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NetBSD/sys/net/bpf.c
pgoyette 7c20c5d3bb Fix regression introduced in tests/net/bpf and tests/net/bpfilter 
The rump code needs to call devsw_attach() in order to assign a dev_major
for bpf;  it then uses this to create rumps /dev/bpf node.  Unfortunately,
this leaves the devsw attached, so when the bpf module tries to initialize
itself, it gets an EEXIST error and fails.

So, once rump has figured what the dev_major should be, call devsw_detach()
to remove the devsw.  Then, when the module initialization code calls
devsw_attach() it will succeed.
2016-07-19 02:47:45 +00:00

2167 lines
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/* $NetBSD: bpf.c,v 1.203 2016/07/19 02:47:45 pgoyette Exp $ */
/*
* 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. 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
* static char rcsid[] =
* "Header: bpf.c,v 1.67 96/09/26 22:00:52 leres Exp ";
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: bpf.c,v 1.203 2016/07/19 02:47:45 pgoyette Exp $");
#if defined(_KERNEL_OPT)
#include "opt_bpf.h"
#include "sl.h"
#include "strip.h"
#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/ioctl.h>
#include <sys/conf.h>
#include <sys/vnode.h>
#include <sys/queue.h>
#include <sys/stat.h>
#include <sys/module.h>
#include <sys/atomic.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/tty.h>
#include <sys/uio.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/poll.h>
#include <sys/sysctl.h>
#include <sys/kauth.h>
#include <net/if.h>
#include <net/slip.h>
#include <net/bpf.h>
#include <net/bpfdesc.h>
#include <net/bpfjit.h>
#include <net/if_arc.h>
#include <net/if_ether.h>
#include <netinet/in.h>
#include <netinet/if_inarp.h>
#include <compat/sys/sockio.h>
#ifndef BPF_BUFSIZE
/*
* 4096 is too small for FDDI frames. 8192 is too small for gigabit Ethernet
* jumbos (circa 9k), ATM, or Intel gig/10gig ethernet jumbos (16k).
*/
# define BPF_BUFSIZE 32768
#endif
#define PRINET 26 /* interruptible */
/*
* The default read buffer size, and limit for BIOCSBLEN, is sysctl'able.
* XXX the default values should be computed dynamically based
* on available memory size and available mbuf clusters.
*/
int bpf_bufsize = BPF_BUFSIZE;
int bpf_maxbufsize = BPF_DFLTBUFSIZE; /* XXX set dynamically, see above */
bool bpf_jit = false;
struct bpfjit_ops bpfjit_module_ops = {
.bj_generate_code = NULL,
.bj_free_code = NULL
};
/*
* Global BPF statistics returned by net.bpf.stats sysctl.
*/
struct bpf_stat bpf_gstats;
/*
* Use a mutex to avoid a race condition between gathering the stats/peers
* and opening/closing the device.
*/
static kmutex_t bpf_mtx;
/*
* 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;
LIST_HEAD(, bpf_d) bpf_list;
static int bpf_allocbufs(struct bpf_d *);
static void bpf_deliver(struct bpf_if *,
void *(*cpfn)(void *, const void *, size_t),
void *, u_int, u_int, const bool);
static void bpf_freed(struct bpf_d *);
static void bpf_ifname(struct ifnet *, struct ifreq *);
static void *bpf_mcpy(void *, const void *, size_t);
static int bpf_movein(struct uio *, int, uint64_t,
struct mbuf **, struct sockaddr *);
static void bpf_attachd(struct bpf_d *, struct bpf_if *);
static void bpf_detachd(struct bpf_d *);
static int bpf_setif(struct bpf_d *, struct ifreq *);
static void bpf_timed_out(void *);
static inline void
bpf_wakeup(struct bpf_d *);
static int bpf_hdrlen(struct bpf_d *);
static void catchpacket(struct bpf_d *, u_char *, u_int, u_int,
void *(*)(void *, const void *, size_t), struct timespec *);
static void reset_d(struct bpf_d *);
static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
static int bpf_setdlt(struct bpf_d *, u_int);
static int bpf_read(struct file *, off_t *, struct uio *, kauth_cred_t,
int);
static int bpf_write(struct file *, off_t *, struct uio *, kauth_cred_t,
int);
static int bpf_ioctl(struct file *, u_long, void *);
static int bpf_poll(struct file *, int);
static int bpf_stat(struct file *, struct stat *);
static int bpf_close(struct file *);
static int bpf_kqfilter(struct file *, struct knote *);
static void bpf_softintr(void *);
static const struct fileops bpf_fileops = {
.fo_read = bpf_read,
.fo_write = bpf_write,
.fo_ioctl = bpf_ioctl,
.fo_fcntl = fnullop_fcntl,
.fo_poll = bpf_poll,
.fo_stat = bpf_stat,
.fo_close = bpf_close,
.fo_kqfilter = bpf_kqfilter,
.fo_restart = fnullop_restart,
};
dev_type_open(bpfopen);
const struct cdevsw bpf_cdevsw = {
.d_open = bpfopen,
.d_close = noclose,
.d_read = noread,
.d_write = nowrite,
.d_ioctl = noioctl,
.d_stop = nostop,
.d_tty = notty,
.d_poll = nopoll,
.d_mmap = nommap,
.d_kqfilter = nokqfilter,
.d_discard = nodiscard,
.d_flag = D_OTHER
};
bpfjit_func_t
bpf_jit_generate(bpf_ctx_t *bc, void *code, size_t size)
{
membar_consumer();
if (bpfjit_module_ops.bj_generate_code != NULL) {
return bpfjit_module_ops.bj_generate_code(bc, code, size);
}
return NULL;
}
void
bpf_jit_freecode(bpfjit_func_t jcode)
{
KASSERT(bpfjit_module_ops.bj_free_code != NULL);
bpfjit_module_ops.bj_free_code(jcode);
}
static int
bpf_movein(struct uio *uio, int linktype, uint64_t mtu, struct mbuf **mp,
struct sockaddr *sockp)
{
struct mbuf *m;
int error;
size_t len;
size_t hlen;
size_t align;
/*
* 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;
align = 0;
break;
case DLT_PPP:
sockp->sa_family = AF_UNSPEC;
hlen = 0;
align = 0;
break;
case DLT_EN10MB:
sockp->sa_family = AF_UNSPEC;
/* XXX Would MAXLINKHDR be better? */
/* 6(dst)+6(src)+2(type) */
hlen = sizeof(struct ether_header);
align = 2;
break;
case DLT_ARCNET:
sockp->sa_family = AF_UNSPEC;
hlen = ARC_HDRLEN;
align = 5;
break;
case DLT_FDDI:
sockp->sa_family = AF_LINK;
/* XXX 4(FORMAC)+6(dst)+6(src) */
hlen = 16;
align = 0;
break;
case DLT_ECONET:
sockp->sa_family = AF_UNSPEC;
hlen = 6;
align = 2;
break;
case DLT_NULL:
sockp->sa_family = AF_UNSPEC;
hlen = 0;
align = 0;
break;
default:
return (EIO);
}
len = uio->uio_resid;
/*
* If there aren't enough bytes for a link level header or the
* packet length exceeds the interface mtu, return an error.
