DECT-NWK: Add basic support for DECT charsets

5 files changed, 97 insertions, 0 deletions

diff --git a/doc/README.dissector b/doc/README.dissector
index 6a28b63e4a..ef38ad955f 100644
--- a/doc/README.dissector
+++ b/doc/README.dissector
@@ -1534,6 +1534,10 @@ currently supported are:
     ENC_KEYPAD_BC_TBCD - keypad-with-B/C "telephony packed BCD" = 0-9, B, C, *, #
     ENC_GB18030 - GB 18030
     ENC_EUC_KR - EUC-KR
+    ENC_DECT_STANDARD_8BITS - DECT standard 8 bit character set as defined in
+        ETSI EN 300 175-5
+    ENC_DECT_STANDARD_4BITS_TBCD - DECT standard 4 bit character set "telephony
+        packet BCD" = 0-9, 0xb = SPACE
 
 Other encodings will be added in the future.
 
diff --git a/epan/charsets.c b/epan/charsets.c
index aaeb0e4585..5e03c9625c 100644
--- a/epan/charsets.c
+++ b/epan/charsets.c
@@ -1880,6 +1880,46 @@ get_t61_string(wmem_allocator_t *scope, const guint8 *ptr, gint length)
     return (guint8 *)wmem_strbuf_finalize(strbuf);
 }
 
+/* The DECT standard charset from ETSI EN 300 175-5 Annex D
+ */
+static const gunichar2 dect_standard_8bits_code_table[] = {
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+    0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+    ' ',  '!',  '\"', '#',  '$',  '%',  '&',  '\'',
+    '(',  ')',  '*',  '+',  ',',  '-',  '.',  '/',
+    '0',  '1',  '2',  '3',  '4',  '5',  '6',  '7',
+    '8',  '9',  ':',  ';',  '<',  '=',  '>',  '?',
+    '@',  'A',  'B',  'C',  'D',  'E',  'F',  'G',
+    'H',  'I',  'J',  'K',  'L',  'M',  'N',  'O',
+    'P',  'Q',  'R',  'S',  'T',  'U',  'V',  'W',
+    'X',  'Y',  'Z',  '[', '\\',  ']',  '^',  '_',
+    '`',  'a',  'b',  'c',  'd',  'e',  'f',  'g',
+    'h',  'i',  'j',  'k',  'l',  'm',  'n',  'o',
+    'p',  'q',  'r',  's',  't',  'u',  'v',  'w',
+    'x',  'y',  'z',  '{',  '|',  '}',  '~', 0x7f,
+};
+
+guint8 *
+get_dect_standard_8bits_string(wmem_allocator_t *scope, const guint8 *ptr, gint length)
+{
+    gint           position;
+    const guint8  *current_byte_ptr;
+    wmem_strbuf_t *strbuf;
+
+    strbuf = wmem_strbuf_sized_new(scope, length+1, 0);
+
+    for (position = 0, current_byte_ptr = ptr; position < length; current_byte_ptr++, position++) {
+        if (!dect_standard_8bits_code_table[*current_byte_ptr]) {
+            wmem_strbuf_append_unichar(strbuf, UNREPL);
+        } else {
+            wmem_strbuf_append_unichar(strbuf, dect_standard_8bits_code_table[*current_byte_ptr]);
+        }
+    }
+
+    return (guint8 *)wmem_strbuf_finalize(strbuf);
+}
 /*
  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
  *
diff --git a/epan/charsets.h b/epan/charsets.h
index 9018a3d3b5..f03bfdc876 100644
--- a/epan/charsets.h
+++ b/epan/charsets.h
@@ -214,6 +214,8 @@ get_euc_kr_string(wmem_allocator_t *scope, const guint8 *ptr, gint length);
 WS_DLL_PUBLIC guint8 *
 get_t61_string(wmem_allocator_t *scope, const guint8 *ptr, gint length);
 
