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 66 #include <net/if.h> 67 #include <net/bpf.h> 68 #include <net/bpfdesc.h> 69 #include <net/netmsg2.h> 70 71 #include <netinet/in.h> 72 #include <netinet/if_ether.h> 73 #include <sys/kernel.h> 74 #include <sys/sysctl.h> 75 76 #include <sys/devfs.h> 77 78 struct netmsg_bpf_output { 79 struct netmsg_base base; 80 struct mbuf *nm_mbuf; 81 struct ifnet *nm_ifp; 82 struct sockaddr *nm_dst; 83 }; 84 85 MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 86 DEVFS_DECLARE_CLONE_BITMAP(bpf); 87 88 #if NBPF <= 1 89 #define BPF_PREALLOCATED_UNITS 4 90 #else 91 #define BPF_PREALLOCATED_UNITS NBPF 92 #endif 93 94 #if NBPF > 0 95 96 /* 97 * The default read buffer size is patchable. 98 */ 99 static int bpf_bufsize = BPF_DEFAULTBUFSIZE; 100 SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW, 101 &bpf_bufsize, 0, "Current size of bpf buffer"); 102 int bpf_maxbufsize = BPF_MAXBUFSIZE; 103 SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW, 104 &bpf_maxbufsize, 0, "Maximum size of bpf buffer"); 105 106 /* 107 * bpf_iflist is the list of interfaces; each corresponds to an ifnet 108 */ 109 static struct bpf_if *bpf_iflist; 110 111 static struct lwkt_token bpf_token = LWKT_TOKEN_INITIALIZER(bpf_token); 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", 0, D_MPSAFE }, 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 lwkt_gettoken(&bpf_token); 268 d->bd_bif = bp; 269 SLIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 270 *bp->bif_driverp = bp; 271 272 EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); 273 lwkt_reltoken(&bpf_token); 274 } 275 276 /* 277 * Detach a file from its interface. 278 */ 279 static void 280 bpf_detachd(struct bpf_d *d) 281 { 282 int error; 283 struct bpf_if *bp; 284 struct ifnet *ifp; 285 286 lwkt_gettoken(&bpf_token); 287 bp = d->bd_bif; 288 ifp = bp->bif_ifp; 289 290 /* Remove d from the interface's descriptor list. */ 291 SLIST_REMOVE(&bp->bif_dlist, d, bpf_d, bd_next); 292 293 if (SLIST_EMPTY(&bp->bif_dlist)) { 294 /* 295 * Let the driver know that there are no more listeners. 296 */ 297 *bp->bif_driverp = NULL; 298 } 299 d->bd_bif = NULL; 300 301 EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); 302 303 /* 304 * Check if this descriptor had requested promiscuous mode. 305 * If so, turn it off. 306 */ 307 if (d->bd_promisc) { 308 d->bd_promisc = 0; 309 error = ifpromisc(ifp, 0); 310 if (error != 0 && error != ENXIO) { 311 /* 312 * ENXIO can happen if a pccard is unplugged, 313 * Something is really wrong if we were able to put 314 * the driver into promiscuous mode, but can't 315 * take it out. 316 */ 317 if_printf(ifp, "bpf_detach: ifpromisc failed(%d)\n", 318 error); 319 } 320 } 321 lwkt_reltoken(&bpf_token); 322 } 323 324 /* 325 * Open ethernet device. Returns ENXIO for illegal minor device number, 326 * EBUSY if file is open by another process. 327 */ 328 /* ARGSUSED */ 329 static int 330 bpfopen(struct dev_open_args *ap) 331 { 332 cdev_t dev = ap->a_head.a_dev; 333 struct bpf_d *d; 334 335 lwkt_gettoken(&bpf_token); 336 if (ap->a_cred->cr_prison) { 337 lwkt_reltoken(&bpf_token); 338 return(EPERM); 339 } 340 341 d = dev->si_drv1; 342 /* 343 * Each minor can be opened by only one process. If the requested 344 * minor is in use, return EBUSY. 345 */ 346 if (d != NULL) { 347 lwkt_reltoken(&bpf_token); 348 return(EBUSY); 349 } 350 351 d = kmalloc(sizeof *d, M_BPF, M_WAITOK | M_ZERO); 352 dev->si_drv1 = d; 353 d->bd_bufsize = bpf_bufsize; 354 d->bd_sig = SIGIO; 355 d->bd_seesent = 1; 356 callout_init(&d->bd_callout); 357 lwkt_reltoken(&bpf_token); 358 359 return(0); 360 } 361 362 static int 363 bpfclone(struct dev_clone_args *ap) 364 { 365 int unit; 366 367 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(bpf), 0); 368 ap->a_dev = make_only_dev(&bpf_ops, unit, 0, 0, 0600, "bpf%d", unit); 369 370 return 0; 371 } 372 373 /* 374 * Close the descriptor by detaching it from its interface, 375 * deallocating its buffers, and marking it free. 376 */ 377 /* ARGSUSED */ 378 static int 379 bpfclose(struct dev_close_args *ap) 380 { 381 cdev_t dev = ap->a_head.a_dev; 382 struct bpf_d *d = dev->si_drv1; 383 384 lwkt_gettoken(&bpf_token); 385 funsetown(&d->bd_sigio); 386 crit_enter(); 387 if (d->bd_state == BPF_WAITING) 388 callout_stop(&d->bd_callout); 389 d->bd_state = BPF_IDLE; 390 if (d->bd_bif != NULL) 391 bpf_detachd(d); 392 crit_exit(); 393 bpf_freed(d); 394 dev->si_drv1 = NULL; 395 if (dev->si_uminor >= BPF_PREALLOCATED_UNITS) { 396 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(bpf), dev->si_uminor); 397 destroy_dev(dev); 398 } 399 kfree(d, M_BPF); 400 lwkt_reltoken(&bpf_token); 401 402 return(0); 403 } 404 405 /* 406 * Rotate the packet buffers in descriptor d. Move the store buffer 407 * into the hold slot, and the free buffer into the store slot. 408 * Zero the length of the new store buffer. 