bpf.c revision 130335
1209139Srpaulo/* 2209139Srpaulo * Copyright (c) 1990, 1991, 1993 3209139Srpaulo * The Regents of the University of California. All rights reserved. 4209139Srpaulo * 5252190Srpaulo * This code is derived from the Stanford/CMU enet packet filter, 6252190Srpaulo * (net/enet.c) distributed as part of 4.3BSD, and code contributed 7209139Srpaulo * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence 8209139Srpaulo * Berkeley Laboratory. 9209139Srpaulo * 10209139Srpaulo * Redistribution and use in source and binary forms, with or without 11209139Srpaulo * modification, are permitted provided that the following conditions 12209139Srpaulo * are met: 13209139Srpaulo * 1. Redistributions of source code must retain the above copyright 14209139Srpaulo * notice, this list of conditions and the following disclaimer. 15214501Srpaulo * 2. Redistributions in binary form must reproduce the above copyright 16209139Srpaulo * notice, this list of conditions and the following disclaimer in the 17209139Srpaulo * documentation and/or other materials provided with the distribution. 18209139Srpaulo * 4. Neither the name of the University nor the names of its contributors 19209139Srpaulo * may be used to endorse or promote products derived from this software 20209139Srpaulo * without specific prior written permission. 21209139Srpaulo * 22209139Srpaulo * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23209139Srpaulo * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24209139Srpaulo * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25209139Srpaulo * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26209139Srpaulo * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27209139Srpaulo * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28209139Srpaulo * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29209139Srpaulo * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30209139Srpaulo * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31209139Srpaulo * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32209139Srpaulo * SUCH DAMAGE. 33209139Srpaulo * 34209139Srpaulo * @(#)bpf.c 8.4 (Berkeley) 1/9/95 35209139Srpaulo * 36209139Srpaulo * $FreeBSD: head/sys/net/bpf.c 130335 2004-06-11 03:47:21Z rwatson $ 37209139Srpaulo */ 38209139Srpaulo 39209139Srpaulo#include "opt_bpf.h" 40209139Srpaulo#include "opt_mac.h" 41209139Srpaulo#include "opt_netgraph.h" 42209139Srpaulo 43209139Srpaulo#include <sys/types.h> 44209139Srpaulo#include <sys/param.h> 45209139Srpaulo#include <sys/systm.h> 46209139Srpaulo#include <sys/conf.h> 47209139Srpaulo#include <sys/mac.h> 48209139Srpaulo#include <sys/malloc.h> 49209139Srpaulo#include <sys/mbuf.h> 50209139Srpaulo#include <sys/time.h> 51209139Srpaulo#include <sys/proc.h> 52209139Srpaulo#include <sys/signalvar.h> 53209139Srpaulo#include <sys/filio.h> 54209139Srpaulo#include <sys/sockio.h> 55209139Srpaulo#include <sys/ttycom.h> 56209139Srpaulo#include <sys/filedesc.h> 57209139Srpaulo 58209139Srpaulo#include <sys/event.h> 59209139Srpaulo#include <sys/file.h> 60209139Srpaulo#include <sys/poll.h> 61209139Srpaulo#include <sys/proc.h> 62209139Srpaulo 63209139Srpaulo#include <sys/socket.h> 64209139Srpaulo#include <sys/vnode.h> 65209139Srpaulo 66209139Srpaulo#include <net/if.h> 67209139Srpaulo#include <net/bpf.h> 68209139Srpaulo#include <net/bpfdesc.h> 69209139Srpaulo 70209139Srpaulo#include <netinet/in.h> 71209139Srpaulo#include <netinet/if_ether.h> 72209139Srpaulo#include <sys/kernel.h> 73209139Srpaulo#include <sys/sysctl.h> 74209139Srpaulo 75209139Srpaulostatic MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 76209139Srpaulo 77209139Srpaulo#if defined(DEV_BPF) || defined(NETGRAPH_BPF) 78209139Srpaulo 79209139Srpaulo#define PRINET 26 /* interruptible */ 80209139Srpaulo 81209139Srpaulo/* 82209139Srpaulo * The default read buffer size is patchable. 83209139Srpaulo */ 84209139Srpaulostatic int bpf_bufsize = 4096; 85209139SrpauloSYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW, 86209139Srpaulo &bpf_bufsize, 0, ""); 87209139Srpaulostatic int bpf_maxbufsize = BPF_MAXBUFSIZE; 88209139SrpauloSYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW, 89209139Srpaulo &bpf_maxbufsize, 0, ""); 90209139Srpaulo 91209139Srpaulo/* 92209139Srpaulo * bpf_iflist is the list of interfaces; each corresponds to an ifnet 93209139Srpaulo */ 94209139Srpaulostatic struct bpf_if *bpf_iflist; 95209139Srpaulostatic struct mtx bpf_mtx; /* bpf global lock */ 96209139Srpaulo 97209139Srpaulostatic int bpf_allocbufs(struct bpf_d *); 98209139Srpaulostatic void bpf_attachd(struct bpf_d *d, struct bpf_if *bp); 99214501Srpaulostatic void bpf_detachd(struct bpf_d *d); 100214501Srpaulostatic void bpf_freed(struct bpf_d *); 101209139Srpaulostatic void bpf_mcopy(const void *, void *, size_t); 102209139Srpaulostatic int bpf_movein(struct uio *, int, 103214501Srpaulo struct mbuf **, struct sockaddr *, int *); 104214501Srpaulostatic int bpf_setif(struct bpf_d *, struct ifreq *); 105209139Srpaulostatic void bpf_timed_out(void *); 106209139Srpaulostatic __inline void 107209139Srpaulo bpf_wakeup(struct bpf_d *); 108209139Srpaulostatic void catchpacket(struct bpf_d *, u_char *, u_int, 109209139Srpaulo u_int, void (*)(const void *, void *, size_t)); 110209139Srpaulostatic void reset_d(struct bpf_d *); 111209139Srpaulostatic int bpf_setf(struct bpf_d *, struct bpf_program *); 112209139Srpaulostatic int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 113209139Srpaulostatic int bpf_setdlt(struct bpf_d *, u_int); 114209139Srpaulostatic void filt_bpfdetach(struct knote *); 115209139Srpaulostatic int filt_bpfread(struct knote *, long); 116209139Srpaulo 117209139Srpaulostatic d_open_t bpfopen; 118209139Srpaulostatic d_close_t bpfclose; 119209139Srpaulostatic d_read_t bpfread; 120209139Srpaulostatic d_write_t bpfwrite; 121209139Srpaulostatic d_ioctl_t bpfioctl; 122209139Srpaulostatic d_poll_t bpfpoll; 123209139Srpaulostatic d_kqfilter_t bpfkqfilter; 124209139Srpaulo 125209139Srpaulostatic struct cdevsw bpf_cdevsw = { 126209139Srpaulo .d_version = D_VERSION, 127209139Srpaulo .d_flags = D_NEEDGIANT, 128209139Srpaulo .d_open = bpfopen, 129209139Srpaulo .d_close = bpfclose, 130209139Srpaulo .d_read = bpfread, 131209139Srpaulo .d_write = bpfwrite, 132209139Srpaulo .d_ioctl = bpfioctl, 133209139Srpaulo .d_poll = bpfpoll, 134209139Srpaulo .d_name = "bpf", 135209139Srpaulo .d_kqfilter = bpfkqfilter, 136209139Srpaulo}; 137209139Srpaulo 138209139Srpaulostatic struct filterops bpfread_filtops = 139209139Srpaulo { 1, NULL, filt_bpfdetach, filt_bpfread }; 140209139Srpaulo 141209139Srpaulostatic int 142209139Srpaulobpf_movein(uio, linktype, mp, sockp, datlen) 143209139Srpaulo struct uio *uio; 144209139Srpaulo int linktype, *datlen; 145209139Srpaulo struct mbuf **mp; 146209139Srpaulo struct sockaddr *sockp; 147209139Srpaulo{ 148209139Srpaulo struct mbuf *m; 149209139Srpaulo int error; 150209139Srpaulo int len; 151209139Srpaulo int hlen; 152209139Srpaulo 153209139Srpaulo /* 154209139Srpaulo * Build a sockaddr based on the data link layer type. 155252190Srpaulo * We do this at this level because the ethernet header 156209139Srpaulo * is copied directly into the data field of the sockaddr. 157209139Srpaulo * In the case of SLIP, there is no header and the packet 158209139Srpaulo * is forwarded as is. 159209139Srpaulo * Also, we are careful to leave room at the front of the mbuf 160209139Srpaulo * for the link level header. 161209139Srpaulo */ 162209139Srpaulo switch (linktype) { 163209139Srpaulo 164209139Srpaulo case DLT_SLIP: 165209139Srpaulo sockp->sa_family = AF_INET; 166209139Srpaulo hlen = 0; 167209139Srpaulo break; 168209139Srpaulo 169209139Srpaulo case DLT_EN10MB: 170209139Srpaulo sockp->sa_family = AF_UNSPEC; 171209139Srpaulo /* XXX Would MAXLINKHDR be better? */ 172209139Srpaulo hlen = ETHER_HDR_LEN; 173209139Srpaulo break; 174209139Srpaulo 175209139Srpaulo case DLT_FDDI: 176209139Srpaulo sockp->sa_family = AF_IMPLINK; 177209139Srpaulo hlen = 0; 178209139Srpaulo break; 179209139Srpaulo 180209139Srpaulo case DLT_RAW: 181209139Srpaulo case DLT_NULL: 182209139Srpaulo sockp->sa_family = AF_UNSPEC; 183209139Srpaulo hlen = 0; 184209139Srpaulo break; 185209139Srpaulo 186209139Srpaulo case DLT_ATM_RFC1483: 187214501Srpaulo /* 188214501Srpaulo * en atm driver requires 4-byte atm pseudo header. 189214501Srpaulo * though it isn't standard, vpi:vci needs to be 190214501Srpaulo * specified anyway. 191214501Srpaulo */ 192209139Srpaulo sockp->sa_family = AF_UNSPEC; 193209139Srpaulo hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ 194209139Srpaulo break; 195209139Srpaulo 196209139Srpaulo case DLT_PPP: 197209139Srpaulo sockp->sa_family = AF_UNSPEC; 198209139Srpaulo hlen = 4; /* This should match PPP_HDRLEN */ 199209139Srpaulo break; 200209139Srpaulo 201209139Srpaulo default: 202209139Srpaulo return (EIO); 203209139Srpaulo } 204209139Srpaulo 205209139Srpaulo len = uio->uio_resid; 206209139Srpaulo *datlen = len - hlen; 207209139Srpaulo if ((unsigned)len > MCLBYTES) 208209139Srpaulo return (EIO); 209209139Srpaulo 210209139Srpaulo if (len > MHLEN) { 211209139Srpaulo m = m_getcl(M_TRYWAIT, MT_DATA, M_PKTHDR); 212209139Srpaulo } else { 213209139Srpaulo MGETHDR(m, M_TRYWAIT, MT_DATA); 214209139Srpaulo } 215209139Srpaulo if (m == NULL) 216209139Srpaulo return (ENOBUFS); 217209139Srpaulo m->m_pkthdr.len = m->m_len = len; 218209139Srpaulo m->m_pkthdr.rcvif = NULL; 219209139Srpaulo *mp = m; 220209139Srpaulo 221209139Srpaulo /* 222209139Srpaulo * Make room for link header. 223209139Srpaulo */ 224209139Srpaulo if (hlen != 0) { 225209139Srpaulo m->m_pkthdr.len -= hlen; 226209139Srpaulo m->m_len -= hlen; 227209139Srpaulo#if BSD >= 199103 228209139Srpaulo m->m_data += hlen; /* XXX */ 229209139Srpaulo#else 230209139Srpaulo m->m_off += hlen; 231209139Srpaulo#endif 232209139Srpaulo error = uiomove(sockp->sa_data, hlen, uio); 233209139Srpaulo if (error) 234209139Srpaulo goto bad; 235209139Srpaulo } 236209139Srpaulo error = uiomove(mtod(m, void *), len - hlen, uio); 237209139Srpaulo if (!error) 238209139Srpaulo return (0); 239209139Srpaulobad: 240209139Srpaulo m_freem(m); 241209139Srpaulo return (error); 242209139Srpaulo} 243209139Srpaulo 244209139Srpaulo/* 245209139Srpaulo * Attach file to the bpf interface, i.e. make d listen on bp. 246209139Srpaulo */ 247209139Srpaulostatic void 248209139Srpaulobpf_attachd(d, bp) 249209139Srpaulo struct bpf_d *d; 250209139Srpaulo struct bpf_if *bp; 251209139Srpaulo{ 252209139Srpaulo /* 253209139Srpaulo * Point d at bp, and add d to the interface's list of listeners. 254209139Srpaulo * Finally, point the driver's bpf cookie at the interface so 255209139Srpaulo * it will divert packets to bpf. 256209139Srpaulo */ 257209139Srpaulo BPFIF_LOCK(bp); 258209139Srpaulo d->bd_bif = bp; 259209139Srpaulo d->bd_next = bp->bif_dlist; 260209139Srpaulo bp->bif_dlist = d; 261209139Srpaulo 262209139Srpaulo *bp->bif_driverp = bp; 263209139Srpaulo BPFIF_UNLOCK(bp); 264209139Srpaulo} 265209139Srpaulo 266209139Srpaulo/* 267209139Srpaulo * Detach a file from its interface. 268209139Srpaulo */ 269209139Srpaulostatic void 270209139Srpaulobpf_detachd(d) 271209139Srpaulo struct bpf_d *d; 272209139Srpaulo{ 273209139Srpaulo int error; 274209139Srpaulo struct bpf_d **p; 275209139Srpaulo struct bpf_if *bp; 276209139Srpaulo 277209139Srpaulo /* XXX locking */ 278209139Srpaulo bp = d->bd_bif; 279209139Srpaulo d->bd_bif = 0; 280209139Srpaulo /* 281209139Srpaulo * Check if this descriptor had requested promiscuous mode. 282209139Srpaulo * If so, turn it off. 283209139Srpaulo */ 284209139Srpaulo if (d->bd_promisc) { 285209139Srpaulo d->bd_promisc = 0; 286209139Srpaulo error = ifpromisc(bp->bif_ifp, 0); 287209139Srpaulo if (error != 0 && error != ENXIO) { 288209139Srpaulo /* 289209139Srpaulo * ENXIO can happen if a pccard is unplugged 290209139Srpaulo * Something is really wrong if we were able to put 291209139Srpaulo * the driver into promiscuous mode, but can't 292209139Srpaulo * take it out. 293209139Srpaulo */ 294209139Srpaulo if_printf(bp->bif_ifp, 295209139Srpaulo "bpf_detach: ifpromisc failed (%d)\n", error); 296209139Srpaulo } 297209139Srpaulo } 298209139Srpaulo /* Remove d from the interface's descriptor list. */ 299209139Srpaulo BPFIF_LOCK(bp); 300209139Srpaulo p = &bp->bif_dlist; 301209139Srpaulo while (*p != d) { 302209139Srpaulo p = &(*p)->bd_next; 303209139Srpaulo if (*p == 0) 304209139Srpaulo panic("bpf_detachd: descriptor not in list"); 305209139Srpaulo } 306209139Srpaulo *p = (*p)->bd_next; 307214501Srpaulo if (bp->bif_dlist == 0) 308214501Srpaulo /* 309209139Srpaulo * Let the driver know that there are no more listeners. 