lib: mgmtd: add xpath arg to notification message

Signed-off-by: Christian Hopps <[email protected]>

lib/mgmt_be_client.c

@@ -333,6 +333,8 @@ static int mgmt_be_send_notification(void *__be_client, const char *xpath,
 	msg->code = MGMT_MSG_CODE_NOTIFY;
 	msg->result_type = format;
 
+	mgmt_msg_native_xpath_encode(msg, xpath);
+
 	darrp = mgmt_msg_native_get_darrp(msg);
 	err = yang_print_tree_append(darrp, tree, format,
 				     (LYD_PRINT_SHRINK | LYD_PRINT_WD_EXPLICIT |
@@ -921,27 +923,40 @@ static void be_client_handle_notify(struct mgmt_be_client *client, void *msgbuf,
 {
 	struct mgmt_msg_notify_data *notif_msg = msgbuf;
 	struct nb_node *nb_node;
-	char notif[XPATH_MAXLEN];
 	struct lyd_node *dnode;
+	const char *data;
+	const char *notif;
 	LY_ERR err;
 
 	debug_be_client("Received notification for client %s", client->name);
 
-	err = yang_parse_notification(notif_msg->result_type,
-				      (char *)notif_msg->result, &dnode);
-	if (err)
+	notif = mgmt_msg_native_xpath_data_decode(notif_msg, msg_len, data);
+	if (!notif || !data) {
+		log_err_be_client("Corrupt notify msg");
 		return;
-
-	lysc_path(dnode->schema, LYSC_PATH_DATA, notif, sizeof(notif));
+	}
 
 	nb_node = nb_node_find(notif);
-	if (!nb_node || !nb_node->cbs.notify) {
-		debug_be_client("No notification callback for %s", notif);
-		goto cleanup;
+	if (!nb_node) {
+		log_err_be_client("No schema found for notification: %s", notif);
+		return;
+	}
+
+	if (!nb_node->cbs.notify) {
+		debug_be_client("No notification callback for: %s", notif);
+		return;
+	}
+
+	err = yang_parse_notification(notif, notif_msg->result_type, data,
+				      &dnode);
+	if (err) {
+		log_err_be_client("Can't parse notification data for: %s",
+				  notif);
+		return;
 	}
 
 	nb_callback_notify(nb_node, notif, dnode);
-cleanup:
+
 	lyd_free_all(dnode);
 }
 

lib/mgmt_fe_client.c

@@ -504,7 +504,8 @@ static void fe_client_handle_native_msg(struct mgmt_fe_client *client,
 	struct mgmt_msg_notify_data *notify_msg;
 	struct mgmt_msg_tree_data *tree_msg;
 	struct mgmt_msg_error *err_msg;
-	char *notify_data = NULL;
+	const char *data = NULL;
+	size_t dlen;
 
 	debug_fe_client("Got native message for session-id %" PRIu64,
 			msg->refer_id);
@@ -563,20 +564,17 @@ static void fe_client_handle_native_msg(struct mgmt_fe_client *client,
 			return;
 		}
 
-		if (notify_msg->result_type != LYD_LYB &&
-		    !MGMT_MSG_VALIDATE_NUL_TERM(notify_msg, msg_len)) {
+		data = mgmt_msg_native_data_decode(notify_msg, msg_len);
+		if (!data) {
 			log_err_fe_client("Corrupt error msg recv");
 			return;
 		}
-		if (notify_msg->result_type == LYD_JSON)
-			notify_data = (char *)notify_msg->result;
-		else
-			notify_data =
-				yang_convert_lyd_format(notify_msg->result,
-							msg_len,
-							notify_msg->result_type,
-							LYD_JSON, true);
-		if (!notify_data) {
+		dlen = mgmt_msg_native_data_len_decode(notify_msg, msg_len);
+		if (notify_msg->result_type != LYD_JSON)
+			data = yang_convert_lyd_format(data, dlen,
+						       notify_msg->result_type,
+						       LYD_JSON, true);
+		if (!data) {
 			log_err_fe_client("Can't convert format %d to JSON",
 					  notify_msg->result_type);
 			return;
@@ -588,11 +586,10 @@ static void fe_client_handle_native_msg(struct mgmt_fe_client *client,
 			session->client->cbs
 				.async_notification(client, client->user_data,
 						    session->client_id,
-						    session->user_ctx,
-						    notify_data);
+						    session->user_ctx, data);
 		}
 		if (notify_msg->result_type != LYD_JSON)
-			darr_free(notify_data);
+			darr_free(data);
 		break;
 	default:
 		log_err_fe_client("unknown native message session-id %" PRIu64

