summaryrefslogtreecommitdiff
path: root/ares_send.c
diff options
context:
space:
mode:
authorAnas Nashif <anas.nashif@intel.com>2012-10-30 20:54:38 (GMT)
committerAnas Nashif <anas.nashif@intel.com>2012-10-30 20:54:38 (GMT)
commitb8e6c26b7b9608dffc84645f17fe4cf534af18dd (patch)
tree61d9fff2984aa043471a1c305cfc4c76d7a099fb /ares_send.c
downloadc-ares-b8e6c26b7b9608dffc84645f17fe4cf534af18dd.zip
c-ares-b8e6c26b7b9608dffc84645f17fe4cf534af18dd.tar.gz
c-ares-b8e6c26b7b9608dffc84645f17fe4cf534af18dd.tar.bz2
Imported Upstream version 1.7.5upstream/1.7.5
Diffstat (limited to 'ares_send.c')
-rw-r--r--ares_send.c134
1 files changed, 134 insertions, 0 deletions
diff --git a/ares_send.c b/ares_send.c
new file mode 100644
index 0000000..37b0704
--- /dev/null
+++ b/ares_send.c
@@ -0,0 +1,134 @@
+
+/* 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.
+ */
+
+#include "ares_setup.h"
+
+#ifdef HAVE_SYS_SOCKET_H
+# include <sys/socket.h>
+#endif
+#ifdef HAVE_NETINET_IN_H
+# include <netinet/in.h>
+#endif
+#ifdef HAVE_ARPA_NAMESER_H
+# include <arpa/nameser.h>
+#else
+# include "nameser.h"
+#endif
+#ifdef HAVE_ARPA_NAMESER_COMPAT_H
+# include <arpa/nameser_compat.h>
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include "ares.h"
+#include "ares_dns.h"
+#include "ares_private.h"
+
+void ares_send(ares_channel channel, const unsigned char *qbuf, int qlen,
+ ares_callback callback, void *arg)
+{
+ struct query *query;
+ int i;
+ struct timeval now;
+
+ /* Verify that the query is at least long enough to hold the header. */
+ if (qlen < HFIXEDSZ || qlen >= (1 << 16))
+ {
+ callback(arg, ARES_EBADQUERY, 0, NULL, 0);
+ return;
+ }
+
+ /* Allocate space for query and allocated fields. */
+ query = malloc(sizeof(struct query));
+ if (!query)
+ {
+ callback(arg, ARES_ENOMEM, 0, NULL, 0);
+ return;
+ }
+ query->tcpbuf = malloc(qlen + 2);
+ if (!query->tcpbuf)
+ {
+ free(query);
+ callback(arg, ARES_ENOMEM, 0, NULL, 0);
+ return;
+ }
+ query->server_info = malloc(channel->nservers *
+ sizeof(query->server_info[0]));
+ if (!query->server_info)
+ {
+ free(query->tcpbuf);
+ free(query);
+ callback(arg, ARES_ENOMEM, 0, NULL, 0);
+ return;
+ }
+
+ /* Compute the query ID. Start with no timeout. */
+ query->qid = (unsigned short)DNS_HEADER_QID(qbuf);
+ query->timeout.tv_sec = 0;
+ query->timeout.tv_usec = 0;
+
+ /* Form the TCP query buffer by prepending qlen (as two
+ * network-order bytes) to qbuf.
+ */
+ query->tcpbuf[0] = (unsigned char)((qlen >> 8) & 0xff);
+ query->tcpbuf[1] = (unsigned char)(qlen & 0xff);
+ memcpy(query->tcpbuf + 2, qbuf, qlen);
+ query->tcplen = qlen + 2;
+
+ /* Fill in query arguments. */
+ query->qbuf = query->tcpbuf + 2;
+ query->qlen = qlen;
+ query->callback = callback;
+ query->arg = arg;
+
+ /* Initialize query status. */
+ query->try_count = 0;
+
+ /* Choose the server to send the query to. If rotation is enabled, keep track
+ * of the next server we want to use. */
+ query->server = channel->last_server;
+ if (channel->rotate == 1)
+ channel->last_server = (channel->last_server + 1) % channel->nservers;
+
+ for (i = 0; i < channel->nservers; i++)
+ {
+ query->server_info[i].skip_server = 0;
+ query->server_info[i].tcp_connection_generation = 0;
+ }
+ query->using_tcp = (channel->flags & ARES_FLAG_USEVC) || qlen > PACKETSZ;
+ query->error_status = ARES_ECONNREFUSED;
+ query->timeouts = 0;
+
+ /* Initialize our list nodes. */
+ ares__init_list_node(&(query->queries_by_qid), query);
+ ares__init_list_node(&(query->queries_by_timeout), query);
+ ares__init_list_node(&(query->queries_to_server), query);
+ ares__init_list_node(&(query->all_queries), query);
+
+ /* Chain the query into the list of all queries. */
+ ares__insert_in_list(&(query->all_queries), &(channel->all_queries));
+ /* Keep track of queries bucketed by qid, so we can process DNS
+ * responses quickly.
+ */
+ ares__insert_in_list(
+ &(query->queries_by_qid),
+ &(channel->queries_by_qid[query->qid % ARES_QID_TABLE_SIZE]));
+
+ /* Perform the first query action. */
+ now = ares__tvnow();
+ ares__send_query(channel, query, &now);
+}