[tor-commits] [tor/master] Write a new set of config validation callbacks.
nickm at torproject.org
nickm at torproject.org
Fri Oct 25 12:15:41 UTC 2019
commit e0ae137df5ca4849e98cc957fc3081cc3f203d70
Author: Nick Mathewson <nickm at torproject.org>
Date: Wed Oct 23 16:00:25 2019 -0400
Write a new set of config validation callbacks.
Unlike legacy_validate_fn_t, these callbacks have separation of
duties, into:
* early normalization and computation.
* validation
* transition checking
* late normalization and computation
Only the first and last steps get mutable objects. Only the
transition-checking step gets to see the previous values of this
object.
---
src/app/config/config.c | 4 ++-
src/lib/confmgt/confparse.c | 46 ++++++++++++++++++------
src/lib/confmgt/confparse.h | 86 +++++++++++++++++++++++++++++++++++++--------
3 files changed, 110 insertions(+), 26 deletions(-)
diff --git a/src/app/config/config.c b/src/app/config/config.c
index b372791a4..deed98d1a 100644
--- a/src/app/config/config.c
+++ b/src/app/config/config.c
@@ -3252,7 +3252,9 @@ STATIC int
options_validate(const or_options_t *old_options, or_options_t *options,
char **msg)
{
- return config_validate(get_options_mgr(), old_options, options, msg);
+ validation_status_t vs;
+ vs = config_validate(get_options_mgr(), old_options, options, msg);
+ return vs < 0 ? -1 : 0;
}
#define REJECT(arg) \
diff --git a/src/lib/confmgt/confparse.c b/src/lib/confmgt/confparse.c
index f1bec76c0..655fc3483 100644
--- a/src/lib/confmgt/confparse.c
+++ b/src/lib/confmgt/confparse.c
@@ -1148,10 +1148,11 @@ config_init(const config_mgr_t *mgr, void *options)
* in order to set ancillary data. If `old_options` is provided, make sure
* that the transition from `old_options` to `options` is permitted.
*
- * On success return 0; on failure set *msg_out to a newly allocated string
- * explaining what is wrong, and return -1.
+ * On success return VSTAT_OK; on failure set *msg_out to a newly allocated
+ * string explaining what is wrong, and return a different validation_status_t
+ * to describe which step failed.
**/
-static int
+static validation_status_t
config_validate_single(const config_format_t *fmt,
const void *old_options, void *options,
char **msg_out)
@@ -1159,13 +1160,37 @@ config_validate_single(const config_format_t *fmt,
tor_assert(fmt);
tor_assert(options);
+ if (fmt->pre_normalize_fn) {
+ if (fmt->pre_normalize_fn(options, msg_out) < 0) {
+ return VSTAT_PRE_NORMALIZE_ERR;
+ }
+ }
+
if (fmt->legacy_validate_fn) {
if (fmt->legacy_validate_fn(old_options, options, msg_out) < 0) {
- return -1;
+ return VSTAT_LEGACY_ERR;
}
}
- return 0;
+ if (fmt->validate_fn) {
+ if (fmt->validate_fn(options, msg_out) < 0) {
+ return VSTAT_VALIDATE_ERR;
+ }
+ }
+
+ if (fmt->check_transition_fn && old_options) {
+ if (fmt->check_transition_fn(old_options, options, msg_out) < 0) {
+ return VSTAT_TRANSITION_ERR;
+ }
+ }
+
+ if (fmt->post_normalize_fn) {
+ if (fmt->post_normalize_fn(options, msg_out) < 0) {
+ return VSTAT_POST_NORMALIZE_ERR;
+ }
+ }
+
+ return VSTAT_OK;
}
/**
@@ -1174,15 +1199,16 @@ config_validate_single(const config_format_t *fmt,
* set ancillary data. If `old_options` is provided, make sure that the
* transition from `old_options` to `options` is permitted.
*
- * On success return 0; on failure set *msg_out to a newly allocated string
- * explaining what is wrong, and return -1.
+ * On success return VSTAT_OK; on failure set *msg_out to a newly allocated
+ * string explaining what is wrong, and return a different validation_status_t
+ * to describe which step failed.
**/
-int
+validation_status_t
config_validate(const config_mgr_t *mgr,
const void *old_options, void *options,
char **msg_out)
{
- int rv;
+ validation_status_t rv;
CONFIG_CHECK(mgr, options);
if (old_options) {
CONFIG_CHECK(mgr, old_options);
@@ -1212,7 +1238,7 @@ config_validate(const config_mgr_t *mgr,
if (rv < 0)
return rv;
- return 0;
+ return VSTAT_OK;
}
/** Allocate and return a new string holding the written-out values of the vars
diff --git a/src/lib/confmgt/confparse.h b/src/lib/confmgt/confparse.h
index fea80f916..7829f1aeb 100644
--- a/src/lib/confmgt/confparse.h
+++ b/src/lib/confmgt/confparse.h
@@ -52,25 +52,59 @@ typedef struct config_deprecation_t {
#define PLURAL(tok) { #tok, #tok "s", 0, 0 }
/**
- * Type of a callback to validate whether a given configuration is
+ * Validation function: verify whether a configuation object is well-formed
+ * and consistent.
