bpf.c revision 174895
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 37#include <sys/cdefs.h> 38__FBSDID("$FreeBSD: head/sys/net/bpf.c 174895 2007-12-25 13:24:02Z rwatson $"); 39 40#include "opt_bpf.h" 41#include "opt_mac.h" 42#include "opt_netgraph.h" 43 44#include <sys/types.h> 45#include <sys/param.h> 46#include <sys/systm.h> 47#include <sys/conf.h> 48#include <sys/fcntl.h> 49#include <sys/malloc.h> 50#include <sys/mbuf.h> 51#include <sys/time.h> 52#include <sys/priv.h> 53#include <sys/proc.h> 54#include <sys/signalvar.h> 55#include <sys/filio.h> 56#include <sys/sockio.h> 57#include <sys/ttycom.h> 58#include <sys/uio.h> 59 60#include <sys/event.h> 61#include <sys/file.h> 62#include <sys/poll.h> 63#include <sys/proc.h> 64 65#include <sys/socket.h> 66 67#include <net/if.h> 68#include <net/bpf.h> 69#ifdef BPF_JITTER 70#include <net/bpf_jitter.h> 71#endif 72#include <net/bpfdesc.h> 73 74#include <netinet/in.h> 75#include <netinet/if_ether.h> 76#include <sys/kernel.h> 77#include <sys/sysctl.h> 78 79#include <net80211/ieee80211_freebsd.h> 80 81#include <security/mac/mac_framework.h> 82 83static MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 84 85#if defined(DEV_BPF) || defined(NETGRAPH_BPF) 86 87#define PRINET 26 /* interruptible */ 88 89#define M_SKIP_BPF M_SKIP_FIREWALL 90 91/* 92 * bpf_iflist is a list of BPF interface structures, each corresponding to a 93 * specific DLT. The same network interface might have several BPF interface 94 * structures registered by different layers in the stack (i.e., 802.11 95 * frames, ethernet frames, etc). 96 */ 97static LIST_HEAD(, bpf_if) bpf_iflist; 98static struct mtx bpf_mtx; /* bpf global lock */ 99static int bpf_bpfd_cnt; 100 101static void bpf_allocbufs(struct bpf_d *); 102static void bpf_attachd(struct bpf_d *, struct bpf_if *); 103static void bpf_detachd(struct bpf_d *); 104static void bpf_freed(struct bpf_d *); 105static void bpf_mcopy(const void *, void *, size_t); 106static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **, 107 struct sockaddr *, int *, struct bpf_insn *); 108static int bpf_setif(struct bpf_d *, struct ifreq *); 109static void bpf_timed_out(void *); 110static __inline void 111 bpf_wakeup(struct bpf_d *); 112static void catchpacket(struct bpf_d *, u_char *, u_int, 113 u_int, void (*)(const void *, void *, size_t), 114 struct timeval *); 115static void reset_d(struct bpf_d *); 116static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 117static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 118static int bpf_setdlt(struct bpf_d *, u_int); 119static void filt_bpfdetach(struct knote *); 120static int filt_bpfread(struct knote *, long); 121static void bpf_drvinit(void *); 122static void bpf_clone(void *, struct ucred *, char *, int, struct cdev **); 123static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); 124 125SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl"); 126static int bpf_bufsize = 4096; 127SYSCTL_INT(_net_bpf, OID_AUTO, bufsize, CTLFLAG_RW, 128 &bpf_bufsize, 0, "Default bpf buffer size"); 129static int bpf_maxbufsize = BPF_MAXBUFSIZE; 130SYSCTL_INT(_net_bpf, OID_AUTO, maxbufsize, CTLFLAG_RW, 131 &bpf_maxbufsize, 0, "Maximum bpf buffer size"); 132static int bpf_maxinsns = BPF_MAXINSNS; 133SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, 134 &bpf_maxinsns, 0, "Maximum bpf program instructions"); 135SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_RW, 136 bpf_stats_sysctl, "bpf statistics portal"); 137 138static d_open_t bpfopen; 139static d_close_t bpfclose; 140static d_read_t bpfread; 141static d_write_t bpfwrite; 142static d_ioctl_t bpfioctl; 143static d_poll_t bpfpoll; 144static d_kqfilter_t bpfkqfilter; 145 146static struct cdevsw bpf_cdevsw = { 147 .d_version = D_VERSION, 148 .d_open = bpfopen, 149 .d_close = bpfclose, 150 .d_read = bpfread, 151 .d_write = bpfwrite, 152 .d_ioctl = bpfioctl, 153 .d_poll = bpfpoll, 154 .d_name = "bpf", 155 .d_kqfilter = bpfkqfilter, 156}; 157 158static struct filterops bpfread_filtops = 159 { 1, NULL, filt_bpfdetach, filt_bpfread }; 160 161static int 162bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, 163 struct sockaddr *sockp, int *hdrlen, struct bpf_insn *wfilter) 164{ 165 const struct ieee80211_bpf_params *p; 166 struct ether_header *eh; 167 struct mbuf *m; 168 int error; 169 int len; 170 int hlen; 171 int slen; 172 173 /* 174 * Build a sockaddr based on the data link layer type. 175 * We do this at this level because the ethernet header 176 * is copied directly into the data field of the sockaddr. 177 * In the case of SLIP, there is no header and the packet 178 * is forwarded as is. 179 * Also, we are careful to leave room at the front of the mbuf 180 * for the link level header. 181 */ 182 switch (linktype) { 183 184 case DLT_SLIP: 185 sockp->sa_family = AF_INET; 186 hlen = 0; 187 break; 188 189 case DLT_EN10MB: 190 sockp->sa_family = AF_UNSPEC; 191 /* XXX Would MAXLINKHDR be better? */ 192 hlen = ETHER_HDR_LEN; 193 break; 194 195 case DLT_FDDI: 196 sockp->sa_family = AF_IMPLINK; 197 hlen = 0; 198 break; 199 200 case DLT_RAW: 201 sockp->sa_family = AF_UNSPEC; 202 hlen = 0; 203 break; 204 205 case DLT_NULL: 206 /* 207 * null interface types require a 4 byte pseudo header which 208 * corresponds to the address family of the packet. 209 */ 210 sockp->sa_family = AF_UNSPEC; 211 hlen = 4; 212 break; 213 214 case DLT_ATM_RFC1483: 215 /* 216 * en atm driver requires 4-byte atm pseudo header. 217 * though it isn't standard, vpi:vci needs to be 218 * specified anyway. 