test dns module

lib_acl/include/net/acl_rfc1035.h

@@ -151,7 +151,7 @@ ACL_API  int acl_rfc1035_query_compare(const ACL_RFC1035_QUERY *a,
 /**
  * Takes the contents of a DNS reply and fills in an array
  * of resource record structures.  The records array is allocated
- * here, and should be freed by calling RFC1035RRDestroy().
+ * here, and should be freed by calling acl_rfc1035_message_destroy().
  * @param buf {const char*} the data of the DNS reply
  * @param sz {size_t} the buf's size
  * @return {ACL_RFC1035_MESSAGE*} return the parsing result
@@ -161,7 +161,7 @@ ACL_API ACL_RFC1035_MESSAGE *acl_rfc1035_response_unpack(const char *buf, size_t
 /**
  * Takes the contents of a DNS request and fills in an array
  * of resource record structures.  The records array is allocated
- * here, and should be freed by calling RFC1035RRDestroy().
+ * here, and should be freed by calling acl_rfc1035_message_destroy().
  * @param buf {const char*} the data of the DNS reply
  * @param sz {size_t} the buf's size
  * @return {ACL_RFC1035_MESSAGE*} return the parsing result

lib_acl/src/net/dns/acl_rfc1035.c

@@ -898,7 +898,6 @@ ACL_RFC1035_MESSAGE *acl_rfc1035_request_unpack(const char *buf, size_t sz)
 	}
 
 	return msg;
-
 }
 
 /****************************************************************************/
@@ -1075,7 +1074,7 @@ size_t acl_rfc1035_build_reply(const ACL_RFC1035_REPLY *reply, char *buf, size_t
 
 	for (i = 0; i < reply->ips->argc; i++) {
 		memset(&rr, 0, sizeof(rr));
-		snprintf(rr.name, sizeof(rr.name), "%s", reply->hostname);
+		ACL_SAFE_STRNCPY(rr.name, reply->hostname, sizeof(rr.name));
 		rr.type = reply->ip_type;
 		rr.tclass = ACL_RFC1035_CLASS_IN;
 		rr.ttl = reply->ttl;
@@ -1092,7 +1091,7 @@ size_t acl_rfc1035_build_reply(const ACL_RFC1035_REPLY *reply, char *buf, size_t
 
 	if (h.nscount) {
 		memset(&rr, 0, sizeof(rr));
-		snprintf(rr.name, sizeof(rr.name), "%s", reply->domain_root);
+		ACL_SAFE_STRNCPY(rr.name, reply->domain_root, sizeof(rr.name));
 		rr.type = ACL_RFC1035_TYPE_NS;
 		rr.tclass = ACL_RFC1035_CLASS_IN;
 		rr.ttl = reply->ttl;
@@ -1104,7 +1103,7 @@ size_t acl_rfc1035_build_reply(const ACL_RFC1035_REPLY *reply, char *buf, size_t
 
 	if (h.arcount) {
 		memset(&rr, 0, sizeof(rr));
-		snprintf(rr.name, sizeof(rr.name), "%s", reply->dns_name);
+		ACL_SAFE_STRNCPY(rr.name, reply->dns_name, sizeof(rr.name));
 		rr.type = reply->ip_type;
 		rr.tclass = ACL_RFC1035_CLASS_IN;
 		rr.ttl = reply->ttl;

lib_fiber/c/src/dns/resolver.c

@@ -479,11 +479,8 @@ static struct addrinfo *ns_lookup(const char *ip, unsigned short port,
 		if (ret == -1) {
 			break;
 		}
-		ret = rfc1035_message_unpack(buf, ret, &message);
+		message = rfc1035_response_unpack(buf, ret);
-		if (ret <= 0) {
+		if (message == NULL) {
-			if (message) {
-				rfc1035_message_destroy(message);
-			}
 			break;
 		}
 

lib_fiber/c/src/dns/rfc1035.c

@@ -10,10 +10,11 @@
 
 #include "common/strops.h"
 #include "common/msg.h"
+#include "common/argv.h"
 #include "rfc1035.h"
 
 #define RFC1035_MAXLABELSZ	63
-#define RFC1035_unpack_error	15
+#define RFC1035_UNPACK_ERROR	15
 
