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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: releng/6.3/sys/net/bpf.c 173886 2007-11-24 19:45:58Z cvs2svn $ 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, 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 > MCLBYTES) 232 return (EIO); 233 234 if (len > MHLEN) { 235 m = m_getcl(M_TRYWAIT, MT_DATA, M_PKTHDR); 236 } else { 237 MGETHDR(m, M_TRYWAIT, MT_DATA); 238 } 239 if (m == NULL) 240 return (ENOBUFS); 241 m->m_pkthdr.len = m->m_len = len; 242 m->m_pkthdr.rcvif = NULL; 243 *mp = m; 244 245 if (m->m_len < hlen) { 246 error = EPERM; 247 goto bad; 248 } 249 250 error = uiomove(mtod(m, u_char *), len, uio); 251 if (error) 252 goto bad; 253 254 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len); 255 if (slen == 0) { 256 error = EPERM; 257 goto bad; 258 } 259 260 /* Check for multicast destination */ 261 switch (linktype) { 262 case DLT_EN10MB: 263 eh = mtod(m, struct ether_header *); 264 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 265 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, 266 ETHER_ADDR_LEN) == 0) 267 m->m_flags |= M_BCAST; 268 else 269 m->m_flags |= M_MCAST; 270 } 271 break; 272 } 273 274 /* 275 * Make room for link header, and copy it to sockaddr 276 */ 277 if (hlen != 0) { 278 bcopy(m->m_data, sockp->sa_data, hlen); 279 m->m_pkthdr.len -= hlen; 280 m->m_len -= hlen; 281 #if BSD >= 199103 282 m->m_data += hlen; /* XXX */ 283 #else 284 m->m_off += hlen; 285 #endif 286 } 287 288 return (0); 289 bad: 290 m_freem(m); 291 return (error); 292 } 293 294 /* 295 * Attach file to the bpf interface, i.e. make d listen on bp. 296 */ 297 static void 298 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 299 { 300 /* 301 * Point d at bp, and add d to the interface's list of listeners. 302 * Finally, point the driver's bpf cookie at the interface so 303 * it will divert packets to bpf. 304 */ 305 BPFIF_LOCK(bp); 306 d->bd_bif = bp; 307 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 308 309 bpf_bpfd_cnt++; 310 BPFIF_UNLOCK(bp); 311 } 312 313 /* 314 * Detach a file from its interface. 315 */ 316 static void 317 bpf_detachd(struct bpf_d *d) 318 { 319 int error; 320 struct bpf_if *bp; 321 struct ifnet *ifp; 322 323 bp = d->bd_bif; 324 BPFIF_LOCK(bp); 325 BPFD_LOCK(d); 326 ifp = d->bd_bif->bif_ifp; 327 328 /* 329 * Remove d from the interface's descriptor list. 330 */ 331 LIST_REMOVE(d, bd_next); 332 333 bpf_bpfd_cnt--; 334 d->bd_bif = NULL; 335 BPFD_UNLOCK(d); 336 BPFIF_UNLOCK(bp); 337 338 /* 339 * Check if this descriptor had requested promiscuous mode. 340 * If so, turn it off. 341 */ 342 if (d->bd_promisc) { 343 d->bd_promisc = 0; 344 error = ifpromisc(ifp, 0); 345 if (error != 0 && error != ENXIO) { 346 /* 347 * ENXIO can happen if a pccard is unplugged 348 * Something is really wrong if we were able to put 349 * the driver into promiscuous mode, but can't 350 * take it out. 351 */ 352 if_printf(bp->bif_ifp, 353 "bpf_detach: ifpromisc failed (%d)\n", error); 354 } 355 } 356 } 357 358 /* 359 * Open ethernet device. Returns ENXIO for illegal minor device number, 360 * EBUSY if file is open by another process. 361 */ 362 /* ARGSUSED */ 363 static int 364 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 365 { 366 struct bpf_d *d; 367 368 mtx_lock(&bpf_mtx); 369 d = dev->si_drv1; 370 /* 371 * Each minor can be opened by only one process. If the requested 372 * minor is in use, return EBUSY. 373 */ 374 if (d != NULL) { 375 mtx_unlock(&bpf_mtx); 376 return (EBUSY); 377 } 378 dev->si_drv1 = (struct bpf_d *)~0; /* mark device in use */ 379 mtx_unlock(&bpf_mtx); 380 381 if ((dev->si_flags & SI_NAMED) == 0) 382 make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600, 383 "bpf%d", dev2unit(dev)); 384 MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 385 dev->si_drv1 = d; 386 d->bd_bufsize = bpf_bufsize; 387 d->bd_sig = SIGIO; 388 d->bd_seesent = 1; 389 d->bd_pid = td->td_proc->p_pid; 390 strlcpy(d->bd_pcomm, td->td_proc->p_comm, MAXCOMLEN); 391 #ifdef MAC 392 mac_init_bpfdesc(d); 393 mac_create_bpfdesc(td->td_ucred, d); 394 #endif 395 mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF); 396 callout_init(&d->bd_callout, NET_CALLOUT_MPSAFE); 397 knlist_init(&d->bd_sel.si_note, &d->bd_mtx, NULL, NULL, NULL); 398 399 return (0); 400 } 401 402 /* 403 * Close the descriptor by detaching it from its interface, 404 * deallocating its buffers, and marking it free. 405 */ 406 /* ARGSUSED */ 407 static int 408 bpfclose(struct cdev *dev, int flags, int fmt, struct thread *td) 409 { 410 struct bpf_d *d = dev->si_drv1; 411 412 BPFD_LOCK(d); 413 if (d->bd_state == BPF_WAITING) 414 callout_stop(&d->bd_callout); 415 d->bd_state = BPF_IDLE; 416 BPFD_UNLOCK(d); 417 funsetown(&d->bd_sigio); 418 mtx_lock(&bpf_mtx); 419 if (d->bd_bif) 420 bpf_detachd(d); 421 mtx_unlock(&bpf_mtx); 422 selwakeuppri(&d->bd_sel, PRINET); 423 #ifdef MAC 424 mac_destroy_bpfdesc(d); 425 #endif /* MAC */ 426 knlist_destroy(&d->bd_sel.si_note); 427 bpf_freed(d); 428 dev->si_drv1 = NULL; 429 free(d, M_BPF); 430 431 return (0); 432 } 433 434 435 /* 436 * Rotate the packet buffers in descriptor d. Move the store buffer 437 * into the hold slot, and the free buffer into the store slot. 438 * Zero the length of the new store buffer. 