Make IPv4/IPv6 DiffServ fields uniform

Replace DSCP/ECT/CE with DSCP/ECN for IPv6.

Introduce short descriptions for DSCP/ECN values.

Formating changes:

 - Make IPv4 and IPv6 as similar as possible.

 - Display short abbreviations only for "Differentiated Services Field".

 - Display DiffServ field as hex for IPv4.

 - Elide leading zeros from hex representation from DiffServ field for IPv6.

 - Display DSCP/ECN as decimal in subtree (same as "IP DSCP" column format).

Change-Id: Ia69d11dc9c1d752eb2e269314287c885506b5353
Reviewed-on: https://code.wireshark.org/review/10360
Reviewed-by: Michael Mann <mmann78@netscape.net>
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

3 files changed, 90 insertions, 89 deletions

diff --git a/epan/dissectors/packet-ip.c b/epan/dissectors/packet-ip.c
index 1c289cdc2d..47debe5809 100644
--- a/epan/dissectors/packet-ip.c
+++ b/epan/dissectors/packet-ip.c
@@ -317,14 +317,7 @@ static dissector_handle_t data_handle;
 #define IP_MF                   0x2000      /* Flag: "More Fragments"   */
 #define IP_OFFSET               0x1FFF      /* "Fragment Offset" part   */
 
-/* Differentiated Services Field. See RFCs 2474, 2597 and 2598. */
-#define IPDSFIELD_DSCP_MASK     0xFC
-#define IPDSFIELD_ECN_MASK      0x03
-#define IPDSFIELD_DSCP_SHIFT    2
-
-#define IPDSFIELD_DSCP(dsfield) (((dsfield)&IPDSFIELD_DSCP_MASK)>>IPDSFIELD_DSCP_SHIFT)
-#define IPDSFIELD_ECN(dsfield)  ((dsfield)&IPDSFIELD_ECN_MASK)
-
+/* Differentiated Services Field. See RFCs 2474, 2597, 2598 and 3168. */
 #define IPDSFIELD_DSCP_DEFAULT  0x00
 #define IPDSFIELD_DSCP_CS1      0x08
 #define IPDSFIELD_DSCP_AF11     0x0A
@@ -1890,6 +1883,32 @@ local_network_control_block_addr_valid_ttl(guint32 addr)
   return IPLOCAL_NETWRK_CTRL_BLK_DEFAULT_TTL;
 }
 
+static const value_string dscp_short_vals[] = {
+  { IPDSFIELD_DSCP_DEFAULT, "CS0"    },
+  { IPDSFIELD_DSCP_CS1,     "CS1"    },
+  { IPDSFIELD_DSCP_AF11,    "AF11"   },
+  { IPDSFIELD_DSCP_AF12,    "AF12"   },
+  { IPDSFIELD_DSCP_AF13,    "AF13"   },
+  { IPDSFIELD_DSCP_CS2,     "CS2"    },
+  { IPDSFIELD_DSCP_AF21,    "AF21"   },
+  { IPDSFIELD_DSCP_AF22,    "AF22"   },
+  { IPDSFIELD_DSCP_AF23,    "AF23"   },
+  { IPDSFIELD_DSCP_CS3,     "CS3"    },
+  { IPDSFIELD_DSCP_AF31,    "AF31"   },
+  { IPDSFIELD_DSCP_AF32,    "AF32"   },
+  { IPDSFIELD_DSCP_AF33,    "AF33"   },
+  { IPDSFIELD_DSCP_CS4,     "CS4"    },
+  { IPDSFIELD_DSCP_AF41,    "AF41"   },
+  { IPDSFIELD_DSCP_AF42,    "AF42"   },
+  { IPDSFIELD_DSCP_AF43,    "AF43"   },
+  { IPDSFIELD_DSCP_CS5,     "CS5"    },
+  { IPDSFIELD_DSCP_EF,      "EF PHB" },
+  { IPDSFIELD_DSCP_CS6,     "CS6"    },
+  { IPDSFIELD_DSCP_CS7,     "CS7"    },
+  { 0,                      NULL     }};
+value_string_ext dscp_short_vals_ext = VALUE_STRING_EXT_INIT(dscp_short_vals);
+
+
 static const value_string dscp_vals[] = {
   { IPDSFIELD_DSCP_DEFAULT, "Default"               },
   { IPDSFIELD_DSCP_CS1,     "Class Selector 1"      },
@@ -1915,12 +1934,21 @@ static const value_string dscp_vals[] = {
   { 0,                      NULL                    }};
 value_string_ext dscp_vals_ext = VALUE_STRING_EXT_INIT(dscp_vals);
 
