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freebsd-skq/sys/net/bpf.c
melifaro e9f6263cd3 Improve logic besides net.bpf.optimize_writers. 
Direct bpf(4) consumers should now work fine with this tunable turned on.
In fact, the only case when optimized_writers can change program
behavior is direct bpf(4) consumer setting its read filter to
catch-all one.

MFC after:	2 weeks
Sponsored by:	Yandex LLC
2014-06-11 11:27:44 +00:00

2932 lines
65 KiB
C
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/*-
* Copyright (c) 1990, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from the Stanford/CMU enet packet filter,
* (net/enet.c) distributed as part of 4.3BSD, and code contributed
* to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
* Berkeley Laboratory.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)bpf.c 8.4 (Berkeley) 1/9/95
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_bpf.h"
#include "opt_compat.h"
#include "opt_netgraph.h"
#include <sys/types.h>
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/rwlock.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/jail.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/time.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/filio.h>
#include <sys/sockio.h>
#include <sys/ttycom.h>
#include <sys/uio.h>
#include <sys/event.h>
#include <sys/file.h>
#include <sys/poll.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_var.h>
#define BPF_INTERNAL
#include <net/bpf.h>
#include <net/bpf_buffer.h>
#ifdef BPF_JITTER
#include <net/bpf_jitter.h>
#endif
#include <net/bpf_zerocopy.h>
#include <net/bpfdesc.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <net80211/ieee80211_freebsd.h>
#include <security/mac/mac_framework.h>
MALLOC_DEFINE(M_BPF, "BPF", "BPF data");
#if defined(DEV_BPF) || defined(NETGRAPH_BPF)
#define PRINET 26 /* interruptible */
#define SIZEOF_BPF_HDR(type) \
(offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen))
#ifdef COMPAT_FREEBSD32
#include <sys/mount.h>
#include <compat/freebsd32/freebsd32.h>
#define BPF_ALIGNMENT32 sizeof(int32_t)
#define BPF_WORDALIGN32(x) (((x)+(BPF_ALIGNMENT32-1))&~(BPF_ALIGNMENT32-1))
#ifndef BURN_BRIDGES
/*
* 32-bit version of structure prepended to each packet. We use this header
* instead of the standard one for 32-bit streams. We mark the a stream as
* 32-bit the first time we see a 32-bit compat ioctl request.
*/
struct bpf_hdr32 {
struct timeval32 bh_tstamp; /* time stamp */
uint32_t bh_caplen; /* length of captured portion */
uint32_t bh_datalen; /* original length of packet */
uint16_t bh_hdrlen; /* length of bpf header (this struct
plus alignment padding) */
};
#endif
struct bpf_program32 {
u_int bf_len;
uint32_t bf_insns;
};
struct bpf_dltlist32 {
u_int bfl_len;
u_int bfl_list;
};
#define BIOCSETF32 _IOW('B', 103, struct bpf_program32)
#define BIOCSRTIMEOUT32 _IOW('B', 109, struct timeval32)
#define BIOCGRTIMEOUT32 _IOR('B', 110, struct timeval32)
#define BIOCGDLTLIST32 _IOWR('B', 121, struct bpf_dltlist32)
#define BIOCSETWF32 _IOW('B', 123, struct bpf_program32)
#define BIOCSETFNR32 _IOW('B', 130, struct bpf_program32)
#endif
/*
* bpf_iflist is a list of BPF interface structures, each corresponding to a
* specific DLT. The same network interface might have several BPF interface
* structures registered by different layers in the stack (i.e., 802.11
* frames, ethernet frames, etc).
*/
static LIST_HEAD(, bpf_if) bpf_iflist, bpf_freelist;
static struct mtx bpf_mtx; /* bpf global lock */
static int bpf_bpfd_cnt;
static void bpf_attachd(struct bpf_d *, struct bpf_if *);
static void bpf_detachd(struct bpf_d *);
static void bpf_detachd_locked(struct bpf_d *);
static void bpf_freed(struct bpf_d *);
static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **,
struct sockaddr *, int *, struct bpf_insn *);
static int bpf_setif(struct bpf_d *, struct ifreq *);
static void bpf_timed_out(void *);
static __inline void
bpf_wakeup(struct bpf_d *);
static void catchpacket(struct bpf_d *, u_char *, u_int, u_int,
void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int),
struct bintime *);
static void reset_d(struct bpf_d *);
static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd);
static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
static int bpf_setdlt(struct bpf_d *, u_int);
static void filt_bpfdetach(struct knote *);
static int filt_bpfread(struct knote *, long);
static void bpf_drvinit(void *);
static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS);
SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl");
int bpf_maxinsns = BPF_MAXINSNS;
SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW,
&bpf_maxinsns, 0, "Maximum bpf program instructions");
static int bpf_zerocopy_enable = 0;
SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW,
&bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions");
static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW,
bpf_stats_sysctl, "bpf statistics portal");
static VNET_DEFINE(int, bpf_optimize_writers) = 0;
#define V_bpf_optimize_writers VNET(bpf_optimize_writers)
SYSCTL_VNET_INT(_net_bpf, OID_AUTO, optimize_writers,
CTLFLAG_RW, &VNET_NAME(bpf_optimize_writers), 0,
"Do not send packets until BPF program is set");
static d_open_t bpfopen;
static d_read_t bpfread;
static d_write_t bpfwrite;
static d_ioctl_t bpfioctl;
static d_poll_t bpfpoll;
static d_kqfilter_t bpfkqfilter;
static struct cdevsw bpf_cdevsw = {
.d_version = D_VERSION,
.d_open = bpfopen,
.d_read = bpfread,
.d_write = bpfwrite,
.d_ioctl = bpfioctl,
.d_poll = bpfpoll,
.d_name = "bpf",
.d_kqfilter = bpfkqfilter,
};
static struct filterops bpfread_filtops = {
.f_isfd = 1,
.f_detach = filt_bpfdetach,
.f_event = filt_bpfread,
};
eventhandler_tag bpf_ifdetach_cookie = NULL;
/*
* LOCKING MODEL USED BY BPF:
* Locks:
* 1) global lock (BPF_LOCK). Mutex, used to protect interface addition/removal,
* some global counters and every bpf_if reference.
* 2) Interface lock. Rwlock, used to protect list of BPF descriptors and their filters.
* 3) Descriptor lock. Mutex, used to protect BPF buffers and various structure fields
* used by bpf_mtap code.
*
* Lock order:
*
* Global lock, interface lock, descriptor lock
*
* We have to acquire interface lock before descriptor main lock due to BPF_MTAP[2]
* working model. In many places (like bpf_detachd) we start with BPF descriptor
* (and we need to at least rlock it to get reliable interface pointer). This
* gives us potential LOR. As a result, we use global lock to protect from bpf_if
* change in every such place.
*
* Changing d->bd_bif is protected by 1) global lock, 2) interface lock and
* 3) descriptor main wlock.
* Reading bd_bif can be protected by any of these locks, typically global lock.
*
* Changing read/write BPF filter is protected by the same three locks,
* the same applies for reading.
*
* Sleeping in global lock is not allowed due to bpfdetach() using it.
*/
/*
* Wrapper functions for various buffering methods. If the set of buffer
* modes expands, we will probably want to introduce a switch data structure
* similar to protosw, et.
*/
static void
bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src,
u_int len)
{
BPFD_LOCK_ASSERT(d);
switch (d->bd_bufmode) {
case BPF_BUFMODE_BUFFER:
return (bpf_buffer_append_bytes(d, buf, offset, src, len));
case BPF_BUFMODE_ZBUF:
d->bd_zcopy++;
return (bpf_zerocopy_append_bytes(d, buf, offset, src, len));
default:
panic("bpf_buf_append_bytes");
}
}
static void
bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src,
u_int len)
{
BPFD_LOCK_ASSERT(d);
switch (d->bd_bufmode) {
case BPF_BUFMODE_BUFFER:
return (bpf_buffer_append_mbuf(d, buf, offset, src, len));
case BPF_BUFMODE_ZBUF:
d->bd_zcopy++;
return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len));
default:
panic("bpf_buf_append_mbuf");
}
}
/*
* This function gets called when the free buffer is re-assigned.
*/
static void
bpf_buf_reclaimed(struct bpf_d *d)
{
BPFD_LOCK_ASSERT(d);
switch (d->bd_bufmode) {
case BPF_BUFMODE_BUFFER:
return;
case BPF_BUFMODE_ZBUF:
bpf_zerocopy_buf_reclaimed(d);
return;
default:
panic("bpf_buf_reclaimed");
}
}
/*
* If the buffer mechanism has a way to decide that a held buffer can be made
* free, then it is exposed via the bpf_canfreebuf() interface. (1) is
* returned if the buffer can be discarded, (0) is returned if it cannot.
*/
static int
bpf_canfreebuf(struct bpf_d *d)
{
BPFD_LOCK_ASSERT(d);
switch (d->bd_bufmode) {
case BPF_BUFMODE_ZBUF:
return (bpf_zerocopy_canfreebuf(d));
}
return (0);
}
/*
* Allow the buffer model to indicate that the current store buffer is
* immutable, regardless of the appearance of space. Return (1) if the
* buffer is writable, and (0) if not.