439 */ 440 #define ROTATE_BUFFERS(d) \ 441 (d)->bd_hbuf = (d)->bd_sbuf; \ 442 (d)->bd_hlen = (d)->bd_slen; \ 443 (d)->bd_sbuf = (d)->bd_fbuf; \ 444 (d)->bd_slen = 0; \ 445 (d)->bd_fbuf = NULL; 446 /* 447 * bpfread - read next chunk of packets from buffers 448 */ 449 static int 450 bpfread(struct cdev *dev, struct uio *uio, int ioflag) 451 { 452 struct bpf_d *d = dev->si_drv1; 453 int timed_out; 454 int error; 455 456 /* 457 * Restrict application to use a buffer the same size as 458 * as kernel buffers. 459 */ 460 if (uio->uio_resid != d->bd_bufsize) 461 return (EINVAL); 462 463 BPFD_LOCK(d); 464 d->bd_pid = curthread->td_proc->p_pid; 465 if (d->bd_state == BPF_WAITING) 466 callout_stop(&d->bd_callout); 467 timed_out = (d->bd_state == BPF_TIMED_OUT); 468 d->bd_state = BPF_IDLE; 469 /* 470 * If the hold buffer is empty, then do a timed sleep, which 471 * ends when the timeout expires or when enough packets 472 * have arrived to fill the store buffer. 473 */ 474 while (d->bd_hbuf == NULL) { 475 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { 476 /* 477 * A packet(s) either arrived since the previous 478 * read or arrived while we were asleep. 479 * Rotate the buffers and return what's here. 480 */ 481 ROTATE_BUFFERS(d); 482 break; 483 } 484 485 /* 486 * No data is available, check to see if the bpf device 487 * is still pointed at a real interface. If not, return 488 * ENXIO so that the userland process knows to rebind 489 * it before using it again. 490 */ 491 if (d->bd_bif == NULL) { 492 BPFD_UNLOCK(d); 493 return (ENXIO); 494 } 495 496 if (ioflag & O_NONBLOCK) { 497 BPFD_UNLOCK(d); 498 return (EWOULDBLOCK); 499 } 500 error = msleep(d, &d->bd_mtx, PRINET|PCATCH, 501 "bpf", d->bd_rtout); 502 if (error == EINTR || error == ERESTART) { 503 BPFD_UNLOCK(d); 504 return (error); 505 } 506 if (error == EWOULDBLOCK) { 507 /* 508 * On a timeout, return what's in the buffer, 509 * which may be nothing. If there is something 510 * in the store buffer, we can rotate the buffers. 511 */ 512 if (d->bd_hbuf) 513 /* 514 * We filled up the buffer in between 515 * getting the timeout and arriving 516 * here, so we don't need to rotate. 517 */ 518 break; 519 520 if (d->bd_slen == 0) { 521 BPFD_UNLOCK(d); 522 return (0); 523 } 524 ROTATE_BUFFERS(d); 525 break; 526 } 527 } 528 /* 529 * At this point, we know we have something in the hold slot. 530 */ 531 BPFD_UNLOCK(d); 532 533 /* 534 * Move data from hold buffer into user space. 535 * We know the entire buffer is transferred since 536 * we checked above that the read buffer is bpf_bufsize bytes. 537 */ 538 error = uiomove(d->bd_hbuf, d->bd_hlen, uio); 539 540 BPFD_LOCK(d); 541 d->bd_fbuf = d->bd_hbuf; 542 d->bd_hbuf = NULL; 543 d->bd_hlen = 0; 544 BPFD_UNLOCK(d); 545 546 return (error); 547 } 548 549 550 /* 551 * If there are processes sleeping on this descriptor, wake them up. 552 */ 553 static __inline void 554 bpf_wakeup(struct bpf_d *d) 555 { 556 557 BPFD_LOCK_ASSERT(d); 558 if (d->bd_state == BPF_WAITING) { 559 callout_stop(&d->bd_callout); 560 d->bd_state = BPF_IDLE; 561 } 562 wakeup(d); 563 if (d->bd_async && d->bd_sig && d->bd_sigio) 564 pgsigio(&d->bd_sigio, d->bd_sig, 0); 565 566 selwakeuppri(&d->bd_sel, PRINET); 567 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 568 } 569 570 static void 571 bpf_timed_out(void *arg) 572 { 573 struct bpf_d *d = (struct bpf_d *)arg; 574 575 BPFD_LOCK(d); 576 if (d->bd_state == BPF_WAITING) { 577 d->bd_state = BPF_TIMED_OUT; 578 if (d->bd_slen != 0) 579 bpf_wakeup(d); 580 } 581 BPFD_UNLOCK(d); 582 } 583 584 static int 585 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 586 { 587 struct bpf_d *d = dev->si_drv1; 588 struct ifnet *ifp; 589 struct mbuf *m; 590 int error; 591 struct sockaddr dst; 592 593 d->bd_pid = curthread->td_proc->p_pid; 594 if (d->bd_bif == NULL) 595 return (ENXIO); 596 597 ifp = d->bd_bif->bif_ifp; 598 599 if ((ifp->if_flags & IFF_UP) == 0) 600 return (ENETDOWN); 601 602 if (uio->uio_resid == 0) 603 return (0); 604 605 bzero(&dst, sizeof(dst)); 606 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp, 607 &m, &dst, d->bd_wfilter); 608 if (error) 609 return (error); 610 611 if (d->bd_hdrcmplt) 612 dst.sa_family = pseudo_AF_HDRCMPLT; 613 614 #ifdef MAC 615 BPFD_LOCK(d); 616 mac_create_mbuf_from_bpfdesc(d, m); 617 BPFD_UNLOCK(d); 618 #endif 619 NET_LOCK_GIANT(); 620 error = (*ifp->if_output)(ifp, m, &dst, NULL); 621 NET_UNLOCK_GIANT(); 622 /* 623 * The driver frees the mbuf. 624 */ 625 return (error); 626 } 627 628 /* 629 * Reset a descriptor by flushing its packet buffer and clearing the 630 * receive and drop counts. 