/*- * Copyright (c) 1990, 1991, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from the Stanford/CMU enet packet filter, * (net/enet.c) distributed as part of 4.3BSD, and code contributed * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence * Berkeley Laboratory. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)bpf.c 8.4 (Berkeley) 1/9/95 */ #include __FBSDID("$FreeBSD$"); #include "opt_bpf.h" #include "opt_compat.h" #include "opt_netgraph.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define BPF_INTERNAL #include #include #ifdef BPF_JITTER #include #endif #include #include #include #include #include #include #include #include #include MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); #if defined(DEV_BPF) || defined(NETGRAPH_BPF) #define PRINET 26 /* interruptible */ #define SIZEOF_BPF_HDR(type) \ (offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen)) #ifdef COMPAT_FREEBSD32 #include #include #define BPF_ALIGNMENT32 sizeof(int32_t) #define BPF_WORDALIGN32(x) (((x)+(BPF_ALIGNMENT32-1))&~(BPF_ALIGNMENT32-1)) #ifndef BURN_BRIDGES /* * 32-bit version of structure prepended to each packet. We use this header * instead of the standard one for 32-bit streams. We mark the a stream as * 32-bit the first time we see a 32-bit compat ioctl request. */ struct bpf_hdr32 { struct timeval32 bh_tstamp; /* time stamp */ uint32_t bh_caplen; /* length of captured portion */ uint32_t bh_datalen; /* original length of packet */ uint16_t bh_hdrlen; /* length of bpf header (this struct plus alignment padding) */ }; #endif struct bpf_program32 { u_int bf_len; uint32_t bf_insns; }; struct bpf_dltlist32 { u_int bfl_len; u_int bfl_list; }; #define BIOCSETF32 _IOW('B', 103, struct bpf_program32) #define BIOCSRTIMEOUT32 _IOW('B', 109, struct timeval32) #define BIOCGRTIMEOUT32 _IOR('B', 110, struct timeval32) #define BIOCGDLTLIST32 _IOWR('B', 121, struct bpf_dltlist32) #define BIOCSETWF32 _IOW('B', 123, struct bpf_program32) #define BIOCSETFNR32 _IOW('B', 130, struct bpf_program32) #endif /* * bpf_iflist is a list of BPF interface structures, each corresponding to a * specific DLT. The same network interface might have several BPF interface * structures registered by different layers in the stack (i.e., 802.11 * frames, ethernet frames, etc). */ static LIST_HEAD(, bpf_if) bpf_iflist; static struct mtx bpf_mtx; /* bpf global lock */ static int bpf_bpfd_cnt; static void bpf_attachd(struct bpf_d *, struct bpf_if *); static void bpf_detachd(struct bpf_d *); static void bpf_detachd_locked(struct bpf_d *); static void bpf_freed(struct bpf_d *); static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **, struct sockaddr *, int *, struct bpf_insn *); static int bpf_setif(struct bpf_d *, struct ifreq *); static void bpf_timed_out(void *); static __inline void bpf_wakeup(struct bpf_d *); static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int), struct bintime *); static void reset_d(struct bpf_d *); static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); static int bpf_setdlt(struct bpf_d *, u_int); static void filt_bpfdetach(struct knote *); static int filt_bpfread(struct knote *, long); static void bpf_drvinit(void *); static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl"); int bpf_maxinsns = BPF_MAXINSNS; SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, &bpf_maxinsns, 0, "Maximum bpf program instructions"); static int bpf_zerocopy_enable = 0; SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW, &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions"); static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW, bpf_stats_sysctl, "bpf statistics portal"); static VNET_DEFINE(int, bpf_optimize_writers) = 0; #define V_bpf_optimize_writers VNET(bpf_optimize_writers) SYSCTL_VNET_INT(_net_bpf, OID_AUTO, optimize_writers, CTLFLAG_RW, &VNET_NAME(bpf_optimize_writers), 0, "Do not send packets until BPF program is set"); static d_open_t bpfopen; static d_read_t bpfread; static d_write_t bpfwrite; static d_ioctl_t bpfioctl; static d_poll_t bpfpoll; static d_kqfilter_t bpfkqfilter; static struct cdevsw bpf_cdevsw = { .d_version = D_VERSION, .d_open = bpfopen, .d_read = bpfread, .d_write = bpfwrite, .d_ioctl = bpfioctl, .d_poll = bpfpoll, .d_name = "bpf", .d_kqfilter = bpfkqfilter, }; static struct filterops bpfread_filtops = { .f_isfd = 1, .f_detach = filt_bpfdetach, .f_event = filt_bpfread, }; /* * LOCKING MODEL USED BY BPF: * Locks: * 1) global lock (BPF_LOCK). Mutex, used to protect interface addition/removal, * some global counters and every bpf_if reference. * 2) Interface lock. Rwlock, used to protect list of BPF descriptors and their filters. * 3) Descriptor lock. Rwlock, used to protect BPF buffers and various structure fields * used by bpf_mtap code. * * Lock order: * * Global lock, interface lock, descriptor lock * * We have to acquire interface lock before descriptor main lock due to BPF_MTAP[2] * working model. In many places (like bpf_detachd) we start with BPF descriptor * (and we need to at least rlock it to get reliable interface pointer). This * gives us potential LOR. As a result, we use global lock to protect from bpf_if * change in every such place. * * Changing d->bd_bif is protected by 1) global lock, 2) interface lock and * 3) descriptor main wlock. * Reading bd_bif can be protected by any of these locks, typically global lock. * * Changing read/write BPF filter is protected by the same three locks, * the same applies for reading. * * Sleeping in global lock is not allowed due to bpfdetach() using it. */ /* * Wrapper functions for various buffering methods. If the set of buffer * modes expands, we will probably want to introduce a switch data structure * similar to protosw, et. */ static void bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src, u_int len) { BPFD_WLOCK_ASSERT(d); switch (d->bd_bufmode) { case BPF_BUFMODE_BUFFER: return (bpf_buffer_append_bytes(d, buf, offset, src, len)); case BPF_BUFMODE_ZBUF: d->bd_zcopy++; return (bpf_zerocopy_append_bytes(d, buf, offset, src, len)); default: panic("bpf_buf_append_bytes"); } } static void bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, u_int len) { BPFD_WLOCK_ASSERT(d); switch (d->bd_bufmode) { case BPF_BUFMODE_BUFFER: return (bpf_buffer_append_mbuf(d, buf, offset, src, len)); case BPF_BUFMODE_ZBUF: d->bd_zcopy++; return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len)); default: panic("bpf_buf_append_mbuf"); } } /* * This function gets called when the free buffer is re-assigned. */ static void bpf_buf_reclaimed(struct bpf_d *d) { BPFD_WLOCK_ASSERT(d); switch (d->bd_bufmode) { case BPF_BUFMODE_BUFFER: return; case BPF_BUFMODE_ZBUF: bpf_zerocopy_buf_reclaimed(d); return; default: panic("bpf_buf_reclaimed"); } } /* * If the buffer mechanism has a way to decide that a held buffer can be made * free, then it is exposed via the bpf_canfreebuf() interface. (1) is * returned if the buffer can be discarded, (0) is returned if it cannot. */ static int bpf_canfreebuf(struct bpf_d *d) { BPFD_LOCK_ASSERT(d); switch (d->bd_bufmode) { case BPF_BUFMODE_ZBUF: return (bpf_zerocopy_canfreebuf(d)); } return (0); } /* * Allow the buffer model to indicate that the current store buffer is * immutable, regardless of the appearance of space. Return (1) if the * buffer is writable, and (0) if not. */ static int bpf_canwritebuf(struct bpf_d *d) { BPFD_LOCK_ASSERT(d); switch (d->bd_bufmode) { case BPF_BUFMODE_ZBUF: return (bpf_zerocopy_canwritebuf(d)); } return (1); } /* * Notify buffer model that an attempt to write to the store buffer has * resulted in a dropped packet, in which case the buffer may be considered * full. */ static void bpf_buffull(struct bpf_d *d) { BPFD_WLOCK_ASSERT(d); switch (d->bd_bufmode) { case BPF_BUFMODE_ZBUF: bpf_zerocopy_buffull(d); break; } } /* * Notify the buffer model that a buffer has moved into the hold position. */ void bpf_bufheld(struct bpf_d *d) { BPFD_WLOCK_ASSERT(d); switch (d->bd_bufmode) { case BPF_BUFMODE_ZBUF: bpf_zerocopy_bufheld(d); break; } } static void bpf_free(struct bpf_d *d) { switch (d->bd_bufmode) { case BPF_BUFMODE_BUFFER: return (bpf_buffer_free(d)); case BPF_BUFMODE_ZBUF: return (bpf_zerocopy_free(d)); default: panic("bpf_buf_free"); } } static int bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) { if (d->bd_bufmode != BPF_BUFMODE_BUFFER) return (EOPNOTSUPP); return (bpf_buffer_uiomove(d, buf, len, uio)); } static int bpf_ioctl_sblen(struct bpf_d *d, u_int *i) { if (d->bd_bufmode != BPF_BUFMODE_BUFFER) return (EOPNOTSUPP); return (bpf_buffer_ioctl_sblen(d, i)); } static int bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i) { if (d->bd_bufmode != BPF_BUFMODE_ZBUF) return (EOPNOTSUPP); return (bpf_zerocopy_ioctl_getzmax(td, d, i)); } static int bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) { if (d->bd_bufmode != BPF_BUFMODE_ZBUF) return (EOPNOTSUPP); return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz)); } static int bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) { if (d->bd_bufmode != BPF_BUFMODE_ZBUF) return (EOPNOTSUPP); return (bpf_zerocopy_ioctl_setzbuf(td, d, bz)); } /* * General BPF functions. */ static int bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, struct sockaddr *sockp, int *hdrlen, struct bpf_insn *wfilter) { const struct ieee80211_bpf_params *p; struct ether_header *eh; struct mbuf *m; int error; int len; int hlen; int slen; /* * Build a sockaddr based on the data link layer type. * We do this at this level because the ethernet header * is copied directly into the data field of the sockaddr. * In the case of SLIP, there is no header and the packet * is forwarded as is. * Also, we are careful to leave room at the front of the mbuf * for the link level header. */ switch (linktype) { case DLT_SLIP: sockp->sa_family = AF_INET; hlen = 0; break; case DLT_EN10MB: sockp->sa_family = AF_UNSPEC; /* XXX Would MAXLINKHDR be better? */ hlen = ETHER_HDR_LEN; break; case DLT_FDDI: sockp->sa_family = AF_IMPLINK; hlen = 0; break; case DLT_RAW: sockp->sa_family = AF_UNSPEC; hlen = 0; break; case DLT_NULL: /* * null interface types require a 4 byte pseudo header which * corresponds to the address family of the packet. */ sockp->sa_family = AF_UNSPEC; hlen = 4; break; case DLT_ATM_RFC1483: /* * en atm driver requires 4-byte atm pseudo header. * though it isn't standard, vpi:vci needs to be * specified anyway. */ sockp->sa_family = AF_UNSPEC; hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ break; case DLT_PPP: sockp->sa_family = AF_UNSPEC; hlen = 4; /* This should match PPP_HDRLEN */ break; case DLT_IEEE802_11: /* IEEE 802.11 wireless */ sockp->sa_family = AF_IEEE80211; hlen = 0; break; case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ sockp->sa_family = AF_IEEE80211; sockp->sa_len = 12; /* XXX != 0 */ hlen = sizeof(struct ieee80211_bpf_params); break; default: return (EIO); } len = uio->uio_resid; if (len - hlen > ifp->if_mtu) return (EMSGSIZE); if ((unsigned)len > MJUM16BYTES) return (EIO); if (len <= MHLEN) MGETHDR(m, M_WAIT, MT_DATA); else if (len <= MCLBYTES) m = m_getcl(M_WAIT, MT_DATA, M_PKTHDR); else m = m_getjcl(M_WAIT, MT_DATA, M_PKTHDR, #if (MJUMPAGESIZE > MCLBYTES) len <= MJUMPAGESIZE ? MJUMPAGESIZE : #endif (len <= MJUM9BYTES ? MJUM9BYTES : MJUM16BYTES)); m->m_pkthdr.len = m->m_len = len; m->m_pkthdr.rcvif = NULL; *mp = m; if (m->m_len < hlen) { error = EPERM; goto bad; } error = uiomove(mtod(m, u_char *), len, uio); if (error) goto bad; slen = bpf_filter(wfilter, mtod(m, u_char *), len, len); if (slen == 0) { error = EPERM; goto bad; } /* Check for multicast destination */ switch (linktype) { case DLT_EN10MB: eh = mtod(m, struct ether_header *); if (ETHER_IS_MULTICAST(eh->ether_dhost)) { if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, ETHER_ADDR_LEN) == 0) m->m_flags |= M_BCAST; else m->m_flags |= M_MCAST; } break; } /* * Make room for link header, and copy it to sockaddr */ if (hlen != 0) { if (sockp->sa_family == AF_IEEE80211) { /* * Collect true length from the parameter header * NB: sockp is known to be zero'd so if we do a * short copy unspecified parameters will be * zero. * NB: packet may not be aligned after stripping * bpf params * XXX check ibp_vers */ p = mtod(m, const struct ieee80211_bpf_params *); hlen = p->ibp_len; if (hlen > sizeof(sockp->sa_data)) { error = EINVAL; goto bad; } } bcopy(m->m_data, sockp->sa_data, hlen); } *hdrlen = hlen; return (0); bad: m_freem(m); return (error); } /* * Attach file to the bpf interface, i.e. make d listen on bp. */ static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp) { int op_w; BPF_LOCK_ASSERT(); /* * Save sysctl value to protect from sysctl change * between reads */ op_w = V_bpf_optimize_writers; if (d->bd_bif != NULL) bpf_detachd_locked(d); /* * Point d at bp, and add d to the interface's list. * Since there are many applicaiotns using BPF for * sending raw packets only (dhcpd, cdpd are good examples) * we can delay adding d to the list of active listeners until * some filter is configured. */ BPFIF_WLOCK(bp); BPFD_WLOCK(d); d->bd_bif = bp; if (op_w != 0) { /* Add to writers-only list */ LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next); /* * We decrement bd_writer on every filter set operation. * First BIOCSETF is done by pcap_open_live() to set up * snap length. After that appliation usually sets its own filter */ d->bd_writer = 2; } else LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); BPFD_WUNLOCK(d); BPFIF_WUNLOCK(bp); bpf_bpfd_cnt++; CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list", __func__, d->bd_pid, d->bd_writer ? "writer" : "active"); if (op_w == 0) EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); } /* * Add d to the list of active bp filters. * Reuqires bpf_attachd() to be called before */ static void bpf_upgraded(struct bpf_d *d) { struct bpf_if *bp; BPF_LOCK_ASSERT(); bp = d->bd_bif; /* * Filter can be set several times without specifying interface. * Mark d as reader and exit. */ if (bp == NULL) { BPFD_WLOCK(d); d->bd_writer = 0; BPFD_WUNLOCK(d); return; } BPFIF_WLOCK(bp); BPFD_WLOCK(d); /* Remove