added mio_dns_rcode_to_bcstr(), mio_dns_find_client_cookie_in_msg.

deleted the cookie_verified field from mio_dns_pkt_info_t
added mio_svc_dnc_checkclientcookie()

mio/bin/t01.c

@@ -705,16 +705,20 @@ static void on_dnc_resolve(mio_svc_dnc_t* dnc, mio_dns_msg_t* reqmsg, mio_errnum
 
 
 		printf (">>>>>>>> RRDLEN = %d\n", (int)pi->_rrdlen);
-		printf (">>>>>>>> RCODE %d EDNS exist %d uplen %d version %d dnssecok %d\n", pi->hdr.rcode, pi->edns.exist, pi->edns.uplen, pi->edns.version, pi->edns.dnssecok);
+		printf (">>>>>>>> RCODE %s(%d) EDNS exist %d uplen %d version %d dnssecok %d\n", mio_dns_rcode_to_bcstr(pi->hdr.rcode), pi->hdr.rcode, pi->edns.exist, pi->edns.uplen, pi->edns.version, pi->edns.dnssecok);
 		if (pi->hdr.rcode == MIO_DNS_RCODE_BADCOOKIE)
 		{
-			/* TODO: must retry */
+			/* TODO: must retry?? there shoudl be no RRs in the payload */
 		}
 
-		if (pi->edns.cookie.client_len > 0 && !pi->edns.cookie_verified) /* TODO: do i need to check if cookie.server_len > 0? */
+		if (mio_svc_dnc_checkclientcookie(dnc, reqmsg, pi) == 0)
 		{
 			/* client cookie is bad.. */
-			printf ("CLIENT COOKIE IS BAD>>>>>>>>>>>>>>>>>>>\n");
+			printf ("CLIENT COOKIE IS BAD>>>>>>>>>>>>>>>>>>>%d\n", mio_svc_dnc_checkclientcookie(dnc, reqmsg, pi));
+		}
+		else
+		{
+			printf ("CLIENT COOKIE IS OK>>>>>>>>>>>>>>>>>>>%d\n", mio_svc_dnc_checkclientcookie(dnc, reqmsg, pi));
 		}
 
 		//if (pi->hdr.rcode != MIO_DNS_RCODE_NOERROR) goto no_data;
@@ -1003,6 +1007,11 @@ static void send_test_query (mio_t* mio, const mio_ntime_t* now, mio_tmrjob_t* j
 	{
 		printf ("resolve attempt failure ---> mailserver.manyhost.net\n");
 	}
+
+	if (!mio_svc_dnc_resolve((mio_svc_dnc_t*)job->ctx, "ns2.switch.ch", MIO_DNS_RRT_A, MIO_SVC_DNC_RESOLVE_FLAG_COOKIE, on_dnc_resolve, 0))
+	{
+		printf ("resolve attempt failure ---> ns2.switch.ch\n");
+	}
 }
 
 int main (int argc, char* argv[])
@@ -1218,8 +1227,8 @@ for (i = 0; i < 5; i++)
 	reply_tmout.nsec = 0;
 
 	//mio_bcstrtoskad (mio, "8.8.8.8:53", &servaddr);
-	//mio_bcstrtoskad (mio, "130.59.31.29:53", &servaddr); // ns2.switch.ch
+	mio_bcstrtoskad (mio, "130.59.31.29:53", &servaddr); // ns2.switch.ch
-	mio_bcstrtoskad (mio, "134.119.216.86:53", &servaddr); // ns.manyhost.net
+	//mio_bcstrtoskad (mio, "134.119.216.86:53", &servaddr); // ns.manyhost.net
 	//mio_bcstrtoskad (mio, "[fe80::c7e2:bd6e:1209:ac1b]:1153", &servaddr);
 	//mio_bcstrtoskad (mio, "[fe80::c7e2:bd6e:1209:ac1b%eno1]:1153", &servaddr);
 
@@ -1332,6 +1341,11 @@ for (i = 0; i < 5; i++)
 		{
 			printf ("resolve attempt failure ---> www.microsoft.com\n");
 		}
+
+		if (!mio_svc_dnc_resolve(dnc, "ns2.switch.ch", MIO_DNS_RRT_CNAME, MIO_SVC_DNC_RESOLVE_FLAG_COOKIE, on_dnc_resolve, 0))
+		{
+			printf ("resolve attempt failure ---> ns2.switch.ch\n");
+		}
 		
 		
 		//if (!mio_svc_dnc_resolve(dnc, "www.microsoft.com", MIO_DNS_RRT_A, MIO_SVC_DNC_RESOLVE_FLAG_BRIEF, on_dnc_resolve_brief, 0))

mio/lib/dns-cli.c

@@ -875,7 +875,7 @@ static void on_dnc_resolve (mio_svc_dnc_t* dnc, mio_dns_msg_t* reqmsg, mio_errnu
 
 		MIO_ASSERT (mio, status == MIO_ENOERR);
 
