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Doug Zongker512536a2010-02-17 16:11:44 -08001/*
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#include <errno.h>
18#include <libgen.h>
19#include <stdio.h>
20#include <stdlib.h>
21#include <string.h>
22#include <sys/stat.h>
23#include <sys/statfs.h>
24#include <sys/types.h>
25#include <fcntl.h>
26#include <unistd.h>
27
28#include "mincrypt/sha.h"
29#include "applypatch.h"
30#include "mtdutils/mtdutils.h"
Doug Zongkerc4351c72010-02-22 14:46:32 -080031#include "edify/expr.h"
Doug Zongker512536a2010-02-17 16:11:44 -080032
33int SaveFileContents(const char* filename, FileContents file);
34int LoadMTDContents(const char* filename, FileContents* file);
35int ParseSha1(const char* str, uint8_t* digest);
36ssize_t FileSink(unsigned char* data, ssize_t len, void* token);
37
38static int mtd_partitions_scanned = 0;
39
40// Read a file into memory; store it and its associated metadata in
41// *file. Return 0 on success.
42int LoadFileContents(const char* filename, FileContents* file) {
Doug Zongker512536a2010-02-17 16:11:44 -080043 file->data = NULL;
Doug Zongker512536a2010-02-17 16:11:44 -080044
Doug Zongkerc4351c72010-02-22 14:46:32 -080045 // A special 'filename' beginning with "MTD:" means to load the
46 // contents of an MTD partition.
47 if (strncmp(filename, "MTD:", 4) == 0) {
48 return LoadMTDContents(filename, file);
49 }
Doug Zongker512536a2010-02-17 16:11:44 -080050
Doug Zongkerc4351c72010-02-22 14:46:32 -080051 if (stat(filename, &file->st) != 0) {
52 printf("failed to stat \"%s\": %s\n", filename, strerror(errno));
53 return -1;
54 }
55
56 file->size = file->st.st_size;
57 file->data = malloc(file->size);
58
59 FILE* f = fopen(filename, "rb");
60 if (f == NULL) {
61 printf("failed to open \"%s\": %s\n", filename, strerror(errno));
62 free(file->data);
63 file->data = NULL;
64 return -1;
65 }
66
67 ssize_t bytes_read = fread(file->data, 1, file->size, f);
68 if (bytes_read != file->size) {
69 printf("short read of \"%s\" (%ld bytes of %ld)\n",
70 filename, (long)bytes_read, (long)file->size);
71 free(file->data);
72 file->data = NULL;
73 return -1;
74 }
75 fclose(f);
76
77 SHA(file->data, file->size, file->sha1);
78 return 0;
Doug Zongker512536a2010-02-17 16:11:44 -080079}
80
81static size_t* size_array;
82// comparison function for qsort()ing an int array of indexes into
83// size_array[].
84static int compare_size_indices(const void* a, const void* b) {
Doug Zongkerc4351c72010-02-22 14:46:32 -080085 int aa = *(int*)a;
86 int bb = *(int*)b;
87 if (size_array[aa] < size_array[bb]) {
88 return -1;
89 } else if (size_array[aa] > size_array[bb]) {
90 return 1;
91 } else {
92 return 0;
93 }
Doug Zongker512536a2010-02-17 16:11:44 -080094}
95
96void FreeFileContents(FileContents* file) {
97 if (file) free(file->data);
98 free(file);
99}
100
101// Load the contents of an MTD partition into the provided
102// FileContents. filename should be a string of the form
103// "MTD:<partition_name>:<size_1>:<sha1_1>:<size_2>:<sha1_2>:...".
104// The smallest size_n bytes for which that prefix of the mtd contents
105// has the corresponding sha1 hash will be loaded. It is acceptable
106// for a size value to be repeated with different sha1s. Will return
107// 0 on success.
108//
109// This complexity is needed because if an OTA installation is
110// interrupted, the partition might contain either the source or the
111// target data, which might be of different lengths. We need to know
112// the length in order to read from MTD (there is no "end-of-file"
113// marker), so the caller must specify the possible lengths and the
114// hash of the data, and we'll do the load expecting to find one of
115// those hashes.