from writers-only list */ LIST_REMOVE(d, bd_next); LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); /* Mark d as reader */ d->bd_writer = 0; BPFD_WUNLOCK(d); BPFIF_WUNLOCK(bp); CTR2(KTR_NET, "%s: upgrade required by pid %d", __func__, d->bd_pid); EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); } /* * Detach a file from its interface. */ static void bpf_detachd(struct bpf_d *d) { BPF_LOCK(); bpf_detachd_locked(d); BPF_UNLOCK(); } static void bpf_detachd_locked(struct bpf_d *d) { int error; struct bpf_if *bp; struct ifnet *ifp; CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid); BPF_LOCK_ASSERT(); /* Check if descriptor is attached */ if ((bp = d->bd_bif) == NULL) return; BPFIF_WLOCK(bp); BPFD_WLOCK(d); /* Save bd_writer value */ error = d->bd_writer; /* * Remove d from the interface's descriptor list. */ LIST_REMOVE(d, bd_next); ifp = bp->bif_ifp; d->bd_bif = NULL; BPFD_WUNLOCK(d); BPFIF_WUNLOCK(bp); bpf_bpfd_cnt--; /* Call event handler iff d is attached */ if (error == 0) EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); /* * Check if this descriptor had requested promiscuous mode. * If so, turn it off. */ if (d->bd_promisc) { d->bd_promisc = 0; CURVNET_SET(ifp->if_vnet); error = ifpromisc(ifp, 0); CURVNET_RESTORE(); if (error != 0 && error != ENXIO) { /* * ENXIO can happen if a pccard is unplugged * Something is really wrong if we were able to put * the driver into promiscuous mode, but can't * take it out. */ if_printf(bp->bif_ifp, "bpf_detach: ifpromisc failed (%d)\n", error); } } } /* * Close the descriptor by detaching it from its interface, * deallocating its buffers, and marking it free. */ static void bpf_dtor(void *data) { struct bpf_d *d = data; BPFD_WLOCK(d); if (d->bd_state == BPF_WAITING) callout_stop(&d->bd_callout); d->bd_state = BPF_IDLE; BPFD_WUNLOCK(d); funsetown(&d->bd_sigio); bpf_detachd(d); #ifdef MAC mac_bpfdesc_destroy(d); #endif /* MAC */ seldrain(&d->bd_sel); knlist_destroy(&d->bd_sel.si_note); callout_drain(&d->bd_callout); bpf_freed(d); free(d, M_BPF); } /* * Open ethernet device. Returns ENXIO for illegal minor device number, * EBUSY if file is open by another process. */ /* ARGSUSED */ static int bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) { struct bpf_d *d; int error; d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); error = devfs_set_cdevpriv(d, bpf_dtor); if (error != 0) { free(d, M_BPF); return (error); } /* * For historical reasons, perform a one-time initialization call to * the buffer routines, even though we're not yet committed to a * particular buffer method. */ bpf_buffer_init(d); d->bd_bufmode = BPF_BUFMODE_BUFFER; d->bd_sig = SIGIO; d->bd_direction = BPF_D_INOUT; BPF_PID_REFRESH(d, td); #ifdef MAC mac_bpfdesc_init(d); mac_bpfdesc_create(td->td_ucred, d); #endif rw_init(&d->bd_lock, "bpf cdev lock"); callout_init_rw(&d->bd_callout, &d->bd_lock, 0); knlist_init_rw_reader(&d->bd_sel.si_note, &d->bd_lock); return (0); } /* * bpfread - read next chunk of packets from buffers */ static int bpfread(struct cdev *dev, struct uio *uio, int ioflag) { struct bpf_d *d; int error; int non_block; int timed_out; error = devfs_get_cdevpriv((void **)&d); if (error != 0) return (error); /* * Restrict application to use a buffer the same size as * as kernel buffers. */ if (uio->uio_resid != d->bd_bufsize) return (EINVAL); non_block = ((ioflag & O_NONBLOCK) != 0); BPFD_WLOCK(d); BPF_PID_REFRESH_CUR(d); if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { BPFD_WUNLOCK(d); return (EOPNOTSUPP); } if (d->bd_state == BPF_WAITING) callout_stop(&d->bd_callout); timed_out = (d->bd_state == BPF_TIMED_OUT); d->bd_state = BPF_IDLE; /* * If the hold buffer is empty, then do a timed sleep, which * ends when the timeout expires or when enough packets * have arrived to fill the store buffer. */ while (d->bd_hbuf == NULL) { if (d->bd_slen != 0) { /* * A packet(s) either arrived since the previous * read or arrived while we were asleep. */ if (d->bd_immediate || non_block || timed_out) { /* * Rotate the buffers and return what's here * if we are in immediate mode, non-blocking * flag is set, or this descriptor timed out. */ ROTATE_BUFFERS(d); break; } } /* * No data is available, check to see if the bpf device * is still pointed at a real interface. If not, return * ENXIO so that the userland process knows to rebind * it before using it again. */ if (d->bd_bif == NULL) { BPFD_WUNLOCK(d); return (ENXIO); } if (non_block) { BPFD_WUNLOCK(d); return (EWOULDBLOCK); } error = rw_sleep(d, &d->bd_lock, PRINET|PCATCH, "bpf", d->bd_rtout); if (error == EINTR || error == ERESTART) { BPFD_WUNLOCK(d); return (error); } if (error == EWOULDBLOCK) { /* * On a timeout, return what's in the buffer, * which may be nothing. If there is something * in the store buffer, we can rotate the buffers. */ if (d->bd_hbuf) /* * We filled up the buffer in between * getting the timeout and arriving * here, so we don't need to rotate. */ break; if (d->bd_slen == 0) { BPFD_WUNLOCK(d); return (0); } ROTATE_BUFFERS(d); break; } } /* * At this point, we know we have something in the hold slot. */ BPFD_WUNLOCK(d); /* * Move data from hold buffer into user space. * We know the entire buffer is transferred since * we checked above that the read buffer is bpf_bufsize bytes. * * XXXRW: More synchronization needed here: what if a second thread * issues a read on the same fd at the same time? Don't want this * getting invalidated. */ error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); BPFD_WLOCK(d); d->bd_fbuf = d->bd_hbuf; d->bd_hbuf = NULL; d->bd_hlen = 0; bpf_buf_reclaimed(d); BPFD_WUNLOCK(d); return (error); } /* * If there are processes sleeping on this descriptor, wake them up. */ static __inline void bpf_wakeup(struct bpf_d *d) { BPFD_WLOCK_ASSERT(d); if (d->bd_state == BPF_WAITING) { callout_stop(&d->bd_callout); d->bd_state = BPF_IDLE; } wakeup(d); if (d->bd_async && d->bd_sig && d->bd_sigio) pgsigio(&d->bd_sigio, d->bd_sig, 0); selwakeuppri(&d->bd_sel, PRINET); KNOTE_LOCKED(&d->bd_sel.si_note, 0); } static void bpf_timed_out(void *arg) { struct bpf_d *d = (struct bpf_d *)arg; BPFD_WLOCK_ASSERT(d); if (callout_pending(&d->bd_callout) || !callout_active(&d->bd_callout)) return; if (d->bd_state == BPF_WAITING) { d->bd_state = BPF_TIMED_OUT; if (d->bd_slen != 0) bpf_wakeup(d); } } static int bpf_ready(struct bpf_d *d) { BPFD_WLOCK_ASSERT(d); if (!bpf_canfreebuf(d) && d->bd_hlen != 0) return (1); if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && d->bd_slen != 0) return (1); return (0); } static int bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) { struct bpf_d *d; struct ifnet *ifp; struct mbuf *m, *mc; struct sockaddr dst; int error, hlen; error = devfs_get_cdevpriv((void **)&d); if (error != 0) return (error); BPF_PID_REFRESH_CUR(d); d->bd_wcount++; /* XXX: locking required */ if (d->bd_bif == NULL) { d->bd_wdcount++; return (ENXIO); } ifp = d->bd_bif->bif_ifp; if ((ifp->if_flags & IFF_UP) == 0) { d->bd_wdcount++; return (ENETDOWN); } if (uio->uio_resid == 0) { d->bd_wdcount++; return (0); } bzero(&dst, sizeof(dst)); m = NULL; hlen = 0; /* XXX: bpf_movein() can sleep */ error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp, &m, &dst, &hlen, d->bd_wfilter); if (error) { d->bd_wdcount++; return (error); } d->bd_wfcount++; if (d->bd_hdrcmplt) dst.sa_family = pseudo_AF_HDRCMPLT; if (d->bd_feedback) { mc = m_dup(m, M_DONTWAIT); if (mc != NULL) mc->m_pkthdr.rcvif = ifp; /* Set M_PROMISC for outgoing packets to be discarded. */ if (d->bd_direction == BPF_D_INOUT) m->m_flags |= M_PROMISC; } else mc = NULL; m->m_pkthdr.len -= hlen; m->m_len -= hlen; m->m_data += hlen; /* XXX */ CURVNET_SET(ifp->if_vnet); #ifdef MAC BPFD_WLOCK(d); mac_bpfdesc_create_mbuf(d, m); if (mc != NULL) mac_bpfdesc_create_mbuf(d, mc); BPFD_WUNLOCK(d); #endif error = (*ifp->if_output)(ifp, m, &dst, NULL); if (error) d->bd_wdcount++; if (mc != NULL) { if (error == 0) (*ifp->if_input)(ifp, mc); else m_freem(mc); } CURVNET_RESTORE(); return (error); } /* * Reset a descriptor by flushing its packet buffer and clearing the receive * and drop counts. This is doable for kernel-only buffers, but with * zero-copy buffers, we can't write to (or rotate) buffers that are * currently owned by userspace. It would be nice if we could encapsulate * this logic in the buffer code rather than here. */ static void reset_d(struct bpf_d *d) { BPFD_WLOCK_ASSERT(d); if ((d->bd_hbuf != NULL) && (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { /* Free the hold buffer. */ d->bd_fbuf = d->bd_hbuf; d->bd_hbuf = NULL; d->bd_hlen = 0; bpf_buf_reclaimed(d); } if (bpf_canwritebuf(d)) d->bd_slen = 0; d->bd_rcount = 0; d->bd_dcount = 0; d->bd_fcount = 0; d->bd_wcount = 0; d->bd_wfcount = 0; d->bd_wdcount = 0; d->bd_zcopy = 0; } /* * FIONREAD Check for read packet available. * SIOCGIFADDR Get interface address - convenient hook to driver. * BIOCGBLEN Get buffer len [for read()]. * BIOCSETF Set read filter. * BIOCSETFNR Set read filter without resetting descriptor. * BIOCSETWF Set write filter. * BIOCFLUSH Flush read packet buffer. * BIOCPROMISC Put interface into promiscuous mode. * BIOCGDLT Get link layer type. * BIOCGETIF Get interface name. * BIOCSETIF Set interface. * BIOCSRTIMEOUT Set read timeout. * BIOCGRTIMEOUT Get read timeout. * BIOCGSTATS Get packet stats. * BIOCIMMEDIATE Set immediate mode. * BIOCVERSION Get filter language version. * BIOCGHDRCMPLT Get "header already complete" flag * BIOCSHDRCMPLT Set "header already complete" flag * BIOCGDIRECTION Get packet direction flag * BIOCSDIRECTION Set packet direction flag * BIOCGTSTAMP Get time stamp format and resolution. * BIOCSTSTAMP Set time stamp format and resolution. * BIOCLOCK Set "locked" flag * BIOCFEEDBACK Set packet feedback mode. * BIOCSETZBUF Set current zero-copy buffer locations. * BIOCGETZMAX Get maximum zero-copy buffer size. * BIOCROTZBUF Force rotation of zero-copy buffer * BIOCSETBUFMODE Set buffer mode. * BIOCGETBUFMODE Get current buffer mode. */ /* ARGSUSED */ static int bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct thread *td) { struct bpf_d *d; int error; error = devfs_get_cdevpriv((void **)&d); if (error != 0) return (error); /* * Refresh PID associated with this descriptor. */ BPFD_WLOCK(d); BPF_PID_REFRESH(d, td); if (d->bd_state == BPF_WAITING) callout_stop(&d->bd_callout); d->bd_state = BPF_IDLE; BPFD_WUNLOCK(d); if (d->bd_locked == 1) { switch (cmd) { case BIOCGBLEN: case BIOCFLUSH: case BIOCGDLT: case BIOCGDLTLIST: #ifdef COMPAT_FREEBSD32 case BIOCGDLTLIST32: #endif case BIOCGETIF: case BIOCGRTIMEOUT: #if defined(COMPAT_FREEBSD32) && !defined(__mips__) case BIOCGRTIMEOUT32: #endif case BIOCGSTATS: case BIOCVERSION: case BIOCGRSIG: case BIOCGHDRCMPLT: case BIOCSTSTAMP: case BIOCFEEDBACK: case FIONREAD: case BIOCLOCK: case BIOCSRTIMEOUT: #if defined(COMPAT_FREEBSD32) && !defined(__mips__) case BIOCSRTIMEOUT32: #endif case BIOCIMMEDIATE: case TIOCGPGRP: case BIOCROTZBUF: break; default: return (EPERM); } } #ifdef COMPAT_FREEBSD32 /* * If we see a 32-bit compat ioctl, mark the stream as 32-bit so * that it will get 32-bit packet headers. */ switch (cmd) { case BIOCSETF32: case BIOCSETFNR32: case BIOCSETWF32: case BIOCGDLTLIST32: case BIOCGRTIMEOUT32: case BIOCSRTIMEOUT32: d->bd_compat32 = 1; } #endif CURVNET_SET(TD_TO_VNET(td)); switch (cmd) { default: error = EINVAL; break; /* * Check for read packet available. */ case FIONREAD: { int n; BPFD_WLOCK(d); n = d->bd_slen; if (d->bd_hbuf) n += d->bd_hlen; BPFD_WUNLOCK(d); *(int *)addr = n; break; } case SIOCGIFADDR: { struct ifnet *ifp; if (d->bd_bif == NULL) error = EINVAL; else { ifp = d->bd_bif->bif_ifp; error = (*ifp->if_ioctl)(ifp, cmd, addr); } break; } /* * Get buffer len [for read()]. */ case BIOCGBLEN: *(u_int *)addr = d->bd_bufsize; break; /* * Set buffer length. */ case BIOCSBLEN: error = bpf_ioctl_sblen(d, (u_int *)addr); break; /* * Set link layer read filter. */ case BIOCSETF: case BIOCSETFNR: case BIOCSETWF: #ifdef COMPAT_FREEBSD32 case BIOCSETF32: case BIOCSETFNR32: case BIOCSETWF32: #endif error = bpf_setf(d, (struct bpf_program *)addr, cmd); break; /* * Flush read packet buffer. */ case BIOCFLUSH: BPFD_WLOCK(d); reset_d(d); BPFD_WUNLOCK(d); break; /* * Put interface into promiscuous mode. */ case BIOCPROMISC: if (d->bd_bif == NULL) { /* * No interface attached yet. */ error = EINVAL; break; } if (d->bd_promisc == 0) { error = ifpromisc(d->bd_bif->bif_ifp, 1); if (error == 0) d->bd_promisc = 1; } break; /* * Get current data link type. */ case BIOCGDLT: if (d->bd_bif == NULL) error = EINVAL; else *(u_int *)addr = d->bd_bif->bif_dlt; break; /* * Get a list of supported data link types. */ #ifdef COMPAT_FREEBSD32 case BIOCGDLTLIST32: { struct bpf_dltlist32 *list32; struct bpf_dltlist dltlist; list32 = (struct bpf_dltlist32 *)addr; dltlist.bfl_len = list32->bfl_len; dltlist.bfl_list = PTRIN(list32->bfl_list); if (d->bd_bif == NULL) error = EINVAL; else { error = bpf_getdltlist(d, &dltlist); if (error == 0) list32->bfl_len = dltlist.bfl_len; } break; } #endif case BIOCGDLTLIST: if (d->bd_bif == NULL) error = EINVAL; else error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); break; /* * Set data link type. */ case BIOCSDLT: BPF_LOCK(); if (d->bd_bif == NULL) error = EINVAL; else error = bpf_setdlt(d, *(u_int *)addr); BPF_UNLOCK(); break; /* * Get interface name. */ case BIOCGETIF: if (d->bd_bif == NULL) error = EINVAL; else { struct ifnet *const ifp = d->bd_bif->bif_ifp; struct ifreq *const ifr = (struct ifreq *)addr; strlcpy(ifr->ifr_name, ifp->if_xname, sizeof(ifr->ifr_name)); } break; /* * Set interface. */ case BIOCSETIF: BPF_LOCK(); error = bpf_setif(d, (struct ifreq *)addr); BPF_UNLOCK(); break; /* * Set read timeout. */ case BIOCSRTIMEOUT: #if defined(COMPAT_FREEBSD32) && !defined(__mips__) case BIOCSRTIMEOUT32: #endif { struct timeval *tv = (struct timeval *)addr; #if defined(COMPAT_FREEBSD32) && !defined(__mips__) struct timeval32 *tv32; struct timeval tv64; if (cmd == BIOCSRTIMEOUT32) { tv32 = (struct timeval32 *)addr; tv = &tv64; tv->tv_sec = tv32->tv_sec; tv->tv_usec = tv32->tv_usec; } else #endif tv = (struct timeval *)addr; /* * Subtract 1 tick from tvtohz() since this isn't * a one-shot timer. */ if ((error = itimerfix(tv)) == 0) d->bd_rtout = tvtohz(tv) - 1; break; } /* * Get read timeout. */ case BIOCGRTIMEOUT: #if defined(COMPAT_FREEBSD32) && !defined(__mips__) case BIOCGRTIMEOUT32: #endif { struct timeval *tv; #if defined(COMPAT_FREEBSD32) && !defined(__mips__) struct timeval32 *tv32; struct timeval tv64; if (cmd == BIOCGRTIMEOUT32) tv = &tv64; else #endif tv = (struct timeval *)addr; tv->tv_sec = d->bd_rtout / hz; tv->tv_usec = (d->bd_rtout % hz) * tick; #if defined(COMPAT_FREEBSD32) && !defined(__mips__) if (cmd == BIOCGRTIMEOUT32) { tv32 = (struct timeval32 *)addr; tv32->tv_sec = tv->tv_sec; tv32->tv_usec = tv->tv_usec; } #endif break; } /* * Get packet stats. */ case BIOCGSTATS: { struct bpf_stat *bs = (struct bpf_stat *)addr; /* XXXCSJP overflow */ bs->bs_recv = d->bd_rcount; bs->bs_drop = d->bd_dcount; break; } /* * Set immediate mode. */ case BIOCIMMEDIATE: d->bd_immediate = *(u_int *)addr; break; case BIOCVERSION: { struct bpf_version *bv = (struct bpf_version *)addr; bv->bv_major = BPF_MAJOR_VERSION; bv->bv_minor = BPF_MINOR_VERSION; break; } /* * Get "header already complete" flag */ case BIOCGHDRCMPLT: *(u_int *)addr = d->bd_hdrcmplt; break; /* * Set "header already complete" flag */ case BIOCSHDRCMPLT: d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; break; /* * Get packet direction flag */ case BIOCGDIRECTION: *(u_int *)addr = d->bd_direction; break; /* * Set packet direction flag */ case BIOCSDIRECTION: { u_int direction; direction = *(u_int *)addr; switch (direction) { case BPF_D_IN: case BPF_D_INOUT: case BPF_D_OUT: d->bd_direction = direction; break; default: error = EINVAL; } } break; /* * Get packet timestamp format and resolution. */ case BIOCGTSTAMP: *(u_int *)addr = d->bd_tstamp; break; /* * Set packet timestamp format and resolution. */ case BIOCSTSTAMP: { u_int func; func = *(u_int *)addr; if (BPF_T_VALID(func)) d->bd_tstamp = func; else error = EINVAL; } break; case BIOCFEEDBACK: d->bd_feedback = *(u_int *)addr; break; case BIOCLOCK: d->bd_locked = 1; break; case FIONBIO: /* Non-blocking I/O */ break; case FIOASYNC: /* Send signal on receive packets */ d->bd_async = *(int *)addr; break; case FIOSETOWN: error = fsetown(*(int *)addr, &d->bd_sigio); break; case FIOGETOWN: *(int *)addr = fgetown(&d->bd_sigio); break; /* This is deprecated, FIOSETOWN should be used instead. */ case TIOCSPGRP: error = fsetown(-(*(int *)addr), &d->bd_sigio); break; /* This is deprecated, FIOGETOWN should be used instead. */ case TIOCGPGRP: *(int *)addr = -fgetown(&d->bd_sigio); break; case BIOCSRSIG: /* Set receive signal */ { u_int sig; sig = *(u_int *)addr; if (sig >= NSIG) error = EINVAL; else d->bd_sig = sig; break; } case BIOCGRSIG: *(u_int *)addr = d->bd_sig; break; case BIOCGETBUFMODE: *(u_int *)addr = d->bd_bufmode; break; case BIOCSETBUFMODE: /* * Allow the buffering mode to be changed as long as we * haven't yet committed to a particular mode. Our * definition of commitment, for now, is whether or not a * buffer has been allocated or an interface attached, since * that's the point where things get tricky. */ switch (*(u_int *)addr) { case BPF_BUFMODE_BUFFER: break; case BPF_BUFMODE_ZBUF: if (bpf_zerocopy_enable) break; /* FALLSTHROUGH */ default: CURVNET_RESTORE(); return (EINVAL); } BPFD_WLOCK(d); if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || d->bd_fbuf != NULL || d->bd_bif != NULL) { BPFD_WUNLOCK(d); CURVNET_RESTORE(); return (EBUSY); } d->bd_bufmode = *(u_int *)addr; BPFD_WUNLOCK(d); break; case BIOCGETZMAX: error = bpf_ioctl_getzmax(td, d, (size_t *)addr); break; case BIOCSETZBUF: error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr); break; case BIOCROTZBUF: error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr); break; } CURVNET_RESTORE(); return (error); } /* * Set d's packet filter program to fp. If this file already has a filter, * free it and replace it. Returns EINVAL for bogus requests. */ static int bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) { struct bpf_insn *fcode, *old; u_int wfilter, flen, size; #ifdef BPF_JITTER bpf_jit_filter *ofunc; #endif int need_upgrade; #ifdef COMPAT_FREEBSD32 struct bpf_program32 *fp32; struct bpf_program fp_swab; if (cmd == BIOCSETWF32 || cmd == BIOCSETF32 || cmd == BIOCSETFNR32) { fp32 = (struct bpf_program32 *)fp; fp_swab.bf_len = fp32->bf_len; fp_swab.bf_insns = (struct bpf_insn *)(uintptr_t)fp32->bf_insns; fp = &fp_swab; if (cmd == BIOCSETWF32) cmd = BIOCSETWF; } #endif /* * Check new filter validness before acquiring any locks. * Allocate memory for new filter, if needed. */ flen = fp->bf_len; if ((flen > bpf_maxinsns) || ((fp->bf_insns == NULL) && (flen != 0))) return (EINVAL); need_upgrade = 0; size = flen * sizeof(*fp->bf_insns); if (size > 0) fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); else fcode = NULL; /* Make compiler happy */ BPF_LOCK(); if (cmd == BIOCSETWF) { old = d->bd_wfilter; wfilter = 1; #ifdef BPF_JITTER ofunc = NULL; #endif } else { wfilter = 0; old = d->bd_rfilter; #ifdef BPF_JITTER ofunc = d->bd_bfilter; #endif } if (fp->bf_insns == NULL) { /* * Protect filter removal by interface lock. * Additionally, we are protected by global lock here. */ if (d->bd_bif != NULL) BPFIF_WLOCK(d->bd_bif); BPFD_WLOCK(d); if (wfilter) d->bd_wfilter = NULL; else { d->bd_rfilter = NULL; #ifdef BPF_JITTER d->bd_bfilter = NULL; #endif if (cmd == BIOCSETF) reset_d(d); } BPFD_WUNLOCK(d); if (d->bd_bif != NULL) BPFIF_WUNLOCK(d->bd_bif); if (old != NULL) free((caddr_t)old, M_BPF); #ifdef BPF_JITTER if (ofunc != NULL) bpf_destroy_jit_filter(ofunc); #endif BPF_UNLOCK(); return (0); } if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && bpf_validate(fcode, (int)flen)) { /* * Protect filter change by interface lock * Additionally, we are protected by global lock here. */ if (d->bd_bif != NULL) BPFIF_WLOCK(d->bd_bif); BPFD_WLOCK(d); if (wfilter) d->bd_wfilter = fcode; else { d->bd_rfilter = fcode; #ifdef BPF_JITTER d->bd_bfilter = bpf_jitter(fcode, flen); #endif if (cmd == BIOCSETF) reset_d(d); /* * Do not require upgrade by first BIOCSETF * (used to set snaplen) by pcap_open_live() */ if ((d->bd_writer != 0) && (--d->bd_writer == 0)) need_upgrade = 1; CTR4(KTR_NET, "%s: filter function set by pid %d, " "bd_writer counter %d, need_upgrade %d", __func__, d->bd_pid, d->bd_writer, need_upgrade); } BPFD_WUNLOCK(d); if (d->bd_bif != NULL) BPFIF_WUNLOCK(d->bd_bif); if (old != NULL) free((caddr_t)old, M_BPF); #ifdef BPF_JITTER if (ofunc != NULL) bpf_destroy_jit_filter(ofunc); #endif /* Move d to active readers list */ if (need_upgrade != 0) bpf_upgraded(d); BPF_UNLOCK(); return (0); } free((caddr_t)fcode, M_BPF); BPF_UNLOCK(); return (EINVAL); } /* * Detach a file from its current interface (if attached at all) and attach * to the interface indicated by the name stored in ifr. * Return an errno or 0. */ static int bpf_setif(struct bpf_d *d, struct ifreq *ifr) { struct bpf_if *bp; struct