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1 /*
2  * dump.c --- dump the contents of an inode out to a file
3  *
4  * Copyright (C) 1994 Theodore Ts'o.  This file may be redistributed
5  * under the terms of the GNU Public License.
6  */
7 
8 #ifndef _GNU_SOURCE
9 #define _GNU_SOURCE /* for O_LARGEFILE */
10 #endif
11 
12 #include <stdio.h>
13 #include <unistd.h>
14 #include <stdlib.h>
15 #include <ctype.h>
16 #include <string.h>
17 #include <time.h>
18 #ifdef HAVE_ERRNO_H
19 #include <errno.h>
20 #endif
21 #include <sys/types.h>
22 #include <sys/stat.h>
23 #include <fcntl.h>
24 #include <utime.h>
25 #ifdef HAVE_GETOPT_H
26 #include <getopt.h>
27 #else
28 extern int optind;
29 extern char *optarg;
30 #endif
31 
32 #include "debugfs.h"
33 
34 #ifndef O_LARGEFILE
35 #define O_LARGEFILE 0
36 #endif
37 
38 /*
39  * The mode_xlate function translates a linux mode into a native-OS mode_t.
40  */
41 static struct {
42 	__u16 lmask;
43 	mode_t mask;
44 } mode_table[] = {
45 	{ LINUX_S_IRUSR, S_IRUSR },
46 	{ LINUX_S_IWUSR, S_IWUSR },
47 	{ LINUX_S_IXUSR, S_IXUSR },
48 	{ LINUX_S_IRGRP, S_IRGRP },
49 	{ LINUX_S_IWGRP, S_IWGRP },
50 	{ LINUX_S_IXGRP, S_IXGRP },
51 	{ LINUX_S_IROTH, S_IROTH },
52 	{ LINUX_S_IWOTH, S_IWOTH },
53 	{ LINUX_S_IXOTH, S_IXOTH },
54 	{ 0, 0 }
55 };
56 
mode_xlate(__u16 lmode)57 static mode_t mode_xlate(__u16 lmode)
58 {
59 	mode_t	mode = 0;
60 	int	i;
61 
62 	for (i=0; mode_table[i].lmask; i++) {
63 		if (lmode & mode_table[i].lmask)
64 			mode |= mode_table[i].mask;
65 	}
66 	return mode;
67 }
68 
fix_perms(const char * cmd,const struct ext2_inode * inode,int fd,const char * name)69 static void fix_perms(const char *cmd, const struct ext2_inode *inode,
70 		      int fd, const char *name)
71 {
72 	struct utimbuf ut;
73 	int i;
74 
75 	if (fd != -1)
76 		i = fchmod(fd, mode_xlate(inode->i_mode));
77 	else
78 		i = chmod(name, mode_xlate(inode->i_mode));
79 	if (i == -1)
80 		com_err(cmd, errno, "while setting permissions of %s", name);
81 
82 #ifndef HAVE_FCHOWN
83 	i = chown(name, inode->i_uid, inode->i_gid);
84 #else
85 	if (fd != -1)
86 		i = fchown(fd, inode->i_uid, inode->i_gid);
87 	else
88 		i = chown(name, inode->i_uid, inode->i_gid);
89 #endif
90 	if (i == -1)
91 		com_err(cmd, errno, "while changing ownership of %s", name);
92 
93 	if (fd != -1)
94 		close(fd);
95 
96 	ut.actime = inode->i_atime;
97 	ut.modtime = inode->i_mtime;
98 	if (utime(name, &ut) == -1)
99 		com_err(cmd, errno, "while setting times of %s", name);
100 }
101 
dump_file(const char * cmdname,ext2_ino_t ino,int fd,int preserve,char * outname)102 static void dump_file(const char *cmdname, ext2_ino_t ino, int fd,
103 		      int preserve, char *outname)
104 {
105 	errcode_t retval;
106 	struct ext2_inode	inode;
107 	char		*buf = 0;
108 	ext2_file_t	e2_file;
109 	int		nbytes;
110 	unsigned int	got, blocksize = current_fs->blocksize;
111 
112 	if (debugfs_read_inode(ino, &inode, cmdname))
113 		return;
114 
115 	retval = ext2fs_file_open(current_fs, ino, 0, &e2_file);
116 	if (retval) {
117 		com_err(cmdname, retval, "while opening ext2 file");
118 		return;
119 	}
120 	retval = ext2fs_get_mem(blocksize, &buf);
121 	if (retval) {
122 		com_err(cmdname, retval, "while allocating memory");
123 		return;
124 	}
125 	while (1) {
126 		retval = ext2fs_file_read(e2_file, buf, blocksize, &got);
127 		if (retval)
128 			com_err(cmdname, retval, "while reading ext2 file");
129 		if (got == 0)
130 			break;
