feat: implement IRA->GSM character set encoding & decoding0.0.10

This adds support for certain characters like @ $ ~ ^

1 files changed, 25 insertions, 0 deletions

diff --git a/src/pdu_decode.c b/src/pdu_decode.c
index 140fd14..934aef5 100644
--- a/src/pdu_decode.c
+++ b/src/pdu_decode.c
@@ -309,6 +309,31 @@ int pdu_decode_user_data(const char *pdu_str, struct pdu_info *pdu, int *nr_octe
 		pdu->user_data[i] = '\0';
 	}
 
+  //Only for 7-bit character sets
+	if ((pdu->data_coding.general.alphabet == PDU_ALPHABET_DEFAULT) ||
+      (pdu->data_coding.general.alphabet == PDU_ALPHABET_CDMA_DEFAULT)) {
+    int read = 0;
+    int store = 0;
+
+    log_debug("Converting from GSM character set to IRA");
+    for (read = 0; read < pdu->user_data_len; read++) {
+      if (pdu->user_data[read] == 0x1B) {
+        //Character from the extended set using the escape char (27)
+        read++;
+        log_debug("GSM before: 0x1B%02X | IRA after: 0x%02X", pdu->user_data[read], strExtendedTable[pdu->user_data[read]]);
+        pdu->user_data[store] = strExtendedTable[pdu->user_data[read]];
+      }
+      else {
+        log_debug("GSM before:   0x%02X | IRA after: 0x%02X", pdu->user_data[read], strGSMTable[pdu->user_data[read]]);
+        pdu->user_data[store] = strGSMTable[pdu->user_data[read]];
+      }
+      store++;
+    }
+    //Update lengths
+    pdu->user_data_len -= read - store;
+    pdu_str -= (read - store) * HEX_BYTE_LEN;
+  }
+
 	return pdu_str - begin;
 }