409 */ 410 #define ROTATE_BUFFERS(d) \ 411 (d)->bd_hbuf = (d)->bd_sbuf; \ 412 (d)->bd_hlen = (d)->bd_slen; \ 413 (d)->bd_sbuf = (d)->bd_fbuf; \ 414 (d)->bd_slen = 0; \ 415 (d)->bd_fbuf = NULL; 416 /* 417 * bpfread - read next chunk of packets from buffers 418 */ 419 static int 420 bpfread(struct dev_read_args *ap) 421 { 422 cdev_t dev = ap->a_head.a_dev; 423 struct bpf_d *d = dev->si_drv1; 424 int timed_out; 425 int error; 426 427 lwkt_gettoken(&bpf_token); 428 /* 429 * Restrict application to use a buffer the same size as 430 * as kernel buffers. 431 */ 432 if (ap->a_uio->uio_resid != d->bd_bufsize) { 433 lwkt_reltoken(&bpf_token); 434 return(EINVAL); 435 } 436 437 crit_enter(); 438 if (d->bd_state == BPF_WAITING) 439 callout_stop(&d->bd_callout); 440 timed_out = (d->bd_state == BPF_TIMED_OUT); 441 d->bd_state = BPF_IDLE; 442 /* 443 * If the hold buffer is empty, then do a timed sleep, which 444 * ends when the timeout expires or when enough packets 445 * have arrived to fill the store buffer. 446 */ 447 while (d->bd_hbuf == NULL) { 448 if ((d->bd_immediate || (ap->a_ioflag & IO_NDELAY) || timed_out) 449 && d->bd_slen != 0) { 450 /* 451 * A packet(s) either arrived since the previous, 452 * We're in immediate mode, or are reading 453 * in non-blocking mode, and a packet(s) 454 * either arrived since the previous 455 * read or arrived while we were asleep. 456 * Rotate the buffers and return what's here. 457 */ 458 ROTATE_BUFFERS(d); 459 break; 460 } 461 462 /* 463 * No data is available, check to see if the bpf device 464 * is still pointed at a real interface. If not, return 465 * ENXIO so that the userland process knows to rebind 466 * it before using it again. 467 */ 468 if (d->bd_bif == NULL) { 469 crit_exit(); 470 lwkt_reltoken(&bpf_token); 471 return(ENXIO); 472 } 473 474 if (ap->a_ioflag & IO_NDELAY) { 475 crit_exit(); 476 lwkt_reltoken(&bpf_token); 477 return(EWOULDBLOCK); 478 } 479 error = tsleep(d, PCATCH, "bpf", d->bd_rtout); 480 if (error == EINTR || error == ERESTART) { 481 crit_exit(); 482 lwkt_reltoken(&bpf_token); 483 return(error); 484 } 485 if (error == EWOULDBLOCK) { 486 /* 487 * On a timeout, return what's in the buffer, 488 * which may be nothing. If there is something 489 * in the store buffer, we can rotate the buffers. 490 */ 491 if (d->bd_hbuf) 492 /* 493 * We filled up the buffer in between 494 * getting the timeout and arriving 495 * here, so we don't need to rotate. 496 */ 497 break; 498 499 if (d->bd_slen == 0) { 500 crit_exit(); 501 lwkt_reltoken(&bpf_token); 502 return(0); 503 } 504 ROTATE_BUFFERS(d); 505 break; 506 } 507 } 508 /* 509 * At this point, we know we have something in the hold slot. 510 */ 511 crit_exit(); 512 513 /* 514 * Move data from hold buffer into user space. 515 * We know the entire buffer is transferred since 516 * we checked above that the read buffer is bpf_bufsize bytes. 517 */ 518 error = uiomove(d->bd_hbuf, d->bd_hlen, ap->a_uio); 519 520 crit_enter(); 521 d->bd_fbuf = d->bd_hbuf; 522 d->bd_hbuf = NULL; 523 d->bd_hlen = 0; 524 crit_exit(); 525 lwkt_reltoken(&bpf_token); 526 527 return(error); 528 } 529 530 531 /* 532 * If there are processes sleeping on this descriptor, wake them up. 533 */ 534 static void 535 bpf_wakeup(struct bpf_d *d) 536 { 537 if (d->bd_state == BPF_WAITING) { 538 callout_stop(&d->bd_callout); 539 d->bd_state = BPF_IDLE; 540 } 541 wakeup(d); 542 if (d->bd_async && d->bd_sig && d->bd_sigio) 543 pgsigio(d->bd_sigio, d->bd_sig, 0); 544 545 KNOTE(&d->bd_kq.ki_note, 0); 546 } 547 548 static void 549 bpf_timed_out(void *arg) 550 { 551 struct bpf_d *d = (struct bpf_d *)arg; 552 553 crit_enter(); 554 if (d->bd_state == BPF_WAITING) { 555 d->bd_state = BPF_TIMED_OUT; 556 if (d->bd_slen != 0) 557 bpf_wakeup(d); 558 } 559 crit_exit(); 560 } 561 562 static void 563 bpf_output_dispatch(netmsg_t msg) 564 { 565 struct netmsg_bpf_output *bmsg = (struct netmsg_bpf_output *)msg; 566 struct ifnet *ifp = bmsg->nm_ifp; 567 int error; 568 569 /* 570 * The driver frees the mbuf. 571 */ 572 error = ifp->if_output(ifp, bmsg->nm_mbuf, bmsg->nm_dst, NULL); 573 lwkt_replymsg(&msg->lmsg, error); 574 } 575 576 static int 577 bpfwrite(struct dev_write_args *ap) 578 { 579 cdev_t dev = ap->a_head.a_dev; 580 struct bpf_d *d = dev->si_drv1; 581 struct ifnet *ifp; 582 struct mbuf *m; 583 int error, ret; 584 struct sockaddr dst; 585 int datlen; 586 struct netmsg_bpf_output bmsg; 587 588 lwkt_gettoken(&bpf_token); 589 if (d->bd_bif == NULL) { 590 lwkt_reltoken(&bpf_token); 591 return(ENXIO); 592 } 593 594 ifp = d->bd_bif->bif_ifp; 595 596 if (ap->a_uio->uio_resid == 0) { 597 lwkt_reltoken(&bpf_token); 598 return(0); 599 } 600 601 error = bpf_movein(ap->a_uio, (int)d->bd_bif->bif_dlt, &m, 602 &dst, &datlen, d->bd_wfilter); 603 if (error) { 604 lwkt_reltoken(&bpf_token); 605 return(error); 606 } 607 608 if (datlen > ifp->if_mtu) { 609 m_freem(m); 610 lwkt_reltoken(&bpf_token); 611 return(EMSGSIZE); 612 } 613 614 if (d->bd_hdrcmplt) 615 dst.sa_family = pseudo_AF_HDRCMPLT; 616 617 netmsg_init(&bmsg.base, NULL, &curthread->td_msgport, 618 0, bpf_output_dispatch); 619 bmsg.nm_mbuf = m; 620 bmsg.nm_ifp = ifp; 621 bmsg.nm_dst = &dst; 622 623 ret = lwkt_domsg(netisr_portfn(0), &bmsg.base.lmsg, 0); 624 lwkt_reltoken(&bpf_token); 625 626 return ret; 627 } 628 629 /* 630 * Reset a descriptor by flushing its packet buffer and clearing the 631 * receive and drop counts. Should be called at splimp. 632 */ 633 static void 634 bpf_resetd(struct bpf_d *d) 635 { 636 if (d->bd_hbuf) { 637 /* Free the hold buffer. */ 638 d->bd_fbuf = d->bd_hbuf; 639 d->bd_hbuf = NULL; 640 } 641 d->bd_slen = 0; 642 d->bd_hlen = 0; 643 d->bd_rcount = 0; 644 d->bd_dcount = 0; 645 } 646 647 /* 648 * FIONREAD Check for read packet available. 649 * SIOCGIFADDR Get interface address - convenient hook to driver. 650 * BIOCGBLEN Get buffer len [for read()]. 651 * BIOCSETF Set ethernet read filter. 652 * BIOCSETWF Set ethernet write filter. 653 * BIOCFLUSH Flush read packet buffer. 654 * BIOCPROMISC Put interface into promiscuous mode. 655 * BIOCGDLT Get link layer type. 656 * BIOCGETIF Get interface name. 657 * BIOCSETIF Set interface. 658 * BIOCSRTIMEOUT Set read timeout. 659 * BIOCGRTIMEOUT Get read timeout. 660 * BIOCGSTATS Get packet stats. 661 * BIOCIMMEDIATE Set immediate mode. 662 * BIOCVERSION Get filter language version. 663 * BIOCGHDRCMPLT Get "header already complete" flag 664 * BIOCSHDRCMPLT Set "header already complete" flag 665 * BIOCGSEESENT Get "see packets sent" flag 666 * BIOCSSEESENT Set "see packets sent" flag 667 * BIOCLOCK Set "locked" flag 668 */ 669 /* ARGSUSED */ 670 static int 671 bpfioctl(struct dev_ioctl_args *ap) 672 { 673 cdev_t dev = ap->a_head.a_dev; 674 struct bpf_d *d = dev->si_drv1; 675 int error = 0; 676 677 lwkt_gettoken(&bpf_token); 678 crit_enter(); 679 if (d->bd_state == BPF_WAITING) 680 callout_stop(&d->bd_callout); 681 d->bd_state = BPF_IDLE; 682 crit_exit(); 683 684 if (d->bd_locked == 1) { 685 switch (ap->a_cmd) { 686 case BIOCGBLEN: 687 case BIOCFLUSH: 688 case BIOCGDLT: 689 case BIOCGDLTLIST: 690 case BIOCGETIF: 691 case BIOCGRTIMEOUT: 692 case BIOCGSTATS: 693 case BIOCVERSION: 694 case BIOCGRSIG: 695 case BIOCGHDRCMPLT: 696 case FIONREAD: 697 case BIOCLOCK: 698 case BIOCSRTIMEOUT: 699 case BIOCIMMEDIATE: 700 case TIOCGPGRP: 701 break; 702 default: 703 lwkt_reltoken(&bpf_token); 704 return (EPERM); 705 } 706 } 707 switch (ap->a_cmd) { 708 default: 709 error = EINVAL; 710 break; 711 712 /* 713 * Check for read packet available. 714 */ 715 case FIONREAD: 716 { 717 int n; 718 719 crit_enter(); 720 n = d->bd_slen; 721 if (d->bd_hbuf) 722 n += d->bd_hlen; 723 crit_exit(); 724 725 *(int *)ap->a_data = n; 726 break; 727 } 728 729 case SIOCGIFADDR: 730 { 731 struct ifnet *ifp; 732 733 if (d->bd_bif == NULL) { 734 error = EINVAL; 735 } else { 736 ifp = d->bd_bif->bif_ifp; 737 ifnet_serialize_all(ifp); 738 error = ifp->if_ioctl(ifp, ap->a_cmd, 739 ap->a_data, ap->a_cred); 740 ifnet_deserialize_all(ifp); 741 } 742 break; 743 } 744 745 /* 746 * Get buffer len [for read()]. 747 */ 748 case BIOCGBLEN: 749 *(u_int *)ap->a_data = d->bd_bufsize; 750 break; 751 752 /* 753 * Set buffer length. 754 */ 755 case BIOCSBLEN: 756 if (d->bd_bif != NULL) { 757 error = EINVAL; 758 } else { 759 u_int size = *(u_int *)ap->a_data; 760 761 if (size > bpf_maxbufsize) 762 *(u_int *)ap->a_data = size = bpf_maxbufsize; 763 else if (size < BPF_MINBUFSIZE) 764 *(u_int *)ap->a_data = size = BPF_MINBUFSIZE; 765 d->bd_bufsize = size; 766 } 767 break; 768 769 /* 770 * Set link layer read filter. 