Chris Zankel | 4bedea9 | 2005-06-23 22:01:12 -0700 | [diff] [blame^] | 1 | #include "zlib.h" |
| 2 | |
| 3 | /* bits taken from ppc */ |
| 4 | |
| 5 | extern void *avail_ram, *end_avail; |
| 6 | |
| 7 | void exit (void) |
| 8 | { |
| 9 | for (;;); |
| 10 | } |
| 11 | |
| 12 | void *zalloc(void *x, unsigned items, unsigned size) |
| 13 | { |
| 14 | void *p = avail_ram; |
| 15 | |
| 16 | size *= items; |
| 17 | size = (size + 7) & -8; |
| 18 | avail_ram += size; |
| 19 | if (avail_ram > end_avail) { |
| 20 | //puts("oops... out of memory\n"); |
| 21 | //pause(); |
| 22 | exit (); |
| 23 | } |
| 24 | return p; |
| 25 | } |
| 26 | |
| 27 | void zfree(void *x, void *addr, unsigned nb) |
| 28 | { |
| 29 | } |
| 30 | |
| 31 | |
| 32 | #define HEAD_CRC 2 |
| 33 | #define EXTRA_FIELD 4 |
| 34 | #define ORIG_NAME 8 |
| 35 | #define COMMENT 0x10 |
| 36 | #define RESERVED 0xe0 |
| 37 | |
| 38 | #define DEFLATED 8 |
| 39 | |
| 40 | void gunzip (void *dst, int dstlen, unsigned char *src, int *lenp) |
| 41 | { |
| 42 | z_stream s; |
| 43 | int r, i, flags; |
| 44 | |
| 45 | /* skip header */ |
| 46 | |
| 47 | i = 10; |
| 48 | flags = src[3]; |
| 49 | if (src[2] != DEFLATED || (flags & RESERVED) != 0) { |
| 50 | //puts("bad gzipped data\n"); |
| 51 | exit(); |
| 52 | } |
| 53 | if ((flags & EXTRA_FIELD) != 0) |
| 54 | i = 12 + src[10] + (src[11] << 8); |
| 55 | if ((flags & ORIG_NAME) != 0) |
| 56 | while (src[i++] != 0) |
| 57 | ; |
| 58 | if ((flags & COMMENT) != 0) |
| 59 | while (src[i++] != 0) |
| 60 | ; |
| 61 | if ((flags & HEAD_CRC) != 0) |
| 62 | i += 2; |
| 63 | if (i >= *lenp) { |
| 64 | //puts("gunzip: ran out of data in header\n"); |
| 65 | exit(); |
| 66 | } |
| 67 | |
| 68 | s.zalloc = zalloc; |
| 69 | s.zfree = zfree; |
| 70 | r = inflateInit2(&s, -MAX_WBITS); |
| 71 | if (r != Z_OK) { |
| 72 | //puts("inflateInit2 returned "); puthex(r); puts("\n"); |
| 73 | exit(); |
| 74 | } |
| 75 | s.next_in = src + i; |
| 76 | s.avail_in = *lenp - i; |
| 77 | s.next_out = dst; |
| 78 | s.avail_out = dstlen; |
| 79 | r = inflate(&s, Z_FINISH); |
| 80 | if (r != Z_OK && r != Z_STREAM_END) { |
| 81 | //puts("inflate returned "); puthex(r); puts("\n"); |
| 82 | exit(); |
| 83 | } |
| 84 | *lenp = s.next_out - (unsigned char *) dst; |
| 85 | inflateEnd(&s); |
| 86 | } |
| 87 | |