*/
static int
bpf_canwritebuf(struct bpf_d *d)
{
BPFD_LOCK_ASSERT(d);
switch (d->bd_bufmode) {
case BPF_BUFMODE_ZBUF:
return (bpf_zerocopy_canwritebuf(d));
}
return (1);
}
/*
* Notify buffer model that an attempt to write to the store buffer has
* resulted in a dropped packet, in which case the buffer may be considered
* full.
*/
static void
bpf_buffull(struct bpf_d *d)
{
BPFD_LOCK_ASSERT(d);
switch (d->bd_bufmode) {
case BPF_BUFMODE_ZBUF:
bpf_zerocopy_buffull(d);
break;
}
}
/*
* Notify the buffer model that a buffer has moved into the hold position.
*/
void
bpf_bufheld(struct bpf_d *d)
{
BPFD_LOCK_ASSERT(d);
switch (d->bd_bufmode) {
case BPF_BUFMODE_ZBUF:
bpf_zerocopy_bufheld(d);
break;
}
}
static void
bpf_free(struct bpf_d *d)
{
switch (d->bd_bufmode) {
case BPF_BUFMODE_BUFFER:
return (bpf_buffer_free(d));
case BPF_BUFMODE_ZBUF:
return (bpf_zerocopy_free(d));
default:
panic("bpf_buf_free");
}
}
static int
bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio)
{
if (d->bd_bufmode != BPF_BUFMODE_BUFFER)
return (EOPNOTSUPP);
return (bpf_buffer_uiomove(d, buf, len, uio));
}
static int
bpf_ioctl_sblen(struct bpf_d *d, u_int *i)
{
if (d->bd_bufmode != BPF_BUFMODE_BUFFER)
return (EOPNOTSUPP);
return (bpf_buffer_ioctl_sblen(d, i));
}
static int
bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i)
{
if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
return (EOPNOTSUPP);
return (bpf_zerocopy_ioctl_getzmax(td, d, i));
}
static int
bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz)
{
if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
return (EOPNOTSUPP);
return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz));
}
static int
bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz)
{
if (d->bd_bufmode != BPF_BUFMODE_ZBUF)
return (EOPNOTSUPP);
return (bpf_zerocopy_ioctl_setzbuf(td, d, bz));
}
/*
* General BPF functions.
*/
static int
bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp,
struct sockaddr *sockp, int *hdrlen, struct bpf_insn *wfilter)
{
const struct ieee80211_bpf_params *p;
struct ether_header *eh;
struct mbuf *m;
int error;
int len;
int hlen;
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.
*/
switch (linktype) {
case DLT_SLIP:
sockp->sa_family = AF_INET;
hlen = 0;
break;
case DLT_EN10MB:
sockp->sa_family = AF_UNSPEC;
/* XXX Would MAXLINKHDR be better? */
hlen = ETHER_HDR_LEN;
break;
case DLT_FDDI:
sockp->sa_family = AF_IMPLINK;
hlen = 0;
break;
case DLT_RAW:
sockp->sa_family = AF_UNSPEC;
hlen = 0;
break;
case DLT_NULL:
/*
* null interface types require a 4 byte pseudo header which
* corresponds to the address family of the packet.
*/
sockp->sa_family = AF_UNSPEC;
hlen = 4;
break;
case DLT_ATM_RFC1483:
/*
* en atm driver requires 4-byte atm pseudo header.
* though it isn't standard, vpi:vci needs to be
* specified anyway.
*/
sockp->sa_family = AF_UNSPEC;
hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
break;
case DLT_PPP:
sockp->sa_family = AF_UNSPEC;
hlen = 4; /* This should match PPP_HDRLEN */
break;
case DLT_IEEE802_11: /* IEEE 802.11 wireless */
sockp->sa_family = AF_IEEE80211;
hlen = 0;
break;
case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */
sockp->sa_family = AF_IEEE80211;
sockp->sa_len = 12; /* XXX != 0 */
hlen = sizeof(struct ieee80211_bpf_params);
break;
default:
return (EIO);
}
len = uio->uio_resid;
if (len < hlen || len - hlen > ifp->if_mtu)
return (EMSGSIZE);
m = m_get2(len, M_WAITOK, MT_DATA, M_PKTHDR);
if (m == NULL)
return (EIO);
m->m_pkthdr.len = m->m_len = len;
*mp = m;
error = uiomove(mtod(m, u_char *), len, uio);
if (error)
goto bad;
slen = bpf_filter(wfilter, mtod(m, u_char *), len, len);
if (slen == 0) {
error = EPERM;
goto bad;
}
/* Check for multicast destination */
switch (linktype) {
case DLT_EN10MB:
eh = mtod(m, struct ether_header *);
if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost,
ETHER_ADDR_LEN) == 0)
m->m_flags |= M_BCAST;
else
m->m_flags |= M_MCAST;
}
break;
}
/*
* Make room for link header, and copy it to sockaddr
*/
if (hlen != 0) {
if (sockp->sa_family == AF_IEEE80211) {
/*
* Collect true length from the parameter header
* NB: sockp is known to be zero'd so if we do a
* short copy unspecified parameters will be
* zero.
* NB: packet may not be aligned after stripping
* bpf params
* XXX check ibp_vers
*/
p = mtod(m, const struct ieee80211_bpf_params *);
hlen = p->ibp_len;
if (hlen > sizeof(sockp->sa_data)) {
error = EINVAL;
goto bad;
}
}
bcopy(mtod(m, const void *), sockp->sa_data, hlen);
}
*hdrlen = hlen;
return (0);
bad:
m_freem(m);
return (error);
}
/*
* Attach file to the bpf interface, i.e. make d listen on bp.
*/
static void
bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
{
int op_w;
BPF_LOCK_ASSERT();
/*
* Save sysctl value to protect from sysctl change
* between reads
*/
op_w = V_bpf_optimize_writers;
if (d->bd_bif != NULL)
bpf_detachd_locked(d);
/*
* Point d at bp, and add d to the interface's list.
* Since there are many applicaiotns using BPF for
* sending raw packets only (dhcpd, cdpd are good examples)
* we can delay adding d to the list of active listeners until
* some filter is configured.
*/
BPFIF_WLOCK(bp);
BPFD_LOCK(d);
d->bd_bif = bp;
if (op_w != 0) {
/* Add to writers-only list */
LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next);
/*
* We decrement bd_writer on every filter set operation.
* First BIOCSETF is done by pcap_open_live() to set up
* snap length. After that appliation usually sets its own filter
*/
d->bd_writer = 2;
} else
LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
BPFD_UNLOCK(d);
BPFIF_WUNLOCK(bp);
bpf_bpfd_cnt++;
CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list",
__func__, d->bd_pid, d->bd_writer ? "writer" : "active");
if (op_w == 0)
EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
}
/*
* Check if we need to upgrade our descriptor @d from write-only mode.
*/
static int
bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, int flen)
{
int is_snap, need_upgrade;
/*
* Check if we've already upgraded or new filter is empty.
*/
if (d->bd_writer == 0 || fcode == NULL)
return (0);
need_upgrade = 0;
/*
* Check if cmd looks like snaplen setting from
* pcap_bpf.c:pcap_open_live().
* Note we're not checking .k value here:
* while pcap_open_live() definitely sets to to non-zero value,
* we'd prefer to treat k=0 (deny ALL) case the same way: e.g.
* do not consider upgrading immediately
*/
if (cmd == BIOCSETF && flen == 1 && fcode[0].code == (BPF_RET | BPF_K))
is_snap = 1;
else
is_snap = 0;
if (is_snap == 0) {
/*
* We're setting first filter and it doesn't look like
* setting snaplen. We're probably using bpf directly.
* Upgrade immediately.
*/
need_upgrade = 1;
} else {
/*
* Do not require upgrade by first BIOCSETF
* (used to set snaplen) by pcap_open_live().
*/
if (--d->bd_writer == 0) {
/*
* First snaplen filter has already
* been set. This is probably catch-all
* filter
*/
need_upgrade = 1;
}
}
CTR5(KTR_NET,
"%s: filter function set by pid %d, "
"bd_writer counter %d, snap %d upgrade %d",
__func__, d->bd_pid, d->bd_writer,
is_snap, need_upgrade);
return (need_upgrade);
}
/*
* Add d to the list of active bp filters.
* Reuqires bpf_attachd() to be called before
*/
static void
bpf_upgraded(struct bpf_d *d)
{
struct bpf_if *bp;
BPF_LOCK_ASSERT();
bp = d->bd_bif;
/*
* Filter can be set several times without specifying interface.
* Mark d as reader and exit.
*/
if (bp == NULL) {
BPFD_LOCK(d);
d->bd_writer = 0;
BPFD_UNLOCK(d);
return;
}
BPFIF_WLOCK(bp);
BPFD_LOCK(d);
/* Remove from writers-only list */
LIST_REMOVE(d, bd_next);
LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next);
/* Mark d as reader */
d->bd_writer = 0;
BPFD_UNLOCK(d);
BPFIF_WUNLOCK(bp);
CTR2(KTR_NET, "%s: upgrade required by pid %d", __func__, d->bd_pid);
EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1);
}
/*
* Detach a file from its interface.
