bpf.c revision 39955
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 * $Id: bpf.c,v 1.41 1998/08/18 10:13:11 ache Exp $ 41 */ 42 43#include "bpfilter.h" 44 45#if NBPFILTER > 0 46 47#ifndef __GNUC__ 48#define inline 49#else 50#define inline __inline 51#endif 52 53#include <sys/param.h> 54#include <sys/systm.h> 55#include <sys/conf.h> 56#include <sys/malloc.h> 57#include <sys/mbuf.h> 58#include <sys/time.h> 59#include <sys/proc.h> 60#include <sys/signalvar.h> 61#include <sys/filio.h> 62#include <sys/sockio.h> 63#include <sys/ttycom.h> 64 65#if defined(sparc) && BSD < 199103 66#include <sys/stream.h> 67#endif 68#include <sys/poll.h> 69 70#include <sys/socket.h> 71#include <sys/vnode.h> 72 73#include <net/if.h> 74#include <net/bpf.h> 75#include <net/bpfdesc.h> 76 77#include <netinet/in.h> 78#include <netinet/if_ether.h> 79#include <sys/kernel.h> 80#include <sys/sysctl.h> 81 82#include "opt_devfs.h" 83 84#ifdef DEVFS 85#include <sys/devfsext.h> 86#endif /*DEVFS*/ 87 88 89/* 90 * Older BSDs don't have kernel malloc. 91 */ 92#if BSD < 199103 93extern bcopy(); 94static caddr_t bpf_alloc(); 95#include <net/bpf_compat.h> 96#define BPF_BUFSIZE (MCLBYTES-8) 97#define UIOMOVE(cp, len, code, uio) uiomove(cp, len, code, uio) 98#else 99#define BPF_BUFSIZE 4096 100#define UIOMOVE(cp, len, code, uio) uiomove(cp, len, uio) 101#endif 102 103#define PRINET 26 /* interruptible */ 104 105/* 106 * The default read buffer size is patchable. 107 */ 108static int bpf_bufsize = BPF_BUFSIZE; 109SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW, 110 &bpf_bufsize, 0, ""); 111 112/* 113 * bpf_iflist is the list of interfaces; each corresponds to an ifnet 114 * bpf_dtab holds the descriptors, indexed by minor device # 115 */ 116static struct bpf_if *bpf_iflist; 117static struct bpf_d bpf_dtab[NBPFILTER]; 118static int bpf_dtab_init; 119 120static int bpf_allocbufs __P((struct bpf_d *)); 121static void bpf_attachd __P((struct bpf_d *d, struct bpf_if *bp)); 122static void bpf_detachd __P((struct bpf_d *d)); 123static void bpf_freed __P((struct bpf_d *)); 124static void bpf_ifname __P((struct ifnet *, struct ifreq *)); 125static void bpf_mcopy __P((const void *, void *, u_int)); 126static int bpf_movein __P((struct uio *, int, 127 struct mbuf **, struct sockaddr *, int *)); 128static int bpf_setif __P((struct bpf_d *, struct ifreq *)); 129static inline void 130 bpf_wakeup __P((struct bpf_d *)); 131static void catchpacket __P((struct bpf_d *, u_char *, u_int, 132 u_int, void (*)(const void *, void *, u_int))); 133static void reset_d __P((struct bpf_d *)); 134static int bpf_setf __P((struct bpf_d *, struct bpf_program *)); 135 136static d_open_t bpfopen; 137static d_close_t bpfclose; 138static d_read_t bpfread; 139static d_write_t bpfwrite; 140static d_ioctl_t bpfioctl; 141static d_poll_t bpfpoll; 142 143#define CDEV_MAJOR 23 144static struct cdevsw bpf_cdevsw = 145 { bpfopen, bpfclose, bpfread, bpfwrite, /*23*/ 146 bpfioctl, nostop, nullreset, nodevtotty,/* bpf */ 147 bpfpoll, nommap, NULL, "bpf", NULL, -1 }; 148 149 150static int 151bpf_movein(uio, linktype, mp, sockp, datlen) 152 register struct uio *uio; 153 int linktype, *datlen; 154 register struct mbuf **mp; 155 register struct sockaddr *sockp; 156{ 157 struct mbuf *m; 158 int error; 159 int len; 160 int hlen; 161 162 /* 163 * Build a sockaddr based on the data link layer type. 164 * We do this at this level because the ethernet header 165 * is copied directly into the data field of the sockaddr. 166 * In the case of SLIP, there is no header and the packet 167 * is forwarded as is. 168 * Also, we are careful to leave room at the front of the mbuf 169 * for the link level header. 