From 8a74805ea6c41e8e17983da6cec06e2466c072d1 Mon Sep 17 00:00:00 2001
From: Andreas Eversberg <jolly@eversberg.eu>
Date: Sat, 11 Nov 2017 08:11:50 +0100
Subject: [PATCH] NMT: Add support for receiving 8-Bit-SMS, because it is
 mandatory

Benefone Dragon uses this coding scheme for SMS-Submit.
---
 src/nmt/sms.c       | 28 ++++++++++++++++++++++------
 src/test/test_sms.c | 39 ++++++++++++++++++++++++++++++++-------
 2 files changed, 54 insertions(+), 13 deletions(-)

diff --git a/src/nmt/sms.c b/src/nmt/sms.c
index d1d2fc6..abb6edf 100644
--- a/src/nmt/sms.c
+++ b/src/nmt/sms.c
@@ -360,8 +360,8 @@ static void sms_submit_report(nmt_t *nmt, uint8_t ref, int error)
  * receive from lower layer
  */
 
-/* decdoe message from 8 bit data */
-static void decode_message(const uint8_t *data, int length, char *message)
+/* decode 7-bit character message from 8 bit data */
+static void decode_message_7(const uint8_t *data, int length, char *message)
 {
 	int fill;
 	int i;
@@ -408,6 +408,7 @@ static int decode_sms_submit(nmt_t *nmt, const uint8_t *data, int length)
 	int orig_digits, dest_digits, msg_chars;
 	uint8_t orig_type, orig_plan, dest_type, dest_plan;
 	int tp_vpf_present = 0;
+	int coding = 0;
 	int rc;
 
 	/* decode ref */
@@ -515,7 +516,13 @@ static int decode_sms_submit(nmt_t *nmt, const uint8_t *data, int length)
 		PDEBUG(DSMS, DEBUG_NOTICE, "short data coding scheme IE\n");
 		return -FSC_ERROR_IN_MS;
 	}
-	if (data[0] != 0) {
+	if (data[0] == 0x00) {
+		PDEBUG(DSMS, DEBUG_DEBUG, "SMS coding is 7 bits (got 0x%02x)\n", data[0]);
+		coding = 7;
+	} else if ((data[0] & 0xf0) == 0x30) {
+		PDEBUG(DSMS, DEBUG_DEBUG, "SMS coding is 8 bits (got 0x%02x)\n", data[0]);
+		coding = 8;
+	} else {
 		PDEBUG(DSMS, DEBUG_NOTICE, "SMS coding unsupported (got 0x%02x)\n", data[0]);
 		return -FSC_ERROR_IN_MS;
 	}
@@ -539,14 +546,23 @@ static int decode_sms_submit(nmt_t *nmt, const uint8_t *data, int length)
 	}
 	msg_data = data + 1;
 	msg_chars = data[0];
-	msg_len = (msg_chars * 7 + 7) / 8;
+	if (coding == 7)
+		msg_len = (msg_chars * 7 + 7) / 8;
+	else
+		msg_len = msg_chars;
 	if (length < 1 + msg_len) {
 		PDEBUG(DSMS, DEBUG_NOTICE, "short read user data IE\n");
 		return -FSC_ERROR_IN_MS;
 	}
 	char message[msg_chars + 1];
-	decode_message(msg_data, msg_len, message);
-	PDEBUG(DSMS, DEBUG_DEBUG, "Decoded message: '%s'\n", message);
+	if (coding == 7) {
+		decode_message_7(msg_data, msg_len, message);
+		PDEBUG(DSMS, DEBUG_DEBUG, "Decoded message: '%s'\n", message);
+	} else {
+		memcpy(message, msg_data, msg_len);
+		message[msg_len] = '\0';
+		PDEBUG(DSMS, DEBUG_DEBUG, "Included message: '%s'\n", message);
+	}
 
 	PDEBUG(DSMS, DEBUG_INFO, "Submitting SMS to upper layer\n");
 
diff --git a/src/test/test_sms.c b/src/test/test_sms.c
index 867113b..1706dd3 100644
--- a/src/test/test_sms.c
+++ b/src/test/test_sms.c
@@ -9,14 +9,22 @@
 #include "../common/timer.h"
 #include "../nmt/nmt.h"
 
-static const uint8_t test_mo_sms_data[] = {
+static const uint8_t test_mo_sms_data1[] = {
 	0x00, 0x00, 0x00, 0xa1, 0x41, 0x0f, 0x11,
 	0x00, 0x04, 0xa1, 0x8a, 0x51,
 	0x00, 0x00, 0xff, 0x05, 0xc8, 0x20, 0x93,
 	0xf9, 0x7c,
 };
+static const uint8_t test_mo_sms_data2[] = {
+	0x00, 0x02, 0x07, 0xa1, 0xa9, 0x62, 0x65,
+	0xf4, 0x41, 0x10, 0x11, 0x02, 0x03, 0xa1,
+	0x21, 0xf3,
+	0x00, 0x30, 0xff, 0x06, 0x48, 0x61, 0x6c,
+	0x6c, 0x6f, 0x21,
+};
 
-static const char *test_mo_sms_text = "HALLO";
+static const char *test_mo_sms_text1 = "HALLO";
+static const char *test_mo_sms_text2 = "Hallo!";
 
 static const char *test_mt_sms_text = "Moin Moin";
 static const char *test_mt_sms_tel = "4948416068";
@@ -121,13 +129,30 @@ int main(void)
 	sms_init_sender(nmt);
 	sms_reset(nmt);
 
-	printf("(submitting SMS)\n");
+	printf("(submitting SMS 7-bit encoded)\n");
 	dms_buffer_count = 0;
-	for (i = 0; i < sizeof(test_mo_sms_data); i++)
-		dms_receive(nmt, test_mo_sms_data + i, 1, 1);
+	for (i = 0; i < sizeof(test_mo_sms_data1); i++)
+		dms_receive(nmt, test_mo_sms_data1 + i, 1, 1);
 
-	assert(dms_buffer_count == strlen(test_mo_sms_text), "Expecting SMS text length to match");
-	assert(!memcmp(dms_buffer, test_mo_sms_text, dms_buffer_count), "Expecting SMS text to match");
+	assert(dms_buffer_count == strlen(test_mo_sms_text1), "Expecting SMS text length to match");
+	assert(!memcmp(dms_buffer, test_mo_sms_text1, dms_buffer_count), "Expecting SMS text to match");
+
+	sms_cleanup_sender(nmt);
+	free(nmt);
+
+	ok();
+
+	nmt = calloc(sizeof(*nmt), 1);
+	sms_init_sender(nmt);
+	sms_reset(nmt);
+
+	printf("(submitting SMS 8-bit encoded)\n");
+	dms_buffer_count = 0;
+	for (i = 0; i < sizeof(test_mo_sms_data2); i++)
+		dms_receive(nmt, test_mo_sms_data2 + i, 1, 1);
+
+	assert(dms_buffer_count == strlen(test_mo_sms_text2), "Expecting SMS text length to match");
+	assert(!memcmp(dms_buffer, test_mo_sms_text2, dms_buffer_count), "Expecting SMS text to match");
 
 	sms_cleanup_sender(nmt);
 	free(nmt);