*/
static void
bpf_detachd(struct bpf_d *d)
{
BPF_LOCK();
bpf_detachd_locked(d);
BPF_UNLOCK();
}
static void
bpf_detachd_locked(struct bpf_d *d)
{
int error;
struct bpf_if *bp;
struct ifnet *ifp;
CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid);
BPF_LOCK_ASSERT();
/* Check if descriptor is attached */
if ((bp = d->bd_bif) == NULL)
return;
BPFIF_WLOCK(bp);
BPFD_LOCK(d);
/* Save bd_writer value */
error = d->bd_writer;
/*
* Remove d from the interface's descriptor list.
*/
LIST_REMOVE(d, bd_next);
ifp = bp->bif_ifp;
d->bd_bif = NULL;
BPFD_UNLOCK(d);
BPFIF_WUNLOCK(bp);
bpf_bpfd_cnt--;
/* Call event handler iff d is attached */
if (error == 0)
EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0);
/*
* Check if this descriptor had requested promiscuous mode.
* If so, turn it off.
*/
if (d->bd_promisc) {
d->bd_promisc = 0;
CURVNET_SET(ifp->if_vnet);
error = ifpromisc(ifp, 0);
CURVNET_RESTORE();
if (error != 0 && error != ENXIO) {
/*
* ENXIO can happen if a pccard is unplugged
* Something is really wrong if we were able to put
* the driver into promiscuous mode, but can't
* take it out.
*/
if_printf(bp->bif_ifp,
"bpf_detach: ifpromisc failed (%d)\n", error);
}
}
}
/*
* Close the descriptor by detaching it from its interface,
* deallocating its buffers, and marking it free.
*/
static void
bpf_dtor(void *data)
{
struct bpf_d *d = data;
BPFD_LOCK(d);
if (d->bd_state == BPF_WAITING)
callout_stop(&d->bd_callout);
d->bd_state = BPF_IDLE;
BPFD_UNLOCK(d);
funsetown(&d->bd_sigio);
bpf_detachd(d);
#ifdef MAC
mac_bpfdesc_destroy(d);
#endif /* MAC */
seldrain(&d->bd_sel);
knlist_destroy(&d->bd_sel.si_note);
callout_drain(&d->bd_callout);
bpf_freed(d);
free(d, M_BPF);
}
/*
* Open ethernet device. Returns ENXIO for illegal minor device number,
* EBUSY if file is open by another process.
*/
/* ARGSUSED */
static int
bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td)
{
struct bpf_d *d;
int error, size;
d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO);
error = devfs_set_cdevpriv(d, bpf_dtor);
if (error != 0) {
free(d, M_BPF);
return (error);
}
/*
* For historical reasons, perform a one-time initialization call to
* the buffer routines, even though we're not yet committed to a
* particular buffer method.
*/
bpf_buffer_init(d);
d->bd_hbuf_in_use = 0;
d->bd_bufmode = BPF_BUFMODE_BUFFER;
d->bd_sig = SIGIO;
d->bd_direction = BPF_D_INOUT;
BPF_PID_REFRESH(d, td);
#ifdef MAC
mac_bpfdesc_init(d);
mac_bpfdesc_create(td->td_ucred, d);
#endif
mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF);
callout_init_mtx(&d->bd_callout, &d->bd_lock, 0);
knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock);
/* Allocate default buffers */
size = d->bd_bufsize;
bpf_buffer_ioctl_sblen(d, &size);
return (0);
}
/*
* bpfread - read next chunk of packets from buffers
*/
static int
bpfread(struct cdev *dev, struct uio *uio, int ioflag)
{
struct bpf_d *d;
int error;
int non_block;
int timed_out;
error = devfs_get_cdevpriv((void **)&d);
if (error != 0)
return (error);
/*
* Restrict application to use a buffer the same size as
* as kernel buffers.
*/
if (uio->uio_resid != d->bd_bufsize)
return (EINVAL);
non_block = ((ioflag & O_NONBLOCK) != 0);
BPFD_LOCK(d);
BPF_PID_REFRESH_CUR(d);
if (d->bd_bufmode != BPF_BUFMODE_BUFFER) {
BPFD_UNLOCK(d);
return (EOPNOTSUPP);
}
if (d->bd_state == BPF_WAITING)
callout_stop(&d->bd_callout);
timed_out = (d->bd_state == BPF_TIMED_OUT);
d->bd_state = BPF_IDLE;
while (d->bd_hbuf_in_use) {
error = mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
PRINET|PCATCH, "bd_hbuf", 0);
if (error != 0) {
BPFD_UNLOCK(d);
return (error);
}
}
/*
* 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_slen != 0) {
/*
* A packet(s) either arrived since the previous
* read or arrived while we were asleep.
*/
if (d->bd_immediate || non_block || timed_out) {
/*
* Rotate the buffers and return what's here
* if we are in immediate mode, non-blocking
* flag is set, or this descriptor timed out.
*/
ROTATE_BUFFERS(d);
break;
}
}
/*
* No data is available, check to see if the bpf device
* is still pointed at a real interface. If not, return
* ENXIO so that the userland process knows to rebind
* it before using it again.
*/
if (d->bd_bif == NULL) {
BPFD_UNLOCK(d);
return (ENXIO);
}
if (non_block) {
BPFD_UNLOCK(d);
return (EWOULDBLOCK);
}
error = msleep(d, &d->bd_lock, PRINET|PCATCH,
"bpf", d->bd_rtout);
if (error == EINTR || error == ERESTART) {
BPFD_UNLOCK(d);
return (error);
}
if (error == EWOULDBLOCK) {
/*
* On a timeout, return what's in the buffer,
* which may be nothing. If there is something
* in the store buffer, we can rotate the buffers.
*/
if (d->bd_hbuf)
/*
* We filled up the buffer in between
* getting the timeout and arriving
* here, so we don't need to rotate.
*/
break;
if (d->bd_slen == 0) {
BPFD_UNLOCK(d);
return (0);
}
ROTATE_BUFFERS(d);
break;
}
}
/*
* At this point, we know we have something in the hold slot.
*/
d->bd_hbuf_in_use = 1;
BPFD_UNLOCK(d);
/*
* Move data from hold buffer into user space.
* We know the entire buffer is transferred since
* we checked above that the read buffer is bpf_bufsize bytes.
*
* We do not have to worry about simultaneous reads because
* we waited for sole access to the hold buffer above.
*/
error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio);
BPFD_LOCK(d);
KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf"));
d->bd_fbuf = d->bd_hbuf;
d->bd_hbuf = NULL;
d->bd_hlen = 0;
bpf_buf_reclaimed(d);
d->bd_hbuf_in_use = 0;
wakeup(&d->bd_hbuf_in_use);
BPFD_UNLOCK(d);
return (error);
}
/*
* If there are processes sleeping on this descriptor, wake them up.
*/
static __inline void
bpf_wakeup(struct bpf_d *d)
{
BPFD_LOCK_ASSERT(d);
if (d->bd_state == BPF_WAITING) {
callout_stop(&d->bd_callout);
d->bd_state = BPF_IDLE;
}
wakeup(d);
if (d->bd_async && d->bd_sig && d->bd_sigio)
pgsigio(&d->bd_sigio, d->bd_sig, 0);
selwakeuppri(&d->bd_sel, PRINET);
KNOTE_LOCKED(&d->bd_sel.si_note, 0);
}
static void
bpf_timed_out(void *arg)
{
struct bpf_d *d = (struct bpf_d *)arg;
BPFD_LOCK_ASSERT(d);
if (callout_pending(&d->bd_callout) || !callout_active(&d->bd_callout))
return;
if (d->bd_state == BPF_WAITING) {
d->bd_state = BPF_TIMED_OUT;
if (d->bd_slen != 0)
bpf_wakeup(d);
}
}
static int
bpf_ready(struct bpf_d *d)
{
BPFD_LOCK_ASSERT(d);
if (!bpf_canfreebuf(d) && d->bd_hlen != 0)
return (1);
if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
d->bd_slen != 0)
return (1);
return (0);
}
static int
bpfwrite(struct cdev *dev, struct uio *uio, int ioflag)
{
struct bpf_d *d;
struct ifnet *ifp;
struct mbuf *m, *mc;
struct sockaddr dst;
int error, hlen;
error = devfs_get_cdevpriv((void **)&d);
if (error != 0)
return (error);
BPF_PID_REFRESH_CUR(d);
d->bd_wcount++;
/* XXX: locking required */
if (d->bd_bif == NULL) {
d->bd_wdcount++;
return (ENXIO);
}
ifp = d->bd_bif->bif_ifp;
if ((ifp->if_flags & IFF_UP) == 0) {
d->bd_wdcount++;
return (ENETDOWN);
}
if (uio->uio_resid == 0) {
d->bd_wdcount++;
return (0);
}
bzero(&dst, sizeof(dst));
m = NULL;
hlen = 0;
/* XXX: bpf_movein() can sleep */
error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp,
&m, &dst, &hlen, d->bd_wfilter);
if (error) {
d->bd_wdcount++;
return (error);
}
d->bd_wfcount++;
if (d->bd_hdrcmplt)
dst.sa_family = pseudo_AF_HDRCMPLT;
if (d->bd_feedback) {
mc = m_dup(m, M_NOWAIT);
if (mc != NULL)
mc->m_pkthdr.rcvif = ifp;
/* Set M_PROMISC for outgoing packets to be discarded. */
if (d->bd_direction == BPF_D_INOUT)
m->m_flags |= M_PROMISC;
} else
mc = NULL;
m->m_pkthdr.len -= hlen;
m->m_len -= hlen;
m->m_data += hlen; /* XXX */
CURVNET_SET(ifp->if_vnet);
#ifdef MAC
BPFD_LOCK(d);
mac_bpfdesc_create_mbuf(d, m);
if (mc != NULL)
mac_bpfdesc_create_mbuf(d, mc);
BPFD_UNLOCK(d);
#endif
error = (*ifp->if_output)(ifp, m, &dst, NULL);
if (error)
d->bd_wdcount++;
if (mc != NULL) {
if (error == 0)
(*ifp->if_input)(ifp, mc);
else
m_freem(mc);
}
CURVNET_RESTORE();
return (error);
}
/*
* Reset a descriptor by flushing its packet buffer and clearing the receive
* and drop counts. This is doable for kernel-only buffers, but with
* zero-copy buffers, we can't write to (or rotate) buffers that are
* currently owned by userspace. It would be nice if we could encapsulate
* this logic in the buffer code rather than here.
