Implemented GUI with zenity

Now the program is completely functional and is using zenity dialogues.
`sources` directory was renamed to `src`. UI related stuff was moved to
`src/gui/ui`.

Makefile

@@ -19,7 +19,7 @@ else
 	LDFLAGS +=
 endif
 
-SOURCES_DIR := ./sources
+SOURCES_DIR := ./src
 BUILD_DIR := ./build
 
 build: $(BUILD_DIR)/main.o $(BUILD_DIR)/sourcefs.o $(BUILD_DIR)/ui-socket.o

sources/ui-socket.c

@@ -1,116 +0,0 @@
-#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
-}

src/main.c

@@ -357,6 +357,28 @@ static int xmp_utimens(const char *path, const struct timespec ts[2],
 }
 #endif
 
+// TODO: move this to other file
+const char *get_process_name_by_pid(const int pid) {
+  char *name = (char *)calloc(1024, sizeof(char));
+  if (name) {
+    sprintf(name, "/proc/%d/cmdline", pid);
+    FILE *f = fopen(name, "r");
+    if (f) {
+      size_t size;
+      size = fread(name, sizeof(char), 1024, f);
+      if (size > 0) {
+        if ('\n' == name[size - 1])
+          name[size - 1] = '\0';
+      }
+      fclose(f);
+    }
+  }
+  return name;
+}
+
+// TODO: move this somewhere else
+const char *real_filename(const char *filename) { return filename; }
+
 static int xmp_create(const char *path, mode_t mode,
                       struct fuse_file_info *fi) {
   int fd;
@@ -367,9 +389,16 @@ static int xmp_create(const char *path, mode_t mode,
 
   pi.PID = fc->pid;
   pi.UID = fc->uid;
-  pi.name = "";
+  pi.name = get_process_name_by_pid(pi.PID);
 
-  printf("%d", ask_access(path, pi));
+  // fprintf(stderr, "%s, %d\n", path, ask_access(path, pi));
+
+  if (ask_access(real_filename(path), pi)) {
+    free(pi.name);
+    return -EACCES;
+  }
+
+  free(pi.name);
 
   fd = source_create(path, fi->flags, mode);
   if (fd == -1)
@@ -388,9 +417,15 @@ static int xmp_open(const char *path, struct fuse_file_info *fi) {
 
   pi.PID = fc->pid;
   pi.UID = fc->uid;
-  pi.name = "";
+  pi.name = get_process_name_by_pid(pi.PID);
 
-  printf("%d", ask_access(path, pi));
+  // fprintf(stderr, "%s, %d\n", path, ask_access(path, pi));
+  if (ask_access(real_filename(path), pi)) {
+    free(pi.name);
+    return -EACCES;
+  }
+
+  free(pi.name);
 
   fd = source_open(path, fi->flags);
   if (fd == -1)
@@ -694,5 +729,7 @@ int main(int argc, char *argv[]) {
     exit(EXIT_FAILURE);
   }
 
-  return fuse_main(argc, argv, &xmp_oper, NULL);
+  ret = fuse_main(argc, argv, &xmp_oper, NULL);
+  free(mountpoint);
+  return ret;
 }

src/sourcefs.c

@@ -13,7 +13,7 @@ static struct source_files_handle {
   int root_fd;
 } handle;
 
-const char *source_fname_translate(const char *filename) {
+const char *source_filename_translate(const char *filename) {
   if (strcmp("/", filename) == 0) {
     return ".";
   } else {
@@ -34,32 +34,32 @@ int source_init(const char *root_path) {
 }
 
 int source_mkdir(const char *filename, mode_t mode) {
-  const char *relative_filename = source_fname_translate(filename);
+  const char *relative_filename = source_filename_translate(filename);
   return mkdirat(handle.root_fd, relative_filename, mode);
 }
 
 int source_unlink(const char *filename) {
-  const char *relative_filename = source_fname_translate(filename);
+  const char *relative_filename = source_filename_translate(filename);
   return unlinkat(handle.root_fd, relative_filename, 0);
 }
 
 int source_stat(const char *restrict filename, struct stat *restrict statbuf) {
-  const char *relative_filename = source_fname_translate(filename);
+  const char *relative_filename = source_filename_translate(filename);
   return fstatat(handle.root_fd, relative_filename, statbuf, 0);
 }
 
 int source_rmdir(const char *filename) {
-  const char *relative_filename = source_fname_translate(filename);
+  const char *relative_filename = source_filename_translate(filename);
   return unlinkat(handle.root_fd, relative_filename, AT_REMOVEDIR);
 }
 
 int source_symlink(const char *target, const char *linkpath) {
-  const char *relative_linkpath = source_fname_translate(linkpath);
+  const char *relative_linkpath = source_filename_translate(linkpath);
   return symlinkat(target, handle.root_fd, relative_linkpath);
 }
 