lib/mgmt_msg_native.h

@@ -77,6 +77,11 @@ extern "C" {
  * mgmt_msg_native_get_msg_len() - Get the total length of the msg.
  * mgmt_msg_native_send_msg() - Send the message.
  *
+ * mgmt_msg_native_xpath_encode() - Encode xpath in xpath, data format message.
+ * mgmt_msg_native_xpath_data_decode() - Decode xpath, data format message.
+ * mgmt_msg_native_xpath_decode() - Get the xpath, from xpath, data format message.
+ * mgmt_msg_native_data_decode() - Get the secondary data from xpath, data message.
+ * mgmt_msg_native_data_len_decode() - Get length of secondary data.
  *
  * -------------------------------------
  * [Advanced Use] Dynamic Array Messages
@@ -299,18 +304,18 @@ _Static_assert(sizeof(struct mgmt_msg_get_data) ==
  * struct mgmt_msg_notify_data - Message carrying notification data.
  *
  * @result_type: ``LYD_FORMAT`` for format of the @result value.
- * @result: The tree data in @result_type format.
- *
+ * @data: The xpath string of the notification followed by the tree data in
+ *        @result_type format.
  */
 struct mgmt_msg_notify_data {
 	struct mgmt_msg_header;
 	uint8_t result_type;
 	uint8_t resv2[7];
 
-	alignas(8) uint8_t result[];
+	alignas(8) char data[];
 };
 _Static_assert(sizeof(struct mgmt_msg_notify_data) ==
-		       offsetof(struct mgmt_msg_notify_data, result),
+		       offsetof(struct mgmt_msg_notify_data, data),
 	       "Size mismatch");
 
 /*
@@ -404,7 +409,12 @@ extern int vmgmt_msg_native_send_error(struct msg_conn *conn,
  * Return: a pointer to the newly appended data.
  */
 #define mgmt_msg_native_append(msg, data, len)                                 \
-	memcpy(darr_append(*mgmt_msg_native_get_darrp(msg), len), data, len)
+	({                                                                     \
+		uint8_t **darrp = mgmt_msg_native_get_darrp(msg);              \
+		uint8_t *p = darr_append_n(*darrp, len);                       \
+		memcpy(p, data, len);                                          \
+		p;                                                             \
+	})
 
 /**
  * mgmt_msg_native_send_msg(msg, short_circuit_ok) - Send a native msg.
@@ -458,6 +468,116 @@ extern int vmgmt_msg_native_send_error(struct msg_conn *conn,
  */
 #define mgmt_msg_native_get_darrp(msg) ((uint8_t **)&(msg))
 