631 */ 632 static void 633 reset_d(struct bpf_d *d) 634 { 635 636 mtx_assert(&d->bd_mtx, MA_OWNED); 637 if (d->bd_hbuf) { 638 /* Free the hold buffer. */ 639 d->bd_fbuf = d->bd_hbuf; 640 d->bd_hbuf = NULL; 641 } 642 d->bd_slen = 0; 643 d->bd_hlen = 0; 644 d->bd_rcount = 0; 645 d->bd_dcount = 0; 646 d->bd_fcount = 0; 647 } 648 649 /* 650 * FIONREAD Check for read packet available. 651 * SIOCGIFADDR Get interface address - convenient hook to driver. 652 * BIOCGBLEN Get buffer len [for read()]. 653 * BIOCSETF Set ethernet read filter. 654 * BIOCSETWF Set ethernet write filter. 655 * BIOCFLUSH Flush read packet buffer. 656 * BIOCPROMISC Put interface into promiscuous mode. 657 * BIOCGDLT Get link layer type. 658 * BIOCGETIF Get interface name. 659 * BIOCSETIF Set interface. 660 * BIOCSRTIMEOUT Set read timeout. 661 * BIOCGRTIMEOUT Get read timeout. 662 * BIOCGSTATS Get packet stats. 663 * BIOCIMMEDIATE Set immediate mode. 664 * BIOCVERSION Get filter language version. 665 * BIOCGHDRCMPLT Get "header already complete" flag 666 * BIOCSHDRCMPLT Set "header already complete" flag 667 * BIOCGSEESENT Get "see packets sent" flag 668 * BIOCSSEESENT Set "see packets sent" flag 669 * BIOCLOCK Set "locked" flag 670 */ 671 /* ARGSUSED */ 672 static int 673 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 674 struct thread *td) 675 { 676 struct bpf_d *d = dev->si_drv1; 677 int error = 0; 678 679 /* 680 * Refresh PID associated with this descriptor. 681 */ 682 d->bd_pid = td->td_proc->p_pid; 683 BPFD_LOCK(d); 684 if (d->bd_state == BPF_WAITING) 685 callout_stop(&d->bd_callout); 686 d->bd_state = BPF_IDLE; 687 BPFD_UNLOCK(d); 688 689 if (d->bd_locked == 1) { 690 switch (cmd) { 691 case BIOCGBLEN: 692 case BIOCFLUSH: 693 case BIOCGDLT: 694 case BIOCGDLTLIST: 695 case BIOCGETIF: 696 case BIOCGRTIMEOUT: 697 case BIOCGSTATS: 698 case BIOCVERSION: 699 case BIOCGRSIG: 700 case BIOCGHDRCMPLT: 701 case FIONREAD: 702 case BIOCLOCK: 703 case BIOCSRTIMEOUT: 704 case BIOCIMMEDIATE: 705 case TIOCGPGRP: 706 break; 707 default: 708 return (EPERM); 709 } 710 } 711 switch (cmd) { 712 713 default: 714 error = EINVAL; 715 break; 716 717 /* 718 * Check for read packet available. 719 */ 720 case FIONREAD: 721 { 722 int n; 723 724 BPFD_LOCK(d); 725 n = d->bd_slen; 726 if (d->bd_hbuf) 727 n += d->bd_hlen; 728 BPFD_UNLOCK(d); 729 730 *(int *)addr = n; 731 break; 732 } 733 734 case SIOCGIFADDR: 735 { 736 struct ifnet *ifp; 737 738 if (d->bd_bif == NULL) 739 error = EINVAL; 740 else { 741 ifp = d->bd_bif->bif_ifp; 742 error = (*ifp->if_ioctl)(ifp, cmd, addr); 743 } 744 break; 745 } 746 747 /* 748 * Get buffer len [for read()]. 749 */ 750 case BIOCGBLEN: 751 *(u_int *)addr = d->bd_bufsize; 752 break; 753 754 /* 755 * Set buffer length. 756 */ 757 case BIOCSBLEN: 758 if (d->bd_bif != NULL) 759 error = EINVAL; 760 else { 761 u_int size = *(u_int *)addr; 762 763 if (size > bpf_maxbufsize) 764 *(u_int *)addr = size = bpf_maxbufsize; 765 else if (size < BPF_MINBUFSIZE) 766 *(u_int *)addr = size = BPF_MINBUFSIZE; 767 d->bd_bufsize = size; 768 } 769 break; 770 771 /* 772 * Set link layer read filter. 773 */ 774 case BIOCSETF: 775 case BIOCSETWF: 776 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 777 break; 778 779 /* 780 * Flush read packet buffer. 781 */ 782 case BIOCFLUSH: 783 BPFD_LOCK(d); 784 reset_d(d); 785 BPFD_UNLOCK(d); 786 break; 787 788 /* 789 * Put interface into promiscuous mode. 790 */ 791 case BIOCPROMISC: 792 if (d->bd_bif == NULL) { 793 /* 794 * No interface attached yet. 795 */ 796 error = EINVAL; 797 break; 798 } 799 if (d->bd_promisc == 0) { 800 mtx_lock(&Giant); 801 error = ifpromisc(d->bd_bif->bif_ifp, 1); 802 mtx_unlock(&Giant); 803 if (error == 0) 804 d->bd_promisc = 1; 805 } 806 break; 807 808 /* 809 * Get current data link type. 810 */ 811 case BIOCGDLT: 812 if (d->bd_bif == NULL) 813 error = EINVAL; 814 else 815 *(u_int *)addr = d->bd_bif->bif_dlt; 816 break; 817 818 /* 819 * Get a list of supported data link types. 