116int LoadMTDContents(const char* filename, FileContents* file) {
Doug Zongkerc4351c72010-02-22 14:46:32 -0800117 char* copy = strdup(filename);
118 const char* magic = strtok(copy, ":");
119 if (strcmp(magic, "MTD") != 0) {
120 printf("LoadMTDContents called with bad filename (%s)\n",
121 filename);
122 return -1;
Doug Zongker512536a2010-02-17 16:11:44 -0800123 }
Doug Zongkerc4351c72010-02-22 14:46:32 -0800124 const char* partition = strtok(NULL, ":");
Doug Zongker512536a2010-02-17 16:11:44 -0800125
Doug Zongkerc4351c72010-02-22 14:46:32 -0800126 int i;
127 int colons = 0;
128 for (i = 0; filename[i] != '\0'; ++i) {
129 if (filename[i] == ':') {
130 ++colons;
131 }
Doug Zongker512536a2010-02-17 16:11:44 -0800132 }
Doug Zongkerc4351c72010-02-22 14:46:32 -0800133 if (colons < 3 || colons%2 == 0) {
134 printf("LoadMTDContents called with bad filename (%s)\n",
135 filename);
136 }
Doug Zongker512536a2010-02-17 16:11:44 -0800137
Doug Zongkerc4351c72010-02-22 14:46:32 -0800138 int pairs = (colons-1)/2; // # of (size,sha1) pairs in filename
139 int* index = malloc(pairs * sizeof(int));
140 size_t* size = malloc(pairs * sizeof(size_t));
141 char** sha1sum = malloc(pairs * sizeof(char*));
Doug Zongker512536a2010-02-17 16:11:44 -0800142
Doug Zongkerc4351c72010-02-22 14:46:32 -0800143 for (i = 0; i < pairs; ++i) {
144 const char* size_str = strtok(NULL, ":");
145 size[i] = strtol(size_str, NULL, 10);
146 if (size[i] == 0) {
147 printf("LoadMTDContents called with bad size (%s)\n", filename);
148 return -1;
149 }
150 sha1sum[i] = strtok(NULL, ":");
151 index[i] = i;
152 }
Doug Zongker512536a2010-02-17 16:11:44 -0800153
Doug Zongkerc4351c72010-02-22 14:46:32 -0800154 // sort the index[] array so it indexes the pairs in order of
155 // increasing size.
156 size_array = size;
157 qsort(index, pairs, sizeof(int), compare_size_indices);
Doug Zongker512536a2010-02-17 16:11:44 -0800158
Doug Zongkerc4351c72010-02-22 14:46:32 -0800159 if (!mtd_partitions_scanned) {
160 mtd_scan_partitions();
161 mtd_partitions_scanned = 1;
162 }
Doug Zongker512536a2010-02-17 16:11:44 -0800163
Doug Zongkerc4351c72010-02-22 14:46:32 -0800164 const MtdPartition* mtd = mtd_find_partition_by_name(partition);
165 if (mtd == NULL) {
166 printf("mtd partition \"%s\" not found (loading %s)\n",
167 partition, filename);
168 return -1;
169 }
Doug Zongker512536a2010-02-17 16:11:44 -0800170
Doug Zongkerc4351c72010-02-22 14:46:32 -0800171 MtdReadContext* ctx = mtd_read_partition(mtd);
172 if (ctx == NULL) {
173 printf("failed to initialize read of mtd partition \"%s\"\n",
174 partition);
175 return -1;
176 }
Doug Zongker512536a2010-02-17 16:11:44 -0800177
Doug Zongkerc4351c72010-02-22 14:46:32 -0800178 SHA_CTX sha_ctx;
179 SHA_init(&sha_ctx);
180 uint8_t parsed_sha[SHA_DIGEST_SIZE];
181
182 // allocate enough memory to hold the largest size.
183 file->data = malloc(size[index[pairs-1]]);
184 char* p = (char*)file->data;
185 file->size = 0; // # bytes read so far
186
187 for (i = 0; i < pairs; ++i) {
188 // Read enough additional bytes to get us up to the next size
189 // (again, we're trying the possibilities in order of increasing
190 // size).
191 size_t next = size[index[i]] - file->size;
192 size_t read = 0;
193 if (next > 0) {
194 read = mtd_read_data(ctx, p, next);
195 if (next != read) {
196 printf("short read (%d bytes of %d) for partition \"%s\"\n",
197 read, next, partition);
198 free(file->data);
199 file->data = NULL;
200 return -1;
201 }
202 SHA_update(&sha_ctx, p, read);
203 file->size += read;
204 }
205
206 // Duplicate the SHA context and finalize the duplicate so we can
207 // check it against this pair's expected hash.
208 SHA_CTX temp_ctx;
209 memcpy(&temp_ctx, &sha_ctx, sizeof(SHA_CTX));
210 const uint8_t* sha_so_far = SHA_final(&temp_ctx);
211
212 if (ParseSha1(sha1sum[index[i]], parsed_sha) != 0) {
213 printf("failed to parse sha1 %s in %s\n",
214 sha1sum[index[i]], filename);
215 free(file->data);
216 file->data = NULL;
217 return -1;
218 }
219
220 if (memcmp(sha_so_far, parsed_sha, SHA_DIGEST_SIZE) == 0) {
221 // we have a match. stop reading the partition; we'll return
222 // the data we've read so far.
