/*      $OpenBSD: fsirand.c,v 1.44 2024/05/09 08:35:40 florian Exp $    */

/*
 * Copyright (c) 1997 Todd C. Miller <millert@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>  /* DEV_BSIZE */
#include <sys/disklabel.h>
#include <sys/ioctl.h>
#include <sys/dkio.h>
#include <sys/resource.h>
#include <sys/time.h>

#include <ufs/ffs/fs.h>
#include <ufs/ufs/dinode.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <util.h>

void usage(int);
int fsirand(char *);

extern char *__progname;

int printonly = 0, force = 0, ignorelabel = 0;

/*
 * Possible locations for the superblock.
 */
static const int sbtry[] = SBLOCKSEARCH;

int
main(int argc, char *argv[])
{
        int n, ex = 0;
        struct rlimit rl;

        while ((n = getopt(argc, argv, "bfp")) != -1) {
                switch (n) {
                case 'b':
                        ignorelabel = 1;
                        break;
                case 'p':
                        printonly = 1;
                        break;
                case 'f':
                        force = 1;
                        break;
                default:
                        usage(1);
                }
        }
        if (argc - optind < 1)
                usage(1);

        /* Increase our data size to the max */
        if (getrlimit(RLIMIT_DATA, &rl) == 0) {
                rl.rlim_cur = rl.rlim_max;
                if (setrlimit(RLIMIT_DATA, &rl) == -1)
                        warn("Can't set resource limit to max data size");
        } else
                warn("Can't get resource limit for data size");

        for (n = optind; n < argc; n++) {
                if (argc - optind != 1)
                        (void)puts(argv[n]);
                ex += fsirand(argv[n]);
                if (n < argc - 1)
                        putchar('\n');
        }

        exit(ex);
}

int
fsirand(char *device)
{
        struct ufs1_dinode *dp1 = NULL;
        struct ufs2_dinode *dp2 = NULL;
        static char *inodebuf;
        size_t ibufsize, isize;
        struct fs *sblock, *tmpsblock;
        ino_t inumber;
        daddr_t sblockloc, dblk;
        char sbuf[SBSIZE], sbuftmp[SBSIZE];
        int devfd, n, i;
        u_int cg;
        char *devpath, *ib;
        u_int32_t bsize = DEV_BSIZE;
        struct disklabel label;

        if ((devfd = opendev(device, printonly ? O_RDONLY : O_RDWR,
            0, &devpath)) == -1) {
                warn("Can't open %s", devpath);
                return (1);
        }

        /* Get block size (usually 512) from disklabel if possible */
        if (!ignorelabel) {
                if (ioctl(devfd, DIOCGDINFO, &label) == -1)
                        warn("Can't read disklabel, using sector size of %d",
                            bsize);
                else
                        bsize = label.d_secsize;
        }

        if (pledge("stdio", NULL) == -1)
                err(1, "pledge");

        /* Read in master superblock */
        (void)memset(&sbuf, 0, sizeof(sbuf));
        sblock = (struct fs *)&sbuf;

        for (i = 0; sbtry[i] != -1; i++) {
                sblockloc = sbtry[i];

                if (lseek(devfd, sblockloc, SEEK_SET) == -1) {
                        warn("Can't seek to superblock (%lld) on %s",
                            (long long)sblockloc, devpath);
                        return (1);
                }

                if ((n = read(devfd, sblock, SBSIZE)) != SBSIZE) {
                        warnx("Can't read superblock on %s: %s", devpath,
                            (n < SBSIZE) ? "short read" : strerror(errno));
                        return (1);
                }

                /* Find a suitable superblock */
                if (sblock->fs_magic != FS_UFS1_MAGIC &&
                    sblock->fs_magic != FS_UFS2_MAGIC)
                        continue; /* Not a superblock */

                /*
                 * Do not look for an FFS1 file system at SBLOCK_UFS2.
                 * Doing so will find the wrong super-block for file
                 * systems with 64k block size.
                 */
                if (sblock->fs_magic == FS_UFS1_MAGIC &&
                    sbtry[i] == SBLOCK_UFS2)
                        continue;

                if (sblock->fs_magic == FS_UFS2_MAGIC &&
                    sblock->fs_sblockloc != sbtry[i])
                        continue; /* Not a superblock */

                break;
        }

        if (sbtry[i] == -1) {
                warnx("Cannot find file system superblock");
                return (1);
        }

        /* Simple sanity checks on the superblock */
        if (sblock->fs_sbsize > SBSIZE) {
                warnx("Superblock size is preposterous");
                return (1);
        }

        if (sblock->fs_postblformat == FS_42POSTBLFMT) {
                warnx("Filesystem format is too old, sorry");
                return (1);
        }

        if (!force && !printonly && sblock->fs_clean != FS_ISCLEAN) {
                warnx("Filesystem is not clean, fsck %s first.", devpath);
                return (1);
        }

