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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 // Access to Zip archives.
19 //
20 
21 #define LOG_TAG "zip"
22 
23 #include <androidfw/ZipUtils.h>
24 #include <utils/Log.h>
25 
26 #include "ZipFile.h"
27 
28 #include <zlib.h>
29 #define DEF_MEM_LEVEL 8                // normally in zutil.h?
30 
31 #include "zopfli/deflate.h"
32 
33 #include <memory.h>
34 #include <sys/stat.h>
35 #include <errno.h>
36 #include <assert.h>
37 
38 using namespace android;
39 
40 /*
41  * Some environments require the "b", some choke on it.
42  */
43 #define FILE_OPEN_RO        "rb"
44 #define FILE_OPEN_RW        "r+b"
45 #define FILE_OPEN_RW_CREATE "w+b"
46 
47 /* should live somewhere else? */
errnoToStatus(int err)48 static status_t errnoToStatus(int err)
49 {
50     if (err == ENOENT)
51         return NAME_NOT_FOUND;
52     else if (err == EACCES)
53         return PERMISSION_DENIED;
54     else
55         return UNKNOWN_ERROR;
56 }
57 
58 /*
59  * Open a file and parse its guts.
60  */
open(const char * zipFileName,int flags)61 status_t ZipFile::open(const char* zipFileName, int flags)
62 {
63     bool newArchive = false;
64 
65     assert(mZipFp == NULL);     // no reopen
66 
67     if ((flags & kOpenTruncate))
68         flags |= kOpenCreate;           // trunc implies create
69 
70     if ((flags & kOpenReadOnly) && (flags & kOpenReadWrite))
71         return INVALID_OPERATION;       // not both
72     if (!((flags & kOpenReadOnly) || (flags & kOpenReadWrite)))
73         return INVALID_OPERATION;       // not neither
74     if ((flags & kOpenCreate) && !(flags & kOpenReadWrite))
75         return INVALID_OPERATION;       // create requires write
76 
77     if (flags & kOpenTruncate) {
78         newArchive = true;
79     } else {
80         newArchive = (access(zipFileName, F_OK) != 0);
81         if (!(flags & kOpenCreate) && newArchive) {
82             /* not creating, must already exist */
83             ALOGD("File %s does not exist", zipFileName);
84             return NAME_NOT_FOUND;
85         }
86     }
87 
88     /* open the file */
89     const char* openflags;
90     if (flags & kOpenReadWrite) {
91         if (newArchive)
92             openflags = FILE_OPEN_RW_CREATE;
93         else
94             openflags = FILE_OPEN_RW;
95     } else {
96         openflags = FILE_OPEN_RO;
97     }
98     mZipFp = fopen(zipFileName, openflags);
99     if (mZipFp == NULL) {
100         int err = errno;
101         ALOGD("fopen failed: %d\n", err);
102         return errnoToStatus(err);
103     }
104 
105     status_t result;
106     if (!newArchive) {
107         /*
108          * Load the central directory.  If that fails, then this probably
109          * isn't a Zip archive.
110          */
111         result = readCentralDir();
112     } else {
113         /*
114          * Newly-created.  The EndOfCentralDir constructor actually
115          * sets everything to be the way we want it (all zeroes).  We
116          * set mNeedCDRewrite so that we create *something* if the
117          * caller doesn't add any files.  (We could also just unlink
118          * the file if it's brand new and nothing was added, but that's
119          * probably doing more than we really should -- the user might
120          * have a need for empty zip files.)
121          */
122         mNeedCDRewrite = true;
123         result = NO_ERROR;
124     }
125 
126     if (flags & kOpenReadOnly)
127         mReadOnly = true;
128     else
129         assert(!mReadOnly);
130 
131     return result;
132 }
133 
134 /*
135  * Return the Nth entry in the archive.
136  */
getEntryByIndex(int idx) const137 ZipEntry* ZipFile::getEntryByIndex(int idx) const
138 {
139     if (idx < 0 || idx >= (int) mEntries.size())
140         return NULL;
141 
142     return mEntries[idx];
143 }
144 
145 /*
146  * Find an entry by name.
147  */
getEntryByName(const char * fileName) const148 ZipEntry* ZipFile::getEntryByName(const char* fileName) const
149 {
150     /*
151      * Do a stupid linear string-compare search.
152      *
153      * There are various ways to speed this up, especially since it's rare
154      * to intermingle changes to the archive with "get by name" calls.  We
155      * don't want to sort the mEntries vector itself, however, because
156      * it's used to recreate the Central Directory.
157      *
158      * (Hash table works, parallel list of pointers in sorted order is good.)
159      */
160     int idx;
161 
162     for (idx = mEntries.size()-1; idx >= 0; idx--) {
163         ZipEntry* pEntry = mEntries[idx];
164         if (!pEntry->getDeleted() &&
165             strcmp(fileName, pEntry->getFileName()) == 0)
166         {
167             return pEntry;
168         }
169     }
170 
171     return NULL;
172 }
173 
174 /*
175  * Empty the mEntries vector.
176  */
discardEntries(void)177 void ZipFile::discardEntries(void)
178 {
179     int count = mEntries.size();
180 
181     while (--count >= 0)
182         delete mEntries[count];
183 
184     mEntries.clear();
185 }
186 
187 
188 /*
189  * Find the central directory and read the contents.
190  *
191  * The fun thing about ZIP archives is that they may or may not be
192  * readable from start to end.  In some cases, notably for archives
193  * that were written to stdout, the only length information is in the
194  * central directory at the end of the file.
195  *
196  * Of course, the central directory can be followed by a variable-length
197  * comment field, so we have to scan through it backwards.  The comment
198  * is at most 64K, plus we have 18 bytes for the end-of-central-dir stuff
199  * itself, plus apparently sometimes people throw random junk on the end
200  * just for the fun of it.
201  *
202  * This is all a little wobbly.  If the wrong value ends up in the EOCD
203  * area, we're hosed.  This appears to be the way that everbody handles
204  * it though, so we're in pretty good company if this fails.