771 */ 772 case BIOCSETF: 773 case BIOCSETWF: 774 error = bpf_setf(d, (struct bpf_program *)ap->a_data, 775 ap->a_cmd); 776 break; 777 778 /* 779 * Flush read packet buffer. 780 */ 781 case BIOCFLUSH: 782 crit_enter(); 783 bpf_resetd(d); 784 crit_exit(); 785 break; 786 787 /* 788 * Put interface into promiscuous mode. 789 */ 790 case BIOCPROMISC: 791 if (d->bd_bif == NULL) { 792 /* 793 * No interface attached yet. 794 */ 795 error = EINVAL; 796 break; 797 } 798 crit_enter(); 799 if (d->bd_promisc == 0) { 800 error = ifpromisc(d->bd_bif->bif_ifp, 1); 801 if (error == 0) 802 d->bd_promisc = 1; 803 } 804 crit_exit(); 805 break; 806 807 /* 808 * Get device parameters. 809 */ 810 case BIOCGDLT: 811 if (d->bd_bif == NULL) 812 error = EINVAL; 813 else 814 *(u_int *)ap->a_data = d->bd_bif->bif_dlt; 815 break; 816 817 /* 818 * Get a list of supported data link types. 819 */ 820 case BIOCGDLTLIST: 821 if (d->bd_bif == NULL) { 822 error = EINVAL; 823 } else { 824 error = bpf_getdltlist(d, 825 (struct bpf_dltlist *)ap->a_data); 826 } 827 break; 828 829 /* 830 * Set data link type. 831 */ 832 case BIOCSDLT: 833 if (d->bd_bif == NULL) 834 error = EINVAL; 835 else 836 error = bpf_setdlt(d, *(u_int *)ap->a_data); 837 break; 838 839 /* 840 * Get interface name. 841 */ 842 case BIOCGETIF: 843 if (d->bd_bif == NULL) { 844 error = EINVAL; 845 } else { 846 struct ifnet *const ifp = d->bd_bif->bif_ifp; 847 struct ifreq *const ifr = (struct ifreq *)ap->a_data; 848 849 strlcpy(ifr->ifr_name, ifp->if_xname, 850 sizeof ifr->ifr_name); 851 } 852 break; 853 854 /* 855 * Set interface. 856 */ 857 case BIOCSETIF: 858 error = bpf_setif(d, (struct ifreq *)ap->a_data); 859 break; 860 861 /* 862 * Set read timeout. 863 */ 864 case BIOCSRTIMEOUT: 865 { 866 struct timeval *tv = (struct timeval *)ap->a_data; 867 868 /* 869 * Subtract 1 tick from tvtohz() since this isn't 870 * a one-shot timer. 871 */ 872 if ((error = itimerfix(tv)) == 0) 873 d->bd_rtout = tvtohz_low(tv); 874 break; 875 } 876 877 /* 878 * Get read timeout. 879 */ 880 case BIOCGRTIMEOUT: 881 { 882 struct timeval *tv = (struct timeval *)ap->a_data; 883 884 tv->tv_sec = d->bd_rtout / hz; 885 tv->tv_usec = (d->bd_rtout % hz) * ustick; 886 break; 887 } 888 889 /* 890 * Get packet stats. 891 */ 892 case BIOCGSTATS: 893 { 894 struct bpf_stat *bs = (struct bpf_stat *)ap->a_data; 895 896 bs->bs_recv = d->bd_rcount; 897 bs->bs_drop = d->bd_dcount; 898 break; 899 } 900 901 /* 902 * Set immediate mode. 903 */ 904 case BIOCIMMEDIATE: 905 d->bd_immediate = *(u_int *)ap->a_data; 906 break; 907 908 case BIOCVERSION: 909 { 910 struct bpf_version *bv = (struct bpf_version *)ap->a_data; 911 912 bv->bv_major = BPF_MAJOR_VERSION; 913 bv->bv_minor = BPF_MINOR_VERSION; 914 break; 915 } 916 917 /* 918 * Get "header already complete" flag 919 */ 920 case BIOCGHDRCMPLT: 921 *(u_int *)ap->a_data = d->bd_hdrcmplt; 922 break; 923 924 /* 925 * Set "header already complete" flag 926 */ 927 case BIOCSHDRCMPLT: 928 d->bd_hdrcmplt = *(u_int *)ap->a_data ? 1 : 0; 929 break; 930 931 /* 932 * Get "see sent packets" flag 933 */ 934 case BIOCGSEESENT: 935 *(u_int *)ap->a_data = d->bd_seesent; 936 break; 937 938 /* 939 * Set "see sent packets" flag 940 */ 941 case BIOCSSEESENT: 942 d->bd_seesent = *(u_int *)ap->a_data; 943 break; 944 945 case FIOASYNC: /* Send signal on receive packets */ 946 d->bd_async = *(int *)ap->a_data; 947 break; 948 949 case FIOSETOWN: 950 error = fsetown(*(int *)ap->a_data, &d->bd_sigio); 951 break; 952 953 case FIOGETOWN: 954 *(int *)ap->a_data = fgetown(&d->bd_sigio); 955 break; 956 957 /* This is deprecated, FIOSETOWN should be used instead. */ 958 case TIOCSPGRP: 959 error = fsetown(-(*(int *)ap->a_data), &d->bd_sigio); 960 break; 961 962 /* This is deprecated, FIOGETOWN should be used instead. */ 963 case TIOCGPGRP: 964 *(int *)ap->a_data = -fgetown(&d->bd_sigio); 965 break; 966 967 case BIOCSRSIG: /* Set receive signal */ 968 { 969 u_int sig; 970 971 sig = *(u_int *)ap->a_data; 972 973 if (sig >= NSIG) 974 error = EINVAL; 975 else 976 d->bd_sig = sig; 977 break; 978 } 979 case BIOCGRSIG: 980 *(u_int *)ap->a_data = d->bd_sig; 981 break; 982 case BIOCLOCK: 983 d->bd_locked = 1; 984 break; 985 } 986 lwkt_reltoken(&bpf_token); 987 988 return(error); 989 } 990 991 /* 992 * Set d's packet filter program to fp. If this file already has a filter, 993 * free it and replace it. Returns EINVAL for bogus requests. 