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src/sys/net/bpf.c

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/* $OpenBSD: bpf.c,v 1.222 2024/01/26 21:14:08 jan Exp $ */
/* $NetBSD: bpf.c,v 1.33 1997/02/21 23:59:35 thorpej Exp $ */
/*
* Copyright (c) 1990, 1991, 1993
* The Regents of the University of California. All rights reserved.
* Copyright (c) 2010, 2014 Henning Brauer <henning@openbsd.org>
*
* 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. 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 8.2 (Berkeley) 3/28/94
*/
#include "bpfilter.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/ioctl.h>
#include <sys/conf.h>
#include <sys/vnode.h>
#include <sys/fcntl.h>
#include <sys/socket.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/rwlock.h>
#include <sys/atomic.h>
#include <sys/event.h>
#include <sys/mutex.h>
#include <sys/refcnt.h>
#include <sys/smr.h>
#include <sys/specdev.h>
#include <sys/sigio.h>
#include <sys/task.h>
#include <sys/time.h>
#include <net/if.h>
#include <net/bpf.h>
#include <net/bpfdesc.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include "vlan.h"
#if NVLAN > 0
#include <net/if_vlan_var.h>
#endif
#define BPF_BUFSIZE 32768
#define BPF_S_IDLE 0
#define BPF_S_WAIT 1
#define BPF_S_DONE 2
#define PRINET 26 /* interruptible */
/*
* The default read buffer size is patchable.
*/
int bpf_bufsize = BPF_BUFSIZE;
int bpf_maxbufsize = BPF_MAXBUFSIZE;
/*
* bpf_iflist is the list of interfaces; each corresponds to an ifnet
* bpf_d_list is the list of descriptors
*/
struct bpf_if *bpf_iflist;
LIST_HEAD(, bpf_d) bpf_d_list;
int bpf_allocbufs(struct bpf_d *);
void bpf_ifname(struct bpf_if*, struct ifreq *);
void bpf_mcopy(const void *, void *, size_t);
int bpf_movein(struct uio *, struct bpf_d *, struct mbuf **,
struct sockaddr *);
int bpf_setif(struct bpf_d *, struct ifreq *);
int bpfkqfilter(dev_t, struct knote *);
void bpf_wakeup(struct bpf_d *);
void bpf_wakeup_cb(void *);
void bpf_wait_cb(void *);
int _bpf_mtap(caddr_t, const struct mbuf *, const struct mbuf *, u_int);
void bpf_catchpacket(struct bpf_d *, u_char *, size_t, size_t,
const struct bpf_hdr *);
int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
int bpf_setdlt(struct bpf_d *, u_int);
void filt_bpfrdetach(struct knote *);
int filt_bpfread(struct knote *, long);
int filt_bpfreadmodify(struct kevent *, struct knote *);
int filt_bpfreadprocess(struct knote *, struct kevent *);
int bpf_sysctl_locked(int *, u_int, void *, size_t *, void *, size_t);
struct bpf_d *bpfilter_lookup(int);
/*
* Called holding ``bd_mtx''.
*/
void bpf_attachd(struct bpf_d *, struct bpf_if *);
void bpf_detachd(struct bpf_d *);
void bpf_resetd(struct bpf_d *);
void bpf_prog_smr(void *);
void bpf_d_smr(void *);
/*
* Reference count access to descriptor buffers
*/
void bpf_get(struct bpf_d *);
void bpf_put(struct bpf_d *);
struct rwlock bpf_sysctl_lk = RWLOCK_INITIALIZER("bpfsz");
int
bpf_movein(struct uio *uio, struct bpf_d *d, struct mbuf **mp,
struct sockaddr *sockp)
{
struct bpf_program_smr *bps;
struct bpf_insn *fcode = NULL;
struct mbuf *m;
struct m_tag *mtag;
int error;
u_int hlen, alen, mlen;
u_int len;
u_int linktype;
u_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.
*/
linktype = d->bd_bif->bif_dlt;
switch (linktype) {
case DLT_SLIP:
sockp->sa_family = AF_INET;
hlen = 0;
break;
case DLT_PPP:
sockp->sa_family = AF_UNSPEC;
hlen = 0;
break;
case DLT_EN10MB:
sockp->sa_family = AF_UNSPEC;
/* XXX Would MAXLINKHDR be better? */
hlen = ETHER_HDR_LEN;
break;
case DLT_IEEE802_11:
case DLT_IEEE802_11_RADIO:
sockp->sa_family = AF_UNSPEC;
hlen = 0;
break;
case DLT_RAW:
case DLT_NULL:
sockp->sa_family = AF_UNSPEC;
hlen = 0;
break;
case DLT_LOOP:
sockp->sa_family = AF_UNSPEC;
hlen = sizeof(u_int32_t);
break;
default:
return (EIO);
}
if (uio->uio_resid > MAXMCLBYTES)
return (EMSGSIZE);
len = uio->uio_resid;
if (len < hlen)
return (EINVAL);
/*
* Get the length of the payload so we can align it properly.
*/
alen = len - hlen;
/*
* Allocate enough space for headers and the aligned payload.
*/
mlen = max(max_linkhdr, hlen) + roundup(alen, sizeof(long));
if (mlen > MAXMCLBYTES)
return (EMSGSIZE);
MGETHDR(m, M_WAIT, MT_DATA);
if (mlen > MHLEN) {
MCLGETL(m, M_WAIT, mlen);
if ((m->m_flags & M_EXT) == 0) {
error = ENOBUFS;
goto bad;
}
}
m_align(m, alen); /* Align the payload. */
m->m_data -= hlen;
m->m_pkthdr.ph_ifidx = 0;
m->m_pkthdr.len = len;
m->m_len = len;
error = uiomove(mtod(m, caddr_t), len, uio);
if (error)
goto bad;
smr_read_enter();
bps = SMR_PTR_GET(&d->bd_wfilter);
if (bps != NULL)
fcode = bps->bps_bf.bf_insns;
slen = bpf_filter(fcode, mtod(m, u_char *), len, len);
smr_read_leave();
if (slen < len) {
error = EPERM;
goto bad;
}
/*
* Make room for link header, and copy it to sockaddr
*/
if (hlen != 0) {
if (linktype == DLT_LOOP) {
u_int32_t af;
/* the link header indicates the address family */
KASSERT(hlen == sizeof(u_int32_t));
memcpy(&af, m->m_data, hlen);
sockp->sa_family = ntohl(af);
} else
memcpy(sockp->sa_data, m->m_data, hlen);
m->m_pkthdr.len -= hlen;
m->m_len -= hlen;
m->m_data += hlen;
}
/*
* Prepend the data link type as a mbuf tag
*/
mtag = m_tag_get(PACKET_TAG_DLT, sizeof(u_int), M_WAIT);
*(u_int *)(mtag + 1) = linktype;
m_tag_prepend(m, mtag);
*mp = m;
return (0);
bad:
m_freem(m);
return (error);
}
/*
* Attach file to the bpf interface, i.e. make d listen on bp.
