Add tvbuff class.

Add exceptions routines.
Convert proto_tree_add_*() routines to require tvbuff_t* argument.
Convert all dissectors to pass NULL argument ("NullTVB" macro == NULL) as
the tvbuff_t* argument to proto_tree_add_*() routines.

dissect_packet() creates a tvbuff_t, wraps the next dissect call in
a TRY block, will print "Short Frame" on the proto_tree if a BoundsError
exception is caught.

The FDDI dissector is converted to use tvbuff's.

svn path=/trunk/; revision=1939

1 files changed, 132 insertions, 132 deletions

diff --git a/packet-q931.c b/packet-q931.c
index bb568c236f..001f33afb2 100644
--- a/packet-q931.c
+++ b/packet-q931.c
@@ -2,7 +2,7 @@
  * Routines for Q.931 frame disassembly
  * Guy Harris <guy@alum.mit.edu>
  *
- * $Id: packet-q931.c,v 1.13 2000/01/13 05:41:21 guy Exp $
+ * $Id: packet-q931.c,v 1.14 2000/05/11 08:15:39 gram Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -314,20 +314,20 @@ dissect_q931_segmented_message_ie(const u_char *pd, int offset, int len,
     proto_tree *tree)
 {
 	if (len != 2) {
-		proto_tree_add_text(tree, offset, len,
+		proto_tree_add_text(tree, NullTVB, offset, len,
 		    "Segmented message: length is %d, should be 2\n", len);
 		return;
 	}
 	if (pd[offset] & 0x80) {
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "First segment: %u segments remaining",
 		    pd[offset] & 0x7F);
 	} else {
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Not first segment: %u segments remaining",
 		    pd[offset] & 0x7F);
 	}
-	proto_tree_add_text(tree, offset + 1, 1,
+	proto_tree_add_text(tree, NullTVB, offset + 1, 1,
 	    "Segmented message type: %u\n", pd[offset + 1]);
 }
 