+/* ------------------------- */
+/* Encode and Decode Helpers */
+/* ------------------------- */
+
+/**
+ * mgmt_msg_native_xpath_encode() - encode an xpath in a xpath, data message.
+ * @msg: Pointer to the native message.
+ * @xpath: The xpath string to encode.
+ *
+ * This function starts the encoding of a message that can be decoded with
+ * `mgmt_msg_native_xpath_data_decode()`. The variable length data is comprised
+ * of a NUL terminated string followed by some data of any format. This starts
+ * the first half of the encoding, after which one can simply append the
+ * secondary data to the message.
+ */
+#define mgmt_msg_native_xpath_encode(msg, xpath)                               \
+	do {                                                                   \
+		size_t __slen = strlen(xpath) + 1;                             \
+		mgmt_msg_native_append(msg, xpath, __slen);                    \
+		(msg)->vsplit = __slen;                                        \
+	} while (0)
+
+/**
+ * mgmt_msg_native_xpath_data_decode() - decode an xpath, data format message.
+ * @msg: Pointer to the native message.
+ * @msglen: Length of the message.
+ * @data: [OUT] Pointer to the data section of the variable data
+ *
+ * This function decodes a message that was encoded with
+ * `mgmt_msg_native_xpath_encode()`. The variable length data is comprised of a
+ * NUL terminated string followed by some data of any format.
+ *
+ * Return:
+ *	The xpath string or NULL if there was an error decoding (i.e., the
+ *	message is corrupt).
+ */
+#define mgmt_msg_native_xpath_data_decode(msg, msglen, data)                   \
+	({                                                                     \
+		size_t __len = (msglen) - sizeof(*msg);                        \
+		const char *__s = NULL;                                        \
+		if (msg->vsplit && msg->vsplit <= __len &&                     \
+		    msg->data[msg->vsplit - 1] == 0) {                         \
+			(data) = msg->data + msg->vsplit;                      \
+			__s = msg->data;                                       \
+		}                                                              \
+		__s;                                                           \
+	})
+
+/**
+ * mgmt_msg_native_xpath_decode() - return the xpath from xpath, data message.
+ * @msg: Pointer to the native message.
+ * @msglen: Length of the message.
+ *
+ * This function decodes the xpath from a message that was encoded with
+ * `mgmt_msg_native_xpath_encode()`. The variable length data is comprised of a
+ * NUL terminated string followed by some data of any format.
+ *
+ * Return:
+ *	The xpath string or NULL if there was an error decoding (i.e., the
+ *	message is corrupt).
+ */
+#define mgmt_msg_native_xpath_decode(msg, msglen)                              \
+	({                                                                     \
+		size_t __len = (msglen) - sizeof(*msg);                        \
+		const char *__s = msg->data;                                   \
+		if (!msg->vsplit || msg->vsplit > __len ||                     \
+		    __s[msg->vsplit - 1] != 0)                                 \
+			__s = NULL;                                            \
+		__s;                                                           \
+	})
+
+/**
+ * mgmt_msg_native_data_decode() - return the data from xpath, data message.
+ * @msg: Pointer to the native message.
+ * @msglen: Length of the message.
+ *
+ * This function decodes the secondary data from a message that was encoded with
+ * `mgmt_msg_native_xpath_encode()`. The variable length data is comprised of a
+ * NUL terminated string followed by some data of any format.
+ *
+ * Return:
+ *	The secondary data or NULL if there was an error decoding (i.e., the
+ *	message is corrupt).
+ */
+#define mgmt_msg_native_data_decode(msg, msglen)                               \
+	({                                                                     \
+		size_t __len = (msglen) - sizeof(*msg);                        \
+		const char *__data = msg->data + msg->vsplit;                  \
+		if (!msg->vsplit || msg->vsplit > __len || __data[-1] != 0)    \
+			__data = NULL;                                         \
+		__data;                                                        \
+	})
+
+/**
+ * mgmt_msg_native_data_len_decode() - len of data in xpath, data format message.
+ * @msg: Pointer to the native message.
+ * @msglen: Length of the message.
+ *
+ * This function returns the length of the secondary variable data from a
+ * message that was encoded with `mgmt_msg_native_xpath_encode()`. The variable
+ * length data is comprised of a NUL terminated string followed by some data of
+ * any format.
+ *
+ * Return:
+ *	The length of the secondary variable data. The message is assumed to be
+ *	validated as not corrupt already.
+ */
+#define mgmt_msg_native_data_len_decode(msg, msglen)                           \
+	((msglen) - sizeof(*msg) - msg->vsplit)
+
 #ifdef __cplusplus
 }
 #endif

lib/yang.c

@@ -714,12 +714,12 @@ static void ly_log_cb(LY_LOG_LEVEL level, const char *msg, const char *path)
 		zlog(priority, "libyang: %s", msg);
 }
 