*/
void
bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
{
MUTEX_ASSERT_LOCKED(&d->bd_mtx);
/*
* 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;
KERNEL_ASSERT_LOCKED();
SMR_SLIST_INSERT_HEAD_LOCKED(&bp->bif_dlist, d, bd_next);
*bp->bif_driverp = bp;
}
/*
* Detach a file from its interface.
*/
void
bpf_detachd(struct bpf_d *d)
{
struct bpf_if *bp;
MUTEX_ASSERT_LOCKED(&d->bd_mtx);
bp = d->bd_bif;
/* Not attached. */
if (bp == NULL)
return;
/* Remove ``d'' from the interface's descriptor list. */
KERNEL_ASSERT_LOCKED();
SMR_SLIST_REMOVE_LOCKED(&bp->bif_dlist, d, bpf_d, bd_next);
if (SMR_SLIST_EMPTY_LOCKED(&bp->bif_dlist)) {
/*
* Let the driver know that there are no more listeners.
*/
*bp->bif_driverp = NULL;
}
d->bd_bif = NULL;
/*
* Check if this descriptor had requested promiscuous mode.
* If so, turn it off.
*/
if (d->bd_promisc) {
int error;
KASSERT(bp->bif_ifp != NULL);
d->bd_promisc = 0;
bpf_get(d);
mtx_leave(&d->bd_mtx);
NET_LOCK();
error = ifpromisc(bp->bif_ifp, 0);
NET_UNLOCK();
mtx_enter(&d->bd_mtx);
bpf_put(d);
if (error && !(error == EINVAL || error == ENODEV ||
error == ENXIO))
/*
* 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");
}
}
void
bpfilterattach(int n)
{
LIST_INIT(&bpf_d_list);
}
/*
* Open ethernet device. Returns ENXIO for illegal minor device number,
* EBUSY if file is open by another process.
*/
int
bpfopen(dev_t dev, int flag, int mode, struct proc *p)
{
struct bpf_d *bd;
int unit = minor(dev);
if (unit & ((1 << CLONE_SHIFT) - 1))
return (ENXIO);
KASSERT(bpfilter_lookup(unit) == NULL);
/* create on demand */
if ((bd = malloc(sizeof(*bd), M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL)
return (EBUSY);
/* Mark "free" and do most initialization. */
bd->bd_unit = unit;
bd->bd_bufsize = bpf_bufsize;
bd->bd_sig = SIGIO;
mtx_init(&bd->bd_mtx, IPL_NET);
task_set(&bd->bd_wake_task, bpf_wakeup_cb, bd);
timeout_set(&bd->bd_wait_tmo, bpf_wait_cb, bd);
smr_init(&bd->bd_smr);
sigio_init(&bd->bd_sigio);
klist_init_mutex(&bd->bd_klist, &bd->bd_mtx);
bd->bd_rtout = 0; /* no timeout by default */
bd->bd_wtout = INFSLP; /* wait for the buffer to fill by default */
refcnt_init(&bd->bd_refcnt);
LIST_INSERT_HEAD(&bpf_d_list, bd, bd_list);
return (0);
}
/*
* Close the descriptor by detaching it from its interface,
* deallocating its buffers, and marking it free.
*/
int
bpfclose(dev_t dev, int flag, int mode, struct proc *p)
{
struct bpf_d *d;
d = bpfilter_lookup(minor(dev));
mtx_enter(&d->bd_mtx);
bpf_detachd(d);
bpf_wakeup(d);
LIST_REMOVE(d, bd_list);
mtx_leave(&d->bd_mtx);
bpf_put(d);
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) \
KASSERT(d->bd_in_uiomove == 0); \
MUTEX_ASSERT_LOCKED(&d->bd_mtx); \
(d)->bd_hbuf = (d)->bd_sbuf; \
(d)->bd_hlen = (d)->bd_slen; \
(d)->bd_sbuf = (d)->bd_fbuf; \
(d)->bd_state = BPF_S_IDLE; \
(d)->bd_slen = 0; \
(d)->bd_fbuf = NULL;
/*
* bpfread - read next chunk of packets from buffers
*/
int
bpfread(dev_t dev, struct uio *uio, int ioflag)
{
uint64_t end, now;
struct bpf_d *d;
caddr_t hbuf;
int error, hlen;
KERNEL_ASSERT_LOCKED();
d = bpfilter_lookup(minor(dev));
if (d->bd_bif == NULL)
return (ENXIO);
bpf_get(d);
mtx_enter(&d->bd_mtx);
/*
* Restrict application to use a buffer the same size as
* as kernel buffers.
*/
if (uio->uio_resid != d->bd_bufsize) {
error = EINVAL;
goto out;
}
/*
* If there's a timeout, mark when the read should end.
