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/* MIT License
*
* Copyright (c) 1998 Massachusetts Institute of Technology
* Copyright (c) The c-ares project and its contributors
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* SPDX-License-Identifier: MIT
*/
#include "ares_private.h"
#include <assert.h>
static void ares__requeue_queries(ares_conn_t *conn,
ares_status_t requeue_status)
{
ares_query_t *query;
ares_timeval_t now;
ares__tvnow(&now);
while ((query = ares__llist_first_val(conn->queries_to_conn)) != NULL) {
ares__requeue_query(query, &now, requeue_status, ARES_TRUE);
}
}
void ares__close_connection(ares_conn_t *conn, ares_status_t requeue_status)
{
ares_server_t *server = conn->server;
ares_channel_t *channel = server->channel;
/* Unlink */
ares__llist_node_claim(
ares__htable_asvp_get_direct(channel->connnode_by_socket, conn->fd));
ares__htable_asvp_remove(channel->connnode_by_socket, conn->fd);
if (conn->flags & ARES_CONN_FLAG_TCP) {
/* Reset any existing input and output buffer. */
ares__buf_consume(server->tcp_parser, ares__buf_len(server->tcp_parser));
ares__buf_consume(server->tcp_send, ares__buf_len(server->tcp_send));
server->tcp_conn = NULL;
}
/* Requeue queries to other connections */
ares__requeue_queries(conn, requeue_status);
ares__llist_destroy(conn->queries_to_conn);
SOCK_STATE_CALLBACK(channel, conn->fd, 0, 0);
ares__close_socket(channel, conn->fd);
ares_free(conn);
}
void ares__close_sockets(ares_server_t *server)
{
ares__llist_node_t *node;
while ((node = ares__llist_node_first(server->connections)) != NULL) {
ares_conn_t *conn = ares__llist_node_val(node);
ares__close_connection(conn, ARES_SUCCESS);
}
}
void ares__check_cleanup_conns(const ares_channel_t *channel)
{
ares__slist_node_t *snode;
if (channel == NULL) {
return; /* LCOV_EXCL_LINE: DefensiveCoding */
}
/* Iterate across each server */
for (snode = ares__slist_node_first(channel->servers); snode != NULL;
snode = ares__slist_node_next(snode)) {
ares_server_t *server = ares__slist_node_val(snode);
ares__llist_node_t *cnode;
/* Iterate across each connection */
cnode = ares__llist_node_first(server->connections);
while (cnode != NULL) {
ares__llist_node_t *next = ares__llist_node_next(cnode);
ares_conn_t *conn = ares__llist_node_val(cnode);
ares_bool_t do_cleanup = ARES_FALSE;
cnode = next;
/* Has connections, not eligible */
if (ares__llist_len(conn->queries_to_conn)) {
continue;
}
/* If we are configured not to stay open, close it out */
if (!(channel->flags & ARES_FLAG_STAYOPEN)) {
do_cleanup = ARES_TRUE;
}
/* If the associated server has failures, close it out. Resetting the
* connection (and specifically the source port number) can help resolve
* situations where packets are being dropped.
*/
if (conn->server->consec_failures > 0) {
do_cleanup = ARES_TRUE;
}
/* If the udp connection hit its max queries, always close it */
if (!(conn->flags & ARES_CONN_FLAG_TCP) && channel->udp_max_queries > 0 &&
conn->total_queries >= channel->udp_max_queries) {
do_cleanup = ARES_TRUE;
}
if (!do_cleanup) {
continue;
}
/* Clean it up */
ares__close_connection(conn, ARES_SUCCESS);
}
}
}
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