219 */ 220 sockp->sa_family = AF_UNSPEC; 221 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 222 break; 223 224 case DLT_PPP: 225 sockp->sa_family = AF_UNSPEC; 226 hlen = 4; /* This should match PPP_HDRLEN */ 227 break; 228 229 case DLT_IEEE802_11: /* IEEE 802.11 wireless */ 230 sockp->sa_family = AF_IEEE80211; 231 hlen = 0; 232 break; 233 234 case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ 235 sockp->sa_family = AF_IEEE80211; 236 sockp->sa_len = 12; /* XXX != 0 */ 237 hlen = sizeof(struct ieee80211_bpf_params); 238 break; 239 240 default: 241 return (EIO); 242 } 243 244 len = uio->uio_resid; 245 246 if (len - hlen > ifp->if_mtu) 247 return (EMSGSIZE); 248 249 if ((unsigned)len > MCLBYTES) 250 return (EIO); 251 252 if (len > MHLEN) { 253 m = m_getcl(M_TRYWAIT, MT_DATA, M_PKTHDR); 254 } else { 255 MGETHDR(m, M_TRYWAIT, MT_DATA); 256 } 257 if (m == NULL) 258 return (ENOBUFS); 259 m->m_pkthdr.len = m->m_len = len; 260 m->m_pkthdr.rcvif = NULL; 261 *mp = m; 262 263 if (m->m_len < hlen) { 264 error = EPERM; 265 goto bad; 266 } 267 268 error = uiomove(mtod(m, u_char *), len, uio); 269 if (error) 270 goto bad; 271 272 slen = bpf_filter(wfilter, mtod(m, u_char *), len, len); 273 if (slen == 0) { 274 error = EPERM; 275 goto bad; 276 } 277 278 /* Check for multicast destination */ 279 switch (linktype) { 280 case DLT_EN10MB: 281 eh = mtod(m, struct ether_header *); 282 if (ETHER_IS_MULTICAST(eh->ether_dhost)) { 283 if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, 284 ETHER_ADDR_LEN) == 0) 285 m->m_flags |= M_BCAST; 286 else 287 m->m_flags |= M_MCAST; 288 } 289 break; 290 } 291 292 /* 293 * Make room for link header, and copy it to sockaddr 294 */ 295 if (hlen != 0) { 296 if (sockp->sa_family == AF_IEEE80211) { 297 /* 298 * Collect true length from the parameter header 299 * NB: sockp is known to be zero'd so if we do a 300 * short copy unspecified parameters will be 301 * zero. 302 * NB: packet may not be aligned after stripping 303 * bpf params 304 * XXX check ibp_vers 305 */ 306 p = mtod(m, const struct ieee80211_bpf_params *); 307 hlen = p->ibp_len; 308 if (hlen > sizeof(sockp->sa_data)) { 309 error = EINVAL; 310 goto bad; 311 } 312 } 313 bcopy(m->m_data, sockp->sa_data, hlen); 314 } 315 *hdrlen = hlen; 316 317 return (0); 318bad: 319 m_freem(m); 320 return (error); 321} 322 323/* 324 * Attach file to the bpf interface, i.e. make d listen on bp. 325 */ 326static void 327bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 328{ 329 /* 330 * Point d at bp, and add d to the interface's list of listeners. 331 * Finally, point the driver's bpf cookie at the interface so 332 * it will divert packets to bpf. 333 */ 334 BPFIF_LOCK(bp); 335 d->bd_bif = bp; 336 LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 337 338 bpf_bpfd_cnt++; 339 BPFIF_UNLOCK(bp); 340} 341 342/* 343 * Detach a file from its interface. 344 */ 345static void 346bpf_detachd(struct bpf_d *d) 347{ 348 int error; 349 struct bpf_if *bp; 350 struct ifnet *ifp; 351 352 bp = d->bd_bif; 353 BPFIF_LOCK(bp); 354 BPFD_LOCK(d); 355 ifp = d->bd_bif->bif_ifp; 356 357 /* 358 * Remove d from the interface's descriptor list. 359 */ 360 LIST_REMOVE(d, bd_next); 361 362 bpf_bpfd_cnt--; 363 d->bd_bif = NULL; 364 BPFD_UNLOCK(d); 365 BPFIF_UNLOCK(bp); 366 367 /* 368 * Check if this descriptor had requested promiscuous mode. 369 * If so, turn it off. 370 */ 371 if (d->bd_promisc) { 372 d->bd_promisc = 0; 373 error = ifpromisc(ifp, 0); 374 if (error != 0 && error != ENXIO) { 375 /* 376 * ENXIO can happen if a pccard is unplugged 377 * Something is really wrong if we were able to put 378 * the driver into promiscuous mode, but can't 379 * take it out. 380 */ 381 if_printf(bp->bif_ifp, 382 "bpf_detach: ifpromisc failed (%d)\n", error); 383 } 384 } 385} 386 387/* 388 * Open ethernet device. Returns ENXIO for illegal minor device number, 389 * EBUSY if file is open by another process. 390 */ 391/* ARGSUSED */ 392static int 393bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 394{ 395 struct bpf_d *d; 396 397 mtx_lock(&bpf_mtx); 398 d = dev->si_drv1; 399 /* 400 * Each minor can be opened by only one process. If the requested 401 * minor is in use, return EBUSY. 402 */ 403 if (d != NULL) { 404 mtx_unlock(&bpf_mtx); 405 return (EBUSY); 406 } 407 dev->si_drv1 = (struct bpf_d *)~0; /* mark device in use */ 408 mtx_unlock(&bpf_mtx); 409 410 if ((dev->si_flags & SI_NAMED) == 0) 411 make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600, 412 "bpf%d", dev2unit(dev)); 413 MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 414 dev->si_drv1 = d; 415 d->bd_bufsize = bpf_bufsize; 416 d->bd_sig = SIGIO; 417 d->bd_direction = BPF_D_INOUT; 418 d->bd_pid = td->td_proc->p_pid; 419#ifdef MAC 420 mac_bpfdesc_init(d); 421 mac_bpfdesc_create(td->td_ucred, d); 422#endif 423 mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF); 424 callout_init(&d->bd_callout, CALLOUT_MPSAFE); 425 knlist_init(&d->bd_sel.si_note, &d->bd_mtx, NULL, NULL, NULL); 426 427 return (0); 428} 429 430/* 431 * Close the descriptor by detaching it from its interface, 432 * deallocating its buffers, and marking it free. 433 */ 434/* ARGSUSED */ 435static int 436bpfclose(struct cdev *dev, int flags, int fmt, struct thread *td) 437{ 438 struct bpf_d *d = dev->si_drv1; 439 440 BPFD_LOCK(d); 441 if (d->bd_state == BPF_WAITING) 442 callout_stop(&d->bd_callout); 443 d->bd_state = BPF_IDLE; 444 BPFD_UNLOCK(d); 445 funsetown(&d->bd_sigio); 446 mtx_lock(&bpf_mtx); 447 if (d->bd_bif) 448 bpf_detachd(d); 449 mtx_unlock(&bpf_mtx); 450 selwakeuppri(&d->bd_sel, PRINET); 451#ifdef MAC 452 mac_bpfdesc_destroy(d); 453#endif /* MAC */ 454 knlist_destroy(&d->bd_sel.si_note); 455 bpf_freed(d); 456 dev->si_drv1 = NULL; 457 free(d, M_BPF); 458 459 return (0); 460} 461 462 463/* 464 * Rotate the packet buffers in descriptor d. Move the store buffer 465 * into the hold slot, and the free buffer into the store slot. 466 * Zero the length of the new store buffer. 