some dns resolver code

2020-02-11 09:02:46 +00:00
parent 89371559bb
commit c6e3b6204b
18 changed files with 2402 additions and 2205 deletions
--- a/mio/lib/Makefile.in
+++ b/mio/lib/Makefile.in
@ -1,7 +1,7 @@
-# Makefile.in generated by automake 1.15 from Makefile.am.
+# Makefile.in generated by automake 1.16.1 from Makefile.am.
 # @configure_input@

-# Copyright (C) 1994-2014 Free Software Foundation, Inc.
+# Copyright (C) 1994-2018 Free Software Foundation, Inc.

 # This Makefile.in is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@ -166,7 +166,19 @@ am__v_at_0 = @
 am__v_at_1 = 
 DEFAULT_INCLUDES = 
 depcomp = $(SHELL) $(top_srcdir)/ac/depcomp
-am__depfiles_maybe = depfiles
+am__maybe_remake_depfiles = depfiles
+am__depfiles_remade = ./$(DEPDIR)/libmio_la-dns.Plo \
+	./$(DEPDIR)/libmio_la-err.Plo ./$(DEPDIR)/libmio_la-fmt.Plo \
+	./$(DEPDIR)/libmio_la-mio.Plo ./$(DEPDIR)/libmio_la-pro.Plo \
+	./$(DEPDIR)/libmio_la-sck-addr.Plo \
+	./$(DEPDIR)/libmio_la-sck.Plo \
+	./$(DEPDIR)/libmio_la-sys-ass.Plo \
+	./$(DEPDIR)/libmio_la-sys-err.Plo \
+	./$(DEPDIR)/libmio_la-sys-log.Plo \
+	./$(DEPDIR)/libmio_la-sys-mux.Plo \
+	./$(DEPDIR)/libmio_la-sys-tim.Plo \
+	./$(DEPDIR)/libmio_la-sys.Plo ./$(DEPDIR)/libmio_la-tmr.Plo \
+	./$(DEPDIR)/libmio_la-utf8.Plo ./$(DEPDIR)/libmio_la-utl.Plo
 am__mv = mv -f
 COMPILE = $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) \
 	$(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS)
@ -356,7 +368,6 @@ pdfdir = @pdfdir@
 prefix = @prefix@
 program_transform_name = @program_transform_name@
 psdir = @psdir@
-runstatedir = @runstatedir@
 sbindir = @sbindir@
 sharedstatedir = @sharedstatedir@
 srcdir = @srcdir@
@ -441,8 +452,8 @@ Makefile: $(srcdir)/Makefile.in $(top_builddir)/config.status
 	  *config.status*) \
 	    cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh;; \
 	  *) \
-	    echo ' cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__depfiles_maybe)'; \
-	    cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__depfiles_maybe);; \
+	    echo ' cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__maybe_remake_depfiles)'; \
+	    cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__maybe_remake_depfiles);; \
 	esac;

 $(top_builddir)/config.status: $(top_srcdir)/configure $(CONFIG_STATUS_DEPENDENCIES)
@ -513,22 +524,28 @@ mostlyclean-compile:
 distclean-compile:
 	-rm -f *.tab.c

-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-dns.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-err.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-fmt.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-mio.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-pro.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-sck-addr.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-sck.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-sys-ass.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-sys-err.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-sys-log.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-sys-mux.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-sys-tim.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-sys.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-tmr.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-utf8.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-utl.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-dns.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-err.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-fmt.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-mio.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-pro.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-sck-addr.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-sck.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-sys-ass.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-sys-err.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-sys-log.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-sys-mux.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-sys-tim.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-sys.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-tmr.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-utf8.Plo@am__quote@ # am--include-marker
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libmio_la-utl.Plo@am__quote@ # am--include-marker
+
+$(am__depfiles_remade):
+	@$(MKDIR_P) $(@D)
+	@echo '# dummy' >$@-t && $(am__mv) $@-t $@
+
+am--depfiles: $(am__depfiles_remade)

 .c.o:
@am__fastdepCC_TRUE@	$(AM_V_CC)depbase=`echo $@ | sed 's|[^/]*$$|$(DEPDIR)/&|;s|\.o$$||'`;\
@ -745,7 +762,10 @@ cscopelist-am: $(am__tagged_files)
 distclean-tags:
 	-rm -f TAGS ID GTAGS GRTAGS GSYMS GPATH tags

