1 /*
2  * Copyright (C) 2007 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 // Read-only access to Zip archives, with minimal heap allocation.
19 //
20 #define LOG_TAG "zipro"
21 //#define LOG_NDEBUG 0
22 #include <androidfw/ZipFileRO.h>
23 #include <utils/Log.h>
24 #include <utils/Compat.h>
25 #include <utils/misc.h>
26 #include <utils/threads.h>
27 #include <ziparchive/zip_archive.h>
28 
29 #include <zlib.h>
30 
31 #include <string.h>
32 #include <fcntl.h>
33 #include <errno.h>
34 #include <assert.h>
35 #include <unistd.h>
36 
37 /*
38  * We must open binary files using open(path, ... | O_BINARY) under Windows.
39  * Otherwise strange read errors will happen.
40  */
41 #ifndef O_BINARY
42 #  define O_BINARY  0
43 #endif
44 
45 using namespace android;
46 
47 class _ZipEntryRO {
48 public:
49     ZipEntry entry;
50     ZipEntryName name;
51     void *cookie;
52 
_ZipEntryRO()53     _ZipEntryRO() : cookie(NULL) {
54     }
55 
56 private:
57     _ZipEntryRO(const _ZipEntryRO& other);
58     _ZipEntryRO& operator=(const _ZipEntryRO& other);
59 };
60 
~ZipFileRO()61 ZipFileRO::~ZipFileRO() {
62     CloseArchive(mHandle);
63     free(mFileName);
64 }
65 
66 /*
67  * Open the specified file read-only.  We memory-map the entire thing and
68  * close the file before returning.
69  */
open(const char * zipFileName)70 /* static */ ZipFileRO* ZipFileRO::open(const char* zipFileName)
71 {
72     ZipArchiveHandle handle;
73     const int32_t error = OpenArchive(zipFileName, &handle);
74     if (error) {
75         ALOGW("Error opening archive %s: %s", zipFileName, ErrorCodeString(error));
76         return NULL;
77     }
78 
79     return new ZipFileRO(handle, strdup(zipFileName));
80 }
81 
82 
findEntryByName(const char * entryName) const83 ZipEntryRO ZipFileRO::findEntryByName(const char* entryName) const
84 {
85     _ZipEntryRO* data = new _ZipEntryRO;
86     const int32_t error = FindEntry(mHandle, entryName, &(data->entry));
87     if (error) {
88         delete data;
89         return NULL;
90     }
91 
92     data->name.name = entryName;
93     data->name.name_length = strlen(entryName);
94 
95     return (ZipEntryRO) data;
96 }
97 
98 /*
99  * Get the useful fields from the zip entry.
100  *
101  * Returns "false" if the offsets to the fields or the contents of the fields
102  * appear to be bogus.
103  */
getEntryInfo(ZipEntryRO entry,int * pMethod,size_t * pUncompLen,size_t * pCompLen,off64_t * pOffset,long * pModWhen,long * pCrc32) const104 bool ZipFileRO::getEntryInfo(ZipEntryRO entry, int* pMethod, size_t* pUncompLen,
105     size_t* pCompLen, off64_t* pOffset, long* pModWhen, long* pCrc32) const
106 {
107     const _ZipEntryRO* zipEntry = reinterpret_cast<_ZipEntryRO*>(entry);
108     const ZipEntry& ze = zipEntry->entry;
109 
110     if (pMethod != NULL) {
111         *pMethod = ze.method;
112     }
113     if (pUncompLen != NULL) {
114         *pUncompLen = ze.uncompressed_length;
115     }
116     if (pCompLen != NULL) {
117         *pCompLen = ze.compressed_length;
118     }
119     if (pOffset != NULL) {
120         *pOffset = ze.offset;
121     }
122     if (pModWhen != NULL) {
123         *pModWhen = ze.mod_time;
124     }
125     if (pCrc32 != NULL) {
126         *pCrc32 = ze.crc32;
127     }
128 
129     return true;
130 }
131 
startIteration(void ** cookie)132 bool ZipFileRO::startIteration(void** cookie)
133 {
134     _ZipEntryRO* ze = new _ZipEntryRO;
135     int32_t error = StartIteration(mHandle, &(ze->cookie), NULL /* prefix */);
136     if (error) {
137         ALOGW("Could not start iteration over %s: %s", mFileName, ErrorCodeString(error));
138         delete ze;
139         return false;
140     }
141 
142     *cookie = ze;
143     return true;
144 }
145 
nextEntry(void * cookie)146 ZipEntryRO ZipFileRO::nextEntry(void* cookie)
147 {
148     _ZipEntryRO* ze = reinterpret_cast<_ZipEntryRO*>(cookie);
149     int32_t error = Next(ze->cookie, &(ze->entry), &(ze->name));
150     if (error) {
151         if (error != -1) {
152             ALOGW("Error iteration over %s: %s", mFileName, ErrorCodeString(error));
153         }
154         return NULL;
155     }
156 
157     return &(ze->entry);
158 }
159 
endIteration(void * cookie)160 void ZipFileRO::endIteration(void* cookie)
161 {
162     delete reinterpret_cast<_ZipEntryRO*>(cookie);
163 }
164 
releaseEntry(ZipEntryRO entry) const165 void ZipFileRO::releaseEntry(ZipEntryRO entry) const
166 {
167     delete reinterpret_cast<_ZipEntryRO*>(entry);
168 }
169 
170 /*
171  * Copy the entry's filename to the buffer.