*/
if (d->bd_rtout != 0) {
now = nsecuptime();
end = now + d->bd_rtout;
if (end < now)
end = UINT64_MAX;
}
/*
* 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_bif == NULL) {
/* interface is gone */
if (d->bd_slen == 0) {
error = EIO;
goto out;
}
ROTATE_BUFFERS(d);
break;
}
if (d->bd_state == BPF_S_DONE) {
/*
* 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;
}
if (ISSET(ioflag, IO_NDELAY)) {
/* User requested non-blocking I/O */
error = EWOULDBLOCK;
} else if (d->bd_rtout == 0) {
/* No read timeout set. */
d->bd_nreaders++;
error = msleep_nsec(d, &d->bd_mtx, PRINET|PCATCH,
"bpf", INFSLP);
d->bd_nreaders--;
} else if ((now = nsecuptime()) < end) {
/* Read timeout has not expired yet. */
d->bd_nreaders++;
error = msleep_nsec(d, &d->bd_mtx, PRINET|PCATCH,
"bpf", end - now);
d->bd_nreaders--;
} else {
/* Read timeout has expired. */
error = EWOULDBLOCK;
}
if (error == EINTR || error == ERESTART)
goto out;
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 != NULL)
/*
* 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) {
error = 0;
goto out;
}
ROTATE_BUFFERS(d);
break;
}
}
/*
* At this point, we know we have something in the hold slot.
*/
hbuf = d->bd_hbuf;
hlen = d->bd_hlen;
d->bd_hbuf = NULL;
d->bd_hlen = 0;
d->bd_fbuf = NULL;
d->bd_in_uiomove = 1;
/*
* 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.
*/
mtx_leave(&d->bd_mtx);
error = uiomove(hbuf, hlen, uio);
mtx_enter(&d->bd_mtx);
/* Ensure that bpf_resetd() or ROTATE_BUFFERS() haven't been called. */
KASSERT(d->bd_fbuf == NULL);
KASSERT(d->bd_hbuf == NULL);
d->bd_fbuf = hbuf;
d->bd_in_uiomove = 0;
out:
mtx_leave(&d->bd_mtx);
bpf_put(d);
return (error);
}
/*
* If there are processes sleeping on this descriptor, wake them up.
*/
void
bpf_wakeup(struct bpf_d *d)
{
MUTEX_ASSERT_LOCKED(&d->bd_mtx);
if (d->bd_nreaders)
wakeup(d);
knote_locked(&d->bd_klist, 0);
/*
* As long as pgsigio() needs to be protected
* by the KERNEL_LOCK() we have to delay the wakeup to
* another context to keep the hot path KERNEL_LOCK()-free.
*/
if (d->bd_async && d->bd_sig) {
bpf_get(d);
if (!task_add(systq, &d->bd_wake_task))
bpf_put(d);
}
}
void
bpf_wakeup_cb(void *xd)
{
struct bpf_d *d = xd;
if (d->bd_async && d->bd_sig)
pgsigio(&d->bd_sigio, d->bd_sig, 0);
bpf_put(d);
}
void
bpf_wait_cb(void *xd)
{
struct bpf_d *d = xd;
mtx_enter(&d->bd_mtx);
if (d->bd_state == BPF_S_WAIT) {
d->bd_state = BPF_S_DONE;
bpf_wakeup(d);
}
mtx_leave(&d->bd_mtx);
bpf_put(d);
}
int
bpfwrite(dev_t dev, struct uio *uio, int ioflag)
{
struct bpf_d *d;
struct ifnet *ifp;
struct mbuf *m;
int error;
struct sockaddr_storage dst;
KERNEL_ASSERT_LOCKED();
d = bpfilter_lookup(minor(dev));
if (d->bd_bif == NULL)
return (ENXIO);
bpf_get(d);
ifp = d->bd_bif->bif_ifp;
if (ifp == NULL || (ifp->if_flags & IFF_UP) == 0) {
error = ENETDOWN;
goto out;
}
if (uio->uio_resid == 0) {
error = 0;
goto out;
}
error = bpf_movein(uio, d, &m, sstosa(&dst));
if (error)
goto out;
if (m->m_pkthdr.len > ifp->if_mtu) {
m_freem(m);
error = EMSGSIZE;
goto out;
}
m->m_pkthdr.ph_rtableid = ifp->if_rdomain;
m->m_pkthdr.pf.prio = ifp->if_llprio;
if (d->bd_hdrcmplt && dst.ss_family == AF_UNSPEC)
dst.ss_family = pseudo_AF_HDRCMPLT;
NET_LOCK();
error = ifp->if_output(ifp, m, sstosa(&dst), NULL);
NET_UNLOCK();
out:
bpf_put(d);
return (error);
}
/*
* Reset a descriptor by flushing its packet buffer and clearing the
* receive and drop counts.
*/
void
bpf_resetd(struct bpf_d *d)
{
MUTEX_ASSERT_LOCKED(&d->bd_mtx);
KASSERT(d->bd_in_uiomove == 0);
if (timeout_del(&d->bd_wait_tmo))
bpf_put(d);
if (d->bd_hbuf != NULL) {
/* Free the hold buffer. */
d->bd_fbuf = d->bd_hbuf;
d->bd_hbuf = NULL;
}
d->bd_state = BPF_S_IDLE;
d->bd_slen = 0;
d->bd_hlen = 0;
d->bd_rcount = 0;
d->bd_dcount = 0;
}
static int
bpf_set_wtout(struct bpf_d *d, uint64_t wtout)
{
mtx_enter(&d->bd_mtx);
d->bd_wtout = wtout;
mtx_leave(&d->bd_mtx);
return (0);
}
static int
bpf_set_wtimeout(struct bpf_d *d, const struct timeval *tv)
{
uint64_t nsec;
if (tv->tv_sec < 0 || !timerisvalid(tv))
return (EINVAL);
nsec = TIMEVAL_TO_NSEC(tv);
if (nsec > MAXTSLP)
return (EOVERFLOW);
return (bpf_set_wtout(d, nsec));
}
static int
bpf_get_wtimeout(struct bpf_d *d, struct timeval *tv)
{
uint64_t nsec;
mtx_enter(&d->bd_mtx);
nsec = d->bd_wtout;
mtx_leave(&d->bd_mtx);
if (nsec == INFSLP)
return (ENXIO);
memset(tv, 0, sizeof(*tv));
NSEC_TO_TIMEVAL(nsec, tv);
return (0);
}
/*
* FIONREAD Check for read packet available.
