...G...... [DEV-1434] added net.dns, net.dns.record, vfs.dir.count, vfs.dir.size metric support to agent2 on windows

* commit 'c7b3eed670171325bca880c57e2a15a0d9616c2b':
  .......... [DEV-1434] fixed warning of windows agent2 compilation
  .......... [DEV-1434] fixed zabbix_agentd compiling
  .......... [DEV-1434] added vfs.dir.* metric support
  .......... [DEV-1434] fixed windows dns metrics
  .......... [DEV-1434] add net.dns, net.dns.record supoprt via C code
  .......... [DEV-1434] moved dns metrics to separate file

(cherry picked from commit 322a38b03c3217a832bef2c0186306a9bd964b2a)

14 files changed, 1072 insertions, 964 deletions

diff --git a/build/mingw/Makefile b/build/mingw/Makefile
index b4db3603ad3..a2450064cab 100644
--- a/build/mingw/Makefile
+++ b/build/mingw/Makefile
@@ -16,6 +16,7 @@ OBJS = \
 	$(OUTPUTDIR)\str.o \
 	$(OUTPUTDIR)\misc.o \
 	$(OUTPUTDIR)\fatal.o \
+	$(OUTPUTDIR)\disk.o \
 	$(OUTPUTDIR)\iprange.o \
 	$(OUTPUTDIR)\md5.o \
 	$(OUTPUTDIR)\sysinfo.o \
@@ -26,6 +27,8 @@ OBJS = \
 	$(OUTPUTDIR)\alias.o \
 	$(OUTPUTDIR)\algodefs.o \
 	$(OUTPUTDIR)\sysinfo_system.o \
+	$(OUTPUTDIR)\sysinfo_dns.o \
+	$(OUTPUTDIR)\sysinfo_dir.o \
 	$(OUTPUTDIR)\eventlog.o
 
 CFLAGS := $(CFLAGS) -O2 -g -DUNICODE -DHAVE_STDINT_H=1 -I$(TOPDIR)\build\win32\include -I$(TOPDIR)\build\mingw -I$(TOPDIR)\include
@@ -95,6 +98,9 @@ $(OUTPUTDIR)\tls_version.o: $(TOPDIR)\src\libs\zbxcrypto\tls_version.c
 $(OUTPUTDIR)\fatal.o: $(TOPDIR)\src\libs\zbxwin32\fatal.c
 	$(CC) $(CFLAGS) -c $^ -o $@
 
+$(OUTPUTDIR)\disk.o: $(TOPDIR)\src\libs\zbxwin32\disk.c
+	$(CC) $(CFLAGS) -c $^ -o $@
+
 $(OUTPUTDIR)\threads.o: $(TOPDIR)\src\libs\zbxsys\threads.c
 	$(CC) $(CFLAGS) -c $^ -o $@
 
@@ -107,7 +113,10 @@ $(OUTPUTDIR)\sysinfo.o: $(TOPDIR)\src\libs\zbxsysinfo\sysinfo.c
 $(OUTPUTDIR)\sysinfo_system.o: $(TOPDIR)\src\libs\zbxsysinfo\common\system.c
 	$(CC) $(CFLAGS) -c $^ -o $@
 
-$(OUTPUTDIR)\sysinfo_net.o: $(TOPDIR)\src\libs\zbxsysinfo\common\net.c
+$(OUTPUTDIR)\sysinfo_dns.o: $(TOPDIR)\src\libs\zbxsysinfo\common\dns.c
+	$(CC) $(CFLAGS) -c $^ -o $@
+
+$(OUTPUTDIR)\sysinfo_dir.o: $(TOPDIR)\src\libs\zbxsysinfo\common\dir.c
 	$(CC) $(CFLAGS) -c $^ -o $@
 
 $(OUTPUTDIR)\vector.o: $(TOPDIR)\src\libs\zbxalgo\vector.c
diff --git a/build/win32/project/Makefile_agent b/build/win32/project/Makefile_agent
index 6d1df2f6726..03103fa7d10 100644
--- a/build/win32/project/Makefile_agent
+++ b/build/win32/project/Makefile_agent
@@ -70,6 +70,7 @@ OBJS = \
 	..\..\..\src\libs\zbxsysinfo\common\file.o \
 	..\..\..\src\libs\zbxsysinfo\common\http.o \
 	..\..\..\src\libs\zbxsysinfo\common\net.o \
+	..\..\..\src\libs\zbxsysinfo\common\dns.o \
 	..\..\..\src\libs\zbxsysinfo\common\system.o \
 	..\..\..\src\libs\zbxsysinfo\common\zabbix_stats.o \
 	..\..\..\src\libs\zbxsysinfo\simple\ntp.o \
diff --git a/include/disk.h b/include/disk.h
index 9dace978a11..d38bca139a2 100644
--- a/include/disk.h
+++ b/include/disk.h
@@ -20,7 +20,7 @@
 #ifndef ZABBIX_DISK_H
 #define ZABBIX_DISK_H
 
-#ifndef _WINDOWS
+#if !defined(_WINDOWS) && !defined(__MINGW32__)
 #	error "This module is only available for Windows OS"
 #endif
 
diff --git a/src/go/pkg/zbxlib/checks_windows.go b/src/go/pkg/zbxlib/checks_windows.go
index 2dba57cd8eb..32d1d67c62d 100644
--- a/src/go/pkg/zbxlib/checks_windows.go
+++ b/src/go/pkg/zbxlib/checks_windows.go
@@ -69,6 +69,14 @@ func resolveMetric(key string) (cfunc unsafe.Pointer) {
 	switch key {
 	case "system.localtime":
 		cfunc = unsafe.Pointer(C.SYSTEM_LOCALTIME)
+	case "net.dns":
+		cfunc = unsafe.Pointer(C.NET_DNS)
+	case "net.dns.record":
+		cfunc = unsafe.Pointer(C.NET_DNS_RECORD)
+	case "vfs.dir.count":
+		cfunc = unsafe.Pointer(C.VFS_DIR_COUNT)
+	case "vfs.dir.size":
+		cfunc = unsafe.Pointer(C.VFS_DIR_SIZE)
 	}
 	return
 }
diff --git a/src/go/pkg/zbxlib/globals_windows.go b/src/go/pkg/zbxlib/globals_windows.go
index 3688ad50808..677468464cf 100644
--- a/src/go/pkg/zbxlib/globals_windows.go
+++ b/src/go/pkg/zbxlib/globals_windows.go
@@ -32,6 +32,7 @@ package zbxlib
 #cgo LDFLAGS: ${SRCDIR}/../../../../build/mingw/output/file.o
 #cgo LDFLAGS: ${SRCDIR}/../../../../build/mingw/output/alias.o
 #cgo LDFLAGS: ${SRCDIR}/../../../../build/mingw/output/fatal.o
+#cgo LDFLAGS: ${SRCDIR}/../../../../build/mingw/output/disk.o
 #cgo LDFLAGS: ${SRCDIR}/../../../../build/mingw/output/threads.o
 #cgo LDFLAGS: ${SRCDIR}/../../../../build/mingw/output/iprange.o
 #cgo LDFLAGS: ${SRCDIR}/../../../../build/mingw/output/md5.o
@@ -41,9 +42,11 @@ package zbxlib
 #cgo LDFLAGS: ${SRCDIR}/../../../../build/mingw/output/algodefs.o
 #cgo LDFLAGS: ${SRCDIR}/../../../../build/mingw/output/logfiles.o
 #cgo LDFLAGS: ${SRCDIR}/../../../../build/mingw/output/sysinfo_system.o
+#cgo LDFLAGS: ${SRCDIR}/../../../../build/mingw/output/sysinfo_dns.o
+#cgo LDFLAGS: ${SRCDIR}/../../../../build/mingw/output/sysinfo_dir.o
 #cgo LDFLAGS: ${SRCDIR}/../../../../build/mingw/output/eventlog.o
 #cgo openssl LDFLAGS: ${SRCDIR}/../../../../build/mingw/output/tls_version.o
-#cgo LDFLAGS: -lpcre -lDbghelp -lpsapi -lws2_32 -lWevtapi
+#cgo LDFLAGS: -lpcre -lDbghelp -lpsapi -lws2_32 -lWevtapi -ldnsapi
 #cgo openssl LDFLAGS: -lssl -lcrypto
 #cgo LDFLAGS: -Wl,--end-group
 
diff --git a/src/go/plugins/plugins_windows.go b/src/go/plugins/plugins_windows.go
index 4a278241084..1d4c967058c 100644
--- a/src/go/plugins/plugins_windows.go
+++ b/src/go/plugins/plugins_windows.go
@@ -36,5 +36,6 @@ import (
 	_ "zabbix.com/plugins/windows/perfmon"
 	_ "zabbix.com/plugins/windows/services"
 	_ "zabbix.com/plugins/zabbix/async"
+	_ "zabbix.com/plugins/zabbix/sync"
 	_ "zabbix.com/plugins/zabbix/stats"
 )
diff --git a/src/go/plugins/zabbix/sync/sync_windows.go b/src/go/plugins/zabbix/sync/sync_windows.go
new file mode 100644
index 00000000000..f534c052d36
--- /dev/null
+++ b/src/go/plugins/zabbix/sync/sync_windows.go
@@ -0,0 +1,29 @@
+/*
+** Zabbix
+** Copyright (C) 2001-2020 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+package zabbixsync
+
+func getMetrics() []string {
+	return []string{
+		"net.dns", "Checks if DNS service is up.",
+		"net.dns.record", "Performs DNS query.",
+		"vfs.dir.count", "Directory entry count.",
+		"vfs.dir.size", "Directory size (in bytes).",
+	}
+}
diff --git a/src/libs/zbxsysinfo/common/Makefile.am b/src/libs/zbxsysinfo/common/Makefile.am
index 36eaba1ec8b..6a3654f92bb 100644
--- a/src/libs/zbxsysinfo/common/Makefile.am
+++ b/src/libs/zbxsysinfo/common/Makefile.am
@@ -11,6 +11,8 @@ libcommonsysinfo_a_SOURCES = \
 	cpu.h \
 	dir.c \
 	dir.h \
+	dns.c \
+	dns.h \
 	file.c \
 	file.h \
 	http.c \
diff --git a/src/libs/zbxsysinfo/common/common.c b/src/libs/zbxsysinfo/common/common.c
index 7588875cdd8..2b76db7b656 100644
--- a/src/libs/zbxsysinfo/common/common.c
+++ b/src/libs/zbxsysinfo/common/common.c
@@ -26,6 +26,7 @@
 #include "dir.h"
 #include "http.h"
 #include "net.h"
+#include "dns.h"
 #include "system.h"
 #include "zabbix_stats.h"
 #include "zbxexec.h"
diff --git a/src/libs/zbxsysinfo/common/dir.c b/src/libs/zbxsysinfo/common/dir.c
index 894f5eb603a..8aeeb90b84f 100644
--- a/src/libs/zbxsysinfo/common/dir.c
+++ b/src/libs/zbxsysinfo/common/dir.c
@@ -23,7 +23,7 @@
 #include "zbxregexp.h"
 #include "log.h"
 