467 */ 468#define ROTATE_BUFFERS(d) \ 469 (d)->bd_hbuf = (d)->bd_sbuf; \ 470 (d)->bd_hlen = (d)->bd_slen; \ 471 (d)->bd_sbuf = (d)->bd_fbuf; \ 472 (d)->bd_slen = 0; \ 473 (d)->bd_fbuf = NULL; 474/* 475 * bpfread - read next chunk of packets from buffers 476 */ 477static int 478bpfread(struct cdev *dev, struct uio *uio, int ioflag) 479{ 480 struct bpf_d *d = dev->si_drv1; 481 int timed_out; 482 int error; 483 484 /* 485 * Restrict application to use a buffer the same size as 486 * as kernel buffers. 487 */ 488 if (uio->uio_resid != d->bd_bufsize) 489 return (EINVAL); 490 491 BPFD_LOCK(d); 492 d->bd_pid = curthread->td_proc->p_pid; 493 if (d->bd_state == BPF_WAITING) 494 callout_stop(&d->bd_callout); 495 timed_out = (d->bd_state == BPF_TIMED_OUT); 496 d->bd_state = BPF_IDLE; 497 /* 498 * If the hold buffer is empty, then do a timed sleep, which 499 * ends when the timeout expires or when enough packets 500 * have arrived to fill the store buffer. 501 */ 502 while (d->bd_hbuf == NULL) { 503 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { 504 /* 505 * A packet(s) either arrived since the previous 506 * read or arrived while we were asleep. 507 * Rotate the buffers and return what's here. 508 */ 509 ROTATE_BUFFERS(d); 510 break; 511 } 512 513 /* 514 * No data is available, check to see if the bpf device 515 * is still pointed at a real interface. If not, return 516 * ENXIO so that the userland process knows to rebind 517 * it before using it again. 518 */ 519 if (d->bd_bif == NULL) { 520 BPFD_UNLOCK(d); 521 return (ENXIO); 522 } 523 524 if (ioflag & O_NONBLOCK) { 525 BPFD_UNLOCK(d); 526 return (EWOULDBLOCK); 527 } 528 error = msleep(d, &d->bd_mtx, PRINET|PCATCH, 529 "bpf", d->bd_rtout); 530 if (error == EINTR || error == ERESTART) { 531 BPFD_UNLOCK(d); 532 return (error); 533 } 534 if (error == EWOULDBLOCK) { 535 /* 536 * On a timeout, return what's in the buffer, 537 * which may be nothing. If there is something 538 * in the store buffer, we can rotate the buffers. 539 */ 540 if (d->bd_hbuf) 541 /* 542 * We filled up the buffer in between 543 * getting the timeout and arriving 544 * here, so we don't need to rotate. 545 */ 546 break; 547 548 if (d->bd_slen == 0) { 549 BPFD_UNLOCK(d); 550 return (0); 551 } 552 ROTATE_BUFFERS(d); 553 break; 554 } 555 } 556 /* 557 * At this point, we know we have something in the hold slot. 558 */ 559 BPFD_UNLOCK(d); 560 561 /* 562 * Move data from hold buffer into user space. 563 * We know the entire buffer is transferred since 564 * we checked above that the read buffer is bpf_bufsize bytes. 565 */ 566 error = uiomove(d->bd_hbuf, d->bd_hlen, uio); 567 568 BPFD_LOCK(d); 569 d->bd_fbuf = d->bd_hbuf; 570 d->bd_hbuf = NULL; 571 d->bd_hlen = 0; 572 BPFD_UNLOCK(d); 573 574 return (error); 575} 576 577 578/* 579 * If there are processes sleeping on this descriptor, wake them up. 580 */ 581static __inline void 582bpf_wakeup(struct bpf_d *d) 583{ 584 585 BPFD_LOCK_ASSERT(d); 586 if (d->bd_state == BPF_WAITING) { 587 callout_stop(&d->bd_callout); 588 d->bd_state = BPF_IDLE; 589 } 590 wakeup(d); 591 if (d->bd_async && d->bd_sig && d->bd_sigio) 592 pgsigio(&d->bd_sigio, d->bd_sig, 0); 593 594 selwakeuppri(&d->bd_sel, PRINET); 595 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 596} 597 598static void 599bpf_timed_out(void *arg) 600{ 601 struct bpf_d *d = (struct bpf_d *)arg; 602 603 BPFD_LOCK(d); 604 if (d->bd_state == BPF_WAITING) { 605 d->bd_state = BPF_TIMED_OUT; 606 if (d->bd_slen != 0) 607 bpf_wakeup(d); 608 } 609 BPFD_UNLOCK(d); 610} 611 612static int 613bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 614{ 615 struct bpf_d *d = dev->si_drv1; 616 struct ifnet *ifp; 617 struct mbuf *m, *mc; 618 struct sockaddr dst; 619 int error, hlen; 620 621 d->bd_pid = curthread->td_proc->p_pid; 622 if (d->bd_bif == NULL) 623 return (ENXIO); 624 625 ifp = d->bd_bif->bif_ifp; 626 627 if ((ifp->if_flags & IFF_UP) == 0) 628 return (ENETDOWN); 629 630 if (uio->uio_resid == 0) 631 return (0); 632 633 bzero(&dst, sizeof(dst)); 634 m = NULL; 635 hlen = 0; 636 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp, 637 &m, &dst, &hlen, d->bd_wfilter); 638 if (error) 639 return (error); 640 641 if (d->bd_hdrcmplt) 642 dst.sa_family = pseudo_AF_HDRCMPLT; 643 644 if (d->bd_feedback) { 645 mc = m_dup(m, M_DONTWAIT); 646 if (mc != NULL) 647 mc->m_pkthdr.rcvif = ifp; 648 /* XXX Do not return the same packet twice. */ 649 if (d->bd_direction == BPF_D_INOUT) 650 m->m_flags |= M_SKIP_BPF; 651 } else 652 mc = NULL; 653 654 m->m_pkthdr.len -= hlen; 655 m->m_len -= hlen; 656 m->m_data += hlen; /* XXX */ 657 658#ifdef MAC 659 BPFD_LOCK(d); 660 mac_bpfdesc_create_mbuf(d, m); 661 if (mc != NULL) 662 mac_bpfdesc_create_mbuf(d, mc); 663 BPFD_UNLOCK(d); 664#endif 665 666 error = (*ifp->if_output)(ifp, m, &dst, NULL); 667 668 if (mc != NULL) { 669 if (error == 0) 670 (*ifp->if_input)(ifp, mc); 671 else 672 m_freem(mc); 673 } 674 675 return (error); 676} 677 678/* 679 * Reset a descriptor by flushing its packet buffer and clearing the 680 * receive and drop counts. 681 */ 682static void 683reset_d(struct bpf_d *d) 684{ 685 686 mtx_assert(&d->bd_mtx, MA_OWNED); 687 if (d->bd_hbuf) { 688 /* Free the hold buffer. */ 689 d->bd_fbuf = d->bd_hbuf; 690 d->bd_hbuf = NULL; 691 } 692 d->bd_slen = 0; 693 d->bd_hlen = 0; 694 d->bd_rcount = 0; 695 d->bd_dcount = 0; 696 d->bd_fcount = 0; 697} 698 699/* 700 * FIONREAD Check for read packet available. 