@@ -522,7 +522,7 @@ dissect_q931_bearer_capability_ie(const u_char *pd, int offset, int len,
 		return;
 	octet = pd[offset];
 	coding_standard = octet & 0x60;
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Coding standard: %s",
 	    val_to_str(coding_standard, q931_bc_coding_standard_vals, NULL));
 	if (coding_standard != Q931_ITU_STANDARDIZED_CODING) {
@@ -530,11 +530,11 @@ dissect_q931_bearer_capability_ie(const u_char *pd, int offset, int len,
 		 * We don't know how the bearer capability is encoded,
 		 * so just dump it as data and be done with it.
 		 */
-		proto_tree_add_text(tree, offset,
+		proto_tree_add_text(tree, NullTVB, offset,
 		    len, "Data: %s", bytes_to_str(&pd[offset], len));
 		return;
 	}
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Information transfer capability: %s",
 	    val_to_str(octet & 0x1F, q931_information_transfer_capability_vals,
 	      "Unknown (0x%02X)"));
@@ -548,7 +548,7 @@ dissect_q931_bearer_capability_ie(const u_char *pd, int offset, int len,
 		if (len == 0)
 			return;
 		octet = pd[offset];
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Out-band negotiation %spossible",
 		    (octet & 0x40) ? "" : "not ");
 		offset += 1;
@@ -558,12 +558,12 @@ dissect_q931_bearer_capability_ie(const u_char *pd, int offset, int len,
 	if (len == 0)
 		return;
 	octet = pd[offset];
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Transfer mode: %s",
 	    val_to_str(octet & 0x60, q931_transfer_mode_vals,
 	      "Unknown (0x%02X)"));
 	it_rate = octet & 0x1F;
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Information transfer rate: %s",
 	    val_to_str(it_rate, q931_information_transfer_rate_vals,
 	      "Unknown (0x%02X)"));
@@ -573,7 +573,7 @@ dissect_q931_bearer_capability_ie(const u_char *pd, int offset, int len,
 	if (it_rate == Q931_IT_RATE_MULTIRATE) {
 		if (len == 0)
 			return;
-		proto_tree_add_text(tree, offset, 1, "Rate multiplier: %u", pd[offset]);
+		proto_tree_add_text(tree, NullTVB, offset, 1, "Rate multiplier: %u", pd[offset]);
 		offset += 1;
 		len -= 1;
 	}
@@ -585,7 +585,7 @@ dissect_q931_bearer_capability_ie(const u_char *pd, int offset, int len,
 		/*
 		 * Layer 1 information.
 		 */
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "User information layer 1 protocol: %s",
 		    val_to_str(octet & 0x1F, q931_uil1_vals,
 		      "Unknown (0x%02X)"));
@@ -597,13 +597,13 @@ dissect_q931_bearer_capability_ie(const u_char *pd, int offset, int len,
 		if (len == 0)
 			return;
 		octet = pd[offset];
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Layer 1 is %s",
 		    (octet & 0x40) ? "Asynchronous" : "Synchronous");
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Layer 1 in-band negotiation is %spossible",
 		    (octet & 0x20) ? "" : "not ");
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "User rate: %s",
 		    val_to_str(octet & 0x1F, q931_l1_user_rate_vals,
 		      "Unknown (0x%02X)"));
@@ -615,20 +615,20 @@ dissect_q931_bearer_capability_ie(const u_char *pd, int offset, int len,
 		if (len == 0)
 			return;
 		octet = pd[offset];
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Intermediate rate: %s",
 		      val_to_str(octet & 0x60, q931_l1_intermediate_rate_vals,
 		       "Unknown (0x%X)"));
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "%s to send data with network independent clock",
 		    (octet & 0x10) ? "Required" : "Not required");
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "%s accept data with network independent clock",
 		    (octet & 0x08) ? "Can" : "Cannot");
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "%s to send data with flow control mechanism",
 		    (octet & 0x04) ? "Required" : "Not required");
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "%s accept data with flow control mechanism",
 		    (octet & 0x02) ? "Can" : "Cannot");
 		offset += 1;
@@ -639,22 +639,22 @@ dissect_q931_bearer_capability_ie(const u_char *pd, int offset, int len,
 		if (len == 0)
 			return;
 		octet = pd[offset];
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Rate adaption header %sincluded",
 		    (octet & 0x40) ? "" : "not ");
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Multiple frame establishment %ssupported",
 		    (octet & 0x20) ? "" : "not ");
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "%s mode of operation",
 		    (octet & 0x10) ? "Protocol sensitive" : "Bit transparent");
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    (octet & 0x08) ?
 		      "Full protocol negotiation" : "LLI = 256 only");
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Message originator is %s",
 		    (octet & 0x04) ? "Assignor only" : "Default assignee");
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Negotiation is done %s",
 		    (octet & 0x02) ? "in-band" : "out-of-band");
 		offset += 1;
@@ -665,15 +665,15 @@ dissect_q931_bearer_capability_ie(const u_char *pd, int offset, int len,
 		if (len == 0)
 			return;
 		octet = pd[offset];
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Stop bits: %s",
 		      val_to_str(octet & 0x60, q931_l1_stop_bits_vals,
 		       "Unknown (0x%X)"));
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Data bits: %s",
 		      val_to_str(octet & 0x18, q931_l1_data_bits_vals,
 		       "Unknown (0x%X)"));
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Parity: %s",
 		      val_to_str(octet & 0x08, q931_l1_parity_vals,
 		       "Unknown (0x%X)"));
@@ -683,19 +683,19 @@ dissect_q931_bearer_capability_ie(const u_char *pd, int offset, int len,
 		if (len == 0)
 			return;
 		octet = pd[offset];
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "%s duplex",
 		    (octet & 0x40) ? "Full" : "Half");
 		modem_type = octet & 0x3F;
 		if (modem_type <= 0x5 ||
 		    (modem_type >= 0x20 && modem_type <= 0x2F)) {
-			proto_tree_add_text(tree, offset, 1,
+			proto_tree_add_text(tree, NullTVB, offset, 1,
 			    "Modem type: National use 0x%02X", modem_type);
 		} else if (modem_type >= 0x30) {
-			proto_tree_add_text(tree, offset, 1,
+			proto_tree_add_text(tree, NullTVB, offset, 1,
 			    "Modem type: User specified 0x%02X", modem_type);
 		} else {
-			proto_tree_add_text(tree, offset, 1,
+			proto_tree_add_text(tree, NullTVB, offset, 1,
 			    "Modem type: %s",
 			      val_to_str(modem_type, q931_l1_modem_type_vals,
 			      NULL));
@@ -714,7 +714,7 @@ l1_done:
 		 * Layer 2 information.
 		 */
 		uil2_protocol = octet & 0x1F;
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "User information layer 2 protocol: %s",
 		    val_to_str(uil2_protocol, q931_uil2_vals,
 		      "Unknown (0x%02X)"));
@@ -730,11 +730,11 @@ l1_done:
 			return;
 		octet = pd[offset];
 		if (uil2_protocol == Q931_UIL2_USER_SPEC) {
-			proto_tree_add_text(tree, offset, 1,
+			proto_tree_add_text(tree, NullTVB, offset, 1,
 			    "User-specified layer 2 protocol information: 0x%02X",
 			    octet & 0x7F);
 		} else {
-			proto_tree_add_text(tree, offset, 1,
+			proto_tree_add_text(tree, NullTVB, offset, 1,
 			    "Mode: %s",
 			    val_to_str(octet & 0x60, q931_mode_vals,
 			      "Unknown (0x%02X)"));
@@ -747,7 +747,7 @@ l1_done:
 		if (len == 0)
 			return;
 		octet = pd[offset];
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Window size: %u k", octet & 0x7F);
 		offset += 1;
 		len -= 1;
@@ -763,7 +763,7 @@ l2_done:
 		 * Layer 3 information.
 		 */
 		uil3_protocol = octet & 0x1F;
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "User information layer 3 protocol: %s",
 		    val_to_str(uil3_protocol, q931_uil3_vals,
 		      "Unknown (0x%02X)"));
@@ -784,7 +784,7 @@ l2_done:
 		case Q931_UIL3_X25_PL:
 		case Q931_UIL3_ISO_8208:
 		case Q931_UIL3_X223:
-			proto_tree_add_text(tree, offset, 1,
+			proto_tree_add_text(tree, NullTVB, offset, 1,
 			    "Mode: %s",
 			    val_to_str(octet & 0x60, q931_mode_vals,
 			      "Unknown (0x%02X)"));
@@ -796,7 +796,7 @@ l2_done:
 			if (len == 0)
 				return;
 			octet = pd[offset];
-			proto_tree_add_text(tree, offset, 1,
+			proto_tree_add_text(tree, NullTVB, offset, 1,
 			    "Default packet size: %u", octet & 0x0F);
 			offset += 1;
 			len -= 1;
@@ -806,14 +806,14 @@ l2_done:
 			if (len == 0)
 				return;
 			octet = pd[offset];
-			proto_tree_add_text(tree, offset, 1,
+			proto_tree_add_text(tree, NullTVB, offset, 1,
 			    "Packet window size: %u", octet & 0x7F);
 			offset += 1;
 			len -= 1;
 			break;
 
