4.4BSD/usr/src/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.
* 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 8.1 (Berkeley) 6/10/93
*
* static char rcsid[] =
* "$Header: bpf.c,v 1.33 91/10/27 21:21:58 mccanne Exp $";
*/
#include "bpfilter.h"
#if NBPFILTER > 0
#ifndef __GNUC__
#define inline
#else
#define inline __inline
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/buf.h>
#include <sys/time.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/ioctl.h>
#include <sys/map.h>
#include <sys/file.h>
#if defined(sparc) && BSD < 199103
#include <sys/stream.h>
#endif
#include <sys/tty.h>
#include <sys/uio.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/bpf.h>
#include <net/bpfdesc.h>
#include <sys/errno.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <sys/kernel.h>
/*
* Older BSDs don't have kernel malloc.
*/
#if BSD < 199103
extern bcopy();
static caddr_t bpf_alloc();
#include <net/bpf_compat.h>
#define BPF_BUFSIZE (MCLBYTES-8)
#define UIOMOVE(cp, len, code, uio) uiomove(cp, len, code, uio)
#else
#define BPF_BUFSIZE 4096
#define UIOMOVE(cp, len, code, uio) uiomove(cp, len, uio)
#endif
#define PRINET 26 /* interruptible */
/*
* The default read buffer size is patchable.
*/
int bpf_bufsize = BPF_BUFSIZE;
/*
* bpf_iflist is the list of interfaces; each corresponds to an ifnet
* bpf_dtab holds the descriptors, indexed by minor device #
*/
struct bpf_if *bpf_iflist;
struct bpf_d bpf_dtab[NBPFILTER];
#if BSD >= 199207
/*
* bpfilterattach() is called at boot time in new systems. We do
* nothing here since old systems will not call this.
*/
/* ARGSUSED */
void
bpfilterattach(n)
int n;
{
}
#endif
static int bpf_allocbufs __P((struct bpf_d *));
static int bpf_allocbufs __P((struct bpf_d *));
static void bpf_freed __P((struct bpf_d *));
static void bpf_freed __P((struct bpf_d *));
static void bpf_ifname __P((struct ifnet *, struct ifreq *));
static void bpf_ifname __P((struct ifnet *, struct ifreq *));
static void bpf_mcopy __P((void *, void *, u_int));
static int bpf_movein __P((struct uio *, int,
struct mbuf **, struct sockaddr *, int *));
static int bpf_setif __P((struct bpf_d *, struct ifreq *));
static int bpf_setif __P((struct bpf_d *, struct ifreq *));
static inline void
bpf_wakeup __P((struct bpf_d *));
static void catchpacket __P((struct bpf_d *, u_char *, u_int,
u_int, void (*)(void *, void *, u_int)));
static void reset_d __P((struct bpf_d *));
static int
bpf_movein(uio, linktype, mp, sockp, datlen)
register struct uio *uio;
int linktype, *datlen;
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;
case DLT_NULL:
sockp->sa_family = AF_UNSPEC;
hlen = 0;
break;
default:
return (EIO);
}
len = uio->uio_resid;
*datlen = len - hlen;
if ((unsigned)len > MCLBYTES)
return (EIO);
MGET(m, M_WAIT, MT_DATA);
if (m == 0)
return (ENOBUFS);
if (len > MLEN) {
#if BSD >= 199103
MCLGET(m, M_WAIT);
if ((m->m_flags & M_EXT) == 0) {
#else
MCLGET(m);
if (m->m_len != MCLBYTES) {
#endif
error = ENOBUFS;
goto bad;
}
}
m->m_len = len;
*mp = m;
/*
* Make room for link header.
*/
if (hlen != 0) {
m->m_len -= hlen;
#if BSD >= 199103
m->m_data += hlen; /* XXX */
#else
m->m_off += hlen;
#endif
error = UIOMOVE((caddr_t)sockp->sa_data, hlen, UIO_WRITE, uio);
if (error)
goto bad;
}
error = UIOMOVE(mtod(m, caddr_t), len - hlen, UIO_WRITE, uio);
if (!error)
return (0);
bad:
m_freem(m);
return (error);
}
/*
* Attach file to the bpf interface, 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, 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.
