Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/net/bpf.c
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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 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)bpf.c 8.4 (Berkeley) 1/9/95 35 * 36 * $FreeBSD$ 37 */ 38 39 #include "opt_bpf.h" 40 #include "opt_mac.h" 41 #include "opt_netgraph.h" 42 43 #include <sys/types.h> 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/conf.h> 47 #include <sys/fcntl.h> 48 #include <sys/mac.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/uio.h> 58 59 #include <sys/event.h> 60 #include <sys/file.h> 61 #include <sys/poll.h> 62 #include <sys/proc.h> 63 64 #include <sys/socket.h> 65 66 #include <net/if.h> 67 #include <net/bpf.h> 68 #include <net/bpfdesc.h> 69 70 #include <netinet/in.h> 71 #include <netinet/if_ether.h> 72 #include <sys/kernel.h> 73 #include <sys/sysctl.h> 74 75 static MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 76 77 #if defined(DEV_BPF) || defined(NETGRAPH_BPF) 78 79 #define PRINET 26 /* interruptible */ 80 81 /* 82 * bpf_iflist is a list of BPF interface structures, each corresponding to a 83 * specific DLT. The same network interface might have several BPF interface 84 * structures registered by different layers in the stack (i.e., 802.11 85 * frames, ethernet frames, etc). 86 */ 87 static LIST_HEAD(, bpf_if) bpf_iflist; 88 static struct mtx bpf_mtx; /* bpf global lock */ 89 static int bpf_bpfd_cnt; 90 91 static int bpf_allocbufs(struct bpf_d *); 92 static void bpf_attachd(struct bpf_d *, struct bpf_if *); 93 static void bpf_detachd(struct bpf_d *); 94 static void bpf_freed(struct bpf_d *); 95 static void bpf_mcopy(const void *, void *, size_t); 96 static int bpf_movein(struct uio *, int, struct ifnet *, 97 struct mbuf **, struct sockaddr *, struct bpf_insn *); 98 static int bpf_setif(struct bpf_d *, struct ifreq *); 99 static void bpf_timed_out(void *); 100 static __inline void 101 bpf_wakeup(struct bpf_d *); 102 static void catchpacket(struct bpf_d *, u_char *, u_int, 103 u_int, void (*)(const void *, void *, size_t), 104 struct timeval *); 105 static void reset_d(struct bpf_d *); 106 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 107 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 108 static int bpf_setdlt(struct bpf_d *, u_int); 109 static void filt_bpfdetach(struct knote *); 110 static int filt_bpfread(struct knote *, long); 111 static void bpf_drvinit(void *); 112 static void bpf_clone(void *, struct ucred *, char *, int, struct cdev **); 113 static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); 114 115 /* 116 * The default read buffer size is patchable. 117 */ 118 SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl"); 119 static int bpf_bufsize = 4096; 120 SYSCTL_INT(_net_bpf, OID_AUTO, bufsize, CTLFLAG_RW, 121 &bpf_bufsize, 0, ""); 122 static int bpf_maxbufsize = BPF_MAXBUFSIZE; 123 SYSCTL_INT(_net_bpf, OID_AUTO, maxbufsize, CTLFLAG_RW, 124 &bpf_maxbufsize, 0, ""); 125 static int bpf_maxinsns = BPF_MAXINSNS; 126 SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, 127 &bpf_maxinsns, 0, "Maximum bpf program instructions"); 128 SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_RW, 129 bpf_stats_sysctl, "bpf statistics portal"); 130 131 static d_open_t bpfopen; 132 static d_close_t bpfclose; 133 static d_read_t bpfread; 134 static d_write_t bpfwrite; 135 static d_ioctl_t bpfioctl; 136 static d_poll_t bpfpoll; 137 static d_kqfilter_t bpfkqfilter; 138 139 static struct cdevsw bpf_cdevsw = { 140 .d_version = D_VERSION, 141 .d_flags = D_NEEDGIANT | D_TRACKCLOSE, 142 .d_open = bpfopen, 143 .d_close = bpfclose, 144 .d_read = bpfread, 145 .d_write = bpfwrite, 146 .d_ioctl = bpfioctl, 147 .d_poll = bpfpoll, 148 .d_name = "bpf", 149 .d_kqfilter = bpfkqfilter, 150 }; 151 152 static struct filterops bpfread_filtops = 153 { 1, NULL, filt_bpfdetach, filt_bpfread }; 154 155 static int 156 bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, 157 struct sockaddr *sockp, struct bpf_insn *wfilter) 158 { 159 struct ether_header *eh; 160 struct mbuf *m; 161 int error; 162 int len; 163 int hlen; 164 int slen; 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) { 176 177 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 = ETHER_HDR_LEN; 186 break; 187 188 case DLT_FDDI: 189 sockp->sa_family = AF_IMPLINK; 190 hlen = 0; 191 break; 192 193 case DLT_RAW: 194 sockp->sa_family = AF_UNSPEC; 195 hlen = 0; 196 break; 197 198 case DLT_NULL: 199 /* 200 * null interface types require a 4 byte pseudo header which 201 * corresponds to the address family of the packet. 202 */ 203 sockp->sa_family = AF_UNSPEC; 204 hlen = 4; 205 break; 206 207 case DLT_ATM_RFC1483: 208 /* 209 * en atm driver requires 4-byte atm pseudo header. 210 * though it isn't standard, vpi:vci needs to be 211 * specified anyway. 