 		case Q931_UIL3_USER_SPEC:
-			proto_tree_add_text(tree, offset, 1,
+			proto_tree_add_text(tree, NullTVB, offset, 1,
 			    "Default packet size: %u octets",
 			    1 << (octet & 0x0F));
 			offset += 1;
@@ -828,7 +828,7 @@ l2_done:
 				return;
 			octet = pd[offset + 1];
 			add_l3_info |= (octet & 0x0F);
-			proto_tree_add_text(tree, offset, 2,
+			proto_tree_add_text(tree, NullTVB, offset, 2,
 			    "Additional layer 3 protocol information: %s",
 			    val_to_str(add_l3_info, nlpid_vals,
 			      "Unknown (0x%02X)"));
@@ -976,7 +976,7 @@ dissect_q931_cause_ie(const u_char *pd, int offset, int len,
 		return;
 	octet = pd[offset];
 	coding_standard = octet & 0x60;
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Coding standard: %s",
 	    val_to_str(coding_standard, q931_cause_coding_standard_vals, NULL));
 	if (coding_standard != Q931_ITU_STANDARDIZED_CODING) {
@@ -984,11 +984,11 @@ dissect_q931_cause_ie(const u_char *pd, int offset, int len,
 		 * We don't know how the cause is encoded,
 		 * so just dump it as data and be done with it.
 		 */
-		proto_tree_add_text(tree, offset,
+		proto_tree_add_text(tree, NullTVB, offset,
 		    len, "Data: %s", bytes_to_str(&pd[offset], len));
 		return;
 	}
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Location: %s",
 	    val_to_str(octet & 0x0F, q931_cause_location_vals,
 	      "Unknown (0x%X)"));
@@ -999,7 +999,7 @@ dissect_q931_cause_ie(const u_char *pd, int offset, int len,
 		if (len == 0)
 			return;
 		octet = pd[offset];
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Recommendation: %s",
 		    val_to_str(octet & 0x7F, q931_cause_recommendation_vals,
 		      "Unknown (0x%X)"));
@@ -1010,7 +1010,7 @@ dissect_q931_cause_ie(const u_char *pd, int offset, int len,
 	if (len == 0)
 		return;
 	octet = pd[offset];
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Cause value: %s",
 	    val_to_str(octet & 0x7F, q931_cause_code_vals,
 	      "Unknown (0x%X)"));
@@ -1019,7 +1019,7 @@ dissect_q931_cause_ie(const u_char *pd, int offset, int len,
 