*/
d->bd_bif = bp;
d->bd_next = bp->bif_dlist;
bp->bif_dlist = d;
*bp->bif_driverp = bp;
}
/*
* Detach a file from its interface.
*/
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: 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)
/*
* Open ethernet device. Returns ENXIO for illegal minor device number,
* EBUSY if file is open by another process.
*/
/* ARGSUSED */
int
bpfopen(dev, flag)
dev_t dev;
int flag;
{
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.
*/
d = &bpf_dtab[minor(dev)];
if (!D_ISFREE(d))
return (EBUSY);
/* Mark "free" and do most initialization. */
bzero((char *)d, sizeof(*d));
d->bd_bufsize = bpf_bufsize;
return (0);
}
/*
* Close the descriptor by detaching it from its interface,
* deallocating its buffers, and marking it free.
*/
/* ARGSUSED */
int
bpfclose(dev, flag)
dev_t dev;
int flag;
{
register struct bpf_d *d = &bpf_dtab[minor(dev)];
register int s;
s = splimp();
if (d->bd_bif)
bpf_detachd(d);
splx(s);
bpf_freed(d);
return (0);
}
/*
* Support for SunOS, which does not have tsleep.
*/
#if BSD < 199103
static
bpf_timeout(arg)
caddr_t arg;
{
struct bpf_d *d = (struct bpf_d *)arg;
d->bd_timedout = 1;
wakeup(arg);
}
#define BPF_SLEEP(chan, pri, s, t) bpf_sleep((struct bpf_d *)chan)
int
bpf_sleep(d)
register struct bpf_d *d;
{
register int rto = d->bd_rtout;
register int st;
if (rto != 0) {
d->bd_timedout = 0;
timeout(bpf_timeout, (caddr_t)d, rto);
}
st = sleep((caddr_t)d, PRINET|PCATCH);
if (rto != 0) {
if (d->bd_timedout == 0)
untimeout(bpf_timeout, (caddr_t)d);
else if (st == 0)
return EWOULDBLOCK;
}
return (st != 0) ? EINTR : 0;
}
#else
#define BPF_SLEEP tsleep
#endif
/*
* 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 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 == 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 = BPF_SLEEP((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_READ, uio);
s = splimp();
d->bd_fbuf = d->bd_hbuf;
d->bd_hbuf = 0;
d->bd_hlen = 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 BSD >= 199103
selwakeup(&d->bd_sel);
/* XXX */
d->bd_sel.si_pid = 0;
#else
if (d->bd_selproc) {
selwakeup(d->bd_selproc, (int)d->bd_selcoll);
d->bd_selcoll = 0;
d->bd_selproc = 0;
}
#endif
}
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;
int datlen;
if (d->bd_bif == 0)
return (ENXIO);
ifp = d->bd_bif->bif_ifp;
if (uio->uio_resid == 0)
return (0);
error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen);
if (error)
return (error);
if (datlen > ifp->if_mtu)
return (EMSGSIZE);
s = splnet();
#if BSD >= 199103
error = (*ifp->if_output)(ifp, m, &dst, (struct rtentry *)0);
#else
error = (*ifp->if_output)(ifp, m, &dst);
#endif
splx(s);
/*
* The driver frees the mbuf.
*/
return (error);
}
/*
* Reset a descriptor by flushing its packet buffer and 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_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.
*/
/* 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 buffer len [for read()].
*/
case BIOCGBLEN:
*(u_int *)addr = d->bd_bufsize;
break;
/*
* Set buffer length.
*/
case BIOCSBLEN:
#if BSD < 199103
error = EINVAL;
#else
if (d->bd_bif != 0)
error = EINVAL;
else {
register 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;
}
#endif
break;
/*
* Set link layer 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) {
error = ifpromisc(d->bd_bif->bif_ifp, 1);
if (error == 0)
d->bd_promisc = 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;
case BIOCVERSION:
{
struct bpf_version *bv = (struct bpf_version *)addr;
bv->bv_major = BPF_MAJOR_VERSION;
bv->bv_minor = BPF_MINOR_VERSION;
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.