170 */ 171 switch (linktype) { 172 173 case DLT_SLIP: 174 sockp->sa_family = AF_INET; 175 hlen = 0; 176 break; 177 178 case DLT_EN10MB: 179 sockp->sa_family = AF_UNSPEC; 180 /* XXX Would MAXLINKHDR be better? */ 181 hlen = sizeof(struct ether_header); 182 break; 183 184 case DLT_FDDI: 185#if defined(__FreeBSD__) || defined(__bsdi__) 186 sockp->sa_family = AF_IMPLINK; 187 hlen = 0; 188#else 189 sockp->sa_family = AF_UNSPEC; 190 /* XXX 4(FORMAC)+6(dst)+6(src)+3(LLC)+5(SNAP) */ 191 hlen = 24; 192#endif 193 break; 194 195 case DLT_RAW: 196 case DLT_NULL: 197 sockp->sa_family = AF_UNSPEC; 198 hlen = 0; 199 break; 200 201#ifdef __FreeBSD__ 202 case DLT_ATM_RFC1483: 203 /* 204 * en atm driver requires 4-byte atm pseudo header. 205 * though it isn't standard, vpi:vci needs to be 206 * specified anyway. 207 */ 208 sockp->sa_family = AF_UNSPEC; 209 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 210 break; 211#endif 212 213 default: 214 return (EIO); 215 } 216 217 len = uio->uio_resid; 218 *datlen = len - hlen; 219 if ((unsigned)len > MCLBYTES) 220 return (EIO); 221 222 MGETHDR(m, M_WAIT, MT_DATA); 223 if (m == 0) 224 return (ENOBUFS); 225 if (len > MHLEN) { 226#if BSD >= 199103 227 MCLGET(m, M_WAIT); 228 if ((m->m_flags & M_EXT) == 0) { 229#else 230 MCLGET(m); 231 if (m->m_len != MCLBYTES) { 232#endif 233 error = ENOBUFS; 234 goto bad; 235 } 236 } 237 m->m_pkthdr.len = m->m_len = len; 238 m->m_pkthdr.rcvif = NULL; 239 *mp = m; 240 /* 241 * Make room for link header. 242 */ 243 if (hlen != 0) { 244 m->m_pkthdr.len -= hlen; 245 m->m_len -= hlen; 246#if BSD >= 199103 247 m->m_data += hlen; /* XXX */ 248#else 249 m->m_off += hlen; 250#endif 251 error = UIOMOVE((caddr_t)sockp->sa_data, hlen, UIO_WRITE, uio); 252 if (error) 253 goto bad; 254 } 255 error = UIOMOVE(mtod(m, caddr_t), len - hlen, UIO_WRITE, uio); 256 if (!error) 257 return (0); 258 bad: 259 m_freem(m); 260 return (error); 261} 262 263/* 264 * Attach file to the bpf interface, i.e. make d listen on bp. 265 * Must be called at splimp. 266 */ 267static void 268bpf_attachd(d, bp) 269 struct bpf_d *d; 270 struct bpf_if *bp; 271{ 272 /* 273 * Point d at bp, and add d to the interface's list of listeners. 274 * Finally, point the driver's bpf cookie at the interface so 275 * it will divert packets to bpf. 276 */ 277 d->bd_bif = bp; 278 d->bd_next = bp->bif_dlist; 279 bp->bif_dlist = d; 280 281 bp->bif_ifp->if_bpf = bp; 282} 283 284/* 285 * Detach a file from its interface. 286 */ 287static void 288bpf_detachd(d) 289 struct bpf_d *d; 290{ 291 struct bpf_d **p; 292 struct bpf_if *bp; 293 294 bp = d->bd_bif; 295 /* 296 * Check if this descriptor had requested promiscuous mode. 297 * If so, turn it off. 298 */ 299 if (d->bd_promisc) { 300 d->bd_promisc = 0; 301 if (ifpromisc(bp->bif_ifp, 0)) 302 /* 303 * Something is really wrong if we were able to put 304 * the driver into promiscuous mode, but can't 305 * take it out. 306 */ 307 panic("bpf: ifpromisc failed"); 308 } 309 /* Remove d from the interface's descriptor list. */ 310 p = &bp->bif_dlist; 311 while (*p != d) { 312 p = &(*p)->bd_next; 313 if (*p == 0) 314 panic("bpf_detachd: descriptor not in list"); 315 } 316 *p = (*p)->bd_next; 317 if (bp->bif_dlist == 0) 318 /* 319 * Let the driver know that there are no more listeners. 320 */ 321 d->bd_bif->bif_ifp->if_bpf = 0; 322 d->bd_bif = 0; 323} 324 325 326/* 327 * Mark a descriptor free by making it point to itself. 328 * This is probably cheaper than marking with a constant since 329 * the address should be in a register anyway. 330 */ 331#define D_ISFREE(d) ((d) == (d)->bd_next) 332#define D_MARKFREE(d) ((d)->bd_next = (d)) 333#define D_MARKUSED(d) ((d)->bd_next = 0) 334 335/* 336 * Open ethernet device. Returns ENXIO for illegal minor device number, 337 * EBUSY if file is open by another process. 