minix/lib/libhgfs/path.c

   1 /* Part of libhgfs - (c) 2009, D.C. van Moolenbroek */
   2
   3 #include "inc.h"
   4
   5 #include <limits.h>
   6
   7 /*===========================================================================*
   8  *                              path_put                                     *
   9  *===========================================================================*/
  10 void path_put(char *path)
  11 {
  12 /* Append the given path name in HGFS format to the RPC buffer. Truncate it
  13  * if it is longer than PATH_MAX bytes.
  14  */
  15   char *p, buf[PATH_MAX];
  16   int len;
  17
  18   /* No leading slashes are allowed. */
  19   for (p = path; *p == '/'; p++);
  20
  21   /* No double or tailing slashes, either. */
  22   for (len = 0; *p && len < sizeof(buf) - 1; len++) {
  23     if (*p == '/') {
  24       for (p++; *p == '/'; p++);
  25
  26       if (!*p) break;
  27
  28       buf[len] = 0;
  29     }
  30     else buf[len] = *p++;
  31   }
  32
  33   RPC_NEXT32 = len;
  34
  35   memcpy(RPC_PTR, buf, len);
  36   RPC_ADVANCE(len);
  37
  38   RPC_NEXT8 = 0;
  39 }
  40
  41 /*===========================================================================*
  42  *                              path_get                                     *
  43  *===========================================================================*/
  44 int path_get(char *path, int max)
  45 {
  46 /* Retrieve a HGFS formatted path name from the RPC buffer. Returns EINVAL if
  47  * the path name is invalid. Returns ENAMETOOLONG if the path name is too
  48  * long. Returns OK on success.
  49  */
  50   char *p, *q;
  51   int n, len;
  52
  53   n = len = RPC_NEXT32;
  54
  55   if (len >= max) return ENAMETOOLONG;
  56
  57   for (p = path, q = RPC_PTR; n--; p++, q++) {
  58     /* We can not deal with a slash in a path component. */
  59     if (*q == '/') return EINVAL;
  60
  61     if (*q == 0) *p = '/';
  62     else *p = *q;
  63   }
  64
  65   RPC_ADVANCE(len);
  66
  67   *p = 0;
  68
  69   return (RPC_NEXT8 != 0) ? EINVAL : OK;
  70 }