223 printf("mtd read matched size %d sha %s\n",
224 size[index[i]], sha1sum[index[i]]);
225 break;
226 }
227
228 p += read;
229 }
230
231 mtd_read_close(ctx);
232
233 if (i == pairs) {
234 // Ran off the end of the list of (size,sha1) pairs without
235 // finding a match.
236 printf("contents of MTD partition \"%s\" didn't match %s\n",
237 partition, filename);
Doug Zongker512536a2010-02-17 16:11:44 -0800238 free(file->data);
239 file->data = NULL;
240 return -1;
Doug Zongker512536a2010-02-17 16:11:44 -0800241 }
242
Doug Zongkerc4351c72010-02-22 14:46:32 -0800243 const uint8_t* sha_final = SHA_final(&sha_ctx);
244 for (i = 0; i < SHA_DIGEST_SIZE; ++i) {
245 file->sha1[i] = sha_final[i];
Doug Zongker512536a2010-02-17 16:11:44 -0800246 }
247
Doug Zongkerc4351c72010-02-22 14:46:32 -0800248 // Fake some stat() info.
249 file->st.st_mode = 0644;
250 file->st.st_uid = 0;
251 file->st.st_gid = 0;
Doug Zongker512536a2010-02-17 16:11:44 -0800252
Doug Zongkerc4351c72010-02-22 14:46:32 -0800253 free(copy);
254 free(index);
255 free(size);
256 free(sha1sum);
Doug Zongker512536a2010-02-17 16:11:44 -0800257
Doug Zongkerc4351c72010-02-22 14:46:32 -0800258 return 0;
Doug Zongker512536a2010-02-17 16:11:44 -0800259}
260
261
262// Save the contents of the given FileContents object under the given
263// filename. Return 0 on success.
264int SaveFileContents(const char* filename, FileContents file) {
Doug Zongkerc4351c72010-02-22 14:46:32 -0800265 int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC);
266 if (fd < 0) {
267 printf("failed to open \"%s\" for write: %s\n",
268 filename, strerror(errno));
269 return -1;
270 }
Doug Zongker512536a2010-02-17 16:11:44 -0800271
Doug Zongkerc4351c72010-02-22 14:46:32 -0800272 ssize_t bytes_written = FileSink(file.data, file.size, &fd);
273 if (bytes_written != file.size) {
274 printf("short write of \"%s\" (%ld bytes of %ld) (%s)\n",
275 filename, (long)bytes_written, (long)file.size,
276 strerror(errno));
277 close(fd);
278 return -1;
279 }
280 fsync(fd);
Doug Zongker512536a2010-02-17 16:11:44 -0800281 close(fd);
Doug Zongker512536a2010-02-17 16:11:44 -0800282
Doug Zongkerc4351c72010-02-22 14:46:32 -0800283 if (chmod(filename, file.st.st_mode) != 0) {
284 printf("chmod of \"%s\" failed: %s\n", filename, strerror(errno));
285 return -1;
286 }
287 if (chown(filename, file.st.st_uid, file.st.st_gid) != 0) {
288 printf("chown of \"%s\" failed: %s\n", filename, strerror(errno));
289 return -1;
290 }
Doug Zongker512536a2010-02-17 16:11:44 -0800291
Doug Zongkerc4351c72010-02-22 14:46:32 -0800292 return 0;
Doug Zongker512536a2010-02-17 16:11:44 -0800293}
294
295// Write a memory buffer to target_mtd partition, a string of the form
296// "MTD:<partition>[:...]". Return 0 on success.
297int WriteToMTDPartition(unsigned char* data, size_t len,
298 const char* target_mtd) {
Doug Zongkerc4351c72010-02-22 14:46:32 -0800299 char* partition = strchr(target_mtd, ':');
300 if (partition == NULL) {
301 printf("bad MTD target name \"%s\"\n", target_mtd);
302 return -1;
303 }
304 ++partition;
305 // Trim off anything after a colon, eg "MTD:boot:blah:blah:blah...".
306 // We want just the partition name "boot".
