 97 /* 98 * The default read buffer size is patchable. 99 */ 100 static int bpf_bufsize = BPF_DEFAULTBUFSIZE; 101 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW, 102 &bpf_bufsize, 0, "Current size of bpf buffer"); 103 int bpf_maxbufsize = BPF_MAXBUFSIZE; 104 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW, 105 &bpf_maxbufsize, 0, "Maximum size of bpf buffer"); 106 107 /* 108 * bpf_iflist is the list of interfaces; each corresponds to an ifnet 109 */ 110 static struct bpf_if *bpf_iflist; 111 112 static int bpf_allocbufs(struct bpf_d *); 113 static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp); 114 static void bpf_detachd(struct bpf_d *d); 115 static void bpf_resetd(struct bpf_d *); 116 static void bpf_freed(struct bpf_d *); 117 static void bpf_mcopy(const void *, void *, size_t); 118 static int bpf_movein(struct uio *, int, struct mbuf **, 119 struct sockaddr *, int *, struct bpf_insn *); 120 static int bpf_setif(struct bpf_d *, struct ifreq *); 121 static void bpf_timed_out(void *); 122 static void bpf_wakeup(struct bpf_d *); 123 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 124 void (*)(const void *, void *, size_t), 125 const struct timeval *); 126 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 127 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 128 static int bpf_setdlt(struct bpf_d *, u_int); 129 static void bpf_drvinit(void *unused); 130 static void bpf_filter_detach(struct knote *kn); 131 static int bpf_filter_read(struct knote *kn, long hint); 132 133 static d_open_t bpfopen; 134 static d_clone_t bpfclone; 135 static d_close_t bpfclose; 136 static d_read_t bpfread; 137 static d_write_t bpfwrite; 138 static d_ioctl_t bpfioctl; 139 static d_kqfilter_t bpfkqfilter; 140 141 #define CDEV_MAJOR 23 142 static struct dev_ops bpf_ops = { 143 { "bpf", 0, 0 }, 144 .d_open = bpfopen, 145 .d_close = bpfclose, 146 .d_read = bpfread, 147 .d_write = bpfwrite, 148 .d_ioctl = bpfioctl, 149 .d_kqfilter = bpfkqfilter 150 }; 151 152 153 static int 154 bpf_movein(struct uio *uio, int linktype, struct mbuf **mp, 155 struct sockaddr *sockp, int *datlen, struct bpf_insn *wfilter) 156 { 157 struct mbuf *m; 158 int error; 159 int len; 160 int hlen; 161 int slen; 162 163 *datlen = 0; 164 *mp = NULL; 165 166 /* 167 * Build a sockaddr based on the data link layer type. 168 * We do this at this level because the ethernet header 169 * is copied directly into the data field of the sockaddr. 170 * In the case of SLIP, there is no header and the packet 171 * is forwarded as is. 172 * Also, we are careful to leave room at the front of the mbuf 173 * for the link level header. 174 */ 175 switch (linktype) { 176 case DLT_SLIP: 177 sockp->sa_family = AF_INET; 178 hlen = 0; 179 break; 180 181 case DLT_EN10MB: 182 sockp->sa_family = AF_UNSPEC; 183 /* XXX Would MAXLINKHDR be better? */ 184 hlen = sizeof(struct ether_header); 185 break; 186 187 case DLT_RAW: 188 case DLT_NULL: 189 sockp->sa_family = AF_UNSPEC; 190 hlen = 0; 191 break; 192 193 case DLT_ATM_RFC1483: 194 /* 195 * en atm driver requires 4-byte atm pseudo header. 196 * though it isn't standard, vpi:vci needs to be 197 * specified anyway. 198 */ 199 sockp->sa_family = AF_UNSPEC; 200 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 201 break; 202 203 case DLT_PPP: 204 sockp->sa_family = AF_UNSPEC; 205 hlen = 4; /* This should match PPP_HDRLEN */ 206 break; 207 208 default: 209 return(EIO); 210 } 211 212 len = uio->uio_resid; 213 *datlen = len - hlen; 214 if ((unsigned)len > MCLBYTES) 215 return(EIO); 216 217 m = m_getl(len, MB_WAIT, MT_DATA, M_PKTHDR, NULL); 218 if (m == NULL) 219 return(ENOBUFS); 220 m->m_pkthdr.len = m->m_len = len; 221 m->m_pkthdr.rcvif = NULL; 222 *mp = m; 223 224 if (m->m_len < hlen) { 225 error = EPERM; 226 goto bad; 227 } 228 229 error = uiomove(mtod(m, u_char *), len, uio); 230 if (error) 231 goto bad; 232 233 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len); 234 if (slen == 0) { 235 error = EPERM; 236 goto bad; 237 } 238 239 /* 240 * Make room for link header, and copy it to sockaddr. 241 */ 242 if (hlen != 0) { 243 bcopy(m->m_data, sockp->sa_data, hlen); 244 m->m_pkthdr.len -= hlen; 245 m->m_len -= hlen; 246 m->m_data += hlen; /* XXX */ 247 } 248 return (0); 249 bad: 250 m_freem(m); 251 return(error); 252 } 253 254 /* 255 * Attach file to the bpf interface, i.e. make d listen on bp. 256 * Must be called at splimp. 257 */ 258 static void 259 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 260 { 261 /* 262 * Point d at bp, and add d to the interface's list of listeners. 