/*

 * ProFTPD - FTP server daemon

 * Copyright (c) 2004-2026 The ProFTPD Project team

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, see <https://www.gnu.org/licenses/>.

 *

 * As a special exemption, The ProFTPD Project team and other respective

 * copyright holders give permission to link this program with OpenSSL, and

 * distribute the resulting executable, without including the source code for

 * OpenSSL in the source distribution.

 */

/* Children management code */

#include "conf.h"

static pool *child_pool = NULL;

static xaset_t *child_list = NULL;

static unsigned long child_listlen = 0;

static void child_list_cleanup(void *user_data) {

  child_list = NULL;

  child_listlen = 0;

}

int child_add(pid_t pid, int fd) {

  pool *p;

  pr_child_t *ch;

  /* If no child-tracking list has been allocated, create one. */

  if (child_pool == NULL) {

    child_pool = make_sub_pool(permanent_pool);

    pr_pool_tag(child_pool, "Child Pool");

  }

  if (child_list == NULL) {

    pool *list_pool;

    list_pool = make_sub_pool(child_pool);

    pr_pool_tag(list_pool, "Child List Pool");

    register_cleanup2(list_pool, NULL, child_list_cleanup);

    child_list = xaset_create(list_pool, NULL);

  }

  p = make_sub_pool(child_pool);

  pr_pool_tag(p, "child session pool");

  ch = pcalloc(p, sizeof(pr_child_t));

  ch->ch_pool = p;

  ch->ch_pid = pid;

  time(&ch->ch_when);

  ch->ch_pipefd = fd;

  ch->ch_dead = FALSE;

  xaset_insert(child_list, (xasetmember_t *) ch);

  child_listlen++;

  return 0;

}

unsigned long child_count(void) {

  return child_listlen;

}

pr_child_t *child_get(pr_child_t *ch) {

  if (ch == NULL) {

    return (pr_child_t *) child_list->xas_list;

  }

  return ch->next;

}

int child_remove(pid_t pid) {

  pr_child_t *ch;

  if (child_list == NULL) {

    errno = EPERM;

    return -1;

  }

  for (ch = (pr_child_t *) child_list->xas_list; ch; ch = ch->next) {

    if (ch->ch_pid == pid) {

      ch->ch_dead = TRUE;

      child_listlen--;

      return 0;

    }

  }

  errno = ENOENT;

  return -1;

}

void child_signal(int signo) {

  pr_child_t *ch;

  if (child_list == NULL) {

    return;

  }

  for (ch = (pr_child_t *) child_list->xas_list; ch; ch = ch->next) {

    if (kill(ch->ch_pid, signo) < 0) {

      pr_trace_msg("signal", 1, "error sending signal %d to PID %lu: %s",

        signo, (unsigned long) ch->ch_pid, strerror(errno));

    }

  }

}

void child_update(void) {

  pr_child_t *ch, *chn = NULL;

  if (child_list == NULL) {

    return;

  }

  /* Scan the child list, removing those entries marked as 'dead'. */

  for (ch = (pr_child_t *) child_list->xas_list; ch; ch = chn) {

    chn = ch->next;

    if (ch->ch_dead) {

      if (ch->ch_pipefd != -1) {

        (void) close(ch->ch_pipefd);

      }

      xaset_remove(child_list, (xasetmember_t *) ch);

      destroy_pool(ch->ch_pool);

    }

  }

  /* If the child list is empty, recover the list pool memory. */

  if (child_list->xas_list == NULL) {

    destroy_pool(child_list->pool);

    child_list = NULL;

    child_listlen = 0;

  }

}