Add return values for most of the plugin function wrappers that returned void.

Previously, they would just exit if there was an error.
Now the error is passed back up the stack so we can use them in
sudo_intercept.so.

src/sudo.c

@@ -108,7 +108,7 @@ static void policy_open(struct sudo_settings *settings,
     char * const user_info[], char * const user_env[]);
 static void policy_close(int exit_status, int error);
 static int policy_show_version(int verbose);
-static void policy_check(int argc, char * const argv[], char *env_add[],
+static bool policy_check(int argc, char * const argv[], char *env_add[],
     char **command_info[], char **argv_out[], char **user_env_out[]);
 static void policy_list(int argc, char * const argv[],
     int verbose, const char *user, char * const envp[]);
@@ -116,7 +116,7 @@ static void policy_validate(char * const argv[], char * const envp[]);
 static void policy_invalidate(int unlinkit);
 
 /* I/O log plugin convenience functions. */
-static void iolog_open(struct sudo_settings *settings, char * const user_info[],
+static bool iolog_open(struct sudo_settings *settings, char * const user_info[],
     char * const command_details[], int argc, char * const argv[],
     char * const user_env[]);
 static void iolog_close(int exit_status, int error);
@@ -133,7 +133,7 @@ static void audit_close(int exit_status, int error);
 static void audit_show_version(int verbose);
 
 /* Approval plugin convenience functions. */
-static void approval_check(struct sudo_settings *settings,
+static bool approval_check(struct sudo_settings *settings,
     char * const user_info[], int submit_optind, char * const submit_argv[],
     char * const submit_envp[], char * const command_info[],
     char * const run_argv[], char * const run_envp[]);
@@ -263,8 +263,9 @@ main(int argc, char *argv[], char *envp[])
 	    break;
 	case MODE_EDIT:
 	case MODE_RUN:
-	    policy_check(nargc, nargv, env_add, &command_info, &argv_out,
-		&user_env_out);
+	    if (!policy_check(nargc, nargv, env_add, &command_info, &argv_out,
+		    &user_env_out))
+		goto access_denied;
 
 	    /* Reset nargv/nargc based on argv_out. */
 	    /* XXX - leaks old nargv in shell mode */
@@ -275,16 +276,19 @@ main(int argc, char *argv[], char *envp[])
 		    U_("plugin did not return a command to execute"));
 
 	    /* Approval plugins run after policy plugin accepts the command. */
-	    approval_check(settings, user_info, submit_optind, argv, envp,
-		command_info, nargv, user_env_out);
+	    if (!approval_check(settings, user_info, submit_optind, argv, envp,
+		    command_info, nargv, user_env_out))
+		goto access_denied;
 
 	    /* Open I/O plugin once policy and approval plugins succeed. */
-	    iolog_open(settings, user_info, command_info, nargc, nargv,
-		user_env_out);
+	    if (!iolog_open(settings, user_info, command_info, nargc, nargv,
+		    user_env_out))
+		goto access_denied;
 
 	    /* Audit the accept event on behalf of the sudo front-end. */
-	    audit_accept("sudo", SUDO_FRONT_END, command_info,
-		nargv, user_env_out);
+	    if (!audit_accept("sudo", SUDO_FRONT_END, command_info,
+		    nargv, user_env_out))
+		goto access_denied;
 
 	    /* Setup command details and run command/edit. */
 	    command_info_to_details(command_info, &command_details);
@@ -329,6 +333,15 @@ main(int argc, char *argv[], char *envp[])
     sudo_debug_exit_int(__func__, __FILE__, __LINE__, sudo_debug_subsys,
 	WEXITSTATUS(status));
     exit(WEXITSTATUS(status));
+
+access_denied:
+    /* Policy/approval failure, close policy and audit plugins before exit. */
+    if (policy_plugin.u.policy->version >= SUDO_API_MKVERSION(1, 15))
+	policy_close(0, EACCES);
+    audit_close(SUDO_PLUGIN_NO_STATUS, 0);
+    sudo_debug_exit_int(__func__, __FILE__, __LINE__, sudo_debug_subsys,
+	EXIT_FAILURE);
+    exit(EXIT_FAILURE);
 }
 
 int
@@ -1158,7 +1171,7 @@ policy_show_version(int verbose)
     debug_return_int(ret);
 }
 