*/
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) == 0 &&
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 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;
char *cp;
int unit, s, error;
/*
* 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 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 == 0) {
error = bpf_allocbufs(d);
if (error != 0)
return (error);
}
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);
}
/*
* Convert an interface name plus unit number of an ifp to a single
* name which is returned in the ifr.
*/
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++)
continue;
/* XXX Assume that unit number is less than 10. */
*d++ = ifp->if_unit + '0';
*d = '\0';
}
/*
* The new select interface passes down the proc pointer; the old select
* stubs had to grab it out of the user struct. This glue allows either case.
*/
#if BSD >= 199103
#define bpf_select bpfselect
#else
int
bpfselect(dev, rw)
register dev_t dev;
int rw;
{
return (bpf_select(dev, rw, u.u_procp));
}
#endif
/*
* Support for select() system call
*
* Return true iff the specific operation will not block indefinitely.
* Otherwise, return false but make a note that a selwakeup() must be done.
*/
int
bpf_select(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);
}
#if BSD >= 199103
selrecord(p, &d->bd_sel);
#else
/*
* 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;
#endif
splx(s);
return (0);
}
/*
* 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(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_arg, dst_arg, len)
void *src_arg, *dst_arg;
register u_int len;
{
register struct mbuf *m;
register u_int count;
u_char *src, *dst;
src = src_arg;
dst = dst_arg;
m = src_arg;
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;
}
}
/*
* 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 != 0; 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);
#if BSD >= 199103
microtime(&hp->bh_tstamp);
#elif defined(sun)
uniqtime(&hp->bh_tstamp);
#else
hp->bh_tstamp = time;
#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_allocbufs(d)
register struct bpf_d *d;
{
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);
}
/*
* Free buffers currently in use by a descriptor.
* Called on close.
*/
static void
bpf_freed(d)
register 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 != 0) {
free(d->bd_sbuf, M_DEVBUF);
if (d->bd_hbuf != 0)
free(d->bd_hbuf, M_DEVBUF);
if (d->bd_fbuf != 0)
free(d->bd_fbuf, M_DEVBUF);
}
if (d->bd_filter)
free((caddr_t)d->bd_filter, M_DEVBUF);
D_MARKFREE(d);
}
/*
* Attach an interface to bpf. driverp is a pointer to a (struct bpf_if *)
* in the driver's softc; dlt is the link layer type; hdrlen is the fixed
* size of the link header (variable length headers not yet supported).
*/
void
bpfattach(driverp, ifp, dlt, hdrlen)
caddr_t *driverp;
struct ifnet *ifp;
u_int dlt, hdrlen;
{
struct bpf_if *bp;
int i;
#if BSD < 199103
static struct bpf_if bpf_ifs[NBPFILTER];
static int bpfifno;
bp = (bpfifno < NBPFILTER) ? &bpf_ifs[bpfifno++] : 0;
#else
bp = (struct bpf_if *)malloc(sizeof(*bp), M_DEVBUF, M_DONTWAIT);
#endif
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);
}
#if BSD >= 199103
/* 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
#if BSD < 199103
/*
* Allocate some memory for bpf. This is temporary SunOS support, and
* is admittedly a hack.
* If resources unavaiable, return 0.
*/
static caddr_t
bpf_alloc(size, canwait)
register int size;
register int canwait;
{
register struct mbuf *m;
if ((unsigned)size > (MCLBYTES-8))
return 0;
MGET(m, canwait, MT_DATA);
if (m == 0)
return 0;
if ((unsigned)size > (MLEN-8)) {
MCLGET(m);
if (m->m_len != MCLBYTES) {
m_freem(m);
return 0;
}
}
*mtod(m, struct mbuf **) = m;
return mtod(m, caddr_t) + 8;
}
#endif
#endif