simg2img.c revision fe4a03182b5b17d333511c72406f926a791345d3 
1/*
2 * Copyright (C) 2010 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 "ext4_utils.h"
18#include "sparse_format.h"
19#include "sparse_crc32.h"
20
21#include <sys/types.h>
22#include <sys/stat.h>
23#include <sys/types.h>
24#include <sys/mman.h>
25#include <unistd.h>
26#include <fcntl.h>
27#include <stdio.h>
28
29#define COPY_BUF_SIZE (1024*1024)
30u8 *copybuf;
31
32/* This will be malloc'ed with the size of blk_sz from the sparse file header */
33u8* zerobuf;
34
35#define SPARSE_HEADER_MAJOR_VER 1
36#define SPARSE_HEADER_LEN       (sizeof(sparse_header_t))
37#define CHUNK_HEADER_LEN (sizeof(chunk_header_t))
38
39void usage()
40{
41  fprintf(stderr, "Usage: simg2img <sparse_image_file> <raw_image_file>\n");
42}
43
44static int read_all(int fd, void *buf, size_t len)
45{
46	size_t total = 0;
47	int ret;
48	char *ptr = buf;
49
50	while (total < len) {
51		ret = read(fd, ptr, len - total);
52
53		if (ret < 0)
54			return ret;
55
56		if (ret == 0)
57			return total;
58
59		ptr += ret;
60		total += ret;
61	}
62
63	return total;
64}
65
66static int write_all(int fd, void *buf, size_t len)
67{
68	size_t total = 0;
69	int ret;
70	char *ptr = buf;
71
72	while (total < len) {
73		ret = write(fd, ptr, len - total);
74
75		if (ret < 0)
76			return ret;
77
78		if (ret == 0)
79			return total;
80
81		ptr += ret;
82		total += ret;
83	}
84
85	return total;
86}
87
88int process_raw_chunk(int in, int out, u32 blocks, u32 blk_sz, u32 *crc32)
89{
90	u64 len = (u64)blocks * blk_sz;
91	int ret;
92	int chunk;
93
94	while (len) {
95		chunk = (len > COPY_BUF_SIZE) ? COPY_BUF_SIZE : len;
96		ret = read_all(in, copybuf, chunk);
97		if (ret != chunk) {
98			fprintf(stderr, "read returned an error copying a raw chunk: %d %d\n",
99					ret, chunk);
100			exit(-1);
101		}
102		*crc32 = sparse_crc32(*crc32, copybuf, chunk);
103		ret = write_all(out, copybuf, chunk);
104		if (ret != chunk) {
105			fprintf(stderr, "write returned an error copying a raw chunk\n");
106			exit(-1);
107		}
108		len -= chunk;
109	}
110
111	return blocks;
112}
113
114
115int process_skip_chunk(int out, u32 blocks, u32 blk_sz, u32 *crc32)
116{
117	/* len needs to be 64 bits, as the sparse file specifies the skip amount
118	 * as a 32 bit value of blocks.
119	 */
120	u64 len = (u64)blocks * blk_sz;
121
122	lseek64(out, len, SEEK_CUR);
123
124	return blocks;
125}
126
127int process_crc32_chunk(int in, u32 crc32)
128{
129	u32 file_crc32;
130	int ret;
131
132	ret = read_all(in, &file_crc32, 4);
133	if (ret != 4) {
134		fprintf(stderr, "read returned an error copying a crc32 chunk\n");
135		exit(-1);
136	}
137
138	if (file_crc32 != crc32) {
139		fprintf(stderr, "computed crc32 of 0x%8.8x, expected 0x%8.8x\n",
140			 crc32, file_crc32);
141		exit(-1);
142	}
143
144	return 0;
145}
146
147int main(int argc, char *argv[])
148{
149	int in;
150	int out;
151	unsigned int i;
152	sparse_header_t sparse_header;
153	chunk_header_t chunk_header;
154	u32 crc32 = 0;
155	u32 total_blocks = 0;
156	int ret;
157
158	if (argc != 3) {
159		usage();
160		exit(-1);
161	}
162
163	if ( (copybuf = malloc(COPY_BUF_SIZE)) == 0) {
164		fprintf(stderr, "Cannot malloc copy buf\n");
165		exit(-1);
166	}
167
168	if (strcmp(argv[1], "-") == 0) {
169		in = STDIN_FILENO;
170	} else {
