Introduce ENC_BCD_ODD_NUM_DIG in order to handle odd number of digits

6 files changed, 45 insertions, 36 deletions

diff --git a/epan/dissectors/packet-e212.c b/epan/dissectors/packet-e212.c
index cb96611204..b979c6d292 100644
--- a/epan/dissectors/packet-e212.c
+++ b/epan/dissectors/packet-e212.c
@@ -3468,14 +3468,17 @@ dissect_e212_imsi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int offse
 {
     proto_item *item;
     proto_tree *subtree;
-    const gchar *imsi_str;
+    const guint8 *imsi_str;
 
     /* Fetch the BCD encoded digits from tvb indicated half byte, formating the digits according to
      * a default digit set of 0-9 returning "?" for overdecadic digits a pointer to the wmem
      * allocated string will be returned.
      */
-    imsi_str = tvb_bcd_dig_to_wmem_packet_str( tvb, offset, length, NULL, skip_first);
-    item = proto_tree_add_string(tree, hf_E212_imsi, tvb, offset, length, imsi_str);
+    if (skip_first) {
+        item = proto_tree_add_item_ret_string(tree, hf_E212_imsi, tvb, offset, length, ENC_BCD_DIGITS_0_9 | ENC_BCD_SKIP_FIRST, wmem_packet_scope(), &imsi_str);
+    } else {
+        item = proto_tree_add_item_ret_string(tree, hf_E212_imsi, tvb, offset, length, ENC_BCD_DIGITS_0_9, wmem_packet_scope(), &imsi_str);
+    }
     if (!is_imsi_string_valid(imsi_str)) {
         expert_add_info(pinfo, item, &ei_E212_imsi_malformed);
     }
diff --git a/epan/dissectors/packet-nas_5gs.c b/epan/dissectors/packet-nas_5gs.c
index 8e2c0d9c87..d44cddc97c 100644
--- a/epan/dissectors/packet-nas_5gs.c
+++ b/epan/dissectors/packet-nas_5gs.c
@@ -954,7 +954,7 @@ de_nas_5gs_mm_5gs_mobile_id(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo,
     guint8 oct, type_id, supi_fmt;
     guint32 scheme_id, fiveg_tmsi;
     tvbuff_t * new_tvb;
-    const char *digit_str, *route_id_str;
+    const char *route_id_str;
     proto_item* ti;
 
     static int * const flags_spare_tid[] = {
@@ -1076,9 +1076,7 @@ de_nas_5gs_mm_5gs_mobile_id(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo,
     case 3:
         /* IMEI */
         proto_tree_add_bitmask_list(tree, tvb, offset, 1, flags_odd_even_tid, ENC_BIG_ENDIAN);
-        new_tvb = tvb_new_subset_length(tvb, offset, len);
-        digit_str = tvb_bcd_dig_to_wmem_packet_str(new_tvb, 0, -1, NULL, TRUE);
-        proto_tree_add_string(tree, hf_nas_5gs_mm_imei, new_tvb, 0, -1, digit_str);
+        proto_tree_add_item(tree, hf_nas_5gs_mm_imei, tvb, offset, len, ENC_BCD_DIGITS_0_9 | ENC_BCD_SKIP_FIRST);
         break;
     case 4:
         /*5G-S-TMSI*/
@@ -1097,9 +1095,8 @@ de_nas_5gs_mm_5gs_mobile_id(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo,
     case 5:
         /* IMEISV */
         proto_tree_add_bitmask_list(tree, tvb, offset, 1, flags_odd_even_tid, ENC_BIG_ENDIAN);
-        new_tvb = tvb_new_subset_length(tvb, offset, len);
-        digit_str = tvb_bcd_dig_to_wmem_packet_str(new_tvb, 0, -1, NULL, TRUE);
-        proto_tree_add_string(tree, hf_nas_5gs_mm_imeisv, new_tvb, 0, -1, digit_str);
+        /* XXXX Do we need the odd/even bit?*/
+        proto_tree_add_item(tree, hf_nas_5gs_mm_imeisv, tvb, offset, len, ENC_BCD_DIGITS_0_9 | ENC_BCD_SKIP_FIRST);
         break;
     case 6:
         /* MAC address */
@@ -3475,12 +3472,10 @@ de_nas_5gs_mm_ue_radio_cap_id(tvbuff_t* tvb, proto_tree* tree, packet_info* pinf
     gchar* add_string _U_, int string_len _U_)
 {
     int curr_offset;
-    const char* digit_str;
 
     curr_offset = offset;
 
