FreeBSD-5.3/sys/net/bpf.c
/*
* 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
*
* $FreeBSD: src/sys/net/bpf.c,v 1.133.2.2 2004/10/11 03:45:21 green Exp $
*/
#include "opt_bpf.h"
#include "opt_mac.h"
#include "opt_netgraph.h"
#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/mac.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/time.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/filio.h>
#include <sys/sockio.h>
#include <sys/ttycom.h>
#include <sys/filedesc.h>
#include <sys/event.h>
#include <sys/file.h>
#include <sys/poll.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/vnode.h>
#include <net/if.h>
#include <net/bpf.h>
#include <net/bpfdesc.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
static MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
#if defined(DEV_BPF) || defined(NETGRAPH_BPF)
#define PRINET 26 /* interruptible */
/*
* The default read buffer size is patchable.
*/
static int bpf_bufsize = 4096;
SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
&bpf_bufsize, 0, "");
static int bpf_maxbufsize = BPF_MAXBUFSIZE;
SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
&bpf_maxbufsize, 0, "");
/*
* bpf_iflist is the list of interfaces; each corresponds to an ifnet
*/
static LIST_HEAD(, bpf_if) bpf_iflist;
static struct mtx bpf_mtx; /* bpf global lock */
static int bpf_allocbufs(struct bpf_d *);
static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp);
static void bpf_detachd(struct bpf_d *d);
static void bpf_freed(struct bpf_d *);
static void bpf_mcopy(const void *, void *, size_t);
static int bpf_movein(struct uio *, int,
struct mbuf **, struct sockaddr *, int *);
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 (*)(const void *, void *, size_t));
static void reset_d(struct bpf_d *);
static int bpf_setf(struct bpf_d *, struct bpf_program *);
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 d_open_t bpfopen;
static d_close_t bpfclose;
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_flags = D_NEEDGIANT,
.d_open = bpfopen,
.d_close = bpfclose,
.d_read = bpfread,
.d_write = bpfwrite,
.d_ioctl = bpfioctl,
.d_poll = bpfpoll,
.d_name = "bpf",
.d_kqfilter = bpfkqfilter,
};
static struct filterops bpfread_filtops =
{ 1, NULL, filt_bpfdetach, filt_bpfread };
static int
bpf_movein(uio, linktype, mp, sockp, datlen)
struct uio *uio;
int linktype, *datlen;
struct mbuf **mp;
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 = ETHER_HDR_LEN;
break;
case DLT_FDDI:
sockp->sa_family = AF_IMPLINK;
hlen = 0;
break;
case DLT_RAW:
case DLT_NULL:
sockp->sa_family = AF_UNSPEC;
hlen = 0;
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;
default:
return (EIO);
}
len = uio->uio_resid;
*datlen = len - hlen;
if ((unsigned)len > MCLBYTES)
return (EIO);
if (len > MHLEN) {
m = m_getcl(M_TRYWAIT, MT_DATA, M_PKTHDR);
} else {
MGETHDR(m, M_TRYWAIT, MT_DATA);
}
if (m == NULL)
return (ENOBUFS);
m->m_pkthdr.len = m->m_len = len;
m->m_pkthdr.rcvif = NULL;
*mp = m;
/*
* Make room for link header.
*/
if (hlen != 0) {
m->m_pkthdr.len -= hlen;
m->m_len -= hlen;
#if BSD >= 199103
m->m_data += hlen; /* XXX */
#else
m->m_off += hlen;
#endif
error = uiomove(sockp->sa_data, hlen, uio);
if (error)
goto bad;
}
error = uiomove(mtod(m, void *), len - hlen, uio);
if (!error)
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(d, bp)
struct bpf_d *d;
struct bpf_if *bp;
{
/*
* Point d at bp, and add d to the interface's list of listeners.
* Finally, point the driver's bpf cookie at the interface so
* it will divert packets to bpf.
*/
BPFIF_LOCK(bp);
d->bd_bif = bp;
LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
*bp->bif_driverp = bp;
BPFIF_UNLOCK(bp);
}
/*
* Detach a file from its interface.
*/
static void
bpf_detachd(d)
struct bpf_d *d;
{
int error;
struct bpf_if *bp;
struct ifnet *ifp;
bp = d->bd_bif;
BPFIF_LOCK(bp);
BPFD_LOCK(d);
ifp = d->bd_bif->bif_ifp;
/*
* Remove d from the interface's descriptor list.