-distdir: $(DISTFILES)
+distdir: $(BUILT_SOURCES)
+	$(MAKE) $(AM_MAKEFLAGS) distdir-am
+
+distdir-am: $(DISTFILES)
 	@srcdirstrip=`echo "$(srcdir)" | sed 's/[].[^$$\\*]/\\\\&/g'`; \
 	topsrcdirstrip=`echo "$(top_srcdir)" | sed 's/[].[^$$\\*]/\\\\&/g'`; \
 	list='$(DISTFILES)'; \
@ -818,7 +838,22 @@ clean-am: clean-generic clean-libLTLIBRARIES clean-libtool \
 	mostlyclean-am

 distclean: distclean-am
-	-rm -rf ./$(DEPDIR)
+		-rm -f ./$(DEPDIR)/libmio_la-dns.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-err.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-fmt.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-mio.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-pro.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-sck-addr.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-sck.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-sys-ass.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-sys-err.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-sys-log.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-sys-mux.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-sys-tim.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-sys.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-tmr.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-utf8.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-utl.Plo
 	-rm -f Makefile
 distclean-am: clean-am distclean-compile distclean-generic \
 	distclean-hdr distclean-tags
@ -865,7 +900,22 @@ install-ps-am:
 installcheck-am:

 maintainer-clean: maintainer-clean-am
-	-rm -rf ./$(DEPDIR)
+		-rm -f ./$(DEPDIR)/libmio_la-dns.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-err.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-fmt.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-mio.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-pro.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-sck-addr.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-sck.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-sys-ass.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-sys-err.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-sys-log.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-sys-mux.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-sys-tim.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-sys.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-tmr.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-utf8.Plo
+	-rm -f ./$(DEPDIR)/libmio_la-utl.Plo
 	-rm -f Makefile
 maintainer-clean-am: distclean-am maintainer-clean-generic

@ -887,9 +937,9 @@ uninstall-am: uninstall-includeHEADERS uninstall-libLTLIBRARIES
 	$(MAKE) $(AM_MAKEFLAGS) uninstall-hook
 .MAKE: all install-am install-data-am install-strip uninstall-am

-.PHONY: CTAGS GTAGS TAGS all all-am check check-am clean clean-generic \
-	clean-libLTLIBRARIES clean-libtool cscopelist-am ctags \
-	ctags-am distclean distclean-compile distclean-generic \
+.PHONY: CTAGS GTAGS TAGS all all-am am--depfiles check check-am clean \
+	clean-generic clean-libLTLIBRARIES clean-libtool cscopelist-am \
+	ctags ctags-am distclean distclean-compile distclean-generic \
 	distclean-hdr distclean-libtool distclean-tags distdir dvi \
 	dvi-am html html-am info info-am install install-am \
 	install-data install-data-am install-data-hook install-dvi \
--- a/mio/lib/dns.c
+++ b/mio/lib/dns.c
@ -28,21 +28,15 @@
 #include <mio-sck.h>
 #include "mio-prv.h"

-typedef struct mio_dns_t mio_dns_t;
+typedef struct mio_svc_dns_t mio_svc_dns_t;

-struct mio_dns_t
+struct mio_svc_dns_t
 {
 	MIO_SVC_HEADERS;
 	/*MIO_DNS_SVC_HEADERS;*/
 };

-struct mio_dnss_t
-{
-	MIO_SVC_HEADERS;
-	/*MIO_DNS_SVC_HEADERS;*/
-};
-
-struct mio_dnsc_t
+struct mio_svc_dnc_t
 {
 	MIO_SVC_HEADERS;
 	/*MIO_DNS_SVC_HEADERS;*/
@ -53,17 +47,17 @@ struct mio_dnsc_t
 	mio_dns_msg_t* pending_req;
 };

-struct dnsc_sck_xtn_t
+struct dnc_sck_xtn_t
 {
-	mio_dnsc_t* dnsc;
+	mio_svc_dnc_t* dnc;
 };
-typedef struct dnsc_sck_xtn_t dnsc_sck_xtn_t;
+typedef struct dnc_sck_xtn_t dnc_sck_xtn_t;

 /* ----------------------------------------------------------------------- */

 #define DN_AT_END(ptr) (ptr[0] == '\0' || (ptr[0] == '.' && ptr[1] == '\0'))

-static mio_oow_t to_dn (mio_dns_t* dns, const mio_bch_t* str, mio_uint8_t* buf, mio_oow_t bufsz)
+static mio_oow_t to_dn (mio_svc_dns_t* dns, const mio_bch_t* str, mio_uint8_t* buf, mio_oow_t bufsz)
 {
 	mio_uint8_t* bp = buf, * be = buf + bufsz;

@ -133,18 +127,18 @@ static mio_oow_t dn_length (mio_uint8_t* ptr, mio_oow_t len)
 #	define dns_msg_to_pkt(msg) ((mio_dns_pkt_t*)((mio_dns_msg_t*)(msg) + 1))
 #endif

