1 files changed, 240 insertions, 0 deletions
diff --git a/lib/util/modules.c b/lib/util/modules.c
new file mode 100644
index 0000000000..52a04be457
--- /dev/null
+++ b/lib/util/modules.c
@@ -0,0 +1,240 @@
+/*
+   Unix SMB/CIFS implementation.
+   Samba utility functions
+   Copyright (C) Jelmer Vernooij 2002-2003,2005-2007
+   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/>.
+*/
+
+#include "includes.h"
+#include "dynconfig/dynconfig.h"
+#include "lib/util/samba_modules.h"
+#include "system/filesys.h"
+#include "system/dir.h"
+
+/**
+ * Obtain the init function from a shared library file
+ */
+init_module_fn load_module(const char *path, bool is_probe, void **handle_out)
+{
+	void *handle;
+	void *init_fn;
+	char *error;
+
+#if _SAMBA_BUILD_ == 3
+	/* Always try to use LAZY symbol resolving; if the plugin has
+	 * backwards compatibility, there might be symbols in the
+	 * plugin referencing to old (removed) functions
+	 */
+	handle = dlopen(path, RTLD_LAZY);
+#else
+	/* This should be a WAF build, where modules should be built
+	 * with no undefined symbols and are already linked against
+	 * the libraries that they are loaded by */
+	handle = dlopen(path, RTLD_NOW);
+#endif
+
+	/* This call should reset any possible non-fatal errors that
+	   occured since last call to dl* functions */
+	error = dlerror();
+
+	if (handle == NULL) {
+		int level = is_probe ? 5 : 0;
+		DEBUG(level, ("Error loading module '%s': %s\n", path, error ? error : ""));
+		return NULL;
+	}
+
+	init_fn = (init_module_fn)dlsym(handle, SAMBA_INIT_MODULE);
+
+	/* we could check dlerror() to determine if it worked, because
+           dlsym() can validly return NULL, but what would we do with
+           a NULL pointer as a module init function? */
+
+	if (init_fn == NULL) {
+		DEBUG(0, ("Unable to find %s() in %s: %s\n",
+			  SAMBA_INIT_MODULE, path, dlerror()));
+		DEBUG(1, ("Loading module '%s' failed\n", path));
+		dlclose(handle);
+		return NULL;
+	}
+
+	if (handle_out) {
+		*handle_out = handle;
+	}
+
+	return (init_module_fn)init_fn;
+}
+
+/**
+ * Obtain list of init functions from the modules in the specified
+ * directory
+ */
+static init_module_fn *load_modules(TALLOC_CTX *mem_ctx, const char *path)
+{
+	DIR *dir;
+	struct dirent *entry;
+	char *filename;
+	int success = 0;
+	init_module_fn *ret = talloc_array(mem_ctx, init_module_fn, 2);
+
+	ret[0] = NULL;
+
+	dir = opendir(path);
+	if (dir == NULL) {
+		talloc_free(ret);
+		return NULL;
+	}
+
+	while((entry = readdir(dir))) {
+		if (ISDOT(entry->d_name) || ISDOTDOT(entry->d_name))
+			continue;
+
+		filename = talloc_asprintf(mem_ctx, "%s/%s", path, entry->d_name);
+
+		ret[success] = load_module(filename, true, NULL);
+		if (ret[success]) {
+			ret = talloc_realloc(mem_ctx, ret, init_module_fn, success+2);
+			success++;
+			ret[success] = NULL;
+		}
+
+		talloc_free(filename);
+	}
+
+	closedir(dir);
+
+	return ret;
+}
+
+/**
+ * Run the specified init functions.
+ *
+ * @return true if all functions ran successfully, false otherwise
+ */
+bool run_init_functions(init_module_fn *fns)
+{
+	int i;
+	bool ret = true;
+
+	if (fns == NULL)
+		return true;
+
+	for (i = 0; fns[i]; i++) { ret &= (bool)NT_STATUS_IS_OK(fns[i]()); }
+
+	return ret;
+}
+
+/**
+ * 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)
+{
+	char *path = modules_path(mem_ctx, subsystem);
+	init_module_fn *ret;
+
+	ret = load_modules(mem_ctx, path);
+
+	talloc_free(path);
+
+	return ret;
+}
+
+
+/* Load a dynamic module.  Only log a level 0 error if we are not checking
+   for the existence of a module (probling). */
+
+static NTSTATUS do_smb_load_module(const char *module_name, bool is_probe)
+{
+	void *handle;
+	init_module_fn init;
+	NTSTATUS status;
+
+	init = load_module(module_name, is_probe, &handle);
+	if (!init) {
+		return NT_STATUS_UNSUCCESSFUL;
+	}
+
+	DEBUG(2, ("Module '%s' loaded\n", module_name));
+
+	status = init();
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("Module '%s' initialization failed: %s\n",
+			    module_name, get_friendly_nt_error_msg(status)));
+		dlclose(handle);
+	}
+
+	return status;
+}
+
+/* Load all modules in list and return number of
+ * modules that has been successfully loaded */
+int smb_load_modules(const char **modules)
+{
+	int i;
+	int success = 0;
+
+	for(i = 0; modules[i]; i++){
+		if(NT_STATUS_IS_OK(do_smb_load_module(modules[i], false))) {
+			success++;
+		}
+	}
+
+	DEBUG(2, ("%d modules successfully loaded\n", success));
+
+	return success;
+}
+
+NTSTATUS smb_probe_module(const char *subsystem, const char *module)
+{
+	char *full_path = NULL;
+	TALLOC_CTX *ctx = talloc_stackframe();
+	NTSTATUS status;
+
+	/* Check for absolute path */
+
+	/* if we make any 'samba multibyte string'
+	   calls here, we break
+	   for loading string modules */
+
+	DEBUG(5, ("Probing module '%s'\n", module));
+
+	if (module[0] == '/') {
+		status = do_smb_load_module(module, true);
+		TALLOC_FREE(ctx);
+		return status;
+	}
+
+	full_path = talloc_asprintf(ctx,
+				    "%s/%s.%s",
+				    modules_path(ctx, subsystem),
+				    module,
+				    shlib_ext());
+	if (!full_path) {
+		TALLOC_FREE(ctx);
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	DEBUG(5, ("Probing module '%s': Trying to load from %s\n",
+		module, full_path));
+
+	status = do_smb_load_module(full_path, true);
+
+	TALLOC_FREE(ctx);
+	return status;
+}