Add proto_tree_add_checksum.

This is an attempt to standardize display/handling of checksum fields for all dissectors.
The main target is for dissectors that do validation, but dissectors that just report the
checksum were also included just to make them easier to find in the future.

Bug: 10620
Bug: 12058
Ping-Bug: 8859
Change-Id: Ia8abd86e42eaf8ed50de6b173409e914b17993bf
Reviewed-on: https://code.wireshark.org/review/16380
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Jeff Morriss <jeff.morriss.ws@gmail.com>
Reviewed-by: Michael Mann <mmann78@netscape.net>

1 files changed, 14 insertions, 29 deletions

diff --git a/epan/dissectors/packet-igmp.c b/epan/dissectors/packet-igmp.c
index 6e9d20da75..f976130c24 100644
--- a/epan/dissectors/packet-igmp.c
+++ b/epan/dissectors/packet-igmp.c
@@ -127,7 +127,7 @@ static int hf_group_type = -1;
 static int hf_reply_code = -1;
 static int hf_reply_pending = -1;
 static int hf_checksum = -1;
-static int hf_checksum_bad = -1;
+static int hf_checksum_status = -1;
 static int hf_identifier = -1;
 static int hf_access_key = -1;
 static int hf_max_resp = -1;
@@ -282,11 +282,9 @@ static const value_string mtrace_fwd_code_vals[] = {
 };
 
 void igmp_checksum(proto_tree *tree, tvbuff_t *tvb, int hf_index,
-	int hf_index_bad, packet_info *pinfo, guint len)
+	int hf_index_status, packet_info *pinfo, guint len)
 {
-	guint16 cksum, hdrcksum;
 	vec_t cksum_vec[1];
-	proto_item *hidden_item;
 
 	if (len == 0) {
 		/*
@@ -295,29 +293,16 @@ void igmp_checksum(proto_tree *tree, tvbuff_t *tvb, int hf_index,
 		len = tvb_reported_length(tvb);
 	}
 
-	hdrcksum = tvb_get_ntohs(tvb, 2);
 	if (!pinfo->fragmented && tvb_captured_length(tvb) >= len) {
 		/*
 		 * The packet isn't part of a fragmented datagram and isn't
 		 * truncated, so we can checksum it.
 		 */
 		SET_CKSUM_VEC_TVB(cksum_vec[0], tvb, 0, len);
-
-		cksum = in_cksum(&cksum_vec[0],1);
-
-		if (cksum == 0) {
-			proto_tree_add_uint_format(tree, hf_index, tvb, 2, 2, hdrcksum,
-				"Header checksum: 0x%04x [correct]", hdrcksum);
-		} else {
-			hidden_item = proto_tree_add_boolean(tree, hf_index_bad,
-				tvb, 2, 2, TRUE);
-			PROTO_ITEM_SET_HIDDEN(hidden_item);
-			proto_tree_add_uint_format(tree, hf_index, tvb, 2, 2, hdrcksum,
-				"Header checksum: 0x%04x [incorrect, should be 0x%04x]",
-				hdrcksum, in_cksum_shouldbe(hdrcksum,cksum));
-		}
+		proto_tree_add_checksum(tree, tvb, 2, hf_index, hf_index_status, NULL, pinfo, in_cksum(&cksum_vec[0], 1),
+                                ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY|PROTO_CHECKSUM_IN_CKSUM);
 	} else
-		proto_tree_add_uint(tree, hf_index, tvb, 2, 2, hdrcksum);
+		proto_tree_add_checksum(tree, tvb, 2, hf_index, -1, NULL, pinfo, 0, ENC_BIG_ENDIAN, PROTO_CHECKSUM_NO_FLAGS);
 
 	return;
 }
@@ -563,7 +548,7 @@ dissect_igmp_v3_report(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tre
 	offset += 1;
 
 	/* checksum */
-	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
+	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_status, pinfo, 0);
 	offset += 2;
 
         proto_tree_add_item(tree, hf_reserved, tvb, offset, 2, ENC_NA);
@@ -598,7 +583,7 @@ dissect_igmp_v3_query(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree
 	offset = dissect_v3_max_resp(tvb, tree, offset);
 
 	/* checksum */
-	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
+	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_status, pinfo, 0);
 	offset += 2;
 
 	/* group address */
@@ -653,7 +638,7 @@ dissect_igmp_v2(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void
 	offset += 1;
 
 	/* checksum */
-	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 8);
+	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_status, pinfo, 8);
 	offset += 2;
 
 	/* group address */
@@ -695,7 +680,7 @@ dissect_igmp_v1(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void
 	offset += 1;
 
 	/* checksum */
-	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 8);
+	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_status, pinfo, 8);
 	offset += 2;
 
 	/* group address */
@@ -730,7 +715,7 @@ dissect_igmp_v0(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void
 	offset += 1;
 
 	/* checksum */
-	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 20);
+	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_status, pinfo, 20);
 	offset += 2;
 
 	/* identifier */
@@ -813,7 +798,7 @@ dissect_igmp_mtrace(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
 	offset += 1;
 
 	/* checksum */
-	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
+	igmp_checksum(tree, tvb, hf_checksum, hf_checksum_status, pinfo, 0);
 	offset += 2;
 
 	/* group address to be traced */
@@ -952,9 +937,9 @@ proto_register_igmp(void)
 			{ "Checksum", "igmp.checksum", FT_UINT16, BASE_HEX,
 			  NULL, 0, "IGMP Checksum", HFILL }},
 
-		{ &hf_checksum_bad,
-			{ "Bad Checksum", "igmp.checksum_bad", FT_BOOLEAN, BASE_NONE,
-			  NULL, 0x0, "Bad IGMP Checksum", HFILL }},
+		{ &hf_checksum_status,
+			{ "Checksum Status", "igmp.checksum.status", FT_UINT8, BASE_NONE,
+			  VALS(proto_checksum_vals), 0x0, NULL, HFILL }},
 
 		{ &hf_identifier,
 			{ "Identifier", "igmp.identifier", FT_UINT32, BASE_DEC,