-static void release_dns_msg (mio_dnsc_t* dnsc, mio_dns_msg_t* msg)
+static void release_dns_msg (mio_svc_dnc_t* dnc, mio_dns_msg_t* msg)
 {
-	mio_t* mio = dnsc->mio;
+	mio_t* mio = dnc->mio;

 MIO_DEBUG1 (mio, "releasing dns msg %d\n", (int)mio_ntoh16(dns_msg_to_pkt(msg)->id));

-	if (msg == dnsc->pending_req || msg->next || msg->prev)
+	if (msg == dnc->pending_req || msg->next || msg->prev)
 	{
 		/* it's chained in the pending request. unchain it */
 		if (msg->next) msg->next->prev = msg->prev;
 		if (msg->prev) msg->prev->next = msg->next;
-		else dnsc->pending_req = msg->next;
+		else dnc->pending_req = msg->next;
 	}

 /* TODO:  add it to the free msg list instead of just freeing it. */
@ -157,7 +151,7 @@ MIO_DEBUG1 (mio, "releasing dns msg %d\n", (int)mio_ntoh16(dns_msg_to_pkt(msg)->
 	mio_freemem (mio, msg);
 }

-static mio_oow_t encode_rdata_in_dns_msg (mio_dnsc_t* dnsc, const mio_dns_brr_t* rr, mio_dns_rrtr_t* rrtr)
+static mio_oow_t encode_rdata_in_dns_msg (mio_svc_dnc_t* dnc, const mio_dns_brr_t* rr, mio_dns_rrtr_t* rrtr)
 {
 	switch (rr->qtype)
 	{
@ -213,9 +207,9 @@ static mio_oow_t encode_rdata_in_dns_msg (mio_dnsc_t* dnsc, const mio_dns_brr_t*
 	return rr->dlen;
 }

-static mio_dns_msg_t* build_dns_msg (mio_dnsc_t* dnsc, mio_dns_bdns_t* bdns, mio_dns_bqr_t* qr, mio_oow_t qr_count, mio_dns_brr_t* rr, mio_oow_t rr_count, mio_dns_bedns_t* edns)
+static mio_dns_msg_t* build_dns_msg (mio_svc_dnc_t* dnc, mio_dns_bdns_t* bdns, mio_dns_bqr_t* qr, mio_oow_t qr_count, mio_dns_brr_t* rr, mio_oow_t rr_count, mio_dns_bedns_t* edns, void* ctx)
 {
-	mio_t* mio = dnsc->mio;
+	mio_t* mio = dnc->mio;
 	mio_oow_t dnlen, msgbufsz, i;
 	mio_dns_msg_t* msg;
 	mio_dns_pkt_t* pkt;
@ -279,18 +273,19 @@ static mio_dns_msg_t* build_dns_msg (mio_dnsc_t* dnsc, mio_dns_bdns_t* bdns, mio

 	msg->buflen = msgbufsz; /* record the buffer size in the preamble */
 	msg->rtmridx = MIO_TMRIDX_INVALID;
-	msg->dev = (mio_dev_t*)dnsc->sck;
+	msg->dev = (mio_dev_t*)dnc->sck;
+	msg->ctx = ctx;

-	pkt = dns_msg_to_pkt(msg); /* actual message begins after the size word */
+	pkt = dns_msg_to_pkt(msg); /* actual packet data begins after the message structure */

-	dn = (mio_uint8_t*)(pkt + 1);
+	dn = (mio_uint8_t*)(pkt + 1); /* skip the dns packet header */
 	for (i = 0; i < qr_count; i++)
 	{
 		/* dnlen includes the ending <zero> */
-		dnlen = to_dn((mio_dns_t*)dnsc, qr[i].qname, dn, mio_count_bcstr(qr[i].qname) + 2);
+		dnlen = to_dn((mio_svc_dns_t*)dnc, qr[i].qname, dn, mio_count_bcstr(qr[i].qname) + 2);
 		if (dnlen <= 0)
 		{
-			release_dns_msg (dnsc, msg);
+			release_dns_msg (dnc, msg);
 			mio_seterrbfmt (mio, MIO_EINVAL, "invalid domain name - %hs", qr[i].qname);
 			return MIO_NULL;
 		}
@ -310,10 +305,10 @@ static mio_dns_msg_t* build_dns_msg (mio_dnsc_t* dnsc, mio_dns_bdns_t* bdns, mio
 			{
 				mio_oow_t rdata_len;

-				dnlen = to_dn((mio_dns_t*)dnsc, rr[i].qname, dn, mio_count_bcstr(rr[i].qname) + 2);
+				dnlen = to_dn((mio_svc_dns_t*)dnc, rr[i].qname, dn, mio_count_bcstr(rr[i].qname) + 2);
 				if (dnlen <= 0)
 				{
-					release_dns_msg (dnsc, msg);
+					release_dns_msg (dnc, msg);
 					mio_seterrbfmt (mio, MIO_EINVAL, "invalid domain name - %hs", rr[i].qname);
 					return MIO_NULL;
 				}
@ -323,7 +318,7 @@ static mio_dns_msg_t* build_dns_msg (mio_dnsc_t* dnsc, mio_dns_bdns_t* bdns, mio
 				rrtr->qclass = mio_hton16(rr[i].qclass);
 				rrtr->ttl = mio_hton32(rr[i].ttl);

