bpf.c revision 69781
1/* 2 * Copyright (c) 1990, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from the Stanford/CMU enet packet filter, 6 * (net/enet.c) distributed as part of 4.3BSD, and code contributed 7 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence 8 * Berkeley Laboratory. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)bpf.c 8.2 (Berkeley) 3/28/94 39 * 40 * $FreeBSD: head/sys/net/bpf.c 69781 2000-12-08 21:51:06Z dwmalone $ 41 */ 42 43#include "bpf.h" 44 45#ifndef __GNUC__ 46#define inline 47#else 48#define inline __inline 49#endif 50 51#include <sys/param.h> 52#include <sys/systm.h> 53#include <sys/conf.h> 54#include <sys/malloc.h> 55#include <sys/mbuf.h> 56#include <sys/time.h> 57#include <sys/proc.h> 58#include <sys/signalvar.h> 59#include <sys/filio.h> 60#include <sys/sockio.h> 61#include <sys/ttycom.h> 62#include <sys/filedesc.h> 63 64#if defined(sparc) && BSD < 199103 65#include <sys/stream.h> 66#endif 67#include <sys/poll.h> 68 69#include <sys/socket.h> 70#include <sys/vnode.h> 71 72#include <net/if.h> 73#include <net/bpf.h> 74#include <net/bpfdesc.h> 75 76#include <netinet/in.h> 77#include <netinet/if_ether.h> 78#include <sys/kernel.h> 79#include <sys/sysctl.h> 80 81static MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 82 83#if NBPF > 0 84 85/* 86 * Older BSDs don't have kernel malloc. 87 */ 88#if BSD < 199103 89extern bcopy(); 90static caddr_t bpf_alloc(); 91#include <net/bpf_compat.h> 92#define BPF_BUFSIZE (MCLBYTES-8) 93#define UIOMOVE(cp, len, code, uio) uiomove(cp, len, code, uio) 94#else 95#define BPF_BUFSIZE 4096 96#define UIOMOVE(cp, len, code, uio) uiomove(cp, len, uio) 97#endif 98 99#define PRINET 26 /* interruptible */ 100 101/* 102 * The default read buffer size is patchable. 103 */ 104static int bpf_bufsize = BPF_BUFSIZE; 105SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW, 106 &bpf_bufsize, 0, ""); 107static int bpf_maxbufsize = BPF_MAXBUFSIZE; 108SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW, 109 &bpf_maxbufsize, 0, ""); 110 111/* 112 * bpf_iflist is the list of interfaces; each corresponds to an ifnet 113 */ 114static struct bpf_if *bpf_iflist; 115 116static int bpf_allocbufs __P((struct bpf_d *)); 117static void bpf_attachd __P((struct bpf_d *d, struct bpf_if *bp)); 118static void bpf_detachd __P((struct bpf_d *d)); 119static void bpf_freed __P((struct bpf_d *)); 120static void bpf_mcopy __P((const void *, void *, size_t)); 121static int bpf_movein __P((struct uio *, int, 122 struct mbuf **, struct sockaddr *, int *)); 123static int bpf_setif __P((struct bpf_d *, struct ifreq *)); 124static inline void 125 bpf_wakeup __P((struct bpf_d *)); 126static void catchpacket __P((struct bpf_d *, u_char *, u_int, 127 u_int, void (*)(const void *, void *, size_t))); 128static void reset_d __P((struct bpf_d *)); 129static int bpf_setf __P((struct bpf_d *, struct bpf_program *)); 130 131static d_open_t bpfopen; 132static d_close_t bpfclose; 133static d_read_t bpfread; 134static d_write_t bpfwrite; 135static d_ioctl_t bpfioctl; 136static d_poll_t bpfpoll; 137 138#define CDEV_MAJOR 23 139static struct cdevsw bpf_cdevsw = { 140 /* open */ bpfopen, 141 /* close */ bpfclose, 142 /* read */ bpfread, 143 /* write */ bpfwrite, 144 /* ioctl */ bpfioctl, 145 /* poll */ bpfpoll, 146 /* mmap */ nommap, 147 /* strategy */ nostrategy, 148 /* name */ "bpf", 149 /* maj */ CDEV_MAJOR, 150 /* dump */ nodump, 151 /* psize */ nopsize, 152 /* flags */ 0, 153 /* bmaj */ -1 154}; 155 156 157static int 158bpf_movein(uio, linktype, mp, sockp, datlen) 159 register struct uio *uio; 160 int linktype, *datlen; 161 register struct mbuf **mp; 162 register struct sockaddr *sockp; 163{ 164 struct mbuf *m; 165 int error; 166 int len; 167 int hlen; 168 169 /* 170 * Build a sockaddr based on the data link layer type. 171 * We do this at this level because the ethernet header 172 * is copied directly into the data field of the sockaddr. 173 * In the case of SLIP, there is no header and the packet 174 * is forwarded as is. 175 * Also, we are careful to leave room at the front of the mbuf 176 * for the link level header. 