-const value_string ecn_vals[] = {
-  { IPDSFIELD_ECT_NOT, "Not-ECT (Not ECN-Capable Transport)" },
-  { IPDSFIELD_ECT_1,   "ECT(1) (ECN-Capable Transport)"      },
-  { IPDSFIELD_ECT_0,   "ECT(0) (ECN-Capable Transport)"      },
-  { IPDSFIELD_CE,      "CE (Congestion Experienced)"         },
-  { 0,                 NULL                                  }};
+static const value_string ecn_short_vals[] = {
+  { IPDSFIELD_ECT_NOT, "Not-ECT" },
+  { IPDSFIELD_ECT_1,   "ECT(1)"  },
+  { IPDSFIELD_ECT_0,   "ECT(0)"  },
+  { IPDSFIELD_CE,      "CE"      },
+  { 0,                 NULL      }};
+value_string_ext ecn_short_vals_ext = VALUE_STRING_EXT_INIT(ecn_short_vals);
+
+static const value_string ecn_vals[] = {
+  { IPDSFIELD_ECT_NOT, "Not ECN-Capable Transport"            },
+  { IPDSFIELD_ECT_1,   "ECN-Capable Transport codepoint '01'" },
+  { IPDSFIELD_ECT_0,   "ECN-Capable Transport codepoint '10'" },
+  { IPDSFIELD_CE,      "Congestion Experienced"               },
+  { 0,                 NULL                                   }};
+value_string_ext ecn_vals_ext = VALUE_STRING_EXT_INIT(ecn_vals);
 
 static const value_string precedence_vals[] = {
   { IPTOS_PREC_ROUTINE,         "routine"              },
@@ -2058,12 +2086,10 @@ dissect_ip_v4(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree)
 
   if (tree) {
     if (g_ip_dscp_actif) {
-      tf = proto_tree_add_uint_format_value(ip_tree, hf_ip_dsfield, tvb, offset + 1,
-        1, iph->ip_tos, "0x%02x (DSCP 0x%02x: %s; ECN 0x%02x: %s)", iph->ip_tos,
-        IPDSFIELD_DSCP(iph->ip_tos), val_to_str_ext_const(IPDSFIELD_DSCP(iph->ip_tos),
-                                                          &dscp_vals_ext, "Unknown DSCP"),
-        IPDSFIELD_ECN(iph->ip_tos), val_to_str_const(IPDSFIELD_ECN(iph->ip_tos),
-                                                     ecn_vals, "Unknown ECN"));
+      tf = proto_tree_add_item(ip_tree, hf_ip_dsfield, tvb, offset + 1, 1, ENC_NA);
+      proto_item_append_text(tf, " (DSCP: %s, ECN: %s)",
+            val_to_str_ext_const(IPDSFIELD_DSCP(iph->ip_tos), &dscp_short_vals_ext, "Unknown"),
+            val_to_str_ext_const(IPDSFIELD_ECN(iph->ip_tos), &ecn_short_vals_ext, "Unknown"));
 
       field_tree = proto_item_add_subtree(tf, ett_ip_dsfield);
       proto_tree_add_item(field_tree, hf_ip_dsfield_dscp, tvb, offset + 1, 1, ENC_NA);
@@ -2608,16 +2634,16 @@ proto_register_ip(void)
         NULL, 0x0F, NULL, HFILL }},
 
     { &hf_ip_dsfield,
-      { "Differentiated Services Field", "ip.dsfield", FT_UINT8, BASE_DEC,
+      { "Differentiated Services Field", "ip.dsfield", FT_UINT8, BASE_HEX,
         NULL, 0x0, NULL, HFILL }},
 
