Wireshark · Ethereal-dev: [Ethereal-dev] packet-gsm_sms.c patch to enable a proper decoding of a 7-bit encoded alphanumeric SM

[Viorel Suman <vsuman@xxxxxxxx>]

Hello,

Attached is a "packet-gsm_sms.c" dissector patch, which
enable a proper decoding of the 7-bit encoded
alphanumeric SMS TP-Originating Address.

Looking for comments/suggestions.
It would be nice to have it checked it.

WBR,

Viorel Suman
Software Developer

Avalanche Mobile BV (http://www.avmob.com)
Busitel 1, Orlyplein 85
1043 DS Amsterdam
The Netherlands

Phone: +31 (0) 20 403 74 70
Fax:   +31 (0) 20 403 73 10

--- ethereal-0.10.9-original/epan/dissectors/packet-gsm_sms.c	2005-01-18 04:39:56.000000000 +0200
+++ ethereal-0.10.9/epan/dissectors/packet-gsm_sms.c	2005-02-17 10:56:26.078736549 +0200
@@ -243,7 +243,6 @@
     guint32		length;
     guint32		i, j;
 
-
     offset = *offset_p;
 
     oct = tvb_get_guint8(tvb, offset);
@@ -331,16 +330,25 @@
     offset++;
 
     j = 0;
-    for (i = 0; i < numdigocts; i++)
+    switch ((oct & 0x70) >> 4)
     {
-	oct = tvb_get_guint8(tvb, offset + i);
+    case 0x05: /* "Alphanumeric (coded according to 3GPP TS 23.038 GSM 7-bit default alphabet)" */
+	i = gsm_sms_char_7bit_unpack(0, numdigocts, sizeof(bigbuf), tvb_get_ptr(tvb, offset, numdigocts), bigbuf);
+	bigbuf[i] = '\0';
+	gsm_sms_char_ascii_decode(bigbuf, bigbuf, i);
+	break;
+    default:
+	for (i = 0; i < numdigocts; i++)
+	{
+	    oct = tvb_get_guint8(tvb, offset + i);
 
-        bigbuf[j++] = digit_table[oct & 0x0f];
-        bigbuf[j++] = digit_table[(oct & 0xf0) >> 4];
+	    bigbuf[j++] = digit_table[oct & 0x0f];
+	    bigbuf[j++] = digit_table[(oct & 0xf0) >> 4];
+	}
+	bigbuf[j++] = '\0';
+	break;
     }
 
-    bigbuf[j++] = '\0';
-
     proto_tree_add_text(subtree,
 	tvb, offset, numdigocts,
 	"Digits: %s",
@@ -348,7 +356,7 @@
 
     proto_item_append_text(item, " - (%s)", bigbuf);
 
-    *offset_p = offset + i;
+    *offset_p = offset + numdigocts;
 }
 
 /* 9.2.3.7 */