338 */ 339/* ARGSUSED */ 340static int 341bpfopen(dev, flags, fmt, p) 342 dev_t dev; 343 int flags; 344 int fmt; 345 struct proc *p; 346{ 347 register struct bpf_d *d; 348 349 if (minor(dev) >= NBPFILTER) 350 return (ENXIO); 351 /* 352 * Each minor can be opened by only one process. If the requested 353 * minor is in use, return EBUSY. 354 */ 355 d = &bpf_dtab[minor(dev)]; 356 if (!D_ISFREE(d)) 357 return (EBUSY); 358 359 /* Mark "free" and do most initialization. */ 360 bzero((char *)d, sizeof(*d)); 361 d->bd_bufsize = bpf_bufsize; 362 d->bd_sig = SIGIO; 363 364 return (0); 365} 366 367/* 368 * Close the descriptor by detaching it from its interface, 369 * deallocating its buffers, and marking it free. 370 */ 371/* ARGSUSED */ 372static int 373bpfclose(dev, flags, fmt, p) 374 dev_t dev; 375 int flags; 376 int fmt; 377 struct proc *p; 378{ 379 register struct bpf_d *d = &bpf_dtab[minor(dev)]; 380 register int s; 381 382 s = splimp(); 383 if (d->bd_bif) 384 bpf_detachd(d); 385 splx(s); 386 bpf_freed(d); 387 388 return (0); 389} 390 391/* 392 * Support for SunOS, which does not have tsleep. 393 */ 394#if BSD < 199103 395static 396bpf_timeout(arg) 397 caddr_t arg; 398{ 399 struct bpf_d *d = (struct bpf_d *)arg; 400 d->bd_timedout = 1; 401 wakeup(arg); 402} 403 404#define BPF_SLEEP(chan, pri, s, t) bpf_sleep((struct bpf_d *)chan) 405 406int 407bpf_sleep(d) 408 register struct bpf_d *d; 409{ 410 register int rto = d->bd_rtout; 411 register int st; 412 413 if (rto != 0) { 414 d->bd_timedout = 0; 415 timeout(bpf_timeout, (caddr_t)d, rto); 416 } 417 st = sleep((caddr_t)d, PRINET|PCATCH); 418 if (rto != 0) { 419 if (d->bd_timedout == 0) 420 untimeout(bpf_timeout, (caddr_t)d); 421 else if (st == 0) 422 return EWOULDBLOCK; 423 } 424 return (st != 0) ? EINTR : 0; 425} 426#else 427#define BPF_SLEEP tsleep 428#endif 429 430/* 431 * Rotate the packet buffers in descriptor d. Move the store buffer 432 * into the hold slot, and the free buffer into the store slot. 433 * Zero the length of the new store buffer. 434 */ 435#define ROTATE_BUFFERS(d) \ 436 (d)->bd_hbuf = (d)->bd_sbuf; \ 437 (d)->bd_hlen = (d)->bd_slen; \ 438 (d)->bd_sbuf = (d)->bd_fbuf; \ 439 (d)->bd_slen = 0; \ 440 (d)->bd_fbuf = 0; 441/* 442 * bpfread - read next chunk of packets from buffers 443 */ 444static int 445bpfread(dev, uio, ioflag) 446 dev_t dev; 447 register struct uio *uio; 448 int ioflag; 449{ 450 register struct bpf_d *d = &bpf_dtab[minor(dev)]; 451 int error; 452 int s; 453 454 /* 455 * Restrict application to use a buffer the same size as 456 * as kernel buffers. 457 */ 458 if (uio->uio_resid != d->bd_bufsize) 459 return (EINVAL); 460 461 s = splimp(); 462 /* 463 * If the hold buffer is empty, then do a timed sleep, which 464 * ends when the timeout expires or when enough packets 465 * have arrived to fill the store buffer. 466 */ 467 while (d->bd_hbuf == 0) { 468 if (d->bd_immediate && d->bd_slen != 0) { 469 /* 470 * A packet(s) either arrived since the previous 471 * read or arrived while we were asleep. 472 * Rotate the buffers and return what's here. 473 */ 474 ROTATE_BUFFERS(d); 475 break; 476 } 477 if (ioflag & IO_NDELAY) 478 error = EWOULDBLOCK; 479 else 480 error = BPF_SLEEP((caddr_t)d, PRINET|PCATCH, "bpf", 481 d->bd_rtout); 482 if (error == EINTR || error == ERESTART) { 483 splx(s); 484 return (error); 485 } 486 if (error == EWOULDBLOCK) { 487 /* 488 * On a timeout, return what's in the buffer, 489 * which may be nothing. If there is something 490 * in the store buffer, we can rotate the buffers. 491 */ 492 if (d->bd_hbuf) 493 /* 494 * We filled up the buffer in between 495 * getting the timeout and arriving 496 * here, so we don't need to rotate. 