Add BASE_PT_ field display types

Avoid displaying duplicate port numbers with transport name resolution disabled and
make some dissector code simpler.

Introduces port_with_resolution_to_str_buf() function and amends UDP/TCP/DCCP/SCTP to
use the new field display type.

Change-Id: Ifb97810b9c669ccbb1a310a2c0ffd6e2b63af210
Reviewed-on: https://code.wireshark.org/review/10625
Petri-Dish: Michael Mann <mmann78@netscape.net>
Reviewed-by: João Valverde <j@v6e.pt>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Michael Mann <mmann78@netscape.net>

9 files changed, 149 insertions, 123 deletions

diff --git a/doc/README.dissector b/doc/README.dissector
index addd967d5a..97db00b14f 100644
--- a/doc/README.dissector
+++ b/doc/README.dissector
@@ -115,6 +115,10 @@ FIELDDISPLAY    --For FT_UINT{8,16,24,32,40,48,56,64} and
                   or BASE_CUSTOM, possibly ORed with BASE_RANGE_STRING,
                   BASE_EXT_STRING or BASE_VAL64_STRING
 
+                --For FT_UINT16:
+
+                  BASE_PT_UDP, BASE_PT_TCP, BASE_PT_DCCP or BASE_PT_SCTP
+
                 --For FT_ABSOLUTE_TIME:
 
                   ABSOLUTE_TIME_LOCAL, ABSOLUTE_TIME_UTC, or
@@ -823,6 +827,11 @@ and the second argument is the value to be formatted.
 
 Both custom_fmt_func_t and custom_fmt_func_64_t are defined in epan/proto.h.
 
+For FT_UINT16 'display' can be used to select a transport layer protocol using one
+of BASE_PT_UDP, BASE_PT_TCP, BASE_PT_DCCP or BASE_PT_SCTP. If transport name
+resolution is enabled the port field label is displayed in decimal and as a well-known
+service name (if one is available).
+
 For FT_BOOLEAN fields that are also bitfields (i.e., 'bitmask' is non-zero),
 'display' is used specify a "field-width" (i.e., tell the proto_tree how
 wide the parent bitfield is). (If the FT_BOOLEAN 'bitmask' is zero, then
diff --git a/epan/addr_resolv.c b/epan/addr_resolv.c
index 648d6274dc..8aab2bdc9c 100644
--- a/epan/addr_resolv.c
+++ b/epan/addr_resolv.c
@@ -621,8 +621,8 @@ wmem_utoa(wmem_allocator_t *allocator, guint port)
 }
 
 
-static gchar
-*serv_name_lookup(const guint port, const port_type proto)
+static const gchar *
+serv_name_lookup(const guint port, const port_type proto)
 {
     serv_port_t *serv_port_table;
     gchar *name;
@@ -659,10 +659,7 @@ static gchar
         } /* proto */
     }
 
-    /* getservbyport() was used here but it was to expensive, if the functionality is desired
-     * it would be better to pre parse etc/services or C:\Windows\System32\drivers\etc at
-     * startup
-     */
+    /* Use numerical port string */
     name = (gchar*)g_malloc(16);
     guint32_to_str_buf(port, name, 16);
 
@@ -3001,6 +2998,20 @@ sctp_port_to_display(wmem_allocator_t *allocator, guint port)
 
 } /* sctp_port_to_display */
 
+int
+port_with_resolution_to_str_buf(gchar *buf, gulong buf_size, port_type port_typ, guint16 port_num)
+{
+    const gchar *port_res_str;
+
+    if (!gbl_resolv_flags.transport_name ||
+            (port_typ == PT_NONE) ||
+            ((port_res_str = serv_name_lookup(port_num, port_typ)) == NULL)) {
+        /* No name resolution support, just return port string */
+        return g_snprintf(buf, buf_size, "%u", port_num);
+    }
+    return g_snprintf(buf, buf_size, "%s (%u)", port_res_str, port_num);
+}
+
 gchar *
 get_ether_name(const guint8 *addr)
 {
diff --git a/epan/addr_resolv.h b/epan/addr_resolv.h
index b3d1f70297..13e48df667 100644
--- a/epan/addr_resolv.h
+++ b/epan/addr_resolv.h
@@ -53,7 +53,7 @@ extern "C" {
 typedef struct _e_addr_resolve {
   gboolean mac_name;                          /**< Whether to resolve Ethernet MAC to manufacturer names */
   gboolean network_name;                      /**< Whether to resolve IPv4, IPv6, and IPX addresses into host names */
-  gboolean transport_name;                    /**< Whether to resolve TCP/UDP ports into service names */
+  gboolean transport_name;                    /**< Whether to resolve TCP/UDP/DCCP/SCTP ports into service names */
   gboolean concurrent_dns;                    /**< Whether to use concurrent DNS name resolution */
   gboolean dns_pkt_addr_resolution;           /**< Whether to resolve addresses using captured DNS packets */
   gboolean use_external_net_name_resolver;    /**< Whether to system's configured DNS server to resolve names */
@@ -141,6 +141,13 @@ extern gchar *dccp_port_to_display(wmem_allocator_t *allocator, guint port);
 WS_DLL_PUBLIC gchar *sctp_port_to_display(wmem_allocator_t *allocator, guint port);
 