205  */
readCentralDir(void)206 status_t ZipFile::readCentralDir(void)
207 {
208     status_t result = NO_ERROR;
209     unsigned char* buf = NULL;
210     off_t fileLength, seekStart;
211     long readAmount;
212     int i;
213 
214     fseek(mZipFp, 0, SEEK_END);
215     fileLength = ftell(mZipFp);
216     rewind(mZipFp);
217 
218     /* too small to be a ZIP archive? */
219     if (fileLength < EndOfCentralDir::kEOCDLen) {
220         ALOGD("Length is %ld -- too small\n", (long)fileLength);
221         result = INVALID_OPERATION;
222         goto bail;
223     }
224 
225     buf = new unsigned char[EndOfCentralDir::kMaxEOCDSearch];
226     if (buf == NULL) {
227         ALOGD("Failure allocating %d bytes for EOCD search",
228              EndOfCentralDir::kMaxEOCDSearch);
229         result = NO_MEMORY;
230         goto bail;
231     }
232 
233     if (fileLength > EndOfCentralDir::kMaxEOCDSearch) {
234         seekStart = fileLength - EndOfCentralDir::kMaxEOCDSearch;
235         readAmount = EndOfCentralDir::kMaxEOCDSearch;
236     } else {
237         seekStart = 0;
238         readAmount = (long) fileLength;
239     }
240     if (fseek(mZipFp, seekStart, SEEK_SET) != 0) {
241         ALOGD("Failure seeking to end of zip at %ld", (long) seekStart);
242         result = UNKNOWN_ERROR;
243         goto bail;
244     }
245 
246     /* read the last part of the file into the buffer */
247     if (fread(buf, 1, readAmount, mZipFp) != (size_t) readAmount) {
248         ALOGD("short file? wanted %ld\n", readAmount);
249         result = UNKNOWN_ERROR;
250         goto bail;
251     }
252 
253     /* find the end-of-central-dir magic */
254     for (i = readAmount - 4; i >= 0; i--) {
255         if (buf[i] == 0x50 &&
256             ZipEntry::getLongLE(&buf[i]) == EndOfCentralDir::kSignature)
257         {
258             ALOGV("+++ Found EOCD at buf+%d\n", i);
259             break;
260         }
261     }
262     if (i < 0) {
263         ALOGD("EOCD not found, not Zip\n");
264         result = INVALID_OPERATION;
265         goto bail;
266     }
267 
268     /* extract eocd values */
269     result = mEOCD.readBuf(buf + i, readAmount - i);
270     if (result != NO_ERROR) {
271         ALOGD("Failure reading %ld bytes of EOCD values", readAmount - i);
272         goto bail;
273     }
274     //mEOCD.dump();
275 
276     if (mEOCD.mDiskNumber != 0 || mEOCD.mDiskWithCentralDir != 0 ||
277         mEOCD.mNumEntries != mEOCD.mTotalNumEntries)
278     {
279         ALOGD("Archive spanning not supported\n");
280         result = INVALID_OPERATION;
281         goto bail;
282     }
283 
284     /*
285      * So far so good.  "mCentralDirSize" is the size in bytes of the
286      * central directory, so we can just seek back that far to find it.
287      * We can also seek forward mCentralDirOffset bytes from the
288      * start of the file.
289      *
290      * We're not guaranteed to have the rest of the central dir in the
291      * buffer, nor are we guaranteed that the central dir will have any
292      * sort of convenient size.  We need to skip to the start of it and
293      * read the header, then the other goodies.
294      *
295      * The only thing we really need right now is the file comment, which
296      * we're hoping to preserve.
297      */
298     if (fseek(mZipFp, mEOCD.mCentralDirOffset, SEEK_SET) != 0) {
299         ALOGD("Failure seeking to central dir offset %ld\n",
300              mEOCD.mCentralDirOffset);
301         result = UNKNOWN_ERROR;
302         goto bail;
303     }
304 
305     /*
306      * Loop through and read the central dir entries.
307      */
308     ALOGV("Scanning %d entries...\n", mEOCD.mTotalNumEntries);
309     int entry;
310     for (entry = 0; entry < mEOCD.mTotalNumEntries; entry++) {
311         ZipEntry* pEntry = new ZipEntry;
312 
313         result = pEntry->initFromCDE(mZipFp);
314         if (result != NO_ERROR) {
315             ALOGD("initFromCDE failed\n");
316             delete pEntry;
317             goto bail;
318         }
319 
320         mEntries.add(pEntry);
321     }
322 
323 
324     /*
325      * If all went well, we should now be back at the EOCD.
326      */
327     {
328         unsigned char checkBuf[4];
329         if (fread(checkBuf, 1, 4, mZipFp) != 4) {
330             ALOGD("EOCD check read failed\n");
331             result = INVALID_OPERATION;
332             goto bail;
333         }
334         if (ZipEntry::getLongLE(checkBuf) != EndOfCentralDir::kSignature) {
335             ALOGD("EOCD read check failed\n");
336             result = UNKNOWN_ERROR;
337             goto bail;
338         }
339         ALOGV("+++ EOCD read check passed\n");
340     }
341 
342 bail:
343     delete[] buf;
344     return result;
345 }
346 
347 
348 /*
349  * Add a new file to the archive.
350  *
351  * This requires creating and populating a ZipEntry structure, and copying
352  * the data into the file at the appropriate position.  The "appropriate
353  * position" is the current location of the central directory, which we
354  * casually overwrite (we can put it back later).
355  *
356  * If we were concerned about safety, we would want to make all changes
357  * in a temp file and then overwrite the original after everything was
358  * safely written.  Not really a concern for us.