310209139Srpaulo */ 311209139Srpaulo *bp->bif_driverp = 0; 312209139Srpaulo BPFIF_UNLOCK(bp); 313209139Srpaulo} 314209139Srpaulo 315209139Srpaulo/* 316209139Srpaulo * Open ethernet device. Returns ENXIO for illegal minor device number, 317209139Srpaulo * EBUSY if file is open by another process. 318209139Srpaulo */ 319209139Srpaulo/* ARGSUSED */ 320209139Srpaulostatic int 321209139Srpaulobpfopen(dev, flags, fmt, td) 322209139Srpaulo dev_t dev; 323209139Srpaulo int flags; 324209139Srpaulo int fmt; 325209139Srpaulo struct thread *td; 326209139Srpaulo{ 327209139Srpaulo struct bpf_d *d; 328209139Srpaulo 329209139Srpaulo mtx_lock(&bpf_mtx); 330209139Srpaulo d = dev->si_drv1; 331209139Srpaulo /* 332209139Srpaulo * Each minor can be opened by only one process. If the requested 333209139Srpaulo * minor is in use, return EBUSY. 334209139Srpaulo */ 335209139Srpaulo if (d) { 336209139Srpaulo mtx_unlock(&bpf_mtx); 337209139Srpaulo return (EBUSY); 338209139Srpaulo } 339209139Srpaulo dev->si_drv1 = (struct bpf_d *)~0; /* mark device in use */ 340209139Srpaulo mtx_unlock(&bpf_mtx); 341209139Srpaulo 342209139Srpaulo if ((dev->si_flags & SI_NAMED) == 0) 343209139Srpaulo make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600, 344209139Srpaulo "bpf%d", dev2unit(dev)); 345209139Srpaulo MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 346209139Srpaulo dev->si_drv1 = d; 347209139Srpaulo d->bd_bufsize = bpf_bufsize; 348209139Srpaulo d->bd_sig = SIGIO; 349209139Srpaulo d->bd_seesent = 1; 350209139Srpaulo#ifdef MAC 351209139Srpaulo mac_init_bpfdesc(d); 352209139Srpaulo mac_create_bpfdesc(td->td_ucred, d); 353209139Srpaulo#endif 354209139Srpaulo mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF); 355209139Srpaulo callout_init(&d->bd_callout, CALLOUT_MPSAFE); 356209139Srpaulo 357209139Srpaulo return (0); 358209139Srpaulo} 359209139Srpaulo 360209139Srpaulo/* 361209139Srpaulo * Close the descriptor by detaching it from its interface, 362209139Srpaulo * deallocating its buffers, and marking it free. 363209139Srpaulo */ 364209139Srpaulo/* ARGSUSED */ 365209139Srpaulostatic int 366209139Srpaulobpfclose(dev, flags, fmt, td) 367209139Srpaulo dev_t dev; 368209139Srpaulo int flags; 369209139Srpaulo int fmt; 370209139Srpaulo struct thread *td; 371209139Srpaulo{ 372209139Srpaulo struct bpf_d *d = dev->si_drv1; 373209139Srpaulo 374209139Srpaulo BPFD_LOCK(d); 375209139Srpaulo if (d->bd_state == BPF_WAITING) 376209139Srpaulo callout_stop(&d->bd_callout); 377209139Srpaulo d->bd_state = BPF_IDLE; 378209139Srpaulo BPFD_UNLOCK(d); 379209139Srpaulo funsetown(&d->bd_sigio); 380209139Srpaulo mtx_lock(&bpf_mtx); 381209139Srpaulo if (d->bd_bif) 382209139Srpaulo bpf_detachd(d); 383209139Srpaulo mtx_unlock(&bpf_mtx); 384209139Srpaulo#ifdef MAC 385209139Srpaulo mac_destroy_bpfdesc(d); 386209139Srpaulo#endif /* MAC */ 387209139Srpaulo bpf_freed(d); 388209139Srpaulo dev->si_drv1 = 0; 389209139Srpaulo free(d, M_BPF); 390209139Srpaulo 391209139Srpaulo return (0); 392209139Srpaulo} 393209139Srpaulo 394209139Srpaulo 395209139Srpaulo/* 396209139Srpaulo * Rotate the packet buffers in descriptor d. Move the store buffer 397209139Srpaulo * into the hold slot, and the free buffer into the store slot. 398209139Srpaulo * Zero the length of the new store buffer. 399209139Srpaulo */ 400209139Srpaulo#define ROTATE_BUFFERS(d) \ 401209139Srpaulo (d)->bd_hbuf = (d)->bd_sbuf; \ 402209139Srpaulo (d)->bd_hlen = (d)->bd_slen; \ 403209139Srpaulo (d)->bd_sbuf = (d)->bd_fbuf; \ 404209139Srpaulo (d)->bd_slen = 0; \ 405209139Srpaulo (d)->bd_fbuf = 0; 406209139Srpaulo/* 407209139Srpaulo * bpfread - read next chunk of packets from buffers 408209139Srpaulo */ 409209139Srpaulostatic int 410209139Srpaulobpfread(dev, uio, ioflag) 411209139Srpaulo dev_t dev; 412209139Srpaulo struct uio *uio; 413209139Srpaulo int ioflag; 414209139Srpaulo{ 415209139Srpaulo struct bpf_d *d = dev->si_drv1; 416209139Srpaulo int timed_out; 417209139Srpaulo int error; 418209139Srpaulo 419209139Srpaulo /* 420214501Srpaulo * Restrict application to use a buffer the same size as 421209139Srpaulo * as kernel buffers. 422209139Srpaulo */ 423209139Srpaulo if (uio->uio_resid != d->bd_bufsize) 424209139Srpaulo return (EINVAL); 425209139Srpaulo 426209139Srpaulo BPFD_LOCK(d); 427209139Srpaulo if (d->bd_state == BPF_WAITING) 428209139Srpaulo callout_stop(&d->bd_callout); 429209139Srpaulo timed_out = (d->bd_state == BPF_TIMED_OUT); 430209139Srpaulo d->bd_state = BPF_IDLE; 431209139Srpaulo /* 432209139Srpaulo * If the hold buffer is empty, then do a timed sleep, which 433209139Srpaulo * ends when the timeout expires or when enough packets 434209139Srpaulo * have arrived to fill the store buffer. 435209139Srpaulo */ 436209139Srpaulo while (d->bd_hbuf == 0) { 437209139Srpaulo if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { 438209139Srpaulo /* 439209139Srpaulo * A packet(s) either arrived since the previous 440209139Srpaulo * read or arrived while we were asleep. 441209139Srpaulo * Rotate the buffers and return what's here. 442209139Srpaulo */ 443209139Srpaulo ROTATE_BUFFERS(d); 444209139Srpaulo break; 445209139Srpaulo } 446209139Srpaulo 447209139Srpaulo /* 448209139Srpaulo * No data is available, check to see if the bpf device 449209139Srpaulo * is still pointed at a real interface. If not, return 450209139Srpaulo * ENXIO so that the userland process knows to rebind 451209139Srpaulo * it before using it again. 452209139Srpaulo */ 453209139Srpaulo if (d->bd_bif == NULL) { 454209139Srpaulo BPFD_UNLOCK(d); 455209139Srpaulo return (ENXIO); 456209139Srpaulo } 457209139Srpaulo 458209139Srpaulo if (ioflag & IO_NDELAY) { 459209139Srpaulo BPFD_UNLOCK(d); 460209139Srpaulo return (EWOULDBLOCK); 461209139Srpaulo } 462209139Srpaulo error = msleep(d, &d->bd_mtx, PRINET|PCATCH, 463209139Srpaulo "bpf", d->bd_rtout); 464209139Srpaulo if (error == EINTR || error == ERESTART) { 465209139Srpaulo BPFD_UNLOCK(d); 466209139Srpaulo return (error); 467209139Srpaulo } 468209139Srpaulo if (error == EWOULDBLOCK) { 469209139Srpaulo /* 470209139Srpaulo * On a timeout, return what's in the buffer, 471209139Srpaulo * which may be nothing. If there is something 472209139Srpaulo * in the store buffer, we can rotate the buffers. 