701 * SIOCGIFADDR Get interface address - convenient hook to driver. 702 * BIOCGBLEN Get buffer len [for read()]. 703 * BIOCSETF Set ethernet read filter. 704 * BIOCSETWF Set ethernet write filter. 705 * BIOCFLUSH Flush read packet buffer. 706 * BIOCPROMISC Put interface into promiscuous mode. 707 * BIOCGDLT Get link layer type. 708 * BIOCGETIF Get interface name. 709 * BIOCSETIF Set interface. 710 * BIOCSRTIMEOUT Set read timeout. 711 * BIOCGRTIMEOUT Get read timeout. 712 * BIOCGSTATS Get packet stats. 713 * BIOCIMMEDIATE Set immediate mode. 714 * BIOCVERSION Get filter language version. 715 * BIOCGHDRCMPLT Get "header already complete" flag 716 * BIOCSHDRCMPLT Set "header already complete" flag 717 * BIOCGDIRECTION Get packet direction flag 718 * BIOCSDIRECTION Set packet direction flag 719 * BIOCLOCK Set "locked" flag 720 * BIOCFEEDBACK Set packet feedback mode. 721 */ 722/* ARGSUSED */ 723static int 724bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 725 struct thread *td) 726{ 727 struct bpf_d *d = dev->si_drv1; 728 int error = 0; 729 730 /* 731 * Refresh PID associated with this descriptor. 732 */ 733 BPFD_LOCK(d); 734 d->bd_pid = td->td_proc->p_pid; 735 if (d->bd_state == BPF_WAITING) 736 callout_stop(&d->bd_callout); 737 d->bd_state = BPF_IDLE; 738 BPFD_UNLOCK(d); 739 740 if (d->bd_locked == 1) { 741 switch (cmd) { 742 case BIOCGBLEN: 743 case BIOCFLUSH: 744 case BIOCGDLT: 745 case BIOCGDLTLIST: 746 case BIOCGETIF: 747 case BIOCGRTIMEOUT: 748 case BIOCGSTATS: 749 case BIOCVERSION: 750 case BIOCGRSIG: 751 case BIOCGHDRCMPLT: 752 case BIOCFEEDBACK: 753 case FIONREAD: 754 case BIOCLOCK: 755 case BIOCSRTIMEOUT: 756 case BIOCIMMEDIATE: 757 case TIOCGPGRP: 758 break; 759 default: 760 return (EPERM); 761 } 762 } 763 switch (cmd) { 764 765 default: 766 error = EINVAL; 767 break; 768 769 /* 770 * Check for read packet available. 771 */ 772 case FIONREAD: 773 { 774 int n; 775 776 BPFD_LOCK(d); 777 n = d->bd_slen; 778 if (d->bd_hbuf) 779 n += d->bd_hlen; 780 BPFD_UNLOCK(d); 781 782 *(int *)addr = n; 783 break; 784 } 785 786 case SIOCGIFADDR: 787 { 788 struct ifnet *ifp; 789 790 if (d->bd_bif == NULL) 791 error = EINVAL; 792 else { 793 ifp = d->bd_bif->bif_ifp; 794 error = (*ifp->if_ioctl)(ifp, cmd, addr); 795 } 796 break; 797 } 798 799 /* 800 * Get buffer len [for read()]. 801 */ 802 case BIOCGBLEN: 803 *(u_int *)addr = d->bd_bufsize; 804 break; 805 806 /* 807 * Set buffer length. 808 */ 809 case BIOCSBLEN: 810 if (d->bd_bif != NULL) 811 error = EINVAL; 812 else { 813 u_int size = *(u_int *)addr; 814 815 if (size > bpf_maxbufsize) 816 *(u_int *)addr = size = bpf_maxbufsize; 817 else if (size < BPF_MINBUFSIZE) 818 *(u_int *)addr = size = BPF_MINBUFSIZE; 819 d->bd_bufsize = size; 820 } 821 break; 822 823 /* 824 * Set link layer read filter. 825 */ 826 case BIOCSETF: 827 case BIOCSETWF: 828 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 829 break; 830 831 /* 832 * Flush read packet buffer. 833 */ 834 case BIOCFLUSH: 835 BPFD_LOCK(d); 836 reset_d(d); 837 BPFD_UNLOCK(d); 838 break; 839 840 /* 841 * Put interface into promiscuous mode. 842 */ 843 case BIOCPROMISC: 844 if (d->bd_bif == NULL) { 845 /* 846 * No interface attached yet. 847 */ 848 error = EINVAL; 849 break; 850 } 851 if (d->bd_promisc == 0) { 852 error = ifpromisc(d->bd_bif->bif_ifp, 1); 853 if (error == 0) 854 d->bd_promisc = 1; 855 } 856 break; 857 858 /* 859 * Get current data link type. 860 */ 861 case BIOCGDLT: 862 if (d->bd_bif == NULL) 863 error = EINVAL; 864 else 865 *(u_int *)addr = d->bd_bif->bif_dlt; 866 break; 867 868 /* 869 * Get a list of supported data link types. 870 */ 871 case BIOCGDLTLIST: 872 if (d->bd_bif == NULL) 873 error = EINVAL; 874 else 875 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 876 break; 877 878 /* 879 * Set data link type. 880 */ 881 case BIOCSDLT: 882 if (d->bd_bif == NULL) 883 error = EINVAL; 884 else 885 error = bpf_setdlt(d, *(u_int *)addr); 886 break; 887 888 /* 889 * Get interface name. 890 */ 891 case BIOCGETIF: 892 if (d->bd_bif == NULL) 893 error = EINVAL; 894 else { 895 struct ifnet *const ifp = d->bd_bif->bif_ifp; 896 struct ifreq *const ifr = (struct ifreq *)addr; 897 898 strlcpy(ifr->ifr_name, ifp->if_xname, 899 sizeof(ifr->ifr_name)); 900 } 901 break; 902 903 /* 904 * Set interface. 905 */ 906 case BIOCSETIF: 907 error = bpf_setif(d, (struct ifreq *)addr); 908 break; 909 910 /* 911 * Set read timeout. 912 */ 913 case BIOCSRTIMEOUT: 914 { 915 struct timeval *tv = (struct timeval *)addr; 916 917 /* 918 * Subtract 1 tick from tvtohz() since this isn't 919 * a one-shot timer. 920 */ 921 if ((error = itimerfix(tv)) == 0) 922 d->bd_rtout = tvtohz(tv) - 1; 923 break; 924 } 925 926 /* 927 * Get read timeout. 928 */ 929 case BIOCGRTIMEOUT: 930 { 931 struct timeval *tv = (struct timeval *)addr; 932 933 tv->tv_sec = d->bd_rtout / hz; 934 tv->tv_usec = (d->bd_rtout % hz) * tick; 935 break; 936 } 937 938 /* 939 * Get packet stats. 