137}; 138 139 140static int 141bpf_movein(uio, linktype, mp, sockp, datlen) 142 struct uio *uio; 143 int linktype, *datlen; 144 struct mbuf **mp; 145 struct sockaddr *sockp; 146{ 147 struct mbuf *m; 148 int error; 149 int len; 150 int hlen; 151 152 /* 153 * Build a sockaddr based on the data link layer type. 154 * We do this at this level because the ethernet header 155 * is copied directly into the data field of the sockaddr. 156 * In the case of SLIP, there is no header and the packet 157 * is forwarded as is. 158 * Also, we are careful to leave room at the front of the mbuf 159 * for the link level header. 160 */ 161 switch (linktype) { 162 163 case DLT_SLIP: 164 sockp->sa_family = AF_INET; 165 hlen = 0; 166 break; 167 168 case DLT_EN10MB: 169 sockp->sa_family = AF_UNSPEC; 170 /* XXX Would MAXLINKHDR be better? */ 171 hlen = ETHER_HDR_LEN; 172 break; 173 174 case DLT_FDDI: 175 sockp->sa_family = AF_IMPLINK; 176 hlen = 0; 177 break; 178 179 case DLT_RAW: 180 case DLT_NULL: 181 sockp->sa_family = AF_UNSPEC; 182 hlen = 0; 183 break; 184 185 case DLT_ATM_RFC1483: 186 /* 187 * en atm driver requires 4-byte atm pseudo header. 188 * though it isn't standard, vpi:vci needs to be 189 * specified anyway. 190 */ 191 sockp->sa_family = AF_UNSPEC; 192 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 193 break; 194 195 case DLT_PPP: 196 sockp->sa_family = AF_UNSPEC; 197 hlen = 4; /* This should match PPP_HDRLEN */ 198 break; 199 200 default: 201 return (EIO); 202 } 203 204 len = uio->uio_resid; 205 *datlen = len - hlen; 206 if ((unsigned)len > MCLBYTES) 207 return (EIO); 208 209 if (len > MHLEN) { 210 m = m_getcl(M_TRYWAIT, MT_DATA, M_PKTHDR); 211 } else { 212 MGETHDR(m, M_TRYWAIT, MT_DATA); 213 } 214 if (m == NULL) 215 return (ENOBUFS); 216 m->m_pkthdr.len = m->m_len = len; 217 m->m_pkthdr.rcvif = NULL; 218 *mp = m; 219 220 /* 221 * Make room for link header. 222 */ 223 if (hlen != 0) { 224 m->m_pkthdr.len -= hlen; 225 m->m_len -= hlen; 226#if BSD >= 199103 227 m->m_data += hlen; /* XXX */ 228#else 229 m->m_off += hlen; 230#endif 231 error = uiomove(sockp->sa_data, hlen, uio); 232 if (error) 233 goto bad; 234 } 235 error = uiomove(mtod(m, void *), len - hlen, uio); 236 if (!error) 237 return (0); 238bad: 239 m_freem(m); 240 return (error); 241} 242 243/* 244 * Attach file to the bpf interface, i.e. make d listen on bp. 245 */ 246static void 247bpf_attachd(d, bp) 248 struct bpf_d *d; 249 struct bpf_if *bp; 250{ 251 /* 252 * Point d at bp, and add d to the interface's list of listeners. 253 * Finally, point the driver's bpf cookie at the interface so 254 * it will divert packets to bpf. 255 */ 256 BPFIF_LOCK(bp); 257 d->bd_bif = bp; 258 d->bd_next = bp->bif_dlist; 259 bp->bif_dlist = d; 260 261 *bp->bif_driverp = bp; 262 BPFIF_UNLOCK(bp); 263} 264 265/* 266 * Detach a file from its interface. 267 */ 268static void 269bpf_detachd(d) 270 struct bpf_d *d; 271{ 272 int error; 273 struct bpf_d **p; 274 struct bpf_if *bp; 275 276 bp = d->bd_bif; 277 /* 278 * Check if this descriptor had requested promiscuous mode. 279 * If so, turn it off. 280 */ 281 if (d->bd_promisc) { 282 d->bd_promisc = 0; 283 error = ifpromisc(bp->bif_ifp, 0); 284 if (error != 0 && error != ENXIO) { 285 /* 286 * ENXIO can happen if a pccard is unplugged 287 * Something is really wrong if we were able to put 288 * the driver into promiscuous mode, but can't 289 * take it out. 290 */ 291 if_printf(bp->bif_ifp, 292 "bpf_detach: ifpromisc failed (%d)\n", error); 293 } 294 } 295 /* Remove d from the interface's descriptor list. */ 296 BPFIF_LOCK(bp); 297 p = &bp->bif_dlist; 298 while (*p != d) { 299 p = &(*p)->bd_next; 300 if (*p == 0) 301 panic("bpf_detachd: descriptor not in list"); 302 } 303 *p = (*p)->bd_next; 304 if (bp->bif_dlist == 0) 305 /* 306 * Let the driver know that there are no more listeners. 307 */ 308 *d->bd_bif->bif_driverp = 0; 309 BPFIF_UNLOCK(bp); 310 d->bd_bif = 0; 311} 312 313/* 314 * Open ethernet device. Returns ENXIO for illegal minor device number, 315 * EBUSY if file is open by another process. 316 */ 317/* ARGSUSED */ 318static int 319bpfopen(dev, flags, fmt, td) 320 dev_t dev; 321 int flags; 322 int fmt; 323 struct thread *td; 324{ 325 struct bpf_d *d; 326 327 mtx_lock(&bpf_mtx); 328 d = dev->si_drv1; 329 /* 330 * Each minor can be opened by only one process. If the requested 331 * minor is in use, return EBUSY. 332 */ 333 if (d) { 334 mtx_unlock(&bpf_mtx); 335 return (EBUSY); 336 } 337 dev->si_drv1 = (struct bpf_d *)~0; /* mark device in use */ 338 mtx_unlock(&bpf_mtx); 339 340 if ((dev->si_flags & SI_NAMED) == 0) 341 make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600, 342 "bpf%d", dev2unit(dev)); 343 MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 344 dev->si_drv1 = d; 345 d->bd_bufsize = bpf_bufsize; 346 d->bd_sig = SIGIO; 347 d->bd_seesent = 1; 348#ifdef MAC 349 mac_init_bpfdesc(d); 350 mac_create_bpfdesc(td->td_ucred, d); 351#endif 352 mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF); 353 callout_init(&d->bd_callout, 1); 354 355 return (0); 356} 357 358/* 359 * Close the descriptor by detaching it from its interface, 360 * deallocating its buffers, and marking it free. 361 */ 362/* ARGSUSED */ 363static int 364bpfclose(dev, flags, fmt, td) 365 dev_t dev; 366 int flags; 367 int fmt; 368 struct thread *td; 369{ 370 struct bpf_d *d = dev->si_drv1; 371 372 BPFD_LOCK(d); 373 if (d->bd_state == BPF_WAITING) 374 callout_stop(&d->bd_callout); 375 d->bd_state = BPF_IDLE; 376 BPFD_UNLOCK(d); 377 funsetown(&d->bd_sigio); 378 mtx_lock(&bpf_mtx); 379 if (d->bd_bif) 380 bpf_detachd(d); 381 mtx_unlock(&bpf_mtx); 382#ifdef MAC 383 mac_destroy_bpfdesc(d); 384#endif /* MAC */ 385 bpf_freed(d); 386 dev->si_drv1 = 0; 387 free(d, M_BPF); 388 389 return (0); 390} 391 392 393/* 394 * Rotate the packet buffers in descriptor d. Move the store buffer 395 * into the hold slot, and the free buffer into the store slot. 396 * Zero the length of the new store buffer. 397 */ 398#define ROTATE_BUFFERS(d) \ 399 (d)->bd_hbuf = (d)->bd_sbuf; \ 400 (d)->bd_hlen = (d)->bd_slen; \ 401 (d)->bd_sbuf = (d)->bd_fbuf; \ 402 (d)->bd_slen = 0; \ 403 (d)->bd_fbuf = 0; 404/* 405 * bpfread - read next chunk of packets from buffers 406 */ 407static int 408bpfread(dev, uio, ioflag) 409 dev_t dev; 410 struct uio *uio; 411 int ioflag; 412{ 413 struct bpf_d *d = dev->si_drv1; 414 int timed_out; 415 int error; 416 417 /* 418 * Restrict application to use a buffer the same size as 419 * as kernel buffers. 420 */ 421 if (uio->uio_resid != d->bd_bufsize) 422 return (EINVAL); 423 424 BPFD_LOCK(d); 425 if (d->bd_state == BPF_WAITING) 426 callout_stop(&d->bd_callout); 427 timed_out = (d->bd_state == BPF_TIMED_OUT); 428 d->bd_state = BPF_IDLE; 429 /* 430 * If the hold buffer is empty, then do a timed sleep, which 431 * ends when the timeout expires or when enough packets 432 * have arrived to fill the store buffer. 433 */ 434 while (d->bd_hbuf == 0) { 435 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { 436 /* 437 * A packet(s) either arrived since the previous 438 * read or arrived while we were asleep. 439 * Rotate the buffers and return what's here. 440 */ 441 ROTATE_BUFFERS(d); 442 break; 443 } 444 445 /* 446 * No data is available, check to see if the bpf device 447 * is still pointed at a real interface. If not, return 448 * ENXIO so that the userland process knows to rebind 449 * it before using it again. 450 */ 451 if (d->bd_bif == NULL) { 452 BPFD_UNLOCK(d); 453 return (ENXIO); 454 } 455 456 if (ioflag & IO_NDELAY) { 457 BPFD_UNLOCK(d); 458 return (EWOULDBLOCK); 459 } 460 error = msleep(d, &d->bd_mtx, PRINET|PCATCH, 461 "bpf", d->bd_rtout); 462 if (error == EINTR || error == ERESTART) { 463 BPFD_UNLOCK(d); 464 return (error); 465 } 466 if (error == EWOULDBLOCK) { 467 /* 468 * On a timeout, return what's in the buffer, 469 * which may be nothing. If there is something 470 * in the store buffer, we can rotate the buffers. 471 */ 472 if (d->bd_hbuf) 473 /* 474 * We filled up the buffer in between 475 * getting the timeout and arriving 476 * here, so we don't need to rotate. 