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 #include <netinet/in.h>
24 #include <arpa/nameser.h>
25 #ifdef HAVE_ARPA_NAMESER_COMPAT_H
26 #include <arpa/nameser_compat.h>
35 #include "ares_private.h"
37 void ares_send(ares_channel channel, const unsigned char *qbuf, int qlen,
38 ares_callback callback, void *arg)
44 /* Verify that the query is at least long enough to hold the header. */
45 if (qlen < HFIXEDSZ || qlen >= (1 << 16))
47 callback(arg, ARES_EBADQUERY, 0, NULL, 0);
51 /* Allocate space for query and allocated fields. */
52 query = malloc(sizeof(struct query));
55 callback(arg, ARES_ENOMEM, 0, NULL, 0);
58 query->tcpbuf = malloc(qlen + 2);
62 callback(arg, ARES_ENOMEM, 0, NULL, 0);
65 query->server_info = malloc(channel->nservers *
66 sizeof(query->server_info[0]));
67 if (!query->server_info)
71 callback(arg, ARES_ENOMEM, 0, NULL, 0);
75 /* Compute the query ID. Start with no timeout. */
76 query->qid = (unsigned short)DNS_HEADER_QID(qbuf);
77 query->timeout.tv_sec = 0;
78 query->timeout.tv_usec = 0;
80 /* Form the TCP query buffer by prepending qlen (as two
81 * network-order bytes) to qbuf.
83 query->tcpbuf[0] = (unsigned char)((qlen >> 8) & 0xff);
84 query->tcpbuf[1] = (unsigned char)(qlen & 0xff);
85 memcpy(query->tcpbuf + 2, qbuf, qlen);
86 query->tcplen = qlen + 2;
88 /* Fill in query arguments. */
89 query->qbuf = query->tcpbuf + 2;
91 query->callback = callback;
94 /* Initialize query status. */
97 for (i = 0; i < channel->nservers; i++)
99 query->server_info[i].skip_server = 0;
100 query->server_info[i].tcp_connection_generation = 0;
102 query->using_tcp = (channel->flags & ARES_FLAG_USEVC) || qlen > PACKETSZ;
103 query->error_status = ARES_ECONNREFUSED;
106 /* Initialize our list nodes. */
107 ares__init_list_node(&(query->queries_by_qid), query);
108 ares__init_list_node(&(query->queries_by_timeout), query);
109 ares__init_list_node(&(query->queries_to_server), query);
110 ares__init_list_node(&(query->all_queries), query);
112 /* Chain the query into the list of all queries. */
113 ares__insert_in_list(&(query->all_queries), &(channel->all_queries));
114 /* Keep track of queries bucketed by qid, so we can process DNS
117 ares__insert_in_list(
118 &(query->queries_by_qid),
119 &(channel->queries_by_qid[query->qid % ARES_QID_TABLE_SIZE]));
121 /* Perform the first query action. */
123 ares__send_query(channel, query, &now);