/
ext2fsutil.c
268 lines (235 loc) · 9.27 KB
/
ext2fsutil.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
#include "ext2fsutil.h"
void getSuperBlock(int parStart, struct ext2_super_block *buf) {
readDisk(parStart * SECTOR_SIZE + SUPER_BLOCK_OFFSET, SUPER_BLOCK_SIZE , buf);
}
void getGroupDescs(int parStart, struct ext2_group_desc *buf, int groupNum) {
readDisk(parStart * SECTOR_SIZE + GROUP_DESC_OFFSET, ONE_GROUP_DESC_SIZE * groupNum, buf);
}
inline int roundUp(int a, int b) {
return (int) ceil(1.0 * a / b);
}
inline int getGroupNumber(struct ext2_super_block *superBlock) {
return roundUp(superBlock->s_blocks_count, superBlock->s_blocks_per_group);
}
// Read All Block Bitmap From All Group
void getBlockBitmap(int parStart, struct ext2_group_desc groupDescs[], int groupNum, unsigned char *blockBitmap, int blockSize) {
int i;
for (i = 0; i < groupNum; ++i)
readDisk(parStart * SECTOR_SIZE + groupDescs[i].bg_block_bitmap * blockSize, blockSize, blockBitmap + i * blockSize);
}
// Read All Inode Bitmap From All Group
void getInodeBitmap(int parStart, struct ext2_group_desc groupDescs[], int groupNum, unsigned char *inodeBitmap, int blockSize) {
int i;
for (i = 0; i < groupNum; ++i)
readDisk(parStart * SECTOR_SIZE + groupDescs[i].bg_inode_bitmap * blockSize, blockSize, inodeBitmap + i * blockSize);
}
// blockNo is local BlockNo
void getGroupBlock(int blockNo, int *groupNo, int *groupBlockNo, struct ext2_super_block *superBlock) {
*groupNo = blockNo / superBlock->s_blocks_per_group;
*groupBlockNo = blockNo % superBlock->s_blocks_per_group;
}
// inodeNo is local inodeNo
void getInodeGroupBlock(int inodeNo, int *groupNo, int *groupInodeNo, struct ext2_super_block *superBlock) {
*groupNo = inodeNo / superBlock->s_inodes_per_group;
*groupInodeNo = inodeNo % superBlock->s_inodes_per_group;
}
/* Read All Inodes From All Groups */
void getInodeTable(int parStart, struct ext2_super_block *superBlock, struct ext2_group_desc groupDescs[], int groupNum, struct ext2_inode *inodeTable, int blockSize) {
int i;
int last = 0;
for (i = 0; i < groupNum; ++i) {
readDisk(parStart * SECTOR_SIZE + groupDescs[i].bg_inode_table * blockSize, INODE_SIZE * superBlock->s_inodes_per_group, inodeTable + last);
last += superBlock->s_inodes_per_group;
}
}
inline void getIndexBit(int Number, int *index, int *bit) {
*index = Number / 8;
*bit = Number % 8;
}
/* ret 1 if in inode bitmap inodeNo is 1, else ret 0 */
/* local inode number */
int isInodeBitmapSet(int inodeNo, unsigned char *inodeBitmap, int groupNum, int blockSize, struct ext2_super_block *superBlock) {
int groupNo;
int groupInodeNo;
getInodeGroupBlock(inodeNo, &groupNo, &groupInodeNo, superBlock);
int index;
int bit;
getIndexBit(groupInodeNo, &index, &bit);
return (inodeBitmap[groupNo * blockSize + index] & (1 << bit)) >> bit;
}
void setInodeBitmapSet(int inodeNo, unsigned char *inodeBitmap, int groupNum, int blockSize, struct ext2_super_block *superBlock, int setbit) {
int groupNo;
int groupInodeNo;
getInodeGroupBlock(inodeNo, &groupNo, &groupInodeNo, superBlock);
int index;
int bit;
getIndexBit(groupInodeNo, &index, &bit);