477 */ 478 break; 479 480 if (d->bd_slen == 0) { 481 BPFD_UNLOCK(d); 482 return (0); 483 } 484 ROTATE_BUFFERS(d); 485 break; 486 } 487 } 488 /* 489 * At this point, we know we have something in the hold slot. 490 */ 491 BPFD_UNLOCK(d); 492 493 /* 494 * Move data from hold buffer into user space. 495 * We know the entire buffer is transferred since 496 * we checked above that the read buffer is bpf_bufsize bytes. 497 */ 498 error = uiomove(d->bd_hbuf, d->bd_hlen, uio); 499 500 BPFD_LOCK(d); 501 d->bd_fbuf = d->bd_hbuf; 502 d->bd_hbuf = 0; 503 d->bd_hlen = 0; 504 BPFD_UNLOCK(d); 505 506 return (error); 507} 508 509 510/* 511 * If there are processes sleeping on this descriptor, wake them up. 512 */ 513static __inline void 514bpf_wakeup(d) 515 struct bpf_d *d; 516{ 517 if (d->bd_state == BPF_WAITING) { 518 callout_stop(&d->bd_callout); 519 d->bd_state = BPF_IDLE; 520 } 521 wakeup(d); 522 if (d->bd_async && d->bd_sig && d->bd_sigio) 523 pgsigio(&d->bd_sigio, d->bd_sig, 0); 524 525 selwakeup(&d->bd_sel); 526} 527 528static void 529bpf_timed_out(arg) 530 void *arg; 531{ 532 struct bpf_d *d = (struct bpf_d *)arg; 533 534 BPFD_LOCK(d); 535 if (d->bd_state == BPF_WAITING) { 536 d->bd_state = BPF_TIMED_OUT; 537 if (d->bd_slen != 0) 538 bpf_wakeup(d); 539 } 540 BPFD_UNLOCK(d); 541} 542 543static int 544bpfwrite(dev, uio, ioflag) 545 dev_t dev; 546 struct uio *uio; 547 int ioflag; 548{ 549 struct bpf_d *d = dev->si_drv1; 550 struct ifnet *ifp; 551 struct mbuf *m; 552 int error; 553 static struct sockaddr dst; 554 int datlen; 555 556 if (d->bd_bif == 0) 557 return (ENXIO); 558 559 ifp = d->bd_bif->bif_ifp; 560 561 if (uio->uio_resid == 0) 562 return (0); 563 564 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen); 565 if (error) 566 return (error); 567 568 if (datlen > ifp->if_mtu) 569 return (EMSGSIZE); 570 571 if (d->bd_hdrcmplt) 572 dst.sa_family = pseudo_AF_HDRCMPLT; 573 574 mtx_lock(&Giant); 575#ifdef MAC 576 mac_create_mbuf_from_bpfdesc(d, m); 577#endif 578 error = (*ifp->if_output)(ifp, m, &dst, (struct rtentry *)0); 579 mtx_unlock(&Giant); 580 /* 581 * The driver frees the mbuf. 582 */ 583 return (error); 584} 585 586/* 587 * Reset a descriptor by flushing its packet buffer and clearing the 588 * receive and drop counts. 589 */ 590static void 591reset_d(d) 592 struct bpf_d *d; 593{ 594 595 mtx_assert(&d->bd_mtx, MA_OWNED); 596 if (d->bd_hbuf) { 597 /* Free the hold buffer. */ 598 d->bd_fbuf = d->bd_hbuf; 599 d->bd_hbuf = 0; 600 } 601 d->bd_slen = 0; 602 d->bd_hlen = 0; 603 d->bd_rcount = 0; 604 d->bd_dcount = 0; 605} 606 607/* 608 * FIONREAD Check for read packet available. 609 * SIOCGIFADDR Get interface address - convenient hook to driver. 610 * BIOCGBLEN Get buffer len [for read()]. 611 * BIOCSETF Set ethernet read filter. 612 * BIOCFLUSH Flush read packet buffer. 613 * BIOCPROMISC Put interface into promiscuous mode. 614 * BIOCGDLT Get link layer type. 615 * BIOCGETIF Get interface name. 616 * BIOCSETIF Set interface. 617 * BIOCSRTIMEOUT Set read timeout. 618 * BIOCGRTIMEOUT Get read timeout. 619 * BIOCGSTATS Get packet stats. 620 * BIOCIMMEDIATE Set immediate mode. 621 * BIOCVERSION Get filter language version. 622 * BIOCGHDRCMPLT Get "header already complete" flag 623 * BIOCSHDRCMPLT Set "header already complete" flag 624 * BIOCGSEESENT Get "see packets sent" flag 625 * BIOCSSEESENT Set "see packets sent" flag 626 */ 627/* ARGSUSED */ 628static int 629bpfioctl(dev, cmd, addr, flags, td) 630 dev_t dev; 631 u_long cmd; 632 caddr_t addr; 633 int flags; 634 struct thread *td; 635{ 636 struct bpf_d *d = dev->si_drv1; 637 int error = 0; 638 639 BPFD_LOCK(d); 640 if (d->bd_state == BPF_WAITING) 641 callout_stop(&d->bd_callout); 642 d->bd_state = BPF_IDLE; 643 BPFD_UNLOCK(d); 644 645 switch (cmd) { 646 647 default: 648 error = EINVAL; 649 break; 650 651 /* 652 * Check for read packet available. 653 */ 654 case FIONREAD: 655 { 656 int n; 657 658 BPFD_LOCK(d); 659 n = d->bd_slen; 660 if (d->bd_hbuf) 661 n += d->bd_hlen; 662 BPFD_UNLOCK(d); 663 664 *(int *)addr = n; 665 break; 666 } 667 668 case SIOCGIFADDR: 669 { 670 struct ifnet *ifp; 671 672 if (d->bd_bif == 0) 673 error = EINVAL; 674 else { 675 ifp = d->bd_bif->bif_ifp; 676 error = (*ifp->if_ioctl)(ifp, cmd, addr); 677 } 678 break; 679 } 680 681 /* 682 * Get buffer len [for read()]. 683 */ 684 case BIOCGBLEN: 685 *(u_int *)addr = d->bd_bufsize; 686 break; 687 688 /* 689 * Set buffer length. 690 */ 691 case BIOCSBLEN: 692 if (d->bd_bif != 0) 693 error = EINVAL; 694 else { 695 u_int size = *(u_int *)addr; 696 697 if (size > bpf_maxbufsize) 698 *(u_int *)addr = size = bpf_maxbufsize; 699 else if (size < BPF_MINBUFSIZE) 700 *(u_int *)addr = size = BPF_MINBUFSIZE; 701 d->bd_bufsize = size; 702 } 703 break; 704 705 /* 706 * Set link layer read filter. 707 */ 708 case BIOCSETF: 709 error = bpf_setf(d, (struct bpf_program *)addr); 710 break; 711 712 /* 713 * Flush read packet buffer. 714 */ 715 case BIOCFLUSH: 716 BPFD_LOCK(d); 717 reset_d(d); 718 BPFD_UNLOCK(d); 719 break; 720 721 /* 722 * Put interface into promiscuous mode. 723 */ 724 case BIOCPROMISC: 725 if (d->bd_bif == 0) { 726 /* 727 * No interface attached yet. 728 */ 729 error = EINVAL; 730 break; 731 } 732 if (d->bd_promisc == 0) { 733 mtx_lock(&Giant); 734 error = ifpromisc(d->bd_bif->bif_ifp, 1); 735 mtx_unlock(&Giant); 736 if (error == 0) 737 d->bd_promisc = 1; 738 } 739 break; 740 741 /* 742 * Get current data link type. 743 */ 744 case BIOCGDLT: 745 if (d->bd_bif == 0) 746 error = EINVAL; 747 else 748 *(u_int *)addr = d->bd_bif->bif_dlt; 749 break; 750 751 /* 752 * Get a list of supported data link types. 753 */ 754 case BIOCGDLTLIST: 755 if (d->bd_bif == 0) 756 error = EINVAL; 757 else 758 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 759 break; 760 761 /* 762 * Set data link type. 763 */ 764 case BIOCSDLT: 765 if (d->bd_bif == 0) 766 error = EINVAL; 767 else 768 error = bpf_setdlt(d, *(u_int *)addr); 769 break; 770 771 /* 772 * Get interface name. 773 */ 774 case BIOCGETIF: 775 if (d->bd_bif == 0) 776 error = EINVAL; 777 else { 778 struct ifnet *const ifp = d->bd_bif->bif_ifp; 779 struct ifreq *const ifr = (struct ifreq *)addr; 780 781 snprintf(ifr->ifr_name, sizeof(ifr->ifr_name), 782 "%s%d", ifp->if_name, ifp->if_unit); 783 } 784 break; 785 786 /* 787 * Set interface. 788 */ 789 case BIOCSETIF: 790 error = bpf_setif(d, (struct ifreq *)addr); 791 break; 792 793 /* 794 * Set read timeout. 795 */ 796 case BIOCSRTIMEOUT: 797 { 798 struct timeval *tv = (struct timeval *)addr; 799 800 /* 801 * Subtract 1 tick from tvtohz() since this isn't 802 * a one-shot timer. 803 */ 804 if ((error = itimerfix(tv)) == 0) 805 d->bd_rtout = tvtohz(tv) - 1; 806 break; 807 } 808 809 /* 810 * Get read timeout. 811 */ 812 case BIOCGRTIMEOUT: 813 { 814 struct timeval *tv = (struct timeval *)addr; 815 816 tv->tv_sec = d->bd_rtout / hz; 817 tv->tv_usec = (d->bd_rtout % hz) * tick; 818 break; 819 } 820 821 /* 822 * Get packet stats. 823 */ 824 case BIOCGSTATS: 825 { 826 struct bpf_stat *bs = (struct bpf_stat *)addr; 827 828 bs->bs_recv = d->bd_rcount; 829 bs->bs_drop = d->bd_dcount; 830 break; 831 } 832 833 /* 834 * Set immediate mode. 835 */ 836 case BIOCIMMEDIATE: 837 d->bd_immediate = *(u_int *)addr; 838 break; 839 840 case BIOCVERSION: 841 { 842 struct bpf_version *bv = (struct bpf_version *)addr; 843 844 bv->bv_major = BPF_MAJOR_VERSION; 845 bv->bv_minor = BPF_MINOR_VERSION; 846 break; 847 } 848 849 /* 850 * Get "header already complete" flag 851 */ 852 case BIOCGHDRCMPLT: 853 *(u_int *)addr = d->bd_hdrcmplt; 854 break; 855 856 /* 857 * Set "header already complete" flag 858 */ 859 case BIOCSHDRCMPLT: 860 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 861 break; 862 863 /* 864 * Get "see sent packets" flag 865 */ 866 case BIOCGSEESENT: 867 *(u_int *)addr = d->bd_seesent; 868 break; 869 870 /* 871 * Set "see sent packets" flag 872 */ 873 case BIOCSSEESENT: 874 d->bd_seesent = *(u_int *)addr; 875 break; 876 877 case FIONBIO: /* Non-blocking I/O */ 878 break; 879 880 case FIOASYNC: /* Send signal on receive packets */ 881 d->bd_async = *(int *)addr; 882 break; 883 884 case FIOSETOWN: 885 error = fsetown(*(int *)addr, &d->bd_sigio); 886 break; 887 888 case FIOGETOWN: 889 *(int *)addr = fgetown(&d->bd_sigio); 890 break; 891 892 /* This is deprecated, FIOSETOWN should be used instead. */ 893 case TIOCSPGRP: 894 error = fsetown(-(*(int *)addr), &d->bd_sigio); 895 break; 896 897 /* This is deprecated, FIOGETOWN should be used instead. */ 898 case TIOCGPGRP: 899 *(int *)addr = -fgetown(&d->bd_sigio); 900 break; 901 902 case BIOCSRSIG: /* Set receive signal */ 903 { 904 u_int sig; 905 906 sig = *(u_int *)addr; 907 908 if (sig >= NSIG) 909 error = EINVAL; 910 else 911 d->bd_sig = sig; 912 break; 913 } 914 case BIOCGRSIG: 915 *(u_int *)addr = d->bd_sig; 916 break; 917 } 918 return (error); 919} 920 921/* 922 * Set d's packet filter program to fp. If this file already has a filter, 923 * free it and replace it. Returns EINVAL for bogus requests. 