lib/gunzip.c

   1 #include <common.h>
   2 #include <zlib.h>
   3 #include <malloc.h>
   4
   5 #define ZALLOC_ALIGNMENT        16
   6
   7 static void *zalloc(void *x, unsigned items, unsigned size)
   8 {
   9         void *p;
  10
  11         size *= items;
  12         size = (size + ZALLOC_ALIGNMENT - 1) & ~(ZALLOC_ALIGNMENT - 1);
  13
  14         p = malloc (size);
  15
  16         return (p);
  17 }
  18
  19 static void zfree(void *x, void *addr, unsigned nb)
  20 {
  21         free (addr);
  22 }
  23
  24 #define HEAD_CRC        2
  25 #define EXTRA_FIELD     4
  26 #define ORIG_NAME       8
  27 #define COMMENT         0x10
  28 #define RESERVED        0xe0
  29
  30 #define DEFLATED        8
  31
  32 int gunzip(void *dst, int dstlen, unsigned char *src, unsigned long *lenp)
  33 {
  34         z_stream s;
  35         int r, i, flags;
  36
  37         /* skip header */
  38         i = 10;
  39         flags = src[3];
  40         if (src[2] != DEFLATED || (flags & RESERVED) != 0) {
  41                 puts ("Error: Bad gzipped data\n");
  42                 return (-1);
  43         }
  44         if ((flags & EXTRA_FIELD) != 0)
  45                 i = 12 + src[10] + (src[11] << 8);
  46         if ((flags & ORIG_NAME) != 0)
  47                 while (src[i++] != 0)
  48                         ;
  49         if ((flags & COMMENT) != 0)
  50                 while (src[i++] != 0)
  51                         ;
  52         if ((flags & HEAD_CRC) != 0)
  53                 i += 2;
  54         if (i >= *lenp) {
  55                 puts ("Error: gunzip out of data in header\n");
  56                 return (-1);
  57         }
  58
  59         s.zalloc = zalloc;
  60         s.zfree = zfree;
  61 #if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
  62         s.outcb = (cb_func)WATCHDOG_RESET;
  63 #else
  64         s.outcb = Z_NULL;
  65 #endif  /* CONFIG_HW_WATCHDOG */
  66
  67         r = inflateInit2(&s, -MAX_WBITS);
  68         if (r != Z_OK) {
  69                 printf ("Error: inflateInit2() returned %d\n", r);
  70                 return (-1);
  71         }
  72         s.next_in = src + i;
  73         s.avail_in = *lenp - i;
  74         s.next_out = dst;
  75         s.avail_out = dstlen;
  76         r = inflate(&s, Z_FINISH);
  77         if (r != Z_OK && r != Z_STREAM_END) {
  78                 printf ("Error: inflate() returned %d\n", r);
  79                 return (-1);
  80         }
  81         *lenp = s.next_out - (unsigned char *) dst;
  82         inflateEnd(&s);
  83
  84         return (0);
  85 }