1/*	$OpenBSD: fsirand.c,v 1.44 2024/05/09 08:35:40 florian Exp $	*/
2
3/*
4 * Copyright (c) 1997 Todd C. Miller <millert@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <sys/param.h>	/* DEV_BSIZE */
20#include <sys/disklabel.h>
21#include <sys/ioctl.h>
22#include <sys/dkio.h>
23#include <sys/resource.h>
24#include <sys/time.h>
25
26#include <ufs/ffs/fs.h>
27#include <ufs/ufs/dinode.h>
28
29#include <err.h>
30#include <errno.h>
31#include <fcntl.h>
32#include <stdio.h>
33#include <stdlib.h>
34#include <string.h>
35#include <unistd.h>
36#include <util.h>
37
38void usage(int);
39int fsirand(char *);
40
41extern char *__progname;
42
43int printonly = 0, force = 0, ignorelabel = 0;
44
45/*
46 * Possible locations for the superblock.
47 */
48static const int sbtry[] = SBLOCKSEARCH;
49
50int
51main(int argc, char *argv[])
52{
53	int n, ex = 0;
54	struct rlimit rl;
55
56	while ((n = getopt(argc, argv, "bfp")) != -1) {
57		switch (n) {
58		case 'b':
59			ignorelabel = 1;
60			break;
61		case 'p':
62			printonly = 1;
63			break;
64		case 'f':
65			force = 1;
66			break;
67		default:
68			usage(1);
69		}
70	}
71	if (argc - optind < 1)
72		usage(1);
73
74	/* Increase our data size to the max */
75	if (getrlimit(RLIMIT_DATA, &rl) == 0) {
76		rl.rlim_cur = rl.rlim_max;
77		if (setrlimit(RLIMIT_DATA, &rl) == -1)
78			warn("Can't set resource limit to max data size");
79	} else
80		warn("Can't get resource limit for data size");
81
82	for (n = optind; n < argc; n++) {
83		if (argc - optind != 1)
84			(void)puts(argv[n]);
85		ex += fsirand(argv[n]);
86		if (n < argc - 1)
87			putchar('\n');
88	}
89
90	exit(ex);
91}
92
93int
94fsirand(char *device)
95{
96	struct ufs1_dinode *dp1 = NULL;
97	struct ufs2_dinode *dp2 = NULL;
98	static char *inodebuf;
99	size_t ibufsize, isize;
100	struct fs *sblock, *tmpsblock;
101	ino_t inumber;
102	daddr_t sblockloc, dblk;
103	char sbuf[SBSIZE], sbuftmp[SBSIZE];
104	int devfd, n, i;
105	u_int cg;
106	char *devpath, *ib;
107	u_int32_t bsize = DEV_BSIZE;
108	struct disklabel label;
109
110	if ((devfd = opendev(device, printonly ? O_RDONLY : O_RDWR,
111	    0, &devpath)) == -1) {
112		warn("Can't open %s", devpath);
113		return (1);
114	}
115
116	/* Get block size (usually 512) from disklabel if possible */
117	if (!ignorelabel) {
118		if (ioctl(devfd, DIOCGDINFO, &label) == -1)
119			warn("Can't read disklabel, using sector size of %d",
120			    bsize);
121		else
122			bsize = label.d_secsize;
123	}
124
125	if (pledge("stdio", NULL) == -1)
126		err(1, "pledge");
127
128	/* Read in master superblock */
129	(void)memset(&sbuf, 0, sizeof(sbuf));
130	sblock = (struct fs *)&sbuf;
131
132	for (i = 0; sbtry[i] != -1; i++) {
133		sblockloc = sbtry[i];
134
135		if (lseek(devfd, sblockloc, SEEK_SET) == -1) {
136			warn("Can't seek to superblock (%lld) on %s",
137			    (long long)sblockloc, devpath);
138			return (1);
139		}
140
141		if ((n = read(devfd, sblock, SBSIZE)) != SBSIZE) {
142			warnx("Can't read superblock on %s: %s", devpath,
143			    (n < SBSIZE) ? "short read" : strerror(errno));
144			return (1);
145		}
146
147		/* Find a suitable superblock */
148		if (sblock->fs_magic != FS_UFS1_MAGIC &&
149		    sblock->fs_magic != FS_UFS2_MAGIC)
150			continue; /* Not a superblock */
151
152		/*
153		 * Do not look for an FFS1 file system at SBLOCK_UFS2.