212 */ 213 sockp->sa_family = AF_UNSPEC; 214 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 215 break; 216 217 case DLT_PPP: 218 sockp->sa_family = AF_UNSPEC; 219 hlen = 4; /* This should match PPP_HDRLEN */ 220 break; 221 222 default: 223 return (EIO); 224 } 225 226 len = uio->uio_resid; 227 228 if (len - hlen > ifp->if_mtu) 229 return (EMSGSIZE); 230 231 if ((unsigned)len > MJUM16BYTES) 232 return (EIO); 233 234 if (len <= MHLEN) 235 MGETHDR(m, M_TRYWAIT, MT_DATA); 236 else if (len <= MCLBYTES) 237 m = m_getcl(M_TRYWAIT, MT_DATA, M_PKTHDR); 238 else 239 m = m_getjcl(M_TRYWAIT, MT_DATA, M_PKTHDR, 240 #if (MJUMPAGESIZE > MCLBYTES) 241 len <= MJUMPAGESIZE ? MJUMPAGESIZE : 242 #endif 243 (len <= MJUM9BYTES ? MJUM9BYTES : MJUM16BYTES)); 244 if (m == NULL) 245 return (ENOBUFS); 246 m->m_pkthdr.len = m->m_len = len; 247 m->m_pkthdr.rcvif = NULL; 248 *mp = m; 249 250 if (m->m_len < hlen) { 251 error = EPERM; 252 goto bad; 253 } 254 255 error = uiomove(mtod(m, u_char *), len, uio); 256 if (error) 257 goto bad; 258 259 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len); 260 if (slen == 0) { 261 error = EPERM; 262 goto bad; 263 } 264 265 /* Check for multicast destination */ 266 switch (linktype) { 267 case DLT_EN10MB: 268 eh = mtod(m, struct ether_header *); 269 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 270 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, 271 ETHER_ADDR_LEN) == 0) 272 m->m_flags |= M_BCAST; 273 else 274 m->m_flags |= M_MCAST; 275 } 276 break; 277 } 278 279 /* 280 * Make room for link header, and copy it to sockaddr 281 */ 282 if (hlen != 0) { 283 bcopy(m->m_data, sockp->sa_data, hlen); 284 m->m_pkthdr.len -= hlen; 285 m->m_len -= hlen; 286 #if BSD >= 199103 287 m->m_data += hlen; /* XXX */ 288 #else 289 m->m_off += hlen; 290 #endif 291 } 292 293 return (0); 294 bad: 295 m_freem(m); 296 return (error); 297 } 298 299 /* 300 * Attach file to the bpf interface, i.e. make d listen on bp. 301 */ 302 static void 303 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 304 { 305 /* 306 * Point d at bp, and add d to the interface's list of listeners. 307 * Finally, point the driver's bpf cookie at the interface so 308 * it will divert packets to bpf. 309 */ 310 BPFIF_LOCK(bp); 311 d->bd_bif = bp; 312 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 313 314 bpf_bpfd_cnt++; 315 BPFIF_UNLOCK(bp); 316 } 317 318 /* 319 * Detach a file from its interface. 320 */ 321 static void 322 bpf_detachd(struct bpf_d *d) 323 { 324 int error; 325 struct bpf_if *bp; 326 struct ifnet *ifp; 327 328 bp = d->bd_bif; 329 BPFIF_LOCK(bp); 330 BPFD_LOCK(d); 331 ifp = d->bd_bif->bif_ifp; 332 333 /* 334 * Remove d from the interface's descriptor list. 335 */ 336 LIST_REMOVE(d, bd_next); 337 338 bpf_bpfd_cnt--; 339 d->bd_bif = NULL; 340 BPFD_UNLOCK(d); 341 BPFIF_UNLOCK(bp); 342 343 /* 344 * Check if this descriptor had requested promiscuous mode. 345 * If so, turn it off. 346 */ 347 if (d->bd_promisc) { 348 d->bd_promisc = 0; 349 error = ifpromisc(ifp, 0); 350 if (error != 0 && error != ENXIO) { 351 /* 352 * ENXIO can happen if a pccard is unplugged 353 * Something is really wrong if we were able to put 354 * the driver into promiscuous mode, but can't 355 * take it out. 356 */ 357 if_printf(bp->bif_ifp, 358 "bpf_detach: ifpromisc failed (%d)\n", error); 359 } 360 } 361 } 362 363 /* 364 * Open ethernet device. Returns ENXIO for illegal minor device number, 365 * EBUSY if file is open by another process. 366 */ 367 /* ARGSUSED */ 368 static int 369 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 370 { 371 struct bpf_d *d; 372 373 mtx_lock(&bpf_mtx); 374 d = dev->si_drv1; 375 /* 376 * Each minor can be opened by only one process. If the requested 377 * minor is in use, return EBUSY. 378 */ 379 if (d != NULL) { 380 mtx_unlock(&bpf_mtx); 381 return (EBUSY); 382 } 383 dev->si_drv1 = (struct bpf_d *)~0; /* mark device in use */ 384 mtx_unlock(&bpf_mtx); 385 386 if ((dev->si_flags & SI_NAMED) == 0) 387 make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600, 388 "bpf%d", dev2unit(dev)); 389 MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 390 dev->si_drv1 = d; 391 d->bd_bufsize = bpf_bufsize; 392 d->bd_sig = SIGIO; 393 d->bd_seesent = 1; 394 d->bd_pid = td->td_proc->p_pid; 395 strlcpy(d->bd_pcomm, td->td_proc->p_comm, MAXCOMLEN); 396 #ifdef MAC 397 mac_init_bpfdesc(d); 398 mac_create_bpfdesc(td->td_ucred, d); 399 #endif 400 mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF); 401 callout_init_mtx(&d->bd_callout, &d->bd_mtx, 0); 402 knlist_init(&d->bd_sel.si_note, &d->bd_mtx, NULL, NULL, NULL); 403 404 return (0); 405 } 406 407 /* 408 * Close the descriptor by detaching it from its interface, 409 * deallocating its buffers, and marking it free. 410 */ 411 /* ARGSUSED */ 412 static int 413 bpfclose(struct cdev *dev, int flags, int fmt, struct thread *td) 414 { 415 struct bpf_d *d = dev->si_drv1; 416 417 BPFD_LOCK(d); 418 if (d->bd_state == BPF_WAITING) 419 callout_stop(&d->bd_callout); 420 d->bd_state = BPF_IDLE; 421 BPFD_UNLOCK(d); 422 funsetown(&d->bd_sigio); 423 mtx_lock(&bpf_mtx); 424 if (d->bd_bif) 425 bpf_detachd(d); 426 mtx_unlock(&bpf_mtx); 427 selwakeuppri(&d->bd_sel, PRINET); 428 #ifdef MAC 429 mac_destroy_bpfdesc(d); 430 #endif /* MAC */ 431 knlist_destroy(&d->bd_sel.si_note); 432 callout_drain(&d->bd_callout); 433 bpf_freed(d); 434 dev->si_drv1 = NULL; 435 free(d, M_BPF); 436 437 return (0); 438 } 439 440 441 /* 442 * Rotate the packet buffers in descriptor d. Move the store buffer 443 * into the hold slot, and the free buffer into the store slot. 444 * Zero the length of the new store buffer. 445 */ 446 #define ROTATE_BUFFERS(d) \ 447 (d)->bd_hbuf = (d)->bd_sbuf; \ 448 (d)->bd_hlen = (d)->bd_slen; \ 449 (d)->bd_sbuf = (d)->bd_fbuf; \ 450 (d)->bd_slen = 0; \ 451 (d)->bd_fbuf = NULL; 452 /* 453 * bpfread - read next chunk of packets from buffers 454 */ 455 static int 456 bpfread(struct cdev *dev, struct uio *uio, int ioflag) 457 { 458 struct bpf_d *d = dev->si_drv1; 459 int error; 460 int non_block; 461 int timed_out; 462 463 /* 464 * Restrict application to use a buffer the same size as 465 * as kernel buffers. 