359  */
addCommon(const char * fileName,const void * data,size_t size,const char * storageName,int sourceType,int compressionMethod,ZipEntry ** ppEntry)360 status_t ZipFile::addCommon(const char* fileName, const void* data, size_t size,
361     const char* storageName, int sourceType, int compressionMethod,
362     ZipEntry** ppEntry)
363 {
364     ZipEntry* pEntry = NULL;
365     status_t result = NO_ERROR;
366     long lfhPosn, startPosn, endPosn, uncompressedLen;
367     FILE* inputFp = NULL;
368     unsigned long crc;
369     time_t modWhen;
370 
371     if (mReadOnly)
372         return INVALID_OPERATION;
373 
374     assert(compressionMethod == ZipEntry::kCompressDeflated ||
375            compressionMethod == ZipEntry::kCompressStored);
376 
377     /* make sure we're in a reasonable state */
378     assert(mZipFp != NULL);
379     assert(mEntries.size() == mEOCD.mTotalNumEntries);
380 
381     /* make sure it doesn't already exist */
382     if (getEntryByName(storageName) != NULL)
383         return ALREADY_EXISTS;
384 
385     if (!data) {
386         inputFp = fopen(fileName, FILE_OPEN_RO);
387         if (inputFp == NULL)
388             return errnoToStatus(errno);
389     }
390 
391     if (fseek(mZipFp, mEOCD.mCentralDirOffset, SEEK_SET) != 0) {
392         result = UNKNOWN_ERROR;
393         goto bail;
394     }
395 
396     pEntry = new ZipEntry;
397     pEntry->initNew(storageName, NULL);
398 
399     /*
400      * From here on out, failures are more interesting.
401      */
402     mNeedCDRewrite = true;
403 
404     /*
405      * Write the LFH, even though it's still mostly blank.  We need it
406      * as a place-holder.  In theory the LFH isn't necessary, but in
407      * practice some utilities demand it.
408      */
409     lfhPosn = ftell(mZipFp);
410     pEntry->mLFH.write(mZipFp);
411     startPosn = ftell(mZipFp);
412 
413     /*
414      * Copy the data in, possibly compressing it as we go.
415      */
416     if (sourceType == ZipEntry::kCompressStored) {
417         if (compressionMethod == ZipEntry::kCompressDeflated) {
418             bool failed = false;
419             result = compressFpToFp(mZipFp, inputFp, data, size, &crc);
420             if (result != NO_ERROR) {
421                 ALOGD("compression failed, storing\n");
422                 failed = true;
423             } else {
424                 /*
425                  * Make sure it has compressed "enough".  This probably ought
426                  * to be set through an API call, but I don't expect our
427                  * criteria to change over time.
428                  */
429                 long src = inputFp ? ftell(inputFp) : size;
430                 long dst = ftell(mZipFp) - startPosn;
431                 if (dst + (dst / 10) > src) {
432                     ALOGD("insufficient compression (src=%ld dst=%ld), storing\n",
433                         src, dst);
434                     failed = true;
435                 }
436             }
437 
438             if (failed) {
439                 compressionMethod = ZipEntry::kCompressStored;
440                 if (inputFp) rewind(inputFp);
441                 fseek(mZipFp, startPosn, SEEK_SET);
442                 /* fall through to kCompressStored case */
443             }
444         }
445         /* handle "no compression" request, or failed compression from above */
446         if (compressionMethod == ZipEntry::kCompressStored) {
447             if (inputFp) {
448                 result = copyFpToFp(mZipFp, inputFp, &crc);
449             } else {
450                 result = copyDataToFp(mZipFp, data, size, &crc);
451             }
452             if (result != NO_ERROR) {
453                 // don't need to truncate; happens in CDE rewrite
454                 ALOGD("failed copying data in\n");
455                 goto bail;
456             }
457         }
458 
459         // currently seeked to end of file
460         uncompressedLen = inputFp ? ftell(inputFp) : size;
461     } else if (sourceType == ZipEntry::kCompressDeflated) {
462         /* we should support uncompressed-from-compressed, but it's not
463          * important right now */
464         assert(compressionMethod == ZipEntry::kCompressDeflated);
465 
466         bool scanResult;
467         int method;
468         long compressedLen;
469 
470         scanResult = ZipUtils::examineGzip(inputFp, &method, &uncompressedLen,
471                         &compressedLen, &crc);
472         if (!scanResult || method != ZipEntry::kCompressDeflated) {
473             ALOGD("this isn't a deflated gzip file?");
474             result = UNKNOWN_ERROR;
475             goto bail;
476         }
477 
478         result = copyPartialFpToFp(mZipFp, inputFp, compressedLen, NULL);
479         if (result != NO_ERROR) {
480             ALOGD("failed copying gzip data in\n");
481             goto bail;
482         }
483     } else {
484         assert(false);
485         result = UNKNOWN_ERROR;
486         goto bail;
487     }
488 
489     /*
490      * We could write the "Data Descriptor", but there doesn't seem to
491      * be any point since we're going to go back and write the LFH.
492      *
493      * Update file offsets.
494      */
495     endPosn = ftell(mZipFp);            // seeked to end of compressed data
496 
497     /*
498      * Success!  Fill out new values.
499      */
500     pEntry->setDataInfo(uncompressedLen, endPosn - startPosn, crc,
501         compressionMethod);
502     modWhen = getModTime(inputFp ? fileno(inputFp) : fileno(mZipFp));
503     pEntry->setModWhen(modWhen);
504     pEntry->setLFHOffset(lfhPosn);
505     mEOCD.mNumEntries++;
506     mEOCD.mTotalNumEntries++;
507     mEOCD.mCentralDirSize = 0;      // mark invalid; set by flush()
508     mEOCD.mCentralDirOffset = endPosn;
509 
510     /*
511      * Go back and write the LFH.
512      */
513     if (fseek(mZipFp, lfhPosn, SEEK_SET) != 0) {
514         result = UNKNOWN_ERROR;
515         goto bail;
516     }
517     pEntry->mLFH.write(mZipFp);
518 
519     /*
520      * Add pEntry to the list.
521      */
522     mEntries.add(pEntry);
523     if (ppEntry != NULL)
524         *ppEntry = pEntry;
525     pEntry = NULL;
526 
527 bail:
528     if (inputFp != NULL)
529         fclose(inputFp);
530     delete pEntry;
531     return result;
532 }
533 
534 /*
535  * Add an entry by copying it from another zip file.  If "padding" is
536  * nonzero, the specified number of bytes will be added to the "extra"
537  * field in the header.
538  *
539  * If "ppEntry" is non-NULL, a pointer to the new entry will be returned.