820 */ 821 case BIOCGDLTLIST: 822 if (d->bd_bif == NULL) 823 error = EINVAL; 824 else 825 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 826 break; 827 828 /* 829 * Set data link type. 830 */ 831 case BIOCSDLT: 832 if (d->bd_bif == NULL) 833 error = EINVAL; 834 else 835 error = bpf_setdlt(d, *(u_int *)addr); 836 break; 837 838 /* 839 * Get interface name. 840 */ 841 case BIOCGETIF: 842 if (d->bd_bif == NULL) 843 error = EINVAL; 844 else { 845 struct ifnet *const ifp = d->bd_bif->bif_ifp; 846 struct ifreq *const ifr = (struct ifreq *)addr; 847 848 strlcpy(ifr->ifr_name, ifp->if_xname, 849 sizeof(ifr->ifr_name)); 850 } 851 break; 852 853 /* 854 * Set interface. 855 */ 856 case BIOCSETIF: 857 error = bpf_setif(d, (struct ifreq *)addr); 858 break; 859 860 /* 861 * Set read timeout. 862 */ 863 case BIOCSRTIMEOUT: 864 { 865 struct timeval *tv = (struct timeval *)addr; 866 867 /* 868 * Subtract 1 tick from tvtohz() since this isn't 869 * a one-shot timer. 870 */ 871 if ((error = itimerfix(tv)) == 0) 872 d->bd_rtout = tvtohz(tv) - 1; 873 break; 874 } 875 876 /* 877 * Get read timeout. 878 */ 879 case BIOCGRTIMEOUT: 880 { 881 struct timeval *tv = (struct timeval *)addr; 882 883 tv->tv_sec = d->bd_rtout / hz; 884 tv->tv_usec = (d->bd_rtout % hz) * tick; 885 break; 886 } 887 888 /* 889 * Get packet stats. 890 */ 891 case BIOCGSTATS: 892 { 893 struct bpf_stat *bs = (struct bpf_stat *)addr; 894 895 bs->bs_recv = d->bd_rcount; 896 bs->bs_drop = d->bd_dcount; 897 break; 898 } 899 900 /* 901 * Set immediate mode. 902 */ 903 case BIOCIMMEDIATE: 904 d->bd_immediate = *(u_int *)addr; 905 break; 906 907 case BIOCVERSION: 908 { 909 struct bpf_version *bv = (struct bpf_version *)addr; 910 911 bv->bv_major = BPF_MAJOR_VERSION; 912 bv->bv_minor = BPF_MINOR_VERSION; 913 break; 914 } 915 916 /* 917 * Get "header already complete" flag 918 */ 919 case BIOCGHDRCMPLT: 920 *(u_int *)addr = d->bd_hdrcmplt; 921 break; 922 923 case BIOCLOCK: 924 d->bd_locked = 1; 925 break; 926 /* 927 * Set "header already complete" flag 928 */ 929 case BIOCSHDRCMPLT: 930 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 931 break; 932 933 /* 934 * Get "see sent packets" flag 935 */ 936 case BIOCGSEESENT: 937 *(u_int *)addr = d->bd_seesent; 938 break; 939 940 /* 941 * Set "see sent packets" flag 942 */ 943 case BIOCSSEESENT: 944 d->bd_seesent = *(u_int *)addr; 945 break; 946 947 case FIONBIO: /* Non-blocking I/O */ 948 break; 949 950 case FIOASYNC: /* Send signal on receive packets */ 951 d->bd_async = *(int *)addr; 952 break; 953 954 case FIOSETOWN: 955 error = fsetown(*(int *)addr, &d->bd_sigio); 956 break; 957 958 case FIOGETOWN: 959 *(int *)addr = fgetown(&d->bd_sigio); 960 break; 961 962 /* This is deprecated, FIOSETOWN should be used instead. */ 963 case TIOCSPGRP: 964 error = fsetown(-(*(int *)addr), &d->bd_sigio); 965 break; 966 967 /* This is deprecated, FIOGETOWN should be used instead. */ 968 case TIOCGPGRP: 969 *(int *)addr = -fgetown(&d->bd_sigio); 970 break; 971 972 case BIOCSRSIG: /* Set receive signal */ 973 { 974 u_int sig; 975 976 sig = *(u_int *)addr; 977 978 if (sig >= NSIG) 979 error = EINVAL; 980 else 981 d->bd_sig = sig; 982 break; 983 } 984 case BIOCGRSIG: 985 *(u_int *)addr = d->bd_sig; 986 break; 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 BPFD_LOCK(d); 1012 if (wfilter) 1013 d->bd_wfilter = NULL; 1014 else 1015 d->bd_rfilter = NULL; 1016 reset_d(d); 1017 BPFD_UNLOCK(d); 1018 if (old != NULL) 1019 free((caddr_t)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 *)malloc(size, M_BPF, M_WAITOK); 1028 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 1029 bpf_validate(fcode, (int)flen)) { 1030 BPFD_LOCK(d); 1031 if (wfilter) 1032 d->bd_wfilter = fcode; 1033 else 1034 d->bd_rfilter = fcode; 1035 reset_d(d); 1036 BPFD_UNLOCK(d); 1037 if (old != NULL) 1038 free((caddr_t)old, M_BPF); 1039 1040 return (0); 1041 } 1042 free((caddr_t)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 || theywant->if_bpf == NULL) 1060 return (ENXIO); 1061 1062 bp = theywant->if_bpf; 1063 /* 1064 * Allocate the packet buffers if we need to. 1065 * If we're already attached to requested interface, 1066 * just flush the buffer. 1067 */ 1068 if (d->bd_sbuf == NULL) { 1069 error = bpf_allocbufs(d); 1070 if (error != 0) 1071 return (error); 1072 } 1073 if (bp != d->bd_bif) { 1074 if (d->bd_bif) 1075 /* 1076 * Detach if attached to something else. 1077 */ 1078 bpf_detachd(d); 1079 1080 bpf_attachd(d, bp); 1081 } 1082 BPFD_LOCK(d); 1083 reset_d(d); 1084 BPFD_UNLOCK(d); 1085 return (0); 1086 } 1087 1088 /* 1089 * Support for select() and poll() system calls 1090 * 1091 * Return true iff the specific operation will not block indefinitely. 