-    digit_str = tvb_bcd_dig_to_wmem_packet_str(tvb, curr_offset, len, NULL, FALSE);
-    proto_tree_add_string(tree, hf_nas_5gs_mm_ue_radio_cap_id, tvb, 0, -1, digit_str);
+    proto_tree_add_item(tree, hf_nas_5gs_mm_ue_radio_cap_id, tvb, curr_offset, len, ENC_BCD_DIGITS_0_9);
 
     return len;
 }
diff --git a/epan/dissectors/packet-nas_eps.c b/epan/dissectors/packet-nas_eps.c
index 715b15f0a0..e3c8530020 100644
--- a/epan/dissectors/packet-nas_eps.c
+++ b/epan/dissectors/packet-nas_eps.c
@@ -1343,8 +1343,6 @@ de_emm_eps_mid(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo,
 {
     guint32   curr_offset;
     guint8    octet;
-    const char     *digit_str;
-    tvbuff_t *new_tvb;
     proto_item* ti;
 
     curr_offset = offset;
@@ -1356,14 +1354,11 @@ de_emm_eps_mid(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo,
     switch (octet&0x7) {
         case 1:
             /* IMSI */
-            new_tvb = tvb_new_subset_length(tvb, curr_offset, len);
-            dissect_e212_imsi(new_tvb, pinfo, tree,  0, len, TRUE);
+            dissect_e212_imsi(tvb, pinfo, tree, curr_offset, len, TRUE);
             break;
         case 3:
             /* IMEI */
-            new_tvb = tvb_new_subset_length(tvb, curr_offset, len);
-            digit_str = tvb_bcd_dig_to_wmem_packet_str(new_tvb, 0, len, NULL, TRUE);
-            proto_tree_add_string(tree, hf_nas_eps_emm_imei, new_tvb, 0, -1, digit_str);
+            proto_tree_add_item(tree, hf_nas_eps_emm_imei, tvb, curr_offset, len, ENC_BCD_DIGITS_0_9 | ENC_BCD_SKIP_FIRST);
             break;
         case 6:
             /* GUTI */
@@ -3701,22 +3696,19 @@ de_esm_remote_ue_context_list(tvbuff_t *tvb, proto_tree *tree, packet_info *pinf
                     break;
                 case 3:
                     {
-                        const gchar *msisdn_str = tvb_bcd_dig_to_wmem_packet_str(tvb, curr_offset, user_id_len, NULL, TRUE);
-                        proto_tree_add_string(subtree, hf_nas_eps_esm_remote_ue_context_list_ue_context_msisdn, tvb, curr_offset, user_id_len, msisdn_str);
+                        proto_tree_add_item(subtree, hf_nas_eps_esm_remote_ue_context_list_ue_context_msisdn, tvb, curr_offset, user_id_len, ENC_BCD_DIGITS_0_9 | ENC_BCD_SKIP_FIRST);
                         curr_offset += user_id_len;
                     }
                     break;
                 case 4:
                     {
-                        const gchar *imei_str = tvb_bcd_dig_to_wmem_packet_str(tvb, curr_offset, user_id_len, NULL, TRUE);
-                        proto_tree_add_string(subtree, hf_nas_eps_esm_remote_ue_context_list_ue_context_imei, tvb, curr_offset, user_id_len, imei_str);
+                        proto_tree_add_item(subtree, hf_nas_eps_esm_remote_ue_context_list_ue_context_imei, tvb, curr_offset, user_id_len, ENC_BCD_DIGITS_0_9 | ENC_BCD_SKIP_FIRST);
                         curr_offset += user_id_len;
                     }
                     break;
                 case 5:
                     {
-                        const gchar *imeisv_str = tvb_bcd_dig_to_wmem_packet_str(tvb, curr_offset, user_id_len, NULL, TRUE);
-                        proto_tree_add_string(subtree, hf_nas_eps_esm_remote_ue_context_list_ue_context_imeisv, tvb, curr_offset, user_id_len, imeisv_str);
+                        proto_tree_add_item(subtree, hf_nas_eps_esm_remote_ue_context_list_ue_context_imeisv, tvb, curr_offset, user_id_len, ENC_BCD_DIGITS_0_9 | ENC_BCD_SKIP_FIRST);
                         curr_offset += user_id_len;
                     }
                     break;
diff --git a/epan/proto.h b/epan/proto.h
index 2a51071562..335e014789 100644
--- a/epan/proto.h
+++ b/epan/proto.h
@@ -515,7 +515,13 @@ void proto_report_dissector_bug(const char *format, ...)
 /* a convenience macro for the above */
 #define ENC_SEP_MASK    0x001F0000
 
-/*
+/* Encodings for BCD strings
+ * Depending if the BCD string has even or odd number of digits
+ * we may need to strip of the last digit/High nibble
+ */
+#define ENC_BCD_ODD_NUM_DIG     0x00010000
+#define ENC_BCD_SKIP_FIRST      0x00020000
+ /*
  * Encodings for time values.
  *
  * Historically FT_TIMEs were only timespecs; the only question was whether
diff --git a/epan/tvbuff.c b/epan/tvbuff.c
index 6efe933ae2..1c80ad79cb 100644
--- a/epan/tvbuff.c
+++ b/epan/tvbuff.c
@@ -2873,6 +2873,7 @@ tvb_get_string_enc(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset,
 			     const gint length, const guint encoding)
 {
 	guint8 *strptr;
+	gboolean odd, skip_first;
 