263 * Finally, point the driver's bpf cookie at the interface so 264 * it will divert packets to bpf. 265 */ 266 d->bd_bif = bp; 267 SLIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 268 *bp->bif_driverp = bp; 269 270 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 271 } 272 273 /* 274 * Detach a file from its interface. 275 */ 276 static void 277 bpf_detachd(struct bpf_d *d) 278 { 279 int error; 280 struct bpf_if *bp; 281 struct ifnet *ifp; 282 283 bp = d->bd_bif; 284 ifp = bp->bif_ifp; 285 286 /* Remove d from the interface's descriptor list. */ 287 SLIST_REMOVE(&bp->bif_dlist, d, bpf_d, bd_next); 288 289 if (SLIST_EMPTY(&bp->bif_dlist)) { 290 /* 291 * Let the driver know that there are no more listeners. 292 */ 293 *bp->bif_driverp = NULL; 294 } 295 d->bd_bif = NULL; 296 297 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); 298 299 /* 300 * Check if this descriptor had requested promiscuous mode. 301 * If so, turn it off. 302 */ 303 if (d->bd_promisc) { 304 d->bd_promisc = 0; 305 error = ifpromisc(ifp, 0); 306 if (error != 0 && error != ENXIO) { 307 /* 308 * ENXIO can happen if a pccard is unplugged, 309 * Something is really wrong if we were able to put 310 * the driver into promiscuous mode, but can't 311 * take it out. 312 */ 313 if_printf(ifp, "bpf_detach: ifpromisc failed(%d)\n", 314 error); 315 } 316 } 317 } 318 319 /* 320 * Open ethernet device. Returns ENXIO for illegal minor device number, 321 * EBUSY if file is open by another process. 322 */ 323 /* ARGSUSED */ 324 static int 325 bpfopen(struct dev_open_args *ap) 326 { 327 cdev_t dev = ap->a_head.a_dev; 328 struct bpf_d *d; 329 330 if (ap->a_cred->cr_prison) 331 return(EPERM); 332 333 d = dev->si_drv1; 334 /* 335 * Each minor can be opened by only one process. If the requested 336 * minor is in use, return EBUSY. 337 */ 338 if (d != NULL) 339 return(EBUSY); 340 341 MALLOC(d, struct bpf_d *, sizeof *d, M_BPF, M_WAITOK | M_ZERO); 342 dev->si_drv1 = d; 343 d->bd_bufsize = bpf_bufsize; 344 d->bd_sig = SIGIO; 345 d->bd_seesent = 1; 346 callout_init(&d->bd_callout); 347 return(0); 348 } 349 350 static int 351 bpfclone(struct dev_clone_args *ap) 352 { 353 int unit; 354 355 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(bpf), 0); 356 ap->a_dev = make_only_dev(&bpf_ops, unit, 0, 0, 0600, "bpf%d", unit); 357 358 return 0; 359 } 360 361 /* 362 * Close the descriptor by detaching it from its interface, 363 * deallocating its buffers, and marking it free. 364 */ 365 /* ARGSUSED */ 366 static int 367 bpfclose(struct dev_close_args *ap) 368 { 369 cdev_t dev = ap->a_head.a_dev; 370 struct bpf_d *d = dev->si_drv1; 371 372 funsetown(d->bd_sigio); 373 crit_enter(); 374 if (d->bd_state == BPF_WAITING) 375 callout_stop(&d->bd_callout); 376 d->bd_state = BPF_IDLE; 377 if (d->bd_bif != NULL) 378 bpf_detachd(d); 379 crit_exit(); 380 bpf_freed(d); 381 dev->si_drv1 = NULL; 382 if (dev->si_uminor >= BPF_PREALLOCATED_UNITS) { 383 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(bpf), dev->si_uminor); 384 destroy_dev(dev); 385 } 386 kfree(d, M_BPF); 387 return(0); 388 } 389 390 /* 391 * Rotate the packet buffers in descriptor d. Move the store buffer 392 * into the hold slot, and the free buffer into the store slot. 393 * Zero the length of the new store buffer. 394 */ 395 #define ROTATE_BUFFERS(d) \ 396 (d)->bd_hbuf = (d)->bd_sbuf; \ 397 (d)->bd_hlen = (d)->bd_slen; \ 398 (d)->bd_sbuf = (d)->bd_fbuf; \ 399 (d)->bd_slen = 0; \ 400 (d)->bd_fbuf = NULL; 401 /* 402 * bpfread - read next chunk of packets from buffers 403 */ 404 static int 405 bpfread(struct dev_read_args *ap) 406 { 407 cdev_t dev = ap->a_head.a_dev; 408 struct bpf_d *d = dev->si_drv1; 409 int timed_out; 410 int error; 411 412 /* 413 * Restrict application to use a buffer the same size as 414 * as kernel buffers. 415 */ 416 if (ap->a_uio->uio_resid != d->bd_bufsize) 417 return(EINVAL); 418 419 crit_enter(); 420 if (d->bd_state == BPF_WAITING) 421 callout_stop(&d->bd_callout); 422 timed_out = (d->bd_state == BPF_TIMED_OUT); 423 d->bd_state = BPF_IDLE; 424 /* 425 * If the hold buffer is empty, then do a timed sleep, which 426 * ends when the timeout expires or when enough packets 427 * have arrived to fill the store buffer. 428 */ 429 while (d->bd_hbuf == NULL) { 430 if ((d->bd_immediate || (ap->a_ioflag & IO_NDELAY) || timed_out) 431 && d->bd_slen != 0) { 432 /* 433 * A packet(s) either arrived since the previous, 434 * We're in immediate mode, or are reading 435 * in non-blocking mode, and a packet(s) 436 * either arrived since the previous 437 * read or arrived while we were asleep. 