| 1 | /* seekable zip */ |
| 2 | |
| 3 | #include "unzip.h" |
| 4 | |
| 5 | #include <stdlib.h> |
| 6 | #include <string.h> |
| 7 | #include <errno.h> |
| 8 | |
| 9 | #include "zlib/zlib.h" |
| 10 | |
| 11 | |
| 12 | #define errormsg(str1,def,fname) printf("%s: " #def ": " str1 "\n", fname); |
| 13 | |
| 14 | |
| 15 | /* from gzio.c . Be careful with binary compatibility */ |
| 16 | typedef struct gz_stream { |
| 17 | z_stream stream; |
| 18 | int z_err; /* error code for last stream operation */ |
| 19 | int z_eof; /* set if end of input file */ |
| 20 | FILE *file; /* .gz file */ |
| 21 | Byte *inbuf; /* input buffer */ |
| 22 | Byte *outbuf; /* output buffer */ |
| 23 | uLong crc; /* crc32 of uncompressed data */ |
| 24 | char *msg; /* error message */ |
| 25 | char *path; /* path name for debugging only */ |
| 26 | int transparent; /* 1 if input file is not a .gz file */ |
| 27 | char mode; /* 'w' or 'r' */ |
| 28 | z_off_t start; /* start of compressed data in file (header skipped) */ |
| 29 | z_off_t in; /* bytes into deflate or inflate */ |
| 30 | z_off_t out; /* bytes out of deflate or inflate */ |
| 31 | int back; /* one character push-back */ |
| 32 | int last; /* true if push-back is last character */ |
| 33 | } gz_stream; |
| 34 | |
| 35 | #ifndef Z_BUFSIZE |
| 36 | # ifdef MAXSEG_64K |
| 37 | # define Z_BUFSIZE 4096 /* minimize memory usage for 16-bit DOS */ |
| 38 | # else |
| 39 | # define Z_BUFSIZE 16384 |
| 40 | # endif |
| 41 | #endif |
| 42 | #ifndef Z_PRINTF_BUFSIZE |
| 43 | # define Z_PRINTF_BUFSIZE 4096 |
| 44 | #endif |
| 45 | |
| 46 | #define ALLOC(size) malloc(size) |
| 47 | |
| 48 | int destroy OF((gz_stream *s)); |
| 49 | |
| 50 | |
| 51 | gzFile zip2gz(ZIP* zip, struct zipent* ent) |
| 52 | { |
| 53 | int err; |
| 54 | gz_stream *s; |
| 55 | const char *path; |
| 56 | int transparent = 0; |
| 57 | uInt len; |
| 58 | |
| 59 | if (!zip || !ent) |
| 60 | return NULL; |
| 61 | |
| 62 | /* zip stuff */ |
| 63 | if (ent->compression_method == 0x0000) |
| 64 | { |
| 65 | /* file is not compressed, simply stored */ |
| 66 | |
| 67 | /* check if size are equal */ |
| 68 | if (ent->compressed_size != ent->uncompressed_size) { |
| 69 | errormsg("Wrong uncompressed size in store compression", ERROR_CORRUPT,zip->zip); |
| 70 | return NULL; |
| 71 | } |
| 72 | |
| 73 | transparent = 1; |
| 74 | } |
| 75 | else if (ent->compression_method == 0x0008) |
| 76 | { |
| 77 | /* file is compressed using "Deflate" method */ |
| 78 | if (ent->version_needed_to_extract > 0x14) { |
| 79 | errormsg("Version too new", ERROR_UNSUPPORTED,zip->zip); |
| 80 | return NULL; |
| 81 | } |
| 82 | |
| 83 | if (ent->os_needed_to_extract != 0x00) { |
| 84 | errormsg("OS not supported", ERROR_UNSUPPORTED,zip->zip); |
| 85 | return NULL; |
| 86 | } |
| 87 | |
| 88 | if (ent->disk_number_start != zip->number_of_this_disk) { |
