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, 5 insertions, 13 deletions

diff --git a/epan/dissectors/packet-gre.c b/epan/dissectors/packet-gre.c
index f81f42885a..4d60a57370 100644
--- a/epan/dissectors/packet-gre.c
+++ b/epan/dissectors/packet-gre.c
@@ -410,29 +410,21 @@ dissect_gre(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
 
         if (flags_and_ver & GRE_CHECKSUM || flags_and_ver & GRE_ROUTING) {
             guint length, reported_length;
-            proto_item *it_checksum;
             vec_t cksum_vec[1];
-            guint16 cksum, computed_cksum;
 
-            it_checksum = proto_tree_add_item(gre_tree, hf_gre_checksum, tvb, offset, 2, ENC_BIG_ENDIAN);
             /* Checksum check !... */
-            cksum = tvb_get_ntohs(tvb, offset);
             length = tvb_captured_length(tvb);
             reported_length = tvb_reported_length(tvb);
             /* The Checksum Present bit is set, and the packet isn't part of a
                fragmented datagram and isn't truncated, so we can checksum it. */
             if ((flags_and_ver & GRE_CHECKSUM) && !pinfo->fragmented && length >= reported_length) {
                 SET_CKSUM_VEC_TVB(cksum_vec[0], tvb, 0, reported_length);
-                computed_cksum = in_cksum(cksum_vec, 1);
-                if (computed_cksum == 0) {
-                    proto_item_append_text(it_checksum," [correct]");
-                } else {
-                    proto_item_append_text(it_checksum," [incorrect, should be 0x%04x]",in_cksum_shouldbe(cksum, computed_cksum));
-                    expert_add_info(pinfo, it_checksum, &ei_gre_checksum_incorrect);
-                }
+                proto_tree_add_checksum(gre_tree, tvb, offset, hf_gre_checksum, -1, &ei_gre_checksum_incorrect, pinfo, in_cksum(cksum_vec, 1),
+                                ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY|PROTO_CHECKSUM_IN_CKSUM);
+            } else {
+                proto_tree_add_checksum(gre_tree, tvb, offset, hf_gre_checksum, -1, &ei_gre_checksum_incorrect, pinfo, 0,
+                                ENC_BIG_ENDIAN, PROTO_CHECKSUM_NO_FLAGS);
             }
-
-
             offset += 2;
 
             proto_tree_add_item(gre_tree, hf_gre_offset, tvb, offset, 2, ENC_BIG_ENDIAN);