Load plugins after parsing arguments and potentially printing the

version.  That way, an error loading or initializing a plugin doesn't
break "sudo -h" or "sudo -V".

src/load_plugins.c

@@ -131,7 +131,7 @@ done:
 /*
  * Load the plugins listed in conf_file.
  */
-void
+int
 sudo_load_plugins(const char *conf_file,
     struct plugin_container *policy_plugin,
     struct plugin_container_list *io_plugins)
@@ -143,47 +143,65 @@ sudo_load_plugins(const char *conf_file,
     struct stat sb;
     void *handle;
     char path[PATH_MAX];
+    int rval = FALSE;
 
     /* Parse sudo.conf */
     plugin_list = sudo_read_conf(conf_file);
 
     tq_foreach_fwd(plugin_list, info) {
 	if (info->path[0] == '/') {
-	    if (strlcpy(path, info->path, sizeof(path)) >= sizeof(path))
+	    if (strlcpy(path, info->path, sizeof(path)) >= sizeof(path)) {
-		errorx(1, "%s: %s", info->path, strerror(ENAMETOOLONG));
+		warningx("%s: %s", info->path, strerror(ENAMETOOLONG));
+		goto done;
+	    }
 	} else {
 	    if (snprintf(path, sizeof(path), "%s%s", _PATH_SUDO_PLUGIN_DIR,
 		info->path) >= sizeof(path)) {
-		errorx(1, "%s%s: %s", _PATH_SUDO_PLUGIN_DIR, info->path,
+		warningx("%s%s: %s", _PATH_SUDO_PLUGIN_DIR, info->path,
 		    strerror(ENAMETOOLONG));
+		goto done;
 	    }
 	}
-	if (stat(path, &sb) != 0)
+	if (stat(path, &sb) != 0) {
-	    error(1, "%s", path);
+	    warning("%s", path);
-	if (sb.st_uid != ROOT_UID)
+	    goto done;
-	    errorx(1, "%s must be owned by uid %d", path, ROOT_UID);
+	}
-	if ((sb.st_mode & (S_IWGRP|S_IWOTH)) != 0)
+	if (sb.st_uid != ROOT_UID) {
-	    errorx(1, "%s must be only be writable by owner", path);
+	    warningx("%s must be owned by uid %d", path, ROOT_UID);
+	    goto done;
+	}
+	if ((sb.st_mode & (S_IWGRP|S_IWOTH)) != 0) {
+	    warningx("%s must be only be writable by owner", path);
+	    goto done;
+	}
 
 	/* Open plugin and map in symbol */
 	handle = dlopen(path, RTLD_LAZY|RTLD_LOCAL);
-	if (!handle)
+	if (!handle) {
-	    errorx(1, "unable to dlopen %s: %s", path, dlerror());
+	    warningx("unable to dlopen %s: %s", path, dlerror());
+	    goto done;
+	}
 	plugin = dlsym(handle, info->symbol_name);
-	if (!plugin)
+	if (!plugin) {
-	    errorx(1, "unable to find symbol %s in %s", info->symbol_name, path);
+	    warningx("unable to find symbol %s in %s", info->symbol_name, path);
+	    goto done;
+	}
 
 	if (plugin->type != SUDO_POLICY_PLUGIN && plugin->type != SUDO_IO_PLUGIN) {
-	    errorx(1, "%s: unknown policy type %d", path, plugin->type);
+	    warningx("%s: unknown policy type %d", path, plugin->type);
+	    goto done;
 	}
 	if (SUDO_API_VERSION_GET_MAJOR(plugin->version) != SUDO_API_VERSION_MAJOR) {
-	    errorx(1, "%s: incompatible policy major version %d, expected %d",
+	    warningx("%s: incompatible policy major version %d, expected %d",
 		path, SUDO_API_VERSION_GET_MAJOR(plugin->version),
 		SUDO_API_VERSION_MAJOR);
+	    goto done;
 	}
 	if (plugin->type == SUDO_POLICY_PLUGIN) {
-	    if (policy_plugin->handle)
+	    if (policy_plugin->handle) {
-		errorx(1, "only a single policy plugin may be loaded");
+		warningx("only a single policy plugin may be loaded");
+		goto done;
+	    }
 	    policy_plugin->handle = handle;
 	    policy_plugin->name = info->symbol_name;
 	    policy_plugin->u.generic = plugin;
@@ -197,8 +215,18 @@ sudo_load_plugins(const char *conf_file,
 	    tq_append(io_plugins, container);
 	}
     }
-    if (policy_plugin->handle == NULL)
+    if (policy_plugin->handle == NULL) {
-	errorx(1, "%s: at least one policy plugin must be specified", conf_file);
+	warningx("%s: at least one policy plugin must be specified", conf_file);
-    if (policy_plugin->u.policy->check_policy == NULL)
+	goto done;
-	errorx(1, "policy plugin %s does not include a check_policy method");
+    }
+    if (policy_plugin->u.policy->check_policy == NULL) {
+	warningx("policy plugin %s does not include a check_policy method",
+	    policy_plugin->name);
+	goto done;
+    }
+
+    rval = TRUE;
+
+done:
+    return rval;
 }

src/sudo.c

@@ -199,20 +199,21 @@ main(int argc, char *argv[], char *envp[])
     memset(&user_details, 0, sizeof(user_details));
     user_info = get_user_info(&user_details);
 
-    /* Read sudo.conf and load plugins. */
-    sudo_load_plugins(_PATH_SUDO_CONF, &policy_plugin, &io_plugins);
-
     /* Parse command line arguments. */
     sudo_mode = parse_args(argc, argv, &nargc, &nargv, &settings, &env_add);
     sudo_debug(9, "sudo_mode %d", sudo_mode);
 
-    /* Print sudo version early, in case policy plugin init fails. */
+    /* Print sudo version early, in case of plugin init failure. */
     if (ISSET(sudo_mode, MODE_VERSION)) {
 	printf("Sudo version %s\n", PACKAGE_VERSION);
 	if (user_details.uid == ROOT_UID)
 	    (void) printf("Configure args: %s\n", CONFIGURE_ARGS);
     }
 
+    /* Read sudo.conf and load plugins. */
+    if (!sudo_load_plugins(_PATH_SUDO_CONF, &policy_plugin, &io_plugins))
+	errorx(1, "fatal error, unable to load plugins");
+
     /* Open policy plugin. */
     ok = policy_open(&policy_plugin, settings, user_info, envp);
     if (ok != TRUE) {

src/sudo_plugin_int.h

@@ -78,7 +78,7 @@ int sudo_conversation(int num_msgs, const struct sudo_conv_message msgs[],
     struct sudo_conv_reply replies[]);
 int _sudo_printf(int msg_type, const char *fmt, ...);
 
-void sudo_load_plugins(const char *conf_file,
+int sudo_load_plugins(const char *conf_file,
     struct plugin_container *policy_plugin,
     struct plugin_container_list *io_plugins);