 #if 0
 #define RFC1035_UNPACK_DEBUG  msg_error("unpack error at %s:%d", __FILE__,__LINE__)
@@ -195,13 +196,13 @@ static int rfc1035_name_unpack(const char *buf, size_t sz, size_t *off,
 
 	if (ns <= 0) {
 		msg_error("%s: ns(%d) <= 0", myname, (int) ns);
-		return -RFC1035_unpack_error;
+		return -RFC1035_UNPACK_ERROR;
 	}
 	do {
 		if (*off >= sz) {
 			msg_error("%s: *off(%d) >= sz(%d)",
 				myname, (int) *off, (int) sz);
-			return -RFC1035_unpack_error;
+			return -RFC1035_UNPACK_ERROR;
 		}
 		c = *(buf + (*off));
 		if (c > 191) {
@@ -260,7 +261,7 @@ static int rfc1035_name_unpack(const char *buf, size_t sz, size_t *off,
 	/* make sure we didn't allow someone to overflow the name buffer */
 	if (no > (int) ns) {
 		msg_error("%s: no(%d) > ns(%d)", myname, no, (int) ns);
-		return -RFC1035_unpack_error;
+		return -RFC1035_UNPACK_ERROR;
 	}
 	return 0;
 }
@@ -282,7 +283,7 @@ const char *rfc1035_strerror(int errnum)
 				"not support the requested kind of query." },
 		{ 5, "Refused: The name server refuses to "
 				"perform the specified operation." },
-		{ RFC1035_unpack_error, "The DNS reply message is corrupt or could "
+		{ RFC1035_UNPACK_ERROR, "The DNS reply message is corrupt or could "
 			"not be safely parsed." },
 		{ -1, NULL },
 	};
@@ -345,48 +346,48 @@ int rfc1035_query_compare(const RFC1035_QUERY * a, const RFC1035_QUERY * b)
  *
  * Returns > 0 (success) or 0 (error)
  */
-static int rfc1035_rr_pack(const RFC1035_RR *RR, char *buf, size_t sz)
+static int rfc1035_rr_pack(const RFC1035_RR *rr, char *buf, size_t sz)
 {
 	const char *myname = "rfc1035_rr_pack";
 	unsigned short s;
 	unsigned int i;
 	int off = 0, off_saved;
 
-	off = rfc1035_name_pack(buf + off, sz, RR->name);
+	off = rfc1035_name_pack(buf + off, sz, rr->name);
-	s = htons(RR->type);
+	s = htons(rr->type);
 	memcpy(buf + off, &s,sizeof(s));
 	off += sizeof(s);
 
-	s = htons(RR->tclass);
+	s = htons(rr->tclass);
 	memcpy(buf + off, &s ,sizeof(s));
 	off += sizeof(s);
     
-	i = htonl(RR->ttl);
+	i = htonl(rr->ttl);
 	memcpy(buf + off, &i ,sizeof(i));
 	off += sizeof(i);
 
-	switch (RR->type) {
+	switch (rr->type) {
 	case RFC1035_TYPE_PTR:
 	case RFC1035_TYPE_NS:
 	case RFC1035_TYPE_CNAME:
 	case RFC1035_TYPE_TXT:
-		if (strlen(RR->rdata) > RFC1035_MAXHOSTNAMESZ) {
+		if (strlen(rr->rdata) > RFC1035_MAXHOSTNAMESZ) {
 			return 0;
 		}
 
 		off_saved = off;
 		off += sizeof(s);
-		off += rfc1035_name_pack(buf + off, sz, RR->rdata);
+		off += rfc1035_name_pack(buf + off, sz, rr->rdata);
 		s = off - off_saved - (unsigned short) sizeof(s);
 		s = htons(s);
 		memcpy(buf + off_saved, &s ,sizeof(s));
 		break;
 	default:
-		s = htons(RR->rdlength);
+		s = htons(rr->rdlength);
 		memcpy(buf + off, &s ,sizeof(s));
 		off += sizeof(s);
-		memcpy(buf + off, RR->rdata, RR->rdlength);
+		memcpy(buf + off, rr->rdata, rr->rdlength);
-		off += RR->rdlength;
+		off += rr->rdlength;
 		break;
 	}
 
@@ -529,7 +530,7 @@ static int rfc1035_header_unpack(const char *buf, size_t sz, size_t *off,
 
 	if (*off != 0) {
 		msg_error("%s: *off(%d) != 0", myname, (int) *off);
-		return -RFC1035_unpack_error;
+		return -RFC1035_UNPACK_ERROR;
 	}
 