-		pi = mio_dns_make_packet_info(mio, data, dlen);
+		pi = mio_dns_make_pkt_info(mio, data, dlen);
 		if (!pi)
 		{
 			status = mio_geterrnum(mio);
@@ -885,21 +885,13 @@ static void on_dnc_resolve (mio_svc_dnc_t* dnc, mio_dns_msg_t* reqmsg, mio_errnu
 		if (resolxtn->flags & MIO_SVC_DNC_RESOLVE_FLAG_COOKIE)
 		{
 			/* ------------------------------------------------- */
-			if (pi->edns.cookie.client_len > 0)
-			{
-				if (MIO_MEMCMP(resolxtn->client_cookie, pi->edns.cookie.data.client, pi->edns.cookie.client_len) == 0)
-				{
-					pi->edns.cookie_verified = 1; /*  UGLY to set data in mio_dns_pkt_info_t */
-				}
-			}
-
 			if (pi->edns.cookie.server_len > 0)
 			{
+				/* remember the server cookie received to use it with other new requests */
 				MIO_MEMCPY (dnc->cookie.data.server, pi->edns.cookie.data.server, pi->edns.cookie.server_len);
 				dnc->cookie.server_len = pi->edns.cookie.server_len;
 			}
-	
+
-				
 #if 0
 			if (pi->hdr.rcode == MIO_DNS_RCODE_BADCOOKIE)
 			{
@@ -983,7 +975,7 @@ static void on_dnc_resolve (mio_svc_dnc_t* dnc, mio_dns_msg_t* reqmsg, mio_errnu
 	}
 
 done:
-	if (pi) mio_dns_free_packet_info(mio_svc_dnc_getmio(dnc), pi);
+	if (pi) mio_dns_free_pkt_info(mio_svc_dnc_getmio(dnc), pi);
 }
 
 mio_dns_msg_t* mio_svc_dnc_resolve (mio_svc_dnc_t* dnc, const mio_bch_t* qname, mio_dns_rrt_t qtype, int resolve_flags, mio_svc_dnc_on_resolve_t on_resolve, mio_oow_t xtnsize)
@@ -1091,6 +1083,29 @@ mio_dns_msg_t* mio_svc_dnc_resolve (mio_svc_dnc_t* dnc, const mio_bch_t* qname,
 	return reqmsg;
 }
 
+int mio_svc_dnc_checkclientcookie (mio_svc_dnc_t* dnc, mio_dns_msg_t* reqmsg, mio_dns_pkt_info_t* respi)
+{
+	mio_uint8_t xb[MIO_DNS_COOKIE_CLIENT_LEN];
+	mio_uint8_t* x;
+
+	x = mio_dns_find_client_cookie_in_msg(reqmsg, &xb);
+	if (x)
+	{
+		/* there is a client cookie in the request. */
+		if (respi->edns.cookie.client_len > 0)
+		{
+			MIO_ASSERT (dnc->mio, respi->edns.cookie.client_len == MIO_DNS_COOKIE_CLIENT_LEN);
+			return MIO_MEMCMP(x, respi->edns.cookie.data.client, MIO_DNS_COOKIE_CLIENT_LEN) == 0; /* 1 if ok, 0 if not */
+		}
+		else
+		{
+			/* no client cookie in the response - the server doesn't support cookie? */
+			return -1;
+		}
+	}
+
+	return 2; /* ok because the request doesn't include the client cookie */
+}
 
 /* TODO: upon startup, read /etc/hosts. setup inotify or find a way to detect file changes..
  *       in resolve, add an option to use entries from /etc/hosts */

mio/lib/dns.c

@@ -463,7 +463,7 @@ oops:
 	return -1;
 }
 
-mio_dns_pkt_info_t* mio_dns_make_packet_info (mio_t* mio, const mio_dns_pkt_t* pkt, mio_oow_t len)
+mio_dns_pkt_info_t* mio_dns_make_pkt_info (mio_t* mio, const mio_dns_pkt_t* pkt, mio_oow_t len)
 {
 	mio_uint16_t i;
 	mio_dns_pkt_info_t pib, * pii;
@@ -544,7 +544,7 @@ oops:
 	return MIO_NULL;
 }
 
