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 #ifdef BPF_JITTER 69 #include <net/bpf_jitter.h> 70 #endif 71 #include <net/bpfdesc.h> 72 73 #include <netinet/in.h> 74 #include <netinet/if_ether.h> 75 #include <sys/kernel.h> 76 #include <sys/sysctl.h> 77 78 #include <net80211/ieee80211_freebsd.h> 79 80 static MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 81 82 #if defined(DEV_BPF) || defined(NETGRAPH_BPF) 83 84 #define PRINET 26 /* interruptible */ 85 86 /* 87 * bpf_iflist is a list of BPF interface structures, each corresponding to a 88 * specific DLT. The same network interface might have several BPF interface 89 * structures registered by different layers in the stack (i.e., 802.11 90 * frames, ethernet frames, etc). 91 */ 92 static LIST_HEAD(, bpf_if) bpf_iflist; 93 static struct mtx bpf_mtx; /* bpf global lock */ 94 static int bpf_bpfd_cnt; 95 96 static int bpf_allocbufs(struct bpf_d *); 97 static void bpf_attachd(struct bpf_d *, struct bpf_if *); 98 static void bpf_detachd(struct bpf_d *); 99 static void bpf_freed(struct bpf_d *); 100 static void bpf_mcopy(const void *, void *, size_t); 101 static int bpf_movein(struct uio *, int, int, 102 struct mbuf **, struct sockaddr *, struct bpf_insn *); 103 static int bpf_setif(struct bpf_d *, struct ifreq *); 104 static void bpf_timed_out(void *); 105 static __inline void 106 bpf_wakeup(struct bpf_d *); 107 static void catchpacket(struct bpf_d *, u_char *, u_int, 108 u_int, void (*)(const void *, void *, size_t), 109 struct timeval *); 110 static void reset_d(struct bpf_d *); 111 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 112 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 113 static int bpf_setdlt(struct bpf_d *, u_int); 114 static void filt_bpfdetach(struct knote *); 115 static int filt_bpfread(struct knote *, long); 116 static void bpf_drvinit(void *); 117 static void bpf_clone(void *, struct ucred *, char *, int, struct cdev **); 118 static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); 119 120 /* 121 * The default read buffer size is patchable. 122 */ 123 SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl"); 124 static int bpf_bufsize = 4096; 125 SYSCTL_INT(_net_bpf, OID_AUTO, bufsize, CTLFLAG_RW, 126 &bpf_bufsize, 0, ""); 127 static int bpf_maxbufsize = BPF_MAXBUFSIZE; 128 SYSCTL_INT(_net_bpf, OID_AUTO, maxbufsize, CTLFLAG_RW, 129 &bpf_maxbufsize, 0, ""); 130 static int bpf_maxinsns = BPF_MAXINSNS; 131 SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, 132 &bpf_maxinsns, 0, "Maximum bpf program instructions"); 133 SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_RW, 134 bpf_stats_sysctl, "bpf statistics portal"); 135 136 static d_open_t bpfopen; 137 static d_close_t bpfclose; 138 static d_read_t bpfread; 139 static d_write_t bpfwrite; 140 static d_ioctl_t bpfioctl; 141 static d_poll_t bpfpoll; 142 static d_kqfilter_t bpfkqfilter; 143 144 static struct cdevsw bpf_cdevsw = { 145 .d_version = D_VERSION, 146 .d_flags = D_NEEDGIANT, 147 .d_open = bpfopen, 148 .d_close = bpfclose, 149 .d_read = bpfread, 150 .d_write = bpfwrite, 151 .d_ioctl = bpfioctl, 152 .d_poll = bpfpoll, 153 .d_name = "bpf", 154 .d_kqfilter = bpfkqfilter, 155 }; 156 157 static struct filterops bpfread_filtops = 158 { 1, NULL, filt_bpfdetach, filt_bpfread }; 159 160 static int 161 bpf_movein(struct uio *uio, int linktype, int mtu, struct mbuf **mp, 162 struct sockaddr *sockp, struct bpf_insn *wfilter) 163 { 164 const struct ieee80211_bpf_params *p; 165 struct mbuf *m; 166 int error; 167 int len; 168 int hlen; 169 int slen; 170 171 /* 172 * Build a sockaddr based on the data link layer type. 173 * We do this at this level because the ethernet header 174 * is copied directly into the data field of the sockaddr. 175 * In the case of SLIP, there is no header and the packet 176 * is forwarded as is. 177 * Also, we are careful to leave room at the front of the mbuf 178 * for the link level header. 179 */ 180 switch (linktype) { 181 182 case DLT_SLIP: 183 sockp->sa_family = AF_INET; 184 hlen = 0; 185 break; 186 187 case DLT_EN10MB: 188 sockp->sa_family = AF_UNSPEC; 189 /* XXX Would MAXLINKHDR be better? */ 190 hlen = ETHER_HDR_LEN; 191 break; 192 193 case DLT_FDDI: 194 sockp->sa_family = AF_IMPLINK; 195 hlen = 0; 196 break; 197 198 case DLT_RAW: 199 sockp->sa_family = AF_UNSPEC; 200 hlen = 0; 201 break; 202 203 case DLT_NULL: 204 /* 205 * null interface types require a 4 byte pseudo header which 206 * corresponds to the address family of the packet. 207 */ 208 sockp->sa_family = AF_UNSPEC; 209 hlen = 4; 210 break; 211 212 case DLT_ATM_RFC1483: 213 /* 214 * en atm driver requires 4-byte atm pseudo header. 215 * though it isn't standard, vpi:vci needs to be 216 * specified anyway. 