1 /* MIT License
2 *
3 * Copyright (c) 1998 Massachusetts Institute of Technology
4 * Copyright (c) The c-ares project and its contributors
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the next
14 * paragraph) shall be included in all copies or substantial portions of the
15 * Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE.
24 *
25 * SPDX-License-Identifier: MIT
26 */
27
28 #include "ares_setup.h"
29
30 #include "ares.h"
31 #include "ares_private.h"
32 #include <assert.h>
33
ares__requeue_queries(struct server_connection *conn)34 static void ares__requeue_queries(struct server_connection *conn)
35 {
36 struct query *query;
37 struct timeval now = ares__tvnow();
38
39 while ((query = ares__llist_first_val(conn->queries_to_conn)) != NULL) {
40 ares__requeue_query(query, &now);
41 }
42 }
43
ares__close_connection(struct server_connection *conn)44 void ares__close_connection(struct server_connection *conn)
45 {
46 struct server_state *server = conn->server;
47 ares_channel_t *channel = server->channel;
48
49 /* Unlink */
50 ares__llist_node_claim(
51 ares__htable_asvp_get_direct(channel->connnode_by_socket, conn->fd));
52 ares__htable_asvp_remove(channel->connnode_by_socket, conn->fd);
53
54 if (conn->is_tcp) {
55 /* Reset any existing input and output buffer. */
56 ares__buf_consume(server->tcp_parser, ares__buf_len(server->tcp_parser));
57 ares__buf_consume(server->tcp_send, ares__buf_len(server->tcp_send));
58 server->tcp_conn = NULL;
59 }
60
61 /* Requeue queries to other connections */
62 ares__requeue_queries(conn);
63
64 ares__llist_destroy(conn->queries_to_conn);
65
66 SOCK_STATE_CALLBACK(channel, conn->fd, 0, 0);
67 ares__close_socket(channel, conn->fd);
68
69 ares_free(conn);
70 }
71
ares__close_sockets(struct server_state *server)72 void ares__close_sockets(struct server_state *server)
73 {
74 ares__llist_node_t *node;
75
76 while ((node = ares__llist_node_first(server->connections)) != NULL) {
77 struct server_connection *conn = ares__llist_node_val(node);
78 ares__close_connection(conn);
79 }
80 }
81
ares__check_cleanup_conn(const ares_channel_t *channel, struct server_connection *conn)82 void ares__check_cleanup_conn(const ares_channel_t *channel,
83 struct server_connection *conn)
84 {
85 ares_bool_t do_cleanup = ARES_FALSE;
86
87 if (channel == NULL || conn == NULL) {
88 return;
89 }
90
91 if (ares__llist_len(conn->queries_to_conn)) {
92 return;
93 }
94
95 /* If we are configured not to stay open, close it out */
96 if (!(channel->flags & ARES_FLAG_STAYOPEN)) {
97 do_cleanup = ARES_TRUE;
98 }
99
100 /* If the udp connection hit its max queries, always close it */
101 if (!conn->is_tcp && channel->udp_max_queries > 0 &&
102 conn->total_queries >= channel->udp_max_queries) {
103 do_cleanup = ARES_TRUE;
104 }
105
106 if (!do_cleanup) {
107 return;
108 }
109
110 ares__close_connection(conn);
111 }
112