| 89 | errormsg("Cannot span disks", ERROR_UNSUPPORTED,zip->zip); |
| 90 | return NULL; |
| 91 | } |
| 92 | |
| 93 | } else { |
| 94 | errormsg("Compression method unsupported", ERROR_UNSUPPORTED, zip->zip); |
| 95 | return NULL; |
| 96 | } |
| 97 | |
| 98 | /* seek to compressed data */ |
| 99 | if (seekcompresszip(zip,ent) != 0) { |
| 100 | return NULL; |
| 101 | } |
| 102 | |
| 103 | path = zip->zip; |
| 104 | |
| 105 | /* normal gzip init for read */ |
| 106 | s = (gz_stream *)ALLOC(sizeof(gz_stream)); |
| 107 | if (!s) return Z_NULL; |
| 108 | |
| 109 | s->stream.zalloc = (alloc_func)0; |
| 110 | s->stream.zfree = (free_func)0; |
| 111 | s->stream.opaque = (voidpf)0; |
| 112 | s->stream.next_in = s->inbuf = Z_NULL; |
| 113 | s->stream.next_out = s->outbuf = Z_NULL; |
| 114 | s->stream.avail_in = s->stream.avail_out = 0; |
| 115 | s->file = NULL; |
| 116 | s->z_err = Z_OK; |
| 117 | s->z_eof = 0; |
| 118 | s->in = 0; |
| 119 | s->out = 0; |
| 120 | s->back = EOF; |
| 121 | s->crc = crc32(0L, Z_NULL, 0); |
| 122 | s->msg = NULL; |
| 123 | s->transparent = transparent; |
| 124 | s->mode = 'r'; |
| 125 | |
| 126 | s->path = (char*)ALLOC(strlen(path)+1); |
| 127 | if (s->path == NULL) { |
| 128 | return destroy(s), (gzFile)Z_NULL; |
| 129 | } |
| 130 | strcpy(s->path, path); /* do this early for debugging */ |
| 131 | |
| 132 | s->stream.next_in = s->inbuf = (Byte*)ALLOC(Z_BUFSIZE); |
| 133 | |
| 134 | err = inflateInit2(&(s->stream), -MAX_WBITS); |
| 135 | /* windowBits is passed < 0 to tell that there is no zlib header. |
| 136 | * Note that in this case inflate *requires* an extra "dummy" byte |
| 137 | * after the compressed stream in order to complete decompression and |
| 138 | * return Z_STREAM_END. Here the gzip CRC32 ensures that 4 bytes are |
| 139 | * present after the compressed stream. |
| 140 | */ |
| 141 | if (err != Z_OK || s->inbuf == Z_NULL) { |
| 142 | return destroy(s), (gzFile)Z_NULL; |
| 143 | } |
| 144 | s->stream.avail_out = Z_BUFSIZE; |
| 145 | |
| 146 | errno = 0; |
| 147 | s->file = zip->fp; |
| 148 | if (s->file == NULL) { |
| 149 | return destroy(s), (gzFile)Z_NULL; |
| 150 | } |
| 151 | |
| 152 | /* check_header(s); */ |
| 153 | errno = 0; |
| 154 | len = (uInt)fread(s->inbuf, 1, Z_BUFSIZE, s->file); |
| 155 | if (len == 0 && ferror(s->file)) s->z_err = Z_ERRNO; |
| 156 | s->stream.avail_in += len; |
| 157 | s->stream.next_in = s->inbuf; |
| 158 | if (s->stream.avail_in < 2) { |
| 159 | return destroy(s), (gzFile)Z_NULL; |
| 160 | } |
| 161 | |
| 162 | s->start = ftell(s->file) - s->stream.avail_in; |
| 163 | |
| 164 | return (gzFile)s; |
| 165 | } |
| 166 | |
| 167 | |
| 168 | int gzerror2(gzFile file) |
| 169 | { |
| 170 | gz_stream *s = (gz_stream*)file; |
| 171 | |
| 172 | if (s == NULL) |
| 173 | return Z_STREAM_ERROR; |
| 174 | |
| 175 | return s->z_err; |
| 176 | } |
| 177 | |
| 178 | |