172  */
getEntryFileName(ZipEntryRO entry,char * buffer,int bufLen) const173 int ZipFileRO::getEntryFileName(ZipEntryRO entry, char* buffer, int bufLen)
174     const
175 {
176     const _ZipEntryRO* zipEntry = reinterpret_cast<_ZipEntryRO*>(entry);
177     const uint16_t requiredSize = zipEntry->name.name_length + 1;
178 
179     if (bufLen < requiredSize) {
180         ALOGW("Buffer too short, requires %d bytes for entry name", requiredSize);
181         return requiredSize;
182     }
183 
184     memcpy(buffer, zipEntry->name.name, requiredSize - 1);
185     buffer[requiredSize - 1] = '\0';
186 
187     return 0;
188 }
189 
190 /*
191  * Create a new FileMap object that spans the data in "entry".
192  */
createEntryFileMap(ZipEntryRO entry) const193 FileMap* ZipFileRO::createEntryFileMap(ZipEntryRO entry) const
194 {
195     const _ZipEntryRO *zipEntry = reinterpret_cast<_ZipEntryRO*>(entry);
196     const ZipEntry& ze = zipEntry->entry;
197     int fd = GetFileDescriptor(mHandle);
198     size_t actualLen = 0;
199 
200     if (ze.method == kCompressStored) {
201         actualLen = ze.uncompressed_length;
202     } else {
203         actualLen = ze.compressed_length;
204     }
205 
206     FileMap* newMap = new FileMap();
207     if (!newMap->create(mFileName, fd, ze.offset, actualLen, true)) {
208         newMap->release();
209         return NULL;
210     }
211 
212     return newMap;
213 }
214 
215 /*
216  * Uncompress an entry, in its entirety, into the provided output buffer.
217  *
218  * This doesn't verify the data's CRC, which might be useful for
219  * uncompressed data.  The caller should be able to manage it.
220  */
uncompressEntry(ZipEntryRO entry,void * buffer,size_t size) const221 bool ZipFileRO::uncompressEntry(ZipEntryRO entry, void* buffer, size_t size) const
222 {
223     _ZipEntryRO *zipEntry = reinterpret_cast<_ZipEntryRO*>(entry);
224     const int32_t error = ExtractToMemory(mHandle, &(zipEntry->entry),
225         (uint8_t*) buffer, size);
226     if (error) {
227         ALOGW("ExtractToMemory failed with %s", ErrorCodeString(error));
228         return false;
229     }
230 
231     return true;
232 }
233 
234 /*
235  * Uncompress an entry, in its entirety, to an open file descriptor.
236  *
237  * This doesn't verify the data's CRC, but probably should.
238  */
uncompressEntry(ZipEntryRO entry,int fd) const239 bool ZipFileRO::uncompressEntry(ZipEntryRO entry, int fd) const
240 {
241     _ZipEntryRO *zipEntry = reinterpret_cast<_ZipEntryRO*>(entry);
242     const int32_t error = ExtractEntryToFile(mHandle, &(zipEntry->entry), fd);
243     if (error) {
244         ALOGW("ExtractToMemory failed with %s", ErrorCodeString(error));
245         return false;
246     }
247 
248     return true;
249 }
250