/*
 * eset_rtp (ESET Real-time file system protection module)
 * Copyright (C) 1992-2023 ESET, spol. s r.o.
 *
 * 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 3 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/>.
 *
 * In case of any questions, you can contact us at ESET, spol. s r.o., Einsteinova 24, 851 01 Bratislava, Slovakia.
 */

#undef CONFIG_FTRACE_SYSCALLS

#include "ertp_handlers.h"
#include "ertp_debug.h"
#include "ertp_event_queue.h"
#include "ertp_ftrace_hooks.h"
#include "ertp_logs.h"

#include <linux/cred.h>
#include <linux/delay.h>
#include <linux/fdtable.h>
#include <linux/file.h>
#include <linux/namei.h>

atomic_t ertp_running_syscalls_counter = ATOMIC_INIT(0);
DECLARE_WAIT_QUEUE_HEAD(ertp_syscall_handlers_unregister_wait);

static void ertp_wait_for_running_syscalls(void) {
  msleep(500);

  atomic_dec(&ertp_running_syscalls_counter);

  ertp_pr_log(ERTP_LOG_HOOKS, "waiting for %d caught syscalls",
              atomic_read(&ertp_running_syscalls_counter));
  wait_event(ertp_syscall_handlers_unregister_wait,
             atomic_read(&ertp_running_syscalls_counter) == 0);

  msleep(500);
}

int ertp_handlers_init(void) {
  int rv;

  atomic_inc(&ertp_running_syscalls_counter);

  rv = ertp_ftrace_hooks_init();
  if (rv != 0) {
    return rv;
  }

  ertp_pr_info("registered syscall handlers");

  return 0;
}

void ertp_handlers_deinit(void) {
  ertp_ftrace_hooks_deinit();
  ertp_wait_for_running_syscalls();
  ertp_pr_info("unregistered syscall handlers");
}