994 */ 995 static int 996 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 997 { 998 struct bpf_insn *fcode, *old; 999 u_int wfilter, flen, size; 1000 1001 if (cmd == BIOCSETWF) { 1002 old = d->bd_wfilter; 1003 wfilter = 1; 1004 } else { 1005 wfilter = 0; 1006 old = d->bd_rfilter; 1007 } 1008 if (fp->bf_insns == NULL) { 1009 if (fp->bf_len != 0) 1010 return(EINVAL); 1011 crit_enter(); 1012 if (wfilter) 1013 d->bd_wfilter = NULL; 1014 else 1015 d->bd_rfilter = NULL; 1016 bpf_resetd(d); 1017 crit_exit(); 1018 if (old != NULL) 1019 kfree(old, M_BPF); 1020 return(0); 1021 } 1022 flen = fp->bf_len; 1023 if (flen > BPF_MAXINSNS) 1024 return(EINVAL); 1025 1026 size = flen * sizeof *fp->bf_insns; 1027 fcode = (struct bpf_insn *)kmalloc(size, M_BPF, M_WAITOK); 1028 if (copyin(fp->bf_insns, fcode, size) == 0 && 1029 bpf_validate(fcode, (int)flen)) { 1030 crit_enter(); 1031 if (wfilter) 1032 d->bd_wfilter = fcode; 1033 else 1034 d->bd_rfilter = fcode; 1035 bpf_resetd(d); 1036 crit_exit(); 1037 if (old != NULL) 1038 kfree(old, M_BPF); 1039 1040 return(0); 1041 } 1042 kfree(fcode, M_BPF); 1043 return(EINVAL); 1044 } 1045 1046 /* 1047 * Detach a file from its current interface (if attached at all) and attach 1048 * to the interface indicated by the name stored in ifr. 1049 * Return an errno or 0. 1050 */ 1051 static int 1052 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 1053 { 1054 struct bpf_if *bp; 1055 int error; 1056 struct ifnet *theywant; 1057 1058 theywant = ifunit(ifr->ifr_name); 1059 if (theywant == NULL) 1060 return(ENXIO); 1061 1062 /* 1063 * Look through attached interfaces for the named one. 1064 */ 1065 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1066 struct ifnet *ifp = bp->bif_ifp; 1067 1068 if (ifp == NULL || ifp != theywant) 1069 continue; 1070 /* skip additional entry */ 1071 if (bp->bif_driverp != &ifp->if_bpf) 1072 continue; 1073 /* 1074 * We found the requested interface. 1075 * Allocate the packet buffers if we need to. 1076 * If we're already attached to requested interface, 1077 * just flush the buffer. 1078 */ 1079 if (d->bd_sbuf == NULL) { 1080 error = bpf_allocbufs(d); 1081 if (error != 0) 1082 return(error); 1083 } 1084 crit_enter(); 1085 if (bp != d->bd_bif) { 1086 if (d->bd_bif != NULL) { 1087 /* 1088 * Detach if attached to something else. 1089 */ 1090 bpf_detachd(d); 1091 } 1092 1093 bpf_attachd(d, bp); 1094 } 1095 bpf_resetd(d); 1096 crit_exit(); 1097 return(0); 1098 } 1099 1100 /* Not found. */ 1101 return(ENXIO); 1102 } 1103 1104 static struct filterops bpf_read_filtops = 1105 { FILTEROP_ISFD, NULL, bpf_filter_detach, bpf_filter_read }; 1106 1107 static int 1108 bpfkqfilter(struct dev_kqfilter_args *ap) 1109 { 1110 cdev_t dev = ap->a_head.a_dev; 1111 struct knote *kn = ap->a_kn; 1112 struct klist *klist; 1113 struct bpf_d *d; 1114 1115 lwkt_gettoken(&bpf_token); 1116 d = dev->si_drv1; 1117 if (d->bd_bif == NULL) { 1118 ap->a_result = 1; 1119 lwkt_reltoken(&bpf_token); 1120 return (0); 1121 } 1122 1123 ap->a_result = 0; 1124 switch (kn->kn_filter) { 1125 case EVFILT_READ: 1126 kn->kn_fop = &bpf_read_filtops; 1127 kn->kn_hook = (caddr_t)d; 1128 break; 1129 default: 1130 ap->a_result = EOPNOTSUPP; 1131 lwkt_reltoken(&bpf_token); 1132 return (0); 1133 } 1134 1135 klist = &d->bd_kq.ki_note; 1136 knote_insert(klist, kn); 1137 lwkt_reltoken(&bpf_token); 1138 1139 return (0); 1140 } 1141 1142 static void 1143 bpf_filter_detach(struct knote *kn) 1144 { 1145 struct klist *klist; 1146 struct bpf_d *d; 1147 1148 d = (struct bpf_d *)kn->kn_hook; 1149 klist = &d->bd_kq.ki_note; 1150 knote_remove(klist, kn); 1151 } 1152 1153 static int 1154 bpf_filter_read(struct knote *kn, long hint) 1155 { 1156 struct bpf_d *d; 1157 int ready = 0; 1158 1159 crit_enter(); 1160 d = (struct bpf_d *)kn->kn_hook; 1161 if (d->bd_hlen != 0 || 1162 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1163 d->bd_slen != 0)) { 1164 ready = 1; 1165 } else { 1166 /* Start the read timeout if necessary. */ 1167 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1168 callout_reset(&d->bd_callout, d->bd_rtout, 1169 bpf_timed_out, d); 1170 d->bd_state = BPF_WAITING; 1171 } 1172 } 1173 crit_exit(); 1174 1175 return (ready); 1176 } 1177 1178 1179 /* 1180 * Process the packet pkt of length pktlen. The packet is parsed 1181 * by each listener's filter, and if accepted, stashed into the 1182 * corresponding buffer. 