540  */
add(const ZipFile * pSourceZip,const ZipEntry * pSourceEntry,int padding,ZipEntry ** ppEntry)541 status_t ZipFile::add(const ZipFile* pSourceZip, const ZipEntry* pSourceEntry,
542     int padding, ZipEntry** ppEntry)
543 {
544     ZipEntry* pEntry = NULL;
545     status_t result;
546     long lfhPosn, endPosn;
547 
548     if (mReadOnly)
549         return INVALID_OPERATION;
550 
551     /* make sure we're in a reasonable state */
552     assert(mZipFp != NULL);
553     assert(mEntries.size() == mEOCD.mTotalNumEntries);
554 
555     if (fseek(mZipFp, mEOCD.mCentralDirOffset, SEEK_SET) != 0) {
556         result = UNKNOWN_ERROR;
557         goto bail;
558     }
559 
560     pEntry = new ZipEntry;
561     if (pEntry == NULL) {
562         result = NO_MEMORY;
563         goto bail;
564     }
565 
566     result = pEntry->initFromExternal(pSourceZip, pSourceEntry);
567     if (result != NO_ERROR)
568         goto bail;
569     if (padding != 0) {
570         result = pEntry->addPadding(padding);
571         if (result != NO_ERROR)
572             goto bail;
573     }
574 
575     /*
576      * From here on out, failures are more interesting.
577      */
578     mNeedCDRewrite = true;
579 
580     /*
581      * Write the LFH.  Since we're not recompressing the data, we already
582      * have all of the fields filled out.
583      */
584     lfhPosn = ftell(mZipFp);
585     pEntry->mLFH.write(mZipFp);
586 
587     /*
588      * Copy the data over.
589      *
590      * If the "has data descriptor" flag is set, we want to copy the DD
591      * fields as well.  This is a fixed-size area immediately following
592      * the data.
593      */
594     if (fseek(pSourceZip->mZipFp, pSourceEntry->getFileOffset(), SEEK_SET) != 0)
595     {
596         result = UNKNOWN_ERROR;
597         goto bail;
598     }
599 
600     off_t copyLen;
601     copyLen = pSourceEntry->getCompressedLen();
602     if ((pSourceEntry->mLFH.mGPBitFlag & ZipEntry::kUsesDataDescr) != 0)
603         copyLen += ZipEntry::kDataDescriptorLen;
604 
605     if (copyPartialFpToFp(mZipFp, pSourceZip->mZipFp, copyLen, NULL)
606         != NO_ERROR)
607     {
608         ALOGW("copy of '%s' failed\n", pEntry->mCDE.mFileName);
609         result = UNKNOWN_ERROR;
610         goto bail;
611     }
612 
613     /*
614      * Update file offsets.
615      */
616     endPosn = ftell(mZipFp);
617 
618     /*
619      * Success!  Fill out new values.
620      */
621     pEntry->setLFHOffset(lfhPosn);      // sets mCDE.mLocalHeaderRelOffset
622     mEOCD.mNumEntries++;
623     mEOCD.mTotalNumEntries++;
624     mEOCD.mCentralDirSize = 0;      // mark invalid; set by flush()
625     mEOCD.mCentralDirOffset = endPosn;
626 
627     /*
628      * Add pEntry to the list.
629      */
630     mEntries.add(pEntry);
631     if (ppEntry != NULL)
632         *ppEntry = pEntry;
633     pEntry = NULL;
634 
635     result = NO_ERROR;
636 
637 bail:
638     delete pEntry;
639     return result;
640 }
641 
642 /*
643  * Add an entry by copying it from another zip file, recompressing with
644  * Zopfli if already compressed.
645  *
646  * If "ppEntry" is non-NULL, a pointer to the new entry will be returned.
647  */
addRecompress(const ZipFile * pSourceZip,const ZipEntry * pSourceEntry,ZipEntry ** ppEntry)648 status_t ZipFile::addRecompress(const ZipFile* pSourceZip, const ZipEntry* pSourceEntry,
649     ZipEntry** ppEntry)
650 {
651     ZipEntry* pEntry = NULL;
652     status_t result;
653     long lfhPosn, startPosn, endPosn, uncompressedLen;
654 
655     if (mReadOnly)
656         return INVALID_OPERATION;
657 
658     /* make sure we're in a reasonable state */
659     assert(mZipFp != NULL);
660     assert(mEntries.size() == mEOCD.mTotalNumEntries);
661 
662     if (fseek(mZipFp, mEOCD.mCentralDirOffset, SEEK_SET) != 0) {
663         result = UNKNOWN_ERROR;
664         goto bail;
665     }
666 
667     pEntry = new ZipEntry;
668     if (pEntry == NULL) {
669         result = NO_MEMORY;
670         goto bail;
671     }
672 
673     result = pEntry->initFromExternal(pSourceZip, pSourceEntry);
674     if (result != NO_ERROR)
675         goto bail;
676 
677     /*
678      * From here on out, failures are more interesting.
679      */
680     mNeedCDRewrite = true;
681 
682     /*
683      * Write the LFH, even though it's still mostly blank.  We need it
684      * as a place-holder.  In theory the LFH isn't necessary, but in
685      * practice some utilities demand it.
686      */
687     lfhPosn = ftell(mZipFp);
688     pEntry->mLFH.write(mZipFp);
689     startPosn = ftell(mZipFp);
690 
691     /*
692      * Copy the data over.
693      *
694      * If the "has data descriptor" flag is set, we want to copy the DD
695      * fields as well.  This is a fixed-size area immediately following
696      * the data.