*/
LIST_REMOVE(d, bd_next);
/*
* Let the driver know that there are no more listeners.
*/
if (LIST_EMPTY(&bp->bif_dlist))
*bp->bif_driverp = NULL;
d->bd_bif = NULL;
BPFD_UNLOCK(d);
BPFIF_UNLOCK(bp);
/*
* Check if this descriptor had requested promiscuous mode.
* If so, turn it off.
*/
if (d->bd_promisc) {
d->bd_promisc = 0;
error = ifpromisc(ifp, 0);
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);
}
}
}
/*
* Open ethernet device. Returns ENXIO for illegal minor device number,
* EBUSY if file is open by another process.
*/
/* ARGSUSED */
static int
bpfopen(dev, flags, fmt, td)
struct cdev *dev;
int flags;
int fmt;
struct thread *td;
{
struct bpf_d *d;
mtx_lock(&bpf_mtx);
d = dev->si_drv1;
/*
* Each minor can be opened by only one process. If the requested
* minor is in use, return EBUSY.
*/
if (d != NULL) {
mtx_unlock(&bpf_mtx);
return (EBUSY);
}
dev->si_drv1 = (struct bpf_d *)~0; /* mark device in use */
mtx_unlock(&bpf_mtx);
if ((dev->si_flags & SI_NAMED) == 0)
make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600,
"bpf%d", dev2unit(dev));
MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO);
dev->si_drv1 = d;
d->bd_bufsize = bpf_bufsize;
d->bd_sig = SIGIO;
d->bd_seesent = 1;
#ifdef MAC
mac_init_bpfdesc(d);
mac_create_bpfdesc(td->td_ucred, d);
#endif
mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF);
callout_init(&d->bd_callout, debug_mpsafenet ? CALLOUT_MPSAFE : 0);
knlist_init(&d->bd_sel.si_note, &d->bd_mtx);
return (0);
}
/*
* Close the descriptor by detaching it from its interface,
* deallocating its buffers, and marking it free.
*/
/* ARGSUSED */
static int
bpfclose(dev, flags, fmt, td)
struct cdev *dev;
int flags;
int fmt;
struct thread *td;
{
struct bpf_d *d = dev->si_drv1;
BPFD_LOCK(d);
if (d->bd_state == BPF_WAITING)
callout_stop(&d->bd_callout);
d->bd_state = BPF_IDLE;
BPFD_UNLOCK(d);
funsetown(&d->bd_sigio);
mtx_lock(&bpf_mtx);
if (d->bd_bif)
bpf_detachd(d);
mtx_unlock(&bpf_mtx);
#ifdef MAC
mac_destroy_bpfdesc(d);
#endif /* MAC */
knlist_destroy(&d->bd_sel.si_note);
bpf_freed(d);
dev->si_drv1 = NULL;
free(d, M_BPF);
return (0);
}
/*
* 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 = NULL;
/*
* bpfread - read next chunk of packets from buffers
*/
static int
bpfread(dev, uio, ioflag)
struct cdev *dev;
struct uio *uio;
int ioflag;
{
struct bpf_d *d = dev->si_drv1;
int timed_out;
int error;
/*
* Restrict application to use a buffer the same size as
* as kernel buffers.
*/
if (uio->uio_resid != d->bd_bufsize)
return (EINVAL);
BPFD_LOCK(d);
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_immediate || timed_out) && 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;
}
/*
* 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_UNLOCK(d);
return (ENXIO);
}
if (ioflag & IO_NDELAY) {
BPFD_UNLOCK(d);
return (EWOULDBLOCK);
}
error = msleep(d, &d->bd_mtx, PRINET|PCATCH,
"bpf", d->bd_rtout);
if (error == EINTR || error == ERESTART) {
BPFD_UNLOCK(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_UNLOCK(d);
return (0);
}
ROTATE_BUFFERS(d);
break;
}
}
/*
* At this point, we know we have something in the hold slot.
*/
BPFD_UNLOCK(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.
*/
error = uiomove(d->bd_hbuf, d->bd_hlen, uio);
BPFD_LOCK(d);
d->bd_fbuf = d->bd_hbuf;
d->bd_hbuf = NULL;
d->bd_hlen = 0;
BPFD_UNLOCK(d);
return (error);
}
/*
* If there are processes sleeping on this descriptor, wake them up.