497 */ 498 break; 499 500 if (d->bd_slen == 0) { 501 splx(s); 502 return (0); 503 } 504 ROTATE_BUFFERS(d); 505 break; 506 } 507 } 508 /* 509 * At this point, we know we have something in the hold slot. 510 */ 511 splx(s); 512 513 /* 514 * Move data from hold buffer into user space. 515 * We know the entire buffer is transferred since 516 * we checked above that the read buffer is bpf_bufsize bytes. 517 */ 518 error = UIOMOVE(d->bd_hbuf, d->bd_hlen, UIO_READ, uio); 519 520 s = splimp(); 521 d->bd_fbuf = d->bd_hbuf; 522 d->bd_hbuf = 0; 523 d->bd_hlen = 0; 524 splx(s); 525 526 return (error); 527} 528 529 530/* 531 * If there are processes sleeping on this descriptor, wake them up. 532 */ 533static inline void 534bpf_wakeup(d) 535 register struct bpf_d *d; 536{ 537 struct proc *p; 538 539 wakeup((caddr_t)d); 540 if (d->bd_async && d->bd_sig) 541 if (d->bd_pgid > 0) 542 gsignal (d->bd_pgid, d->bd_sig); 543 else if (p = pfind (-d->bd_pgid)) 544 psignal (p, d->bd_sig); 545 546#if BSD >= 199103 547 selwakeup(&d->bd_sel); 548 /* XXX */ 549 d->bd_sel.si_pid = 0; 550#else 551 if (d->bd_selproc) { 552 selwakeup(d->bd_selproc, (int)d->bd_selcoll); 553 d->bd_selcoll = 0; 554 d->bd_selproc = 0; 555 } 556#endif 557} 558 559static int 560bpfwrite(dev, uio, ioflag) 561 dev_t dev; 562 struct uio *uio; 563 int ioflag; 564{ 565 register struct bpf_d *d = &bpf_dtab[minor(dev)]; 566 struct ifnet *ifp; 567 struct mbuf *m; 568 int error, s; 569 static struct sockaddr dst; 570 int datlen; 571 572 if (d->bd_bif == 0) 573 return (ENXIO); 574 575 ifp = d->bd_bif->bif_ifp; 576 577 if (uio->uio_resid == 0) 578 return (0); 579 580 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen); 581 if (error) 582 return (error); 583 584 if (datlen > ifp->if_mtu) 585 return (EMSGSIZE); 586 587 s = splnet(); 588#if BSD >= 199103 589 error = (*ifp->if_output)(ifp, m, &dst, (struct rtentry *)0); 590#else 591 error = (*ifp->if_output)(ifp, m, &dst); 592#endif 593 splx(s); 594 /* 595 * The driver frees the mbuf. 596 */ 597 return (error); 598} 599 600/* 601 * Reset a descriptor by flushing its packet buffer and clearing the 602 * receive and drop counts. Should be called at splimp. 603 */ 604static void 605reset_d(d) 606 struct bpf_d *d; 607{ 608 if (d->bd_hbuf) { 609 /* Free the hold buffer. */ 610 d->bd_fbuf = d->bd_hbuf; 611 d->bd_hbuf = 0; 612 } 613 d->bd_slen = 0; 614 d->bd_hlen = 0; 615 d->bd_rcount = 0; 616 d->bd_dcount = 0; 617} 618 619/* 620 * FIONREAD Check for read packet available. 621 * SIOCGIFADDR Get interface address - convenient hook to driver. 622 * BIOCGBLEN Get buffer len [for read()]. 623 * BIOCSETF Set ethernet read filter. 624 * BIOCFLUSH Flush read packet buffer. 625 * BIOCPROMISC Put interface into promiscuous mode. 626 * BIOCGDLT Get link layer type. 627 * BIOCGETIF Get interface name. 628 * BIOCSETIF Set interface. 629 * BIOCSRTIMEOUT Set read timeout. 630 * BIOCGRTIMEOUT Get read timeout. 631 * BIOCGSTATS Get packet stats. 632 * BIOCIMMEDIATE Set immediate mode. 633 * BIOCVERSION Get filter language version. 634 */ 635/* ARGSUSED */ 636static int 637bpfioctl(dev, cmd, addr, flags, p) 638 dev_t dev; 639 u_long cmd; 640 caddr_t addr; 641 int flags; 642 struct proc *p; 643{ 644 register struct bpf_d *d = &bpf_dtab[minor(dev)]; 645 int s, error = 0; 646 647 switch (cmd) { 648 649 default: 650 error = EINVAL; 651 break; 652 653 /* 654 * Check for read packet available. 655 */ 656 case FIONREAD: 657 { 658 int n; 659 660 s = splimp(); 661 n = d->bd_slen; 662 if (d->bd_hbuf) 663 n += d->bd_hlen; 664 splx(s); 665 666 *(int *)addr = n; 667 break; 668 } 669 670 case SIOCGIFADDR: 671 { 672 struct ifnet *ifp; 673 674 if (d->bd_bif == 0) 675 error = EINVAL; 676 else { 677 ifp = d->bd_bif->bif_ifp; 678 error = (*ifp->if_ioctl)(ifp, cmd, addr); 679 } 680 break; 681 } 682 683 /* 684 * Get buffer len [for read()]. 