on temporary nameserver failure. This is necessary to get
getipnodebyname(3) to correctly return h_errno=TRY_AGAIN instead
of HOST_NOT_FOUND.
Reviewed by: green, thomas
MFC after: 1 week
The getaddrinfo(3), getipnodebyname(3) and resolver(3) can coincide now
with what should be totally reentrant, and h_errno values will now
be preserved correctly, but this does not affect interfaces such as
gethostbyname(3) which are still mostly non-reentrant.
In all of these relevant functions, the thread-safety has been pushed
down as far as it seems possible right now. This means that operations
that are selected via nsdispatch(3) (i.e. files, yp, dns) are protected
still under global locks that getaddrinfo(3) defines, but where possible
the locking is greatly reduced. The most noticeable improvement is
that multiple DNS lookups can now be run at the same time, and this
shows major improvement in performance of DNS-lookup threaded programs,
and solves the "Mozilla tab serialization" problem.
No single-threaded applications need to be recompiled. Multi-threaded
applications that reference "_res" to change resolver(3) options will
need to be recompiled, and ones which reference "h_errno" will also
if they desire the correct h_errno values. If the applications already
understood that _res and h_errno were not thread-safe and had their own
locking, they will see no performance improvement but will not
actually break in any way.
Please note that when NSS modules are used, or when nsdispatch(3)
defaults to adding any lookups of its own to the individual libc
_nsdispatch() calls, those MUST be reentrant as well.
Only warnings that could be fixed without changing the generated object
code and without restructuring the source code have been handled.
Reviewed by: /sbin/md5
and getipnodeby*() thread-safe.
Our res_*() is not thread-safe. So, we share lock between
getaddrinfo() and getipnodeby*(). Still, we cannot use
getaddrinfo() and getipnodeby*() in conjunction with other
functions which call res_*().
Requested by: many people
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
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
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
when parsing certain DNS records during a reverse address resolution. Thus
when code tries to examine the returned host name, it dereferences a null
pointer :-(
Problem noticed by: ps
from
all AAAA trial, then all A trial
to
try AAAA and A for each trial
TODO: more fix for the case where IPv4 mapped IPv6 addr is disabled
Reviewed by: ume
(shortend format, etc)
Current KAME getaddrinfo() supports only d.d.d.d format IPv4
addr. But traditionally inet_aton() and etc support other formats.
(shortend format and octal/deciaml/hex format)
Aboud this,
-As far as the discussion on freebsd-current, many people
think traditional format should also be supported by getaddrinfo().
-X/Open spec requires getaddrinfo() also support those
traditional IPv4 format.
-RFC2553 say nothing about it.
-As the result of confirmation in ietf/ipng list, there is
no clear concensus yet, and the reply was, "RFC2553 update
and X/Open spec will be in sync"
So takeing these conditions into account, I think
getaddrinfo() should also support traditional IPv4 format.
Specified by: Marc Schneiders <marc@oldserver.demon.nl>
Approved by: jkh
just use _foo() <-- foo(). In the case of a libpthread that doesn't do
call conversion (such as linuxthreads and our upcoming libpthread), this
is adequate. In the case of libc_r, we still need three names, which are
now _thread_sys_foo() <-- _foo() <-- foo().
Convert all internal libc usage of: aio_suspend(), close(), fsync(), msync(),
nanosleep(), open(), fcntl(), read(), and write() to _foo() instead of foo().
Remove all internal libc usage of: creat(), pause(), sleep(), system(),
tcdrain(), wait(), and waitpid().
Make thread cancellation fully POSIX-compliant.
Suggested by: deischen
points. For library functions, the pattern is __sleep() <--
_libc_sleep() <-- sleep(). The arrows represent weak aliases. For
system calls, the pattern is _read() <-- _libc_read() <-- read().