-#ifdef _WINDOWS
+#if defined(_WINDOWS) || defined(__MINGW32__)
 #	include "disk.h"
 #endif
 
@@ -183,7 +183,7 @@ static int	prepare_common_parameters(const AGENT_REQUEST *request, AGENT_RESULT
 	if ('\0' != *(*dir + 1) && ':' != *(*dir + strlen(*dir) - 2))
 		zbx_rtrim(*dir, "/\\");
 
-#ifdef _WINDOWS
+#if defined(_WINDOWS) || defined(__MINGW32__)
 	if (0 != zbx_stat(*dir, status))
 #else
 	if (0 != lstat(*dir, status))
@@ -422,7 +422,7 @@ static void	descriptors_vector_destroy(zbx_vector_ptr_t *descriptors)
  * sockets, etc.).                                                            *
  *                                                                            *
  *****************************************************************************/
-#ifdef _WINDOWS
+#if defined(_WINDOWS) || defined(__MINGW32__)
 
 #define		DW2UI64(h,l) 	((zbx_uint64_t)h << 32 | l)
 #define		FT2UT(ft) 	(time_t)(DW2UI64(ft.dwHighDateTime,ft.dwLowDateTime) / 10000000ULL - 11644473600ULL)
@@ -706,7 +706,7 @@ err1:
 
 	return ret;
 }
-#else /* not _WINDOWS */
+#else /* not _WINDOWS or __MINGW32__ */
 static int	vfs_dir_size(AGENT_REQUEST *request, AGENT_RESULT *result)
 {
 	char			*dir = NULL;
@@ -873,8 +873,8 @@ int	VFS_DIR_SIZE(AGENT_REQUEST *request, AGENT_RESULT *result)
  * Comments: under Widows we only support entry types "file" and "dir"        *
  *                                                                            *
  *****************************************************************************/
-#ifdef _WINDOWS
-static int	vfs_dir_count(const AGENT_REQUEST *request, AGENT_RESULT *result, HANDLE timeout_event)
+#if defined(_WINDOWS) || defined(__MINGW32__)
+static int	vfs_dir_count(AGENT_REQUEST *request, AGENT_RESULT *result, HANDLE timeout_event)
 {
 	char			*dir = NULL;
 	int			types, max_depth, ret = SYSINFO_RET_FAIL;
@@ -1051,7 +1051,7 @@ err1:
 