if (setbit)
inodeBitmap[groupNo * blockSize + index] |= (1 << bit);
else
inodeBitmap[groupNo * blockSize + index] &= (~(1 << bit));
}
void setBlockBitmapSet(int blockNo, unsigned char *blockBitmap, int groupNum, int blockSize, struct ext2_super_block *superBlock, int setbit) {
//printf("%d\n", blockNo);
int groupNo;
int groupBlockNo;
getGroupBlock(blockNo, &groupNo, &groupBlockNo, superBlock);
int index;
int bit;
getIndexBit(groupBlockNo, &index, &bit);
if (setbit)
blockBitmap[groupNo * blockSize + index] |= (1 << bit);
else
blockBitmap[groupNo * blockSize + index] &= (~(1 << bit));
}
/* ret 1 if in block bitmap blockno is 1, else ret 0 */
/* local block Number */
int isBlockBitmapSet(int blockNo, unsigned char *blockBitmap, int groupNum, int blockSize, struct ext2_super_block *superBlock) {
int groupNo;
int groupBlockNo;
getGroupBlock(blockNo, &groupNo, &groupBlockNo, superBlock);
int index;
int bit;
getIndexBit(groupBlockNo, &index, &bit);
return (blockBitmap[groupNo * blockSize + index] & (1 << bit)) >> bit;
}
inline int isDirectory(struct ext2_inode *inode) {
int temp = inode->i_mode & 0xF000;
return temp == EXT2_S_IFDIR;
}
inline int isSymbolicLink(struct ext2_inode *inode) {
int temp = inode->i_mode & 0xF000;
return temp == EXT2_S_IFLNK;
}
inline int isRegFile(struct ext2_inode *inode) {
int temp = inode->i_mode & 0xF000;
return temp == EXT2_S_IFREG;
}
inline int localNo(int x) {
return x - 1;
}
// get all data from one inode
void getData(int parStart, struct ext2_inode *inode, int blockSize, unsigned char* buf) {
int i, j, k;
int tempSize = 0;
int totalSize = inode->i_size;
int len = blockSize / sizeof(int);
int* indblock = malloc(blockSize);
int* dindblock = malloc(blockSize);
int* tindblock = malloc(blockSize);
// Direct Blocks
for (i = 0; i < EXT2_NDIR_BLOCKS; ++i) {
readDisk(parStart * SECTOR_SIZE + blockSize * inode->i_block[i], blockSize, buf + tempSize);
tempSize += blockSize;
if (tempSize >= totalSize) goto FREE_MEMORY;
}
// Indirect Blocks
readDisk(parStart * SECTOR_SIZE + blockSize * inode->i_block[EXT2_IND_BLOCK], blockSize, indblock);
for (i = 0; i < len; ++i) {
readDisk(parStart * SECTOR_SIZE + blockSize * indblock[i], blockSize, buf + tempSize);
tempSize += blockSize;
if (tempSize >= totalSize) goto FREE_MEMORY;
}
// Doubly-indirect Blocks
readDisk(parStart * SECTOR_SIZE + blockSize * inode->i_block[EXT2_DIND_BLOCK], blockSize, dindblock);
for (i = 0; i < len; ++i) {
readDisk(parStart * SECTOR_SIZE + blockSize * dindblock[i], blockSize, indblock);
for (j = 0; j < len; ++j) {
readDisk(parStart * SECTOR_SIZE + blockSize * indblock[j], blockSize, buf + tempSize);
tempSize += blockSize;
if (tempSize >= totalSize) goto FREE_MEMORY;
}
}
// Thriply-indirect Blocks
readDisk(parStart * SECTOR_SIZE + blockSize * inode->i_block[EXT2_TIND_BLOCK], blockSize, tindblock);
for (i = 0; i < len; ++i) {
readDisk(parStart * SECTOR_SIZE + blockSize * tindblock[i], blockSize, dindblock);
for (j = 0; j < len; ++j) {
readDisk(parStart * SECTOR_SIZE + blockSize * dindblock[j], blockSize, indblock);
for (k = 0; k < len; ++k) {