 	if (len == 0)
 		return;
-	proto_tree_add_text(tree, offset, len,
+	proto_tree_add_text(tree, NullTVB, offset, len,
 	    "Diagnostics: %s",
 	    bytes_to_str(&pd[offset], len));
 }
@@ -1068,7 +1068,7 @@ dissect_q931_call_state_ie(const u_char *pd, int offset, int len,
 		return;
 	octet = pd[offset];
 	coding_standard = octet & 0x60;
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Coding standard: %s",
 	    val_to_str(coding_standard, q931_coding_standard_vals, NULL));
 	if (coding_standard != Q931_ITU_STANDARDIZED_CODING) {
@@ -1076,11 +1076,11 @@ dissect_q931_call_state_ie(const u_char *pd, int offset, int len,
 		 * We don't know how the call state is encoded,
 		 * so just dump it as data and be done with it.
 		 */
-		proto_tree_add_text(tree, offset,
+		proto_tree_add_text(tree, NullTVB, offset,
 		    len, "Data: %s", bytes_to_str(&pd[offset], len));
 		return;
 	}
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Call state: %s",
 	    val_to_str(octet & 0x3F, q931_call_state_vals,
 	      "Unknown (0x%02X)"));
@@ -1129,25 +1129,25 @@ dissect_q931_channel_identification_ie(const u_char *pd, int offset, int len,
 	if (len == 0)
 		return;
 	octet = pd[offset];
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Interface %s identified",
 	    (octet & Q931_INTERFACE_IDENTIFIED) ? "explicitly" : "implicitly");
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "%s interface",
 	    (octet & Q931_NOT_BASIC_CHANNEL) ? "Not basic" : "Basic");
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Indicated channel is %s",
 	    (octet & 0x08) ? "required" : "preferred");
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Indicated channel is %sthe D-channel",
 	    (octet & 0x04) ? "" : "not ");
 	if (octet & Q931_NOT_BASIC_CHANNEL) {
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Channel selection: %s",
 		    val_to_str(octet & 0x03, q931_not_basic_channel_selection_vals,
 		      NULL));
 	} else {
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Channel selection: %s",
 		    val_to_str(octet & 0x03, q931_basic_channel_selection_vals,
 		      NULL));
@@ -1172,7 +1172,7 @@ dissect_q931_channel_identification_ie(const u_char *pd, int offset, int len,
 		 * last octet of the interface identifier?
 		 */
 		if (identifier_len != 0) {
-			proto_tree_add_text(tree, identifier_offset,
+			proto_tree_add_text(tree, NullTVB, identifier_offset,
 			    identifier_len, "Interface identifier: %s",
 			    bytes_to_str(&pd[identifier_offset],
 			      identifier_len));
@@ -1184,7 +1184,7 @@ dissect_q931_channel_identification_ie(const u_char *pd, int offset, int len,
 			return;
 		octet = pd[offset];
 		coding_standard = octet & 0x60;
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Coding standard: %s",
 		    val_to_str(coding_standard, q931_coding_standard_vals,
 		      NULL));
@@ -1194,14 +1194,14 @@ dissect_q931_channel_identification_ie(const u_char *pd, int offset, int len,
 			 * encoded, so just dump it as data and be done
 			 * with it.
 			 */
-			proto_tree_add_text(tree, offset,
+			proto_tree_add_text(tree, NullTVB, offset,
 			    len, "Data: %s", bytes_to_str(&pd[offset], len));
 			return;
 		}
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Channel is indicated by %s",
 		    (octet & Q931_IS_SLOT_MAP) ? "slot map" : "number");
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "%s type: %s",
 		    (octet & Q931_IS_SLOT_MAP) ? "Map element" : "Channel",
 		    val_to_str(octet & 0x0F, q931_element_type_vals,
@@ -1237,7 +1237,7 @@ dissect_q931_progress_indicator_ie(const u_char *pd, int offset, int len,
 		return;
 	octet = pd[offset];
 	coding_standard = octet & 0x60;
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Coding standard: %s",
 	    val_to_str(coding_standard, q931_cause_coding_standard_vals, NULL));
 	if (coding_standard != Q931_ITU_STANDARDIZED_CODING) {
@@ -1245,11 +1245,11 @@ dissect_q931_progress_indicator_ie(const u_char *pd, int offset, int len,
 		 * We don't know how the progress indicator is encoded,
 		 * so just dump it as data and be done with it.
 		 */
-		proto_tree_add_text(tree, offset,
+		proto_tree_add_text(tree, NullTVB, offset,
 		    len, "Data: %s", bytes_to_str(&pd[offset], len));
 		return;
 	}
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Location: %s",
 	    val_to_str(octet & 0x0F, q931_cause_location_vals,
 	      "Unknown (0x%X)"));
@@ -1259,7 +1259,7 @@ dissect_q931_progress_indicator_ie(const u_char *pd, int offset, int len,