438 * Rotate the buffers and return what's here. 439 */ 440 ROTATE_BUFFERS(d); 441 break; 442 } 443 444 /* 445 * No data is available, check to see if the bpf device 446 * is still pointed at a real interface. If not, return 447 * ENXIO so that the userland process knows to rebind 448 * it before using it again. 449 */ 450 if (d->bd_bif == NULL) { 451 crit_exit(); 452 return(ENXIO); 453 } 454 455 if (ap->a_ioflag & IO_NDELAY) { 456 crit_exit(); 457 return(EWOULDBLOCK); 458 } 459 error = tsleep(d, PCATCH, "bpf", d->bd_rtout); 460 if (error == EINTR || error == ERESTART) { 461 crit_exit(); 462 return(error); 463 } 464 if (error == EWOULDBLOCK) { 465 /* 466 * On a timeout, return what's in the buffer, 467 * which may be nothing. If there is something 468 * in the store buffer, we can rotate the buffers. 469 */ 470 if (d->bd_hbuf) 471 /* 472 * We filled up the buffer in between 473 * getting the timeout and arriving 474 * here, so we don't need to rotate. 475 */ 476 break; 477 478 if (d->bd_slen == 0) { 479 crit_exit(); 480 return(0); 481 } 482 ROTATE_BUFFERS(d); 483 break; 484 } 485 } 486 /* 487 * At this point, we know we have something in the hold slot. 488 */ 489 crit_exit(); 490 491 /* 492 * Move data from hold buffer into user space. 493 * We know the entire buffer is transferred since 494 * we checked above that the read buffer is bpf_bufsize bytes. 495 */ 496 error = uiomove(d->bd_hbuf, d->bd_hlen, ap->a_uio); 497 498 crit_enter(); 499 d->bd_fbuf = d->bd_hbuf; 500 d->bd_hbuf = NULL; 501 d->bd_hlen = 0; 502 crit_exit(); 503 504 return(error); 505 } 506 507 508 /* 509 * If there are processes sleeping on this descriptor, wake them up. 510 */ 511 static void 512 bpf_wakeup(struct bpf_d *d) 513 { 514 if (d->bd_state == BPF_WAITING) { 515 callout_stop(&d->bd_callout); 516 d->bd_state = BPF_IDLE; 517 } 518 wakeup(d); 519 if (d->bd_async && d->bd_sig && d->bd_sigio) 520 pgsigio(d->bd_sigio, d->bd_sig, 0); 521 522 get_mplock(); 523 KNOTE(&d->bd_kq.ki_note, 0); 524 rel_mplock(); 525 } 526 527 static void 528 bpf_timed_out(void *arg) 529 { 530 struct bpf_d *d = (struct bpf_d *)arg; 531 532 crit_enter(); 533 if (d->bd_state == BPF_WAITING) { 534 d->bd_state = BPF_TIMED_OUT; 535 if (d->bd_slen != 0) 536 bpf_wakeup(d); 537 } 538 crit_exit(); 539 } 540 541 static void 542 bpf_output_dispatch(netmsg_t msg) 543 { 544 struct netmsg_bpf_output *bmsg = (struct netmsg_bpf_output *)msg; 545 struct ifnet *ifp = bmsg->nm_ifp; 546 int error; 547 548 /* 549 * The driver frees the mbuf. 550 */ 551 error = ifp->if_output(ifp, bmsg->nm_mbuf, bmsg->nm_dst, NULL); 552 lwkt_replymsg(&msg->lmsg, error); 553 } 554 555 static int 556 bpfwrite(struct dev_write_args *ap) 557 { 558 cdev_t dev = ap->a_head.a_dev; 559 struct bpf_d *d = dev->si_drv1; 560 struct ifnet *ifp; 561 struct mbuf *m; 562 int error; 563 struct sockaddr dst; 564 int datlen; 565 struct netmsg_bpf_output bmsg; 566 567 if (d->bd_bif == NULL) 568 return(ENXIO); 569 570 ifp = d->bd_bif->bif_ifp; 571 572 if (ap->a_uio->uio_resid == 0) 573 return(0); 574 575 error = bpf_movein(ap->a_uio, (int)d->bd_bif->bif_dlt, &m, 576 &dst, &datlen, d->bd_wfilter); 577 if (error) 578 return(error); 579 580 if (datlen > ifp->if_mtu) { 581 m_freem(m); 582 return(EMSGSIZE); 583 } 584 585 if (d->bd_hdrcmplt) 586 dst.sa_family = pseudo_AF_HDRCMPLT; 587 588 netmsg_init(&bmsg.base, NULL, &curthread->td_msgport, 589 0, bpf_output_dispatch); 590 bmsg.nm_mbuf = m; 591 bmsg.nm_ifp = ifp; 592 bmsg.nm_dst = &dst; 593 594 return lwkt_domsg(cpu_portfn(0), &bmsg.base.lmsg, 0); 595 } 596 597 /* 598 * Reset a descriptor by flushing its packet buffer and clearing the 599 * receive and drop counts. Should be called at splimp. 600 */ 601 static void 602 bpf_resetd(struct bpf_d *d) 603 { 604 if (d->bd_hbuf) { 605 /* Free the hold buffer. */ 606 d->bd_fbuf = d->bd_hbuf; 607 d->bd_hbuf = NULL; 608 } 609 d->bd_slen = 0; 610 d->bd_hlen = 0; 611 d->bd_rcount = 0; 612 d->bd_dcount = 0; 613 } 614 615 /* 616 * FIONREAD Check for read packet available. 617 * SIOCGIFADDR Get interface address - convenient hook to driver. 618 * BIOCGBLEN Get buffer len [for read()]. 619 * BIOCSETF Set ethernet read filter. 620 * BIOCSETWF Set ethernet write filter. 621 * BIOCFLUSH Flush read packet buffer. 622 * BIOCPROMISC Put interface into promiscuous mode. 623 * BIOCGDLT Get link layer type. 624 * BIOCGETIF Get interface name. 625 * BIOCSETIF Set interface. 626 * BIOCSRTIMEOUT Set read timeout. 627 * BIOCGRTIMEOUT Get read timeout. 628 * BIOCGSTATS Get packet stats. 629 * BIOCIMMEDIATE Set immediate mode. 630 * BIOCVERSION Get filter language version. 