POCSAG: Allow all 128 ASCII characters to be transmitted

To allow all 128 ASCII characters, a null-terminated string cannot be
used. Instead a length is used to define string length, to allow
null-character in that the message string.

The print function in frame.c is improved and used to present the
string.

src/pocsag/frame.c

@@ -38,7 +38,7 @@
 static const char numeric[16] = "0123456789RU -][";
 static const char hex[16] = "0123456789abcdef";
 
-static const char *ctrlchar[32] = {
+static const char *ctrl_char[33] = {
 	"<NUL>",
 	"<SOH>",
 	"<STX>",
@@ -71,8 +71,37 @@ static const char *ctrlchar[32] = {
 	"<GS>",
 	"<RS>",
 	"<US>",
+	"<DEL>",
 };
 
+const char *print_message(const char *message, int message_length)
+{
+	static char message_print[1024];
+	const char *c;
+	int i, ii, clen;
+
+	/* i is input counter, ii is output counter */
+	for (i = 0, ii = 0; i < message_length; i++) {
+		if (message[i] >= 0 && message[i] <= 31)
+			c = ctrl_char[(int)message[i]];
+		else if (message[i] == 127)
+			c = ctrl_char[(int)message[32]];
+		else {
+			message_print[ii++] = message[i];
+			continue;
+		}
+		clen = strlen(c);
+		if (ii + clen == sizeof(message_print))
+			break;
+		memcpy(message_print + ii, c, clen);
+		ii += clen;
+	}
+	message_print[ii++] = '\0';
+
+	return message_print;
+}
+
+
 static uint32_t pocsag_crc(uint32_t word)
 {
 	uint32_t denominator = 0x76900000;
@@ -371,11 +400,8 @@ int64_t get_codeword(pocsag_t *pocsag)
 			/* encode address */
 			word = encode_address(msg);
 			/* link message, if there is data to be sent */
-			if ((msg->function == POCSAG_FUNCTION_NUMERIC || msg->function == POCSAG_FUNCTION_ALPHA) && msg->data_length) {
+			if (msg->function == POCSAG_FUNCTION_NUMERIC || msg->function == POCSAG_FUNCTION_ALPHA) {
-				char text[msg->data_length + 1];
+				LOGP_CHAN(DPOCSAG, LOGL_INFO, " -> Message text is \"%s\".\n", print_message(msg->data, msg->data_length));
-				memcpy(text, msg->data, msg->data_length);
-				text[msg->data_length] = '\0';
-				LOGP_CHAN(DPOCSAG, LOGL_INFO, " -> Message text is \"%s\".\n", text);
 				pocsag->current_msg = msg;
 				msg->data_index = 0;
 				msg->bit_index = 0;
@@ -420,31 +446,18 @@ int64_t get_codeword(pocsag_t *pocsag)
 
 static void done_rx_msg(pocsag_t *pocsag)
 {
+	const char *text;
+
 	if (!pocsag->rx_msg_valid)
 		return;
 
 	pocsag->rx_msg_valid = 0;
 
 	LOGP_CHAN(DPOCSAG, LOGL_INFO, "Received message from RIC '%d' / function '%d' (%s)\n", pocsag->rx_msg_ric, pocsag->rx_msg_function, pocsag_function_name[pocsag->rx_msg_function]);
-	{
+	text = print_message(pocsag->rx_msg_data, pocsag->rx_msg_data_length);
-		char text[pocsag->rx_msg_data_length * 5 + 1];
+	if (pocsag->rx_msg_function == POCSAG_FUNCTION_NUMERIC || pocsag->rx_msg_function == POCSAG_FUNCTION_ALPHA)
-		int i, j;
+		LOGP_CHAN(DPOCSAG, LOGL_INFO, " -> Message text is \"%s\".\n", text);
-		for (i = 0, j = 0; i < pocsag->rx_msg_data_length; i++) {
+	pocsag_msg_receive(pocsag->language, pocsag->sender.kanal, pocsag->rx_msg_ric, pocsag->rx_msg_function, text);
-			if (pocsag->rx_msg_data[i] == 127) {
-				strcpy(text + j, "<DEL>");
-				j += strlen(text + j);
-			} else
-			if (pocsag->rx_msg_data[i] < 32) {
-				strcpy(text + j, ctrlchar[(int)pocsag->rx_msg_data[i]]);
-				j += strlen(text + j);
-			} else
-				text[j++] = pocsag->rx_msg_data[i];
-		}
-		text[j] = '\0';
-		if ((pocsag->rx_msg_function == POCSAG_FUNCTION_NUMERIC || pocsag->rx_msg_function == POCSAG_FUNCTION_ALPHA) && text[0])
-			LOGP_CHAN(DPOCSAG, LOGL_INFO, " -> Message text is \"%s\".\n", text);
-		pocsag_msg_receive(pocsag->language, pocsag->sender.kanal, pocsag->rx_msg_ric, pocsag->rx_msg_function, text);
-	}
 }
 