307 partition = strdup(partition);
308 char* end = strchr(partition, ':');
309 if (end != NULL)
310 *end = '\0';
Doug Zongker512536a2010-02-17 16:11:44 -0800311
Doug Zongkerc4351c72010-02-22 14:46:32 -0800312 if (!mtd_partitions_scanned) {
313 mtd_scan_partitions();
314 mtd_partitions_scanned = 1;
315 }
Doug Zongker512536a2010-02-17 16:11:44 -0800316
Doug Zongkerc4351c72010-02-22 14:46:32 -0800317 const MtdPartition* mtd = mtd_find_partition_by_name(partition);
318 if (mtd == NULL) {
319 printf("mtd partition \"%s\" not found for writing\n", partition);
320 return -1;
321 }
Doug Zongker512536a2010-02-17 16:11:44 -0800322
Doug Zongkerc4351c72010-02-22 14:46:32 -0800323 MtdWriteContext* ctx = mtd_write_partition(mtd);
324 if (ctx == NULL) {
325 printf("failed to init mtd partition \"%s\" for writing\n",
326 partition);
327 return -1;
328 }
Doug Zongker512536a2010-02-17 16:11:44 -0800329
Doug Zongkerc4351c72010-02-22 14:46:32 -0800330 size_t written = mtd_write_data(ctx, (char*)data, len);
331 if (written != len) {
332 printf("only wrote %d of %d bytes to MTD %s\n",
333 written, len, partition);
334 mtd_write_close(ctx);
335 return -1;
336 }
Doug Zongker512536a2010-02-17 16:11:44 -0800337
Doug Zongkerc4351c72010-02-22 14:46:32 -0800338 if (mtd_erase_blocks(ctx, -1) < 0) {
339 printf("error finishing mtd write of %s\n", partition);
340 mtd_write_close(ctx);
341 return -1;
342 }
Doug Zongker512536a2010-02-17 16:11:44 -0800343
Doug Zongkerc4351c72010-02-22 14:46:32 -0800344 if (mtd_write_close(ctx)) {
345 printf("error closing mtd write of %s\n", partition);
346 return -1;
347 }
Doug Zongker512536a2010-02-17 16:11:44 -0800348
Doug Zongkerc4351c72010-02-22 14:46:32 -0800349 free(partition);
350 return 0;
Doug Zongker512536a2010-02-17 16:11:44 -0800351}
352
353
354// Take a string 'str' of 40 hex digits and parse it into the 20
355// byte array 'digest'. 'str' may contain only the digest or be of
356// the form "<digest>:<anything>". Return 0 on success, -1 on any
357// error.
358int ParseSha1(const char* str, uint8_t* digest) {
Doug Zongkerc4351c72010-02-22 14:46:32 -0800359 int i;
360 const char* ps = str;
361 uint8_t* pd = digest;
362 for (i = 0; i < SHA_DIGEST_SIZE * 2; ++i, ++ps) {
363 int digit;
364 if (*ps >= '0' && *ps <= '9') {
365 digit = *ps - '0';
366 } else if (*ps >= 'a' && *ps <= 'f') {
367 digit = *ps - 'a' + 10;
368 } else if (*ps >= 'A' && *ps <= 'F') {
369 digit = *ps - 'A' + 10;
370 } else {
371 return -1;
372 }
373 if (i % 2 == 0) {
374 *pd = digit << 4;
375 } else {
376 *pd |= digit;
377 ++pd;
378 }
Doug Zongker512536a2010-02-17 16:11:44 -0800379 }
Doug Zongkerc4351c72010-02-22 14:46:32 -0800380 if (*ps != '\0') return -1;
381 return 0;
Doug Zongker512536a2010-02-17 16:11:44 -0800382}
383
Doug Zongkerc4351c72010-02-22 14:46:32 -0800384// Search an array of sha1 strings for one matching the given sha1.
385// Return the index of the match on success, or -1 if no match is
386// found.
387int FindMatchingPatch(uint8_t* sha1, char** const patch_sha1_str,
388 int num_patches) {
389 int i;
390 uint8_t patch_sha1[SHA_DIGEST_SIZE];
391 for (i = 0; i < num_patches; ++i) {
392 if (ParseSha1(patch_sha1_str[i], patch_sha1) == 0 &&
393 memcmp(patch_sha1, sha1, SHA_DIGEST_SIZE) == 0) {
394 return i;
395 }
Doug Zongker512536a2010-02-17 16:11:44 -0800396 }
Doug Zongkerc4351c72010-02-22 14:46:32 -0800397 return -1;
Doug Zongker512536a2010-02-17 16:11:44 -0800398}
399
400// Returns 0 if the contents of the file (argv[2]) or the cached file
401// match any of the sha1's on the command line (argv[3:]). Returns
402// nonzero otherwise.
