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Commit Graph

201 Commits

Author SHA1 Message Date
Jung-uk Kim
12dc95824b Make bpf_maxinsns visible from ng_bpf.c.
Pass me the pointyhat, please.
2008-08-29 20:34:06 +00:00
Ed Schouten
136600fe59 Change bpf(4) to use the cdevpriv API.
Right now the bpf(4) driver uses the cloning API to generate /dev/bpf%u.
When an application such as tcpdump needs a BPF, it opens /dev/bpf0,
/dev/bpf1, etc. until it opens the first available device node. We used
this approach, because our devfs implementation didn't allow
per-descriptor data.

Now that we can, make it use devfs_get_cdevpriv() to obtain the private
data. To remain compatible with the existing implementation, add a
symlink from /dev/bpf0 to /dev/bpf. I've already changed libpcap to
compile with HAVE_CLONING_BPF, which makes it use /dev/bpf. There may be
other applications in the base system (dhclient) that use the loop to
obtain a valid bpf.

Discussed on:	src-committers
Approved by:	csjp
2008-08-13 15:41:21 +00:00
Christian S.J. Peron
a05cf8c6db Annotate why we do not call BPF_CHECK_DIRECTION() in this tapping routine.
There is no way for the caller to tell us which direction this packet is
going.  With the bpf_mtap{2} routines, we can check the interface pointer.

MFC after:	2 weeks
2008-08-01 21:38:46 +00:00
Jung-uk Kim
968c88bc75 Allow injecting big packets via bpf(4) up to min(MTU, 16K-byte).
MFC after:	1 week
2008-07-14 22:41:48 +00:00
David Malone
f11c35082b Add a new ioctl for changing the read filter (BIOCSETFNR). This is
just like BIOCSETF but it doesn't drop all the packets buffered on
the discriptor and reset the statistics.

Also, when setting the write filter, don't drop packets waiting to
be read or reset the statistics.

PR:		118486
Submitted by:	Matthew Luckie <mluckie@cs.waikato.ac.nz>
MFC after:	1 month
2008-07-07 09:25:49 +00:00
Christian S.J. Peron
29f612ec71 Make sure we are clearing the ZBUF_FLAG_IMMUTABLE any time a free buffer
is reclaimed by the kernel.  This fixes a bug resulted in the kernel
over writing packet data while user-space was still processing it when
zerocopy is enabled.  (Or a panic if invariants was enabled).

Discussed with:	rwatson
2008-07-05 20:11:28 +00:00
John Baldwin
7fb547c7f5 Set D_TRACKCLOSE to avoid a race in devfs that could lead to orphaned bpf
devices never getting fully closed.

MFC after:	3 days
2008-05-09 19:29:08 +00:00
Jung-uk Kim
f81a2a4956 Check packet directions more properly instead of just checking received
interface is null.

PR:		kern/123138
Submitted by:	Dmitry (hanabana at mail dot ru)
MFC after:	1 week
2008-04-28 19:42:11 +00:00
Jung-uk Kim
8cd892f752 Revert the previous commit and use M_PROMISC flag instead.
It is safer because it will never be used for outgoing packets.
2008-04-15 17:08:24 +00:00
Jung-uk Kim
9a3a0f9278 Remove M_SKIP_FIREWALL abuse and add more appropriate check.
Pointyhat to:	jkim
Reported by:	Eugene Grosbein (eugen at kuzbass dot ru)
MFC after:	3 days
2008-04-15 00:50:01 +00:00
Robert Watson
a7a91e6592 Maintain and observe a ZBUF_FLAG_IMMUTABLE flag on zero-copy BPF
buffer kernel descriptors, which is used to allow the buffer
currently in the BPF "store" position to be assigned to userspace
when it fills, even if userspace hasn't acknowledged the buffer
in the "hold" position yet.  To implement this, notify the buffer
model when a buffer becomes full, and check that the store buffer
is writable, not just for it being full, before trying to append
new packet data.  Shared memory buffers will be assigned to
userspace at most once per fill, be it in the store or in the
hold position.

This removes the restriction that at most one shared memory can
by owned by userspace, reducing the chances that userspace will
need to call select() after acknowledging one buffer in order to
wait for the next buffer when under high load.  This more fully
realizes the goal of zero system calls in order to process a
high-speed packet stream from BPF.