 void put_codeword(pocsag_t *pocsag, uint32_t word, int8_t slot, int8_t subslot)

src/pocsag/frame.h

@@ -1,4 +1,5 @@
 
+const char *print_message(const char *message, int message_length);
 int64_t get_codeword(pocsag_t *pocsag);
 void put_codeword(pocsag_t *pocsag, uint32_t word, int8_t slot, int8_t subslot);
 

src/pocsag/main.c

@@ -224,10 +224,9 @@ static void myhandler(void)
 		}
 		/* send msg */
 		if (i < pos) {
-			buffer[i] = '\0';
 			pos = 0;
 			if (tx)
-				pocsag_msg_send(language, buffer);
+				pocsag_msg_send(language, buffer, i);
 			else
 				LOGP(DPOCSAG, LOGL_ERROR, "Failed to send message, transmitter is not enabled!\n");
 		}

src/pocsag/pocsag.c

@@ -204,7 +204,7 @@ void pocsag_new_state(pocsag_t *pocsag, enum pocsag_state new_state)
 }
 
 /* Create msg instance */
-static pocsag_msg_t *pocsag_msg_create(pocsag_t *pocsag, uint32_t callref, uint32_t ric, enum pocsag_function function, const char *text)
+static pocsag_msg_t *pocsag_msg_create(pocsag_t *pocsag, uint32_t callref, uint32_t ric, enum pocsag_function function, const char *message, size_t message_length)
 {
 	pocsag_msg_t *msg, **msgp;
 
@@ -216,9 +216,9 @@ static pocsag_msg_t *pocsag_msg_create(pocsag_t *pocsag, uint32_t callref, uint3
 		LOGP(DPOCSAG, LOGL_ERROR, "No mem!\n");
 		abort();
 	}
-	if (strlen(text) > sizeof(msg->data)) {
+	if (message_length > sizeof(msg->data)) {
 		LOGP(DPOCSAG, LOGL_ERROR, "Text too long!\n");
-		return NULL;
+		message_length = sizeof(msg->data);
 	}
 
 	/* init */
@@ -226,8 +226,8 @@ static pocsag_msg_t *pocsag_msg_create(pocsag_t *pocsag, uint32_t callref, uint3
 	msg->ric = ric;
 	msg->function = function;
 	msg->repeat = 0;
-	strncpy(msg->data, text, sizeof(msg->data));
+	memcpy(msg->data, message, message_length);
-	msg->data_length = (strlen(text) < sizeof(msg->data)) ? strlen(text) : sizeof(msg->data);
+	msg->data_length = message_length;
 	msg->padding = pocsag->padding;
 
 	/* link */
@@ -285,14 +285,14 @@ static int pocsag_scan_or_loopback(pocsag_t *pocsag)
 			message[0] = '\0';
 		}
 		LOGP_CHAN(DPOCSAG, LOGL_NOTICE, "Transmitting %s message '%s' with RIC '%d'.\n", pocsag_function_name[pocsag->default_function], message, pocsag->scan_from);
-		pocsag_msg_create(pocsag, 0, pocsag->scan_from, pocsag->default_function, message);
+		pocsag_msg_create(pocsag, 0, pocsag->scan_from, pocsag->default_function, message, strlen(message));
 		pocsag->scan_from++;
 		return 1;
 	}
 
 	if (pocsag->sender.loopback) {
 		LOGP(DPOCSAG, LOGL_INFO, "Sending message for loopback test.\n");
-		pocsag_msg_create(pocsag, 0, 1234567, POCSAG_FUNCTION_NUMERIC, "1234");
+		pocsag_msg_create(pocsag, 0, 1234567, POCSAG_FUNCTION_NUMERIC, "1234", 4);
 		return 1;
 	}
 
@@ -406,25 +406,46 @@ void pocsag_destroy(sender_t *sender)
 }
 
 /* application sends us a message, we need to deliver */
-void pocsag_msg_send(enum pocsag_language language, const char *text)
+void pocsag_msg_send(enum pocsag_language language, const char *text, size_t text_length)
 {
-	char buffer[strlen(text) + 1], *p = buffer, *ric_string, *function_string, *message;
+	char ric_string[text_length + 1];
+	char function_string[text_length + 1];
+	char message[text_length];
 	uint32_t ric;
 	uint8_t function;
 	pocsag_t *pocsag;
-	int i, j, k;
+	int message_length = 0;
+	int i, ii, j, k;
 	int rc;
 