940 */ 941 case BIOCGSTATS: 942 { 943 struct bpf_stat *bs = (struct bpf_stat *)addr; 944 945 bs->bs_recv = d->bd_rcount; 946 bs->bs_drop = d->bd_dcount; 947 break; 948 } 949 950 /* 951 * Set immediate mode. 952 */ 953 case BIOCIMMEDIATE: 954 d->bd_immediate = *(u_int *)addr; 955 break; 956 957 case BIOCVERSION: 958 { 959 struct bpf_version *bv = (struct bpf_version *)addr; 960 961 bv->bv_major = BPF_MAJOR_VERSION; 962 bv->bv_minor = BPF_MINOR_VERSION; 963 break; 964 } 965 966 /* 967 * Get "header already complete" flag 968 */ 969 case BIOCGHDRCMPLT: 970 *(u_int *)addr = d->bd_hdrcmplt; 971 break; 972 973 /* 974 * Set "header already complete" flag 975 */ 976 case BIOCSHDRCMPLT: 977 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 978 break; 979 980 /* 981 * Get packet direction flag 982 */ 983 case BIOCGDIRECTION: 984 *(u_int *)addr = d->bd_direction; 985 break; 986 987 /* 988 * Set packet direction flag 989 */ 990 case BIOCSDIRECTION: 991 { 992 u_int direction; 993 994 direction = *(u_int *)addr; 995 switch (direction) { 996 case BPF_D_IN: 997 case BPF_D_INOUT: 998 case BPF_D_OUT: 999 d->bd_direction = direction; 1000 break; 1001 default: 1002 error = EINVAL; 1003 } 1004 } 1005 break; 1006 1007 case BIOCFEEDBACK: 1008 d->bd_feedback = *(u_int *)addr; 1009 break; 1010 1011 case BIOCLOCK: 1012 d->bd_locked = 1; 1013 break; 1014 1015 case FIONBIO: /* Non-blocking I/O */ 1016 break; 1017 1018 case FIOASYNC: /* Send signal on receive packets */ 1019 d->bd_async = *(int *)addr; 1020 break; 1021 1022 case FIOSETOWN: 1023 error = fsetown(*(int *)addr, &d->bd_sigio); 1024 break; 1025 1026 case FIOGETOWN: 1027 *(int *)addr = fgetown(&d->bd_sigio); 1028 break; 1029 1030 /* This is deprecated, FIOSETOWN should be used instead. */ 1031 case TIOCSPGRP: 1032 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1033 break; 1034 1035 /* This is deprecated, FIOGETOWN should be used instead. */ 1036 case TIOCGPGRP: 1037 *(int *)addr = -fgetown(&d->bd_sigio); 1038 break; 1039 1040 case BIOCSRSIG: /* Set receive signal */ 1041 { 1042 u_int sig; 1043 1044 sig = *(u_int *)addr; 1045 1046 if (sig >= NSIG) 1047 error = EINVAL; 1048 else 1049 d->bd_sig = sig; 1050 break; 1051 } 1052 case BIOCGRSIG: 1053 *(u_int *)addr = d->bd_sig; 1054 break; 1055 } 1056 return (error); 1057} 1058 1059/* 1060 * Set d's packet filter program to fp. If this file already has a filter, 1061 * free it and replace it. Returns EINVAL for bogus requests. 1062 */ 1063static int 1064bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1065{ 1066 struct bpf_insn *fcode, *old; 1067 u_int wfilter, flen, size; 1068#ifdef BPF_JITTER 1069 bpf_jit_filter *ofunc; 1070#endif 1071 1072 if (cmd == BIOCSETWF) { 1073 old = d->bd_wfilter; 1074 wfilter = 1; 1075#ifdef BPF_JITTER 1076 ofunc = NULL; 1077#endif 1078 } else { 1079 wfilter = 0; 1080 old = d->bd_rfilter; 1081#ifdef BPF_JITTER 1082 ofunc = d->bd_bfilter; 1083#endif 1084 } 1085 if (fp->bf_insns == NULL) { 1086 if (fp->bf_len != 0) 1087 return (EINVAL); 1088 BPFD_LOCK(d); 1089 if (wfilter) 1090 d->bd_wfilter = NULL; 1091 else { 1092 d->bd_rfilter = NULL; 1093#ifdef BPF_JITTER 1094 d->bd_bfilter = NULL; 1095#endif 1096 } 1097 reset_d(d); 1098 BPFD_UNLOCK(d); 1099 if (old != NULL) 1100 free((caddr_t)old, M_BPF); 1101#ifdef BPF_JITTER 1102 if (ofunc != NULL) 1103 bpf_destroy_jit_filter(ofunc); 1104#endif 1105 return (0); 1106 } 1107 flen = fp->bf_len; 1108 if (flen > bpf_maxinsns) 1109 return (EINVAL); 1110 1111 size = flen * sizeof(*fp->bf_insns); 1112 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); 1113 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 1114 bpf_validate(fcode, (int)flen)) { 1115 BPFD_LOCK(d); 1116 if (wfilter) 1117 d->bd_wfilter = fcode; 1118 else { 1119 d->bd_rfilter = fcode; 1120#ifdef BPF_JITTER 1121 d->bd_bfilter = bpf_jitter(fcode, flen); 1122#endif 1123 } 1124 reset_d(d); 1125 BPFD_UNLOCK(d); 1126 if (old != NULL) 1127 free((caddr_t)old, M_BPF); 1128#ifdef BPF_JITTER 1129 if (ofunc != NULL) 1130 bpf_destroy_jit_filter(ofunc); 1131#endif 1132 1133 return (0); 1134 } 1135 free((caddr_t)fcode, M_BPF); 1136 return (EINVAL); 1137} 1138 1139/* 1140 * Detach a file from its current interface (if attached at all) and attach 1141 * to the interface indicated by the name stored in ifr. 1142 * Return an errno or 0. 1143 */ 1144static int 1145bpf_setif(struct bpf_d *d, struct ifreq *ifr) 1146{ 1147 struct bpf_if *bp; 1148 struct ifnet *theywant; 1149 1150 theywant = ifunit(ifr->ifr_name); 1151 if (theywant == NULL || theywant->if_bpf == NULL) 1152 return (ENXIO); 1153 1154 bp = theywant->if_bpf; 1155 /* 1156 * Allocate the packet buffers if we need to. 1157 * If we're already attached to requested interface, 1158 * just flush the buffer. 1159 */ 1160 if (d->bd_sbuf == NULL) 1161 bpf_allocbufs(d); 1162 if (bp != d->bd_bif) { 1163 if (d->bd_bif) 1164 /* 1165 * Detach if attached to something else. 1166 */ 1167 bpf_detachd(d); 1168 1169 bpf_attachd(d, bp); 1170 } 1171 BPFD_LOCK(d); 1172 reset_d(d); 1173 BPFD_UNLOCK(d); 1174 return (0); 1175} 1176 1177/* 1178 * Support for select() and poll() system calls 1179 * 1180 * Return true iff the specific operation will not block indefinitely. 1181 * Otherwise, return false but make a note that a selwakeup() must be done. 1182 */ 1183static int 1184bpfpoll(struct cdev *dev, int events, struct thread *td) 1185{ 1186 struct bpf_d *d; 1187 int revents; 1188 1189 d = dev->si_drv1; 1190 if (d->bd_bif == NULL) 1191 return (ENXIO); 1192 1193 /* 1194 * Refresh PID associated with this descriptor. 1195 */ 1196 revents = events & (POLLOUT | POLLWRNORM); 1197 BPFD_LOCK(d); 1198 d->bd_pid = td->td_proc->p_pid; 1199 if (events & (POLLIN | POLLRDNORM)) { 1200 if (bpf_ready(d)) 1201 revents |= events & (POLLIN | POLLRDNORM); 1202 else { 1203 selrecord(td, &d->bd_sel); 1204 /* Start the read timeout if necessary. */ 1205 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1206 callout_reset(&d->bd_callout, d->bd_rtout, 1207 bpf_timed_out, d); 1208 d->bd_state = BPF_WAITING; 1209 } 1210 } 1211 } 1212 BPFD_UNLOCK(d); 1213 return (revents); 1214} 1215 1216/* 1217 * Support for kevent() system call. Register EVFILT_READ filters and 1218 * reject all others. 1219 */ 1220int 1221bpfkqfilter(struct cdev *dev, struct knote *kn) 1222{ 1223 struct bpf_d *d = (struct bpf_d *)dev->si_drv1; 1224 1225 if (kn->kn_filter != EVFILT_READ) 1226 return (1); 1227 1228 /* 1229 * Refresh PID associated with this descriptor. 