217 */ 218 sockp->sa_family = AF_UNSPEC; 219 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 220 break; 221 222 case DLT_PPP: 223 sockp->sa_family = AF_UNSPEC; 224 hlen = 4; /* This should match PPP_HDRLEN */ 225 break; 226 227 case DLT_IEEE802_11: /* IEEE 802.11 wireless */ 228 sockp->sa_family = AF_IEEE80211; 229 hlen = 0; 230 break; 231 232 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ 233 sockp->sa_family = AF_IEEE80211; 234 sockp->sa_len = 12; /* XXX != 0 */ 235 hlen = sizeof(struct ieee80211_bpf_params); 236 break; 237 238 default: 239 return (EIO); 240 } 241 242 len = uio->uio_resid; 243 244 if (len - hlen > mtu) 245 return (EMSGSIZE); 246 247 if ((unsigned)len > MCLBYTES) 248 return (EIO); 249 250 if (len > MHLEN) { 251 m = m_getcl(M_TRYWAIT, MT_DATA, M_PKTHDR); 252 } else { 253 MGETHDR(m, M_TRYWAIT, MT_DATA); 254 } 255 if (m == NULL) 256 return (ENOBUFS); 257 m->m_pkthdr.len = m->m_len = len; 258 m->m_pkthdr.rcvif = NULL; 259 *mp = m; 260 261 if (m->m_len < hlen) { 262 error = EPERM; 263 goto bad; 264 } 265 266 error = uiomove(mtod(m, u_char *), len, uio); 267 if (error) 268 goto bad; 269 270 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len); 271 if (slen == 0) { 272 error = EPERM; 273 goto bad; 274 } 275 276 /* 277 * Make room for link header, and copy it to sockaddr 278 */ 279 if (hlen != 0) { 280 if (sockp->sa_family == AF_IEEE80211) { 281 /* 282 * Collect true length from the parameter header 283 * NB: sockp is known to be zero'd so if we do a 284 * short copy unspecified parameters will be 285 * zero. 286 * NB: packet may not be aligned after stripping 287 * bpf params 288 * XXX check ibp_vers 289 */ 290 p = mtod(m, const struct ieee80211_bpf_params *); 291 hlen = p->ibp_len; 292 if (hlen > sizeof(sockp->sa_data)) { 293 error = EINVAL; 294 goto bad; 295 } 296 } 297 bcopy(m->m_data, sockp->sa_data, hlen); 298 m->m_pkthdr.len -= hlen; 299 m->m_len -= hlen; 300 #if BSD >= 199103 301 m->m_data += hlen; /* XXX */ 302 #else 303 m->m_off += hlen; 304 #endif 305 } 306 307 return (0); 308 bad: 309 m_freem(m); 310 return (error); 311 } 312 313 /* 314 * Attach file to the bpf interface, i.e. make d listen on bp. 315 */ 316 static void 317 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 318 { 319 /* 320 * Point d at bp, and add d to the interface's list of listeners. 321 * Finally, point the driver's bpf cookie at the interface so 322 * it will divert packets to bpf. 323 */ 324 BPFIF_LOCK(bp); 325 d->bd_bif = bp; 326 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 327 328 bpf_bpfd_cnt++; 329 BPFIF_UNLOCK(bp); 330 } 331 332 /* 333 * Detach a file from its interface. 334 */ 335 static void 336 bpf_detachd(struct bpf_d *d) 337 { 338 int error; 339 struct bpf_if *bp; 340 struct ifnet *ifp; 341 342 bp = d->bd_bif; 343 BPFIF_LOCK(bp); 344 BPFD_LOCK(d); 345 ifp = d->bd_bif->bif_ifp; 346 347 /* 348 * Remove d from the interface's descriptor list. 349 */ 350 LIST_REMOVE(d, bd_next); 351 352 bpf_bpfd_cnt--; 353 d->bd_bif = NULL; 354 BPFD_UNLOCK(d); 355 BPFIF_UNLOCK(bp); 356 357 /* 358 * Check if this descriptor had requested promiscuous mode. 359 * If so, turn it off. 360 */ 361 if (d->bd_promisc) { 362 d->bd_promisc = 0; 363 error = ifpromisc(ifp, 0); 364 if (error != 0 && error != ENXIO) { 365 /* 366 * ENXIO can happen if a pccard is unplugged 367 * Something is really wrong if we were able to put 368 * the driver into promiscuous mode, but can't 369 * take it out. 370 */ 371 if_printf(bp->bif_ifp, 372 "bpf_detach: ifpromisc failed (%d)\n", error); 373 } 374 } 375 } 376 377 /* 378 * Open ethernet device. Returns ENXIO for illegal minor device number, 379 * EBUSY if file is open by another process. 380 */ 381 /* ARGSUSED */ 382 static int 383 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 384 { 385 struct bpf_d *d; 386 387 mtx_lock(&bpf_mtx); 388 d = dev->si_drv1; 389 /* 390 * Each minor can be opened by only one process. If the requested 391 * minor is in use, return EBUSY. 392 */ 393 if (d != NULL) { 394 mtx_unlock(&bpf_mtx); 395 return (EBUSY); 396 } 397 dev->si_drv1 = (struct bpf_d *)~0; /* mark device in use */ 398 mtx_unlock(&bpf_mtx); 399 400 if ((dev->si_flags & SI_NAMED) == 0) 401 make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600, 402 "bpf%d", dev2unit(dev)); 403 MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 404 dev->si_drv1 = d; 405 d->bd_bufsize = bpf_bufsize; 406 d->bd_sig = SIGIO; 407 d->bd_seesent = 1; 408 d->bd_pid = td->td_proc->p_pid; 409 #ifdef MAC 410 mac_init_bpfdesc(d); 411 mac_create_bpfdesc(td->td_ucred, d); 412 #endif 413 mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF); 414 callout_init(&d->bd_callout, NET_CALLOUT_MPSAFE); 415 knlist_init(&d->bd_sel.si_note, &d->bd_mtx, NULL, NULL, NULL); 416 417 return (0); 418 } 419 420 /* 421 * Close the descriptor by detaching it from its interface, 422 * deallocating its buffers, and marking it free. 423 */ 424 /* ARGSUSED */ 425 static int 426 bpfclose(struct cdev *dev, int flags, int fmt, struct thread *td) 427 { 428 struct bpf_d *d = dev->si_drv1; 429 430 BPFD_LOCK(d); 431 if (d->bd_state == BPF_WAITING) 432 callout_stop(&d->bd_callout); 433 d->bd_state = BPF_IDLE; 434 BPFD_UNLOCK(d); 435 funsetown(&d->bd_sigio); 436 mtx_lock(&bpf_mtx); 437 if (d->bd_bif) 438 bpf_detachd(d); 439 mtx_unlock(&bpf_mtx); 440 selwakeuppri(&d->bd_sel, PRINET); 441 #ifdef MAC 442 mac_destroy_bpfdesc(d); 443 #endif /* MAC */ 444 knlist_destroy(&d->bd_sel.si_note); 445 bpf_freed(d); 446 dev->si_drv1 = NULL; 447 free(d, M_BPF); 448 449 return (0); 450 } 451 452 453 /* 454 * Rotate the packet buffers in descriptor d. Move the store buffer 455 * into the hold slot, and the free buffer into the store slot. 456 * Zero the length of the new store buffer. 