srv_lookup: Portability fixes, handle compressed responses

srv_lookup works on cygwin and openbsd now.

Provide ns_initparse, friends, and types where they aren't provided by
platform.

Use dn_expandname instead of custom parser so compressed DNS responses
are handled correctly.

1 files changed, 10 insertions, 17 deletions

diff --git a/lib/misc.c b/lib/misc.c
index 2506e291..f1da03cb 100644
--- a/lib/misc.c
+++ b/lib/misc.c
@@ -524,7 +524,7 @@ struct ns_srv_reply **srv_lookup( char *service, char *protocol, char *domain )
 	const unsigned char *buf;
 	ns_msg nsh;
 	ns_rr rr;
-	int i, n, len, size;
+	int n, len, size;
 	
 	g_snprintf( name, sizeof( name ), "_%s._%s.%s", service, protocol, domain );
 	
@@ -537,27 +537,20 @@ struct ns_srv_reply **srv_lookup( char *service, char *protocol, char *domain )
 	n = 0;
 	while( ns_parserr( &nsh, ns_s_an, n, &rr ) == 0 )
 	{
-		size = ns_rr_rdlen( rr );
+		char name[NS_MAXDNAME];
+
+		if( ns_rr_rdlen( rr ) < 7)
+		    break;
+
 		buf = ns_rr_rdata( rr );
 		
-		len = 0;
-		for( i = 6; i < size && buf[i]; i += buf[i] + 1 )
-			len += buf[i] + 1;
-		
-		if( i > size )
+		if( dn_expand(querybuf, querybuf + size, &buf[6], name, NS_MAXDNAME) == -1 )
 			break;
+
+		len = strlen(name) + 1;
 		
 		reply = g_malloc( sizeof( struct ns_srv_reply ) + len );
-		memcpy( reply->name, buf + 7, len );
-		
-		for( i = buf[6]; i < len && buf[7+i]; i += buf[7+i] + 1 )
-			reply->name[i] = '.';
-		
-		if( i > len )
-		{
-			g_free( reply );
-			break;
-		}
+		memcpy( reply->name, name, len );
 		
 		reply->prio = ( buf[0] << 8 ) | buf[1];
 		reply->weight = ( buf[2] << 8 ) | buf[3];