685 */ 686 case BIOCGBLEN: 687 *(u_int *)addr = d->bd_bufsize; 688 break; 689 690 /* 691 * Set buffer length. 692 */ 693 case BIOCSBLEN: 694#if BSD < 199103 695 error = EINVAL; 696#else 697 if (d->bd_bif != 0) 698 error = EINVAL; 699 else { 700 register u_int size = *(u_int *)addr; 701 702 if (size > BPF_MAXBUFSIZE) 703 *(u_int *)addr = size = BPF_MAXBUFSIZE; 704 else if (size < BPF_MINBUFSIZE) 705 *(u_int *)addr = size = BPF_MINBUFSIZE; 706 d->bd_bufsize = size; 707 } 708#endif 709 break; 710 711 /* 712 * Set link layer read filter. 713 */ 714 case BIOCSETF: 715 error = bpf_setf(d, (struct bpf_program *)addr); 716 break; 717 718 /* 719 * Flush read packet buffer. 720 */ 721 case BIOCFLUSH: 722 s = splimp(); 723 reset_d(d); 724 splx(s); 725 break; 726 727 /* 728 * Put interface into promiscuous mode. 729 */ 730 case BIOCPROMISC: 731 if (d->bd_bif == 0) { 732 /* 733 * No interface attached yet. 734 */ 735 error = EINVAL; 736 break; 737 } 738 s = splimp(); 739 if (d->bd_promisc == 0) { 740 error = ifpromisc(d->bd_bif->bif_ifp, 1); 741 if (error == 0) 742 d->bd_promisc = 1; 743 } 744 splx(s); 745 break; 746 747 /* 748 * Get device parameters. 749 */ 750 case BIOCGDLT: 751 if (d->bd_bif == 0) 752 error = EINVAL; 753 else 754 *(u_int *)addr = d->bd_bif->bif_dlt; 755 break; 756 757 /* 758 * Set interface name. 759 */ 760 case BIOCGETIF: 761 if (d->bd_bif == 0) 762 error = EINVAL; 763 else 764 bpf_ifname(d->bd_bif->bif_ifp, (struct ifreq *)addr); 765 break; 766 767 /* 768 * Set interface. 769 */ 770 case BIOCSETIF: 771 error = bpf_setif(d, (struct ifreq *)addr); 772 break; 773 774 /* 775 * Set read timeout. 776 */ 777 case BIOCSRTIMEOUT: 778 { 779 struct timeval *tv = (struct timeval *)addr; 780 781 d->bd_rtout = tv->tv_sec * hz + tv->tv_usec / tick; 782 if (d->bd_rtout == 0 && tv->tv_usec != 0) 783 d->bd_rtout = 1; 784 break; 785 } 786 787 /* 788 * Get read timeout. 789 */ 790 case BIOCGRTIMEOUT: 791 { 792 struct timeval *tv = (struct timeval *)addr; 793 u_long msec = d->bd_rtout; 794 795 msec *= tick / 1000; 796 tv->tv_sec = msec / 1000; 797 tv->tv_usec = msec % 1000; 798 break; 799 } 800 801 /* 802 * Get packet stats. 803 */ 804 case BIOCGSTATS: 805 { 806 struct bpf_stat *bs = (struct bpf_stat *)addr; 807 808 bs->bs_recv = d->bd_rcount; 809 bs->bs_drop = d->bd_dcount; 810 break; 811 } 812 813 /* 814 * Set immediate mode. 815 */ 816 case BIOCIMMEDIATE: 817 d->bd_immediate = *(u_int *)addr; 818 break; 819 820 case BIOCVERSION: 821 { 822 struct bpf_version *bv = (struct bpf_version *)addr; 823 824 bv->bv_major = BPF_MAJOR_VERSION; 825 bv->bv_minor = BPF_MINOR_VERSION; 826 break; 827 } 828 829 case FIONBIO: /* Non-blocking I/O */ 830 break; 831 832 case FIOASYNC: /* Send signal on receive packets */ 833 d->bd_async = *(int *)addr; 834 break; 835 836/* N.B. ioctl (FIOSETOWN) and fcntl (F_SETOWN) both end up doing the 837 equivalent of a TIOCSPGRP and hence end up here. *However* TIOCSPGRP's arg 838 is a process group if it's positive and a process id if it's negative. This 839 is exactly the opposite of what the other two functions want! Therefore 840 there is code in ioctl and fcntl to negate the arg before calling here. */ 841 842 case TIOCSPGRP: /* Process or group to send signals to */ 843 d->bd_pgid = *(int *)addr; 844 break; 845 846 case TIOCGPGRP: 847 *(int *)addr = d->bd_pgid; 848 break; 849 850 case BIOCSRSIG: /* Set receive signal */ 851 { 852 u_int sig; 853 854 sig = *(u_int *)addr; 855 856 if (sig >= NSIG) 857 error = EINVAL; 858 else 859 d->bd_sig = sig; 860 break; 861 } 862 case BIOCGRSIG: 863 *(u_int *)addr = d->bd_sig; 864 break; 865 } 866 return (error); 867} 868 869/* 870 * Set d's packet filter program to fp. If this file already has a filter, 871 * free it and replace it. Returns EINVAL for bogus requests. 