473209139Srpaulo */ 474209139Srpaulo if (d->bd_hbuf) 475209139Srpaulo /* 476209139Srpaulo * We filled up the buffer in between 477209139Srpaulo * getting the timeout and arriving 478209139Srpaulo * here, so we don't need to rotate. 479209139Srpaulo */ 480209139Srpaulo break; 481209139Srpaulo 482209139Srpaulo if (d->bd_slen == 0) { 483209139Srpaulo BPFD_UNLOCK(d); 484209139Srpaulo return (0); 485209139Srpaulo } 486209139Srpaulo ROTATE_BUFFERS(d); 487209139Srpaulo break; 488209139Srpaulo } 489209139Srpaulo } 490209139Srpaulo /* 491209139Srpaulo * At this point, we know we have something in the hold slot. 492209139Srpaulo */ 493209139Srpaulo BPFD_UNLOCK(d); 494209139Srpaulo 495209139Srpaulo /* 496209139Srpaulo * Move data from hold buffer into user space. 497209139Srpaulo * We know the entire buffer is transferred since 498209139Srpaulo * we checked above that the read buffer is bpf_bufsize bytes. 499209139Srpaulo */ 500209139Srpaulo error = uiomove(d->bd_hbuf, d->bd_hlen, uio); 501209139Srpaulo 502209139Srpaulo BPFD_LOCK(d); 503209139Srpaulo d->bd_fbuf = d->bd_hbuf; 504209139Srpaulo d->bd_hbuf = 0; 505209139Srpaulo d->bd_hlen = 0; 506209139Srpaulo BPFD_UNLOCK(d); 507209139Srpaulo 508209139Srpaulo return (error); 509209139Srpaulo} 510209139Srpaulo 511209139Srpaulo 512209139Srpaulo/* 513209139Srpaulo * If there are processes sleeping on this descriptor, wake them up. 514209139Srpaulo */ 515209139Srpaulostatic __inline void 516209139Srpaulobpf_wakeup(d) 517209139Srpaulo struct bpf_d *d; 518209139Srpaulo{ 519209139Srpaulo if (d->bd_state == BPF_WAITING) { 520209139Srpaulo callout_stop(&d->bd_callout); 521209139Srpaulo d->bd_state = BPF_IDLE; 522209139Srpaulo } 523209139Srpaulo wakeup(d); 524209139Srpaulo if (d->bd_async && d->bd_sig && d->bd_sigio) 525209139Srpaulo pgsigio(&d->bd_sigio, d->bd_sig, 0); 526209139Srpaulo 527209139Srpaulo selwakeuppri(&d->bd_sel, PRINET); 528209139Srpaulo KNOTE(&d->bd_sel.si_note, 0); 529209139Srpaulo} 530209139Srpaulo 531209139Srpaulostatic void 532209139Srpaulobpf_timed_out(arg) 533209139Srpaulo void *arg; 534209139Srpaulo{ 535209139Srpaulo struct bpf_d *d = (struct bpf_d *)arg; 536209139Srpaulo 537209139Srpaulo BPFD_LOCK(d); 538209139Srpaulo if (d->bd_state == BPF_WAITING) { 539209139Srpaulo d->bd_state = BPF_TIMED_OUT; 540209139Srpaulo if (d->bd_slen != 0) 541209139Srpaulo bpf_wakeup(d); 542209139Srpaulo } 543209139Srpaulo BPFD_UNLOCK(d); 544209139Srpaulo} 545209139Srpaulo 546209139Srpaulostatic int 547209139Srpaulobpfwrite(dev, uio, ioflag) 548209139Srpaulo dev_t dev; 549209139Srpaulo struct uio *uio; 550209139Srpaulo int ioflag; 551209139Srpaulo{ 552209139Srpaulo struct bpf_d *d = dev->si_drv1; 553209139Srpaulo struct ifnet *ifp; 554209139Srpaulo struct mbuf *m; 555209139Srpaulo int error; 556209139Srpaulo struct sockaddr dst; 557209139Srpaulo int datlen; 558209139Srpaulo 559209139Srpaulo if (d->bd_bif == 0) 560209139Srpaulo return (ENXIO); 561209139Srpaulo 562209139Srpaulo ifp = d->bd_bif->bif_ifp; 563209139Srpaulo 564209139Srpaulo if (uio->uio_resid == 0) 565209139Srpaulo return (0); 566209139Srpaulo 567209139Srpaulo bzero(&dst, sizeof(dst)); 568209139Srpaulo error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen); 569209139Srpaulo if (error) 570209139Srpaulo return (error); 571209139Srpaulo 572209139Srpaulo if (datlen > ifp->if_mtu) 573209139Srpaulo return (EMSGSIZE); 574209139Srpaulo 575209139Srpaulo if (d->bd_hdrcmplt) 576209139Srpaulo dst.sa_family = pseudo_AF_HDRCMPLT; 577209139Srpaulo 578209139Srpaulo#ifdef MAC 579209139Srpaulo BPFD_LOCK(d); 580209139Srpaulo mac_create_mbuf_from_bpfdesc(d, m); 581209139Srpaulo BPFD_UNLOCK(d); 582209139Srpaulo#endif 583209139Srpaulo NET_LOCK_GIANT(); 584209139Srpaulo error = (*ifp->if_output)(ifp, m, &dst, (struct rtentry *)0); 585209139Srpaulo NET_UNLOCK_GIANT(); 586209139Srpaulo /* 587209139Srpaulo * The driver frees the mbuf. 588209139Srpaulo */ 589209139Srpaulo return (error); 590209139Srpaulo} 591209139Srpaulo 592209139Srpaulo/* 593209139Srpaulo * Reset a descriptor by flushing its packet buffer and clearing the 594209139Srpaulo * receive and drop counts. 595209139Srpaulo */ 596209139Srpaulostatic void 597209139Srpauloreset_d(d) 598209139Srpaulo struct bpf_d *d; 599209139Srpaulo{ 600209139Srpaulo 601209139Srpaulo mtx_assert(&d->bd_mtx, MA_OWNED); 602209139Srpaulo if (d->bd_hbuf) { 603209139Srpaulo /* Free the hold buffer. */ 604209139Srpaulo d->bd_fbuf = d->bd_hbuf; 605209139Srpaulo d->bd_hbuf = 0; 606209139Srpaulo } 607209139Srpaulo d->bd_slen = 0; 608209139Srpaulo d->bd_hlen = 0; 609209139Srpaulo d->bd_rcount = 0; 610209139Srpaulo d->bd_dcount = 0; 611209139Srpaulo} 612209139Srpaulo 613209139Srpaulo/* 614209139Srpaulo * FIONREAD Check for read packet available. 615209139Srpaulo * SIOCGIFADDR Get interface address - convenient hook to driver. 616209139Srpaulo * BIOCGBLEN Get buffer len [for read()]. 617209139Srpaulo * BIOCSETF Set ethernet read filter. 618209139Srpaulo * BIOCFLUSH Flush read packet buffer. 619209139Srpaulo * BIOCPROMISC Put interface into promiscuous mode. 620209139Srpaulo * BIOCGDLT Get link layer type. 621209139Srpaulo * BIOCGETIF Get interface name. 622209139Srpaulo * BIOCSETIF Set interface. 623209139Srpaulo * BIOCSRTIMEOUT Set read timeout. 624209139Srpaulo * BIOCGRTIMEOUT Get read timeout. 625209139Srpaulo * BIOCGSTATS Get packet stats. 626209139Srpaulo * BIOCIMMEDIATE Set immediate mode. 627209139Srpaulo * BIOCVERSION Get filter language version. 