177 */ 178 switch (linktype) { 179 180 case DLT_SLIP: 181 sockp->sa_family = AF_INET; 182 hlen = 0; 183 break; 184 185 case DLT_EN10MB: 186 sockp->sa_family = AF_UNSPEC; 187 /* XXX Would MAXLINKHDR be better? */ 188 hlen = sizeof(struct ether_header); 189 break; 190 191 case DLT_FDDI: 192#if defined(__FreeBSD__) || defined(__bsdi__) 193 sockp->sa_family = AF_IMPLINK; 194 hlen = 0; 195#else 196 sockp->sa_family = AF_UNSPEC; 197 /* XXX 4(FORMAC)+6(dst)+6(src)+3(LLC)+5(SNAP) */ 198 hlen = 24; 199#endif 200 break; 201 202 case DLT_RAW: 203 case DLT_NULL: 204 sockp->sa_family = AF_UNSPEC; 205 hlen = 0; 206 break; 207 208#ifdef __FreeBSD__ 209 case DLT_ATM_RFC1483: 210 /* 211 * en atm driver requires 4-byte atm pseudo header. 212 * though it isn't standard, vpi:vci needs to be 213 * specified anyway. 214 */ 215 sockp->sa_family = AF_UNSPEC; 216 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 217 break; 218#endif 219 220 case DLT_PPP: 221 sockp->sa_family = AF_UNSPEC; 222 hlen = 4; /* This should match PPP_HDRLEN */ 223 break; 224 225 default: 226 return (EIO); 227 } 228 229 len = uio->uio_resid; 230 *datlen = len - hlen; 231 if ((unsigned)len > MCLBYTES) 232 return (EIO); 233 234 MGETHDR(m, M_WAIT, MT_DATA); 235 if (m == 0) 236 return (ENOBUFS); 237 if (len > MHLEN) { 238#if BSD >= 199103 239 MCLGET(m, M_WAIT); 240 if ((m->m_flags & M_EXT) == 0) { 241#else 242 MCLGET(m); 243 if (m->m_len != MCLBYTES) { 244#endif 245 error = ENOBUFS; 246 goto bad; 247 } 248 } 249 m->m_pkthdr.len = m->m_len = len; 250 m->m_pkthdr.rcvif = NULL; 251 *mp = m; 252 /* 253 * Make room for link header. 254 */ 255 if (hlen != 0) { 256 m->m_pkthdr.len -= hlen; 257 m->m_len -= hlen; 258#if BSD >= 199103 259 m->m_data += hlen; /* XXX */ 260#else 261 m->m_off += hlen; 262#endif 263 error = UIOMOVE((caddr_t)sockp->sa_data, hlen, UIO_WRITE, uio); 264 if (error) 265 goto bad; 266 } 267 error = UIOMOVE(mtod(m, caddr_t), len - hlen, UIO_WRITE, uio); 268 if (!error) 269 return (0); 270 bad: 271 m_freem(m); 272 return (error); 273} 274 275/* 276 * Attach file to the bpf interface, i.e. make d listen on bp. 277 * Must be called at splimp. 278 */ 279static void 280bpf_attachd(d, bp) 281 struct bpf_d *d; 282 struct bpf_if *bp; 283{ 284 /* 285 * Point d at bp, and add d to the interface's list of listeners. 286 * Finally, point the driver's bpf cookie at the interface so 287 * it will divert packets to bpf. 288 */ 289 d->bd_bif = bp; 290 d->bd_next = bp->bif_dlist; 291 bp->bif_dlist = d; 292 293 bp->bif_ifp->if_bpf = bp; 294} 295 296/* 297 * Detach a file from its interface. 298 */ 299static void 300bpf_detachd(d) 301 struct bpf_d *d; 302{ 303 int error; 304 struct bpf_d **p; 305 struct bpf_if *bp; 306 307 bp = d->bd_bif; 308 /* 309 * Check if this descriptor had requested promiscuous mode. 310 * If so, turn it off. 311 */ 312 if (d->bd_promisc) { 313 d->bd_promisc = 0; 314 error = ifpromisc(bp->bif_ifp, 0); 315 if (error != 0 && error != ENXIO) { 316 /* 317 * ENXIO can happen if a pccard is unplugged 318 * Something is really wrong if we were able to put 319 * the driver into promiscuous mode, but can't 320 * take it out. 321 */ 322 printf("%s%d: ifpromisc failed %d\n", 323 bp->bif_ifp->if_name, bp->bif_ifp->if_unit, error); 324 } 325 } 326 /* Remove d from the interface's descriptor list. */ 327 p = &bp->bif_dlist; 328 while (*p != d) { 329 p = &(*p)->bd_next; 330 if (*p == 0) 331 panic("bpf_detachd: descriptor not in list"); 332 } 333 *p = (*p)->bd_next; 334 if (bp->bif_dlist == 0) 335 /* 336 * Let the driver know that there are no more listeners. 337 */ 338 d->bd_bif->bif_ifp->if_bpf = 0; 339 d->bd_bif = 0; 340} 341 342/* 343 * Open ethernet device. Returns ENXIO for illegal minor device number, 344 * EBUSY if file is open by another process. 345 */ 346/* ARGSUSED */ 347static int 348bpfopen(dev, flags, fmt, p) 349 dev_t dev; 350 int flags; 351 int fmt; 352 struct proc *p; 353{ 354 register struct bpf_d *d; 355 356 if (p->p_prison) 357 return (EPERM); 358 359 d = dev->si_drv1; 360 /* 361 * Each minor can be opened by only one process. If the requested 362 * minor is in use, return EBUSY. 