-LY_ERR yang_parse_notification(LYD_FORMAT format, const char *data,
-			       struct lyd_node **notif)
+LY_ERR yang_parse_notification(const char *xpath, LYD_FORMAT format,
+			       const char *data, struct lyd_node **notif)
 {
-	struct lyd_node *tree, *dnode;
+	struct lyd_node *tree;
+	struct ly_set *set = NULL;
 	struct ly_in *in = NULL;
-	bool found = false;
 	LY_ERR err;
 
 	err = ly_in_new_memory(data, &in);
@@ -736,26 +736,20 @@ LY_ERR yang_parse_notification(LYD_FORMAT format, const char *data,
 		return err;
 	}
 
-	/*
-	 * Notification can be a child of some data node, so traverse the tree
-	 * until we find the notification.
-	 */
-	LYD_TREE_DFS_BEGIN (tree, dnode) {
-		if (dnode->schema->nodetype == LYS_NOTIF) {
-			found = true;
-			break;
-		}
-		LYD_TREE_DFS_END(tree, dnode);
+	err = lyd_find_xpath3(NULL, tree, xpath, NULL, &set);
+	if (err) {
+		zlog_err("Failed to parse notification: %s", ly_last_errmsg());
+		lyd_free_all(tree);
+		return err;
 	}
-
-	if (!found) {
-		zlog_err("Notification not found in the parsed tree");
+	if (set->count == 0) {
+		zlog_err("Notification not found in the parsed tree: %s", xpath);
+		ly_set_free(set, NULL);
 		lyd_free_all(tree);
 		return LY_ENOTFOUND;
 	}
-
-	*notif = dnode;
-
+	*notif = set->dnodes[0];
+	ly_set_free(set, NULL);
 	return LY_SUCCESS;
 }
 
@@ -790,9 +784,9 @@ uint8_t *yang_print_tree(const struct lyd_node *root, LYD_FORMAT format,
 	return darr;
 }
 
-char *yang_convert_lyd_format(const uint8_t *data, size_t data_len,
-				     LYD_FORMAT in_format,
-				     LYD_FORMAT out_format, bool shrink)
+char *yang_convert_lyd_format(const char *data, size_t data_len,
+			      LYD_FORMAT in_format, LYD_FORMAT out_format,
+			      bool shrink)
 {
 	struct lyd_node *tree = NULL;
 	uint32_t options = LYD_PRINT_WD_EXPLICIT | LYD_PRINT_WITHSIBLINGS;

lib/yang.h

@@ -611,15 +611,16 @@ extern void yang_debugging_set(bool enable);
  * Parse a YANG notification.
  *
  * Args:
+ *	xpath: xpath of notification.
  *	format: LYD_FORMAT of input data.
  *	data: input data.
  *	notif: pointer to the libyang data tree to store the parsed notification.
  *	       If the notification is not on the top level of the yang model,
  *	       the pointer to the notification node is still returned, but it's
  *	       part of the full data tree with all its parents.
  */
-extern LY_ERR yang_parse_notification(LYD_FORMAT format, const char *data,
-				      struct lyd_node **notif);
+extern LY_ERR yang_parse_notification(const char *xpath, LYD_FORMAT format,
+				      const char *data, struct lyd_node **notif);
 
 /*
  * "Print" the yang tree in `root` into dynamic sized array.
@@ -647,7 +648,7 @@ extern uint8_t *yang_print_tree(const struct lyd_node *root, LYD_FORMAT format,
  * Return:
  *	A darr based string or NULL for error.
  */
-extern char *yang_convert_lyd_format(const uint8_t *data, size_t msg_len,
+extern char *yang_convert_lyd_format(const char *data, size_t msg_len,
 				     LYD_FORMAT in_format,
 				     LYD_FORMAT out_format, bool shrink);