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1 /*
2  * Copyright (C) 2008 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  * Some utility functions for use with command-line utilities.
18  */
19 #include "DexFile.h"
20 #include "ZipArchive.h"
21 #include "CmdUtils.h"
22 
23 #include <stdlib.h>
24 #include <string.h>
25 #include <strings.h>
26 #include <fcntl.h>
27 #include <errno.h>
28 
29 #ifndef O_BINARY
30 #define O_BINARY 0
31 #endif
32 
33 /*
34  * Extract "classes.dex" from archive file.
35  *
36  * If "quiet" is set, don't report common errors.
37  */
dexUnzipToFile(const char * zipFileName,const char * outFileName,bool quiet)38 UnzipToFileResult dexUnzipToFile(const char* zipFileName,
39     const char* outFileName, bool quiet)
40 {
41     UnzipToFileResult result = kUTFRSuccess;
42     static const char* kFileToExtract = "classes.dex";
43     ZipArchive archive;
44     ZipEntry entry;
45     bool unlinkOnFailure = false;
46     int fd = -1;
47 
48     if (dexZipOpenArchive(zipFileName, &archive) != 0) {
49         if (!quiet) {
50             fprintf(stderr, "Unable to open '%s' as zip archive\n",
51                 zipFileName);
52         }
53         result = kUTFRNotZip;
54         goto bail;
55     }
56 
57     fd = open(outFileName, O_WRONLY | O_CREAT | O_EXCL, 0600);
58     if (fd < 0) {
59         fprintf(stderr, "Unable to create output file '%s': %s\n",
60             outFileName, strerror(errno));
61         result = kUTFROutputFileProblem;
62         goto bail;
63     }
64 
65     unlinkOnFailure = true;
66 
67     entry = dexZipFindEntry(&archive, kFileToExtract);
68     if (entry == NULL) {
69         if (!quiet) {
70             fprintf(stderr, "Unable to find '%s' in '%s'\n",
71                 kFileToExtract, zipFileName);
72         }
73         result = kUTFRNoClassesDex;
74         goto bail;
75     }
76 
77     if (dexZipExtractEntryToFile(&archive, entry, fd) != 0) {
78         fprintf(stderr, "Extract of '%s' from '%s' failed\n",
79             kFileToExtract, zipFileName);
80         result = kUTFRBadZip;
81         goto bail;
82     }
83 
84 bail:
85     if (fd >= 0)
86         close(fd);
87     if (unlinkOnFailure && result != kUTFRSuccess)
88         unlink(outFileName);
89     dexZipCloseArchive(&archive);
90     return result;
91 }
92 
93 /*
94  * Map the specified DEX file read-only (possibly after expanding it into a
95  * temp file from a Jar).  Pass in a MemMapping struct to hold the info.
96  * If the file is an unoptimized DEX file, then byte-swapping and structural
97  * verification are performed on it before the memory is made read-only.
98  *
99  * The temp file is deleted after the map succeeds.
100  *
101  * This is intended for use by tools (e.g. dexdump) that need to get a
102  * read-only copy of a DEX file that could be in a number of different states.
103  *
104  * If "tempFileName" is NULL, a default value is used.  The temp file is
105  * deleted after the map succeeds.
106  *
107  * If "quiet" is set, don't report common errors.
108  *
109  * Returns 0 (kUTFRSuccess) on success.
110  */
dexOpenAndMap(const char * fileName,const char * tempFileName,MemMapping * pMap,bool quiet)111 UnzipToFileResult dexOpenAndMap(const char* fileName, const char* tempFileName,
112     MemMapping* pMap, bool quiet)
113 {
114     UnzipToFileResult result = kUTFRGenericFailure;
115     int len = strlen(fileName);
116     char tempNameBuf[32];
117     bool removeTemp = false;
118     int fd = -1;
119 
120     if (len < 5) {
121         if (!quiet) {
122             fprintf(stderr,
123                 "ERROR: filename must end in .dex, .zip, .jar, or .apk\n");
124         }
125         result = kUTFRBadArgs;
126         goto bail;
127     }
128 
129     if (strcasecmp(fileName + len -3, "dex") != 0) {
130         if (tempFileName == NULL) {
131             /*
132              * Try .zip/.jar/.apk, all of which are Zip archives with
133              * "classes.dex" inside.  We need to extract the compressed
134              * data to a temp file, the location of which varies.
