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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   Copyright (C) 2021 Namjae Jeon <linkinjeon@kernel.org>
4  */
5 
6 #include <stdio.h>
7 #include <stdlib.h>
8 #include <string.h>
9 #include <unistd.h>
10 #include <getopt.h>
11 #include <errno.h>
12 #include <locale.h>
13 #include <inttypes.h>
14 
15 #include "exfat_ondisk.h"
16 #include "libexfat.h"
17 
18 #define EXFAT_MIN_SECT_SIZE_BITS		9
19 #define EXFAT_MAX_SECT_SIZE_BITS		12
20 #define BITS_PER_BYTE				8
21 #define BITS_PER_BYTE_MASK			0x7
22 
23 static const unsigned char used_bit[] = {
24 	0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 1, 2, 2, 3,/*  0 ~  19*/
25 	2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 1, 2, 2, 3, 2, 3, 3, 4,/* 20 ~  39*/
26 	2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5,/* 40 ~  59*/
27 	4, 5, 5, 6, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,/* 60 ~  79*/
28 	2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 2, 3, 3, 4,/* 80 ~  99*/
29 	3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6,/*100 ~ 119*/
30 	4, 5, 5, 6, 5, 6, 6, 7, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4,/*120 ~ 139*/
31 	3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,/*140 ~ 159*/
32 	2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5,/*160 ~ 179*/
33 	4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 2, 3, 3, 4, 3, 4, 4, 5,/*180 ~ 199*/
34 	3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6,/*200 ~ 219*/
35 	5, 6, 6, 7, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,/*220 ~ 239*/
36 	4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8             /*240 ~ 255*/
37 };
38 
usage(void)39 static void usage(void)
40 {
41 	fprintf(stderr, "Usage: dump.exfat\n");
42 	fprintf(stderr, "\t-V | --version                        Show version\n");
43 	fprintf(stderr, "\t-h | --help                           Show help\n");
44 
45 	exit(EXIT_FAILURE);
46 }
47 
48 static struct option opts[] = {
49 	{"version",		no_argument,		NULL,	'V' },
50 	{"help",		no_argument,		NULL,	'h' },
51 	{"?",			no_argument,		NULL,	'?' },
52 	{NULL,			0,			NULL,	 0  }
53 };
54 
exfat_count_used_clusters(unsigned char * bitmap,unsigned long long bitmap_len)55 static unsigned int exfat_count_used_clusters(unsigned char *bitmap,
56 		unsigned long long bitmap_len)
57 {
58 	unsigned int count = 0;
59 	unsigned long long i;
60 
61 	for (i = 0; i < bitmap_len; i++)
62 		count += used_bit[bitmap[i]];
63 
64 	return count;
65 }
66 
exfat_show_ondisk_all_info(struct exfat_blk_dev * bd)67 static int exfat_show_ondisk_all_info(struct exfat_blk_dev *bd)
68 {
69 	struct pbr *ppbr;
70 	struct bsx64 *pbsx;
71 	struct exfat_dentry *ed;
72 	unsigned int root_clu_off, bitmap_clu_off, bitmap_clu;
73 	unsigned int total_clus, used_clus, clu_offset, root_clu;
74 	unsigned long long bitmap_len;
75 	int ret;
76 	unsigned char *bitmap;
77 	char *volume_label;
78 
79 	ppbr = malloc(EXFAT_MAX_SECTOR_SIZE);
80 	if (!ppbr) {
81 		exfat_err("Cannot allocate pbr: out of memory\n");
82 		return -ENOMEM;
83 	}
84 
85 	/* read main boot sector */
86 	if (exfat_read(bd->dev_fd, (char *)ppbr, EXFAT_MAX_SECTOR_SIZE,
87 			0) != (ssize_t)EXFAT_MAX_SECTOR_SIZE) {
88 		exfat_err("main boot sector read failed\n");
89 		ret = -EIO;
90 		goto free_ppbr;
91 	}
92 
93 	if (memcmp(ppbr->bpb.oem_name, "EXFAT   ", 8) != 0) {
94 		exfat_err("Bad fs_name in boot sector, which does not describe a valid exfat filesystem\n");
95 		ret = -EINVAL;
96 		goto free_ppbr;
97 	}
98 
99 	pbsx = &ppbr->bsx;
100 
101 	if (pbsx->sect_size_bits < EXFAT_MIN_SECT_SIZE_BITS ||
102 	    pbsx->sect_size_bits > EXFAT_MAX_SECT_SIZE_BITS) {
103 		exfat_err("bogus sector size bits : %u\n",
104 				pbsx->sect_size_bits);
105 		ret = -EINVAL;
106 		goto free_ppbr;
107 	}
108 
109 	if (pbsx->sect_per_clus_bits > 25 - pbsx->sect_size_bits) {
110 		exfat_err("bogus sectors bits per cluster : %u\n",
111 				pbsx->sect_per_clus_bits);
112 		ret = -EINVAL;
113 		goto free_ppbr;
114 	}
115 
116 	bd->sector_size_bits = pbsx->sect_size_bits;
117 	bd->sector_size = 1 << pbsx->sect_size_bits;
118 
119 	clu_offset = le32_to_cpu(pbsx->clu_offset);
120 	total_clus = le32_to_cpu(pbsx->clu_count);
121 	root_clu = le32_to_cpu(pbsx->root_cluster);
122 
123 	exfat_info("-------------- Dump Boot sector region --------------\n");