*/
if (len - hlen > mtu)
return (EMSGSIZE);
/*
* XXX Avoid complicated buffer chaining ---
* bail if it won't fit in a single mbuf.
* (Take into account possible alignment bytes)
*/
if (len + align > MCLBYTES)
return (EIO);
m = m_gethdr(M_WAIT, MT_DATA);
m_reset_rcvif(m);
m->m_pkthdr.len = (int)(len - hlen);
if (len + align > MHLEN) {
m_clget(m, M_WAIT);
if ((m->m_flags & M_EXT) == 0) {
error = ENOBUFS;
goto bad;
}
}
/* Insure the data is properly aligned */
if (align > 0) {
m->m_data += align;
m->m_len -= (int)align;
}
error = uiomove(mtod(m, void *), len, uio);
if (error)
goto bad;
if (hlen != 0) {
memcpy(sockp->sa_data, mtod(m, void *), hlen);
m->m_data += hlen; /* XXX */
len -= hlen;
}
m->m_len = (int)len;
*mp = m;
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 splnet.
*/
static void
bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
{
KASSERT(mutex_owned(&bpf_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;
d->bd_next = bp->bif_dlist;
bp->bif_dlist = d;
*bp->bif_driverp = bp;
}
/*
* Detach a file from its interface.
*/
static void
bpf_detachd(struct bpf_d *d)
{
struct bpf_d **p;
struct bpf_if *bp;
KASSERT(mutex_owned(&bpf_mtx));
bp = d->bd_bif;
/*
* Check if this descriptor had requested promiscuous mode.
* If so, turn it off.
*/
if (d->bd_promisc) {
int error __diagused;
d->bd_promisc = 0;
/*
* Take device out of promiscuous mode. Since we were
* able to enter promiscuous mode, we should be able
* to turn it off. But we can get an error if
* the interface was configured down, so only panic
* if we don't get an unexpected error.
*/
error = ifpromisc(bp->bif_ifp, 0);
#ifdef DIAGNOSTIC
if (error)
printf("%s: ifpromisc failed: %d", __func__, error);
#endif
}
/* Remove d from the interface's descriptor list. */
p = &bp->bif_dlist;
while (*p != d) {
p = &(*p)->bd_next;
if (*p == NULL)
panic("%s: descriptor not in list", __func__);
}
*p = (*p)->bd_next;
if (bp->bif_dlist == NULL)
/*
* Let the driver know that there are no more listeners.
*/
*d->bd_bif->bif_driverp = NULL;
d->bd_bif = NULL;
}
static void
bpf_init(void)
{
mutex_init(&bpf_mtx, MUTEX_DEFAULT, IPL_NONE);
LIST_INIT(&bpf_list);
bpf_gstats.bs_recv = 0;
bpf_gstats.bs_drop = 0;
bpf_gstats.bs_capt = 0;
return;
}
/*
* bpfilterattach() is called at boot time. We don't need to do anything
* here, since any initialization will happen as part of module init code.
*/
/* ARGSUSED */
void
bpfilterattach(int n)
{
}
/*
* Open ethernet device. Clones.
*/
/* ARGSUSED */
int
bpfopen(dev_t dev, int flag, int mode, struct lwp *l)
{
struct bpf_d *d;
struct file *fp;
int error, fd;
/* falloc() will fill in the descriptor for us. */
if ((error = fd_allocfile(&fp, &fd)) != 0)
return error;
d = malloc(sizeof(*d), M_DEVBUF, M_WAITOK|M_ZERO);
d->bd_bufsize = bpf_bufsize;
d->bd_seesent = 1;
d->bd_feedback = 0;
d->bd_pid = l->l_proc->p_pid;
#ifdef _LP64
if (curproc->p_flag & PK_32)
d->bd_compat32 = 1;
#endif
getnanotime(&d->bd_btime);
d->bd_atime = d->bd_mtime = d->bd_btime;
callout_init(&d->bd_callout, 0);
selinit(&d->bd_sel);
d->bd_sih = softint_establish(SOFTINT_CLOCK, bpf_softintr, d);
d->bd_jitcode = NULL;
mutex_enter(&bpf_mtx);
LIST_INSERT_HEAD(&bpf_list, d, bd_list);
mutex_exit(&bpf_mtx);
return fd_clone(fp, fd, flag, &bpf_fileops, d);
}
/*
* Close the descriptor by detaching it from its interface,
* deallocating its buffers, and marking it free.
*/
/* ARGSUSED */
static int
bpf_close(struct file *fp)
{
struct bpf_d *d;
int s;
KERNEL_LOCK(1, NULL);
mutex_enter(&bpf_mtx);
if ((d = fp->f_bpf) == NULL) {
mutex_exit(&bpf_mtx);
KERNEL_UNLOCK_ONE(NULL);
return 0;
}
/*
* Refresh the PID associated with this bpf file.