135              *
136              * On the device we must use /sdcard because most other
137              * directories aren't writable (either because of permissions
138              * or because the volume is mounted read-only).  On desktop
139              * it's nice to use the designated temp directory.
140              */
141             if (access("/tmp", W_OK) == 0) {
142                 sprintf(tempNameBuf, "/tmp/dex-temp-%d", getpid());
143             } else if (access("/sdcard", W_OK) == 0) {
144                 sprintf(tempNameBuf, "/sdcard/dex-temp-%d", getpid());
145             } else {
146                 fprintf(stderr,
147                     "NOTE: /tmp and /sdcard unavailable for temp files\n");
148                 sprintf(tempNameBuf, "dex-temp-%d", getpid());
149             }
150 
151             tempFileName = tempNameBuf;
152         }
153 
154         result = dexUnzipToFile(fileName, tempFileName, quiet);
155 
156         if (result == kUTFRSuccess) {
157             //printf("+++ Good unzip to '%s'\n", tempFileName);
158             fileName = tempFileName;
159             removeTemp = true;
160         } else if (result == kUTFRNotZip) {
161             if (!quiet) {
162                 fprintf(stderr, "Not Zip, retrying as DEX\n");
163             }
164         } else {
165             if (!quiet && result == kUTFRNoClassesDex) {
166                 fprintf(stderr, "Zip has no classes.dex\n");
167             }
168             goto bail;
169         }
170     }
171 
172     result = kUTFRGenericFailure;
173 
174     /*
175      * Pop open the (presumed) DEX file.
176      */
177     fd = open(fileName, O_RDONLY | O_BINARY);
178     if (fd < 0) {
179         if (!quiet) {
180             fprintf(stderr, "ERROR: unable to open '%s': %s\n",
181                 fileName, strerror(errno));
182         }
183         goto bail;
184     }
185 
186     if (sysMapFileInShmemWritableReadOnly(fd, pMap) != 0) {
187         fprintf(stderr, "ERROR: Unable to map '%s'\n", fileName);
188         goto bail;
189     }
190 
191     /*
192      * This call will fail if the file exists on a filesystem that
193      * doesn't support mprotect(). If that's the case, then the file
194      * will have already been mapped private-writable by the previous
195      * call, so we don't need to do anything special if this call
196      * returns non-zero.
197      */
198     sysChangeMapAccess(pMap->addr, pMap->length, true, pMap);
199 
200     if (dexSwapAndVerifyIfNecessary((u1*) pMap->addr, pMap->length)) {
201         fprintf(stderr, "ERROR: Failed structural verification of '%s'\n",
202             fileName);
203         goto bail;
204     }
205 
206     /*
207      * Similar to above, this call will fail if the file wasn't ever
208      * read-only to begin with. This is innocuous, though it is
209      * undesirable from a memory hygiene perspective.
210      */
211     sysChangeMapAccess(pMap->addr, pMap->length, false, pMap);
212 
213     /*
214      * Success!  Close the file and return with the start/length in pMap.
215      */
216     result = kUTFRSuccess;
217 
218 bail:
219     if (fd >= 0)
220         close(fd);
221     if (removeTemp) {
222         /* this will fail if the OS doesn't allow removal of a mapped file */
223         if (unlink(tempFileName) != 0) {
224             fprintf(stderr, "WARNING: unable to remove temp '%s'\n",
225                 tempFileName);
226         }
227     }
228     return result;
229 }
230