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, 30 insertions, 45 deletions

diff --git a/epan/dissectors/packet-icmpv6.c b/epan/dissectors/packet-icmpv6.c
index 642b7edf39..3d830c7248 100644
--- a/epan/dissectors/packet-icmpv6.c
+++ b/epan/dissectors/packet-icmpv6.c
@@ -97,7 +97,7 @@ static int proto_icmpv6 = -1;
 static int hf_icmpv6_type = -1;
 static int hf_icmpv6_code = -1;
 static int hf_icmpv6_checksum = -1;
-static int hf_icmpv6_checksum_bad = -1;
+static int hf_icmpv6_checksum_status = -1;
 static int hf_icmpv6_reserved = -1;
 static int hf_icmpv6_data = -1;
 static int hf_icmpv6_unknown_data = -1;
@@ -3470,12 +3470,12 @@ static int
 dissect_icmpv6(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
 {
     proto_tree         *icmp6_tree = NULL, *flag_tree = NULL;
-    proto_item         *ti         = NULL, *hidden_item, *checksum_item = NULL, *code_item = NULL, *ti_flag = NULL;
+    proto_item         *ti         = NULL, *checksum_item = NULL, *code_item = NULL, *ti_flag = NULL;
     const char         *code_name  = NULL;
     guint               length     = 0, reported_length;
     vec_t               cksum_vec[4];
     guint32             phdr[2];
-    guint16             cksum, computed_cksum;
+    guint16             cksum;
     int                 offset;
     tvbuff_t           *next_tvb;
     guint8              icmp6_type, icmp6_code;
@@ -3540,46 +3540,32 @@ dissect_icmpv6(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
         col_set_str(pinfo->cinfo, COL_INFO, "Direct IPv6 Connectivity Test");
     }
 
-    if (tree) {
-        if (code_name)
-            proto_item_append_text(code_item, " (%s)", code_name);
-        checksum_item = proto_tree_add_item(icmp6_tree, hf_icmpv6_checksum, tvb, offset, 2, ENC_BIG_ENDIAN);
-    }
+    if (code_name)
+        proto_item_append_text(code_item, " (%s)", code_name);
 