631 * BIOCGHDRCMPLT Get "header already complete" flag 632 * BIOCSHDRCMPLT Set "header already complete" flag 633 * BIOCGSEESENT Get "see packets sent" flag 634 * BIOCSSEESENT Set "see packets sent" flag 635 * BIOCLOCK Set "locked" flag 636 */ 637 /* ARGSUSED */ 638 static int 639 bpfioctl(struct dev_ioctl_args *ap) 640 { 641 cdev_t dev = ap->a_head.a_dev; 642 struct bpf_d *d = dev->si_drv1; 643 int error = 0; 644 645 crit_enter(); 646 if (d->bd_state == BPF_WAITING) 647 callout_stop(&d->bd_callout); 648 d->bd_state = BPF_IDLE; 649 crit_exit(); 650 651 if (d->bd_locked == 1) { 652 switch (ap->a_cmd) { 653 case BIOCGBLEN: 654 case BIOCFLUSH: 655 case BIOCGDLT: 656 case BIOCGDLTLIST: 657 case BIOCGETIF: 658 case BIOCGRTIMEOUT: 659 case BIOCGSTATS: 660 case BIOCVERSION: 661 case BIOCGRSIG: 662 case BIOCGHDRCMPLT: 663 case FIONREAD: 664 case BIOCLOCK: 665 case BIOCSRTIMEOUT: 666 case BIOCIMMEDIATE: 667 case TIOCGPGRP: 668 break; 669 default: 670 return (EPERM); 671 } 672 } 673 switch (ap->a_cmd) { 674 default: 675 error = EINVAL; 676 break; 677 678 /* 679 * Check for read packet available. 680 */ 681 case FIONREAD: 682 { 683 int n; 684 685 crit_enter(); 686 n = d->bd_slen; 687 if (d->bd_hbuf) 688 n += d->bd_hlen; 689 crit_exit(); 690 691 *(int *)ap->a_data = n; 692 break; 693 } 694 695 case SIOCGIFADDR: 696 { 697 struct ifnet *ifp; 698 699 if (d->bd_bif == NULL) { 700 error = EINVAL; 701 } else { 702 ifp = d->bd_bif->bif_ifp; 703 ifnet_serialize_all(ifp); 704 error = ifp->if_ioctl(ifp, ap->a_cmd, 705 ap->a_data, ap->a_cred); 706 ifnet_deserialize_all(ifp); 707 } 708 break; 709 } 710 711 /* 712 * Get buffer len [for read()]. 713 */ 714 case BIOCGBLEN: 715 *(u_int *)ap->a_data = d->bd_bufsize; 716 break; 717 718 /* 719 * Set buffer length. 720 */ 721 case BIOCSBLEN: 722 if (d->bd_bif != NULL) { 723 error = EINVAL; 724 } else { 725 u_int size = *(u_int *)ap->a_data; 726 727 if (size > bpf_maxbufsize) 728 *(u_int *)ap->a_data = size = bpf_maxbufsize; 729 else if (size < BPF_MINBUFSIZE) 730 *(u_int *)ap->a_data = size = BPF_MINBUFSIZE; 731 d->bd_bufsize = size; 732 } 733 break; 734 735 /* 736 * Set link layer read filter. 737 */ 738 case BIOCSETF: 739 case BIOCSETWF: 740 error = bpf_setf(d, (struct bpf_program *)ap->a_data, 741 ap->a_cmd); 742 break; 743 744 /* 745 * Flush read packet buffer. 746 */ 747 case BIOCFLUSH: 748 crit_enter(); 749 bpf_resetd(d); 750 crit_exit(); 751 break; 752 753 /* 754 * Put interface into promiscuous mode. 755 */ 756 case BIOCPROMISC: 757 if (d->bd_bif == NULL) { 758 /* 759 * No interface attached yet. 760 */ 761 error = EINVAL; 762 break; 763 } 764 crit_enter(); 765 if (d->bd_promisc == 0) { 766 error = ifpromisc(d->bd_bif->bif_ifp, 1); 767 if (error == 0) 768 d->bd_promisc = 1; 769 } 770 crit_exit(); 771 break; 772 773 /* 774 * Get device parameters. 775 */ 776 case BIOCGDLT: 777 if (d->bd_bif == NULL) 778 error = EINVAL; 779 else 780 *(u_int *)ap->a_data = d->bd_bif->bif_dlt; 781 break; 782 783 /* 784 * Get a list of supported data link types. 785 */ 786 case BIOCGDLTLIST: 787 if (d->bd_bif == NULL) { 788 error = EINVAL; 789 } else { 790 error = bpf_getdltlist(d, 791 (struct bpf_dltlist *)ap->a_data); 792 } 793 break; 794 795 /* 796 * Set data link type. 797 */ 798 case BIOCSDLT: 799 if (d->bd_bif == NULL) 800 error = EINVAL; 801 else 802 error = bpf_setdlt(d, *(u_int *)ap->a_data); 803 break; 804 805 /* 806 * Get interface name. 807 */ 808 case BIOCGETIF: 809 if (d->bd_bif == NULL) { 810 error = EINVAL; 811 } else { 812 struct ifnet *const ifp = d->bd_bif->bif_ifp; 813 struct ifreq *const ifr = (struct ifreq *)ap->a_data; 814 815 strlcpy(ifr->ifr_name, ifp->if_xname, 816 sizeof ifr->ifr_name); 817 } 818 break; 819 820 /* 821 * Set interface. 822 */ 823 case BIOCSETIF: 824 error = bpf_setif(d, (struct ifreq *)ap->a_data); 825 break; 826 827 /* 828 * Set read timeout. 829 */ 830 case BIOCSRTIMEOUT: 831 { 832 struct timeval *tv = (struct timeval *)ap->a_data; 833 834 /* 835 * Subtract 1 tick from tvtohz() since this isn't 836 * a one-shot timer. 837 */ 838 if ((error = itimerfix(tv)) == 0) 839 d->bd_rtout = tvtohz_low(tv); 840 break; 841 } 842 843 /* 844 * Get read timeout. 845 */ 846 case BIOCGRTIMEOUT: 847 { 848 struct timeval *tv = (struct timeval *)ap->a_data; 849 850 tv->tv_sec = d->bd_rtout / hz; 851 tv->tv_usec = (d->bd_rtout % hz) * ustick; 852 break; 853 } 854 855 /* 856 * Get packet stats. 857 */ 858 case BIOCGSTATS: 859 { 860 struct bpf_stat *bs = (struct bpf_stat *)ap->a_data; 861 862 bs->bs_recv = d->bd_rcount; 863 bs->bs_drop = d->bd_dcount; 864 break; 865 } 866 867 /* 868 * Set immediate mode. 869 */ 870 case BIOCIMMEDIATE: 871 d->bd_immediate = *(u_int *)ap->a_data; 872 break; 873 874 case BIOCVERSION: 875 { 876 struct bpf_version *bv = (struct bpf_version *)ap->a_data; 877 878 bv->bv_major = BPF_MAJOR_VERSION; 879 bv->bv_minor = BPF_MINOR_VERSION; 880 break; 881 } 882 883 /* 884 * Get "header already complete" flag 885 */ 886 case BIOCGHDRCMPLT: 887 *(u_int *)ap->a_data = d->bd_hdrcmplt; 888 break; 889 890 /* 891 * Set "header already complete" flag 892 */ 893 case BIOCSHDRCMPLT: 894 d->bd_hdrcmplt = *(u_int *)ap->a_data ? 