*/
d->bd_pid = curproc->p_pid;
s = splnet();
if (d->bd_state == BPF_WAITING)
callout_stop(&d->bd_callout);
d->bd_state = BPF_IDLE;
if (d->bd_bif)
bpf_detachd(d);
splx(s);
bpf_freed(d);
LIST_REMOVE(d, bd_list);
fp->f_bpf = NULL;
mutex_exit(&bpf_mtx);
KERNEL_UNLOCK_ONE(NULL);
callout_destroy(&d->bd_callout);
seldestroy(&d->bd_sel);
softint_disestablish(d->bd_sih);
free(d, M_DEVBUF);
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
bpf_read(struct file *fp, off_t *offp, struct uio *uio,
kauth_cred_t cred, int flags)
{
struct bpf_d *d = fp->f_bpf;
int timed_out;
int error;
int s;
getnanotime(&d->bd_atime);
/*
* Restrict application to use a buffer the same size as
* the kernel buffers.
*/
if (uio->uio_resid != d->bd_bufsize)
return (EINVAL);
KERNEL_LOCK(1, NULL);
s = splnet();
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 (fp->f_flag & FNONBLOCK) {
if (d->bd_slen == 0) {
splx(s);
KERNEL_UNLOCK_ONE(NULL);
return (EWOULDBLOCK);
}
ROTATE_BUFFERS(d);
break;
}
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;
}
error = tsleep(d, PRINET|PCATCH, "bpf",
d->bd_rtout);
if (error == EINTR || error == ERESTART) {
splx(s);
KERNEL_UNLOCK_ONE(NULL);
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);
KERNEL_UNLOCK_ONE(NULL);
return (0);
}
ROTATE_BUFFERS(d);
break;
}
if (error != 0)
goto done;
}
/*
* At this point, we know we have something in the hold slot.
*/
splx(s);
/*
* Move data from hold buffer into user space.
* We know the entire buffer is transferred since
* we checked above that the read buffer is bpf_bufsize bytes.
*/
error = uiomove(d->bd_hbuf, d->bd_hlen, uio);
s = splnet();
d->bd_fbuf = d->bd_hbuf;
d->bd_hbuf = NULL;
d->bd_hlen = 0;
done:
splx(s);
KERNEL_UNLOCK_ONE(NULL);
return (error);
}
/*
* If there are processes sleeping on this descriptor, wake them up.
*/
static inline void
bpf_wakeup(struct bpf_d *d)
{
wakeup(d);
if (d->bd_async)
softint_schedule(d->bd_sih);
selnotify(&d->bd_sel, 0, 0);
}
static void
bpf_softintr(void *cookie)
{
struct bpf_d *d;
d = cookie;
if (d->bd_async)
fownsignal(d->bd_pgid, SIGIO, 0, 0, NULL);
}
static void
bpf_timed_out(void *arg)
{
struct bpf_d *d = arg;
int s;
s = splnet();
if (d->bd_state == BPF_WAITING) {
d->bd_state = BPF_TIMED_OUT;
if (d->bd_slen != 0)
bpf_wakeup(d);
}
splx(s);
}
static int
bpf_write(struct file *fp, off_t *offp, struct uio *uio,
kauth_cred_t cred, int flags)
{
struct bpf_d *d = fp->f_bpf;
struct ifnet *ifp;
struct mbuf *m, *mc;
int error, s;
static struct sockaddr_storage dst;
m = NULL; /* XXX gcc */
KERNEL_LOCK(1, NULL);
if (d->bd_bif == NULL) {
KERNEL_UNLOCK_ONE(NULL);
return (ENXIO);
}
getnanotime(&d->bd_mtime);
ifp = d->bd_bif->bif_ifp;
if (uio->uio_resid == 0) {
KERNEL_UNLOCK_ONE(NULL);
return (0);
}
error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp->if_mtu, &m,
(struct sockaddr *) &dst);
if (error) {
KERNEL_UNLOCK_ONE(NULL);
return (error);
}
if (m->m_pkthdr.len > ifp->if_mtu) {
KERNEL_UNLOCK_ONE(NULL);
m_freem(m);
return (EMSGSIZE);
}
if (d->bd_hdrcmplt)
dst.ss_family = pseudo_AF_HDRCMPLT;
if (d->bd_feedback) {
mc = m_dup(m, 0, M_COPYALL, M_NOWAIT);
if (mc != NULL)
m_set_rcvif(mc, ifp);
/* Set M_PROMISC for outgoing packets to be discarded. */
if (1 /*d->bd_direction == BPF_D_INOUT*/)
m->m_flags |= M_PROMISC;
} else
mc = NULL;
s = splsoftnet();
error = if_output_lock(ifp, ifp, m, (struct sockaddr *) &dst, NULL);
if (mc != NULL) {
if (error == 0)
ifp->_if_input(ifp, mc);
else
m_freem(mc);
}
splx(s);
KERNEL_UNLOCK_ONE(NULL);
/*
* 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 splnet.
*/
static void
reset_d(struct bpf_d *d)
{
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;
d->bd_ccount = 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.
* 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.
* BIOCSFEEDBACK Set packet feedback mode.
* BIOCGFEEDBACK Get packet feedback mode.
* BIOCGSEESENT Get "see sent packets" mode.
* BIOCSSEESENT Set "see sent packets" mode.
*/
/* ARGSUSED */
static int
bpf_ioctl(struct file *fp, u_long cmd, void *addr)
{
struct bpf_d *d = fp->f_bpf;
int s, error = 0;
/*
* Refresh the PID associated with this bpf file.
*/
KERNEL_LOCK(1, NULL);
d->bd_pid = curproc->p_pid;
#ifdef _LP64
if (curproc->p_flag & PK_32)
d->bd_compat32 = 1;
else
d->bd_compat32 = 0;
#endif
s = splnet();
if (d->bd_state == BPF_WAITING)
callout_stop(&d->bd_callout);
d->bd_state = BPF_IDLE;
splx(s);
switch (cmd) {
default:
error = EINVAL;
break;
/*
* Check for read packet available.
