Refactoring validity check and prefix processing of dialed number

Command line help shows how many digits and what prefixes can be dialed.

Giving a station ID via command line will be checked for being valid.

The number to call the mobile statione will be checked for being valid.

Prefixes that are defined for a nework will be removed from station ID
automatically.

Multiple station ID lengths are supported:
 * C-Netz: 7 or 8 digits, depending on area code length
 * A-Netz: 5 or 7 digits; number is truncated to last 5 digits.
 * IMTS/MTS: 5 or 7 digits, depending on phone's selector switch.

src/cnetz/cnetz.c

@@ -178,6 +178,28 @@ double cnetz_kanal2freq(int kanal, int unterband)
 	return freq * 1e6;
 }
 
+/* check if number is a valid station ID */
+const char *cnetz_number_valid(const char *number)
+{
+	/* assume that the number has valid length(s) and digits */
+
+	if (number[0] > '7')
+		return "Digit 1 (mobile country code) exceeds 7.";
+	if (number[7]) {
+		if ((number[1] - '0') == 0)
+			return "Digit 2 and 3 (mobile network code) of 8-digit number must be at least 10.";
+		if ((number[1] - '0') * 10 + (number[2] - '0') > 31)
+			return "Digit 2 and 3 (mobile network code) of 8-digit number exceed 31.";
+		if (atoi(number + 3) > 65535)
+			return "Digit 4 to 8 (mobile subscriber suffix) of 8-digit number exceed 65535.";
+	} else {
+		if (atoi(number + 2) > 65535)
+			return "Digit 3 to 7 (mobile subscriber suffix) of 7-digit number exceed 65535.";
+	}
+
+	return NULL;
+}
+
 /* convert power level to P-bits by selecting next higher level */
 static uint8_t cnetz_power2bits(int power)
 {
@@ -571,39 +593,15 @@ int call_down_setup(int callref, const char __attribute__((unused)) *caller_id,
 	uint8_t futln_nat;
 	uint8_t futln_fuvst;
 	int futln_rest; /* use int for checking size > 65535 */
-	int len;
-	int i;
-
-	/* 1. check if number is invalid, return INVALNUMBER */
-	len = strlen(dialing);
-	if (len >= 11 && !strncmp(dialing, "0161", 4)) {
-		dialing += 4;
-		len -= 4;
-	}
-	if (len < 7 || len > 8) {
-inval:
-		PDEBUG(DCNETZ, DEBUG_NOTICE, "Outgoing call to invalid number '%s', rejecting!\n", dialing);
-		return -CAUSE_INVALNUMBER;
-	}
-	for (i = 0; i < len; i++) {
-		if (dialing[i] < '0' || dialing[i] > '9')
-			goto inval;
-	}
 
+	/* 1. split number into elements */
 	futln_nat = dialing[0] - '0';
-	if (len == 7)
-		futln_fuvst = dialing[1] - '0';
-	else {
+	if (dialing[7]) {
 		futln_fuvst = (dialing[1] - '0') * 10 + (dialing[2] - '0');
-		if (futln_fuvst > 31) {
-			PDEBUG(DCNETZ, DEBUG_NOTICE, "Digit 2 and 3 '%02d' must not exceed '31', but they do!\n", futln_fuvst);
-			goto inval;
-		}
-	}
-	futln_rest = atoi(dialing + len - 5);
-	if (futln_rest > 65535) {
-		PDEBUG(DCNETZ, DEBUG_NOTICE, "Last 5 digits '%05d' must not exceed '65535', but they do!\n", futln_rest);
-		goto inval;
+		futln_rest = atoi(dialing + 3);
+	} else {
+		futln_fuvst = dialing[1] - '0';
+		futln_rest = atoi(dialing + 2);
 	}
 
 	/* 2. check if the subscriber is attached */

src/cnetz/cnetz.h

@@ -133,6 +133,7 @@ struct cnetz {
 	transaction_t		*trans_list;		/* list of transactions */
 };
 
+const char *cnetz_number_valid(const char *number);
 double cnetz_kanal2freq(int kanal, int unterband);
 void cnetz_channel_list(void);
 int cnetz_channel_by_short_name(const char *short_name);

src/cnetz/main.c

@@ -226,8 +226,7 @@ void print_help(const char *arg0)
 	printf("        requires a DC coupled signal, which is produced by SDR.\n");
 	printf("        Use 'auto' to select 'slope' for sound card input and 'level' for SDR\n");
 	printf("        input. (default = '%s')\n", (demod == FSK_DEMOD_LEVEL) ? "level" : (demod == FSK_DEMOD_SLOPE) ? "slope" : "auto");
-	printf("\nstation-id: Give 7 digit station-id, you don't need to enter it for every\n");
-	printf("        start of this program.\n");
+	main_mobile_print_station_id();
 	main_mobile_print_hotkeys();
 	printf("Press 'i' key to dump list of currently attached subscribers.\n");
 }
@@ -458,10 +457,24 @@ error_fuz:
 	return 1;
 }
 
+static const struct number_lengths number_lengths[] = {
+	{ 7, "regular number format" },
+	{ 8, "extended number format" },
+	{ 0, NULL }
+};
+
+static const char *number_prefixes[] = {
+	"0161xxxxxxx",
+	"0161xxxxxxxx",
+	"+49161xxxxxxx",
+	"+49161xxxxxxxx",
+	NULL
+};
+
 int main(int argc, char *argv[])
 {
 	int rc, argi;
-	const char *station_id = "";
+	const char *station_id = NULL;
 	int mandatory = 0;
 	int polarity;
 	int teilnehmergruppensperre = 0;
@@ -475,7 +488,7 @@ int main(int argc, char *argv[])
 
 	init_station();
 
-	main_mobile_init();
+	main_mobile_init("0123456789", number_lengths, number_prefixes, cnetz_number_valid);
 
 	/* handle options / config file */
 	add_options();
@@ -488,10 +501,9 @@ int main(int argc, char *argv[])
 
 	if (argi < argc) {
 		station_id = argv[argi];
-		if (strlen(station_id) != 7) {
-			printf("Given station ID '%s' does not have 7 digits\n", station_id);
-			return 0;
-		}
+		rc = main_mobile_number_ask(station_id, "station ID");
+		if (rc)
+			return rc;
 	}
 
 	/* resolve name of base station */
@@ -645,7 +657,7 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	main_mobile("cnetz", &quit, NULL, station_id, 7);
+	main_mobile_loop("cnetz", &quit, NULL, station_id);
 
 fail:
 	flush_db();