1 : 0; 895 break; 896 897 /* 898 * Get "see sent packets" flag 899 */ 900 case BIOCGSEESENT: 901 *(u_int *)ap->a_data = d->bd_seesent; 902 break; 903 904 /* 905 * Set "see sent packets" flag 906 */ 907 case BIOCSSEESENT: 908 d->bd_seesent = *(u_int *)ap->a_data; 909 break; 910 911 case FIOASYNC: /* Send signal on receive packets */ 912 d->bd_async = *(int *)ap->a_data; 913 break; 914 915 case FIOSETOWN: 916 error = fsetown(*(int *)ap->a_data, &d->bd_sigio); 917 break; 918 919 case FIOGETOWN: 920 *(int *)ap->a_data = fgetown(d->bd_sigio); 921 break; 922 923 /* This is deprecated, FIOSETOWN should be used instead. */ 924 case TIOCSPGRP: 925 error = fsetown(-(*(int *)ap->a_data), &d->bd_sigio); 926 break; 927 928 /* This is deprecated, FIOGETOWN should be used instead. */ 929 case TIOCGPGRP: 930 *(int *)ap->a_data = -fgetown(d->bd_sigio); 931 break; 932 933 case BIOCSRSIG: /* Set receive signal */ 934 { 935 u_int sig; 936 937 sig = *(u_int *)ap->a_data; 938 939 if (sig >= NSIG) 940 error = EINVAL; 941 else 942 d->bd_sig = sig; 943 break; 944 } 945 case BIOCGRSIG: 946 *(u_int *)ap->a_data = d->bd_sig; 947 break; 948 case BIOCLOCK: 949 d->bd_locked = 1; 950 break; 951 } 952 return(error); 953 } 954 955 /* 956 * Set d's packet filter program to fp. If this file already has a filter, 957 * free it and replace it. Returns EINVAL for bogus requests. 958 */ 959 static int 960 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 961 { 962 struct bpf_insn *fcode, *old; 963 u_int wfilter, flen, size; 964 965 if (cmd == BIOCSETWF) { 966 old = d->bd_wfilter; 967 wfilter = 1; 968 } else { 969 wfilter = 0; 970 old = d->bd_rfilter; 971 } 972 if (fp->bf_insns == NULL) { 973 if (fp->bf_len != 0) 974 return(EINVAL); 975 crit_enter(); 976 if (wfilter) 977 d->bd_wfilter = NULL; 978 else 979 d->bd_rfilter = NULL; 980 bpf_resetd(d); 981 crit_exit(); 982 if (old != NULL) 983 kfree(old, M_BPF); 984 return(0); 985 } 986 flen = fp->bf_len; 987 if (flen > BPF_MAXINSNS) 988 return(EINVAL); 989 990 size = flen * sizeof *fp->bf_insns; 991 fcode = (struct bpf_insn *)kmalloc(size, M_BPF, M_WAITOK); 992 if (copyin(fp->bf_insns, fcode, size) == 0 && 993 bpf_validate(fcode, (int)flen)) { 994 crit_enter(); 995 if (wfilter) 996 d->bd_wfilter = fcode; 997 else 998 d->bd_rfilter = fcode; 999 bpf_resetd(d); 1000 crit_exit(); 1001 if (old != NULL) 1002 kfree(old, M_BPF); 1003 1004 return(0); 1005 } 1006 kfree(fcode, M_BPF); 1007 return(EINVAL); 1008 } 1009 1010 /* 1011 * Detach a file from its current interface (if attached at all) and attach 1012 * to the interface indicated by the name stored in ifr. 1013 * Return an errno or 0. 1014 */ 1015 static int 1016 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 1017 { 1018 struct bpf_if *bp; 1019 int error; 1020 struct ifnet *theywant; 1021 1022 theywant = ifunit(ifr->ifr_name); 1023 if (theywant == NULL) 1024 return(ENXIO); 1025 1026 /* 1027 * Look through attached interfaces for the named one. 1028 */ 1029 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1030 struct ifnet *ifp = bp->bif_ifp; 1031 1032 if (ifp == NULL || ifp != theywant) 1033 continue; 1034 /* skip additional entry */ 1035 if (bp->bif_driverp != &ifp->if_bpf) 1036 continue; 1037 /* 1038 * We found the requested interface. 1039 * Allocate the packet buffers if we need to. 1040 * If we're already attached to requested interface, 1041 * just flush the buffer. 1042 */ 1043 if (d->bd_sbuf == NULL) { 1044 error = bpf_allocbufs(d); 1045 if (error != 0) 1046 return(error); 1047 } 1048 crit_enter(); 1049 if (bp != d->bd_bif) { 1050 if (d->bd_bif != NULL) { 1051 /* 1052 * Detach if attached to something else. 1053 */ 1054 bpf_detachd(d); 1055 } 1056 1057 bpf_attachd(d, bp); 1058 } 1059 bpf_resetd(d); 1060 crit_exit(); 1061 return(0); 1062 } 1063 1064 /* Not found. */ 1065 return(ENXIO); 1066 } 1067 1068 static struct filterops bpf_read_filtops = 1069 { FILTEROP_ISFD, NULL, bpf_filter_detach, bpf_filter_read }; 1070 1071 static int 1072 bpfkqfilter(struct dev_kqfilter_args *ap) 1073 { 1074 cdev_t dev = ap->a_head.a_dev; 1075 struct knote *kn = ap->a_kn; 1076 struct klist *klist; 1077 struct bpf_d *d; 1078 1079 d = dev->si_drv1; 1080 if (d->bd_bif == NULL) { 1081 ap->a_result = 1; 1082 return (0); 1083 } 1084 1085 ap->a_result = 0; 1086 switch (kn->kn_filter) { 1087 case EVFILT_READ: 