 	/*
@@ -579,7 +580,7 @@ static int rfc1035_header_unpack(const char *buf, size_t sz, size_t *off,
 
 	if (*off != 12) {
 		msg_error("%s: *off(%d) != 12", myname, (int) *off);
-		return -RFC1035_unpack_error;
+		return -RFC1035_UNPACK_ERROR;
 	}
 	return 0;
 }
@@ -724,7 +725,7 @@ static int rfc1035_rr_unpack(const char *buf, size_t sz, size_t *off, RFC1035_RR
 	if (*off > sz) {
 		msg_error("%s: *off(%d) > sz(%d)",
 			myname, (int) *off, (int) sz);
-		return -RFC1035_unpack_error;
+		return -RFC1035_UNPACK_ERROR;
 	}
 
 	return 0;
@@ -764,45 +765,40 @@ static RFC1035_RR *rfc1035_unpack2rr(const char *buf, size_t sz,
 	return rr;
 }
 
-int rfc1035_message_unpack(const char *buf, size_t sz, RFC1035_MESSAGE **answer)
+RFC1035_MESSAGE *rfc1035_response_unpack(const char *buf, size_t sz)
 {
 	int i, nr;
 	size_t off = 0;
 	RFC1035_MESSAGE *msg;
 
 	errno = 0;
-	*answer = NULL;
 	msg = (RFC1035_MESSAGE*) calloc(1, sizeof(*msg));
 
 	if (rfc1035_header_unpack(buf + off, sz - off, &off, msg)) {
 		RFC1035_UNPACK_DEBUG;
-		rfc1035_set_errno(RFC1035_unpack_error);
+		rfc1035_set_errno(RFC1035_UNPACK_ERROR);
 		rfc1035_message_destroy(msg);
-		*answer = NULL;
+		return NULL;
-		return -RFC1035_unpack_error;
 	}
 
 	if (msg->rcode) {
-		int ret = -((int) msg->rcode);
 		RFC1035_UNPACK_DEBUG;
 		rfc1035_set_errno((int) msg->rcode);
 		rfc1035_message_destroy(msg);
-		*answer = NULL;
+		return NULL;
-		return ret;
 	}
 
 	if (msg->ancount == 0) {
 		rfc1035_message_destroy(msg);
-		*answer = NULL;
+		return NULL;
-		return 0;
 	}
 
 	if (msg->qdcount != 1) {
 		/* This can not be an answer to our queries.. */
 		RFC1035_UNPACK_DEBUG;
-		rfc1035_set_errno(RFC1035_unpack_error);
+		rfc1035_set_errno(RFC1035_UNPACK_ERROR);
 		rfc1035_message_destroy(msg);
-		return -RFC1035_unpack_error;
+		return NULL;
 	}
 
 	msg->query = (RFC1035_QUERY*) calloc((int) msg->qdcount,
@@ -811,9 +807,9 @@ int rfc1035_message_unpack(const char *buf, size_t sz, RFC1035_MESSAGE **answer)
 	for (i = 0; i < (int) msg->qdcount; i++) {
 		if (rfc1035_query_unpack(buf, sz, &off, &msg->query[i])) {
 			RFC1035_UNPACK_DEBUG;
-			rfc1035_set_errno(RFC1035_unpack_error);
+			rfc1035_set_errno(RFC1035_UNPACK_ERROR);
 			rfc1035_message_destroy(msg);
-			return -RFC1035_unpack_error;
+			return NULL;
 		}
 	}
 
@@ -826,12 +822,10 @@ int rfc1035_message_unpack(const char *buf, size_t sz, RFC1035_MESSAGE **answer)
 		 */
 		RFC1035_UNPACK_DEBUG;
 		rfc1035_message_destroy(msg);
-		*answer = NULL;
+		rfc1035_set_errno(RFC1035_UNPACK_ERROR);
-		rfc1035_set_errno(RFC1035_unpack_error);
+		return NULL;
-		return -RFC1035_unpack_error;
 	}
 
-
 	if (msg->nscount > 0) {
 		msg->authority = rfc1035_unpack2rr(buf, sz, &off,
 			msg->nscount, &nr);
@@ -839,9 +833,8 @@ int rfc1035_message_unpack(const char *buf, size_t sz, RFC1035_MESSAGE **answer)
 		if (msg->authority == NULL) {
 			RFC1035_UNPACK_DEBUG;
 			rfc1035_message_destroy(msg);
-			*answer = NULL;
+			rfc1035_set_errno(RFC1035_UNPACK_ERROR);
-			rfc1035_set_errno(RFC1035_unpack_error);
+			return NULL;
-			return -RFC1035_unpack_error;
 		}
 	}
 
