mop3/kernel/fs/iso9660fs.c

#include <desc.h>
#include <device/device.h>
#include <devices.h>
#include <dir_entry.h>
#include <fs/def_vfs_op.h>
#include <fs/iso9660fs.h>
#include <fs/lib9660.h>
#include <fs/vfs.h>
#include <libk/std.h>
#include <libk/string.h>
#include <mm/malloc.h>
#include <proc/proc.h>
#include <proc/reschedule.h>
#include <status.h>
#include <sys/debug.h>

#define ISO9660_SECTOR_SIZE 2048

static bool iso9660fs_read_sector (l9660_fs* fs, void* buf, uint32_t sector) {
  uint64_t fd;
  struct vfs_volume* volume = fs->udata;
  struct device* back_device = volume->back_device;

  size_t sector_size;
  size_t phys_sector, phys_sector_count;
  int ret;

  spin_lock (&back_device->lock, &fd);

  ret = device_op (back_device, XDRV_GET_SECTOR_SIZE, fs->proc, fs->rctx, &fd, &sector_size);
  if (ret < 0) {
    spin_unlock (&back_device->lock, fd);
    return false;
  }

  vfs_translate (sector, 1, ISO9660_SECTOR_SIZE, sector_size, &phys_sector, &phys_sector_count);

  ret = device_op (back_device, XDRV_READ, fs->proc, fs->rctx, &fd, &phys_sector,
                   &phys_sector_count, buf);

  if (ret < 0) {
    spin_unlock (&back_device->lock, fd);
    return false;
  }

  spin_unlock (&back_device->lock, fd);

  return true;
}

static bool iso9660fs_is_cat (l9660_dirent* dirent) {
  if (dirent->name_len < 4)
    return false;

  size_t end = dirent->name_len;

  for (size_t i = 0; i < dirent->name_len; i++) {
    if (dirent->name[i] == ';') {
      end = i;
      break;
    }
  }

  if (end < 4)
    return false;

  const char* n = dirent->name;

  return (n[end - 4] == '.' &&
          (n[end - 3] == 'c' || n[end - 3] == 'C') &&
          (n[end - 2] == 'a' || n[end - 2] == 'A') &&
          (n[end - 1] == 't' || n[end - 1] == 'T'));
}

static bool iso9660fs_is_special_entry (l9660_dirent* dirent) {
  return (dirent->name_len == 1 && (dirent->name[0] == '\0' || dirent->name[0] == '\1')) ||
      iso9660fs_is_cat (dirent);
}

static void iso9660fs_copy_visible_name (char* dst, size_t dst_size, l9660_dirent* dirent) {
  size_t i = 0;

  if (dst_size == 0)
    return;

  while (i + 1 < dst_size && i < dirent->name_len) {
    if (dirent->name[i] == ';')
      break;

    dst[i] = dirent->name[i];
    i++;
  }

  dst[i] = '\0';
}

static l9660_status iso9660fs_count_dir_entries (l9660_dir* dir, size_t* count) {
  l9660_status status;
  l9660_dirent* dirent = NULL;

  *count = 0;
  status = l9660_seekdir (dir, 0);

  if (status != L9660_OK)
    return status;

  for (;;) {
    status = l9660_readdir (dir, &dirent);

    if (status != L9660_OK)
      return status;

    if (dirent == NULL)
      break;

    if (iso9660fs_is_special_entry (dirent))
      continue;

    (*count)++;
  }

  return L9660_OK;
}

DEFINE_VFS_MOUNT (iso9660fs_mount) {
  l9660_fs* fs_ctx = malloc (sizeof (*fs_ctx));

  if (fs_ctx == NULL)
    return -ST_OOM_ERROR;

  memset (fs_ctx, 0, sizeof (*fs_ctx));
  fs_ctx->udata = volume;
  volume->udata = fs_ctx;

  fs_ctx->proc = proc;
  fs_ctx->rctx = rctx;

  l9660_status status = l9660_openfs (fs_ctx, &iso9660fs_read_sector);

  if (status != L9660_OK) {
    free (fs_ctx);
    return -ST_MOUNT_ERROR;
  }

  return ST_OK;
}

DEFINE_VFS_UNMOUNT (iso9660fs_unmount) {
  l9660_fs* fs_ctx = volume->udata;

  free (fs_ctx);

  return ST_OK;
}

DEFINE_VFS_FORMAT (iso9660fs_format) { return -ST_FORMAT_ERROR; }

DEFINE_VFS_DESCRIBE (iso9660fs_describe) {
  l9660_fs* fs = volume->udata;

