= Implement name service switch modules (NSS modules). NSS modules

  may be built into libc (`static NSS modules') or dynamically loaded
  via dlopen (`dynamic NSS modules').  Modules are loaded/initialized
  at configuration time (i.e.  when nsdispatch is called and nsswitch.conf
  is read or re-read).

= Make the nsdispatch(3) core thread-safe.

= New status code for nsdispatch(3) `NS_RETURN', currently used to
  signal ERANGE-type issues.

= syslog(3) problems, don't warn/err/abort.

= Try harder to avoid namespace pollution.

= Implement some shims to assist in porting NSS modules written for
  the GNU C Library nsswitch interface.

Sponsored by:	DARPA, Network Associates Laboratories

1 files changed, 80 insertions, 0 deletions

diff --git a/lib/libc/include/nss_tls.h b/lib/libc/include/nss_tls.h
new file mode 100644
index 0000000..be6b74f
--- /dev/null
+++ b/lib/libc/include/nss_tls.h
@@ -0,0 +1,80 @@
+/*-
+ * Copyright (c) 2003 Networks Associates Technology, Inc.
+ * All rights reserved.
+ *
+ * This software was developed for the FreeBSD Project by
+ * Jacques A. Vidrine, Safeport Network Services, and Network
+ * Associates Laboratories, the Security Research Division of Network
+ * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
+ * ("CBOSS"), as part of the DARPA CHATS research program.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ *
+ * Macros which generate thread local storage handling code in NSS modules.
+ */
+#ifndef _NSS_TLS_H_
+#define _NSS_TLS_H_
+
+#define NSS_TLS_HANDLING(name)					\
+static pthread_key_t name##_state_key;				\
+static	void	 name##_keyinit(void);				\
+static	int	 name##_getstate(struct name##_state **);	\
+\
+static void								\
+name##_keyinit(void)							\
+{									\
+	(void)_pthread_key_create(&name##_state_key, name##_endstate);	\
+}									\
+\
+static int							\
+name##_getstate(struct name##_state **p)			\
+{								\
+	static struct name##_state st;				\
+	static pthread_once_t	keyinit = PTHREAD_ONCE_INIT;	\
+	int			rv;				\
+								\
+	if (!__isthreaded || _pthread_main_np() != 0) {		\
+		*p = &st;					\
+		return (0);					\
+	}							\
+	rv = _pthread_once(&keyinit, name##_keyinit);		\
+	if (rv != 0)						\
+		return (rv);					\
+	*p = _pthread_getspecific(name##_state_key);		\
+	if (*p != NULL)						\
+		return (0);					\
+	*p = calloc(1, sizeof(*p));				\
+	if (*p == NULL)						\
+		return (ENOMEM);				\
+	rv = _pthread_setspecific(name##_state_key, *p);	\
+	if (rv != 0) {						\
+		free(*p);					\
+		*p = NULL;					\
+	}							\
+	return (rv);						\
+}								\
+/* allow the macro invocation to end with a semicolon */	\
+typedef int _##name##_bmVjdGFy
+
+#endif /* _NSS_TLS_H_ */