-				rdata_len = encode_rdata_in_dns_msg(dnsc, &rr[i], rrtr);
+				rdata_len = encode_rdata_in_dns_msg(dnc, &rr[i], rrtr);
 				dn = (mio_uint8_t*)(rrtr + 1) + rdata_len;

 				match_count++;
@ -368,8 +363,8 @@ static mio_dns_msg_t* build_dns_msg (mio_dnsc_t* dnsc, mio_dns_bdns_t* bdns, mio

 	if (bdns->id < 0)
 	{
-		pkt->id = mio_hton16(dnsc->seq);
-		dnsc->seq++;
+		pkt->id = mio_hton16(dnc->seq);
+		dnc->seq++;
 	}
 	else
 	{
@ -392,10 +387,10 @@ static mio_dns_msg_t* build_dns_msg (mio_dnsc_t* dnsc, mio_dns_bdns_t* bdns, mio
 	return msg;
 }

-static int parse_dns_pkt (mio_dnsc_t* dnsc, mio_dns_pkt_t* pkt, mio_oow_t len)
+static int parse_dns_pkt (mio_svc_dnc_t* dnc, mio_dns_pkt_t* pkt, mio_oow_t len)
 {

-	mio_t* mio = dnsc->mio;
+	mio_t* mio = dnc->mio;
 	mio_dns_bdns_t* bdns;
 	mio_uint16_t i, rrc;
 	mio_uint8_t* dn;
@ -501,10 +496,10 @@ return 0;

 /* ----------------------------------------------------------------------- */

-static int dnsc_on_read (mio_dev_sck_t* dev, const void* data, mio_iolen_t dlen, const mio_sckaddr_t* srcaddr)
+static int dnc_on_read (mio_dev_sck_t* dev, const void* data, mio_iolen_t dlen, const mio_sckaddr_t* srcaddr)
 {
 	mio_t* mio = dev->mio;
-	mio_dnsc_t* dnsc = ((dnsc_sck_xtn_t*)mio_dev_sck_getxtn(dev))->dnsc;
+	mio_svc_dnc_t* dnc = ((dnc_sck_xtn_t*)mio_dev_sck_getxtn(dev))->dnc;
 	mio_dns_pkt_t* pkt;
 	mio_dns_msg_t* reqmsg;
 	mio_uint16_t id;
@ -523,10 +518,10 @@ static int dnsc_on_read (mio_dev_sck_t* dev, const void* data, mio_iolen_t dlen,

 	id = mio_ntoh16(pkt->id);

-	/* if id doesn't matche one of the pending requests sent,  drop */
+	/* if id doesn't match one of the pending requests sent,  drop it */

 /* TODO: improve performance */
-	reqmsg = dnsc->pending_req;
+	reqmsg = dnc->pending_req;
 	while (reqmsg)
 	{
 		mio_dns_pkt_t* reqpkt = dns_msg_to_pkt(reqmsg);
@ -534,9 +529,12 @@ static int dnsc_on_read (mio_dev_sck_t* dev, const void* data, mio_iolen_t dlen,
 		{
 MIO_DEBUG1 (mio, "received dns response...id %d\n", id);
 			/* TODO: parse the response... perform actual work. pass the result back?? */
-			parse_dns_pkt (dnsc, pkt, dlen);
+			/*parse_dns_pkt (dnc, pkt, dlen);*/

-			release_dns_msg (dnsc, reqmsg);
+			if (MIO_LIKELY(reqmsg->ctx))
+				((mio_svc_dnc_on_reply_t)reqmsg->ctx) (dnc, reqmsg, MIO_ENOERR, data, dlen);
+
+			release_dns_msg (dnc, reqmsg);
 			return 0;
 		}
 		reqmsg = reqmsg->next;
@ -547,25 +545,28 @@ MIO_DEBUG1 (mio, "received dns response...id %d\n", id);
 	return 0;
 }

