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

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

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

Approved by: re (implicit)

- When there is no room for returning the result, nss backend
have to return ERANGE and terminate with NS_RETURN.
- When gethostbyname_r(3) and the friends end with an error,
set errno to the value nss backend returns, and return errno
value.

PR: kern/131623
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.

- make reentrant version of netdb functions glibc style API, and
expose them to outside of libc.
- make netdb functions NSS friendly.

Reviewed by: arch@ and current@ (no objection)

Update the resolver in libc to BIND9's one.

Since, res_sendsigned(3) and the friends use MD5 functions, it is
hard to include them without having MD5 functions in libc. So,
res_sendsigned(3) is not merged into libc.

Since, res_update(3) in BIND9 is not binary compatible with our
res_update(3), res_update(3) is leaved as is, except some
necessary modifications.
The res_update(3) and the friends are not essential part of the
resolver. They are not defined in resolv.h but defined in
res_update.h separately in BIND9. Further, they are not called from
our tree. So, I hide them from our resolv.h, but leave them only
for binary backward compatibility (perhaps, no one calls them).

Since, struct __res_state_ext is not exposed in BIND9, I hide it
from our resolv.h. And, global variable _res_ext is removed. It
breaks binary backward compatibility. But, since it is not used from
outside of our libc, I think it is safe.

Reviewed by: arch@ (no objection)

- Remove padding for ABI compatibility of n_net member from struct
netent.
- Change 1st argument of getnetbyaddr() to an uint32_t on 64 bit
arch as well to confirm to POSIX-2001.

These changes break ABI compatibility on 64 bit arch.
There is similar padding issue for ai_addrlen of struct addrinfo.
However, it is leaved as is for now.

Discussed on: arch@, standards@ and current@
X-MFC after: never

- The ai_addrlen of a struct addrinfo used to be a size_t, per
RFC 2553. In XNS5.2, and subsequently in POSIX-2001 and RFC
3493, it was changed to a socklen_t. And, the n_net of a
struct netent used to be an unsigned long integer. In XNS5,
and subsequently in POSIX-2001, it was changed to an uint32_t.
To accomodate for this while preserving ABI compatibility with
the old interface, we need to prepend or append 32 bits of
padding, depending on the (LP64) architecture's endianness.
- Correct 1st argument of getnetbyaddr() to uint32_t on 32
bit arch. Stay as is on 64 bit arch for ABI backward
compatibility for now.

Reviewed by: das, peter
MFC after: 2 weeks

make getnetby*() thread-safe.

Unbreak world.

getnetbyname fixes:
Do not choke on malformed network addresses.
Return n_name in static space, not on the function's stack.

MFC after: 1 week

Allocate 64K recieve buffer for DNS responses.
Though res_query.c also defines and refers MAXPACKET, it is not
related to ansbuf. So, I didn't touch res_query.c.

Add forgotten newlines in debug messages.

Check for truncation in calls to res_send/res_query/res_search.
Fail when it is detected.

Backout the increase of MAXPACKET from 1024 to 65536: it
broke pthreads.

Reported by: mbr, tjr

When using res_send/res_query/res_search, the caller must either
insure enough space is available for the response, or be prepared
to resize the buffer and retry as necessary.

Do the conservative thing and make sure enough space is available.

Reviewed by: silence on freebsd-audit

Remove two stray lines that snuck in the cvs merge

Initialize a pointer that was left uninitialized with the previous
commit.

Include more robust checking of end of buffer that more completely
plugs the hole.

Don't allow buffer overflow here either.

Fix the style of the SCM ID's.
I believe have made all of libc .c's as consistent as possible.

Remove 'register' keyword.

Remove _THREAD_SAFE and make libc thread-safe by default by
adding (weak definitions to) stubs for some of the pthread
functions. If the threads library is linked in, the real
pthread functions will pulled in.

Use the following convention for system calls wrapped by the
threads library:
__sys_foo - actual system call
_foo - weak definition to __sys_foo
foo - weak definition to __sys_foo

Change all libc uses of system calls wrapped by the threads
library from foo to _foo. In order to define the prototypes
for _foo(), we introduce namespace.h and un-namespace.h
(suggested by bde). All files that need to reference these
system calls, should include namespace.h before any standard
includes, then include un-namespace.h after the standard
includes and before any local includes. <db.h> is an exception
and shouldn't be included in between namespace.h and
un-namespace.h namespace.h will define foo to _foo, and
un-namespace.h will undefine foo.

Try to eliminate some of the recursive calls to MT-safe
functions in libc/stdio in preparation for adding a mutex
to FILE. We have recursive mutexes, but would like to avoid
using them if possible.

Remove uneeded includes of <errno.h> from a few files.

Add $FreeBSD$ to a few files in order to pass commitprep.

Approved by: -arch

Add nsswitch support. By creating an /etc/nsswitch.conf file, you can
configure FreeBSD so that various databases such as passwd and group can be
looked up using flat files, NIS, or Hesiod.

= Hesiod has been added to libc (see hesiod(3)).

= A library routine for parsing nsswitch.conf and invoking callback
functions as specified has been added to libc (see nsdispatch(3)).

= The following C library functions have been modified to use nsdispatch:
. getgrent, getgrnam, getgrgid
. getpwent, getpwnam, getpwuid
. getusershell
. getaddrinfo
. gethostbyname, gethostbyname2, gethostbyaddr
. getnetbyname, getnetbyaddr
. getipnodebyname, getipnodebyaddr, getnodebyname, getnodebyaddr

= host.conf has been removed from src/etc. rc.network has been modified
to warn that host.conf is no longer used at boot time. In addition, if
there is a host.conf but no nsswitch.conf, the latter is created at boot
time from the former.

Obtained from: NetBSD

$Id$ -> $FreeBSD$

handle long usernames more carefully
Reviewed by: guido
Obtained from: OpenBSD (Theo de Raadt)

Merge in bind-4.9.6 resolver changes. Note that they resolve the
overflow problem differently.

Revert $FreeBSD$ to $Id$

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Here goes.. Bring the 4.9.5-P1 resolver into -current. This has the
DNSSEC stuff, among other things. There are also some renamed functions,
I've left out the res_stubs.c from this commit in case cvs bombs out..

Merge in bind-4.9.4-P1 resolver...

General -Wall warning cleanup, part I.
Submitted-By: Kent Vander Velden <graphix@iastate.edu>

The last of the bind-4.9.3-REL resolver merges.

As above.

Remove trailing whitespace.

remove need for -DDEBUG from resolver code (conflict with db/hash)

get* rework and new bind code