3 /* Copyright 1998 by the Massachusetts Institute of Technology.
5 * Permission to use, copy, modify, and distribute this
6 * software and its documentation for any purpose and without
7 * fee is hereby granted, provided that the above copyright
8 * notice appear in all copies and that both that copyright
9 * notice and this permission notice appear in supporting
10 * documentation, and that the name of M.I.T. not be used in
11 * advertising or publicity pertaining to distribution of the
12 * software without specific, written prior permission.
13 * M.I.T. makes no representations about the suitability of
14 * this software for any purpose. It is provided "as is"
15 * without express or implied warranty.
20 #if defined(WIN32) && !defined(WATT32)
23 #ifdef HAVE_NETINET_IN_H
24 #include <netinet/in.h>
26 #ifdef HAVE_ARPA_NAMESER_H
27 #include <arpa/nameser.h>
29 #ifdef HAVE_ARPA_NAMESER_COMPAT_H
30 #include <arpa/nameser_compat.h>
39 #include "ares_private.h"
41 void ares_send(ares_channel channel, const unsigned char *qbuf, int qlen,
42 ares_callback callback, void *arg)
48 /* Verify that the query is at least long enough to hold the header. */
49 if (qlen < HFIXEDSZ || qlen >= (1 << 16))
51 callback(arg, ARES_EBADQUERY, 0, NULL, 0);
55 /* Allocate space for query and allocated fields. */
56 query = malloc(sizeof(struct query));
59 callback(arg, ARES_ENOMEM, 0, NULL, 0);
62 query->tcpbuf = malloc(qlen + 2);
66 callback(arg, ARES_ENOMEM, 0, NULL, 0);
69 query->server_info = malloc(channel->nservers *
70 sizeof(query->server_info[0]));
71 if (!query->server_info)
75 callback(arg, ARES_ENOMEM, 0, NULL, 0);
79 /* Compute the query ID. Start with no timeout. */
80 query->qid = (unsigned short)DNS_HEADER_QID(qbuf);
81 query->timeout.tv_sec = 0;
82 query->timeout.tv_usec = 0;
84 /* Form the TCP query buffer by prepending qlen (as two
85 * network-order bytes) to qbuf.
87 query->tcpbuf[0] = (unsigned char)((qlen >> 8) & 0xff);
88 query->tcpbuf[1] = (unsigned char)(qlen & 0xff);
89 memcpy(query->tcpbuf + 2, qbuf, qlen);
90 query->tcplen = qlen + 2;
92 /* Fill in query arguments. */
93 query->qbuf = query->tcpbuf + 2;
95 query->callback = callback;
98 /* Initialize query status. */
101 for (i = 0; i < channel->nservers; i++)
103 query->server_info[i].skip_server = 0;
104 query->server_info[i].tcp_connection_generation = 0;
106 query->using_tcp = (channel->flags & ARES_FLAG_USEVC) || qlen > PACKETSZ;
107 query->error_status = ARES_ECONNREFUSED;
110 /* Initialize our list nodes. */
111 ares__init_list_node(&(query->queries_by_qid), query);
112 ares__init_list_node(&(query->queries_by_timeout), query);
113 ares__init_list_node(&(query->queries_to_server), query);
114 ares__init_list_node(&(query->all_queries), query);
116 /* Chain the query into the list of all queries. */
117 ares__insert_in_list(&(query->all_queries), &(channel->all_queries));
118 /* Keep track of queries bucketed by qid, so we can process DNS
121 ares__insert_in_list(
122 &(query->queries_by_qid),
123 &(channel->queries_by_qid[query->qid % ARES_QID_TABLE_SIZE]));
125 /* Perform the first query action. */
127 ares__send_query(channel, query, &now);