Update bpf.4 to reflect that both buffers may be owned by userspace
at once; caution against assuming this.
2008-04-07 02:51:00 +00:00
Ruslan Ermilov
ea26d58729 Replaced the misleading uses of a historical artefact M_TRYWAIT with M_WAIT.
Removed dead code that assumed that M_TRYWAIT can return NULL; it's not true
since the advent of MBUMA.

Reviewed by:	arch

There are ongoing disputes as to whether we want to switch to directly using
UMA flags M_WAITOK/M_NOWAIT for mbuf(9) allocation.
2008-03-25 09:39:02 +00:00
Robert Watson
fa0c2b3474 Check for a NULL free buffer pointer in BPF before invoking
bpf_canfreebuf() in order to avoid potentially calling a non-inlinable
but trivial function in zero-copy buffer mode for every packet
received when we couldn't free the buffer anyway.

MFC after:	4 months
2008-03-25 07:41:33 +00:00
Christian S.J. Peron
4d621040ff Introduce support for zero-copy BPF buffering, which reduces the
overhead of packet capture by allowing a user process to directly "loan"
buffer memory to the kernel rather than using read(2) to explicitly copy
data from kernel address space.

The user process will issue new BPF ioctls to set the shared memory
buffer mode and provide pointers to buffers and their size. The kernel
then wires and maps the pages into kernel address space using sf_buf(9),
which on supporting architectures will use the direct map region. The
current "buffered" access mode remains the default, and support for
zero-copy buffers must, for the time being, be explicitly enabled using
a sysctl for the kernel to accept requests to use it.

The kernel and user process synchronize use of the buffers with atomic
operations, avoiding the need for system calls under load; the user
process may use select()/poll()/kqueue() to manage blocking while
waiting for network data if the user process is able to consume data
faster than the kernel generates it. Patchs to libpcap are available
to allow libpcap applications to transparently take advantage of this
support. Detailed information on the new API may be found in bpf(4),
including specific atomic operations and memory barriers required to
synchronize buffer use safely.

These changes modify the base BPF implementation to (roughly) abstrac
the current buffer model, allowing the new shared memory model to be
added, and add new monitoring statistics for netstat to print. The
implementation, with the exception of some monitoring hanges that break
the netstat monitoring ABI for BPF, will be MFC'd.

Zerocopy bpf buffers are still considered experimental are disabled
by default. To experiment with this new facility, adjust the
net.bpf.zerocopy_enable sysctl variable to 1.

Changes to libpcap will be made available as a patch for the time being,
and further refinements to the implementation are expected.

Sponsored by:		Seccuris Inc.
In collaboration with:	rwatson
Tested by:		pwood, gallatin
MFC after:		4 months [1]

[1] Certain portions will probably not be MFCed, specifically things
    that can break the monitoring ABI.
2008-03-24 13:49:17 +00:00
Robert Watson
237fdd787b In keeping with style(9)'s recommendations on macros, use a ';'
after each SYSINIT() macro invocation.  This makes a number of
lightweight C parsers much happier with the FreeBSD kernel
source, including cflow's prcc and lxr.

MFC after:	1 month
Discussed with:	imp, rink
2008-03-16 10:58:09 +00:00
Robert Watson
31b32e6dc3 Add comment that bpfread() has multi-threading issues.
Fix minor white space nit.
2008-02-02 20:35:05 +00:00
Robert Watson
c786600793 Use __FBSDID() in the kernel BPF implementation.
MFC after:	3 days
2007-12-25 13:24:02 +00:00
Robert Watson
2a0a392e1c Remove trailing whitespace from lines in BPF.
MFC after:	3 days
2007-12-23 14:10:33 +00:00
Robert Watson
30d239bc4c Merge first in a series of TrustedBSD MAC Framework KPI changes
from Mac OS X Leopard--rationalize naming for entry points to
the following general forms:

  mac_<object>_<method/action>
  mac_<object>_check_<method/action>

The previous naming scheme was inconsistent and mostly
reversed from the new scheme.  Also, make object types more
consistent and remove spaces from object types that contain
multiple parts ("posix_sem" -> "posixsem") to make mechanical
parsing easier.  Introduce a new "netinet" object type for
certain IPv4/IPv6-related methods.  Also simplify, slightly,
some entry point names.

All MAC policy modules will need to be recompiled, and modules
not updates as part of this commit will need to be modified to
conform to the new KPI.

