fix: properly decode LE910-SVG multi-part messages0.0.13

2 files changed, 27 insertions, 11 deletions

diff --git a/src/pdu.h b/src/pdu.h
index 9dfddd4..0143f1f 100644
--- a/src/pdu.h
+++ b/src/pdu.h
@@ -54,6 +54,7 @@ enum {
 	PDU_ALPHABET_CDMA_DEFAULT = 2, //7-bit
 	PDU_ALPHABET_EIGHT = 4,
 	PDU_ALPHABET_CDMA_EIGHT = 8,
+	PDU_ALPHABET_DEFAULT_MULTI = 9,
 };
 
 struct pdu_info {
diff --git a/src/pdu_decode.c b/src/pdu_decode.c
index d6ad385..459916c 100644
--- a/src/pdu_decode.c
+++ b/src/pdu_decode.c
@@ -88,9 +88,6 @@ int pdu_decode_cdma_timestamp(const char *pdu_str, struct tm *tm)
 {
 	char buf[PDU_CDMA_TIMESTAMP_LEN + 1];
 	char *cp;
-	int off_upper;
-	int off_lower;
-	int off;
 
 	STRLEN_CHECK(pdu_str, PDU_CDMA_TIMESTAMP_LEN, -1);
 
@@ -182,6 +179,7 @@ int pdu_decode_user_data(const char *pdu_str, struct pdu_info *pdu, int *nr_octe
 	const char *begin = pdu_str;
 	int tmp;
 	uint8_t octets[PDU_OCTETS_MAX + 1];
+  int user_data_start_index = 0;
 	int i;
 
 	STRLEN_CHECK(pdu_str, HEX_BYTE_LEN, -1);
@@ -207,9 +205,21 @@ int pdu_decode_user_data(const char *pdu_str, struct pdu_info *pdu, int *nr_octe
 		}
 
 		*nr_octets = octet_align(pdu->user_data_len);
+  } else if (pdu->data_coding.general.alphabet == PDU_ALPHABET_DEFAULT_MULTI) {
+    //GSM style 8 bit conversion but with UDH multi-part header (LE910-SVG)
+		log_debug("data coding alphabet is nine");
+
+		if (pdu->user_data_len > PDU_UD_7BIT_MAX) {
+			log_warning("pdu contains invalid user-data-len: 0x%02X",
+					pdu->user_data_len);
+			pdu->user_data_len = PDU_UD_7BIT_MAX;
+		}
+
+		*nr_octets = octet_align(pdu->user_data_len);
   } else if (pdu->data_coding.general.alphabet == PDU_ALPHABET_CDMA_DEFAULT) {
-		log_debug("data coding alphabet is cdma default");
+    log_debug("data coding alphabet is cdma default");
 
+    // Encoding 02 is 7 bit for LE910-SVG but 8 bit for other CDMA radios
     if (!strcmp(Global.core.model, "LE910-SVG")) {
       if (pdu->user_data_len > PDU_UD_7BIT_MAX) {
         log_warning("pdu contains invalid user-data-len: 0x%02X", pdu->user_data_len);
@@ -257,11 +267,13 @@ int pdu_decode_user_data(const char *pdu_str, struct pdu_info *pdu, int *nr_octe
 		pdu_str += HEX_BYTE_LEN;
 	}
 
-	if (pdu->data_coding.general.alphabet == PDU_ALPHABET_DEFAULT) {
+	if ((pdu->data_coding.general.alphabet == PDU_ALPHABET_DEFAULT) ||
+      (pdu->data_coding.general.alphabet == PDU_ALPHABET_DEFAULT_MULTI)) {
 		// Keep UDH for concatenated SMS.
 		// Otherwise it is impossible to process correctly concatenated SMS.
 		i = 0;
-		if (pdu->type.user_data_header) {
+		if (pdu->type.user_data_header ||
+        (pdu->data_coding.general.alphabet == PDU_ALPHABET_DEFAULT_MULTI)) {
 			for (i = 0; i <= octets[0]; ++i) {
 				pdu->user_data[i] = octets[i];
 			}
@@ -272,8 +284,10 @@ int pdu_decode_user_data(const char *pdu_str, struct pdu_info *pdu, int *nr_octe
 				i++;
 			}
 		}
+    user_data_start_index = i;
 		for (; i < pdu->user_data_len; i++) {
 			pdu->user_data[i] = decode_septet(octets, i);
+      log_debug("DECODE: i: %d octet: 0x%02X --> data: 0x%02X", i, octets[i], pdu->user_data[i]);
 		}
 		pdu->user_data[i] = '\0';
   } else if (pdu->data_coding.general.alphabet == PDU_ALPHABET_CDMA_DEFAULT) {
@@ -296,7 +310,7 @@ int pdu_decode_user_data(const char *pdu_str, struct pdu_info *pdu, int *nr_octe
       log_debug("DECODE: i: %d octet: 0x%02X --> data: 0x%02X", i, octets[i], pdu->user_data[i]);
 		}
     //Remove padded byte for data length of 7 characters if not LE910-SVG
-    if (strcmp(Global.core.model, "LE910-SVG") && pdu->user_data[i-1] == 0) {
+    if (strcmp(Global.core.model, "LE910-SVG") && (pdu->user_data[i-1] == 0)) {
       log_debug("Removing padded char");
       i--;
       pdu->user_data_len--;
@@ -310,12 +324,13 @@ int pdu_decode_user_data(const char *pdu_str, struct pdu_info *pdu, int *nr_octe
 	}
 
   //Only for GSM 7-bit character set
-	if (pdu->data_coding.general.alphabet == PDU_ALPHABET_DEFAULT) {
-    int read = 0;
-    int store = 0;
+	if ((pdu->data_coding.general.alphabet == PDU_ALPHABET_DEFAULT) ||
+      (pdu->data_coding.general.alphabet == PDU_ALPHABET_DEFAULT_MULTI)) {
+    int read = user_data_start_index;
+    int store = user_data_start_index;
 
     log_debug("Converting from GSM character set to IRA");
-    for (read = 0; read < pdu->user_data_len; read++) {
+    for (; read < pdu->user_data_len; read++) {
       if (pdu->user_data[read] == 0x1B) {
         //Character from the extended set using the escape char (27)
         read++;