lib/libsffs/util.c

   1 /* This file contains various utility functions.
   2  *
   3  * The entry points into this file are:
   4  *   get_name           retrieve a path component string from VFS
   5  *   do_noop            handle file system calls that do nothing and succeed
   6  *   no_sys             handle file system calls that are not implemented
   7  *
   8  * Created:
   9  *   April 2009 (D.C. van Moolenbroek)
  10  */
  11
  12 #include "inc.h"
  13
  14 /*===========================================================================*
  15  *                              get_name                                     *
  16  *===========================================================================*/
  17 int get_name(grant, len, name)
  18 cp_grant_id_t grant;            /* memory grant for the path component */
  19 size_t len;                     /* length of the name, including '\0' */
  20 char name[NAME_MAX+1];          /* buffer in which store the result */
  21 {
  22 /* Retrieve a path component from the caller, using a given grant.
  23  */
  24   int r;
  25
  26   /* Copy in the name of the directory entry. */
  27   if (len <= 1) return EINVAL;
  28   if (len > NAME_MAX+1) return ENAMETOOLONG;
  29
  30   r = sys_safecopyfrom(m_in.m_source, grant, 0, (vir_bytes) name, len);
  31
  32   if (r != OK) return r;
  33
  34   if (name[len-1] != 0) {
  35         printf("%s: VFS did not zero-terminate path component!\n", sffs_name);
  36
  37         return EINVAL;
  38   }
  39
  40   return OK;
  41 }
  42
  43 /*===========================================================================*
  44  *                              do_noop                                      *
  45  *===========================================================================*/
  46 int do_noop()
  47 {
  48 /* Generic handler for no-op system calls.
  49  */
  50
  51   return OK;
  52 }
  53
  54 /*===========================================================================*
  55  *                              no_sys                                       *
  56  *===========================================================================*/
  57 int no_sys()
  58 {
  59 /* Generic handler for unimplemented system calls.
  60  */
  61
  62   return ENOSYS;
  63 }