1/*
2 * Copyright (C) 2006 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17//
18// Zip archive entries.
19//
20// The ZipEntry class is tightly meshed with the ZipFile class.
21//
22#ifndef __LIBS_ZIPENTRY_H
23#define __LIBS_ZIPENTRY_H
24
25#include <utils/Errors.h>
26
27#include <stdlib.h>
28#include <stdio.h>
29#include <time.h>
30
31namespace android {
32
33class ZipFile;
34
35/*
36 * ZipEntry objects represent a single entry in a Zip archive.
37 *
38 * You can use one of these to get or set information about an entry, but
39 * there are no functions here for accessing the data itself.  (We could
40 * tuck a pointer to the ZipFile in here for convenience, but that raises
41 * the likelihood of using ZipEntry objects after discarding the ZipFile.)
42 *
43 * File information is stored in two places: next to the file data (the Local
44 * File Header, and possibly a Data Descriptor), and at the end of the file
45 * (the Central Directory Entry).  The two must be kept in sync.
46 */
47class ZipEntry {
48public:
49    friend class ZipFile;
50
51    ZipEntry(void)
52        : mDeleted(false), mMarked(false)
53        {}
54    ~ZipEntry(void) {}
55
56    /*
57     * Returns "true" if the data is compressed.
58     */
59    bool isCompressed(void) const {
60        return mCDE.mCompressionMethod != kCompressStored;
61    }
62    int getCompressionMethod(void) const { return mCDE.mCompressionMethod; }
63
64    /*
65     * Return the uncompressed length.
66     */
67    off_t getUncompressedLen(void) const { return mCDE.mUncompressedSize; }
68
69    /*
70     * Return the compressed length.  For uncompressed data, this returns
71     * the same thing as getUncompresesdLen().
72     */
73    off_t getCompressedLen(void) const { return mCDE.mCompressedSize; }
74
75    /*
76     * Return the offset of the local file header.
77     */
78    off_t getLFHOffset(void) const { return mCDE.mLocalHeaderRelOffset; }
79
80    /*
81     * Return the absolute file offset of the start of the compressed or
82     * uncompressed data.
83     */
84    off_t getFileOffset(void) const {
85        return mCDE.mLocalHeaderRelOffset +
86                LocalFileHeader::kLFHLen +
87                mLFH.mFileNameLength +
88                mLFH.mExtraFieldLength;
89    }
90
91    /*
92     * Return the data CRC.
93     */
94    unsigned long getCRC32(void) const { return mCDE.mCRC32; }
95
96    /*
97     * Return file modification time in UNIX seconds-since-epoch.
98     */
99    time_t getModWhen(void) const;
100
101    /*
102     * Return the archived file name.
103     */
104    const char* getFileName(void) const { return (const char*) mCDE.mFileName; }
105
106    /*
107     * Application-defined "mark".  Can be useful when synchronizing the
108     * contents of an archive with contents on disk.
109     */
110    bool getMarked(void) const { return mMarked; }
111    void setMarked(bool val) { mMarked = val; }
112
113    /*
114     * Some basic functions for raw data manipulation.  "LE" means
115     * Little Endian.
116     */
117    static inline unsigned short getShortLE(const unsigned char* buf) {
118        return buf[0] | (buf[1] << 8);
119    }
120    static inline unsigned long getLongLE(const unsigned char* buf) {
121        return buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
122    }
123    static inline void putShortLE(unsigned char* buf, short val) {
124        buf[0] = (unsigned char) val;
125        buf[1] = (unsigned char) (val >> 8);
126    }
127    static inline void putLongLE(unsigned char* buf, long val) {
128        buf[0] = (unsigned char) val;
129        buf[1] = (unsigned char) (val >> 8);
130        buf[2] = (unsigned char) (val >> 16);
131        buf[3] = (unsigned char) (val >> 24);
132    }
133
134    /* defined for Zip archives */
135    enum {
136        kCompressStored     = 0,        // no compression
137        // shrunk           = 1,
138        // reduced 1        = 2,
139        // reduced 2        = 3,
140        // reduced 3        = 4,
141        // reduced 4        = 5,
142        // imploded         = 6,
143        // tokenized        = 7,
144        kCompressDeflated   = 8,        // standard deflate
145        // Deflate64        = 9,
146        // lib imploded     = 10,
147        // reserved         = 11,
148        // bzip2            = 12,
149    };
150
151    /*
152     * Deletion flag.  If set, the entry will be removed on the next
153     * call to "flush".
154     */
155    bool getDeleted(void) const { return mDeleted; }
156
157protected:
158    /*
159     * Initialize the structure from the file, which is pointing at
160     * our Central Directory entry.
161     */
162    status_t initFromCDE(FILE* fp);
163
164    /*
165     * Initialize the structure for a new file.  We need the filename
166     * and comment so that we can properly size the LFH area.  The
167     * filename is mandatory, the comment is optional.
168     */
169    void initNew(const char* fileName, const char* comment);
170
171    /*
172     * Initialize the structure with the contents of a ZipEntry from
173     * another file.
174     */
175    status_t initFromExternal(const ZipFile* pZipFile, const ZipEntry* pEntry);
176
177    /*
178     * Add some pad bytes to the LFH.  We do this by adding or resizing
179     * the "extra" field.
180     */
181    status_t addPadding(int padding);
182
183    /*
184     * Set information about the data for this entry.
