DNS: move DNS name resolution pref to Name Resolution prefs

Move the boolean flag for using captured DNS packet info for name resolution
to the Name Resolution preferences settings, as it was rather surprising to
disable Name Resolution preferences and still have names being resolved. Also
disble them all if the '-n' command line switch is used, and re-enable it for
a 'd' character in the '-N' option.

Bug: 10337
Change-Id: Ie4d47bab0100db3360cc447cd3e446b2e39aa917
Reviewed-on: https://code.wireshark.org/review/9786
Petri-Dish: Hadriel Kaplan <hadrielk@yahoo.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Hadriel Kaplan <hadrielk@yahoo.com>

4 files changed, 51 insertions, 24 deletions

diff --git a/epan/addr_resolv.c b/epan/addr_resolv.c
index 76b9c7e078..ee0f1aa9ab 100644
--- a/epan/addr_resolv.c
+++ b/epan/addr_resolv.c
@@ -299,7 +299,15 @@ ipv6_equal(gconstpointer v1, gconstpointer v2)
 /*
  * Flag controlling what names to resolve.
  */
-e_addr_resolve gbl_resolv_flags = {TRUE, FALSE, FALSE, TRUE, TRUE, FALSE};
+e_addr_resolve gbl_resolv_flags = {
+    TRUE,   /* mac_name */
+    FALSE,  /* network_name */
+    FALSE,  /* transport_name */
+    TRUE,   /* concurrent_dns */
+    TRUE,   /* dns_pkt_addr_resolution */
+    TRUE,   /* use_external_net_name_resolver */
+    FALSE   /* load_hosts_file_from_profile_only */
+};
 #if defined(HAVE_C_ARES) || defined(HAVE_GNU_ADNS)
 static guint name_resolve_concurrency = 500;
 #endif
@@ -2414,6 +2422,11 @@ addr_resolve_pref_init(module_t *nameres)
             " capture file name resolution blocks and DNS packets in the capture.",
             &gbl_resolv_flags.network_name);
 
+    prefs_register_bool_preference(nameres, "dns_pkt_addr_resolution",
+            "Use captured DNS packet data for address resolution",
+            "Whether address/name pairs found in captured DNS packets should be used by Wireshark for name resolution.",
+            &gbl_resolv_flags.dns_pkt_addr_resolution);
+
     prefs_register_bool_preference(nameres, "use_external_name_resolver",
             "Use an external network name resolver",
             "Use your system's configured name resolver"
@@ -2453,6 +2466,16 @@ addr_resolve_pref_init(module_t *nameres)
 
 }
 
+void
+disable_name_resolution(void) {
+    gbl_resolv_flags.mac_name                           = FALSE;
+    gbl_resolv_flags.network_name                       = FALSE;
+    gbl_resolv_flags.transport_name                     = FALSE;
+    gbl_resolv_flags.concurrent_dns                     = FALSE;
+    gbl_resolv_flags.dns_pkt_addr_resolution            = FALSE;
+    gbl_resolv_flags.use_external_net_name_resolver     = FALSE;
+}
+
 #ifdef HAVE_C_ARES
 gboolean
 host_name_lookup_process(void) {
diff --git a/epan/addr_resolv.h b/epan/addr_resolv.h
index 25bd0156d1..c60e2c5180 100644
--- a/epan/addr_resolv.h
+++ b/epan/addr_resolv.h
@@ -47,13 +47,17 @@ extern "C" {
 #define MAXNAMELEN  	64	/* max name length (hostname and port name) */
 #endif
 
+/**
+ * @brief Flags to control name resolution.
+ */
 typedef struct _e_addr_resolve {
-  gboolean mac_name;
-  gboolean network_name;
-  gboolean transport_name;
-  gboolean concurrent_dns;
-  gboolean use_external_net_name_resolver;
-  gboolean load_hosts_file_from_profile_only;
+  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 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 */
+  gboolean load_hosts_file_from_profile_only; /**< Whether to only load the hosts in the current profile, not hosts files */
 } e_addr_resolve;
 
 struct hashether;
@@ -138,6 +142,11 @@ WS_DLL_PUBLIC gchar *sctp_port_to_display(wmem_allocator_t *allocator, guint por
 struct pref_module;
 extern void addr_resolve_pref_init(struct pref_module *nameres);
 