*/
static void
reset_d(struct bpf_d *d)
{
BPFD_LOCK_ASSERT(d);
while (d->bd_hbuf_in_use)
mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET,
"bd_hbuf", 0);
if ((d->bd_hbuf != NULL) &&
(d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) {
/* Free the hold buffer. */
d->bd_fbuf = d->bd_hbuf;
d->bd_hbuf = NULL;
d->bd_hlen = 0;
bpf_buf_reclaimed(d);
}
if (bpf_canwritebuf(d))
d->bd_slen = 0;
d->bd_rcount = 0;
d->bd_dcount = 0;
d->bd_fcount = 0;
d->bd_wcount = 0;
d->bd_wfcount = 0;
d->bd_wdcount = 0;
d->bd_zcopy = 0;
}
/*
* FIONREAD Check for read packet available.
* SIOCGIFADDR Get interface address - convenient hook to driver.
* BIOCGBLEN Get buffer len [for read()].
* BIOCSETF Set read filter.
* BIOCSETFNR Set read filter without resetting descriptor.
* BIOCSETWF Set write 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
* BIOCGDIRECTION Get packet direction flag
* BIOCSDIRECTION Set packet direction flag
* BIOCGTSTAMP Get time stamp format and resolution.
* BIOCSTSTAMP Set time stamp format and resolution.
* BIOCLOCK Set "locked" flag
* BIOCFEEDBACK Set packet feedback mode.
* BIOCSETZBUF Set current zero-copy buffer locations.
* BIOCGETZMAX Get maximum zero-copy buffer size.
* BIOCROTZBUF Force rotation of zero-copy buffer
* BIOCSETBUFMODE Set buffer mode.
* BIOCGETBUFMODE Get current buffer mode.
*/
/* ARGSUSED */
static int
bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags,
struct thread *td)
{
struct bpf_d *d;
int error;
error = devfs_get_cdevpriv((void **)&d);
if (error != 0)
return (error);
/*
* Refresh PID associated with this descriptor.
*/
BPFD_LOCK(d);
BPF_PID_REFRESH(d, td);
if (d->bd_state == BPF_WAITING)
callout_stop(&d->bd_callout);
d->bd_state = BPF_IDLE;
BPFD_UNLOCK(d);
if (d->bd_locked == 1) {
switch (cmd) {
case BIOCGBLEN:
case BIOCFLUSH:
case BIOCGDLT:
case BIOCGDLTLIST:
#ifdef COMPAT_FREEBSD32
case BIOCGDLTLIST32:
#endif
case BIOCGETIF:
case BIOCGRTIMEOUT:
#if defined(COMPAT_FREEBSD32) && !defined(__mips__)
case BIOCGRTIMEOUT32:
#endif
case BIOCGSTATS:
case BIOCVERSION:
case BIOCGRSIG:
case BIOCGHDRCMPLT:
case BIOCSTSTAMP:
case BIOCFEEDBACK:
case FIONREAD:
case BIOCLOCK:
case BIOCSRTIMEOUT:
#if defined(COMPAT_FREEBSD32) && !defined(__mips__)
case BIOCSRTIMEOUT32:
#endif
case BIOCIMMEDIATE:
case TIOCGPGRP:
case BIOCROTZBUF:
break;
default:
return (EPERM);
}
}
#ifdef COMPAT_FREEBSD32
/*
* If we see a 32-bit compat ioctl, mark the stream as 32-bit so
* that it will get 32-bit packet headers.
*/
switch (cmd) {
case BIOCSETF32:
case BIOCSETFNR32:
case BIOCSETWF32:
case BIOCGDLTLIST32:
case BIOCGRTIMEOUT32:
case BIOCSRTIMEOUT32:
BPFD_LOCK(d);
d->bd_compat32 = 1;
BPFD_UNLOCK(d);
}
#endif
CURVNET_SET(TD_TO_VNET(td));
switch (cmd) {
default:
error = EINVAL;
break;
/*
* Check for read packet available.
*/
case FIONREAD:
{
int n;
BPFD_LOCK(d);
n = d->bd_slen;
while (d->bd_hbuf_in_use)
mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
PRINET, "bd_hbuf", 0);
if (d->bd_hbuf)
n += d->bd_hlen;
BPFD_UNLOCK(d);
*(int *)addr = n;
break;
}
case SIOCGIFADDR:
{
struct ifnet *ifp;
if (d->bd_bif == NULL)
error = EINVAL;
else {
ifp = d->bd_bif->bif_ifp;
error = (*ifp->if_ioctl)(ifp, cmd, addr);
}
break;
}
/*
* Get buffer len [for read()].
*/
case BIOCGBLEN:
BPFD_LOCK(d);
*(u_int *)addr = d->bd_bufsize;
BPFD_UNLOCK(d);
break;
/*
* Set buffer length.
*/
case BIOCSBLEN:
error = bpf_ioctl_sblen(d, (u_int *)addr);
break;
/*
* Set link layer read filter.
*/
case BIOCSETF:
case BIOCSETFNR:
case BIOCSETWF:
#ifdef COMPAT_FREEBSD32
case BIOCSETF32:
case BIOCSETFNR32:
case BIOCSETWF32:
#endif
error = bpf_setf(d, (struct bpf_program *)addr, cmd);
break;
/*
* Flush read packet buffer.
*/
case BIOCFLUSH:
BPFD_LOCK(d);
reset_d(d);
BPFD_UNLOCK(d);
break;
/*
* Put interface into promiscuous mode.
*/
case BIOCPROMISC:
if (d->bd_bif == NULL) {
/*
* No interface attached yet.
*/
error = EINVAL;
break;
}
if (d->bd_promisc == 0) {
error = ifpromisc(d->bd_bif->bif_ifp, 1);
if (error == 0)
d->bd_promisc = 1;
}
break;
/*
* Get current data link type.
*/
case BIOCGDLT:
BPF_LOCK();
if (d->bd_bif == NULL)
error = EINVAL;
else
*(u_int *)addr = d->bd_bif->bif_dlt;
BPF_UNLOCK();
break;
/*
* Get a list of supported data link types.
*/
#ifdef COMPAT_FREEBSD32
case BIOCGDLTLIST32:
{
struct bpf_dltlist32 *list32;
struct bpf_dltlist dltlist;
list32 = (struct bpf_dltlist32 *)addr;
dltlist.bfl_len = list32->bfl_len;
dltlist.bfl_list = PTRIN(list32->bfl_list);
BPF_LOCK();
if (d->bd_bif == NULL)
error = EINVAL;
else {
error = bpf_getdltlist(d, &dltlist);
if (error == 0)
list32->bfl_len = dltlist.bfl_len;
}
BPF_UNLOCK();
break;
}
#endif
case BIOCGDLTLIST:
BPF_LOCK();
if (d->bd_bif == NULL)
error = EINVAL;
else
error = bpf_getdltlist(d, (struct bpf_dltlist *)addr);
BPF_UNLOCK();
break;
/*
* Set data link type.
*/
case BIOCSDLT:
BPF_LOCK();
if (d->bd_bif == NULL)
error = EINVAL;
else
error = bpf_setdlt(d, *(u_int *)addr);
BPF_UNLOCK();
break;
/*
* Get interface name.
*/
case BIOCGETIF:
BPF_LOCK();
if (d->bd_bif == NULL)
error = EINVAL;
else {
struct ifnet *const ifp = d->bd_bif->bif_ifp;
struct ifreq *const ifr = (struct ifreq *)addr;
strlcpy(ifr->ifr_name, ifp->if_xname,
sizeof(ifr->ifr_name));
}
BPF_UNLOCK();
break;
/*
* Set interface.