Doug Zongkerc4351c72010-02-22 14:46:32 -0800403int applypatch_check(const char* filename,
404 int num_patches, char** const patch_sha1_str) {
405 FileContents file;
406 file.data = NULL;
Doug Zongker512536a2010-02-17 16:11:44 -0800407
Doug Zongkerc4351c72010-02-22 14:46:32 -0800408 // It's okay to specify no sha1s; the check will pass if the
409 // LoadFileContents is successful. (Useful for reading MTD
410 // partitions, where the filename encodes the sha1s; no need to
411 // check them twice.)
412 if (LoadFileContents(filename, &file) != 0 ||
413 (num_patches > 0 &&
414 FindMatchingPatch(file.sha1, patch_sha1_str, num_patches) < 0)) {
415 printf("file \"%s\" doesn't have any of expected "
416 "sha1 sums; checking cache\n", filename);
Doug Zongker512536a2010-02-17 16:11:44 -0800417
Doug Zongkerc4351c72010-02-22 14:46:32 -0800418 free(file.data);
Doug Zongker512536a2010-02-17 16:11:44 -0800419
Doug Zongkerc4351c72010-02-22 14:46:32 -0800420 // If the source file is missing or corrupted, it might be because
421 // we were killed in the middle of patching it. A copy of it
422 // should have been made in CACHE_TEMP_SOURCE. If that file
423 // exists and matches the sha1 we're looking for, the check still
424 // passes.
425
426 if (LoadFileContents(CACHE_TEMP_SOURCE, &file) != 0) {
427 printf("failed to load cache file\n");
428 return 1;
429 }
430
431 if (FindMatchingPatch(file.sha1, patch_sha1_str, num_patches) < 0) {
432 printf("cache bits don't match any sha1 for \"%s\"\n", filename);
433 free(file.data);
434 return 1;
435 }
436 }
Doug Zongker512536a2010-02-17 16:11:44 -0800437
438 free(file.data);
Doug Zongkerc4351c72010-02-22 14:46:32 -0800439 return 0;
Doug Zongker512536a2010-02-17 16:11:44 -0800440}
441
442int ShowLicenses() {
Doug Zongkerc4351c72010-02-22 14:46:32 -0800443 ShowBSDiffLicense();
444 return 0;
Doug Zongker512536a2010-02-17 16:11:44 -0800445}
446
447ssize_t FileSink(unsigned char* data, ssize_t len, void* token) {
Doug Zongkerc4351c72010-02-22 14:46:32 -0800448 int fd = *(int *)token;
449 ssize_t done = 0;
450 ssize_t wrote;
451 while (done < (ssize_t) len) {
452 wrote = write(fd, data+done, len-done);
453 if (wrote <= 0) {
454 printf("error writing %d bytes: %s\n", (int)(len-done), strerror(errno));
455 return done;
456 }
457 done += wrote;
Doug Zongker512536a2010-02-17 16:11:44 -0800458 }
Doug Zongkerc4351c72010-02-22 14:46:32 -0800459 return done;
Doug Zongker512536a2010-02-17 16:11:44 -0800460}
461
462typedef struct {
Doug Zongkerc4351c72010-02-22 14:46:32 -0800463 unsigned char* buffer;
464 ssize_t size;
465 ssize_t pos;
Doug Zongker512536a2010-02-17 16:11:44 -0800466} MemorySinkInfo;
467
468ssize_t MemorySink(unsigned char* data, ssize_t len, void* token) {
Doug Zongkerc4351c72010-02-22 14:46:32 -0800469 MemorySinkInfo* msi = (MemorySinkInfo*)token;
470 if (msi->size - msi->pos < len) {
471 return -1;
472 }
473 memcpy(msi->buffer + msi->pos, data, len);
474 msi->pos += len;
475 return len;
Doug Zongker512536a2010-02-17 16:11:44 -0800476}
477
478// Return the amount of free space (in bytes) on the filesystem
479// containing filename. filename must exist. Return -1 on error.
480size_t FreeSpaceForFile(const char* filename) {
Doug Zongkerc4351c72010-02-22 14:46:32 -0800481 struct statfs sf;
482 if (statfs(filename, &sf) != 0) {
483 printf("failed to statfs %s: %s\n", filename, strerror(errno));
484 return -1;
485 }
486 return sf.f_bsize * sf.f_bfree;
Doug Zongker512536a2010-02-17 16:11:44 -0800487}
488
Doug Zongkerc4351c72010-02-22 14:46:32 -0800489int CacheSizeCheck(size_t bytes) {
490 if (MakeFreeSpaceOnCache(bytes) < 0) {
491 printf("unable to make %ld bytes available on /cache\n", (long)bytes);
492 return 1;
493 } else {
494 return 0;
495 }
496}
497
498
499// This function applies binary patches to files in a way that is safe
Doug Zongker512536a2010-02-17 16:11:44 -0800500// (the original file is not touched until we have the desired
501// replacement for it) and idempotent (it's okay to run this program
502// multiple times).