1092 * Otherwise, return false but make a note that a selwakeup() must be done. 1093 */ 1094 static int 1095 bpfpoll(struct cdev *dev, int events, struct thread *td) 1096 { 1097 struct bpf_d *d; 1098 int revents; 1099 1100 d = dev->si_drv1; 1101 if (d->bd_bif == NULL) 1102 return (ENXIO); 1103 1104 /* 1105 * Refresh PID associated with this descriptor. 1106 */ 1107 d->bd_pid = td->td_proc->p_pid; 1108 revents = events & (POLLOUT | POLLWRNORM); 1109 BPFD_LOCK(d); 1110 if (events & (POLLIN | POLLRDNORM)) { 1111 if (bpf_ready(d)) 1112 revents |= events & (POLLIN | POLLRDNORM); 1113 else { 1114 selrecord(td, &d->bd_sel); 1115 /* Start the read timeout if necessary. */ 1116 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1117 callout_reset(&d->bd_callout, d->bd_rtout, 1118 bpf_timed_out, d); 1119 d->bd_state = BPF_WAITING; 1120 } 1121 } 1122 } 1123 BPFD_UNLOCK(d); 1124 return (revents); 1125 } 1126 1127 /* 1128 * Support for kevent() system call. Register EVFILT_READ filters and 1129 * reject all others. 1130 */ 1131 int 1132 bpfkqfilter(struct cdev *dev, struct knote *kn) 1133 { 1134 struct bpf_d *d = (struct bpf_d *)dev->si_drv1; 1135 1136 if (kn->kn_filter != EVFILT_READ) 1137 return (1); 1138 1139 /* 1140 * Refresh PID associated with this descriptor. 1141 */ 1142 d->bd_pid = curthread->td_proc->p_pid; 1143 kn->kn_fop = &bpfread_filtops; 1144 kn->kn_hook = d; 1145 knlist_add(&d->bd_sel.si_note, kn, 0); 1146 1147 return (0); 1148 } 1149 1150 static void 1151 filt_bpfdetach(struct knote *kn) 1152 { 1153 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1154 1155 knlist_remove(&d->bd_sel.si_note, kn, 0); 1156 } 1157 1158 static int 1159 filt_bpfread(struct knote *kn, long hint) 1160 { 1161 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1162 int ready; 1163 1164 BPFD_LOCK_ASSERT(d); 1165 ready = bpf_ready(d); 1166 if (ready) { 1167 kn->kn_data = d->bd_slen; 1168 if (d->bd_hbuf) 1169 kn->kn_data += d->bd_hlen; 1170 } 1171 else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1172 callout_reset(&d->bd_callout, d->bd_rtout, 1173 bpf_timed_out, d); 1174 d->bd_state = BPF_WAITING; 1175 } 1176 1177 return (ready); 1178 } 1179 1180 /* 1181 * Incoming linkage from device drivers. Process the packet pkt, of length 1182 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1183 * by each process' filter, and if accepted, stashed into the corresponding 1184 * buffer. 1185 */ 1186 void 1187 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1188 { 1189 struct bpf_d *d; 1190 u_int slen; 1191 int gottime; 1192 struct timeval tv; 1193 1194 gottime = 0; 1195 BPFIF_LOCK(bp); 1196 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1197 BPFD_LOCK(d); 1198 ++d->bd_rcount; 1199 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 1200 if (slen != 0) { 1201 d->bd_fcount++; 1202 if (!gottime) { 1203 microtime(&tv); 1204 gottime = 1; 1205 } 1206 #ifdef MAC 1207 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1208 #endif 1209 catchpacket(d, pkt, pktlen, slen, bcopy, &tv); 1210 } 1211 BPFD_UNLOCK(d); 1212 } 1213 BPFIF_UNLOCK(bp); 1214 } 1215 1216 /* 1217 * Copy data from an mbuf chain into a buffer. This code is derived 1218 * from m_copydata in sys/uipc_mbuf.c. 1219 */ 1220 static void 1221 bpf_mcopy(const void *src_arg, void *dst_arg, size_t len) 1222 { 1223 const struct mbuf *m; 1224 u_int count; 1225 u_char *dst; 1226 1227 m = src_arg; 1228 dst = dst_arg; 1229 while (len > 0) { 1230 if (m == NULL) 1231 panic("bpf_mcopy"); 1232 count = min(m->m_len, len); 1233 bcopy(mtod(m, void *), dst, count); 1234 m = m->m_next; 1235 dst += count; 1236 len -= count; 1237 } 1238 } 1239 1240 /* 1241 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1242 */ 1243 void 1244 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1245 { 1246 struct bpf_d *d; 1247 u_int pktlen, slen; 1248 int gottime; 1249 struct timeval tv; 1250 1251 gottime = 0; 1252 1253 pktlen = m_length(m, NULL); 1254 1255 BPFIF_LOCK(bp); 1256 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1257 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1258 continue; 1259 BPFD_LOCK(d); 1260 ++d->bd_rcount; 1261 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 1262 if (slen != 0) { 1263 d->bd_fcount++; 1264 if (!gottime) { 1265 microtime(&tv); 1266 gottime = 1; 1267 } 1268 #ifdef MAC 1269 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1270 #endif 1271 catchpacket(d, (u_char *)m, pktlen, slen, 1272 bpf_mcopy, &tv); 1273 } 1274 BPFD_UNLOCK(d); 1275 } 1276 BPFIF_UNLOCK(bp); 1277 } 1278 1279 /* 1280 * Incoming linkage from device drivers, when packet is in 1281 * an mbuf chain and to be prepended by a contiguous header. 