628209139Srpaulo * BIOCGHDRCMPLT Get "header already complete" flag 629209139Srpaulo * BIOCSHDRCMPLT Set "header already complete" flag 630209139Srpaulo * BIOCGSEESENT Get "see packets sent" flag 631209139Srpaulo * BIOCSSEESENT Set "see packets sent" flag 632209139Srpaulo */ 633209139Srpaulo/* ARGSUSED */ 634209139Srpaulostatic int 635209139Srpaulobpfioctl(dev, cmd, addr, flags, td) 636209139Srpaulo dev_t dev; 637209139Srpaulo u_long cmd; 638209139Srpaulo caddr_t addr; 639209139Srpaulo int flags; 640209139Srpaulo struct thread *td; 641209139Srpaulo{ 642209139Srpaulo struct bpf_d *d = dev->si_drv1; 643252190Srpaulo int error = 0; 644209139Srpaulo 645209139Srpaulo BPFD_LOCK(d); 646209139Srpaulo if (d->bd_state == BPF_WAITING) 647209139Srpaulo callout_stop(&d->bd_callout); 648209139Srpaulo d->bd_state = BPF_IDLE; 649209139Srpaulo BPFD_UNLOCK(d); 650209139Srpaulo 651209139Srpaulo switch (cmd) { 652209139Srpaulo 653209139Srpaulo default: 654209139Srpaulo error = EINVAL; 655209139Srpaulo break; 656209139Srpaulo 657209139Srpaulo /* 658209139Srpaulo * Check for read packet available. 659209139Srpaulo */ 660209139Srpaulo case FIONREAD: 661209139Srpaulo { 662209139Srpaulo int n; 663209139Srpaulo 664209139Srpaulo BPFD_LOCK(d); 665209139Srpaulo n = d->bd_slen; 666209139Srpaulo if (d->bd_hbuf) 667209139Srpaulo n += d->bd_hlen; 668252190Srpaulo BPFD_UNLOCK(d); 669209139Srpaulo 670209139Srpaulo *(int *)addr = n; 671209139Srpaulo break; 672209139Srpaulo } 673209139Srpaulo 674209139Srpaulo case SIOCGIFADDR: 675209139Srpaulo { 676209139Srpaulo struct ifnet *ifp; 677209139Srpaulo 678209139Srpaulo if (d->bd_bif == 0) 679209139Srpaulo error = EINVAL; 680209139Srpaulo else { 681209139Srpaulo ifp = d->bd_bif->bif_ifp; 682209139Srpaulo error = (*ifp->if_ioctl)(ifp, cmd, addr); 683209139Srpaulo } 684209139Srpaulo break; 685209139Srpaulo } 686209139Srpaulo 687209139Srpaulo /* 688209139Srpaulo * Get buffer len [for read()]. 689209139Srpaulo */ 690209139Srpaulo case BIOCGBLEN: 691209139Srpaulo *(u_int *)addr = d->bd_bufsize; 692209139Srpaulo break; 693209139Srpaulo 694209139Srpaulo /* 695209139Srpaulo * Set buffer length. 696209139Srpaulo */ 697209139Srpaulo case BIOCSBLEN: 698209139Srpaulo if (d->bd_bif != 0) 699209139Srpaulo error = EINVAL; 700209139Srpaulo else { 701209139Srpaulo u_int size = *(u_int *)addr; 702209139Srpaulo 703209139Srpaulo if (size > bpf_maxbufsize) 704209139Srpaulo *(u_int *)addr = size = bpf_maxbufsize; 705209139Srpaulo else if (size < BPF_MINBUFSIZE) 706209139Srpaulo *(u_int *)addr = size = BPF_MINBUFSIZE; 707209139Srpaulo d->bd_bufsize = size; 708209139Srpaulo } 709209139Srpaulo break; 710209139Srpaulo 711209139Srpaulo /* 712209139Srpaulo * Set link layer read filter. 713209139Srpaulo */ 714209139Srpaulo case BIOCSETF: 715209139Srpaulo error = bpf_setf(d, (struct bpf_program *)addr); 716209139Srpaulo break; 717209139Srpaulo 718209139Srpaulo /* 719209139Srpaulo * Flush read packet buffer. 720214501Srpaulo */ 721214501Srpaulo case BIOCFLUSH: 722214501Srpaulo BPFD_LOCK(d); 723214501Srpaulo reset_d(d); 724214501Srpaulo BPFD_UNLOCK(d); 725214501Srpaulo break; 726214501Srpaulo 727214501Srpaulo /* 728214501Srpaulo * Put interface into promiscuous mode. 729214501Srpaulo */ 730214501Srpaulo case BIOCPROMISC: 731214501Srpaulo if (d->bd_bif == 0) { 732214501Srpaulo /* 733209139Srpaulo * No interface attached yet. 734209139Srpaulo */ 735209139Srpaulo error = EINVAL; 736214501Srpaulo break; 737209139Srpaulo } 738209139Srpaulo if (d->bd_promisc == 0) { 739209139Srpaulo mtx_lock(&Giant); 740209139Srpaulo error = ifpromisc(d->bd_bif->bif_ifp, 1); 741 mtx_unlock(&Giant); 742 if (error == 0) 743 d->bd_promisc = 1; 744 } 745 break; 746 747 /* 748 * Get current data link type. 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 * Get a list of supported data link types. 759 */ 760 case BIOCGDLTLIST: 761 if (d->bd_bif == 0) 762 error = EINVAL; 763 else 764 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 765 break; 766 767 /* 768 * Set data link type. 769 */ 770 case BIOCSDLT: 771 if (d->bd_bif == 0) 772 error = EINVAL; 773 else 774 error = bpf_setdlt(d, *(u_int *)addr); 775 break; 776 777 /* 778 * Get interface name. 779 */ 780 case BIOCGETIF: 781 if (d->bd_bif == 0) 782 error = EINVAL; 783 else { 784 struct ifnet *const ifp = d->bd_bif->bif_ifp; 785 struct ifreq *const ifr = (struct ifreq *)addr; 786 787 strlcpy(ifr->ifr_name, ifp->if_xname, 788 sizeof(ifr->ifr_name)); 789 } 790 break; 791 792 /* 793 * Set interface. 794 */ 795 case BIOCSETIF: 796 error = bpf_setif(d, (struct ifreq *)addr); 797 break; 798 799 /* 800 * Set read timeout. 801 */ 802 case BIOCSRTIMEOUT: 803 { 804 struct timeval *tv = (struct timeval *)addr; 805 806 /* 807 * Subtract 1 tick from tvtohz() since this isn't 808 * a one-shot timer. 809 */ 810 if ((error = itimerfix(tv)) == 0) 811 d->bd_rtout = tvtohz(tv) - 1; 812 break; 813 } 814 815 /* 816 * Get read timeout. 817 */ 818 case BIOCGRTIMEOUT: 819 { 820 struct timeval *tv = (struct timeval *)addr; 821 822 tv->tv_sec = d->bd_rtout / hz; 823 tv->tv_usec = (d->bd_rtout % hz) * tick; 824 break; 825 } 826 827 /* 828 * Get packet stats. 829 */ 830 case BIOCGSTATS: 831 { 832 struct bpf_stat *bs = (struct bpf_stat *)addr; 833 834 bs->bs_recv = d->bd_rcount; 835 bs->bs_drop = d->bd_dcount; 836 break; 837 } 838 839 /* 840 * Set immediate mode. 841 */ 842 case BIOCIMMEDIATE: 843 d->bd_immediate = *(u_int *)addr; 844 break; 845 846 case BIOCVERSION: 847 { 848 struct bpf_version *bv = (struct bpf_version *)addr; 849 850 bv->bv_major = BPF_MAJOR_VERSION; 851 bv->bv_minor = BPF_MINOR_VERSION; 852 break; 853 } 854 855 /* 856 * Get "header already complete" flag 857 */ 858 case BIOCGHDRCMPLT: 859 *(u_int *)addr = d->bd_hdrcmplt; 860 break; 861 862 /* 863 * Set "header already complete" flag 864 */ 865 case BIOCSHDRCMPLT: 866 d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; 867 break; 868 869 /* 870 * Get "see sent packets" flag 871 */ 872 case BIOCGSEESENT: 873 *(u_int *)addr = d->bd_seesent; 874 break; 875 876 /* 877 * Set "see sent packets" flag 878 */ 879 case BIOCSSEESENT: 880 d->bd_seesent = *(u_int *)addr; 881 break; 882 883 case FIONBIO: /* Non-blocking I/O */ 884 break; 885 886 case FIOASYNC: /* Send signal on receive packets */ 887 d->bd_async = *(int *)addr; 888 break; 889 890 case FIOSETOWN: 891 error = fsetown(*(int *)addr, &d->bd_sigio); 892 break; 893 894 case FIOGETOWN: 895 *(int *)addr = fgetown(&d->bd_sigio); 896 break; 897 898 /* This is deprecated, FIOSETOWN should be used instead. */ 899 case TIOCSPGRP: 900 error = fsetown(-(*(int *)addr), &d->bd_sigio); 901 break; 902 903 /* This is deprecated, FIOGETOWN should be used instead. */ 904 case TIOCGPGRP: 905 *(int *)addr = -fgetown(&d->bd_sigio); 906 break; 907 908 case BIOCSRSIG: /* Set receive signal */ 909 { 910 u_int sig; 911 912 sig = *(u_int *)addr; 913 914 if (sig >= NSIG) 915 error = EINVAL; 916 else 917 d->bd_sig = sig; 918 break; 919 } 920 case BIOCGRSIG: 921 *(u_int *)addr = d->bd_sig; 922 break; 923 } 924 return (error); 925} 926 927/* 928 * Set d's packet filter program to fp. If this file already has a filter, 929 * free it and replace it. Returns EINVAL for bogus requests. 