*/
case FIONREAD:
{
int n;
s = splnet();
n = d->bd_slen;
if (d->bd_hbuf)
n += d->bd_hlen;
splx(s);
*(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;
d->bd_bufsize = size;
}
break;
/*
* Set link layer read filter.
*/
case BIOCSETF:
error = bpf_setf(d, addr);
break;
/*
* Flush read packet buffer.
*/
case BIOCFLUSH:
s = splnet();
reset_d(d);
splx(s);
break;
/*
* Put interface into promiscuous mode.
*/
case BIOCPROMISC:
if (d->bd_bif == NULL) {
/*
* No interface attached yet.
*/
error = EINVAL;
break;
}
s = splnet();
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 == NULL)
error = EINVAL;
else
*(u_int *)addr = d->bd_bif->bif_dlt;
break;
/*
* Get a list of supported device parameters.
*/
case BIOCGDLTLIST:
if (d->bd_bif == NULL)
error = EINVAL;
else
error = bpf_getdltlist(d, addr);
break;
/*
* Set device parameters.
*/
case BIOCSDLT:
mutex_enter(&bpf_mtx);
if (d->bd_bif == NULL)
error = EINVAL;
else
error = bpf_setdlt(d, *(u_int *)addr);
mutex_exit(&bpf_mtx);
break;
/*
* Set interface name.
*/
#ifdef OBIOCGETIF
case OBIOCGETIF:
#endif
case BIOCGETIF:
if (d->bd_bif == NULL)
error = EINVAL;
else
bpf_ifname(d->bd_bif->bif_ifp, addr);
break;
/*
* Set interface.
*/
#ifdef OBIOCSETIF
case OBIOCSETIF:
#endif
case BIOCSETIF:
mutex_enter(&bpf_mtx);
error = bpf_setif(d, addr);
mutex_exit(&bpf_mtx);
break;
/*
* Set read timeout.
*/
case BIOCSRTIMEOUT:
{
struct timeval *tv = addr;
/* Compute number of ticks. */
d->bd_rtout = tv->tv_sec * hz + tv->tv_usec / tick;
if ((d->bd_rtout == 0) && (tv->tv_usec != 0))
d->bd_rtout = 1;
break;
}
#ifdef BIOCGORTIMEOUT
/*
* Get read timeout.
*/
case BIOCGORTIMEOUT:
{
struct timeval50 *tv = addr;
tv->tv_sec = d->bd_rtout / hz;
tv->tv_usec = (d->bd_rtout % hz) * tick;
break;
}
#endif
#ifdef BIOCSORTIMEOUT
/*
* Set read timeout.
*/
case BIOCSORTIMEOUT:
{
struct timeval50 *tv = addr;
/* Compute number of ticks. */
d->bd_rtout = tv->tv_sec * hz + tv->tv_usec / tick;
if ((d->bd_rtout == 0) && (tv->tv_usec != 0))
d->bd_rtout = 1;
break;
}
#endif
/*
* Get read timeout.
*/
case BIOCGRTIMEOUT:
{
struct timeval *tv = 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 = addr;
bs->bs_recv = d->bd_rcount;
bs->bs_drop = d->bd_dcount;
bs->bs_capt = d->bd_ccount;
break;
}
case BIOCGSTATSOLD:
{
struct bpf_stat_old *bs = 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 = 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;
/*
* 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;
/*
* Set "feed packets from bpf back to input" mode
*/
case BIOCSFEEDBACK:
d->bd_feedback = *(u_int *)addr;
break;
/*
* Get "feed packets from bpf back to input" mode
*/
case BIOCGFEEDBACK:
*(u_int *)addr = d->bd_feedback;
break;
case FIONBIO: /* Non-blocking I/O */
/*
* No need to do anything special as we use IO_NDELAY in
* bpfread() as an indication of whether or not to block
* the read.
*/
break;
case FIOASYNC: /* Send signal on receive packets */
d->bd_async = *(int *)addr;
break;
case TIOCSPGRP: /* Process or group to send signals to */
case FIOSETOWN:
error = fsetown(&d->bd_pgid, cmd, addr);
break;
case TIOCGPGRP:
case FIOGETOWN:
error = fgetown(d->bd_pgid, cmd, addr);
break;
}
KERNEL_UNLOCK_ONE(NULL);
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)
{
struct bpf_insn *fcode, *old;
bpfjit_func_t jcode, oldj;
size_t flen, size;
int s;
jcode = NULL;
flen = fp->bf_len;
if ((fp->bf_insns == NULL && flen) || flen > BPF_MAXINSNS) {
return EINVAL;
}
if (flen) {
/*
* Allocate the buffer, copy the byte-code from
* userspace and validate it.
*/
size = flen * sizeof(*fp->bf_insns);
fcode = malloc(size, M_DEVBUF, M_WAITOK);
if (copyin(fp->bf_insns, fcode, size) != 0 ||
!bpf_validate(fcode, (int)flen)) {
free(fcode, M_DEVBUF);
return EINVAL;
}
membar_consumer();
if (bpf_jit)
jcode = bpf_jit_generate(NULL, fcode, flen);
} else {
fcode = NULL;
}
s = splnet();
old = d->bd_filter;
d->bd_filter = fcode;
oldj = d->bd_jitcode;
d->bd_jitcode = jcode;
reset_d(d);
splx(s);
if (old) {
free(old, M_DEVBUF);
}
if (oldj) {
bpf_jit_freecode(oldj);
}
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.
*/
static int
bpf_setif(struct bpf_d *d, struct ifreq *ifr)
{
struct bpf_if *bp;
char *cp;
int unit_seen, i, s, error;
KASSERT(mutex_owned(&bpf_mtx));
/*
* Make sure the provided name has a unit number, and default
* it to '0' if not specified.
* XXX This is ugly ... do this differently?