     { &hf_ip_dsfield_dscp,
-      { "Differentiated Services Codepoint", "ip.dsfield.dscp", FT_UINT8, BASE_HEX | BASE_EXT_STRING,
+      { "Differentiated Services Codepoint", "ip.dsfield.dscp", FT_UINT8, BASE_DEC | BASE_EXT_STRING,
         &dscp_vals_ext, IPDSFIELD_DSCP_MASK, NULL, HFILL }},
 
     { &hf_ip_dsfield_ecn,
-      { "Explicit Congestion Notification", "ip.dsfield.ecn", FT_UINT8, BASE_HEX,
-        VALS(ecn_vals), IPDSFIELD_ECN_MASK, NULL, HFILL }},
+      { "Explicit Congestion Notification", "ip.dsfield.ecn", FT_UINT8, BASE_DEC | BASE_EXT_STRING,
+        &ecn_vals_ext, IPDSFIELD_ECN_MASK, NULL, HFILL }},
 
     { &hf_ip_tos,
       { "Type of Service", "ip.tos", FT_UINT8, BASE_DEC,
diff --git a/epan/dissectors/packet-ip.h b/epan/dissectors/packet-ip.h
index 7456e134e1..698e5047e0 100644
--- a/epan/dissectors/packet-ip.h
+++ b/epan/dissectors/packet-ip.h
@@ -42,15 +42,26 @@ typedef struct _ws_ip
     address ip_dst;
 } ws_ip;
 
+/* Differentiated Services Codepoint  */
+#define IPDSFIELD_DSCP_MASK     0xFC
+#define IPDSFIELD_DSCP(dsfield) (((dsfield) & IPDSFIELD_DSCP_MASK) >> 2)
+
+/* Explicit Congestion Notification */
+#define IPDSFIELD_ECN_MASK      0x03
+#define IPDSFIELD_ECN(dsfield)  ((dsfield) & IPDSFIELD_ECN_MASK)
+
 void capture_ip(const guchar *, int, int, packet_counts *);
 
 gboolean ip_try_dissect(gboolean heur_first, tvbuff_t *tvb,
                         packet_info *pinfo, proto_tree *tree, ws_ip *iph);
 
-/* Export the DSCP extended value-string table for other protocols */
+/* Export the DSCP/ECN extended value-string table for other protocols */
 WS_DLL_PUBLIC value_string_ext dscp_vals_ext;
+WS_DLL_PUBLIC value_string_ext ecn_vals_ext;
+WS_DLL_PUBLIC value_string_ext dscp_short_vals_ext;
+WS_DLL_PUBLIC value_string_ext ecn_short_vals_ext;
 
-#endif
+#endif /* __PACKET_IP_H__ */
 
 /*
  * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
diff --git a/epan/dissectors/packet-ipv6.c b/epan/dissectors/packet-ipv6.c
index b9aa008251..330b26bb79 100644
--- a/epan/dissectors/packet-ipv6.c
+++ b/epan/dissectors/packet-ipv6.c
@@ -86,36 +86,6 @@ void proto_reg_handoff_ipv6(void);
 #define IP6OPT_RTALERT_RSVP             1       /* Datagram contains RSVP msg */
 #define IP6OPT_RTALERT_ACTNET           2       /* Datagram contains ACTNET msg */
 