Sponsored by:	SPARTA (original patches against Mac OS X)
Obtained from:	TrustedBSD Project, Apple Computer
2007-10-24 19:04:04 +00:00
Christian S.J. Peron
50ed6e0713 Make sure that we refresh the PID on read(2) and write(2) operations.
This fixes the process portion of the bpf(4) stats if the peer forks
into the background after it's opened the descriptor.  This bug
results in the following behavior for netstat -B:

# netstat -B
  Pid  Netif  Flags      Recv      Drop     Match Sblen Hblen Command
netstat: kern.proc.pid failed: No such process
78023    em0 p--s--   2237404     43119   2237404 13986     0 ??????

MFC after:	1 week
2007-10-12 14:58:34 +00:00
Andrew Thompson
cb44b6dfe8 Check for multicast destination on bpf injected packets and update the M_*CAST
flags, the absense of these flags causes problems in other areas such as
bridging which expect them to be correct.

At the moment only Ethernet DLTs are checked.

Reviewed by:	bms, csjp, sam
Approved by:	re (bmah)
2007-09-10 00:03:06 +00:00
Robert Watson
0bf686c125 Remove the now-unused NET_{LOCK,UNLOCK,ASSERT}_GIANT() macros, which
previously conditionally acquired Giant based on debug.mpsafenet.  As that
has now been removed, they are no longer required.  Removing them
significantly simplifies error-handling in the socket layer, eliminated
quite a bit of unwinding of locking in error cases.

While here clean up the now unneeded opt_net.h, which previously was used
for the NET_WITH_GIANT kernel option.  Clean up some related gotos for
consistency.

Reviewed by:	bz, csjp
Tested by:	kris
Approved by:	re (kensmith)
2007-08-06 14:26:03 +00:00
Robert Watson
c6b2899785 Replace references to NET_CALLOUT_MPSAFE with CALLOUT_MPSAFE, and remove
definition of NET_CALLOUT_MPSAFE, which is no longer required now that
debug.mpsafenet has been removed.

The once over:	bz
Approved by:	re (kensmith)
2007-07-28 07:31:30 +00:00
Christian S.J. Peron
d83e603ac7 Silence some gcc 4 warnings. It is expected that the bpf_movein() routine
will intialize the the header length and re-initialize the mbuf pointer
to reference the mbuf that is allocated after moving user supplied packet
data in.
2007-06-17 21:51:43 +00:00
Christian S.J. Peron
5632c9822a - Conditionally pickup Giant around the network interface
ioctl routines if we are running with !mpsafenet
- Change un-conditional Giant acquisition around ifpromisc
  to occur only if we are running with !mpsafenet

With these locking bits in place, we can now remove the Giant
requirement from BPF, so drop the D_NEEDGIANT device flag.
This change removes Giant acquisitions around BPF device
handlers (read, write, ioctl etc).

MFC after:	1 month
Discussed with:	rwatson
2007-06-15 02:53:51 +00:00
Jung-uk Kim
560a54e10c Add three new ioctl(2) commands for bpf(4).
- BIOCGDIRECTION and BIOCSDIRECTION get or set the setting determining
whether incoming, outgoing, or all packets on the interface should be
returned by BPF.  Set to BPF_D_IN to see only incoming packets on the
interface.  Set to BPF_D_INOUT to see packets originating locally and
remotely on the interface.  Set to BPF_D_OUT to see only outgoing
packets on the interface.  This setting is initialized to BPF_D_INOUT
by default.  BIOCGSEESENT and BIOCSSEESENT are obsoleted by these but
kept for backward compatibility.

- BIOCFEEDBACK sets packet feedback mode.  This allows injected packets
to be fed back as input to the interface when output via the interface is
successful.  When BPF_D_INOUT direction is set, injected outgoing packet
is not returned by BPF to avoid duplication.  This flag is initialized to
zero by default.

Note that libpcap has been modified to support BPF_D_OUT direction for
pcap_setdirection(3) and PCAP_D_OUT direction is functional now.

Reviewed by:	rwatson
2007-02-26 22:24:14 +00:00
Robert Watson
5d1f828354 Remove slightly dubious comment; add descriptive strings for several
sysctls.

MFC after:	3 days
2007-01-28 16:38:44 +00:00
Robert Watson
acd3428b7d Sweep kernel replacing suser(9) calls with priv(9) calls, assigning
specific privilege names to a broad range of privileges.  These may
require some future tweaking.

Sponsored by:           nCircle Network Security, Inc.
Obtained from:          TrustedBSD Project
Discussed on:           arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
                        Alex Lyashkov <umka at sevcity dot net>,
                        Skip Ford <skip dot ford at verizon dot net>,
                        Antoine Brodin <antoine dot brodin at laposte dot net>
2006-11-06 13:42:10 +00:00
Robert Watson
aed5570872 Complete break-out of sys/sys/mac.h into sys/security/mac/mac_framework.h
begun with a repo-copy of mac.h to mac_framework.h.  sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.