*/
case BIOCSETIF:
BPF_LOCK();
error = bpf_setif(d, (struct ifreq *)addr);
BPF_UNLOCK();
break;
/*
* Set read timeout.
*/
case BIOCSRTIMEOUT:
#if defined(COMPAT_FREEBSD32) && !defined(__mips__)
case BIOCSRTIMEOUT32:
#endif
{
struct timeval *tv = (struct timeval *)addr;
#if defined(COMPAT_FREEBSD32) && !defined(__mips__)
struct timeval32 *tv32;
struct timeval tv64;
if (cmd == BIOCSRTIMEOUT32) {
tv32 = (struct timeval32 *)addr;
tv = &tv64;
tv->tv_sec = tv32->tv_sec;
tv->tv_usec = tv32->tv_usec;
} else
#endif
tv = (struct timeval *)addr;
/*
* Subtract 1 tick from tvtohz() since this isn't
* a one-shot timer.
*/
if ((error = itimerfix(tv)) == 0)
d->bd_rtout = tvtohz(tv) - 1;
break;
}
/*
* Get read timeout.
*/
case BIOCGRTIMEOUT:
#if defined(COMPAT_FREEBSD32) && !defined(__mips__)
case BIOCGRTIMEOUT32:
#endif
{
struct timeval *tv;
#if defined(COMPAT_FREEBSD32) && !defined(__mips__)
struct timeval32 *tv32;
struct timeval tv64;
if (cmd == BIOCGRTIMEOUT32)
tv = &tv64;
else
#endif
tv = (struct timeval *)addr;
tv->tv_sec = d->bd_rtout / hz;
tv->tv_usec = (d->bd_rtout % hz) * tick;
#if defined(COMPAT_FREEBSD32) && !defined(__mips__)
if (cmd == BIOCGRTIMEOUT32) {
tv32 = (struct timeval32 *)addr;
tv32->tv_sec = tv->tv_sec;
tv32->tv_usec = tv->tv_usec;
}
#endif
break;
}
/*
* Get packet stats.
*/
case BIOCGSTATS:
{
struct bpf_stat *bs = (struct bpf_stat *)addr;
/* XXXCSJP overflow */
bs->bs_recv = d->bd_rcount;
bs->bs_drop = d->bd_dcount;
break;
}
/*
* Set immediate mode.
*/
case BIOCIMMEDIATE:
BPFD_LOCK(d);
d->bd_immediate = *(u_int *)addr;
BPFD_UNLOCK(d);
break;
case BIOCVERSION:
{
struct bpf_version *bv = (struct bpf_version *)addr;
bv->bv_major = BPF_MAJOR_VERSION;
bv->bv_minor = BPF_MINOR_VERSION;
break;
}
/*
* Get "header already complete" flag
*/
case BIOCGHDRCMPLT:
BPFD_LOCK(d);
*(u_int *)addr = d->bd_hdrcmplt;
BPFD_UNLOCK(d);
break;
/*
* Set "header already complete" flag
*/
case BIOCSHDRCMPLT:
BPFD_LOCK(d);
d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0;
BPFD_UNLOCK(d);
break;
/*
* Get packet direction flag
*/
case BIOCGDIRECTION:
BPFD_LOCK(d);
*(u_int *)addr = d->bd_direction;
BPFD_UNLOCK(d);
break;
/*
* Set packet direction flag
*/
case BIOCSDIRECTION:
{
u_int direction;
direction = *(u_int *)addr;
switch (direction) {
case BPF_D_IN:
case BPF_D_INOUT:
case BPF_D_OUT:
BPFD_LOCK(d);
d->bd_direction = direction;
BPFD_UNLOCK(d);
break;
default:
error = EINVAL;
}
}
break;
/*
* Get packet timestamp format and resolution.
*/
case BIOCGTSTAMP:
BPFD_LOCK(d);
*(u_int *)addr = d->bd_tstamp;
BPFD_UNLOCK(d);
break;
/*
* Set packet timestamp format and resolution.
*/
case BIOCSTSTAMP:
{
u_int func;
func = *(u_int *)addr;
if (BPF_T_VALID(func))
d->bd_tstamp = func;
else
error = EINVAL;
}
break;
case BIOCFEEDBACK:
BPFD_LOCK(d);
d->bd_feedback = *(u_int *)addr;
BPFD_UNLOCK(d);
break;
case BIOCLOCK:
BPFD_LOCK(d);
d->bd_locked = 1;
BPFD_UNLOCK(d);
break;
case FIONBIO: /* Non-blocking I/O */
break;
case FIOASYNC: /* Send signal on receive packets */
BPFD_LOCK(d);
d->bd_async = *(int *)addr;
BPFD_UNLOCK(d);
break;
case FIOSETOWN:
/*
* XXX: Add some sort of locking here?
* fsetown() can sleep.
*/
error = fsetown(*(int *)addr, &d->bd_sigio);
break;
case FIOGETOWN:
BPFD_LOCK(d);
*(int *)addr = fgetown(&d->bd_sigio);
BPFD_UNLOCK(d);
break;
/* This is deprecated, FIOSETOWN should be used instead. */
case TIOCSPGRP:
error = fsetown(-(*(int *)addr), &d->bd_sigio);
break;
/* This is deprecated, FIOGETOWN should be used instead. */
case TIOCGPGRP:
*(int *)addr = -fgetown(&d->bd_sigio);
break;
case BIOCSRSIG: /* Set receive signal */
{
u_int sig;
sig = *(u_int *)addr;
if (sig >= NSIG)
error = EINVAL;
else {
BPFD_LOCK(d);
d->bd_sig = sig;
BPFD_UNLOCK(d);
}
break;
}
case BIOCGRSIG:
BPFD_LOCK(d);
*(u_int *)addr = d->bd_sig;
BPFD_UNLOCK(d);
break;
case BIOCGETBUFMODE:
BPFD_LOCK(d);
*(u_int *)addr = d->bd_bufmode;
BPFD_UNLOCK(d);
break;
case BIOCSETBUFMODE:
/*
* Allow the buffering mode to be changed as long as we
* haven't yet committed to a particular mode. Our
* definition of commitment, for now, is whether or not a
* buffer has been allocated or an interface attached, since
* that's the point where things get tricky.
*/
switch (*(u_int *)addr) {
case BPF_BUFMODE_BUFFER:
break;
case BPF_BUFMODE_ZBUF:
if (bpf_zerocopy_enable)
break;
/* FALLSTHROUGH */
default:
CURVNET_RESTORE();
return (EINVAL);
}
BPFD_LOCK(d);
if (d->bd_sbuf != NULL || d->bd_hbuf != NULL ||
d->bd_fbuf != NULL || d->bd_bif != NULL) {
BPFD_UNLOCK(d);
CURVNET_RESTORE();
return (EBUSY);
}
d->bd_bufmode = *(u_int *)addr;
BPFD_UNLOCK(d);
break;
case BIOCGETZMAX:
error = bpf_ioctl_getzmax(td, d, (size_t *)addr);
break;
case BIOCSETZBUF:
error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr);
break;
case BIOCROTZBUF:
error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr);
break;
}
CURVNET_RESTORE();
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.
*
* Note we need global lock here to serialize bpf_setf() and bpf_setif() calls
* since reading d->bd_bif can't be protected by d or interface lock due to
* lock order.
*
* Additionally, we have to acquire interface write lock due to bpf_mtap() uses
* interface read lock to read all filers.
*
*/
static int
bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd)
{
#ifdef COMPAT_FREEBSD32
struct bpf_program fp_swab;
struct bpf_program32 *fp32;
#endif
struct bpf_insn *fcode, *old;
#ifdef BPF_JITTER
bpf_jit_filter *jfunc, *ofunc;
#endif
size_t size;
u_int flen;
int need_upgrade;
#ifdef COMPAT_FREEBSD32
switch (cmd) {
case BIOCSETF32:
case BIOCSETWF32:
case BIOCSETFNR32:
fp32 = (struct bpf_program32 *)fp;
fp_swab.bf_len = fp32->bf_len;
fp_swab.bf_insns = (struct bpf_insn *)(uintptr_t)fp32->bf_insns;
fp = &fp_swab;
switch (cmd) {
case BIOCSETF32:
cmd = BIOCSETF;
break;
case BIOCSETWF32:
cmd = BIOCSETWF;
break;
}
break;
}
#endif
fcode = NULL;
#ifdef BPF_JITTER
jfunc = ofunc = NULL;
#endif
need_upgrade = 0;
/*
* Check new filter validness before acquiring any locks.
* Allocate memory for new filter, if needed.