1088 kn->kn_fop = &bpf_read_filtops; 1089 kn->kn_hook = (caddr_t)d; 1090 break; 1091 default: 1092 ap->a_result = EOPNOTSUPP; 1093 return (0); 1094 } 1095 1096 klist = &d->bd_kq.ki_note; 1097 knote_insert(klist, kn); 1098 1099 return (0); 1100 } 1101 1102 static void 1103 bpf_filter_detach(struct knote *kn) 1104 { 1105 struct klist *klist; 1106 struct bpf_d *d; 1107 1108 d = (struct bpf_d *)kn->kn_hook; 1109 klist = &d->bd_kq.ki_note; 1110 knote_remove(klist, kn); 1111 } 1112 1113 static int 1114 bpf_filter_read(struct knote *kn, long hint) 1115 { 1116 struct bpf_d *d; 1117 int ready = 0; 1118 1119 crit_enter(); 1120 d = (struct bpf_d *)kn->kn_hook; 1121 if (d->bd_hlen != 0 || 1122 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1123 d->bd_slen != 0)) { 1124 ready = 1; 1125 } else { 1126 /* Start the read timeout if necessary. */ 1127 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1128 callout_reset(&d->bd_callout, d->bd_rtout, 1129 bpf_timed_out, d); 1130 d->bd_state = BPF_WAITING; 1131 } 1132 } 1133 crit_exit(); 1134 1135 return (ready); 1136 } 1137 1138 1139 /* 1140 * Process the packet pkt of length pktlen. The packet is parsed 1141 * by each listener's filter, and if accepted, stashed into the 1142 * corresponding buffer. 1143 */ 1144 void 1145 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1146 { 1147 struct bpf_d *d; 1148 struct timeval tv; 1149 int gottime = 0; 1150 u_int slen; 1151 1152 get_mplock(); 1153 1154 /* Re-check */ 1155 if (bp == NULL) { 1156 rel_mplock(); 1157 return; 1158 } 1159 1160 /* 1161 * Note that the ipl does not have to be raised at this point. 1162 * The only problem that could arise here is that if two different 1163 * interfaces shared any data. This is not the case. 1164 */ 1165 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1166 ++d->bd_rcount; 1167 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 1168 if (slen != 0) { 1169 if (!gottime) { 1170 microtime(&tv); 1171 gottime = 1; 1172 } 1173 catchpacket(d, pkt, pktlen, slen, ovbcopy, &tv); 1174 } 1175 } 1176 1177 rel_mplock(); 1178 } 1179 1180 /* 1181 * Copy data from an mbuf chain into a buffer. This code is derived 1182 * from m_copydata in sys/uipc_mbuf.c. 1183 */ 1184 static void 1185 bpf_mcopy(const void *src_arg, void *dst_arg, size_t len) 1186 { 1187 const struct mbuf *m; 1188 u_int count; 1189 u_char *dst; 1190 1191 m = src_arg; 1192 dst = dst_arg; 1193 while (len > 0) { 1194 if (m == NULL) 1195 panic("bpf_mcopy"); 1196 count = min(m->m_len, len); 1197 bcopy(mtod(m, void *), dst, count); 1198 m = m->m_next; 1199 dst += count; 1200 len -= count; 1201 } 1202 } 1203 1204 /* 1205 * Process the packet in the mbuf chain m. The packet is parsed by each 1206 * listener's filter, and if accepted, stashed into the corresponding 1207 * buffer. 1208 */ 1209 void 1210 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1211 { 1212 struct bpf_d *d; 1213 u_int pktlen, slen; 1214 struct timeval tv; 1215 int gottime = 0; 1216 1217 get_mplock(); 1218 1219 /* Re-check */ 1220 if (bp == NULL) { 1221 rel_mplock(); 1222 return; 1223 } 1224 1225 /* Don't compute pktlen, if no descriptor is attached. */ 1226 if (SLIST_EMPTY(&bp->bif_dlist)) { 1227 rel_mplock(); 1228 return; 1229 } 1230 1231 pktlen = m_lengthm(m, NULL); 1232 1233 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1234 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1235 continue; 1236 ++d->bd_rcount; 1237 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 1238 if (slen != 0) { 1239 if (!gottime) { 1240 microtime(&tv); 1241 gottime = 1; 1242 } 1243 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy, 1244 &tv); 1245 } 1246 } 1247 1248 rel_mplock(); 1249 } 1250 1251 /* 1252 * Incoming linkage from device drivers, where we have a mbuf chain 1253 * but need to prepend some arbitrary header from a linear buffer. 1254 * 1255 * Con up a minimal dummy header to pacify bpf. Allocate (only) a 1256 * struct m_hdr on the stack. This is safe as bpf only reads from the 1257 * fields in this header that we initialize, and will not try to free 1258 * it or keep a pointer to it. 1259 */ 1260 void 1261 bpf_mtap_hdr(struct bpf_if *arg, caddr_t data, u_int dlen, struct mbuf *m, u_int direction) 1262 { 1263 struct m_hdr mh; 1264 1265 mh.mh_flags = 0; 1266 mh.mh_next = m; 1267 mh.mh_len = dlen; 1268 mh.mh_data = data; 1269 1270 return bpf_mtap(arg, (struct mbuf *) &mh); 1271 } 1272 1273 void 1274 bpf_mtap_family(struct bpf_if *bp, struct mbuf *m, sa_family_t family) 1275 { 1276 u_int family4; 1277 1278 KKASSERT(family != AF_UNSPEC); 1279 1280 family4 = (u_int)family; 1281 bpf_ptap(bp, m, &family4, sizeof(family4)); 1282 } 1283 1284 /* 1285 * Process the packet in the mbuf chain m with the header in m prepended. 