930 */ 931static int 932bpf_setf(d, fp) 933 struct bpf_d *d; 934 struct bpf_program *fp; 935{ 936 struct bpf_insn *fcode, *old; 937 u_int flen, size; 938 939 old = d->bd_filter; 940 if (fp->bf_insns == 0) { 941 if (fp->bf_len != 0) 942 return (EINVAL); 943 BPFD_LOCK(d); 944 d->bd_filter = 0; 945 reset_d(d); 946 BPFD_UNLOCK(d); 947 if (old != 0) 948 free((caddr_t)old, M_BPF); 949 return (0); 950 } 951 flen = fp->bf_len; 952 if (flen > BPF_MAXINSNS) 953 return (EINVAL); 954 955 size = flen * sizeof(*fp->bf_insns); 956 fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); 957 if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && 958 bpf_validate(fcode, (int)flen)) { 959 BPFD_LOCK(d); 960 d->bd_filter = fcode; 961 reset_d(d); 962 BPFD_UNLOCK(d); 963 if (old != 0) 964 free((caddr_t)old, M_BPF); 965 966 return (0); 967 } 968 free((caddr_t)fcode, M_BPF); 969 return (EINVAL); 970} 971 972/* 973 * Detach a file from its current interface (if attached at all) and attach 974 * to the interface indicated by the name stored in ifr. 975 * Return an errno or 0. 976 */ 977static int 978bpf_setif(d, ifr) 979 struct bpf_d *d; 980 struct ifreq *ifr; 981{ 982 struct bpf_if *bp; 983 int error; 984 struct ifnet *theywant; 985 986 theywant = ifunit(ifr->ifr_name); 987 if (theywant == 0) 988 return ENXIO; 989 990 /* 991 * Look through attached interfaces for the named one. 992 */ 993 mtx_lock(&bpf_mtx); 994 for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) { 995 struct ifnet *ifp = bp->bif_ifp; 996 997 if (ifp == 0 || ifp != theywant) 998 continue; 999 /* skip additional entry */ 1000 if (bp->bif_driverp != (struct bpf_if **)&ifp->if_bpf) 1001 continue; 1002 1003 mtx_unlock(&bpf_mtx); 1004 /* 1005 * We found the requested interface. 1006 * If it's not up, return an error. 1007 * Allocate the packet buffers if we need to. 1008 * If we're already attached to requested interface, 1009 * just flush the buffer. 1010 */ 1011 if ((ifp->if_flags & IFF_UP) == 0) 1012 return (ENETDOWN); 1013 1014 if (d->bd_sbuf == 0) { 1015 error = bpf_allocbufs(d); 1016 if (error != 0) 1017 return (error); 1018 } 1019 if (bp != d->bd_bif) { 1020 if (d->bd_bif) 1021 /* 1022 * Detach if attached to something else. 1023 */ 1024 bpf_detachd(d); 1025 1026 bpf_attachd(d, bp); 1027 } 1028 BPFD_LOCK(d); 1029 reset_d(d); 1030 BPFD_UNLOCK(d); 1031 return (0); 1032 } 1033 mtx_unlock(&bpf_mtx); 1034 /* Not found. */ 1035 return (ENXIO); 1036} 1037 1038/* 1039 * Support for select() and poll() system calls 1040 * 1041 * Return true iff the specific operation will not block indefinitely. 1042 * Otherwise, return false but make a note that a selwakeup() must be done. 1043 */ 1044static int 1045bpfpoll(dev, events, td) 1046 dev_t dev; 1047 int events; 1048 struct thread *td; 1049{ 1050 struct bpf_d *d; 1051 int revents; 1052 1053 d = dev->si_drv1; 1054 if (d->bd_bif == NULL) 1055 return (ENXIO); 1056 1057 revents = events & (POLLOUT | POLLWRNORM); 1058 BPFD_LOCK(d); 1059 if (events & (POLLIN | POLLRDNORM)) { 1060 if (bpf_ready(d)) 1061 revents |= events & (POLLIN | POLLRDNORM); 1062 else { 1063 selrecord(td, &d->bd_sel); 1064 /* Start the read timeout if necessary. */ 1065 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1066 callout_reset(&d->bd_callout, d->bd_rtout, 1067 bpf_timed_out, d); 1068 d->bd_state = BPF_WAITING; 1069 } 1070 } 1071 } 1072 BPFD_UNLOCK(d); 1073 return (revents); 1074} 1075 1076/* 1077 * Support for kevent() system call. Register EVFILT_READ filters and 1078 * reject all others. 1079 */ 1080int 1081bpfkqfilter(dev, kn) 1082 dev_t dev; 1083 struct knote *kn; 1084{ 1085 struct bpf_d *d = (struct bpf_d *)dev->si_drv1; 1086 1087 if (kn->kn_filter != EVFILT_READ) 1088 return (1); 1089 1090 kn->kn_fop = &bpfread_filtops; 1091 kn->kn_hook = d; 1092 BPFD_LOCK(d); 1093 SLIST_INSERT_HEAD(&d->bd_sel.si_note, kn, kn_selnext); 1094 BPFD_UNLOCK(d); 1095 1096 return (0); 1097} 1098 1099static void 1100filt_bpfdetach(kn) 1101 struct knote *kn; 1102{ 1103 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1104 1105 BPFD_LOCK(d); 1106 SLIST_REMOVE(&d->bd_sel.si_note, kn, knote, kn_selnext); 1107 BPFD_UNLOCK(d); 1108} 1109 1110static int 1111filt_bpfread(kn, hint) 1112 struct knote *kn; 1113 long hint; 1114{ 1115 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 1116 int ready; 1117 1118 BPFD_LOCK(d); 1119 ready = bpf_ready(d); 1120 if (ready) { 1121 kn->kn_data = d->bd_slen; 1122 if (d->bd_hbuf) 1123 kn->kn_data += d->bd_hlen; 1124 } 1125 else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 1126 callout_reset(&d->bd_callout, d->bd_rtout, 1127 bpf_timed_out, d); 1128 d->bd_state = BPF_WAITING; 1129 } 1130 BPFD_UNLOCK(d); 1131 1132 return (ready); 1133} 1134 1135/* 1136 * Incoming linkage from device drivers. Process the packet pkt, of length 1137 * pktlen, which is stored in a contiguous buffer. The packet is parsed 1138 * by each process' filter, and if accepted, stashed into the corresponding 1139 * buffer. 