*/
unit_seen = 0;
cp = ifr->ifr_name;
cp[sizeof(ifr->ifr_name) - 1] = '\0'; /* sanity */
while (*cp++)
if (*cp >= '0' && *cp <= '9')
unit_seen = 1;
if (!unit_seen) {
/* Make sure to leave room for the '\0'. */
for (i = 0; i < (IFNAMSIZ - 1); ++i) {
if ((ifr->ifr_name[i] >= 'a' &&
ifr->ifr_name[i] <= 'z') ||
(ifr->ifr_name[i] >= 'A' &&
ifr->ifr_name[i] <= 'Z'))
continue;
ifr->ifr_name[i] = '0';
}
}
/*
* Look through attached interfaces for the named one.
*/
for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
struct ifnet *ifp = bp->bif_ifp;
if (ifp == NULL ||
strcmp(ifp->if_xname, ifr->ifr_name) != 0)
continue;
/* skip additional entry */
if (bp->bif_driverp != &ifp->if_bpf)
continue;
/*
* We found the requested interface.
* Allocate the packet buffers if we need to.
* If we're already attached to requested interface,
* just flush the buffer.
*/
if (d->bd_sbuf == NULL) {
error = bpf_allocbufs(d);
if (error != 0)
return (error);
}
s = splnet();
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);
}
/*
* Copy the interface name to the ifreq.
*/
static void
bpf_ifname(struct ifnet *ifp, struct ifreq *ifr)
{
memcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ);
}
static int
bpf_stat(struct file *fp, struct stat *st)
{
struct bpf_d *d = fp->f_bpf;
(void)memset(st, 0, sizeof(*st));
KERNEL_LOCK(1, NULL);
st->st_dev = makedev(cdevsw_lookup_major(&bpf_cdevsw), d->bd_pid);
st->st_atimespec = d->bd_atime;
st->st_mtimespec = d->bd_mtime;
st->st_ctimespec = st->st_birthtimespec = d->bd_btime;
st->st_uid = kauth_cred_geteuid(fp->f_cred);
st->st_gid = kauth_cred_getegid(fp->f_cred);
st->st_mode = S_IFCHR;
KERNEL_UNLOCK_ONE(NULL);
return 0;
}
/*
* Support for poll() system call
*
* Return true iff the specific operation will not block indefinitely - with
* the assumption that it is safe to positively acknowledge a request for the
* ability to write to the BPF device.
* Otherwise, return false but make a note that a selnotify() must be done.
*/
static int
bpf_poll(struct file *fp, int events)
{
struct bpf_d *d = fp->f_bpf;
int s = splnet();
int revents;
/*
* Refresh the PID associated with this bpf file.
*/
KERNEL_LOCK(1, NULL);
d->bd_pid = curproc->p_pid;
revents = events & (POLLOUT | POLLWRNORM);
if (events & (POLLIN | POLLRDNORM)) {
/*
* An imitation of the FIONREAD ioctl code.
*/
if (d->bd_hlen != 0 ||
((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
d->bd_slen != 0)) {
revents |= events & (POLLIN | POLLRDNORM);
} else {
selrecord(curlwp, &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;
}
}
}
KERNEL_UNLOCK_ONE(NULL);
splx(s);
return (revents);
}
static void
filt_bpfrdetach(struct knote *kn)
{
struct bpf_d *d = kn->kn_hook;
int s;
KERNEL_LOCK(1, NULL);
s = splnet();
SLIST_REMOVE(&d->bd_sel.sel_klist, kn, knote, kn_selnext);
splx(s);
KERNEL_UNLOCK_ONE(NULL);
}
static int
filt_bpfread(struct knote *kn, long hint)
{
struct bpf_d *d = kn->kn_hook;
int rv;
KERNEL_LOCK(1, NULL);
kn->kn_data = d->bd_hlen;
if (d->bd_immediate)
kn->kn_data += d->bd_slen;
rv = (kn->kn_data > 0);
KERNEL_UNLOCK_ONE(NULL);
return rv;
}
static const struct filterops bpfread_filtops =
{ 1, NULL, filt_bpfrdetach, filt_bpfread };
static int
bpf_kqfilter(struct file *fp, struct knote *kn)
{
struct bpf_d *d = fp->f_bpf;
struct klist *klist;
int s;
KERNEL_LOCK(1, NULL);
switch (kn->kn_filter) {
case EVFILT_READ:
klist = &d->bd_sel.sel_klist;
kn->kn_fop = &bpfread_filtops;
break;
default:
KERNEL_UNLOCK_ONE(NULL);
return (EINVAL);
}
kn->kn_hook = d;
s = splnet();
SLIST_INSERT_HEAD(klist, kn, kn_selnext);
splx(s);
KERNEL_UNLOCK_ONE(NULL);
return (0);
}
/*
* Copy data from an mbuf chain into a buffer. This code is derived
* from m_copydata in sys/uipc_mbuf.c.
*/
static void *
bpf_mcpy(void *dst_arg, const void *src_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_mcpy");
count = min(m->m_len, len);
memcpy(dst, mtod(m, const void *), count);
m = m->m_next;
dst += count;
len -= count;
}
return dst_arg;
}
/*
* Dispatch a packet to all the listeners on interface bp.
*
* pkt pointer to the packet, either a data buffer or an mbuf chain
* buflen buffer length, if pkt is a data buffer
* cpfn a function that can copy pkt into the listener's buffer
* pktlen length of the packet
* rcv true if packet came in
*/
static inline void
bpf_deliver(struct bpf_if *bp, void *(*cpfn)(void *, const void *, size_t),
void *pkt, u_int pktlen, u_int buflen, const bool rcv)
{
uint32_t mem[BPF_MEMWORDS];
bpf_args_t args = {
.pkt = (const uint8_t *)pkt,
.wirelen = pktlen,
.buflen = buflen,
.mem = mem,
.arg = NULL
};
bool gottime = false;
struct timespec ts;
/*
* 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.