1282 */ 1283 void 1284 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 1285 { 1286 struct mbuf mb; 1287 struct bpf_d *d; 1288 u_int pktlen, slen; 1289 int gottime; 1290 struct timeval tv; 1291 1292 gottime = 0; 1293 1294 pktlen = m_length(m, NULL); 1295 /* 1296 * Craft on-stack mbuf suitable for passing to bpf_filter. 1297 * Note that we cut corners here; we only setup what's 1298 * absolutely needed--this mbuf should never go anywhere else. 1299 */ 1300 mb.m_next = m; 1301 mb.m_data = data; 1302 mb.m_len = dlen; 1303 pktlen += dlen; 1304 1305 BPFIF_LOCK(bp); 1306 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1307 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1308 continue; 1309 BPFD_LOCK(d); 1310 ++d->bd_rcount; 1311 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 1312 if (slen != 0) { 1313 d->bd_fcount++; 1314 if (!gottime) { 1315 microtime(&tv); 1316 gottime = 1; 1317 } 1318 #ifdef MAC 1319 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1320 #endif 1321 catchpacket(d, (u_char *)&mb, pktlen, slen, 1322 bpf_mcopy, &tv); 1323 } 1324 BPFD_UNLOCK(d); 1325 } 1326 BPFIF_UNLOCK(bp); 1327 } 1328 1329 /* 1330 * Move the packet data from interface memory (pkt) into the 1331 * store buffer. "cpfn" is the routine called to do the actual data 1332 * transfer. bcopy is passed in to copy contiguous chunks, while 1333 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1334 * pkt is really an mbuf. 1335 */ 1336 static void 1337 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 1338 void (*cpfn)(const void *, void *, size_t), struct timeval *tv) 1339 { 1340 struct bpf_hdr *hp; 1341 int totlen, curlen; 1342 int hdrlen = d->bd_bif->bif_hdrlen; 1343 int do_wakeup = 0; 1344 1345 BPFD_LOCK_ASSERT(d); 1346 /* 1347 * Figure out how many bytes to move. If the packet is 1348 * greater or equal to the snapshot length, transfer that 1349 * much. Otherwise, transfer the whole packet (unless 1350 * we hit the buffer size limit). 1351 */ 1352 totlen = hdrlen + min(snaplen, pktlen); 1353 if (totlen > d->bd_bufsize) 1354 totlen = d->bd_bufsize; 1355 1356 /* 1357 * Round up the end of the previous packet to the next longword. 1358 */ 1359 curlen = BPF_WORDALIGN(d->bd_slen); 1360 if (curlen + totlen > d->bd_bufsize) { 1361 /* 1362 * This packet will overflow the storage buffer. 1363 * Rotate the buffers if we can, then wakeup any 1364 * pending reads. 1365 */ 1366 if (d->bd_fbuf == NULL) { 1367 /* 1368 * We haven't completed the previous read yet, 1369 * so drop the packet. 1370 */ 1371 ++d->bd_dcount; 1372 return; 1373 } 1374 ROTATE_BUFFERS(d); 1375 do_wakeup = 1; 1376 curlen = 0; 1377 } 1378 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1379 /* 1380 * Immediate mode is set, or the read timeout has 1381 * already expired during a select call. A packet 1382 * arrived, so the reader should be woken up. 1383 */ 1384 do_wakeup = 1; 1385 1386 /* 1387 * Append the bpf header. 1388 */ 1389 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1390 hp->bh_tstamp = *tv; 1391 hp->bh_datalen = pktlen; 1392 hp->bh_hdrlen = hdrlen; 1393 /* 1394 * Copy the packet data into the store buffer and update its length. 1395 */ 1396 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1397 d->bd_slen = curlen + totlen; 1398 1399 if (do_wakeup) 1400 bpf_wakeup(d); 1401 } 1402 1403 /* 1404 * Initialize all nonzero fields of a descriptor. 1405 */ 1406 static int 1407 bpf_allocbufs(struct bpf_d *d) 1408 { 1409 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1410 if (d->bd_fbuf == NULL) 1411 return (ENOBUFS); 1412 1413 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1414 if (d->bd_sbuf == NULL) { 1415 free(d->bd_fbuf, M_BPF); 1416 return (ENOBUFS); 1417 } 1418 d->bd_slen = 0; 1419 d->bd_hlen = 0; 1420 return (0); 1421 } 1422 1423 /* 1424 * Free buffers currently in use by a descriptor. 1425 * Called on close. 1426 */ 1427 static void 1428 bpf_freed(struct bpf_d *d) 1429 { 1430 /* 1431 * We don't need to lock out interrupts since this descriptor has 1432 * been detached from its interface and it yet hasn't been marked 1433 * free. 1434 */ 1435 if (d->bd_sbuf != NULL) { 1436 free(d->bd_sbuf, M_BPF); 1437 if (d->bd_hbuf != NULL) 1438 free(d->bd_hbuf, M_BPF); 1439 if (d->bd_fbuf != NULL) 1440 free(d->bd_fbuf, M_BPF); 1441 } 1442 if (d->bd_rfilter) 1443 free((caddr_t)d->bd_rfilter, M_BPF); 1444 if (d->bd_wfilter) 1445 free((caddr_t)d->bd_wfilter, M_BPF); 1446 mtx_destroy(&d->bd_mtx); 1447 } 1448 1449 /* 1450 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1451 * fixed size of the link header (variable length headers not yet supported). 