library/2946: thread locking under lib/libc/net insufficient

>Number: 2946
>Category: library
>Synopsis: thread locking under lib/libc/net insufficient
>Confidential: no
net
>Environment:

	System      : OpenBSD 3.2
	Architecture: OpenBSD.i386
	Machine     : i386

>Description:

	we are using non-thread-safe resolver code under lib/libc/net,
	with some _THREAD_PRIVATE_MUTEX().  _THREAD_PRIVATE_MUTEX() are not
	sufficient from multiple aspects.
	- if user applications use res_* directly, it's not thread safe.
	- since getaddrinfo.c and gethostnamadr.c uses different
	  _THREAD_PRIVATE_MUTEX(), race can occur if user application uses
	  these functions together from other threads.

        the only solution would be to move to BIND8 resolver.

>Release-Note:
 Jun-ichiro itojun Hagino Received on Thu Nov 7 16:57:12 2002