124 	exfat_info("Volume Length(sectors): \t\t%" PRIu64 "\n",
125 			le64_to_cpu(pbsx->vol_length));
126 	exfat_info("FAT Offset(sector offset): \t\t%u\n",
127 			le32_to_cpu(pbsx->fat_offset));
128 	exfat_info("FAT Length(sectors): \t\t\t%u\n",
129 			le32_to_cpu(pbsx->fat_length));
130 	exfat_info("Cluster Heap Offset (sector offset): \t%u\n", clu_offset);
131 	exfat_info("Cluster Count: \t\t\t\t%u\n", total_clus);
132 	exfat_info("Root Cluster (cluster offset): \t\t%u\n", root_clu);
133 	exfat_info("Volume Serial: \t\t\t\t0x%x\n", le32_to_cpu(pbsx->vol_serial));
134 	exfat_info("Sector Size Bits: \t\t\t%u\n", pbsx->sect_size_bits);
135 	exfat_info("Sector per Cluster bits: \t\t%u\n\n", pbsx->sect_per_clus_bits);
136 
137 	bd->cluster_size =
138 		1 << (pbsx->sect_per_clus_bits + pbsx->sect_size_bits);
139 	root_clu_off = exfat_clus_to_blk_dev_off(bd, clu_offset, root_clu);
140 
141 	ed = malloc(sizeof(struct exfat_dentry)*3);
142 	if (!ed) {
143 		exfat_err("failed to allocate memory\n");
144 		ret = -ENOMEM;
145 		goto free_ppbr;
146 	}
147 
148 	ret = exfat_read(bd->dev_fd, ed, sizeof(struct exfat_dentry)*3,
149 			root_clu_off);
150 	if (ret < 0) {
151 		exfat_err("bitmap entry read failed: %d\n", errno);
152 		ret = -EIO;
153 		goto free_entry;
154 	}
155 
156 	volume_label = exfat_conv_volume_label(&ed[0]);
157 	if (!volume_label) {
158 		ret = -EINVAL;
159 		goto free_entry;
160 	}
161 
162 	bitmap_clu = le32_to_cpu(ed[1].bitmap_start_clu);
163 	bitmap_clu_off = exfat_clus_to_blk_dev_off(bd, clu_offset,
164 			bitmap_clu);
165 	bitmap_len = le64_to_cpu(ed[1].bitmap_size);
166 
167 	exfat_info("----------------- Dump Root entries -----------------\n");
168 	exfat_info("Volume entry type: \t\t\t0x%x\n", ed[0].type);
169 	exfat_info("Volume label: \t\t\t\t%s\n", volume_label);
170 	exfat_info("Volume label character count: \t\t%u\n", ed[0].vol_char_cnt);
171 
172 	exfat_info("Bitmap entry type: \t\t\t0x%x\n", ed[1].type);
173 	exfat_info("Bitmap start cluster: \t\t\t%x\n", bitmap_clu);
174 	exfat_info("Bitmap size: \t\t\t\t%llu\n", bitmap_len);
175 
176 	exfat_info("Upcase table entry type: \t\t0x%x\n", ed[2].type);
177 	exfat_info("Upcase table start cluster: \t\t%x\n",
178 			le32_to_cpu(ed[2].upcase_start_clu));
179 	exfat_info("Upcase table size: \t\t\t%" PRIu64 "\n\n",
180 			le64_to_cpu(ed[2].upcase_size));
181 
182 	bitmap = malloc(bitmap_len);
183 	if (!bitmap) {
184 		exfat_err("bitmap allocation failed\n");
185 		ret = -ENOMEM;
186 		goto free_volume_label;
187 	}
188 
189 	ret = exfat_read(bd->dev_fd, bitmap, bitmap_len, bitmap_clu_off);
190 	if (ret < 0) {
191 		exfat_err("bitmap entry read failed: %d\n", errno);
192 		ret = -EIO;
193 		free(bitmap);
194 		goto free_volume_label;
195 	}
196 
197 	total_clus = le32_to_cpu(pbsx->clu_count);
198 	used_clus = exfat_count_used_clusters(bitmap, bitmap_len);
199 
200 	exfat_info("---------------- Show the statistics ----------------\n");
201 	exfat_info("Cluster size:  \t\t\t\t%u\n", bd->cluster_size);
202 	exfat_info("Total Clusters: \t\t\t%u\n", total_clus);
203 	exfat_info("Free Clusters: \t\t\t\t%u\n", total_clus-used_clus);
204 	ret = 0;
205 
206 	free(bitmap);
207 
208 free_volume_label:
209 	free(volume_label);
210 free_entry:
211 	free(ed);
212 free_ppbr:
213 	free(ppbr);
214 	return ret;
215 }
216 
main(int argc,char * argv[])217 int main(int argc, char *argv[])
218 {
219 	int c;
220 	int ret = EXIT_FAILURE;
221 	struct exfat_blk_dev bd;
222 	struct exfat_user_input ui;
223 	bool version_only = false;
224 
225 	init_user_input(&ui);
226 
227 	if (!setlocale(LC_CTYPE, ""))
228 		exfat_err("failed to init locale/codeset\n");
229 
230 	opterr = 0;
231 	while ((c = getopt_long(argc, argv, "iVh", opts, NULL)) != EOF)
232 		switch (c) {
233 		case 'V':
234 			version_only = true;
235 			break;
236 		case '?':
237 		case 'h':
238 		default:
239 			usage();
240 	}
241 
242 	show_version();
243 	if (version_only)
244 		exit(EXIT_FAILURE);
245 
246 	if (argc < 2)
247 		usage();
248 
249 	memset(ui.dev_name, 0, sizeof(ui.dev_name));
250 	snprintf(ui.dev_name, sizeof(ui.dev_name), "%s", argv[1]);
251 
252 	ret = exfat_get_blk_dev_info(&ui, &bd);
253 	if (ret < 0)
254 		goto out;
255 
256 	ret = exfat_show_ondisk_all_info(&bd);
257 	close(bd.dev_fd);
258 
259 out:
260 	return ret;
261 }
262