sys/src/libc/9sys/convD2M.c

   1 #include        <u.h>
   2 #include        <libc.h>
   3 #include        <fcall.h>
   4
   5 uint
   6 sizeD2M(Dir *d)
   7 {
   8         char *sv[4];
   9         int i, ns;
  10
  11         sv[0] = d->name;
  12         sv[1] = d->uid;
  13         sv[2] = d->gid;
  14         sv[3] = d->muid;
  15
  16         ns = 0;
  17         for(i = 0; i < 4; i++)
  18                 if(sv[i])
  19                         ns += strlen(sv[i]);
  20
  21         return STATFIXLEN + ns;
  22 }
  23
  24 uint
  25 convD2M(Dir *d, uchar *buf, uint nbuf)
  26 {
  27         uchar *p, *ebuf;
  28         char *sv[4];
  29         int i, ns, nsv[4], ss;
  30
  31         if(nbuf < BIT16SZ)
  32                 return 0;
  33
  34         p = buf;
  35         ebuf = buf + nbuf;
  36
  37         sv[0] = d->name;
  38         sv[1] = d->uid;
  39         sv[2] = d->gid;
  40         sv[3] = d->muid;
  41
  42         ns = 0;
  43         for(i = 0; i < 4; i++){
  44                 if(sv[i])
  45                         nsv[i] = strlen(sv[i]);
  46                 else
  47                         nsv[i] = 0;
  48                 ns += nsv[i];
  49         }
  50
  51         ss = STATFIXLEN + ns;
  52
  53         /* set size before erroring, so user can know how much is needed */
  54         /* note that length excludes count field itself */
  55         PBIT16(p, ss-BIT16SZ);
  56         p += BIT16SZ;
  57
  58         if(ss > nbuf)
  59                 return BIT16SZ;
  60
  61         PBIT16(p, d->type);
  62         p += BIT16SZ;
  63         PBIT32(p, d->dev);
  64         p += BIT32SZ;
  65         PBIT8(p, d->qid.type);
  66         p += BIT8SZ;
  67         PBIT32(p, d->qid.vers);
  68         p += BIT32SZ;
  69         PBIT64(p, d->qid.path);
  70         p += BIT64SZ;
  71         PBIT32(p, d->mode);
  72         p += BIT32SZ;
  73         PBIT32(p, d->atime);
  74         p += BIT32SZ;
  75         PBIT32(p, d->mtime);
  76         p += BIT32SZ;
  77         PBIT64(p, d->length);
  78         p += BIT64SZ;
  79
  80         for(i = 0; i < 4; i++){
  81                 ns = nsv[i];
  82                 if(p + ns + BIT16SZ > ebuf)
  83                         return 0;
  84                 PBIT16(p, ns);
  85                 p += BIT16SZ;
  86                 if(ns)
  87                         memmove(p, sv[i], ns);
  88                 p += ns;
  89         }
  90
  91         if(ss != p - buf)
  92                 return 0;
  93
  94         return p - buf;
  95 }