/*-
 * Copyright (c) 2002 McAfee, Inc.
 * All rights reserved.
 *
 * This software was developed for the FreeBSD Project by Marshall
 * Kirk McKusick and McAfee Research,, the Security Research Division of
 * McAfee, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as
 * part of the DARPA CHATS research program
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
/*-
 * Copyright (c) 1998 Robert Nordier
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are freely
 * permitted provided that the above copyright notice and this
 * paragraph and the following disclaimer are duplicated in all
 * such forms.
 *
 * This software is provided "AS IS" and without any express or
 * implied warranties, including, without limitation, the implied
 * warranties of merchantability and fitness for a particular
 * purpose.
 */

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

#ifdef UFS_SMALL_CGBASE
/* XXX: Revert to old (broken for over 1.5Tb filesystems) version of cgbase
   (see sys/ufs/ffs/fs.h rev 1.39) so that small boot loaders (e.g. boot2) can
   support both UFS1 and UFS2. */
#undef cgbase
#define cgbase(fs, c)   ((ufs2_daddr_t)((fs)->fs_fpg * (c)))
#endif

typedef uint32_t        ufs_ino_t;

/*
 * We use 4k `virtual' blocks for filesystem data, whatever the actual
 * filesystem block size. FFS blocks are always a multiple of 4k.
 */
#define VBLKSHIFT       12
#define VBLKSIZE        (1 << VBLKSHIFT)
#define VBLKMASK        (VBLKSIZE - 1)
#define DBPERVBLK       (VBLKSIZE / DEV_BSIZE)
#define INDIRPERVBLK(fs) (NINDIR(fs) / ((fs)->fs_bsize >> VBLKSHIFT))
#define IPERVBLK(fs)    (INOPB(fs) / ((fs)->fs_bsize >> VBLKSHIFT))
#define INO_TO_VBA(fs, ipervblk, x) \
    (fsbtodb(fs, cgimin(fs, ino_to_cg(fs, x))) + \
    (((x) % (fs)->fs_ipg) / (ipervblk) * DBPERVBLK))
#define INO_TO_VBO(ipervblk, x) ((x) % ipervblk)
#define FS_TO_VBA(fs, fsb, off) (fsbtodb(fs, fsb) + \
    ((off) / VBLKSIZE) * DBPERVBLK)
#define FS_TO_VBO(fs, fsb, off) ((off) & VBLKMASK)

/* Buffers that must not span a 64k boundary. */
struct dmadat {
        char blkbuf[VBLKSIZE];  /* filesystem blocks */
        char indbuf[VBLKSIZE];  /* indir blocks */
        char sbbuf[SBLOCKSIZE]; /* superblock */
        char secbuf[DEV_BSIZE]; /* for MBR/disklabel */
};
static struct dmadat *dmadat;

static ufs_ino_t lookup(const char *);
static ssize_t fsread(ufs_ino_t, void *, size_t);

static uint8_t ls, dsk_meta;
static uint32_t fs_off;

static __inline uint8_t
fsfind(const char *name, ufs_ino_t * ino)
{
        static char buf[DEV_BSIZE];
        static struct direct d;
        char *s;
        ssize_t n;

        fs_off = 0;
        while ((n = fsread(*ino, buf, DEV_BSIZE)) > 0)
                for (s = buf; s < buf + DEV_BSIZE;) {
                        memcpy(&d, s, sizeof(struct direct));
                        if (ls)
                                printf("%s ", d.d_name);
                        else if (!strcmp(name, d.d_name)) {
                                *ino = d.d_ino;
                                return d.d_type;
                        }
                        /*
                         * Check for corrupt directory entry and bail out
                         * rather than spin forever hoping that the user
                         * has other options.
                         */
                        if (d.d_reclen == 0)
                                return 0;
                        s += d.d_reclen;
                }
        if (n != -1 && ls)
                printf("\n");
        return 0;
}

static ufs_ino_t
lookup(const char *path)
{
        static char name[UFS_MAXNAMLEN + 1];
        const char *s;
        ufs_ino_t ino;
        ssize_t n;
        uint8_t dt;

        ino = UFS_ROOTINO;
        dt = DT_DIR;
        for (;;) {
                if (*path == '/')
                        path++;
                if (!*path)
                        break;
                for (s = path; *s && *s != '/'; s++);
                if ((n = s - path) > UFS_MAXNAMLEN)
                        return 0;
                ls = *path == '?' && n == 1 && !*s;
                memcpy(name, path, n);
                name[n] = 0;
                if (dt != DT_DIR) {
                        printf("%s: not a directory.\n", name);
                        return (0);
                }
                if ((dt = fsfind(name, &ino)) <= 0)
                        break;
                path = s;
        }
        return dt == DT_REG ? ino : 0;
}

/*
 * Possible superblock locations ordered from most to least likely.
 */
static int sblock_try[] = SBLOCKSEARCH;

#if defined(UFS2_ONLY)
#define DIP(field) dp2.field
#elif defined(UFS1_ONLY)
#define DIP(field) dp1.field
#else
#define DIP(field) fs.fs_magic == FS_UFS1_MAGIC ? dp1.field : dp2.field
#endif

static ssize_t
fsread_size(ufs_ino_t inode, void *buf, size_t nbyte, size_t *fsizep)
{
#ifndef UFS2_ONLY
        static struct ufs1_dinode dp1;
        ufs1_daddr_t addr1;
#endif
#ifndef UFS1_ONLY
        static struct ufs2_dinode dp2;
#endif
        static struct fs fs;
        static ufs_ino_t inomap;
        char *blkbuf;
        void *indbuf;
        char *s;
        size_t n, nb, size, off, vboff;
        ufs_lbn_t lbn;
        ufs2_daddr_t addr2, vbaddr;
        static ufs2_daddr_t blkmap, indmap;
        u_int u;