This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.

Obtained from:	TrustedBSD Project
Sponsored by:	SPARTA
2006-10-22 11:52:19 +00:00
Robert Watson
a359443290 Since bpf_allocbufs() uses malloc() with M_WAITOK, don't check return
values for NULL or return an error state.  Assert that all three bpf
buffer pointers are NULL before starting.

MFC after:	1 week
2006-08-09 16:30:26 +00:00
Sam Leffler
246b546762 add support for 802.11 packet injection via bpf
Together with:	Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Reviewed by:	arch@
MFC after:	1 month
2006-07-26 03:15:16 +00:00
David Malone
91433904b5 Rather than calling mircotime() in catchpacket(), make catchpacket()
take a timeval indicating when the packet was captured. Move
microtime() to the calling functions and grab the timestamp as soon
as we know that we're going to call catchpacket at least once.

This means that we call microtime() once per matched packet, as
opposed to once per matched packet per bpf listener. It also means
that we return the same timestamp to all bpf listeners, rather than
slightly different ones.

It would be more accurate to call microtime() even earlier for all
packets, as you have to grab (1+#listener) locks before you can
determine if the packet will be logged. You could always grab a
timestamp before the locks, but microtime() can be costly, so this
didn't seem like a good idea.

(I guess most ethernet interfaces will have a bpf listener these
days because of dhclient. That means that we could be doing two bpf
locks on most packets going through the interface.)

PR:		71711
2006-07-24 15:42:04 +00:00
Christian S.J. Peron
4b19419ee7 Adjust descriptor locking to tell the kqueue subsystem that our descriptor is
already locked. The reason to do this is to avoid two lock+unlock operations
in a row. We need the lock here to serialize access to bd_pid for stats
collection purposes.

Drop the locks all together on detach, as they will be picked up by
knlist_remove.

This should fix a failed locking assertion when kqueue is being used with bpf
descriptors.

Discussed with:	jmg
2006-07-03 20:02:06 +00:00
Christian S.J. Peron
19ba8395e1 Since we are doing some bpf(4) clean up, change a couple of function prototypes
to be consistent. Also, ANSI'fy function definitions. There is no functional
change here.
2006-06-15 15:39:12 +00:00
Christian S.J. Peron
7eae78a419 If bpf(4) has not been compiled into the kernel, initialize the bpf interface
pointer to a zeroed, statically allocated bpf_if structure. This way the
LIST_EMPTY() macro will always return true. This allows us to remove the
additional unconditional memory reference for each packet in the fast path.

Discussed with:	sam
2006-06-14 02:23:28 +00:00
Christian S.J. Peron
16d878cc99 Fix the following bpf(4) race condition which can result in a panic:
(1) bpf peer attaches to interface netif0
	(2) Packet is received by netif0
	(3) ifp->if_bpf pointer is checked and handed off to bpf
	(4) bpf peer detaches from netif0 resulting in ifp->if_bpf being
	    initialized to NULL.
	(5) ifp->if_bpf is dereferenced by bpf machinery
	(6) Kaboom

This race condition likely explains the various different kernel panics
reported around sending SIGINT to tcpdump or dhclient processes. But really
this race can result in kernel panics anywhere you have frequent bpf attach
and detach operations with high packet per second load.

Summary of changes:

- Remove the bpf interface's "driverp" member
- When we attach bpf interfaces, we now set the ifp->if_bpf member to the
  bpf interface structure. Once this is done, ifp->if_bpf should never be
  NULL. [1]
- Introduce bpf_peers_present function, an inline operation which will do
  a lockless read bpf peer list associated with the interface. It should
  be noted that the bpf code will pickup the bpf_interface lock before adding
  or removing bpf peers. This should serialize the access to the bpf descriptor
  list, removing the race.
- Expose the bpf_if structure in bpf.h so that the bpf_peers_present function
  can use it. This also removes the struct bpf_if; hack that was there.
- Adjust all consumers of the raw if_bpf structure to use bpf_peers_present

Now what happens is:

	(1) Packet is received by netif0
	(2) Check to see if bpf descriptor list is empty
	(3) Pickup the bpf interface lock
	(4) Hand packet off to process

From the attach/detach side:

	(1) Pickup the bpf interface lock
	(2) Add/remove from bpf descriptor list

Now that we are storing the bpf interface structure with the ifnet, there is
is no need to walk the bpf interface list to locate the correct bpf interface.
We now simply look up the interface, and initialize the pointer. This has a
nice side effect of changing a bpf interface attach operation from O(N) (where
N is the number of bpf interfaces), to O(1).