1183 */ 1184 void 1185 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1186 { 1187 struct bpf_d *d; 1188 struct timeval tv; 1189 int gottime = 0; 1190 u_int slen; 1191 1192 lwkt_gettoken(&bpf_token); 1193 /* Re-check */ 1194 if (bp == NULL) { 1195 lwkt_reltoken(&bpf_token); 1196 return; 1197 } 1198 1199 /* 1200 * Note that the ipl does not have to be raised at this point. 1201 * The only problem that could arise here is that if two different 1202 * interfaces shared any data. This is not the case. 1203 */ 1204 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1205 ++d->bd_rcount; 1206 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 1207 if (slen != 0) { 1208 if (!gottime) { 1209 microtime(&tv); 1210 gottime = 1; 1211 } 1212 catchpacket(d, pkt, pktlen, slen, ovbcopy, &tv); 1213 } 1214 } 1215 lwkt_reltoken(&bpf_token); 1216 } 1217 1218 /* 1219 * Copy data from an mbuf chain into a buffer. This code is derived 1220 * from m_copydata in sys/uipc_mbuf.c. 1221 */ 1222 static void 1223 bpf_mcopy(const void *src_arg, void *dst_arg, size_t len) 1224 { 1225 const struct mbuf *m; 1226 u_int count; 1227 u_char *dst; 1228 1229 m = src_arg; 1230 dst = dst_arg; 1231 while (len > 0) { 1232 if (m == NULL) 1233 panic("bpf_mcopy"); 1234 count = min(m->m_len, len); 1235 bcopy(mtod(m, void *), dst, count); 1236 m = m->m_next; 1237 dst += count; 1238 len -= count; 1239 } 1240 } 1241 1242 /* 1243 * Process the packet in the mbuf chain m. The packet is parsed by each 1244 * listener's filter, and if accepted, stashed into the corresponding 1245 * buffer. 1246 */ 1247 void 1248 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1249 { 1250 struct bpf_d *d; 1251 u_int pktlen, slen; 1252 struct timeval tv; 1253 int gottime = 0; 1254 1255 lwkt_gettoken(&bpf_token); 1256 /* Re-check */ 1257 if (bp == NULL) { 1258 lwkt_reltoken(&bpf_token); 1259 return; 1260 } 1261 1262 /* Don't compute pktlen, if no descriptor is attached. */ 1263 if (SLIST_EMPTY(&bp->bif_dlist)) { 1264 lwkt_reltoken(&bpf_token); 1265 return; 1266 } 1267 1268 pktlen = m_lengthm(m, NULL); 1269 1270 SLIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1271 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1272 continue; 1273 ++d->bd_rcount; 1274 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 1275 if (slen != 0) { 1276 if (!gottime) { 1277 microtime(&tv); 1278 gottime = 1; 1279 } 1280 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy, 1281 &tv); 1282 } 1283 } 1284 lwkt_reltoken(&bpf_token); 1285 } 1286 1287 /* 1288 * Incoming linkage from device drivers, where we have a mbuf chain 1289 * but need to prepend some arbitrary header from a linear buffer. 1290 * 1291 * Con up a minimal dummy header to pacify bpf. Allocate (only) a 1292 * struct m_hdr on the stack. This is safe as bpf only reads from the 1293 * fields in this header that we initialize, and will not try to free 1294 * it or keep a pointer to it. 1295 */ 1296 void 1297 bpf_mtap_hdr(struct bpf_if *arg, caddr_t data, u_int dlen, struct mbuf *m, u_int direction) 1298 { 1299 struct m_hdr mh; 1300 1301 mh.mh_flags = 0; 1302 mh.mh_next = m; 1303 mh.mh_len = dlen; 1304 mh.mh_data = data; 1305 1306 return bpf_mtap(arg, (struct mbuf *) &mh); 1307 } 1308 1309 void 1310 bpf_mtap_family(struct bpf_if *bp, struct mbuf *m, sa_family_t family) 1311 { 1312 u_int family4; 1313 1314 KKASSERT(family != AF_UNSPEC); 1315 1316 family4 = (u_int)family; 1317 bpf_ptap(bp, m, &family4, sizeof(family4)); 1318 } 1319 1320 /* 1321 * Process the packet in the mbuf chain m with the header in m prepended. 1322 * The packet is parsed by each listener's filter, and if accepted, 1323 * stashed into the corresponding buffer. 1324 */ 1325 void 1326 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen) 1327 { 1328 struct mbuf mb; 1329 1330 /* 1331 * Craft on-stack mbuf suitable for passing to bpf_mtap. 1332 * Note that we cut corners here; we only setup what's 1333 * absolutely needed--this mbuf should never go anywhere else. 1334 */ 1335 mb.m_next = m; 1336 mb.m_data = __DECONST(void *, data); /* LINTED */ 1337 mb.m_len = dlen; 1338 mb.m_pkthdr.rcvif = m->m_pkthdr.rcvif; 1339 1340 bpf_mtap(bp, &mb); 1341 } 1342 1343 /* 1344 * Move the packet data from interface memory (pkt) into the 1345 * store buffer. Return 1 if it's time to wakeup a listener (buffer full), 1346 * otherwise 0. "copy" is