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 using namespace android;
38 
39 class _ZipEntryRO {
40 public:
41     ZipEntry entry;
42     std::string_view name;
43     void *cookie;
44 
_ZipEntryRO()45     _ZipEntryRO() : cookie(NULL) {}
46 
~_ZipEntryRO()47     ~_ZipEntryRO() {
48       EndIteration(cookie);
49     }
50 
51 private:
52     _ZipEntryRO(const _ZipEntryRO& other);
53     _ZipEntryRO& operator=(const _ZipEntryRO& other);
54 };
55 
~ZipFileRO()56 ZipFileRO::~ZipFileRO() {
57     CloseArchive(mHandle);
58     if (mFileName != NULL) {
59         free(mFileName);
60     }
61 }
62 
63 /*
64  * Open the specified file read-only.  We memory-map the entire thing and
65  * close the file before returning.
66  */
open(const char * zipFileName)67 /* static */ ZipFileRO* ZipFileRO::open(const char* zipFileName)
68 {
69     ZipArchiveHandle handle;
70     const int32_t error = OpenArchive(zipFileName, &handle);
71     if (error) {
72         ALOGW("Error opening archive %s: %s", zipFileName, ErrorCodeString(error));
73         CloseArchive(handle);
74         return NULL;
75     }
76 
77     return new ZipFileRO(handle, strdup(zipFileName));
78 }
79 
80 
openFd(int fd,const char * debugFileName,bool assume_ownership)81 /* static */ ZipFileRO* ZipFileRO::openFd(int fd, const char* debugFileName,
82         bool assume_ownership)
83 {
84     ZipArchiveHandle handle;
85     const int32_t error = OpenArchiveFd(fd, debugFileName, &handle, assume_ownership);
86     if (error) {
87         ALOGW("Error opening archive fd %d %s: %s", fd, debugFileName, ErrorCodeString(error));
88         CloseArchive(handle);
89         return NULL;
90     }
91 
92     return new ZipFileRO(handle, strdup(debugFileName));
93 }
94 
findEntryByName(const char * entryName) const95 ZipEntryRO ZipFileRO::findEntryByName(const char* entryName) const
96 {
97     _ZipEntryRO* data = new _ZipEntryRO;
98 
99     data->name = entryName;
100 
101     const int32_t error = FindEntry(mHandle, entryName, &(data->entry));
102     if (error) {
103         delete data;
104         return NULL;
105     }
106 
107     return (ZipEntryRO) data;
108 }
109 
110 /*
111  * Get the useful fields from the zip entry.
112  *
113  * Returns "false" if the offsets to the fields or the contents of the fields
114  * appear to be bogus.
115  */
getEntryInfo(ZipEntryRO entry,uint16_t * pMethod,uint32_t * pUncompLen,uint32_t * pCompLen,off64_t * pOffset,uint32_t * pModWhen,uint32_t * pCrc32) const116 bool ZipFileRO::getEntryInfo(ZipEntryRO entry, uint16_t* pMethod,
117     uint32_t* pUncompLen, uint32_t* pCompLen, off64_t* pOffset,
118     uint32_t* pModWhen, uint32_t* pCrc32) const
119 {
120     const _ZipEntryRO* zipEntry = reinterpret_cast<_ZipEntryRO*>(entry);
121     const ZipEntry& ze = zipEntry->entry;
122 
123     if (pMethod != NULL) {
124         *pMethod = ze.method;
125     }
126     if (pUncompLen != NULL) {
127         *pUncompLen = ze.uncompressed_length;
128     }
129     if (pCompLen != NULL) {
130         *pCompLen = ze.compressed_length;
131     }
132     if (pOffset != NULL) {
133         *pOffset = ze.offset;
134     }
135     if (pModWhen != NULL) {
136         *pModWhen = ze.mod_time;
137     }
138     if (pCrc32 != NULL) {
139         *pCrc32 = ze.crc32;
140     }
141 
142     return true;
143 }
144 
startIteration(void ** cookie)145 bool ZipFileRO::startIteration(void** cookie) {
146   return startIteration(cookie, NULL, NULL);
147 }
148 
startIteration(void ** cookie,const char * prefix,const char * suffix)149 bool ZipFileRO::startIteration(void** cookie, const char* prefix, const char* suffix)
150 {
151     _ZipEntryRO* ze = new _ZipEntryRO;
152     int32_t error = StartIteration(mHandle, &(ze->cookie),
153                                    prefix ? prefix : "", suffix ? suffix : "");
154     if (error) {
155         ALOGW("Could not start iteration over %s: %s", mFileName != NULL ? mFileName : "<null>",
156                 ErrorCodeString(error));
157         delete ze;
158         return false;
159     }
160 
161     *cookie = ze;
162     return true;
163 }
164 
nextEntry(void * cookie)165 ZipEntryRO ZipFileRO::nextEntry(void* cookie)
166 {
167     _ZipEntryRO* ze = reinterpret_cast<_ZipEntryRO*>(cookie);
168     int32_t error = Next(ze->cookie, &(ze->entry), &(ze->name));
169     if (error) {
170         if (error != -1) {
171             ALOGW("Error iteration over %s: %s", mFileName != NULL ? mFileName : "<null>",
172                     ErrorCodeString(error));
173         }
174         return NULL;
175     }
176 
177     return &(ze->entry);
178 }
179 
endIteration(void * cookie)180 void ZipFileRO::endIteration(void* cookie)
181 {
182     delete reinterpret_cast<_ZipEntryRO*>(cookie);
183 }
184 
releaseEntry(ZipEntryRO entry) const185 void ZipFileRO::releaseEntry(ZipEntryRO entry) const
186 {
187     delete reinterpret_cast<_ZipEntryRO*>(entry);
188 }
189 
190 /*
191  * Copy the entry's filename to the buffer.
