MFC r337904:

Allow the use of TCP instead of UDP for queries by setting options usevc
in resolv.conf which sets RES_USEVC.

Reviewed by: ume

Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Don't leak addrinfo if ai->ai_addrlen <= minsiz test fails.

If the ai->ai_addrlen <= minsiz test fails, then freeaddrinfo()
does not get called to free the memory just allocated by getaddrinfo().
Fix by moving ai->ai_addrlen <= minsiz to a separate nested if
block, and keep freeaddrinfo() in the outer block so that freeaddrinfo()
will be called whenever getaddrinfo() succeeds.

Reported by: Coverity
CID: 1273652
Reviewed by: ume
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D6756

libc: spelling fixes.

Mostly on comments.

libc: do not include <sys/types.h> where <sys/param.h> was already included

According to style(9):
> normally, include <sys/types.h> OR <sys/param.h>, but not both.
(<sys/param.h> already includes <sys/types.h> when LOCORE is not defined).

libc: replace 0 with NULL for pointers.

While here also cleanup some surrounding code; particularly
drop some malloc() casts.

Found with devel/coccinelle.

Reviewed by: bde (previous version - all new bugs are mine)

Allow users override `DEBUG` on the command line via DEBUG_FLAGS="-DDEBUG" with
lib/libc/resolv by conditionalizing its definition

MFC after: 3 days
Reviewed by: ume, vangyzen
Differential Revision: https://reviews.freebsd.org/D4519

resolver: preserve binary compatibility; reduce header pollution

In r289315, I added new fields to res_state. This broke binary
backward compatibility. It also broke some ports (and possibly
other code) by requiring the definition of time_t and struct timespec.

Fix these problems by moving the new fields into __res_state_ext.

Suggested by: ume
Reviewed by: ume
MFC after: 3 days
Sponsored by: Dell Inc.
Differential Revision: https://reviews.freebsd.org/D4472

resolver: automatically reload /etc/resolv.conf

On each resolver query, use stat(2) to see if the modification time
of /etc/resolv.conf has changed. If so, reload the file and reinitialize
the resolver library. However, only call stat(2) if at least two seconds
have passed since the last call to stat(2), since calling it on every
query could kill performance.

This new behavior is enabled by default. Add a "reload-period" option
to disable it or change the period of the test.

Document this behavior and option in resolv.conf(5).

Polish the man page just enough to appease igor.

https://lists.freebsd.org/pipermail/freebsd-arch/2015-October/017342.html

Reviewed by: kp, wblock
Discussed with: jilles, imp, alfred
MFC after: 1 month
Relnotes: yes
Sponsored by: Dell Inc.
Differential Revision: https://reviews.freebsd.org/D3867

Use ANSI C prototypes. Eliminates -Wold-style-definition warnings.

Update our stub resolver to final version of libbind.

Obtained from: ISC

libc: Make various internal file descriptors from fopen() close-on-exec.

Merge BIND 9.4.2 into main chunk.

Merge BIND 9.4.1 into main chunk.

MFC after: 2 weeks

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

_close() should be called instead of close() here.

- 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