924 */ 925static int 926bpf_setf(d, fp) 927 struct bpf_d *d; 928 struct bpf_program *fp; 929{ 930 struct bpf_insn *fcode, *old; 931 u_int flen, size; 932 933 old = d->bd_filter; 934 if (fp->bf_insns == 0) { 935 if (fp->bf_len != 0) 936 return (EINVAL); 937 BPFD_LOCK(d); 938 d->bd_filter = 0; 939 reset_d(d); 940 BPFD_UNLOCK(d); 941 if (old != 0) 942 free((caddr_t)old, M_BPF); 943 return (0); 944 } 945 flen = fp->bf_len; 946 if (flen > BPF_MAXINSNS) 947 return (EINVAL); 948 949 size = flen * sizeof(*fp->bf_insns); 950 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); 951 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 952 bpf_validate(fcode, (int)flen)) { 953 BPFD_LOCK(d); 954 d->bd_filter = fcode; 955 reset_d(d); 956 BPFD_UNLOCK(d); 957 if (old != 0) 958 free((caddr_t)old, M_BPF); 959 960 return (0); 961 } 962 free((caddr_t)fcode, M_BPF); 963 return (EINVAL); 964} 965 966/* 967 * Detach a file from its current interface (if attached at all) and attach 968 * to the interface indicated by the name stored in ifr. 969 * Return an errno or 0. 970 */ 971static int 972bpf_setif(d, ifr) 973 struct bpf_d *d; 974 struct ifreq *ifr; 975{ 976 struct bpf_if *bp; 977 int error; 978 struct ifnet *theywant; 979 980 theywant = ifunit(ifr->ifr_name); 981 if (theywant == 0) 982 return ENXIO; 983 984 /* 985 * Look through attached interfaces for the named one. 986 */ 987 mtx_lock(&bpf_mtx); 988 for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) { 989 struct ifnet *ifp = bp->bif_ifp; 990 991 if (ifp == 0 || ifp != theywant) 992 continue; 993 /* skip additional entry */ 994 if (bp->bif_driverp != (struct bpf_if **)&ifp->if_bpf) 995 continue; 996 997 mtx_unlock(&bpf_mtx); 998 /* 999 * We found the requested interface. 1000 * If it's not up, return an error. 1001 * Allocate the packet buffers if we need to. 1002 * If we're already attached to requested interface, 1003 * just flush the buffer. 1004 */ 1005 if ((ifp->if_flags & IFF_UP) == 0) 1006 return (ENETDOWN); 1007 1008 if (d->bd_sbuf == 0) { 1009 error = bpf_allocbufs(d); 1010 if (error != 0) 1011 return (error); 1012 } 1013 if (bp != d->bd_bif) { 1014 if (d->bd_bif) 1015 /* 1016 * Detach if attached to something else. 1017 */ 1018 bpf_detachd(d); 1019 1020 bpf_attachd(d, bp); 1021 } 1022 BPFD_LOCK(d); 1023 reset_d(d); 1024 BPFD_UNLOCK(d); 1025 return (0); 1026 } 1027 mtx_unlock(&bpf_mtx); 1028 /* Not found. */ 1029 return (ENXIO); 1030} 1031 1032/* 1033 * Support for select() and poll() system calls 1034 * 1035 * Return true iff the specific operation will not block indefinitely. 1036 * Otherwise, return false but make a note that a selwakeup() must be done. 1037 */ 1038static int 1039bpfpoll(dev, events, td) 1040 dev_t dev; 1041 int events; 1042 struct thread *td; 1043{ 1044 struct bpf_d *d; 1045 int revents; 1046 1047 d = dev->si_drv1; 1048 if (d->bd_bif == NULL) 1049 return (ENXIO); 1050 1051 revents = events & (POLLOUT | POLLWRNORM); 1052 BPFD_LOCK(d); 1053 if (events & (POLLIN | POLLRDNORM)) { 1054 /* 1055 * An imitation of the FIONREAD ioctl code. 1056 * XXX not quite. An exact imitation: 1057 * if (d->b_slen != 0 || 1058 * (d->bd_hbuf != NULL && d->bd_hlen != 0) 1059 */ 1060 if (d->bd_hlen != 0 || 1061 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1062 d->bd_slen != 0)) 1063 revents |= events & (POLLIN | POLLRDNORM); 1064 else { 1065 selrecord(td, &d->bd_sel); 1066 /* Start the read timeout if necessary. */ 1067 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1068 callout_reset(&d->bd_callout, d->bd_rtout, 1069 bpf_timed_out, d); 1070 d->bd_state = BPF_WAITING; 1071 } 1072 } 1073 } 1074 BPFD_UNLOCK(d); 1075 return (revents); 1076} 1077 1078/* 1079 * Incoming linkage from device drivers. Process the packet pkt, of length 1080 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1081 * by each process' filter, and if accepted, stashed into the corresponding 1082 * buffer. 1083 */ 1084void 1085bpf_tap(bp, pkt, pktlen) 1086 struct bpf_if *bp; 1087 u_char *pkt; 1088 u_int pktlen; 1089{ 1090 struct bpf_d *d; 1091 u_int slen; 1092 1093 BPFIF_LOCK(bp); 1094 for (d = bp->bif_dlist; d != 0; d = d->bd_next) { 1095 BPFD_LOCK(d); 1096 ++d->bd_rcount; 1097 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen); 1098 if (slen != 0) { 1099#ifdef MAC 1100 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1101#endif 1102 catchpacket(d, pkt, pktlen, slen, bcopy); 1103 } 1104 BPFD_UNLOCK(d); 1105 } 1106 BPFIF_UNLOCK(bp); 1107} 1108 1109/* 1110 * Copy data from an mbuf chain into a buffer. This code is derived 1111 * from m_copydata in sys/uipc_mbuf.c. 1112 */ 1113static void 1114bpf_mcopy(src_arg, dst_arg, len) 1115 const void *src_arg; 1116 void *dst_arg; 1117 size_t len; 1118{ 1119 const struct mbuf *m; 1120 u_int count; 1121 u_char *dst; 1122 1123 m = src_arg; 1124 dst = dst_arg; 1125 while (len > 0) { 1126 if (m == 0) 1127 panic("bpf_mcopy"); 1128 count = min(m->m_len, len); 1129 bcopy(mtod(m, void *), dst, count); 1130 m = m->m_next; 1131 dst += count; 1132 len -= count; 1133 } 1134} 1135 1136/* 1137 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1138 */ 1139void 1140bpf_mtap(bp, m) 1141 struct bpf_if *bp; 1142 struct mbuf *m; 1143{ 1144 struct bpf_d *d; 1145 u_int pktlen, slen; 1146 1147 pktlen = m_length(m, NULL); 1148 if (pktlen == m->m_len) { 1149 bpf_tap(bp, mtod(m, u_char *), pktlen); 1150 return; 1151 } 1152 1153 BPFIF_LOCK(bp); 1154 for (d = bp->bif_dlist; d != 0; d = d->bd_next) { 1155 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1156 continue; 1157 BPFD_LOCK(d); 1158 ++d->bd_rcount; 1159 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0); 1160 if (slen != 0) 1161#ifdef MAC 1162 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1163#endif 1164 catchpacket(d, (u_char *)m, pktlen, slen, 1165 bpf_mcopy); 1166 BPFD_UNLOCK(d); 1167 } 1168 BPFIF_UNLOCK(bp); 1169} 1170 1171/* 1172 * Move the packet data from interface memory (pkt) into the 1173 * store buffer. Return 1 if it's time to wakeup a listener (buffer full), 1174 * otherwise 0. "copy" is the routine called to do the actual data 1175 * transfer. bcopy is passed in to copy contiguous chunks, while 1176 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1177 * pkt is really an mbuf. 1178 */ 1179static void 1180catchpacket(d, pkt, pktlen, snaplen, cpfn) 1181 struct bpf_d *d; 1182 u_char *pkt; 1183 u_int pktlen, snaplen; 1184 void (*cpfn)(const void *, void *, size_t); 1185{ 1186 struct bpf_hdr *hp; 1187 int totlen, curlen; 1188 int hdrlen = d->bd_bif->bif_hdrlen; 1189 /* 1190 * Figure out how many bytes to move. If the packet is 1191 * greater or equal to the snapshot length, transfer that 1192 * much. Otherwise, transfer the whole packet (unless 1193 * we hit the buffer size limit). 1194 */ 1195 totlen = hdrlen + min(snaplen, pktlen); 1196 if (totlen > d->bd_bufsize) 1197 totlen = d->bd_bufsize; 1198 1199 /* 1200 * Round up the end of the previous packet to the next longword. 