+ *
+ * On success, return 0. On failure, set <b>msg_out</b> to a newly allocated
+ * string containing an error message, and return -1. */
+typedef int (*validate_fn_t)(const void *value, char **msg_out);
+/**
+ * Validation function: verify whether a configuration object (`value`) is an
+ * allowable value given the previous configuration value (`old_value`).
+ *
+ * On success, return 0. On failure, set <b>msg_out</b> to a newly allocated
+ * string containing an error message, and return -1. */
+typedef int (*check_transition_fn_t)(const void *old_value, const void *value,
+ char **msg_out);
+/**
+ * Validation function: normalize members of `value`, and compute derived
+ * members.
+ *
+ * This function is called before any other validation of `value`, and must
+ * not assume that validate_fn or check_transition_fn has passed.
+ *
+ * On success, return 0. On failure, set <b>msg_out</b> to a newly allocated
+ * string containing an error message, and return -1. */
+typedef int (*pre_normalize_fn_t)(void *value, char **msg_out);
+/**
+ * Validation function: normalize members of `value`, and compute derived
+ * members.
+ *
+ * This function is called after validation of `value`, and may
+ * assume that validate_fn or check_transition_fn has passed.
+ *
+ * On success, return 0. On failure, set <b>msg_out</b> to a newly allocated
+ * string containing an error message, and return -1. */
+typedef int (*post_normalize_fn_t)(void *value, char **msg_out);
+
+/**
+ * Legacy function to validate whether a given configuration is
* well-formed and consistent.
*
* The configuration to validate is passed as <b>newval</b>. The previous
- * configuration, if any, is provided in <b>oldval</b>. The
- * <b>default_val</b> argument receives a configuration object initialized
- * with default values for all its fields. The <b>from_setconf</b> argument
- * is true iff the input comes from a SETCONF controller command.
+ * configuration, if any, is provided in <b>oldval</b>.
+ *
+ * This API is deprecated, since it mixes the responsibilities of
+ * pre_normalize_fn_t, post_normalize_fn_t, validate_fn_t, and
+ * check_transition_fn_t. No new instances of this function type should
+ * be written.
*
* On success, return 0. On failure, set *<b>msg_out</b> to a newly allocated
* error message, and return -1.
- *
- * REFACTORING NOTE: Currently, this callback type is only used from inside
- * config_dump(); later in our refactoring, it will be cleaned up and used
- * more generally.
*/
typedef int (*legacy_validate_fn_t)(const void *oldval,
- void *newval,
- char **msg_out);
+ void *newval,
+ char **msg_out);
struct config_mgr_t;
@@ -98,7 +132,18 @@ typedef struct config_format_t {
const config_var_t *vars; /**< List of variables we recognize, their default
* values, and where we stick them in the
* structure. */
- legacy_validate_fn_t legacy_validate_fn; /**< Function to validate config. */
+
+ /** Early-stage normalization callback. Invoked by config_validate(). */
+ pre_normalize_fn_t pre_normalize_fn;
+ /** Configuration validation function. Invoked by config_validate(). */
+ validate_fn_t validate_fn;
+ /** Legacy validation function. Invoked by config_validate(). */
+ legacy_validate_fn_t legacy_validate_fn;
+ /** Transition checking function. Invoked by config_validate(). */
+ check_transition_fn_t check_transition_fn;
+ /** Late-stage normalization callback. Invoked by config_validate(). */
+ post_normalize_fn_t post_normalize_fn;
+
clear_cfg_fn_t clear_fn; /**< Function to clear the configuration. */
/** If present, extra denotes a LINELIST variable for unrecognized
* lines. Otherwise, unrecognized lines are an error. */
@@ -169,9 +214,20 @@ int config_is_same(const config_mgr_t *fmt,
struct config_line_t *config_get_changes(const config_mgr_t *mgr,
const void *options1, const void *options2);
void config_init(const config_mgr_t *mgr, void *options);
-int config_validate(const config_mgr_t *mgr,
- const void *old_options, void *options,
- char **msg_out);
+
+/** An enumeration to report which validation step failed. */
+typedef enum {
+ VSTAT_PRE_NORMALIZE_ERR = -5,
+ VSTAT_VALIDATE_ERR = -4,
+ VSTAT_LEGACY_ERR = -3,
+ VSTAT_TRANSITION_ERR = -2,
+ VSTAT_POST_NORMALIZE_ERR = -1,
+ VSTAT_OK = 0,
+} validation_status_t;
+
+validation_status_t config_validate(const config_mgr_t *mgr,
+ const void *old_options, void *options,
+ char **msg_out);
void *config_dup(const config_mgr_t *mgr, const void *old);
char *config_dump(const config_mgr_t *mgr, const void *default_options,
const void *options, int minimal,
More information about the tor-commits
mailing list