* BIOCGBLEN Get buffer len [for read()].
* BIOCSETF Set ethernet read filter.
* BIOCFLUSH Flush read packet buffer.
* BIOCPROMISC Put interface into promiscuous mode.
* BIOCGDLTLIST Get supported link layer types.
* BIOCGDLT Get link layer type.
* BIOCSDLT Set link layer type.
* BIOCGETIF Get interface name.
* BIOCSETIF Set interface.
* BIOCSRTIMEOUT Set read timeout.
* BIOCGRTIMEOUT Get read timeout.
* BIOCSWTIMEOUT Set wait timeout.
* BIOCGWTIMEOUT Get wait timeout.
* BIOCDWTIMEOUT Del wait 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
*/
int
bpfioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
{
struct bpf_d *d;
int error = 0;
d = bpfilter_lookup(minor(dev));
if (d->bd_locked && suser(p) != 0) {
/* list of allowed ioctls when locked and not root */
switch (cmd) {
case BIOCGBLEN:
case BIOCFLUSH:
case BIOCGDLT:
case BIOCGDLTLIST:
case BIOCGETIF:
case BIOCGRTIMEOUT:
case BIOCGWTIMEOUT:
case BIOCGSTATS:
case BIOCVERSION:
case BIOCGRSIG:
case BIOCGHDRCMPLT:
case FIONREAD:
case BIOCLOCK:
case BIOCSRTIMEOUT:
case BIOCSWTIMEOUT:
case BIOCDWTIMEOUT:
case BIOCIMMEDIATE:
case TIOCGPGRP:
case BIOCGDIRFILT:
break;
default:
return (EPERM);
}
}
bpf_get(d);
switch (cmd) {
default:
error = EINVAL;
break;
/*
* Check for read packet available.
*/
case FIONREAD:
{
int n;
mtx_enter(&d->bd_mtx);
n = d->bd_slen;
if (d->bd_hbuf != NULL)
n += d->bd_hlen;
mtx_leave(&d->bd_mtx);
*(int *)addr = n;
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;
mtx_enter(&d->bd_mtx);
d->bd_bufsize = size;
mtx_leave(&d->bd_mtx);
}
break;
/*
* Set link layer read filter.
*/
case BIOCSETF:
error = bpf_setf(d, (struct bpf_program *)addr, 0);
break;
/*
* Set link layer write filter.
*/
case BIOCSETWF:
error = bpf_setf(d, (struct bpf_program *)addr, 1);
break;
/*
* Flush read packet buffer.
*/
case BIOCFLUSH:
mtx_enter(&d->bd_mtx);
bpf_resetd(d);
mtx_leave(&d->bd_mtx);
break;
/*
* Put interface into promiscuous mode.
*/
case BIOCPROMISC:
if (d->bd_bif == NULL) {
/*
* No interface attached yet.
*/
error = EINVAL;
} else if (d->bd_bif->bif_ifp != NULL) {
if (d->bd_promisc == 0) {
MUTEX_ASSERT_UNLOCKED(&d->bd_mtx);
NET_LOCK();
error = ifpromisc(d->bd_bif->bif_ifp, 1);
NET_UNLOCK();
if (error == 0)
d->bd_promisc = 1;
}
}
break;
/*
* Get a list of supported device parameters.
*/
case BIOCGDLTLIST:
if (d->bd_bif == NULL)
error = EINVAL;
else
error = bpf_getdltlist(d, (struct bpf_dltlist *)addr);
break;
/*
* Get device parameters.
*/
case BIOCGDLT:
if (d->bd_bif == NULL)
error = EINVAL;
else
*(u_int *)addr = d->bd_bif->bif_dlt;
break;
/*
* Set device parameters.
*/
case BIOCSDLT:
if (d->bd_bif == NULL)
error = EINVAL;
else {
mtx_enter(&d->bd_mtx);
error = bpf_setdlt(d, *(u_int *)addr);
mtx_leave(&d->bd_mtx);
}
break;
/*
* Set interface name.
*/
case BIOCGETIF:
if (d->bd_bif == NULL)
error = EINVAL;
else
bpf_ifname(d->bd_bif, (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;
uint64_t rtout;
if (tv->tv_sec < 0 || !timerisvalid(tv)) {
error = EINVAL;
break;
}
rtout = TIMEVAL_TO_NSEC(tv);
if (rtout > MAXTSLP) {
error = EOVERFLOW;
break;
}
mtx_enter(&d->bd_mtx);
d->bd_rtout = rtout;
mtx_leave(&d->bd_mtx);
break;
}
/*
* Get read timeout.
*/
case BIOCGRTIMEOUT:
{
struct timeval *tv = (struct timeval *)addr;
memset(tv, 0, sizeof(*tv));
mtx_enter(&d->bd_mtx);
NSEC_TO_TIMEVAL(d->bd_rtout, tv);
mtx_leave(&d->bd_mtx);
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:
error = bpf_set_wtout(d, *(int *)addr ? 0 : INFSLP);
break;
/*
* Wait timeout.