363 */ 364 if (d) 365 return (EBUSY); 366 if ((dev->si_flags & SI_NAMED) == 0) 367 make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600, 368 "bpf%d", dev2unit(dev)); 369 MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 370 dev->si_drv1 = d; 371 d->bd_bufsize = bpf_bufsize; 372 d->bd_sig = SIGIO; 373 d->bd_seesent = 1; 374 375 return (0); 376} 377 378/* 379 * Close the descriptor by detaching it from its interface, 380 * deallocating its buffers, and marking it free. 381 */ 382/* ARGSUSED */ 383static int 384bpfclose(dev, flags, fmt, p) 385 dev_t dev; 386 int flags; 387 int fmt; 388 struct proc *p; 389{ 390 register struct bpf_d *d = dev->si_drv1; 391 register int s; 392 393 funsetown(d->bd_sigio); 394 s = splimp(); 395 if (d->bd_bif) 396 bpf_detachd(d); 397 splx(s); 398 bpf_freed(d); 399 dev->si_drv1 = 0; 400 FREE(d, M_BPF); 401 402 return (0); 403} 404 405/* 406 * Support for SunOS, which does not have tsleep. 407 */ 408#if BSD < 199103 409static 410bpf_timeout(arg) 411 caddr_t arg; 412{ 413 struct bpf_d *d = (struct bpf_d *)arg; 414 d->bd_timedout = 1; 415 wakeup(arg); 416} 417 418#define BPF_SLEEP(chan, pri, s, t) bpf_sleep((struct bpf_d *)chan) 419 420int 421bpf_sleep(d) 422 register struct bpf_d *d; 423{ 424 register int rto = d->bd_rtout; 425 register int st; 426 427 if (rto != 0) { 428 d->bd_timedout = 0; 429 timeout(bpf_timeout, (caddr_t)d, rto); 430 } 431 st = sleep((caddr_t)d, PRINET|PCATCH); 432 if (rto != 0) { 433 if (d->bd_timedout == 0) 434 untimeout(bpf_timeout, (caddr_t)d); 435 else if (st == 0) 436 return EWOULDBLOCK; 437 } 438 return (st != 0) ? EINTR : 0; 439} 440#else 441#define BPF_SLEEP tsleep 442#endif 443 444/* 445 * Rotate the packet buffers in descriptor d. Move the store buffer 446 * into the hold slot, and the free buffer into the store slot. 447 * Zero the length of the new store buffer. 448 */ 449#define ROTATE_BUFFERS(d) \ 450 (d)->bd_hbuf = (d)->bd_sbuf; \ 451 (d)->bd_hlen = (d)->bd_slen; \ 452 (d)->bd_sbuf = (d)->bd_fbuf; \ 453 (d)->bd_slen = 0; \ 454 (d)->bd_fbuf = 0; 455/* 456 * bpfread - read next chunk of packets from buffers 457 */ 458static int 459bpfread(dev, uio, ioflag) 460 dev_t dev; 461 register struct uio *uio; 462 int ioflag; 463{ 464 register struct bpf_d *d = dev->si_drv1; 465 int error; 466 int s; 467 468 /* 469 * Restrict application to use a buffer the same size as 470 * as kernel buffers. 471 */ 472 if (uio->uio_resid != d->bd_bufsize) 473 return (EINVAL); 474 475 s = splimp(); 476 /* 477 * If the hold buffer is empty, then do a timed sleep, which 478 * ends when the timeout expires or when enough packets 479 * have arrived to fill the store buffer. 480 */ 481 while (d->bd_hbuf == 0) { 482 if (d->bd_immediate && d->bd_slen != 0) { 483 /* 484 * A packet(s) either arrived since the previous 485 * read or arrived while we were asleep. 486 * Rotate the buffers and return what's here. 487 */ 488 ROTATE_BUFFERS(d); 489 break; 490 } 491 492 /* 493 * No data is available, check to see if the bpf device 494 * is still pointed at a real interface. If not, return 495 * ENXIO so that the userland process knows to rebind 496 * it before using it again. 497 */ 498 if (d->bd_bif == NULL) { 499 splx(s); 500 return (ENXIO); 501 } 502 503 if (ioflag & IO_NDELAY) 504 error = EWOULDBLOCK; 505 else 506 error = BPF_SLEEP((caddr_t)d, PRINET|PCATCH, "bpf", 507 d->bd_rtout); 508 if (error == EINTR || error == ERESTART) { 509 splx(s); 510 return (error); 511 } 512 if (error == EWOULDBLOCK) { 513 /* 514 * On a timeout, return what's in the buffer, 515 * which may be nothing. If there is something 516 * in the store buffer, we can rotate the buffers. 517 */ 518 if (d->bd_hbuf) 519 /* 520 * We filled up the buffer in between 521 * getting the timeout and arriving 522 * here, so we don't need to rotate. 523 */ 524 break; 525 526 if (d->bd_slen == 0) { 527 splx(s); 528 return (0); 529 } 530 ROTATE_BUFFERS(d); 531 break; 532 } 533 } 534 /* 535 * At this point, we know we have something in the hold slot. 536 */ 537 splx(s); 538 539 /* 540 * Move data from hold buffer into user space. 