--- branches/ros-branch-0_2_9/reactos/lib/dnsapi/dnsapi/query.c 2005-12-11 21:17:58 UTC (rev 20082)
+++ branches/ros-branch-0_2_9/reactos/lib/dnsapi/dnsapi/query.c 2005-12-11 21:18:32 UTC (rev 20083)
@@ -34,8 +34,10 @@
char *xstrsave(const char *str) {
char *p;
- p= RtlAllocateHeap( RtlGetProcessHeap(), 0, strlen(str)+1 );
- strcpy(p,str);
+ p = RtlAllocateHeap( RtlGetProcessHeap(), 0, strlen(str)+1 );
+ if ( NULL != p ) {
+ strcpy(p,str);
+ }
return p;
}
@@ -50,6 +52,8 @@
int quflags = 0;
int adns_error;
adns_answer *answer;
+ LPSTR CurrentName;
+ unsigned CNameLoop;
*QueryResultSet = 0;
@@ -64,31 +68,78 @@
return DnsIntTranslateAdnsToDNS_STATUS( adns_error );
}
- adns_error = adns_synchronous( astate,
- Name,
- adns_r_addr,
- quflags,
- &answer );
+ /*
+ * adns doesn't resolve chained CNAME records (a CNAME which points to
+ * another CNAME pointing to another... pointing to an A record), according
+ * to a mailing list thread the authors believe that chained CNAME records
+ * are invalid and the DNS entries should be fixed. That's a nice academic
+ * standpoint, but there certainly are chained CNAME records out there,
+ * even some fairly major ones (at the time of this writing
+ * download.mozilla.org is a chained CNAME). Everyone else seems to resolve
+ * these fine, so we should too. So we loop here to try to resolve CNAME
+ * chains ourselves. Of course, there must be a limit to protect against
+ * CNAME loops.
+ */
+
+#define CNAME_LOOP_MAX 16
+
+ CurrentName = (LPSTR) Name;
+ for ( CNameLoop = 0; CNameLoop < CNAME_LOOP_MAX; CNameLoop++ ) {
+ adns_error = adns_synchronous( astate,
+ CurrentName,
+ adns_r_addr,
+ quflags,
+ &answer );
- if( adns_error != adns_s_ok ) {
- adns_finish( astate );
- return DnsIntTranslateAdnsToDNS_STATUS( adns_error );
+ if( adns_error != adns_s_ok ) {
+ adns_finish( astate );
+ if ( CurrentName != Name ) {
+ RtlFreeHeap( CurrentName, 0, GetProcessHeap() );
+ }
+ return DnsIntTranslateAdnsToDNS_STATUS( adns_error );
+ }
+
+ if( answer && answer->rrs.addr ) {
+ if ( CurrentName != Name ) {
+ RtlFreeHeap( CurrentName, 0, GetProcessHeap() );
+ }
+ *QueryResultSet =
+ (PDNS_RECORD)RtlAllocateHeap( RtlGetProcessHeap(), 0,
+ sizeof( DNS_RECORD ) );
+ if ( NULL == *QueryResultSet ) {
+ adns_finish( astate );
+ return ERROR_OUTOFMEMORY;
+ }
+ (*QueryResultSet)->pNext = NULL;
+ (*QueryResultSet)->wType = Type;
+ (*QueryResultSet)->wDataLength = sizeof(DNS_A_DATA);
+ (*QueryResultSet)->Data.A.IpAddress =
+ answer->rrs.addr->addr.inet.sin_addr.s_addr;
+ adns_finish( astate );
+ (*QueryResultSet)->pName = xstrsave( Name );
+ return NULL != (*QueryResultSet)->pName ? ERROR_SUCCESS :
+ ERROR_OUTOFMEMORY;
+ }
+ if ( NULL == answer || adns_s_prohibitedcname != answer->status ||
+ NULL == answer->cname ) {
+ adns_finish( astate );
+ if ( CurrentName != Name ) {
+ RtlFreeHeap( CurrentName, 0, GetProcessHeap() );
+ }
+ return ERROR_FILE_NOT_FOUND;
+ }
+ if ( CurrentName != Name ) {
+ RtlFreeHeap( CurrentName, 0, GetProcessHeap() );
+ }
+ CurrentName = xstrsave( answer->cname );
+ if ( NULL == CurrentName ) {
+ adns_finish( astate );
+ return ERROR_OUTOFMEMORY;
+ }
}
-
- if( answer && answer->rrs.addr ) {
- *QueryResultSet =
- (PDNS_RECORD)RtlAllocateHeap( RtlGetProcessHeap(), 0,
- sizeof( DNS_RECORD ) );
- (*QueryResultSet)->pNext = NULL;
- (*QueryResultSet)->wType = Type;
- (*QueryResultSet)->pName = xstrsave( Name );
- (*QueryResultSet)->wDataLength = sizeof(DNS_A_DATA);
- (*QueryResultSet)->Data.A.IpAddress =
- answer->rrs.addr->addr.inet.sin_addr.s_addr;
- adns_finish( astate );
- return ERROR_SUCCESS;
- } else
- return ERROR_FILE_NOT_FOUND;
+ adns_finish( astate );
+ RtlFreeHeap( CurrentName, 0, GetProcessHeap() );
+ return ERROR_FILE_NOT_FOUND;
default:
return ERROR_OUTOFMEMORY; /* XXX arty: find a better error code. */
}