503//
Doug Zongkerc4351c72010-02-22 14:46:32 -0800504// - if the sha1 hash of <target_filename> is <target_sha1_string>,
505// does nothing and exits successfully.
Doug Zongker512536a2010-02-17 16:11:44 -0800506//
Doug Zongkerc4351c72010-02-22 14:46:32 -0800507// - otherwise, if the sha1 hash of <source_filename> is one of the
508// entries in <patch_sha1_str>, the corresponding patch from
509// <patch_data> (which must be a VAL_BLOB) is applied to produce a
510// new file (the type of patch is automatically detected from the
511// blob daat). If that new file has sha1 hash <target_sha1_str>,
512// moves it to replace <target_filename>, and exits successfully.
513// Note that if <source_filename> and <target_filename> are not the
514// same, <source_filename> is NOT deleted on success.
515// <target_filename> may be the string "-" to mean "the same as
516// source_filename".
Doug Zongker512536a2010-02-17 16:11:44 -0800517//
518// - otherwise, or if any error is encountered, exits with non-zero
519// status.
520//
Doug Zongkerc4351c72010-02-22 14:46:32 -0800521// <source_filename> may refer to an MTD partition to read the source
522// data. See the comments for the LoadMTDContents() function above
523// for the format of such a filename.
Doug Zongker512536a2010-02-17 16:11:44 -0800524
Doug Zongkerc4351c72010-02-22 14:46:32 -0800525int applypatch(const char* source_filename,
526 const char* target_filename,
527 const char* target_sha1_str,
528 size_t target_size,
529 int num_patches,
530 char** const patch_sha1_str,
531 Value** patch_data) {
532 printf("\napplying patch to %s\n", source_filename);
Doug Zongker512536a2010-02-17 16:11:44 -0800533
Doug Zongkerc4351c72010-02-22 14:46:32 -0800534 if (target_filename[0] == '-' &&
535 target_filename[1] == '\0') {
536 target_filename = source_filename;
Doug Zongker512536a2010-02-17 16:11:44 -0800537 }
538
Doug Zongkerc4351c72010-02-22 14:46:32 -0800539 uint8_t target_sha1[SHA_DIGEST_SIZE];
540 if (ParseSha1(target_sha1_str, target_sha1) != 0) {
541 printf("failed to parse tgt-sha1 \"%s\"\n", target_sha1_str);
Doug Zongker512536a2010-02-17 16:11:44 -0800542 return 1;
Doug Zongkerc4351c72010-02-22 14:46:32 -0800543 }
Doug Zongker512536a2010-02-17 16:11:44 -0800544
Doug Zongkerc4351c72010-02-22 14:46:32 -0800545 FileContents copy_file;
546 FileContents source_file;
547 const Value* source_patch_value = NULL;
548 const Value* copy_patch_value = NULL;
549 int made_copy = 0;
Doug Zongker512536a2010-02-17 16:11:44 -0800550
Doug Zongkerc4351c72010-02-22 14:46:32 -0800551 // We try to load the target file into the source_file object.
552 if (LoadFileContents(target_filename, &source_file) == 0) {
553 if (memcmp(source_file.sha1, target_sha1, SHA_DIGEST_SIZE) == 0) {
554 // The early-exit case: the patch was already applied, this file
555 // has the desired hash, nothing for us to do.
556 printf("\"%s\" is already target; no patch needed\n",
557 target_filename);
558 return 0;
559 }
560 }
Doug Zongker512536a2010-02-17 16:11:44 -0800561
Doug Zongkerc4351c72010-02-22 14:46:32 -0800562 if (source_file.data == NULL ||
563 (target_filename != source_filename &&
564 strcmp(target_filename, source_filename) != 0)) {
565 // Need to load the source file: either we failed to load the
566 // target file, or we did but it's different from the source file.
567 free(source_file.data);
568 LoadFileContents(source_filename, &source_file);
569 }
570
571 if (source_file.data != NULL) {
572 int to_use = FindMatchingPatch(source_file.sha1,
573 patch_sha1_str, num_patches);
574 if (to_use >= 0) {
575 source_patch_value = patch_data[to_use];
576 }
577 }
578
579 if (source_patch_value == NULL) {
580 free(source_file.data);
581 printf("source file is bad; trying copy\n");
582
583 if (LoadFileContents(CACHE_TEMP_SOURCE, &copy_file) < 0) {
584 // fail.