*/
static __inline void
bpf_wakeup(d)
struct bpf_d *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(arg)
void *arg;
{
struct bpf_d *d = (struct bpf_d *)arg;
BPFD_LOCK(d);
if (d->bd_state == BPF_WAITING) {
d->bd_state = BPF_TIMED_OUT;
if (d->bd_slen != 0)
bpf_wakeup(d);
}
BPFD_UNLOCK(d);
}
static int
bpfwrite(dev, uio, ioflag)
struct cdev *dev;
struct uio *uio;
int ioflag;
{
struct bpf_d *d = dev->si_drv1;
struct ifnet *ifp;
struct mbuf *m;
int error;
struct sockaddr dst;
int datlen;
if (d->bd_bif == NULL)
return (ENXIO);
ifp = d->bd_bif->bif_ifp;
if (uio->uio_resid == 0)
return (0);
bzero(&dst, sizeof(dst));
error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen);
if (error)
return (error);
if (datlen > ifp->if_mtu)
return (EMSGSIZE);
if (d->bd_hdrcmplt)
dst.sa_family = pseudo_AF_HDRCMPLT;
#ifdef MAC
BPFD_LOCK(d);
mac_create_mbuf_from_bpfdesc(d, m);
BPFD_UNLOCK(d);
#endif
NET_LOCK_GIANT();
error = (*ifp->if_output)(ifp, m, &dst, NULL);
NET_UNLOCK_GIANT();
/*
* The driver frees the mbuf.
*/
return (error);
}
/*
* Reset a descriptor by flushing its packet buffer and clearing the
* receive and drop counts.
*/
static void
reset_d(d)
struct bpf_d *d;
{
mtx_assert(&d->bd_mtx, MA_OWNED);
if (d->bd_hbuf) {
/* Free the hold buffer. */
d->bd_fbuf = d->bd_hbuf;
d->bd_hbuf = NULL;
}
d->bd_slen = 0;
d->bd_hlen = 0;
d->bd_rcount = 0;
d->bd_dcount = 0;
}
/*
* FIONREAD Check for read packet available.
* SIOCGIFADDR Get interface address - convenient hook to driver.
* 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.
* BIOCVERSION Get filter language version.
* BIOCGHDRCMPLT Get "header already complete" flag
* BIOCSHDRCMPLT Set "header already complete" flag
* BIOCGSEESENT Get "see packets sent" flag
* BIOCSSEESENT Set "see packets sent" flag
*/
/* ARGSUSED */
static int
bpfioctl(dev, cmd, addr, flags, td)
struct cdev *dev;
u_long cmd;
caddr_t addr;
int flags;
struct thread *td;
{
struct bpf_d *d = dev->si_drv1;
int error = 0;
BPFD_LOCK(d);
if (d->bd_state == BPF_WAITING)
callout_stop(&d->bd_callout);
d->bd_state = BPF_IDLE;
BPFD_UNLOCK(d);
switch (cmd) {
default:
error = EINVAL;
break;
/*
* Check for read packet available.
*/
case FIONREAD:
{
int n;
BPFD_LOCK(d);
n = d->bd_slen;
if (d->bd_hbuf)
n += d->bd_hlen;
BPFD_UNLOCK(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:
if (d->bd_bif != NULL)
error = EINVAL;
else {
u_int size = *(u_int *)addr;
if (size > bpf_maxbufsize)
*(u_int *)addr = size = bpf_maxbufsize;
else if (size < BPF_MINBUFSIZE)
*(u_int *)addr = size = BPF_MINBUFSIZE;
d->bd_bufsize = size;
}
break;
/*
* Set link layer read filter.
*/
case BIOCSETF:
error = bpf_setf(d, (struct bpf_program *)addr);
break;
/*
* Flush read packet buffer.
*/
case BIOCFLUSH:
BPFD_LOCK(d);
reset_d(d);
BPFD_UNLOCK(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) {
mtx_lock(&Giant);
error = ifpromisc(d->bd_bif->bif_ifp, 1);
mtx_unlock(&Giant);
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.
*/
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:
if (d->bd_bif == NULL)
error = EINVAL;
else
error = bpf_setdlt(d, *(u_int *)addr);
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:
error = bpf_setif(d, (struct ifreq *)addr);
break;
/*
* Set read timeout.