-/* Differentiated Services Field. See RFCs 2474, 2597 and 2598. */
-#define IPDSFIELD_DSCP_MASK     0xFC
-#define IPDSFIELD_ECN_MASK      0x03
-#define IPDSFIELD_DSCP_SHIFT    2
-#define IPDSFIELD_DSCP(dsfield) (((dsfield)&IPDSFIELD_DSCP_MASK)>>IPDSFIELD_DSCP_SHIFT)
-#define IPDSFIELD_ECN(dsfield)  ((dsfield)&IPDSFIELD_ECN_MASK)
-#define IPDSFIELD_DSCP_DEFAULT  0x00
-#define IPDSFIELD_DSCP_CS1      0x08
-#define IPDSFIELD_DSCP_CS2      0x10
-#define IPDSFIELD_DSCP_CS3      0x18
-#define IPDSFIELD_DSCP_CS4      0x20
-#define IPDSFIELD_DSCP_CS5      0x28
-#define IPDSFIELD_DSCP_CS6      0x30
-#define IPDSFIELD_DSCP_CS7      0x38
-#define IPDSFIELD_DSCP_AF11     0x0A
-#define IPDSFIELD_DSCP_AF12     0x0C
-#define IPDSFIELD_DSCP_AF13     0x0E
-#define IPDSFIELD_DSCP_AF21     0x12
-#define IPDSFIELD_DSCP_AF22     0x14
-#define IPDSFIELD_DSCP_AF23     0x16
-#define IPDSFIELD_DSCP_AF31     0x1A
-#define IPDSFIELD_DSCP_AF32     0x1C
-#define IPDSFIELD_DSCP_AF33     0x1E
-#define IPDSFIELD_DSCP_AF41     0x22
-#define IPDSFIELD_DSCP_AF42     0x24
-#define IPDSFIELD_DSCP_AF43     0x26
-#define IPDSFIELD_DSCP_EF       0x2E
-#define IPDSFIELD_ECT_MASK      0x02
-#define IPDSFIELD_CE_MASK       0x01
-
 /* RPL Routing header */
 #define IP6RRPL_BITMASK_CMPRI     0xF0000000
 #define IP6RRPL_BITMASK_CMPRE     0x0F000000
@@ -145,7 +115,9 @@ static int proto_ipv6_dstopts                   = -1;
 
 static int hf_ipv6_version                      = -1;
 static int hf_ip_version                        = -1;
-static int hf_ipv6_class                        = -1;
+static int hf_ipv6_tclass                       = -1;
+static int hf_ipv6_tclass_dscp                  = -1;
+static int hf_ipv6_tclass_ecn                   = -1;
 static int hf_ipv6_flow                         = -1;
 static int hf_ipv6_plen                         = -1;
 static int hf_ipv6_nxt                          = -1;
@@ -292,9 +264,6 @@ static int hf_ipv6_shim6_opt_fii        = -1;
 static int hf_ipv6_shim6_validator      = -1;
 static int hf_ipv6_shim6_cga_parameter_data_structure = -1;
 static int hf_ipv6_shim6_cga_signature  = -1;
-static int hf_ipv6_traffic_class_dscp   = -1;
-static int hf_ipv6_traffic_class_ect    = -1;
-static int hf_ipv6_traffic_class_ce     = -1;
 
 #ifdef HAVE_GEOIP_V6
 static int hf_geoip_country             = -1;
@@ -1971,10 +1940,10 @@ dissect_shim6(tvbuff_t *tvb, packet_info * pinfo, proto_tree *tree, void* data _
 static void
 dissect_ipv6(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 {
-    proto_tree    *ipv6_tree, *ipv6_tc_tree;
-    proto_item    *ipv6_item, *ipv6_tc, *ti, *pi;
+    proto_tree    *ipv6_tree, *pt;
+    proto_item    *ipv6_item, *ti, *pi;
     proto_item    *ti_ipv6_plen = NULL, *ti_ipv6_version;
-    guint8         nxt;
+    guint8         nxt, tfc;
     int            advance;
     guint32        plen;
     gboolean       frag;
@@ -2031,7 +2000,8 @@ dissect_ipv6(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
         return;
     }
 
-    col_add_fstr(pinfo->cinfo, COL_DSCP_VALUE, "%u", IPDSFIELD_DSCP(IPv6_HDR_TCLS(ipv6)));
+    tfc = IPv6_HDR_TCLS(ipv6);
+    col_add_fstr(pinfo->cinfo, COL_DSCP_VALUE, "%u", IPDSFIELD_DSCP(tfc));
 
     /* Get extension header and payload length */
     plen = g_ntohs(ipv6->ip6_plen);
@@ -2045,18 +2015,18 @@ dissect_ipv6(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
     p_add_proto_data(pinfo->pool, pinfo, proto_ipv6, IPV6_PROTO_META, ipv6_info);
 