1230 */ 1231 BPFD_LOCK(d); 1232 d->bd_pid = curthread->td_proc->p_pid; 1233 kn->kn_fop = &bpfread_filtops; 1234 kn->kn_hook = d; 1235 knlist_add(&d->bd_sel.si_note, kn, 1); 1236 BPFD_UNLOCK(d); 1237 1238 return (0); 1239} 1240 1241static void 1242filt_bpfdetach(struct knote *kn) 1243{ 1244 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1245 1246 knlist_remove(&d->bd_sel.si_note, kn, 0); 1247} 1248 1249static int 1250filt_bpfread(struct knote *kn, long hint) 1251{ 1252 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1253 int ready; 1254 1255 BPFD_LOCK_ASSERT(d); 1256 ready = bpf_ready(d); 1257 if (ready) { 1258 kn->kn_data = d->bd_slen; 1259 if (d->bd_hbuf) 1260 kn->kn_data += d->bd_hlen; 1261 } 1262 else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1263 callout_reset(&d->bd_callout, d->bd_rtout, 1264 bpf_timed_out, d); 1265 d->bd_state = BPF_WAITING; 1266 } 1267 1268 return (ready); 1269} 1270 1271/* 1272 * Incoming linkage from device drivers. Process the packet pkt, of length 1273 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1274 * by each process' filter, and if accepted, stashed into the corresponding 1275 * buffer. 1276 */ 1277void 1278bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1279{ 1280 struct bpf_d *d; 1281 u_int slen; 1282 int gottime; 1283 struct timeval tv; 1284 1285 gottime = 0; 1286 BPFIF_LOCK(bp); 1287 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1288 BPFD_LOCK(d); 1289 ++d->bd_rcount; 1290#ifdef BPF_JITTER 1291 if (bpf_jitter_enable != 0 && d->bd_bfilter != NULL) 1292 slen = (*(d->bd_bfilter->func))(pkt, pktlen, pktlen); 1293 else 1294#endif 1295 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 1296 if (slen != 0) { 1297 d->bd_fcount++; 1298 if (!gottime) { 1299 microtime(&tv); 1300 gottime = 1; 1301 } 1302#ifdef MAC 1303 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 1304#endif 1305 catchpacket(d, pkt, pktlen, slen, bcopy, &tv); 1306 } 1307 BPFD_UNLOCK(d); 1308 } 1309 BPFIF_UNLOCK(bp); 1310} 1311 1312/* 1313 * Copy data from an mbuf chain into a buffer. This code is derived 1314 * from m_copydata in sys/uipc_mbuf.c. 1315 */ 1316static void 1317bpf_mcopy(const void *src_arg, void *dst_arg, size_t len) 1318{ 1319 const struct mbuf *m; 1320 u_int count; 1321 u_char *dst; 1322 1323 m = src_arg; 1324 dst = dst_arg; 1325 while (len > 0) { 1326 if (m == NULL) 1327 panic("bpf_mcopy"); 1328 count = min(m->m_len, len); 1329 bcopy(mtod(m, void *), dst, count); 1330 m = m->m_next; 1331 dst += count; 1332 len -= count; 1333 } 1334} 1335 1336#define BPF_CHECK_DIRECTION(d, m) \ 1337 if (((d)->bd_direction == BPF_D_IN && (m)->m_pkthdr.rcvif == NULL) || \ 1338 ((d)->bd_direction == BPF_D_OUT && (m)->m_pkthdr.rcvif != NULL)) 1339 1340/* 1341 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1342 */ 1343void 1344bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1345{ 1346 struct bpf_d *d; 1347 u_int pktlen, slen; 1348 int gottime; 1349 struct timeval tv; 1350 1351 if (m->m_flags & M_SKIP_BPF) { 1352 m->m_flags &= ~M_SKIP_BPF; 1353 return; 1354 } 1355 1356 gottime = 0; 1357 1358 pktlen = m_length(m, NULL); 1359 1360 BPFIF_LOCK(bp); 1361 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1362 BPF_CHECK_DIRECTION(d, m) 1363 continue; 1364 BPFD_LOCK(d); 1365 ++d->bd_rcount; 1366#ifdef BPF_JITTER 1367 /* XXX We cannot handle multiple mbufs. */ 1368 if (bpf_jitter_enable != 0 && d->bd_bfilter != NULL && 1369 m->m_next == NULL) 1370 slen = (*(d->bd_bfilter->func))(mtod(m, u_char *), 1371 pktlen, pktlen); 1372 else 1373#endif 1374 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 1375 if (slen != 0) { 1376 d->bd_fcount++; 1377 if (!gottime) { 1378 microtime(&tv); 1379 gottime = 1; 1380 } 1381#ifdef MAC 1382 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 1383#endif 1384 catchpacket(d, (u_char *)m, pktlen, slen, 1385 bpf_mcopy, &tv); 1386 } 1387 BPFD_UNLOCK(d); 1388 } 1389 BPFIF_UNLOCK(bp); 1390} 1391 1392/* 1393 * Incoming linkage from device drivers, when packet is in 1394 * an mbuf chain and to be prepended by a contiguous header. 1395 */ 1396void 1397bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 1398{ 1399 struct mbuf mb; 1400 struct bpf_d *d; 1401 u_int pktlen, slen; 1402 int gottime; 1403 struct timeval tv; 1404 1405 if (m->m_flags & M_SKIP_BPF) { 1406 m->m_flags &= ~M_SKIP_BPF; 1407 return; 1408 } 1409 1410 gottime = 0; 1411 1412 pktlen = m_length(m, NULL); 1413 /* 1414 * Craft on-stack mbuf suitable for passing to bpf_filter. 1415 * Note that we cut corners here; we only setup what's 1416 * absolutely needed--this mbuf should never go anywhere else. 1417 */ 1418 mb.m_next = m; 1419 mb.m_data = data; 1420 mb.m_len = dlen; 1421 pktlen += dlen; 1422 1423 BPFIF_LOCK(bp); 1424 LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 1425 BPF_CHECK_DIRECTION(d, m) 1426 continue; 1427 BPFD_LOCK(d); 1428 ++d->bd_rcount; 1429 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 1430 if (slen != 0) { 1431 d->bd_fcount++; 1432 if (!gottime) { 1433 microtime(&tv); 1434 gottime = 1; 1435 } 1436#ifdef MAC 1437 if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) 1438#endif 1439 catchpacket(d, (u_char *)&mb, pktlen, slen, 1440 bpf_mcopy, &tv); 1441 } 1442 BPFD_UNLOCK(d); 1443 } 1444 BPFIF_UNLOCK(bp); 1445} 1446 1447#undef BPF_CHECK_DIRECTION 1448 1449/* 1450 * Move the packet data from interface memory (pkt) into the 1451 * store buffer. "cpfn" is the routine called to do the actual data 1452 * transfer. bcopy is passed in to copy contiguous chunks, while 1453 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1454 * pkt is really an mbuf. 1455 */ 1456static void 1457catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 1458 void (*cpfn)(const void *, void *, size_t), struct timeval *tv) 1459{ 1460 struct bpf_hdr *hp; 1461 int totlen, curlen; 1462 int hdrlen = d->bd_bif->bif_hdrlen; 1463 int do_wakeup = 0; 1464 1465 BPFD_LOCK_ASSERT(d); 1466 /* 1467 * Figure out how many bytes to move. If the packet is 1468 * greater or equal to the snapshot length, transfer that 1469 * much. Otherwise, transfer the whole packet (unless 1470 * we hit the buffer size limit). 