585 printf("failed to read copy file\n");
586 return 1;
Doug Zongker512536a2010-02-17 16:11:44 -0800587 }
588
Doug Zongkerc4351c72010-02-22 14:46:32 -0800589 int to_use = FindMatchingPatch(copy_file.sha1,
590 patch_sha1_str, num_patches);
Doug Zongker8cd9e4f2010-08-12 17:38:09 -0700591 if (to_use >= 0) {
Doug Zongkerc4351c72010-02-22 14:46:32 -0800592 copy_patch_value = patch_data[to_use];
Doug Zongker512536a2010-02-17 16:11:44 -0800593 }
594
Doug Zongkerc4351c72010-02-22 14:46:32 -0800595 if (copy_patch_value == NULL) {
596 // fail.
597 printf("copy file doesn't match source SHA-1s either\n");
598 return 1;
Doug Zongker512536a2010-02-17 16:11:44 -0800599 }
Doug Zongker512536a2010-02-17 16:11:44 -0800600 }
601
Doug Zongkerc4351c72010-02-22 14:46:32 -0800602 int retry = 1;
603 SHA_CTX ctx;
604 int output;
605 MemorySinkInfo msi;
606 FileContents* source_to_use;
607 char* outname;
608
609 // assume that target_filename (eg "/system/app/Foo.apk") is located
610 // on the same filesystem as its top-level directory ("/system").
611 // We need something that exists for calling statfs().
612 char target_fs[strlen(target_filename)+1];
613 char* slash = strchr(target_filename+1, '/');
614 if (slash != NULL) {
615 int count = slash - target_filename;
616 strncpy(target_fs, target_filename, count);
617 target_fs[count] = '\0';
Doug Zongker512536a2010-02-17 16:11:44 -0800618 } else {
Doug Zongkerc4351c72010-02-22 14:46:32 -0800619 strcpy(target_fs, target_filename);
Doug Zongker512536a2010-02-17 16:11:44 -0800620 }
621
Doug Zongkerc4351c72010-02-22 14:46:32 -0800622 do {
623 // Is there enough room in the target filesystem to hold the patched
624 // file?
625
626 if (strncmp(target_filename, "MTD:", 4) == 0) {
627 // If the target is an MTD partition, we're actually going to
628 // write the output to /tmp and then copy it to the partition.
629 // statfs() always returns 0 blocks free for /tmp, so instead
630 // we'll just assume that /tmp has enough space to hold the file.
631
632 // We still write the original source to cache, in case the MTD
633 // write is interrupted.
634 if (MakeFreeSpaceOnCache(source_file.size) < 0) {
635 printf("not enough free space on /cache\n");
636 return 1;
637 }
638 if (SaveFileContents(CACHE_TEMP_SOURCE, source_file) < 0) {
639 printf("failed to back up source file\n");
640 return 1;
641 }
642 made_copy = 1;
643 retry = 0;
644 } else {
645 int enough_space = 0;
646 if (retry > 0) {
647 size_t free_space = FreeSpaceForFile(target_fs);
Doug Zongker201cd462010-08-13 09:41:21 -0700648 enough_space =
649 (free_space > (256 << 10)) && // 256k (two-block) minimum
Doug Zongkerc4351c72010-02-22 14:46:32 -0800650 (free_space > (target_size * 3 / 2)); // 50% margin of error
651 printf("target %ld bytes; free space %ld bytes; retry %d; enough %d\n",
652 (long)target_size, (long)free_space, retry, enough_space);
653 }
654
655 if (!enough_space) {
656 retry = 0;
657 }
658
659 if (!enough_space && source_patch_value != NULL) {
660 // Using the original source, but not enough free space. First
661 // copy the source file to cache, then delete it from the original
662 // location.
663
664 if (strncmp(source_filename, "MTD:", 4) == 0) {
665 // It's impossible to free space on the target filesystem by
666 // deleting the source if the source is an MTD partition. If
667 // we're ever in a state where we need to do this, fail.
668 printf("not enough free space for target but source is MTD\n");
669 return 1;
670 }
671
672 if (MakeFreeSpaceOnCache(source_file.size) < 0) {
673 printf("not enough free space on /cache\n");
674 return 1;
675 }
676
677 if (SaveFileContents(CACHE_TEMP_SOURCE, source_file) < 0) {
678 printf("failed to back up source file\n");
679 return 1;
680 }
681 made_copy = 1;
682 unlink(source_filename);
683
684 size_t free_space = FreeSpaceForFile(target_fs);
685 printf("(now %ld bytes free for target)\n", (long)free_space);
686 }
687 }
688
689 const Value* patch;
690 if (source_patch_value != NULL) {
691 source_to_use = &source_file;
692 patch = source_patch_value;
693 } else {
694 source_to_use = &copy_file;
695 patch = copy_patch_value;
696 }
697
698 if (patch->type != VAL_BLOB) {
699 printf("patch is not a blob\n");
700 return 1;
701 }
702
703 SinkFn sink = NULL;
704 void* token = NULL;
705 output = -1;
706 outname = NULL;
707 if (strncmp(target_filename, "MTD:", 4) == 0) {
708 // We store the decoded output in memory.