131 		nbytes = write(fd, buf, got);
132 		if ((unsigned) nbytes != got)
133 			com_err(cmdname, errno, "while writing file");
134 	}
135 	if (buf)
136 		ext2fs_free_mem(&buf);
137 	retval = ext2fs_file_close(e2_file);
138 	if (retval) {
139 		com_err(cmdname, retval, "while closing ext2 file");
140 		return;
141 	}
142 
143 	if (preserve)
144 		fix_perms("dump_file", &inode, fd, outname);
145 
146 	return;
147 }
148 
do_dump(int argc,char ** argv)149 void do_dump(int argc, char **argv)
150 {
151 	ext2_ino_t	inode;
152 	int		fd;
153 	int		c;
154 	int		preserve = 0;
155 	char		*in_fn, *out_fn;
156 
157 	reset_getopt();
158 	while ((c = getopt (argc, argv, "p")) != EOF) {
159 		switch (c) {
160 		case 'p':
161 			preserve++;
162 			break;
163 		default:
164 		print_usage:
165 			com_err(argv[0], 0, "Usage: dump_inode [-p] "
166 				"<file> <output_file>");
167 			return;
168 		}
169 	}
170 	if (optind != argc-2)
171 		goto print_usage;
172 
173 	if (check_fs_open(argv[0]))
174 		return;
175 
176 	in_fn = argv[optind];
177 	out_fn = argv[optind+1];
178 
179 	inode = string_to_inode(in_fn);
180 	if (!inode)
181 		return;
182 
183 	fd = open(out_fn, O_CREAT | O_WRONLY | O_TRUNC | O_LARGEFILE, 0666);
184 	if (fd < 0) {
185 		com_err(argv[0], errno, "while opening %s for dump_inode",
186 			out_fn);
187 		return;
188 	}
189 
190 	dump_file(argv[0], inode, fd, preserve, out_fn);
191 	if (close(fd) != 0) {
192 		com_err(argv[0], errno, "while closing %s for dump_inode",
193 			out_fn);
194 		return;
195 	}
196 
197 	return;
198 }
199 
rdump_symlink(ext2_ino_t ino,struct ext2_inode * inode,const char * fullname)200 static void rdump_symlink(ext2_ino_t ino, struct ext2_inode *inode,
201 			  const char *fullname)
202 {
203 	ext2_file_t e2_file;
204 	char *buf;
205 	errcode_t retval;
206 
207 	buf = malloc(inode->i_size + 1);
208 	if (!buf) {
209 		com_err("rdump", errno, "while allocating for symlink");
210 		goto errout;
211 	}
212 
213 	/* Apparently, this is the right way to detect and handle fast
214 	 * symlinks; see do_stat() in debugfs.c. */
215 	if (inode->i_blocks == 0)
216 		strcpy(buf, (char *) inode->i_block);
217 	else {
218 		unsigned bytes = inode->i_size;
219 		char *p = buf;
220 		retval = ext2fs_file_open(current_fs, ino, 0, &e2_file);
221 		if (retval) {
222 			com_err("rdump", retval, "while opening symlink");
223 			goto errout;
224 		}
225 		for (;;) {
226 			unsigned int got;
227 			retval = ext2fs_file_read(e2_file, p, bytes, &got);
228 			if (retval) {
229 				com_err("rdump", retval, "while reading symlink");
230 				goto errout;
231 			}
232 			bytes -= got;
233 			p += got;
234 			if (got == 0 || bytes == 0)
235 				break;
236 		}
237 		buf[inode->i_size] = 0;
238 		retval = ext2fs_file_close(e2_file);
239 		if (retval)
240 			com_err("rdump", retval, "while closing symlink");
241 	}
242 
243 	if (symlink(buf, fullname) == -1) {
244 		com_err("rdump", errno, "while creating symlink %s -> %s", buf, fullname);
245 		goto errout;
246 	}
247 
248 errout:
249 	free(buf);
250 }
251 
252 static int rdump_dirent(struct ext2_dir_entry *, int, int, char *, void *);
253 
rdump_inode(ext2_ino_t ino,struct ext2_inode * inode,const char * name,const char * dumproot)254 static void rdump_inode(ext2_ino_t ino, struct ext2_inode *inode,
255 			const char *name, const char *dumproot)
256 {
257 	char *fullname;
258 
259 	/* There are more efficient ways to do this, but this method
260 	 * requires only minimal debugging. */