 	return ret;
 }
-#else /* not _WINDOWS */
+#else /* not _WINDOWS or __MINGW32__ */
 static int	vfs_dir_count(AGENT_REQUEST *request, AGENT_RESULT *result)
 {
 	char			*dir = NULL;
diff --git a/src/libs/zbxsysinfo/common/dns.c b/src/libs/zbxsysinfo/common/dns.c
new file mode 100644
index 00000000000..dd43cd386db
--- /dev/null
+++ b/src/libs/zbxsysinfo/common/dns.c
@@ -0,0 +1,913 @@
+/*
+** Zabbix
+** Copyright (C) 2001-2020 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+#include "common.h"
+#include "sysinfo.h"
+
+#include "comms.h"
+#include "log.h"
+#include "cfg.h"
+
+#include "dns.h"
+#include "zbxalgo.h"
+
+#if defined(_WINDOWS) || defined(__MINGW32__)
+#	include <windns.h>
+#	pragma comment(lib, "Dnsapi.lib") /* add the library for DnsQuery function */
+#endif
+
+#if defined(HAVE_RES_QUERY) || defined(_WINDOWS) || defined(__MINGW32__)
+
+static const char	*decode_type(int q_type)
+{
+	static ZBX_THREAD_LOCAL char	buf[16];
+
+	switch (q_type)
+	{
+		case T_A:
+			return "A";	/* address */
+		case T_AAAA:
+			return "AAAA";	/* v6 address */
+		case T_NS:
+			return "NS";	/* name server */
+		case T_MD:
+			return "MD";	/* mail destination */		/* obsolete */
+		case T_MF:
+			return "MF";	/* mail forwarder */		/* obsolete */
+		case T_CNAME:
+			return "CNAME";	/* canonical name */
+		case T_SOA:
+			return "SOA";	/* start of authority */
+		case T_MB:
+			return "MB";	/* mailbox */			/* experimental */
+		case T_MG:
+			return "MG";	/* mail group member */		/* experimental */
+		case T_MR:
+			return "MR";	/* mail rename */		/* experimental */
+		case T_NULL:
+			return "NULL";	/* null */			/* obsolete */
+		case T_WKS:
+			return "WKS";	/* well-known service */	/* obsolete */
+		case T_PTR:
+			return "PTR";	/* domain name pointer */
+		case T_HINFO:
+			return "HINFO";	/* host information */
+		case T_MINFO:
+			return "MINFO";	/* mailbox information */	/* experimental */
+		case T_MX:
+			return "MX";	/* mail exchanger */
+		case T_TXT:
+			return "TXT";	/* text */
+		case T_SRV:
+			return "SRV";	/* service locator */
+		default:
+			zbx_snprintf(buf, sizeof(buf), "T_%d", q_type);
+			return buf;
+	}
+}
+
+#if !defined(_WINDOWS) && !defined(__MINGW32__)
+static char	*get_name(unsigned char *msg, unsigned char *msg_end, unsigned char **msg_ptr)
+{
+	int		res;
+	static char	buffer[MAX_STRING_LEN];
+
+	if (-1 == (res = dn_expand(msg, msg_end, *msg_ptr, buffer, sizeof(buffer))))
+		return NULL;
+
+	*msg_ptr += res;
+
+	return buffer;
+}
+#endif	/* !defined(_WINDOWS) && !defined(__MINGW32__)*/
+
+/* Replace zbx_inet_ntop with inet_ntop in case of drop Windows XP/W2k3 support */
+#if defined(_WINDOWS) || defined(__MINGW32__)
+const char *zbx_inet_ntop(int af, const void *src, char *dst, size_t size)
+{
+	struct sockaddr_storage ss;
+	unsigned long s = size;
+
+	memset(&ss, '\0', sizeof(ss));
+	ss.ss_family = af;
+
+	switch(af)
+	{
+		case AF_INET:
+			((struct sockaddr_in *)&ss)->sin_addr = *(struct in_addr *)src;
+			break;
+		case AF_INET6:
+			((struct sockaddr_in6 *)&ss)->sin6_addr = *(struct in6_addr *)src;
+			break;
+		default:
+			return NULL;
+	}
+
+	return (0 == WSAAddressToStringA((struct sockaddr *)&ss, sizeof(ss), NULL, dst, &s))? dst : NULL;
+}
+#endif
+#endif	/* defined(HAVE_RES_QUERY) || defined(_WINDOWS) || defined(__MINGW32__) */
+
+static int	dns_query(AGENT_REQUEST *request, AGENT_RESULT *result, int short_answer)
+{
+#if defined(HAVE_RES_QUERY) || defined(_WINDOWS) || defined(__MINGW32__)
+
+	size_t			offset = 0;
+	int			res, type, retrans, retry, use_tcp, i, ret = SYSINFO_RET_FAIL, ip_type = AF_INET;
+	char			*ip, zone[MAX_STRING_LEN], buffer[MAX_STRING_LEN], *zone_str, *param,
+				tmp[MAX_STRING_LEN];
+	struct in_addr		inaddr;
+	struct in6_addr		in6addr;
+#if !defined(_WINDOWS) && !defined(__MINGW32__)
+#if defined(HAVE_RES_NINIT) && !defined(_AIX)
+	/* It seems that on some AIX systems with no updates installed res_ninit() can */
+	/* corrupt stack (see ZBX-14559). Use res_init() on AIX. */
+	struct __res_state	res_state_local;
+#else	/* thread-unsafe resolver API */
+	int			saved_retrans, saved_retry, saved_nscount = 0;
+	unsigned long		saved_options;
+	struct sockaddr_in	saved_ns;
+#	if defined(HAVE_RES_U_EXT)		/* thread-unsafe resolver API /Linux/ */
+	int			save_nssocks, saved_nscount6;
+#	endif
+#endif
+
+#if defined(HAVE_RES_EXT_EXT)		/* AIX */
+	union res_sockaddr_union	saved_ns6;
+#elif defined(HAVE_RES_U_EXT_EXT)	/* BSD */
+	struct sockaddr_in6		saved_ns6;
+#else
+	struct sockaddr_in6		*saved_ns6;
+#endif
+	struct sockaddr_in6	sockaddrin6;
+	struct addrinfo		hint, *hres = NULL;
+#endif
+	typedef struct
+	{
+		const char	*name;
+		int		type;
+	}
+	resolv_querytype_t;
+
+	static const resolv_querytype_t	qt[] =
+	{
+		{"ANY",		T_ANY},
+		{"A",		T_A},
+		{"AAAA",	T_AAAA},
+		{"NS",		T_NS},
+		{"MD",		T_MD},
+		{"MF",		T_MF},
+		{"CNAME",	T_CNAME},
+		{"SOA",		T_SOA},
+		{"MB",		T_MB},
+		{"MG",		T_MG},
+		{"MR",		T_MR},
+		{"NULL",	T_NULL},
+#if !defined(_WINDOWS) && !defined(__MINGW32__)
+		{"WKS",		T_WKS},
+#endif
+		{"PTR",		T_PTR},
+		{"HINFO",	T_HINFO},
+		{"MINFO",	T_MINFO},
+		{"MX",		T_MX},
+		{"TXT",		T_TXT},
+		{"SRV",		T_SRV},
+		{NULL}
+	};
+
+#if defined(_WINDOWS) || defined(__MINGW32__)
+	PDNS_RECORD	pQueryResults, pDnsRecord;
+	wchar_t		*wzone;
+	char		tmp2[MAX_STRING_LEN];
+	DWORD		options;
+#else
+	char		*name;
+	unsigned char	*msg_end, *msg_ptr, *p;
+	int		num_answers, num_query, q_type, q_class, q_len, value, c, n;
+	struct servent	*s;
+	HEADER		*hp;
+	struct protoent	*pr;
+#if PACKETSZ > 1024
+	unsigned char	buf[PACKETSZ];
+#else
+	unsigned char	buf[1024];
+#endif
+
+	typedef union
+	{
+		HEADER		h;
+#if defined(NS_PACKETSZ)
+		unsigned char	buffer[NS_PACKETSZ];
+#elif defined(PACKETSZ)
+		unsigned char	buffer[PACKETSZ];
+#else
+		unsigned char	buffer[512];
+#endif
+	}
+	answer_t;
+
+	answer_t	answer;
+#endif	/* defined(_WINDOWS) || defined(__MINGW32__) */
+	zbx_vector_str_t	answers;
+
+	*buffer = '\0';
+
+	if (6 < request->nparam)
+	{
+		SET_MSG_RESULT(result, zbx_strdup(NULL, "Too many parameters."));
+		return SYSINFO_RET_FAIL;
+	}
+
+	ip = get_rparam(request, 0);
+	zone_str = get_rparam(request, 1);
+
+#if !defined(_WINDOWS) && !defined(__MINGW32__)
+	memset(&hint, '\0', sizeof(hint));
+	hint.ai_family = PF_UNSPEC;
+	hint.ai_flags = AI_NUMERICHOST;
+
+	if (NULL != ip && '\0' != *ip && 0 == getaddrinfo(ip, NULL, &hint, &hres) && AF_INET6 == hres->ai_family)
+		ip_type = hres->ai_family;
+
+	if (NULL != hres)
+		freeaddrinfo(hres);
+#endif
+	if (NULL == zone_str || '\0' == *zone_str)
+		strscpy(zone, "zabbix.com");
+	else
+		strscpy(zone, zone_str);
+
+	param = get_rparam(request, 2);
+
+	if (NULL == param || '\0' == *param)
+		type = T_SOA;
+	else
+	{
+		for (i = 0; NULL != qt[i].name; i++)
+		{
+			if (0 == strcasecmp(qt[i].name, param))
+			{
+				type = qt[i].type;
+				break;
+			}
+		}
+
+		if (NULL == qt[i].name)
+		{
+			SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid third parameter."));
+			return SYSINFO_RET_FAIL;
+		}
+	}
+
+	param = get_rparam(request, 3);
+
+	if (NULL == param || '\0' == *param)
+		retrans = 1;
+	else if (SUCCEED != is_uint31(param, &retrans) || 0 == retrans)
+	{
+		SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid fourth parameter."));
+		return SYSINFO_RET_FAIL;
+	}
+
+	param = get_rparam(request, 4);
+
+	if (NULL == param || '\0' == *param)
+		retry = 2;
+	else if (SUCCEED != is_uint31(param, &retry) || 0 == retry)
+	{
+		SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid fifth parameter."));
+		return SYSINFO_RET_FAIL;
+	}
+
+	param = get_rparam(request, 5);
+
+	if (NULL == param || '\0' == *param || 0 == strcmp(param, "udp"))
+		use_tcp = 0;
+	else if (0 == strcmp(param, "tcp"))
+		use_tcp = 1;
+	else
+	{
+		SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid sixth parameter."));
+		return SYSINFO_RET_FAIL;
+	}
+
+#if defined(_WINDOWS) || defined(__MINGW32__)
+	options = DNS_QUERY_STANDARD | DNS_QUERY_BYPASS_CACHE;
+	if (0 != use_tcp)
+		options |= DNS_QUERY_USE_TCP_ONLY;
+
+	wzone = zbx_utf8_to_unicode(zone);
+	res = DnsQuery(wzone, type, options, NULL, &pQueryResults, NULL);
+	zbx_free(wzone);
+
+	if (1 == short_answer)
+	{
+		SET_UI64_RESULT(result, DNS_RCODE_NOERROR != res ? 0 : 1);
+		ret = SYSINFO_RET_OK;
+		goto clean_dns;
+	}
+
+	if (DNS_RCODE_NOERROR != res)
+	{
+		SET_MSG_RESULT(result, zbx_dsprintf(NULL, "Cannot perform DNS query: [%d]", res));
+		return SYSINFO_RET_FAIL;
+	}
+
+	pDnsRecord = pQueryResults;
+	zbx_vector_str_create(&answers);
+
+	while (NULL != pDnsRecord)
+	{
+		if (DnsSectionAnswer != pDnsRecord->Flags.S.Section)
+		{
+			pDnsRecord = pDnsRecord->pNext;
+			continue;
+		}
+
+		if (NULL == pDnsRecord->pName)
+			goto clean;
+
+		offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "%-20s",
+				zbx_unicode_to_utf8_static(pDnsRecord->pName, tmp, sizeof(tmp)));
+		offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %-8s",
+				decode_type(pDnsRecord->wType));
+
+		switch (pDnsRecord->wType)
+		{
+			case T_A:
+				inaddr.s_addr = pDnsRecord->Data.A.IpAddress;
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
+						inet_ntoa(inaddr));
+				break;
+			case T_AAAA:
+				memcpy(&in6addr.s6_addr, &(pDnsRecord->Data.AAAA.Ip6Address), sizeof(in6addr.s6_addr));
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
+						zbx_inet_ntop(AF_INET6, &in6addr, tmp, sizeof(tmp)));
+				break;
+			case T_NS:
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
+						zbx_unicode_to_utf8_static(pDnsRecord->Data.NS.pNameHost, tmp, sizeof(tmp)));
+				break;
+			case T_MD:
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
+						zbx_unicode_to_utf8_static(pDnsRecord->Data.MD.pNameHost, tmp, sizeof(tmp)));