1452 */ 1453 void 1454 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1455 { 1456 1457 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1458 } 1459 1460 /* 1461 * Attach an interface to bpf. ifp is a pointer to the structure 1462 * defining the interface to be attached, dlt is the link layer type, 1463 * and hdrlen is the fixed size of the link header (variable length 1464 * headers are not yet supporrted). 1465 */ 1466 void 1467 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1468 { 1469 struct bpf_if *bp; 1470 1471 bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1472 if (bp == NULL) 1473 panic("bpfattach"); 1474 1475 LIST_INIT(&bp->bif_dlist); 1476 bp->bif_ifp = ifp; 1477 bp->bif_dlt = dlt; 1478 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1479 KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized")); 1480 *driverp = bp; 1481 1482 mtx_lock(&bpf_mtx); 1483 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 1484 mtx_unlock(&bpf_mtx); 1485 1486 /* 1487 * Compute the length of the bpf header. This is not necessarily 1488 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1489 * that the network layer header begins on a longword boundary (for 1490 * performance reasons and to alleviate alignment restrictions). 1491 */ 1492 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1493 1494 if (bootverbose) 1495 if_printf(ifp, "bpf attached\n"); 1496 } 1497 1498 /* 1499 * Detach bpf from an interface. This involves detaching each descriptor 1500 * associated with the interface, and leaving bd_bif NULL. Notify each 1501 * descriptor as it's detached so that any sleepers wake up and get 1502 * ENXIO. 1503 */ 1504 void 1505 bpfdetach(struct ifnet *ifp) 1506 { 1507 struct bpf_if *bp; 1508 struct bpf_d *d; 1509 1510 /* Locate BPF interface information */ 1511 mtx_lock(&bpf_mtx); 1512 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1513 if (ifp == bp->bif_ifp) 1514 break; 1515 } 1516 1517 /* Interface wasn't attached */ 1518 if ((bp == NULL) || (bp->bif_ifp == NULL)) { 1519 mtx_unlock(&bpf_mtx); 1520 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 1521 return; 1522 } 1523 1524 LIST_REMOVE(bp, bif_next); 1525 mtx_unlock(&bpf_mtx); 1526 1527 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { 1528 bpf_detachd(d); 1529 BPFD_LOCK(d); 1530 bpf_wakeup(d); 1531 BPFD_UNLOCK(d); 1532 } 1533 1534 mtx_destroy(&bp->bif_mtx); 1535 free(bp, M_BPF); 1536 } 1537 1538 /* 1539 * Get a list of available data link type of the interface. 1540 */ 1541 static int 1542 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 1543 { 1544 int n, error; 1545 struct ifnet *ifp; 1546 struct bpf_if *bp; 1547 1548 ifp = d->bd_bif->bif_ifp; 1549 n = 0; 1550 error = 0; 1551 mtx_lock(&bpf_mtx); 1552 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1553 if (bp->bif_ifp != ifp) 1554 continue; 1555 if (bfl->bfl_list != NULL) { 1556 if (n >= bfl->bfl_len) { 1557 mtx_unlock(&bpf_mtx); 1558 return (ENOMEM); 1559 } 1560 error = copyout(&bp->bif_dlt, 1561 bfl->bfl_list + n, sizeof(u_int)); 1562 } 1563 n++; 1564 } 1565 mtx_unlock(&bpf_mtx); 1566 bfl->bfl_len = n; 1567 return (error); 1568 } 1569 1570 /* 1571 * Set the data link type of a BPF instance. 1572 */ 1573 static int 1574 bpf_setdlt(struct bpf_d *d, u_int dlt) 1575 { 1576 int error, opromisc; 1577 struct ifnet *ifp; 1578 struct bpf_if *bp; 1579 1580 if (d->bd_bif->bif_dlt == dlt) 1581 return (0); 1582 ifp = d->bd_bif->bif_ifp; 1583 mtx_lock(&bpf_mtx); 1584 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1585 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1586 break; 1587 } 1588 mtx_unlock(&bpf_mtx); 1589 if (bp != NULL) { 1590 opromisc = d->bd_promisc; 1591 bpf_detachd(d); 1592 bpf_attachd(d, bp); 1593 BPFD_LOCK(d); 1594 reset_d(d); 1595 BPFD_UNLOCK(d); 1596 if (opromisc) { 1597 error = ifpromisc(bp->bif_ifp, 1); 1598 if (error) 1599 if_printf(bp->bif_ifp, 1600 "bpf_setdlt: ifpromisc failed (%d)\n", 1601 error); 1602 else 1603 d->bd_promisc = 1; 1604 } 1605 } 1606 return (bp == NULL ? EINVAL : 0); 1607 } 1608 1609 static void 1610 bpf_clone(void *arg, struct ucred *cred, char *name, int namelen, 1611 struct cdev **dev) 1612 { 1613 int u; 1614 1615 if (*dev != NULL) 1616 return; 1617 if (dev_stdclone(name, NULL, "bpf", &u) != 1) 1618 return; 1619 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, 1620 "bpf%d", u); 1621 dev_ref(*dev); 1622 (*dev)->si_flags |= SI_CHEAPCLONE; 1623 return; 1624 } 1625 1626 static void 1627 bpf_drvinit(void *unused) 1628 { 1629 1630 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 1631 