device_link_service: add new function device_link_service_receive_message

2 files changed, 58 insertions, 17 deletions

diff --git a/src/device_link_service.c b/src/device_link_service.c
index e9aa675..6083d80 100644
--- a/src/device_link_service.c
+++ b/src/device_link_service.c
@@ -25,44 +25,49 @@
 #include "debug.h"
 
 /**
- * Internally used function to extract the message string from a DLMessage*
+ * Internally used function to extract the message string from a DL* message
  * plist.
  *
  * @param dl_msg The DeviceLink property list to parse.
+ * @param message A pointer that will be set to a newly allocated char*
+ *     containing the DLMessage* string from the given plist. It is up to
+ *     the caller to free the allocated memory. If this parameter is NULL
+ *     it will be ignored.
  *
- * @return An allocated char* with the DLMessage from the given plist,
- *     or NULL when the plist does not contain any DLMessage. It is up to
- *     the caller to free the allocated memory.
+ * @return 1 if the given plist is a DL* message, or 0 if the plist does not
+ *     contain any DL* message.
  */
-static char *device_link_service_get_message(plist_t dl_msg)
+static int device_link_service_get_message(plist_t dl_msg, char **message)
 {
-        plist_t cmd = 0;
+        plist_t cmd = NULL;
         char *cmd_str = NULL;
 
         /* sanity check */
         if ((plist_get_node_type(dl_msg) != PLIST_ARRAY) || (plist_array_get_size(dl_msg) < 1)) {
-                return NULL;
+                return 0;
         }
 
         /* get dl command */
         cmd = plist_array_get_item(dl_msg, 0);
         if (!cmd || (plist_get_node_type(cmd) != PLIST_STRING)) {
-                return NULL;
+                return 0;
         }
 
         plist_get_string_val(cmd, &cmd_str);
         if (!cmd_str) {
-                return NULL;
+                return 0;
         }
 
-        if ((strlen(cmd_str) < (strlen("DLMessage")+1))
-            || (strncmp(cmd_str, "DLMessage", strlen("DLMessage")))) {
+        if ((strlen(cmd_str) < 9) || (strncmp(cmd_str, "DL", 2))) {
                 free(cmd_str);
-                return NULL;
+                return 0;
         }
 
-        /* we got a DLMessage* command */
-        return cmd_str;
+        if (message)
+                *message = cmd_str;
+
+        /* we got a DL* message */
+        return 1;
 }
 
 /**
@@ -153,7 +158,7 @@ device_link_service_error_t device_link_service_version_exchange(device_link_ser
                 err = DEVICE_LINK_SERVICE_E_MUX_ERROR;
                 goto leave;
         }
-        msg = device_link_service_get_message(array);
+        device_link_service_get_message(array, &msg);
         if (!msg || strcmp(msg, "DLMessageVersionExchange")) {
                 debug_info("Did not receive DLMessageVersionExchange from device!");
                 err = DEVICE_LINK_SERVICE_E_PLIST_ERROR;
@@ -208,7 +213,7 @@ device_link_service_error_t device_link_service_version_exchange(device_link_ser
                 err = DEVICE_LINK_SERVICE_E_MUX_ERROR;
                 goto leave;
         }
-        msg = device_link_service_get_message(array);
+        device_link_service_get_message(array, &msg);
         if (!msg || strcmp(msg, "DLMessageDeviceReady")) {
                 debug_info("Did not get DLMessageDeviceReady!");
                 err = DEVICE_LINK_SERVICE_E_PLIST_ERROR;
@@ -313,6 +318,40 @@ device_link_service_error_t device_link_service_send_process_message(device_link
 }
 
 /**
+ * Receives a DL* message plist
+ *
+ * @param client The connected device link service client used for receiving.
+ * @param msg_plist Pointer to a plist that will be set to the contents of the
+ *    message plist upon successful return.
+ * @param dlmessage A pointer that will be set to a newly allocated char*
+ *     containing the DL* string from the given plist. It is up to the caller
+ *     to free the allocated memory. If this parameter is NULL
+ *     it will be ignored.
+ *
+ * @return DEVICE_LINK_SERVICE_E_SUCCESS if a DL* message was received,
+ *    DEVICE_LINK_SERVICE_E_INVALID_ARG if client or message is invalid,
+ *    DEVICE_LINK_SERVICE_E_PLIST_ERROR if the received plist is invalid
+ *    or is not a DL* message plist, or DEVICE_LINK_SERVICE_E_MUX_ERROR if
+ *    receiving from the device failed.
+ */
+device_link_service_error_t device_link_service_receive_message(device_link_service_client_t client, plist_t *msg_plist, char **dlmessage)
+{
+        if (!client || !client->parent || !msg_plist)
+                return DEVICE_LINK_SERVICE_E_INVALID_ARG;
+
+        *msg_plist = NULL;
+        if (property_list_service_receive_plist(client->parent, msg_plist) != PROPERTY_LIST_SERVICE_E_SUCCESS) {
+                return DEVICE_LINK_SERVICE_E_MUX_ERROR;
+        }
+
+        if (!device_link_service_get_message(*msg_plist, dlmessage)) {
+                debug_info("Did not receive a DL* message as expected!");
+                return DEVICE_LINK_SERVICE_E_PLIST_ERROR;
+        }
+        return DEVICE_LINK_SERVICE_E_SUCCESS;
+}
+
+/**
  * Receives a DLMessageProcessMessage plist.
  *
  * @param client The connected device link service client used for receiving.
@@ -337,7 +376,8 @@ device_link_service_error_t device_link_service_receive_process_message(device_l
 
         device_link_service_error_t err = DEVICE_LINK_SERVICE_E_UNKNOWN_ERROR;
 
-        char *msg = device_link_service_get_message(pmsg);
+        char *msg = NULL;
+        device_link_service_get_message(pmsg, &msg);
         if (!msg || strcmp(msg, "DLMessageProcessMessage")) {
                 debug_info("Did not receive DLMessageProcessMessage as expected!");
                 err = DEVICE_LINK_SERVICE_E_PLIST_ERROR;
diff --git a/src/device_link_service.h b/src/device_link_service.h
index 8b58ccf..9953f77 100644
--- a/src/device_link_service.h
+++ b/src/device_link_service.h
@@ -45,6 +45,7 @@ device_link_service_error_t device_link_service_client_new(idevice_t device, uin
 device_link_service_error_t device_link_service_client_free(device_link_service_client_t client);
 device_link_service_error_t device_link_service_version_exchange(device_link_service_client_t client, uint64_t version_major, uint64_t version_minor);
 device_link_service_error_t device_link_service_send_ping(device_link_service_client_t client, const char *message);
+device_link_service_error_t device_link_service_receive_message(device_link_service_client_t client, plist_t *msg_plist, char **dlmessage);
 device_link_service_error_t device_link_service_send_process_message(device_link_service_client_t client, plist_t message);
 device_link_service_error_t device_link_service_receive_process_message(device_link_service_client_t client, plist_t *message);
 device_link_service_error_t device_link_service_disconnect(device_link_service_client_t client);