1201 */ 1202 curlen = BPF_WORDALIGN(d->bd_slen); 1203 if (curlen + totlen > d->bd_bufsize) { 1204 /* 1205 * This packet will overflow the storage buffer. 1206 * Rotate the buffers if we can, then wakeup any 1207 * pending reads. 1208 */ 1209 if (d->bd_fbuf == 0) { 1210 /* 1211 * We haven't completed the previous read yet, 1212 * so drop the packet. 1213 */ 1214 ++d->bd_dcount; 1215 return; 1216 } 1217 ROTATE_BUFFERS(d); 1218 bpf_wakeup(d); 1219 curlen = 0; 1220 } 1221 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1222 /* 1223 * Immediate mode is set, or the read timeout has 1224 * already expired during a select call. A packet 1225 * arrived, so the reader should be woken up. 1226 */ 1227 bpf_wakeup(d); 1228 1229 /* 1230 * Append the bpf header. 1231 */ 1232 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1233 microtime(&hp->bh_tstamp); 1234 hp->bh_datalen = pktlen; 1235 hp->bh_hdrlen = hdrlen; 1236 /* 1237 * Copy the packet data into the store buffer and update its length. 1238 */ 1239 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1240 d->bd_slen = curlen + totlen; 1241} 1242 1243/* 1244 * Initialize all nonzero fields of a descriptor. 1245 */ 1246static int 1247bpf_allocbufs(d) 1248 struct bpf_d *d; 1249{ 1250 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1251 if (d->bd_fbuf == 0) 1252 return (ENOBUFS); 1253 1254 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1255 if (d->bd_sbuf == 0) { 1256 free(d->bd_fbuf, M_BPF); 1257 return (ENOBUFS); 1258 } 1259 d->bd_slen = 0; 1260 d->bd_hlen = 0; 1261 return (0); 1262} 1263 1264/* 1265 * Free buffers currently in use by a descriptor. 1266 * Called on close. 1267 */ 1268static void 1269bpf_freed(d) 1270 struct bpf_d *d; 1271{ 1272 /* 1273 * We don't need to lock out interrupts since this descriptor has 1274 * been detached from its interface and it yet hasn't been marked 1275 * free. 1276 */ 1277 if (d->bd_sbuf != 0) { 1278 free(d->bd_sbuf, M_BPF); 1279 if (d->bd_hbuf != 0) 1280 free(d->bd_hbuf, M_BPF); 1281 if (d->bd_fbuf != 0) 1282 free(d->bd_fbuf, M_BPF); 1283 } 1284 if (d->bd_filter) 1285 free((caddr_t)d->bd_filter, M_BPF); 1286 mtx_destroy(&d->bd_mtx); 1287} 1288 1289/* 1290 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1291 * fixed size of the link header (variable length headers not yet supported). 1292 */ 1293void 1294bpfattach(ifp, dlt, hdrlen) 1295 struct ifnet *ifp; 1296 u_int dlt, hdrlen; 1297{ 1298 1299 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1300} 1301 1302/* 1303 * Attach an interface to bpf. ifp is a pointer to the structure 1304 * defining the interface to be attached, dlt is the link layer type, 1305 * and hdrlen is the fixed size of the link header (variable length 1306 * headers are not yet supporrted). 1307 */ 1308void 1309bpfattach2(ifp, dlt, hdrlen, driverp) 1310 struct ifnet *ifp; 1311 u_int dlt, hdrlen; 1312 struct bpf_if **driverp; 1313{ 1314 struct bpf_if *bp; 1315 bp = (struct bpf_if *)malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1316 if (bp == 0) 1317 panic("bpfattach"); 1318 1319 bp->bif_dlist = 0; 1320 bp->bif_driverp = driverp; 1321 bp->bif_ifp = ifp; 1322 bp->bif_dlt = dlt; 1323 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1324 1325 mtx_lock(&bpf_mtx); 1326 bp->bif_next = bpf_iflist; 1327 bpf_iflist = bp; 1328 mtx_unlock(&bpf_mtx); 1329 1330 *bp->bif_driverp = 0; 1331 1332 /* 1333 * Compute the length of the bpf header. This is not necessarily 1334 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1335 * that the network layer header begins on a longword boundary (for 1336 * performance reasons and to alleviate alignment restrictions). 1337 */ 1338 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1339 1340 if (bootverbose) 1341 if_printf(ifp, "bpf attached\n"); 1342} 1343 1344/* 1345 * Detach bpf from an interface. This involves detaching each descriptor 1346 * associated with the interface, and leaving bd_bif NULL. Notify each 1347 * descriptor as it's detached so that any sleepers wake up and get 1348 * ENXIO. 1349 */ 1350void 1351bpfdetach(ifp) 1352 struct ifnet *ifp; 1353{ 1354 struct bpf_if *bp, *bp_prev; 1355 struct bpf_d *d; 1356 1357 /* Locate BPF interface information */ 1358 bp_prev = NULL; 1359 1360 mtx_lock(&bpf_mtx); 1361 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1362 if (ifp == bp->bif_ifp) 1363 break; 1364 bp_prev = bp; 1365 } 1366 1367 /* Interface wasn't attached */ 1368 if (bp->bif_ifp == NULL) { 1369 mtx_unlock(&bpf_mtx); 1370 printf("bpfdetach: %s%d was not attached\n", ifp->if_name, 1371 ifp->if_unit); 1372 return; 1373 } 1374 1375 if (bp_prev) { 1376 bp_prev->bif_next = bp->bif_next; 1377 } else { 1378 bpf_iflist = bp->bif_next; 1379 } 1380 mtx_unlock(&bpf_mtx); 1381 1382 while ((d = bp->bif_dlist) != NULL) { 1383 bpf_detachd(d); 1384 BPFD_LOCK(d); 1385 bpf_wakeup(d); 1386 BPFD_UNLOCK(d); 1387 } 1388 1389 mtx_destroy(&bp->bif_mtx); 1390 free(bp, M_BPF); 1391} 1392 1393/* 1394 * Get a list of available data link type of the interface. 1395 */ 1396static int 1397bpf_getdltlist(d, bfl) 1398 struct bpf_d *d; 1399 struct bpf_dltlist *bfl; 1400{ 1401 int n, error; 1402 struct ifnet *ifp; 1403 struct bpf_if *bp; 1404 1405 ifp = d->bd_bif->bif_ifp; 1406 n = 0; 1407 error = 0; 1408 mtx_lock(&bpf_mtx); 1409 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1410 if (bp->bif_ifp != ifp) 1411 continue; 1412 if (bfl->bfl_list != NULL) { 1413 if (n >= bfl->bfl_len) { 1414 mtx_unlock(&bpf_mtx); 1415 return (ENOMEM); 1416 } 1417 error = copyout(&bp->bif_dlt, 1418 bfl->bfl_list + n, sizeof(u_int)); 1419 } 1420 n++; 1421 } 1422 mtx_unlock(&bpf_mtx); 1423 bfl->bfl_len = n; 1424 return (error); 1425} 1426 1427/* 1428 * Set the data link type of a BPF instance. 1429 */ 1430static int 1431bpf_setdlt(d, dlt) 1432 struct bpf_d *d; 1433 u_int dlt; 1434{ 1435 int error, opromisc; 1436 struct ifnet *ifp; 1437 struct bpf_if *bp; 1438 1439 if (d->bd_bif->bif_dlt == dlt) 1440 return (0); 1441 ifp = d->bd_bif->bif_ifp; 1442 mtx_lock(&bpf_mtx); 1443 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1444 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1445 break; 1446 } 1447 mtx_unlock(&bpf_mtx); 1448 if (bp != NULL) { 1449 BPFD_LOCK(d); 1450 opromisc = d->bd_promisc; 1451 bpf_detachd(d); 1452 bpf_attachd(d, bp); 1453 reset_d(d); 1454 BPFD_UNLOCK(d); 1455 if (opromisc) { 1456 error = ifpromisc(bp->bif_ifp, 1); 1457 if (error) 1458 if_printf(bp->bif_ifp, 1459 "bpf_setdlt: ifpromisc failed (%d)\n", 1460 error); 1461 else 1462 d->bd_promisc = 1; 1463 } 1464 } 1465 return (bp == NULL ? EINVAL : 0); 1466} 1467 1468static void bpf_drvinit(void *unused); 1469 1470static void bpf_clone(void *arg, char *name, int namelen, dev_t *dev); 1471 1472static void 1473bpf_clone(arg, name, namelen, dev) 1474 void *arg; 1475 char *name; 1476 int namelen; 1477 dev_t *dev; 1478{ 1479 int u; 1480 1481 if (*dev != NODEV) 1482 return; 1483 if (dev_stdclone(name, NULL, "bpf", &u) != 1) 1484 return; 1485 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, 1486 "bpf%d", u); 1487 (*dev)->si_flags |= SI_CHEAPCLONE; 1488 return; 1489} 1490 1491static void 1492bpf_drvinit(unused) 1493 void *unused; 1494{ 1495 1496 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 1497 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); 1498} 1499 1500SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL) 1501 1502#else /* !DEV_BPF && !NETGRAPH_BPF */ 1503/* 1504 * NOP stubs to allow bpf-using drivers to load and function. 1505 * 1506 * A 'better' implementation would allow the core bpf functionality 1507 * to be loaded at runtime. 1508 */ 1509 1510void 1511bpf_tap(bp, pkt, pktlen) 1512 struct bpf_if *bp; 1513 u_char *pkt; 1514 u_int pktlen; 1515{ 1516} 1517 1518void 1519bpf_mtap(bp, m) 1520 struct bpf_if *bp; 1521 struct mbuf *m; 1522{ 1523} 1524 1525void 1526bpfattach(ifp, dlt, hdrlen) 1527 struct ifnet *ifp; 1528 u_int dlt, hdrlen; 1529{ 1530} 1531 1532void 1533bpfdetach(ifp) 1534 struct ifnet *ifp; 1535{ 1536} 1537 1538u_int 1539bpf_filter(pc, p, wirelen, buflen) 1540 const struct bpf_insn *pc; 1541 u_char *p; 1542 u_int wirelen; 1543 u_int buflen; 1544{ 1545 return -1; /* "no filter" behaviour */ 1546} 1547 1548int 1549bpf_validate(f, len) 1550 const struct bpf_insn *f; 1551 int len; 1552{ 1553 return 0; /* false */ 1554} 1555 1556#endif /* !DEV_BPF && !NETGRAPH_BPF */