readDisk(parStart * SECTOR_SIZE + blockSize * indblock[k], blockSize, buf + tempSize);
tempSize += blockSize;
if (tempSize >= totalSize) goto FREE_MEMORY;
}
}
}
FREE_MEMORY:
free(indblock);
free(dindblock);
free(tindblock);
}
void AnalyzeDir(struct ext2_inode *inode, unsigned char *buf) {
int tempSize = 0;
int totalSize = inode->i_size;
struct ext2_dir_entry_2 *dir;
while (tempSize < totalSize) {
dir = (struct ext2_dir_entry_2 *)(buf + tempSize);
printf("%d %d %d %d %s\n", dir->inode, dir->rec_len, dir->name_len, dir->file_type, strndupa(dir->name, dir->name_len));
tempSize += dir->rec_len;
}
}
void ext2fsutilTest(int start, int length) {
struct ext2_super_block x;
getSuperBlock(start, &x);
int groupNum = getGroupNumber(&x);
int blockSize = EXT2_BLOCK_SIZE(&x);
struct ext2_group_desc groupDescs[MAX_GROUP_NUM];
getGroupDescs(start, groupDescs, groupNum);
unsigned char *blockBitmap = malloc(blockSize * groupNum + 1);
getBlockBitmap(start, groupDescs, groupNum, blockBitmap, blockSize);
unsigned char *inodeBitmap = malloc(blockSize * groupNum + 1);
getInodeBitmap(start, groupDescs, groupNum, inodeBitmap, blockSize);
struct ext2_inode *inodeTable = malloc(sizeof(struct ext2_inode) * x.s_inodes_per_group * groupNum);
getInodeTable(start, &x, groupDescs, groupNum, inodeTable, blockSize);
unsigned char *buf = malloc(inodeTable[localNo(EXT2_ROOT_INO)].i_size);
getData(start, inodeTable + 1, blockSize, buf);
AnalyzeDir(inodeTable + 1, buf);
/* struct ext2_inode *inode;
//we already know /lion is on inode 4017
inode = inodeTable + 4016;
printf("%d\n", isDirectory(inode));
unsigned char *lionbuf = malloc(inode->i_size);
getData(start, inode, blockSize, lionbuf);
AnalyzeDir(inode, lionbuf);
//we already know /lion/tigers is on inode 4018
inode = inodeTable + 4017;
printf("%d\n", isDirectory(inode));
unsigned char *tigersbuf= malloc(inode->i_size);
getData(start, inode, blockSize, tigersbuf);
AnalyzeDir(inode, tigersbuf);
//we already know /lion/tigers/bears is on inode 4019
inode = inodeTable + 4018;
printf("%d\n", isDirectory(inode));
unsigned char *bearsbuf= malloc(inode->i_size);
getData(start, inode, blockSize, bearsbuf);
AnalyzeDir(inode, bearsbuf);
//we already know /lion/tigers/bears/ohmy.txt is on inode 4021
inode = inodeTable + 4020;
printf("%d\n", isDirectory(inode));
unsigned char *txtbuf= malloc(inode->i_size);
getData(start, inode, blockSize, txtbuf);
//printf("%s", txtbuf);
printf("%d\n", isBlockBitmapSet(localNo(inode->i_block[0]), blockBitmap, groupNum, blockSize, &x));
free(txtbuf);
free(bearsbuf);
free(tigersbuf);
free(lionbuf); */
/* struct ext2_inode *inode;
//we already know /oz/tornado/glinda is on inode 30
inode = inodeTable + 29;
printf("%d\n", isSymbolicLink(inode));
printf("%d %d %d %d\n", inode->i_size, inode->i_blocks, inode->i_block[0], inode->i_block[1]);
int i;
for (i = 0; i < inode->i_size; ++i)
printf("%c", ((unsigned char *)inode->i_block)[i]);
printf("\n");
// unsigned char *ozbuf = malloc(inode->i_size);
// getData(start, inode, blockSize, ozbuf);
// printf("%s\n", ozbuf);
// AnalyzeDir(inode, ozbuf);
// free(ozbuf);
*/
free(buf);
free(blockBitmap);
free(inodeBitmap);
}