     if (tree) {
-        /* !!! warning: (4-bit) version, (6-bit) DSCP, (1-bit) ECN-ECT, (1-bit) ECN-CE and (20-bit) Flow */
-        ipv6_tc = proto_tree_add_item(ipv6_tree, hf_ipv6_class, tvb,
-                                      offset + IP6H_CTL_FLOW, 4, ENC_BIG_ENDIAN);
-
-        ipv6_tc_tree = proto_item_add_subtree(ipv6_tc, ett_ipv6_traffic_class);
-
-        proto_tree_add_item(ipv6_tc_tree, hf_ipv6_traffic_class_dscp, tvb,
-                            offset + IP6H_CTL_FLOW, 4, ENC_BIG_ENDIAN);
-        proto_tree_add_item(ipv6_tc_tree, hf_ipv6_traffic_class_ect, tvb,
+        /* !!! warning: (4-bit) version, (6-bit) DSCP, (2-bit) ECN and (20-bit) Flow */
+
+        /* _format_value() used to elide leading zeros from hex representation for IPv6 Traffic Class */
+        ti = proto_tree_add_uint_format_value(ipv6_tree, hf_ipv6_tclass, tvb,
+                            offset + IP6H_CTL_FLOW, 4, g_ntohl(ipv6->ip6_flow), "0x%02x", tfc);
+        proto_item_append_text(ti, " (DSCP: %s, ECN: %s)",
+                            val_to_str_ext_const(IPDSFIELD_DSCP(tfc), &dscp_short_vals_ext, "Unknown"),
+                            val_to_str_ext_const(IPDSFIELD_ECN(tfc), &ecn_short_vals_ext, "Unknown"));
+        pt = proto_item_add_subtree(ti, ett_ipv6_traffic_class);
+        proto_tree_add_item(pt, hf_ipv6_tclass_dscp, tvb,
                             offset + IP6H_CTL_FLOW, 4, ENC_BIG_ENDIAN);
-
-        proto_tree_add_item(ipv6_tc_tree, hf_ipv6_traffic_class_ce, tvb,
+        proto_tree_add_item(pt, hf_ipv6_tclass_ecn, tvb,
                             offset + IP6H_CTL_FLOW, 4, ENC_BIG_ENDIAN);
 
         proto_tree_add_item(ipv6_tree, hf_ipv6_flow, tvb,
@@ -2430,9 +2400,15 @@ proto_register_ipv6(void)
         { &hf_ip_version,
           { "Version",              "ip.version",
             FT_UINT8, BASE_DEC, NULL, 0xF0, NULL, HFILL }},
-        { &hf_ipv6_class,
-          { "Traffic class",        "ipv6.class",
+        { &hf_ipv6_tclass,
+          { "Traffic class",        "ipv6.tclass",
             FT_UINT32, BASE_HEX, NULL, 0x0FF00000, NULL, HFILL }},
+        { &hf_ipv6_tclass_dscp,
+          { "Differentiated Services Codepoint", "ipv6.tclass.dscp",
+            FT_UINT32, BASE_DEC | BASE_EXT_STRING, &dscp_vals_ext, 0x0FC00000, NULL, HFILL }},
+        { &hf_ipv6_tclass_ecn,
+          { "Explicit Congestion Notification", "ipv6.tclass.ecn",
+            FT_UINT32, BASE_DEC | BASE_EXT_STRING, &ecn_vals_ext, 0x00300000, NULL, HFILL }},
         { &hf_ipv6_flow,
           { "Flowlabel",            "ipv6.flow",
             FT_UINT32, BASE_HEX, NULL, 0x000FFFFF, NULL, HFILL }},
@@ -3150,18 +3126,6 @@ proto_register_ipv6(void)
           { "CGA Signature", "ipv6.shim6.cga_signature",
             FT_BYTES, BASE_NONE, NULL, 0x0,
             NULL, HFILL }},
-
-        { &hf_ipv6_traffic_class_dscp,
-          { "Differentiated Services Field", "ipv6.traffic_class.dscp",
-            FT_UINT32, BASE_HEX | BASE_EXT_STRING, &dscp_vals_ext, 0x0FC00000, NULL, HFILL }},
-
-        { &hf_ipv6_traffic_class_ect,
-          { "ECN-Capable Transport (ECT)", "ipv6.traffic_class.ect",
-            FT_BOOLEAN, 32, TFS(&tfs_set_notset), 0x0200000, NULL, HFILL }},
-
-        { &hf_ipv6_traffic_class_ce,
-          { "ECN-CE",               "ipv6.traffic_class.ce",
-            FT_BOOLEAN, 32, TFS(&tfs_set_notset), 0x0100000, NULL, HFILL }},
     };
     static gint *ett[] = {
         &ett_ipv6,