Fix assertion failure in parsing NSAP records from text

CHANGES

@@ -1,3 +1,6 @@
+4177.	[bug]		Fix assertion failure in parsing NSAP records from
+			text. [RT #40285]
+
 4176.	[bug]		Address race issues with lwresd. [RT #40284]
 
 4175.	[bug]		TKEY with GSS-API keys needed bigger buffers.

bin/tests/system/checkzone/zones/bad-nsap-empty.db

@@ -0,0 +1,21 @@
+; Copyright (C) 2015  Internet Systems Consortium, Inc. ("ISC")
+;
+; Permission to use, copy, modify, and/or distribute this software for any
+; purpose with or without fee is hereby granted, provided that the above
+; copyright notice and this permission notice appear in all copies.
+;
+; THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+; REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+; AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+; INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+; LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+; OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+; PERFORMANCE OF THIS SOFTWARE.
+
+$TTL 600
+@		SOA	ns hostmaster 2011012708 3600 1200 604800 1200
+		NS	ns
+ns		A	192.0.2.1
+
+; NSAP with an odd number of hex digits
+example NSAP 0x47000580005a0000000001e133ffffff000161000

bin/tests/system/checkzone/zones/bad-nsap-odd-nibble.db

@@ -0,0 +1,21 @@
+; Copyright (C) 2015  Internet Systems Consortium, Inc. ("ISC")
+;
+; Permission to use, copy, modify, and/or distribute this software for any
+; purpose with or without fee is hereby granted, provided that the above
+; copyright notice and this permission notice appear in all copies.
+;
+; THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+; REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+; AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+; INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+; LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+; OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+; PERFORMANCE OF THIS SOFTWARE.
+
+$TTL 600
+@		SOA	ns hostmaster 2011012708 3600 1200 604800 1200
+		NS	ns
+ns		A	192.0.2.1
+
+; empty NSAP address
+example NSAP 0x

bin/tests/system/checkzone/zones/good-nsap.db

@@ -0,0 +1,21 @@
+; Copyright (C) 2015  Internet Systems Consortium, Inc. ("ISC")
+;
+; Permission to use, copy, modify, and/or distribute this software for any
+; purpose with or without fee is hereby granted, provided that the above
+; copyright notice and this permission notice appear in all copies.
+;
+; THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+; REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+; AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+; INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+; LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+; OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+; PERFORMANCE OF THIS SOFTWARE.
+
+$TTL 600
+@		SOA	ns hostmaster 2011012708 3600 1200 604800 1200
+		NS	ns
+ns		A	192.0.2.1
+
+; empty NSAP address
+example NSAP 0x47.0005.80.005a00.0000....0001.e133.ffffff000162.00

lib/dns/rdata/in_1/nsap_22.c

@@ -31,7 +31,8 @@ fromtext_in_nsap(ARGS_FROMTEXT) {
 	isc_token_t token;
 	isc_textregion_t *sr;
 	int n;
-	int digits;
+	isc_boolean_t valid = ISC_FALSE;
+	int digits = 0;
 	unsigned char c = 0;
 
 	REQUIRE(type == 22);
@@ -52,7 +53,6 @@ fromtext_in_nsap(ARGS_FROMTEXT) {
 	if (sr->base[0] != '0' || (sr->base[1] != 'x' && sr->base[1] != 'X'))
 		RETTOK(DNS_R_SYNTAX);
 	isc_textregion_consume(sr, 2);
-	digits = 0;
 	while (sr->length > 0) {
 		if (sr->base[0] == '.') {
 			isc_textregion_consume(sr, 1);
@@ -64,11 +64,13 @@ fromtext_in_nsap(ARGS_FROMTEXT) {
 		c += n;
 		if (++digits == 2) {
 			RETERR(mem_tobuffer(target, &c, 1));
+			valid = ISC_TRUE;
 			digits = 0;
+			c = 0;
 		}
 		isc_textregion_consume(sr, 1);
 	}
-	if (digits)
+	if (digits != 0 || !valid)
 		RETTOK(ISC_R_UNEXPECTEDEND);
 	return (ISC_R_SUCCESS);
 }