*/
case BIOCSWTIMEOUT:
error = bpf_set_wtimeout(d, (const struct timeval *)addr);
break;
case BIOCGWTIMEOUT:
error = bpf_get_wtimeout(d, (struct timeval *)addr);
break;
case BIOCDWTIMEOUT:
error = bpf_set_wtout(d, INFSLP);
break;
case BIOCVERSION:
{
struct bpf_version *bv = (struct bpf_version *)addr;
bv->bv_major = BPF_MAJOR_VERSION;
bv->bv_minor = BPF_MINOR_VERSION;
break;
}
case BIOCGHDRCMPLT: /* get "header already complete" flag */
*(u_int *)addr = d->bd_hdrcmplt;
break;
case BIOCSHDRCMPLT: /* set "header already complete" flag */
d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0;
break;
case BIOCLOCK: /* set "locked" flag (no reset) */
d->bd_locked = 1;
break;
case BIOCGFILDROP: /* get "filter-drop" flag */
*(u_int *)addr = d->bd_fildrop;
break;
case BIOCSFILDROP: { /* set "filter-drop" flag */
unsigned int fildrop = *(u_int *)addr;
switch (fildrop) {
case BPF_FILDROP_PASS:
case BPF_FILDROP_CAPTURE:
case BPF_FILDROP_DROP:
d->bd_fildrop = fildrop;
break;
default:
error = EINVAL;
break;
}
break;
}
case BIOCGDIRFILT: /* get direction filter */
*(u_int *)addr = d->bd_dirfilt;
break;
case BIOCSDIRFILT: /* set direction filter */
d->bd_dirfilt = (*(u_int *)addr) &
(BPF_DIRECTION_IN|BPF_DIRECTION_OUT);
break;
case FIONBIO: /* Non-blocking I/O */
/* let vfs to keep track of this */
break;
case FIOASYNC: /* Send signal on receive packets */
d->bd_async = *(int *)addr;
break;
case FIOSETOWN: /* Process or group to send signals to */
case TIOCSPGRP:
error = sigio_setown(&d->bd_sigio, cmd, addr);
break;
case FIOGETOWN:
case TIOCGPGRP:
sigio_getown(&d->bd_sigio, cmd, addr);
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;
}
bpf_put(d);
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(struct bpf_d *d, struct bpf_program *fp, int wf)
{
struct bpf_program_smr *bps, *old_bps;
struct bpf_insn *fcode;
u_int flen, size;
KERNEL_ASSERT_LOCKED();
if (fp->bf_insns == 0) {
if (fp->bf_len != 0)
return (EINVAL);
bps = NULL;
} else {
flen = fp->bf_len;
if (flen > BPF_MAXINSNS)
return (EINVAL);
fcode = mallocarray(flen, sizeof(*fp->bf_insns), M_DEVBUF,
M_WAITOK | M_CANFAIL);
if (fcode == NULL)
return (ENOMEM);
size = flen * sizeof(*fp->bf_insns);
if (copyin(fp->bf_insns, fcode, size) != 0 ||
bpf_validate(fcode, (int)flen) == 0) {
free(fcode, M_DEVBUF, size);
return (EINVAL);
}
bps = malloc(sizeof(*bps), M_DEVBUF, M_WAITOK);
smr_init(&bps->bps_smr);
bps->bps_bf.bf_len = flen;
bps->bps_bf.bf_insns = fcode;
}
if (wf == 0) {
old_bps = SMR_PTR_GET_LOCKED(&d->bd_rfilter);
SMR_PTR_SET_LOCKED(&d->bd_rfilter, bps);
} else {
old_bps = SMR_PTR_GET_LOCKED(&d->bd_wfilter);
SMR_PTR_SET_LOCKED(&d->bd_wfilter, bps);
}
mtx_enter(&d->bd_mtx);
bpf_resetd(d);
mtx_leave(&d->bd_mtx);
if (old_bps != NULL)
smr_call(&old_bps->bps_smr, bpf_prog_smr, old_bps);
return (0);
}
/*
* 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.
*/
int
bpf_setif(struct bpf_d *d, struct ifreq *ifr)
{
struct bpf_if *bp, *candidate = NULL;
int error = 0;
/*
* Look through attached interfaces for the named one.
*/
for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
if (strcmp(bp->bif_name, ifr->ifr_name) != 0)
continue;
if (candidate == NULL || candidate->bif_dlt > bp->bif_dlt)
candidate = bp;
}
/* Not found. */
if (candidate == NULL)
return (ENXIO);
/*
* Allocate the packet buffers if we need to.
* If we're already attached to requested interface,
* just flush the buffer.
*/
mtx_enter(&d->bd_mtx);
if (d->bd_sbuf == NULL) {
if ((error = bpf_allocbufs(d)))
goto out;
}
if (candidate != d->bd_bif) {
/*
* Detach if attached to something else.
*/
bpf_detachd(d);
bpf_attachd(d, candidate);
}
bpf_resetd(d);
out:
mtx_leave(&d->bd_mtx);
return (error);
}
/*
* Copy the interface name to the ifreq.
*/
void
bpf_ifname(struct bpf_if *bif, struct ifreq *ifr)
{
bcopy(bif->bif_name, ifr->ifr_name, sizeof(ifr->ifr_name));
}
const struct filterops bpfread_filtops = {
.f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE,
.f_attach = NULL,
.f_detach = filt_bpfrdetach,
.f_event = filt_bpfread,
.f_modify = filt_bpfreadmodify,
.f_process = filt_bpfreadprocess,
};
int
bpfkqfilter(dev_t dev, struct knote *kn)
{
struct bpf_d *d;
struct klist *klist;
KERNEL_ASSERT_LOCKED();
d = bpfilter_lookup(minor(dev));
if (d == NULL)
return (ENXIO);
switch (kn->kn_filter) {
case EVFILT_READ:
klist = &d->bd_klist;
kn->kn_fop = &bpfread_filtops;
break;
default:
return (EINVAL);
}
bpf_get(d);
kn->kn_hook = d;
klist_insert(klist, kn);
return (0);
}
void
filt_bpfrdetach(struct knote *kn)
{
struct bpf_d *d = kn->kn_hook;
klist_remove(&d->bd_klist, kn);
bpf_put(d);
}
int
filt_bpfread(struct knote *kn, long hint)
{
struct bpf_d *d = kn->kn_hook;
MUTEX_ASSERT_LOCKED(&d->bd_mtx);
kn->kn_data = d->bd_hlen;
if (d->bd_wtout == 0)
kn->kn_data += d->bd_slen;
return (kn->kn_data > 0);
}
int
filt_bpfreadmodify(struct kevent *kev, struct knote *kn)
{
struct bpf_d *d = kn->kn_hook;
int active;
mtx_enter(&d->bd_mtx);
active = knote_modify_fn(kev, kn, filt_bpfread);
mtx_leave(&d->bd_mtx);
return (active);
}
int
filt_bpfreadprocess(struct knote *kn, struct kevent *kev)
{
struct bpf_d *d = kn->kn_hook;
int active;
mtx_enter(&d->bd_mtx);
active = knote_process_fn(kn, kev, filt_bpfread);
mtx_leave(&d->bd_mtx);
return (active);
}
/*
* Copy data from an mbuf chain into a buffer. This code is derived
* from m_copydata in sys/uipc_mbuf.c.