1471 */ 1472 totlen = hdrlen + min(snaplen, pktlen); 1473 if (totlen > d->bd_bufsize) 1474 totlen = d->bd_bufsize; 1475 1476 /* 1477 * Round up the end of the previous packet to the next longword. 1478 */ 1479 curlen = BPF_WORDALIGN(d->bd_slen); 1480 if (curlen + totlen > d->bd_bufsize) { 1481 /* 1482 * This packet will overflow the storage buffer. 1483 * Rotate the buffers if we can, then wakeup any 1484 * pending reads. 1485 */ 1486 if (d->bd_fbuf == NULL) { 1487 /* 1488 * We haven't completed the previous read yet, 1489 * so drop the packet. 1490 */ 1491 ++d->bd_dcount; 1492 return; 1493 } 1494 ROTATE_BUFFERS(d); 1495 do_wakeup = 1; 1496 curlen = 0; 1497 } 1498 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1499 /* 1500 * Immediate mode is set, or the read timeout has 1501 * already expired during a select call. A packet 1502 * arrived, so the reader should be woken up. 1503 */ 1504 do_wakeup = 1; 1505 1506 /* 1507 * Append the bpf header. 1508 */ 1509 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1510 hp->bh_tstamp = *tv; 1511 hp->bh_datalen = pktlen; 1512 hp->bh_hdrlen = hdrlen; 1513 /* 1514 * Copy the packet data into the store buffer and update its length. 1515 */ 1516 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1517 d->bd_slen = curlen + totlen; 1518 1519 if (do_wakeup) 1520 bpf_wakeup(d); 1521} 1522 1523/* 1524 * Initialize all nonzero fields of a descriptor. 1525 */ 1526static void 1527bpf_allocbufs(struct bpf_d *d) 1528{ 1529 1530 KASSERT(d->bd_fbuf == NULL, ("bpf_allocbufs: bd_fbuf != NULL")); 1531 KASSERT(d->bd_sbuf == NULL, ("bpf_allocbufs: bd_sbuf != NULL")); 1532 KASSERT(d->bd_hbuf == NULL, ("bpf_allocbufs: bd_hbuf != NULL")); 1533 1534 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1535 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1536 d->bd_slen = 0; 1537 d->bd_hlen = 0; 1538} 1539 1540/* 1541 * Free buffers currently in use by a descriptor. 1542 * Called on close. 1543 */ 1544static void 1545bpf_freed(struct bpf_d *d) 1546{ 1547 /* 1548 * We don't need to lock out interrupts since this descriptor has 1549 * been detached from its interface and it yet hasn't been marked 1550 * free. 1551 */ 1552 if (d->bd_sbuf != NULL) { 1553 free(d->bd_sbuf, M_BPF); 1554 if (d->bd_hbuf != NULL) 1555 free(d->bd_hbuf, M_BPF); 1556 if (d->bd_fbuf != NULL) 1557 free(d->bd_fbuf, M_BPF); 1558 } 1559 if (d->bd_rfilter) { 1560 free((caddr_t)d->bd_rfilter, M_BPF); 1561#ifdef BPF_JITTER 1562 bpf_destroy_jit_filter(d->bd_bfilter); 1563#endif 1564 } 1565 if (d->bd_wfilter) 1566 free((caddr_t)d->bd_wfilter, M_BPF); 1567 mtx_destroy(&d->bd_mtx); 1568} 1569 1570/* 1571 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1572 * fixed size of the link header (variable length headers not yet supported). 1573 */ 1574void 1575bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1576{ 1577 1578 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1579} 1580 1581/* 1582 * Attach an interface to bpf. ifp is a pointer to the structure 1583 * defining the interface to be attached, dlt is the link layer type, 1584 * and hdrlen is the fixed size of the link header (variable length 1585 * headers are not yet supporrted). 1586 */ 1587void 1588bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1589{ 1590 struct bpf_if *bp; 1591 1592 bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1593 if (bp == NULL) 1594 panic("bpfattach"); 1595 1596 LIST_INIT(&bp->bif_dlist); 1597 bp->bif_ifp = ifp; 1598 bp->bif_dlt = dlt; 1599 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1600 KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized")); 1601 *driverp = bp; 1602 1603 mtx_lock(&bpf_mtx); 1604 LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); 1605 mtx_unlock(&bpf_mtx); 1606 1607 /* 1608 * Compute the length of the bpf header. This is not necessarily 1609 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1610 * that the network layer header begins on a longword boundary (for 1611 * performance reasons and to alleviate alignment restrictions). 1612 */ 1613 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1614 1615 if (bootverbose) 1616 if_printf(ifp, "bpf attached\n"); 1617} 1618 1619/* 1620 * Detach bpf from an interface. This involves detaching each descriptor 1621 * associated with the interface, and leaving bd_bif NULL. Notify each 1622 * descriptor as it's detached so that any sleepers wake up and get 1623 * ENXIO. 1624 */ 1625void 1626bpfdetach(struct ifnet *ifp) 1627{ 1628 struct bpf_if *bp; 1629 struct bpf_d *d; 1630 1631 /* Locate BPF interface information */ 1632 mtx_lock(&bpf_mtx); 1633 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1634 if (ifp == bp->bif_ifp) 1635 break; 1636 } 1637 1638 /* Interface wasn't attached */ 1639 if ((bp == NULL) || (bp->bif_ifp == NULL)) { 1640 mtx_unlock(&bpf_mtx); 1641 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 1642 return; 1643 } 1644 1645 LIST_REMOVE(bp, bif_next); 1646 mtx_unlock(&bpf_mtx); 1647 1648 while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { 1649 bpf_detachd(d); 1650 BPFD_LOCK(d); 1651 bpf_wakeup(d); 1652 BPFD_UNLOCK(d); 1653 } 1654 1655 mtx_destroy(&bp->bif_mtx); 1656 free(bp, M_BPF); 1657} 1658 1659/* 1660 * Get a list of available data link type of the interface. 