+				break;
+			case T_MF:
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
+						zbx_unicode_to_utf8_static(pDnsRecord->Data.MF.pNameHost, tmp, sizeof(tmp)));
+				break;
+			case T_CNAME:
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
+						zbx_unicode_to_utf8_static(pDnsRecord->Data.CNAME.pNameHost, tmp, sizeof(tmp)));
+				break;
+			case T_SOA:
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s %s %lu %lu %lu %lu %lu",
+						zbx_unicode_to_utf8_static(pDnsRecord->Data.SOA.pNamePrimaryServer, tmp, sizeof(tmp)),
+						zbx_unicode_to_utf8_static(pDnsRecord->Data.SOA.pNameAdministrator, tmp2, sizeof(tmp2)),
+						pDnsRecord->Data.SOA.dwSerialNo,
+						pDnsRecord->Data.SOA.dwRefresh,
+						pDnsRecord->Data.SOA.dwRetry,
+						pDnsRecord->Data.SOA.dwExpire,
+						pDnsRecord->Data.SOA.dwDefaultTtl);
+				break;
+			case T_MB:
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
+						zbx_unicode_to_utf8_static(pDnsRecord->Data.MB.pNameHost, tmp, sizeof(tmp)));
+				break;
+			case T_MG:
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
+						zbx_unicode_to_utf8_static(pDnsRecord->Data.MG.pNameHost, tmp, sizeof(tmp)));
+				break;
+			case T_MR:
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
+						zbx_unicode_to_utf8_static(pDnsRecord->Data.MR.pNameHost, tmp, sizeof(tmp)));
+				break;
+			case T_NULL:
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " len:%lu",
+						pDnsRecord->Data.Null.dwByteCount);
+				break;
+			case T_PTR:
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
+						zbx_unicode_to_utf8_static(pDnsRecord->Data.PTR.pNameHost, tmp, sizeof(tmp)));
+				break;
+			case T_HINFO:
+				for (i = 0; i < (int)(pDnsRecord->Data.HINFO.dwStringCount); i++)
+					offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " \"%s\"",
+							zbx_unicode_to_utf8_static(pDnsRecord->Data.HINFO.pStringArray[i], tmp, sizeof(tmp)));
+				break;
+			case T_MINFO:
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s %s",
+						zbx_unicode_to_utf8_static(pDnsRecord->Data.MINFO.pNameMailbox, tmp, sizeof(tmp)),
+						zbx_unicode_to_utf8_static(pDnsRecord->Data.MINFO.pNameErrorsMailbox, tmp2, sizeof(tmp2)));
+				break;
+			case T_MX:
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %hu %s",
+						pDnsRecord->Data.MX.wPreference,
+						zbx_unicode_to_utf8_static(pDnsRecord->Data.MX.pNameExchange, tmp, sizeof(tmp)));
+				break;
+			case T_TXT:
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " \"");
+
+				for (i = 0; i < (int)(pDnsRecord->Data.TXT.dwStringCount); i++)
+					offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "%s ",
+							zbx_unicode_to_utf8_static(pDnsRecord->Data.TXT.pStringArray[i], tmp, sizeof(tmp)));
+
+				if (0 < i)
+					offset -= 1;	/* remove the trailing space */
+
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "\"");
+
+				break;
+			case T_SRV:
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %hu %hu %hu %s",
+						pDnsRecord->Data.SRV.wPriority,
+						pDnsRecord->Data.SRV.wWeight,
+						pDnsRecord->Data.SRV.wPort,
+						zbx_unicode_to_utf8_static(pDnsRecord->Data.SRV.pNameTarget, tmp, sizeof(tmp)));
+				break;
+			default:
+				break;
+		}
+
+		zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "\n");
+
+		pDnsRecord = pDnsRecord->pNext;
+		zbx_vector_str_append(&answers, zbx_strdup(NULL, buffer));
+		offset = 0;
+		*buffer = '\0';
+	}
+#else	/* !defined(_WINDOWS) && !defined(__MINGW32__) */
+#if defined(HAVE_RES_NINIT) && !defined(_AIX)
+	memset(&res_state_local, 0, sizeof(res_state_local));
+	if (-1 == res_ninit(&res_state_local))	/* initialize always, settings might have changed */
+#else
+	if (-1 == res_init())	/* initialize always, settings might have changed */
+#endif
+	{
+		SET_MSG_RESULT(result, zbx_dsprintf(NULL, "Cannot initialize DNS subsystem: %s", zbx_strerror(errno)));
+		return SYSINFO_RET_FAIL;
+	}
+
+#if defined(HAVE_RES_NINIT) && !defined(_AIX)
+	if (-1 == (res = res_nmkquery(&res_state_local, QUERY, zone, C_IN, type, NULL, 0, NULL, buf, sizeof(buf))))
+#else
+	if (-1 == (res = res_mkquery(QUERY, zone, C_IN, type, NULL, 0, NULL, buf, sizeof(buf))))
+#endif
+	{
+		SET_MSG_RESULT(result, zbx_dsprintf(NULL, "Cannot create DNS query: %s", zbx_strerror(errno)));
+		return SYSINFO_RET_FAIL;
+	}
+
+	if (NULL != ip && '\0' != *ip && AF_INET == ip_type)
+	{
+		if (0 == inet_aton(ip, &inaddr))
+		{
+			SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid IP address."));
+			return SYSINFO_RET_FAIL;
+		}
+
+#if defined(HAVE_RES_NINIT) && !defined(_AIX)
+		res_state_local.nsaddr_list[0].sin_addr = inaddr;
+		res_state_local.nsaddr_list[0].sin_family = AF_INET;
+		res_state_local.nsaddr_list[0].sin_port = htons(ZBX_DEFAULT_DNS_PORT);
+		res_state_local.nscount = 1;
+#else	/* thread-unsafe resolver API */
+		memcpy(&saved_ns, &(_res.nsaddr_list[0]), sizeof(struct sockaddr_in));
+		saved_nscount = _res.nscount;
+
+		_res.nsaddr_list[0].sin_addr = inaddr;
+		_res.nsaddr_list[0].sin_family = AF_INET;
+		_res.nsaddr_list[0].sin_port = htons(ZBX_DEFAULT_DNS_PORT);
+		_res.nscount = 1;
+#endif
+	}
+	else if (NULL != ip && '\0' != *ip && AF_INET6 == ip_type)
+	{
+		if (0 == inet_pton(ip_type, ip, &in6addr))
+		{
+			SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid IPv6 address."));
+			return SYSINFO_RET_FAIL;
+		}
+
+		memset(&sockaddrin6, '\0', sizeof(sockaddrin6));
+#if defined(HAVE_RES_SIN6_LEN)
+		sockaddrin6.sin6_len = sizeof(sockaddrin6);
+#endif
+		sockaddrin6.sin6_family = AF_INET6;
+		sockaddrin6.sin6_addr = in6addr;
+		sockaddrin6.sin6_port = htons(ZBX_DEFAULT_DNS_PORT);
+#if defined(HAVE_RES_NINIT) && !defined(_AIX) && (defined(HAVE_RES_U_EXT) || defined(HAVE_RES_U_EXT_EXT))
+		memset(&res_state_local.nsaddr_list[0], '\0', sizeof(res_state_local.nsaddr_list[0]));
+#		ifdef HAVE_RES_U_EXT			/* Linux */
+		saved_ns6 = res_state_local._u._ext.nsaddrs[0];
+		res_state_local._u._ext.nsaddrs[0] = &sockaddrin6;
+		res_state_local._u._ext.nssocks[0] = -1;
+		res_state_local._u._ext.nscount6 = 1;	/* CentOS */
+#		elif HAVE_RES_U_EXT_EXT			/* BSD */
+		if (NULL != res_state_local._u._ext.ext)
+			memcpy(res_state_local._u._ext.ext, &sockaddrin6, sizeof(sockaddrin6));
+
+		res_state_local.nsaddr_list[0].sin_port = htons(ZBX_DEFAULT_DNS_PORT);
+#		endif
+		res_state_local.nscount = 1;
+#else
+		memcpy(&saved_ns, &(_res.nsaddr_list[0]), sizeof(struct sockaddr_in));
+		saved_nscount = _res.nscount;
+#		if defined(HAVE_RES_U_EXT) || defined(HAVE_RES_U_EXT_EXT) || defined(HAVE_RES_EXT_EXT)
+		memset(&_res.nsaddr_list[0], '\0', sizeof(_res.nsaddr_list[0]));
+		_res.nscount = 1;
+#		endif
+#		if defined(HAVE_RES_U_EXT)		/* thread-unsafe resolver API /Linux/ */
+		saved_nscount6 = _res._u._ext.nscount6;
+		saved_ns6 = _res._u._ext.nsaddrs[0];
+		save_nssocks = _res._u._ext.nssocks[0];
+		_res._u._ext.nsaddrs[0] = &sockaddrin6;
+		_res._u._ext.nssocks[0] = -1;
+		_res._u._ext.nscount6 = 1;
+#		elif defined(HAVE_RES_U_EXT_EXT)	/* thread-unsafe resolver API /BSD/ */
+		memcpy(&saved_ns6, _res._u._ext.ext, sizeof(saved_ns6));
+		_res.nsaddr_list[0].sin_port = htons(ZBX_DEFAULT_DNS_PORT);
+
+		if (NULL != _res._u._ext.ext)
+			memcpy(_res._u._ext.ext, &sockaddrin6, sizeof(sockaddrin6));
+#		elif defined(HAVE_RES_EXT_EXT)		/* thread-unsafe resolver API /AIX/ */
+		memcpy(&saved_ns6, &(_res._ext.ext.nsaddrs[0]), sizeof(saved_ns6));
+		memcpy(&_res._ext.ext.nsaddrs[0], &sockaddrin6, sizeof(sockaddrin6));
+#		endif /* #if defined(HAVE_RES_U_EXT) */
+#endif /* #if defined(HAVE_RES_NINIT) && !defined(_AIX) && (defined(HAVE_RES_U_EXT) || defined(HAVE_RES_U_EXT_EXT)) */
+	}
+
+#if defined(HAVE_RES_NINIT) && !defined(_AIX) && (defined(HAVE_RES_U_EXT) || defined(HAVE_RES_U_EXT_EXT))
+	if (0 != use_tcp)
+		res_state_local.options |= RES_USEVC;
+
+	res_state_local.retrans = retrans;
+	res_state_local.retry = retry;
+
+	res = res_nsend(&res_state_local, buf, res, answer.buffer, sizeof(answer.buffer));
+
+#	ifdef HAVE_RES_U_EXT	/* Linux */
+	if (NULL != ip && '\0' != *ip && AF_INET6 == ip_type)
+		res_state_local._u._ext.nsaddrs[0] = saved_ns6;
+#	endif
+#	ifdef HAVE_RES_NDESTROY
+	res_ndestroy(&res_state_local);
+#	else
+	res_nclose(&res_state_local);
+#	endif
+#else	/* thread-unsafe resolver API */
+	saved_options = _res.options;
+	saved_retrans = _res.retrans;
+	saved_retry = _res.retry;
+
+	if (0 != use_tcp)
+		_res.options |= RES_USEVC;
+
+	_res.retrans = retrans;
+	_res.retry = retry;
+
+	res = res_send(buf, res, answer.buffer, sizeof(answer.buffer));
+
+	_res.options = saved_options;
+	_res.retrans = saved_retrans;
+	_res.retry = saved_retry;
+
+	if (NULL != ip && '\0' != *ip)
+	{
+		if (AF_INET6 == ip_type)
+		{
+#			if defined(HAVE_RES_U_EXT)		/* Linux */
+			_res._u._ext.nsaddrs[0] = saved_ns6;
+			_res._u._ext.nssocks[0] = save_nssocks;
+			_res._u._ext.nscount6 = saved_nscount6;
+#			elif defined(HAVE_RES_U_EXT_EXT)	/* BSD */
+			if (NULL != _res._u._ext.ext)
+				memcpy(_res._u._ext.ext, &saved_ns6, sizeof(saved_ns6));
+#			elif defined(HAVE_RES_EXT_EXT)		/* AIX */
+			memcpy(&_res._ext.ext.nsaddrs[0], &saved_ns6, sizeof(saved_ns6));
+#			endif
+		}
+
+		memcpy(&(_res.nsaddr_list[0]), &saved_ns, sizeof(struct sockaddr_in));
+		_res.nscount = saved_nscount;
+	}
+#endif
+	hp = (HEADER *)answer.buffer;
+
+	if (1 == short_answer)
+	{
+		SET_UI64_RESULT(result, NOERROR != hp->rcode || 0 == ntohs(hp->ancount) || -1 == res ? 0 : 1);
+		return SYSINFO_RET_OK;
+	}
+
+	if (NOERROR != hp->rcode || 0 == ntohs(hp->ancount) || -1 == res)
+	{
+		SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot perform DNS query."));
+		return SYSINFO_RET_FAIL;
+	}
+
+	msg_end = answer.buffer + res;
+
+	num_answers = ntohs(answer.h.ancount);
+	num_query = ntohs(answer.h.qdcount);