154		 * Doing so will find the wrong super-block for file
155		 * systems with 64k block size.
156		 */
157		if (sblock->fs_magic == FS_UFS1_MAGIC &&
158		    sbtry[i] == SBLOCK_UFS2)
159			continue;
160
161		if (sblock->fs_magic == FS_UFS2_MAGIC &&
162		    sblock->fs_sblockloc != sbtry[i])
163		    	continue; /* Not a superblock */
164
165		break;
166	}
167
168	if (sbtry[i] == -1) {
169		warnx("Cannot find file system superblock");
170		return (1);
171	}
172
173	/* Simple sanity checks on the superblock */
174	if (sblock->fs_sbsize > SBSIZE) {
175		warnx("Superblock size is preposterous");
176		return (1);
177	}
178
179	if (sblock->fs_postblformat == FS_42POSTBLFMT) {
180		warnx("Filesystem format is too old, sorry");
181		return (1);
182	}
183
184	if (!force && !printonly && sblock->fs_clean != FS_ISCLEAN) {
185		warnx("Filesystem is not clean, fsck %s first.", devpath);
186		return (1);
187	}
188
189	/* Make sure backup superblocks are sane. */
190	tmpsblock = (struct fs *)&sbuftmp;
191	for (cg = 0; cg < sblock->fs_ncg; cg++) {
192		dblk = fsbtodb(sblock, cgsblock(sblock, cg));
193		if (lseek(devfd, (off_t)dblk * bsize, SEEK_SET) == -1) {
194			warn("Can't seek to %lld", (long long)dblk * bsize);
195			return (1);
196		} else if ((n = read(devfd, tmpsblock, SBSIZE)) != SBSIZE) {
197			warn("Can't read backup superblock %d on %s: %s",
198			    cg + 1, devpath, (n < SBSIZE) ? "short read"
199			    : strerror(errno));
200			return (1);
201		}
202		if (tmpsblock->fs_magic != FS_UFS1_MAGIC &&
203		    tmpsblock->fs_magic != FS_UFS2_MAGIC) {
204			warnx("Bad magic number in backup superblock %d on %s",
205			    cg + 1, devpath);
206			return (1);
207		}
208		if (tmpsblock->fs_sbsize > SBSIZE) {
209			warnx("Size of backup superblock %d on %s is preposterous",
210			    cg + 1, devpath);
211			return (1);
212		}
213	}
214
215	/* XXX - should really cap buffer at 512kb or so */
216	if (sblock->fs_magic == FS_UFS1_MAGIC)
217		isize = sizeof(struct ufs1_dinode);
218	else
219		isize = sizeof(struct ufs2_dinode);
220
221	if ((ib = reallocarray(inodebuf, sblock->fs_ipg, isize)) == NULL)
222		errx(1, "Can't allocate memory for inode buffer");
223	inodebuf = ib;
224	ibufsize = sblock->fs_ipg * isize;
225
226	if (printonly && (sblock->fs_id[0] || sblock->fs_id[1])) {
227		if (sblock->fs_inodefmt >= FS_44INODEFMT && sblock->fs_id[0]) {
228			time_t t = sblock->fs_id[0];	/* XXX 2038 */
229			char *ct = ctime(&t);
230			if (ct)
231				(void)printf("%s was randomized on %s", devpath,
232				    ct);
233			else
234				(void)printf("%s was randomized on %lld\n",
235				    devpath, t);
236		}
237		(void)printf("fsid: %x %x\n", sblock->fs_id[0],
238		    sblock->fs_id[1]);
239	}
240
241	/* Randomize fs_id unless old 4.2BSD filesystem */
242	if ((sblock->fs_inodefmt >= FS_44INODEFMT) && !printonly) {
243		/* Randomize fs_id and write out new sblock and backups */
