vici: Add a callback based recursive parser function

src/libcharon/plugins/vici/libvici.c

@@ -94,6 +94,8 @@ struct vici_res_t {
 	char *name;
 	/** currently enumerating value */
 	chunk_t value;
+	/** section nesting level of callback parser */
+	int level;
 };
 
 /**
@@ -495,6 +497,7 @@ void* vici_parse_value(vici_res_t *res, int *len)
 			*len = res->value.len;
 			return res->value.ptr;
 		default:
+			*len = 0;
 			errno = EINVAL;
 			return NULL;
 	}
@@ -522,6 +525,98 @@ char* vici_parse_value_str(vici_res_t *res)
 	}
 }
 
+int vici_parse_cb(vici_res_t *res, vici_parse_section_cb_t section,
+				  vici_parse_value_cb_t kv, vici_parse_value_cb_t li,
+				  void *user)
+{
+	char *name, *list = NULL;
+	void *value;
+	int base, len, ret;
+
+	base = res->level;
+
+	while (TRUE)
+	{
+		switch (vici_parse(res))
+		{
+			case VICI_PARSE_KEY_VALUE:
+				if (res->level == base)
+				{
+					if (kv)
+					{
+						name = vici_parse_name(res);
+						value = vici_parse_value(res, &len);
+						if (name && value)
+						{
+							ret = kv(user, res, name, value, len);
+							if (ret)
+							{
+								return ret;
+							}
+						}
+					}
+				}
+				break;
+			case VICI_PARSE_BEGIN_SECTION:
+				if (res->level++ == base)
+				{
+					if (section)
+					{
+						name = vici_parse_name(res);
+						if (name)
+						{
+							ret = section(user, res, name);
+							if (ret)
+							{
+								return ret;
+							}
+						}
+					}
+				}
+				break;
+			case VICI_PARSE_END_SECTION:
+				if (res->level-- == base)
+				{
+					return 0;
+				}
+				break;
+			case VICI_PARSE_END:
+				res->level = 0;
+				return 0;
+			case VICI_PARSE_BEGIN_LIST:
+				if (res->level == base)
+				{
+					list = vici_parse_name(res);
+				}
+				break;
+			case VICI_PARSE_LIST_ITEM:
+				if (list && li)
+				{
+					value = vici_parse_value(res, &len);
+					if (value)
+					{
+						ret = li(user, res, list, value, len);
+						if (ret)
+						{
+							return ret;
+						}
+					}
+				}
+				break;
+			case VICI_PARSE_END_LIST:
+				if (res->level == base)
+				{
+					list = NULL;
+				}
+				break;
+			case VICI_PARSE_ERROR:
+				res->level = 0;
+				errno = EBADMSG;
+				return 1;
+		}
+	}
+}
+
 void* vici_find(vici_res_t *res, int *len, char *fmt, ...)
 {
 	va_list args;

src/libcharon/plugins/vici/libvici.h

@@ -123,6 +123,29 @@ typedef enum {
  */
 typedef void (*vici_event_cb_t)(void *user, char *name, vici_res_t *msg);
 
+/**
+ * Callback function for key/value and list items, invoked by vici_parse_cb().
+ *
+ * @param user		user data, as passed to vici_parse_cb()
+ * @param res		message currently parsing
+ * @param name		name of key or list
+ * @param value		value buffer
+ * @param len		length of value buffer
+ * @return			0 if parsed successfully
+ */
+typedef int	(*vici_parse_value_cb_t)(void *user, vici_res_t *res, char *name,
+									 void *value, int len);
+
+/**
+ * Callback function for sections, invoked by vici_parse_cb().
+ *
+ * @param user		user data, as passed to vici_parse_cb()
+ * @param res		message currently parsing
+ * @param name		name of the section
+ * @return			0 if parsed successfully
+ */
+typedef int (*vici_parse_section_cb_t)(void *user, vici_res_t *res, char *name);
+
 /**
  * Open a new vici connection.
  *
@@ -309,6 +332,24 @@ void* vici_parse_value(vici_res_t *res, int *len);
 char* vici_parse_value_str(vici_res_t *res);
 
 /**
+ * Parse a complete message with callbacks.
+ *
+ * Any of the callbacks may be NULL to skip this kind of item. Callbacks are
+ * invoked for the current section level only. To descent into sections, call
+ * vici_parse_cb() from within a section callback.
+ *
+ * @param res		message to parse
+ * @param section	callback invoked for each section
+ * @param kv		callback invoked for key/value pairs
+ * @param li		callback invoked for list items
+ * @param user		user data to pass to callbacks
+ * @return			0 if parsing successful
+ */
+int vici_parse_cb(vici_res_t *res, vici_parse_section_cb_t section,
+				  vici_parse_value_cb_t kv, vici_parse_value_cb_t li,
+				  void *user);
+
+/*
  * Find a blob value in a message for a given key.
  *
  * Sections can be selected by prefixing them separated by dots.