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 #define _FILE_OFFSET_BITS 64
18 #define _LARGEFILE64_SOURCE 1
19 
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #include <sys/types.h>
23 #include <sys/mman.h>
24 #include <fcntl.h>
25 #include <libgen.h>
26 #include <unistd.h>
27 
28 #include <sparse/sparse.h>
29 
30 #include "ext4_utils.h"
31 #include "make_ext4fs.h"
32 #include "allocate.h"
33 
34 #if defined(__APPLE__) && defined(__MACH__)
35 #define off64_t off_t
36 #endif
37 
38 #ifndef USE_MINGW /* O_BINARY is windows-specific flag */
39 #define O_BINARY 0
40 #endif
41 
42 extern struct fs_info info;
43 
44 static int verbose = 0;
45 
usage(char * path)46 static void usage(char *path)
47 {
48 	fprintf(stderr, "%s [ options ] <image or block device> <output image>\n", path);
49 	fprintf(stderr, "\n");
50 	fprintf(stderr, "  -c include CRC block\n");
51 	fprintf(stderr, "  -v verbose output\n");
52 	fprintf(stderr, "  -z gzip output\n");
53 	fprintf(stderr, "  -S don't use sparse output format\n");
54 }
55 
build_sparse_ext(int fd,const char * filename)56 static int build_sparse_ext(int fd, const char *filename)
57 {
58 	unsigned int i;
59 	unsigned int block;
60 	int start_contiguous_block;
61 	u8 *block_bitmap;
62 	off64_t ret;
63 
64 	block_bitmap = malloc(info.block_size);
65 	if (!block_bitmap)
66 		critical_error("failed to allocate block bitmap");
67 
68 	if (aux_info.first_data_block > 0)
69 		sparse_file_add_file(ext4_sparse_file, filename, 0,
70 				info.block_size * aux_info.first_data_block, 0);
71 
72 	for (i = 0; i < aux_info.groups; i++) {
73 		u32 first_block = aux_info.first_data_block + i * info.blocks_per_group;
74 		u32 last_block = min(info.blocks_per_group, aux_info.len_blocks - first_block);
75 
76 		ret = lseek64(fd, (u64)info.block_size * aux_info.bg_desc[i].bg_block_bitmap,
77 				SEEK_SET);
78 		if (ret < 0)
79 			critical_error_errno("failed to seek to block group bitmap %d", i);
80 
81 		ret = read(fd, block_bitmap, info.block_size);
82 		if (ret < 0)
83 			critical_error_errno("failed to read block group bitmap %d", i);
84 		if (ret != (int)info.block_size)
85 			critical_error("failed to read all of block group bitmap %d", i);
86 
87 		start_contiguous_block = -1;
88 		for (block = 0; block < last_block; block++) {
89 			if (start_contiguous_block >= 0) {
90 				if (!bitmap_get_bit(block_bitmap, block)) {
91 					u32 start_block = first_block + start_contiguous_block;
92 					u32 len_blocks = block - start_contiguous_block;
93 
94 					sparse_file_add_file(ext4_sparse_file, filename,
95 							(u64)info.block_size * start_block,
96 							info.block_size * len_blocks, start_block);
97 					start_contiguous_block = -1;
98 				}
99 			} else {
100 				if (bitmap_get_bit(block_bitmap, block))
101 					start_contiguous_block = block;
102 			}
103 		}
104 
105 		if (start_contiguous_block >= 0) {
106 			u32 start_block = first_block + start_contiguous_block;
107 			u32 len_blocks = last_block - start_contiguous_block;
108 			sparse_file_add_file(ext4_sparse_file, filename,
109 					(u64)info.block_size * start_block,
110 					info.block_size * len_blocks, start_block);
111 		}
112 	}
113 
114 	return 0;
115 }
116 
main(int argc,char ** argv)117 int main(int argc, char **argv)
118 {
119 	int opt;
120 	const char *in = NULL;
121 	const char *out = NULL;
122 	int gzip = 0;
123 	int sparse = 1;
124 	int infd, outfd;
125 	int crc = 0;
126 
127 	while ((opt = getopt(argc, argv, "cvzS")) != -1) {
128 		switch (opt) {
129 		case 'c':
130 			crc = 1;
131 			break;
132 		case 'v':
133 			verbose = 1;
134 			break;
135 		case 'z':
136 			gzip = 1;
137 			break;
138 		case 'S':
139 			sparse = 0;
140 			break;
141 		}
142 	}
143 
144 	if (optind >= argc) {
145 		fprintf(stderr, "Expected image or block device after options\n");
146 		usage(argv[0]);
147 		exit(EXIT_FAILURE);
148 	}
149 
150 	in = argv[optind++];
151 
152 	if (optind >= argc) {
153 		fprintf(stderr, "Expected output image after input image\n");
154 		usage(argv[0]);
155 		exit(EXIT_FAILURE);
156 	}
157 
158 	out = argv[optind++];
159 
160 	if (optind < argc) {
161 		fprintf(stderr, "Unexpected argument: %s\n", argv[optind]);
162 		usage(argv[0]);
163 		exit(EXIT_FAILURE);
164 	}
165 
166 	infd = open(in, O_RDONLY);
167 
168 	if (infd < 0)
169 		critical_error_errno("failed to open input image");
170 
171 	read_ext(infd, verbose);
172 
173 	ext4_sparse_file = sparse_file_new(info.block_size, info.len);
174 
175 	build_sparse_ext(infd, in);
176 
177 	close(infd);
178 
179 	if (strcmp(out, "-")) {
180 		outfd = open(out, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
181 		if (outfd < 0) {
182 			error_errno("open");
183 			return EXIT_FAILURE;
184 		}
185 	} else {
186 		outfd = STDOUT_FILENO;
187 	}
188 
189 	write_ext4_image(outfd, gzip, sparse, crc);
190 	close(outfd);
191 
192 	sparse_file_destroy(ext4_sparse_file);
193 
194 	return 0;
195 }
196