 	if (len == 0)
 		return;
 	octet = pd[offset];
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Progress description: %s",
 	    val_to_str(octet & 0x7F, q931_progress_description_vals,
 	      "Unknown (0x%02X)"));
@@ -1294,7 +1294,7 @@ dissect_q931_ns_facilities_ie(const u_char *pd, int offset, int len,
 		return;
 	octet = pd[offset];
 	netid_len = octet & 0x7F;
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Network identification length: %u",
 	    netid_len);
 	offset += 1;
@@ -1303,11 +1303,11 @@ dissect_q931_ns_facilities_ie(const u_char *pd, int offset, int len,
 		if (len == 0)
 			return;
 		octet = pd[offset];
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Type of network identification: %s",
 		    val_to_str(octet & 0x70, q931_netid_type_vals,
 		      "Unknown (0x%02X)"));
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Network identification plan: %s",
 		    val_to_str(octet & 0x0F, q931_netid_plan_vals,
 		      "Unknown (0x%02X)"));
@@ -1320,7 +1320,7 @@ dissect_q931_ns_facilities_ie(const u_char *pd, int offset, int len,
 		if (netid_len > len)
 			netid_len = len;
 		if (netid_len != 0) {
-			proto_tree_add_text(tree, offset, netid_len,
+			proto_tree_add_text(tree, NullTVB, offset, netid_len,
 			    "Network identification: %.*s",
 			    netid_len, &pd[offset]);
 			offset += netid_len;
@@ -1334,7 +1334,7 @@ dissect_q931_ns_facilities_ie(const u_char *pd, int offset, int len,
 	 */
 	 if (len == 0)
 	 	return;
-	proto_tree_add_text(tree, offset,
+	proto_tree_add_text(tree, NullTVB, offset,
 	    len, "Network-specific facility specification: %s",
 	    bytes_to_str(&pd[offset], len));
 }
@@ -1358,7 +1358,7 @@ dissect_q931_notification_indicator_ie(const u_char *pd, int offset, int len,
 	if (len == 0)
 		return;
 	octet = pd[offset];
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Notification description: %s",
 	    val_to_str(octet & 0x7F, q931_notification_description_vals,
 	      "Unknown (0x%02X)"));
@@ -1372,7 +1372,7 @@ dissect_q931_date_time_ie(const u_char *pd, int offset, int len,
     proto_tree *tree)
 {
 	if (len != 6) {
-		proto_tree_add_text(tree, offset, len,
+		proto_tree_add_text(tree, NullTVB, offset, len,
 		    "Date/time: length is %d, should be 6\n", len);
 		return;
 	}
@@ -1380,7 +1380,7 @@ dissect_q931_date_time_ie(const u_char *pd, int offset, int len,
 	 * XXX - what is "year" relative to?  Is "month" 0-origin or
 	 * 1-origin?  Q.931 doesn't say....
 	 */
-	proto_tree_add_text(tree, offset, 6,
+	proto_tree_add_text(tree, NullTVB, offset, 6,
 	    "Date/time: %02u-%02u-%02u %02u:%02u:%02u",
 	    pd[offset + 0], pd[offset + 1], pd[offset + 2],
 	    pd[offset + 3], pd[offset + 4], pd[offset + 5]);
@@ -1418,11 +1418,11 @@ dissect_q931_signal_ie(const u_char *pd, int offset, int len,
     proto_tree *tree)
 {
 	if (len != 1) {
-		proto_tree_add_text(tree, offset, len,
+		proto_tree_add_text(tree, NullTVB, offset, len,
 		    "Signal: length is %d, should be 1\n", len);
 		return;
 	}
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Signal: %s",
 	    val_to_str(pd[offset], q931_signal_vals, "Unknown (0x%02X)"));
 }
@@ -1450,23 +1450,23 @@ dissect_q931_information_rate_ie(const u_char *pd, int offset, int len,
     proto_tree *tree)
 {
 	if (len != 4) {
-		proto_tree_add_text(tree, offset, len,
+		proto_tree_add_text(tree, NullTVB, offset, len,
 		    "Information rate: length is %d, should be 4\n", len);
 		return;
 	}
-	proto_tree_add_text(tree, offset + 0, 1,
+	proto_tree_add_text(tree, NullTVB, offset + 0, 1,
 	    "Incoming information rate: %s",
 	    val_to_str(pd[offset + 0] & 0x1F, q931_throughput_class_vals,
 	      "Unknown (0x%02X)"));
-	proto_tree_add_text(tree, offset + 1, 1,
+	proto_tree_add_text(tree, NullTVB, offset + 1, 1,
 	    "Outgoing information rate: %s",
 	    val_to_str(pd[offset + 1] & 0x1F, q931_throughput_class_vals,
 	      "Unknown (0x%02X)"));
-	proto_tree_add_text(tree, offset + 2, 1,
+	proto_tree_add_text(tree, NullTVB, offset + 2, 1,
 	    "Minimum incoming information rate: %s",
 	    val_to_str(pd[offset + 2] & 0x1F, q931_throughput_class_vals,
 	      "Unknown (0x%02X)"));
-	proto_tree_add_text(tree, offset + 3, 1,
+	proto_tree_add_text(tree, NullTVB, offset + 3, 1,
 	    "Minimum outgoing information rate: %s",
 	    val_to_str(pd[offset + 3] & 0x1F, q931_throughput_class_vals,
 	      "Unknown (0x%02X)"));
@@ -1530,17 +1530,17 @@ dissect_q931_guint16_value(const u_char *pd, int offset, int len,
 	len -= 1;
 	value_len++;
 
