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 /*
18  * Zip alignment tool
19  */
20 #include "ZipFile.h"
21 
22 #include <stdlib.h>
23 #include <stdio.h>
24 
25 using namespace android;
26 
27 /*
28  * Show program usage.
29  */
usage(void)30 void usage(void)
31 {
32     fprintf(stderr, "Zip alignment utility\n");
33     fprintf(stderr, "Copyright (C) 2009 The Android Open Source Project\n\n");
34     fprintf(stderr,
35         "Usage: zipalign [-f] [-p] [-v] [-z] <align> infile.zip outfile.zip\n"
36         "       zipalign -c [-v] <align> infile.zip\n\n" );
37     fprintf(stderr,
38         "  <align>: alignment in bytes, e.g. '4' provides 32-bit alignment\n");
39     fprintf(stderr, "  -c: check alignment only (does not modify file)\n");
40     fprintf(stderr, "  -f: overwrite existing outfile.zip\n");
41     fprintf(stderr, "  -p: page align stored shared object files\n");
42     fprintf(stderr, "  -v: verbose output\n");
43     fprintf(stderr, "  -z: recompress using Zopfli\n");
44 }
45 
getAlignment(bool pageAlignSharedLibs,int defaultAlignment,ZipEntry * pEntry)46 static int getAlignment(bool pageAlignSharedLibs, int defaultAlignment,
47     ZipEntry* pEntry) {
48 
49     static const int kPageAlignment = 4096;
50 
51     if (!pageAlignSharedLibs) {
52         return defaultAlignment;
53     }
54 
55     const char* ext = strrchr(pEntry->getFileName(), '.');
56     if (ext && strcmp(ext, ".so") == 0) {
57         return kPageAlignment;
58     }
59 
60     return defaultAlignment;
61 }
62 
63 /*
64  * Copy all entries from "pZin" to "pZout", aligning as needed.
65  */
copyAndAlign(ZipFile * pZin,ZipFile * pZout,int alignment,bool zopfli,bool pageAlignSharedLibs)66 static int copyAndAlign(ZipFile* pZin, ZipFile* pZout, int alignment, bool zopfli,
67     bool pageAlignSharedLibs)
68 {
69     int numEntries = pZin->getNumEntries();
70     ZipEntry* pEntry;
71     int bias = 0;
72     status_t status;
73 
74     for (int i = 0; i < numEntries; i++) {
75         ZipEntry* pNewEntry;
76         int padding = 0;
77 
78         pEntry = pZin->getEntryByIndex(i);
79         if (pEntry == NULL) {
80             fprintf(stderr, "ERROR: unable to retrieve entry %d\n", i);
81             return 1;
82         }
83 
84         if (pEntry->isCompressed()) {
85             /* copy the entry without padding */
86             //printf("--- %s: orig at %ld len=%ld (compressed)\n",
87             //    pEntry->getFileName(), (long) pEntry->getFileOffset(),
88             //    (long) pEntry->getUncompressedLen());
89 
90             if (zopfli) {
91                 status = pZout->addRecompress(pZin, pEntry, &pNewEntry);
92                 bias += pNewEntry->getCompressedLen() - pEntry->getCompressedLen();
93             } else {
94                 status = pZout->add(pZin, pEntry, padding, &pNewEntry);
95             }
96         } else {
97             const int alignTo = getAlignment(pageAlignSharedLibs, alignment, pEntry);
98 
99             /*
100              * Copy the entry, adjusting as required.  We assume that the
101              * file position in the new file will be equal to the file
102              * position in the original.
103              */
104             long newOffset = pEntry->getFileOffset() + bias;
105             padding = (alignTo - (newOffset % alignTo)) % alignTo;
106 
107             //printf("--- %s: orig at %ld(+%d) len=%ld, adding pad=%d\n",
108             //    pEntry->getFileName(), (long) pEntry->getFileOffset(),
109             //    bias, (long) pEntry->getUncompressedLen(), padding);
110             status = pZout->add(pZin, pEntry, padding, &pNewEntry);
111         }
112 
113         if (status != NO_ERROR)
114             return 1;
115         bias += padding;
116         //printf(" added '%s' at %ld (pad=%d)\n",
117         //    pNewEntry->getFileName(), (long) pNewEntry->getFileOffset(),
118         //    padding);
119     }
120 
121     return 0;
122 }
123 
124 /*
125  * Process a file.  We open the input and output files, failing if the
126  * output file exists and "force" wasn't specified.