[1] From now on, we can no longer check ifp->if_bpf to tell us whether or
    not we have any bpf peers that might be interested in receiving packets.

In collaboration with:	sam@
MFC after:	1 month
2006-06-02 19:59:33 +00:00
Ruslan Ermilov
293c06a186 Fix -Wundef warnings. 2006-05-30 19:24:01 +00:00
Christian S.J. Peron
1fc9e38706 Pickup locks for the BPF interface structure. It's quite possible that
bpf(4) descriptors can be added and removed on this interface while we
are processing stats.

MFC after:	2 weeks
2006-05-07 03:21:43 +00:00
Jung-uk Kim
848c454cc1 Add BPF Just-In-Time compiler support for ng_bpf(4).
The sysctl is changed from net.bpf.jitter.enable to net.bpf_jitter.enable
and this controls both bpf(4) and ng_bpf(4) now.
2005-12-07 21:30:47 +00:00
Jung-uk Kim
ae275efcae Add experimental BPF Just-In-Time compiler for amd64 and i386.
Use the following kernel configuration option to enable:

	options BPF_JITTER

If you want to use bpf_filter() instead (e. g., debugging), do:

	sysctl net.bpf.jitter.enable=0

to turn it off.

Currently BIOCSETWF and bpf_mtap2() are unsupported, and bpf_mtap() is
partially supported because 1) no need, 2) avoid expensive m_copydata(9).

Obtained from:	WinPcap 3.1 (for i386)
2005-12-06 02:58:12 +00:00
Christian S.J. Peron
cb1d4f92ec Protect PID initializations for statistics by the bpf descriptor
locks. Also while we are here, protect the bpf descriptor during
knlist_remove{add} operations.

Discussed with:	rwatson
2005-10-04 15:06:10 +00:00
Andre Oppermann
035ba19027 Undo a tad little optimization to bpf_mtap() introduced in rev. 1.95
which broke the correct handling of the BIOCGSEESENT flag in the bpf
listener.

PR:		kern/56441
Submitted by:	<vys at renet.ru>
MFC after:	3 days
2005-09-14 16:37:05 +00:00
Christian S.J. Peron
b75a24a075 Instead of caching the PID which opened the bpf descriptor, continuously
refresh the PID which has the descriptor open. The PID is refreshed in various
operations like ioctl(2), kevent(2) or poll(2). This produces more accurate
information about current bpf consumers. While we are here remove the bd_pcomm
member of the bpf stats structure because now that we have an accurate PID we
can lookup the via the kern.proc.pid sysctl variable. This is the trick that
NetBSD decided to use to deal with this issue.

Special care needs to be taken when MFC'ing this change, as we have made a
change to the bpf stats structure. What will end up happening is we will leave
the pcomm structure but just mark it as being un-used. This way we keep the ABI
in tact.

MFC after:	1 month
Discussed with:	Rui Paulo < rpaulo at NetBSD dot org >
2005-09-05 23:08:04 +00:00
Christian S.J. Peron
93e39f0b93 Introduce two new ioctl(2) commands, BIOCLOCK and BIOCSETWF. These commands
enhance the security of bpf(4) by further relinquishing the privilege of
the bpf(4) consumer (assuming the ioctl commands are being implemented).

Once BIOCLOCK is executed, the device becomes locked which prevents the
execution of ioctl(2) commands which can change the underly parameters of the
bpf(4) device. An example might be the setting of bpf(4) filter programs or
attaching to different network interfaces.

BIOCSETWF can be used to set write filters for outgoing packets. Currently if
a bpf(4) consumer is compromised, the bpf(4) descriptor can essentially be used
as a raw socket, regardless of consumer's UID. Write filters give users the
ability to constrain which packets can be sent through the bpf(4) descriptor.

These features are currently implemented by a couple programs which came from
OpenBSD, such as the new dhclient and pflogd.

-Modify bpf_setf(9) to accept a "cmd" parameter. This will be used to specify
 whether a read or write filter is to be set.
-Add a bpf(4) filter program as a parameter to bpf_movein(9) as we will run the
 filter program on the mbuf data once we move the packet in from user-space.
-Rather than execute two uiomove operations, (one for the link header and the
 other for the packet data), execute one and manually copy the linker header
 into the sockaddr structure via bcopy.
-Restructure bpf_setf to compensate for write filters, as well as read.
-Adjust bpf(4) stats structures to include a bd_locked member.