     cksum = tvb_get_ntohs(tvb, offset);
-
-    if (1) { /* There's an expert info in here so always execute */
-        length = tvb_captured_length(tvb);
-        reported_length = tvb_reported_length(tvb);
-        if (!pinfo->fragmented && length >= reported_length && !pinfo->flags.in_error_pkt) {
-            /* The packet isn't part of a fragmented datagram, isn't truncated,
-             * and we aren't in an ICMP error packet, so we can checksum it.
-             */
-
-            /* Set up the fields of the pseudo-header. */
-            SET_CKSUM_VEC_PTR(cksum_vec[0], (const guint8 *)pinfo->src.data, pinfo->src.len);
-            SET_CKSUM_VEC_PTR(cksum_vec[1], (const guint8 *)pinfo->dst.data, pinfo->dst.len);
-            phdr[0] = g_htonl(reported_length);
-            phdr[1] = g_htonl(IP_PROTO_ICMPV6);
-            SET_CKSUM_VEC_PTR(cksum_vec[2], (const guint8 *)&phdr, 8);
-            SET_CKSUM_VEC_TVB(cksum_vec[3], tvb, 0, reported_length);
-            computed_cksum = in_cksum(cksum_vec, 4);
-
-            if (computed_cksum == 0) {
-                hidden_item = proto_tree_add_boolean(icmp6_tree, hf_icmpv6_checksum_bad, tvb, offset, 2, FALSE);
-                PROTO_ITEM_SET_HIDDEN(hidden_item);
-                proto_item_append_text(checksum_item, " [correct]");
-            } else {
-                hidden_item = proto_tree_add_boolean(icmp6_tree, hf_icmpv6_checksum_bad, tvb, offset, 2, TRUE);
-                PROTO_ITEM_SET_HIDDEN(hidden_item);
-                proto_item_append_text(checksum_item, " [incorrect, should be 0x%04x]", in_cksum_shouldbe(cksum, computed_cksum));
-                expert_add_info_format(pinfo, checksum_item, &ei_icmpv6_checksum,
-                                       "ICMPv6 Checksum Incorrect, should be 0x%04x", in_cksum_shouldbe(cksum, computed_cksum));
-            }
-        } else {
-                proto_item_append_text(checksum_item, " [%s]",
-                    pinfo->flags.in_error_pkt ? "in ICMP error packet" : "fragmented datagram");
-        }
+    length = tvb_captured_length(tvb);
+    reported_length = tvb_reported_length(tvb);
+    if (!pinfo->fragmented && length >= reported_length && !pinfo->flags.in_error_pkt) {
+        /* The packet isn't part of a fragmented datagram, isn't truncated,
+            * and we aren't in an ICMP error packet, so we can checksum it.
+            */
+
+        /* Set up the fields of the pseudo-header. */
+        SET_CKSUM_VEC_PTR(cksum_vec[0], (const guint8 *)pinfo->src.data, pinfo->src.len);
+        SET_CKSUM_VEC_PTR(cksum_vec[1], (const guint8 *)pinfo->dst.data, pinfo->dst.len);
+        phdr[0] = g_htonl(reported_length);
+        phdr[1] = g_htonl(IP_PROTO_ICMPV6);
+        SET_CKSUM_VEC_PTR(cksum_vec[2], (const guint8 *)&phdr, 8);
+        SET_CKSUM_VEC_TVB(cksum_vec[3], tvb, 0, reported_length);
+
+        proto_tree_add_checksum(icmp6_tree, tvb, 2, hf_icmpv6_checksum, hf_icmpv6_checksum_status, &ei_icmpv6_checksum, pinfo, in_cksum(cksum_vec, 4),
+							ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY|PROTO_CHECKSUM_IN_CKSUM);
+    } else {
+		checksum_item = proto_tree_add_checksum(icmp6_tree, tvb, 2, hf_icmpv6_checksum, hf_icmpv6_checksum_status, &ei_icmpv6_checksum, pinfo, 0,
+								ENC_BIG_ENDIAN, PROTO_CHECKSUM_NO_FLAGS);
+        proto_item_append_text(checksum_item, " [%s]",
+            pinfo->flags.in_error_pkt ? "in ICMP error packet" : "fragmented datagram");
     }
     offset += 2;
 
@@ -3612,8 +3598,7 @@ dissect_icmpv6(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
              * Shouldn't the nonce be at least 8 then?  Why not just use (-1),
              * as it could really be any length, couldn't it?
              */
-            if (tree)
-                proto_tree_add_item(icmp6_tree, hf_icmpv6_nonce, tvb, offset, 4, ENC_NA);
+            proto_tree_add_item(icmp6_tree, hf_icmpv6_nonce, tvb, offset, 4, ENC_NA);
             offset += 4;
         } else {
             if (!pinfo->flags.in_error_pkt) {
@@ -4158,8 +4143,8 @@ proto_register_icmpv6(void)
         { &hf_icmpv6_checksum,
           { "Checksum", "icmpv6.checksum", FT_UINT16, BASE_HEX, NULL, 0x0,
             "Used to detect data corruption in the ICMPv6 message and parts of the IPv6 header", HFILL }},
-        { &hf_icmpv6_checksum_bad,
-          { "Bad Checksum", "icmpv6.checksum_bad", FT_BOOLEAN, BASE_NONE, NULL, 0x0,
+        { &hf_icmpv6_checksum_status,
+          { "Checksum Status", "icmpv6.checksum.status", FT_UINT8, BASE_NONE, VALS(proto_checksum_vals), 0x0,
             NULL, HFILL }},
         { &hf_icmpv6_reserved,
           { "Reserved", "icmpv6.reserved", FT_BYTES, BASE_NONE, NULL, 0x0,