+
+	msg_ptr = answer.buffer + HFIXEDSZ;
+	zbx_vector_str_create(&answers);
+
+	/* skipping query records */
+	for (; 0 < num_query && msg_ptr < msg_end; num_query--)
+		msg_ptr += dn_skipname(msg_ptr, msg_end) + QFIXEDSZ;
+
+	for (; 0 < num_answers && msg_ptr < msg_end; num_answers--)
+	{
+		if (NULL == (name = get_name(answer.buffer, msg_end, &msg_ptr)))
+		{
+			SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
+			ret = SYSINFO_RET_FAIL;
+			goto clean;
+		}
+
+		offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "%-20s", name);
+
+		GETSHORT(q_type, msg_ptr);
+		GETSHORT(q_class, msg_ptr);
+		msg_ptr += INT32SZ;		/* skipping TTL */
+		GETSHORT(q_len, msg_ptr);
+		offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %-8s", decode_type(q_type));
+
+		switch (q_type)
+		{
+			case T_A:
+				switch (q_class)
+				{
+					case C_IN:
+					case C_HS:
+						memcpy(&inaddr, msg_ptr, INADDRSZ);
+						offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
+								inet_ntoa(inaddr));
+						break;
+					default:
+						;
+				}
+
+				msg_ptr += q_len;
+
+				break;
+			case T_AAAA:
+				switch (q_class)
+				{
+					case C_IN:
+					case C_HS:
+						memcpy(&in6addr, msg_ptr, IN6ADDRSZ);
+						offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
+								inet_ntop(AF_INET6, &in6addr, tmp, sizeof(tmp)));
+						break;
+					default:
+						;
+				}
+
+				msg_ptr += q_len;
+
+				break;
+			case T_NS:
+			case T_CNAME:
+			case T_MB:
+			case T_MD:
+			case T_MF:
+			case T_MG:
+			case T_MR:
+			case T_PTR:
+				if (NULL == (name = get_name(answer.buffer, msg_end, &msg_ptr)))
+				{
+					SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
+					return SYSINFO_RET_FAIL;
+				}
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", name);
+				break;
+			case T_MX:
+				GETSHORT(value, msg_ptr);	/* preference */
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
+
+				if (NULL == (name = get_name(answer.buffer, msg_end, &msg_ptr)))	/* exchange */
+				{
+					SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
+					return SYSINFO_RET_FAIL;
+				}
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", name);
+
+				break;
+			case T_SOA:
+				if (NULL == (name = get_name(answer.buffer, msg_end, &msg_ptr)))	/* source host */
+				{
+					SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
+					return SYSINFO_RET_FAIL;
+				}
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", name);
+
+				if (NULL == (name = get_name(answer.buffer, msg_end, &msg_ptr)))	/* administrator */
+				{
+					SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
+					return SYSINFO_RET_FAIL;
+				}
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", name);
+
+				GETLONG(value, msg_ptr);	/* serial number */
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
+
+				GETLONG(value, msg_ptr);	/* refresh time */
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
+
+				GETLONG(value, msg_ptr);	/* retry time */
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
+
+				GETLONG(value, msg_ptr);	/* expire time */
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
+
+				GETLONG(value, msg_ptr);	/* minimum TTL */
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
+
+				break;
+			case T_NULL:
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " len:%d", q_len);
+				msg_ptr += q_len;
+				break;
+			case T_WKS:
+				if (INT32SZ + 1 > q_len)
+				{
+					SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
+					return SYSINFO_RET_FAIL;
+				}
+
+				p = msg_ptr + q_len;
+
+				memcpy(&inaddr, msg_ptr, INADDRSZ);
+				msg_ptr += INT32SZ;
+
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", inet_ntoa(inaddr));
+
+				if (NULL != (pr = getprotobynumber(*msg_ptr)))
+					offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", pr->p_name);
+				else
+					offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", (int)*msg_ptr);
+
+				msg_ptr++;
+				n = 0;
+
+				while (msg_ptr < p)
+				{
+					c = *msg_ptr++;
+
+					do
+					{
+						if (0 != (c & 0200))
+						{
+							s = getservbyport((int)htons(n), pr ? pr->p_name : NULL);
+
+							if (NULL != s)
+								offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", s->s_name);
+							else
+								offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " #%d", n);
+						}
+
+						c <<= 1;
+					}
+					while (0 != (++n & 07));
+				}
+
+				break;
+			case T_HINFO:
+				p = msg_ptr + q_len;
+				c = *msg_ptr++;
+
+				if (0 != c)
+				{
+					offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " \"%.*s\"", c, msg_ptr);
+					msg_ptr += c;
+				}
+
+				if (msg_ptr < p)
+				{
+					c = *msg_ptr++;
+
+					if (0 != c)
+					{
+						offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " \"%.*s\"", c, msg_ptr);
+						msg_ptr += c;
+					}
+				}
+
+				break;
+			case T_MINFO:
+				if (NULL == (name = get_name(answer.buffer, msg_end, &msg_ptr)))	/* mailbox responsible for mailing lists */
+				{
+					SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
+					return SYSINFO_RET_FAIL;
+				}
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", name);
+
+				if (NULL == (name = get_name(answer.buffer, msg_end, &msg_ptr)))	/* mailbox for error messages */
+				{
+					SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
+					return SYSINFO_RET_FAIL;
+				}
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", name);
+
+				break;
+			case T_TXT:
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " \"");
+				p = msg_ptr + q_len;
+
+				while (msg_ptr < p)
+				{
+					for (c = *msg_ptr++; 0 < c && msg_ptr < p; c--)
+						offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "%c", *msg_ptr++);
+				}
+
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "\"");
+
+				break;
+			case T_SRV:
+				GETSHORT(value, msg_ptr);       /* priority */
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
+
+				GETSHORT(value, msg_ptr);       /* weight */
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
+
+				GETSHORT(value, msg_ptr);       /* port */
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
+
+				if (NULL == (name = get_name(answer.buffer, msg_end, &msg_ptr)))	/* target */
+				{
+					SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
+					return SYSINFO_RET_FAIL;
+				}
+				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", name);
+
+				break;
+			default:
+				msg_ptr += q_len;
+				break;
+		}
+
+		zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "\n");
+
+		zbx_vector_str_append(&answers, zbx_strdup(NULL, buffer));
+		offset = 0;
+		*buffer = '\0';
+	}
+#endif	/* defined(_WINDOWS) || defined(__MINGW32__) */
+
+	zbx_vector_str_sort(&answers, ZBX_DEFAULT_STR_COMPARE_FUNC);
+
+	for (i = 0; i < answers.values_num; i++)
+		offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "%s", answers.values[i]);
+
+	if (0 != offset)
+		buffer[--offset] = '\0';
+
+	SET_TEXT_RESULT(result, zbx_strdup(NULL, buffer));
+	ret = SYSINFO_RET_OK;
+
+clean:
+	zbx_vector_str_clear_ext(&answers, zbx_str_free);
+	zbx_vector_str_destroy(&answers);
+#if defined(_WINDOWS) || defined(__MINGW32__)
+clean_dns:
+	if (DNS_RCODE_NOERROR == res)
+		DnsRecordListFree(pQueryResults, DnsFreeRecordList);
+#endif
+
+	return ret;
+
+#else	/* all HAVE_RES_QUERY and _WINDOWS and __MINGW32__not defined */
+
+	return SYSINFO_RET_FAIL;
+
+#endif	/* defined(HAVE_RES_QUERY) || defined(_WINDOWS) || defined(__MINGW32__)*/
+}
+
+int	NET_DNS(AGENT_REQUEST *request, AGENT_RESULT *result)
+{
+	return dns_query(request, result, 1);
+}
+
+int	NET_DNS_RECORD(AGENT_REQUEST *request, AGENT_RESULT *result)
+{
+	return dns_query(request, result, 0);
+}
diff --git a/src/libs/zbxsysinfo/common/dns.h b/src/libs/zbxsysinfo/common/dns.h
new file mode 100644
index 00000000000..7d87d40b8fa
--- /dev/null
+++ b/src/libs/zbxsysinfo/common/dns.h
@@ -0,0 +1,95 @@
+/*
+** Zabbix
+** Copyright (C) 2001-2020 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+#ifndef ZABBIX_SYSINFO_COMMON_DNS_H
+#define ZABBIX_SYSINFO_COMMON_DNS_H
+
+#include "sysinfo.h"
+
+#if defined(HAVE_RES_QUERY) || defined(_WINDOWS) || defined(__MINGW32__)
+
+#	if !defined(C_IN) && !defined(_WINDOWS) && !defined(__MINGW32__)
+#		define C_IN	ns_c_in
+#	endif
+
+/* define DNS record types to use common names on all systems, see RFC1035 standard for the types */
+#	ifndef T_ANY
+#		define T_ANY	255
+#	endif
+#	ifndef T_A
+#		define T_A	1
+#	endif
+#	ifndef T_NS
+#		define T_NS	2
+#	endif
+#	ifndef T_MD
+#		define T_MD	3
+#	endif
+#	ifndef T_MF
+#		define T_MF	4
+#	endif
+#	ifndef T_CNAME
+#		define T_CNAME	5
+#	endif
+#	ifndef T_SOA
+#		define T_SOA	6
+#	endif
+#	ifndef T_MB
+#		define T_MB	7
+#	endif
+#	ifndef T_MG
+#		define T_MG	8
+#	endif
+#	ifndef T_MR
+#		define T_MR	9
+#	endif
+#	ifndef T_NULL
+#		define T_NULL	10
+#	endif
+#	ifndef T_WKS
+#		define T_WKS	11
+#	endif
+#	ifndef T_PTR
+#		define T_PTR	12
+#	endif
+#	ifndef T_HINFO
+#		define T_HINFO	13
+#	endif
+#	ifndef T_MINFO
+#		define T_MINFO	14
+#	endif
+#	ifndef T_MX
+#		define T_MX	15
+#	endif
+#	ifndef T_TXT
+#		define T_TXT	16
+#	endif
+#	ifndef T_AAAA
+#		define T_AAAA	28
+#	endif
+#	ifndef T_SRV
+#		define T_SRV	33
+#	endif
+
+#endif /* defined(HAVE_RES_QUERY) || defined(_WINDOWS) || defined(__MINGW32__) */
+
+int	NET_DNS(AGENT_REQUEST *request, AGENT_RESULT *result);
+int	NET_DNS_RECORD(AGENT_REQUEST *request, AGENT_RESULT *result);
+
+#endif /* ZABBIX_SYSINFO_COMMON_NET_H */
diff --git a/src/libs/zbxsysinfo/common/net.c b/src/libs/zbxsysinfo/common/net.c
index c535a56c204..7d8027990f7 100644
--- a/src/libs/zbxsysinfo/common/net.c
+++ b/src/libs/zbxsysinfo/common/net.c
@@ -27,11 +27,6 @@
 #include "net.h"
 #include "zbxalgo.h"
 
