lib/util: consolidate module loading into common code

This creates a samba-modules private libary that handles the details.

Andrew Bartlett

lib/util/samba_modules.h

@@ -0,0 +1,65 @@
+/*
+   Unix SMB/CIFS implementation.
+   Handling of idle/exit events
+   Copyright (C) Stefan (metze) Metzmacher	2003
+   Copyright (C) Andrew Bartlett 2011
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef _SAMBA_MODULES_H
+#define _SAMBA_MODULES_H
+
+/* Module support */
+typedef NTSTATUS (init_module_function) (void);
+typedef NTSTATUS (*init_module_fn) (void);
+
+NTSTATUS init_samba_module(void);
+
+/* this needs to be a string which is not in the C library. We
+   previously used "init_module", but that meant that modules which
+   did not define this function ended up calling the C library
+   function init_module() which makes a system call */
+#define SAMBA_INIT_MODULE "samba_init_module"
+
+/**
+ * Obtain the init function from a shared library file
+ */
+init_module_fn load_module(TALLOC_CTX *mem_ctx, const char *path);
+
+/**
+ * Obtain list of init functions from the modules in the specified
+ * directory
+ */
+init_module_fn *load_modules(TALLOC_CTX *mem_ctx, const char *path);
+
+/**
+ * Run the specified init functions.
+ *
+ * @return true if all functions ran successfully, false otherwise
+ */
+bool run_init_functions(init_module_fn *fns);
+
+/**
+ * Load the initialization functions from DSO files for a specific subsystem.
+ *
+ * Will return an array of function pointers to initialization functions
+ */
+init_module_fn *load_samba_modules(TALLOC_CTX *mem_ctx, const char *subsystem);
+
+NTSTATUS smb_load_module(const char *module_name);
+int smb_load_modules(const char **modules);
+NTSTATUS smb_probe_module(const char *subsystem, const char *module);
+
+#endif /* _SAMBA_MODULES_H */