| 132}; 133 134 135static int 136bpf_movein(uio, linktype, mp, sockp, datlen) 137 struct uio *uio; 138 int linktype, *datlen; 139 struct mbuf **mp; 140 struct sockaddr *sockp; 141{ 142 struct mbuf *m; 143 int error; 144 int len; 145 int hlen; 146 147 /* 148 * Build a sockaddr based on the data link layer type. 149 * We do this at this level because the ethernet header 150 * is copied directly into the data field of the sockaddr. 151 * In the case of SLIP, there is no header and the packet 152 * is forwarded as is. 153 * Also, we are careful to leave room at the front of the mbuf 154 * for the link level header. 155 */ 156 switch (linktype) { 157 158 case DLT_SLIP: 159 sockp->sa_family = AF_INET; 160 hlen = 0; 161 break; 162 163 case DLT_EN10MB: 164 sockp->sa_family = AF_UNSPEC; 165 /* XXX Would MAXLINKHDR be better? */ 166 hlen = ETHER_HDR_LEN; 167 break; 168 169 case DLT_FDDI: 170 sockp->sa_family = AF_IMPLINK; 171 hlen = 0; 172 break; 173 174 case DLT_RAW: 175 case DLT_NULL: 176 sockp->sa_family = AF_UNSPEC; 177 hlen = 0; 178 break; 179 180 case DLT_ATM_RFC1483: 181 /* 182 * en atm driver requires 4-byte atm pseudo header. 183 * though it isn't standard, vpi:vci needs to be 184 * specified anyway. 185 */ 186 sockp->sa_family = AF_UNSPEC; 187 hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 188 break; 189 190 case DLT_PPP: 191 sockp->sa_family = AF_UNSPEC; 192 hlen = 4; /* This should match PPP_HDRLEN */ 193 break; 194 195 default: 196 return (EIO); 197 } 198 199 len = uio->uio_resid; 200 *datlen = len - hlen; 201 if ((unsigned)len > MCLBYTES) 202 return (EIO); 203 204 if (len > MHLEN) { 205 m = m_getcl(M_TRYWAIT, MT_DATA, M_PKTHDR); 206 } else { 207 MGETHDR(m, M_TRYWAIT, MT_DATA); 208 } 209 if (m == NULL) 210 return (ENOBUFS); 211 m->m_pkthdr.len = m->m_len = len; 212 m->m_pkthdr.rcvif = NULL; 213 *mp = m; 214 215 /* 216 * Make room for link header. 217 */ 218 if (hlen != 0) { 219 m->m_pkthdr.len -= hlen; 220 m->m_len -= hlen; 221#if BSD >= 199103 222 m->m_data += hlen; /* XXX */ 223#else 224 m->m_off += hlen; 225#endif 226 error = uiomove(sockp->sa_data, hlen, uio); 227 if (error) 228 goto bad; 229 } 230 error = uiomove(mtod(m, void *), len - hlen, uio); 231 if (!error) 232 return (0); 233bad: 234 m_freem(m); 235 return (error); 236} 237 238/* 239 * Attach file to the bpf interface, i.e. make d listen on bp. 240 */ 241static void 242bpf_attachd(d, bp) 243 struct bpf_d *d; 244 struct bpf_if *bp; 245{ 246 /* 247 * Point d at bp, and add d to the interface's list of listeners. 248 * Finally, point the driver's bpf cookie at the interface so 249 * it will divert packets to bpf. 250 */ 251 BPFIF_LOCK(bp); 252 d->bd_bif = bp; 253 d->bd_next = bp->bif_dlist; 254 bp->bif_dlist = d; 255 256 *bp->bif_driverp = bp; 257 BPFIF_UNLOCK(bp); 258} 259 260/* 261 * Detach a file from its interface. 262 */ 263static void 264bpf_detachd(d) 265 struct bpf_d *d; 266{ 267 int error; 268 struct bpf_d **p; 269 struct bpf_if *bp; 270 271 bp = d->bd_bif; 272 /* 273 * Check if this descriptor had requested promiscuous mode. 274 * If so, turn it off. 275 */ 276 if (d->bd_promisc) { 277 d->bd_promisc = 0; 278 error = ifpromisc(bp->bif_ifp, 0); 279 if (error != 0 && error != ENXIO) { 280 /* 281 * ENXIO can happen if a pccard is unplugged 282 * Something is really wrong if we were able to put 283 * the driver into promiscuous mode, but can't 284 * take it out. 285 */ 286 if_printf(bp->bif_ifp, 287 "bpf_detach: ifpromisc failed (%d)\n", error); 288 } 289 } 290 /* Remove d from the interface's descriptor list. */ 291 BPFIF_LOCK(bp); 292 p = &bp->bif_dlist; 293 while (*p != d) { 294 p = &(*p)->bd_next; 295 if (*p == 0) 296 panic("bpf_detachd: descriptor not in list"); 297 } 298 *p = (*p)->bd_next; 299 if (bp->bif_dlist == 0) 300 /* 301 * Let the driver know that there are no more listeners. 302 */ 303 *d->bd_bif->bif_driverp = 0; 304 BPFIF_UNLOCK(bp); 305 d->bd_bif = 0; 306} 307 308/* 309 * Open ethernet device. Returns ENXIO for illegal minor device number, 310 * EBUSY if file is open by another process. 311 */ 312/* ARGSUSED */ 313static int 314bpfopen(dev, flags, fmt, td) 315 dev_t dev; 316 int flags; 317 int fmt; 318 struct thread *td; 319{ 320 struct bpf_d *d; 321 322 mtx_lock(&bpf_mtx); 323 d = dev->si_drv1; 324 /* 325 * Each minor can be opened by only one process. If the requested 326 * minor is in use, return EBUSY. 327 */ 328 if (d) { 329 mtx_unlock(&bpf_mtx); 330 return (EBUSY); 331 } 332 dev->si_drv1 = (struct bpf_d *)~0; /* mark device in use */ 333 mtx_unlock(&bpf_mtx); 334 335 if ((dev->si_flags & SI_NAMED) == 0) 336 make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600, 337 "bpf%d", dev2unit(dev)); 338 MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 339 dev->si_drv1 = d; 340 d->bd_bufsize = bpf_bufsize; 341 d->bd_sig = SIGIO; 342 d->bd_seesent = 1; 343#ifdef MAC 344 mac_init_bpfdesc(d); 345 mac_create_bpfdesc(td->td_ucred, d); 346#endif 347 mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF); 348 callout_init(&d->bd_callout, 1); 349 350 return (0); 351} 352 353/* 354 * Close the descriptor by detaching it from its interface, 355 * deallocating its buffers, and marking it free. 356 */ 357/* ARGSUSED */ 358static int 359bpfclose(dev, flags, fmt, td) 360 dev_t dev; 361 int flags; 362 int fmt; 363 struct thread *td; 364{ 365 struct bpf_d *d = dev->si_drv1; 366 367 BPFD_LOCK(d); 368 if (d->bd_state == BPF_WAITING) 369 callout_stop(&d->bd_callout); 370 d->bd_state = BPF_IDLE; 371 BPFD_UNLOCK(d); 372 funsetown(&d->bd_sigio); 373 mtx_lock(&bpf_mtx); 374 if (d->bd_bif) 375 bpf_detachd(d); 376 mtx_unlock(&bpf_mtx); 377#ifdef MAC 378 mac_destroy_bpfdesc(d); 379#endif /* MAC */ 380 bpf_freed(d); 381 dev->si_drv1 = 0; 382 free(d, M_BPF); 383 384 return (0); 385} 386 387 388/* 389 * Rotate the packet buffers in descriptor d. Move the store buffer 390 * into the hold slot, and the free buffer into the store slot. 391 * Zero the length of the new store buffer. 392 */ 393#define ROTATE_BUFFERS(d) \ 394 (d)->bd_hbuf = (d)->bd_sbuf; \ 395 (d)->bd_hlen = (d)->bd_slen; \ 396 (d)->bd_sbuf = (d)->bd_fbuf; \ 397 (d)->bd_slen = 0; \ 398 (d)->bd_fbuf = 0; 399/* 400 * bpfread - read next chunk of packets from buffers 401 */ 402static int 403bpfread(dev, uio, ioflag) 404 dev_t dev; 405 struct uio *uio; 406 int ioflag; 407{ 408 struct bpf_d *d = dev->si_drv1; 409 int timed_out; 410 int error; 411 412 /* 413 * Restrict application to use a buffer the same size as 414 * as kernel buffers. 415 */ 416 if (uio->uio_resid != d->bd_bufsize) 417 return (EINVAL); 418 419 BPFD_LOCK(d); 420 if (d->bd_state == BPF_WAITING) 421 callout_stop(&d->bd_callout); 422 timed_out = (d->bd_state == BPF_TIMED_OUT); 423 d->bd_state = BPF_IDLE; 424 /* 425 * If the hold buffer is empty, then do a timed sleep, which 426 * ends when the timeout expires or when enough packets 427 * have arrived to fill the store buffer. 428 */ 429 while (d->bd_hbuf == 0) { 430 if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { 431 /* 432 * A packet(s) either arrived since the previous 433 * read or arrived while we were asleep. 434 * Rotate the buffers and return what's here. 435 */ 436 ROTATE_BUFFERS(d); 437 break; 438 } 439 440 /* 441 * No data is available, check to see if the bpf device 442 * is still pointed at a real interface. If not, return 443 * ENXIO so that the userland process knows to rebind 444 * it before using it again. 445 */ 446 if (d->bd_bif == NULL) { 447 BPFD_UNLOCK(d); 448 return (ENXIO); 449 } 450 451 if (ioflag & IO_NDELAY) { 452 BPFD_UNLOCK(d); 453 return (EWOULDBLOCK); 454 } 455 error = msleep(d, &d->bd_mtx, PRINET|PCATCH, 456 "bpf", d->bd_rtout); 457 if (error == EINTR || error == ERESTART) { 458 BPFD_UNLOCK(d); 459 return (error); 460 } 461 if (error == EWOULDBLOCK) { 462 /* 463 * On a timeout, return what's in the buffer, 464 * which may be nothing. If there is something 465 * in the store buffer, we can rotate the buffers. 