-static void dnsc_on_read_timeout (mio_t* mio, const mio_ntime_t* now, mio_tmrjob_t* job)
+static void dnc_on_read_timeout (mio_t* mio, const mio_ntime_t* now, mio_tmrjob_t* job)
 {
-	mio_dns_msg_t* msg = (mio_dns_msg_t*)job->ctx;
-	mio_dev_sck_t* dev = (mio_dev_sck_t*)msg->dev;
-	mio_dnsc_t* dnsc = ((dnsc_sck_xtn_t*)mio_dev_sck_getxtn(dev))->dnsc;
+	mio_dns_msg_t* reqmsg = (mio_dns_msg_t*)job->ctx;
+	mio_dev_sck_t* dev = (mio_dev_sck_t*)reqmsg->dev;
+	mio_svc_dnc_t* dnc = ((dnc_sck_xtn_t*)mio_dev_sck_getxtn(dev))->dnc;

-	MIO_ASSERT (mio, msg->rtmridx == MIO_TMRIDX_INVALID);
+	MIO_ASSERT (mio, reqmsg->rtmridx == MIO_TMRIDX_INVALID);

 MIO_DEBUG0 (mio, "unable to receive dns response in time...\n");
-	release_dns_msg (dnsc, msg);
+
+	if (MIO_LIKELY(reqmsg->ctx))
+		((mio_svc_dnc_on_reply_t)reqmsg->ctx) (dnc, reqmsg, MIO_ETMOUT, MIO_NULL, 0);
+
+	release_dns_msg (dnc, reqmsg);
 }


-static int dnsc_on_write (mio_dev_sck_t* dev, mio_iolen_t wrlen, void* wrctx, const mio_sckaddr_t* dstaddr)
+static int dnc_on_write (mio_dev_sck_t* dev, mio_iolen_t wrlen, void* wrctx, const mio_sckaddr_t* dstaddr)
 {
 	mio_t* mio = dev->mio;
 	mio_dns_msg_t* msg = (mio_dns_msg_t*)wrctx;
-	mio_dnsc_t* dnsc = ((dnsc_sck_xtn_t*)mio_dev_sck_getxtn(dev))->dnsc;
-	
+	mio_svc_dnc_t* dnc = ((dnc_sck_xtn_t*)mio_dev_sck_getxtn(dev))->dnc;

 MIO_DEBUG1 (mio, "sent dns message %d\n", (int)mio_ntoh16(dns_msg_to_pkt(msg)->id));

@ -577,7 +578,7 @@ MIO_DEBUG1 (mio, "sent dns message %d\n", (int)mio_ntoh16(dns_msg_to_pkt(msg)->i
 		mio_tmrjob_t tmrjob;
 		mio_ntime_t tmout;

-		/* TODO: make this configurable. or accept dnsc->config.read_timeout... */
+		/* TODO: make this configurable. or accept dnc->config.read_timeout... */
 		tmout.sec = 3;
 		tmout.nsec = 0;

@ -585,140 +586,166 @@ MIO_DEBUG1 (mio, "sent dns message %d\n", (int)mio_ntoh16(dns_msg_to_pkt(msg)->i
 		tmrjob.ctx = msg;
 		mio_gettime (mio, &tmrjob.when);
 		MIO_ADD_NTIME (&tmrjob.when, &tmrjob.when, &tmout);
-		tmrjob.handler = dnsc_on_read_timeout;
+		tmrjob.handler = dnc_on_read_timeout;
 		tmrjob.idxptr = &msg->rtmridx;
 		msg->rtmridx = mio_instmrjob(mio, &tmrjob);
 		if (msg->rtmridx == MIO_TMRIDX_INVALID)
 		{
+			if (MIO_LIKELY(msg->ctx))
+				((mio_svc_dnc_on_reply_t)msg->ctx) (dnc, msg, mio_geterrnum(mio), MIO_NULL, 0);
+			release_dns_msg (dnc, msg);
+
 			MIO_DEBUG0 (mio, "unable to schedule timeout...\n");
-			release_dns_msg (dnsc, msg);
 			return 0;
 		}

 		/* TODO: improve performance. hashing by id? */
-		if (dnsc->pending_req)
+
+		/* chain it to the peing request list */
+		if (dnc->pending_req)
 		{
-			dnsc->pending_req->prev = msg;
-			msg->next = dnsc->pending_req;
+			dnc->pending_req->prev = msg;
+			msg->next = dnc->pending_req;
 		}
-		dnsc->pending_req = msg;
+		dnc->pending_req = msg;
+	}
+	else
+	{
+		/* sent an answer - we don't need this any more */
+		/* also we don't call the on_reply callback stored in msg->ctx as this is not a reply context */
+		release_dns_msg (dnc, msg);
 	}

 	return 0;
 }

-static void dnsc_on_connect (mio_dev_sck_t* dev)
+static void dnc_on_connect (mio_dev_sck_t* dev)
 {
 }

-static void dnsc_on_disconnect (mio_dev_sck_t* dev)
+static void dnc_on_disconnect (mio_dev_sck_t* dev)
 {
 }