*/
void
bpf_mcopy(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, caddr_t), (caddr_t)dst, count);
m = m->m_next;
dst += count;
len -= count;
}
}
int
bpf_mtap(caddr_t arg, const struct mbuf *m, u_int direction)
{
return _bpf_mtap(arg, m, m, direction);
}
int
_bpf_mtap(caddr_t arg, const struct mbuf *mp, const struct mbuf *m,
u_int direction)
{
struct bpf_if *bp = (struct bpf_if *)arg;
struct bpf_d *d;
size_t pktlen, slen;
const struct mbuf *m0;
struct bpf_hdr tbh;
int gothdr = 0;
int drop = 0;
if (m == NULL)
return (0);
if (bp == NULL)
return (0);
pktlen = 0;
for (m0 = m; m0 != NULL; m0 = m0->m_next)
pktlen += m0->m_len;
smr_read_enter();
SMR_SLIST_FOREACH(d, &bp->bif_dlist, bd_next) {
struct bpf_program_smr *bps;
struct bpf_insn *fcode = NULL;
atomic_inc_long(&d->bd_rcount);
if (ISSET(d->bd_dirfilt, direction))
continue;
bps = SMR_PTR_GET(&d->bd_rfilter);
if (bps != NULL)
fcode = bps->bps_bf.bf_insns;
slen = bpf_mfilter(fcode, m, pktlen);
if (slen == 0)
continue;
if (d->bd_fildrop != BPF_FILDROP_PASS)
drop = 1;
if (d->bd_fildrop != BPF_FILDROP_DROP) {
if (!gothdr) {
struct timeval tv;
memset(&tbh, 0, sizeof(tbh));
if (ISSET(mp->m_flags, M_PKTHDR)) {
tbh.bh_ifidx = mp->m_pkthdr.ph_ifidx;
tbh.bh_flowid = mp->m_pkthdr.ph_flowid;
tbh.bh_flags = mp->m_pkthdr.pf.prio;
if (ISSET(mp->m_pkthdr.csum_flags,
M_FLOWID))
SET(tbh.bh_flags, BPF_F_FLOWID);
tbh.bh_csumflags =
mp->m_pkthdr.csum_flags;
m_microtime(mp, &tv);
} else
microtime(&tv);
tbh.bh_tstamp.tv_sec = tv.tv_sec;
tbh.bh_tstamp.tv_usec = tv.tv_usec;
SET(tbh.bh_flags, direction << BPF_F_DIR_SHIFT);
gothdr = 1;
}
mtx_enter(&d->bd_mtx);
bpf_catchpacket(d, (u_char *)m, pktlen, slen, &tbh);
mtx_leave(&d->bd_mtx);
}
}
smr_read_leave();
return (drop);
}
/*
* Incoming linkage from device drivers, where a data buffer should be
* prepended by an arbitrary header. In this situation we already have a
* way of representing a chain of memory buffers, ie, mbufs, so reuse
* the existing functionality by attaching the buffers to mbufs.
*
* Con up a minimal mbuf chain to pacify bpf by allocating (only) a
* struct m_hdr each for the header and data on the stack.
*/
int
bpf_tap_hdr(caddr_t arg, const void *hdr, unsigned int hdrlen,
const void *buf, unsigned int buflen, u_int direction)
{
struct m_hdr mh, md;
struct mbuf *m0 = NULL;
struct mbuf **mp = &m0;
if (hdr != NULL) {
mh.mh_flags = 0;
mh.mh_next = NULL;
mh.mh_len = hdrlen;
mh.mh_data = (void *)hdr;
*mp = (struct mbuf *)&mh;
mp = &mh.mh_next;
}
if (buf != NULL) {
md.mh_flags = 0;
md.mh_next = NULL;
md.mh_len = buflen;
md.mh_data = (void *)buf;
*mp = (struct mbuf *)&md;
}
return bpf_mtap(arg, m0, direction);
}
/*
* Incoming linkage from device drivers, where we have a mbuf chain
* but need to prepend some arbitrary header from a linear buffer.
*
* Con up a minimal dummy header to pacify bpf. Allocate (only) a
* struct m_hdr on the stack. This is safe as bpf only reads from the
* fields in this header that we initialize, and will not try to free
* it or keep a pointer to it.
*/
int
bpf_mtap_hdr(caddr_t arg, const void *data, u_int dlen, const struct mbuf *m,
u_int direction)
{
struct m_hdr mh;
const struct mbuf *m0;
if (dlen > 0) {
mh.mh_flags = 0;
mh.mh_next = (struct mbuf *)m;
mh.mh_len = dlen;
mh.mh_data = (void *)data;
m0 = (struct mbuf *)&mh;
} else
m0 = m;
return _bpf_mtap(arg, m, m0, direction);
}
/*
* Incoming linkage from device drivers, where we have a mbuf chain
* but need to prepend the address family.
*
* Con up a minimal dummy header to pacify bpf. We allocate (only) a
* struct m_hdr on the stack. This is safe as bpf only reads from the
* fields in this header that we initialize, and will not try to free
* it or keep a pointer to it.
*/
int
bpf_mtap_af(caddr_t arg, u_int32_t af, const struct mbuf *m, u_int direction)
{
u_int32_t afh;
afh = htonl(af);
return bpf_mtap_hdr(arg, &afh, sizeof(afh), m, direction);
}
/*
* Incoming linkage from device drivers, where we have a mbuf chain
* but need to prepend a VLAN encapsulation header.
*
* Con up a minimal dummy header to pacify bpf. Allocate (only) a
* struct m_hdr on the stack. This is safe as bpf only reads from the
* fields in this header that we initialize, and will not try to free
* it or keep a pointer to it.
