/* 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, NULL, NULL);

  }

}

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) {

    server->tcp_conn = NULL;

  }

  ares_buf_destroy(conn->in_buf);

  ares_buf_destroy(conn->out_buf);

  /* Requeue queries to other connections */

  ares_requeue_queries(conn, requeue_status);

  ares_llist_destroy(conn->queries_to_conn);

  ares_conn_sock_state_cb_update(conn, ARES_CONN_STATE_NONE);

  ares_socket_close(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 connection has been retired for new queries, close it out once

       * idle.  Resetting the connection (and specifically the source port

       * number) can help resolve situations where packets are being dropped.

       */

      if (conn->flags & ARES_CONN_FLAG_NONEW) {

        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);

    }

  }

}