New APIs: base64-in and base64-out for uploading/downloading base64 content.

daemon/base64.c

@@ -0,0 +1,150 @@
+/* libguestfs - the guestfsd daemon
+ * Copyright (C) 2010 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+
+#include "../src/guestfs_protocol.h"
+#include "daemon.h"
+#include "actions.h"
+
+static int
+write_cb (void *fd_ptr, const void *buf, size_t len)
+{
+  int fd = *(int *)fd_ptr;
+  return xwrite (fd, buf, len);
+}
+
+/* Has one FileIn parameter. */
+int
+do_base64_in (const char *file)
+{
+  int err, r;
+  FILE *fp;
+  char *cmd;
+
+  if (asprintf_nowarn (&cmd, "base64 -d > %R", file) == -1) {
+    err = errno;
+    cancel_receive ();
+    errno = err;
+    reply_with_perror ("asprintf");
+    return -1;
+  }
+
+  if (verbose)
+    fprintf (stderr, "%s\n", cmd);
+
+  fp = popen (cmd, "w");
+  if (fp == NULL) {
+    err = errno;
+    cancel_receive ();
+    errno = err;
+    reply_with_perror ("%s", cmd);
+    free (cmd);
+    return -1;
+  }
+  free (cmd);
+
+  /* The semantics of fwrite are too undefined, so write to the
+   * file descriptor directly instead.
+   */
+  int fd = fileno (fp);
+
+  r = receive_file (write_cb, &fd);
+  if (r == -1) {		/* write error */
+    cancel_receive ();
+    reply_with_error ("write error on file: %s", file);
+    pclose (fp);
+    return -1;
+  }
+  if (r == -2) {		/* cancellation from library */
+    pclose (fp);
+    /* Do NOT send any error. */
+    return -1;
+  }
+
+  if (pclose (fp) != 0) {
+    if (r == -1)                /* if r == 0, file transfer ended already */
+      cancel_receive ();
+    reply_with_error ("base64 subcommand failed on file: %s", file);
+    return -1;
+  }
+
+  return 0;
+}
+
+/* Has one FileOut parameter. */
+int
+do_base64_out (const char *file)
+{
+  int r;
+  FILE *fp;
+  char *cmd;
+  char buf[GUESTFS_MAX_CHUNK_SIZE];
+
+  if (asprintf_nowarn (&cmd, "base64 %R", file) == -1) {
+    reply_with_perror ("asprintf");
+    return -1;
+  }
+
+  if (verbose)
+    fprintf (stderr, "%s\n", cmd);
+
+  fp = popen (cmd, "r");
+  if (fp == NULL) {
+    reply_with_perror ("%s", cmd);
+    free (cmd);
+    return -1;
+  }
+  free (cmd);
+
+  /* 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 = fread (buf, 1, sizeof buf, fp)) > 0) {
+    if (send_file_write (buf, r) < 0) {
+      pclose (fp);
+      return -1;
+    }
+  }
+
+  if (ferror (fp)) {
+    perror (file);
+    send_file_end (1);		/* Cancel. */
+    pclose (fp);
+    return -1;
+  }
+
+  if (pclose (fp) != 0) {
+    perror (file);
+    send_file_end (1);		/* Cancel. */
+    return -1;
+  }
+
+  if (send_file_end (0))	/* Normal end of file. */
+    return -1;
+
+  return 0;
+}