+/*
+ * disable_name_resolution() sets all relevant gbl_resolv_flags to FALSE.
+ */
+WS_DLL_PUBLIC void disable_name_resolution(void);
+
 /** If we're using c-ares or ADNS, process outstanding host name lookups.
  *  This is called from a GLIB timeout in Wireshark and before processing
  *  each packet in TShark.
diff --git a/epan/dissectors/packet-dns.c b/epan/dissectors/packet-dns.c
index 2964961ece..96eb76fffc 100644
--- a/epan/dissectors/packet-dns.c
+++ b/epan/dissectors/packet-dns.c
@@ -420,9 +420,6 @@ static range_t *global_dns_udp_port_range;
 /* desegmentation of DNS over TCP */
 static gboolean dns_desegment = TRUE;
 
-/* whether or not to use DNS data we see in packets to resolve addresses */
-static gboolean dns_use_for_addr_resolution = TRUE;
-
 /* Dissector handle for GSSAPI */
 static dissector_handle_t gssapi_handle;
 static dissector_handle_t ntlmssp_handle;
@@ -1814,7 +1811,7 @@ dissect_dns_answer(tvbuff_t *tvb, int offsetx, int dns_data_offset,
       proto_item_append_text(trr, ", addr %s", addr);
       proto_tree_add_item(rr_tree, hf_dns_a, tvb, cur_offset, 4, ENC_BIG_ENDIAN);
 
-      if (dns_use_for_addr_resolution && (dns_class & 0x7f) == C_IN) {
+      if (gbl_resolv_flags.dns_pkt_addr_resolution && (dns_class & 0x7f) == C_IN) {
         guint32 addr_int;
         tvb_memcpy(tvb, &addr_int, cur_offset, sizeof(addr_int));
         add_ipv4_name(addr_int, name);
@@ -2425,7 +2422,7 @@ dissect_dns_answer(tvbuff_t *tvb, int offsetx, int dns_data_offset,
       proto_tree_add_item(rr_tree, hf_dns_aaaa, tvb, cur_offset, 16, ENC_NA);
 
 
-      if (dns_use_for_addr_resolution && (dns_class & 0x7f) == C_IN) {
+      if (gbl_resolv_flags.dns_pkt_addr_resolution && (dns_class & 0x7f) == C_IN) {
         struct e_in6_addr  addr_in6;
         tvb_memcpy(tvb, &addr_in6, cur_offset, sizeof(addr_in6));
         add_ipv6_name(&addr_in6, name);
@@ -5616,10 +5613,11 @@ proto_register_dns(void)
     " To use this option, you must also enable \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.",
     &dns_desegment);
 
-  prefs_register_bool_preference(dns_module, "use_for_addr_resolution",
-    "Use DNS packet data for address resolution",
-    "Whether address/name pairs found in dissected DNS packets should be used by Wireshark for name resolution.",
-    &dns_use_for_addr_resolution);
+  prefs_register_obsolete_preference(dns_module, "use_for_addr_resolution");
+
+  prefs_register_static_text_preference(dns_module, "text_use_for_addr_resolution",
+                                        "DNS address resolution settings can be changed in the Name Resolution preferences",
+                                        "DNS address resolution settings can be changed in the Name Resolution preferences");
 
   dns_tsig_dissector_table = register_dissector_table("dns.tsig.mac", "DNS TSIG MAC Dissectors", FT_STRING, BASE_NONE);
 
diff --git a/epan/prefs.c b/epan/prefs.c
index 4b993001ef..16f08be70c 100644
--- a/epan/prefs.c
+++ b/epan/prefs.c
@@ -3761,6 +3761,9 @@ string_to_name_resolve(const char *string, e_addr_resolve *name_resolve)
         case 'C':
             name_resolve->concurrent_dns = TRUE;
             break;
+        case 'd':
+            name_resolve->dns_pkt_addr_resolution = TRUE;
+            break;
         default:
             /*
              * Unrecognized letter.
@@ -3936,17 +3939,11 @@ set_pref(gchar *pref_name, const gchar *value, void *private_data _U_,
             gbl_resolv_flags.concurrent_dns = TRUE;
         }
         else if (g_ascii_strcasecmp(value, "false") == 0) {
-            gbl_resolv_flags.mac_name = FALSE;
-            gbl_resolv_flags.network_name = FALSE;
-            gbl_resolv_flags.transport_name = FALSE;
-            gbl_resolv_flags.concurrent_dns = FALSE;
+            disable_name_resolution();
         }
         else {
             /* start out with none set */
-            gbl_resolv_flags.mac_name = FALSE;
-            gbl_resolv_flags.network_name = FALSE;
-            gbl_resolv_flags.transport_name = FALSE;
-            gbl_resolv_flags.concurrent_dns = FALSE;
+            disable_name_resolution();
             if (string_to_name_resolve(value, &gbl_resolv_flags) != '\0')
                 return PREFS_SET_SYNTAX_ERR;
         }