457 */ 458 #define ROTATE_BUFFERS(d) \ 459 (d)->bd_hbuf = (d)->bd_sbuf; \ 460 (d)->bd_hlen = (d)->bd_slen; \ 461 (d)->bd_sbuf = (d)->bd_fbuf; \ 462 (d)->bd_slen = 0; \ 463 (d)->bd_fbuf = NULL; 464 /* 465 * bpfread - read next chunk of packets from buffers 466 */ 467 static int 468 bpfread(struct cdev *dev, struct uio *uio, int ioflag) 469 { 470 struct bpf_d *d = dev->si_drv1; 471 int timed_out; 472 int error; 473 474 /* 475 * Restrict application to use a buffer the same size as 476 * as kernel buffers. 477 */ 478 if (uio->uio_resid != d->bd_bufsize) 479 return (EINVAL); 480 481 BPFD_LOCK(d); 482 if (d->bd_state == BPF_WAITING) 483 callout_stop(&d->bd_callout); 484 timed_out = (d->bd_state == BPF_TIMED_OUT); 485 d->bd_state = BPF_IDLE; 486 /* 487 * If the hold buffer is empty, then do a timed sleep, which 488 * ends when the timeout expires or when enough packets 489 * have arrived to fill the store buffer. 490 */ 491 while (d->bd_hbuf == NULL) { 492 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { 493 /* 494 * A packet(s) either arrived since the previous 495 * read or arrived while we were asleep. 496 * Rotate the buffers and return what's here. 497 */ 498 ROTATE_BUFFERS(d); 499 break; 500 } 501 502 /* 503 * No data is available, check to see if the bpf device 504 * is still pointed at a real interface. If not, return 505 * ENXIO so that the userland process knows to rebind 506 * it before using it again. 507 */ 508 if (d->bd_bif == NULL) { 509 BPFD_UNLOCK(d); 510 return (ENXIO); 511 } 512 513 if (ioflag & O_NONBLOCK) { 514 BPFD_UNLOCK(d); 515 return (EWOULDBLOCK); 516 } 517 error = msleep(d, &d->bd_mtx, PRINET|PCATCH, 518 "bpf", d->bd_rtout); 519 if (error == EINTR || error == ERESTART) { 520 BPFD_UNLOCK(d); 521 return (error); 522 } 523 if (error == EWOULDBLOCK) { 524 /* 525 * On a timeout, return what's in the buffer, 526 * which may be nothing. If there is something 527 * in the store buffer, we can rotate the buffers. 528 */ 529 if (d->bd_hbuf) 530 /* 531 * We filled up the buffer in between 532 * getting the timeout and arriving 533 * here, so we don't need to rotate. 534 */ 535 break; 536 537 if (d->bd_slen == 0) { 538 BPFD_UNLOCK(d); 539 return (0); 540 } 541 ROTATE_BUFFERS(d); 542 break; 543 } 544 } 545 /* 546 * At this point, we know we have something in the hold slot. 547 */ 548 BPFD_UNLOCK(d); 549 550 /* 551 * Move data from hold buffer into user space. 552 * We know the entire buffer is transferred since 553 * we checked above that the read buffer is bpf_bufsize bytes. 554 */ 555 error = uiomove(d->bd_hbuf, d->bd_hlen, uio); 556 557 BPFD_LOCK(d); 558 d->bd_fbuf = d->bd_hbuf; 559 d->bd_hbuf = NULL; 560 d->bd_hlen = 0; 561 BPFD_UNLOCK(d); 562 563 return (error); 564 } 565 566 567 /* 568 * If there are processes sleeping on this descriptor, wake them up. 569 */ 570 static __inline void 571 bpf_wakeup(struct bpf_d *d) 572 { 573 574 BPFD_LOCK_ASSERT(d); 575 if (d->bd_state == BPF_WAITING) { 576 callout_stop(&d->bd_callout); 577 d->bd_state = BPF_IDLE; 578 } 579 wakeup(d); 580 if (d->bd_async && d->bd_sig && d->bd_sigio) 581 pgsigio(&d->bd_sigio, d->bd_sig, 0); 582 583 selwakeuppri(&d->bd_sel, PRINET); 584 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 585 } 586 587 static void 588 bpf_timed_out(void *arg) 589 { 590 struct bpf_d *d = (struct bpf_d *)arg; 591 592 BPFD_LOCK(d); 593 if (d->bd_state == BPF_WAITING) { 594 d->bd_state = BPF_TIMED_OUT; 595 if (d->bd_slen != 0) 596 bpf_wakeup(d); 597 } 598 BPFD_UNLOCK(d); 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 if (d->bd_bif == NULL) 611 return (ENXIO); 612 613 ifp = d->bd_bif->bif_ifp; 614 615 if ((ifp->if_flags & IFF_UP) == 0) 616 return (ENETDOWN); 617 618 if (uio->uio_resid == 0) 619 return (0); 620 621 bzero(&dst, sizeof(dst)); 622 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp->if_mtu, 623 &m, &dst, d->bd_wfilter); 624 if (error) 625 return (error); 626 627 if (d->bd_hdrcmplt) 628 dst.sa_family = pseudo_AF_HDRCMPLT; 629 630 #ifdef MAC 631 BPFD_LOCK(d); 632 mac_create_mbuf_from_bpfdesc(d, m); 633 BPFD_UNLOCK(d); 634 #endif 635 NET_LOCK_GIANT(); 636 error = (*ifp->if_output)(ifp, m, &dst, NULL); 637 NET_UNLOCK_GIANT(); 638 /* 639 * The driver frees the mbuf. 640 */ 641 return (error); 642 } 643 644 /* 645 * Reset a descriptor by flushing its packet buffer and clearing the 646 * receive and drop counts. 647 */ 648 static void 649 reset_d(struct bpf_d *d) 650 { 651 652 mtx_assert(&d->bd_mtx, MA_OWNED); 653 if (d->bd_hbuf) { 654 /* Free the hold buffer. */ 655 d->bd_fbuf = d->bd_hbuf; 656 d->bd_hbuf = NULL; 657 } 658 d->bd_slen = 0; 659 d->bd_hlen = 0; 660 d->bd_rcount = 0; 661 d->bd_dcount = 0; 662 d->bd_fcount = 0; 663 } 664 665 /* 666 * FIONREAD Check for read packet available. 667 * SIOCGIFADDR Get interface address - convenient hook to driver. 668 * BIOCGBLEN Get buffer len [for read()]. 669 * BIOCSETF Set ethernet read filter. 670 * BIOCSETWF Set ethernet write filter. 671 * BIOCFLUSH Flush read packet buffer. 672 * BIOCPROMISC Put interface into promiscuous mode. 673 * BIOCGDLT Get link layer type. 674 * BIOCGETIF Get interface name. 675 * BIOCSETIF Set interface. 676 * BIOCSRTIMEOUT Set read timeout. 677 * BIOCGRTIMEOUT Get read timeout. 678 * BIOCGSTATS Get packet stats. 679 * BIOCIMMEDIATE Set immediate mode. 680 * BIOCVERSION Get filter language version. 681 * BIOCGHDRCMPLT Get "header already complete" flag 682 * BIOCSHDRCMPLT Set "header already complete" flag 683 * BIOCGSEESENT Get "see packets sent" flag 684 * BIOCSSEESENT Set "see packets sent" flag 685 * BIOCLOCK Set "locked" flag 686 */ 687 /* ARGSUSED */ 688 static int 689 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 690 struct thread *td) 691 { 692 struct bpf_d *d = dev->si_drv1; 693 int error = 0; 694 695 /* 696 * Refresh PID associated with this descriptor. 