+
+/* Receive file chunks, repeatedly calling 'cb'. */
+int
+receive_file (receive_cb cb, void *opaque)
+{
+ guestfs_chunk chunk;
+ char lenbuf[4];
+ char *buf;
+ XDR xdr;
+ int r;
+ uint32_t len;
+
+ for (;;) {
+ /* Read the length word. */
+ xread (sock, lenbuf, 4);
+ xdrmem_create (&xdr, lenbuf, 4, XDR_DECODE);
+ xdr_uint32_t (&xdr, &len);
+ xdr_destroy (&xdr);
+
+ if (len == GUESTFS_CANCEL_FLAG)
+ continue; /* Just ignore it. */
+
+ if (len > GUESTFS_MESSAGE_MAX) {
+ fprintf (stderr, "guestfsd: incoming message is too long (%u bytes)\n",
+ len);
+ exit (1);
+ }
+
+ buf = malloc (len);
+ if (!buf) {
+ perror ("malloc");
+ return -1;
+ }
+
+ xread (sock, buf, len);
+
+ xdrmem_create (&xdr, buf, len, XDR_DECODE);
+ memset (&chunk, 0, sizeof chunk);
+ if (!xdr_guestfs_chunk (&xdr, &chunk)) {
+ xdr_destroy (&xdr);
+ free (buf);
+ return -1;
+ }
+ xdr_destroy (&xdr);
+ free (buf);
+
+ if (verbose)
+ printf ("receive_file: got chunk: cancel = %d, len = %d, buf = %p\n",
+ chunk.cancel, chunk.data.data_len, chunk.data.data_val);
+
+ if (chunk.cancel) {
+ fprintf (stderr, "receive_file: received cancellation from library\n");
+ xdr_free ((xdrproc_t) xdr_guestfs_chunk, (char *) &chunk);
+ return -2;
+ }
+ if (chunk.data.data_len == 0) {
+ xdr_free ((xdrproc_t) xdr_guestfs_chunk, (char *) &chunk);
+ return 0; /* end of file */
+ }
+
+ if (cb)
+ r = cb (opaque, chunk.data.data_val, chunk.data.data_len);
+ else
+ r = 0;
+
+ xdr_free ((xdrproc_t) xdr_guestfs_chunk, (char *) &chunk);
+ if (r == -1) /* write error */
+ return -1;
+ }
+}
+
+/* Send a cancellation flag back to the library. */
+void
+cancel_receive (void)
+{
+ XDR xdr;
+ char fbuf[4];
+ uint32_t flag = GUESTFS_CANCEL_FLAG;
+
+ xdrmem_create (&xdr, fbuf, sizeof fbuf, XDR_ENCODE);
+ xdr_uint32_t (&xdr, &flag);
+ xdr_destroy (&xdr);
+
+ if (xwrite (sock, fbuf, sizeof fbuf) == -1) {
+ perror ("write to socket");
+ return;
+ }
+
+ /* Keep receiving chunks and discarding, until library sees cancel. */
+ (void) receive_file (NULL, NULL);
+}
+
+static int check_for_library_cancellation (void);
+static int send_chunk (const guestfs_chunk *);
+
+/* Also check if the library sends us a cancellation message. */
+int
+send_file_write (const void *buf, int len)
+{
+ guestfs_chunk chunk;
+ int cancel;
+
+ if (len > GUESTFS_MAX_CHUNK_SIZE) {
+ fprintf (stderr, "send_file_write: len (%d) > GUESTFS_MAX_CHUNK_SIZE (%d)\n",
+ len, GUESTFS_MAX_CHUNK_SIZE);
+ return -1;
+ }
+
+ cancel = check_for_library_cancellation ();
+
+ if (cancel) {
+ chunk.cancel = 1;
+ chunk.data.data_len = 0;
+ chunk.data.data_val = NULL;
+ } else {
+ chunk.cancel = 0;
+ chunk.data.data_len = len;
+ chunk.data.data_val = (char *) buf;
+ }
+
+ if (send_chunk (&chunk) == -1)
+ return -1;
+
+ if (cancel) return -2;
+ return 0;
+}
+
+static int
+check_for_library_cancellation (void)
+{
+ fd_set rset;
+ struct timeval tv;
+ int r;
+ char buf[4];
+ uint32_t flag;
+ XDR xdr;
+
+ FD_ZERO (&rset);
+ FD_SET (sock, &rset);
+ tv.tv_sec = 0;
+ tv.tv_usec = 0;
+ r = select (sock+1, &rset, NULL, NULL, &tv);
+ if (r == -1) {
+ perror ("select");
+ return 0;
+ }
+ if (r == 0)
+ return 0;
+
+ /* Read the message from the daemon. */
+ r = xread (sock, buf, sizeof buf);
+ if (r == -1) {
+ perror ("read");
+ return 0;
+ }
+
+ xdrmem_create (&xdr, buf, sizeof buf, XDR_DECODE);
+ xdr_uint32_t (&xdr, &flag);
+ xdr_destroy (&xdr);
+
+ if (flag != GUESTFS_CANCEL_FLAG) {
+ fprintf (stderr, "check_for_library_cancellation: read 0x%x from library, expected 0x%x\n",
+ flag, GUESTFS_CANCEL_FLAG);
+ return 0;
+ }
+
+ return 1;
+}
+
+void
+send_file_end (int cancel)
+{
+ guestfs_chunk chunk;
+
+ chunk.cancel = cancel;
+ chunk.data.data_len = 0;
+ chunk.data.data_val = NULL;
+ send_chunk (&chunk);
+}
+
+static int
+send_chunk (const guestfs_chunk *chunk)
+{
+ char buf[GUESTFS_MAX_CHUNK_SIZE + 48];
+ char lenbuf[4];
+ XDR xdr;
+ uint32_t len;
+
+ xdrmem_create (&xdr, buf, sizeof buf, XDR_ENCODE);
+ if (!xdr_guestfs_chunk (&xdr, (guestfs_chunk *) chunk)) {
+ fprintf (stderr, "send_chunk: failed to encode chunk\n");
+ xdr_destroy (&xdr);
+ return -1;
+ }
+
+ len = xdr_getpos (&xdr);
+ xdr_destroy (&xdr);
+
+ xdrmem_create (&xdr, lenbuf, 4, XDR_ENCODE);
+ xdr_uint32_t (&xdr, &len);
+ xdr_destroy (&xdr);
+
+ (void) xwrite (sock, lenbuf, 4);
+ (void) xwrite (sock, buf, len);
+
+ return 0;
+}
git.annexia.org / libguestfs.git / commitdiff