1 /* MIT License
2 *
3 * Copyright (c) 2005 Daniel Stenberg
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a copy
6 * of this software and associated documentation files (the "Software"), to deal
7 * in the Software without restriction, including without limitation the rights
8 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9 * copies of the Software, and to permit persons to whom the Software is
10 * furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice (including the next
13 * paragraph) shall be included in all copies or substantial portions of the
14 * Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22 * SOFTWARE.
23 *
24 * SPDX-License-Identifier: MIT
25 */
26
27 #include "ares_setup.h"
28
29 #include "ares.h"
30 #include "ares_private.h"
31
ares_getsock(ares_channel_t * channel,ares_socket_t * socks,int numsocks)32 int ares_getsock(ares_channel_t *channel, ares_socket_t *socks,
33 int numsocks) /* size of the 'socks' array */
34 {
35 ares__slist_node_t *snode;
36 size_t sockindex = 0;
37 unsigned int bitmap = 0;
38 unsigned int setbits = 0xffffffff;
39
40 /* Are there any active queries? */
41 size_t active_queries;
42
43 if (channel == NULL || numsocks <= 0) {
44 return 0;
45 }
46
47 ares__channel_lock(channel);
48
49 active_queries = ares__llist_len(channel->all_queries);
50
51 for (snode = ares__slist_node_first(channel->servers); snode != NULL;
52 snode = ares__slist_node_next(snode)) {
53 struct server_state *server = ares__slist_node_val(snode);
54 ares__llist_node_t *node;
55
56 for (node = ares__llist_node_first(server->connections); node != NULL;
57 node = ares__llist_node_next(node)) {
58 const struct server_connection *conn = ares__llist_node_val(node);
59
60 if (sockindex >= (size_t)numsocks || sockindex >= ARES_GETSOCK_MAXNUM) {
61 break;
62 }
63
64 /* We only need to register interest in UDP sockets if we have
65 * outstanding queries.
66 */
67 if (!active_queries && !conn->is_tcp) {
68 continue;
69 }
70
71 socks[sockindex] = conn->fd;
72
73 if (active_queries || conn->is_tcp) {
74 bitmap |= ARES_GETSOCK_READABLE(setbits, sockindex);
75 }
76
77 if (conn->is_tcp && ares__buf_len(server->tcp_send)) {
78 /* then the tcp socket is also writable! */
79 bitmap |= ARES_GETSOCK_WRITABLE(setbits, sockindex);
80 }
81
82 sockindex++;
83 }
84 }
85
86 ares__channel_unlock(channel);
87 return (int)bitmap;
88 }
89