697 */ 698 BPFD_LOCK(d); 699 d->bd_pid = td->td_proc->p_pid; 700 if (d->bd_state == BPF_WAITING) 701 callout_stop(&d->bd_callout); 702 d->bd_state = BPF_IDLE; 703 BPFD_UNLOCK(d); 704 705 if (d->bd_locked == 1) { 706 switch (cmd) { 707 case BIOCGBLEN: 708 case BIOCFLUSH: 709 case BIOCGDLT: 710 case BIOCGDLTLIST: 711 case BIOCGETIF: 712 case BIOCGRTIMEOUT: 713 case BIOCGSTATS: 714 case BIOCVERSION: 715 case BIOCGRSIG: 716 case BIOCGHDRCMPLT: 717 case FIONREAD: 718 case BIOCLOCK: 719 case BIOCSRTIMEOUT: 720 case BIOCIMMEDIATE: 721 case TIOCGPGRP: 722 break; 723 default: 724 return (EPERM); 725 } 726 } 727 switch (cmd) { 728 729 default: 730 error = EINVAL; 731 break; 732 733 /* 734 * Check for read packet available. 735 */ 736 case FIONREAD: 737 { 738 int n; 739 740 BPFD_LOCK(d); 741 n = d->bd_slen; 742 if (d->bd_hbuf) 743 n += d->bd_hlen; 744 BPFD_UNLOCK(d); 745 746 *(int *)addr = n; 747 break; 748 } 749 750 case SIOCGIFADDR: 751 { 752 struct ifnet *ifp; 753 754 if (d->bd_bif == NULL) 755 error = EINVAL; 756 else { 757 ifp = d->bd_bif->bif_ifp; 758 error = (*ifp->if_ioctl)(ifp, cmd, addr); 759 } 760 break; 761 } 762 763 /* 764 * Get buffer len [for read()]. 765 */ 766 case BIOCGBLEN: 767 *(u_int *)addr = d->bd_bufsize; 768 break; 769 770 /* 771 * Set buffer length. 772 */ 773 case BIOCSBLEN: 774 if (d->bd_bif != NULL) 775 error = EINVAL; 776 else { 777 u_int size = *(u_int *)addr; 778 779 if (size > bpf_maxbufsize) 780 *(u_int *)addr = size = bpf_maxbufsize; 781 else if (size < BPF_MINBUFSIZE) 782 *(u_int *)addr = size = BPF_MINBUFSIZE; 783 d->bd_bufsize = size; 784 } 785 break; 786 787 /* 788 * Set link layer read filter. 789 */ 790 case BIOCSETF: 791 case BIOCSETWF: 792 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 793 break; 794 795 /* 796 * Flush read packet buffer. 797 */ 798 case BIOCFLUSH: 799 BPFD_LOCK(d); 800 reset_d(d); 801 BPFD_UNLOCK(d); 802 break; 803 804 /* 805 * Put interface into promiscuous mode. 806 */ 807 case BIOCPROMISC: 808 if (d->bd_bif == NULL) { 809 /* 810 * No interface attached yet. 811 */ 812 error = EINVAL; 813 break; 814 } 815 if (d->bd_promisc == 0) { 816 mtx_lock(&Giant); 817 error = ifpromisc(d->bd_bif->bif_ifp, 1); 818 mtx_unlock(&Giant); 819 if (error == 0) 820 d->bd_promisc = 1; 821 } 822 break; 823 824 /* 825 * Get current data link type. 826 */ 827 case BIOCGDLT: 828 if (d->bd_bif == NULL) 829 error = EINVAL; 830 else 831 *(u_int *)addr = d->bd_bif->bif_dlt; 832 break; 833 834 /* 835 * Get a list of supported data link types. 836 */ 837 case BIOCGDLTLIST: 838 if (d->bd_bif == NULL) 839 error = EINVAL; 840 else 841 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 842 break; 843 844 /* 845 * Set data link type. 846 */ 847 case BIOCSDLT: 848 if (d->bd_bif == NULL) 849 error = EINVAL; 850 else 851 error = bpf_setdlt(d, *(u_int *)addr); 852 break; 853 854 /* 855 * Get interface name. 856 */ 857 case BIOCGETIF: 858 if (d->bd_bif == NULL) 859 error = EINVAL; 860 else { 861 struct ifnet *const ifp = d->bd_bif->bif_ifp; 862 struct ifreq *const ifr = (struct ifreq *)addr; 863 864 strlcpy(ifr->ifr_name, ifp->if_xname, 865 sizeof(ifr->ifr_name)); 866 } 867 break; 868 869 /* 870 * Set interface. 871 */ 872 case BIOCSETIF: 873 error = bpf_setif(d, (struct ifreq *)addr); 874 break; 875 876 /* 877 * Set read timeout. 878 */ 879 case BIOCSRTIMEOUT: 880 { 881 struct timeval *tv = (struct timeval *)addr; 882 883 /* 884 * Subtract 1 tick from tvtohz() since this isn't 885 * a one-shot timer. 886 */ 887 if ((error = itimerfix(tv)) == 0) 888 d->bd_rtout = tvtohz(tv) - 1; 889 break; 890 } 891 892 /* 893 * Get read timeout. 894 */ 895 case BIOCGRTIMEOUT: 896 { 897 struct timeval *tv = (struct timeval *)addr; 898 899 tv->tv_sec = d->bd_rtout / hz; 900 tv->tv_usec = (d->bd_rtout % hz) * tick; 901 break; 902 } 903 904 /* 905 * Get packet stats. 906 */ 907 case BIOCGSTATS: 908 { 909 struct bpf_stat *bs = (struct bpf_stat *)addr; 910 911 bs->bs_recv = d->bd_rcount; 912 bs->bs_drop = d->bd_dcount; 913 break; 914 } 915 916 /* 917 * Set immediate mode. 918 */ 919 case BIOCIMMEDIATE: 920 d->bd_immediate = *(u_int *)addr; 921 break; 922 923 case BIOCVERSION: 924 { 925 struct bpf_version *bv = (struct bpf_version *)addr; 926 927 bv->bv_major = BPF_MAJOR_VERSION; 928 bv->bv_minor = BPF_MINOR_VERSION; 929 break; 930 } 931 932 /* 933 * Get "header already complete" flag 934 */ 935 case BIOCGHDRCMPLT: 936 *(u_int *)addr = d->bd_hdrcmplt; 937 break; 938 939 case BIOCLOCK: 940 d->bd_locked = 1; 941 break; 942 /* 943 * Set "header already complete" flag 944 */ 945 case BIOCSHDRCMPLT: 946 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 947 break; 948 949 /* 950 * Get "see sent packets" flag 951 */ 952 case BIOCGSEESENT: 953 *(u_int *)addr = d->bd_seesent; 954 break; 955 956 /* 957 * Set "see sent packets" flag 958 */ 959 case BIOCSSEESENT: 960 d->bd_seesent = *(u_int *)addr; 961 break; 962 963 case FIONBIO: /* Non-blocking I/O */ 964 break; 965 966 case FIOASYNC: /* Send signal on receive packets */ 967 d->bd_async = *(int *)addr; 968 break; 969 970 case FIOSETOWN: 971 error = fsetown(*(int *)addr, &d->bd_sigio); 972 