466 */ 467 if (uio->uio_resid != d->bd_bufsize) 468 return (EINVAL); 469 470 non_block = ((ioflag & O_NONBLOCK) != 0); 471 472 BPFD_LOCK(d); 473 d->bd_pid = curthread->td_proc->p_pid; 474 if (d->bd_state == BPF_WAITING) 475 callout_stop(&d->bd_callout); 476 timed_out = (d->bd_state == BPF_TIMED_OUT); 477 d->bd_state = BPF_IDLE; 478 /* 479 * If the hold buffer is empty, then do a timed sleep, which 480 * ends when the timeout expires or when enough packets 481 * have arrived to fill the store buffer. 482 */ 483 while (d->bd_hbuf == NULL) { 484 if (d->bd_slen != 0) { 485 /* 486 * A packet(s) either arrived since the previous 487 * read or arrived while we were asleep. 488 */ 489 if (d->bd_immediate || non_block || timed_out) { 490 /* 491 * Rotate the buffers and return what's here 492 * if we are in immediate mode, non-blocking 493 * flag is set, or this descriptor timed out. 494 */ 495 ROTATE_BUFFERS(d); 496 break; 497 } 498 } 499 500 /* 501 * No data is available, check to see if the bpf device 502 * is still pointed at a real interface. If not, return 503 * ENXIO so that the userland process knows to rebind 504 * it before using it again. 505 */ 506 if (d->bd_bif == NULL) { 507 BPFD_UNLOCK(d); 508 return (ENXIO); 509 } 510 511 if (non_block) { 512 BPFD_UNLOCK(d); 513 return (EWOULDBLOCK); 514 } 515 error = msleep(d, &d->bd_mtx, PRINET|PCATCH, 516 "bpf", d->bd_rtout); 517 if (error == EINTR || error == ERESTART) { 518 BPFD_UNLOCK(d); 519 return (error); 520 } 521 if (error == EWOULDBLOCK) { 522 /* 523 * On a timeout, return what's in the buffer, 524 * which may be nothing. If there is something 525 * in the store buffer, we can rotate the buffers. 526 */ 527 if (d->bd_hbuf) 528 /* 529 * We filled up the buffer in between 530 * getting the timeout and arriving 531 * here, so we don't need to rotate. 532 */ 533 break; 534 535 if (d->bd_slen == 0) { 536 BPFD_UNLOCK(d); 537 return (0); 538 } 539 ROTATE_BUFFERS(d); 540 break; 541 } 542 } 543 /* 544 * At this point, we know we have something in the hold slot. 545 */ 546 BPFD_UNLOCK(d); 547 548 /* 549 * Move data from hold buffer into user space. 550 * We know the entire buffer is transferred since 551 * we checked above that the read buffer is bpf_bufsize bytes. 552 */ 553 error = uiomove(d->bd_hbuf, d->bd_hlen, uio); 554 555 BPFD_LOCK(d); 556 d->bd_fbuf = d->bd_hbuf; 557 d->bd_hbuf = NULL; 558 d->bd_hlen = 0; 559 BPFD_UNLOCK(d); 560 561 return (error); 562 } 563 564 565 /* 566 * If there are processes sleeping on this descriptor, wake them up. 567 */ 568 static __inline void 569 bpf_wakeup(struct bpf_d *d) 570 { 571 572 BPFD_LOCK_ASSERT(d); 573 if (d->bd_state == BPF_WAITING) { 574 callout_stop(&d->bd_callout); 575 d->bd_state = BPF_IDLE; 576 } 577 wakeup(d); 578 if (d->bd_async && d->bd_sig && d->bd_sigio) 579 pgsigio(&d->bd_sigio, d->bd_sig, 0); 580 581 selwakeuppri(&d->bd_sel, PRINET); 582 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 583 } 584 585 static void 586 bpf_timed_out(void *arg) 587 { 588 struct bpf_d *d = (struct bpf_d *)arg; 589 590 BPFD_LOCK_ASSERT(d); 591 592 if (callout_pending(&d->bd_callout) || !callout_active(&d->bd_callout)) 593 return; 594 if (d->bd_state == BPF_WAITING) { 595 d->bd_state = BPF_TIMED_OUT; 596 if (d->bd_slen != 0) 597 bpf_wakeup(d); 598 } 599 } 600 601 static int 602 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 603 { 604 struct bpf_d *d = dev->si_drv1; 605 struct ifnet *ifp; 606 struct mbuf *m; 607 int error; 608 struct sockaddr dst; 609 610 d->bd_pid = curthread->td_proc->p_pid; 611 if (d->bd_bif == NULL) 612 return (ENXIO); 613 614 ifp = d->bd_bif->bif_ifp; 615 616 if ((ifp->if_flags & IFF_UP) == 0) 617 return (ENETDOWN); 618 619 if (uio->uio_resid == 0) 620 return (0); 621 622 bzero(&dst, sizeof(dst)); 623 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp, 624 &m, &dst, d->bd_wfilter); 625 if (error) 626 return (error); 627 628 if (d->bd_hdrcmplt) 629 dst.sa_family = pseudo_AF_HDRCMPLT; 630 631 #ifdef MAC 632 BPFD_LOCK(d); 633 mac_create_mbuf_from_bpfdesc(d, m); 634 BPFD_UNLOCK(d); 635 #endif 636 NET_LOCK_GIANT(); 637 error = (*ifp->if_output)(ifp, m, &dst, NULL); 638 NET_UNLOCK_GIANT(); 639 /* 640 * The driver frees the mbuf. 641 */ 642 return (error); 643 } 644 645 /* 646 * Reset a descriptor by flushing its packet buffer and clearing the 647 * receive and drop counts. 648 */ 649 static void 650 reset_d(struct bpf_d *d) 651 { 652 653 mtx_assert(&d->bd_mtx, MA_OWNED); 654 if (d->bd_hbuf) { 655 /* Free the hold buffer. */ 656 d->bd_fbuf = d->bd_hbuf; 657 d->bd_hbuf = NULL; 658 } 659 d->bd_slen = 0; 660 d->bd_hlen = 0; 661 d->bd_rcount = 0; 662 d->bd_dcount = 0; 663 d->bd_fcount = 0; 664 } 665 666 /* 667 * FIONREAD Check for read packet available. 668 * SIOCGIFADDR Get interface address - convenient hook to driver. 669 * BIOCGBLEN Get buffer len [for read()]. 670 * BIOCSETF Set ethernet read filter. 671 * BIOCSETWF Set ethernet write filter. 672 * BIOCFLUSH Flush read packet buffer. 673 * BIOCPROMISC Put interface into promiscuous mode. 674 * BIOCGDLT Get link layer type. 675 * BIOCGETIF Get interface name. 676 * BIOCSETIF Set interface. 677 * BIOCSRTIMEOUT Set read timeout. 678 * BIOCGRTIMEOUT Get read timeout. 679 * BIOCGSTATS Get packet stats. 680 * BIOCIMMEDIATE Set immediate mode. 681 * BIOCVERSION Get filter language version. 