ifnet *theywant; BPF_LOCK_ASSERT(); theywant = ifunit(ifr->ifr_name); if (theywant == NULL || theywant->if_bpf == NULL) return (ENXIO); bp = theywant->if_bpf; /* * Behavior here depends on the buffering model. If we're using * kernel memory buffers, then we can allocate them here. If we're * using zero-copy, then the user process must have registered * buffers by the time we get here. If not, return an error. * * XXXRW: There are locking issues here with multi-threaded use: what * if two threads try to set the interface at once? */ switch (d->bd_bufmode) { case BPF_BUFMODE_BUFFER: if (d->bd_sbuf == NULL) bpf_buffer_alloc(d); KASSERT(d->bd_sbuf != NULL, ("bpf_setif: bd_sbuf NULL")); break; case BPF_BUFMODE_ZBUF: if (d->bd_sbuf == NULL) return (EINVAL); break; default: panic("bpf_setif: bufmode %d", d->bd_bufmode); } if (bp != d->bd_bif) bpf_attachd(d, bp); BPFD_WLOCK(d); reset_d(d); BPFD_WUNLOCK(d); return (0); } /* * Support for select() and poll() system calls * * Return true iff the specific operation will not block indefinitely. * Otherwise, return false but make a note that a selwakeup() must be done. */ static int bpfpoll(struct cdev *dev, int events, struct thread *td) { struct bpf_d *d; int revents; if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) return (events & (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); /* * Refresh PID associated with this descriptor. */ revents = events & (POLLOUT | POLLWRNORM); BPFD_WLOCK(d); BPF_PID_REFRESH(d, td); if (events & (POLLIN | POLLRDNORM)) { if (bpf_ready(d)) revents |= events & (POLLIN | POLLRDNORM); else { selrecord(td, &d->bd_sel); /* Start the read timeout if necessary. */ if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { callout_reset(&d->bd_callout, d->bd_rtout, bpf_timed_out, d); d->bd_state = BPF_WAITING; } } } BPFD_WUNLOCK(d); return (revents); } /* * Support for kevent() system call. Register EVFILT_READ filters and * reject all others. */ int bpfkqfilter(struct cdev *dev, struct knote *kn) { struct bpf_d *d; if (devfs_get_cdevpriv((void **)&d) != 0 || kn->kn_filter != EVFILT_READ) return (1); /* * Refresh PID associated with this descriptor. */ BPFD_WLOCK(d); BPF_PID_REFRESH_CUR(d); kn->kn_fop = &bpfread_filtops; kn->kn_hook = d; knlist_add(&d->bd_sel.si_note, kn, 1); BPFD_WUNLOCK(d); return (0); } static void filt_bpfdetach(struct knote *kn) { struct bpf_d *d = (struct bpf_d *)kn->kn_hook; knlist_remove(&d->bd_sel.si_note, kn, 0); } static int filt_bpfread(struct knote *kn, long hint) { struct bpf_d *d = (struct bpf_d *)kn->kn_hook; int ready; BPFD_WLOCK_ASSERT(d); ready = bpf_ready(d); if (ready) { kn->kn_data = d->bd_slen; if (d->bd_hbuf) kn->kn_data += d->bd_hlen; } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { callout_reset(&d->bd_callout, d->bd_rtout, bpf_timed_out, d); d->bd_state = BPF_WAITING; } return (ready); } #define BPF_TSTAMP_NONE 0 #define BPF_TSTAMP_FAST 1 #define BPF_TSTAMP_NORMAL 2 #define BPF_TSTAMP_EXTERN 3 static int bpf_ts_quality(int tstype) { if (tstype == BPF_T_NONE) return (BPF_TSTAMP_NONE); if ((tstype & BPF_T_FAST) != 0) return (BPF_TSTAMP_FAST); return (BPF_TSTAMP_NORMAL); } static int bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m) { struct m_tag *tag; int quality; quality = bpf_ts_quality(tstype); if (quality == BPF_TSTAMP_NONE) return (quality); if (m != NULL) { tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL); if (tag != NULL) { *bt = *(struct bintime *)(tag + 1); return (BPF_TSTAMP_EXTERN); } } if (quality == BPF_TSTAMP_NORMAL) binuptime(bt); else getbinuptime(bt); return (quality); } /* * Incoming linkage from device drivers. Process the packet pkt, of length * pktlen, which is stored in a contiguous buffer. The packet is parsed * by each process' filter, and if accepted, stashed into the corresponding * buffer. */ void bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) { struct bintime bt; struct bpf_d *d; #ifdef BPF_JITTER bpf_jit_filter *bf; #endif u_int slen; int gottime; gottime = BPF_TSTAMP_NONE; BPFIF_RLOCK(bp); LIST_FOREACH(d, &bp->bif_dlist, bd_next) { /* * We are not using any locks for d here because: * 1) any filter change is protected by interface * write lock * 2) destroying/detaching d is protected by interface * write lock, too */ /* XXX: Do not protect counter for the sake of performance. */ ++d->bd_rcount; /* * NB: We dont call BPF_CHECK_DIRECTION() here since there is no * way for the caller to indiciate to us whether this packet * is inbound or outbound. In the bpf_mtap() routines, we use * the interface pointers on the mbuf to figure it out. */ #ifdef BPF_JITTER bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; if (bf != NULL) slen = (*(bf->func))(pkt, pktlen, pktlen); else #endif slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); if (slen != 0) { /* * Filter matches. Let's to acquire write lock. */ BPFD_WLOCK(d); d->bd_fcount++; if (gottime < bpf_ts_quality(d->bd_tstamp)) gottime = bpf_gettime(&bt, d->bd_tstamp, NULL); #ifdef MAC if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) #endif catchpacket(d, pkt, pktlen, slen, bpf_append_bytes, &bt); BPFD_WUNLOCK(d); } } BPFIF_RUNLOCK(bp); } #define BPF_CHECK_DIRECTION(d, r, i) \ (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ ((d)->bd_direction == BPF_D_OUT && (r) == (i))) /* * Incoming linkage from device drivers, when packet is in an mbuf chain. * Locking model is explained in bpf_tap(). */ void bpf_mtap(struct bpf_if *bp, struct mbuf *m) { struct bintime bt; struct bpf_d *d; #ifdef BPF_JITTER bpf_jit_filter *bf; #endif u_int pktlen, slen; int gottime; /* Skip outgoing duplicate packets. */ if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { m->m_flags &= ~M_PROMISC; return; } pktlen = m_length(m, NULL); gottime = BPF_TSTAMP_NONE; BPFIF_RLOCK(bp); LIST_FOREACH(d, &bp->bif_dlist, bd_next) { if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) continue; ++d->bd_rcount; #ifdef BPF_JITTER bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; /* XXX We cannot handle multiple mbufs. */ if (bf != NULL && m->m_next == NULL) slen = (*(bf->func))(mtod(m, u_char *), pktlen, pktlen); else #endif slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); if (slen != 0) { BPFD_WLOCK(d); d->bd_fcount++; if (gottime < bpf_ts_quality(d->bd_tstamp)) gottime = bpf_gettime(&bt, d->bd_tstamp, m); #ifdef MAC if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) #endif catchpacket(d, (u_char *)m, pktlen, slen, bpf_append_mbuf, &bt); BPFD_WUNLOCK(d); } } BPFIF_RUNLOCK(bp); } /* * Incoming linkage from device drivers, when packet is in * an mbuf chain and to be prepended by a contiguous header. */ void bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) { struct bintime bt; struct mbuf mb; struct bpf_d *d; u_int pktlen, slen; int gottime; /* Skip outgoing duplicate packets. */ if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { m->m_flags &= ~M_PROMISC; return; } pktlen = m_length(m, NULL); /* * Craft on-stack mbuf suitable for passing to bpf_filter. * Note that we cut corners here; we