1286 * The packet is parsed by each listener's filter, and if accepted, 1287 * stashed into the corresponding buffer. 1288 */ 1289 void 1290 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen) 1291 { 1292 struct mbuf mb; 1293 1294 /* 1295 * Craft on-stack mbuf suitable for passing to bpf_mtap. 1296 * Note that we cut corners here; we only setup what's 1297 * absolutely needed--this mbuf should never go anywhere else. 1298 */ 1299 mb.m_next = m; 1300 mb.m_data = __DECONST(void *, data); /* LINTED */ 1301 mb.m_len = dlen; 1302 mb.m_pkthdr.rcvif = m->m_pkthdr.rcvif; 1303 1304 bpf_mtap(bp, &mb); 1305 } 1306 1307 /* 1308 * Move the packet data from interface memory (pkt) into the 1309 * store buffer. Return 1 if it's time to wakeup a listener (buffer full), 1310 * otherwise 0. "copy" is the routine called to do the actual data 1311 * transfer. bcopy is passed in to copy contiguous chunks, while 1312 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1313 * pkt is really an mbuf. 1314 */ 1315 static void 1316 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 1317 void (*cpfn)(const void *, void *, size_t), 1318 const struct timeval *tv) 1319 { 1320 struct bpf_hdr *hp; 1321 int totlen, curlen; 1322 int hdrlen = d->bd_bif->bif_hdrlen; 1323 int wakeup = 0; 1324 /* 1325 * Figure out how many bytes to move. If the packet is 1326 * greater or equal to the snapshot length, transfer that 1327 * much. Otherwise, transfer the whole packet (unless 1328 * we hit the buffer size limit). 1329 */ 1330 totlen = hdrlen + min(snaplen, pktlen); 1331 if (totlen > d->bd_bufsize) 1332 totlen = d->bd_bufsize; 1333 1334 /* 1335 * Round up the end of the previous packet to the next longword. 1336 */ 1337 curlen = BPF_WORDALIGN(d->bd_slen); 1338 if (curlen + totlen > d->bd_bufsize) { 1339 /* 1340 * This packet will overflow the storage buffer. 1341 * Rotate the buffers if we can, then wakeup any 1342 * pending reads. 1343 */ 1344 if (d->bd_fbuf == NULL) { 1345 /* 1346 * We haven't completed the previous read yet, 1347 * so drop the packet. 1348 */ 1349 ++d->bd_dcount; 1350 return; 1351 } 1352 ROTATE_BUFFERS(d); 1353 wakeup = 1; 1354 curlen = 0; 1355 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) { 1356 /* 1357 * Immediate mode is set, or the read timeout has 1358 * already expired during a select call. A packet 1359 * arrived, so the reader should be woken up. 1360 */ 1361 wakeup = 1; 1362 } 1363 1364 /* 1365 * Append the bpf header. 1366 */ 1367 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1368 hp->bh_tstamp = *tv; 1369 hp->bh_datalen = pktlen; 1370 hp->bh_hdrlen = hdrlen; 1371 /* 1372 * Copy the packet data into the store buffer and update its length. 1373 */ 1374 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1375 d->bd_slen = curlen + totlen; 1376 1377 if (wakeup) 1378 bpf_wakeup(d); 1379 } 1380 1381 /* 1382 * Initialize all nonzero fields of a descriptor. 1383 */ 1384 static int 1385 bpf_allocbufs(struct bpf_d *d) 1386 { 1387 d->bd_fbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK); 1388 d->bd_sbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK); 1389 d->bd_slen = 0; 1390 d->bd_hlen = 0; 1391 return(0); 1392 } 1393 1394 /* 1395 * Free buffers and packet filter program currently in use by a descriptor. 1396 * Called on close. 1397 */ 1398 static void 1399 bpf_freed(struct bpf_d *d) 1400 { 1401 /* 1402 * We don't need to lock out interrupts since this descriptor has 1403 * been detached from its interface and it yet hasn't been marked 1404 * free. 1405 */ 1406 if (d->bd_sbuf != NULL) { 1407 kfree(d->bd_sbuf, M_BPF); 1408 if (d->bd_hbuf != NULL) 1409 kfree(d->bd_hbuf, M_BPF); 1410 if (d->bd_fbuf != NULL) 1411 kfree(d->bd_fbuf, M_BPF); 1412 } 1413 if (d->bd_rfilter) 1414 kfree(d->bd_rfilter, M_BPF); 1415 if (d->bd_wfilter) 1416 kfree(d->bd_wfilter, M_BPF); 1417 } 1418 1419 /* 1420 * Attach an interface to bpf. ifp is a pointer to the structure 1421 * defining the interface to be attached, dlt is the link layer type, 1422 * and hdrlen is the fixed size of the link header (variable length 1423 * headers are not yet supported). 1424 */ 1425 void 1426 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1427 { 1428 bpfattach_dlt(ifp, dlt, hdrlen, &ifp->if_bpf); 1429 } 1430 1431 void 1432 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1433 { 1434 struct bpf_if *bp; 1435 1436 bp = kmalloc(sizeof *bp, M_BPF, M_WAITOK | M_ZERO); 1437 1438 SLIST_INIT(&bp->bif_dlist); 1439 bp->bif_ifp = ifp; 1440 bp->bif_dlt = dlt; 1441 bp->bif_driverp = driverp; 1442 *bp->bif_driverp = NULL; 1443 1444 bp->bif_next = bpf_iflist; 1445 bpf_iflist = bp; 1446 1447 /* 1448 * Compute the length of the bpf header. This is not necessarily 1449 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1450 * that the network layer header begins on a longword boundary (for 1451 * performance reasons and to alleviate alignment restrictions). 