/*- * Copyright (c) 1991 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 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 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 7.4 (Berkeley) 6/17/91 * * static char rcsid[] = * "$Header: /cvsroot/src/sys/net/bpf.c,v 1.1.1.1 1993/03/21 09:45:37 cgd Exp $"; */ #include "bpfilter.h" #if (NBPFILTER > 0) #include #include #include #include #include #include #include #include #include #ifdef sparc #include #endif #include #include #include #include #include #include #include #include #include #include #include #define PRINET 26 /* interruptible */ /* * The default read buffer size is patchable. */ int bpf_bufsize = MCLBYTES; /* * bpf_iflist is the list of interfaces; each corresponds to an ifnet * bpf_dtab holds the descriptors, indexed by minor device # * * We really don't need NBPFILTER bpf_if entries, but this eliminates * the need to account for all possible drivers here. * This problem will go away when these structures are allocated dynamically. */ static struct bpf_if *bpf_iflist; static struct bpf_d bpf_dtab[NBPFILTER]; static void bpf_ifname(); static void catchpacket(); static int bpf_setif(); static int bpf_initd(); static int bpf_movein(uio, linktype, mp, sockp) register struct uio *uio; int linktype; register struct mbuf **mp; register struct sockaddr *sockp; { struct mbuf *m; int error; int len; int hlen; /* * 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 = sizeof(struct ether_header); break; case DLT_FDDI: sockp->sa_family = AF_UNSPEC; /* XXX 4(FORMAC)+6(dst)+6(src)+3(LLC)+5(SNAP) */ hlen = 24; break; default: return (EIO); } len = uio->uio_resid; if ((unsigned)len > MCLBYTES) return (EIO); MGET(m, M_WAIT, MT_DATA); if (m == 0) return (ENOBUFS); if (len > MLEN) { MCLGET(m, M_WAIT); if ((m->m_flags & M_EXT) == 0) { error = ENOBUFS; goto bad; } } m->m_len = len; *mp = m; /* * Make room for link header. */ if (hlen) { m->m_len -= hlen; m->m_data += hlen; /* XXX */ error = uiomove((caddr_t)sockp->sa_data, hlen, uio); if (error) goto bad; } error = uiomove(mtod(m, caddr_t), len - hlen, uio); if (!error) return (0); bad: m_freem(m); return (error); } /* * Attach 'd' to the bpf interface 'bp', i.e. make 'd' listen on 'bp'. * Must be called at splimp. */ static void bpf_attachd(d, bp) struct bpf_d *d; struct bpf_if *bp; { /* Point d at bp. */ d->bd_bif = bp; /* Add d to bp's list of listeners. */ d->bd_next = bp->bif_dlist; bp->bif_dlist = d; /* * Let the driver know we're here (if it doesn't already). */ *bp->bif_driverp = bp; } static void bpf_detachd(d) struct bpf_d *d; { struct bpf_d **p; struct bpf_if *bp; bp = d->bd_bif; /* * Check if this descriptor had requested promiscuous mode. * If so, turn it off. */ if (d->bd_promisc) { d->bd_promisc = 0; if (ifpromisc(bp->bif_ifp, 0)) /* * Something is really wrong if we were able to put * the driver into promiscuous mode, but can't * take it out. */ panic("bpf_detachd: ifpromisc failed"); } /* Remove 'd' from the interface's descriptor list. */ p = &bp->bif_dlist; while (*p != d) { p = &(*p)->bd_next; if (*p == 0) panic("bpf_detachd: descriptor not in list"); } *p = (*p)->bd_next; if (bp->bif_dlist == 0) /* * Let the driver know that there are no more listeners. */ *d->bd_bif->bif_driverp = 0; d->bd_bif = 0; } /* * Mark a descriptor free by making it point to itself. * This is probably cheaper than marking with a constant since * the address should be in a register anyway. */ #define D_ISFREE(d) ((d) == (d)->bd_next) #define D_MARKFREE(d) ((d)->bd_next = (d)) #define D_MARKUSED(d) ((d)->bd_next = 0) /* * bpfopen - open ethernet device * * Errors: ENXIO - illegal minor device number * EBUSY - too many files open */ /* ARGSUSED */ int bpfopen(dev, flag) dev_t dev; int flag; { int error, s; register struct bpf_d *d; if (minor(dev) >= NBPFILTER) return (ENXIO); /* * Each minor can be opened by only one process. If the requested * minor is in use, return EBUSY. */ s = splimp(); d = &bpf_dtab[minor(dev)]; if (!D_ISFREE(d)) { splx(s); return (EBUSY); } else /* Mark "free" and do most initialization. */ bzero((char *)d, sizeof(*d)); splx(s); error = bpf_initd(d); if (error) { D_MARKFREE(d); return (error); } return (0); } /* * Close the descriptor by detaching it from its interface, * deallocating its buffers, and marking it free. */ /* ARGSUSED */ bpfclose(dev, flag) dev_t dev; int flag; { register struct bpf_d *d = &bpf_dtab[minor(dev)]; int s; s = splimp(); if (d->bd_bif) bpf_detachd(d); splx(s); /* Free the buffer space. */ if (d->bd_hbuf) free(d->bd_hbuf, M_DEVBUF); if (d->bd_fbuf) free(d->bd_fbuf, M_DEVBUF); free(d->bd_sbuf, M_DEVBUF); if (d->bd_filter) free((caddr_t)d->bd_filter, M_DEVBUF); D_MARKFREE(d); } /* * Rotate the packet buffers in descriptor d. Move the store buffer * into the hold slot, and the free buffer into the store slot. * Zero the length of the new store buffer. */ #define ROTATE_BUFFERS(d) \ (d)->bd_hbuf = (d)->bd_sbuf; \ (d)->bd_hlen = (d)->bd_slen; \ (d)->bd_sbuf = (d)->bd_fbuf; \ (d)->bd_slen = 0; \ (d)->bd_fbuf = 0; /* * bpfread - read next chunk of packets from buffers */ int bpfread(dev, uio) dev_t dev; register struct uio *uio; { register struct bpf_d *d = &bpf_dtab[minor(dev)]; int error; int s; /* * Restrict application to use a buffer the same size as * as kernel buffers. */ if (uio->uio_resid != d->bd_bufsize) return (EINVAL); s = splimp(); /* * If the hold buffer is empty, then set a timer and sleep * until either the timeout has occurred or enough packets have * arrived to fill the store buffer. */ while (d->bd_hbuf == 0) { if (d->bd_immediate && d->bd_slen != 0) { /* * A packet(s) either arrived since the previous * read or arrived while we were asleep. * Rotate the buffers and return what's here. */ ROTATE_BUFFERS(d); break; } error = tsleep((caddr_t)d, PRINET|PCATCH, "bpf", d->bd_rtout); if (error == EINTR || error == ERESTART) { splx(s); 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) { splx(s); return (0); } ROTATE_BUFFERS(d); break; } } /* * At this point, we know we have something in the hold slot. */ splx(s); /* * 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. */ error = uiomove(d->bd_hbuf, d->bd_hlen, uio); s = splimp(); d->bd_fbuf = d->bd_hbuf; d->bd_hbuf = 0; splx(s); return (error); } /* * If there are processes sleeping on this descriptor, wake them up. */ static inline void bpf_wakeup(d) register struct bpf_d *d; { wakeup((caddr_t)d); if (d->bd_selproc) { selwakeup(d->bd_selproc, (int)d->bd_selcoll); d->bd_selcoll = 0; d->bd_selproc = 0; } } int bpfwrite(dev, uio) dev_t dev; struct uio *uio; { register struct bpf_d *d = &bpf_dtab[minor(dev)]; struct ifnet *ifp; struct mbuf *m; int error, s; static struct sockaddr dst; if (d->bd_bif == 0) return (ENXIO); ifp = d->bd_bif->bif_ifp; if (uio->uio_resid == 0) return (0); if (uio->uio_resid > ifp->if_mtu) return (EMSGSIZE); error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst); if (error) return (error); s = splnet(); error = (*ifp->if_output)(ifp, m, &dst); splx(s); /* * The driver frees the mbuf. */ return (error); } /* * Reset a descriptor by flushing its packet bufferand clearing the receive * and drop counts. Should be called at splimp. */ static void reset_d(d) struct bpf_d *d; { if (d->bd_hbuf) { /* Free the hold buffer. */ d->bd_fbuf = d->bd_hbuf; d->bd_hbuf = 0; } d->bd_slen = 0; d->bd_rcount = 0; d->bd_dcount = 0; } /* * FIONREAD Check for read packet available. * SIOCGIFADDR Get interface address - convenient hook to driver. * BIOCGFLEN Get max filter len. * BIOCGBLEN Get buffer len [for read()]. * BIOCSETF Set ethernet read 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. */ /* ARGSUSED */ int bpfioctl(dev, cmd, addr, flag) dev_t dev; int cmd; caddr_t addr; int flag; { register struct bpf_d *d = &bpf_dtab[minor(dev)]; int s, error = 0; switch (cmd) { default: error = EINVAL; break; /* * Check for read packet available. */ case FIONREAD: { int n; s = splimp(); n = d->bd_slen; if (d->bd_hbuf) n += d->bd_hlen; splx(s); *(int *)addr = n; break; } case SIOCGIFADDR: { struct ifnet *ifp; if (d->bd_bif == 0) error = EINVAL; else { ifp = d->bd_bif->bif_ifp; error = (*ifp->if_ioctl)(ifp, cmd, addr); } break; } /* * Get max filter len. */ case BIOCGFLEN: *(u_int *)addr = BPF_MAXINSNS; break; /* * Get buffer len [for read()]. */ case BIOCGBLEN: *(u_int *)addr = d->bd_bufsize; break; /* * Set ethernet read filter. */ case BIOCSETF: error = bpf_setf(d, (struct bpf_program *)addr); break; /* * Flush read packet buffer. */ case BIOCFLUSH: s = splimp(); reset_d(d); splx(s); break; /* * Put interface into promiscuous mode. */ case BIOCPROMISC: if (d->bd_bif == 0) { /* * No interface attached yet. */ error = EINVAL; break; } s = splimp(); if (d->bd_promisc == 0) { d->bd_promisc = 1; error = ifpromisc(d->bd_bif->bif_ifp, 1); } splx(s); break; /* * Get device parameters. */ case BIOCGDLT: if (d->bd_bif == 0) error = EINVAL; else *(u_int *)addr = d->bd_bif->bif_dlt; break; /* * Set interface name. */ case BIOCGETIF: if (d->bd_bif == 0) error = EINVAL; else bpf_ifname(d->bd_bif->bif_ifp, (struct ifreq *)addr); break; /* * Set interface. */ case BIOCSETIF: error = bpf_setif(d, (struct ifreq *)addr); break; /* * Set read timeout. */ case BIOCSRTIMEOUT: { struct timeval *tv = (struct timeval *)addr; u_long msec; /* Compute number of milliseconds. */ msec = tv->tv_sec * 1000 + tv->tv_usec / 1000; /* Scale milliseconds to ticks. Assume hard clock has millisecond or greater resolution (i.e. tick >= 1000). For 10ms hardclock, tick/1000 = 10, so rtout<-msec/10. */ d->bd_rtout = msec / (tick / 1000); break; } /* * Get read timeout. */ case BIOCGRTIMEOUT: { struct timeval *tv = (struct timeval *)addr; u_long msec = d->bd_rtout; msec *= tick / 1000; tv->tv_sec = msec / 1000; tv->tv_usec = msec % 1000; break; } /* * Get packet stats. */ case BIOCGSTATS: { struct bpf_stat *bs = (struct bpf_stat *)addr; 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; } return (error); } /* * Set d's packet filter program to 'fp'. If 'd' already has a filter, * free it and replace it. Returns EINVAL for bogus requests. */ int bpf_setf(d, fp) struct bpf_d *d; struct bpf_program *fp; { struct bpf_insn *fcode, *old; u_int flen, size; int s; old = d->bd_filter; if (fp->bf_insns == 0) { if (fp->bf_len != 0) return (EINVAL); s = splimp(); d->bd_filter = 0; reset_d(d); splx(s); if (old != 0) free((caddr_t)old, M_DEVBUF); return (0); } flen = fp->bf_len; if (flen > BPF_MAXINSNS) return (EINVAL); size = flen * sizeof(*fp->bf_insns); fcode = (struct bpf_insn *)malloc(size, M_DEVBUF, M_WAITOK); if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size)) return (EINVAL); if (bpf_validate(fcode, (int)flen)) { s = splimp(); d->bd_filter = fcode; reset_d(d); splx(s); if (old != 0) free((caddr_t)old, M_DEVBUF); return (0); } free((caddr_t)fcode, M_DEVBUF); return (EINVAL); } /* * Detach 'd' from its current interface (if attached at all) and attach to * the interface named 'name'. Return ioctl error code or 0. */ static int bpf_setif(d, ifr) struct bpf_d *d; struct ifreq *ifr; { struct bpf_if *bp; char *cp; int unit, s; /* * Separate string into name part and unit number. Put a null * byte at the end of the name part, and compute the number. * If the a unit number is unspecified, the default is 0, * as initialized above. XXX This should be common code. */ unit = 0; cp = ifr->ifr_name; cp[sizeof(ifr->ifr_name) - 1] = '\0'; while (*cp++) { if (*cp >= '0' && *cp <= '9') { unit = *cp - '0'; *cp++ = '\0'; while (*cp) unit = 10 * unit + *cp++ - '0'; break; } } /* * Look through attached interfaces for the named one. */ for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) { struct ifnet *ifp = bp->bif_ifp; if (ifp == 0 || unit != ifp->if_unit || strcmp(ifp->if_name, ifr->ifr_name) != 0) continue; /* * We found the requested interface. If we're * already attached to it, just flush the buffer. * If it's not up, return an error. */ if ((ifp->if_flags & IFF_UP) == 0) return (ENETDOWN); s = splimp(); if (bp != d->bd_bif) { if (d->bd_bif) /* * Detach if attached to something else. */ bpf_detachd(d); bpf_attachd(d, bp); } reset_d(d); splx(s); return (0); } /* Not found. */ return (ENXIO); } /* * Lookup the name of the 'ifp' interface and return it in 'ifr->ifr_name'. * We augment the ifp's base name with its unit number. */ static void bpf_ifname(ifp, ifr) struct ifnet *ifp; struct ifreq *ifr; { char *s = ifp->if_name; char *d = ifr->ifr_name; while (*d++ = *s++) ; /* XXX Assume that unit number is less than 10. */ *d++ = ifp->if_unit + '0'; *d = '\0'; } /* * Support for select() system call * Inspired by the code in tty.c for the same purpose. * * bpfselect - returns true iff the specific operation * will not block indefinitely. Otherwise, return * false but make a note that a selwakeup() must be done. */ int bpfselect(dev, rw, p) register dev_t dev; int rw; struct proc *p; { register struct bpf_d *d; register int s; if (rw != FREAD) return (0); /* * An imitation of the FIONREAD ioctl code. */ d = &bpf_dtab[minor(dev)]; s = splimp(); if (d->bd_hlen != 0 || (d->bd_immediate && d->bd_slen != 0)) { /* * There is data waiting. */ splx(s); return (1); } /* * No data ready. If there's already a select() waiting on this * minor device then this is a collision. This shouldn't happen * because minors really should not be shared, but if a process * forks while one of these is open, it is possible that both * processes could select on the same descriptor. */ if (d->bd_selproc && d->bd_selproc->p_wchan == (caddr_t)&selwait) d->bd_selcoll = 1; else d->bd_selproc = p; splx(s); return (0); } /* * bpf_tap - incoming linkage from device drivers */ void bpf_tap(arg, pkt, pktlen) caddr_t arg; register u_char *pkt; register u_int pktlen; { struct bpf_if *bp; register struct bpf_d *d; register u_int slen; /* * Note that the ipl does not have to be raised at this point. * The only problem that could arise here is that if two different * interfaces shared any data. This is not the case. */ bp = (struct bpf_if *)arg; for (d = bp->bif_dlist; d != 0; d = d->bd_next) { ++d->bd_rcount; slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen); if (slen != 0) catchpacket(d, pkt, pktlen, slen, bcopy); } } /* * Copy data from an mbuf chain into a buffer. This code is derived * from m_copydata in sys/uipc_mbuf.c. */ static void bpf_mcopy(src, dst, len) u_char *src; u_char *dst; register int len; { register struct mbuf *m = (struct mbuf *)src; register unsigned count; while (len > 0) { if (m == 0) panic("bpf_mcopy"); count = MIN(m->m_len, len); bcopy(mtod(m, caddr_t), (caddr_t)dst, count); m = m->m_next; dst += count; len -= count; } } /* * bpf_mtap - incoming linkage from device drivers, when packet * is in an mbuf chain */ void bpf_mtap(arg, m) caddr_t arg; struct mbuf *m; { struct bpf_if *bp = (struct bpf_if *)arg; struct bpf_d *d; u_int pktlen, slen; struct mbuf *m0; pktlen = 0; for (m0 = m; m0 != m; m0 = m0->m_next) pktlen += m0->m_len; for (d = bp->bif_dlist; d != 0; d = d->bd_next) { ++d->bd_rcount; slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0); if (slen != 0) catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy); } } /* * Move the packet data from interface memory (pkt) into the * store buffer. Return 1 if it's time to wakeup a listener (buffer full), * otherwise 0. 