break; 973 974 case FIOGETOWN: 975 *(int *)addr = fgetown(&d->bd_sigio); 976 break; 977 978 /* This is deprecated, FIOSETOWN should be used instead. */ 979 case TIOCSPGRP: 980 error = fsetown(-(*(int *)addr), &d->bd_sigio); 981 break; 982 983 /* This is deprecated, FIOGETOWN should be used instead. */ 984 case TIOCGPGRP: 985 *(int *)addr = -fgetown(&d->bd_sigio); 986 break; 987 988 case BIOCSRSIG: /* Set receive signal */ 989 { 990 u_int sig; 991 992 sig = *(u_int *)addr; 993 994 if (sig >= NSIG) 995 error = EINVAL; 996 else 997 d->bd_sig = sig; 998 break; 999 } 1000 case BIOCGRSIG: 1001 *(u_int *)addr = d->bd_sig; 1002 break; 1003 } 1004 return (error); 1005 } 1006 1007 /* 1008 * Set d's packet filter program to fp. If this file already has a filter, 1009 * free it and replace it. Returns EINVAL for bogus requests. 1010 */ 1011 static int 1012 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1013 { 1014 struct bpf_insn *fcode, *old; 1015 u_int wfilter, flen, size; 1016 #ifdef BPF_JITTER 1017 bpf_jit_filter *ofunc; 1018 #endif 1019 1020 if (cmd == BIOCSETWF) { 1021 old = d->bd_wfilter; 1022 wfilter = 1; 1023 #ifdef BPF_JITTER 1024 ofunc = NULL; 1025 #endif 1026 } else { 1027 wfilter = 0; 1028 old = d->bd_rfilter; 1029 #ifdef BPF_JITTER 1030 ofunc = d->bd_bfilter; 1031 #endif 1032 } 1033 if (fp->bf_insns == NULL) { 1034 if (fp->bf_len != 0) 1035 return (EINVAL); 1036 BPFD_LOCK(d); 1037 if (wfilter) 1038 d->bd_wfilter = NULL; 1039 else { 1040 d->bd_rfilter = NULL; 1041 #ifdef BPF_JITTER 1042 d->bd_bfilter = NULL; 1043 #endif 1044 } 1045 reset_d(d); 1046 BPFD_UNLOCK(d); 1047 if (old != NULL) 1048 free((caddr_t)old, M_BPF); 1049 #ifdef BPF_JITTER 1050 if (ofunc != NULL) 1051 bpf_destroy_jit_filter(ofunc); 1052 #endif 1053 return (0); 1054 } 1055 flen = fp->bf_len; 1056 if (flen > bpf_maxinsns) 1057 return (EINVAL); 1058 1059 size = flen * sizeof(*fp->bf_insns); 1060 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); 1061 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 1062 bpf_validate(fcode, (int)flen)) { 1063 BPFD_LOCK(d); 1064 if (wfilter) 1065 d->bd_wfilter = fcode; 1066 else { 1067 d->bd_rfilter = fcode; 1068 #ifdef BPF_JITTER 1069 d->bd_bfilter = bpf_jitter(fcode, flen); 1070 #endif 1071 } 1072 reset_d(d); 1073 BPFD_UNLOCK(d); 1074 if (old != NULL) 1075 free((caddr_t)old, M_BPF); 1076 #ifdef BPF_JITTER 1077 if (ofunc != NULL) 1078 bpf_destroy_jit_filter(ofunc); 1079 #endif 1080 1081 return (0); 1082 } 1083 free((caddr_t)fcode, M_BPF); 1084 return (EINVAL); 1085 } 1086 1087 /* 1088 * Detach a file from its current interface (if attached at all) and attach 1089 * to the interface indicated by the name stored in ifr. 1090 * Return an errno or 0. 1091 */ 1092 static int 1093 bpf_setif(struct bpf_d *d, struct ifreq *ifr) 1094 { 1095 struct bpf_if *bp; 1096 int error; 1097 struct ifnet *theywant; 1098 1099 theywant = ifunit(ifr->ifr_name); 1100 if (theywant == NULL || theywant->if_bpf == NULL) 1101 return (ENXIO); 1102 1103 bp = theywant->if_bpf; 1104 /* 1105 * Allocate the packet buffers if we need to. 1106 * If we're already attached to requested interface, 1107 * just flush the buffer. 1108 */ 1109 if (d->bd_sbuf == NULL) { 1110 error = bpf_allocbufs(d); 1111 if (error != 0) 1112 return (error); 1113 } 1114 if (bp != d->bd_bif) { 1115 if (d->bd_bif) 1116 /* 1117 * Detach if attached to something else. 1118 */ 1119 bpf_detachd(d); 1120 1121 bpf_attachd(d, bp); 1122 } 1123 BPFD_LOCK(d); 1124 reset_d(d); 1125 BPFD_UNLOCK(d); 1126 return (0); 1127 } 1128 1129 /* 1130 * Support for select() and poll() system calls 1131 * 1132 * Return true iff the specific operation will not block indefinitely. 1133 * Otherwise, return false but make a note that a selwakeup() must be done. 1134 */ 1135 static int 1136 bpfpoll(struct cdev *dev, int events, struct thread *td) 1137 { 1138 struct bpf_d *d; 1139 int revents; 1140 1141 d = dev->si_drv1; 1142 if (d->bd_bif == NULL) 1143 return (ENXIO); 1144 1145 /* 1146 * Refresh PID associated with this descriptor. 1147 */ 1148 revents = events & (POLLOUT | POLLWRNORM); 1149 BPFD_LOCK(d); 1150 d->bd_pid = td->td_proc->p_pid; 1151 if (events & (POLLIN | POLLRDNORM)) { 1152 if (bpf_ready(d)) 1153 revents |= events & (POLLIN | POLLRDNORM); 1154 else { 1155 selrecord(td, &d->bd_sel); 1156 /* Start the read timeout if necessary. */ 1157 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1158 callout_reset(&d->bd_callout, d->bd_rtout, 1159 bpf_timed_out, d); 1160 d->bd_state = BPF_WAITING; 1161 } 1162 } 1163 } 1164 BPFD_UNLOCK(d); 1165 return (revents); 1166 } 1167 1168 /* 1169 * Support for kevent() system call. Register EVFILT_READ filters and 1170 * reject all others. 1171 */ 1172 int 1173 bpfkqfilter(struct cdev *dev, struct knote *kn) 1174 { 1175 struct bpf_d *d = (struct bpf_d *)dev->si_drv1; 1176 1177 if (kn->kn_filter != EVFILT_READ) 1178 return (1); 1179 1180 /* 1181 * Refresh PID associated with this descriptor. 