 /*
+ * port_with_resolution_to_str_buf() prints the "<resolved> (<numerical>)" port
+ * string to 'buf'. Return value is the same as g_snprintf().
+ */
+WS_DLL_PUBLIC int port_with_resolution_to_str_buf(gchar *buf, gulong buf_size,
+                                        port_type port_typ, guint16 port_num);
+
+/*
  * Asynchronous host name lookup initialization, processing, and cleanup
  */
 
diff --git a/epan/dissectors/packet-dccp.c b/epan/dissectors/packet-dccp.c
index 0caef2e8b6..9e6dd39788 100644
--- a/epan/dissectors/packet-dccp.c
+++ b/epan/dissectors/packet-dccp.c
@@ -56,6 +56,8 @@
 #include <epan/expert.h>
 #include <epan/conversation.h>
 #include <epan/tap.h>
+#include <wsutil/utf8_entities.h>
+
 #include "packet-dccp.h"
 
 /*
@@ -607,6 +609,7 @@ dissect_dccp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_
     guint      advertised_dccp_header_len = 0;
     guint      options_len                = 0;
     e_dccphdr *dccph;
+    gchar     *src_port_str, *dst_port_str;
 
     dccph = wmem_new0(wmem_packet_scope(), e_dccphdr);
 
@@ -618,43 +621,33 @@ dissect_dccp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_
     col_set_str(pinfo->cinfo, COL_PROTOCOL, "DCCP");
     col_clear(pinfo->cinfo, COL_INFO);
 
-    dccp_item = proto_tree_add_item(tree, proto_dccp, tvb, offset, -1, ENC_NA);
-    dccp_tree = proto_item_add_subtree(dccp_item, ett_dccp);
-
     /* Extract generic header */
     dccph->sport = tvb_get_ntohs(tvb, offset);
-    proto_tree_add_uint_format_value(dccp_tree, hf_dccp_srcport, tvb,
-                                     offset, 2, dccph->sport,
-                                     "%s (%u)",
-                                     dccp_port_to_display(wmem_packet_scope(), dccph->sport),
-                                     dccph->sport);
+    dccph->dport = tvb_get_ntohs(tvb, offset);
+
+    src_port_str = dccp_port_to_display(wmem_packet_scope(), dccph->sport);
+    dst_port_str = dccp_port_to_display(wmem_packet_scope(), dccph->dport);
+    col_add_lstr(pinfo->cinfo, COL_INFO,
+                 src_port_str,
+                " "UTF8_RIGHTWARDS_ARROW" ",
+                dst_port_str,
+                COL_ADD_LSTR_TERMINATOR);
+
+    dccp_item = proto_tree_add_item(tree, proto_dccp, tvb, offset, -1, ENC_NA);
     if (dccp_summary_in_tree) {
-        proto_item_append_text(dccp_item, ", Src Port: %s (%u)",
-                               dccp_port_to_display(wmem_packet_scope(), dccph->sport), dccph->sport);
+        proto_item_append_text(dccp_item, ", Src Port: %s (%u), Dst Port: %s (%u)",
+                               src_port_str, dccph->sport,
+                               dst_port_str, dccph->dport);
     }
-    col_add_fstr(pinfo->cinfo, COL_INFO,
-                 "%s ", dccp_port_to_display(wmem_packet_scope(), dccph->sport));
-    hidden_item =
-        proto_tree_add_uint(dccp_tree, hf_dccp_port, tvb, offset, 2,
-                            dccph->sport);
+    dccp_tree = proto_item_add_subtree(dccp_item, ett_dccp);
+
+    proto_tree_add_item(dccp_tree, hf_dccp_srcport, tvb, offset, 2, ENC_BIG_ENDIAN);
+    hidden_item = proto_tree_add_item(dccp_tree, hf_dccp_port, tvb, offset, 2, ENC_BIG_ENDIAN);
     PROTO_ITEM_SET_HIDDEN(hidden_item);
     offset += 2;
 