244		sblock->fs_id[0] = (u_int32_t)time(NULL);
245		sblock->fs_id[1] = arc4random();
246
247		if (lseek(devfd, SBOFF, SEEK_SET) == -1) {
248			warn("Can't seek to superblock (%lld) on %s",
249			    (long long)SBOFF, devpath);
250			return (1);
251		}
252		if ((n = write(devfd, sblock, SBSIZE)) != SBSIZE) {
253			warn("Can't write superblock on %s: %s", devpath,
254			    (n < SBSIZE) ? "short write" : strerror(errno));
255			return (1);
256		}
257	}
258
259	/* For each cylinder group, randomize inodes and update backup sblock */
260	for (cg = 0, inumber = 0; cg < sblock->fs_ncg; cg++) {
261		/* Update superblock if appropriate */
262		if ((sblock->fs_inodefmt >= FS_44INODEFMT) && !printonly) {
263			dblk = fsbtodb(sblock, cgsblock(sblock, cg));
264			if (lseek(devfd, (off_t)dblk * bsize,
265			    SEEK_SET) == -1) {
266				warn("Can't seek to %lld",
267				    (long long)dblk * bsize);
268				return (1);
269			} else if ((n = write(devfd, sblock, SBSIZE)) !=
270			    SBSIZE) {
271				warn("Can't read backup superblock %d on %s: %s",
272				    cg + 1, devpath, (n < SBSIZE) ? "short write"
273				    : strerror(errno));
274				return (1);
275			}
276		}
277
278		/* Read in inodes, then print or randomize generation nums */
279		dblk = fsbtodb(sblock, ino_to_fsba(sblock, inumber));
280		if (lseek(devfd, (off_t)dblk * bsize, SEEK_SET) == -1) {
281			warn("Can't seek to %lld", (long long)dblk * bsize);
282			return (1);
283		} else if ((n = read(devfd, inodebuf, ibufsize)) != ibufsize) {
284			warnx("Can't read inodes: %s",
285			    (n < ibufsize) ? "short read" : strerror(errno));
286			return (1);
287		}
288
289		for (n = 0; n < sblock->fs_ipg; n++, inumber++) {
290			if (sblock->fs_magic == FS_UFS1_MAGIC)
291				dp1 = &((struct ufs1_dinode *)inodebuf)[n];
292			else
293				dp2 = &((struct ufs2_dinode *)inodebuf)[n];
294			if (inumber >= ROOTINO) {
295				if (printonly)
296					(void)printf("ino %llu gen %x\n",
297					    (unsigned long long)inumber,
298					    sblock->fs_magic == FS_UFS1_MAGIC ?
299					    dp1->di_gen : dp2->di_gen);
300				else if (sblock->fs_magic == FS_UFS1_MAGIC)
301					dp1->di_gen = arc4random();
302				else
303					dp2->di_gen = arc4random();
304			}
305		}
306
307		/* Write out modified inodes */
308		if (!printonly) {
309			if (lseek(devfd, (off_t)dblk * bsize, SEEK_SET) == -1) {
310				warn("Can't seek to %lld",
311				    (long long)dblk * bsize);
312				return (1);
313			} else if ((n = write(devfd, inodebuf, ibufsize)) !=
314				 ibufsize) {
315				warnx("Can't write inodes: %s",
316				    (n != ibufsize) ? "short write" :
317				    strerror(errno));
318				return (1);
319			}
320		}
321	}
322	(void)close(devfd);
323
324	return(0);
325}
326
327void
328usage(int ex)
329{
330	(void)fprintf(stderr, "usage: %s [-bfp] special ...\n",
331	    __progname);
332	exit(ex);
333}
334