[client,common] add custom line parser option

freerdp_client_settings_parse_command_line_arguments_ex allows supplying
user defined options to be parsed with the default ones from
client/common.
A callback must be implemented to handle the supplied arguments.

client/common/cmdline.c

@@ -506,36 +506,53 @@ BOOL freerdp_client_print_command_line_help(int argc, char** argv)
 	return freerdp_client_print_command_line_help_ex(argc, argv, NULL);
 }
 
-BOOL freerdp_client_print_command_line_help_ex(int argc, char** argv,
+static COMMAND_LINE_ARGUMENT_A* create_merged_args(const COMMAND_LINE_ARGUMENT_A* custom,
-                                               const COMMAND_LINE_ARGUMENT_A* custom)
+                                                   SSIZE_T count, size_t* pcount)
 {
-	const char* name = "FreeRDP";
+	WINPR_ASSERT(pcount);
-
+	if (count < 0)
-	size_t count = 0;
+	{
 		const COMMAND_LINE_ARGUMENT_A* cur = custom;
+		count = 0;
 		while (cur && cur->Name)
 		{
 			count++;
 			cur++;
 		}
+	}
 
-	/* allocate a merged copy of implementation defined and default arguments */
 	COMMAND_LINE_ARGUMENT_A* largs =
 	    calloc(count + ARRAYSIZE(global_cmd_args), sizeof(COMMAND_LINE_ARGUMENT_A));
+	*pcount = 0;
 	if (!largs)
-		return FALSE;
+		NULL;
 
-	count = 0;
+	size_t lcount = 0;
-	cur = custom;
+	const COMMAND_LINE_ARGUMENT_A* cur = custom;
 	while (cur && cur->Name)
 	{
-		largs[count++] = *cur++;
+		largs[lcount++] = *cur++;
 	}
+
 	cur = global_cmd_args;
 	while (cur && cur->Name)
 	{
-		largs[count++] = *cur++;
+		largs[lcount++] = *cur++;
 	}
+	*pcount = lcount;
+	return largs;
+}
+
+BOOL freerdp_client_print_command_line_help_ex(int argc, char** argv,
+                                               const COMMAND_LINE_ARGUMENT_A* custom)
+{
+	const char* name = "FreeRDP";
+
+	/* allocate a merged copy of implementation defined and default arguments */
+	size_t lcount = 0;
+	COMMAND_LINE_ARGUMENT_A* largs = create_merged_args(custom, -1, &lcount);
+	if (!largs)
+		return FALSE;
 
 	if (argc > 0)
 		name = argv[0];
@@ -552,7 +569,8 @@ BOOL freerdp_client_print_command_line_help_ex(int argc, char** argv,
 	printf("    +toggle -toggle (enables or disables toggle, where '/' is a synonym of '+')\n");
 	printf("\n");
 
-	freerdp_client_print_command_line_args(largs, count);
+	freerdp_client_print_command_line_args(largs, lcount);
+	free(largs);
 
 	printf("\n");
 	printf("Examples:\n");
@@ -2773,8 +2791,10 @@ static void fill_credential_strings(COMMAND_LINE_ARGUMENT_A* args)
 	}
 }
 
-static int freerdp_client_settings_parse_command_line_arguments_int(rdpSettings* settings, int argc,
+static int freerdp_client_settings_parse_command_line_arguments_int(
-                                                                    char* argv[], BOOL allowUnknown)
+    rdpSettings* settings, int argc, char* argv[], BOOL allowUnknown,
+    COMMAND_LINE_ARGUMENT_A* largs, size_t count,
+    int (*handle_option)(const COMMAND_LINE_ARGUMENT* arg, void* custom), void* handle_userdata)
 {
 	char* user = NULL;
 	char* str;
@@ -2785,8 +2805,6 @@ static int freerdp_client_settings_parse_command_line_arguments_int(rdpSettings*
 	BOOL promptForPassword = FALSE;
 	BOOL compatibility = FALSE;
 	const COMMAND_LINE_ARGUMENT_A* arg;
-	COMMAND_LINE_ARGUMENT_A largs[ARRAYSIZE(global_cmd_args)];
-	memcpy(largs, global_cmd_args, sizeof(global_cmd_args));
 