466 */ 467 if (d->bd_hbuf) 468 /* 469 * We filled up the buffer in between 470 * getting the timeout and arriving 471 * here, so we don't need to rotate. 472 */ 473 break; 474 475 if (d->bd_slen == 0) { 476 BPFD_UNLOCK(d); 477 return (0); 478 } 479 ROTATE_BUFFERS(d); 480 break; 481 } 482 } 483 /* 484 * At this point, we know we have something in the hold slot. 485 */ 486 BPFD_UNLOCK(d); 487 488 /* 489 * Move data from hold buffer into user space. 490 * We know the entire buffer is transferred since 491 * we checked above that the read buffer is bpf_bufsize bytes. 492 */ 493 error = uiomove(d->bd_hbuf, d->bd_hlen, uio); 494 495 BPFD_LOCK(d); 496 d->bd_fbuf = d->bd_hbuf; 497 d->bd_hbuf = 0; 498 d->bd_hlen = 0; 499 BPFD_UNLOCK(d); 500 501 return (error); 502} 503 504 505/* 506 * If there are processes sleeping on this descriptor, wake them up. 507 */ 508static __inline void 509bpf_wakeup(d) 510 struct bpf_d *d; 511{ 512 if (d->bd_state == BPF_WAITING) { 513 callout_stop(&d->bd_callout); 514 d->bd_state = BPF_IDLE; 515 } 516 wakeup(d); 517 if (d->bd_async && d->bd_sig && d->bd_sigio) 518 pgsigio(&d->bd_sigio, d->bd_sig, 0); 519 520 selwakeup(&d->bd_sel); 521} 522 523static void 524bpf_timed_out(arg) 525 void *arg; 526{ 527 struct bpf_d *d = (struct bpf_d *)arg; 528 529 BPFD_LOCK(d); 530 if (d->bd_state == BPF_WAITING) { 531 d->bd_state = BPF_TIMED_OUT; 532 if (d->bd_slen != 0) 533 bpf_wakeup(d); 534 } 535 BPFD_UNLOCK(d); 536} 537 538static int 539bpfwrite(dev, uio, ioflag) 540 dev_t dev; 541 struct uio *uio; 542 int ioflag; 543{ 544 struct bpf_d *d = dev->si_drv1; 545 struct ifnet *ifp; 546 struct mbuf *m; 547 int error; 548 static struct sockaddr dst; 549 int datlen; 550 551 if (d->bd_bif == 0) 552 return (ENXIO); 553 554 ifp = d->bd_bif->bif_ifp; 555 556 if (uio->uio_resid == 0) 557 return (0); 558 559 error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen); 560 if (error) 561 return (error); 562 563 if (datlen > ifp->if_mtu) 564 return (EMSGSIZE); 565 566 if (d->bd_hdrcmplt) 567 dst.sa_family = pseudo_AF_HDRCMPLT; 568 569 mtx_lock(&Giant); 570#ifdef MAC 571 mac_create_mbuf_from_bpfdesc(d, m); 572#endif 573 error = (*ifp->if_output)(ifp, m, &dst, (struct rtentry *)0); 574 mtx_unlock(&Giant); 575 /* 576 * The driver frees the mbuf. 577 */ 578 return (error); 579} 580 581/* 582 * Reset a descriptor by flushing its packet buffer and clearing the 583 * receive and drop counts. 584 */ 585static void 586reset_d(d) 587 struct bpf_d *d; 588{ 589 590 mtx_assert(&d->bd_mtx, MA_OWNED); 591 if (d->bd_hbuf) { 592 /* Free the hold buffer. */ 593 d->bd_fbuf = d->bd_hbuf; 594 d->bd_hbuf = 0; 595 } 596 d->bd_slen = 0; 597 d->bd_hlen = 0; 598 d->bd_rcount = 0; 599 d->bd_dcount = 0; 600} 601 602/* 603 * FIONREAD Check for read packet available. 604 * SIOCGIFADDR Get interface address - convenient hook to driver. 605 * BIOCGBLEN Get buffer len [for read()]. 606 * BIOCSETF Set ethernet read filter. 607 * BIOCFLUSH Flush read packet buffer. 608 * BIOCPROMISC Put interface into promiscuous mode. 609 * BIOCGDLT Get link layer type. 610 * BIOCGETIF Get interface name. 611 * BIOCSETIF Set interface. 612 * BIOCSRTIMEOUT Set read timeout. 613 * BIOCGRTIMEOUT Get read timeout. 614 * BIOCGSTATS Get packet stats. 615 * BIOCIMMEDIATE Set immediate mode. 616 * BIOCVERSION Get filter language version. 617 * BIOCGHDRCMPLT Get "header already complete" flag 618 * BIOCSHDRCMPLT Set "header already complete" flag 619 * BIOCGSEESENT Get "see packets sent" flag 620 * BIOCSSEESENT Set "see packets sent" flag 621 */ 622/* ARGSUSED */ 623static int 624bpfioctl(dev, cmd, addr, flags, td) 625 dev_t dev; 626 u_long cmd; 627 caddr_t addr; 628 int flags; 629 struct thread *td; 630{ 631 struct bpf_d *d = dev->si_drv1; 632 int error = 0; 633 634 BPFD_LOCK(d); 635 if (d->bd_state == BPF_WAITING) 636 callout_stop(&d->bd_callout); 637 d->bd_state = BPF_IDLE; 638 BPFD_UNLOCK(d); 639 640 switch (cmd) { 641 642 default: 643 error = EINVAL; 644 break; 645 646 /* 647 * Check for read packet available. 648 */ 649 case FIONREAD: 650 { 651 int n; 652 653 BPFD_LOCK(d); 654 n = d->bd_slen; 655 if (d->bd_hbuf) 656 n += d->bd_hlen; 657 BPFD_UNLOCK(d); 658 659 *(int *)addr = n; 660 break; 661 } 662 663 case SIOCGIFADDR: 664 { 665 struct ifnet *ifp; 666 667 if (d->bd_bif == 0) 668 error = EINVAL; 669 else { 670 ifp = d->bd_bif->bif_ifp; 671 error = (*ifp->if_ioctl)(ifp, cmd, addr); 672 } 673 break; 674 } 675 676 /* 677 * Get buffer len [for read()]. 678 */ 679 case BIOCGBLEN: 680 *(u_int *)addr = d->bd_bufsize; 681 break; 682 683 /* 684 * Set buffer length. 685 */ 686 case BIOCSBLEN: 687 if (d->bd_bif != 0) 688 error = EINVAL; 689 else { 690 u_int size = *(u_int *)addr; 691 692 if (size > bpf_maxbufsize) 693 *(u_int *)addr = size = bpf_maxbufsize; 694 else if (size < BPF_MINBUFSIZE) 695 *(u_int *)addr = size = BPF_MINBUFSIZE; 696 d->bd_bufsize = size; 697 } 698 break; 699 700 /* 701 * Set link layer read filter. 702 */ 703 case BIOCSETF: 704 error = bpf_setf(d, (struct bpf_program *)addr); 705 break; 706 707 /* 708 * Flush read packet buffer. 709 */ 710 case BIOCFLUSH: 711 BPFD_LOCK(d); 712 reset_d(d); 713 BPFD_UNLOCK(d); 714 break; 715 716 /* 717 * Put interface into promiscuous mode. 718 */ 719 case BIOCPROMISC: 720 if (d->bd_bif == 0) { 721 /* 722 * No interface attached yet. 723 */ 724 error = EINVAL; 725 break; 726 } 727 if (d->bd_promisc == 0) { 728 mtx_lock(&Giant); 729 error = ifpromisc(d->bd_bif->bif_ifp, 1); 730 mtx_unlock(&Giant); 731 if (error == 0) 732 d->bd_promisc = 1; 733 } 734 break; 735 736 /* 737 * Get current data link type. 738 */ 739 case BIOCGDLT: 740 if (d->bd_bif == 0) 741 error = EINVAL; 742 else 743 *(u_int *)addr = d->bd_bif->bif_dlt; 744 break; 745 746 /* 747 * Get a list of supported data link types. 748 */ 749 case BIOCGDLTLIST: 750 if (d->bd_bif == 0) 751 error = EINVAL; 752 else 753 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 754 break; 755 756 /* 757 * Set data link type. 758 */ 759 case BIOCSDLT: 760 if (d->bd_bif == 0) 761 error = EINVAL; 762 else 763 error = bpf_setdlt(d, *(u_int *)addr); 764 break; 765 766 /* 767 * Get interface name. 768 */ 769 case BIOCGETIF: 770 if (d->bd_bif == 0) 771 error = EINVAL; 772 else { 773 struct ifnet *const ifp = d->bd_bif->bif_ifp; 774 struct ifreq *const ifr = (struct ifreq *)addr; 775 776 snprintf(ifr->ifr_name, sizeof(ifr->ifr_name), 777 "%s%d", ifp->if_name, ifp->if_unit); 778 } 779 break; 780 781 /* 782 * Set interface. 783 */ 784 case BIOCSETIF: 785 error = bpf_setif(d, (struct ifreq *)addr); 786 break; 787 788 /* 789 * Set read timeout. 790 */ 791 case BIOCSRTIMEOUT: 792 { 793 struct timeval *tv = (struct timeval *)addr; 794 795 /* 796 * Subtract 1 tick from tvtohz() since this isn't 797 * a one-shot timer. 798 */ 799 if ((error = itimerfix(tv)) == 0) 800 d->bd_rtout = tvtohz(tv) - 1; 801 break; 802 } 803 804 /* 805 * Get read timeout. 806 */ 807 case BIOCGRTIMEOUT: 808 { 809 struct timeval *tv = (struct timeval *)addr; 810 811 tv->tv_sec = d->bd_rtout / hz; 812 tv->tv_usec = (d->bd_rtout % hz) * tick; 813 break; 814 } 815 816 /* 817 * Get packet stats. 