541 * We know the entire buffer is transferred since 542 * we checked above that the read buffer is bpf_bufsize bytes. 543 */ 544 error = UIOMOVE(d->bd_hbuf, d->bd_hlen, UIO_READ, uio); 545 546 s = splimp(); 547 d->bd_fbuf = d->bd_hbuf; 548 d->bd_hbuf = 0; 549 d->bd_hlen = 0; 550 splx(s); 551 552 return (error); 553} 554 555 556/* 557 * If there are processes sleeping on this descriptor, wake them up. 558 */ 559static inline void 560bpf_wakeup(d) 561 register struct bpf_d *d; 562{ 563 wakeup((caddr_t)d); 564 if (d->bd_async && d->bd_sig && d->bd_sigio) 565 pgsigio(d->bd_sigio, d->bd_sig, 0); 566 567#if BSD >= 199103 568 selwakeup(&d->bd_sel); 569 /* XXX */ 570 d->bd_sel.si_pid = 0; 571#else 572 if (d->bd_selproc) { 573 selwakeup(d->bd_selproc, (int)d->bd_selcoll); 574 d->bd_selcoll = 0; 575 d->bd_selproc = 0; 576 } 577#endif 578} 579 580static int 581bpfwrite(dev, uio, ioflag) 582 dev_t dev; 583 struct uio *uio; 584 int ioflag; 585{ 586 register struct bpf_d *d = dev->si_drv1; 587 struct ifnet *ifp; 588 struct mbuf *m; 589 int error, s; 590 static struct sockaddr dst; 591 int datlen; 592 593 if (d->bd_bif == 0) 594 return (ENXIO); 595 596 ifp = d->bd_bif->bif_ifp; 597 598 if (uio->uio_resid == 0) 599 return (0); 600 601 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen); 602 if (error) 603 return (error); 604 605 if (datlen > ifp->if_mtu) 606 return (EMSGSIZE); 607 608 if (d->bd_hdrcmplt) 609 dst.sa_family = pseudo_AF_HDRCMPLT; 610 611 s = splnet(); 612#if BSD >= 199103 613 error = (*ifp->if_output)(ifp, m, &dst, (struct rtentry *)0); 614#else 615 error = (*ifp->if_output)(ifp, m, &dst); 616#endif 617 splx(s); 618 /* 619 * The driver frees the mbuf. 620 */ 621 return (error); 622} 623 624/* 625 * Reset a descriptor by flushing its packet buffer and clearing the 626 * receive and drop counts. Should be called at splimp. 627 */ 628static void 629reset_d(d) 630 struct bpf_d *d; 631{ 632 if (d->bd_hbuf) { 633 /* Free the hold buffer. */ 634 d->bd_fbuf = d->bd_hbuf; 635 d->bd_hbuf = 0; 636 } 637 d->bd_slen = 0; 638 d->bd_hlen = 0; 639 d->bd_rcount = 0; 640 d->bd_dcount = 0; 641} 642 643/* 644 * FIONREAD Check for read packet available. 645 * SIOCGIFADDR Get interface address - convenient hook to driver. 646 * BIOCGBLEN Get buffer len [for read()]. 647 * BIOCSETF Set ethernet read filter. 648 * BIOCFLUSH Flush read packet buffer. 649 * BIOCPROMISC Put interface into promiscuous mode. 650 * BIOCGDLT Get link layer type. 651 * BIOCGETIF Get interface name. 652 * BIOCSETIF Set interface. 653 * BIOCSRTIMEOUT Set read timeout. 654 * BIOCGRTIMEOUT Get read timeout. 655 * BIOCGSTATS Get packet stats. 656 * BIOCIMMEDIATE Set immediate mode. 657 * BIOCVERSION Get filter language version. 658 * BIOCGHDRCMPLT Get "header already complete" flag 659 * BIOCSHDRCMPLT Set "header already complete" flag 660 * BIOCGSEESENT Get "see packets sent" flag 661 * BIOCSSEESENT Set "see packets sent" flag 662 */ 663/* ARGSUSED */ 664static int 665bpfioctl(dev, cmd, addr, flags, p) 666 dev_t dev; 667 u_long cmd; 668 caddr_t addr; 669 int flags; 670 struct proc *p; 671{ 672 register struct bpf_d *d = dev->si_drv1; 673 int s, error = 0; 674 675 switch (cmd) { 676 677 default: 678 error = EINVAL; 679 break; 680 681 /* 682 * Check for read packet available. 683 */ 684 case FIONREAD: 685 { 686 int n; 687 688 s = splimp(); 689 n = d->bd_slen; 690 if (d->bd_hbuf) 691 n += d->bd_hlen; 692 splx(s); 693 694 *(int *)addr = n; 695 break; 696 } 697 698 case SIOCGIFADDR: 699 { 700 struct ifnet *ifp; 701 702 if (d->bd_bif == 0) 703 error = EINVAL; 704 else { 705 ifp = d->bd_bif->bif_ifp; 706 error = (*ifp->if_ioctl)(ifp, cmd, addr); 707 } 708 break; 709 } 710 711 /* 712 * Get buffer len [for read()]. 713 */ 714 case BIOCGBLEN: 715 *(u_int *)addr = d->bd_bufsize; 716 break; 717 718 /* 719 * Set buffer length. 720 */ 721 case BIOCSBLEN: 722#if BSD < 199103 723 error = EINVAL; 724#else 725 if (d->bd_bif != 0) 726 error = EINVAL; 727 else { 728 register u_int size = *(u_int *)addr; 729 730 if (size > bpf_maxbufsize) 731 *(u_int *)addr = size = bpf_maxbufsize; 732 else if (size < BPF_MINBUFSIZE) 733 *(u_int *)addr = size = BPF_MINBUFSIZE; 734 d->bd_bufsize = size; 735 } 736#endif 737 break; 738 739 /* 740 * Set link layer read filter. 