@@ -852,14 +845,57 @@ int rfc1035_message_unpack(const char *buf, size_t sz, RFC1035_MESSAGE **answer)
 		if (msg->additional == NULL) {
 			RFC1035_UNPACK_DEBUG;
 			rfc1035_message_destroy(msg);
-			*answer = NULL;
+			rfc1035_set_errno(RFC1035_UNPACK_ERROR);
-			rfc1035_set_errno(RFC1035_unpack_error);
+			return NULL;
-			return -RFC1035_unpack_error;
 		}
 	}
 
-	*answer = msg;
+	return msg;
-	return (int) msg->ancount;
+}
+
+RFC1035_MESSAGE *rfc1035_request_unpack(const char *buf, size_t sz)
+{
+	int i;
+	size_t off = 0;
+	RFC1035_MESSAGE *msg;
+
+	errno = 0;
+	msg = (RFC1035_MESSAGE*) calloc(1, sizeof(*msg));
+
+	if (rfc1035_header_unpack(buf + off, sz - off, &off, msg)) {
+		RFC1035_UNPACK_DEBUG;
+		rfc1035_set_errno(RFC1035_UNPACK_ERROR);
+		rfc1035_message_destroy(msg);
+		return NULL;
+	}
+
+	if (msg->rcode) {
+		RFC1035_UNPACK_DEBUG;
+		rfc1035_set_errno((int) msg->rcode);
+		rfc1035_message_destroy(msg);
+		return NULL;
+	}
+
+	if (msg->qdcount != 1) {
+		/* This can not be an answer to our queries.. */
+		RFC1035_UNPACK_DEBUG;
+		rfc1035_set_errno(RFC1035_UNPACK_ERROR);
+		rfc1035_message_destroy(msg);
+		return NULL;
+	}
+
+	msg->query = (RFC1035_QUERY*) calloc((int) msg->qdcount,
+			sizeof(RFC1035_QUERY));
+
+	for (i = 0; i < (int) msg->qdcount; i++) {
+		if (rfc1035_query_unpack(buf, sz, &off, &msg->query[i])) {
+			RFC1035_UNPACK_DEBUG;
+			rfc1035_set_errno(RFC1035_UNPACK_ERROR);
+			rfc1035_message_destroy(msg);
+		}
+	}
+
+	return msg;
 }
 
 /****************************************************************************/
@@ -1004,6 +1040,8 @@ static size_t save_addr2rr(int type, const char *src, RFC1035_RR *rr)
 	}
 }
 
+#define SAFE_FREE(x) do { if ((x)) free ((x)); } while(0)
+
 size_t rfc1035_build_reply(const RFC1035_REPLY *reply, char *buf, size_t sz)
 {
 	RFC1035_MESSAGE h;
@@ -1011,6 +1049,11 @@ size_t rfc1035_build_reply(const RFC1035_REPLY *reply, char *buf, size_t sz)
 	size_t offset = 0;
 	int   i;
 
+	if (reply->ips == NULL || reply->ips->argc <= 0) {
+		msg_error("ips null");
+		return 0;
+	}
+
 	memset(&h, '\0', sizeof(h));
 	h.id = reply->qid;
 	h.qr = 1;		/* response */
@@ -1031,11 +1074,7 @@ size_t rfc1035_build_reply(const RFC1035_REPLY *reply, char *buf, size_t sz)
 
 	for (i = 0; i < reply->ips->argc; i++) {
 		memset(&rr, 0, sizeof(rr));
-#ifdef SYS_WIN
+		SAFE_STRNCPY(rr.name, reply->hostname, sizeof(rr.name));
-		_snprintf(rr.name, sizeof(rr.name), "%s", reply->hostname);
-#else
-		snprintf(rr.name, sizeof(rr.name), "%s", reply->hostname);
-#endif
 		rr.type = reply->ip_type;
 		rr.tclass = htons(RFC1035_CLASS_IN);
 		rr.ttl = reply->ttl;
@@ -1047,16 +1086,12 @@ size_t rfc1035_build_reply(const RFC1035_REPLY *reply, char *buf, size_t sz)
 		}
 
 		offset += rfc1035_rr_pack(&rr, buf + offset, sz - offset);
-		free(rr.rdata);
+		SAFE_FREE(rr.rdata);
 	}
 