LIST_INIT(&bpf_iflist); 1632 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); 1633 } 1634 1635 static void 1636 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 1637 { 1638 1639 bzero(d, sizeof(*d)); 1640 BPFD_LOCK_ASSERT(bd); 1641 d->bd_immediate = bd->bd_immediate; 1642 d->bd_promisc = bd->bd_promisc; 1643 d->bd_hdrcmplt = bd->bd_hdrcmplt; 1644 d->bd_seesent = bd->bd_seesent; 1645 d->bd_async = bd->bd_async; 1646 d->bd_rcount = bd->bd_rcount; 1647 d->bd_dcount = bd->bd_dcount; 1648 d->bd_fcount = bd->bd_fcount; 1649 d->bd_sig = bd->bd_sig; 1650 d->bd_slen = bd->bd_slen; 1651 d->bd_hlen = bd->bd_hlen; 1652 d->bd_bufsize = bd->bd_bufsize; 1653 d->bd_pid = bd->bd_pid; 1654 strlcpy(d->bd_ifname, 1655 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 1656 strlcpy(d->bd_pcomm, bd->bd_pcomm, MAXCOMLEN); 1657 d->bd_locked = bd->bd_locked; 1658 } 1659 1660 static int 1661 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 1662 { 1663 struct xbpf_d *xbdbuf, *xbd; 1664 int index, error; 1665 struct bpf_if *bp; 1666 struct bpf_d *bd; 1667 1668 /* 1669 * XXX This is not technically correct. It is possible for non 1670 * privileged users to open bpf devices. It would make sense 1671 * if the users who opened the devices were able to retrieve 1672 * the statistics for them, too. 1673 */ 1674 error = suser(req->td); 1675 if (error) 1676 return (error); 1677 if (req->oldptr == NULL) 1678 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 1679 if (bpf_bpfd_cnt == 0) 1680 return (SYSCTL_OUT(req, 0, 0)); 1681 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 1682 mtx_lock(&bpf_mtx); 1683 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 1684 mtx_unlock(&bpf_mtx); 1685 free(xbdbuf, M_BPF); 1686 return (ENOMEM); 1687 } 1688 index = 0; 1689 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1690 BPFIF_LOCK(bp); 1691 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 1692 xbd = &xbdbuf[index++]; 1693 BPFD_LOCK(bd); 1694 bpfstats_fill_xbpf(xbd, bd); 1695 BPFD_UNLOCK(bd); 1696 } 1697 BPFIF_UNLOCK(bp); 1698 } 1699 mtx_unlock(&bpf_mtx); 1700 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 1701 free(xbdbuf, M_BPF); 1702 return (error); 1703 } 1704 1705 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL) 1706 1707 #else /* !DEV_BPF && !NETGRAPH_BPF */ 1708 /* 1709 * NOP stubs to allow bpf-using drivers to load and function. 1710 * 1711 * A 'better' implementation would allow the core bpf functionality 1712 * to be loaded at runtime. 1713 */ 1714 static struct bpf_if bp_null; 1715 1716 void 1717 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1718 { 1719 } 1720 1721 void 1722 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1723 { 1724 } 1725 1726 void 1727 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 1728 { 1729 } 1730 1731 void 1732 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1733 { 1734 1735 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1736 } 1737 1738 void 1739 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1740 { 1741 1742 *driverp = &bp_null; 1743 } 1744 1745 void 1746 bpfdetach(struct ifnet *ifp) 1747 { 1748 } 1749 1750 u_int 1751 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 1752 { 1753 return -1; /* "no filter" behaviour */ 1754 } 1755 1756 int 1757 bpf_validate(const struct bpf_insn *f, int len) 1758 { 1759 return 0; /* false */ 1760 } 1761 1762 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 1763 1764 /* 1765 * ABI compatibility hacks. Older drivers check if_bpf against NULL 1766 * to see if there are active listeners. In the new ABI, if_bpf is 1767 * always non-NULL, so bpf_*tap() are always invoked. We check for 1768 * listeners in these wrappers and call the real functions if needed. 1769 */ 1770 #undef bpf_tap 1771 #undef bpf_mtap 1772 #undef bpf_mtap2 1773 1774 void bpf_tap(struct bpf_if *, u_char *, u_int); 1775 void bpf_mtap(struct bpf_if *, struct mbuf *); 1776 void bpf_mtap2(struct bpf_if *, void *, u_int, struct mbuf *); 1777 1778 void 1779 bpf_tap(bp, pkt, pktlen) 1780 struct bpf_if *bp; 1781 u_char *pkt; 1782 u_int pktlen; 1783 { 1784 1785 if (bpf_peers_present(bp)) 1786 bpf_tap_new(bp, pkt, pktlen); 1787 } 1788 1789 void 1790 bpf_mtap(bp, m) 1791 struct bpf_if *bp; 1792 struct mbuf *m; 1793 { 1794 1795 if (bpf_peers_present(bp)) 1796 bpf_mtap_new(bp, m); 1797 } 1798 1799 void 1800 bpf_mtap2(bp, d, l, m) 1801 struct bpf_if *bp; 1802 void *d; 1803 u_int l; 1804 struct mbuf *m; 1805 { 1806 1807 if (bpf_peers_present(bp)) 1808 bpf_mtap2_new(bp, d, l, m); 1809 }
Cache object: 29d087cb4df65c1dc5670527881ccf6a
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