-mio_dnsc_t* mio_dnsc_start (mio_t* mio)
+mio_svc_dnc_t* mio_svc_dnc_start (mio_t* mio)
 {
-	mio_dnsc_t* dnsc = MIO_NULL;
+	mio_svc_dnc_t* dnc = MIO_NULL;
 	mio_dev_sck_make_t mkinfo;
-	dnsc_sck_xtn_t* xtn;
+	dnc_sck_xtn_t* xtn;

-	dnsc = (mio_dnsc_t*)mio_callocmem(mio, MIO_SIZEOF(*dnsc));
-	if (!dnsc) goto oops;
+	dnc = (mio_svc_dnc_t*)mio_callocmem(mio, MIO_SIZEOF(*dnc));
+	if (!dnc) goto oops;

-	dnsc->mio = mio;
-	dnsc->stop = mio_dnsc_stop;
+	dnc->mio = mio;
+	dnc->stop = mio_svc_dnc_stop;

 	MIO_MEMSET (&mkinfo, 0, MIO_SIZEOF(mkinfo));
 	mkinfo.type = MIO_DEV_SCK_UDP4; /* or UDP6 depending on the binding address */
-	mkinfo.on_write = dnsc_on_write;
-	mkinfo.on_read = dnsc_on_read;
-	mkinfo.on_connect = dnsc_on_connect;
-	mkinfo.on_disconnect = dnsc_on_disconnect;
-	dnsc->sck = mio_dev_sck_make(mio, MIO_SIZEOF(*xtn), &mkinfo);
-	if (!dnsc->sck) goto oops;
+	mkinfo.on_write = dnc_on_write;
+	mkinfo.on_read = dnc_on_read;
+	mkinfo.on_connect = dnc_on_connect;
+	mkinfo.on_disconnect = dnc_on_disconnect;
+	dnc->sck = mio_dev_sck_make(mio, MIO_SIZEOF(*xtn), &mkinfo);
+	if (!dnc->sck) goto oops;

-	xtn = (dnsc_sck_xtn_t*)mio_dev_sck_getxtn(dnsc->sck);
-	xtn->dnsc = dnsc;
+	xtn = (dnc_sck_xtn_t*)mio_dev_sck_getxtn(dnc->sck);
+	xtn->dnc = dnc;

 	/* TODO: bind if requested */
 	/*if (mio_dev_sck_bind(dev, ....) <= -1) goto oops;*/
 {
-mio_uint32_t ia = 0x01010101; /* 1.1.1.1 */
-	mio_sckaddr_initforip4 (&dnsc->serveraddr, 53, (mio_ip4addr_t*)&ia);
+mio_uint32_t ia = 0x01010101; /* 1.1.1.1 */ /* TODO: accept as parameter ... */
+	mio_sckaddr_initforip4 (&dnc->serveraddr, 53, (mio_ip4addr_t*)&ia);
 }

-	MIO_SVC_REGISTER (mio, (mio_svc_t*)dnsc);
-	return dnsc;
+	MIO_SVC_REGISTER (mio, (mio_svc_t*)dnc);
+	return dnc;

 oops:
-	if (dnsc)
+	if (dnc)
 	{
-		if (dnsc->sck) mio_dev_sck_kill (dnsc->sck);
-		mio_freemem (mio, dnsc);
+		if (dnc->sck) mio_dev_sck_kill (dnc->sck);
+		mio_freemem (mio, dnc);
 	}
 	return MIO_NULL;
 }

-void mio_dnsc_stop (mio_dnsc_t* dnsc)
+void mio_svc_dnc_stop (mio_svc_dnc_t* dnc)
 {
-	mio_t* mio = dnsc->mio;
-	if (dnsc->sck) mio_dev_sck_kill (dnsc->sck);
-	MIO_SVC_UNREGISTER (mio, dnsc);
-	while (dnsc->pending_req) release_dns_msg (dnsc, dnsc->pending_req);
-	mio_freemem (mio, dnsc);
+	mio_t* mio = dnc->mio;
+	if (dnc->sck) mio_dev_sck_kill (dnc->sck);
+	MIO_SVC_UNREGISTER (mio, dnc);
+	while (dnc->pending_req) release_dns_msg (dnc, dnc->pending_req);
+	mio_freemem (mio, dnc);
 }


-int mio_dnsc_sendmsg (mio_dnsc_t* dnsc, mio_dns_bdns_t* bdns, mio_dns_bqr_t* qr, mio_oow_t qr_count, mio_dns_brr_t* rr, mio_oow_t rr_count, mio_dns_bedns_t* edns)
+int mio_svc_dnc_sendmsg (mio_svc_dnc_t* dnc, mio_dns_bdns_t* bdns, mio_dns_bqr_t* qr, mio_oow_t qr_count, mio_dns_brr_t* rr, mio_oow_t rr_count, mio_dns_bedns_t* edns, mio_svc_dnc_on_reply_t on_reply)
 {
 	/* send a request or a response */
 	mio_dns_msg_t* msg;

