Allow ENUM query functions to report lookup errors

The ENUM dialplan functions do not report DNS query errors properly. It is
useful to differentiate between failed query (e.g. non-existent domain) vs. no
data records of the appropriate type. This is required to make overlapped
dialing work.

(closes issue ASTERISK-13769)
Review: https://reviewboard.asterisk.org/r/1355/
Patch-by: Timo Teras


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@331201 65c4cc65-6c06-0410-ace0-fbb531ad65f3

UPGRADE.txt

@@ -22,7 +22,10 @@
 
 From 10 to 12:
 
-* No significant changes as of yet.
+func_enum:
+ - ENUM query functions now return a count of -1 on lookup error to
+   differentiate between a failed query and a successful query with 0 results
+   matching the specified type.
 
 From 1.8 to 10:
 

funcs/func_enum.c

@@ -82,7 +82,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 				<para>The number of the result that you want to retrieve.</para>
 				<para>Results start at <literal>1</literal>. If this argument is specified
 				as <literal>getnum</literal>, then it will return the total number of results 
-				that are available.</para>
+				that are available or -1 on error.</para>
 			</parameter>
 		</syntax>
 		<description>
@@ -105,7 +105,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 					<option name="c">
 						<para>Returns an integer count of the number of NAPTRs of a certain RR type.</para>
 						<para>Combination of <literal>c</literal> and Method-type of <literal>ALL</literal> will
-						return a count of all NAPTRs for the record.</para>
+						return a count of all NAPTRs for the record or -1 on error.</para>
 					</option>
 					<option name="u">
 						<para>Returns the full URI and does not strip off the URI-scheme.</para>
@@ -363,7 +363,7 @@ static int enum_result_read(struct ast_channel *chan, const char *cmd, char *dat
 	erds = datastore->data;
 
 	if (!strcasecmp(args.resultnum, "getnum")) {
-		snprintf(buf, len, "%u", erds->context->naptr_rrs_count);
+		snprintf(buf, len, "%d", erds->context->naptr_rrs_count);
 		res = 0;
 		goto finish;
 	}

main/enum.c

@@ -856,6 +856,7 @@ int ast_get_enum(struct ast_channel *chan, const char *number, char *dst, int ds
 
 	if (ret < 0) {
 		ast_debug(1, "No such number found: %s (%s)\n", tmp, strerror(errno));
+		context->naptr_rrs_count = -1;
 		strcpy(dst, "0");
 		ret = 0;
 	}
@@ -896,7 +897,7 @@ int ast_get_enum(struct ast_channel *chan, const char *number, char *dst, int ds
 	} else if (!(context->options & ENUMLOOKUP_OPTIONS_COUNT)) {
 		context->dst[0] = 0;
 	} else if ((context->options & ENUMLOOKUP_OPTIONS_COUNT)) {
-		snprintf(context->dst, context->dstlen, "%d", context->count);
+		snprintf(context->dst, context->dstlen, "%d", context->naptr_rrs_count + context->count);
 	}
 
 	if (chan) {