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(const 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   const char *p;
  16   char buf[PATH_MAX];
  17   unsigned int len;
  18
  19   /* No leading slashes are allowed. */
  20   for (p = path; *p == '/'; p++);
  21
  22   /* No double or tailing slashes, either. */
  23   for (len = 0; *p && len < sizeof(buf) - 1; len++) {
  24     if (*p == '/') {
  25       for (p++; *p == '/'; p++);
  26
  27       if (!*p) break;
  28
  29       buf[len] = 0;
  30     }
  31     else buf[len] = *p++;
  32   }
  33
  34   RPC_NEXT32 = len;
  35
  36   memcpy(RPC_PTR, buf, len);
  37   RPC_ADVANCE(len);
  38
  39   RPC_NEXT8 = 0;
  40 }
  41
  42 /*===========================================================================*
  43  *                              path_get                                     *
  44  *===========================================================================*/
  45 int path_get(char *path, int max)
  46 {
  47 /* Retrieve a HGFS formatted path name from the RPC buffer. Returns EINVAL if
  48  * the path name is invalid. Returns ENAMETOOLONG if the path name is too
  49  * long. Returns OK on success.
  50  */
  51   char *p, *q;
  52   int n, len;
  53
  54   n = len = RPC_NEXT32;
  55
  56   if (len >= max) return ENAMETOOLONG;
  57
  58   for (p = path, q = RPC_PTR; n--; p++, q++) {
  59     /* We can not deal with a slash in a path component. */
  60     if (*q == '/') return EINVAL;
  61
  62     if (*q == 0) *p = '/';
  63     else *p = *q;
  64   }
  65
  66   RPC_ADVANCE(len);
  67
  68   *p = 0;
  69
  70   return (RPC_NEXT8 != 0) ? EINVAL : OK;
  71 }