697      */
698     if (fseek(pSourceZip->mZipFp, pSourceEntry->getFileOffset(), SEEK_SET) != 0)
699     {
700         result = UNKNOWN_ERROR;
701         goto bail;
702     }
703 
704     uncompressedLen = pSourceEntry->getUncompressedLen();
705 
706     if (pSourceEntry->isCompressed()) {
707         void *buf = pSourceZip->uncompress(pSourceEntry);
708         if (buf == NULL) {
709             result = NO_MEMORY;
710             goto bail;
711         }
712         long startPosn = ftell(mZipFp);
713         unsigned long crc;
714         if (compressFpToFp(mZipFp, NULL, buf, uncompressedLen, &crc) != NO_ERROR) {
715             ALOGW("recompress of '%s' failed\n", pEntry->mCDE.mFileName);
716             result = UNKNOWN_ERROR;
717             free(buf);
718             goto bail;
719         }
720         long endPosn = ftell(mZipFp);
721         pEntry->setDataInfo(uncompressedLen, endPosn - startPosn,
722             pSourceEntry->getCRC32(), ZipEntry::kCompressDeflated);
723         free(buf);
724     } else {
725         off_t copyLen;
726         copyLen = pSourceEntry->getCompressedLen();
727         if ((pSourceEntry->mLFH.mGPBitFlag & ZipEntry::kUsesDataDescr) != 0)
728             copyLen += ZipEntry::kDataDescriptorLen;
729 
730         if (copyPartialFpToFp(mZipFp, pSourceZip->mZipFp, copyLen, NULL)
731             != NO_ERROR)
732         {
733             ALOGW("copy of '%s' failed\n", pEntry->mCDE.mFileName);
734             result = UNKNOWN_ERROR;
735             goto bail;
736         }
737     }
738 
739     /*
740      * Update file offsets.
741      */
742     endPosn = ftell(mZipFp);
743 
744     /*
745      * Success!  Fill out new values.
746      */
747     pEntry->setLFHOffset(lfhPosn);
748     mEOCD.mNumEntries++;
749     mEOCD.mTotalNumEntries++;
750     mEOCD.mCentralDirSize = 0;      // mark invalid; set by flush()
751     mEOCD.mCentralDirOffset = endPosn;
752 
753     /*
754      * Go back and write the LFH.
755      */
756     if (fseek(mZipFp, lfhPosn, SEEK_SET) != 0) {
757         result = UNKNOWN_ERROR;
758         goto bail;
759     }
760     pEntry->mLFH.write(mZipFp);
761 
762     /*
763      * Add pEntry to the list.
764      */
765     mEntries.add(pEntry);
766     if (ppEntry != NULL)
767         *ppEntry = pEntry;
768     pEntry = NULL;
769 
770     result = NO_ERROR;
771 
772 bail:
773     delete pEntry;
774     return result;
775 }
776 
777 /*
778  * Copy all of the bytes in "src" to "dst".
779  *
780  * On exit, "srcFp" will be seeked to the end of the file, and "dstFp"
781  * will be seeked immediately past the data.
782  */
copyFpToFp(FILE * dstFp,FILE * srcFp,unsigned long * pCRC32)783 status_t ZipFile::copyFpToFp(FILE* dstFp, FILE* srcFp, unsigned long* pCRC32)
784 {
785     unsigned char tmpBuf[32768];
786     size_t count;
787 
788     *pCRC32 = crc32(0L, Z_NULL, 0);
789 
790     while (1) {
791         count = fread(tmpBuf, 1, sizeof(tmpBuf), srcFp);
792         if (ferror(srcFp) || ferror(dstFp))
793             return errnoToStatus(errno);
794         if (count == 0)
795             break;
796 
797         *pCRC32 = crc32(*pCRC32, tmpBuf, count);
798 
799         if (fwrite(tmpBuf, 1, count, dstFp) != count) {
800             ALOGD("fwrite %d bytes failed\n", (int) count);
801             return UNKNOWN_ERROR;
802         }
803     }
804 
805     return NO_ERROR;
806 }
807 
808 /*
809  * Copy all of the bytes in "src" to "dst".
810  *
811  * On exit, "dstFp" will be seeked immediately past the data.
812  */
copyDataToFp(FILE * dstFp,const void * data,size_t size,unsigned long * pCRC32)813 status_t ZipFile::copyDataToFp(FILE* dstFp,
814     const void* data, size_t size, unsigned long* pCRC32)
815 {
816     size_t count;
817 
818     *pCRC32 = crc32(0L, Z_NULL, 0);
819     if (size > 0) {
820         *pCRC32 = crc32(*pCRC32, (const unsigned char*)data, size);
821         if (fwrite(data, 1, size, dstFp) != size) {
822             ALOGD("fwrite %d bytes failed\n", (int) size);
823             return UNKNOWN_ERROR;
824         }
825     }
826 
827     return NO_ERROR;
828 }
829 
830 /*
831  * Copy some of the bytes in "src" to "dst".
832  *
833  * If "pCRC32" is NULL, the CRC will not be computed.
834  *
835  * On exit, "srcFp" will be seeked to the end of the file, and "dstFp"
836  * will be seeked immediately past the data just written.
837  */
copyPartialFpToFp(FILE * dstFp,FILE * srcFp,long length,unsigned long * pCRC32)838 status_t ZipFile::copyPartialFpToFp(FILE* dstFp, FILE* srcFp, long length,
839     unsigned long* pCRC32)
840 {
841     unsigned char tmpBuf[32768];
842     size_t count;
843 
844     if (pCRC32 != NULL)
845         *pCRC32 = crc32(0L, Z_NULL, 0);
846 
847     while (length) {
848         long readSize;
849 
850         readSize = sizeof(tmpBuf);
851         if (readSize > length)
852             readSize = length;
853 
854         count = fread(tmpBuf, 1, readSize, srcFp);
855         if ((long) count != readSize) {     // error or unexpected EOF
856             ALOGD("fread %d bytes failed\n", (int) readSize);
857             return UNKNOWN_ERROR;
858         }
859 
860         if (pCRC32 != NULL)
861             *pCRC32 = crc32(*pCRC32, tmpBuf, count);
862 
863         if (fwrite(tmpBuf, 1, count, dstFp) != count) {
864             ALOGD("fwrite %d bytes failed\n", (int) count);
865             return UNKNOWN_ERROR;
866         }
867 
868         length -= readSize;
869     }
870 
871     return NO_ERROR;
872 }
873 
874 /*
875  * Compress all of the data in "srcFp" and write it to "dstFp".
876  *
877  * On exit, "srcFp" will be seeked to the end of the file, and "dstFp"
878  * will be seeked immediately past the compressed data.