 	/* Command line detection fails if only a .rdp or .msrcIncident file
 	 * is supplied. Check this case first, only then try to detect
@@ -4623,6 +4641,12 @@ static int freerdp_client_settings_parse_command_line_arguments_int(rdpSettings*
 		}
 		CommandLineSwitchDefault(arg)
 		{
+			if (handle_option)
+			{
+				const int rc = handle_option(arg, handle_userdata);
+				if (rc != 0)
+					return rc;
+			}
 		}
 		CommandLineSwitchEnd(arg)
 	} while ((arg = CommandLineFindNextArgumentA(arg)) != NULL);
@@ -4848,10 +4872,19 @@ cleanup:
 
 int freerdp_client_settings_parse_command_line_arguments(rdpSettings* settings, int oargc,
                                                          char* oargv[], BOOL allowUnknown)
+{
+	return freerdp_client_settings_parse_command_line_arguments_ex(
+	    settings, oargc, oargv, allowUnknown, NULL, 0, NULL, NULL);
+}
+
+int freerdp_client_settings_parse_command_line_arguments_ex(
+    rdpSettings* settings, int oargc, char** oargv, BOOL allowUnknown,
+    COMMAND_LINE_ARGUMENT_A* args, size_t count,
+    int (*handle_option)(const COMMAND_LINE_ARGUMENT* arg, void* custom), void* handle_userdata)
 {
 	int argc = oargc;
 	char** argv = oargv;
-
+	int res = -1;
 	int aargc = 0;
 	char** aargv = NULL;
 	if ((argc == 2) && option_starts_with("/args-from:", argv[1]))
@@ -4888,8 +4921,15 @@ int freerdp_client_settings_parse_command_line_arguments(rdpSettings* settings,
 		argv = aargv;
 	}
 
-	int res = freerdp_client_settings_parse_command_line_arguments_int(settings, argc, argv,
+	size_t lcount = 0;
-	                                                                   allowUnknown);
+	COMMAND_LINE_ARGUMENT_A* largs = create_merged_args(args, count, &lcount);
+	if (!largs)
+		goto fail;
+
+	res = freerdp_client_settings_parse_command_line_arguments_int(
+	    settings, argc, argv, allowUnknown, largs, lcount, handle_option, handle_userdata);
+fail:
+	free(largs);
 	argv_free(aargc, aargv);
 	return res;
 }

include/freerdp/client/cmdline.h

@@ -31,9 +31,39 @@ extern "C"
 {
 #endif
 
+	/** \brief parses command line arguments to appropriate settings values.
+	 *
+	 * \param settings The settings instance to store the parsed values to
+	 * \param argc the number of argv values
+	 * \param argv an array of strings (char pointer)
+	 * \param allowUnknown Allow unknown command line arguments or \b FALSE if not.
+	 *
+	 * \return \b 0 in case of success, a negative number in case of failure.
+	 */
 	FREERDP_API int freerdp_client_settings_parse_command_line_arguments(rdpSettings* settings,
 	                                                                     int argc, char** argv,
 	                                                                     BOOL allowUnknown);
+
+	/** \brief parses command line arguments to appropriate settings values. Additionally allows
+	 * supplying custom command line arguments and a handler function.
+	 *
+	 * \param settings The settings instance to store the parsed values to
+	 * \param argc the number of argv values
+	 * \param argv an array of strings (char pointer)
+	 * \param allowUnknown Allow unknown command line arguments or \b FALSE if not.
+	 * \param args Pointer to the custom arguments
+	 * \param count The number of custom arguments
+	 * \param handle_option the handler function for custom arguments.
+	 * \param handle_userdata custom data supplied to \b handle_option as context
+	 *
+	 * \return \b 0 in case of success, a negative number in case of failure.
+	 */
+	FREERDP_API int freerdp_client_settings_parse_command_line_arguments_ex(
+	    rdpSettings* settings, int argc, char** argv, BOOL allowUnknown,
+	    COMMAND_LINE_ARGUMENT_A* args, size_t count,
+	    int (*handle_option)(const COMMAND_LINE_ARGUMENT* arg, void* custom),
+	    void* handle_userdata);
+
 	FREERDP_API int freerdp_client_settings_command_line_status_print(rdpSettings* settings,
 	                                                                  int status, int argc,
 	                                                                  char** argv);