709 msi.buffer = malloc(target_size);
710 if (msi.buffer == NULL) {
711 printf("failed to alloc %ld bytes for output\n",
712 (long)target_size);
713 return 1;
714 }
715 msi.pos = 0;
716 msi.size = target_size;
717 sink = MemorySink;
718 token = &msi;
719 } else {
720 // We write the decoded output to "<tgt-file>.patch".
721 outname = (char*)malloc(strlen(target_filename) + 10);
722 strcpy(outname, target_filename);
723 strcat(outname, ".patch");
724
725 output = open(outname, O_WRONLY | O_CREAT | O_TRUNC);
726 if (output < 0) {
727 printf("failed to open output file %s: %s\n",
728 outname, strerror(errno));
729 return 1;
730 }
731 sink = FileSink;
732 token = &output;
733 }
734
735 char* header = patch->data;
736 ssize_t header_bytes_read = patch->size;
737
738 SHA_init(&ctx);
739
740 int result;
741
742 if (header_bytes_read >= 8 &&
743 memcmp(header, "BSDIFF40", 8) == 0) {
744 result = ApplyBSDiffPatch(source_to_use->data, source_to_use->size,
745 patch, 0, sink, token, &ctx);
746 } else if (header_bytes_read >= 8 &&
747 memcmp(header, "IMGDIFF2", 8) == 0) {
748 result = ApplyImagePatch(source_to_use->data, source_to_use->size,
749 patch, sink, token, &ctx);
750 } else {
751 printf("Unknown patch file format\n");
752 return 1;
753 }
754
755 if (output >= 0) {
756 fsync(output);
757 close(output);
758 }
759
760 if (result != 0) {
761 if (retry == 0) {
762 printf("applying patch failed\n");
763 return result != 0;
764 } else {
765 printf("applying patch failed; retrying\n");
766 }
767 if (outname != NULL) {
768 unlink(outname);
769 }
770 } else {
771 // succeeded; no need to retry
772 break;
773 }
774 } while (retry-- > 0);
775
776 const uint8_t* current_target_sha1 = SHA_final(&ctx);
777 if (memcmp(current_target_sha1, target_sha1, SHA_DIGEST_SIZE) != 0) {
778 printf("patch did not produce expected sha1\n");
Doug Zongker512536a2010-02-17 16:11:44 -0800779 return 1;
Doug Zongkerc4351c72010-02-22 14:46:32 -0800780 }
781
782 if (output < 0) {
783 // Copy the temp file to the MTD partition.
784 if (WriteToMTDPartition(msi.buffer, msi.pos, target_filename) != 0) {
785 printf("write of patched data to %s failed\n", target_filename);
786 return 1;
787 }
788 free(msi.buffer);
Doug Zongker512536a2010-02-17 16:11:44 -0800789 } else {
Doug Zongkerc4351c72010-02-22 14:46:32 -0800790 // Give the .patch file the same owner, group, and mode of the
791 // original source file.
792 if (chmod(outname, source_to_use->st.st_mode) != 0) {
793 printf("chmod of \"%s\" failed: %s\n", outname, strerror(errno));
794 return 1;
795 }
796 if (chown(outname, source_to_use->st.st_uid,
797 source_to_use->st.st_gid) != 0) {
798 printf("chown of \"%s\" failed: %s\n", outname, strerror(errno));
799 return 1;
800 }
Doug Zongker512536a2010-02-17 16:11:44 -0800801
Doug Zongkerc4351c72010-02-22 14:46:32 -0800802 // Finally, rename the .patch file to replace the target file.
803 if (rename(outname, target_filename) != 0) {
804 printf("rename of .patch to \"%s\" failed: %s\n",
805 target_filename, strerror(errno));
806 return 1;
807 }
Doug Zongker512536a2010-02-17 16:11:44 -0800808 }
809
Doug Zongkerc4351c72010-02-22 14:46:32 -0800810 // If this run of applypatch created the copy, and we're here, we
811 // can delete it.
812 if (made_copy) unlink(CACHE_TEMP_SOURCE);
Doug Zongker512536a2010-02-17 16:11:44 -0800813
Doug Zongkerc4351c72010-02-22 14:46:32 -0800814 // Success!
815 return 0;
Doug Zongker512536a2010-02-17 16:11:44 -0800816}