1452 */ 1453 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1454 1455 if (bootverbose) 1456 if_printf(ifp, "bpf attached\n"); 1457 } 1458 1459 /* 1460 * Detach bpf from an interface. This involves detaching each descriptor 1461 * associated with the interface, and leaving bd_bif NULL. Notify each 1462 * descriptor as it's detached so that any sleepers wake up and get 1463 * ENXIO. 1464 */ 1465 void 1466 bpfdetach(struct ifnet *ifp) 1467 { 1468 struct bpf_if *bp, *bp_prev; 1469 struct bpf_d *d; 1470 1471 crit_enter(); 1472 1473 /* Locate BPF interface information */ 1474 bp_prev = NULL; 1475 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1476 if (ifp == bp->bif_ifp) 1477 break; 1478 bp_prev = bp; 1479 } 1480 1481 /* Interface wasn't attached */ 1482 if (bp->bif_ifp == NULL) { 1483 crit_exit(); 1484 kprintf("bpfdetach: %s was not attached\n", ifp->if_xname); 1485 return; 1486 } 1487 1488 while ((d = SLIST_FIRST(&bp->bif_dlist)) != NULL) { 1489 bpf_detachd(d); 1490 bpf_wakeup(d); 1491 } 1492 1493 if (bp_prev != NULL) 1494 bp_prev->bif_next = bp->bif_next; 1495 else 1496 bpf_iflist = bp->bif_next; 1497 1498 kfree(bp, M_BPF); 1499 1500 crit_exit(); 1501 } 1502 1503 /* 1504 * Get a list of available data link type of the interface. 1505 */ 1506 static int 1507 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 1508 { 1509 int n, error; 1510 struct ifnet *ifp; 1511 struct bpf_if *bp; 1512 1513 ifp = d->bd_bif->bif_ifp; 1514 n = 0; 1515 error = 0; 1516 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1517 if (bp->bif_ifp != ifp) 1518 continue; 1519 if (bfl->bfl_list != NULL) { 1520 if (n >= bfl->bfl_len) { 1521 return (ENOMEM); 1522 } 1523 error = copyout(&bp->bif_dlt, 1524 bfl->bfl_list + n, sizeof(u_int)); 1525 } 1526 n++; 1527 } 1528 bfl->bfl_len = n; 1529 return(error); 1530 } 1531 1532 /* 1533 * Set the data link type of a BPF instance. 1534 */ 1535 static int 1536 bpf_setdlt(struct bpf_d *d, u_int dlt) 1537 { 1538 int error, opromisc; 1539 struct ifnet *ifp; 1540 struct bpf_if *bp; 1541 1542 if (d->bd_bif->bif_dlt == dlt) 1543 return (0); 1544 ifp = d->bd_bif->bif_ifp; 1545 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1546 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1547 break; 1548 } 1549 if (bp != NULL) { 1550 opromisc = d->bd_promisc; 1551 crit_enter(); 1552 bpf_detachd(d); 1553 bpf_attachd(d, bp); 1554 bpf_resetd(d); 1555 if (opromisc) { 1556 error = ifpromisc(bp->bif_ifp, 1); 1557 if (error) { 1558 if_printf(bp->bif_ifp, 1559 "bpf_setdlt: ifpromisc failed (%d)\n", 1560 error); 1561 } else { 1562 d->bd_promisc = 1; 1563 } 1564 } 1565 crit_exit(); 1566 } 1567 return(bp == NULL ? EINVAL : 0); 1568 } 1569 1570 static void 1571 bpf_drvinit(void *unused) 1572 { 1573 int i; 1574 1575 make_autoclone_dev(&bpf_ops, &DEVFS_CLONE_BITMAP(bpf), 1576 bpfclone, 0, 0, 0600, "bpf"); 1577 for (i = 0; i < BPF_PREALLOCATED_UNITS; i++) { 1578 make_dev(&bpf_ops, i, 0, 0, 0600, "bpf%d", i); 1579 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(bpf), i); 1580 } 1581 } 1582 1583 static void 1584 bpf_drvuninit(void *unused) 1585 { 1586 devfs_clone_handler_del("bpf"); 1587 dev_ops_remove_all(&bpf_ops); 1588 devfs_clone_bitmap_uninit(&DEVFS_CLONE_BITMAP(bpf)); 1589 } 1590 1591 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL) 1592 SYSUNINIT(bpfdev, SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvuninit, NULL); 1593 1594 #else /* !BPF */ 1595 /* 1596 * NOP stubs to allow bpf-using drivers to load and function. 1597 * 1598 * A 'better' implementation would allow the core bpf functionality 1599 * to be loaded at runtime. 1600 */ 1601 1602 void 1603 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1604 { 1605 } 1606 1607 void 1608 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1609 { 1610 } 1611 1612 void 1613 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen) 1614 { 1615 } 1616 1617 void 1618 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1619 { 1620 } 1621 1622 void 1623 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1624 { 1625 } 1626 1627 void 1628 bpfdetach(struct ifnet *ifp) 1629 { 1630 } 1631 1632 u_int 1633 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 1634 { 1635 return -1; /* "no filter" behaviour */ 1636 } 1637 1638 #endif /* !BPF */ 1639