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, 19 insertions, 51 deletions

diff --git a/epan/dissectors/packet-isis-lsp.c b/epan/dissectors/packet-isis-lsp.c
index 827c6c8b16..3c5e82db14 100644
--- a/epan/dissectors/packet-isis-lsp.c
+++ b/epan/dissectors/packet-isis-lsp.c
@@ -156,8 +156,7 @@ static int hf_isis_lsp_srlg_ipv4_local = -1;
 static int hf_isis_lsp_srlg_ipv4_remote = -1;
 static int hf_isis_lsp_srlg_value = -1;
 static int hf_isis_lsp_checksum = -1;
-static int hf_isis_lsp_checksum_bad = -1;
-static int hf_isis_lsp_checksum_good = -1;
+static int hf_isis_lsp_checksum_status = -1;
 static int hf_isis_lsp_clv_ipv4_int_addr = -1;
 static int hf_isis_lsp_clv_ipv6_int_addr = -1;
 static int hf_isis_lsp_clv_te_router_id = -1;
@@ -3105,25 +3104,6 @@ dissect_lsp_prefix_neighbors_clv(tvbuff_t *tvb, packet_info* pinfo, proto_tree *
     }
 }
 
-static void isis_lsp_checkum_additional_info(tvbuff_t * tvb, packet_info * pinfo,
-    proto_item * it_cksum, int offset, gboolean is_cksum_correct)
-{
-    proto_tree * checksum_tree;
-    proto_item * item;
-
-    checksum_tree = proto_item_add_subtree(it_cksum, ett_isis_lsp_cksum);
-    item = proto_tree_add_boolean(checksum_tree, hf_isis_lsp_checksum_good, tvb,
-                                  offset, 2, is_cksum_correct);
-    PROTO_ITEM_SET_GENERATED(item);
-    item = proto_tree_add_boolean(checksum_tree, hf_isis_lsp_checksum_bad, tvb,
-                                  offset, 2, !is_cksum_correct);
-    PROTO_ITEM_SET_GENERATED(item);
-    if (!is_cksum_correct) {
-        expert_add_info(pinfo, item, &ie_isis_lsp_checksum_bad);
-        col_append_str(pinfo->cinfo, COL_INFO, " [ISIS CHECKSUM INCORRECT]");
-    }
-}
-
 static const isis_clv_handle_t clv_l1_lsp_opts[] = {
     {
         ISIS_CLV_AREA_ADDRESS,
@@ -3475,7 +3455,6 @@ dissect_isis_lsp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int offset
     guint16        pdu_length, lifetime, checksum, cacl_checksum=0;
     guint8        lsp_info;
     int        len, offset_checksum;
-    proto_item    *it_cksum;
     char* system_id;
 
     col_set_str(pinfo->cinfo, COL_PROTOCOL, "ISIS LSP");
@@ -3511,28 +3490,23 @@ dissect_isis_lsp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int offset
     offset += 4;
 
     checksum = lifetime ? tvb_get_ntohs(tvb, offset) : 0;
-    switch (check_and_get_checksum(tvb, offset_checksum, pdu_length-12, checksum, offset, &cacl_checksum)) {
-        case NO_CKSUM :
-            checksum = tvb_get_ntohs(tvb, offset);
-            proto_tree_add_uint_format_value(lsp_tree, hf_isis_lsp_checksum, tvb, offset, 2, checksum,
-                    "0x%04x [unused]", checksum);
-        break;
-        case DATA_MISSING :
+    if (checksum == 0) {
+        /* No checksum present */
+        proto_tree_add_checksum(lsp_tree, tvb, offset_checksum, hf_isis_lsp_checksum, hf_isis_lsp_checksum_status, &ie_isis_lsp_checksum_bad, pinfo, 0, ENC_BIG_ENDIAN, PROTO_CHECKSUM_NOT_PRESENT);
+    } else {
+        if (osi_check_and_get_checksum(tvb, offset_checksum, pdu_length-12, offset, &cacl_checksum)) {
+            /* Successfully processed checksum, verify it */
+            proto_tree_add_checksum(lsp_tree, tvb, offset_checksum, hf_isis_lsp_checksum, hf_isis_lsp_checksum_status, &ie_isis_lsp_checksum_bad, pinfo, cacl_checksum, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);
+            if (cacl_checksum != checksum) {
+                col_append_str(pinfo->cinfo, COL_INFO, " [ISIS CHECKSUM INCORRECT]");
+            }
+
+        } else {
+            proto_tree_add_checksum(lsp_tree, tvb, offset_checksum, hf_isis_lsp_checksum, hf_isis_lsp_checksum_status, &ie_isis_lsp_checksum_bad, pinfo, 0, ENC_BIG_ENDIAN, PROTO_CHECKSUM_NO_FLAGS);
             proto_tree_add_expert_format(tree, pinfo, &ei_isis_lsp_long_packet, tvb, offset, -1,
                     "Packet length %d went beyond packet",
                      tvb_reported_length_remaining(tvb, offset_checksum));
-        break;
-        case CKSUM_NOT_OK :
-            it_cksum = proto_tree_add_uint_format_value(lsp_tree, hf_isis_lsp_checksum, tvb, offset, 2, checksum,
-                    "0x%04x [incorrect, should be 0x%04x]",
-                    checksum, cacl_checksum);
-            isis_lsp_checkum_additional_info(tvb, pinfo, it_cksum, offset, FALSE);
-        break;
-        case CKSUM_OK :
-            it_cksum = proto_tree_add_uint_format_value(lsp_tree, hf_isis_lsp_checksum, tvb, offset, 2, checksum,
-                    "0x%04x [correct]", checksum);
-                isis_lsp_checkum_additional_info(tvb, pinfo, it_cksum, offset, TRUE);
-        break;
+        }
     }
     offset += 2;
 
@@ -3675,16 +3649,10 @@ proto_register_isis_lsp(void)
               NULL, HFILL }
         },
 
-        { &hf_isis_lsp_checksum_good,
-            { "Good Checksum", "isis.lsp.checksum_good",
-              FT_BOOLEAN, BASE_NONE, NULL, 0x0,
-              "Good IS-IS LSP Checksum", HFILL }
-        },
-
-        { &hf_isis_lsp_checksum_bad,
-            { "Bad Checksum", "isis.lsp.checksum_bad",
-              FT_BOOLEAN, BASE_NONE, NULL, 0x0,
-              "Bad IS-IS LSP Checksum", HFILL }
+        { &hf_isis_lsp_checksum_status,
+            { "Checksum Status", "isis.lsp.checksum.status",
+              FT_UINT8, BASE_NONE, VALS(proto_checksum_vals), 0x0,
+              NULL, HFILL }
         },
 
         { &hf_isis_lsp_clv_ipv4_int_addr,