It should be noted that the FreeBSD and OpenBSD implementations differ a bit in
the sense that we unconditionally enforce the lock, where OpenBSD enforces it
only if the calling credential is not root.

Idea from:	OpenBSD
Reviewed by:	mlaier
2005-08-22 19:35:48 +00:00
Christian S.J. Peron
4ddfb5312a Add missing braces around bpf_filter which were missed when I
merged the bpfstat code.

Pointed out by:	iedowse
Pointy hat to:	csjp
MFC after:	3 days
2005-08-18 22:30:52 +00:00
Robert Watson
6a113b3de7 Merge the dev_clone and dev_clone_cred event handlers into a single
event handler, dev_clone, which accepts a credential argument.
Implementors of the event can ignore it if they're not interested,
and most do.  This avoids having multiple event handler types and
fall-back/precedence logic in devfs.

This changes the kernel API for /dev cloning, and may affect third
party packages containg cloning kernel modules.

Requested by:	phk
MFC after:	3 days
2005-08-08 19:55:32 +00:00
Christian S.J. Peron
422a63da6e Rather than hold a mutex over calls to SYSCTL_OUT allocate a
temporary buffer then pass the array to user-space once we have
dropped the lock.

While we are here, drop an assertion which could result in a
kernel panic under certain race conditions.

Pointed out by:	rwatson
2005-07-26 17:21:56 +00:00
Christian S.J. Peron
69f7644bc9 Introduce new sysctl variable: net.bpf.stats. This sysctl variable can
be used to pass statistics regarding dropped, matched and received
packet counts from the kernel to user-space. While we are here
introduce a new counter for filtered or matched packets. We currently
keep track of packets received or dropped by the bpf device, but not
how many packets actually matched the bpf filter.

-Introduce net.bpf.stats sysctl OID
-Move sysctl variables after the function prototypes so we can
 reference bpf_stats_sysctl(9) without build errors.
-Introduce bpf descriptor counter which is used mainly for sizing
 of the xbpf_d array.
-Introduce a xbpf_d structure which will act as an external
 representation of the bpf_d structure.
-Add a the following members to the bpfd structure:

	bd_fcount	- Number of packets which matched bpf filter
	bd_pid		- PID which opened the bpf device
	bd_pcomm	- Process name which opened the device.

It should be noted that it's possible that the process which opened
the device could be long gone at the time of stats collection. An
example might be a process that opens the bpf device forks then exits
leaving the child process with the bpf fd.

Reviewed by:	mdodd
2005-07-24 17:21:17 +00:00
Suleiman Souhlal
571dcd15e2 Fix the recent panics/LORs/hangs created by my kqueue commit by:
- Introducing the possibility of using locks different than mutexes
for the knlist locking. In order to do this, we add three arguments to
knlist_init() to specify the functions to use to lock, unlock and
check if the lock is owned. If these arguments are NULL, we assume
mtx_lock, mtx_unlock and mtx_owned, respectively.

- Using the vnode lock for the knlist locking, when doing kqueue operations
on a vnode. This way, we don't have to lock the vnode while holding a
mutex, in filt_vfsread.

Reviewed by:	jmg
Approved by:	re (scottl), scottl (mentor override)
Pointyhat to:	ssouhlal
Will be happy:	everyone
2005-07-01 16:28:32 +00:00
David Malone
01399f34a5 Fix some long standing bugs in writing to the BPF device attached to
a DLT_NULL interface. In particular:

        1) Consistently use type u_int32_t for the header of a
           DLT_NULL device - it continues to represent the address
           family as always.
        2) In the DLT_NULL case get bpf_movein to store the u_int32_t
           in a sockaddr rather than in the mbuf, to be consistent
           with all the DLT types.
        3) Consequently fix a bug in bpf_movein/bpfwrite which
           only permitted packets up to 4 bytes less than the MTU
           to be written.
        4) Fix all DLT_NULL devices to have the code required to
           allow writing to their bpf devices.
        5) Move the code to allow writing to if_lo from if_simloop
           to looutput, because it only applies to DLT_NULL devices
           but was being applied to other devices that use if_simloop
           possibly incorrectly.

PR:		82157
Submitted by:	Matthew Luckie <mjl@luckie.org.nz>
Approved by:	re (scottl)
2005-06-26 18:11:11 +00:00