741 */ 742 case BIOCSETF: 743 error = bpf_setf(d, (struct bpf_program *)addr); 744 break; 745 746 /* 747 * Flush read packet buffer. 748 */ 749 case BIOCFLUSH: 750 s = splimp(); 751 reset_d(d); 752 splx(s); 753 break; 754 755 /* 756 * Put interface into promiscuous mode. 757 */ 758 case BIOCPROMISC: 759 if (d->bd_bif == 0) { 760 /* 761 * No interface attached yet. 762 */ 763 error = EINVAL; 764 break; 765 } 766 s = splimp(); 767 if (d->bd_promisc == 0) { 768 error = ifpromisc(d->bd_bif->bif_ifp, 1); 769 if (error == 0) 770 d->bd_promisc = 1; 771 } 772 splx(s); 773 break; 774 775 /* 776 * Get device parameters. 777 */ 778 case BIOCGDLT: 779 if (d->bd_bif == 0) 780 error = EINVAL; 781 else 782 *(u_int *)addr = d->bd_bif->bif_dlt; 783 break; 784 785 /* 786 * Get interface name. 787 */ 788 case BIOCGETIF: 789 if (d->bd_bif == 0) 790 error = EINVAL; 791 else { 792 struct ifnet *const ifp = d->bd_bif->bif_ifp; 793 struct ifreq *const ifr = (struct ifreq *)addr; 794 795 snprintf(ifr->ifr_name, sizeof(ifr->ifr_name), 796 "%s%d", ifp->if_name, ifp->if_unit); 797 } 798 break; 799 800 /* 801 * Set interface. 802 */ 803 case BIOCSETIF: 804 error = bpf_setif(d, (struct ifreq *)addr); 805 break; 806 807 /* 808 * Set read timeout. 809 */ 810 case BIOCSRTIMEOUT: 811 { 812 struct timeval *tv = (struct timeval *)addr; 813 814 /* 815 * Subtract 1 tick from tvtohz() since this isn't 816 * a one-shot timer. 817 */ 818 if ((error = itimerfix(tv)) == 0) 819 d->bd_rtout = tvtohz(tv) - 1; 820 break; 821 } 822 823 /* 824 * Get read timeout. 825 */ 826 case BIOCGRTIMEOUT: 827 { 828 struct timeval *tv = (struct timeval *)addr; 829 830 tv->tv_sec = d->bd_rtout / hz; 831 tv->tv_usec = (d->bd_rtout % hz) * tick; 832 break; 833 } 834 835 /* 836 * Get packet stats. 837 */ 838 case BIOCGSTATS: 839 { 840 struct bpf_stat *bs = (struct bpf_stat *)addr; 841 842 bs->bs_recv = d->bd_rcount; 843 bs->bs_drop = d->bd_dcount; 844 break; 845 } 846 847 /* 848 * Set immediate mode. 849 */ 850 case BIOCIMMEDIATE: 851 d->bd_immediate = *(u_int *)addr; 852 break; 853 854 case BIOCVERSION: 855 { 856 struct bpf_version *bv = (struct bpf_version *)addr; 857 858 bv->bv_major = BPF_MAJOR_VERSION; 859 bv->bv_minor = BPF_MINOR_VERSION; 860 break; 861 } 862 863 /* 864 * Get "header already complete" flag 865 */ 866 case BIOCGHDRCMPLT: 867 *(u_int *)addr = d->bd_hdrcmplt; 868 break; 869 870 /* 871 * Set "header already complete" flag 872 */ 873 case BIOCSHDRCMPLT: 874 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 875 break; 876 877 /* 878 * Get "see sent packets" flag 879 */ 880 case BIOCGSEESENT: 881 *(u_int *)addr = d->bd_seesent; 882 break; 883 884 /* 885 * Set "see sent packets" flag 886 */ 887 case BIOCSSEESENT: 888 d->bd_seesent = *(u_int *)addr; 889 break; 890 891 case FIONBIO: /* Non-blocking I/O */ 892 break; 893 894 case FIOASYNC: /* Send signal on receive packets */ 895 d->bd_async = *(int *)addr; 896 break; 897 898 case FIOSETOWN: 899 error = fsetown(*(int *)addr, &d->bd_sigio); 900 break; 901 902 case FIOGETOWN: 903 *(int *)addr = fgetown(d->bd_sigio); 904 break; 905 906 /* This is deprecated, FIOSETOWN should be used instead. */ 907 case TIOCSPGRP: 908 error = fsetown(-(*(int *)addr), &d->bd_sigio); 909 break; 910 911 /* This is deprecated, FIOGETOWN should be used instead. */ 912 case TIOCGPGRP: 913 *(int *)addr = -fgetown(d->bd_sigio); 914 break; 915 916 case BIOCSRSIG: /* Set receive signal */ 917 { 918 u_int sig; 919 920 sig = *(u_int *)addr; 921 922 if (sig >= NSIG) 923 error = EINVAL; 924 else 925 d->bd_sig = sig; 926 break; 927 } 928 case BIOCGRSIG: 929 *(u_int *)addr = d->bd_sig; 930 break; 931 } 932 return (error); 933} 934 935/* 936 * Set d's packet filter program to fp. If this file already has a filter, 937 * free it and replace it. Returns EINVAL for bogus requests. 