the routine called to do the actual data 1347 * transfer. bcopy is passed in to copy contiguous chunks, while 1348 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1349 * pkt is really an mbuf. 1350 */ 1351 static void 1352 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 1353 void (*cpfn)(const void *, void *, size_t), 1354 const struct timeval *tv) 1355 { 1356 struct bpf_hdr *hp; 1357 int totlen, curlen; 1358 int hdrlen = d->bd_bif->bif_hdrlen; 1359 int wakeup = 0; 1360 /* 1361 * Figure out how many bytes to move. If the packet is 1362 * greater or equal to the snapshot length, transfer that 1363 * much. Otherwise, transfer the whole packet (unless 1364 * we hit the buffer size limit). 1365 */ 1366 totlen = hdrlen + min(snaplen, pktlen); 1367 if (totlen > d->bd_bufsize) 1368 totlen = d->bd_bufsize; 1369 1370 /* 1371 * Round up the end of the previous packet to the next longword. 1372 */ 1373 curlen = BPF_WORDALIGN(d->bd_slen); 1374 if (curlen + totlen > d->bd_bufsize) { 1375 /* 1376 * This packet will overflow the storage buffer. 1377 * Rotate the buffers if we can, then wakeup any 1378 * pending reads. 1379 */ 1380 if (d->bd_fbuf == NULL) { 1381 /* 1382 * We haven't completed the previous read yet, 1383 * so drop the packet. 1384 */ 1385 ++d->bd_dcount; 1386 return; 1387 } 1388 ROTATE_BUFFERS(d); 1389 wakeup = 1; 1390 curlen = 0; 1391 } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) { 1392 /* 1393 * Immediate mode is set, or the read timeout has 1394 * already expired during a select call. A packet 1395 * arrived, so the reader should be woken up. 1396 */ 1397 wakeup = 1; 1398 } 1399 1400 /* 1401 * Append the bpf header. 1402 */ 1403 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1404 hp->bh_tstamp = *tv; 1405 hp->bh_datalen = pktlen; 1406 hp->bh_hdrlen = hdrlen; 1407 /* 1408 * Copy the packet data into the store buffer and update its length. 1409 */ 1410 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1411 d->bd_slen = curlen + totlen; 1412 1413 if (wakeup) 1414 bpf_wakeup(d); 1415 } 1416 1417 /* 1418 * Initialize all nonzero fields of a descriptor. 1419 */ 1420 static int 1421 bpf_allocbufs(struct bpf_d *d) 1422 { 1423 d->bd_fbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK); 1424 d->bd_sbuf = kmalloc(d->bd_bufsize, M_BPF, M_WAITOK); 1425 d->bd_slen = 0; 1426 d->bd_hlen = 0; 1427 return(0); 1428 } 1429 1430 /* 1431 * Free buffers and packet filter program currently in use by a descriptor. 1432 * Called on close. 1433 */ 1434 static void 1435 bpf_freed(struct bpf_d *d) 1436 { 1437 /* 1438 * We don't need to lock out interrupts since this descriptor has 1439 * been detached from its interface and it yet hasn't been marked 1440 * free. 1441 */ 1442 if (d->bd_sbuf != NULL) { 1443 kfree(d->bd_sbuf, M_BPF); 1444 if (d->bd_hbuf != NULL) 1445 kfree(d->bd_hbuf, M_BPF); 1446 if (d->bd_fbuf != NULL) 1447 kfree(d->bd_fbuf, M_BPF); 1448 } 1449 if (d->bd_rfilter) 1450 kfree(d->bd_rfilter, M_BPF); 1451 if (d->bd_wfilter) 1452 kfree(d->bd_wfilter, M_BPF); 1453 } 1454 1455 /* 1456 * Attach an interface to bpf. ifp is a pointer to the structure 1457 * defining the interface to be attached, dlt is the link layer type, 1458 * and hdrlen is the fixed size of the link header (variable length 1459 * headers are not yet supported). 1460 */ 1461 void 1462 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1463 { 1464 bpfattach_dlt(ifp, dlt, hdrlen, &ifp->if_bpf); 1465 } 1466 1467 void 1468 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1469 { 1470 struct bpf_if *bp; 1471 1472 bp = kmalloc(sizeof *bp, M_BPF, M_WAITOK | M_ZERO); 1473 1474 lwkt_gettoken(&bpf_token); 1475 1476 SLIST_INIT(&bp->bif_dlist); 1477 bp->bif_ifp = ifp; 1478 bp->bif_dlt = dlt; 1479 bp->bif_driverp = driverp; 1480 *bp->bif_driverp = NULL; 1481 1482 bp->bif_next = bpf_iflist; 1483 bpf_iflist = bp; 1484 1485 /* 1486 * Compute the length of the bpf header. This is not necessarily 1487 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1488 * that the network layer header begins on a longword boundary (for 1489 * performance reasons and to alleviate alignment restrictions). 1490 */ 1491 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1492 1493 lwkt_reltoken(&bpf_token); 1494 1495 if (bootverbose) 1496 if_printf(ifp, "bpf attached\n"); 1497 } 1498 1499 /* 1500 * Detach bpf from an interface. This involves detaching each descriptor 1501 * associated with the interface, and leaving bd_bif NULL. Notify each 1502 * descriptor as it's detached so that any sleepers wake up and get 1503 * ENXIO. 