*/
int
bpf_mtap_ether(caddr_t arg, const struct mbuf *m, u_int direction)
{
#if NVLAN > 0
struct ether_vlan_header evh;
struct m_hdr mh, md;
if ((m->m_flags & M_VLANTAG) == 0)
#endif
{
return _bpf_mtap(arg, m, m, direction);
}
#if NVLAN > 0
KASSERT(m->m_len >= ETHER_HDR_LEN);
memcpy(&evh, mtod(m, char *), ETHER_HDR_LEN);
evh.evl_proto = evh.evl_encap_proto;
evh.evl_encap_proto = htons(ETHERTYPE_VLAN);
evh.evl_tag = htons(m->m_pkthdr.ether_vtag);
mh.mh_flags = 0;
mh.mh_data = (caddr_t)&evh;
mh.mh_len = sizeof(evh);
mh.mh_next = (struct mbuf *)&md;
md.mh_flags = 0;
md.mh_data = m->m_data + ETHER_HDR_LEN;
md.mh_len = m->m_len - ETHER_HDR_LEN;
md.mh_next = m->m_next;
return _bpf_mtap(arg, m, (struct mbuf *)&mh, direction);
#endif
}
/*
* Move the packet data from interface memory (pkt) into the
* store buffer. Wake up listeners if needed.
* "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.
*/
void
bpf_catchpacket(struct bpf_d *d, u_char *pkt, size_t pktlen, size_t snaplen,
const struct bpf_hdr *tbh)
{
struct bpf_hdr *bh;
int totlen, curlen;
int hdrlen, do_wakeup = 0;
MUTEX_ASSERT_LOCKED(&d->bd_mtx);
if (d->bd_bif == NULL)
return;
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;
}
/* cancel pending wtime */
if (timeout_del(&d->bd_wait_tmo))
bpf_put(d);
ROTATE_BUFFERS(d);
do_wakeup = 1;
curlen = 0;
}
/*
* Append the bpf header.
*/
bh = (struct bpf_hdr *)(d->bd_sbuf + curlen);
*bh = *tbh;
bh->bh_datalen = pktlen;
bh->bh_hdrlen = hdrlen;
bh->bh_caplen = totlen - hdrlen;
/*
* Copy the packet data into the store buffer and update its length.
*/
bpf_mcopy(pkt, (u_char *)bh + hdrlen, bh->bh_caplen);
d->bd_slen = curlen + totlen;
switch (d->bd_wtout) {
case 0:
/*
* Immediate mode is set. A packet arrived so any
* reads should be woken up.
*/
if (d->bd_state == BPF_S_IDLE)
d->bd_state = BPF_S_DONE;
do_wakeup = 1;
break;
case INFSLP:
break;
default:
if (d->bd_state == BPF_S_IDLE) {
d->bd_state = BPF_S_WAIT;
bpf_get(d);
if (!timeout_add_nsec(&d->bd_wait_tmo, d->bd_wtout))
bpf_put(d);
}
break;
}
if (do_wakeup)
bpf_wakeup(d);
}
/*
* Initialize all nonzero fields of a descriptor.
*/
int
bpf_allocbufs(struct bpf_d *d)
{
MUTEX_ASSERT_LOCKED(&d->bd_mtx);
d->bd_fbuf = malloc(d->bd_bufsize, M_DEVBUF, M_NOWAIT);
if (d->bd_fbuf == NULL)
return (ENOMEM);
d->bd_sbuf = malloc(d->bd_bufsize, M_DEVBUF, M_NOWAIT);
if (d->bd_sbuf == NULL) {
free(d->bd_fbuf, M_DEVBUF, d->bd_bufsize);
d->bd_fbuf = NULL;
return (ENOMEM);
}
d->bd_slen = 0;
d->bd_hlen = 0;
return (0);
}
void
bpf_prog_smr(void *bps_arg)
{
struct bpf_program_smr *bps = bps_arg;
free(bps->bps_bf.bf_insns, M_DEVBUF,
bps->bps_bf.bf_len * sizeof(struct bpf_insn));
free(bps, M_DEVBUF, sizeof(struct bpf_program_smr));
}
void
bpf_d_smr(void *smr)
{
struct bpf_d *bd = smr;
sigio_free(&bd->bd_sigio);
free(bd->bd_sbuf, M_DEVBUF, bd->bd_bufsize);
free(bd->bd_hbuf, M_DEVBUF, bd->bd_bufsize);
free(bd->bd_fbuf, M_DEVBUF, bd->bd_bufsize);
if (bd->bd_rfilter != NULL)
bpf_prog_smr(bd->bd_rfilter);
if (bd->bd_wfilter != NULL)
bpf_prog_smr(bd->bd_wfilter);
klist_free(&bd->bd_klist);
free(bd, M_DEVBUF, sizeof(*bd));
}
void
bpf_get(struct bpf_d *bd)
{
refcnt_take(&bd->bd_refcnt);
}
/*
* Free buffers currently in use by a descriptor
* when the reference count drops to zero.
