bpf(4): fix couple more nits

bpf(4): fix couple of overlooked markup nits

bpf(4): spaces around + in instruction tables

Makes them easier on the eyes.

bpf(4): use nicer glyphs for some operations in PS output

bpf(4): make all instruction tables align

Define string max-insn and use it in all tables for the width of the
first column (nroff has variables, shocking, I know). Define only the
width of the first column, the last column gets all the remaining width.

bpf(4): use \[<-] instead of <-

bpf(4): assorted markup tweaks

This is mostly non-controversial changes to the cargo-culted markup.
While here - add missing .It to BIOCLOCK so that it's not buried in
the text for the previous item and comment out a paragraph about an
ancient SunOS bug.

bpf.4: fix a garbled item heading

Make the BIOCSDIRECTION & BIOCGDIRECTION entry like those around it.

man, bpf: support loopback interfaces for send

bpf.4: amend caveat about what types of links can be written to

Try to be clearer about what's supported. A peripheral issue noted in
PR pkg/55446.

Use more markup.

bpf(4): Add ioctls BIOCSETWF and BIOCLOCK

Once BIOCLOCK is executed, the device becomes locked which prevents the
execution of ioctl(2) commands which can change the underlying 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.

Taken from OpenBSD.

Implement the BPF direction filter (BIOC[GS]DIRECTION). It provides backward
compatibility with BIOC[GS]SEESENT ioctl. The userland interface is the same
as FreeBSD.

This change also fixes a bug that the direction is misunderstand on some
environment by passing the direction to bpf_mtap*() instead of checking
m->m_pkthdr.rcvif.

branches: 1.60.2;
Remove Tn. Fix some mandoc lint warnings.

Fix another column width.

Use .Fn when describing C macros

Fix column width in postscript output.

Remove workaround for ancient HTML generation code.

branches: 1.55.16;
Sort SEE ALSO. Use .An. Bump date.

Use .Sy for 'Just-In-Time', add a reference to bpfjit(4).

branches: 1.53.2;
New sentence, new line. Bump date for previous.

Implement BPF_COP/BPF_COPX instructions in the misc category (BPF_MISC)
which add a capability to call external functions in a predetermined way.

It can be thought as a BPF "coprocessor" -- a generic mechanism to offload
more complex packet inspection operations. There is no default coprocessor
and this functionality is not targeted to the /dev/bpf. This is primarily
targeted to the kernel subsystems, therefore there is no way to set a custom
coprocessor at the userlevel.

Discussed on: tech-net@
OK: core@

Document net.bpf.jit sysctl.

branches: 1.50.6;
Fix typos and style glitches. Remove outdated info about only
Ethernet, SLIP, and PPP being supported, and no network types with
variable-length headers (such as 802.11).
Document BIOCSRSIG and BIOCGRSIG.

From Guy Harris in PR#40703.

Document that overflow in P[X+k:n] terminates a filter program.
Based on a discussion with Christos on source-changes-d.

Remove duplicate RCS Id. New sentence, new line.

PR/45750: Alexander Nasonov: Type of k in bpf_insn is bpf(9) is different
from sys/net/bpf.h

branches: 1.46.6;
Remove SIOCGIFADDR. Noted by Ross Patterson in PR kern/21513.

branches: 1.45.2;
Use .In instead of .Aq Pa for header files.

FreeBSD -> .Fx, add RCS Id.

Document BIOC{G,S}FEEDBACK; I forgot who sent me the patch, so whoever created
it, thanks!

update type of bh_tstamp

grammar fix

Fix markup.

branches: 1.39.26; 1.39.28;
New sentence, new line. Use more markup.
Bump date for previous.

If user buffers do not match kernel buffers our kernel returns EINVAL,
not EIO.

There can be as many bpf clones as you want and the kernel doesn't
enforce any number.

u_intN_t -> uintN_t

Remove BIOC[GS]RSIG and fix BIOC[GS]HDRCMPLT typo.

Bump date for 1.32.
Use .Aq instead of \*[Lt]\*[Gt] and mark up paths with .Pa.

Change 'headers' to 'network layer headers' as suggested by Tetsuya Isaki.

PR misc/31139: bpf(4) does not describe some ioctls, by Tetsuya Isaki.
IOCTLs explained: BIO[GS]HDRCMPLT and IO[GS]SEESENT.

Remove trailing whitespace.

Added a new section called "SYSCTLS" explaining the purpose of
net.bpf.maxbufsize, net.bpf.stats and net.bpf.peers.
Bump the date.

Reviewed by: wiz@

Since bpf is now a clonable device, remove references to /dev/bpfX.
Update the structs so that they match bpf.h and bpfdesc.h.
Bump date.

ok christos@

branches: 1.28.2;
Removed accidental repetitious words.

Add Ns.

Fix some macro abuses.

Uppercase ULTRIX. Igor Sobrado in PR 19678.

.Nm does not need a dummy argument ("") before punctuation or
for correct formatting of the SYNOPSIS any longer.

"Utilize" has exactly the same meaning as "use," but it is more
difficult to read and understand. Most manuals of English style
therefore say that you should use "use".

typo (be -> by)

Fix typo in last.

Mark up error values and NULL.

Add 2 APIs to get a list of available DLTs and use one for them.
BIOCGDLTLIST (struct bpf_dltlist)
BIOCSDLT (u_int)

Two major fixes for PS output; also cut down on Ns and No misuses.

Generate <>& symbolically. I'm avoiding .../dist/... directories for now.

Edit -mdoc usage.

* There is no -indent option to .Bd or .Bl, although you would
never know that from its frequent use in this tree. There is a
"-offset indent" combination that makes sense, and you can certainly
say "-width indent".

* Also, you can't markup the -width option argument, tho you CAN
use a callable macro. So "-width Ar filename" doesn't make sense,
but either "-width Ar" or "-width filename" does, as might something
like "-width xxfilename" for a little extra space.

* There are a lot of needlessly complex hanging tag macros in man4 used
to create simple item lists. Those should be simplified one of these
days before someone copies and edits yet another man4 page.

Whitespace, paragraph, punctuation, citation fixes. Sort sections.

Use EAGAIN instead of EWOULDBLOCK. The actual numeric value is
same, but EAGAIN is the posixly correct name.
Addresses misc/12960.

insure -> ensure

Convert to use mdoc macros more. The pervious commit, which partially
converted to mdoc, just results malformed output.

Misc small fixes to try to standardise the format to make it easier
to parse by an automated script (say one that just might want to
generate webpage summaries of available drivers :)

branches: 1.10.8;
don't xref nonexistent filio(2)

PR misc/3375, submitted by der Mouse <mouse@Rodents.Montreal.QC.CA>.
The if_name fields are really called ifr_name.

misc. updates and fixes from LBL version (bpf-1.1).

Update from Stu Grossman <grossman@cygnus.com>, documenting his enhancements.

fix tcpdump cross reference

Merged with 4.4lite.
Changed to conform to NetBSD's new RCS Id convention.

cleared with mccanne: "the bug is in the bpf man page. SIOCGIFADDR
should go away. Link addresses should be looked up with SIOCGIFCONF."

Add RCS identifiers, remove some completely useless RCS logs and patchkit
headers, and a few other insignificant changes.

error found by hpeyerl, cleared by mccanne

branches: 1.1.1;
fixed epsilon problem in tp man page, added bpf man page.