*/
case BIOCSRTIMEOUT:
{
struct timeval *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:
{
struct timeval *tv = (struct timeval *)addr;
tv->tv_sec = d->bd_rtout / hz;
tv->tv_usec = (d->bd_rtout % hz) * tick;
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;
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 "see sent packets" flag
*/
case BIOCGSEESENT:
*(u_int *)addr = d->bd_seesent;
break;
/*
* Set "see sent packets" flag
*/
case BIOCSSEESENT:
d->bd_seesent = *(u_int *)addr;
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;
}
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(d, fp)
struct bpf_d *d;
struct bpf_program *fp;
{
struct bpf_insn *fcode, *old;
u_int flen, size;
old = d->bd_filter;
if (fp->bf_insns == NULL) {
if (fp->bf_len != 0)
return (EINVAL);
BPFD_LOCK(d);
d->bd_filter = NULL;
reset_d(d);
BPFD_UNLOCK(d);
if (old != NULL)
free((caddr_t)old, M_BPF);
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_BPF, M_WAITOK);
if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 &&
bpf_validate(fcode, (int)flen)) {
BPFD_LOCK(d);
d->bd_filter = fcode;
reset_d(d);
BPFD_UNLOCK(d);
if (old != NULL)
free((caddr_t)old, M_BPF);
return (0);
}
free((caddr_t)fcode, M_BPF);
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(d, ifr)
struct bpf_d *d;
struct ifreq *ifr;
{
struct bpf_if *bp;
int error;
struct ifnet *theywant;
theywant = ifunit(ifr->ifr_name);
if (theywant == NULL)
return ENXIO;
/*
* Look through attached interfaces for the named one.
*/
mtx_lock(&bpf_mtx);
LIST_FOREACH(bp, &bpf_iflist, bif_next) {
struct ifnet *ifp = bp->bif_ifp;
if (ifp == NULL || ifp != theywant)
continue;
/* skip additional entry */
if (bp->bif_driverp != (struct bpf_if **)&ifp->if_bpf)
continue;
mtx_unlock(&bpf_mtx);
/*
* We found the requested interface.
* If it's not up, return an error.
* Allocate the packet buffers if we need to.
* If we're already attached to requested interface,
* just flush the buffer.
*/
if ((ifp->if_flags & IFF_UP) == 0)
return (ENETDOWN);
if (d->bd_sbuf == NULL) {
error = bpf_allocbufs(d);
if (error != 0)
return (error);
}
if (bp != d->bd_bif) {
if (d->bd_bif)
/*
* Detach if attached to something else.
*/
bpf_detachd(d);
bpf_attachd(d, bp);
}
BPFD_LOCK(d);
reset_d(d);
BPFD_UNLOCK(d);
return (0);
}
mtx_unlock(&bpf_mtx);
/* Not found. */
return (ENXIO);
}
/*
* 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(dev, events, td)
struct cdev *dev;
int events;
struct thread *td;
{
struct bpf_d *d;
int revents;
d = dev->si_drv1;
if (d->bd_bif == NULL)
return (ENXIO);
revents = events & (POLLOUT | POLLWRNORM);
BPFD_LOCK(d);
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_UNLOCK(d);
return (revents);
}
/*
* Support for kevent() system call. Register EVFILT_READ filters and
* reject all others.
*/
int
bpfkqfilter(dev, kn)
struct cdev *dev;
struct knote *kn;
{
struct bpf_d *d = (struct bpf_d *)dev->si_drv1;
if (kn->kn_filter != EVFILT_READ)
return (1);
kn->kn_fop = &bpfread_filtops;
kn->kn_hook = d;
knlist_add(&d->bd_sel.si_note, kn, 0);
return (0);
}
static void
filt_bpfdetach(kn)
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(kn, hint)
struct knote *kn;
long hint;
{
struct bpf_d *d = (struct bpf_d *)kn->kn_hook;
int ready;
BPFD_LOCK(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;
}
BPFD_UNLOCK(d);
return (ready);
}
/*
* 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(bp, pkt, pktlen)
struct bpf_if *bp;
u_char *pkt;
u_int pktlen;
{
struct bpf_d *d;
u_int slen;
/*
* Lockless read to avoid cost of locking the interface if there are
* no descriptors attached.
*/
if (LIST_EMPTY(&bp->bif_dlist))
return;
BPFIF_LOCK(bp);
LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
BPFD_LOCK(d);
++d->bd_rcount;
slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen);
if (slen != 0) {
#ifdef MAC
if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0)
#endif
catchpacket(d, pkt, pktlen, slen, bcopy);
}
BPFD_UNLOCK(d);
}
BPFIF_UNLOCK(bp);
}
/*
* 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_arg, dst_arg, len)
const void *src_arg;
void *dst_arg;
size_t len;
{
const struct mbuf *m;
u_int count;
u_char *dst;
m = src_arg;
dst = dst_arg;
while (len > 0) {
if (m == NULL)
panic("bpf_mcopy");
count = min(m->m_len, len);
bcopy(mtod(m, void *), dst, count);
m = m->m_next;
dst += count;
len -= count;
}
}
/*
* Incoming linkage from device drivers, when packet is in an mbuf chain.