-	proto_tree_add_text(tree, offset, value_len, "%s: %u ms", label,
+	proto_tree_add_text(tree, NullTVB, offset, value_len, "%s: %u ms", label,
 	    value);
 	return value_len;
 
 past_end:
-	proto_tree_add_text(tree, offset, len,
+	proto_tree_add_text(tree, NullTVB, offset, len,
 	    "%s goes past end of information element", label);
 	return -1;
 
 bad_length:
-	proto_tree_add_text(tree, offset, len, "%s isn't 3 octets long",
+	proto_tree_add_text(tree, NullTVB, offset, len, "%s isn't 3 octets long",
 	    label);
 	return -1;
 }
@@ -1611,18 +1611,18 @@ dissect_q931_pl_binary_parameters_ie(const u_char *pd, int offset, int len,
 	if (len == 0)
 		return;
 	octet = pd[offset];
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Fast select: %s",
 	    val_to_str(octet & 0x18, q931_fast_selected_vals,
 	      NULL));
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "%s",
 	    (octet & 0x04) ? "No request/request denied" :
 	    		     "Request indicated/request accepted");
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "%s confirmation",
 	    (octet & 0x02) ? "Link-by-link" : "End-to-end");
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Modulus %u sequencing",
 	    (octet & 0x01) ? 8 : 128);
 }
@@ -1636,14 +1636,14 @@ dissect_q931_pl_window_size_ie(const u_char *pd, int offset, int len,
 {
 	if (len == 0)
 		return;
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Forward value: %u", pd[offset] & 0x7F);
 	offset += 1;
 	len -= 1;
 
 	if (len == 0)
 		return;
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Backward value: %u", pd[offset] & 0x7F);
 }
 
@@ -1656,14 +1656,14 @@ dissect_q931_packet_size_ie(const u_char *pd, int offset, int len,
 {
 	if (len == 0)
 		return;
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Forward value: %u", pd[offset] & 0x7F);
 	offset += 1;
 	len -= 1;
 
 	if (len == 0)
 		return;
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Backward value: %u", pd[offset] & 0x7F);
 }
 
@@ -1681,7 +1681,7 @@ dissect_q931_cug_ie(const u_char *pd, int offset, int len, proto_tree *tree)
 {
 	if (len == 0)
 		return;
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "CUG indication: %s",
 	    val_to_str(pd[offset] & 0x07, q931_cug_indication_vals,
 	      "Unknown (0x%02X)"));
@@ -1690,7 +1690,7 @@ dissect_q931_cug_ie(const u_char *pd, int offset, int len, proto_tree *tree)
 
 	if (len == 0)
 		return;
-	proto_tree_add_text(tree, offset, len, "CUG index code: %.*s", len,
+	proto_tree_add_text(tree, NullTVB, offset, len, "CUG index code: %.*s", len,
 	    &pd[offset]);
 }
 
@@ -1708,7 +1708,7 @@ dissect_q931_reverse_charge_ind_ie(const u_char *pd, int offset, int len,
 {
 	if (len == 0)
 		return;
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Reverse charging indication: %s",
 	    val_to_str(pd[offset] & 0x07, q931_reverse_charging_indication_vals,
 	      "Unknown (0x%02X)"));
@@ -1772,11 +1772,11 @@ dissect_q931_number_ie(const u_char *pd, int offset, int len,
 	if (len == 0)
 		return;
 	octet = pd[offset];
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Type of number: %s",
 	    val_to_str(octet & 0x70, q931_number_type_vals,
 	      "Unknown (0x%02X)"));
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Numbering plan: %s",
 	    val_to_str(octet & 0x0F, q931_numbering_plan_vals,
 	      "Unknown (0x%02X)"));
@@ -1787,11 +1787,11 @@ dissect_q931_number_ie(const u_char *pd, int offset, int len,
 		if (len == 0)
 			return;
 		octet = pd[offset];
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Presentation indicator: %s",
 		    val_to_str(octet & 0x60, q931_presentation_indicator_vals,
 		      "Unknown (0x%X)"));
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Screening indicator: %s",
 		    val_to_str(octet & 0x03, q931_screening_indicator_vals,
 		      "Unknown (0x%X)"));
@@ -1806,7 +1806,7 @@ dissect_q931_number_ie(const u_char *pd, int offset, int len,
 		if (len == 0)
 			return;
 		octet = pd[offset];
-		proto_tree_add_text(tree, offset, 1,
+		proto_tree_add_text(tree, NullTVB, offset, 1,
 		    "Reason for redirection: %s",
 		    val_to_str(octet & 0x0F, q931_redirection_reason_vals,
 		      "Unknown (0x%X)"));
@@ -1816,7 +1816,7 @@ dissect_q931_number_ie(const u_char *pd, int offset, int len,
 
 	if (len == 0)
 		return;
-	proto_tree_add_text(tree, offset, len, "Number: %.*s",
+	proto_tree_add_text(tree, NullTVB, offset, len, "Number: %.*s",
 	    len, &pd[offset]);
 }
 
@@ -1844,11 +1844,11 @@ dissect_q931_party_subaddr_ie(const u_char *pd, int offset, int len,
 	if (len == 0)
 		return;
 	octet = pd[offset];
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Type of subaddress: %s",
 	    val_to_str(octet & 0x70, q931_subaddress_type_vals,
 	      "Unknown (0x%02X)"));
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Odd/even indicator: %s",
 	    val_to_str(octet & 0x10, q931_odd_even_indicator_vals,
 	      NULL));
@@ -1857,7 +1857,7 @@ dissect_q931_party_subaddr_ie(const u_char *pd, int offset, int len,
 
 	if (len == 0)
 		return;
-	proto_tree_add_text(tree, offset, len, "Subaddress: %s",
+	proto_tree_add_text(tree, NullTVB, offset, len, "Subaddress: %s",
 	    bytes_to_str(&pd[offset], len));
 }
 