185     */
186    void setDataInfo(long uncompLen, long compLen, unsigned long crc32,
187        int compressionMethod);
188
189    /*
190     * Set the modification date.
191     */
192    void setModWhen(time_t when);
193
194    /*
195     * Set the offset of the local file header, relative to the start of
196     * the current file.
197     */
198    void setLFHOffset(off_t offset) {
199        mCDE.mLocalHeaderRelOffset = (long) offset;
200    }
201
202    /* mark for deletion; used by ZipFile::remove() */
203    void setDeleted(void) { mDeleted = true; }
204
205private:
206    /* these are private and not defined */
207    ZipEntry(const ZipEntry& src);
208    ZipEntry& operator=(const ZipEntry& src);
209
210    /* returns "true" if the CDE and the LFH agree */
211    bool compareHeaders(void) const;
212    void copyCDEtoLFH(void);
213
214    bool        mDeleted;       // set if entry is pending deletion
215    bool        mMarked;        // app-defined marker
216
217    /*
218     * Every entry in the Zip archive starts off with one of these.
219     */
220    class LocalFileHeader {
221    public:
222        LocalFileHeader(void) :
223            mVersionToExtract(0),
224            mGPBitFlag(0),
225            mCompressionMethod(0),
226            mLastModFileTime(0),
227            mLastModFileDate(0),
228            mCRC32(0),
229            mCompressedSize(0),
230            mUncompressedSize(0),
231            mFileNameLength(0),
232            mExtraFieldLength(0),
233            mFileName(NULL),
234            mExtraField(NULL)
235        {}
236        virtual ~LocalFileHeader(void) {
237            delete[] mFileName;
238            delete[] mExtraField;
239        }
240
241        status_t read(FILE* fp);
242        status_t write(FILE* fp);
243
244        // unsigned long mSignature;
245        unsigned short  mVersionToExtract;
246        unsigned short  mGPBitFlag;
247        unsigned short  mCompressionMethod;
248        unsigned short  mLastModFileTime;
249        unsigned short  mLastModFileDate;
250        unsigned long   mCRC32;
251        unsigned long   mCompressedSize;
252        unsigned long   mUncompressedSize;
253        unsigned short  mFileNameLength;
254        unsigned short  mExtraFieldLength;
255        unsigned char*  mFileName;
256        unsigned char*  mExtraField;
257
258        enum {
259            kSignature      = 0x04034b50,
260            kLFHLen         = 30,       // LocalFileHdr len, excl. var fields
261        };
262
263        void dump(void) const;
264    };
265
266    /*
267     * Every entry in the Zip archive has one of these in the "central
268     * directory" at the end of the file.
269     */
270    class CentralDirEntry {
271    public:
272        CentralDirEntry(void) :
273            mVersionMadeBy(0),
274            mVersionToExtract(0),
275            mGPBitFlag(0),
276            mCompressionMethod(0),
277            mLastModFileTime(0),
278            mLastModFileDate(0),
279            mCRC32(0),
280            mCompressedSize(0),
281            mUncompressedSize(0),
282            mFileNameLength(0),
283            mExtraFieldLength(0),
284            mFileCommentLength(0),
285            mDiskNumberStart(0),
286            mInternalAttrs(0),
287            mExternalAttrs(0),
288            mLocalHeaderRelOffset(0),
289            mFileName(NULL),
290            mExtraField(NULL),
291            mFileComment(NULL)
292        {}
293        virtual ~CentralDirEntry(void) {
294            delete[] mFileName;
295            delete[] mExtraField;
296            delete[] mFileComment;
297        }
298
299        status_t read(FILE* fp);
300        status_t write(FILE* fp);
301
302        CentralDirEntry& operator=(const CentralDirEntry& src);
303
304        // unsigned long mSignature;
305        unsigned short  mVersionMadeBy;
306        unsigned short  mVersionToExtract;
307        unsigned short  mGPBitFlag;
308        unsigned short  mCompressionMethod;
309        unsigned short  mLastModFileTime;
310        unsigned short  mLastModFileDate;
311        unsigned long   mCRC32;
312        unsigned long   mCompressedSize;
313        unsigned long   mUncompressedSize;
314        unsigned short  mFileNameLength;
315        unsigned short  mExtraFieldLength;
316        unsigned short  mFileCommentLength;
317        unsigned short  mDiskNumberStart;
318        unsigned short  mInternalAttrs;
319        unsigned long   mExternalAttrs;
320        unsigned long   mLocalHeaderRelOffset;
321        unsigned char*  mFileName;
322        unsigned char*  mExtraField;
323        unsigned char*  mFileComment;
324
325        void dump(void) const;
326
327        enum {
328            kSignature      = 0x02014b50,
329            kCDELen         = 46,       // CentralDirEnt len, excl. var fields
330        };
331    };
332
333    enum {
334        //kDataDescriptorSignature  = 0x08074b50,   // currently unused
335        kDataDescriptorLen  = 16,           // four 32-bit fields
336
337        kDefaultVersion     = 20,           // need deflate, nothing much else
338        kDefaultMadeBy      = 0x0317,       // 03=UNIX, 17=spec v2.3
339        kUsesDataDescr      = 0x0008,       // GPBitFlag bit 3
340    };
341
342    LocalFileHeader     mLFH;
343    CentralDirEntry     mCDE;
344};
345
346}; // namespace android
347
348#endif // __LIBS_ZIPENTRY_H
349