682 * BIOCGHDRCMPLT Get "header already complete" flag 683 * BIOCSHDRCMPLT Set "header already complete" flag 684 * BIOCGSEESENT Get "see packets sent" flag 685 * BIOCSSEESENT Set "see packets sent" flag 686 * BIOCLOCK Set "locked" flag 687 */ 688 /* ARGSUSED */ 689 static int 690 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 691 struct thread *td) 692 { 693 struct bpf_d *d = dev->si_drv1; 694 int error = 0; 695 696 /* 697 * Refresh PID associated with this descriptor. 698 */ 699 d->bd_pid = td->td_proc->p_pid; 700 BPFD_LOCK(d); 701 if (d->bd_state == BPF_WAITING) 702 callout_stop(&d->bd_callout); 703 d->bd_state = BPF_IDLE; 704 BPFD_UNLOCK(d); 705 706 if (d->bd_locked == 1) { 707 switch (cmd) { 708 case BIOCGBLEN: 709 case BIOCFLUSH: 710 case BIOCGDLT: 711 case BIOCGDLTLIST: 712 case BIOCGETIF: 713 case BIOCGRTIMEOUT: 714 case BIOCGSTATS: 715 case BIOCVERSION: 716 case BIOCGRSIG: 717 case BIOCGHDRCMPLT: 718 case FIONREAD: 719 case BIOCLOCK: 720 case BIOCSRTIMEOUT: 721 case BIOCIMMEDIATE: 722 case TIOCGPGRP: 723 break; 724 default: 725 return (EPERM); 726 } 727 } 728 switch (cmd) { 729 730 default: 731 error = EINVAL; 732 break; 733 734 /* 735 * Check for read packet available. 736 */ 737 case FIONREAD: 738 { 739 int n; 740 741 BPFD_LOCK(d); 742 n = d->bd_slen; 743 if (d->bd_hbuf) 744 n += d->bd_hlen; 745 BPFD_UNLOCK(d); 746 747 *(int *)addr = n; 748 break; 749 } 750 751 case SIOCGIFADDR: 752 { 753 struct ifnet *ifp; 754 755 if (d->bd_bif == NULL) 756 error = EINVAL; 757 else { 758 ifp = d->bd_bif->bif_ifp; 759 error = (*ifp->if_ioctl)(ifp, cmd, addr); 760 } 761 break; 762 } 763 764 /* 765 * Get buffer len [for read()]. 766 */ 767 case BIOCGBLEN: 768 *(u_int *)addr = d->bd_bufsize; 769 break; 770 771 /* 772 * Set buffer length. 773 */ 774 case BIOCSBLEN: 775 if (d->bd_bif != NULL) 776 error = EINVAL; 777 else { 778 u_int size = *(u_int *)addr; 779 780 if (size > bpf_maxbufsize) 781 *(u_int *)addr = size = bpf_maxbufsize; 782 else if (size < BPF_MINBUFSIZE) 783 *(u_int *)addr = size = BPF_MINBUFSIZE; 784 d->bd_bufsize = size; 785 } 786 break; 787 788 /* 789 * Set link layer read filter. 790 */ 791 case BIOCSETF: 792 case BIOCSETWF: 793 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 794 break; 795 796 /* 797 * Flush read packet buffer. 798 */ 799 case BIOCFLUSH: 800 BPFD_LOCK(d); 801 reset_d(d); 802 BPFD_UNLOCK(d); 803 break; 804 805 /* 806 * Put interface into promiscuous mode. 807 */ 808 case BIOCPROMISC: 809 if (d->bd_bif == NULL) { 810 /* 811 * No interface attached yet. 812 */ 813 error = EINVAL; 814 break; 815 } 816 if (d->bd_promisc == 0) { 817 mtx_lock(&Giant); 818 error = ifpromisc(d->bd_bif->bif_ifp, 1); 819 mtx_unlock(&Giant); 820 if (error == 0) 821 d->bd_promisc = 1; 822 } 823 break; 824 825 /* 826 * Get current data link type. 827 */ 828 case BIOCGDLT: 829 if (d->bd_bif == NULL) 830 error = EINVAL; 831 else 832 *(u_int *)addr = d->bd_bif->bif_dlt; 833 break; 834 835 /* 836 * Get a list of supported data link types. 837 */ 838 case BIOCGDLTLIST: 839 if (d->bd_bif == NULL) 840 error = EINVAL; 841 else 842 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 843 break; 844 845 /* 846 * Set data link type. 847 */ 848 case BIOCSDLT: 849 if (d->bd_bif == NULL) 850 error = EINVAL; 851 else 852 error = bpf_setdlt(d, *(u_int *)addr); 853 break; 854 855 /* 856 * Get interface name. 857 */ 858 case BIOCGETIF: 859 if (d->bd_bif == NULL) 860 error = EINVAL; 861 else { 862 struct ifnet *const ifp = d->bd_bif->bif_ifp; 863 struct ifreq *const ifr = (struct ifreq *)addr; 864 865 strlcpy(ifr->ifr_name, ifp->if_xname, 866 sizeof(ifr->ifr_name)); 867 } 868 break; 869 870 /* 871 * Set interface. 872 */ 873 case BIOCSETIF: 874 error = bpf_setif(d, (struct ifreq *)addr); 875 break; 876 877 /* 878 * Set read timeout. 879 */ 880 case BIOCSRTIMEOUT: 881 { 882 struct timeval *tv = (struct timeval *)addr; 883 884 /* 885 * Subtract 1 tick from tvtohz() since this isn't 886 * a one-shot timer. 887 */ 888 if ((error = itimerfix(tv)) == 0) 889 d->bd_rtout = tvtohz(tv) - 1; 890 break; 891 } 892 893 /* 894 * Get read timeout. 895 */ 896 case BIOCGRTIMEOUT: 897 { 898 struct timeval *tv = (struct timeval *)addr; 899 900 tv->tv_sec = d->bd_rtout / hz; 901 tv->tv_usec = (d->bd_rtout % hz) * tick; 902 break; 903 } 904 905 /* 906 * Get packet stats. 907 */ 908 case BIOCGSTATS: 909 { 910 struct bpf_stat *bs = (struct bpf_stat *)addr; 911 912 bs->bs_recv = d->bd_rcount; 913 bs->bs_drop = d->bd_dcount; 914 break; 915 } 916 917 /* 918 * Set immediate mode. 919 */ 920 case BIOCIMMEDIATE: 921 d->bd_immediate = *(u_int *)addr; 922 break; 923 924 case BIOCVERSION: 925 { 926 struct bpf_version *bv = (struct bpf_version *)addr; 927 928 bv->bv_major = BPF_MAJOR_VERSION; 929 bv->bv_minor = BPF_MINOR_VERSION; 930 break; 931 } 932 933 /* 934 * Get "header already complete" flag 935 */ 936 case BIOCGHDRCMPLT: 937 *(u_int *)addr = d->bd_hdrcmplt; 938 break; 939 940 case BIOCLOCK: 941 d->bd_locked = 1; 942 break; 943 /* 944 * Set "header already complete" flag 945 */ 946 case BIOCSHDRCMPLT: 947 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 948 break; 949 950 /* 951 * Get "see sent packets" flag 952 */ 953 case BIOCGSEESENT: 954 *(u_int *)addr = d->bd_seesent; 955 break; 956 957 /* 958 * Set "see sent packets" flag 959 */ 960 case BIOCSSEESENT: 961 d->bd_seesent = *(u_int *)addr; 962 break; 963 964 case FIONBIO: /* Non-blocking I/O */ 965 break; 966 967 case FIOASYNC: /* Send