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1 | /* seekable zip */ |
2 | |
3 | #include "unzip.h" |
4 | |
5 | #include <stdlib.h> |
6 | #include <string.h> |
7 | #include <errno.h> |
8 | |
83bd0b76 |
9 | #include "zlib/zlib.h" |
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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 | |