only setup what's * absolutely needed--this mbuf should never go anywhere else. */ mb.m_next = m; mb.m_data = data; mb.m_len = dlen; pktlen += dlen; gottime = BPF_TSTAMP_NONE; BPFIF_RLOCK(bp); LIST_FOREACH(d, &bp->bif_dlist, bd_next) { if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) continue; ++d->bd_rcount; slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); if (slen != 0) { BPFD_WLOCK(d); d->bd_fcount++; if (gottime < bpf_ts_quality(d->bd_tstamp)) gottime = bpf_gettime(&bt, d->bd_tstamp, m); #ifdef MAC if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) #endif catchpacket(d, (u_char *)&mb, pktlen, slen, bpf_append_mbuf, &bt); BPFD_WUNLOCK(d); } } BPFIF_RUNLOCK(bp); } #undef BPF_CHECK_DIRECTION #undef BPF_TSTAMP_NONE #undef BPF_TSTAMP_FAST #undef BPF_TSTAMP_NORMAL #undef BPF_TSTAMP_EXTERN static int bpf_hdrlen(struct bpf_d *d) { int hdrlen; hdrlen = d->bd_bif->bif_hdrlen; #ifndef BURN_BRIDGES if (d->bd_tstamp == BPF_T_NONE || BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME) #ifdef COMPAT_FREEBSD32 if (d->bd_compat32) hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32); else #endif hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr); else #endif hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr); #ifdef COMPAT_FREEBSD32 if (d->bd_compat32) hdrlen = BPF_WORDALIGN32(hdrlen); else #endif hdrlen = BPF_WORDALIGN(hdrlen); return (hdrlen - d->bd_bif->bif_hdrlen); } static void bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype) { struct bintime bt2; struct timeval tsm; struct timespec tsn; if ((tstype & BPF_T_MONOTONIC) == 0) { bt2 = *bt; bintime_add(&bt2, &boottimebin); bt = &bt2; } switch (BPF_T_FORMAT(tstype)) { case BPF_T_MICROTIME: bintime2timeval(bt, &tsm); ts->bt_sec = tsm.tv_sec; ts->bt_frac = tsm.tv_usec; break; case BPF_T_NANOTIME: bintime2timespec(bt, &tsn); ts->bt_sec = tsn.tv_sec; ts->bt_frac = tsn.tv_nsec; break; case BPF_T_BINTIME: ts->bt_sec = bt->sec; ts->bt_frac = bt->frac; break; } } /* * Move the packet data from interface memory (pkt) into the * store buffer. "cpfn" is the routine called to do the actual data * transfer. bcopy is passed in to copy contiguous chunks, while * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, * pkt is really an mbuf. */ static void catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), struct bintime *bt) { struct bpf_xhdr hdr; #ifndef BURN_BRIDGES struct bpf_hdr hdr_old; #ifdef COMPAT_FREEBSD32 struct bpf_hdr32 hdr32_old; #endif #endif int caplen, curlen, hdrlen, totlen; int do_wakeup = 0; int do_timestamp; int tstype; BPFD_WLOCK_ASSERT(d); /* * Detect whether user space has released a buffer back to us, and if * so, move it from being a hold buffer to a free buffer. This may * not be the best place to do it (for example, we might only want to * run this check if we need the space), but for now it's a reliable * spot to do it. */ if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { d->bd_fbuf = d->bd_hbuf; d->bd_hbuf = NULL; d->bd_hlen = 0; bpf_buf_reclaimed(d); } /* * Figure out how many bytes to move. If the packet is * greater or equal to the snapshot length, transfer that * much. Otherwise, transfer the whole packet (unless * we hit the buffer size limit). */ hdrlen = bpf_hdrlen(d); totlen = hdrlen + min(snaplen, pktlen); if (totlen > d->bd_bufsize) totlen = d->bd_bufsize; /* * Round up the end of the previous packet to the next longword. * * Drop the packet if there's no room and no hope of room * If the packet would overflow the storage buffer or the storage * buffer is considered immutable by the buffer model, try to rotate * the buffer and wakeup pending processes. */ #ifdef COMPAT_FREEBSD32 if (d->bd_compat32) curlen = BPF_WORDALIGN32(d->bd_slen); else #endif curlen = BPF_WORDALIGN(d->bd_slen); if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { if (d->bd_fbuf == NULL) { /* * There's no room in the store buffer, and no * prospect of room, so drop the packet. Notify the * buffer model. */ bpf_buffull(d); ++d->bd_dcount; return; } ROTATE_BUFFERS(d); do_wakeup = 1; curlen = 0; } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) /* * Immediate mode is set, or the read timeout has already * expired during a select call. A packet arrived, so the * reader should be woken up. */ do_wakeup = 1; caplen = totlen - hdrlen; tstype = d->bd_tstamp; do_timestamp = tstype != BPF_T_NONE; #ifndef BURN_BRIDGES if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) { struct bpf_ts ts; if (do_timestamp) bpf_bintime2ts(bt, &ts, tstype); #ifdef COMPAT_FREEBSD32 if (d->bd_compat32) { bzero(&hdr32_old, sizeof(hdr32_old)); if (do_timestamp) { hdr32_old.bh_tstamp.tv_sec = ts.bt_sec; hdr32_old.bh_tstamp.tv_usec = ts.bt_frac; } hdr32_old.bh_datalen = pktlen; hdr32_old.bh_hdrlen = hdrlen; hdr32_old.bh_caplen = caplen; bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old, sizeof(hdr32_old)); goto copy; } #endif bzero(&hdr_old, sizeof(hdr_old)); if (do_timestamp) { hdr_old.bh_tstamp.tv_sec = ts.bt_sec; hdr_old.bh_tstamp.tv_usec = ts.bt_frac; } hdr_old.bh_datalen = pktlen; hdr_old.bh_hdrlen = hdrlen; hdr_old.bh_caplen = caplen; bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old, sizeof(hdr_old)); goto copy; } #endif /* * Append the bpf header. Note we append the actual header size, but * move forward the length of the header plus padding. */ bzero(&hdr, sizeof(hdr)); if (do_timestamp) bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype); hdr.bh_datalen = pktlen; hdr.bh_hdrlen = hdrlen; hdr.bh_caplen = caplen; bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); /* * Copy the packet data into the store buffer and update its length. */ #ifndef BURN_BRIDGES copy: #endif (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen); d->bd_slen = curlen + totlen; if (do_wakeup) bpf_wakeup(d); } /* * Free buffers currently in use by a descriptor. * Called on close. */ static void bpf_freed(struct bpf_d *d) { /* * We don't need to lock out interrupts since this descriptor has * been detached from its interface and it yet hasn't been marked * free. */ bpf_free(d); if (d->bd_rfilter != NULL) { free((caddr_t)d->bd_rfilter, M_BPF); #ifdef BPF_JITTER if (d->bd_bfilter != NULL) bpf_destroy_jit_filter(d->bd_bfilter); #endif } if (d->bd_wfilter != NULL) free((caddr_t)d->bd_wfilter, M_BPF); rw_destroy(&d->bd_lock); } /* * Attach an interface to bpf. dlt is the link layer type; hdrlen is the * fixed size of the link header (variable length headers not yet supported). */ void bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) { bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); } /* * Attach an interface to bpf. ifp is a pointer to the structure * defining the interface to be attached, dlt is the link layer type, * and hdrlen is the fixed size of the link header (variable length * headers are not yet supporrted). */ void bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) { struct bpf_if *bp; bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); if (bp == NULL) panic("bpfattach"); LIST_INIT(&bp->bif_dlist); LIST_INIT(&bp->bif_wlist); bp->bif_ifp = ifp; bp->bif_dlt = dlt; rw_init(&bp->bif_lock, "bpf interface lock"); KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized")); *driverp = bp; BPF_LOCK(); LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); BPF_UNLOCK(); bp->bif_hdrlen = hdrlen; if (bootverbose) if_printf(ifp, "bpf attached\n"); } /* * Detach bpf from an interface. This involves detaching each descriptor * associated with the interface. Notify each descriptor as it's detached * so that any sleepers wake up and get ENXIO. */ void bpfdetach(struct ifnet *ifp) { struct bpf_if *bp; struct bpf_d *d; #ifdef INVARIANTS int ndetached; ndetached = 0; #endif /* Find all bpf_if struct's which reference ifp and detach them. */ do { BPF_LOCK(); LIST_FOREACH(bp, &bpf_iflist, bif_next) { if (ifp == bp->bif_ifp) break; } if (bp != NULL) LIST_REMOVE(bp, bif_next); BPF_UNLOCK(); if (bp != NULL) { #ifdef INVARIANTS ndetached++; #endif while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { bpf_detachd(d); BPFD_WLOCK(d); bpf_wakeup(d); BPFD_WUNLOCK(d); } /* Free writer-only descriptors */ while ((d = LIST_FIRST(&bp->bif_wlist)) != NULL) { bpf_detachd(d); BPFD_WLOCK(d); bpf_wakeup(d); BPFD_WUNLOCK(d); } rw_destroy(&bp->bif_lock); free(bp, M_BPF); } } while (bp != NULL); #ifdef INVARIANTS if (ndetached == 0) printf("bpfdetach: %s was not attached\n", ifp->if_xname); #endif } /* * Get a list of available data link type of the interface. */ static int bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) { int n, error; struct ifnet *ifp; struct bpf_if *bp; ifp = d->bd_bif->bif_ifp; n = 0; error = 0; BPF_LOCK(); LIST_FOREACH(bp, &bpf_iflist, bif_next) { if (bp->bif_ifp != ifp) continue; if (bfl->bfl_list != NULL) { if (n >= bfl->bfl_len) { BPF_UNLOCK(); return (ENOMEM); } error = copyout(&bp->bif_dlt, bfl->bfl_list + n, sizeof(u_int)); } n++; } BPF_UNLOCK(); bfl->bfl_len = n; return (error); } /* * Set the data link type of a BPF instance. */ static int bpf_setdlt(struct bpf_d *d, u_int dlt) { int error, opromisc; struct ifnet *ifp; struct bpf_if *bp; BPF_LOCK_ASSERT(); if (d->bd_bif->bif_dlt == dlt) return (0); ifp = d->bd_bif->bif_ifp; LIST_FOREACH(bp, &bpf_iflist, bif_next) { if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) break; } if (bp != NULL) { opromisc = d->bd_promisc; bpf_attachd(d, bp); BPFD_WLOCK(d); reset_d(d); BPFD_WUNLOCK(d); if (opromisc) { error = ifpromisc(bp->bif_ifp, 1); if (error) if_printf(bp->bif_ifp, "bpf_setdlt: ifpromisc failed (%d)\n", error); else d->bd_promisc = 1; } } return (bp == NULL ? EINVAL : 0); } static void bpf_drvinit(void *unused) { struct cdev *dev; mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); LIST_INIT(&bpf_iflist); dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); /* For compatibility */ make_dev_alias(dev, "bpf0"); } /* * Zero out the various packet counters associated with all of the bpf * descriptors. At some point, we will probably want to get a bit more * granular and allow the user to specify descriptors to be zeroed. */ static void bpf_zero_counters(void) { struct bpf_if *bp; struct bpf_d *bd; BPF_LOCK(); LIST_FOREACH(bp, &bpf_iflist, bif_next) { BPFIF_RLOCK(bp); LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { BPFD_WLOCK(bd); bd->bd_rcount = 0; bd->bd_dcount = 0; bd->bd_fcount = 0; bd->bd_wcount = 0; bd->bd_wfcount = 0; bd->bd_zcopy = 0; BPFD_WUNLOCK(bd); } BPFIF_RUNLOCK(bp); } BPF_UNLOCK(); } /* * Fill filter statistics */ static void bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) { bzero(d, sizeof(*d)); BPFD_LOCK_ASSERT(bd); d->bd_structsize = sizeof(*d); /* XXX: reading should be protected by global lock */ d->bd_immediate = bd->bd_immediate; d->bd_promisc = bd->bd_promisc; d->bd_hdrcmplt = bd->bd_hdrcmplt; d->bd_direction = bd->bd_direction; d->bd_feedback = bd->bd_feedback; d->bd_async = bd->bd_async; d->bd_rcount = bd->bd_rcount; d->bd_dcount = bd->bd_dcount; d->bd_fcount = bd->bd_fcount; d->bd_sig = bd->bd_sig; d->bd_slen = bd->bd_slen; d->bd_hlen = bd->bd_hlen; d->bd_bufsize = bd->bd_bufsize; d->bd_pid = bd->bd_pid; strlcpy(d->bd_ifname, bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); d->bd_locked = bd->bd_locked; d->bd_wcount = bd->bd_wcount; d->bd_wdcount = bd->bd_wdcount; d->bd_wfcount = bd->bd_wfcount; d->bd_zcopy = bd->bd_zcopy; d->bd_bufmode = bd->bd_bufmode; } /* * Handle `netstat -B' stats request */ static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) { struct xbpf_d *xbdbuf, *xbd, zerostats; int index, error; struct bpf_if *bp; struct bpf_d *bd; /* * XXX This is not technically correct. It is possible for non * privileged users to open bpf devices. It would make sense * if the users who opened the devices were able to retrieve * the statistics for them, too. */ error = priv_check(req->td, PRIV_NET_BPF); if (error) return (error); /* * Check to see if the user is requesting that the counters be * zeroed out. Explicitly check that the supplied data is zeroed, * as we aren't allowing the user to set the counters currently. */ if (req->newptr != NULL) { if (req->newlen != sizeof(zerostats)) return (EINVAL); bzero(&zerostats, sizeof(zerostats)); xbd = req->newptr; if (bcmp(xbd, &zerostats, sizeof(*xbd)) != 0) return (EINVAL); bpf_zero_counters(); return (0); } if (req->oldptr == NULL) return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); if (bpf_bpfd_cnt == 0) return (SYSCTL_OUT(req, 0, 0)); xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); BPF_LOCK(); if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { BPF_UNLOCK(); free(xbdbuf, M_BPF); return (ENOMEM); } index = 0; LIST_FOREACH(bp, &bpf_iflist, bif_next) { BPFIF_RLOCK(bp); /* Send writers-only first */ LIST_FOREACH(bd, &bp->bif_wlist, bd_next) { xbd = &xbdbuf[index++]; BPFD_RLOCK(bd); bpfstats_fill_xbpf(xbd, bd); BPFD_RUNLOCK(bd); } LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { xbd = &xbdbuf[index++]; BPFD_RLOCK(bd); bpfstats_fill_xbpf(xbd, bd); BPFD_RUNLOCK(bd); } BPFIF_RUNLOCK(bp); } BPF_UNLOCK(); error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); free(xbdbuf, M_BPF); return (error); } SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL); #else /* !DEV_BPF && !NETGRAPH_BPF */ /* * NOP stubs to allow bpf-using drivers to load and function. * * A 'better' implementation would allow the core bpf functionality * to be loaded at runtime. */ static struct bpf_if bp_null; void bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) { } void bpf_mtap(struct bpf_if *bp, struct mbuf *m) { } void bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) { } void bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) { bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); } void bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) { *driverp = &bp_null; } void bpfdetach(struct ifnet *ifp) { } u_int bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) { return -1; /* "no filter" behaviour */ } int bpf_validate(const struct bpf_insn *f, int len) { return 0; /* false */ } #endif /* !DEV_BPF && !NETGRAPH_BPF */