-#ifdef _WINDOWS
-#	include <windns.h>
-#	pragma comment(lib, "Dnsapi.lib") /* add the library for DnsQuery function */
-#endif
-
 int	tcp_expect(const char *host, unsigned short port, int timeout, const char *request,
 		int (*validate_func)(const char *), const char *sendtoclose, int *value_int)
 {
@@ -114,883 +109,3 @@ int	NET_TCP_PORT(AGENT_REQUEST *request, AGENT_RESULT *result)
 
 	return ret;
 }
-
-#if defined(HAVE_RES_QUERY) || defined(_WINDOWS)
-
-static const char	*decode_type(int q_type)
-{
-	static ZBX_THREAD_LOCAL char	buf[16];
-
-	switch (q_type)
-	{
-		case T_A:
-			return "A";	/* address */
-		case T_AAAA:
-			return "AAAA";	/* v6 address */
-		case T_NS:
-			return "NS";	/* name server */
-		case T_MD:
-			return "MD";	/* mail destination */		/* obsolete */
-		case T_MF:
-			return "MF";	/* mail forwarder */		/* obsolete */
-		case T_CNAME:
-			return "CNAME";	/* canonical name */
-		case T_SOA:
-			return "SOA";	/* start of authority */
-		case T_MB:
-			return "MB";	/* mailbox */			/* experimental */
-		case T_MG:
-			return "MG";	/* mail group member */		/* experimental */
-		case T_MR:
-			return "MR";	/* mail rename */		/* experimental */
-		case T_NULL:
-			return "NULL";	/* null */			/* obsolete */
-		case T_WKS:
-			return "WKS";	/* well-known service */	/* obsolete */
-		case T_PTR:
-			return "PTR";	/* domain name pointer */
-		case T_HINFO:
-			return "HINFO";	/* host information */
-		case T_MINFO:
-			return "MINFO";	/* mailbox information */	/* experimental */
-		case T_MX:
-			return "MX";	/* mail exchanger */
-		case T_TXT:
-			return "TXT";	/* text */
-		case T_SRV:
-			return "SRV";	/* service locator */
-		default:
-			zbx_snprintf(buf, sizeof(buf), "T_%d", q_type);
-			return buf;
-	}
-}
-
-#if !defined(_WINDOWS)
-static char	*get_name(unsigned char *msg, unsigned char *msg_end, unsigned char **msg_ptr)
-{
-	int		res;
-	static char	buffer[MAX_STRING_LEN];
-
-	if (-1 == (res = dn_expand(msg, msg_end, *msg_ptr, buffer, sizeof(buffer))))
-		return NULL;
-
-	*msg_ptr += res;
-
-	return buffer;
-}
-#endif	/* !defined(_WINDOWS) */
-
-/* Replace zbx_inet_ntop with inet_ntop in case of drop Windows XP/W2k3 support */
-#if defined(_WINDOWS)
-const char *zbx_inet_ntop(int af, const void *src, char *dst, size_t size)
-{
-	struct sockaddr_storage ss;
-	unsigned long s = size;
-
-	memset(&ss, '\0', sizeof(ss));
-	ss.ss_family = af;
-
-	switch(af)
-	{
-		case AF_INET:
-			((struct sockaddr_in *)&ss)->sin_addr = *(struct in_addr *)src;
-			break;
-		case AF_INET6:
-			((struct sockaddr_in6 *)&ss)->sin6_addr = *(struct in6_addr *)src;
-			break;
-		default:
-			return NULL;
-	}
-
-	return (0 == WSAAddressToStringA((struct sockaddr *)&ss, sizeof(ss), NULL, dst, &s))? dst : NULL;
-}
-#endif
-#endif	/* defined(HAVE_RES_QUERY) || defined(_WINDOWS) */
-
-static int	dns_query(AGENT_REQUEST *request, AGENT_RESULT *result, int short_answer)
-{
-#if defined(HAVE_RES_QUERY) || defined(_WINDOWS)
-
-	size_t			offset = 0;
-	int			res, type, retrans, retry, use_tcp, i, ret = SYSINFO_RET_FAIL, ip_type = AF_INET;
-	char			*ip, zone[MAX_STRING_LEN], buffer[MAX_STRING_LEN], *zone_str, *param,
-				tmp[MAX_STRING_LEN];
-	struct in_addr		inaddr;
-	struct in6_addr		in6addr;
-#ifndef _WINDOWS
-#if defined(HAVE_RES_NINIT) && !defined(_AIX)
-	/* It seems that on some AIX systems with no updates installed res_ninit() can */
-	/* corrupt stack (see ZBX-14559). Use res_init() on AIX. */
-	struct __res_state	res_state_local;
-#else	/* thread-unsafe resolver API */
-	int			saved_retrans, saved_retry, saved_nscount = 0;
-	unsigned long		saved_options;
-	struct sockaddr_in	saved_ns;
-#	if defined(HAVE_RES_U_EXT)		/* thread-unsafe resolver API /Linux/ */
-	int			save_nssocks, saved_nscount6;
-#	endif
-#endif
-
-#if defined(HAVE_RES_EXT_EXT)		/* AIX */
-	union res_sockaddr_union	saved_ns6;
-#elif defined(HAVE_RES_U_EXT_EXT)	/* BSD */
-	struct sockaddr_in6		saved_ns6;
-#else
-	struct sockaddr_in6		*saved_ns6;
-#endif
-	struct sockaddr_in6	sockaddrin6;
-	struct addrinfo		hint, *hres = NULL;
-#endif
-	typedef struct
-	{
-		const char	*name;
-		int		type;
-	}
-	resolv_querytype_t;
-
-	static const resolv_querytype_t	qt[] =
-	{
-		{"ANY",		T_ANY},
-		{"A",		T_A},
-		{"AAAA",	T_AAAA},
-		{"NS",		T_NS},
-		{"MD",		T_MD},
-		{"MF",		T_MF},
-		{"CNAME",	T_CNAME},
-		{"SOA",		T_SOA},
-		{"MB",		T_MB},
-		{"MG",		T_MG},
-		{"MR",		T_MR},
-		{"NULL",	T_NULL},
-#ifndef _WINDOWS
-		{"WKS",		T_WKS},
-#endif
-		{"PTR",		T_PTR},
-		{"HINFO",	T_HINFO},
-		{"MINFO",	T_MINFO},
-		{"MX",		T_MX},
-		{"TXT",		T_TXT},
-		{"SRV",		T_SRV},
-		{NULL}
-	};
-
-#ifdef _WINDOWS
-	PDNS_RECORD	pQueryResults, pDnsRecord;
-	wchar_t		*wzone;
-	char		tmp2[MAX_STRING_LEN];
-	DWORD		options;
-#else
-	char		*name;
-	unsigned char	*msg_end, *msg_ptr, *p;
-	int		num_answers, num_query, q_type, q_class, q_len, value, c, n;
-	struct servent	*s;
-	HEADER		*hp;
-	struct protoent	*pr;
-#if PACKETSZ > 1024
-	unsigned char	buf[PACKETSZ];
-#else
-	unsigned char	buf[1024];
-#endif
-
-	typedef union
-	{
-		HEADER		h;
-#if defined(NS_PACKETSZ)
-		unsigned char	buffer[NS_PACKETSZ];
-#elif defined(PACKETSZ)
-		unsigned char	buffer[PACKETSZ];
-#else
-		unsigned char	buffer[512];
-#endif
-	}
-	answer_t;
-
-	answer_t	answer;
-#endif	/* _WINDOWS */
-	zbx_vector_str_t	answers;
-
-	*buffer = '\0';
-
-	if (6 < request->nparam)
-	{
-		SET_MSG_RESULT(result, zbx_strdup(NULL, "Too many parameters."));
-		return SYSINFO_RET_FAIL;
-	}
-
-	ip = get_rparam(request, 0);
-	zone_str = get_rparam(request, 1);
-
-#ifndef _WINDOWS
-	memset(&hint, '\0', sizeof(hint));
-	hint.ai_family = PF_UNSPEC;
-	hint.ai_flags = AI_NUMERICHOST;
-
-	if (NULL != ip && '\0' != *ip && 0 == getaddrinfo(ip, NULL, &hint, &hres) && AF_INET6 == hres->ai_family)
-		ip_type = hres->ai_family;
-
-	if (NULL != hres)
-		freeaddrinfo(hres);
-#endif
-	if (NULL == zone_str || '\0' == *zone_str)
-		strscpy(zone, "zabbix.com");
-	else
-		strscpy(zone, zone_str);
-
-	param = get_rparam(request, 2);
-
-	if (NULL == param || '\0' == *param)
-		type = T_SOA;
-	else
-	{
-		for (i = 0; NULL != qt[i].name; i++)
-		{
-			if (0 == strcasecmp(qt[i].name, param))
-			{
-				type = qt[i].type;
-				break;
-			}
-		}
-
-		if (NULL == qt[i].name)
-		{
-			SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid third parameter."));
-			return SYSINFO_RET_FAIL;
-		}
-	}
-
-	param = get_rparam(request, 3);
-
-	if (NULL == param || '\0' == *param)
-		retrans = 1;
-	else if (SUCCEED != is_uint31(param, &retrans) || 0 == retrans)
-	{
-		SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid fourth parameter."));
-		return SYSINFO_RET_FAIL;
-	}
-
-	param = get_rparam(request, 4);
-
-	if (NULL == param || '\0' == *param)
-		retry = 2;
-	else if (SUCCEED != is_uint31(param, &retry) || 0 == retry)
-	{
-		SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid fifth parameter."));
-		return SYSINFO_RET_FAIL;
-	}
-
-	param = get_rparam(request, 5);
-
-	if (NULL == param || '\0' == *param || 0 == strcmp(param, "udp"))
-		use_tcp = 0;
-	else if (0 == strcmp(param, "tcp"))
-		use_tcp = 1;
-	else
-	{
-		SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid sixth parameter."));
-		return SYSINFO_RET_FAIL;
-	}
-
-#ifdef _WINDOWS
-	options = DNS_QUERY_STANDARD | DNS_QUERY_BYPASS_CACHE;
-	if (0 != use_tcp)
-		options |= DNS_QUERY_USE_TCP_ONLY;
-
-	wzone = zbx_utf8_to_unicode(zone);
-	res = DnsQuery(wzone, type, options, NULL, &pQueryResults, NULL);
-	zbx_free(wzone);
-
-	if (1 == short_answer)
-	{
-		SET_UI64_RESULT(result, DNS_RCODE_NOERROR != res ? 0 : 1);
-		ret = SYSINFO_RET_OK;
-		goto clean_dns;
-	}
-
-	if (DNS_RCODE_NOERROR != res)
-	{
-		SET_MSG_RESULT(result, zbx_dsprintf(NULL, "Cannot perform DNS query: [%d]", res));
-		return SYSINFO_RET_FAIL;
-	}
-
-	pDnsRecord = pQueryResults;
-	zbx_vector_str_create(&answers);
-
-	while (NULL != pDnsRecord)
-	{
-		if (DnsSectionAnswer != pDnsRecord->Flags.S.Section)
-		{
-			pDnsRecord = pDnsRecord->pNext;
-			continue;
-		}
-
-		if (NULL == pDnsRecord->pName)
-			goto clean;
-
-		offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "%-20s",
-				zbx_unicode_to_utf8_static(pDnsRecord->pName, tmp, sizeof(tmp)));
-		offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %-8s",
-				decode_type(pDnsRecord->wType));
-
-		switch (pDnsRecord->wType)
-		{
-			case T_A:
-				inaddr.s_addr = pDnsRecord->Data.A.IpAddress;
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
-						inet_ntoa(inaddr));
-				break;
-			case T_AAAA:
-				memcpy(&in6addr.s6_addr, &(pDnsRecord->Data.AAAA.Ip6Address), sizeof(in6addr.s6_addr));
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
-						zbx_inet_ntop(AF_INET6, &in6addr, tmp, sizeof(tmp)));
-				break;
-			case T_NS:
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
-						zbx_unicode_to_utf8_static(pDnsRecord->Data.NS.pNameHost, tmp, sizeof(tmp)));
-				break;
-			case T_MD:
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
-						zbx_unicode_to_utf8_static(pDnsRecord->Data.MD.pNameHost, tmp, sizeof(tmp)));
-				break;
-			case T_MF:
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
-						zbx_unicode_to_utf8_static(pDnsRecord->Data.MF.pNameHost, tmp, sizeof(tmp)));
-				break;
-			case T_CNAME:
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
-						zbx_unicode_to_utf8_static(pDnsRecord->Data.CNAME.pNameHost, tmp, sizeof(tmp)));
-				break;
-			case T_SOA:
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s %s %lu %lu %lu %lu %lu",
-						zbx_unicode_to_utf8_static(pDnsRecord->Data.SOA.pNamePrimaryServer, tmp, sizeof(tmp)),
-						zbx_unicode_to_utf8_static(pDnsRecord->Data.SOA.pNameAdministrator, tmp2, sizeof(tmp2)),
-						pDnsRecord->Data.SOA.dwSerialNo,
-						pDnsRecord->Data.SOA.dwRefresh,
-						pDnsRecord->Data.SOA.dwRetry,
-						pDnsRecord->Data.SOA.dwExpire,
-						pDnsRecord->Data.SOA.dwDefaultTtl);
-				break;
-			case T_MB:
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
-						zbx_unicode_to_utf8_static(pDnsRecord->Data.MB.pNameHost, tmp, sizeof(tmp)));
-				break;
-			case T_MG:
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
-						zbx_unicode_to_utf8_static(pDnsRecord->Data.MG.pNameHost, tmp, sizeof(tmp)));
-				break;
-			case T_MR:
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
-						zbx_unicode_to_utf8_static(pDnsRecord->Data.MR.pNameHost, tmp, sizeof(tmp)));
-				break;
-			case T_NULL:
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " len:%lu",
-						pDnsRecord->Data.Null.dwByteCount);
-				break;
-			case T_PTR:
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
-						zbx_unicode_to_utf8_static(pDnsRecord->Data.PTR.pNameHost, tmp, sizeof(tmp)));
-				break;
-			case T_HINFO:
-				for (i = 0; i < (int)(pDnsRecord->Data.HINFO.dwStringCount); i++)
-					offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " \"%s\"",
-							zbx_unicode_to_utf8_static(pDnsRecord->Data.HINFO.pStringArray[i], tmp, sizeof(tmp)));
-				break;
-			case T_MINFO:
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s %s",
-						zbx_unicode_to_utf8_static(pDnsRecord->Data.MINFO.pNameMailbox, tmp, sizeof(tmp)),
-						zbx_unicode_to_utf8_static(pDnsRecord->Data.MINFO.pNameErrorsMailbox, tmp2, sizeof(tmp2)));
-				break;
-			case T_MX:
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %hu %s",
-						pDnsRecord->Data.MX.wPreference,
-						zbx_unicode_to_utf8_static(pDnsRecord->Data.MX.pNameExchange, tmp, sizeof(tmp)));
-				break;
-			case T_TXT:
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " \"");
-
-				for (i = 0; i < (int)(pDnsRecord->Data.TXT.dwStringCount); i++)
-					offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "%s ",
-							zbx_unicode_to_utf8_static(pDnsRecord->Data.TXT.pStringArray[i], tmp, sizeof(tmp)));
-
-				if (0 < i)
-					offset -= 1;	/* remove the trailing space */
-
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "\"");
-
-				break;
-			case T_SRV:
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %hu %hu %hu %s",
-						pDnsRecord->Data.SRV.wPriority,
-						pDnsRecord->Data.SRV.wWeight,
-						pDnsRecord->Data.SRV.wPort,
-						zbx_unicode_to_utf8_static(pDnsRecord->Data.SRV.pNameTarget, tmp, sizeof(tmp)));
-				break;
-			default:
-				break;
-		}
-
-		zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "\n");
-
-		pDnsRecord = pDnsRecord->pNext;
-		zbx_vector_str_append(&answers, zbx_strdup(NULL, buffer));
-		offset = 0;
-		*buffer = '\0';
-	}
-#else	/* not _WINDOWS */
-#if defined(HAVE_RES_NINIT) && !defined(_AIX)
-	memset(&res_state_local, 0, sizeof(res_state_local));
-	if (-1 == res_ninit(&res_state_local))	/* initialize always, settings might have changed */
-#else
-	if (-1 == res_init())	/* initialize always, settings might have changed */
-#endif
-	{
-		SET_MSG_RESULT(result, zbx_dsprintf(NULL, "Cannot initialize DNS subsystem: %s", zbx_strerror(errno)));
-		return SYSINFO_RET_FAIL;
-	}
-
-#if defined(HAVE_RES_NINIT) && !defined(_AIX)
-	if (-1 == (res = res_nmkquery(&res_state_local, QUERY, zone, C_IN, type, NULL, 0, NULL, buf, sizeof(buf))))
-#else
-	if (-1 == (res = res_mkquery(QUERY, zone, C_IN, type, NULL, 0, NULL, buf, sizeof(buf))))
-#endif
-	{
-		SET_MSG_RESULT(result, zbx_dsprintf(NULL, "Cannot create DNS query: %s", zbx_strerror(errno)));
-		return SYSINFO_RET_FAIL;
-	}
-
