+ int fd, r, is_dev;
+ char buf[GUESTFS_MAX_CHUNK_SIZE];
+
+ is_dev = STRPREFIX (filename, "/dev/");
+
+ if (!is_dev) CHROOT_IN;
+ fd = open (filename, O_RDONLY);
+ if (!is_dev) CHROOT_OUT;
+ if (fd == -1) {
+ reply_with_perror ("%s", filename);
+ return -1;
+ }
+
+ /* Calculate the size of the file or device for notification messages. */
+ uint64_t total, sent = 0;
+ if (!is_dev) {
+ struct stat statbuf;
+ if (fstat (fd, &statbuf) == -1) {
+ reply_with_perror ("%s", filename);
+ close (fd);
+ return -1;
+ }
+ total = statbuf.st_size;
+ } else {
+ int64_t size = do_blockdev_getsize64 (filename);
+ if (size == -1) {
+ /* do_blockdev_getsize64 has already sent a reply. */
+ close (fd);
+ return -1;
+ }
+ total = (uint64_t) size;
+ }
+
+ /* Now we must send the reply message, before the file contents. After
+ * this there is no opportunity in the protocol to send any error
+ * message back. Instead we can only cancel the transfer.
+ */
+ reply (NULL, NULL);
+
+ while ((r = read (fd, buf, sizeof buf)) > 0) {
+ if (send_file_write (buf, r) < 0) {
+ close (fd);
+ return -1;
+ }
+
+ sent += r;
+ notify_progress (sent, total);
+ }
+
+ if (r == -1) {
+ perror (filename);
+ send_file_end (1); /* Cancel. */
+ close (fd);
+ return -1;
+ }
+
+ if (close (fd) == -1) {
+ perror (filename);
+ send_file_end (1); /* Cancel. */
+ return -1;
+ }
+
+ if (send_file_end (0)) /* Normal end of file. */
+ return -1;
+
+ return 0;