Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

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

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

Revert previous commit...

Pointyhat to: kevlo (myself)

Prefer NULL over 0 for pointers

Make kttcp work in -stable (and -current)

- Removed kttcp_sosend() and kttcp_soreceive() in favor of using
sosend() / soreceive() with UIO_NOCOPY. The locking changes in the
socket layer make merging the kttcp_so* and the so* routines a real
pain. It was a lot easier to just use the integrated routines.

- Eliminated KTTCP_MAX_XMIT restrictions on send and receive sizes
because I encountered no problems with streams larger than MAX_INT.
MAX_INT bytes is only good for a few seconds at 4Gb/sec ;)

- Removed Giant from send / recv routines.

- Fixed character device protos, cdevsw init, etc, to work in 5.x /
6.x

Reviewed by: sam
MFC after: 1 week

Update for so_state->sb_state, SB_* flag renames.

Submitted by: rik

fixup include filenames; this stuff used to be in the kernel source tree

add in-kernel ttcp performance tool