-static void
+static bool
 policy_check(int argc, char * const argv[],
     char *env_add[], char **command_info[], char **argv_out[],
     char **user_env_out[])
@@ -1195,17 +1208,10 @@ policy_check(int argc, char * const argv[],
 	    usage();
 	    break;
 	}
-
-	/* Policy must be closed after auditing to avoid use after free. */
-	if (policy_plugin.u.policy->version >= SUDO_API_MKVERSION(1, 15))
-	    policy_close(0, 0);
-	audit_close(SUDO_PLUGIN_NO_STATUS, 0);
-	exit(EXIT_FAILURE); /* policy plugin printed error message */
+	debug_return_bool(false);
     }
-    audit_accept(policy_plugin.name, SUDO_POLICY_PLUGIN, *command_info,
-	*argv_out, *user_env_out);
-
-    debug_return;
+    debug_return_bool(audit_accept(policy_plugin.name, SUDO_POLICY_PLUGIN,
+	*command_info, *argv_out, *user_env_out));
 }
 
 static void
@@ -1411,7 +1417,7 @@ iolog_open_int(struct plugin_container *plugin, struct sudo_settings *settings,
     debug_return_int(ret);
 }
 
-static void
+static bool
 iolog_open(struct sudo_settings *settings, char * const user_info[],
     char * const command_info[], int argc, char * const argv[],
     char * const user_env[])
@@ -1420,7 +1426,6 @@ iolog_open(struct sudo_settings *settings, char * const user_info[],
     const char *errstr = NULL;
     debug_decl(iolog_open, SUDO_DEBUG_PCOMM);
 
-    /* XXX - iolog_open should audit errors */
     TAILQ_FOREACH_SAFE(plugin, &io_plugins, entries, next) {
 	int ok = iolog_open_int(plugin, settings, user_info,
 	    command_info, argc, argv, user_env, &errstr);
@@ -1429,20 +1434,22 @@ iolog_open(struct sudo_settings *settings, char * const user_info[],
 	    break;
 	case 0:
 	    /* I/O plugin asked to be disabled, remove and free. */
-	    /* XXX - audit */
 	    unlink_plugin(&io_plugins, plugin);
 	    break;
 	case -2:
 	    usage();
 	    break;
 	default:
-	    /* XXX - audit error */
-	    sudo_fatalx(U_("error initializing I/O plugin %s"),
+	    sudo_warnx(U_("error initializing I/O plugin %s"),
 		plugin->name);
+	    audit_error(plugin->name, SUDO_IO_PLUGIN,
+		errstr ? errstr : _("error initializing I/O plugin"),
+		command_info);
+	    debug_return_bool(false);
 	}
     }
 
-    debug_return;
+    debug_return_bool(true);
 }
 
 static void
@@ -1640,12 +1647,13 @@ audit_show_version(int verbose)
  * Error from plugin or front-end.
  * The error will not be sent to plugin source, if specified.
  */
-static void
+static bool
 audit_error2(struct plugin_container *source, const char *plugin_name,
     unsigned int plugin_type, const char *audit_msg, char * const command_info[])
 {
     struct plugin_container *plugin;
     const char *errstr = NULL;
+    bool ret = true;
     int ok;
     debug_decl(audit_error2, SUDO_DEBUG_PCOMM);
 
@@ -1671,10 +1679,11 @@ audit_error2(struct plugin_container *source, const char *plugin_name,
 		plugin->name, ok);
 	    sudo_warnx(U_("%s: unable to log error event%s%s"),
 		plugin->name, errstr ? ": " : "", errstr ? errstr : "");
+	    ret = false;
 	}
     }
 
-    debug_return;
+    debug_return_bool(ret);
 }
 
 /*
@@ -1682,7 +1691,7 @@ audit_error2(struct plugin_container *source, const char *plugin_name,
  * See command_info[] for additional info.
  * XXX - actual environment may be updated by policy_init_session().
  */
-void
+bool
 audit_accept(const char *plugin_name, unsigned int plugin_type,
     char * const command_info[], char * const run_argv[],
     char * const run_envp[])
@@ -1707,26 +1716,26 @@ audit_accept(const char *plugin_name, unsigned int plugin_type,
 	    sudo_warnx(U_("%s: unable to log accept event%s%s"),
 		plugin->name, errstr ? ": " : "", errstr ? errstr : "");
 