-    dccph->dport = tvb_get_ntohs(tvb, offset);
-    proto_tree_add_uint_format_value(dccp_tree, hf_dccp_dstport, tvb,
-                                     offset, 2, dccph->dport,
-                                     "%s (%u)",
-                                     dccp_port_to_display(wmem_packet_scope(), dccph->dport),
-                                     dccph->dport);
-    if (dccp_summary_in_tree) {
-        proto_item_append_text(dccp_item, ", Dst Port: %s (%u)",
-                               dccp_port_to_display(wmem_packet_scope(), dccph->dport), dccph->dport);
-    }
-    col_append_fstr(pinfo->cinfo, COL_INFO, " > %s",
-                    dccp_port_to_display(wmem_packet_scope(), dccph->dport));
-    hidden_item =
-        proto_tree_add_uint(dccp_tree, hf_dccp_port, tvb, offset, 2,
-                            dccph->dport);
+    proto_tree_add_item(dccp_tree, hf_dccp_dstport, tvb, offset, 2, ENC_BIG_ENDIAN);
+    hidden_item = proto_tree_add_item(dccp_tree, hf_dccp_port, tvb, offset, 2, ENC_BIG_ENDIAN);
     PROTO_ITEM_SET_HIDDEN(hidden_item);
     offset += 2;
 
@@ -1054,7 +1047,7 @@ proto_register_dccp(void)
             &hf_dccp_srcport,
             {
                 "Source Port", "dccp.srcport",
-                FT_UINT16, BASE_DEC, NULL, 0x0,
+                FT_UINT16, BASE_PT_DCCP, NULL, 0x0,
                 NULL, HFILL
             }
         },
@@ -1062,7 +1055,7 @@ proto_register_dccp(void)
             &hf_dccp_dstport,
             {
                 "Destination Port", "dccp.dstport",
-                FT_UINT16, BASE_DEC, NULL, 0x0,
+                FT_UINT16, BASE_PT_DCCP, NULL, 0x0,
                 NULL, HFILL
             }
         },
@@ -1070,7 +1063,7 @@ proto_register_dccp(void)
             &hf_dccp_port,
             {
                 "Source or Destination Port", "dccp.port",
-                FT_UINT16, BASE_DEC, NULL, 0x0,
+                FT_UINT16, BASE_PT_DCCP, NULL, 0x0,
                 NULL, HFILL
             }
         },
diff --git a/epan/dissectors/packet-sctp.c b/epan/dissectors/packet-sctp.c
index 21720a7183..2cbdddb7ef 100644
--- a/epan/dissectors/packet-sctp.c
+++ b/epan/dissectors/packet-sctp.c
@@ -4736,9 +4736,9 @@ proto_register_sctp(void)
 
