ICFS/sources/ui-socket.c

#define _GNU_SOURCE
#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>

#define MAX_MESSAGE_SIZE 1024

// Mutex for thread safety
static pthread_mutex_t socket_mutex = PTHREAD_MUTEX_INITIALIZER;
static int ui_socket_fd = -1; // Global socket file descriptor

int init_ui_socket(const char *filename) {
  if (!filename) {
    return -1;
  }

  // Create the socket
  ui_socket_fd = socket(AF_UNIX, SOCK_STREAM, 0);
  if (ui_socket_fd == -1) {
    perror("socket");
    return -1;
  }

  // Remove the socket file if it already exists
  if (unlink(filename) == -1 &&
      errno != ENOENT) { // ENOENT means the file does not exist, which is fine
    perror("unlink");
    close(ui_socket_fd);
    ui_socket_fd = -1;
    return -1;
  }

  // Set up the socket address structure
  struct sockaddr_un addr;
  memset(&addr, 0, sizeof(struct sockaddr_un));
  addr.sun_family = AF_UNIX;
  strncpy(addr.sun_path, filename, sizeof(addr.sun_path) - 1);

  // Bind the socket
  if (bind(ui_socket_fd, (struct sockaddr *)&addr,
           sizeof(struct sockaddr_un)) == -1) {
    perror("bind");
    close(ui_socket_fd);
    ui_socket_fd = -1;
    return -1;
  }

  // Listen for incoming connections
  if (listen(ui_socket_fd, 5) == -1) {
    perror("listen");
    close(ui_socket_fd);
    ui_socket_fd = -1;
    return -1;
  }

  return 0;
}

int ask_access(const char *filename, struct process_info pi) {
  if (!filename || ui_socket_fd == -1) {
    return -1;
  }

  // Lock the mutex for thread safety
  pthread_mutex_lock(&socket_mutex);

  int client_fd = accept(ui_socket_fd, NULL, NULL);
  if (client_fd == -1) {
    perror("accept");
    pthread_mutex_unlock(&socket_mutex);
    return -1;
  }

  // Prepare the message to send to the GUI
  char message[MAX_MESSAGE_SIZE];
  int len_filename = strlen(filename);
  int len_name = strlen(pi.name);

  snprintf(message, sizeof(message), "r%04d%s%04d%04d%s%04d", len_filename,
           filename, pi.PID, len_name, pi.name, pi.UID);

  // Send the message to the GUI
  if (send(client_fd, message, strlen(message), 0) == -1) {
    perror("send");
    close(client_fd);
    pthread_mutex_unlock(&socket_mutex);
    return -1;
  }

  // Receive the response from the GUI
  char response[2];
  if (recv(client_fd, response, sizeof(response), 0) == -1) {
    perror("recv");
    close(client_fd);
    pthread_mutex_unlock(&socket_mutex);
    return -1;
  }

  close(client_fd);
  pthread_mutex_unlock(&socket_mutex);

  // Process the response
  if (response[0] == 'a' && response[1] == 'y') {
    return 0; // Access granted
  } else if (response[0] == 'a' && response[1] == 'n') {
    return 1; // Access denied
  }

  return -1; // Invalid response
}