1504 */ 1505 void 1506 bpfdetach(struct ifnet *ifp) 1507 { 1508 struct bpf_if *bp, *bp_prev; 1509 struct bpf_d *d; 1510 1511 lwkt_gettoken(&bpf_token); 1512 crit_enter(); 1513 1514 /* Locate BPF interface information */ 1515 bp_prev = NULL; 1516 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1517 if (ifp == bp->bif_ifp) 1518 break; 1519 bp_prev = bp; 1520 } 1521 1522 /* Interface wasn't attached */ 1523 if (bp->bif_ifp == NULL) { 1524 crit_exit(); 1525 lwkt_reltoken(&bpf_token); 1526 kprintf("bpfdetach: %s was not attached\n", ifp->if_xname); 1527 return; 1528 } 1529 1530 while ((d = SLIST_FIRST(&bp->bif_dlist)) != NULL) { 1531 bpf_detachd(d); 1532 bpf_wakeup(d); 1533 } 1534 1535 if (bp_prev != NULL) 1536 bp_prev->bif_next = bp->bif_next; 1537 else 1538 bpf_iflist = bp->bif_next; 1539 1540 kfree(bp, M_BPF); 1541 1542 crit_exit(); 1543 lwkt_reltoken(&bpf_token); 1544 } 1545 1546 /* 1547 * Get a list of available data link type of the interface. 1548 */ 1549 static int 1550 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 1551 { 1552 int n, error; 1553 struct ifnet *ifp; 1554 struct bpf_if *bp; 1555 1556 ifp = d->bd_bif->bif_ifp; 1557 n = 0; 1558 error = 0; 1559 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1560 if (bp->bif_ifp != ifp) 1561 continue; 1562 if (bfl->bfl_list != NULL) { 1563 if (n >= bfl->bfl_len) { 1564 return (ENOMEM); 1565 } 1566 error = copyout(&bp->bif_dlt, 1567 bfl->bfl_list + n, sizeof(u_int)); 1568 } 1569 n++; 1570 } 1571 bfl->bfl_len = n; 1572 return(error); 1573 } 1574 1575 /* 1576 * Set the data link type of a BPF instance. 1577 */ 1578 static int 1579 bpf_setdlt(struct bpf_d *d, u_int dlt) 1580 { 1581 int error, opromisc; 1582 struct ifnet *ifp; 1583 struct bpf_if *bp; 1584 1585 if (d->bd_bif->bif_dlt == dlt) 1586 return (0); 1587 ifp = d->bd_bif->bif_ifp; 1588 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1589 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1590 break; 1591 } 1592 if (bp != NULL) { 1593 opromisc = d->bd_promisc; 1594 crit_enter(); 1595 bpf_detachd(d); 1596 bpf_attachd(d, bp); 1597 bpf_resetd(d); 1598 if (opromisc) { 1599 error = ifpromisc(bp->bif_ifp, 1); 1600 if (error) { 1601 if_printf(bp->bif_ifp, 1602 "bpf_setdlt: ifpromisc failed (%d)\n", 1603 error); 1604 } else { 1605 d->bd_promisc = 1; 1606 } 1607 } 1608 crit_exit(); 1609 } 1610 return(bp == NULL ? EINVAL : 0); 1611 } 1612 1613 void 1614 bpf_gettoken(void) 1615 { 1616 lwkt_gettoken(&bpf_token); 1617 } 1618 1619 void 1620 bpf_reltoken(void) 1621 { 1622 lwkt_reltoken(&bpf_token); 1623 } 1624 1625 static void 1626 bpf_drvinit(void *unused) 1627 { 1628 int i; 1629 1630 make_autoclone_dev(&bpf_ops, &DEVFS_CLONE_BITMAP(bpf), 1631 bpfclone, 0, 0, 0600, "bpf"); 1632 for (i = 0; i < BPF_PREALLOCATED_UNITS; i++) { 1633 make_dev(&bpf_ops, i, 0, 0, 0600, "bpf%d", i); 1634 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(bpf), i); 1635 } 1636 } 1637 1638 static void 1639 bpf_drvuninit(void *unused) 1640 { 1641 devfs_clone_handler_del("bpf"); 1642 dev_ops_remove_all(&bpf_ops); 1643 devfs_clone_bitmap_uninit(&DEVFS_CLONE_BITMAP(bpf)); 1644 } 1645 1646 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL) 1647 SYSUNINIT(bpfdev, SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvuninit, NULL); 1648 1649 #else /* !BPF */ 1650 /* 1651 * NOP stubs to allow bpf-using drivers to load and function. 1652 * 1653 * A 'better' implementation would allow the core bpf functionality 1654 * to be loaded at runtime. 1655 */ 1656 1657 void 1658 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1659 { 1660 } 1661 1662 void 1663 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1664 { 1665 } 1666 1667 void 1668 bpf_ptap(struct bpf_if *bp, struct mbuf *m, const void *data, u_int dlen) 1669 { 1670 } 1671 1672 void 1673 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1674 { 1675 } 1676 1677 void 1678 bpfattach_dlt(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1679 { 1680 } 1681 1682 void 1683 bpfdetach(struct ifnet *ifp) 1684 { 1685 } 1686 1687 u_int 1688 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 1689 { 1690 return -1; /* "no filter" behaviour */ 1691 } 1692 1693 void 1694 bpf_gettoken(void) 1695 { 1696 } 1697 1698 void 1699 bpf_reltoken(void) 1700 { 1701 } 1702 1703 #endif /* !BPF */ 1704