signal on receive packets */ 968 d->bd_async = *(int *)addr; 969 break; 970 971 case FIOSETOWN: 972 error = fsetown(*(int *)addr, &d->bd_sigio); 973 break; 974 975 case FIOGETOWN: 976 *(int *)addr = fgetown(&d->bd_sigio); 977 break; 978 979 /* This is deprecated, FIOSETOWN should be used instead. */ 980 case TIOCSPGRP: 981 error = fsetown(-(*(int *)addr), &d->bd_sigio); 982 break; 983 984 /* This is deprecated, FIOGETOWN should be used instead. */ 985 case TIOCGPGRP: 986 *(int *)addr = -fgetown(&d->bd_sigio); 987 break; 988 989 case BIOCSRSIG: /* Set receive signal */ 990 { 991 u_int sig; 992 993 sig = *(u_int *)addr; 994 995 if (sig >= NSIG) 996 error = EINVAL; 997 else 998 d->bd_sig = sig; 999 break; 1000 } 1001 case BIOCGRSIG: 1002 *(u_int *)addr = d->bd_sig; 1003 break; 1004 } 1005 return (error); 1006 } 1007 1008 /* 1009 * Set d's packet filter program to fp. If this file already has a filter, 1010 * free it and replace it. Returns EINVAL for bogus requests. 1011 */ 1012 static int 1013 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1014 { 1015 struct bpf_insn *fcode, *old; 1016 u_int wfilter, flen, size; 1017 1018 if (cmd == BIOCSETWF) { 1019 old = d->bd_wfilter; 1020 wfilter = 1; 1021 } else { 1022 wfilter = 0; 1023 old = d->bd_rfilter; 1024 } 1025 if (fp->bf_insns == NULL) { 1026 if (fp->bf_len != 0) 1027 return (EINVAL); 1028 BPFD_LOCK(d); 1029 if (wfilter) 1030 d->bd_wfilter = NULL; 1031 else 1032 d->bd_rfilter = NULL; 1033 reset_d(d); 1034 BPFD_UNLOCK(d); 1035 if (old != NULL) 1036 free((caddr_t)old, M_BPF); 1037 return (0); 1038 } 1039 flen = fp->bf_len; 1040 if (flen > bpf_maxinsns) 1041 return (EINVAL); 1042 1043 size = flen * sizeof(*fp->bf_insns); 1044 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); 1045 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 1046 bpf_validate(fcode, (int)flen)) { 1047 BPFD_LOCK(d); 1048 if (wfilter) 1049 d->bd_wfilter = fcode; 1050 else 1051 d->bd_rfilter = fcode; 1052 reset_d(d); 1053 BPFD_UNLOCK(d); 1054 if (old != NULL) 1055 free((caddr_t)old, M_BPF); 1056 1057 return (0); 1058 } 1059 free((caddr_t)fcode, M_BPF); 1060 return (EINVAL); 1061 } 1062 1063 /* 1064 * Detach a file from its current interface (if attached at all) and attach 1065 * to the interface indicated by the name stored in ifr. 1066 * Return an errno or 0. 1067 */ 1068 static int 1069 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 1070 { 1071 struct bpf_if *bp; 1072 int error; 1073 struct ifnet *theywant; 1074 1075 theywant = ifunit(ifr->ifr_name); 1076 if (theywant == NULL || theywant->if_bpf == NULL) 1077 return (ENXIO); 1078 1079 bp = theywant->if_bpf; 1080 /* 1081 * Allocate the packet buffers if we need to. 1082 * If we're already attached to requested interface, 1083 * just flush the buffer. 1084 */ 1085 if (d->bd_sbuf == NULL) { 1086 error = bpf_allocbufs(d); 1087 if (error != 0) 1088 return (error); 1089 } 1090 if (bp != d->bd_bif) { 1091 if (d->bd_bif) 1092 /* 1093 * Detach if attached to something else. 1094 */ 1095 bpf_detachd(d); 1096 1097 bpf_attachd(d, bp); 1098 } 1099 BPFD_LOCK(d); 1100 reset_d(d); 1101 BPFD_UNLOCK(d); 1102 return (0); 1103 } 1104 1105 /* 1106 * Support for select() and poll() system calls 1107 * 1108 * Return true iff the specific operation will not block indefinitely. 1109 * Otherwise, return false but make a note that a selwakeup() must be done. 1110 */ 1111 static int 1112 bpfpoll(struct cdev *dev, int events, struct thread *td) 1113 { 1114 struct bpf_d *d; 1115 int revents; 1116 1117 d = dev->si_drv1; 1118 if (d->bd_bif == NULL) 1119 return (ENXIO); 1120 1121 /* 1122 * Refresh PID associated with this descriptor. 1123 */ 1124 d->bd_pid = td->td_proc->p_pid; 1125 revents = events & (POLLOUT | POLLWRNORM); 1126 BPFD_LOCK(d); 1127 if (events & (POLLIN | POLLRDNORM)) { 1128 if (bpf_ready(d)) 1129 revents |= events & (POLLIN | POLLRDNORM); 1130 else { 1131 selrecord(td, &d->bd_sel); 1132 /* Start the read timeout if necessary. */ 1133 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1134 callout_reset(&d->bd_callout, d->bd_rtout, 1135 bpf_timed_out, d); 1136 d->bd_state = BPF_WAITING; 1137 } 1138 } 1139 } 1140 BPFD_UNLOCK(d); 1141 return (revents); 1142 } 1143 1144 /* 1145 * Support for kevent() system call. Register EVFILT_READ filters and 1146 * reject all others. 1147 */ 1148 int 1149 bpfkqfilter(struct cdev *dev, struct knote *kn) 1150 { 1151 struct bpf_d *d = (struct bpf_d *)dev->si_drv1; 1152 1153 if (kn->kn_filter != EVFILT_READ) 1154 return (1); 1155 1156 /* 1157 * Refresh PID associated with this descriptor. 1158 */ 1159 d->bd_pid = curthread->td_proc->p_pid; 1160 kn->kn_fop = &bpfread_filtops; 1161 kn->kn_hook = d; 1162 knlist_add(&d->bd_sel.si_note, kn, 0); 1163 1164 return (0); 1165 } 1166 1167 static void 1168 filt_bpfdetach(struct knote *kn) 1169 { 1170 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1171 1172 knlist_remove(&d->bd_sel.si_note, kn, 0); 1173 } 1174 1175 static int 1176 filt_bpfread(struct knote *kn, long hint) 1177 { 1178 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1179 int ready; 1180 1181 BPFD_LOCK_ASSERT(d); 1182 ready = bpf_ready(d); 1183 if (ready) { 1184 kn->kn_data = d->bd_slen; 1185 if (d->bd_hbuf) 1186 kn->kn_data += d->bd_hlen; 1187 } 1188 else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1189 callout_reset(&d->bd_callout, d->bd_rtout, 1190 bpf_timed_out, d); 1191 d->bd_state = BPF_WAITING; 1192 } 1193 1194 return (ready); 1195 } 1196 1197 /* 1198 * Incoming linkage from device drivers. Process the packet pkt, of length 1199 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1200 * by each process' filter, and if accepted, stashed into the corresponding 1201 * buffer. 