        /* Make sure backup superblocks are sane. */
        tmpsblock = (struct fs *)&sbuftmp;
        for (cg = 0; cg < sblock->fs_ncg; cg++) {
                dblk = fsbtodb(sblock, cgsblock(sblock, cg));
                if (lseek(devfd, (off_t)dblk * bsize, SEEK_SET) == -1) {
                        warn("Can't seek to %lld", (long long)dblk * bsize);
                        return (1);
                } else if ((n = read(devfd, tmpsblock, SBSIZE)) != SBSIZE) {
                        warn("Can't read backup superblock %d on %s: %s",
                            cg + 1, devpath, (n < SBSIZE) ? "short read"
                            : strerror(errno));
                        return (1);
                }
                if (tmpsblock->fs_magic != FS_UFS1_MAGIC &&
                    tmpsblock->fs_magic != FS_UFS2_MAGIC) {
                        warnx("Bad magic number in backup superblock %d on %s",
                            cg + 1, devpath);
                        return (1);
                }
                if (tmpsblock->fs_sbsize > SBSIZE) {
                        warnx("Size of backup superblock %d on %s is preposterous",
                            cg + 1, devpath);
                        return (1);
                }
        }

        /* XXX - should really cap buffer at 512kb or so */
        if (sblock->fs_magic == FS_UFS1_MAGIC)
                isize = sizeof(struct ufs1_dinode);
        else
                isize = sizeof(struct ufs2_dinode);

        if ((ib = reallocarray(inodebuf, sblock->fs_ipg, isize)) == NULL)
                errx(1, "Can't allocate memory for inode buffer");
        inodebuf = ib;
        ibufsize = sblock->fs_ipg * isize;

        if (printonly && (sblock->fs_id[0] || sblock->fs_id[1])) {
                if (sblock->fs_inodefmt >= FS_44INODEFMT && sblock->fs_id[0]) {
                        time_t t = sblock->fs_id[0];    /* XXX 2038 */
                        char *ct = ctime(&t);
                        if (ct)
                                (void)printf("%s was randomized on %s", devpath,
                                    ct);
                        else
                                (void)printf("%s was randomized on %lld\n",
                                    devpath, t);
                }
                (void)printf("fsid: %x %x\n", sblock->fs_id[0],
                    sblock->fs_id[1]);
        }

        /* Randomize fs_id unless old 4.2BSD filesystem */
        if ((sblock->fs_inodefmt >= FS_44INODEFMT) && !printonly) {
                /* Randomize fs_id and write out new sblock and backups */
                sblock->fs_id[0] = (u_int32_t)time(NULL);
                sblock->fs_id[1] = arc4random();

                if (lseek(devfd, SBOFF, SEEK_SET) == -1) {
                        warn("Can't seek to superblock (%lld) on %s",
                            (long long)SBOFF, devpath);
                        return (1);
                }
                if ((n = write(devfd, sblock, SBSIZE)) != SBSIZE) {
                        warn("Can't write superblock on %s: %s", devpath,
                            (n < SBSIZE) ? "short write" : strerror(errno));
                        return (1);
                }
        }

        /* For each cylinder group, randomize inodes and update backup sblock */
        for (cg = 0, inumber = 0; cg < sblock->fs_ncg; cg++) {
                /* Update superblock if appropriate */
                if ((sblock->fs_inodefmt >= FS_44INODEFMT) && !printonly) {
                        dblk = fsbtodb(sblock, cgsblock(sblock, cg));
                        if (lseek(devfd, (off_t)dblk * bsize,
                            SEEK_SET) == -1) {
                                warn("Can't seek to %lld",
                                    (long long)dblk * bsize);
                                return (1);
                        } else if ((n = write(devfd, sblock, SBSIZE)) !=
                            SBSIZE) {
                                warn("Can't read backup superblock %d on %s: %s",
                                    cg + 1, devpath, (n < SBSIZE) ? "short write"
                                    : strerror(errno));
                                return (1);
                        }
                }

                /* Read in inodes, then print or randomize generation nums */
                dblk = fsbtodb(sblock, ino_to_fsba(sblock, inumber));
                if (lseek(devfd, (off_t)dblk * bsize, SEEK_SET) == -1) {
                        warn("Can't seek to %lld", (long long)dblk * bsize);
                        return (1);
                } else if ((n = read(devfd, inodebuf, ibufsize)) != ibufsize) {
                        warnx("Can't read inodes: %s",
                            (n < ibufsize) ? "short read" : strerror(errno));
                        return (1);
                }

                for (n = 0; n < sblock->fs_ipg; n++, inumber++) {
                        if (sblock->fs_magic == FS_UFS1_MAGIC)
                                dp1 = &((struct ufs1_dinode *)inodebuf)[n];
                        else
                                dp2 = &((struct ufs2_dinode *)inodebuf)[n];
                        if (inumber >= ROOTINO) {
                                if (printonly)
                                        (void)printf("ino %llu gen %x\n",
                                            (unsigned long long)inumber,
                                            sblock->fs_magic == FS_UFS1_MAGIC ?
                                            dp1->di_gen : dp2->di_gen);
                                else if (sblock->fs_magic == FS_UFS1_MAGIC)
                                        dp1->di_gen = arc4random();
                                else
                                        dp2->di_gen = arc4random();
                        }
                }

                /* Write out modified inodes */
                if (!printonly) {
                        if (lseek(devfd, (off_t)dblk * bsize, SEEK_SET) == -1) {
                                warn("Can't seek to %lld",
                                    (long long)dblk * bsize);
                                return (1);
                        } else if ((n = write(devfd, inodebuf, ibufsize)) !=
                                 ibufsize) {
                                warnx("Can't write inodes: %s",
                                    (n != ibufsize) ? "short write" :
                                    strerror(errno));
                                return (1);
                        }
                }
        }
        (void)close(devfd);

        return(0);
}

void
usage(int ex)
{
        (void)fprintf(stderr, "usage: %s [-bfp] special ...\n",
            __progname);
        exit(ex);
}