   /* Setup list of header fields */
   static hf_register_info hf[] = {
-    { &hf_source_port,                              { "Source port",                                    "sctp.srcport",                                         FT_UINT16,  BASE_DEC,  NULL,                                           0x0,                                NULL, HFILL } },
-    { &hf_destination_port,                         { "Destination port",                               "sctp.dstport",                                         FT_UINT16,  BASE_DEC,  NULL,                                           0x0,                                NULL, HFILL } },
-    { &hf_port,                                     { "Port",                                           "sctp.port",                                            FT_UINT16,  BASE_DEC,  NULL,                                           0x0,                                NULL, HFILL } },
+    { &hf_source_port,                              { "Source port",                                    "sctp.srcport",                                         FT_UINT16,  BASE_PT_SCTP, NULL,                                        0x0,                                NULL, HFILL } },
+    { &hf_destination_port,                         { "Destination port",                               "sctp.dstport",                                         FT_UINT16,  BASE_PT_SCTP, NULL,                                        0x0,                                NULL, HFILL } },
+    { &hf_port,                                     { "Port",                                           "sctp.port",                                            FT_UINT16,  BASE_PT_SCTP, NULL,                                        0x0,                                NULL, HFILL } },
     { &hf_verification_tag,                         { "Verification tag",                               "sctp.verification_tag",                                FT_UINT32,  BASE_HEX,  NULL,                                           0x0,                                NULL, HFILL } },
     { &hf_checksum,                                 { "Checksum",                                       "sctp.checksum",                                        FT_UINT32,  BASE_HEX,  NULL,                                           0x0,                                NULL, HFILL } },
     { &hf_checksum_bad,                             { "Bad checksum",                                   "sctp.checksum_bad",                                    FT_BOOLEAN, BASE_NONE, NULL,                                           0x0,                                NULL, HFILL } },
@@ -4786,7 +4786,7 @@ proto_register_sctp(void)
     { &hf_sack_chunk_gap_block_end_tsn,             { "End TSN",                                        "sctp.sack_gap_block_end_tsn",                          FT_UINT32,  BASE_DEC,  NULL,                                           0x0,                                NULL, HFILL } },
     { &hf_sack_chunk_number_tsns_gap_acked,         { "Number of TSNs in gap acknowledgement blocks",   "sctp.sack_number_of_tsns_gap_acked",                   FT_UINT32,  BASE_DEC,  NULL,                                           0x0,                                NULL, HFILL } },
     { &hf_sack_chunk_duplicate_tsn,                 { "Duplicate TSN",                                  "sctp.sack_duplicate_tsn",                              FT_UINT16,  BASE_DEC,  NULL,                                           0x0,                                NULL, HFILL } },
-    { &hf_nr_sack_chunk_ns,                         { "Nounce sum",                                     "sctp.nr_sack_nounce_sum",                              FT_UINT8,   BASE_DEC,  NULL,                                           SCTP_NR_SACK_CHUNK_NS_BIT,             NULL, HFILL } },
+    { &hf_nr_sack_chunk_ns,                         { "Nounce sum",                                     "sctp.nr_sack_nounce_sum",                              FT_UINT8,   BASE_DEC,  NULL,                                           SCTP_NR_SACK_CHUNK_NS_BIT,          NULL, HFILL } },
     { &hf_nr_sack_chunk_cumulative_tsn_ack,         { "Cumulative TSN ACK",                             "sctp.nr_sack_cumulative_tsn_ack",                      FT_UINT32,  BASE_DEC,  NULL,                                           0x0,                                NULL, HFILL } },
     { &hf_nr_sack_chunk_adv_rec_window_credit,      { "Advertised receiver window credit (a_rwnd)",     "sctp.nr_sack_a_rwnd",                                  FT_UINT32,  BASE_DEC,  NULL,                                           0x0,                                NULL, HFILL } },
     { &hf_nr_sack_chunk_number_of_gap_blocks,       { "Number of gap acknowledgement blocks",           "sctp.nr_sack_number_of_gap_blocks",                    FT_UINT16,  BASE_DEC,  NULL,                                           0x0,                                NULL, HFILL } },
diff --git a/epan/dissectors/packet-tcp.c b/epan/dissectors/packet-tcp.c
index 21011f470c..36c82b701a 100644
--- a/epan/dissectors/packet-tcp.c
+++ b/epan/dissectors/packet-tcp.c
@@ -4388,13 +4388,11 @@ dissect_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
         tcp_tree = proto_item_add_subtree(ti, ett_tcp);
         p_add_proto_data(pinfo->pool, pinfo, proto_tcp, pinfo->curr_layer_num, tcp_tree);
 
-        proto_tree_add_uint_format_value(tcp_tree, hf_tcp_srcport, tvb, offset, 2, tcph->th_sport,
-                                   "%s (%u)", src_port_str, tcph->th_sport);
-        proto_tree_add_uint_format_value(tcp_tree, hf_tcp_dstport, tvb, offset + 2, 2, tcph->th_dport,
-                                   "%s (%u)", dst_port_str, tcph->th_dport);
-        hidden_item = proto_tree_add_uint(tcp_tree, hf_tcp_port, tvb, offset, 2, tcph->th_sport);
+        proto_tree_add_item(tcp_tree, hf_tcp_srcport, tvb, offset, 2, ENC_BIG_ENDIAN);
+        proto_tree_add_item(tcp_tree, hf_tcp_dstport, tvb, offset + 2, 2, ENC_BIG_ENDIAN);
+        hidden_item = proto_tree_add_item(tcp_tree, hf_tcp_port, tvb, offset, 2, ENC_BIG_ENDIAN);
         PROTO_ITEM_SET_HIDDEN(hidden_item);
-        hidden_item = proto_tree_add_uint(tcp_tree, hf_tcp_port, tvb, offset + 2, 2, tcph->th_dport);
+        hidden_item = proto_tree_add_item(tcp_tree, hf_tcp_port, tvb, offset + 2, 2, ENC_BIG_ENDIAN);
         PROTO_ITEM_SET_HIDDEN(hidden_item);
 
