MFC r258065,r258594,r259430,r260222,r261407,r261408,r263479,r264021,r266351,r269603:

r258065 (by pjd):

Bring in libnv library for managing name/value pairs. The following types
are currently supported:

• NV_TYPE_NULL - only name, no data;
• NV_TYPE_BOOL - boolean (true or false);
• NV_TYPE_NUMBER - 64bit unsigned integer;
• NV_TYPE_STRING - C string;
• NV_TYPE_NVLIST - nested nvlist;
• NV_TYPE_DESCRIPTOR - file descriptor;
• NV_TYPE_BINARY - binary data.

For detailed documentation and examples see nv(3) manual page.

Sponsored by: The FreeBSD Foundation

r258594 (by pjd):

Fix double free().

Reported by: Coverity
Coverity CID: 1130048

r259430 (by pjd):

MFp4 @1189139:

Get rid of the msg_peek() function, which has a problem. If there was less
data in the socket buffer than requested by the caller, the function would busy
loop, as select(2) will always return immediately.

We can just receive nvlhdr now, because some time ago we splitted receive of
data from the receive of descriptors.

r260222 (by pjd):

MFp4 @1189711:

Fix resource leaks on nvlist_destroy().

Reported by: Mariusz Zaborski <oshogbo@FreeBSD.org>

r261407 (by pjd):

Fix sending empty nvlist.

Submitted by: Mariusz Zaborski <oshogbo@FreeBSD.org>

r261408 (by pjd):

Assert input arguments to buf_send() and buf_recv().

Submitted by: Mariusz Zaborski <oshogbo@FreeBSD.org>

r263479 (by bdrewery):

nv(3) was not in 10.0.

It might be MFC'd to stable/10 for 10.1, but for now update the manual to
avoid confusion on its availability.

Discussed with: pjd

r264021 (by jilles):

libnv: Don't lose big-endian flag when receiving a message.

A bug caused the "big endian" flag to be lost when receiving a message. As a
result, the bits are interpreted as little endian and an extremely large
allocation is attempted.

This change fixes ping(8)'s communication to casperd(8) on big-endian
architectures.

Reported by: Anton Shterenlikht
Tested by: danfe

r266351 (by rstone):

Correct a typo.

r269603:

Integrate lib/libnv into the build/kyua

Rename all of the TAP test applications from <test> to <test>_test
to match the convention described in the TestSuite wiki page

Phabric: D538
Approved by: jmmv (mentor)
Sponsored by: EMC / Isilon Storage Division