261 	fullname = malloc(strlen(dumproot) + strlen(name) + 2);
262 	if (!fullname) {
263 		com_err("rdump", errno, "while allocating memory");
264 		return;
265 	}
266 	sprintf(fullname, "%s/%s", dumproot, name);
267 
268 	if (LINUX_S_ISLNK(inode->i_mode))
269 		rdump_symlink(ino, inode, fullname);
270 	else if (LINUX_S_ISREG(inode->i_mode)) {
271 		int fd;
272 		fd = open(fullname, O_WRONLY | O_CREAT | O_TRUNC | O_LARGEFILE, S_IRWXU);
273 		if (fd == -1) {
274 			com_err("rdump", errno, "while dumping %s", fullname);
275 			goto errout;
276 		}
277 		dump_file("rdump", ino, fd, 1, fullname);
278 		if (close(fd) != 0) {
279 			com_err("rdump", errno, "while dumping %s", fullname);
280 			goto errout;
281 		}
282 	}
283 	else if (LINUX_S_ISDIR(inode->i_mode) && strcmp(name, ".") && strcmp(name, "..")) {
284 		errcode_t retval;
285 
286 		/* Create the directory with 0700 permissions, because we
287 		 * expect to have to create entries it.  Then fix its perms
288 		 * once we've done the traversal. */
289 		if (mkdir(fullname, S_IRWXU) == -1) {
290 			com_err("rdump", errno, "while making directory %s", fullname);
291 			goto errout;
292 		}
293 
294 		retval = ext2fs_dir_iterate(current_fs, ino, 0, 0,
295 					    rdump_dirent, (void *) fullname);
296 		if (retval)
297 			com_err("rdump", retval, "while dumping %s", fullname);
298 
299 		fix_perms("rdump", inode, -1, fullname);
300 	}
301 	/* else do nothing (don't dump device files, sockets, fifos, etc.) */
302 
303 errout:
304 	free(fullname);
305 }
306 
rdump_dirent(struct ext2_dir_entry * dirent,int offset EXT2FS_ATTR ((unused)),int blocksize EXT2FS_ATTR ((unused)),char * buf EXT2FS_ATTR ((unused)),void * private)307 static int rdump_dirent(struct ext2_dir_entry *dirent,
308 			int offset EXT2FS_ATTR((unused)),
309 			int blocksize EXT2FS_ATTR((unused)),
310 			char *buf EXT2FS_ATTR((unused)), void *private)
311 {
312 	char name[EXT2_NAME_LEN + 1];
313 	int thislen;
314 	const char *dumproot = private;
315 	struct ext2_inode inode;
316 
317 	thislen = dirent->name_len & 0xFF;
318 	strncpy(name, dirent->name, thislen);
319 	name[thislen] = 0;
320 
321 	if (debugfs_read_inode(dirent->inode, &inode, name))
322 		return 0;
323 
324 	rdump_inode(dirent->inode, &inode, name, dumproot);
325 
326 	return 0;
327 }
328 
do_rdump(int argc,char ** argv)329 void do_rdump(int argc, char **argv)
330 {
331 	ext2_ino_t ino;
332 	struct ext2_inode inode;
333 	struct stat st;
334 	int i;
335 	char *p;
336 
337 	if (common_args_process(argc, argv, 3, 3, "rdump",
338 				"<directory> <native directory>", 0))
339 		return;
340 
341 	ino = string_to_inode(argv[1]);
342 	if (!ino)
343 		return;
344 
345 	/* Ensure ARGV[2] is a directory. */
346 	i = stat(argv[2], &st);
347 	if (i == -1) {
348 		com_err("rdump", errno, "while statting %s", argv[2]);
349 		return;
350 	}
351 	if (!S_ISDIR(st.st_mode)) {
352 		com_err("rdump", 0, "%s is not a directory", argv[2]);
353 		return;
354 	}
355 
356 	if (debugfs_read_inode(ino, &inode, argv[1]))
357 		return;
358 
359 	p = strrchr(argv[1], '/');
360 	if (p)
361 		p++;
362 	else
363 		p = argv[1];
364 
365 	rdump_inode(ino, &inode, p, argv[2]);
366 }
367 
do_cat(int argc,char ** argv)368 void do_cat(int argc, char **argv)
369 {
370 	ext2_ino_t	inode;
371 
372 	if (common_inode_args_process(argc, argv, &inode, 0))
373 		return;
374 
375 	fflush(stdout);
376 	fflush(stderr);
377 	dump_file(argv[0], inode, 1, 0, argv[2]);
378 
379 	return;
380 }
381 
382