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+/* Copyright 1998 by the Massachusetts Institute of Technology.
+ *
+ * Permission to use, copy, modify, and distribute this
+ * software and its documentation for any purpose and without
+ * fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting
+ * documentation, and that the name of M.I.T. not be used in
+ * advertising or publicity pertaining to distribution of the
+ * software without specific, written prior permission.
+ * M.I.T. makes no representations about the suitability of
+ * this software for any purpose. It is provided "as is"
+ * without express or implied warranty.
+ */
+
+static const char rcsid[] = "$Id$";
+
+#include <sys/types.h>
+
+#ifdef WIN32
+#include "nameser.h"
+#else
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+#endif
+
+#include <stdlib.h>
+#include "ares.h"
+#include "ares_dns.h"
+#include "ares_private.h"
+
+struct qquery {
+ ares_callback callback;
+ void *arg;
+};
+
+static void qcallback(void *arg, int status, unsigned char *abuf, int alen);
+
+void ares_query(ares_channel channel, const char *name, int dnsclass,
+ int type, ares_callback callback, void *arg)
+{
+ struct qquery *qquery;
+ unsigned char *qbuf;
+ int qlen, rd, status;
+
+ /* Compose the query. */
+ rd = !(channel->flags & ARES_FLAG_NORECURSE);
+ status = ares_mkquery(name, dnsclass, type, channel->next_id, rd, &qbuf,
+ &qlen);
+ channel->next_id++;
+ if (status != ARES_SUCCESS)
+ {
+ callback(arg, status, NULL, 0);
+ return;
+ }
+
+ /* Allocate and fill in the query structure. */
+ qquery = malloc(sizeof(struct qquery));
+ if (!qquery)
+ {
+ ares_free_string(qbuf);
+ callback(arg, ARES_ENOMEM, NULL, 0);
+ return;
+ }
+ qquery->callback = callback;
+ qquery->arg = arg;
+
+ /* Send it off. qcallback will be called when we get an answer. */
+ ares_send(channel, qbuf, qlen, qcallback, qquery);
+ ares_free_string(qbuf);
+}
+
+static void qcallback(void *arg, int status, unsigned char *abuf, int alen)
+{
+ struct qquery *qquery = (struct qquery *) arg;
+ unsigned int ancount;
+ int rcode;
+
+ if (status != ARES_SUCCESS)
+ qquery->callback(qquery->arg, status, abuf, alen);
+ else
+ {
+ /* Pull the response code and answer count from the packet. */
+ rcode = DNS_HEADER_RCODE(abuf);
+ ancount = DNS_HEADER_ANCOUNT(abuf);
+
+ /* Convert errors. */
+ switch (rcode)
+ {
+ case NOERROR:
+ status = (ancount > 0) ? ARES_SUCCESS : ARES_ENODATA;
+ break;
+ case FORMERR:
+ status = ARES_EFORMERR;
+ break;
+ case SERVFAIL:
+ status = ARES_ESERVFAIL;
+ break;
+ case NXDOMAIN:
+ status = ARES_ENOTFOUND;
+ break;
+ case NOTIMP:
+ status = ARES_ENOTIMP;
+ break;
+ case REFUSED:
+ status = ARES_EREFUSED;
+ break;
+ }
+ qquery->callback(qquery->arg, status, abuf, alen);
+ }
+ free(qquery);
+}