-	strcpy(buffer, text);
+	for (i = 0; text_length; i++) {
-	ric_string = strsep(&p, ",");
+		if (*text == ',')
-	function_string = strsep(&p, ",");
+			break;
-	message = p;
+		ric_string[i] = *text++;
-
+		text_length--;
-	if (!ric_string || !function_string) {
+	}
+	ric_string[i] = '\0';
+	if (!text_length) {
 inval:
 		LOGP(DNMT, LOGL_NOTICE, "Given message MUST be in the following format: RIC,function[,<message with comma and spaces>] (function must be A = 0 = numeric, B = 1 or C = 2 = beep, D = 3 = alphanumeric)\n");
 		return;
 	}
+	text++;
+	text_length--;
+	for (i = 0; text_length; i++) {
+		if (*text == ',')
+			break;
+		function_string[i] = *text++;
+		text_length--;
+	}
+	function_string[i] = '\0';
+	if (text_length) {
+		text++;
+		text_length--;
+		memcpy(message, text, text_length);
+		message_length = text_length;
+	}
+
 	ric = atoi(ric_string);
 	if (ric > 2097151) {
 		LOGP(DNMT, LOGL_NOTICE, "Illegal RIC %d. Maximum allowed RIC is (2^21)-1. (2097151)\n", ric);
@@ -443,42 +464,43 @@ inval:
 	}
 	function = rc;
 
-	if (message && (function == 1 || function == 2)) {
+	if (message_length && (function == 1 || function == 2)) {
 		LOGP(DNMT, LOGL_NOTICE, "Message text is not allowed with function %d.\n", function);
 		goto inval;
 	}
 
-	if (message && language != LANGUAGE_DEFAULT) {
+	if (message_length && language != LANGUAGE_DEFAULT) {
 		i = 0;
-		p = message;
+		/* input counter is ii, output counter is i */
-		while (*p) {
+		for (ii = 0; ii < message_length; i++) {
 			/* encode special chracter */
 			for (j = 0; pocsag_lang[j][0]; j++) {
 				for (k = 0; pocsag_lang[j][k + 1]; k++) {
-					/* implies that (p[k] == '\0') causes to break */
+					/* break if input buffer ends */
-					if (p[k] != pocsag_lang[j][k + 1])
+					if (ii + k == message_length)
+						break;
+					/* break if string does not match */
+					if (message[ii + k] != pocsag_lang[j][k + 1])
 						break;
 				}
+				/* break, if k-loop was completed */
 				if (!pocsag_lang[j][k + 1])
 					break;
 			}
-			/* if character matches */
+			/* if character matches (k-loop was completed, j-loop not) */
 			if (pocsag_lang[j][0]) {
-				message[i++] = pocsag_lang[j][0];
+				message[i] = pocsag_lang[j][0];
-				p += k;
+				ii += k;
 			} else
-				message[i++] = *p++;
+				message[i] = message[ii++];
 		}
-		message[i] = '\0';
+		message_length = i;
 	}
 
-	if (!message)
+	LOGP(DNMT, LOGL_INFO, "Message for ID '%d/%d' with text '%s'\n", ric, function, print_message(message, message_length));
-		message="";
-
-	LOGP(DNMT, LOGL_INFO, "Message for ID '%d/%d' with text '%s'\n", ric, function, message);
 
 	pocsag = (pocsag_t *) sender_head;
-	pocsag_msg_create(pocsag, 0, ric, function, message);
+	pocsag_msg_create(pocsag, 0, ric, function, message, message_length);
 }
 
 void call_down_clock(void)
@@ -535,7 +557,7 @@ int call_down_setup(int callref, const char *caller_id, enum number_type __attri
 		message = pocsag->default_message;
 
 	/* create call process to page station */
-	msg = pocsag_msg_create(pocsag, callref, ric, function, message);
+	msg = pocsag_msg_create(pocsag, callref, ric, function, message, strlen(message));
 	if (!msg)
 		return -CAUSE_INVALNUMBER;
 	return -CAUSE_NORMAL;

src/pocsag/pocsag.h

@@ -102,7 +102,7 @@ void pocsag_new_state(pocsag_t *pocsag, enum pocsag_state new_state);
 void pocsag_msg_receive(enum pocsag_language language, const char *channel, uint32_t ric, enum pocsag_function function, const char *message);
 int pocsag_create(const char *kanal, double frequency, const char *device, int use_sdr, int samplerate, double rx_gain, double tx_gain, int tx, int rx, enum pocsag_language language, int baudrate, double deviation, double polarity, enum pocsag_function function, const char *message, char padding, uint32_t scan_from, uint32_t scan_to, const char *write_rx_wave, const char *write_tx_wave, const char *read_rx_wave, const char *read_tx_wave, int loopback);
 void pocsag_destroy(sender_t *sender);
-void pocsag_msg_send(enum pocsag_language language, const char *text);
+void pocsag_msg_send(enum pocsag_language language, const char *text, size_t text_length);
 void pocsag_msg_destroy(pocsag_msg_t *msg);
 void pocsag_get_id(pocsag_t *euro, char *id);
 void pocsag_receive_id(pocsag_t *euro, char *id);