872 */ 873static int 874bpf_setf(d, fp) 875 struct bpf_d *d; 876 struct bpf_program *fp; 877{ 878 struct bpf_insn *fcode, *old; 879 u_int flen, size; 880 int s; 881 882 old = d->bd_filter; 883 if (fp->bf_insns == 0) { 884 if (fp->bf_len != 0) 885 return (EINVAL); 886 s = splimp(); 887 d->bd_filter = 0; 888 reset_d(d); 889 splx(s); 890 if (old != 0) 891 free((caddr_t)old, M_DEVBUF); 892 return (0); 893 } 894 flen = fp->bf_len; 895 if (flen > BPF_MAXINSNS) 896 return (EINVAL); 897 898 size = flen * sizeof(*fp->bf_insns); 899 fcode = (struct bpf_insn *)malloc(size, M_DEVBUF, M_WAITOK); 900 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 901 bpf_validate(fcode, (int)flen)) { 902 s = splimp(); 903 d->bd_filter = fcode; 904 reset_d(d); 905 splx(s); 906 if (old != 0) 907 free((caddr_t)old, M_DEVBUF); 908 909 return (0); 910 } 911 free((caddr_t)fcode, M_DEVBUF); 912 return (EINVAL); 913} 914 915/* 916 * Detach a file from its current interface (if attached at all) and attach 917 * to the interface indicated by the name stored in ifr. 918 * Return an errno or 0. 919 */ 920static int 921bpf_setif(d, ifr) 922 struct bpf_d *d; 923 struct ifreq *ifr; 924{ 925 struct bpf_if *bp; 926 int s, error; 927 struct ifnet *theywant; 928 929 theywant = ifunit(ifr->ifr_name); 930 if (theywant == 0) 931 return ENXIO; 932 933 /* 934 * Look through attached interfaces for the named one. 935 */ 936 for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) { 937 struct ifnet *ifp = bp->bif_ifp; 938 939 if (ifp == 0 || ifp != theywant) 940 continue; 941 /* 942 * We found the requested interface. 943 * If it's not up, return an error. 944 * Allocate the packet buffers if we need to. 945 * If we're already attached to requested interface, 946 * just flush the buffer. 947 */ 948 if ((ifp->if_flags & IFF_UP) == 0) 949 return (ENETDOWN); 950 951 if (d->bd_sbuf == 0) { 952 error = bpf_allocbufs(d); 953 if (error != 0) 954 return (error); 955 } 956 s = splimp(); 957 if (bp != d->bd_bif) { 958 if (d->bd_bif) 959 /* 960 * Detach if attached to something else. 961 */ 962 bpf_detachd(d); 963 964 bpf_attachd(d, bp); 965 } 966 reset_d(d); 967 splx(s); 968 return (0); 969 } 970 /* Not found. */ 971 return (ENXIO); 972} 973 974/* 975 * Convert an interface name plus unit number of an ifp to a single 976 * name which is returned in the ifr. 977 */ 978static void 979bpf_ifname(ifp, ifr) 980 struct ifnet *ifp; 981 struct ifreq *ifr; 982{ 983 char *s = ifp->if_name; 984 char *d = ifr->ifr_name; 985 986 while (*d++ = *s++) 987 continue; 988 d--; /* back to the null */ 989 /* XXX Assume that unit number is less than 10. */ 990 *d++ = ifp->if_unit + '0'; 991 *d = '\0'; 992} 993 994/* 995 * Support for select() and poll() system calls 996 * 997 * Return true iff the specific operation will not block indefinitely. 998 * Otherwise, return false but make a note that a selwakeup() must be done. 999 */ 1000int 1001bpfpoll(dev, events, p) 1002 register dev_t dev; 1003 int events; 1004 struct proc *p; 1005{ 1006 register struct bpf_d *d; 1007 register int s; 1008 int revents = 0; 1009 1010 /* 1011 * An imitation of the FIONREAD ioctl code. 1012 */ 1013 d = &bpf_dtab[minor(dev)]; 1014 1015 s = splimp(); 1016 if (events & (POLLIN | POLLRDNORM)) 1017 if (d->bd_hlen != 0 || (d->bd_immediate && d->bd_slen != 0)) 1018 revents |= events & (POLLIN | POLLRDNORM); 1019 else 1020 selrecord(p, &d->bd_sel); 1021 1022 splx(s); 1023 return (revents); 1024} 1025 1026/* 1027 * Incoming linkage from device drivers. Process the packet pkt, of length 1028 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1029 * by each process' filter, and if accepted, stashed into the corresponding 1030 * buffer. 