 	DISSECTOR_ASSERT(tvb && tvb->initialized);
 
@@ -3053,7 +3054,9 @@ tvb_get_string_enc(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset,
 		/*
 		 * Packed BCD, with digits 0-9.
 		 */
-		strptr = tvb_get_bcd_string(scope, tvb, offset, length, &Dgt0_9_bcd, FALSE);
+		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, &Dgt0_9_bcd, skip_first, odd);
 		break;
 
 	case ENC_KEYPAD_ABC_TBCD:
@@ -3061,7 +3064,9 @@ tvb_get_string_enc(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset,
 		 * Keypad-with-a/b/c "telephony BCD" - packed BCD, with
 		 * digits 0-9 and symbols *, #, a, b, and c.
 		 */
-		strptr = tvb_get_bcd_string(scope, tvb, offset, length, &Dgt_keypad_abc_tbcd, FALSE);
+		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_keypad_abc_tbcd, skip_first, odd);
 		break;
 
 	case ENC_KEYPAD_BC_TBCD:
@@ -3069,7 +3074,9 @@ tvb_get_string_enc(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset,
 		 * Keypad-with-B/C "telephony BCD" - packed BCD, with
 		 * digits 0-9 and symbols B, C, *, and #.
 		 */
-		strptr = tvb_get_bcd_string(scope, tvb, offset, length, &Dgt_ansi_tbcd, FALSE);
+		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_ansi_tbcd, skip_first, odd);
 		break;
 
 	case ENC_3GPP_TS_23_038_7BITS_UNPACKED:
@@ -4130,10 +4137,11 @@ tvb_bytes_to_str_punct(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset
  * byte), formating the digits into characters according to the
  * input digit set, and return a pointer to a UTF-8 string, allocated
  * using the wmem scope.  A high-order nibble of 0xf is considered a
- * 'filler' and will end the conversion.
+ * 'filler' and will end the conversion. Similarrily if odd is set thje last
+ * high nibble will be omitted.
  */
 gchar *
-tvb_get_bcd_string(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, gint len, const dgt_set_t *dgt, gboolean skip_first)
+tvb_get_bcd_string(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, gint len, const dgt_set_t *dgt, gboolean skip_first, gboolean odd)
 {
 	const guint8 *ptr;
 	int           i = 0;
@@ -4185,7 +4193,10 @@ tvb_get_bcd_string(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, gi
 			 */
 			break;
 		}
-
+		if ((len == 1) && (odd == TRUE )){
+			/* Last octet, skipp last high nibble incase of odd number digits*/
+			break;
+		}
 		digit_str[i] = dgt->out[octet & 0x0f];
 		i++;
 
@@ -4196,13 +4207,14 @@ tvb_get_bcd_string(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, gi
 	return digit_str;
 }
 
+/* XXXX Fix me - needs odd indicator added */
 const gchar *
 tvb_bcd_dig_to_wmem_packet_str(tvbuff_t *tvb, const gint offset, const gint len, const dgt_set_t *dgt, gboolean skip_first)
 {
 	if (!dgt)
 		dgt = &Dgt0_9_bcd;
 
-	return tvb_get_bcd_string(wmem_packet_scope(), tvb, offset, len, dgt, skip_first);
+	return tvb_get_bcd_string(wmem_packet_scope(), tvb, offset, len, dgt, skip_first, FALSE);
 }
 
 /*
diff --git a/epan/tvbuff.h b/epan/tvbuff.h
index 3d06d09290..01ca3fcb24 100644
--- a/epan/tvbuff.h
+++ b/epan/tvbuff.h
@@ -951,11 +951,12 @@ WS_DLL_PUBLIC const gchar *tvb_bcd_dig_to_wmem_packet_str(tvbuff_t *tvb,
  * byte), formating the digits into characters according to the
  * input digit set, and return a pointer to a UTF-8 string, allocated
  * using the wmem scope.  A high-order nibble of 0xf is considered a
- * 'filler' and will end the conversion.
+ * 'filler' and will end the conversion. If odd is set the high order
+ * nibble in the last octet will be skipped
  */
 WS_DLL_PUBLIC gchar *tvb_get_bcd_string(wmem_allocator_t *scope, tvbuff_t *tvb,
     const gint offset, gint len, const dgt_set_t *dgt,
-    gboolean skip_first);
+    gboolean skip_first, gboolean odd);
 
 /** Locate a sub-tvbuff within another tvbuff, starting at position
  * 'haystack_offset'. Returns the index of the beginning of 'needle' within