818 */ 819 case BIOCGSTATS: 820 { 821 struct bpf_stat *bs = (struct bpf_stat *)addr; 822 823 bs->bs_recv = d->bd_rcount; 824 bs->bs_drop = d->bd_dcount; 825 break; 826 } 827 828 /* 829 * Set immediate mode. 830 */ 831 case BIOCIMMEDIATE: 832 d->bd_immediate = *(u_int *)addr; 833 break; 834 835 case BIOCVERSION: 836 { 837 struct bpf_version *bv = (struct bpf_version *)addr; 838 839 bv->bv_major = BPF_MAJOR_VERSION; 840 bv->bv_minor = BPF_MINOR_VERSION; 841 break; 842 } 843 844 /* 845 * Get "header already complete" flag 846 */ 847 case BIOCGHDRCMPLT: 848 *(u_int *)addr = d->bd_hdrcmplt; 849 break; 850 851 /* 852 * Set "header already complete" flag 853 */ 854 case BIOCSHDRCMPLT: 855 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 856 break; 857 858 /* 859 * Get "see sent packets" flag 860 */ 861 case BIOCGSEESENT: 862 *(u_int *)addr = d->bd_seesent; 863 break; 864 865 /* 866 * Set "see sent packets" flag 867 */ 868 case BIOCSSEESENT: 869 d->bd_seesent = *(u_int *)addr; 870 break; 871 872 case FIONBIO: /* Non-blocking I/O */ 873 break; 874 875 case FIOASYNC: /* Send signal on receive packets */ 876 d->bd_async = *(int *)addr; 877 break; 878 879 case FIOSETOWN: 880 error = fsetown(*(int *)addr, &d->bd_sigio); 881 break; 882 883 case FIOGETOWN: 884 *(int *)addr = fgetown(&d->bd_sigio); 885 break; 886 887 /* This is deprecated, FIOSETOWN should be used instead. */ 888 case TIOCSPGRP: 889 error = fsetown(-(*(int *)addr), &d->bd_sigio); 890 break; 891 892 /* This is deprecated, FIOGETOWN should be used instead. */ 893 case TIOCGPGRP: 894 *(int *)addr = -fgetown(&d->bd_sigio); 895 break; 896 897 case BIOCSRSIG: /* Set receive signal */ 898 { 899 u_int sig; 900 901 sig = *(u_int *)addr; 902 903 if (sig >= NSIG) 904 error = EINVAL; 905 else 906 d->bd_sig = sig; 907 break; 908 } 909 case BIOCGRSIG: 910 *(u_int *)addr = d->bd_sig; 911 break; 912 } 913 return (error); 914} 915 916/* 917 * Set d's packet filter program to fp. If this file already has a filter, 918 * free it and replace it. Returns EINVAL for bogus requests. 919 */ 920static int 921bpf_setf(d, fp) 922 struct bpf_d *d; 923 struct bpf_program *fp; 924{ 925 struct bpf_insn *fcode, *old; 926 u_int flen, size; 927 928 old = d->bd_filter; 929 if (fp->bf_insns == 0) { 930 if (fp->bf_len != 0) 931 return (EINVAL); 932 BPFD_LOCK(d); 933 d->bd_filter = 0; 934 reset_d(d); 935 BPFD_UNLOCK(d); 936 if (old != 0) 937 free((caddr_t)old, M_BPF); 938 return (0); 939 } 940 flen = fp->bf_len; 941 if (flen > BPF_MAXINSNS) 942 return (EINVAL); 943 944 size = flen * sizeof(*fp->bf_insns); 945 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); 946 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 947 bpf_validate(fcode, (int)flen)) { 948 BPFD_LOCK(d); 949 d->bd_filter = fcode; 950 reset_d(d); 951 BPFD_UNLOCK(d); 952 if (old != 0) 953 free((caddr_t)old, M_BPF); 954 955 return (0); 956 } 957 free((caddr_t)fcode, M_BPF); 958 return (EINVAL); 959} 960 961/* 962 * Detach a file from its current interface (if attached at all) and attach 963 * to the interface indicated by the name stored in ifr. 964 * Return an errno or 0. 965 */ 966static int 967bpf_setif(d, ifr) 968 struct bpf_d *d; 969 struct ifreq *ifr; 970{ 971 struct bpf_if *bp; 972 int error; 973 struct ifnet *theywant; 974 975 theywant = ifunit(ifr->ifr_name); 976 if (theywant == 0) 977 return ENXIO; 978 979 /* 980 * Look through attached interfaces for the named one. 981 */ 982 mtx_lock(&bpf_mtx); 983 for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) { 984 struct ifnet *ifp = bp->bif_ifp; 985 986 if (ifp == 0 || ifp != theywant) 987 continue; 988 /* skip additional entry */ 989 if (bp->bif_driverp != (struct bpf_if **)&ifp->if_bpf) 990 continue; 991 992 mtx_unlock(&bpf_mtx); 993 /* 994 * We found the requested interface. 995 * If it's not up, return an error. 996 * Allocate the packet buffers if we need to. 997 * If we're already attached to requested interface, 998 * just flush the buffer. 999 */ 1000 if ((ifp->if_flags & IFF_UP) == 0) 1001 return (ENETDOWN); 1002 1003 if (d->bd_sbuf == 0) { 1004 error = bpf_allocbufs(d); 1005 if (error != 0) 1006 return (error); 1007 } 1008 if (bp != d->bd_bif) { 1009 if (d->bd_bif) 1010 /* 1011 * Detach if attached to something else. 1012 */ 1013 bpf_detachd(d); 1014 1015 bpf_attachd(d, bp); 1016 } 1017 BPFD_LOCK(d); 1018 reset_d(d); 1019 BPFD_UNLOCK(d); 1020 return (0); 1021 } 1022 mtx_unlock(&bpf_mtx); 1023 /* Not found. */ 1024 return (ENXIO); 1025} 1026 1027/* 1028 * Support for select() and poll() system calls 1029 * 1030 * Return true iff the specific operation will not block indefinitely. 1031 * Otherwise, return false but make a note that a selwakeup() must be done. 1032 */ 1033static int 1034bpfpoll(dev, events, td) 1035 dev_t dev; 1036 int events; 1037 struct thread *td; 1038{ 1039 struct bpf_d *d; 1040 int revents; 1041 1042 d = dev->si_drv1; 1043 if (d->bd_bif == NULL) 1044 return (ENXIO); 1045 1046 revents = events & (POLLOUT | POLLWRNORM); 1047 BPFD_LOCK(d); 1048 if (events & (POLLIN | POLLRDNORM)) { 1049 /* 1050 * An imitation of the FIONREAD ioctl code. 1051 * XXX not quite. An exact imitation: 1052 * if (d->b_slen != 0 || 1053 * (d->bd_hbuf != NULL && d->bd_hlen != 0) 1054 */ 1055 if (d->bd_hlen != 0 || 1056 ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && 1057 d->bd_slen != 0)) 1058 revents |= events & (POLLIN | POLLRDNORM); 1059 else { 1060 selrecord(td, &d->bd_sel); 1061 /* Start the read timeout if necessary. */ 1062 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1063 callout_reset(&d->bd_callout, d->bd_rtout, 1064 bpf_timed_out, d); 1065 d->bd_state = BPF_WAITING; 1066 } 1067 } 1068 } 1069 BPFD_UNLOCK(d); 1070 return (revents); 1071} 1072 1073/* 1074 * Incoming linkage from device drivers. Process the packet pkt, of length 1075 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1076 * by each process' filter, and if accepted, stashed into the corresponding 1077 * buffer. 1078 */ 1079void 1080bpf_tap(bp, pkt, pktlen) 1081 struct bpf_if *bp; 1082 u_char *pkt; 1083 u_int pktlen; 1084{ 1085 struct bpf_d *d; 1086 u_int slen; 1087 1088 BPFIF_LOCK(bp); 1089 for (d = bp->bif_dlist; d != 0; d = d->bd_next) { 1090 BPFD_LOCK(d); 1091 ++d->bd_rcount; 1092 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen); 1093 if (slen != 0) { 1094#ifdef MAC 1095 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1096#endif 1097 catchpacket(d, pkt, pktlen, slen, bcopy); 1098 } 1099 BPFD_UNLOCK(d); 1100 } 1101 BPFIF_UNLOCK(bp); 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 size_t len; 1113{ 1114 const struct mbuf *m; 1115 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(bp, m) 1136 struct bpf_if *bp; 1137 struct mbuf *m; 1138{ 1139 struct bpf_d *d; 1140 u_int pktlen, slen; 1141 1142 pktlen = m_length(m, NULL); 1143 if (pktlen == m->m_len) { 1144 bpf_tap(bp, mtod(m, u_char *), pktlen); 1145 return; 1146 } 1147 1148 BPFIF_LOCK(bp); 1149 for (d = bp->bif_dlist; d != 0; d = d->bd_next) { 1150 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1151 continue; 1152 BPFD_LOCK(d); 1153 ++d->bd_rcount; 1154 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0); 1155 if (slen != 0) 1156#ifdef MAC 1157 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1158#endif 1159 catchpacket(d, (u_char *)m, pktlen, slen, 1160 bpf_mcopy); 1161 BPFD_UNLOCK(d); 1162 } 1163 BPFIF_UNLOCK(bp); 1164} 1165 1166/* 1167 * Move the packet data from interface memory (pkt) into the 1168 * store buffer. Return 1 if it's time to wakeup a listener (buffer full), 1169 * otherwise 0. "copy" is the routine called to do the actual data 1170 * transfer. bcopy is passed in to copy contiguous chunks, while 1171 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1172 * pkt is really an mbuf. 1173 */ 1174static void 1175catchpacket(d, pkt, pktlen, snaplen, cpfn) 1176 struct bpf_d *d; 1177 u_char *pkt; 1178 u_int pktlen, snaplen; 1179 void (*cpfn)(const void *, void *, size_t); 1180{ 1181 struct bpf_hdr *hp; 1182 int totlen, curlen; 1183 int hdrlen = d->bd_bif->bif_hdrlen; 1184 /* 1185 * Figure out how many bytes to move. If the packet is 1186 * greater or equal to the snapshot length, transfer that 1187 * much. Otherwise, transfer the whole packet (unless 1188 * we hit the buffer size limit). 1189 */ 1190 totlen = hdrlen + min(snaplen, pktlen); 1191 if (totlen > d->bd_bufsize) 1192 totlen = d->bd_bufsize; 1193 1194 /* 1195 * Round up the end of the previous packet to the next longword. 1196 */ 1197 curlen = BPF_WORDALIGN(d->bd_slen); 1198 if (curlen + totlen > d->bd_bufsize) { 1199 /* 1200 * This packet will overflow the storage buffer. 1201 * Rotate the buffers if we can, then wakeup any 1202 * pending reads. 1203 */ 1204 if (d->bd_fbuf == 0) { 1205 /* 1206 * We haven't completed the previous read yet, 1207 * so drop the packet. 