1031 */ 1032void 1033bpf_tap(ifp, pkt, pktlen) 1034 struct ifnet *ifp; 1035 register u_char *pkt; 1036 register u_int pktlen; 1037{ 1038 struct bpf_if *bp; 1039 register struct bpf_d *d; 1040 register u_int slen; 1041 /* 1042 * Note that the ipl does not have to be raised at this point. 1043 * The only problem that could arise here is that if two different 1044 * interfaces shared any data. This is not the case. 1045 */ 1046 bp = ifp->if_bpf; 1047 for (d = bp->bif_dlist; d != 0; d = d->bd_next) { 1048 ++d->bd_rcount; 1049 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen); 1050 if (slen != 0) 1051 catchpacket(d, pkt, pktlen, slen, bcopy); 1052 } 1053} 1054 1055/* 1056 * Copy data from an mbuf chain into a buffer. This code is derived 1057 * from m_copydata in sys/uipc_mbuf.c. 1058 */ 1059static void 1060bpf_mcopy(src_arg, dst_arg, len) 1061 const void *src_arg; 1062 void *dst_arg; 1063 register u_int len; 1064{ 1065 register const struct mbuf *m; 1066 register u_int count; 1067 u_char *dst; 1068 1069 m = src_arg; 1070 dst = dst_arg; 1071 while (len > 0) { 1072 if (m == 0) 1073 panic("bpf_mcopy"); 1074 count = min(m->m_len, len); 1075 bcopy(mtod(m, void *), dst, count); 1076 m = m->m_next; 1077 dst += count; 1078 len -= count; 1079 } 1080} 1081 1082/* 1083 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1084 */ 1085void 1086bpf_mtap(ifp, m) 1087 struct ifnet *ifp; 1088 struct mbuf *m; 1089{ 1090 struct bpf_if *bp = ifp->if_bpf; 1091 struct bpf_d *d; 1092 u_int pktlen, slen; 1093 struct mbuf *m0; 1094 1095 pktlen = 0; 1096 for (m0 = m; m0 != 0; m0 = m0->m_next) 1097 pktlen += m0->m_len; 1098 1099 for (d = bp->bif_dlist; d != 0; d = d->bd_next) { 1100 ++d->bd_rcount; 1101 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0); 1102 if (slen != 0) 1103 catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy); 1104 } 1105} 1106 1107/* 1108 * Move the packet data from interface memory (pkt) into the 1109 * store buffer. Return 1 if it's time to wakeup a listener (buffer full), 1110 * otherwise 0. "copy" is the routine called to do the actual data 1111 * transfer. bcopy is passed in to copy contiguous chunks, while 1112 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1113 * pkt is really an mbuf. 1114 */ 1115static void 1116catchpacket(d, pkt, pktlen, snaplen, cpfn) 1117 register struct bpf_d *d; 1118 register u_char *pkt; 1119 register u_int pktlen, snaplen; 1120 register void (*cpfn) __P((const void *, void *, u_int)); 1121{ 1122 register struct bpf_hdr *hp; 1123 register int totlen, curlen; 1124 register int hdrlen = d->bd_bif->bif_hdrlen; 1125 /* 1126 * Figure out how many bytes to move. If the packet is 1127 * greater or equal to the snapshot length, transfer that 1128 * much. Otherwise, transfer the whole packet (unless 1129 * we hit the buffer size limit). 1130 */ 1131 totlen = hdrlen + min(snaplen, pktlen); 1132 if (totlen > d->bd_bufsize) 1133 totlen = d->bd_bufsize; 1134 1135 /* 1136 * Round up the end of the previous packet to the next longword. 1137 */ 1138 curlen = BPF_WORDALIGN(d->bd_slen); 1139 if (curlen + totlen > d->bd_bufsize) { 1140 /* 1141 * This packet will overflow the storage buffer. 1142 * Rotate the buffers if we can, then wakeup any 1143 * pending reads. 1144 */ 1145 if (d->bd_fbuf == 0) { 1146 /* 1147 * We haven't completed the previous read yet, 1148 * so drop the packet. 1149 */ 1150 ++d->bd_dcount; 1151 return; 1152 } 1153 ROTATE_BUFFERS(d); 1154 bpf_wakeup(d); 1155 curlen = 0; 1156 } 1157 else if (d->bd_immediate) 1158 /* 1159 * Immediate mode is set. A packet arrived so any 1160 * reads should be woken up. 1161 */ 1162 bpf_wakeup(d); 1163 1164 /* 1165 * Append the bpf header. 