+WS_DLL_PUBLIC guint8 *
+get_dect_standard_8bits_string(wmem_allocator_t *scope, const guint8 *ptr, gint length);
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */
diff --git a/epan/proto.h b/epan/proto.h
index 3881de3da4..e77810ad08 100644
--- a/epan/proto.h
+++ b/epan/proto.h
@@ -426,6 +426,8 @@ void proto_report_dissector_bug(const char *format, ...)
 #define ENC_GB18030                       0x00000050
 #define ENC_EUC_KR                        0x00000052
 #define ENC_APN_STR                       0x00000054 /* The encoding the APN/DNN field follows 3GPP TS 23.003 [2] clause 9.1.*/
+#define ENC_DECT_STANDARD_8BITS           0x00000056 /* DECT standard character set as defined in ETSI EN 300 175-5 Annex D */
+#define ENC_DECT_STANDARD_4BITS_TBCD      0x00000058 /* DECT standard 4bits character set as defined in ETSI EN 300 175-5 Annex D (BCD with 0xb = SPACE)*/
 /*
  * TODO:
  *
diff --git a/epan/tvbuff.c b/epan/tvbuff.c
index 4f0bfdab82..0ddea8bd95 100644
--- a/epan/tvbuff.c
+++ b/epan/tvbuff.c
@@ -1722,6 +1722,7 @@ validate_single_byte_ascii_encoding(const guint encoding)
 	    case ENC_KEYPAD_BC_TBCD:
 	    case ENC_ETSI_TS_102_221_ANNEX_A:
 	    case ENC_APN_STR:
+		case ENC_DECT_STANDARD_4BITS_TBCD:
 	    REPORT_DISSECTOR_BUG("Invalid string encoding type passed to tvb_get_string_XXX");
 	    break;
 	    default:
@@ -3009,6 +3010,13 @@ static const dgt_set_t Dgt_ansi_tbcd = {
 	}
 };
 
+static const dgt_set_t Dgt_dect_standard_4bits_tbcd = {
+	{
+		/*  0   1   2   3   4   5   6   7   8   9   a   b   c   d   e  f */
+		   '0','1','2','3','4','5','6','7','8','9','?',' ','?','?','?','?'
+	}
+};
+
 static guint8 *
 tvb_get_apn_string(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset,
 			     gint length)
@@ -3076,6 +3084,15 @@ end:
 	return (guint8 *) wmem_strbuf_finalize(str);
 }
 
+static guint8 *
+tvb_get_dect_standard_8bits_string(wmem_allocator_t *scope, tvbuff_t *tvb, gint offset, gint length)
+{
+	const guint8  *ptr;
+
+	ptr = ensure_contiguous(tvb, offset, length);
+	return get_dect_standard_8bits_string(scope, ptr, length);
+}
+
 /*
  * Given a tvbuff, an offset, a length, and an encoding, allocate a
  * buffer big enough to hold a non-null-terminated string of that length
@@ -3313,6 +3330,20 @@ tvb_get_string_enc(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset,
 	case ENC_APN_STR:
 		strptr = tvb_get_apn_string(scope, tvb, offset, length);
 		break;
+
+	case ENC_DECT_STANDARD_8BITS:
+		strptr = tvb_get_dect_standard_8bits_string(scope, tvb, offset, length);
+		break;
+
+	case ENC_DECT_STANDARD_4BITS_TBCD:
+		/*
+		 * DECT standard 4bits "telephony BCD" - packed BCD, with
+		 * digits 0-9 and symbol SPACE for 0xb.
+		 */
+		odd = (encoding & ENC_BCD_ODD_NUM_DIG) >> 16;
+		skip_first = (encoding & ENC_BCD_SKIP_FIRST) >> 17;
+		strptr = tvb_get_bcd_string(scope, tvb, offset, length, &Dgt_dect_standard_4bits_tbcd, skip_first, odd, FALSE);
+		break;
 	}
 	return strptr;
 }
@@ -3545,6 +3576,20 @@ tvb_get_euc_kr_stringz(wmem_allocator_t *scope, tvbuff_t *tvb, gint offset, gint
 	return get_euc_kr_string(scope, ptr, size);
 }
 
+static guint8 *
+tvb_get_dect_standard_8bits_stringz(wmem_allocator_t *scope, tvbuff_t *tvb, gint offset, gint *lengthp)
+{
+	guint	       size;
+	const guint8  *ptr;
+
+	size = tvb_strsize(tvb, offset);
+	ptr  = ensure_contiguous(tvb, offset, size);
+	/* XXX, conversion between signed/unsigned integer */
+	if (lengthp)
+		*lengthp = size;
+	return get_t61_string(scope, ptr, size);
+}
+
 guint8 *
 tvb_get_stringz_enc(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, gint *lengthp, const guint encoding)
 {
@@ -3727,6 +3772,10 @@ tvb_get_stringz_enc(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, g
 	case ENC_EUC_KR:
 		strptr = tvb_get_euc_kr_stringz(scope, tvb, offset, lengthp);
 		break;
+
+	case ENC_DECT_STANDARD_8BITS:
+		strptr = tvb_get_dect_standard_8bits_stringz(scope, tvb, offset, lengthp);
+		break;
 	}
 
 	return strptr;