938 */ 939static int 940bpf_setf(d, fp) 941 struct bpf_d *d; 942 struct bpf_program *fp; 943{ 944 struct bpf_insn *fcode, *old; 945 u_int flen, size; 946 int s; 947 948 old = d->bd_filter; 949 if (fp->bf_insns == 0) { 950 if (fp->bf_len != 0) 951 return (EINVAL); 952 s = splimp(); 953 d->bd_filter = 0; 954 reset_d(d); 955 splx(s); 956 if (old != 0) 957 free((caddr_t)old, M_BPF); 958 return (0); 959 } 960 flen = fp->bf_len; 961 if (flen > BPF_MAXINSNS) 962 return (EINVAL); 963 964 size = flen * sizeof(*fp->bf_insns); 965 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); 966 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 967 bpf_validate(fcode, (int)flen)) { 968 s = splimp(); 969 d->bd_filter = fcode; 970 reset_d(d); 971 splx(s); 972 if (old != 0) 973 free((caddr_t)old, M_BPF); 974 975 return (0); 976 } 977 free((caddr_t)fcode, M_BPF); 978 return (EINVAL); 979} 980 981/* 982 * Detach a file from its current interface (if attached at all) and attach 983 * to the interface indicated by the name stored in ifr. 984 * Return an errno or 0. 985 */ 986static int 987bpf_setif(d, ifr) 988 struct bpf_d *d; 989 struct ifreq *ifr; 990{ 991 struct bpf_if *bp; 992 int s, error; 993 struct ifnet *theywant; 994 995 theywant = ifunit(ifr->ifr_name); 996 if (theywant == 0) 997 return ENXIO; 998 999 /* 1000 * Look through attached interfaces for the named one. 1001 */ 1002 for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) { 1003 struct ifnet *ifp = bp->bif_ifp; 1004 1005 if (ifp == 0 || ifp != theywant) 1006 continue; 1007 /* 1008 * We found the requested interface. 1009 * If it's not up, return an error. 1010 * Allocate the packet buffers if we need to. 1011 * If we're already attached to requested interface, 1012 * just flush the buffer. 1013 */ 1014 if ((ifp->if_flags & IFF_UP) == 0) 1015 return (ENETDOWN); 1016 1017 if (d->bd_sbuf == 0) { 1018 error = bpf_allocbufs(d); 1019 if (error != 0) 1020 return (error); 1021 } 1022 s = splimp(); 1023 if (bp != d->bd_bif) { 1024 if (d->bd_bif) 1025 /* 1026 * Detach if attached to something else. 1027 */ 1028 bpf_detachd(d); 1029 1030 bpf_attachd(d, bp); 1031 } 1032 reset_d(d); 1033 splx(s); 1034 return (0); 1035 } 1036 /* Not found. */ 1037 return (ENXIO); 1038} 1039 1040/* 1041 * Support for select() and poll() system calls 1042 * 1043 * Return true iff the specific operation will not block indefinitely. 1044 * Otherwise, return false but make a note that a selwakeup() must be done. 1045 */ 1046int 1047bpfpoll(dev, events, p) 1048 register dev_t dev; 1049 int events; 1050 struct proc *p; 1051{ 1052 register struct bpf_d *d; 1053 register int s; 1054 int revents = 0; 1055 1056 /* 1057 * An imitation of the FIONREAD ioctl code. 1058 */ 1059 d = dev->si_drv1; 1060 1061 if (d->bd_bif == NULL) 1062 return (ENXIO); 1063 1064 s = splimp(); 1065 if (events & (POLLIN | POLLRDNORM)) { 1066 if (d->bd_hlen != 0 || (d->bd_immediate && d->bd_slen != 0)) 1067 revents |= events & (POLLIN | POLLRDNORM); 1068 else 1069 selrecord(p, &d->bd_sel); 1070 } 1071 splx(s); 1072 return (revents); 1073} 1074 1075/* 1076 * Incoming linkage from device drivers. Process the packet pkt, of length 1077 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1078 * by each process' filter, and if accepted, stashed into the corresponding 1079 * buffer. 1080 */ 1081void 1082bpf_tap(ifp, pkt, pktlen) 1083 struct ifnet *ifp; 1084 register u_char *pkt; 1085 register u_int pktlen; 1086{ 1087 struct bpf_if *bp; 1088 register struct bpf_d *d; 1089 register u_int slen; 1090 /* 1091 * Note that the ipl does not have to be raised at this point. 