/*
 * 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.
 */

#include <linux/file.h>
#include <linux/namei.h>

#include "ertp_event_check.h"
#include "ertp_ftrace_utils.h"
#include "ertp_handlers_close.h"
#include "ertp_logs.h"
#include "ertp_path.h"

#ifdef ERTP_KERNEL_USES_SYSCALL_WRAPPER
sys_regs_t ertp_original_native_64_close;
sys_regs_t ertp_original_native_32_close;

sys_regs_t ertp_original_native_64_dup2;
sys_regs_t ertp_original_native_32_dup2;

sys_regs_t ertp_original_native_64_dup3;
sys_regs_t ertp_original_native_32_dup3;

#else

sys_close_t ertp_original_native_64_close;

sys_dup2_t ertp_original_native_64_dup2;

sys_dup3_t ertp_original_native_64_dup3;

#endif

static void check_close(unsigned int fd) {
  struct file *file = fget(fd);

  if (file) {
    ertp_check_close(file);
    fput(file);
  } else {
    ertp_pr_log(ERTP_LOG_CLOSE, "cannot get file object for file descriptor %d",
                fd);
  }
}
#ifdef ERTP_KERNEL_USES_SYSCALL_WRAPPER

asmlinkage long notrace ertp_handler_native_64_close(struct pt_regs *regs) {
  unsigned int fd = ERTP_SYSCALL64_ARG0(unsigned int, regs);
  long ret = 0;

  check_close(fd);
  ret = ertp_original_native_64_close(regs);

  ertp_handler_end();
  return ret;
}

asmlinkage long notrace ertp_handler_native_32_close(struct pt_regs *regs) {
  unsigned int fd = ERTP_SYSCALL32_ARG0(unsigned int, regs);
  long ret = 0;

  check_close(fd);
  ret = ertp_original_native_32_close(regs);

  ertp_handler_end();
  return ret;
}

#else

asmlinkage long notrace ertp_handler_native_64_close(unsigned int fd) {
  long ret;
  check_close(fd);

  ret = ertp_original_native_64_close(fd);

  ertp_handler_end();
  return ret;
}

#endif
#ifdef ERTP_KERNEL_USES_SYSCALL_WRAPPER

asmlinkage long notrace ertp_handler_native_64_dup2(struct pt_regs *regs) {
  unsigned int newfd = ERTP_SYSCALL64_ARG1(unsigned int, regs);
  long ret = 0;

  check_close(newfd);
  ret = ertp_original_native_64_dup2(regs);

  ertp_handler_end();
  return ret;
}

asmlinkage long notrace ertp_handler_native_32_dup2(struct pt_regs *regs) {
  unsigned int newfd = ERTP_SYSCALL32_ARG1(unsigned int, regs);
  long ret = 0;

  check_close(newfd);
  ret = ertp_original_native_32_dup2(regs);

  ertp_handler_end();
  return ret;
}

#else

asmlinkage long notrace ertp_handler_native_64_dup2(unsigned int oldfd,
                                                    unsigned int newfd) {
  long ret;
  check_close(newfd);

  ret = ertp_original_native_64_dup2(oldfd, newfd);

  ertp_handler_end();
  return ret;
}

#endif
#ifdef ERTP_KERNEL_USES_SYSCALL_WRAPPER

asmlinkage long notrace ertp_handler_native_64_dup3(struct pt_regs *regs) {
  unsigned int newfd = ERTP_SYSCALL64_ARG1(unsigned int, regs);
  long ret = 0;

  check_close(newfd);
  ret = ertp_original_native_64_dup3(regs);

  ertp_handler_end();
  return ret;
}

asmlinkage long notrace ertp_handler_native_32_dup3(struct pt_regs *regs) {
  unsigned int newfd = ERTP_SYSCALL32_ARG1(unsigned int, regs);
  long ret = 0;

  check_close(newfd);
  ret = ertp_original_native_32_dup3(regs);

  ertp_handler_end();
  return ret;
}

#else

asmlinkage long notrace ertp_handler_native_64_dup3(unsigned int oldfd,
                                                    unsigned int newfd,
                                                    int flags) {
  long ret;
  check_close(newfd);

  ret = ertp_original_native_64_dup3(oldfd, newfd, flags);

  ertp_handler_end();
  return ret;
}

#endif