-	    /* Notify other audit plugins and exit. */
+	    /* Notify other audit plugins and return. */
 	    audit_error2(plugin, plugin->name, SUDO_AUDIT_PLUGIN,
 		errstr ? errstr : _("audit plugin error"), command_info);
-	    audit_close(SUDO_PLUGIN_NO_STATUS, 0);
-	    exit(EXIT_FAILURE);
+	    debug_return_bool(false);
 	}
     }
 
-    debug_return;
+    debug_return_bool(true);
 }
 
 /*
  * Command rejected by policy or I/O plugin.
  */
-void
+bool
 audit_reject(const char *plugin_name, unsigned int plugin_type,
     const char *audit_msg, char * const command_info[])
 {
     struct plugin_container *plugin;
     const char *errstr = NULL;
+    bool ret = true;
     int ok;
     debug_decl(audit_reject, SUDO_DEBUG_PCOMM);
 
@@ -1748,20 +1757,24 @@ audit_reject(const char *plugin_name, unsigned int plugin_type,
 	    /* Notify other audit plugins. */
 	    audit_error2(plugin, plugin->name, SUDO_AUDIT_PLUGIN,
 		errstr ? errstr : _("audit plugin error"), command_info);
+
+	    ret = false;
+	    break;
 	}
     }
 
-    debug_return;
+    debug_return_bool(ret);
 }
 
 /*
  * Error from plugin or front-end.
  */
-void
+bool
 audit_error(const char *plugin_name, unsigned int plugin_type,
     const char *audit_msg, char * const command_info[])
 {
-    audit_error2(NULL, plugin_name, plugin_type, audit_msg, command_info);
+    return audit_error2(NULL, plugin_name, plugin_type, audit_msg,
+	command_info);
 }
 
 static int
@@ -1843,7 +1856,7 @@ approval_show_version(int verbose, struct sudo_settings *settings,
  * This is a "one-shot" plugin that has no open/close and is only
  * called if the policy plugin accepts the command first.
  */
-static void
+static bool
 approval_check(struct sudo_settings *settings, char * const user_info[],
     int submit_optind, char * const submit_argv[], char * const submit_envp[],
     char * const command_info[], char * const run_argv[],
@@ -1880,8 +1893,9 @@ approval_check(struct sudo_settings *settings, char * const user_info[],
 		command_info);
 	    break;
 	case 1:
-	    audit_accept(plugin->name, SUDO_APPROVAL_PLUGIN, command_info,
-		run_argv, run_envp);
+	    if (!audit_accept(plugin->name, SUDO_APPROVAL_PLUGIN, command_info,
+		    run_argv, run_envp))
+		ok = -1;
 	    break;
 	case -1:
 	    audit_error(plugin->name, SUDO_APPROVAL_PLUGIN,
@@ -1900,16 +1914,11 @@ approval_check(struct sudo_settings *settings, char * const user_info[],
 	    sudo_debug_set_active_instance(sudo_debug_instance);
 	}
 
-	/* On error, close policy and audit plugins then exit. */
-	if (ok != 1) {
-	    if (policy_plugin.u.policy->version >= SUDO_API_MKVERSION(1, 15))
-		policy_close(0, EPERM);
-	    audit_close(SUDO_PLUGIN_NO_STATUS, 0);
-	    exit(EXIT_FAILURE); /* approval plugin printed error message */
-	}
+	if (ok != 1)
+	    debug_return_bool(false);
     }
 
-    debug_return;
+    debug_return_bool(true);
 }
 
 static void

src/sudo.h

@@ -223,12 +223,12 @@ int os_init_common(int argc, char *argv[], char *envp[]);
 bool gc_add(enum sudo_gc_types type, void *v);
 bool set_user_groups(struct command_details *details);
 struct sudo_plugin_event *sudo_plugin_event_alloc(void);
-void audit_accept(const char *plugin_name, unsigned int plugin_type,
+bool audit_accept(const char *plugin_name, unsigned int plugin_type,
     char * const command_info[], char * const run_argv[],
     char * const run_envp[]);
-void audit_reject(const char *plugin_name, unsigned int plugin_type,
+bool audit_reject(const char *plugin_name, unsigned int plugin_type,
     const char *audit_msg, char * const command_info[]);
-void audit_error(const char *plugin_name, unsigned int plugin_type,
+bool audit_error(const char *plugin_name, unsigned int plugin_type,
     const char *audit_msg, char * const command_info[]);
 extern const char *list_user;
 extern struct user_details user_details;