1092 * The only problem that could arise here is that if two different 1093 * interfaces shared any data. This is not the case. 1094 */ 1095 bp = ifp->if_bpf; 1096 for (d = bp->bif_dlist; d != 0; d = d->bd_next) { 1097 ++d->bd_rcount; 1098 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen); 1099 if (slen != 0) 1100 catchpacket(d, pkt, pktlen, slen, bcopy); 1101 } 1102} 1103 1104/* 1105 * Copy data from an mbuf chain into a buffer. This code is derived 1106 * from m_copydata in sys/uipc_mbuf.c. 1107 */ 1108static void 1109bpf_mcopy(src_arg, dst_arg, len) 1110 const void *src_arg; 1111 void *dst_arg; 1112 register size_t len; 1113{ 1114 register const struct mbuf *m; 1115 register u_int count; 1116 u_char *dst; 1117 1118 m = src_arg; 1119 dst = dst_arg; 1120 while (len > 0) { 1121 if (m == 0) 1122 panic("bpf_mcopy"); 1123 count = min(m->m_len, len); 1124 bcopy(mtod(m, void *), dst, count); 1125 m = m->m_next; 1126 dst += count; 1127 len -= count; 1128 } 1129} 1130 1131/* 1132 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1133 */ 1134void 1135bpf_mtap(ifp, m) 1136 struct ifnet *ifp; 1137 struct mbuf *m; 1138{ 1139 struct bpf_if *bp = ifp->if_bpf; 1140 struct bpf_d *d; 1141 u_int pktlen, slen; 1142 struct mbuf *m0; 1143 1144 pktlen = 0; 1145 for (m0 = m; m0 != 0; m0 = m0->m_next) 1146 pktlen += m0->m_len; 1147 1148 for (d = bp->bif_dlist; d != 0; d = d->bd_next) { 1149 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1150 continue; 1151 ++d->bd_rcount; 1152 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0); 1153 if (slen != 0) 1154 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy); 1155 } 1156} 1157 1158/* 1159 * Move the packet data from interface memory (pkt) into the 1160 * store buffer. Return 1 if it's time to wakeup a listener (buffer full), 1161 * otherwise 0. "copy" is the routine called to do the actual data 1162 * transfer. bcopy is passed in to copy contiguous chunks, while 1163 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1164 * pkt is really an mbuf. 1165 */ 1166static void 1167catchpacket(d, pkt, pktlen, snaplen, cpfn) 1168 register struct bpf_d *d; 1169 register u_char *pkt; 1170 register u_int pktlen, snaplen; 1171 register void (*cpfn) __P((const void *, void *, size_t)); 1172{ 1173 register struct bpf_hdr *hp; 1174 register int totlen, curlen; 1175 register int hdrlen = d->bd_bif->bif_hdrlen; 1176 /* 1177 * Figure out how many bytes to move. If the packet is 1178 * greater or equal to the snapshot length, transfer that 1179 * much. Otherwise, transfer the whole packet (unless 1180 * we hit the buffer size limit). 1181 */ 1182 totlen = hdrlen + min(snaplen, pktlen); 1183 if (totlen > d->bd_bufsize) 1184 totlen = d->bd_bufsize; 1185 1186 /* 1187 * Round up the end of the previous packet to the next longword. 1188 */ 1189 curlen = BPF_WORDALIGN(d->bd_slen); 1190 if (curlen + totlen > d->bd_bufsize) { 1191 /* 1192 * This packet will overflow the storage buffer. 1193 * Rotate the buffers if we can, then wakeup any 1194 * pending reads. 1195 */ 1196 if (d->bd_fbuf == 0) { 1197 /* 1198 * We haven't completed the previous read yet, 1199 * so drop the packet. 1200 */ 1201 ++d->bd_dcount; 1202 return; 1203 } 1204 ROTATE_BUFFERS(d); 1205 bpf_wakeup(d); 1206 curlen = 0; 1207 } 1208 else if (d->bd_immediate) 1209 /* 1210 * Immediate mode is set. A packet arrived so any 1211 * reads should be woken up. 1212 */ 1213 bpf_wakeup(d); 1214 1215 /* 1216 * Append the bpf header. 1217 */ 1218 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1219#if BSD >= 199103 1220 microtime(&hp->bh_tstamp); 1221#elif defined(sun) 1222 uniqtime(&hp->bh_tstamp); 1223#else 1224 hp->bh_tstamp = time; 1225#endif 1226 hp->bh_datalen = pktlen; 1227 hp->bh_hdrlen = hdrlen; 1228 /* 1229 * Copy the packet data into the store buffer and update its length. 1230 */ 1231 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1232 d->bd_slen = curlen + totlen; 1233} 1234 1235/* 1236 * Initialize all nonzero fields of a descriptor. 1237 */ 1238static int 1239bpf_allocbufs(d) 1240 register struct bpf_d *d; 1241{ 1242 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1243 if (d->bd_fbuf == 0) 1244 return (ENOBUFS); 1245 1246 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1247 if (d->bd_sbuf == 0) { 1248 free(d->bd_fbuf, M_BPF); 1249 return (ENOBUFS); 1250 } 1251 d->bd_slen = 0; 1252 d->bd_hlen = 0; 1253 return (0); 1254} 1255 1256/* 1257 * Free buffers currently in use by a descriptor. 1258 * Called on close. 