127  */
process(const char * inFileName,const char * outFileName,int alignment,bool force,bool zopfli,bool pageAlignSharedLibs)128 static int process(const char* inFileName, const char* outFileName,
129     int alignment, bool force, bool zopfli, bool pageAlignSharedLibs)
130 {
131     ZipFile zin, zout;
132 
133     //printf("PROCESS: align=%d in='%s' out='%s' force=%d\n",
134     //    alignment, inFileName, outFileName, force);
135 
136     /* this mode isn't supported -- do a trivial check */
137     if (strcmp(inFileName, outFileName) == 0) {
138         fprintf(stderr, "Input and output can't be same file\n");
139         return 1;
140     }
141 
142     /* don't overwrite existing unless given permission */
143     if (!force && access(outFileName, F_OK) == 0) {
144         fprintf(stderr, "Output file '%s' exists\n", outFileName);
145         return 1;
146     }
147 
148     if (zin.open(inFileName, ZipFile::kOpenReadOnly) != NO_ERROR) {
149         fprintf(stderr, "Unable to open '%s' as zip archive\n", inFileName);
150         return 1;
151     }
152     if (zout.open(outFileName,
153             ZipFile::kOpenReadWrite|ZipFile::kOpenCreate|ZipFile::kOpenTruncate)
154         != NO_ERROR)
155     {
156         fprintf(stderr, "Unable to open '%s' as zip archive\n", outFileName);
157         return 1;
158     }
159 
160     int result = copyAndAlign(&zin, &zout, alignment, zopfli, pageAlignSharedLibs);
161     if (result != 0) {
162         printf("zipalign: failed rewriting '%s' to '%s'\n",
163             inFileName, outFileName);
164     }
165     return result;
166 }
167 
168 /*
169  * Verify the alignment of a zip archive.
170  */
verify(const char * fileName,int alignment,bool verbose,bool pageAlignSharedLibs)171 static int verify(const char* fileName, int alignment, bool verbose,
172     bool pageAlignSharedLibs)
173 {
174     ZipFile zipFile;
175     bool foundBad = false;
176 
177     if (verbose)
178         printf("Verifying alignment of %s (%d)...\n", fileName, alignment);
179 
180     if (zipFile.open(fileName, ZipFile::kOpenReadOnly) != NO_ERROR) {
181         fprintf(stderr, "Unable to open '%s' for verification\n", fileName);
182         return 1;
183     }
184 
185     int numEntries = zipFile.getNumEntries();
186     ZipEntry* pEntry;
187 
188     for (int i = 0; i < numEntries; i++) {
189         pEntry = zipFile.getEntryByIndex(i);
190         if (pEntry->isCompressed()) {
191             if (verbose) {
192                 printf("%8ld %s (OK - compressed)\n",
193                     (long) pEntry->getFileOffset(), pEntry->getFileName());
194             }
195         } else {
196             long offset = pEntry->getFileOffset();
197             const int alignTo = getAlignment(pageAlignSharedLibs, alignment, pEntry);
198             if ((offset % alignTo) != 0) {
199                 if (verbose) {
200                     printf("%8ld %s (BAD - %ld)\n",
201                         (long) offset, pEntry->getFileName(),
202                         offset % alignTo);
203                 }
204                 foundBad = true;
205             } else {
206                 if (verbose) {
207                     printf("%8ld %s (OK)\n",
208                         (long) offset, pEntry->getFileName());
209                 }
210             }
211         }
212     }
213 
214     if (verbose)
215         printf("Verification %s\n", foundBad ? "FAILED" : "succesful");
216 
217     return foundBad ? 1 : 0;
218 }
219 
220 /*
221  * Parse args.
222  */
main(int argc,char * const argv[])223 int main(int argc, char* const argv[])
224 {
225     bool wantUsage = false;
226     bool check = false;
227     bool force = false;
228     bool verbose = false;
229     bool zopfli = false;
230     bool pageAlignSharedLibs = false;
231     int result = 1;
232     int alignment;
233     char* endp;
234 
235     if (argc < 4) {
236         wantUsage = true;
237         goto bail;
238     }
239 
240     argc--;
241     argv++;
242 
243     while (argc && argv[0][0] == '-') {
244         const char* cp = argv[0] +1;
245 
246         while (*cp != '\0') {
247             switch (*cp) {
248             case 'c':
249                 check = true;
250                 break;
251             case 'f':
252                 force = true;
253                 break;
254             case 'v':
255                 verbose = true;
256                 break;
257             case 'z':
258                 zopfli = true;
259                 break;
260             case 'p':
261                 pageAlignSharedLibs = true;
262                 break;
263             default:
264                 fprintf(stderr, "ERROR: unknown flag -%c\n", *cp);
265                 wantUsage = true;
266                 goto bail;
267             }
268 
269             cp++;
270         }
271 
272         argc--;
273         argv++;
274     }
275 
276     if (!((check && argc == 2) || (!check && argc == 3))) {
277         wantUsage = true;
278         goto bail;
279     }
280 
281     alignment = strtol(argv[0], &endp, 10);
282     if (*endp != '\0' || alignment <= 0) {
283         fprintf(stderr, "Invalid value for alignment: %s\n", argv[0]);
284         wantUsage = true;
285         goto bail;
286     }
287 
288     if (check) {
289         /* check existing archive for correct alignment */
290         result = verify(argv[1], alignment, verbose, pageAlignSharedLibs);
291     } else {
292         /* create the new archive */
293         result = process(argv[1], argv[2], alignment, force, zopfli, pageAlignSharedLibs);
294 
295         /* trust, but verify */
296         if (result == 0) {
297             result = verify(argv[2], alignment, verbose, pageAlignSharedLibs);
298         }
299     }
300 
301 bail:
302     if (wantUsage) {
303         usage();
304         result = 2;
305     }
306 
307     return result;
308 }
309