*/
flen = fp->bf_len;
if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0))
return (EINVAL);
size = flen * sizeof(*fp->bf_insns);
if (size > 0) {
/* We're setting up new filter. Copy and check actual data. */
fcode = malloc(size, M_BPF, M_WAITOK);
if (copyin(fp->bf_insns, fcode, size) != 0 ||
!bpf_validate(fcode, flen)) {
free(fcode, M_BPF);
return (EINVAL);
}
#ifdef BPF_JITTER
/* Filter is copied inside fcode and is perfectly valid. */
jfunc = bpf_jitter(fcode, flen);
#endif
}
BPF_LOCK();
/*
* Set up new filter.
* Protect filter change by interface lock.
* Additionally, we are protected by global lock here.
*/
if (d->bd_bif != NULL)
BPFIF_WLOCK(d->bd_bif);
BPFD_LOCK(d);
if (cmd == BIOCSETWF) {
old = d->bd_wfilter;
d->bd_wfilter = fcode;
} else {
old = d->bd_rfilter;
d->bd_rfilter = fcode;
#ifdef BPF_JITTER
ofunc = d->bd_bfilter;
d->bd_bfilter = jfunc;
#endif
if (cmd == BIOCSETF)
reset_d(d);
need_upgrade = bpf_check_upgrade(cmd, d, fcode, flen);
}
BPFD_UNLOCK(d);
if (d->bd_bif != NULL)
BPFIF_WUNLOCK(d->bd_bif);
if (old != NULL)
free(old, M_BPF);
#ifdef BPF_JITTER
if (ofunc != NULL)
bpf_destroy_jit_filter(ofunc);
#endif
/* Move d to active readers list. */
if (need_upgrade != 0)
bpf_upgraded(d);
BPF_UNLOCK();
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;
struct ifnet *theywant;
BPF_LOCK_ASSERT();
theywant = ifunit(ifr->ifr_name);
if (theywant == NULL || theywant->if_bpf == NULL)
return (ENXIO);
bp = theywant->if_bpf;
/* Check if interface is not being detached from BPF */
BPFIF_RLOCK(bp);
if (bp->flags & BPFIF_FLAG_DYING) {
BPFIF_RUNLOCK(bp);
return (ENXIO);
}
BPFIF_RUNLOCK(bp);
/*
* Behavior here depends on the buffering model. If we're using
* kernel memory buffers, then we can allocate them here. If we're
* using zero-copy, then the user process must have registered
* buffers by the time we get here. If not, return an error.
*/
switch (d->bd_bufmode) {
case BPF_BUFMODE_BUFFER:
case BPF_BUFMODE_ZBUF:
if (d->bd_sbuf == NULL)
return (EINVAL);
break;
default:
panic("bpf_setif: bufmode %d", d->bd_bufmode);
}
if (bp != d->bd_bif)
bpf_attachd(d, bp);
BPFD_LOCK(d);
reset_d(d);
BPFD_UNLOCK(d);
return (0);
}
/*
* Support for select() and poll() system calls
*
* Return true iff the specific operation will not block indefinitely.
* Otherwise, return false but make a note that a selwakeup() must be done.
*/
static int
bpfpoll(struct cdev *dev, int events, struct thread *td)
{
struct bpf_d *d;
int revents;
if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL)
return (events &
(POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM));
/*
* Refresh PID associated with this descriptor.
*/
revents = events & (POLLOUT | POLLWRNORM);
BPFD_LOCK(d);
BPF_PID_REFRESH(d, td);
if (events & (POLLIN | POLLRDNORM)) {
if (bpf_ready(d))
revents |= events & (POLLIN | POLLRDNORM);
else {
selrecord(td, &d->bd_sel);
/* Start the read timeout if necessary. */
if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
callout_reset(&d->bd_callout, d->bd_rtout,
bpf_timed_out, d);
d->bd_state = BPF_WAITING;
}
}
}
BPFD_UNLOCK(d);
return (revents);
}
/*
* Support for kevent() system call. Register EVFILT_READ filters and
* reject all others.
*/
int
bpfkqfilter(struct cdev *dev, struct knote *kn)
{
struct bpf_d *d;
if (devfs_get_cdevpriv((void **)&d) != 0 ||
kn->kn_filter != EVFILT_READ)
return (1);
/*
* Refresh PID associated with this descriptor.
*/
BPFD_LOCK(d);
BPF_PID_REFRESH_CUR(d);
kn->kn_fop = &bpfread_filtops;
kn->kn_hook = d;
knlist_add(&d->bd_sel.si_note, kn, 1);
BPFD_UNLOCK(d);
return (0);
}
static void
filt_bpfdetach(struct knote *kn)
{
struct bpf_d *d = (struct bpf_d *)kn->kn_hook;
knlist_remove(&d->bd_sel.si_note, kn, 0);
}
static int
filt_bpfread(struct knote *kn, long hint)
{
struct bpf_d *d = (struct bpf_d *)kn->kn_hook;
int ready;
BPFD_LOCK_ASSERT(d);
ready = bpf_ready(d);
if (ready) {
kn->kn_data = d->bd_slen;
while (d->bd_hbuf_in_use)
mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
PRINET, "bd_hbuf", 0);
if (d->bd_hbuf)
kn->kn_data += d->bd_hlen;
} else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
callout_reset(&d->bd_callout, d->bd_rtout,
bpf_timed_out, d);
d->bd_state = BPF_WAITING;
}
return (ready);
}
#define BPF_TSTAMP_NONE 0
#define BPF_TSTAMP_FAST 1
#define BPF_TSTAMP_NORMAL 2
#define BPF_TSTAMP_EXTERN 3
static int
bpf_ts_quality(int tstype)
{
if (tstype == BPF_T_NONE)
return (BPF_TSTAMP_NONE);
if ((tstype & BPF_T_FAST) != 0)
return (BPF_TSTAMP_FAST);
return (BPF_TSTAMP_NORMAL);
}
static int
bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m)
{
struct m_tag *tag;
int quality;
quality = bpf_ts_quality(tstype);
if (quality == BPF_TSTAMP_NONE)
return (quality);
if (m != NULL) {
tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL);
if (tag != NULL) {
*bt = *(struct bintime *)(tag + 1);
return (BPF_TSTAMP_EXTERN);
}
}
if (quality == BPF_TSTAMP_NORMAL)
binuptime(bt);
else
getbinuptime(bt);
return (quality);
}
/*
* 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(struct bpf_if *bp, u_char *pkt, u_int pktlen)
{
struct bintime bt;
struct bpf_d *d;
#ifdef BPF_JITTER
bpf_jit_filter *bf;
#endif
u_int slen;
int gottime;
gottime = BPF_TSTAMP_NONE;
BPFIF_RLOCK(bp);
LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
/*
* We are not using any locks for d here because:
* 1) any filter change is protected by interface
* write lock
* 2) destroying/detaching d is protected by interface
* write lock, too
*/
/* XXX: Do not protect counter for the sake of performance. */
++d->bd_rcount;
/*
* NB: We dont call BPF_CHECK_DIRECTION() here since there is no
* way for the caller to indiciate to us whether this packet
* is inbound or outbound. In the bpf_mtap() routines, we use
* the interface pointers on the mbuf to figure it out.
*/
#ifdef BPF_JITTER
bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL;
if (bf != NULL)
slen = (*(bf->func))(pkt, pktlen, pktlen);
else
#endif
slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen);
if (slen != 0) {
/*
* Filter matches. Let's to acquire write lock.
*/
BPFD_LOCK(d);
d->bd_fcount++;
if (gottime < bpf_ts_quality(d->bd_tstamp))
gottime = bpf_gettime(&bt, d->bd_tstamp, NULL);
#ifdef MAC
if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
#endif
catchpacket(d, pkt, pktlen, slen,
bpf_append_bytes, &bt);
BPFD_UNLOCK(d);
}
}
BPFIF_RUNLOCK(bp);
}
#define BPF_CHECK_DIRECTION(d, r, i) \
(((d)->bd_direction == BPF_D_IN && (r) != (i)) || \
((d)->bd_direction == BPF_D_OUT && (r) == (i)))
/*
* Incoming linkage from device drivers, when packet is in an mbuf chain.
* Locking model is explained in bpf_tap().
*/
void
bpf_mtap(struct bpf_if *bp, struct mbuf *m)
{
struct bintime bt;
struct bpf_d *d;
#ifdef BPF_JITTER
bpf_jit_filter *bf;
#endif
u_int pktlen, slen;
int gottime;
/* Skip outgoing duplicate packets. */
if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) {
m->m_flags &= ~M_PROMISC;
return;
}
pktlen = m_length(m, NULL);
gottime = BPF_TSTAMP_NONE;
BPFIF_RLOCK(bp);
LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp))
continue;
++d->bd_rcount;
#ifdef BPF_JITTER
bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL;
/* XXX We cannot handle multiple mbufs. */
if (bf != NULL && m->m_next == NULL)
slen = (*(bf->func))(mtod(m, u_char *), pktlen, pktlen);
else
#endif
slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0);
if (slen != 0) {
BPFD_LOCK(d);
d->bd_fcount++;
if (gottime < bpf_ts_quality(d->bd_tstamp))
gottime = bpf_gettime(&bt, d->bd_tstamp, m);
#ifdef MAC
if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
#endif
catchpacket(d, (u_char *)m, pktlen, slen,
bpf_append_mbuf, &bt);
BPFD_UNLOCK(d);
}
}
BPFIF_RUNLOCK(bp);
}
/*
* Incoming linkage from device drivers, when packet is in
* an mbuf chain and to be prepended by a contiguous header.