1140 */ 1141void 1142bpf_tap(bp, pkt, pktlen) 1143 struct bpf_if *bp; 1144 u_char *pkt; 1145 u_int pktlen; 1146{ 1147 struct bpf_d *d; 1148 u_int slen; 1149 1150 BPFIF_LOCK(bp); 1151 for (d = bp->bif_dlist; d != 0; d = d->bd_next) { 1152 BPFD_LOCK(d); 1153 ++d->bd_rcount; 1154 slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen); 1155 if (slen != 0) { 1156#ifdef MAC 1157 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1158#endif 1159 catchpacket(d, pkt, pktlen, slen, bcopy); 1160 } 1161 BPFD_UNLOCK(d); 1162 } 1163 BPFIF_UNLOCK(bp); 1164} 1165 1166/* 1167 * Copy data from an mbuf chain into a buffer. This code is derived 1168 * from m_copydata in sys/uipc_mbuf.c. 1169 */ 1170static void 1171bpf_mcopy(src_arg, dst_arg, len) 1172 const void *src_arg; 1173 void *dst_arg; 1174 size_t len; 1175{ 1176 const struct mbuf *m; 1177 u_int count; 1178 u_char *dst; 1179 1180 m = src_arg; 1181 dst = dst_arg; 1182 while (len > 0) { 1183 if (m == 0) 1184 panic("bpf_mcopy"); 1185 count = min(m->m_len, len); 1186 bcopy(mtod(m, void *), dst, count); 1187 m = m->m_next; 1188 dst += count; 1189 len -= count; 1190 } 1191} 1192 1193/* 1194 * Incoming linkage from device drivers, when packet is in an mbuf chain. 1195 */ 1196void 1197bpf_mtap(bp, m) 1198 struct bpf_if *bp; 1199 struct mbuf *m; 1200{ 1201 struct bpf_d *d; 1202 u_int pktlen, slen; 1203 1204 pktlen = m_length(m, NULL); 1205 if (pktlen == m->m_len) { 1206 bpf_tap(bp, mtod(m, u_char *), pktlen); 1207 return; 1208 } 1209 1210 BPFIF_LOCK(bp); 1211 for (d = bp->bif_dlist; d != 0; d = d->bd_next) { 1212 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1213 continue; 1214 BPFD_LOCK(d); 1215 ++d->bd_rcount; 1216 slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0); 1217 if (slen != 0) 1218#ifdef MAC 1219 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1220#endif 1221 catchpacket(d, (u_char *)m, pktlen, slen, 1222 bpf_mcopy); 1223 BPFD_UNLOCK(d); 1224 } 1225 BPFIF_UNLOCK(bp); 1226} 1227 1228/* 1229 * Incoming linkage from device drivers, when packet is in 1230 * an mbuf chain and to be prepended by a contiguous header. 1231 */ 1232void 1233bpf_mtap2(bp, data, dlen, m) 1234 struct bpf_if *bp; 1235 void *data; 1236 u_int dlen; 1237 struct mbuf *m; 1238{ 1239 struct mbuf mb; 1240 struct bpf_d *d; 1241 u_int pktlen, slen; 1242 1243 pktlen = m_length(m, NULL); 1244 /* 1245 * Craft on-stack mbuf suitable for passing to bpf_filter. 1246 * Note that we cut corners here; we only setup what's 1247 * absolutely needed--this mbuf should never go anywhere else. 1248 */ 1249 mb.m_next = m; 1250 mb.m_data = data; 1251 mb.m_len = dlen; 1252 pktlen += dlen; 1253 1254 BPFIF_LOCK(bp); 1255 for (d = bp->bif_dlist; d != 0; d = d->bd_next) { 1256 if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL)) 1257 continue; 1258 BPFD_LOCK(d); 1259 ++d->bd_rcount; 1260 slen = bpf_filter(d->bd_filter, (u_char *)&mb, pktlen, 0); 1261 if (slen != 0) 1262#ifdef MAC 1263 if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0) 1264#endif 1265 catchpacket(d, (u_char *)&mb, pktlen, slen, 1266 bpf_mcopy); 1267 BPFD_UNLOCK(d); 1268 } 1269 BPFIF_UNLOCK(bp); 1270} 1271 1272/* 1273 * Move the packet data from interface memory (pkt) into the 1274 * store buffer. "cpfn" is the routine called to do the actual data 1275 * transfer. bcopy is passed in to copy contiguous chunks, while 1276 * bpf_mcopy is passed in to copy mbuf chains. In the latter case, 1277 * pkt is really an mbuf. 1278 */ 1279static void 1280catchpacket(d, pkt, pktlen, snaplen, cpfn) 1281 struct bpf_d *d; 1282 u_char *pkt; 1283 u_int pktlen, snaplen; 1284 void (*cpfn)(const void *, void *, size_t); 1285{ 1286 struct bpf_hdr *hp; 1287 int totlen, curlen; 1288 int hdrlen = d->bd_bif->bif_hdrlen; 1289 1290 /* 1291 * Figure out how many bytes to move. If the packet is 1292 * greater or equal to the snapshot length, transfer that 1293 * much. Otherwise, transfer the whole packet (unless 1294 * we hit the buffer size limit). 1295 */ 1296 totlen = hdrlen + min(snaplen, pktlen); 1297 if (totlen > d->bd_bufsize) 1298 totlen = d->bd_bufsize; 1299 1300 /* 1301 * Round up the end of the previous packet to the next longword. 1302 */ 1303 curlen = BPF_WORDALIGN(d->bd_slen); 1304 if (curlen + totlen > d->bd_bufsize) { 1305 /* 1306 * This packet will overflow the storage buffer. 1307 * Rotate the buffers if we can, then wakeup any 1308 * pending reads. 1309 */ 1310 if (d->bd_fbuf == 0) { 1311 /* 1312 * We haven't completed the previous read yet, 1313 * so drop the packet. 1314 */ 1315 ++d->bd_dcount; 1316 return; 1317 } 1318 ROTATE_BUFFERS(d); 1319 bpf_wakeup(d); 1320 curlen = 0; 1321 } 1322 else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) 1323 /* 1324 * Immediate mode is set, or the read timeout has 1325 * already expired during a select call. A packet 1326 * arrived, so the reader should be woken up. 1327 */ 1328 bpf_wakeup(d); 1329 1330 /* 1331 * Append the bpf header. 1332 */ 1333 hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); 1334 microtime(&hp->bh_tstamp); 1335 hp->bh_datalen = pktlen; 1336 hp->bh_hdrlen = hdrlen; 1337 /* 1338 * Copy the packet data into the store buffer and update its length. 1339 */ 1340 (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); 1341 d->bd_slen = curlen + totlen; 1342} 1343 1344/* 1345 * Initialize all nonzero fields of a descriptor. 1346 */ 1347static int 1348bpf_allocbufs(d) 1349 struct bpf_d *d; 1350{ 1351 d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1352 if (d->bd_fbuf == 0) 1353 return (ENOBUFS); 1354 1355 d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); 1356 if (d->bd_sbuf == 0) { 1357 free(d->bd_fbuf, M_BPF); 1358 return (ENOBUFS); 1359 } 1360 d->bd_slen = 0; 1361 d->bd_hlen = 0; 1362 return (0); 1363} 1364 1365/* 1366 * Free buffers currently in use by a descriptor. 1367 * Called on close. 1368 */ 1369static void 1370bpf_freed(d) 1371 struct bpf_d *d; 1372{ 1373 /* 1374 * We don't need to lock out interrupts since this descriptor has 1375 * been detached from its interface and it yet hasn't been marked 1376 * free. 1377 */ 1378 if (d->bd_sbuf != 0) { 1379 free(d->bd_sbuf, M_BPF); 1380 if (d->bd_hbuf != 0) 1381 free(d->bd_hbuf, M_BPF); 1382 if (d->bd_fbuf != 0) 1383 free(d->bd_fbuf, M_BPF); 1384 } 1385 if (d->bd_filter) 1386 free((caddr_t)d->bd_filter, M_BPF); 1387 mtx_destroy(&d->bd_mtx); 1388} 1389 1390/* 1391 * Attach an interface to bpf. dlt is the link layer type; hdrlen is the 1392 * fixed size of the link header (variable length headers not yet supported). 