        /* Basic parameter validation. */
        if ((buf == NULL && nbyte != 0) || dmadat == NULL)
                return (-1);

        blkbuf = dmadat->blkbuf;
        indbuf = dmadat->indbuf;

        /*
         * Force probe if inode is zero to ensure we have a valid fs, otherwise
         * when probing multiple paritions, reads from subsequent parititions
         * will incorrectly succeed.
         */
        if (!dsk_meta || inode == 0) {
                inomap = 0;
                dsk_meta = 0;
                for (n = 0; sblock_try[n] != -1; n++) {
                        if (dskread(dmadat->sbbuf, sblock_try[n] / DEV_BSIZE,
                            SBLOCKSIZE / DEV_BSIZE))
                                return -1;
                        memcpy(&fs, dmadat->sbbuf, sizeof(struct fs));
                        if ((
#if defined(UFS1_ONLY)
                            fs.fs_magic == FS_UFS1_MAGIC
#elif defined(UFS2_ONLY)
                            (fs.fs_magic == FS_UFS2_MAGIC &&
                            fs.fs_sblockloc == sblock_try[n])
#else
                            fs.fs_magic == FS_UFS1_MAGIC ||
                            (fs.fs_magic == FS_UFS2_MAGIC &&
                            fs.fs_sblockloc == sblock_try[n])
#endif
                            ) &&
                            fs.fs_bsize <= MAXBSIZE &&
                            fs.fs_bsize >= (int32_t)sizeof(struct fs))
                                break;
                }
                if (sblock_try[n] == -1) {
                        return -1;
                }
                dsk_meta++;
        } else
                memcpy(&fs, dmadat->sbbuf, sizeof(struct fs));
        if (!inode)
                return 0;
        if (inomap != inode) {
                n = IPERVBLK(&fs);
                if (dskread(blkbuf, INO_TO_VBA(&fs, n, inode), DBPERVBLK))
                        return -1;
                n = INO_TO_VBO(n, inode);
#if defined(UFS1_ONLY)
                memcpy(&dp1, (struct ufs1_dinode *)(void *)blkbuf + n,
                    sizeof(dp1));
#elif defined(UFS2_ONLY)
                memcpy(&dp2, (struct ufs2_dinode *)(void *)blkbuf + n,
                    sizeof(dp2));
#else
                if (fs.fs_magic == FS_UFS1_MAGIC)
                        memcpy(&dp1, (struct ufs1_dinode *)(void *)blkbuf + n,
                            sizeof(dp1));
                else
                        memcpy(&dp2, (struct ufs2_dinode *)(void *)blkbuf + n,
                            sizeof(dp2));
#endif
                inomap = inode;
                fs_off = 0;
                blkmap = indmap = 0;
        }
        s = buf;
        size = DIP(di_size);
        n = size - fs_off;
        if (nbyte > n)
                nbyte = n;
        nb = nbyte;
        while (nb) {
                lbn = lblkno(&fs, fs_off);
                off = blkoff(&fs, fs_off);
                if (lbn < UFS_NDADDR) {
                        addr2 = DIP(di_db[lbn]);
                } else if (lbn < UFS_NDADDR + NINDIR(&fs)) {
                        n = INDIRPERVBLK(&fs);
                        addr2 = DIP(di_ib[0]);
                        u = (u_int)(lbn - UFS_NDADDR) / n * DBPERVBLK;
                        vbaddr = fsbtodb(&fs, addr2) + u;
                        if (indmap != vbaddr) {
                                if (dskread(indbuf, vbaddr, DBPERVBLK))
                                        return -1;
                                indmap = vbaddr;
                        }
                        n = (lbn - UFS_NDADDR) & (n - 1);
#if defined(UFS1_ONLY)
                        memcpy(&addr1, (ufs1_daddr_t *)indbuf + n,
                            sizeof(ufs1_daddr_t));
                        addr2 = addr1;
#elif defined(UFS2_ONLY)
                        memcpy(&addr2, (ufs2_daddr_t *)indbuf + n,
                            sizeof(ufs2_daddr_t));
#else
                        if (fs.fs_magic == FS_UFS1_MAGIC) {
                                memcpy(&addr1, (ufs1_daddr_t *)indbuf + n,
                                    sizeof(ufs1_daddr_t));
                                addr2 = addr1;
                        } else
                                memcpy(&addr2, (ufs2_daddr_t *)indbuf + n,
                                    sizeof(ufs2_daddr_t));
#endif
                } else
                        return -1;
                vbaddr = fsbtodb(&fs, addr2) + (off >> VBLKSHIFT) * DBPERVBLK;
                vboff = off & VBLKMASK;
                n = sblksize(&fs, (off_t)size, lbn) - (off & ~VBLKMASK);
                if (n > VBLKSIZE)
                        n = VBLKSIZE;
                if (blkmap != vbaddr) {
                        if (dskread(blkbuf, vbaddr, n >> DEV_BSHIFT))
                                return -1;
                        blkmap = vbaddr;
                }
                n -= vboff;
                if (n > nb)
                        n = nb;
                memcpy(s, blkbuf + vboff, n);
                s += n;
                fs_off += n;
                nb -= n;
        }

        if (fsizep != NULL)
                *fsizep = size;

        return nbyte;
}

static ssize_t
fsread(ufs_ino_t inode, void *buf, size_t nbyte)
{

        return fsread_size(inode, buf, nbyte, NULL);
}