-	msg = build_dns_msg(dnsc, bdns, qr, qr_count, rr, rr_count, edns);
+	msg = build_dns_msg(dnc, bdns, qr, qr_count, rr, rr_count, edns, on_reply);
 	if (!msg) return -1;

-	/* TODO: optionally, override dnsc->serveraddr and use the target address passed as a parameter */
-	if (mio_dev_sck_write(dnsc->sck, dns_msg_to_pkt(msg), msg->pktlen, msg, &dnsc->serveraddr) <= -1)
+	/* TODO: optionally, override dnc->serveraddr and use the target address passed as a parameter */
+	if (mio_dev_sck_write(dnc->sck, dns_msg_to_pkt(msg), msg->pktlen, msg, &dnc->serveraddr) <= -1)
 	{
-		release_dns_msg (dnsc, msg);
+		release_dns_msg (dnc, msg);
 		return -1;
 	}

 	return 0;
 }

-int mio_dnsc_sendreq (mio_dnsc_t* dnsc, mio_dns_bdns_t* bdns, mio_dns_bqr_t* qr, mio_oow_t qr_count, mio_dns_bedns_t* edns)
+int mio_svc_dnc_sendreq (mio_svc_dnc_t* dnc, mio_dns_bdns_t* bdns, mio_dns_bqr_t* qr, mio_oow_t qr_count, mio_dns_bedns_t* edns, mio_svc_dnc_on_reply_t on_reply)
 {
 	/* send requests without resource record */
 	mio_oow_t i;
 	for (i = 0; i < qr_count; i++)
 	{
-		if (mio_dnsc_sendmsg(dnsc, bdns, &qr[i], 1, MIO_NULL, 0, edns) <= -1) return -1;
+		if (mio_svc_dnc_sendmsg(dnc, bdns, &qr[i], 1, MIO_NULL, 0, edns, on_reply) <= -1) return -1;
 	}
 	return 0;
 }

-#if 0
-static void dnss_on_request (mio_dnss_t* dnss, mio_dns_req_t* req)
+static void on_dnc_resolve_reply (mio_svc_dnc_t* dnc, mio_dns_msg_t* reqmsg, mio_errnum_t status, const void* data, mio_oow_t dlen)
 {
-	mio_dnss_reply (dnss, rep); /* reply send timeout??? */
 }

-/* ----------------------------------------------------------------------- */
-
-
-int main ()
+int mio_svc_dnc_resolve (mio_svc_dnc_t* dnc, const mio_bch_t* qname, mio_dns_qtype_t qtype, mio_svc_dnc_on_reply_t on_reply)
 {
-	mio = mio_open ();
+	static mio_dns_bdns_t qhdr =
+	{
+		-1,              /* id */
+		0,                  /* qr */
+		MIO_DNS_OPCODE_QUERY, /* opcode */
+		0, /* aa */
+		0, /* tc */
+		1, /* rd */
+		0, /* ra */
+		0, /* ad */
+		0, /* cd */
+		MIO_DNS_RCODE_NOERROR /* rcode */
+	};

-	dnss1 = mio_dnss_start(mio, "1.1.1.1:53,2.2.2.2:53", dnss_on_request);
-	mio_dnss_end (dnss1);
+	static mio_dns_bedns_t qedns =
+	{
+		4096, /* uplen */

-	dnsc1 = mio_dnsc_start (mio, "8.8.8.8:53,1.1.1.1:53"); /* option - send to all, send one by one */
-	mio_dnsc_resolve (dnsc1, "A:www.google.com", dnsc_on_response);
-	mio_dnsc_end (dnsc1);
+		0,    /* edns version */
+		0,    /* dnssec ok */

-	mio_close (mio);
-	return 0;
+		0,    /* number of edns options */
+		MIO_NULL
+	};
+
+	mio_dns_bqr_t qr;
+
+	qr.qname = (mio_bch_t*)qname;
+	qr.qtype = qtype;
+	qr.qclass = MIO_DNS_QCLASS_IN;
+
+	return mio_svc_dnc_sendreq(dnc, &qhdr, &qr, 1, &qedns, on_reply);
 }

-#endif
--- a/mio/lib/mio-dns.h
+++ b/mio/lib/mio-dns.h
@ -120,6 +120,7 @@ struct mio_dns_msg_t
 	mio_oow_t      pktlen;
 	mio_tmridx_t   rtmridx;
 	mio_dev_t*     dev;
+	void*          ctx;
 	mio_dns_msg_t* prev;
 	mio_dns_msg_t* next;
 };
@ -205,8 +206,7 @@ typedef struct mio_dns_eopt_t mio_dns_eopt_t;