-	if (NULL != ip && '\0' != *ip && AF_INET == ip_type)
-	{
-		if (0 == inet_aton(ip, &inaddr))
-		{
-			SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid IP address."));
-			return SYSINFO_RET_FAIL;
-		}
-
-#if defined(HAVE_RES_NINIT) && !defined(_AIX)
-		res_state_local.nsaddr_list[0].sin_addr = inaddr;
-		res_state_local.nsaddr_list[0].sin_family = AF_INET;
-		res_state_local.nsaddr_list[0].sin_port = htons(ZBX_DEFAULT_DNS_PORT);
-		res_state_local.nscount = 1;
-#else	/* thread-unsafe resolver API */
-		memcpy(&saved_ns, &(_res.nsaddr_list[0]), sizeof(struct sockaddr_in));
-		saved_nscount = _res.nscount;
-
-		_res.nsaddr_list[0].sin_addr = inaddr;
-		_res.nsaddr_list[0].sin_family = AF_INET;
-		_res.nsaddr_list[0].sin_port = htons(ZBX_DEFAULT_DNS_PORT);
-		_res.nscount = 1;
-#endif
-	}
-	else if (NULL != ip && '\0' != *ip && AF_INET6 == ip_type)
-	{
-		if (0 == inet_pton(ip_type, ip, &in6addr))
-		{
-			SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid IPv6 address."));
-			return SYSINFO_RET_FAIL;
-		}
-
-		memset(&sockaddrin6, '\0', sizeof(sockaddrin6));
-#if defined(HAVE_RES_SIN6_LEN)
-		sockaddrin6.sin6_len = sizeof(sockaddrin6);
-#endif
-		sockaddrin6.sin6_family = AF_INET6;
-		sockaddrin6.sin6_addr = in6addr;
-		sockaddrin6.sin6_port = htons(ZBX_DEFAULT_DNS_PORT);
-#if defined(HAVE_RES_NINIT) && !defined(_AIX) && (defined(HAVE_RES_U_EXT) || defined(HAVE_RES_U_EXT_EXT))
-		memset(&res_state_local.nsaddr_list[0], '\0', sizeof(res_state_local.nsaddr_list[0]));
-#		ifdef HAVE_RES_U_EXT			/* Linux */
-		saved_ns6 = res_state_local._u._ext.nsaddrs[0];
-		res_state_local._u._ext.nsaddrs[0] = &sockaddrin6;
-		res_state_local._u._ext.nssocks[0] = -1;
-		res_state_local._u._ext.nscount6 = 1;	/* CentOS */
-#		elif HAVE_RES_U_EXT_EXT			/* BSD */
-		if (NULL != res_state_local._u._ext.ext)
-			memcpy(res_state_local._u._ext.ext, &sockaddrin6, sizeof(sockaddrin6));
-
-		res_state_local.nsaddr_list[0].sin_port = htons(ZBX_DEFAULT_DNS_PORT);
-#		endif
-		res_state_local.nscount = 1;
-#else
-		memcpy(&saved_ns, &(_res.nsaddr_list[0]), sizeof(struct sockaddr_in));
-		saved_nscount = _res.nscount;
-#		if defined(HAVE_RES_U_EXT) || defined(HAVE_RES_U_EXT_EXT) || defined(HAVE_RES_EXT_EXT)
-		memset(&_res.nsaddr_list[0], '\0', sizeof(_res.nsaddr_list[0]));
-		_res.nscount = 1;
-#		endif
-#		if defined(HAVE_RES_U_EXT)		/* thread-unsafe resolver API /Linux/ */
-		saved_nscount6 = _res._u._ext.nscount6;
-		saved_ns6 = _res._u._ext.nsaddrs[0];
-		save_nssocks = _res._u._ext.nssocks[0];
-		_res._u._ext.nsaddrs[0] = &sockaddrin6;
-		_res._u._ext.nssocks[0] = -1;
-		_res._u._ext.nscount6 = 1;
-#		elif defined(HAVE_RES_U_EXT_EXT)	/* thread-unsafe resolver API /BSD/ */
-		memcpy(&saved_ns6, _res._u._ext.ext, sizeof(saved_ns6));
-		_res.nsaddr_list[0].sin_port = htons(ZBX_DEFAULT_DNS_PORT);
-
-		if (NULL != _res._u._ext.ext)
-			memcpy(_res._u._ext.ext, &sockaddrin6, sizeof(sockaddrin6));
-#		elif defined(HAVE_RES_EXT_EXT)		/* thread-unsafe resolver API /AIX/ */
-		memcpy(&saved_ns6, &(_res._ext.ext.nsaddrs[0]), sizeof(saved_ns6));
-		memcpy(&_res._ext.ext.nsaddrs[0], &sockaddrin6, sizeof(sockaddrin6));
-#		endif /* #if defined(HAVE_RES_U_EXT) */
-#endif /* #if defined(HAVE_RES_NINIT) && !defined(_AIX) && (defined(HAVE_RES_U_EXT) || defined(HAVE_RES_U_EXT_EXT)) */
-	}
-
-#if defined(HAVE_RES_NINIT) && !defined(_AIX) && (defined(HAVE_RES_U_EXT) || defined(HAVE_RES_U_EXT_EXT))
-	if (0 != use_tcp)
-		res_state_local.options |= RES_USEVC;
-
-	res_state_local.retrans = retrans;
-	res_state_local.retry = retry;
-
-	res = res_nsend(&res_state_local, buf, res, answer.buffer, sizeof(answer.buffer));
-
-#	ifdef HAVE_RES_U_EXT	/* Linux */
-	if (NULL != ip && '\0' != *ip && AF_INET6 == ip_type)
-		res_state_local._u._ext.nsaddrs[0] = saved_ns6;
-#	endif
-#	ifdef HAVE_RES_NDESTROY
-	res_ndestroy(&res_state_local);
-#	else
-	res_nclose(&res_state_local);
-#	endif
-#else	/* thread-unsafe resolver API */
-	saved_options = _res.options;
-	saved_retrans = _res.retrans;
-	saved_retry = _res.retry;
-
-	if (0 != use_tcp)
-		_res.options |= RES_USEVC;
-
-	_res.retrans = retrans;
-	_res.retry = retry;
-
-	res = res_send(buf, res, answer.buffer, sizeof(answer.buffer));
-
-	_res.options = saved_options;
-	_res.retrans = saved_retrans;
-	_res.retry = saved_retry;
-
-	if (NULL != ip && '\0' != *ip)
-	{
-		if (AF_INET6 == ip_type)
-		{
-#			if defined(HAVE_RES_U_EXT)		/* Linux */
-			_res._u._ext.nsaddrs[0] = saved_ns6;
-			_res._u._ext.nssocks[0] = save_nssocks;
-			_res._u._ext.nscount6 = saved_nscount6;
-#			elif defined(HAVE_RES_U_EXT_EXT)	/* BSD */
-			if (NULL != _res._u._ext.ext)
-				memcpy(_res._u._ext.ext, &saved_ns6, sizeof(saved_ns6));
-#			elif defined(HAVE_RES_EXT_EXT)		/* AIX */
-			memcpy(&_res._ext.ext.nsaddrs[0], &saved_ns6, sizeof(saved_ns6));
-#			endif
-		}
-
-		memcpy(&(_res.nsaddr_list[0]), &saved_ns, sizeof(struct sockaddr_in));
-		_res.nscount = saved_nscount;
-	}
-#endif
-	hp = (HEADER *)answer.buffer;
-
-	if (1 == short_answer)
-	{
-		SET_UI64_RESULT(result, NOERROR != hp->rcode || 0 == ntohs(hp->ancount) || -1 == res ? 0 : 1);
-		return SYSINFO_RET_OK;
-	}
-
-	if (NOERROR != hp->rcode || 0 == ntohs(hp->ancount) || -1 == res)
-	{
-		SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot perform DNS query."));
-		return SYSINFO_RET_FAIL;
-	}
-
-	msg_end = answer.buffer + res;
-
-	num_answers = ntohs(answer.h.ancount);
-	num_query = ntohs(answer.h.qdcount);
-
-	msg_ptr = answer.buffer + HFIXEDSZ;
-	zbx_vector_str_create(&answers);
-
-	/* skipping query records */
-	for (; 0 < num_query && msg_ptr < msg_end; num_query--)
-		msg_ptr += dn_skipname(msg_ptr, msg_end) + QFIXEDSZ;
-
-	for (; 0 < num_answers && msg_ptr < msg_end; num_answers--)
-	{
-		if (NULL == (name = get_name(answer.buffer, msg_end, &msg_ptr)))
-		{
-			SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
-			ret = SYSINFO_RET_FAIL;
-			goto clean;
-		}
-
-		offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "%-20s", name);
-
-		GETSHORT(q_type, msg_ptr);
-		GETSHORT(q_class, msg_ptr);
-		msg_ptr += INT32SZ;		/* skipping TTL */
-		GETSHORT(q_len, msg_ptr);
-		offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %-8s", decode_type(q_type));
-
-		switch (q_type)
-		{
-			case T_A:
-				switch (q_class)
-				{
-					case C_IN:
-					case C_HS:
-						memcpy(&inaddr, msg_ptr, INADDRSZ);
-						offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
-								inet_ntoa(inaddr));
-						break;
-					default:
-						;
-				}
-
-				msg_ptr += q_len;
-
-				break;
-			case T_AAAA:
-				switch (q_class)
-				{
-					case C_IN:
-					case C_HS:
-						memcpy(&in6addr, msg_ptr, IN6ADDRSZ);
-						offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s",
-								inet_ntop(AF_INET6, &in6addr, tmp, sizeof(tmp)));
-						break;
-					default:
-						;
-				}
-
-				msg_ptr += q_len;
-
-				break;
-			case T_NS:
-			case T_CNAME:
-			case T_MB:
-			case T_MD:
-			case T_MF:
-			case T_MG:
-			case T_MR:
-			case T_PTR:
-				if (NULL == (name = get_name(answer.buffer, msg_end, &msg_ptr)))
-				{
-					SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
-					return SYSINFO_RET_FAIL;
-				}
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", name);
-				break;
-			case T_MX:
-				GETSHORT(value, msg_ptr);	/* preference */
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
-
-				if (NULL == (name = get_name(answer.buffer, msg_end, &msg_ptr)))	/* exchange */
-				{
-					SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
-					return SYSINFO_RET_FAIL;
-				}
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", name);
-
-				break;
-			case T_SOA:
-				if (NULL == (name = get_name(answer.buffer, msg_end, &msg_ptr)))	/* source host */
-				{
-					SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
-					return SYSINFO_RET_FAIL;
-				}
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", name);
-
-				if (NULL == (name = get_name(answer.buffer, msg_end, &msg_ptr)))	/* administrator */
-				{
-					SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
-					return SYSINFO_RET_FAIL;
-				}
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", name);
-
-				GETLONG(value, msg_ptr);	/* serial number */
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
-
-				GETLONG(value, msg_ptr);	/* refresh time */
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
-
-				GETLONG(value, msg_ptr);	/* retry time */
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
-
-				GETLONG(value, msg_ptr);	/* expire time */
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
-
-				GETLONG(value, msg_ptr);	/* minimum TTL */
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
-
-				break;
-			case T_NULL:
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " len:%d", q_len);
-				msg_ptr += q_len;
-				break;
-			case T_WKS:
-				if (INT32SZ + 1 > q_len)
-				{
-					SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
-					return SYSINFO_RET_FAIL;
-				}
-
-				p = msg_ptr + q_len;
-
-				memcpy(&inaddr, msg_ptr, INADDRSZ);
-				msg_ptr += INT32SZ;
-
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", inet_ntoa(inaddr));
-
-				if (NULL != (pr = getprotobynumber(*msg_ptr)))
-					offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", pr->p_name);
-				else
-					offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", (int)*msg_ptr);
-
-				msg_ptr++;
-				n = 0;
-
-				while (msg_ptr < p)
-				{
-					c = *msg_ptr++;
-
-					do
-					{
-						if (0 != (c & 0200))
-						{
-							s = getservbyport((int)htons(n), pr ? pr->p_name : NULL);
-
-							if (NULL != s)
-								offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", s->s_name);
-							else
-								offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " #%d", n);
-						}
-
-						c <<= 1;
-					}
-					while (0 != (++n & 07));
-				}
-
-				break;
-			case T_HINFO:
-				p = msg_ptr + q_len;
-				c = *msg_ptr++;
-
-				if (0 != c)
-				{
-					offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " \"%.*s\"", c, msg_ptr);
-					msg_ptr += c;
-				}
-
-				if (msg_ptr < p)
-				{
-					c = *msg_ptr++;
-
-					if (0 != c)
-					{
-						offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " \"%.*s\"", c, msg_ptr);
-						msg_ptr += c;
-					}
-				}
-
-				break;
-			case T_MINFO:
-				if (NULL == (name = get_name(answer.buffer, msg_end, &msg_ptr)))	/* mailbox responsible for mailing lists */
-				{
-					SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
-					return SYSINFO_RET_FAIL;
-				}
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", name);
-
-				if (NULL == (name = get_name(answer.buffer, msg_end, &msg_ptr)))	/* mailbox for error messages */
-				{
-					SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
-					return SYSINFO_RET_FAIL;
-				}
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", name);
-
-				break;
-			case T_TXT:
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " \"");
-				p = msg_ptr + q_len;
-
-				while (msg_ptr < p)
-				{
-					for (c = *msg_ptr++; 0 < c && msg_ptr < p; c--)
-						offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "%c", *msg_ptr++);
-				}
-
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "\"");
-
-				break;
-			case T_SRV:
-				GETSHORT(value, msg_ptr);       /* priority */
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
-
-				GETSHORT(value, msg_ptr);       /* weight */
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
-
-				GETSHORT(value, msg_ptr);       /* port */
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %d", value);
-
-				if (NULL == (name = get_name(answer.buffer, msg_end, &msg_ptr)))	/* target */
-				{
-					SET_MSG_RESULT(result, zbx_strdup(NULL, "Cannot decode DNS response."));
-					return SYSINFO_RET_FAIL;
-				}
-				offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, " %s", name);
-
-				break;
-			default:
-				msg_ptr += q_len;
-				break;
-		}
-
-		zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "\n");
-
-		zbx_vector_str_append(&answers, zbx_strdup(NULL, buffer));
-		offset = 0;
-		*buffer = '\0';
-	}
-#endif	/* _WINDOWS */
-
-	zbx_vector_str_sort(&answers, ZBX_DEFAULT_STR_COMPARE_FUNC);
-
-	for (i = 0; i < answers.values_num; i++)
-		offset += zbx_snprintf(buffer + offset, sizeof(buffer) - offset, "%s", answers.values[i]);
-
-	if (0 != offset)
-		buffer[--offset] = '\0';
-
-	SET_TEXT_RESULT(result, zbx_strdup(NULL, buffer));
-	ret = SYSINFO_RET_OK;
-
-clean:
-	zbx_vector_str_clear_ext(&answers, zbx_str_free);
-	zbx_vector_str_destroy(&answers);
-#ifdef _WINDOWS
-clean_dns:
-	if (DNS_RCODE_NOERROR == res)
-		DnsRecordListFree(pQueryResults, DnsFreeRecordList);
-#endif
-
-	return ret;
-
-#else	/* both HAVE_RES_QUERY and _WINDOWS not defined */
-
-	return SYSINFO_RET_FAIL;
-
-#endif	/* defined(HAVE_RES_QUERY) || defined(_WINDOWS) */
-}
-
-int	NET_DNS(AGENT_REQUEST *request, AGENT_RESULT *result)
-{
-	return dns_query(request, result, 1);
-}
-
-int	NET_DNS_RECORD(AGENT_REQUEST *request, AGENT_RESULT *result)
-{
-	return dns_query(request, result, 0);
-}
diff --git a/src/libs/zbxsysinfo/common/net.h b/src/libs/zbxsysinfo/common/net.h
index 0141abf08b8..fe0f5f61e74 100644
--- a/src/libs/zbxsysinfo/common/net.h
+++ b/src/libs/zbxsysinfo/common/net.h
@@ -22,73 +22,6 @@
 
