Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Exit with proper status when wake() fails.

PR: bin/153527
Submitted by: Douglas Steinwand
MFC after: 2 weeks

style(9).

MFC after: 2 weeks

If there is only one NIC in the system that is up and running, the
interface specifier on the command line can be ommited.

Besides of this, the bpf is being reused for each machine
that has to be woken up.

Submitted by: Marc Balmer <marc@msys.ch>

Fix wake(8) synopsis to make it clear that at least one lladdr is required
as an argument.

Submitted by: Marc Balmer <marc@msys.ch>
MFC after: 3 days

- Properly order headers, local variables and prototypes. [1]
- Remove unneeded headers.
- Return non-zero error code in usage().

Approved by: re (kib)
Suggested by: bde [1]

- Fix the bug in write(2) called with incorrect parameters resulting in writes
always started from the start of the packet.
- Fix usage string (multiple addresses can be specified).
- Make the source more style(9) compliant.
- Improve error reporting (do not silently fail if something goes
wrong).
- Make functions static.
- Use warns level 6.

Approved by: re (kib)
Discussed with: Marc Balmer <marc@msys.ch>, brian, mbr

Add wake, a tool to send Wake on LAN frames to hosts on a local Ethernet network

Submitted by: Marc Balmer <marc@msys.ch>
Reviewed by: rwatson
Approved by: re

M usr.sbin/Makefile
A usr.sbin/wake
AM usr.sbin/wake/wake.c
AM usr.sbin/wake/Makefile
AM usr.sbin/wake/wake.8