 	if (h.nscount) {
 		memset(&rr, 0, sizeof(rr));
-#ifdef SYS_WIN
+		SAFE_STRNCPY(rr.name, reply->domain_root, sizeof(rr.name));
-		_snprintf(rr.name, sizeof(rr.name), "%s", reply->domain_root);
-#else
-		snprintf(rr.name, sizeof(rr.name), "%s", reply->domain_root);
-#endif
 		rr.type = RFC1035_TYPE_NS;
 		rr.tclass = RFC1035_CLASS_IN;
 		rr.ttl = reply->ttl;
@@ -1067,16 +1102,12 @@ size_t rfc1035_build_reply(const RFC1035_REPLY *reply, char *buf, size_t sz)
 		rr.rdata = strdup(reply->dns_name);
 #endif
 		offset += rfc1035_rr_pack(&rr, buf + offset, sz - offset);
-		free(rr.rdata);
+		SAFE_FREE(rr.rdata);
 	}
 
 	if (h.arcount) {
 		memset(&rr, 0, sizeof(rr));
-#ifdef SYS_WIN
+		SAFE_STRNCPY(rr.name, reply->dns_name, sizeof(rr.name));
-		_snprintf(rr.name, sizeof(rr.name), "%s", reply->dns_name);
-#else
-		snprintf(rr.name, sizeof(rr.name), "%s", reply->dns_name);
-#endif
 		rr.type = reply->ip_type;
 		rr.tclass = RFC1035_CLASS_IN;
 		rr.ttl = reply->ttl;
@@ -1088,7 +1119,7 @@ size_t rfc1035_build_reply(const RFC1035_REPLY *reply, char *buf, size_t sz)
 		}
 
 		offset += rfc1035_rr_pack(&rr, buf + offset, sz - offset);
-		free(rr.rdata);
+		SAFE_FREE(rr.rdata);
 	}
 
 	return offset;

lib_fiber/c/src/dns/rfc1035.h

@@ -5,12 +5,12 @@
 extern "C" {
 #endif
 
-#include "common/argv.h"
-
 #ifdef	ACL_UNIX
 #include <netinet/in.h>
 #endif
 
+struct ARGV;
+
 /* RFC1035 - DNS */
 #define RFC1035_MAXHOSTNAMESZ 256
 
@@ -151,16 +151,24 @@ void rfc1035_set_query_id(char *buf, size_t sz, unsigned short qid);
 int rfc1035_query_compare(const RFC1035_QUERY *a, const RFC1035_QUERY *b);
 
 /**
- * Takes the contents of a DNS reply and fills in an array
+ * Takes the contents of a DNS request and fills in an array
  * of resource record structures.  The records array is allocated
- * here, and should be freed by calling RFC1035RRDestroy().
+ * here, and should be freed by calling rfc1035_messager_destroy().
  * @param buf {const char*} the data of the DNS reply
  * @param sz {size_t} the buf's size
- * @param answer {RFC1035_MESSAGE*} store the parsing result
+ * @return {RFC1035_MESSAGE*} return the parsing result
- * @return {int} Returns number of records unpacked, zero if DNS reply
- * 	indicates zero answers, or an error number < 0.
  */
-int rfc1035_message_unpack(const char *buf, size_t sz, RFC1035_MESSAGE **answer);
+RFC1035_MESSAGE *rfc1035_request_unpack(const char *buf, size_t sz);
+
+/**
+ * Takes the contents of a DNS reply and fills in an array
+ * of resource record structures.  The records array is allocated
+ * here, and should be freed by calling rfc1035_messager_destroy().
+ * @param buf {const char*} the data of the DNS reply
+ * @param sz {size_t} the buf's size
+ * @return {RFC1035_MESSAGE*} return the parsing result
+ */
+RFC1035_MESSAGE *rfc1035_response_unpack(const char *buf, size_t sz);
 