1393 */ 1394void 1395bpfattach(ifp, dlt, hdrlen) 1396 struct ifnet *ifp; 1397 u_int dlt, hdrlen; 1398{ 1399 1400 bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); 1401} 1402 1403/* 1404 * Attach an interface to bpf. ifp is a pointer to the structure 1405 * defining the interface to be attached, dlt is the link layer type, 1406 * and hdrlen is the fixed size of the link header (variable length 1407 * headers are not yet supporrted). 1408 */ 1409void 1410bpfattach2(ifp, dlt, hdrlen, driverp) 1411 struct ifnet *ifp; 1412 u_int dlt, hdrlen; 1413 struct bpf_if **driverp; 1414{ 1415 struct bpf_if *bp; 1416 bp = (struct bpf_if *)malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); 1417 if (bp == 0) 1418 panic("bpfattach"); 1419 1420 bp->bif_dlist = 0; 1421 bp->bif_driverp = driverp; 1422 bp->bif_ifp = ifp; 1423 bp->bif_dlt = dlt; 1424 mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); 1425 1426 mtx_lock(&bpf_mtx); 1427 bp->bif_next = bpf_iflist; 1428 bpf_iflist = bp; 1429 mtx_unlock(&bpf_mtx); 1430 1431 *bp->bif_driverp = 0; 1432 1433 /* 1434 * Compute the length of the bpf header. This is not necessarily 1435 * equal to SIZEOF_BPF_HDR because we want to insert spacing such 1436 * that the network layer header begins on a longword boundary (for 1437 * performance reasons and to alleviate alignment restrictions). 1438 */ 1439 bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; 1440 1441 if (bootverbose) 1442 if_printf(ifp, "bpf attached\n"); 1443} 1444 1445/* 1446 * Detach bpf from an interface. This involves detaching each descriptor 1447 * associated with the interface, and leaving bd_bif NULL. Notify each 1448 * descriptor as it's detached so that any sleepers wake up and get 1449 * ENXIO. 1450 */ 1451void 1452bpfdetach(ifp) 1453 struct ifnet *ifp; 1454{ 1455 struct bpf_if *bp, *bp_prev; 1456 struct bpf_d *d; 1457 1458 /* Locate BPF interface information */ 1459 bp_prev = NULL; 1460 1461 mtx_lock(&bpf_mtx); 1462 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1463 if (ifp == bp->bif_ifp) 1464 break; 1465 bp_prev = bp; 1466 } 1467 1468 /* Interface wasn't attached */ 1469 if ((bp == NULL) || (bp->bif_ifp == NULL)) { 1470 mtx_unlock(&bpf_mtx); 1471 printf("bpfdetach: %s was not attached\n", ifp->if_xname); 1472 return; 1473 } 1474 1475 if (bp_prev) { 1476 bp_prev->bif_next = bp->bif_next; 1477 } else { 1478 bpf_iflist = bp->bif_next; 1479 } 1480 mtx_unlock(&bpf_mtx); 1481 1482 while ((d = bp->bif_dlist) != NULL) { 1483 bpf_detachd(d); 1484 BPFD_LOCK(d); 1485 bpf_wakeup(d); 1486 BPFD_UNLOCK(d); 1487 } 1488 1489 mtx_destroy(&bp->bif_mtx); 1490 free(bp, M_BPF); 1491} 1492 1493/* 1494 * Get a list of available data link type of the interface. 1495 */ 1496static int 1497bpf_getdltlist(d, bfl) 1498 struct bpf_d *d; 1499 struct bpf_dltlist *bfl; 1500{ 1501 int n, error; 1502 struct ifnet *ifp; 1503 struct bpf_if *bp; 1504 1505 ifp = d->bd_bif->bif_ifp; 1506 n = 0; 1507 error = 0; 1508 mtx_lock(&bpf_mtx); 1509 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1510 if (bp->bif_ifp != ifp) 1511 continue; 1512 if (bfl->bfl_list != NULL) { 1513 if (n >= bfl->bfl_len) { 1514 mtx_unlock(&bpf_mtx); 1515 return (ENOMEM); 1516 } 1517 error = copyout(&bp->bif_dlt, 1518 bfl->bfl_list + n, sizeof(u_int)); 1519 } 1520 n++; 1521 } 1522 mtx_unlock(&bpf_mtx); 1523 bfl->bfl_len = n; 1524 return (error); 1525} 1526 1527/* 1528 * Set the data link type of a BPF instance. 1529 */ 1530static int 1531bpf_setdlt(d, dlt) 1532 struct bpf_d *d; 1533 u_int dlt; 1534{ 1535 int error, opromisc; 1536 struct ifnet *ifp; 1537 struct bpf_if *bp; 1538 1539 if (d->bd_bif->bif_dlt == dlt) 1540 return (0); 1541 ifp = d->bd_bif->bif_ifp; 1542 mtx_lock(&bpf_mtx); 1543 for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { 1544 if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) 1545 break; 1546 } 1547 mtx_unlock(&bpf_mtx); 1548 if (bp != NULL) { 1549 BPFD_LOCK(d); 1550 opromisc = d->bd_promisc; 1551 bpf_detachd(d); 1552 bpf_attachd(d, bp); 1553 reset_d(d); 1554 BPFD_UNLOCK(d); 1555 if (opromisc) { 1556 error = ifpromisc(bp->bif_ifp, 1); 1557 if (error) 1558 if_printf(bp->bif_ifp, 1559 "bpf_setdlt: ifpromisc failed (%d)\n", 1560 error); 1561 else 1562 d->bd_promisc = 1; 1563 } 1564 } 1565 return (bp == NULL ? EINVAL : 0); 1566} 1567 1568static void bpf_drvinit(void *unused); 1569 1570static void bpf_clone(void *arg, char *name, int namelen, dev_t *dev); 1571 1572static void 1573bpf_clone(arg, name, namelen, dev) 1574 void *arg; 1575 char *name; 1576 int namelen; 1577 dev_t *dev; 1578{ 1579 int u; 1580 1581 if (*dev != NODEV) 1582 return; 1583 if (dev_stdclone(name, NULL, "bpf", &u) != 1) 1584 return; 1585 *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, 1586 "bpf%d", u); 1587 (*dev)->si_flags |= SI_CHEAPCLONE; 1588 return; 1589} 1590 1591static void 1592bpf_drvinit(unused) 1593 void *unused; 1594{ 1595 1596 mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); 1597 EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); 1598} 1599 1600SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL) 1601 1602#else /* !DEV_BPF && !NETGRAPH_BPF */ 1603/* 1604 * NOP stubs to allow bpf-using drivers to load and function. 1605 * 1606 * A 'better' implementation would allow the core bpf functionality 1607 * to be loaded at runtime. 1608 */ 1609 1610void 1611bpf_tap(bp, pkt, pktlen) 1612 struct bpf_if *bp; 1613 u_char *pkt; 1614 u_int pktlen; 1615{ 1616} 1617 1618void 1619bpf_mtap(bp, m) 1620 struct bpf_if *bp; 1621 struct mbuf *m; 1622{ 1623} 1624 1625void 1626bpf_mtap2(bp, d, l, m) 1627 struct bpf_if *bp; 1628 void *d; 1629 u_int l; 1630 struct mbuf *m; 1631{ 1632} 1633 1634void 1635bpfattach(ifp, dlt, hdrlen) 1636 struct ifnet *ifp; 1637 u_int dlt, hdrlen; 1638{ 1639} 1640 1641void 1642bpfattach2(ifp, dlt, hdrlen, driverp) 1643 struct ifnet *ifp; 1644 u_int dlt, hdrlen; 1645 struct bpf_if **driverp; 1646{ 1647} 1648 1649void 1650bpfdetach(ifp) 1651 struct ifnet *ifp; 1652{ 1653} 1654 1655u_int 1656bpf_filter(pc, p, wirelen, buflen) 1657 const struct bpf_insn *pc; 1658 u_char *p; 1659 u_int wirelen; 1660 u_int buflen; 1661{ 1662 return -1; /* "no filter" behaviour */ 1663} 1664 1665int 1666bpf_validate(f, len) 1667 const struct bpf_insn *f; 1668 int len; 1669{ 1670 return 0; /* false */ 1671} 1672 1673#endif /* !DEV_BPF && !NETGRAPH_BPF */ 1674