879  */
compressFpToFp(FILE * dstFp,FILE * srcFp,const void * data,size_t size,unsigned long * pCRC32)880 status_t ZipFile::compressFpToFp(FILE* dstFp, FILE* srcFp,
881     const void* data, size_t size, unsigned long* pCRC32)
882 {
883     status_t result = NO_ERROR;
884     const size_t kBufSize = 1024 * 1024;
885     unsigned char* inBuf = NULL;
886     unsigned char* outBuf = NULL;
887     size_t outSize = 0;
888     bool atEof = false;     // no feof() aviailable yet
889     unsigned long crc;
890     ZopfliOptions options;
891     unsigned char bp = 0;
892 
893     ZopfliInitOptions(&options);
894 
895     crc = crc32(0L, Z_NULL, 0);
896 
897     if (data) {
898         crc = crc32(crc, (const unsigned char*)data, size);
899         ZopfliDeflate(&options, 2, true, (const unsigned char*)data, size, &bp,
900             &outBuf, &outSize);
901     } else {
902         /*
903          * Create an input buffer and an output buffer.
904          */
905         inBuf = new unsigned char[kBufSize];
906         if (inBuf == NULL) {
907             result = NO_MEMORY;
908             goto bail;
909         }
910 
911         /*
912          * Loop while we have data.
913          */
914         do {
915             size_t getSize;
916             getSize = fread(inBuf, 1, kBufSize, srcFp);
917             if (ferror(srcFp)) {
918                 ALOGD("deflate read failed (errno=%d)\n", errno);
919                 delete[] inBuf;
920                 goto bail;
921             }
922             if (getSize < kBufSize) {
923                 ALOGV("+++  got %d bytes, EOF reached\n",
924                     (int)getSize);
925                 atEof = true;
926             }
927 
928             crc = crc32(crc, inBuf, getSize);
929             ZopfliDeflate(&options, 2, atEof, inBuf, getSize, &bp, &outBuf, &outSize);
930         } while (!atEof);
931         delete[] inBuf;
932     }
933 
934     ALOGV("+++ writing %d bytes\n", (int)outSize);
935     if (fwrite(outBuf, 1, outSize, dstFp) != outSize) {
936         ALOGD("write %d failed in deflate\n", (int)outSize);
937         goto bail;
938     }
939 
940     *pCRC32 = crc;
941 
942 bail:
943     free(outBuf);
944 
945     return result;
946 }
947 
948 /*
949  * Mark an entry as deleted.
950  *
951  * We will eventually need to crunch the file down, but if several files
952  * are being removed (perhaps as part of an "update" process) we can make
953  * things considerably faster by deferring the removal to "flush" time.
954  */
remove(ZipEntry * pEntry)955 status_t ZipFile::remove(ZipEntry* pEntry)
956 {
957     /*
958      * Should verify that pEntry is actually part of this archive, and
959      * not some stray ZipEntry from a different file.
960      */
961 
962     /* mark entry as deleted, and mark archive as dirty */
963     pEntry->setDeleted();
964     mNeedCDRewrite = true;
965     return NO_ERROR;
966 }
967 
968 /*
969  * Flush any pending writes.
970  *
971  * In particular, this will crunch out deleted entries, and write the
972  * Central Directory and EOCD if we have stomped on them.
973  */
flush(void)974 status_t ZipFile::flush(void)
975 {
976     status_t result = NO_ERROR;
977     long eocdPosn;
978     int i, count;
979 
980     if (mReadOnly)
981         return INVALID_OPERATION;
982     if (!mNeedCDRewrite)
983         return NO_ERROR;
984 
985     assert(mZipFp != NULL);
986 
987     result = crunchArchive();
988     if (result != NO_ERROR)
989         return result;
990 
991     if (fseek(mZipFp, mEOCD.mCentralDirOffset, SEEK_SET) != 0)
992         return UNKNOWN_ERROR;
993 
994     count = mEntries.size();
995     for (i = 0; i < count; i++) {
996         ZipEntry* pEntry = mEntries[i];
997         pEntry->mCDE.write(mZipFp);
998     }
999 
1000     eocdPosn = ftell(mZipFp);
1001     mEOCD.mCentralDirSize = eocdPosn - mEOCD.mCentralDirOffset;
1002 
1003     mEOCD.write(mZipFp);
1004 
1005     /*
1006      * If we had some stuff bloat up during compression and get replaced
1007      * with plain files, or if we deleted some entries, there's a lot
1008      * of wasted space at the end of the file.  Remove it now.
1009      */
1010     if (ftruncate(fileno(mZipFp), ftell(mZipFp)) != 0) {
1011         ALOGW("ftruncate failed %ld: %s\n", ftell(mZipFp), strerror(errno));
1012         // not fatal
1013     }
1014 
1015     /* should we clear the "newly added" flag in all entries now? */
1016 
1017     mNeedCDRewrite = false;
1018     return NO_ERROR;
1019 }
1020 
1021 /*
1022  * Crunch deleted files out of an archive by shifting the later files down.
1023  *
1024  * Because we're not using a temp file, we do the operation inside the
1025  * current file.
1026  */
crunchArchive(void)1027 status_t ZipFile::crunchArchive(void)
1028 {
1029     status_t result = NO_ERROR;
1030     int i, count;
1031     long delCount, adjust;
1032 
1033 #if 0
1034     printf("CONTENTS:\n");
1035     for (i = 0; i < (int) mEntries.size(); i++) {
1036         printf(" %d: lfhOff=%ld del=%d\n",
1037             i, mEntries[i]->getLFHOffset(), mEntries[i]->getDeleted());
1038     }
1039     printf("  END is %ld\n", (long) mEOCD.mCentralDirOffset);
1040 #endif
1041 
1042     /*
1043      * Roll through the set of files, shifting them as appropriate.  We
1044      * could probably get a slight performance improvement by sliding
1045      * multiple files down at once (because we could use larger reads
1046      * when operating on batches of small files), but it's not that useful.