@@ -1876,11 +1876,11 @@ dissect_q931_restart_indicator_ie(const u_char *pd, int offset, int len,
     proto_tree *tree)
 {
 	if (len != 1) {
-		proto_tree_add_text(tree, offset, len,
+		proto_tree_add_text(tree, NullTVB, offset, len,
 		    "Restart indicator: length is %d, should be 1\n", len);
 		return;
 	}
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Restart indicator: %s",
 	    val_to_str(pd[offset] & 0x07, q931_restart_indicator_class_vals,
 	      "Unknown (0x%02X)"));
@@ -1930,7 +1930,7 @@ dissect_q931_high_layer_compat_ie(const u_char *pd, int offset, int len,
 		return;
 	octet = pd[offset];
 	coding_standard = octet & 0x60;
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Coding standard: %s",
 	    val_to_str(coding_standard, q931_coding_standard_vals, NULL));
 	if (coding_standard != Q931_ITU_STANDARDIZED_CODING) {
@@ -1938,7 +1938,7 @@ dissect_q931_high_layer_compat_ie(const u_char *pd, int offset, int len,
 		 * We don't know how the call state is encoded,
 		 * so just dump it as data and be done with it.
 		 */
-		proto_tree_add_text(tree, offset,
+		proto_tree_add_text(tree, NullTVB, offset,
 		    len, "Data: %s", bytes_to_str(&pd[offset], len));
 		return;
 	}
@@ -1947,7 +1947,7 @@ dissect_q931_high_layer_compat_ie(const u_char *pd, int offset, int len,
 		return;
 	octet = pd[offset];
 	characteristics = octet & 0x7F;
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "High layer characteristics identification: %s",
 	    val_to_str(characteristics, q931_high_layer_characteristics_vals,
 	      NULL));
@@ -1959,12 +1959,12 @@ dissect_q931_high_layer_compat_ie(const u_char *pd, int offset, int len,
 			return;
 		octet = pd[offset];
 		if (characteristics == Q931_AUDIOVISUAL) {
-			proto_tree_add_text(tree, offset, 1,
+			proto_tree_add_text(tree, NullTVB, offset, 1,
 			    "Extended audiovisual characteristics identification: %s",
 			    val_to_str(octet & 0x7F, q931_audiovisual_characteristics_vals,
 			      NULL));
 		} else {
-			proto_tree_add_text(tree, offset, 1,
+			proto_tree_add_text(tree, NullTVB, offset, 1,
 			    "Extended high layer characteristics identification: %s",
 			    val_to_str(octet & 0x7F, q931_high_layer_characteristics_vals,
 			      NULL));
@@ -1998,7 +1998,7 @@ dissect_q931_user_user_ie(const u_char *pd, int offset, int len,
 	if (len == 0)
 		return;
 	octet = pd[offset];
-	proto_tree_add_text(tree, offset, 1,
+	proto_tree_add_text(tree, NullTVB, offset, 1,
 	    "Protocol discriminator: %s",
 	    val_to_str(octet, q931_protocol_discriminator_vals,
 	    "Unknown (0x%02x)"));
@@ -2010,12 +2010,12 @@ dissect_q931_user_user_ie(const u_char *pd, int offset, int len,
 	switch (octet) {
 
 	case Q931_PROTOCOL_DISCRIMINATOR_IA5:
-		proto_tree_add_text(tree, offset, len, "User information: %.*s",
+		proto_tree_add_text(tree, NullTVB, offset, len, "User information: %.*s",
 		    len, &pd[offset]);
 		break;
 
 	default:
-		proto_tree_add_text(tree, offset, len, "User information: %s",
+		proto_tree_add_text(tree, NullTVB, offset, len, "User information: %s",
 		    bytes_to_str(&pd[offset], len));
 		break;
 	}
@@ -2029,7 +2029,7 @@ dissect_q931_ia5_ie(const u_char *pd, int offset, int len, proto_tree *tree,
     char *label)
 {
 	if (len != 0) {
-		proto_tree_add_text(tree, offset, len, "%s: %.*s", label, len,
+		proto_tree_add_text(tree, NullTVB, offset, len, "%s: %.*s", label, len,
 		    &pd[offset]);
 	}
 }
@@ -2061,22 +2061,22 @@ dissect_q931(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
 		col_add_str(fd, COL_PROTOCOL, "Q.931");
 
 	if (tree) {
-		ti = proto_tree_add_item(tree, proto_q931, offset,
+		ti = proto_tree_add_item(tree, proto_q931, NullTVB, offset,
 		    END_OF_FRAME, NULL);
 		q931_tree = proto_item_add_subtree(ti, ett_q931);
 