*/
void
bpf_put(struct bpf_d *bd)
{
if (refcnt_rele(&bd->bd_refcnt) == 0)
return;
smr_call(&bd->bd_smr, bpf_d_smr, bd);
}
void *
bpfsattach(caddr_t *bpfp, const char *name, u_int dlt, u_int hdrlen)
{
struct bpf_if *bp;
if ((bp = malloc(sizeof(*bp), M_DEVBUF, M_NOWAIT)) == NULL)
panic("bpfattach");
SMR_SLIST_INIT(&bp->bif_dlist);
bp->bif_driverp = (struct bpf_if **)bpfp;
bp->bif_name = name;
bp->bif_ifp = NULL;
bp->bif_dlt = dlt;
bp->bif_next = bpf_iflist;
bpf_iflist = bp;
*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;
return (bp);
}
void
bpfattach(caddr_t *driverp, struct ifnet *ifp, u_int dlt, u_int hdrlen)
{
struct bpf_if *bp;
bp = bpfsattach(driverp, ifp->if_xname, dlt, hdrlen);
bp->bif_ifp = ifp;
}
/* Detach an interface from its attached bpf device. */
void
bpfdetach(struct ifnet *ifp)
{
struct bpf_if *bp, *nbp;
KERNEL_ASSERT_LOCKED();
for (bp = bpf_iflist; bp; bp = nbp) {
nbp = bp->bif_next;
if (bp->bif_ifp == ifp)
bpfsdetach(bp);
}
ifp->if_bpf = NULL;
}
void
bpfsdetach(void *p)
{
struct bpf_if *bp = p, *tbp;
struct bpf_d *bd;
int maj;
KERNEL_ASSERT_LOCKED();
/* Locate the major number. */
for (maj = 0; maj < nchrdev; maj++)
if (cdevsw[maj].d_open == bpfopen)
break;
while ((bd = SMR_SLIST_FIRST_LOCKED(&bp->bif_dlist))) {
vdevgone(maj, bd->bd_unit, bd->bd_unit, VCHR);
klist_invalidate(&bd->bd_klist);
}
for (tbp = bpf_iflist; tbp; tbp = tbp->bif_next) {
if (tbp->bif_next == bp) {
tbp->bif_next = bp->bif_next;
break;
}
}
if (bpf_iflist == bp)
bpf_iflist = bp->bif_next;
free(bp, M_DEVBUF, sizeof(*bp));
}
int
bpf_sysctl_locked(int *name, u_int namelen, void *oldp, size_t *oldlenp,
void *newp, size_t newlen)
{
switch (name[0]) {
case NET_BPF_BUFSIZE:
return sysctl_int_bounded(oldp, oldlenp, newp, newlen,
&bpf_bufsize, BPF_MINBUFSIZE, bpf_maxbufsize);
case NET_BPF_MAXBUFSIZE:
return sysctl_int_bounded(oldp, oldlenp, newp, newlen,
&bpf_maxbufsize, BPF_MINBUFSIZE, INT_MAX);
default:
return (EOPNOTSUPP);
}
}
int
bpf_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
size_t newlen)
{
int flags = RW_INTR;
int error;
if (namelen != 1)
return (ENOTDIR);
flags |= (newp == NULL) ? RW_READ : RW_WRITE;
error = rw_enter(&bpf_sysctl_lk, flags);
if (error != 0)
return (error);
error = bpf_sysctl_locked(name, namelen, oldp, oldlenp, newp, newlen);
rw_exit(&bpf_sysctl_lk);
return (error);
}
struct bpf_d *
bpfilter_lookup(int unit)
{
struct bpf_d *bd;
KERNEL_ASSERT_LOCKED();
LIST_FOREACH(bd, &bpf_d_list, bd_list)
if (bd->bd_unit == unit)
return (bd);
return (NULL);
}
/*
* Get a list of available data link type of the interface.
*/
int
bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
{
int n, error;
struct bpf_if *bp;
const char *name;
name = d->bd_bif->bif_name;
n = 0;
error = 0;
for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
if (strcmp(name, bp->bif_name) != 0)
continue;
if (bfl->bfl_list != NULL) {
if (n >= bfl->bfl_len)
return (ENOMEM);
error = copyout(&bp->bif_dlt,
bfl->bfl_list + n, sizeof(u_int));
if (error)
break;
}
n++;
}
bfl->bfl_len = n;
return (error);
}
/*
* Set the data link type of a BPF instance.
*/
int
bpf_setdlt(struct bpf_d *d, u_int dlt)
{
const char *name;
struct bpf_if *bp;
MUTEX_ASSERT_LOCKED(&d->bd_mtx);
if (d->bd_bif->bif_dlt == dlt)
return (0);
name = d->bd_bif->bif_name;
for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
if (strcmp(name, bp->bif_name) != 0)
continue;
if (bp->bif_dlt == dlt)
break;
}
if (bp == NULL)
return (EINVAL);
bpf_detachd(d);
bpf_attachd(d, bp);
bpf_resetd(d);
return (0);
}
u_int32_t bpf_mbuf_ldw(const void *, u_int32_t, int *);
u_int32_t bpf_mbuf_ldh(const void *, u_int32_t, int *);
u_int32_t bpf_mbuf_ldb(const void *, u_int32_t, int *);
int bpf_mbuf_copy(const struct mbuf *, u_int32_t,
void *, u_int32_t);
const struct bpf_ops bpf_mbuf_ops = {
bpf_mbuf_ldw,
bpf_mbuf_ldh,
bpf_mbuf_ldb,
};
int
bpf_mbuf_copy(const struct mbuf *m, u_int32_t off, void *buf, u_int32_t len)
{
u_int8_t *cp = buf;
u_int32_t count;
while (off >= m->m_len) {
off -= m->m_len;
m = m->m_next;
if (m == NULL)
return (-1);
}
for (;;) {
count = min(m->m_len - off, len);
memcpy(cp, m->m_data + off, count);
len -= count;
if (len == 0)
return (0);
m = m->m_next;
if (m == NULL)
break;
cp += count;
off = 0;
}
return (-1);
}
u_int32_t
bpf_mbuf_ldw(const void *m0, u_int32_t k, int *err)
{
u_int32_t v;
if (bpf_mbuf_copy(m0, k, &v, sizeof(v)) != 0) {
*err = 1;
return (0);
}
*err = 0;
return ntohl(v);
}
u_int32_t
bpf_mbuf_ldh(const void *m0, u_int32_t k, int *err)
{
u_int16_t v;
if (bpf_mbuf_copy(m0, k, &v, sizeof(v)) != 0) {
*err = 1;
return (0);
}
*err = 0;
return ntohs(v);
}
u_int32_t
bpf_mbuf_ldb(const void *m0, u_int32_t k, int *err)
{
const struct mbuf *m = m0;
u_int8_t v;
while (k >= m->m_len) {
k -= m->m_len;
m = m->m_next;
if (m == NULL) {
*err = 1;
return (0);
}
}
v = m->m_data[k];
*err = 0;
return v;
}
u_int
bpf_mfilter(const struct bpf_insn *pc, const struct mbuf *m, u_int wirelen)
{
return _bpf_filter(pc, &bpf_mbuf_ops, m, wirelen);
}
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