1182 */ 1183 BPFD_LOCK(d); 1184 d->bd_pid = curthread->td_proc->p_pid; 1185 kn->kn_fop = &bpfread_filtops; 1186 kn->kn_hook = d; 1187 knlist_add(&d->bd_sel.si_note, kn, 1); 1188 BPFD_UNLOCK(d); 1189 1190 return (0); 1191 } 1192 1193 static void 1194 filt_bpfdetach(struct knote *kn) 1195 { 1196 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1197 1198 knlist_remove(&d->bd_sel.si_note, kn, 0); 1199 } 1200 1201 static int 1202 filt_bpfread(struct knote *kn, long hint) 1203 { 1204 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1205 int ready; 1206 1207 BPFD_LOCK_ASSERT(d); 1208 ready = bpf_ready(d); 1209 if (ready) { 1210 kn->kn_data = d->bd_slen; 1211 if (d->bd_hbuf) 1212 kn->kn_data += d->bd_hlen; 1213 } 1214 else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1215 callout_reset(&d->bd_callout, d->bd_rtout, 1216 bpf_timed_out, d); 1217 d->bd_state = BPF_WAITING; 1218 } 1219 1220 return (ready); 1221 } 1222 1223 /* 1224 * Incoming linkage from device drivers. Process the packet pkt, of length 1225 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1226 * by each process' filter, and if accepted, stashed into the corresponding 1227 * buffer. 1228 */ 1229 void 1230 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1231 { 1232 struct bpf_d *d; 1233 u_int slen; 1234 int gottime; 1235 struct timeval tv; 1236 1237 gottime = 0; 1238 BPFIF_LOCK(bp); 1239 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1240 BPFD_LOCK(d); 1241 ++d->bd_rcount; 1242 #ifdef BPF_JITTER 1243 if (bpf_jitter_enable != 0 && d->bd_bfilter != NULL) 1244 slen = (*(d->bd_bfilter->func))(pkt, pktlen, pktlen); 1245 else 1246 #endif 1247 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 1248 if (slen != 0) { 1249 d->bd_fcount++; 1250 if (!gottime) { 1251 microtime(&tv); 1252 gottime = 1; 1253 } 1254 #ifdef MAC 1255 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1256 #endif 1257 catchpacket(d, pkt, pktlen, slen, bcopy, &tv); 1258 } 1259 BPFD_UNLOCK(d); 1260 } 1261 BPFIF_UNLOCK(bp); 1262 } 1263 1264 /* 1265 * Copy data from an mbuf chain into a buffer. This code is derived 1266 * from m_copydata in sys/uipc_mbuf.c. 1267 */ 1268 static void 1269 bpf_mcopy(const void *src_arg, void *dst_arg, size_t len) 1270 { 1271 const struct mbuf *m; 1272 u_int count; 1273 u_char *dst; 1274 1275 m = src_arg; 1276 dst = dst_arg; 1277 while (len > 0) { 1278 if (m == NULL) 1279 panic("bpf_mcopy"); 1280 count = min(m->m_len, len); 1281 bcopy(mtod(m, void *), dst, count); 1282 m = m->m_next; 1283 dst += count; 1284 len -= count; 1285 } 1286 } 1287 1288 /* 1289 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1290 */ 1291 void 1292 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1293 { 1294 struct bpf_d *d; 1295 u_int pktlen, slen; 1296 int gottime; 1297 struct timeval tv; 1298 1299 gottime = 0; 1300 1301 pktlen = m_length(m, NULL); 1302 1303 BPFIF_LOCK(bp); 1304 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1305 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1306 continue; 1307 BPFD_LOCK(d); 1308 ++d->bd_rcount; 1309 #ifdef BPF_JITTER 1310 /* XXX We cannot handle multiple mbufs. */ 1311 if (bpf_jitter_enable != 0 && d->bd_bfilter != NULL && 1312 m->m_next == NULL) 1313 slen = (*(d->bd_bfilter->func))(mtod(m, u_char *), 1314 pktlen, pktlen); 1315 else 1316 #endif 1317 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 1318 if (slen != 0) { 1319 d->bd_fcount++; 1320 if (!gottime) { 1321 microtime(&tv); 1322 gottime = 1; 1323 } 1324 #ifdef MAC 1325 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1326 #endif 1327 catchpacket(d, (u_char *)m, pktlen, slen, 1328 bpf_mcopy, &tv); 1329 } 1330 BPFD_UNLOCK(d); 1331 } 1332 BPFIF_UNLOCK(bp); 1333 } 1334 1335 /* 1336 * Incoming linkage from device drivers, when packet is in 1337 * an mbuf chain and to be prepended by a contiguous header. 1338 */ 1339 void 1340 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 1341 { 1342 struct mbuf mb; 1343 struct bpf_d *d; 1344 u_int pktlen, slen; 1345 int gottime; 1346 struct timeval tv; 1347 1348 gottime = 0; 1349 1350 pktlen = m_length(m, NULL); 1351 /* 1352 * Craft on-stack mbuf suitable for passing to bpf_filter. 1353 * Note that we cut corners here; we only setup what's 1354 * absolutely needed--this mbuf should never go anywhere else. 1355 */ 1356 mb.m_next = m; 1357 mb.m_data = data; 1358 mb.m_len = dlen; 1359 pktlen += dlen; 1360 1361 BPFIF_LOCK(bp); 1362 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1363 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1364 continue; 1365 BPFD_LOCK(d); 1366 ++d->bd_rcount; 1367 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 1368 if (slen != 0) { 1369 d->bd_fcount++; 1370 if (!gottime) { 1371 microtime(&tv); 1372 gottime = 1; 1373 } 1374 #ifdef MAC 1375 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1376 #endif 1377 catchpacket(d, (u_char *)&mb, pktlen, slen, 1378 bpf_mcopy, &tv); 1379 } 1380 BPFD_UNLOCK(d); 1381 } 1382 BPFIF_UNLOCK(bp); 1383 } 1384 1385 /* 1386 * Move the packet data from interface memory (pkt) into the 1387 * store buffer. "cpfn" is the routine called to do the actual data 1388 * transfer. bcopy is passed in to copy contiguous chunks, while 1389 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1390 * pkt is really an mbuf. 1391 */ 1392 static void 1393 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 1394 void (*cpfn)(const void *, void *, size_t), struct timeval *tv) 1395 { 1396 struct bpf_hdr *hp; 1397 int totlen, curlen; 1398 int hdrlen = d->bd_bif->bif_hdrlen; 1399 int do_wakeup = 0; 1400 1401 BPFD_LOCK_ASSERT(d); 1402 /* 1403 * Figure out how many bytes to move. If the packet is 1404 * greater or equal to the snapshot length, transfer that 1405 * much. Otherwise, transfer the whole packet (unless 1406 * we hit the buffer size limit). 