1661 */ 1662static int 1663bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 1664{ 1665 int n, error; 1666 struct ifnet *ifp; 1667 struct bpf_if *bp; 1668 1669 ifp = d->bd_bif->bif_ifp; 1670 n = 0; 1671 error = 0; 1672 mtx_lock(&bpf_mtx); 1673 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1674 if (bp->bif_ifp != ifp) 1675 continue; 1676 if (bfl->bfl_list != NULL) { 1677 if (n >= bfl->bfl_len) { 1678 mtx_unlock(&bpf_mtx); 1679 return (ENOMEM); 1680 } 1681 error = copyout(&bp->bif_dlt, 1682 bfl->bfl_list + n, sizeof(u_int)); 1683 } 1684 n++; 1685 } 1686 mtx_unlock(&bpf_mtx); 1687 bfl->bfl_len = n; 1688 return (error); 1689} 1690 1691/* 1692 * Set the data link type of a BPF instance. 1693 */ 1694static int 1695bpf_setdlt(struct bpf_d *d, u_int dlt) 1696{ 1697 int error, opromisc; 1698 struct ifnet *ifp; 1699 struct bpf_if *bp; 1700 1701 if (d->bd_bif->bif_dlt == dlt) 1702 return (0); 1703 ifp = d->bd_bif->bif_ifp; 1704 mtx_lock(&bpf_mtx); 1705 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1706 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1707 break; 1708 } 1709 mtx_unlock(&bpf_mtx); 1710 if (bp != NULL) { 1711 opromisc = d->bd_promisc; 1712 bpf_detachd(d); 1713 bpf_attachd(d, bp); 1714 BPFD_LOCK(d); 1715 reset_d(d); 1716 BPFD_UNLOCK(d); 1717 if (opromisc) { 1718 error = ifpromisc(bp->bif_ifp, 1); 1719 if (error) 1720 if_printf(bp->bif_ifp, 1721 "bpf_setdlt: ifpromisc failed (%d)\n", 1722 error); 1723 else 1724 d->bd_promisc = 1; 1725 } 1726 } 1727 return (bp == NULL ? EINVAL : 0); 1728} 1729 1730static void 1731bpf_clone(void *arg, struct ucred *cred, char *name, int namelen, 1732 struct cdev **dev) 1733{ 1734 int u; 1735 1736 if (*dev != NULL) 1737 return; 1738 if (dev_stdclone(name, NULL, "bpf", &u) != 1) 1739 return; 1740 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, 1741 "bpf%d", u); 1742 dev_ref(*dev); 1743 (*dev)->si_flags |= SI_CHEAPCLONE; 1744 return; 1745} 1746 1747static void 1748bpf_drvinit(void *unused) 1749{ 1750 1751 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 1752 LIST_INIT(&bpf_iflist); 1753 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); 1754} 1755 1756static void 1757bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 1758{ 1759 1760 bzero(d, sizeof(*d)); 1761 BPFD_LOCK_ASSERT(bd); 1762 d->bd_immediate = bd->bd_immediate; 1763 d->bd_promisc = bd->bd_promisc; 1764 d->bd_hdrcmplt = bd->bd_hdrcmplt; 1765 d->bd_direction = bd->bd_direction; 1766 d->bd_feedback = bd->bd_feedback; 1767 d->bd_async = bd->bd_async; 1768 d->bd_rcount = bd->bd_rcount; 1769 d->bd_dcount = bd->bd_dcount; 1770 d->bd_fcount = bd->bd_fcount; 1771 d->bd_sig = bd->bd_sig; 1772 d->bd_slen = bd->bd_slen; 1773 d->bd_hlen = bd->bd_hlen; 1774 d->bd_bufsize = bd->bd_bufsize; 1775 d->bd_pid = bd->bd_pid; 1776 strlcpy(d->bd_ifname, 1777 bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); 1778 d->bd_locked = bd->bd_locked; 1779} 1780 1781static int 1782bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 1783{ 1784 struct xbpf_d *xbdbuf, *xbd; 1785 int index, error; 1786 struct bpf_if *bp; 1787 struct bpf_d *bd; 1788 1789 /* 1790 * XXX This is not technically correct. It is possible for non 1791 * privileged users to open bpf devices. It would make sense 1792 * if the users who opened the devices were able to retrieve 1793 * the statistics for them, too. 1794 */ 1795 error = priv_check(req->td, PRIV_NET_BPF); 1796 if (error) 1797 return (error); 1798 if (req->oldptr == NULL) 1799 return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); 1800 if (bpf_bpfd_cnt == 0) 1801 return (SYSCTL_OUT(req, 0, 0)); 1802 xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); 1803 mtx_lock(&bpf_mtx); 1804 if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { 1805 mtx_unlock(&bpf_mtx); 1806 free(xbdbuf, M_BPF); 1807 return (ENOMEM); 1808 } 1809 index = 0; 1810 LIST_FOREACH(bp, &bpf_iflist, bif_next) { 1811 BPFIF_LOCK(bp); 1812 LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 1813 xbd = &xbdbuf[index++]; 1814 BPFD_LOCK(bd); 1815 bpfstats_fill_xbpf(xbd, bd); 1816 BPFD_UNLOCK(bd); 1817 } 1818 BPFIF_UNLOCK(bp); 1819 } 1820 mtx_unlock(&bpf_mtx); 1821 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 1822 free(xbdbuf, M_BPF); 1823 return (error); 1824} 1825 1826SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL) 1827 1828#else /* !DEV_BPF && !NETGRAPH_BPF */ 1829/* 1830 * NOP stubs to allow bpf-using drivers to load and function. 1831 * 1832 * A 'better' implementation would allow the core bpf functionality 1833 * to be loaded at runtime. 1834 */ 1835static struct bpf_if bp_null; 1836 1837void 1838bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 1839{ 1840} 1841 1842void 1843bpf_mtap(struct bpf_if *bp, struct mbuf *m) 1844{ 1845} 1846 1847void 1848bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 1849{ 1850} 1851 1852void 1853bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 1854{ 1855 1856 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1857} 1858 1859void 1860bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) 1861{ 1862 1863 *driverp = &bp_null; 1864} 1865 1866void 1867bpfdetach(struct ifnet *ifp) 1868{ 1869} 1870 1871u_int 1872bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 1873{ 1874 return -1; /* "no filter" behaviour */ 1875} 1876 1877int 1878bpf_validate(const struct bpf_insn *f, int len) 1879{ 1880 return 0; /* false */ 1881} 1882 1883#endif /* !DEV_BPF && !NETGRAPH_BPF */ 1884