  fs->proc = proc;
  fs->rctx = rctx;

  l9660_status status;
  l9660_dir root_dir;
  l9660_file file;
  l9660_dir dir;

  const char* relpath = path;
  if (relpath[0] == '/')
    relpath++;

  status = l9660_fs_open_root (&root_dir, fs);

  if (status != L9660_OK)
    return -ST_NOT_FOUND;

  if (relpath[0] == '\0') {
    desc->type = FS_DIR;
    status = iso9660fs_count_dir_entries (&root_dir, &desc->size);

    if (status != L9660_OK)
      return -ST_NOT_FOUND;

    return ST_OK;
  }

  status = l9660_openat (&file, &root_dir, relpath);

  if (status == L9660_OK) {
    desc->type = FS_FILE;
    desc->size = file.length;
  } else {
    status = l9660_opendirat (&dir, &root_dir, relpath);

    if (status != L9660_OK)
      return -ST_NOT_FOUND;

    desc->type = FS_DIR;
    status = iso9660fs_count_dir_entries (&dir, &desc->size);

    if (status != L9660_OK)
      return -ST_NOT_FOUND;
  }

  return ST_OK;
}

DEFINE_VFS_READ_FILE (iso9660fs_read_file) {
  l9660_fs* fs = volume->udata;

  fs->proc = proc;
  fs->rctx = rctx;

  l9660_status status;
  l9660_dir root_dir;
  l9660_file file;

  status = l9660_fs_open_root (&root_dir, fs);

  if (status != L9660_OK)
    return -ST_NOT_FOUND;

  const char* relpath = path;
  if (relpath[0] == '/')
    relpath++;

  status = l9660_openat (&file, &root_dir, relpath);

  if (status != L9660_OK)
    return -ST_NOT_FOUND;

  status = l9660_seek (&file, L9660_SEEK_SET, off);

  if (status != L9660_OK)
    return -ST_OOB_ERROR;

  size_t n;
  status = l9660_read (&file, buffer, size, &n);

  if (status != L9660_OK)
    return -ST_XDRV_READ_ERROR;

  return ST_OK;
}

DEFINE_VFS_WRITE_FILE (iso9660fs_write_file) { return -ST_XDRV_WRITE_ERROR; }

DEFINE_VFS_READ_DIR_ENTRY (iso9660fs_read_dir_entry) {
  l9660_fs* fs = volume->udata;

  fs->proc = proc;
  fs->rctx = rctx;

  l9660_status status;
  l9660_dir root_dir;
  l9660_dir dir;
  l9660_dirent* dirent;

  const char* relpath = path;
  if (relpath[0] == '/')
    relpath++;

  status = l9660_fs_open_root (&root_dir, fs);

  if (status != L9660_OK)
    return -ST_NOT_FOUND;

  if (relpath[0] == '\0') {
    dir = root_dir;
  } else {
    status = l9660_opendirat (&dir, &root_dir, relpath);

    if (status != L9660_OK)
      return -ST_NOT_FOUND;
  }

  status = l9660_seekdir (&dir, 0);

  if (status != L9660_OK)
    return status;

  size_t ent = 0;

  for (;;) {
    status = l9660_readdir (&dir, &dirent);

    if (status != L9660_OK)
      return status;

    if (dirent == NULL)
      break;

    if (iso9660fs_is_special_entry (dirent))
      continue;

    if (ent == entry_num) {
      char namebuf[256];
      size_t out_len;

      const char* rockridge_name = l9660_get_rockridge_name (dirent, namebuf, &out_len);

      if (rockridge_name == NULL) {
        iso9660fs_copy_visible_name (namebuf, sizeof (namebuf), dirent);
      }

      entry->path[0] = '\0';

      strncat (entry->path, path, PATH_MAX - 1);

      if (strcmp (path, "/") != 0)
        strncat (entry->path, "/", PATH_MAX - strlen (entry->path) - 1);

      strncat (entry->path, namebuf, PATH_MAX - strlen (entry->path) - 1);

      break;
    }

    ent++;
  }

  return ST_OK;
}

DEFINE_VFS_CREATE_FILE (iso9660fs_create_file) { return -ST_XDRV_WRITE_ERROR; }

DEFINE_VFS_CREATE_DIR (iso9660fs_create_dir) { return -ST_XDRV_WRITE_ERROR; }

DEFINE_VFS_REMOVE (iso9660fs_remove) { return -ST_REMOVE_ERROR; }