1259 */ 1260static void 1261bpf_freed(d) 1262 register struct bpf_d *d; 1263{ 1264 /* 1265 * We don't need to lock out interrupts since this descriptor has 1266 * been detached from its interface and it yet hasn't been marked 1267 * free. 1268 */ 1269 if (d->bd_sbuf != 0) { 1270 free(d->bd_sbuf, M_BPF); 1271 if (d->bd_hbuf != 0) 1272 free(d->bd_hbuf, M_BPF); 1273 if (d->bd_fbuf != 0) 1274 free(d->bd_fbuf, M_BPF); 1275 } 1276 if (d->bd_filter) 1277 free((caddr_t)d->bd_filter, M_BPF); 1278} 1279 1280/* 1281 * Attach an interface to bpf. driverp is a pointer to a (struct bpf_if *) 1282 * in the driver's softc; dlt is the link layer type; hdrlen is the fixed 1283 * size of the link header (variable length headers not yet supported). 1284 */ 1285void 1286bpfattach(ifp, dlt, hdrlen) 1287 struct ifnet *ifp; 1288 u_int dlt, hdrlen; 1289{ 1290 struct bpf_if *bp; 1291 bp = (struct bpf_if *)malloc(sizeof(*bp), M_BPF, M_DONTWAIT); 1292 if (bp == 0) 1293 panic("bpfattach"); 1294 1295 bp->bif_dlist = 0; 1296 bp->bif_ifp = ifp; 1297 bp->bif_dlt = dlt; 1298 1299 bp->bif_next = bpf_iflist; 1300 bpf_iflist = bp; 1301 1302 bp->bif_ifp->if_bpf = 0; 1303 1304 /* 1305 * Compute the length of the bpf header. This is not necessarily 1306 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1307 * that the network layer header begins on a longword boundary (for 1308 * performance reasons and to alleviate alignment restrictions). 1309 */ 1310 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1311 1312 if (bootverbose) 1313 printf("bpf: %s%d attached\n", ifp->if_name, ifp->if_unit); 1314} 1315 1316/* 1317 * Detach bpf from an interface. This involves detaching each descriptor 1318 * associated with the interface, and leaving bd_bif NULL. Notify each 1319 * descriptor as it's detached so that any sleepers wake up and get 1320 * ENXIO. 1321 */ 1322void 1323bpfdetach(ifp) 1324 struct ifnet *ifp; 1325{ 1326 struct bpf_if *bp, *bp_prev; 1327 struct bpf_d *d; 1328 int s; 1329 1330 s = splimp(); 1331 1332 /* Locate BPF interface information */ 1333 bp_prev = NULL; 1334 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1335 if (ifp == bp->bif_ifp) 1336 break; 1337 bp_prev = bp; 1338 } 1339 1340 /* Interface wasn't attached */ 1341 if (bp->bif_ifp == NULL) { 1342 splx(s); 1343 printf("bpfdetach: %s%d was not attached\n", ifp->if_name, 1344 ifp->if_unit); 1345 return; 1346 } 1347 1348 while ((d = bp->bif_dlist) != NULL) { 1349 bpf_detachd(d); 1350 bpf_wakeup(d); 1351 } 1352 1353 if (bp_prev) { 1354 bp_prev->bif_next = bp->bif_next; 1355 } else { 1356 bpf_iflist = bp->bif_next; 1357 } 1358 1359 free(bp, M_BPF); 1360 1361 splx(s); 1362} 1363 1364static void bpf_drvinit __P((void *unused)); 1365 1366static void bpf_clone __P((void *arg, char *name, int namelen, dev_t *dev)); 1367 1368static void 1369bpf_clone(arg, name, namelen, dev) 1370 void *arg; 1371 char *name; 1372 int namelen; 1373 dev_t *dev; 1374{ 1375 int u; 1376 1377 if (*dev != NODEV) 1378 return; 1379 if (dev_stdclone(name, NULL, "bpf", &u) != 1) 1380 return; 1381 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, 1382 "bpf%d", u); 1383 (*dev)->si_flags |= SI_CHEAPCLONE; 1384 return; 1385} 1386 1387static void 1388bpf_drvinit(unused) 1389 void *unused; 1390{ 1391 1392 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); 1393 cdevsw_add(&bpf_cdevsw); 1394} 1395 1396SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL) 1397 1398#else /* !BPF */ 1399/* 1400 * NOP stubs to allow bpf-using drivers to load and function. 1401 * 1402 * A 'better' implementation would allow the core bpf functionality 1403 * to be loaded at runtime. 1404 */ 1405 1406void 1407bpf_tap(ifp, pkt, pktlen) 1408 struct ifnet *ifp; 1409 register u_char *pkt; 1410 register u_int pktlen; 1411{ 1412} 1413 1414void 1415bpf_mtap(ifp, m) 1416 struct ifnet *ifp; 1417 struct mbuf *m; 1418{ 1419} 1420 1421void 1422bpfattach(ifp, dlt, hdrlen) 1423 struct ifnet *ifp; 1424 u_int dlt, hdrlen; 1425{ 1426} 1427 1428void 1429bpfdetach(ifp) 1430 struct ifnet *ifp; 1431{ 1432} 1433 1434u_int 1435bpf_filter(pc, p, wirelen, buflen) 1436 register const struct bpf_insn *pc; 1437 register u_char *p; 1438 u_int wirelen; 1439 register u_int buflen; 1440{ 1441 return -1; /* "no filter" behaviour */ 1442} 1443 1444#endif /* !BPF */ 1445