1047      */
1048     count = mEntries.size();
1049     delCount = adjust = 0;
1050     for (i = 0; i < count; i++) {
1051         ZipEntry* pEntry = mEntries[i];
1052         long span;
1053 
1054         if (pEntry->getLFHOffset() != 0) {
1055             long nextOffset;
1056 
1057             /* Get the length of this entry by finding the offset
1058              * of the next entry.  Directory entries don't have
1059              * file offsets, so we need to find the next non-directory
1060              * entry.
1061              */
1062             nextOffset = 0;
1063             for (int ii = i+1; nextOffset == 0 && ii < count; ii++)
1064                 nextOffset = mEntries[ii]->getLFHOffset();
1065             if (nextOffset == 0)
1066                 nextOffset = mEOCD.mCentralDirOffset;
1067             span = nextOffset - pEntry->getLFHOffset();
1068 
1069             assert(span >= ZipEntry::LocalFileHeader::kLFHLen);
1070         } else {
1071             /* This is a directory entry.  It doesn't have
1072              * any actual file contents, so there's no need to
1073              * move anything.
1074              */
1075             span = 0;
1076         }
1077 
1078         //printf("+++ %d: off=%ld span=%ld del=%d [count=%d]\n",
1079         //    i, pEntry->getLFHOffset(), span, pEntry->getDeleted(), count);
1080 
1081         if (pEntry->getDeleted()) {
1082             adjust += span;
1083             delCount++;
1084 
1085             delete pEntry;
1086             mEntries.removeAt(i);
1087 
1088             /* adjust loop control */
1089             count--;
1090             i--;
1091         } else if (span != 0 && adjust > 0) {
1092             /* shuffle this entry back */
1093             //printf("+++ Shuffling '%s' back %ld\n",
1094             //    pEntry->getFileName(), adjust);
1095             result = filemove(mZipFp, pEntry->getLFHOffset() - adjust,
1096                         pEntry->getLFHOffset(), span);
1097             if (result != NO_ERROR) {
1098                 /* this is why you use a temp file */
1099                 ALOGE("error during crunch - archive is toast\n");
1100                 return result;
1101             }
1102 
1103             pEntry->setLFHOffset(pEntry->getLFHOffset() - adjust);
1104         }
1105     }
1106 
1107     /*
1108      * Fix EOCD info.  We have to wait until the end to do some of this
1109      * because we use mCentralDirOffset to determine "span" for the
1110      * last entry.
1111      */
1112     mEOCD.mCentralDirOffset -= adjust;
1113     mEOCD.mNumEntries -= delCount;
1114     mEOCD.mTotalNumEntries -= delCount;
1115     mEOCD.mCentralDirSize = 0;  // mark invalid; set by flush()
1116 
1117     assert(mEOCD.mNumEntries == mEOCD.mTotalNumEntries);
1118     assert(mEOCD.mNumEntries == count);
1119 
1120     return result;
1121 }
1122 
1123 /*
1124  * Works like memmove(), but on pieces of a file.
1125  */
filemove(FILE * fp,off_t dst,off_t src,size_t n)1126 status_t ZipFile::filemove(FILE* fp, off_t dst, off_t src, size_t n)
1127 {
1128     if (dst == src || n <= 0)
1129         return NO_ERROR;
1130 
1131     unsigned char readBuf[32768];
1132 
1133     if (dst < src) {
1134         /* shift stuff toward start of file; must read from start */
1135         while (n != 0) {
1136             size_t getSize = sizeof(readBuf);
1137             if (getSize > n)
1138                 getSize = n;
1139 
1140             if (fseek(fp, (long) src, SEEK_SET) != 0) {
1141                 ALOGD("filemove src seek %ld failed\n", (long) src);
1142                 return UNKNOWN_ERROR;
1143             }
1144 
1145             if (fread(readBuf, 1, getSize, fp) != getSize) {
1146                 ALOGD("filemove read %ld off=%ld failed\n",
1147                     (long) getSize, (long) src);
1148                 return UNKNOWN_ERROR;
1149             }
1150 
1151             if (fseek(fp, (long) dst, SEEK_SET) != 0) {
1152                 ALOGD("filemove dst seek %ld failed\n", (long) dst);
1153                 return UNKNOWN_ERROR;
1154             }
1155 
1156             if (fwrite(readBuf, 1, getSize, fp) != getSize) {
1157                 ALOGD("filemove write %ld off=%ld failed\n",
1158                     (long) getSize, (long) dst);
1159                 return UNKNOWN_ERROR;
1160             }
1161 
1162             src += getSize;
1163             dst += getSize;
1164             n -= getSize;
1165         }
1166     } else {
1167         /* shift stuff toward end of file; must read from end */
1168         assert(false);      // write this someday, maybe
1169         return UNKNOWN_ERROR;
1170     }
1171 
1172     return NO_ERROR;
1173 }
1174 
1175 
1176 /*
1177  * Get the modification time from a file descriptor.
1178  */
getModTime(int fd)1179 time_t ZipFile::getModTime(int fd)
1180 {
1181     struct stat sb;
1182 
1183     if (fstat(fd, &sb) < 0) {
1184         ALOGD("HEY: fstat on fd %d failed\n", fd);
1185         return (time_t) -1;
1186     }
1187 
1188     return sb.st_mtime;
1189 }
1190 
1191 
1192 #if 0       /* this is a bad idea */
1193 /*
1194  * Get a copy of the Zip file descriptor.
1195  *
1196  * We don't allow this if the file was opened read-write because we tend
1197  * to leave the file contents in an uncertain state between calls to
1198  * flush().  The duplicated file descriptor should only be valid for reads.
1199  */
1200 int ZipFile::getZipFd(void) const
1201 {
1202     if (!mReadOnly)
1203         return INVALID_OPERATION;
1204     assert(mZipFp != NULL);
1205 
1206     int fd;
1207     fd = dup(fileno(mZipFp));
1208     if (fd < 0) {
1209         ALOGD("didn't work, errno=%d\n", errno);
1210     }
1211 
1212     return fd;
1213 }
1214 #endif
1215 
1216 
1217 #if 0
1218 /*
1219  * Expand data.