*/
void
bpf_mtap(bp, m)
struct bpf_if *bp;
struct mbuf *m;
{
struct bpf_d *d;
u_int pktlen, slen;
/*
* Lockless read to avoid cost of locking the interface if there are
* no descriptors attached.
*/
if (LIST_EMPTY(&bp->bif_dlist))
return;
pktlen = m_length(m, NULL);
if (pktlen == m->m_len) {
bpf_tap(bp, mtod(m, u_char *), pktlen);
return;
}
BPFIF_LOCK(bp);
LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
continue;
BPFD_LOCK(d);
++d->bd_rcount;
slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0);
if (slen != 0)
#ifdef MAC
if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0)
#endif
catchpacket(d, (u_char *)m, pktlen, slen,
bpf_mcopy);
BPFD_UNLOCK(d);
}
BPFIF_UNLOCK(bp);
}
/*
* Incoming linkage from device drivers, when packet is in
* an mbuf chain and to be prepended by a contiguous header.
*/
void
bpf_mtap2(bp, data, dlen, m)
struct bpf_if *bp;
void *data;
u_int dlen;
struct mbuf *m;
{
struct mbuf mb;
struct bpf_d *d;
u_int pktlen, slen;
/*
* Lockless read to avoid cost of locking the interface if there are
* no descriptors attached.
*/
if (LIST_EMPTY(&bp->bif_dlist))
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;
BPFIF_LOCK(bp);
LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
if (!d->bd_seesent && (m->m_pkthdr.rcvif == NULL))
continue;
BPFD_LOCK(d);
++d->bd_rcount;
slen = bpf_filter(d->bd_filter, (u_char *)&mb, pktlen, 0);
if (slen != 0)
#ifdef MAC
if (mac_check_bpfdesc_receive(d, bp->bif_ifp) == 0)
#endif
catchpacket(d, (u_char *)&mb, pktlen, slen,
bpf_mcopy);
BPFD_UNLOCK(d);
}
BPFIF_UNLOCK(bp);
}
/*
* 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_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)
struct bpf_d *d;
u_char *pkt;
u_int pktlen, snaplen;
void (*cpfn)(const void *, void *, size_t);
{
struct bpf_hdr *hp;
int totlen, curlen;
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 == NULL) {
/*
* 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 || 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.
*/
bpf_wakeup(d);
/*
* Append the bpf header.
*/
hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
microtime(&hp->bh_tstamp);
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_allocbufs(d)
struct bpf_d *d;
{
d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK);
if (d->bd_fbuf == NULL)
return (ENOBUFS);
d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK);
if (d->bd_sbuf == NULL) {
free(d->bd_fbuf, M_BPF);
return (ENOBUFS);
}
d->bd_slen = 0;
d->bd_hlen = 0;
return (0);
}
/*
* Free buffers currently in use by a descriptor.
* Called on close.
*/
static void
bpf_freed(d)
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.
*/
if (d->bd_sbuf != NULL) {
free(d->bd_sbuf, M_BPF);
if (d->bd_hbuf != NULL)
free(d->bd_hbuf, M_BPF);
if (d->bd_fbuf != NULL)
free(d->bd_fbuf, M_BPF);
}
if (d->bd_filter)
free((caddr_t)d->bd_filter, M_BPF);
mtx_destroy(&d->bd_mtx);
}
/*
* 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(ifp, dlt, hdrlen)
struct ifnet *ifp;
u_int dlt, 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(ifp, dlt, hdrlen, driverp)
struct ifnet *ifp;
u_int dlt, hdrlen;
struct bpf_if **driverp;
{
struct bpf_if *bp;
bp = (struct bpf_if *)malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO);
if (bp == NULL)
panic("bpfattach");
LIST_INIT(&bp->bif_dlist);
bp->bif_driverp = driverp;
bp->bif_ifp = ifp;
bp->bif_dlt = dlt;
mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF);
mtx_lock(&bpf_mtx);
LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next);
mtx_unlock(&bpf_mtx);
*bp->bif_driverp = NULL;
/*
* 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;
if (bootverbose)
if_printf(ifp, "bpf attached\n");
}
/*
* Detach bpf from an interface. This involves detaching each descriptor
* associated with the interface, and leaving bd_bif NULL. Notify each
* descriptor as it's detached so that any sleepers wake up and get
* ENXIO.
