New API call: fill - fill a file with octets

[libguestfs.git] / daemon / fill.c

diff --git a/daemon/fill.c b/daemon/fill.c
new file mode 100644 (file)
index 0000000..b1b0f5e
--- /dev/null
+++ b/daemon/fill.c
@@ -0,0 +1,76 @@
+/* libguestfs - the guestfsd daemon
+ * Copyright (C) 2009 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 <unistd.h>
+#include <fcntl.h>
+
+#include "../src/guestfs_protocol.h"
+#include "daemon.h"
+#include "actions.h"
+
+int
+do_fill (int c, int len, const char *path)
+{
+  int fd;
+  ssize_t r;
+  size_t len_sz;
+  size_t n;
+  char buf[BUFSIZ];
+
+  if (c < 0 || c > 255) {
+    reply_with_error ("fill: %d: byte number must be in range 0..255", c);
+    return -1;
+  }
+  memset (buf, c, BUFSIZ);
+  if (len < 0) {
+    reply_with_error ("fill: %d: length is < 0", len);
+    return -1;
+  }
+  len_sz = (size_t) len;
+
+  CHROOT_IN;
+  fd = open (path, O_WRONLY | O_CREAT | O_NOCTTY, 0666);
+  CHROOT_OUT;
+
+  if (fd == -1) {
+    reply_with_perror ("open: %s", path);
+    return -1;
+  }
+
+  n = 0;
+  while (n < len_sz) {
+    r = write (fd, buf, len_sz - n < BUFSIZ ? len_sz - n : BUFSIZ);
+    if (r == -1) {
+      reply_with_perror ("write: %s", path);
+      close (fd);
+      return -1;
+    }
+    n += r;
+  }
+
+  if (close (fd) == -1) {
+    reply_with_perror ("close: %s", path);
+    return -1;
+  }
+
+  return 0;
+}