*/
for (struct bpf_d *d = bp->bif_dlist; d != NULL; d = d->bd_next) {
u_int slen;
if (!d->bd_seesent && !rcv) {
continue;
}
d->bd_rcount++;
bpf_gstats.bs_recv++;
if (d->bd_jitcode)
slen = d->bd_jitcode(NULL, &args);
else
slen = bpf_filter_ext(NULL, d->bd_filter, &args);
if (!slen) {
continue;
}
if (!gottime) {
gottime = true;
nanotime(&ts);
}
catchpacket(d, pkt, pktlen, slen, cpfn, &ts);
}
}
/*
* 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.
*/
static void
_bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
{
bpf_deliver(bp, memcpy, pkt, pktlen, pktlen, true);
}
/*
* Incoming linkage from device drivers, when the head of the packet is in
* a buffer, and the tail is in an mbuf chain.
*/
static void
_bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m)
{
u_int pktlen;
struct mbuf mb;
/* Skip outgoing duplicate packets. */
if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif_index == 0) {
m->m_flags &= ~M_PROMISC;
return;
}
pktlen = m_length(m) + dlen;
/*
* 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.
*/
(void)memset(&mb, 0, sizeof(mb));
mb.m_next = m;
mb.m_data = data;
mb.m_len = dlen;
bpf_deliver(bp, bpf_mcpy, &mb, pktlen, 0, m->m_pkthdr.rcvif_index != 0);
}
/*
* Incoming linkage from device drivers, when packet is in an mbuf chain.
*/
static void
_bpf_mtap(struct bpf_if *bp, struct mbuf *m)
{
void *(*cpfn)(void *, const void *, size_t);
u_int pktlen, buflen;
void *marg;
/* Skip outgoing duplicate packets. */
if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif_index == 0) {
m->m_flags &= ~M_PROMISC;
return;
}
pktlen = m_length(m);
if (pktlen == m->m_len) {
cpfn = (void *)memcpy;
marg = mtod(m, void *);
buflen = pktlen;
} else {
cpfn = bpf_mcpy;
marg = m;
buflen = 0;
}
bpf_deliver(bp, cpfn, marg, pktlen, buflen, m->m_pkthdr.rcvif_index != 0);
}
/*
* We need to prepend the address family as
* a four byte field. Cons up a dummy header
* to pacify bpf. This is safe because bpf
* will only read from the mbuf (i.e., it won't
* try to free it or keep a pointer a to it).
*/
static void
_bpf_mtap_af(struct bpf_if *bp, uint32_t af, struct mbuf *m)
{
struct mbuf m0;
m0.m_flags = 0;
m0.m_next = m;
m0.m_len = 4;
m0.m_data = (char *)&af;
_bpf_mtap(bp, &m0);
}
/*
* Put the SLIP pseudo-"link header" in place.
* Note this M_PREPEND() should never fail,
* swince we know we always have enough space
* in the input buffer.
*/
static void
_bpf_mtap_sl_in(struct bpf_if *bp, u_char *chdr, struct mbuf **m)
{
int s;
u_char *hp;
M_PREPEND(*m, SLIP_HDRLEN, M_DONTWAIT);
if (*m == NULL)
return;
hp = mtod(*m, u_char *);
hp[SLX_DIR] = SLIPDIR_IN;
(void)memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN);
s = splnet();
_bpf_mtap(bp, *m);
splx(s);
m_adj(*m, SLIP_HDRLEN);
}
/*
* Put the SLIP pseudo-"link header" in
* place. The compressed header is now
* at the beginning of the mbuf.
*/
static void
_bpf_mtap_sl_out(struct bpf_if *bp, u_char *chdr, struct mbuf *m)
{
struct mbuf m0;
u_char *hp;
int s;
m0.m_flags = 0;
m0.m_next = m;
m0.m_data = m0.m_dat;
m0.m_len = SLIP_HDRLEN;
hp = mtod(&m0, u_char *);
hp[SLX_DIR] = SLIPDIR_OUT;
(void)memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN);
s = splnet();
_bpf_mtap(bp, &m0);
splx(s);
m_freem(m);
}
static int
bpf_hdrlen(struct bpf_d *d)
{
int hdrlen = d->bd_bif->bif_hdrlen;
/*
* 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).
*/
#ifdef _LP64
if (d->bd_compat32)
return (BPF_WORDALIGN32(hdrlen + SIZEOF_BPF_HDR32) - hdrlen);
else
#endif
return (BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen);
}
/*
* Move the packet data from interface memory (pkt) into the
* store buffer. Call the wakeup functions if it's time to wakeup
* a listener (buffer full), "cpfn" is the routine called to do the
* actual data transfer. memcpy is passed in to copy contiguous chunks,
* while bpf_mcpy is passed in to copy mbuf chains. In the latter case,
* pkt is really an mbuf.
*/
static void
catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
void *(*cpfn)(void *, const void *, size_t), struct timespec *ts)
{
char *h;
int totlen, curlen, caplen;
int hdrlen = bpf_hdrlen(d);
int do_wakeup = 0;
++d->bd_ccount;
++bpf_gstats.bs_capt;
/*
* 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;
/*
* If we adjusted totlen to fit the bufsize, it could be that
* totlen is smaller than hdrlen because of the link layer header.
*/
caplen = totlen - hdrlen;
if (caplen < 0)
caplen = 0;
/*
* Round up the end of the previous packet to the next longword.
*/
#ifdef _LP64
if (d->bd_compat32)
curlen = BPF_WORDALIGN32(d->bd_slen);
else
#endif
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;
++bpf_gstats.bs_drop;
return;
}
ROTATE_BUFFERS(d);
do_wakeup = 1;
curlen = 0;
} else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) {
/*
* Immediate mode is set, or the read timeout has
* already expired during a select call. A packet
* arrived, so the reader should be woken up.
*/
do_wakeup = 1;
}
/*
* Append the bpf header.