1202 */ 1203 void 1204 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1205 { 1206 struct bpf_d *d; 1207 u_int slen; 1208 int gottime; 1209 struct timeval tv; 1210 1211 gottime = 0; 1212 BPFIF_LOCK(bp); 1213 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1214 BPFD_LOCK(d); 1215 ++d->bd_rcount; 1216 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 1217 if (slen != 0) { 1218 d->bd_fcount++; 1219 if (!gottime) { 1220 microtime(&tv); 1221 gottime = 1; 1222 } 1223 #ifdef MAC 1224 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1225 #endif 1226 catchpacket(d, pkt, pktlen, slen, bcopy, &tv); 1227 } 1228 BPFD_UNLOCK(d); 1229 } 1230 BPFIF_UNLOCK(bp); 1231 } 1232 1233 /* 1234 * Copy data from an mbuf chain into a buffer. This code is derived 1235 * from m_copydata in sys/uipc_mbuf.c. 1236 */ 1237 static void 1238 bpf_mcopy(const void *src_arg, void *dst_arg, size_t len) 1239 { 1240 const struct mbuf *m; 1241 u_int count; 1242 u_char *dst; 1243 1244 m = src_arg; 1245 dst = dst_arg; 1246 while (len > 0) { 1247 if (m == NULL) 1248 panic("bpf_mcopy"); 1249 count = min(m->m_len, len); 1250 bcopy(mtod(m, void *), dst, count); 1251 m = m->m_next; 1252 dst += count; 1253 len -= count; 1254 } 1255 } 1256 1257 /* 1258 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1259 */ 1260 void 1261 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1262 { 1263 struct bpf_d *d; 1264 u_int pktlen, slen; 1265 int gottime; 1266 struct timeval tv; 1267 1268 gottime = 0; 1269 1270 pktlen = m_length(m, NULL); 1271 1272 BPFIF_LOCK(bp); 1273 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1274 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1275 continue; 1276 BPFD_LOCK(d); 1277 ++d->bd_rcount; 1278 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 1279 if (slen != 0) { 1280 d->bd_fcount++; 1281 if (!gottime) { 1282 microtime(&tv); 1283 gottime = 1; 1284 } 1285 #ifdef MAC 1286 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1287 #endif 1288 catchpacket(d, (u_char *)m, pktlen, slen, 1289 bpf_mcopy, &tv); 1290 } 1291 BPFD_UNLOCK(d); 1292 } 1293 BPFIF_UNLOCK(bp); 1294 } 1295 1296 /* 1297 * Incoming linkage from device drivers, when packet is in 1298 * an mbuf chain and to be prepended by a contiguous header. 1299 */ 1300 void 1301 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 1302 { 1303 struct mbuf mb; 1304 struct bpf_d *d; 1305 u_int pktlen, slen; 1306 int gottime; 1307 struct timeval tv; 1308 1309 gottime = 0; 1310 1311 pktlen = m_length(m, NULL); 1312 /* 1313 * Craft on-stack mbuf suitable for passing to bpf_filter. 1314 * Note that we cut corners here; we only setup what's 1315 * absolutely needed--this mbuf should never go anywhere else. 1316 */ 1317 mb.m_next = m; 1318 mb.m_data = data; 1319 mb.m_len = dlen; 1320 pktlen += dlen; 1321 1322 BPFIF_LOCK(bp); 1323 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1324 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1325 continue; 1326 BPFD_LOCK(d); 1327 ++d->bd_rcount; 1328 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 1329 if (slen != 0) { 1330 d->bd_fcount++; 1331 if (!gottime) { 1332 microtime(&tv); 1333 gottime = 1; 1334 } 1335 #ifdef MAC 1336 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1337 #endif 1338 catchpacket(d, (u_char *)&mb, pktlen, slen, 1339 bpf_mcopy, &tv); 1340 } 1341 BPFD_UNLOCK(d); 1342 } 1343 BPFIF_UNLOCK(bp); 1344 } 1345 1346 /* 1347 * Move the packet data from interface memory (pkt) into the 1348 * store buffer. "cpfn" is the routine called to do the actual data 1349 * transfer. bcopy is passed in to copy contiguous chunks, while 1350 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1351 * pkt is really an mbuf. 1352 */ 1353 static void 1354 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 1355 void (*cpfn)(const void *, void *, size_t), struct timeval *tv) 1356 { 1357 struct bpf_hdr *hp; 1358 int totlen, curlen; 1359 int hdrlen = d->bd_bif->bif_hdrlen; 1360 int do_wakeup = 0; 1361 1362 BPFD_LOCK_ASSERT(d); 1363 /* 1364 * Figure out how many bytes to move. If the packet is 1365 * greater or equal to the snapshot length, transfer that 1366 * much. Otherwise, transfer the whole packet (unless 1367 * we hit the buffer size limit). 1368 */ 1369 totlen = hdrlen + min(snaplen, pktlen); 1370 if (totlen > d->bd_bufsize) 1371 totlen = d->bd_bufsize; 1372 1373 /* 1374 * Round up the end of the previous packet to the next longword. 1375 */ 1376 curlen = BPF_WORDALIGN(d->bd_slen); 1377 if (curlen + totlen > d->bd_bufsize) { 1378 /* 1379 * This packet will overflow the storage buffer. 1380 * Rotate the buffers if we can, then wakeup any 1381 * pending reads. 1382 */ 1383 if (d->bd_fbuf == NULL) { 1384 /* 1385 * We haven't completed the previous read yet, 1386 * so drop the packet. 1387 */ 1388 ++d->bd_dcount; 1389 return; 1390 } 1391 ROTATE_BUFFERS(d); 1392 do_wakeup = 1; 1393 curlen = 0; 1394 } 1395 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1396 /* 1397 * Immediate mode is set, or the read timeout has 1398 * already expired during a select call. A packet 1399 * arrived, so the reader should be woken up. 1400 */ 1401 do_wakeup = 1; 1402 1403 /* 1404 * Append the bpf header. 