ICFS/src/ui-socket.c

/*
  ICFS: Interactively Controlled File System
  Copyright (C) 2024-2025  Fedir Kovalov

  This program can be distributed under the terms of the GNU GPLv2.
  See the file LICENSE.
*/

#include <stddef.h>
#include <sys/types.h>
#include <time.h>
#define _GNU_SOURCE
#include "perm_permissions_table.h"
#include "temp_permissions_table.h"
#include "ui-socket.h"
#include <errno.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>

int init_ui_socket(const char *perm_permissions_db_filename) {
  char line[256];
  FILE *fp;

  if (init_temp_permissions_table()) {
    fprintf(stderr, "Could not initialize temporary permissions table.\n");
    return 1;
  }

  if (init_perm_permissions_table(perm_permissions_db_filename)) {
    fprintf(stderr, "Could not initialize permanent permissions table.\n");
    return 1;
  }

  // Test if Zenity is installed (get version)
  fp = popen("zenity --version", "r");
  if (fp == NULL) {
    perror("Pipe returned an error");
    return 1;
  }

  while (fgets(line, sizeof(line), fp))
    printf("%s", line);
  pclose(fp);
  return 0;
}

void destroy_ui_socket() {
  destroy_temp_permissions_table();
  destroy_perm_permissions_table();
}

/**
 * Asks the user if the process should be allowed to access the file using the
 * GUI
 *
 * @param filename: The file that the process is trying to access
 * @param pi: The process information
 * @return: 0 if access is denied, 1 if access is allowed, 2 if access is
 * allowed for the runtime of the process
 */
int ask_access(const char *filename, struct process_info pi) {
  FILE *fp;
  size_t command_len =
      139 + sizeof(pid_t) * 8 + strlen(pi.name) + strlen(filename);
  char *command = (char *)malloc(command_len);
  snprintf(command, command_len,
           "zenity --question --extra-button \"Allow this time\" --title "
           "\"Allow Access?\" --text \"Allow process "
           "<tt>%s</tt> with PID <tt>%d</tt> to access <tt>%s</tt>\"",
           pi.name, pi.PID, filename);

  // Zenity Question Message Popup
  fp = popen(command, "r");
  free(command);

  if (fp == NULL) {
    perror("Pipe returned a error");
    return -1;
  }

  // if the user clicks the "Allow this time" button, `zenity` will only
  // write it to `stdout`, but the exit code will still be `1`. So, we need
  // to manually check the output.
  char buffer[1024];
  while (fgets(buffer, sizeof(buffer), fp)) {
    printf("%s", buffer);
    if (strcmp(buffer, "Allow this time\n") == 0) {
      pclose(fp);
      return 2;
    }
  }

  int zenity_exit_code = WEXITSTATUS(pclose(fp));
  fprintf(stderr, "zenity returned %d\n", zenity_exit_code);
  // zenity returns 1 on "No" >:(
  if (zenity_exit_code == 0) {
    return 1;
  }

  return 0;
}

/**
 * Check access according to:
 * 1. temp permission table
 * 2. permanent permission table
 * 3. user descision
 *
 * @param filename: The file that the process is trying to access
 * @pram pi: The process information
 * @param opts: options (GRANT_TEMP, GRANT_PERM)
 * @return: 0 if access is denied, 1 if access is allowed
 */
int interactive_access(const char *filename, struct process_info pi, int opts) {

  if (check_temp_access(filename, pi) || check_perm_access(filename, pi)) {
    // access was already granted before
    return 1;
  }

  // if noth GRANT_TEMP and GRANT_PERM are selected, then only permanent
  // permissions are granted

  if (opts & GRANT_PERM) {
    give_perm_access(filename, pi);
    return 1;
  }
  if (opts & GRANT_TEMP) {
    give_temp_access(filename, pi);
    return 1;
  }

  int user_response = ask_access(filename, pi);
  if (user_response == 1) {
    // user said "yes"
    give_perm_access(filename, pi);
    return 1;
  } else if (user_response == 2) {
    // user said "yes, but only this time"
    give_temp_access(filename, pi);
    return 1;
  }

  // otherwise "no"
  return 0;
}