         /*  If we're dissecting the headers of a TCP packet in an ICMP packet
@@ -5122,20 +5120,18 @@ tcp_cleanup(void)
 void
 proto_register_tcp(void)
 {
-    static value_string tcp_ports[65536+1];
-
     static hf_register_info hf[] = {
 
         { &hf_tcp_srcport,
-        { "Source Port",        "tcp.srcport", FT_UINT16, BASE_DEC, VALS(tcp_ports), 0x0,
+        { "Source Port",        "tcp.srcport", FT_UINT16, BASE_PT_TCP, NULL, 0x0,
             NULL, HFILL }},
 
         { &hf_tcp_dstport,
-        { "Destination Port",       "tcp.dstport", FT_UINT16, BASE_DEC, VALS(tcp_ports), 0x0,
+        { "Destination Port",       "tcp.dstport", FT_UINT16, BASE_PT_TCP, NULL, 0x0,
             NULL, HFILL }},
 
         { &hf_tcp_port,
-        { "Source or Destination Port", "tcp.port", FT_UINT16, BASE_DEC, VALS(tcp_ports), 0x0,
+        { "Source or Destination Port", "tcp.port", FT_UINT16, BASE_PT_TCP, NULL, 0x0,
             NULL, HFILL }},
 
         { &hf_tcp_stream,
@@ -5978,28 +5974,6 @@ proto_register_tcp(void)
     module_t *tcp_module;
     expert_module_t* expert_tcp;
 
-    {
-        int i, j;
-        gboolean transport_name_old = gbl_resolv_flags.transport_name;
-
-        gbl_resolv_flags.transport_name = TRUE;
-        for (i = 0, j = 0; i <= 65535; i++) {
-            const char *serv = tcp_port_to_display(wmem_epan_scope(), i);
-
-            if (serv) {
-                value_string *p = &tcp_ports[j++];
-
-                p->value = i;
-                p->strptr = serv;
-            }
-        }
-        /* NULL terminate */
-        tcp_ports[j].value = 0;
-        tcp_ports[j].strptr = NULL;
-
-        gbl_resolv_flags.transport_name = transport_name_old;
-    }
-
     proto_tcp = proto_register_protocol("Transmission Control Protocol", "TCP", "tcp");
     register_dissector("tcp", dissect_tcp, proto_tcp);
     proto_register_field_array(proto_tcp, hf, array_length(hf));
diff --git a/epan/dissectors/packet-udp.c b/epan/dissectors/packet-udp.c
index d0acf286ad..800f1e8f4b 100644
--- a/epan/dissectors/packet-udp.c
+++ b/epan/dissectors/packet-udp.c
@@ -54,8 +54,6 @@ static dissector_handle_t udplite_handle;
 static int udp_tap = -1;
 static int udp_follow_tap = -1;
 
-static value_string udp_ports[65536+1];
-
 static header_field_info *hfi_udp = NULL;
 static header_field_info *hfi_udplite = NULL;
 
@@ -63,15 +61,15 @@ static header_field_info *hfi_udplite = NULL;
 #define UDPLITE_HFI_INIT HFI_INIT(proto_udplite)
 
 static header_field_info hfi_udp_srcport UDP_HFI_INIT =
-{ "Source Port", "udp.srcport", FT_UINT16, BASE_DEC, VALS(udp_ports), 0x0,
+{ "Source Port", "udp.srcport", FT_UINT16, BASE_PT_UDP, NULL, 0x0,
   NULL, HFILL };
 
 static header_field_info hfi_udp_dstport UDP_HFI_INIT =
-{ "Destination Port", "udp.dstport", FT_UINT16, BASE_DEC, VALS(udp_ports), 0x0,
+{ "Destination Port", "udp.dstport", FT_UINT16, BASE_PT_UDP, NULL, 0x0,
   NULL, HFILL };
 
