From Michael Lum via https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=9550 :

GSM SMS UDH EMS control expects 4 octets instead of 3 with OPTIONAL 4th

svn path=/trunk/; revision=53940

1 files changed, 21 insertions, 14 deletions

diff --git a/epan/dissectors/packet-gsm_sms.c b/epan/dissectors/packet-gsm_sms.c
index edfabf3377..1ad9fc87ae 100644
--- a/epan/dissectors/packet-gsm_sms.c
+++ b/epan/dissectors/packet-gsm_sms.c
@@ -2093,7 +2093,7 @@ dis_iei_tf(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint8 length)
     proto_tree  *subtree_colour;
 
 
-    EXACT_DATA_CHECK(length, 4);
+    SHORT_DATA_CHECK(length, 3);
     oct = tvb_get_guint8(tvb, offset);
 
     proto_tree_add_text(tree, tvb, offset, 1,
@@ -2178,23 +2178,28 @@ dis_iei_tf(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint8 length)
                         oct & 0x80 , str);
 
     offset++;
-    oct = tvb_get_guint8(tvb, offset);
-    item_colour = proto_tree_add_text(tree, tvb, offset, 1, "Text Colour");
 
-    subtree_colour = proto_item_add_subtree(item_colour, ett_udh_tfc);
+    if (length > 3)
+    {
+        oct = tvb_get_guint8(tvb, offset);
+        item_colour = proto_tree_add_text(tree, tvb, offset, 1, "Text Colour");
 
+        subtree_colour = proto_item_add_subtree(item_colour, ett_udh_tfc);
 
-    str = val_to_str_ext_const(oct & 0x0f, &text_color_values_ext, "Unknown");
-    proto_tree_add_text(subtree_colour, tvb, offset, 1,
-                        "Foreground Colour : 0x%x %s",
-                        oct & 0x0f , str);
 
-    str = val_to_str_ext_const((oct >> 4) & 0x0f, &text_color_values_ext, "Unknown");
-    proto_tree_add_text(subtree_colour,
-                        tvb, offset, 1,
-                        "Background Colour : 0x%x %s",
-                        (oct >> 4) & 0x0f , str);
+        str = val_to_str_ext_const(oct & 0x0f, &text_color_values_ext, "Unknown");
+        proto_tree_add_text(subtree_colour, tvb, offset, 1,
+                            "Foreground Colour : 0x%x %s",
+                            oct & 0x0f , str);
 
+        str = val_to_str_ext_const((oct >> 4) & 0x0f, &text_color_values_ext, "Unknown");
+        proto_tree_add_text(subtree_colour,
+                            tvb, offset, 1,
+                            "Background Colour : 0x%x %s",
+                            (oct >> 4) & 0x0f , str);
+
+        offset++;
+    }
 }
 
 /* 9.2.3.24.10.1.2 */
@@ -3777,7 +3782,7 @@ proto_register_gsm_sms(void)
         };
 
     /* Setup protocol subtree array */
-#define NUM_INDIVIDUAL_PARMS        12
+#define NUM_INDIVIDUAL_PARMS        14
     gint *ett[NUM_INDIVIDUAL_PARMS/*+NUM_MSGS*/+NUM_UDH_IEIS+2];
 
     ett[0]  = &ett_gsm_sms;
@@ -3792,6 +3797,8 @@ proto_register_gsm_sms(void)
     ett[9]  = &ett_dcs;
     ett[10] = &ett_ud;
     ett[11] = &ett_udh;
+    ett[12] = &ett_udh_tfm;
+    ett[13] = &ett_udh_tfc;
 
     last_offset = NUM_INDIVIDUAL_PARMS;