1407 */ 1408 totlen = hdrlen + min(snaplen, pktlen); 1409 if (totlen > d->bd_bufsize) 1410 totlen = d->bd_bufsize; 1411 1412 /* 1413 * Round up the end of the previous packet to the next longword. 1414 */ 1415 curlen = BPF_WORDALIGN(d->bd_slen); 1416 if (curlen + totlen > d->bd_bufsize) { 1417 /* 1418 * This packet will overflow the storage buffer. 1419 * Rotate the buffers if we can, then wakeup any 1420 * pending reads. 1421 */ 1422 if (d->bd_fbuf == NULL) { 1423 /* 1424 * We haven't completed the previous read yet, 1425 * so drop the packet. 1426 */ 1427 ++d->bd_dcount; 1428 return; 1429 } 1430 ROTATE_BUFFERS(d); 1431 do_wakeup = 1; 1432 curlen = 0; 1433 } 1434 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1435 /* 1436 * Immediate mode is set, or the read timeout has 1437 * already expired during a select call. A packet 1438 * arrived, so the reader should be woken up. 1439 */ 1440 do_wakeup = 1; 1441 1442 /* 1443 * Append the bpf header. 1444 */ 1445 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1446 hp->bh_tstamp = *tv; 1447 hp->bh_datalen = pktlen; 1448 hp->bh_hdrlen = hdrlen; 1449 /* 1450 * Copy the packet data into the store buffer and update its length. 1451 */ 1452 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1453 d->bd_slen = curlen + totlen; 1454 1455 if (do_wakeup) 1456 bpf_wakeup(d); 1457 } 1458 1459 /* 1460 * Initialize all nonzero fields of a descriptor. 1461 */ 1462 static int 1463 bpf_allocbufs(struct bpf_d *d) 1464 { 1465 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1466 if (d->bd_fbuf == NULL) 1467 return (ENOBUFS); 1468 1469 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1470 if (d->bd_sbuf == NULL) { 1471 free(d->bd_fbuf, M_BPF); 1472 return (ENOBUFS); 1473 } 1474 d->bd_slen = 0; 1475 d->bd_hlen = 0; 1476 return (0); 1477 } 1478 1479 /* 1480 * Free buffers currently in use by a descriptor. 1481 * Called on close. 1482 */ 1483 static void 1484 bpf_freed(struct bpf_d *d) 1485 { 1486 /* 1487 * We don't need to lock out interrupts since this descriptor has 1488 * been detached from its interface and it yet hasn't been marked 1489 * free. 1490 */ 1491 if (d->bd_sbuf != NULL) { 1492 free(d->bd_sbuf, M_BPF); 1493 if (d->bd_hbuf != NULL) 1494 free(d->bd_hbuf, M_BPF); 1495 if (d->bd_fbuf != NULL) 1496 free(d->bd_fbuf, M_BPF); 1497 } 1498 if (d->bd_rfilter) { 1499 free((caddr_t)d->bd_rfilter, M_BPF); 1500 #ifdef BPF_JITTER 1501 bpf_destroy_jit_filter(d->bd_bfilter); 1502 #endif 1503 } 1504 if (d->bd_wfilter) 1505 free((caddr_t)d->bd_wfilter, M_BPF); 1506 mtx_destroy(&d->bd_mtx); 1507 } 1508 1509 /* 1510 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1511 * fixed size of the link header (variable length headers not yet supported). 1512 */ 1513 void 1514 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1515 { 1516 1517 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1518 } 1519 1520 /* 1521 * Attach an interface to bpf. ifp is a pointer to the structure 1522 * defining the interface to be attached, dlt is the link layer type, 1523 * and hdrlen is the fixed size of the link header (variable length 1524 * headers are not yet supporrted). 1525 */ 1526 void 1527 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1528 { 1529 struct bpf_if *bp; 1530 1531 bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1532 if (bp == NULL) 1533 panic("bpfattach"); 1534 1535 LIST_INIT(&bp->bif_dlist); 1536 bp->bif_ifp = ifp; 1537 bp->bif_dlt = dlt; 1538 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1539 KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized")); 1540 *driverp = bp; 1541 1542 mtx_lock(&bpf_mtx); 1543 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 1544 mtx_unlock(&bpf_mtx); 1545 1546 /* 1547 * Compute the length of the bpf header. This is not necessarily 1548 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1549 * that the network layer header begins on a longword boundary (for 1550 * performance reasons and to alleviate alignment restrictions). 1551 */ 1552 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1553 1554 if (bootverbose) 1555 if_printf(ifp, "bpf attached\n"); 1556 } 1557 1558 /* 1559 * Detach bpf from an interface. This involves detaching each descriptor 1560 * associated with the interface, and leaving bd_bif NULL. Notify each 1561 * descriptor as it's detached so that any sleepers wake up and get 1562 * ENXIO. 1563 */ 1564 void 1565 bpfdetach(struct ifnet *ifp) 1566 { 1567 struct bpf_if *bp; 1568 struct bpf_d *d; 1569 1570 /* Locate BPF interface information */ 1571 mtx_lock(&bpf_mtx); 1572 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1573 if (ifp == bp->bif_ifp) 1574 break; 1575 } 1576 1577 /* Interface wasn't attached */ 1578 if ((bp == NULL) || (bp->bif_ifp == NULL)) { 1579 mtx_unlock(&bpf_mtx); 1580 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 1581 return; 1582 } 1583 1584 LIST_REMOVE(bp, bif_next); 1585 mtx_unlock(&bpf_mtx); 1586 1587 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { 1588 bpf_detachd(d); 1589 BPFD_LOCK(d); 1590 bpf_wakeup(d); 1591 BPFD_UNLOCK(d); 1592 } 1593 1594 mtx_destroy(&bp->bif_mtx); 1595 free(bp, M_BPF); 1596 } 1597 1598 /* 1599 * Get a list of available data link type of the interface. 