 static header_field_info hfi_udp_port UDP_HFI_INIT =
-{ "Source or Destination Port", "udp.port", FT_UINT16, BASE_DEC, VALS(udp_ports), 0x0,
+{ "Source or Destination Port", "udp.port", FT_UINT16, BASE_PT_UDP, NULL, 0x0,
   NULL, HFILL };
 
 static header_field_info hfi_udp_stream UDP_HFI_INIT =
@@ -733,8 +731,7 @@ dissect(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 ip_proto)
     udp_tree = proto_item_add_subtree(ti, ett_udp);
 
     p_add_proto_data(pinfo->pool, pinfo, hfi_udp->id, pinfo->curr_layer_num, udp_tree);
-    port_item = proto_tree_add_uint_format_value(udp_tree, hfi_udp_srcport.id, tvb, offset, 2, udph->uh_sport,
-                                                 "%s (%u)", src_port_str, udph->uh_sport);
+    port_item = proto_tree_add_item(udp_tree, &hfi_udp_srcport, tvb, offset, 2, ENC_BIG_ENDIAN);
     /* The beginning port number, 32768 + 666 (33434), is from LBL's traceroute.c source code and this code
      * further assumes that 3 attempts are made per hop */
     if ((udph->uh_sport > (32768 + 666)) && (udph->uh_sport <= (32768 + 666 + 30)))
@@ -743,17 +740,16 @@ dissect(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 ip_proto)
                                    ((udph->uh_sport - 32768 - 666 - 1) % 3) + 1
                                    );
 
-    port_item = proto_tree_add_uint_format_value(udp_tree, hfi_udp_dstport.id, tvb, offset + 2, 2, udph->uh_dport,
-        "%s (%u)", dst_port_str, udph->uh_dport);
+    port_item = proto_tree_add_item(udp_tree, &hfi_udp_dstport, tvb, offset + 2, 2, ENC_BIG_ENDIAN);
     if ((udph->uh_dport > (32768 + 666)) && (udph->uh_dport <= (32768 + 666 + 30)))
             expert_add_info_format(pinfo, port_item, &ei_udp_possible_traceroute, "Possible traceroute: hop #%u, attempt #%u",
                                    ((udph->uh_dport - 32768 - 666 - 1) / 3) + 1,
                                    ((udph->uh_dport - 32768 - 666 - 1) % 3) + 1
                                    );
 
-    hidden_item = proto_tree_add_uint(udp_tree, &hfi_udp_port, tvb, offset, 2, udph->uh_sport);
+    hidden_item = proto_tree_add_item(udp_tree, &hfi_udp_port, tvb, offset, 2, ENC_BIG_ENDIAN);
     PROTO_ITEM_SET_HIDDEN(hidden_item);
-    hidden_item = proto_tree_add_uint(udp_tree, &hfi_udp_port, tvb, offset+2, 2, udph->uh_dport);
+    hidden_item = proto_tree_add_item(udp_tree, &hfi_udp_port, tvb, offset+2, 2, ENC_BIG_ENDIAN);
     PROTO_ITEM_SET_HIDDEN(hidden_item);
   }
 
@@ -1091,27 +1087,7 @@ proto_register_udp(void)
   static decode_as_t udp_da = {"udp", "Transport", "udp.port", 3, 2, udp_da_values, "UDP", "port(s) as",
                                decode_as_default_populate_list, decode_as_default_reset, decode_as_default_change, NULL};
 
-  int proto_udp, proto_udplite, i, j;
-  gboolean transport_name_old = gbl_resolv_flags.transport_name;
-
-  gbl_resolv_flags.transport_name = TRUE;
-  for (i = 0, j = 0; i <= 65535; i++) {
-    const char *serv = udp_port_to_display(wmem_epan_scope(), i);
-
-    if (serv) {
-        value_string *p = &udp_ports[j++];
-
-        p->value = i;
-        p->strptr = serv;
-    }
-  }
-
-  /* NULL terminate */
-  udp_ports[j].value = 0;
-  udp_ports[j].strptr = NULL;
-
-  gbl_resolv_flags.transport_name = transport_name_old;
-
+  int proto_udp, proto_udplite;
 