*/
h = (char *)d->bd_sbuf + curlen;
#ifdef _LP64
if (d->bd_compat32) {
struct bpf_hdr32 *hp32;
hp32 = (struct bpf_hdr32 *)h;
hp32->bh_tstamp.tv_sec = ts->tv_sec;
hp32->bh_tstamp.tv_usec = ts->tv_nsec / 1000;
hp32->bh_datalen = pktlen;
hp32->bh_hdrlen = hdrlen;
hp32->bh_caplen = caplen;
} else
#endif
{
struct bpf_hdr *hp;
hp = (struct bpf_hdr *)h;
hp->bh_tstamp.tv_sec = ts->tv_sec;
hp->bh_tstamp.tv_usec = ts->tv_nsec / 1000;
hp->bh_datalen = pktlen;
hp->bh_hdrlen = hdrlen;
hp->bh_caplen = caplen;
}
/*
* Copy the packet data into the store buffer and update its length.
*/
(*cpfn)(h + hdrlen, pkt, caplen);
d->bd_slen = curlen + totlen;
/*
* Call bpf_wakeup after bd_slen has been updated so that kevent(2)
* will cause filt_bpfread() to be called with it adjusted.
*/
if (do_wakeup)
bpf_wakeup(d);
}
/*
* Initialize all nonzero fields of a descriptor.
*/
static int
bpf_allocbufs(struct bpf_d *d)
{
d->bd_fbuf = malloc(d->bd_bufsize, M_DEVBUF, M_NOWAIT);
if (!d->bd_fbuf)
return (ENOBUFS);
d->bd_sbuf = malloc(d->bd_bufsize, M_DEVBUF, M_NOWAIT);
if (!d->bd_sbuf) {
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(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_DEVBUF);
if (d->bd_hbuf != NULL)
free(d->bd_hbuf, M_DEVBUF);
if (d->bd_fbuf != NULL)
free(d->bd_fbuf, M_DEVBUF);
}
if (d->bd_filter)
free(d->bd_filter, M_DEVBUF);
if (d->bd_jitcode != NULL) {
bpf_jit_freecode(d->bd_jitcode);
}
}
/*
* Attach an interface to bpf. dlt is the link layer type;
* hdrlen is the fixed size of the link header for the specified dlt
* (variable length headers not yet supported).
*/
static void
_bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
{
struct bpf_if *bp;
bp = malloc(sizeof(*bp), M_DEVBUF, M_DONTWAIT);
if (bp == NULL)
panic("bpfattach");
mutex_enter(&bpf_mtx);
bp->bif_dlist = NULL;
bp->bif_driverp = driverp;
bp->bif_ifp = ifp;
bp->bif_dlt = dlt;
bp->bif_next = bpf_iflist;
bpf_iflist = bp;
*bp->bif_driverp = NULL;
bp->bif_hdrlen = hdrlen;
mutex_exit(&bpf_mtx);
#if 0
printf("bpf: %s attached\n", ifp->if_xname);
#endif
}
/*
* Remove an interface from bpf.
*/
static void
_bpfdetach(struct ifnet *ifp)
{
struct bpf_if *bp, **pbp;
struct bpf_d *d;
int s;
mutex_enter(&bpf_mtx);
/* Nuke the vnodes for any open instances */
LIST_FOREACH(d, &bpf_list, bd_list) {
if (d->bd_bif != NULL && d->bd_bif->bif_ifp == ifp) {
/*
* Detach the descriptor from an interface now.
* It will be free'ed later by close routine.
*/
s = splnet();
d->bd_promisc = 0; /* we can't touch device. */
bpf_detachd(d);
splx(s);
}
}
again:
for (bp = bpf_iflist, pbp = &bpf_iflist;
bp != NULL; pbp = &bp->bif_next, bp = bp->bif_next) {
if (bp->bif_ifp == ifp) {
*pbp = bp->bif_next;
free(bp, M_DEVBUF);
goto again;
}
}
mutex_exit(&bpf_mtx);
}
/*
* Change the data link type of a interface.
*/
static void
_bpf_change_type(struct ifnet *ifp, u_int dlt, u_int hdrlen)
{
struct bpf_if *bp;
for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
if (bp->bif_driverp == &ifp->if_bpf)
break;
}
if (bp == NULL)
panic("bpf_change_type");
bp->bif_dlt = dlt;
bp->bif_hdrlen = hdrlen;
}
/*
* Get a list of available data link type of the interface.
*/
static int
bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
{
int n, error;
struct ifnet *ifp;
struct bpf_if *bp;
ifp = d->bd_bif->bif_ifp;
n = 0;
error = 0;
for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
if (bp->bif_ifp != ifp)
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));
}
n++;
}
bfl->bfl_len = n;
return error;
}
/*
* Set the data link type of a BPF instance.
*/
static int
bpf_setdlt(struct bpf_d *d, u_int dlt)
{
int s, error, opromisc;
struct ifnet *ifp;
struct bpf_if *bp;
KASSERT(mutex_owned(&bpf_mtx));
if (d->bd_bif->bif_dlt == dlt)
return 0;
ifp = d->bd_bif->bif_ifp;
for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
break;
}
if (bp == NULL)
return EINVAL;
s = splnet();
opromisc = d->bd_promisc;
bpf_detachd(d);
bpf_attachd(d, bp);
reset_d(d);
if (opromisc) {
error = ifpromisc(bp->bif_ifp, 1);
if (error)
printf("%s: bpf_setdlt: ifpromisc failed (%d)\n",
bp->bif_ifp->if_xname, error);
else
d->bd_promisc = 1;
}
splx(s);
return 0;
}
static int
sysctl_net_bpf_maxbufsize(SYSCTLFN_ARGS)
{
int newsize, error;
struct sysctlnode node;
node = *rnode;
node.sysctl_data = &newsize;
newsize = bpf_maxbufsize;
error = sysctl_lookup(SYSCTLFN_CALL(&node));
if (error || newp == NULL)
return (error);
if (newsize < BPF_MINBUFSIZE || newsize > BPF_MAXBUFSIZE)
return (EINVAL);
bpf_maxbufsize = newsize;
return (0);
}
#if defined(MODULAR) || defined(BPFJIT)
static int
sysctl_net_bpf_jit(SYSCTLFN_ARGS)
{
bool newval;
int error;
struct sysctlnode node;
node = *rnode;
node.sysctl_data = &newval;
newval = bpf_jit;
error = sysctl_lookup(SYSCTLFN_CALL(&node));
if (error != 0 || newp == NULL)
return error;
bpf_jit = newval;
/*
* Do a full sync to publish new bpf_jit value and
* update bpfjit_module_ops.bj_generate_code variable.