192  */
getEntryFileName(ZipEntryRO entry,char * buffer,size_t bufLen) const193 int ZipFileRO::getEntryFileName(ZipEntryRO entry, char* buffer, size_t bufLen)
194     const
195 {
196     const _ZipEntryRO* zipEntry = reinterpret_cast<_ZipEntryRO*>(entry);
197     const uint16_t requiredSize = zipEntry->name.length() + 1;
198 
199     if (bufLen < requiredSize) {
200         ALOGW("Buffer too short, requires %d bytes for entry name", requiredSize);
201         return requiredSize;
202     }
203 
204     memcpy(buffer, zipEntry->name.data(), requiredSize - 1);
205     buffer[requiredSize - 1] = '\0';
206 
207     return 0;
208 }
209 
210 /*
211  * Create a new FileMap object that spans the data in "entry".
212  */
createEntryFileMap(ZipEntryRO entry) const213 FileMap* ZipFileRO::createEntryFileMap(ZipEntryRO entry) const
214 {
215     const _ZipEntryRO *zipEntry = reinterpret_cast<_ZipEntryRO*>(entry);
216     const ZipEntry& ze = zipEntry->entry;
217     int fd = GetFileDescriptor(mHandle);
218     size_t actualLen = 0;
219 
220     if (ze.method == kCompressStored) {
221         actualLen = ze.uncompressed_length;
222     } else {
223         actualLen = ze.compressed_length;
224     }
225 
226     FileMap* newMap = new FileMap();
227     if (!newMap->create(mFileName, fd, ze.offset, actualLen, true)) {
228         delete newMap;
229         return NULL;
230     }
231 
232     return newMap;
233 }
234 
235 /*
236  * Uncompress an entry, in its entirety, into the provided output buffer.
237  *
238  * This doesn't verify the data's CRC, which might be useful for
239  * uncompressed data.  The caller should be able to manage it.
240  */
uncompressEntry(ZipEntryRO entry,void * buffer,size_t size) const241 bool ZipFileRO::uncompressEntry(ZipEntryRO entry, void* buffer, size_t size) const
242 {
243     _ZipEntryRO *zipEntry = reinterpret_cast<_ZipEntryRO*>(entry);
244     const int32_t error = ExtractToMemory(mHandle, &(zipEntry->entry),
245         (uint8_t*) buffer, size);
246     if (error) {
247         ALOGW("ExtractToMemory failed with %s", ErrorCodeString(error));
248         return false;
249     }
250 
251     return true;
252 }
253 
254 /*
255  * Uncompress an entry, in its entirety, to an open file descriptor.
256  *
257  * This doesn't verify the data's CRC, but probably should.
258  */
uncompressEntry(ZipEntryRO entry,int fd) const259 bool ZipFileRO::uncompressEntry(ZipEntryRO entry, int fd) const
260 {
261     _ZipEntryRO *zipEntry = reinterpret_cast<_ZipEntryRO*>(entry);
262     const int32_t error = ExtractEntryToFile(mHandle, &(zipEntry->entry), fd);
263     if (error) {
264         ALOGW("ExtractToMemory failed with %s", ErrorCodeString(error));
265         return false;
266     }
267 
268     return true;
269 }
270