   proto_udp = proto_register_protocol("User Datagram Protocol",
                                       "UDP", "udp");
diff --git a/epan/proto.c b/epan/proto.c
index 3bbb04c0fe..5e6b032227 100644
--- a/epan/proto.c
+++ b/epan/proto.c
@@ -5923,8 +5923,30 @@ static const value_string hf_display[] = {
 	{ ABSOLUTE_TIME_LOCAL,		  "ABSOLUTE_TIME_LOCAL"		   },
 	{ ABSOLUTE_TIME_UTC,		  "ABSOLUTE_TIME_UTC"		   },
 	{ ABSOLUTE_TIME_DOY_UTC,	  "ABSOLUTE_TIME_DOY_UTC"	   },
+	{ BASE_PT_UDP,			  "BASE_PT_UDP"			   },
+	{ BASE_PT_TCP,			  "BASE_PT_TCP"			   },
+	{ BASE_PT_DCCP,			  "BASE_PT_DCCP"		   },
+	{ BASE_PT_SCTP,			  "BASE_PT_SCTP"		   },
 	{ 0,				  NULL } };
 
+static inline port_type
+display_to_port_type(field_display_e e)
+{
+	switch (e) {
+	case BASE_PT_UDP:
+		return PT_UDP;
+	case BASE_PT_TCP:
+		return PT_TCP;
+	case BASE_PT_DCCP:
+		return PT_DCCP;
+	case BASE_PT_SCTP:
+		return PT_SCTP;
+	default:
+		break;
+	}
+	return PT_NONE;
+}
+
 /* temporary function containing assert part for easier profiling */
 static void
 tmp_fld_check_assert(header_field_info *hfinfo)
@@ -6062,6 +6084,26 @@ tmp_fld_check_assert(header_field_info *hfinfo)
 		case FT_UINT48:
 		case FT_UINT56:
 		case FT_UINT64:
+			if (IS_BASE_PORT(hfinfo->display)) {
+				tmp_str = val_to_str_wmem(NULL, hfinfo->display, hf_display, "(Unknown: 0x%x)");
+				if (hfinfo->type != FT_UINT16) {
+					g_error("Field '%s' (%s) has 'display' value %s but it can only be used with FT_UINT16, not %s\n",
+						hfinfo->name, hfinfo->abbrev,
+						tmp_str, ftype_name(hfinfo->type));
+				}
+				if (hfinfo->strings != NULL) {
+					g_error("Field '%s' (%s) is an %s (%s) but has a strings value\n",
+						hfinfo->name, hfinfo->abbrev,
+						ftype_name(hfinfo->type), tmp_str);
+				}
+				if (hfinfo->bitmask != 0) {
+					g_error("Field '%s' (%s) is an %s (%s) but has a bitmask\n",
+						hfinfo->name, hfinfo->abbrev,
+						ftype_name(hfinfo->type), tmp_str);
+				}
+				wmem_free(NULL, tmp_str);
+				break;
+			}
 			/*  Require integral types (other than frame number,
 			 *  which is always displayed in decimal) to have a
 			 *  number base.
@@ -6992,7 +7034,7 @@ fill_label_number(field_info *fi, gchar *label_str, gboolean is_signed)
 		fmtfunc(tmp, value);
 		label_fill(label_str, 0, hfinfo, tmp);
 	}
-    else if (hfinfo->strings && hfinfo->type != FT_FRAMENUM) { /* Add fill_label_framenum? */
+	else if (hfinfo->strings && hfinfo->type != FT_FRAMENUM) { /* Add fill_label_framenum? */
 		const char *val_str = hf_try_val_to_str_const(value, hfinfo, "Unknown");
 
 		out = hfinfo_number_vals_format(hfinfo, buf, value);
@@ -7001,6 +7043,13 @@ fill_label_number(field_info *fi, gchar *label_str, gboolean is_signed)
 		else
 			label_fill_descr(label_str, 0, hfinfo, val_str, out);
 	}
+	else if (IS_BASE_PORT(hfinfo->display)) {
+		gchar tmp[ITEM_LABEL_LENGTH];
+
+		port_with_resolution_to_str_buf(tmp, sizeof(tmp),
+			display_to_port_type((field_display_e)hfinfo->display), value);
+		label_fill(label_str, 0, hfinfo, tmp);
+	}
 	else {
 		out = hfinfo_number_value_format(hfinfo, buf, value);
 
diff --git a/epan/proto.h b/epan/proto.h
index 3f0cef278d..0b98ba39e5 100644
--- a/epan/proto.h
+++ b/epan/proto.h
@@ -497,9 +497,8 @@ WS_DLL_PUBLIC WS_MSVC_NORETURN void proto_report_dissector_bug(const char *messa
 /* For integral types, the display format is a BASE_* field_display_e value
  * possibly ORed with BASE_*_STRING */
 