 #include <mio-upac.h>

-typedef struct mio_dnss_t mio_dnss_t;
-typedef struct mio_dnsc_t mio_dnsc_t;
+/* ---------------------------------------------------------------- */

 /*
 #define MIO_DNS_HDR_MAKE_FLAGS(qr,opcode,aa,tc,rd,ra,ad,cd,rcode) \
@ -324,34 +324,56 @@ struct mio_dns_bedns_t
 };
 typedef struct mio_dns_bedns_t mio_dns_bedns_t;

+/* ---------------------------------------------------------------- */
+
+typedef struct mio_svc_dns_t mio_svc_dns_t;
+typedef struct mio_svc_dnc_t mio_svc_dnc_t;
+
+typedef void (*mio_svc_dnc_on_reply_t) (
+	mio_svc_dnc_t* dnc,
+	mio_dns_msg_t* reqmsg,
+	mio_errnum_t   status,
+	const void*    data,
+	mio_oow_t      len
+);
+
 #if defined(__cplusplus)
 extern "C" {
 #endif

-MIO_EXPORT mio_dnsc_t* mio_dnsc_start (
+MIO_EXPORT mio_svc_dnc_t* mio_svc_dnc_start (
 	mio_t* mio
 );

-MIO_EXPORT void mio_dnsc_stop (
-	mio_dnsc_t* dnsc
+MIO_EXPORT void mio_svc_dnc_stop (
+	mio_svc_dnc_t* dnc
 );

-MIO_EXPORT int mio_dnsc_sendreq (
-	mio_dnsc_t*      dnsc,
-	mio_dns_bdns_t*  bdns,
-	mio_dns_bqr_t*   qr,
-	mio_oow_t        qr_count,
-	mio_dns_bedns_t* edns
+MIO_EXPORT int mio_svc_dnc_sendreq (
+	mio_svc_dnc_t*         dnc,
+	mio_dns_bdns_t*        bdns,
+	mio_dns_bqr_t*         qr,
+	mio_oow_t              qr_count,
+	mio_dns_bedns_t*       edns,
+	mio_svc_dnc_on_reply_t on_reply
 );

-MIO_EXPORT int mio_dnsc_sendmsg (
-	mio_dnsc_t*      dnsc,
-	mio_dns_bdns_t*  bdns,
-	mio_dns_bqr_t*   qr,
-	mio_oow_t        qr_count,
-	mio_dns_brr_t*   rr,
-	mio_oow_t        rr_count,
-	mio_dns_bedns_t* edns
+MIO_EXPORT int mio_svc_dnc_sendmsg (
+	mio_svc_dnc_t*         dnc,
+	mio_dns_bdns_t*        bdns,
+	mio_dns_bqr_t*         qr,
+	mio_oow_t              qr_count,
+	mio_dns_brr_t*         rr,
+	mio_oow_t              rr_count,
+	mio_dns_bedns_t*       edns,
+	mio_svc_dnc_on_reply_t on_reply
+);
+
+MIO_EXPORT int mio_svc_dnc_resolve (
+	mio_svc_dnc_t*         dnc,
+	const mio_bch_t*       qname,
+	mio_dns_qtype_t        qtype,
+	mio_svc_dnc_on_reply_t on_reply
 );

 #if defined(__cplusplus)
--- a/mio/lib/mio.c
+++ b/mio/lib/mio.c
@ -677,11 +677,11 @@ mio_dev_t* mio_dev_make (mio_t* mio, mio_oow_t dev_size, mio_dev_mth_t* dev_mth,
 	if (!(dev->dev_cap & MIO_DEV_CAP_OUT)) dev->dev_cap |= MIO_DEV_CAP_OUT_CLOSED;

 	if (mio_dev_watch(dev, MIO_DEV_WATCH_START, 0) <= -1) goto oops_after_make;
-
 	/* and place the new device object at the back of the active device list */
 	APPEND_DEVICE_TO_LIST (&mio->actdev, dev);
 	dev->dev_cap |= MIO_DEV_CAP_ACTIVE;

+
 	return dev;

 oops_after_make:
--- a/mio/lib/sys-err.c
+++ b/mio/lib/sys-err.c
@ -27,6 +27,7 @@
 #include "mio-prv.h"

 #include <errno.h>
+#include <string.h>

 static mio_errnum_t errno_to_errnum (int errcode)
 {
@ -240,6 +241,7 @@ mio_errnum_t mio_sys_syserrstrb (mio_t* mio, int syserr_type, int syserr_code, m
 			return errno_to_errnum(syserr_code);
 	}

+
 	if (buf) mio_copy_bcstr (buf, len, "system error");
 	return MIO_ESYSERR;
 }