*/
void
bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m)
{
struct bintime bt;
struct mbuf mb;
struct bpf_d *d;
u_int pktlen, slen;
int gottime;
/* Skip outgoing duplicate packets. */
if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) {
m->m_flags &= ~M_PROMISC;
return;
}
pktlen = m_length(m, NULL);
/*
* Craft on-stack mbuf suitable for passing to bpf_filter.
* Note that we cut corners here; we only setup what's
* absolutely needed--this mbuf should never go anywhere else.
*/
mb.m_next = m;
mb.m_data = data;
mb.m_len = dlen;
pktlen += dlen;
gottime = BPF_TSTAMP_NONE;
BPFIF_RLOCK(bp);
LIST_FOREACH(d, &bp->bif_dlist, bd_next) {
if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp))
continue;
++d->bd_rcount;
slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0);
if (slen != 0) {
BPFD_LOCK(d);
d->bd_fcount++;
if (gottime < bpf_ts_quality(d->bd_tstamp))
gottime = bpf_gettime(&bt, d->bd_tstamp, m);
#ifdef MAC
if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0)
#endif
catchpacket(d, (u_char *)&mb, pktlen, slen,
bpf_append_mbuf, &bt);
BPFD_UNLOCK(d);
}
}
BPFIF_RUNLOCK(bp);
}
#undef BPF_CHECK_DIRECTION
#undef BPF_TSTAMP_NONE
#undef BPF_TSTAMP_FAST
#undef BPF_TSTAMP_NORMAL
#undef BPF_TSTAMP_EXTERN
static int
bpf_hdrlen(struct bpf_d *d)
{
int hdrlen;
hdrlen = d->bd_bif->bif_hdrlen;
#ifndef BURN_BRIDGES
if (d->bd_tstamp == BPF_T_NONE ||
BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME)
#ifdef COMPAT_FREEBSD32
if (d->bd_compat32)
hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32);
else
#endif
hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr);
else
#endif
hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr);
#ifdef COMPAT_FREEBSD32
if (d->bd_compat32)
hdrlen = BPF_WORDALIGN32(hdrlen);
else
#endif
hdrlen = BPF_WORDALIGN(hdrlen);
return (hdrlen - d->bd_bif->bif_hdrlen);
}
static void
bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype)
{
struct bintime bt2;
struct timeval tsm;
struct timespec tsn;
if ((tstype & BPF_T_MONOTONIC) == 0) {
bt2 = *bt;
bintime_add(&bt2, &boottimebin);
bt = &bt2;
}
switch (BPF_T_FORMAT(tstype)) {
case BPF_T_MICROTIME:
bintime2timeval(bt, &tsm);
ts->bt_sec = tsm.tv_sec;
ts->bt_frac = tsm.tv_usec;
break;
case BPF_T_NANOTIME:
bintime2timespec(bt, &tsn);
ts->bt_sec = tsn.tv_sec;
ts->bt_frac = tsn.tv_nsec;
break;
case BPF_T_BINTIME:
ts->bt_sec = bt->sec;
ts->bt_frac = bt->frac;
break;
}
}
/*
* Move the packet data from interface memory (pkt) into the
* store buffer. "cpfn" is the routine called to do the actual data
* transfer. bcopy is passed in to copy contiguous chunks, while
* bpf_append_mbuf 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)(struct bpf_d *, caddr_t, u_int, void *, u_int),
struct bintime *bt)
{
struct bpf_xhdr hdr;
#ifndef BURN_BRIDGES
struct bpf_hdr hdr_old;
#ifdef COMPAT_FREEBSD32
struct bpf_hdr32 hdr32_old;
#endif
#endif
int caplen, curlen, hdrlen, totlen;
int do_wakeup = 0;
int do_timestamp;
int tstype;
BPFD_LOCK_ASSERT(d);
/*
* Detect whether user space has released a buffer back to us, and if
* so, move it from being a hold buffer to a free buffer. This may
* not be the best place to do it (for example, we might only want to
* run this check if we need the space), but for now it's a reliable
* spot to do it.
*/
if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) {
while (d->bd_hbuf_in_use)
mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
PRINET, "bd_hbuf", 0);
d->bd_fbuf = d->bd_hbuf;
d->bd_hbuf = NULL;
d->bd_hlen = 0;
bpf_buf_reclaimed(d);
}
/*
* 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).
*/
hdrlen = bpf_hdrlen(d);
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.
*
* Drop the packet if there's no room and no hope of room
* If the packet would overflow the storage buffer or the storage
* buffer is considered immutable by the buffer model, try to rotate
* the buffer and wakeup pending processes.
*/
#ifdef COMPAT_FREEBSD32
if (d->bd_compat32)
curlen = BPF_WORDALIGN32(d->bd_slen);
else
#endif
curlen = BPF_WORDALIGN(d->bd_slen);
if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) {
if (d->bd_fbuf == NULL) {
/*
* There's no room in the store buffer, and no
* prospect of room, so drop the packet. Notify the
* buffer model.
*/
bpf_buffull(d);
++d->bd_dcount;
return;
}
while (d->bd_hbuf_in_use)
mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
PRINET, "bd_hbuf", 0);
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;
caplen = totlen - hdrlen;
tstype = d->bd_tstamp;
do_timestamp = tstype != BPF_T_NONE;
#ifndef BURN_BRIDGES
if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) {
struct bpf_ts ts;
if (do_timestamp)
bpf_bintime2ts(bt, &ts, tstype);
#ifdef COMPAT_FREEBSD32
if (d->bd_compat32) {
bzero(&hdr32_old, sizeof(hdr32_old));
if (do_timestamp) {
hdr32_old.bh_tstamp.tv_sec = ts.bt_sec;
hdr32_old.bh_tstamp.tv_usec = ts.bt_frac;
}
hdr32_old.bh_datalen = pktlen;
hdr32_old.bh_hdrlen = hdrlen;
hdr32_old.bh_caplen = caplen;
bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old,
sizeof(hdr32_old));
goto copy;
}
#endif
bzero(&hdr_old, sizeof(hdr_old));
if (do_timestamp) {
hdr_old.bh_tstamp.tv_sec = ts.bt_sec;
hdr_old.bh_tstamp.tv_usec = ts.bt_frac;
}
hdr_old.bh_datalen = pktlen;
hdr_old.bh_hdrlen = hdrlen;
hdr_old.bh_caplen = caplen;
bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old,
sizeof(hdr_old));
goto copy;
}
#endif
/*
* Append the bpf header. Note we append the actual header size, but
* move forward the length of the header plus padding.
*/
bzero(&hdr, sizeof(hdr));
if (do_timestamp)
bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype);
hdr.bh_datalen = pktlen;
hdr.bh_hdrlen = hdrlen;
hdr.bh_caplen = caplen;
bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr));
/*
* Copy the packet data into the store buffer and update its length.
*/
#ifndef BURN_BRIDGES
copy:
#endif
(*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen);
d->bd_slen = curlen + totlen;
if (do_wakeup)
bpf_wakeup(d);
}
/*
* 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.
*/
bpf_free(d);
if (d->bd_rfilter != NULL) {
free((caddr_t)d->bd_rfilter, M_BPF);
#ifdef BPF_JITTER
if (d->bd_bfilter != NULL)
bpf_destroy_jit_filter(d->bd_bfilter);
#endif
}
if (d->bd_wfilter != NULL)
free((caddr_t)d->bd_wfilter, M_BPF);
mtx_destroy(&d->bd_lock);
}
/*
* Attach an interface to bpf. dlt is the link layer type; hdrlen is the
* fixed size of the link header (variable length headers not yet supported).
*/
void
bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
{
bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf);
}
/*
* Attach an interface to bpf. ifp is a pointer to the structure
* defining the interface to be attached, dlt is the link layer type,
* and hdrlen is the fixed size of the link header (variable length
* headers are not yet supporrted).
*/
void
bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
{
struct bpf_if *bp;
bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO);
if (bp == NULL)
panic("bpfattach");
LIST_INIT(&bp->bif_dlist);
LIST_INIT(&bp->bif_wlist);
bp->bif_ifp = ifp;
bp->bif_dlt = dlt;
rw_init(&bp->bif_lock, "bpf interface lock");
KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized"));
*driverp = bp;
BPF_LOCK();
LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next);
BPF_UNLOCK();
bp->bif_hdrlen = hdrlen;
if (bootverbose)
if_printf(ifp, "bpf attached\n");
}
/*
* Detach bpf from an interface. This involves detaching each descriptor
* associated with the interface. Notify each descriptor as it's detached
* so that any sleepers wake up and get ENXIO.
