125 строки
3.6 KiB
C
125 строки
3.6 KiB
C
/* $Id$ */
|
|
|
|
/* 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 "setup.h"
|
|
|
|
#if defined(WIN32) && !defined(WATT32)
|
|
#include "nameser.h"
|
|
#else
|
|
#include <netinet/in.h>
|
|
#include <arpa/nameser.h>
|
|
#ifdef HAVE_ARPA_NAMESER_COMPAT_H
|
|
#include <arpa/nameser_compat.h>
|
|
#endif
|
|
#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 = 0;
|
|
query->server = 0;
|
|
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);
|
|
}
|