1220  */
1221 bool ZipFile::uncompress(const ZipEntry* pEntry, void* buf) const
1222 {
1223     return false;
1224 }
1225 #endif
1226 
1227 // free the memory when you're done
uncompress(const ZipEntry * entry) const1228 void* ZipFile::uncompress(const ZipEntry* entry) const
1229 {
1230     size_t unlen = entry->getUncompressedLen();
1231     size_t clen = entry->getCompressedLen();
1232 
1233     void* buf = malloc(unlen);
1234     if (buf == NULL) {
1235         return NULL;
1236     }
1237 
1238     fseek(mZipFp, 0, SEEK_SET);
1239 
1240     off_t offset = entry->getFileOffset();
1241     if (fseek(mZipFp, offset, SEEK_SET) != 0) {
1242         goto bail;
1243     }
1244 
1245     switch (entry->getCompressionMethod())
1246     {
1247         case ZipEntry::kCompressStored: {
1248             ssize_t amt = fread(buf, 1, unlen, mZipFp);
1249             if (amt != (ssize_t)unlen) {
1250                 goto bail;
1251             }
1252 #if 0
1253             printf("data...\n");
1254             const unsigned char* p = (unsigned char*)buf;
1255             const unsigned char* end = p+unlen;
1256             for (int i=0; i<32 && p < end; i++) {
1257                 printf("0x%08x ", (int)(offset+(i*0x10)));
1258                 for (int j=0; j<0x10 && p < end; j++) {
1259                     printf(" %02x", *p);
1260                     p++;
1261                 }
1262                 printf("\n");
1263             }
1264 #endif
1265 
1266             }
1267             break;
1268         case ZipEntry::kCompressDeflated: {
1269             if (!ZipUtils::inflateToBuffer(mZipFp, buf, unlen, clen)) {
1270                 goto bail;
1271             }
1272             }
1273             break;
1274         default:
1275             goto bail;
1276     }
1277     return buf;
1278 
1279 bail:
1280     free(buf);
1281     return NULL;
1282 }
1283 
1284 
1285 /*
1286  * ===========================================================================
1287  *      ZipFile::EndOfCentralDir
1288  * ===========================================================================
1289  */
1290 
1291 /*
1292  * Read the end-of-central-dir fields.
1293  *
1294  * "buf" should be positioned at the EOCD signature, and should contain
1295  * the entire EOCD area including the comment.
1296  */
readBuf(const unsigned char * buf,int len)1297 status_t ZipFile::EndOfCentralDir::readBuf(const unsigned char* buf, int len)
1298 {
1299     /* don't allow re-use */
1300     assert(mComment == NULL);
1301 
1302     if (len < kEOCDLen) {
1303         /* looks like ZIP file got truncated */
1304         ALOGD(" Zip EOCD: expected >= %d bytes, found %d\n",
1305             kEOCDLen, len);
1306         return INVALID_OPERATION;
1307     }
1308 
1309     /* this should probably be an assert() */
1310     if (ZipEntry::getLongLE(&buf[0x00]) != kSignature)
1311         return UNKNOWN_ERROR;
1312 
1313     mDiskNumber = ZipEntry::getShortLE(&buf[0x04]);
1314     mDiskWithCentralDir = ZipEntry::getShortLE(&buf[0x06]);
1315     mNumEntries = ZipEntry::getShortLE(&buf[0x08]);
1316     mTotalNumEntries = ZipEntry::getShortLE(&buf[0x0a]);
1317     mCentralDirSize = ZipEntry::getLongLE(&buf[0x0c]);
1318     mCentralDirOffset = ZipEntry::getLongLE(&buf[0x10]);
1319     mCommentLen = ZipEntry::getShortLE(&buf[0x14]);
1320 
1321     // TODO: validate mCentralDirOffset
1322 
1323     if (mCommentLen > 0) {
1324         if (kEOCDLen + mCommentLen > len) {
1325             ALOGD("EOCD(%d) + comment(%d) exceeds len (%d)\n",
1326                 kEOCDLen, mCommentLen, len);
1327             return UNKNOWN_ERROR;
1328         }
1329         mComment = new unsigned char[mCommentLen];
1330         memcpy(mComment, buf + kEOCDLen, mCommentLen);
1331     }
1332 
1333     return NO_ERROR;
1334 }
1335 
1336 /*
1337  * Write an end-of-central-directory section.
1338  */
write(FILE * fp)1339 status_t ZipFile::EndOfCentralDir::write(FILE* fp)
1340 {
1341     unsigned char buf[kEOCDLen];
1342 
1343     ZipEntry::putLongLE(&buf[0x00], kSignature);
1344     ZipEntry::putShortLE(&buf[0x04], mDiskNumber);
1345     ZipEntry::putShortLE(&buf[0x06], mDiskWithCentralDir);
1346     ZipEntry::putShortLE(&buf[0x08], mNumEntries);
1347     ZipEntry::putShortLE(&buf[0x0a], mTotalNumEntries);
1348     ZipEntry::putLongLE(&buf[0x0c], mCentralDirSize);
1349     ZipEntry::putLongLE(&buf[0x10], mCentralDirOffset);
1350     ZipEntry::putShortLE(&buf[0x14], mCommentLen);
1351 
1352     if (fwrite(buf, 1, kEOCDLen, fp) != kEOCDLen)
1353         return UNKNOWN_ERROR;
1354     if (mCommentLen > 0) {
1355         assert(mComment != NULL);
1356         if (fwrite(mComment, mCommentLen, 1, fp) != mCommentLen)
1357             return UNKNOWN_ERROR;
1358     }
1359 
1360     return NO_ERROR;
1361 }
1362 
1363 /*
1364  * Dump the contents of an EndOfCentralDir object.
1365  */
dump(void) const1366 void ZipFile::EndOfCentralDir::dump(void) const
1367 {
1368     ALOGD(" EndOfCentralDir contents:\n");
1369     ALOGD("  diskNum=%u diskWCD=%u numEnt=%u totalNumEnt=%u\n",
1370         mDiskNumber, mDiskWithCentralDir, mNumEntries, mTotalNumEntries);
1371     ALOGD("  centDirSize=%lu centDirOff=%lu commentLen=%u\n",
1372         mCentralDirSize, mCentralDirOffset, mCommentLen);
1373 }
1374 
1375