 /**
  * destroy and free the message created by RFC1035MessageUnpack()

lib_fiber/samples/dns_perf/main.cpp

@@ -5,7 +5,6 @@
 #include <thread>
 #include "lib_acl.h"
 #include "acl_cpp/lib_acl.hpp"
-#include "fiber/libfiber.h"
 #include "fiber/go_fiber.hpp"
 
 static char   __dns_ip[256];
@@ -127,7 +126,7 @@ int main(int argc, char *argv[])
 	}
 
 	acl_msg_stdout_enable(1);
-	acl_fiber_msg_stdout_enable(1);
+	acl::fiber::stdout_open(true);
 
 	struct timeval begin;
 	gettimeofday(&begin, NULL);

lib_fiber/samples/dns_server/Makefile

@@ -0,0 +1,3 @@
+include ../Makefile_cpp.in
+PROG = dns_server
+CFLAGS += -std=c++11 -I../../c/src/dns -I../../c/src/common

lib_fiber/samples/dns_server/main.cpp

@@ -0,0 +1,149 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <getopt.h>
+#include "acl_cpp/lib_acl.hpp"
+#include "fiber/go_fiber.hpp"
+
+#include "rfc1035.h"
+#include "argv.h"
+
+static RFC1035_MESSAGE* parse_request(const char* data, size_t len)
+{
+	RFC1035_MESSAGE *request;
+	request = rfc1035_request_unpack(data, len);
+	if (request == NULL) {
+		logger_error("unpack request error, size=%d", (int) len);
+		return NULL;
+	}
+	RFC1035_QUERY *query = request->query;
+	if (query == NULL || query->name[0] == 0) {
+		rfc1035_message_destroy(request);
+		return NULL;
+	}
+
+#if 0
+	printf(">>>ask name=%s, query type=%d, class=%d\n",
+		query->name, query->qtype, query->qclass);
+#endif
+
+	switch (query->qtype) {
+	case RFC1035_TYPE_A:
+		break;
+	case RFC1035_TYPE_AAAA:
+		break;
+	default:
+		logger_error("unsport qtype=%d, qclass=%d",
+			query->qtype, query->qclass);
+		rfc1035_message_destroy(request);
+		return NULL;
+	}
+
+	return request;
+}
+
+static size_t build_reply(const RFC1035_MESSAGE* request, char* buf, size_t size)
+{
+	ARGV* ips = argv_alloc(5);
+	argv_add(ips, "192.168.1.1", NULL);
+	argv_add(ips, "192.168.1.2", NULL);
+	argv_add(ips, "192.168.1.3", NULL);
+
+	RFC1035_REPLY reply;
+	reply.hostname = request->query->name;
+	reply.domain_root = NULL;
+	reply.dns_name = NULL;
+	reply.dns_ip = NULL;
+	reply.ips = ips;
+
+	reply.ip_type = RFC1035_TYPE_A;
+	reply.ttl = 600;
+	reply.qid = request->id;
+
+	size_t n = rfc1035_build_reply(&reply, buf, size);
+	argv_free(ips);
+	return n;
+}
+
+static void handle_pkt(acl::socket_stream& stream, const char* data, size_t len)
+{
+	RFC1035_MESSAGE* request = parse_request(data, len);
+	if (request == NULL) {
+		logger_error("parse request error");
+		return;
+	}
+
+	char buf[1024];
+	size_t ret = build_reply(request, buf, sizeof(buf));
+	rfc1035_message_destroy(request);
+	if (!ret) {
+		logger_error("build reply error");
+		return;
+	}
+
+	if (stream.write(buf, ret) == -1) {
+		logger_error("write error");
+	}
+}
+
+static void dns_server(acl::socket_stream& stream)
+{
+	char buf[1024];
+	int ret;
+
+	while (true) {
+		ret = stream.read(buf, sizeof(buf), false);
+		if (ret == -1) {
+			continue;
+		}
+		buf[ret] = 0;
+		handle_pkt(stream, buf, ret);
+	}
+}
+
+static void usage(const char *procname)
+{
+	printf("usage: %s -h [help]\r\n"
+		" -s addr\r\n"
+		, procname);
+}
+
+int main(int argc, char *argv[])
+{
+	int   ch;
+	acl::string addr("127.0.0.1:53");
+
+	while ((ch = getopt(argc, argv, "hs:")) > 0) {
+		switch (ch) {
+		case 'h':
+			usage(argv[0]);
+			return 0;
+		case 's':
+			addr = optarg;
+			break;
+		default:
+			break;
+		}
+	}
+
+	if (addr.empty()) {
+		usage(argv[0]);
+		return 0;
+	}
+
+	acl::log::stdout_open(true);
+	acl::fiber::stdout_open(true);
+
+	acl::socket_stream stream;
+	if (!stream.bind_udp(addr)) {
+		printf("bind %s error %s\r\n", addr.c_str(), acl::last_serror());
+		return 1;
+	}
+
+	go[&] {
+		dns_server(stream);
+	};
+
+	acl::fiber::schedule();
+	return 0;
+}