171		if ((in = open(argv[1], O_RDONLY)) == 0) {
172			fprintf(stderr, "Cannot open input file %s\n", argv[1]);
173			exit(-1);
174		}
175	}
176
177	if (strcmp(argv[2], "-") == 0) {
178		out = STDOUT_FILENO;
179	} else {
180		if ((out = open(argv[2], O_WRONLY | O_CREAT | O_TRUNC)) == 0) {
181			fprintf(stderr, "Cannot open output file %s\n", argv[2]);
182			exit(-1);
183		}
184	}
185
186	ret = read_all(in, &sparse_header, sizeof(sparse_header));
187	if (ret != sizeof(sparse_header)) {
188		fprintf(stderr, "Error reading sparse file header\n");
189		exit(-1);
190	}
191
192	if (sparse_header.magic != SPARSE_HEADER_MAGIC) {
193		fprintf(stderr, "Bad magic\n");
194		exit(-1);
195	}
196
197	if (sparse_header.major_version != SPARSE_HEADER_MAJOR_VER) {
198		fprintf(stderr, "Unknown major version number\n");
199		exit(-1);
200	}
201
202	if (sparse_header.file_hdr_sz > SPARSE_HEADER_LEN) {
203		/* Skip the remaining bytes in a header that is longer than
204		 * we expected.
205		 */
206		lseek64(in, sparse_header.file_hdr_sz - SPARSE_HEADER_LEN, SEEK_CUR);
207	}
208
209	if ( (zerobuf = malloc(sparse_header.blk_sz)) == 0) {
210		fprintf(stderr, "Cannot malloc zero buf\n");
211		exit(-1);
212	}
213
214	for (i=0; i<sparse_header.total_chunks; i++) {
215		ret = read_all(in, &chunk_header, sizeof(chunk_header));
216		if (ret != sizeof(chunk_header)) {
217			fprintf(stderr, "Error reading chunk header\n");
218			exit(-1);
219		}
220
221		if (sparse_header.chunk_hdr_sz > CHUNK_HEADER_LEN) {
222			/* Skip the remaining bytes in a header that is longer than
223			 * we expected.
224			 */
225			lseek64(in, sparse_header.chunk_hdr_sz - CHUNK_HEADER_LEN, SEEK_CUR);
226		}
227
228		switch (chunk_header.chunk_type) {
229		    case CHUNK_TYPE_RAW:
230			if (chunk_header.total_sz != (sparse_header.chunk_hdr_sz +
231				 (chunk_header.chunk_sz * sparse_header.blk_sz)) ) {
232				fprintf(stderr, "Bogus chunk size for chunk %d, type Raw\n", i);
233				exit(-1);
234			}
235			total_blocks += process_raw_chunk(in, out,
236					 chunk_header.chunk_sz, sparse_header.blk_sz, &crc32);
237			break;
238		    case CHUNK_TYPE_DONT_CARE:
239			if (chunk_header.total_sz != sparse_header.chunk_hdr_sz) {
240				fprintf(stderr, "Bogus chunk size for chunk %d, type Dont Care\n", i);
241				exit(-1);
242			}
243			total_blocks += process_skip_chunk(out,
244					 chunk_header.chunk_sz, sparse_header.blk_sz, &crc32);
245			break;
246		    case CHUNK_TYPE_CRC32:
247			process_crc32_chunk(in, crc32);
248			break;
249		    default:
250			fprintf(stderr, "Unknown chunk type 0x%4.4x\n", chunk_header.chunk_type);
251		}
252
253	}
254
255	/* If the last chunk was a skip, then the code just did a seek, but
256	 * no write, and the file won't actually be the correct size.  This
257	 * will make the file the correct size.  Make sure the offset is
258	 * computed in 64 bits, and the function called can handle 64 bits.
259	 */
260	if (ftruncate64(out, (u64)total_blocks * sparse_header.blk_sz)) {
261		fprintf(stderr, "Error calling ftruncate() to set the image size\n");
262		exit(-1);
263	}
264
265	close(in);
266	close(out);
267
268	if (sparse_header.total_blks != total_blocks) {
269		fprintf(stderr, "Wrote %d blocks, expected to write %d blocks\n",
270			 total_blocks, sparse_header.total_blks);
271		exit(-1);
272	}
273
274	exit(0);
275}
276
277