util-vserver-0.30.208

[util-vserver.git] / src / mask2prefix.c

diff --git a/src/mask2prefix.c b/src/mask2prefix.c
new file mode 100644 (file)
index 0000000..21ffba7
--- /dev/null
+++ b/src/mask2prefix.c
@@ -0,0 +1,70 @@
+// $Id: mask2prefix.c,v 1.1 2003/10/09 01:41:06 ensc Exp $    --*- c++ -*--
+
+// Copyright (C) 2003 Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de>
+//  
+// 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; version 2 of the License.
+//  
+// 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include "util.h"
+#include <stdlib.h>
+
+static inline void
+showHelp(int fd, int exit_code)
+{
+  WRITE_MSG(fd,
+           "Usage:  mask2prefix <mask>\n");
+  exit(exit_code);
+}
+
+int main(int argc, char *argv[])
+{
+  char         *err_ptr, *ptr;
+  int          len = 0;
+  size_t       i;
+  
+  if (argc!=2) showHelp(2,255);
+
+  ptr = argv[1];
+  for (i=0; i<4; ++i) {
+    unsigned int       val = strtol(ptr, &err_ptr, 10);
+
+    switch (*err_ptr) {
+      case '.' :
+      case '\0'        :  break;
+      default  :
+       WRITE_MSG(2, "Invalid mask specified\n");
+       return 255;
+    }
+    
+    if (val>=0x100) {
+      WRITE_MSG(2, "Invalid mask specified\n");
+      return 255;
+    }
+
+    while (val&0x80) {
+      ++len;
+      val <<= 1;
+    }
+
+    if (val!=0xff00) break;
+
+    ptr = err_ptr+1;
+  }
+
+  return len;
+}