1600 */ 1601 static int 1602 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 1603 { 1604 int n, error; 1605 struct ifnet *ifp; 1606 struct bpf_if *bp; 1607 1608 ifp = d->bd_bif->bif_ifp; 1609 n = 0; 1610 error = 0; 1611 mtx_lock(&bpf_mtx); 1612 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1613 if (bp->bif_ifp != ifp) 1614 continue; 1615 if (bfl->bfl_list != NULL) { 1616 if (n >= bfl->bfl_len) { 1617 mtx_unlock(&bpf_mtx); 1618 return (ENOMEM); 1619 } 1620 error = copyout(&bp->bif_dlt, 1621 bfl->bfl_list + n, sizeof(u_int)); 1622 } 1623 n++; 1624 } 1625 mtx_unlock(&bpf_mtx); 1626 bfl->bfl_len = n; 1627 return (error); 1628 } 1629 1630 /* 1631 * Set the data link type of a BPF instance. 1632 */ 1633 static int 1634 bpf_setdlt(struct bpf_d *d, u_int dlt) 1635 { 1636 int error, opromisc; 1637 struct ifnet *ifp; 1638 struct bpf_if *bp; 1639 1640 if (d->bd_bif->bif_dlt == dlt) 1641 return (0); 1642 ifp = d->bd_bif->bif_ifp; 1643 mtx_lock(&bpf_mtx); 1644 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1645 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1646 break; 1647 } 1648 mtx_unlock(&bpf_mtx); 1649 if (bp != NULL) { 1650 opromisc = d->bd_promisc; 1651 bpf_detachd(d); 1652 bpf_attachd(d, bp); 1653 BPFD_LOCK(d); 1654 reset_d(d); 1655 BPFD_UNLOCK(d); 1656 if (opromisc) { 1657 error = ifpromisc(bp->bif_ifp, 1); 1658 if (error) 1659 if_printf(bp->bif_ifp, 1660 "bpf_setdlt: ifpromisc failed (%d)\n", 1661 error); 1662 else 1663 d->bd_promisc = 1; 1664 } 1665 } 1666 return (bp == NULL ? EINVAL : 0); 1667 } 1668 1669 static void 1670 bpf_clone(void *arg, struct ucred *cred, char *name, int namelen, 1671 struct cdev **dev) 1672 { 1673 int u; 1674 1675 if (*dev != NULL) 1676 return; 1677 if (dev_stdclone(name, NULL, "bpf", &u) != 1) 1678 return; 1679 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, 1680 "bpf%d", u); 1681 dev_ref(*dev); 1682 (*dev)->si_flags |= SI_CHEAPCLONE; 1683 return; 1684 } 1685 1686 static void 1687 bpf_drvinit(void *unused) 1688 { 1689 1690 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 1691 LIST_INIT(&bpf_iflist); 1692 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); 1693 } 1694 1695 static void 1696 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 1697 { 1698 1699 bzero(d, sizeof(*d)); 1700 BPFD_LOCK_ASSERT(bd); 1701 d->bd_immediate = bd->bd_immediate; 1702 d->bd_promisc = bd->bd_promisc; 1703 d->bd_hdrcmplt = bd->bd_hdrcmplt; 1704 d->bd_seesent = bd->bd_seesent; 1705 d->bd_async = bd->bd_async; 1706 d->bd_rcount = bd->bd_rcount; 1707 d->bd_dcount = bd->bd_dcount; 1708 d->bd_fcount = bd->bd_fcount; 1709 d->bd_sig = bd->bd_sig; 1710 d->bd_slen = bd->bd_slen; 1711 d->bd_hlen = bd->bd_hlen; 1712 d->bd_bufsize = bd->bd_bufsize; 1713 d->bd_pid = bd->bd_pid; 1714 strlcpy(d->bd_ifname, 1715 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 1716 d->bd_locked = bd->bd_locked; 1717 } 1718 1719 static int 1720 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 1721 { 1722 struct xbpf_d *xbdbuf, *xbd; 1723 int index, error; 1724 struct bpf_if *bp; 1725 struct bpf_d *bd; 1726 1727 /* 1728 * XXX This is not technically correct. It is possible for non 1729 * privileged users to open bpf devices. It would make sense 1730 * if the users who opened the devices were able to retrieve 1731 * the statistics for them, too. 1732 */ 1733 error = suser(req->td); 1734 if (error) 1735 return (error); 1736 if (req->oldptr == NULL) 1737 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 1738 if (bpf_bpfd_cnt == 0) 1739 return (SYSCTL_OUT(req, 0, 0)); 1740 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 1741 mtx_lock(&bpf_mtx); 1742 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 1743 mtx_unlock(&bpf_mtx); 1744 free(xbdbuf, M_BPF); 1745 return (ENOMEM); 1746 } 1747 index = 0; 1748 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1749 BPFIF_LOCK(bp); 1750 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 1751 xbd = &xbdbuf[index++]; 1752 BPFD_LOCK(bd); 1753 bpfstats_fill_xbpf(xbd, bd); 1754 BPFD_UNLOCK(bd); 1755 } 1756 BPFIF_UNLOCK(bp); 1757 } 1758 mtx_unlock(&bpf_mtx); 1759 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 1760 free(xbdbuf, M_BPF); 1761 return (error); 1762 } 1763 1764 SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL) 1765 1766 #else /* !DEV_BPF && !NETGRAPH_BPF */ 1767 /* 1768 * NOP stubs to allow bpf-using drivers to load and function. 1769 * 1770 * A 'better' implementation would allow the core bpf functionality 1771 * to be loaded at runtime. 1772 */ 1773 static struct bpf_if bp_null; 1774 1775 void 1776 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1777 { 1778 } 1779 1780 void 1781 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1782 { 1783 } 1784 1785 void 1786 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 1787 { 1788 } 1789 1790 void 1791 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1792 { 1793 1794 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1795 } 1796 1797 void 1798 bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1799 { 1800 1801 *driverp = &bp_null; 1802 } 1803 1804 void 1805 bpfdetach(struct ifnet *ifp) 1806 { 1807 } 1808 1809 u_int 1810 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 1811 { 1812 return -1; /* "no filter" behaviour */ 1813 } 1814 1815 int 1816 bpf_validate(const struct bpf_insn *f, int len) 1817 { 1818 return 0; /* false */ 1819 } 1820 1821 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 1822