*/
void
bpfdetach(ifp)
struct ifnet *ifp;
{
struct bpf_if *bp;
struct bpf_d *d;
/* Locate BPF interface information */
mtx_lock(&bpf_mtx);
LIST_FOREACH(bp, &bpf_iflist, bif_next) {
if (ifp == bp->bif_ifp)
break;
}
/* Interface wasn't attached */
if ((bp == NULL) || (bp->bif_ifp == NULL)) {
mtx_unlock(&bpf_mtx);
printf("bpfdetach: %s was not attached\n", ifp->if_xname);
return;
}
LIST_REMOVE(bp, bif_next);
mtx_unlock(&bpf_mtx);
while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) {
bpf_detachd(d);
BPFD_LOCK(d);
bpf_wakeup(d);
BPFD_UNLOCK(d);
}
mtx_destroy(&bp->bif_mtx);
free(bp, M_BPF);
}
/*
* Get a list of available data link type of the interface.
*/
static int
bpf_getdltlist(d, bfl)
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;
mtx_lock(&bpf_mtx);
LIST_FOREACH(bp, &bpf_iflist, bif_next) {
if (bp->bif_ifp != ifp)
continue;
if (bfl->bfl_list != NULL) {
if (n >= bfl->bfl_len) {
mtx_unlock(&bpf_mtx);
return (ENOMEM);
}
error = copyout(&bp->bif_dlt,
bfl->bfl_list + n, sizeof(u_int));
}
n++;
}
mtx_unlock(&bpf_mtx);
bfl->bfl_len = n;
return (error);
}
/*
* Set the data link type of a BPF instance.
*/
static int
bpf_setdlt(d, dlt)
struct bpf_d *d;
u_int dlt;
{
int error, opromisc;
struct ifnet *ifp;
struct bpf_if *bp;
if (d->bd_bif->bif_dlt == dlt)
return (0);
ifp = d->bd_bif->bif_ifp;
mtx_lock(&bpf_mtx);
LIST_FOREACH(bp, &bpf_iflist, bif_next) {
if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
break;
}
mtx_unlock(&bpf_mtx);
if (bp != NULL) {
opromisc = d->bd_promisc;
bpf_detachd(d);
bpf_attachd(d, bp);
BPFD_LOCK(d);
reset_d(d);
BPFD_UNLOCK(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);
static void bpf_clone(void *arg, char *name, int namelen, struct cdev **dev);
static void
bpf_clone(arg, name, namelen, dev)
void *arg;
char *name;
int namelen;
struct cdev **dev;
{
int u;
if (*dev != NULL)
return;
if (dev_stdclone(name, NULL, "bpf", &u) != 1)
return;
*dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600,
"bpf%d", u);
(*dev)->si_flags |= SI_CHEAPCLONE;
return;
}
static void
bpf_drvinit(unused)
void *unused;
{
mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF);
LIST_INIT(&bpf_iflist);
EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000);
}
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.
*/
void
bpf_tap(bp, pkt, pktlen)
struct bpf_if *bp;
u_char *pkt;
u_int pktlen;
{
}
void
bpf_mtap(bp, m)
struct bpf_if *bp;
struct mbuf *m;
{
}
void
bpf_mtap2(bp, d, l, m)
struct bpf_if *bp;
void *d;
u_int l;
struct mbuf *m;
{
}
void
bpfattach(ifp, dlt, hdrlen)
struct ifnet *ifp;
u_int dlt, hdrlen;
{
}
void
bpfattach2(ifp, dlt, hdrlen, driverp)
struct ifnet *ifp;
u_int dlt, hdrlen;
struct bpf_if **driverp;
{
}
void
bpfdetach(ifp)
struct ifnet *ifp;
{
}
u_int
bpf_filter(pc, p, wirelen, buflen)
const struct bpf_insn *pc;
u_char *p;
u_int wirelen;
u_int buflen;
{
return -1; /* "no filter" behaviour */
}
int
bpf_validate(f, len)
const struct bpf_insn *f;
int len;
{
return 0; /* false */
}
#endif /* !DEV_BPF && !NETGRAPH_BPF */