 #include "sysinfo.h"
 
-#if defined(HAVE_RES_QUERY) || defined(_WINDOWS)
-
-#	if !defined(C_IN) && !defined(_WINDOWS)
-#		define C_IN	ns_c_in
-#	endif
-
-/* define DNS record types to use common names on all systems, see RFC1035 standard for the types */
-#	ifndef T_ANY
-#		define T_ANY	255
-#	endif
-#	ifndef T_A
-#		define T_A	1
-#	endif
-#	ifndef T_NS
-#		define T_NS	2
-#	endif
-#	ifndef T_MD
-#		define T_MD	3
-#	endif
-#	ifndef T_MF
-#		define T_MF	4
-#	endif
-#	ifndef T_CNAME
-#		define T_CNAME	5
-#	endif
-#	ifndef T_SOA
-#		define T_SOA	6
-#	endif
-#	ifndef T_MB
-#		define T_MB	7
-#	endif
-#	ifndef T_MG
-#		define T_MG	8
-#	endif
-#	ifndef T_MR
-#		define T_MR	9
-#	endif
-#	ifndef T_NULL
-#		define T_NULL	10
-#	endif
-#	ifndef T_WKS
-#		define T_WKS	11
-#	endif
-#	ifndef T_PTR
-#		define T_PTR	12
-#	endif
-#	ifndef T_HINFO
-#		define T_HINFO	13
-#	endif
-#	ifndef T_MINFO
-#		define T_MINFO	14
-#	endif
-#	ifndef T_MX
-#		define T_MX	15
-#	endif
-#	ifndef T_TXT
-#		define T_TXT	16
-#	endif
-#	ifndef T_AAAA
-#		define T_AAAA	28
-#	endif
-#	ifndef T_SRV
-#		define T_SRV	33
-#	endif
-
-#endif /* defined(HAVE_RES_QUERY) || defined(_WINDOWS) */
-
 extern char	*CONFIG_SOURCE_IP;
 
 #define ZBX_TCP_EXPECT_FAIL	-1
@@ -98,8 +31,6 @@ extern char	*CONFIG_SOURCE_IP;
 int	tcp_expect(const char *host, unsigned short port, int timeout, const char *request,
 		int(*validate_func)(const char *), const char *sendtoclose, int *value_int);
 
-int	NET_DNS(AGENT_REQUEST *request, AGENT_RESULT *result);
-int	NET_DNS_RECORD(AGENT_REQUEST *request, AGENT_RESULT *result);
 int	NET_TCP_PORT(AGENT_REQUEST *request, AGENT_RESULT *result);
 
 #endif /* ZABBIX_SYSINFO_COMMON_NET_H */