1405 */ 1406 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1407 hp->bh_tstamp = *tv; 1408 hp->bh_datalen = pktlen; 1409 hp->bh_hdrlen = hdrlen; 1410 /* 1411 * Copy the packet data into the store buffer and update its length. 1412 */ 1413 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1414 d->bd_slen = curlen + totlen; 1415 1416 if (do_wakeup) 1417 bpf_wakeup(d); 1418 } 1419 1420 /* 1421 * Initialize all nonzero fields of a descriptor. 1422 */ 1423 static int 1424 bpf_allocbufs(struct bpf_d *d) 1425 { 1426 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1427 if (d->bd_fbuf == NULL) 1428 return (ENOBUFS); 1429 1430 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1431 if (d->bd_sbuf == NULL) { 1432 free(d->bd_fbuf, M_BPF); 1433 return (ENOBUFS); 1434 } 1435 d->bd_slen = 0; 1436 d->bd_hlen = 0; 1437 return (0); 1438 } 1439 1440 /* 1441 * Free buffers currently in use by a descriptor. 1442 * Called on close. 1443 */ 1444 static void 1445 bpf_freed(struct bpf_d *d) 1446 { 1447 /* 1448 * We don't need to lock out interrupts since this descriptor has 1449 * been detached from its interface and it yet hasn't been marked 1450 * free. 1451 */ 1452 if (d->bd_sbuf != NULL) { 1453 free(d->bd_sbuf, M_BPF); 1454 if (d->bd_hbuf != NULL) 1455 free(d->bd_hbuf, M_BPF); 1456 if (d->bd_fbuf != NULL) 1457 free(d->bd_fbuf, M_BPF); 1458 } 1459 if (d->bd_rfilter) 1460 free((caddr_t)d->bd_rfilter, M_BPF); 1461 if (d->bd_wfilter) 1462 free((caddr_t)d->bd_wfilter, M_BPF); 1463 mtx_destroy(&d->bd_mtx); 1464 } 1465 1466 /* 1467 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1468 * fixed size of the link header (variable length headers not yet supported). 1469 */ 1470 void 1471 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1472 { 1473 1474 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1475 } 1476 1477 /* 1478 * Attach an interface to bpf. ifp is a pointer to the structure 1479 * defining the interface to be attached, dlt is the link layer type, 1480 * and hdrlen is the fixed size of the link header (variable length 1481 * headers are not yet supporrted). 1482 */ 1483 void 1484 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1485 { 1486 struct bpf_if *bp; 1487 1488 bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1489 if (bp == NULL) 1490 panic("bpfattach"); 1491 1492 LIST_INIT(&bp->bif_dlist); 1493 bp->bif_ifp = ifp; 1494 bp->bif_dlt = dlt; 1495 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1496 KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized")); 1497 *driverp = bp; 1498 1499 mtx_lock(&bpf_mtx); 1500 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 1501 mtx_unlock(&bpf_mtx); 1502 1503 /* 1504 * Compute the length of the bpf header. This is not necessarily 1505 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1506 * that the network layer header begins on a longword boundary (for 1507 * performance reasons and to alleviate alignment restrictions). 1508 */ 1509 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1510 1511 if (bootverbose) 1512 if_printf(ifp, "bpf attached\n"); 1513 } 1514 1515 /* 1516 * Detach bpf from an interface. This involves detaching each descriptor 1517 * associated with the interface, and leaving bd_bif NULL. Notify each 1518 * descriptor as it's detached so that any sleepers wake up and get 1519 * ENXIO. 1520 */ 1521 void 1522 bpfdetach(struct ifnet *ifp) 1523 { 1524 struct bpf_if *bp; 1525 struct bpf_d *d; 1526 1527 /* Locate BPF interface information */ 1528 mtx_lock(&bpf_mtx); 1529 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1530 if (ifp == bp->bif_ifp) 1531 break; 1532 } 1533 1534 /* Interface wasn't attached */ 1535 if ((bp == NULL) || (bp->bif_ifp == NULL)) { 1536 mtx_unlock(&bpf_mtx); 1537 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 1538 return; 1539 } 1540 1541 LIST_REMOVE(bp, bif_next); 1542 mtx_unlock(&bpf_mtx); 1543 1544 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { 1545 bpf_detachd(d); 1546 BPFD_LOCK(d); 1547 bpf_wakeup(d); 1548 BPFD_UNLOCK(d); 1549 } 1550 1551 mtx_destroy(&bp->bif_mtx); 1552 free(bp, M_BPF); 1553 } 1554 1555 /* 1556 * Get a list of available data link type of the interface. 1557 */ 1558 static int 1559 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 1560 { 1561 int n, error; 1562 struct ifnet *ifp; 1563 struct bpf_if *bp; 1564 1565 ifp = d->bd_bif->bif_ifp; 1566 n = 0; 1567 error = 0; 1568 mtx_lock(&bpf_mtx); 1569 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1570 if (bp->bif_ifp != ifp) 1571 continue; 1572 if (bfl->bfl_list != NULL) { 1573 if (n >= bfl->bfl_len) { 1574 mtx_unlock(&bpf_mtx); 1575 return (ENOMEM); 1576 } 1577 error = copyout(&bp->bif_dlt, 1578 bfl->bfl_list + n, sizeof(u_int)); 1579 } 1580 n++; 1581 } 1582 mtx_unlock(&bpf_mtx); 1583 bfl->bfl_len = n; 1584 return (error); 1585 } 1586 1587 /* 1588 * Set the data link type of a BPF instance. 