Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFC r228537:

Remove meaningless self-assignment in res_send.c, otherwise clang will
warn about it. I guess this was originally done to silence a bogus
warning by an older version of gcc, but I could not reproduce it with
any version of gcc that I have access to.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Merge the resolver part of BIND 9.4.3 into HEAD.
It includes the following fix:

2426. [bug] libbind: inet_net_pton() can sometimes return the
wrong value if excessively large netmasks are
supplied. [RT #18512]

Reported by: Maksymilian Arciemowicz <cxib__at__securityreason.com>

Merge BIND 9.4.1 into main chunk.

MFC after: 2 weeks

Only reject file descriptors higher than FD_SETSIZE if we are not using
poll(2) or kqueue(2). Previously we rejected fd's higher than FD_SETSIZE
for kevent(2), and larger than sysconf(_SC_OPEN_MAX) for poll(2). However,
the check for poll(2) wasn't really needed. open(2) and socket(2) won't
return an fd you can't pass to either poll(2) or kevent(2). This fixes
a but where gethostbyname() would fail if you had more than 1023 files
open in a process.

MFC after: 1 week
Reviewed by: ume
Found by: ps

Per Regents of the University of Calfornia letter, remove advertising
clause.

# If I've done so improperly on a file, please let me know.

Merge BIND9 9.3.3 into main chunk.

Obtained from: ISC
MFC after: 1 week

Merge res_send.c of BIND9 9.3.3rc2 into main chunk. It includes
following fix:

Retransmission timeouts should be based on which attempt
it is to the nameserver and not the nameserver itself.

Obtained from: ISC
MFC after: 3 days

Check if the filedes of kevent is expected one. Though our
old resolver opened just one socket, BIND9's resolver may
open more than one sockets. And, BIND9's resolver doesn't
close the socket on timeout. So, we need this check.

Reported by: freebsd-cvs-src__at__oldach.net (Helge Oldach), bz
Hinted by: rwatson

- Merge our local changes.
- Exclude unnecessary functions for us.

This commit was generated by cvs2svn to compensate for changes in r156952,
which included commits to RCS files with non-trunk default branches.

Vendor import of BIND 9.3.2