sys/src/libventi/root.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <venti.h>
   4 #include "cvt.h"
   5
   6 static int
   7 checksize(int n)
   8 {
   9         if(n < 256 || n > VtMaxLumpSize) {
  10                 werrstr("bad block size");
  11                 return -1;
  12         }
  13         return 0;
  14 }
  15
  16 void
  17 vtrootpack(VtRoot *r, uchar *p)
  18 {
  19         uchar *op = p;
  20
  21         U16PUT(p, VtRootVersion);
  22         p += 2;
  23         memmove(p, r->name, sizeof(r->name));
  24         p += sizeof(r->name);
  25         memmove(p, r->type, sizeof(r->type));
  26         p += sizeof(r->type);
  27         memmove(p, r->score, VtScoreSize);
  28         p +=  VtScoreSize;
  29         U16PUT(p, r->blocksize);
  30         p += 2;
  31         memmove(p, r->prev, VtScoreSize);
  32         p += VtScoreSize;
  33
  34         assert(p-op == VtRootSize);
  35 }
  36
  37 int
  38 vtrootunpack(VtRoot *r, uchar *p)
  39 {
  40         uchar *op = p;
  41         uint vers;
  42         memset(r, 0, sizeof(*r));
  43
  44         vers = U16GET(p);
  45         if(vers != VtRootVersion) {
  46                 werrstr("unknown root version");
  47                 return -1;
  48         }
  49         p += 2;
  50         memmove(r->name, p, sizeof(r->name));
  51         r->name[sizeof(r->name)-1] = 0;
  52         p += sizeof(r->name);
  53         memmove(r->type, p, sizeof(r->type));
  54         r->type[sizeof(r->type)-1] = 0;
  55         p += sizeof(r->type);
  56         memmove(r->score, p, VtScoreSize);
  57         p +=  VtScoreSize;
  58         r->blocksize = U16GET(p);
  59         if(checksize(r->blocksize) < 0)
  60                 return -1;
  61         p += 2;
  62         memmove(r->prev, p, VtScoreSize);
  63         p += VtScoreSize;
  64
  65         assert(p-op == VtRootSize);
  66         return 0;
  67 }