-		proto_tree_add_item(q931_tree, hf_q931_discriminator, offset, 1, pd[offset]);
+		proto_tree_add_item(q931_tree, hf_q931_discriminator, NullTVB, offset, 1, pd[offset]);
 	}
 	offset += 1;
 	call_ref_len = pd[offset] & 0xF;	/* XXX - do as a bit field? */
 	if (q931_tree != NULL)
-		proto_tree_add_item(q931_tree, hf_q931_call_ref_len, offset, 1, call_ref_len);
+		proto_tree_add_item(q931_tree, hf_q931_call_ref_len, NullTVB, offset, 1, call_ref_len);
 	offset += 1;
 	if (call_ref_len != 0) {
 		/* XXX - split this into flag and value */
 		memcpy(call_ref, &pd[offset], call_ref_len);
 		if (q931_tree != NULL)
-			proto_tree_add_item(q931_tree, hf_q931_call_ref, offset, call_ref_len, call_ref);
+			proto_tree_add_item(q931_tree, hf_q931_call_ref, NullTVB, offset, call_ref_len, call_ref);
 		offset += call_ref_len;
 	}
 	message_type = pd[offset];
@@ -2086,7 +2086,7 @@ dissect_q931(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
 		      "Unknown message type (0x%02X)"));
 	}
 	if (q931_tree != NULL)
-		proto_tree_add_item(q931_tree, hf_q931_message_type, offset, 1, message_type);
+		proto_tree_add_item(q931_tree, hf_q931_message_type, NullTVB, offset, 1, message_type);
 	offset += 1;
 
 	/*
@@ -2107,7 +2107,7 @@ dissect_q931(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
 			    !(info_element & Q931_IE_SHIFT_LOCKING);
 			codeset = info_element & Q931_IE_SHIFT_CODESET;
 			if (q931_tree != NULL) {
-				proto_tree_add_text(q931_tree, offset, 1,
+				proto_tree_add_text(q931_tree, NullTVB, offset, 1,
 				    "%s shift to codeset %u: %s",
 				    (non_locking_shift ? "Non-locking" : "Locking"),
 				    codeset,
@@ -2122,21 +2122,21 @@ dissect_q931(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
 
 			case Q931_IE_MORE_DATA:
 				if (q931_tree != NULL) {
-					proto_tree_add_text(q931_tree, offset, 1,
+					proto_tree_add_text(q931_tree, NullTVB, offset, 1,
 					    "More data");
 				}
 				break;
 
 			case Q931_IE_SENDING_COMPLETE:
 				if (q931_tree != NULL) {
-					proto_tree_add_text(q931_tree, offset, 1,
+					proto_tree_add_text(q931_tree, NullTVB, offset, 1,
 					    "Sending complete");
 				}
 				break;
 
 			default:
 				if (q931_tree != NULL) {
-					proto_tree_add_text(q931_tree, offset, 1,
+					proto_tree_add_text(q931_tree, NullTVB, offset, 1,
 					    "Unknown information element (0x%02X",
 					    info_element);
 				}
@@ -2149,7 +2149,7 @@ dissect_q931(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
 
 		case Q931_IE_CONGESTION_LEVEL:
 			if (q931_tree != NULL) {
-				proto_tree_add_text(q931_tree, offset, 1,
+				proto_tree_add_text(q931_tree, NullTVB, offset, 1,
 				    "Congestion level: %s",
 				    val_to_str(info_element & Q931_IE_SO_IE_MASK,
 				      q931_congestion_level_vals,
@@ -2162,7 +2162,7 @@ dissect_q931(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
 
 		case Q931_IE_REPEAT_INDICATOR:
 			if (q931_tree != NULL) {
-				proto_tree_add_text(q931_tree, offset, 1,
+				proto_tree_add_text(q931_tree, NullTVB, offset, 1,
 				    "Repeat indicator: %s",
 				    val_to_str(info_element & Q931_IE_SO_IE_MASK,
 				      q931_repeat_indication_vals,
@@ -2186,16 +2186,16 @@ dissect_q931(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
 		if (!BYTES_ARE_IN_FRAME(offset + 2, info_element_len))
 			break;	/* ran past end of frame */
 		if (q931_tree != NULL) {
-			ti = proto_tree_add_text(q931_tree, offset,
+			ti = proto_tree_add_text(q931_tree, NullTVB, offset,
 			    1+1+info_element_len, "%s",
 			    val_to_str(info_element, q931_info_element_vals,
 			      "Unknown information element (0x%02X)"));
 			ie_tree = proto_item_add_subtree(ti, ett_q931_ie);
-			proto_tree_add_text(ie_tree, offset, 1,
+			proto_tree_add_text(ie_tree, NullTVB, offset, 1,
 			    "Information element: %s",
 			    val_to_str(info_element, q931_info_element_vals,
 			      "Unknown (0x%02X)"));
-			proto_tree_add_text(ie_tree, offset + 1, 1,
+			proto_tree_add_text(ie_tree, NullTVB, offset + 1, 1,
 			    "Length: %u", info_element_len);
 
 			switch (info_element) {
@@ -2333,7 +2333,7 @@ dissect_q931(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
 				break;
 
 			default:
-				proto_tree_add_text(ie_tree, offset + 2,
+				proto_tree_add_text(ie_tree, NullTVB, offset + 2,
 				    info_element_len, "Data: %s",
 				    bytes_to_str(&pd[offset + 2],
 				      info_element_len));