Use dissect_e212_imsi() to dissect IMSI

Fix dissection when MCC starts in the high nibble.
Replace deprecated APIs

Change-Id: Ic08a1db9ee7ebb535bf7914191807304e9f88981
Reviewed-on: https://code.wireshark.org/review/3736
Reviewed-by: Anders Broman <a.broman58@gmail.com>

2 files changed, 100 insertions, 50 deletions

diff --git a/epan/dissectors/packet-e212.c b/epan/dissectors/packet-e212.c
index 30a07aa52a..c23027d362 100644
--- a/epan/dissectors/packet-e212.c
+++ b/epan/dissectors/packet-e212.c
@@ -2783,6 +2783,94 @@ dissect_e212_mcc_mnc_in_address(tvbuff_t *tvb, packet_info *pinfo, proto_tree *t
         return 5;
 }
 
+/*
+ * MNC of length 2:
+ *
+ *     8   7   6   5   4   3   2   1
+ *   +---+---+---+---+---+---+---+---+
+ *   |  MCC digit 1  |  Other data   |  octet x
+ *   +---------------+---------------+
+ *   |  MNC digit 1  |  MCC digit 2  |  octet x+1
+ *   +---------------+---------------+
+ *   | MNC digit  3  |  MNC digit 2  |  octet x+2
+ *   +---------------+---------------+
+ *
+ * MNC of length 3:
+ *
+ *     8   7   6   5   4   3   2   1
+ *   +---+---+---+---+---+---+---+---+
+ *   |  MCC digit 1  |  Other data   |  octet x
+ *   +---------------+---------------+
+ *   |  MCC digit 3  |  MCC digit 2  |  octet x+1
+ *   +---------------+---------------+
+ *   |  MNC digit 2  |  MNC digit 1  |  octet x+2
+ *   +---------------+---------------+
+ *   |  .....        |  MNC digit 3  |  octet x+3
+ *   +---------------+---------------+
+ */
+static int
+dissect_e212_mcc_mnc_high_nibble(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int offset)
+{
+
+    guint32     start_offset;
+    guint8      octet;
+    guint16     mcc, mnc;
+    guint8      mcc1, mcc2, mcc3, mnc1, mnc2, mnc3;
+    proto_item *item;
+    gboolean    long_mnc;
+
+    long_mnc = FALSE;
+    start_offset = offset;
+
+    /* MCC digits 1 */
+    octet = tvb_get_guint8(tvb,offset);
+    mcc1  = octet >> 4;
+    offset++;
+
+    /* MCC digits 1 and 2 */
+    octet = tvb_get_guint8(tvb,offset);
+    mcc2  = octet & 0x0f;
+    mcc3  = octet >> 4;
+    offset++;
+
+	/* MNC digit 1 and MNC digit 2 */
+    octet = tvb_get_guint8(tvb,offset);
+    mnc1  = octet & 0x0f;
+    mnc2  = octet >> 4;
+    offset++;
+
+    /* MNC digits 3 */
+    octet = tvb_get_guint8(tvb,offset);
+    mnc3  = octet & 0x0f;
+
+    mcc   = 100 * mcc1 + 10 * mcc2 + mcc3;
+    mnc   = 10 * mnc1 + mnc2;
+
+    /* Try to match the MCC and 2 digits MNC with an entry in our list of operators */
+    if (!try_val_to_str_ext(mcc * 1000 + 10 * mnc, &mcc_mnc_codes_ext)) {
+        mnc = 10 * mnc + mnc3;
+        long_mnc = TRUE;
+    }
+
+    item = proto_tree_add_uint(tree, hf_E212_mcc , tvb, start_offset, 2, mcc );
+
+    if (long_mnc)
+        item = proto_tree_add_uint_format_value(tree, hf_E212_mnc , tvb, start_offset + 1, 2, mnc,
+                   "%s (%03u)",
+                   val_to_str_ext_const(mcc * 1000 + mnc, &mcc_mnc_codes_ext, "Unknown"),
+                   mnc);
+    else
+        item = proto_tree_add_uint_format_value(tree, hf_E212_mnc , tvb, start_offset + 1, 2, mnc,
+                   "%s (%02u)",
+                   val_to_str_ext_const(mcc * 1000 + 10 * mnc, &mcc_mnc_codes_ext, "Unknown"),
+                   mnc);
+
+    if (long_mnc)
+        return 7;
+    else
+        return 5;
+
+}
 const gchar *
 dissect_e212_imsi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int offset, int length, gboolean skip_first)
 {
@@ -2799,7 +2887,11 @@ dissect_e212_imsi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int offse
 
     subtree = proto_item_add_subtree(item, ett_e212_imsi);
 