*/
void
bpfdetach(struct ifnet *ifp)
{
struct bpf_if *bp, *bp_temp;
struct bpf_d *d;
int ndetached;
ndetached = 0;
BPF_LOCK();
/* Find all bpf_if struct's which reference ifp and detach them. */
LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) {
if (ifp != bp->bif_ifp)
continue;
LIST_REMOVE(bp, bif_next);
/* Add to to-be-freed list */
LIST_INSERT_HEAD(&bpf_freelist, bp, bif_next);
ndetached++;
/*
* Delay freeing bp till interface is detached
* and all routes through this interface are removed.
* Mark bp as detached to restrict new consumers.
*/
BPFIF_WLOCK(bp);
bp->flags |= BPFIF_FLAG_DYING;
BPFIF_WUNLOCK(bp);
CTR4(KTR_NET, "%s: sheduling free for encap %d (%p) for if %p",
__func__, bp->bif_dlt, bp, ifp);
/* Free common descriptors */
while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) {
bpf_detachd_locked(d);
BPFD_LOCK(d);
bpf_wakeup(d);
BPFD_UNLOCK(d);
}
/* Free writer-only descriptors */
while ((d = LIST_FIRST(&bp->bif_wlist)) != NULL) {
bpf_detachd_locked(d);
BPFD_LOCK(d);
bpf_wakeup(d);
BPFD_UNLOCK(d);
}
}
BPF_UNLOCK();
#ifdef INVARIANTS
if (ndetached == 0)
printf("bpfdetach: %s was not attached\n", ifp->if_xname);
#endif
}
/*
* Interface departure handler.
* Note departure event does not guarantee interface is going down.
* Interface renaming is currently done via departure/arrival event set.
*
* Departure handled is called after all routes pointing to
* given interface are removed and interface is in down state
* restricting any packets to be sent/received. We assume it is now safe
* to free data allocated by BPF.
*/
static void
bpf_ifdetach(void *arg __unused, struct ifnet *ifp)
{
struct bpf_if *bp, *bp_temp;
int nmatched = 0;
BPF_LOCK();
/*
* Find matching entries in free list.
* Nothing should be found if bpfdetach() was not called.
*/
LIST_FOREACH_SAFE(bp, &bpf_freelist, bif_next, bp_temp) {
if (ifp != bp->bif_ifp)
continue;
CTR3(KTR_NET, "%s: freeing BPF instance %p for interface %p",
__func__, bp, ifp);
LIST_REMOVE(bp, bif_next);
rw_destroy(&bp->bif_lock);
free(bp, M_BPF);
nmatched++;
}
BPF_UNLOCK();
/*
* Note that we cannot zero other pointers to
* custom DLTs possibly used by given interface.
*/
if (nmatched != 0)
ifp->if_bpf = NULL;
}
/*
* 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;
BPF_LOCK_ASSERT();
ifp = d->bd_bif->bif_ifp;
n = 0;
error = 0;
LIST_FOREACH(bp, &bpf_iflist, 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 error, opromisc;
struct ifnet *ifp;
struct bpf_if *bp;
BPF_LOCK_ASSERT();
if (d->bd_bif->bif_dlt == dlt)
return (0);
ifp = d->bd_bif->bif_ifp;
LIST_FOREACH(bp, &bpf_iflist, bif_next) {
if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
break;
}
if (bp != NULL) {
opromisc = d->bd_promisc;
bpf_attachd(d, bp);
BPFD_LOCK(d);
reset_d(d);
BPFD_UNLOCK(d);
if (opromisc) {
error = ifpromisc(bp->bif_ifp, 1);
if (error)
if_printf(bp->bif_ifp,
"bpf_setdlt: ifpromisc failed (%d)\n",
error);
else
d->bd_promisc = 1;
}
}
return (bp == NULL ? EINVAL : 0);
}
static void
bpf_drvinit(void *unused)
{
struct cdev *dev;
mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF);
LIST_INIT(&bpf_iflist);
LIST_INIT(&bpf_freelist);
dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf");
/* For compatibility */
make_dev_alias(dev, "bpf0");
/* Register interface departure handler */
bpf_ifdetach_cookie = EVENTHANDLER_REGISTER(
ifnet_departure_event, bpf_ifdetach, NULL,
EVENTHANDLER_PRI_ANY);
}
/*
* Zero out the various packet counters associated with all of the bpf
* descriptors. At some point, we will probably want to get a bit more
* granular and allow the user to specify descriptors to be zeroed.
*/
static void
bpf_zero_counters(void)
{
struct bpf_if *bp;
struct bpf_d *bd;
BPF_LOCK();
LIST_FOREACH(bp, &bpf_iflist, bif_next) {
BPFIF_RLOCK(bp);
LIST_FOREACH(bd, &bp->bif_dlist, bd_next) {
BPFD_LOCK(bd);
bd->bd_rcount = 0;
bd->bd_dcount = 0;
bd->bd_fcount = 0;
bd->bd_wcount = 0;
bd->bd_wfcount = 0;
bd->bd_zcopy = 0;
BPFD_UNLOCK(bd);
}
BPFIF_RUNLOCK(bp);
}
BPF_UNLOCK();
}
/*
* Fill filter statistics
*/
static void
bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd)
{
bzero(d, sizeof(*d));
BPFD_LOCK_ASSERT(bd);
d->bd_structsize = sizeof(*d);
/* XXX: reading should be protected by global lock */
d->bd_immediate = bd->bd_immediate;
d->bd_promisc = bd->bd_promisc;
d->bd_hdrcmplt = bd->bd_hdrcmplt;
d->bd_direction = bd->bd_direction;
d->bd_feedback = bd->bd_feedback;
d->bd_async = bd->bd_async;
d->bd_rcount = bd->bd_rcount;
d->bd_dcount = bd->bd_dcount;
d->bd_fcount = bd->bd_fcount;
d->bd_sig = bd->bd_sig;
d->bd_slen = bd->bd_slen;
d->bd_hlen = bd->bd_hlen;
d->bd_bufsize = bd->bd_bufsize;
d->bd_pid = bd->bd_pid;
strlcpy(d->bd_ifname,
bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ);
d->bd_locked = bd->bd_locked;
d->bd_wcount = bd->bd_wcount;
d->bd_wdcount = bd->bd_wdcount;
d->bd_wfcount = bd->bd_wfcount;
d->bd_zcopy = bd->bd_zcopy;
d->bd_bufmode = bd->bd_bufmode;
}
/*
* Handle `netstat -B' stats request
*/
static int
bpf_stats_sysctl(SYSCTL_HANDLER_ARGS)
{
struct xbpf_d *xbdbuf, *xbd, zerostats;
int index, error;
struct bpf_if *bp;
struct bpf_d *bd;
/*
* XXX This is not technically correct. It is possible for non
* privileged users to open bpf devices. It would make sense
* if the users who opened the devices were able to retrieve
* the statistics for them, too.
*/
error = priv_check(req->td, PRIV_NET_BPF);
if (error)
return (error);
/*
* Check to see if the user is requesting that the counters be
* zeroed out. Explicitly check that the supplied data is zeroed,
* as we aren't allowing the user to set the counters currently.
*/
if (req->newptr != NULL) {
if (req->newlen != sizeof(zerostats))
return (EINVAL);
bzero(&zerostats, sizeof(zerostats));
xbd = req->newptr;
if (bcmp(xbd, &zerostats, sizeof(*xbd)) != 0)
return (EINVAL);
bpf_zero_counters();
return (0);
}
if (req->oldptr == NULL)
return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd)));
if (bpf_bpfd_cnt == 0)
return (SYSCTL_OUT(req, 0, 0));
xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK);
BPF_LOCK();
if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) {
BPF_UNLOCK();
free(xbdbuf, M_BPF);
return (ENOMEM);
}
index = 0;
LIST_FOREACH(bp, &bpf_iflist, bif_next) {
BPFIF_RLOCK(bp);
/* Send writers-only first */
LIST_FOREACH(bd, &bp->bif_wlist, bd_next) {
xbd = &xbdbuf[index++];
BPFD_LOCK(bd);
bpfstats_fill_xbpf(xbd, bd);
BPFD_UNLOCK(bd);
}
LIST_FOREACH(bd, &bp->bif_dlist, bd_next) {
xbd = &xbdbuf[index++];
BPFD_LOCK(bd);
bpfstats_fill_xbpf(xbd, bd);
BPFD_UNLOCK(bd);
}
BPFIF_RUNLOCK(bp);
}
BPF_UNLOCK();
error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd));
free(xbdbuf, M_BPF);
return (error);
}
SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL);
#else /* !DEV_BPF && !NETGRAPH_BPF */
/*
* NOP stubs to allow bpf-using drivers to load and function.
*
* A 'better' implementation would allow the core bpf functionality
* to be loaded at runtime.
*/
static struct bpf_if bp_null;
void
bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
{
}
void
bpf_mtap(struct bpf_if *bp, struct mbuf *m)
{
}
void
bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m)
{
}
void
bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
{
bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf);
}
void
bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
{
*driverp = &bp_null;
}
void
bpfdetach(struct ifnet *ifp)
{
}
u_int
bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen)
{
return -1; /* "no filter" behaviour */
}
int
bpf_validate(const struct bpf_insn *f, int len)
{
return 0; /* false */
}
#endif /* !DEV_BPF && !NETGRAPH_BPF */
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