1208 */ 1209 ++d->bd_dcount; 1210 return; 1211 } 1212 ROTATE_BUFFERS(d); 1213 bpf_wakeup(d); 1214 curlen = 0; 1215 } 1216 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1217 /* 1218 * Immediate mode is set, or the read timeout has 1219 * already expired during a select call. A packet 1220 * arrived, so the reader should be woken up. 1221 */ 1222 bpf_wakeup(d); 1223 1224 /* 1225 * Append the bpf header. 1226 */ 1227 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1228 microtime(&hp->bh_tstamp); 1229 hp->bh_datalen = pktlen; 1230 hp->bh_hdrlen = hdrlen; 1231 /* 1232 * Copy the packet data into the store buffer and update its length. 1233 */ 1234 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1235 d->bd_slen = curlen + totlen; 1236} 1237 1238/* 1239 * Initialize all nonzero fields of a descriptor. 1240 */ 1241static int 1242bpf_allocbufs(d) 1243 struct bpf_d *d; 1244{ 1245 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1246 if (d->bd_fbuf == 0) 1247 return (ENOBUFS); 1248 1249 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1250 if (d->bd_sbuf == 0) { 1251 free(d->bd_fbuf, M_BPF); 1252 return (ENOBUFS); 1253 } 1254 d->bd_slen = 0; 1255 d->bd_hlen = 0; 1256 return (0); 1257} 1258 1259/* 1260 * Free buffers currently in use by a descriptor. 1261 * Called on close. 1262 */ 1263static void 1264bpf_freed(d) 1265 struct bpf_d *d; 1266{ 1267 /* 1268 * We don't need to lock out interrupts since this descriptor has 1269 * been detached from its interface and it yet hasn't been marked 1270 * free. 1271 */ 1272 if (d->bd_sbuf != 0) { 1273 free(d->bd_sbuf, M_BPF); 1274 if (d->bd_hbuf != 0) 1275 free(d->bd_hbuf, M_BPF); 1276 if (d->bd_fbuf != 0) 1277 free(d->bd_fbuf, M_BPF); 1278 } 1279 if (d->bd_filter) 1280 free((caddr_t)d->bd_filter, M_BPF); 1281 mtx_destroy(&d->bd_mtx); 1282} 1283 1284/* 1285 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1286 * fixed size of the link header (variable length headers not yet supported). 1287 */ 1288void 1289bpfattach(ifp, dlt, hdrlen) 1290 struct ifnet *ifp; 1291 u_int dlt, hdrlen; 1292{ 1293 1294 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1295} 1296 1297/* 1298 * Attach an interface to bpf. ifp is a pointer to the structure 1299 * defining the interface to be attached, dlt is the link layer type, 1300 * and hdrlen is the fixed size of the link header (variable length 1301 * headers are not yet supporrted). 1302 */ 1303void 1304bpfattach2(ifp, dlt, hdrlen, driverp) 1305 struct ifnet *ifp; 1306 u_int dlt, hdrlen; 1307 struct bpf_if **driverp; 1308{ 1309 struct bpf_if *bp; 1310 bp = (struct bpf_if *)malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1311 if (bp == 0) 1312 panic("bpfattach"); 1313 1314 bp->bif_dlist = 0; 1315 bp->bif_driverp = driverp; 1316 bp->bif_ifp = ifp; 1317 bp->bif_dlt = dlt; 1318 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1319 1320 mtx_lock(&bpf_mtx); 1321 bp->bif_next = bpf_iflist; 1322 bpf_iflist = bp; 1323 mtx_unlock(&bpf_mtx); 1324 1325 *bp->bif_driverp = 0; 1326 1327 /* 1328 * Compute the length of the bpf header. This is not necessarily 1329 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1330 * that the network layer header begins on a longword boundary (for 1331 * performance reasons and to alleviate alignment restrictions). 1332 */ 1333 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1334 1335 if (bootverbose) 1336 if_printf(ifp, "bpf attached\n"); 1337} 1338 1339/* 1340 * Detach bpf from an interface. This involves detaching each descriptor 1341 * associated with the interface, and leaving bd_bif NULL. Notify each 1342 * descriptor as it's detached so that any sleepers wake up and get 1343 * ENXIO. 1344 */ 1345void 1346bpfdetach(ifp) 1347 struct ifnet *ifp; 1348{ 1349 struct bpf_if *bp, *bp_prev; 1350 struct bpf_d *d; 1351 1352 /* Locate BPF interface information */ 1353 bp_prev = NULL; 1354 1355 mtx_lock(&bpf_mtx); 1356 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1357 if (ifp == bp->bif_ifp) 1358 break; 1359 bp_prev = bp; 1360 } 1361 1362 /* Interface wasn't attached */ 1363 if (bp->bif_ifp == NULL) { 1364 mtx_unlock(&bpf_mtx); 1365 printf("bpfdetach: %s%d was not attached\n", ifp->if_name, 1366 ifp->if_unit); 1367 return; 1368 } 1369 1370 if (bp_prev) { 1371 bp_prev->bif_next = bp->bif_next; 1372 } else { 1373 bpf_iflist = bp->bif_next; 1374 } 1375 mtx_unlock(&bpf_mtx); 1376 1377 while ((d = bp->bif_dlist) != NULL) { 1378 bpf_detachd(d); 1379 BPFD_LOCK(d); 1380 bpf_wakeup(d); 1381 BPFD_UNLOCK(d); 1382 } 1383 1384 mtx_destroy(&bp->bif_mtx); 1385 free(bp, M_BPF); 1386} 1387 1388/* 1389 * Get a list of available data link type of the interface. 1390 */ 1391static int 1392bpf_getdltlist(d, bfl) 1393 struct bpf_d *d; 1394 struct bpf_dltlist *bfl; 1395{ 1396 int n, error; 1397 struct ifnet *ifp; 1398 struct bpf_if *bp; 1399 1400 ifp = d->bd_bif->bif_ifp; 1401 n = 0; 1402 error = 0; 1403 mtx_lock(&bpf_mtx); 1404 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1405 if (bp->bif_ifp != ifp) 1406 continue; 1407 if (bfl->bfl_list != NULL) { 1408 if (n >= bfl->bfl_len) { 1409 mtx_unlock(&bpf_mtx); 1410 return (ENOMEM); 1411 } 1412 error = copyout(&bp->bif_dlt, 1413 bfl->bfl_list + n, sizeof(u_int)); 1414 } 1415 n++; 1416 } 1417 mtx_unlock(&bpf_mtx); 1418 bfl->bfl_len = n; 1419 return (error); 1420} 1421 1422/* 1423 * Set the data link type of a BPF instance. 1424 */ 1425static int 1426bpf_setdlt(d, dlt) 1427 struct bpf_d *d; 1428 u_int dlt; 1429{ 1430 int error, opromisc; 1431 struct ifnet *ifp; 1432 struct bpf_if *bp; 1433 1434 if (d->bd_bif->bif_dlt == dlt) 1435 return (0); 1436 ifp = d->bd_bif->bif_ifp; 1437 mtx_lock(&bpf_mtx); 1438 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1439 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1440 break; 1441 } 1442 mtx_unlock(&bpf_mtx); 1443 if (bp != NULL) { 1444 BPFD_LOCK(d); 1445 opromisc = d->bd_promisc; 1446 bpf_detachd(d); 1447 bpf_attachd(d, bp); 1448 reset_d(d); 1449 BPFD_UNLOCK(d); 1450 if (opromisc) { 1451 error = ifpromisc(bp->bif_ifp, 1); 1452 if (error) 1453 if_printf(bp->bif_ifp, 1454 "bpf_setdlt: ifpromisc failed (%d)\n", 1455 error); 1456 else 1457 d->bd_promisc = 1; 1458 } 1459 } 1460 return (bp == NULL ? EINVAL : 0); 1461} 1462 1463static void bpf_drvinit(void *unused); 1464 1465static void bpf_clone(void *arg, char *name, int namelen, dev_t *dev); 1466 1467static void 1468bpf_clone(arg, name, namelen, dev) 1469 void *arg; 1470 char *name; 1471 int namelen; 1472 dev_t *dev; 1473{ 1474 int u; 1475 1476 if (*dev != NODEV) 1477 return; 1478 if (dev_stdclone(name, NULL, "bpf", &u) != 1) 1479 return; 1480 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, 1481 "bpf%d", u); 1482 (*dev)->si_flags |= SI_CHEAPCLONE; 1483 return; 1484} 1485 1486static void 1487bpf_drvinit(unused) 1488 void *unused; 1489{ 1490 1491 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 1492 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); 1493} 1494 1495SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL) 1496 1497#else /* !DEV_BPF && !NETGRAPH_BPF */ 1498/* 1499 * NOP stubs to allow bpf-using drivers to load and function. 1500 * 1501 * A 'better' implementation would allow the core bpf functionality 1502 * to be loaded at runtime. 1503 */ 1504 1505void 1506bpf_tap(bp, pkt, pktlen) 1507 struct bpf_if *bp; 1508 u_char *pkt; 1509 u_int pktlen; 1510{ 1511} 1512 1513void 1514bpf_mtap(bp, m) 1515 struct bpf_if *bp; 1516 struct mbuf *m; 1517{ 1518} 1519 1520void 1521bpfattach(ifp, dlt, hdrlen) 1522 struct ifnet *ifp; 1523 u_int dlt, hdrlen; 1524{ 1525} 1526 1527void 1528bpfdetach(ifp) 1529 struct ifnet *ifp; 1530{ 1531} 1532 1533u_int 1534bpf_filter(pc, p, wirelen, buflen) 1535 const struct bpf_insn *pc; 1536 u_char *p; 1537 u_int wirelen; 1538 u_int buflen; 1539{ 1540 return -1; /* "no filter" behaviour */ 1541} 1542 1543int 1544bpf_validate(f, len) 1545 const struct bpf_insn *f; 1546 int len; 1547{ 1548 return 0; /* false */ 1549} 1550 1551#endif /* !DEV_BPF && !NETGRAPH_BPF */
|