-void mio_dns_free_packet_info (mio_t* mio, mio_dns_pkt_info_t* pi)
+void mio_dns_free_pkt_info (mio_t* mio, mio_dns_pkt_info_t* pi)
 {
 /* TODO: better management */
 	mio_freemem (mio, pi);
@@ -874,3 +874,71 @@ void mio_dns_free_msg (mio_t* mio, mio_dns_msg_t* msg)
 /* TODO: better management */
 	mio_freemem (mio, msg);
 }
+
+mio_uint8_t* mio_dns_find_client_cookie_in_msg (mio_dns_msg_t* reqmsg, mio_uint8_t (*cookie)[MIO_DNS_COOKIE_CLIENT_LEN])
+{
+	mio_dns_rrtr_t* edns_rrtr;
+	mio_dns_eopt_t* eopt;
+	mio_uint16_t rem, dlen;
+
+	/* this function doesn't check malformed packet assuming
+	 * reqmsg points to the packet message created with mio_dns_make_msg().
+	 * such a packet message must be well-formed */
+	if (reqmsg->ednsrrtroff <= 0) return MIO_NULL; /* doesn't exist */
+
+	edns_rrtr = (mio_dns_rrtr_t*)((mio_uint8_t*)mio_dns_msg_to_pkt(reqmsg) + reqmsg->ednsrrtroff);
+	rem = mio_ntoh16(edns_rrtr->dlen);
+
+	eopt = (mio_dns_eopt_t*)(edns_rrtr + 1);
+	while (rem >= MIO_SIZEOF(mio_dns_eopt_t))
+	{
+		dlen = mio_ntoh16(eopt->dlen);
+		if (eopt->code == MIO_CONST_HTON16(MIO_DNS_EOPT_COOKIE))
+		{
+			if (cookie) MIO_MEMCPY (cookie, eopt + 1, MIO_DNS_COOKIE_CLIENT_LEN);
+			return (mio_uint8_t*)(eopt + 1);
+		}
+
+		rem -= dlen;
+		eopt = (mio_dns_eopt_t*)((mio_uint8_t*)(eopt + 1) + dlen);
+	}
+
+	return MIO_NULL;
+}
+
+
+mio_bch_t* mio_dns_rcode_to_bcstr (mio_dns_rcode_t rcode)
+{
+	mio_bch_t* _errmsg[] =
+	{
+		"NOERR",
+		"FORMERR",
+		"SERVFAIL",
+		"NXDOMAIN",
+		"NOTIMPL",
+		"REFUSED",
+		"YXDOMAIN",
+		"YXRRSET",
+		"NXRRSET",
+		"NOAUTH",
+		"NOTZONE", /* 10 */
+
+		"UNKNOWNERR",
+		"UNKNOWNERR",
+		"UNKNOWNERR",
+		"UNKNOWNERR",
+		"UNKNOWNERR",
+		"UNKNOWNERR",
+
+		"BADVERS", /* 16 */
+		"BADSIG",
+		"BADTIME",
+		"BADMODE",
+		"BADNAME",
+		"BADALG",
+		"BADTRUNC",
+		"BADCOOKIE"
+	};
+
+	return rcode < MIO_COUNTOF(_errmsg)? _errmsg[rcode]: "UNKNOWNERR";
+}

mio/lib/mio-dns.h

@@ -458,7 +458,6 @@ struct mio_dns_pkt_info_t
 		mio_uint8_t  version; 
 		mio_uint8_t  dnssecok;
 		mio_dns_cookie_t cookie;
-		int cookie_verified; /* UGLY: set via mio_svc_dnc_resolve() only. mio_dns_make_packet_info() doesn't set this */
 	} edns;
 
 	mio_uint16_t qdcount; /* number of questions */
@@ -540,15 +539,27 @@ MIO_EXPORT mio_dns_msg_t* mio_svc_dnc_resolve (
 	mio_oow_t                xtnsize
 );
 
+/*
+ * -1: cookie in the request but no client cookie in the response. this may be ok or not ok depending on your policy 
+ * 0: client cookie mismatch in the request in the response
+ * 1: client cookie match in the request in the response
+ * 2: no client cookie in the requset. so it deson't case about the response 
+ */
+MIO_EXPORT int mio_svc_dnc_checkclientcookie (
+	mio_svc_dnc_t*      dnc,
+	mio_dns_msg_t*      reqmsg,
+	mio_dns_pkt_info_t* respi
+);
+
 /* ---------------------------------------------------------------- */
 
-MIO_EXPORT mio_dns_pkt_info_t* mio_dns_make_packet_info (
+MIO_EXPORT mio_dns_pkt_info_t* mio_dns_make_pkt_info (
 	mio_t*                mio,
 	const mio_dns_pkt_t*  pkt,
 	mio_oow_t             len
 );
 
-MIO_EXPORT void mio_dns_free_packet_info (
+MIO_EXPORT void mio_dns_free_pkt_info (
 	mio_t*                mio,
 	mio_dns_pkt_info_t*   pi
 );
@@ -577,6 +588,18 @@ MIO_EXPORT void mio_dns_free_msg (
 	mio_dns_msg_t*        msg
 );
 
+/* 
+ * return the pointer to the client cookie data in the packet.
+ * if cookie is not MIO_NULL, it copies the client cookie there.
+ */
+MIO_EXPORT mio_uint8_t* mio_dns_find_client_cookie_in_msg (
+	mio_dns_msg_t* reqmsg,
+	mio_uint8_t  (*cookie)[MIO_DNS_COOKIE_CLIENT_LEN]
+);
+
+MIO_EXPORT mio_bch_t* mio_dns_rcode_to_bcstr (
+	mio_dns_rcode_t rcode
+);
 
 #if defined(__cplusplus)
 }