-/** FIELD_DISPLAY_E_MASK selects the field_display_e value.  Its current
- * value means that we may have at most 16 field_display_e values. */
-#define FIELD_DISPLAY_E_MASK 0x0F
+/** FIELD_DISPLAY_E_MASK selects the field_display_e value. */
+#define FIELD_DISPLAY_E_MASK 0xFF
 
 typedef enum {
 /* Integral types */
@@ -514,28 +513,36 @@ typedef enum {
 /* String types */
 	STR_ASCII    = BASE_NONE, /**< shows non-printable ASCII characters as C-style escapes */
 	/* XXX, support for format_text_wsp() ? */
-	STR_UNICODE  = 7,         /**< shows non-printable UNICODE characters as \\uXXXX (XXX for now non-printable characters display depends on UI) */
+	STR_UNICODE  = 7,   /**< shows non-printable UNICODE characters as \\uXXXX (XXX for now non-printable characters display depends on UI) */
 
 /* Byte types */
-	SEP_DOT = 8,        /**< hexadecimal bytes with a period (.) between each byte */
-	SEP_DASH  = 9,      /**< hexadecimal bytes with a dash (-) between each byte */
-	SEP_COLON = 10,     /**< hexadecimal bytes with a colon (:) between each byte */
-	SEP_SPACE  = 11,     /**< hexadecimal bytes with a space between each byte */
+	SEP_DOT      = 8,   /**< hexadecimal bytes with a period (.) between each byte */
+	SEP_DASH     = 9,   /**< hexadecimal bytes with a dash (-) between each byte */
+	SEP_COLON    = 10,  /**< hexadecimal bytes with a colon (:) between each byte */
+	SEP_SPACE    = 11,  /**< hexadecimal bytes with a space between each byte */
 
 /* Address types */
-	BASE_NETMASK  = 12   /**< Used for IPv4 address that shouldn't be resolved (like for netmasks) */
+	BASE_NETMASK = 12,  /**< Used for IPv4 address that shouldn't be resolved (like for netmasks) */
 
+/* Port types */
+	BASE_PT_UDP  = 13,  /**< UDP port */
+	BASE_PT_TCP  = 14,  /**< TCP port */
+	BASE_PT_DCCP = 15,  /**< DCCP port */
+	BASE_PT_SCTP = 16,  /**< SCTP port */
 } field_display_e;
 
 /* Following constants have to be ORed with a field_display_e when dissector
  * want to use specials value-string MACROs for a header_field_info */
-#define BASE_RANGE_STRING 0x10
-#define BASE_EXT_STRING   0x20
-#define BASE_VAL64_STRING 0x40
+#define BASE_RANGE_STRING 0x100
+#define BASE_EXT_STRING   0x200
+#define BASE_VAL64_STRING 0x400
 
 /** BASE_ values that cause the field value to be displayed twice */
 #define IS_BASE_DUAL(b) ((b)==BASE_DEC_HEX||(b)==BASE_HEX_DEC)
 
+/** BASE_PT_ values display decimal and transport port service name */
+#define IS_BASE_PORT(b) (((b)==BASE_PT_UDP||(b)==BASE_PT_TCP||(b)==BASE_PT_DCCP||(b)==BASE_PT_SCTP))
+
 /* For FT_ABSOLUTE_TIME, the display format is an absolute_time_display_e
  * as per time_fmt.h. */
 
@@ -554,7 +561,7 @@ struct _header_field_info {
 	const char		*name;           /**< [FIELDNAME] full name of this field */
 	const char		*abbrev;         /**< [FIELDABBREV] abbreviated name of this field */
 	enum ftenum		 type;           /**< [FIELDTYPE] field type, one of FT_ (from ftypes.h) */
-	int			     display;        /**< [FIELDDISPLAY] one of BASE_, or field bit-width if FT_BOOLEAN and non-zero bitmask */
+	int			 display;        /**< [FIELDDISPLAY] one of BASE_, or field bit-width if FT_BOOLEAN and non-zero bitmask */
 	const void		*strings;        /**< [FIELDCONVERT] value_string, val64_string, range_string or true_false_string,
 				                      typically converted by VALS(), RVALS() or TFS().
 				                      If this is an FT_PROTOCOL then it points to the