 DIR *source_opendir(const char *filename) {
-  const char *relative_filename = source_fname_translate(filename);
+  const char *relative_filename = source_filename_translate(filename);
   int fd = openat(handle.root_fd, relative_filename, NULL);
   if (fd < 0) {
     perror("Openat failed");
@@ -70,33 +70,33 @@ DIR *source_opendir(const char *filename) {
 }
 
 int source_rename(const char *oldpath, const char *newpath) {
-  const char *relative_oldpath = source_fname_translate(oldpath);
-  const char *relative_newpath = source_fname_translate(newpath);
+  const char *relative_oldpath = source_filename_translate(oldpath);
+  const char *relative_newpath = source_filename_translate(newpath);
   return renameat(handle.root_fd, relative_oldpath, handle.root_fd,
                   relative_newpath);
 }
 
 int source_link(const char *oldpath, const char *newpath) {
-  const char *relative_oldpath = source_fname_translate(oldpath);
-  const char *relative_newpath = source_fname_translate(newpath);
+  const char *relative_oldpath = source_filename_translate(oldpath);
+  const char *relative_newpath = source_filename_translate(newpath);
   return linkat(handle.root_fd, relative_oldpath, handle.root_fd,
                 relative_newpath, 0);
   // NOTE: perhaps the flags here need to be reevaluated.
 }
 
 int source_chmod(const char *filename, mode_t mode) {
-  const char *relative_filename = source_fname_translate(filename);
+  const char *relative_filename = source_filename_translate(filename);
   return fchmodat(handle.root_fd, relative_filename, mode, 0);
   // NOTE: perhaps the flags here need to be reevaluated.
 }
 
 int source_chown(const char *filename, uid_t owner, gid_t group) {
-  const char *relative_filename = source_fname_translate(filename);
+  const char *relative_filename = source_filename_translate(filename);
   return fchownat(handle.root_fd, filename, owner, group, AT_SYMLINK_NOFOLLOW);
 }
 
 int source_truncate(const char *filename, off_t length) {
-  const char *relative_filename = source_fname_translate(filename);
+  const char *relative_filename = source_filename_translate(filename);
   int fd = openat(handle.root_fd, relative_filename, NULL);
   if (fd < 0) {
     perror("Openat failed");
@@ -106,11 +106,11 @@ int source_truncate(const char *filename, off_t length) {
 }
 
 int source_open(const char *filename, int flags) {
-  const char *relative_filename = source_fname_translate(filename);
+  const char *relative_filename = source_filename_translate(filename);
   return openat(handle.root_fd, relative_filename, flags);
 }
 
 int source_create(const char *filename, int flags, mode_t mode) {
-  const char *relative_filename = source_fname_translate(filename);
+  const char *relative_filename = source_filename_translate(filename);
   return openat(handle.root_fd, relative_filename, flags, mode);
 }

src/ui-socket.c

@@ -0,0 +1,56 @@
+#include <stddef.h>
+#include <sys/types.h>
+#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>
+
+int init_ui_socket(const char *filename) {
+  char line[256];
+  FILE *fp;
+
+  // Test if Zenity is installed (get version)
+  fp = popen("zenity --version", "r");
+  if (fp == NULL) {
+    perror("Pipe returned a error");
+    return 1;
+  } else {
+    while (fgets(line, sizeof(line), fp))
+      printf("%s", line);
+    pclose(fp);
+    return 0;
+  }
+}
+
+/*
+ * This function is called from the FUSE operations functions. Those are called
+ * from separate threads. Therefore, there can be multiple threads that try to
+ * ask for access at the same time, but we have to
+ */
+
+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 --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;
+  } else {
+    return WEXITSTATUS(pclose(fp));
+  }
+}

src/ui-socket.h

@@ -17,8 +17,6 @@ struct process_info {
 // For default socket location, set socket_path = NULL.
 int init_ui_socket(const char *socket_path);
 
-// TODO: design an interface for asking user for permission.
-
 int ask_access(const char *filename, struct process_info pi);
 
 #endif // !UI_SOCKET_H