1166 */ 1167 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1168#if BSD >= 199103 1169 microtime(&hp->bh_tstamp); 1170#elif defined(sun) 1171 uniqtime(&hp->bh_tstamp); 1172#else 1173 hp->bh_tstamp = time; 1174#endif 1175 hp->bh_datalen = pktlen; 1176 hp->bh_hdrlen = hdrlen; 1177 /* 1178 * Copy the packet data into the store buffer and update its length. 1179 */ 1180 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1181 d->bd_slen = curlen + totlen; 1182} 1183 1184/* 1185 * Initialize all nonzero fields of a descriptor. 1186 */ 1187static int 1188bpf_allocbufs(d) 1189 register struct bpf_d *d; 1190{ 1191 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_DEVBUF, M_WAITOK); 1192 if (d->bd_fbuf == 0) 1193 return (ENOBUFS); 1194 1195 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_DEVBUF, M_WAITOK); 1196 if (d->bd_sbuf == 0) { 1197 free(d->bd_fbuf, M_DEVBUF); 1198 return (ENOBUFS); 1199 } 1200 d->bd_slen = 0; 1201 d->bd_hlen = 0; 1202 return (0); 1203} 1204 1205/* 1206 * Free buffers currently in use by a descriptor. 1207 * Called on close. 1208 */ 1209static void 1210bpf_freed(d) 1211 register struct bpf_d *d; 1212{ 1213 /* 1214 * We don't need to lock out interrupts since this descriptor has 1215 * been detached from its interface and it yet hasn't been marked 1216 * free. 1217 */ 1218 if (d->bd_sbuf != 0) { 1219 free(d->bd_sbuf, M_DEVBUF); 1220 if (d->bd_hbuf != 0) 1221 free(d->bd_hbuf, M_DEVBUF); 1222 if (d->bd_fbuf != 0) 1223 free(d->bd_fbuf, M_DEVBUF); 1224 } 1225 if (d->bd_filter) 1226 free((caddr_t)d->bd_filter, M_DEVBUF); 1227 1228 D_MARKFREE(d); 1229} 1230 1231/* 1232 * Attach an interface to bpf. driverp is a pointer to a (struct bpf_if *) 1233 * in the driver's softc; dlt is the link layer type; hdrlen is the fixed 1234 * size of the link header (variable length headers not yet supported). 1235 */ 1236void 1237bpfattach(ifp, dlt, hdrlen) 1238 struct ifnet *ifp; 1239 u_int dlt, hdrlen; 1240{ 1241 struct bpf_if *bp; 1242 int i; 1243 bp = (struct bpf_if *)malloc(sizeof(*bp), M_DEVBUF, M_DONTWAIT); 1244 if (bp == 0) 1245 panic("bpfattach"); 1246 1247 bp->bif_dlist = 0; 1248 bp->bif_ifp = ifp; 1249 bp->bif_dlt = dlt; 1250 1251 bp->bif_next = bpf_iflist; 1252 bpf_iflist = bp; 1253 1254 bp->bif_ifp->if_bpf = 0; 1255 1256 /* 1257 * Compute the length of the bpf header. This is not necessarily 1258 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1259 * that the network layer header begins on a longword boundary (for 1260 * performance reasons and to alleviate alignment restrictions). 1261 */ 1262 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1263 1264 /* 1265 * Mark all the descriptors free if this hasn't been done. 1266 */ 1267 if (!bpf_dtab_init) { 1268 for (i = 0; i < NBPFILTER; ++i) 1269 D_MARKFREE(&bpf_dtab[i]); 1270 bpf_dtab_init = 1; 1271 } 1272 1273 if (bootverbose) 1274 printf("bpf: %s%d attached\n", ifp->if_name, ifp->if_unit); 1275} 1276 1277#ifdef DEVFS 1278static void *bpf_devfs_token[NBPFILTER]; 1279#endif 1280 1281static int bpf_devsw_installed; 1282 1283static void bpf_drvinit __P((void *unused)); 1284static void 1285bpf_drvinit(unused) 1286 void *unused; 1287{ 1288 dev_t dev; 1289#ifdef DEVFS 1290 int i; 1291#endif 1292 1293 if( ! bpf_devsw_installed ) { 1294 dev = makedev(CDEV_MAJOR, 0); 1295 cdevsw_add(&dev,&bpf_cdevsw, NULL); 1296 bpf_devsw_installed = 1; 1297#ifdef DEVFS 1298 1299 for ( i = 0 ; i < NBPFILTER ; i++ ) { 1300 bpf_devfs_token[i] = 1301 devfs_add_devswf(&bpf_cdevsw, i, DV_CHR, 0, 0, 1302 0600, "bpf%d", i); 1303 } 1304#endif 1305 } 1306} 1307 1308SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL) 1309 1310#endif 1311