*/
membar_sync();
if (newval && bpfjit_module_ops.bj_generate_code == NULL) {
printf("JIT compilation is postponed "
"until after bpfjit module is loaded\n");
}
return 0;
}
#endif
static int
sysctl_net_bpf_peers(SYSCTLFN_ARGS)
{
int error, elem_count;
struct bpf_d *dp;
struct bpf_d_ext dpe;
size_t len, needed, elem_size, out_size;
char *sp;
if (namelen == 1 && name[0] == CTL_QUERY)
return (sysctl_query(SYSCTLFN_CALL(rnode)));
if (namelen != 2)
return (EINVAL);
/* BPF peers is privileged information. */
error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
KAUTH_REQ_NETWORK_INTERFACE_GETPRIV, NULL, NULL, NULL);
if (error)
return (EPERM);
len = (oldp != NULL) ? *oldlenp : 0;
sp = oldp;
elem_size = name[0];
elem_count = name[1];
out_size = MIN(sizeof(dpe), elem_size);
needed = 0;
if (elem_size < 1 || elem_count < 0)
return (EINVAL);
mutex_enter(&bpf_mtx);
LIST_FOREACH(dp, &bpf_list, bd_list) {
if (len >= elem_size && elem_count > 0) {
#define BPF_EXT(field) dpe.bde_ ## field = dp->bd_ ## field
BPF_EXT(bufsize);
BPF_EXT(promisc);
BPF_EXT(state);
BPF_EXT(immediate);
BPF_EXT(hdrcmplt);
BPF_EXT(seesent);
BPF_EXT(pid);
BPF_EXT(rcount);
BPF_EXT(dcount);
BPF_EXT(ccount);
#undef BPF_EXT
if (dp->bd_bif)
(void)strlcpy(dpe.bde_ifname,
dp->bd_bif->bif_ifp->if_xname,
IFNAMSIZ - 1);
else
dpe.bde_ifname[0] = '\0';
error = copyout(&dpe, sp, out_size);
if (error)
break;
sp += elem_size;
len -= elem_size;
}
needed += elem_size;
if (elem_count > 0 && elem_count != INT_MAX)
elem_count--;
}
mutex_exit(&bpf_mtx);
*oldlenp = needed;
return (error);
}
static struct sysctllog *bpf_sysctllog;
static void
sysctl_net_bpf_setup(void)
{
const struct sysctlnode *node;
node = NULL;
sysctl_createv(&bpf_sysctllog, 0, NULL, &node,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "bpf",
SYSCTL_DESCR("BPF options"),
NULL, 0, NULL, 0,
CTL_NET, CTL_CREATE, CTL_EOL);
if (node != NULL) {
#if defined(MODULAR) || defined(BPFJIT)
sysctl_createv(&bpf_sysctllog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
CTLTYPE_BOOL, "jit",
SYSCTL_DESCR("Toggle Just-In-Time compilation"),
sysctl_net_bpf_jit, 0, &bpf_jit, 0,
CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL);
#endif
sysctl_createv(&bpf_sysctllog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
CTLTYPE_INT, "maxbufsize",
SYSCTL_DESCR("Maximum size for data capture buffer"),
sysctl_net_bpf_maxbufsize, 0, &bpf_maxbufsize, 0,
CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL);
sysctl_createv(&bpf_sysctllog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_STRUCT, "stats",
SYSCTL_DESCR("BPF stats"),
NULL, 0, &bpf_gstats, sizeof(bpf_gstats),
CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL);
sysctl_createv(&bpf_sysctllog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_STRUCT, "peers",
SYSCTL_DESCR("BPF peers"),
sysctl_net_bpf_peers, 0, NULL, 0,
CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL);
}
}
struct bpf_ops bpf_ops_kernel = {
.bpf_attach = _bpfattach,
.bpf_detach = _bpfdetach,
.bpf_change_type = _bpf_change_type,
.bpf_tap = _bpf_tap,
.bpf_mtap = _bpf_mtap,
.bpf_mtap2 = _bpf_mtap2,
.bpf_mtap_af = _bpf_mtap_af,
.bpf_mtap_sl_in = _bpf_mtap_sl_in,
.bpf_mtap_sl_out = _bpf_mtap_sl_out,
};
MODULE(MODULE_CLASS_DRIVER, bpf, "bpf_filter");
static int
bpf_modcmd(modcmd_t cmd, void *arg)
{
#ifdef _MODULE
devmajor_t bmajor, cmajor;
#endif
int error = 0;
switch (cmd) {
case MODULE_CMD_INIT:
bpf_init();
#ifdef _MODULE
bmajor = cmajor = NODEVMAJOR;
error = devsw_attach("bpf", NULL, &bmajor,
&bpf_cdevsw, &cmajor);
if (error)
break;
#endif
bpf_ops_handover_enter(&bpf_ops_kernel);
atomic_swap_ptr(&bpf_ops, &bpf_ops_kernel);
bpf_ops_handover_exit();
sysctl_net_bpf_setup();
break;
case MODULE_CMD_FINI:
/*
* While there is no reference counting for bpf callers,
* unload could at least in theory be done similarly to
* system call disestablishment. This should even be
* a little simpler:
*
* 1) replace op vector with stubs
* 2) post update to all cpus with xc
* 3) check that nobody is in bpf anymore
* (it's doubtful we'd want something like l_sysent,
* but we could do something like *signed* percpu
* counters. if the sum is 0, we're good).
* 4) if fail, unroll changes
*
* NOTE: change won't be atomic to the outside. some
* packets may be not captured even if unload is
* not succesful. I think packet capture not working
* is a perfectly logical consequence of trying to
* disable packet capture.
*/
error = EOPNOTSUPP;
/* insert sysctl teardown */
break;
default:
error = ENOTTY;
break;
}
return error;
}
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