1589 */ 1590 static int 1591 bpf_setdlt(struct bpf_d *d, u_int dlt) 1592 { 1593 int error, opromisc; 1594 struct ifnet *ifp; 1595 struct bpf_if *bp; 1596 1597 if (d->bd_bif->bif_dlt == dlt) 1598 return (0); 1599 ifp = d->bd_bif->bif_ifp; 1600 mtx_lock(&bpf_mtx); 1601 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1602 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1603 break; 1604 } 1605 mtx_unlock(&bpf_mtx); 1606 if (bp != NULL) { 1607 opromisc = d->bd_promisc; 1608 bpf_detachd(d); 1609 bpf_attachd(d, bp); 1610 BPFD_LOCK(d); 1611 reset_d(d); 1612 BPFD_UNLOCK(d); 1613 if (opromisc) { 1614 error = ifpromisc(bp->bif_ifp, 1); 1615 if (error) 1616 if_printf(bp->bif_ifp, 1617 "bpf_setdlt: ifpromisc failed (%d)\n", 1618 error); 1619 else 1620 d->bd_promisc = 1; 1621 } 1622 } 1623 return (bp == NULL ? EINVAL : 0); 1624 } 1625 1626 static void 1627 bpf_clone(void *arg, struct ucred *cred, char *name, int namelen, 1628 struct cdev **dev) 1629 { 1630 int u; 1631 1632 if (*dev != NULL) 1633 return; 1634 if (dev_stdclone(name, NULL, "bpf", &u) != 1) 1635 return; 1636 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, 1637 "bpf%d", u); 1638 dev_ref(*dev); 1639 (*dev)->si_flags |= SI_CHEAPCLONE; 1640 return; 1641 } 1642 1643 static void 1644 bpf_drvinit(void *unused) 1645 { 1646 1647 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 1648 LIST_INIT(&bpf_iflist); 1649 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); 1650 } 1651 1652 static void 1653 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 1654 { 1655 1656 bzero(d, sizeof(*d)); 1657 BPFD_LOCK_ASSERT(bd); 1658 d->bd_immediate = bd->bd_immediate; 1659 d->bd_promisc = bd->bd_promisc; 1660 d->bd_hdrcmplt = bd->bd_hdrcmplt; 1661 d->bd_seesent = bd->bd_seesent; 1662 d->bd_async = bd->bd_async; 1663 d->bd_rcount = bd->bd_rcount; 1664 d->bd_dcount = bd->bd_dcount; 1665 d->bd_fcount = bd->bd_fcount; 1666 d->bd_sig = bd->bd_sig; 1667 d->bd_slen = bd->bd_slen; 1668 d->bd_hlen = bd->bd_hlen; 1669 d->bd_bufsize = bd->bd_bufsize; 1670 d->bd_pid = bd->bd_pid; 1671 strlcpy(d->bd_ifname, 1672 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 1673 strlcpy(d->bd_pcomm, bd->bd_pcomm, MAXCOMLEN); 1674 d->bd_locked = bd->bd_locked; 1675 } 1676 1677 static int 1678 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 1679 { 1680 struct xbpf_d *xbdbuf, *xbd; 1681 int index, error; 1682 struct bpf_if *bp; 1683 struct bpf_d *bd; 1684 1685 /* 1686 * XXX This is not technically correct. It is possible for non 1687 * privileged users to open bpf devices. It would make sense 1688 * if the users who opened the devices were able to retrieve 1689 * the statistics for them, too. 1690 */ 1691 error = suser(req->td); 1692 if (error) 1693 return (error); 1694 if (req->oldptr == NULL) 1695 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 1696 if (bpf_bpfd_cnt == 0) 1697 return (SYSCTL_OUT(req, 0, 0)); 1698 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 1699 mtx_lock(&bpf_mtx); 1700 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 1701 mtx_unlock(&bpf_mtx); 1702 free(xbdbuf, M_BPF); 1703 return (ENOMEM); 1704 } 1705 index = 0; 1706 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1707 BPFIF_LOCK(bp); 1708 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 1709 xbd = &xbdbuf[index++]; 1710 BPFD_LOCK(bd); 1711 bpfstats_fill_xbpf(xbd, bd); 1712 BPFD_UNLOCK(bd); 1713 } 1714 BPFIF_UNLOCK(bp); 1715 } 1716 mtx_unlock(&bpf_mtx); 1717 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 1718 free(xbdbuf, M_BPF); 1719 return (error); 1720 } 1721 1722 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL) 1723 1724 #else /* !DEV_BPF && !NETGRAPH_BPF */ 1725 /* 1726 * NOP stubs to allow bpf-using drivers to load and function. 1727 * 1728 * A 'better' implementation would allow the core bpf functionality 1729 * to be loaded at runtime. 1730 */ 1731 static struct bpf_if bp_null; 1732 1733 void 1734 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1735 { 1736 } 1737 1738 void 1739 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1740 { 1741 } 1742 1743 void 1744 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 1745 { 1746 } 1747 1748 void 1749 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1750 { 1751 1752 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1753 } 1754 1755 void 1756 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1757 { 1758 1759 *driverp = &bp_null; 1760 } 1761 1762 void 1763 bpfdetach(struct ifnet *ifp) 1764 { 1765 } 1766 1767 u_int 1768 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 1769 { 1770 return -1; /* "no filter" behaviour */ 1771 } 1772 1773 int 1774 bpf_validate(const struct bpf_insn *f, int len) 1775 { 1776 return 0; /* false */ 1777 } 1778 1779 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 1780 1781 /* 1782 * ABI compatibility hacks. Older drivers check if_bpf against NULL 1783 * to see if there are active listeners. In the new ABI, if_bpf is 1784 * always non-NULL, so bpf_*tap() are always invoked. We check for 1785 * listeners in these wrappers and call the real functions if needed. 1786 */ 1787 #undef bpf_tap 1788 #undef bpf_mtap 1789 #undef bpf_mtap2 1790 1791 void bpf_tap(struct bpf_if *, u_char *, u_int); 1792 void bpf_mtap(struct bpf_if *, struct mbuf *); 1793 void bpf_mtap2(struct bpf_if *, void *, u_int, struct mbuf *); 1794 1795 void 1796 bpf_tap(bp, pkt, pktlen) 1797 struct bpf_if *bp; 1798 u_char *pkt; 1799 u_int pktlen; 1800 { 1801 1802 if (bpf_peers_present(bp)) 1803 bpf_tap_new(bp, pkt, pktlen); 1804 } 1805 1806 void 1807 bpf_mtap(bp, m) 1808 struct bpf_if *bp; 1809 struct mbuf *m; 1810 { 1811 1812 if (bpf_peers_present(bp)) 1813 bpf_mtap_new(bp, m); 1814 } 1815 1816 void 1817 bpf_mtap2(bp, d, l, m) 1818 struct bpf_if *bp; 1819 void *d; 1820 u_int l; 1821 struct mbuf *m; 1822 { 1823 1824 if (bpf_peers_present(bp)) 1825 bpf_mtap2_new(bp, d, l, m); 1826 }
Cache object: fd8b330d784d2e16a4a3d243d1c5c582
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