From: Michael Sawyer <source@isc.org>
Date: Fri, 13 Oct 2000 17:54:00 +0000 (+0000)
Subject: Add +besteffort option to dig (on by default) which will cause the
X-Git-Tag: v9.0.1^4~49
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=233514c1da6c51f056dad8bd2c8a82deea5ce3ef;p=thirdparty%2Fbind9.git

Add +besteffort option to dig (on by default) which will cause the
message parser to accept somewhat malformed packets.
---

diff --git a/bin/dig/dig.c b/bin/dig/dig.c
index fb5cf0e5833..dc34a05bb36 100644
--- a/bin/dig/dig.c
+++ b/bin/dig/dig.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: dig.c,v 1.111 2000/10/11 17:44:00 mws Exp $ */
+/* $Id: dig.c,v 1.112 2000/10/13 17:53:57 mws Exp $ */
 
 #include <config.h>
 #include <stdlib.h>
@@ -161,6 +161,7 @@ show_usage(void) {
 "                 +[no]ignore         (Don't revert to TCP for TC responses.)"
 "\n"
 "                 +[no]fail           (Don't try next server on SERVFAIL)\n"
+"                 +[no]besteffort     (Try and parse even illegal messages)\n"
 "                 +[no]aaonly         (Set AA flag in query)\n"
 "                 +[no]adflag         (Set AD flag in query)\n"
 "                 +[no]cdflag         (Set CD flag in query)\n"
@@ -638,16 +639,25 @@ plus_option(char *option, isc_boolean_t is_batchfile,
 			goto invalid_option;
 		}
 		break;
-	case 'b': /* bufsize */
-		if (value == NULL)
-			goto need_value;
-		if (!state)
+	case 'b':
+		switch (tolower(cmd[1])) {
+		case 'e':/* besteffort */
+			lookup->besteffort = state;
+			break;
+		case 'u':/* bufsize */
+			if (value == NULL)
+				goto need_value;
+			if (!state)
+				goto invalid_option;
+			lookup->udpsize = atoi(value);
+			if (lookup->udpsize <= 0)
+				lookup->udpsize = 0;
+			if (lookup->udpsize > COMMSIZE)
+				lookup->udpsize = COMMSIZE;
+			break;
+		default:
 			goto invalid_option;
-		lookup->udpsize = atoi(value);
-		if (lookup->udpsize <= 0)
-			lookup->udpsize = 0;
-		if (lookup->udpsize > COMMSIZE)
-			lookup->udpsize = COMMSIZE;
+		}
 		break;
 	case 'c':
 		switch (tolower(cmd[1])) {
diff --git a/bin/dig/dighost.c b/bin/dig/dighost.c
index 9871e928520..eac7dc65ace 100644
--- a/bin/dig/dighost.c
+++ b/bin/dig/dighost.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: dighost.c,v 1.143 2000/10/12 01:16:12 bwelling Exp $ */
+/* $Id: dighost.c,v 1.144 2000/10/13 17:53:58 mws Exp $ */
 
 /*
  * Notice to programmers:  Do not use this code as an example of how to
@@ -301,6 +301,7 @@ make_empty_lookup(void) {
 	looknew->identify = ISC_FALSE;
 	looknew->ignore = ISC_FALSE;
 	looknew->servfail_stops = ISC_FALSE;
+	looknew->besteffort = ISC_TRUE;
 	looknew->udpsize = 0;
 	looknew->recurse = ISC_TRUE;
 	looknew->aaonly = ISC_FALSE;
@@ -357,6 +358,7 @@ clone_lookup(dig_lookup_t *lookold, isc_boolean_t servers) {
 	looknew->identify = lookold->identify;
 	looknew->ignore = lookold->ignore;
 	looknew->servfail_stops = lookold->servfail_stops;
+	looknew->besteffort = lookold->besteffort;
 	looknew->udpsize = lookold->udpsize;
 	looknew->recurse = lookold->recurse;
         looknew->aaonly = lookold->aaonly;
@@ -2238,9 +2240,15 @@ recv_done(isc_task_t *task, isc_event_t *event) {
 			l->msgcounter++;
 		}
 		debug("before parse starts");
-		result = dns_message_parse(msg, b,
+		if (l->besteffort)
+			result = dns_message_parse(msg, b,
+					   DNS_MESSAGEPARSE_PRESERVEORDER
+					   |DNS_MESSAGEPARSE_BESTEFFORT);
+		else
+			result = dns_message_parse(msg, b,
 					   DNS_MESSAGEPARSE_PRESERVEORDER);
-		if (result != ISC_R_SUCCESS) {
+		if (result != ISC_R_SUCCESS && 
+		    result != DNS_R_RECOVERABLE ) {
 			printf(";; Got bad packet: %s\n",
 			       dns_result_totext(result));
 			hex_dump(b);
@@ -2253,6 +2261,9 @@ recv_done(isc_task_t *task, isc_event_t *event) {
 			UNLOCK_LOOKUP;
 			return;
 		}
+		if (result == DNS_R_RECOVERABLE)
+			printf(";; Warning: Message parser reports malformed "
+			       "message packet.\n");
 		if (((msg->flags & DNS_MESSAGEFLAG_TC) != 0) 
 		    && ! l->ignore && !l->tcp_mode) {
 			printf(";; Truncated, retrying in TCP mode.\n");
diff --git a/bin/dig/include/dig/dig.h b/bin/dig/include/dig/dig.h
index a7ac8a1d635..98b87162d9d 100644
--- a/bin/dig/include/dig/dig.h
+++ b/bin/dig/include/dig/dig.h
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: dig.h,v 1.52 2000/10/11 17:44:03 mws Exp $ */
+/* $Id: dig.h,v 1.53 2000/10/13 17:54:00 mws Exp $ */
 
 #ifndef DIG_H
 #define DIG_H
@@ -95,7 +95,8 @@ struct dig_lookup {
 		section_authority,
 		section_additional,
 		servfail_stops,
-		new_search;
+		new_search,
+		besteffort;
 	char textname[MXNAME]; /* Name we're going to be looking up */
 	char cmdline[MXNAME];
 	dns_rdatatype_t rdtype;