'copy' is the routine called to do the actual data * transfer. 'bcopy' is passed in to copy contiguous chunks, while * 'bpf_mcopy' is passed in to copy mbuf chains. In the latter * case, 'pkt' is really an mbuf. */ static void catchpacket(d, pkt, pktlen, snaplen, cpfn) register struct bpf_d *d; register u_char *pkt; register u_int pktlen, snaplen; register void (*cpfn)(); { register struct bpf_hdr *hp; register int totlen, curlen; register int hdrlen = d->bd_bif->bif_hdrlen; /* * 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). */ 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. */ curlen = BPF_WORDALIGN(d->bd_slen); if (curlen + totlen > d->bd_bufsize) { /* * This packet will overflow the storage buffer. * Rotate the buffers if we can, then wakeup any * pending reads. */ if (d->bd_fbuf == 0) { /* * We haven't completed the previous read yet, * so drop the packet. */ ++d->bd_dcount; return; } ROTATE_BUFFERS(d); bpf_wakeup(d); curlen = 0; } else if (d->bd_immediate) /* * Immediate mode is set. A packet arrived so any * reads should be woken up. */ bpf_wakeup(d); /* * Append the bpf header. */ hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); #ifdef sun uniqtime(&hp->bh_tstamp); #else #ifdef hp300 microtime(&hp->bh_tstamp); #else hp->bh_tstamp = time; #endif #endif hp->bh_datalen = pktlen; hp->bh_hdrlen = hdrlen; /* * Copy the packet data into the store buffer and update its length. */ (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); d->bd_slen = curlen + totlen; } /* * Initialize all nonzero fields of a descriptor. */ static int bpf_initd(d) register struct bpf_d *d; { d->bd_bufsize = bpf_bufsize; d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_DEVBUF, M_WAITOK); if (d->bd_fbuf == 0) return (ENOBUFS); d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_DEVBUF, M_WAITOK); if (d->bd_sbuf == 0) { free(d->bd_fbuf, M_DEVBUF); return (ENOBUFS); } d->bd_slen = 0; d->bd_hlen = 0; return (0); } /* * Register 'ifp' with bpf. XXX * and 'driverp' is a pointer to the 'struct bpf_if *' in the driver's softc. */ void bpfattach(driverp, ifp, dlt, hdrlen) caddr_t *driverp; struct ifnet *ifp; u_int dlt, hdrlen; { struct bpf_if *bp; int i; bp = (struct bpf_if *)malloc(sizeof(*bp), M_DEVBUF, M_DONTWAIT); if (bp == 0) panic("bpfattach"); bp->bif_dlist = 0; bp->bif_driverp = (struct bpf_if **)driverp; bp->bif_ifp = ifp; bp->bif_dlt = dlt; bp->bif_next = bpf_iflist; bpf_iflist = bp; *bp->bif_driverp = 0; /* * Compute the length of the bpf header. This is not necessarily * equal to SIZEOF_BPF_HDR because we want to insert spacing such * that the network layer header begins on a longword boundary (for * performance reasons and to alleviate alignment restrictions). */ bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen; /* * Mark all the descriptors free if this hasn't been done. */ if (!D_ISFREE(&bpf_dtab[0])) for (i = 0; i < NBPFILTER; ++i) D_MARKFREE(&bpf_dtab[i]); printf("bpf: %s%d attached\n", ifp->if_name, ifp->if_unit); } /* XXX This routine belongs in net/if.c. */ /* * Set/clear promiscuous mode on interface ifp based on the truth value` * of pswitch. The calls are reference counted so that only the first * on request actually has an effect, as does the final off request. * Results are undefined if the off and on requests are not matched. */ int ifpromisc(ifp, pswitch) struct ifnet *ifp; int pswitch; { struct ifreq ifr; /* * If the device is not configured up, we cannot put it in * promiscuous mode. */ if ((ifp->if_flags & IFF_UP) == 0) return (ENETDOWN); if (pswitch) { if (ifp->if_pcount++ != 0) return (0); ifp->if_flags |= IFF_PROMISC; } else { if (--ifp->if_pcount > 0) return (0); ifp->if_flags &= ~IFF_PROMISC; } ifr.ifr_flags = ifp->if_flags; return ((*ifp->if_ioctl)(ifp, SIOCSIFFLAGS, (caddr_t)&ifr)); } #endif (NBPFILTER > 0)