-    dissect_e212_mcc_mnc_in_address(tvb, pinfo, subtree, offset);
+	if(skip_first){
+	    dissect_e212_mcc_mnc_high_nibble(tvb, pinfo, subtree, offset);
+	}else{
+	    dissect_e212_mcc_mnc_in_address(tvb, pinfo, subtree, offset);
+	}
 
     return imsi_str;
 }
diff --git a/epan/dissectors/packet-nas_eps.c b/epan/dissectors/packet-nas_eps.c
index 8ad5e7fbf4..c21e4db532 100644
--- a/epan/dissectors/packet-nas_eps.c
+++ b/epan/dissectors/packet-nas_eps.c
@@ -1009,47 +1009,6 @@ static const value_string nas_eps_emm_eps_att_type_vals[] = {
 /*
  * 9.9.3.12 EPS mobile identity
  */
-static char *
-unpack_eps_mid_digits(tvbuff_t *tvb) {
-
-    int     length;
-    guint8  octet;
-    int     i      = 0;
-    int     offset = 0;
-    char   *digit_str;
-
-    length = tvb_length(tvb);
-
-    digit_str = (char *)wmem_alloc(wmem_packet_scope(), length*2);
-
-    /* Get identity digit 1 */
-    octet = tvb_get_guint8(tvb,offset);
-    digit_str[i++] = (((octet>>4) & 0x0f) + '0');
-    offset++;
-
-    /* Loop on following octets to retrieve other identity digits */
-    while ( offset < length ) {
-
-        octet = tvb_get_guint8(tvb,offset);
-        digit_str[i] = ((octet & 0x0f) + '0');
-        i++;
-
-        /*
-         * unpack second value in byte
-         */
-        octet = octet >> 4;
-
-        if (octet == 0x0f)  /* odd number bytes - hit filler */
-            break;
-
-        digit_str[i] = ((octet & 0x0f) + '0');
-        i++;
-        offset++;
-
-    }
-    digit_str[i]= '\0';
-    return digit_str;
-}
 
 static const value_string nas_eps_emm_type_of_id_vals[] = {
     { 0,    "reserved"},
@@ -1069,7 +1028,7 @@ de_emm_eps_mid(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo,
 {
     guint32   curr_offset;
     guint8    octet;
-    char     *digit_str;
+    const char     *digit_str;
     tvbuff_t *new_tvb;
 
     curr_offset = offset;
@@ -1082,13 +1041,12 @@ de_emm_eps_mid(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo,
         case 1:
             /* IMSI */
             new_tvb = tvb_new_subset_length(tvb, curr_offset, len);
-            digit_str = unpack_eps_mid_digits(new_tvb);
-            proto_tree_add_string(tree, hf_nas_eps_emm_imsi, new_tvb, 0, -1, digit_str);
+			dissect_e212_imsi(new_tvb, pinfo, tree,  0, len, TRUE);
             break;
         case 3:
             /* IMEI */
             new_tvb = tvb_new_subset_length(tvb, curr_offset, len);
-            digit_str = unpack_eps_mid_digits(new_tvb);
+            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);
             break;
         case 6:
@@ -4671,7 +4629,7 @@ disect_nas_eps_esm_msg(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int
     void       (*msg_fcn_p)(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo, guint32 offset, guint len);
     guint8       oct;
 
-    len = tvb_length(tvb);
+    len = tvb_reported_length(tvb);
     /*
      * EPS bearer identity 9.3.2
      */
@@ -4736,7 +4694,7 @@ dissect_nas_eps_emm_msg(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int
     void       (*msg_fcn_p)(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo, guint32 offset, guint len);
     guint8       security_header_type, oct;
 
-    len = tvb_length(tvb);
+    len = tvb_reported_length(tvb);
 
     /* 9.3.1    Security header type */
     if (second_header) {
@@ -4820,7 +4778,7 @@ dissect_nas_eps_plain(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
         /* Protocol discriminator Protocol discriminator 9.2 M V 1/2 */
         proto_tree_add_item(nas_eps_tree, hf_gsm_a_L3_protocol_discriminator, tvb, 0, 1, ENC_BIG_ENDIAN);
         offset++;
-        nas_emm_service_req(tvb, nas_eps_tree, pinfo, offset, tvb_length(tvb)-offset);
+        nas_emm_service_req(tvb, nas_eps_tree, pinfo, offset, tvb_reported_length(tvb)-offset);
         return;
     }
 
@@ -4897,7 +4855,7 @@ dissect_nas_eps(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
     guint32     len;
     guint32     msg_auth_code;
 
-    len = tvb_length(tvb);
+    len = tvb_reported_length(tvb);
     /* The protected NAS message header is 6 octets long, and the NAS message header is at least 2 octets long. */
     /* If the length of the tvbuffer is less than 8 octets, we can safely conclude the message is not protected. */
     if (len < 8) {