/*      $NetBSD: ffs.c,v 1.33 2022/11/17 06:40:40 chs Exp $     */

/*-
* Copyright (c) 2002 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matt Fredette.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/

#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif

#include <sys/cdefs.h>
#if !defined(__lint)
__RCSID("$NetBSD: ffs.c,v 1.33 2022/11/17 06:40:40 chs Exp $");
#endif  /* !__lint */

#include <sys/param.h>

#if !HAVE_NBTOOL_CONFIG_H
#include <sys/mount.h>
#endif

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

#include "installboot.h"

/* From <dev/raidframe/raidframevar.h> */
#define RF_PROTECTED_SECTORS 64L

#undef DIRBLKSIZ

#include <ufs/ufs/dinode.h>
#include <ufs/ufs/dir.h>
#include <ufs/ffs/fs.h>
#include <ufs/ffs/ffs_extern.h>
#ifndef NO_FFS_SWAP
#include <ufs/ufs/ufs_bswap.h>
#else
#define ffs_sb_swap(fs_a, fs_b)
#define ffs_dinode1_swap(inode_a, inode_b)
#define ffs_dinode2_swap(inode_a, inode_b)
#endif

static int      ffs_match_common(ib_params *, off_t);
static int      ffs_read_disk_block(ib_params *, uint64_t, int, char []);
static int      ffs_find_disk_blocks_ufs1(ib_params *, ino_t,
                   int (*)(ib_params *, void *, uint64_t, uint32_t), void *);
static int      ffs_find_disk_blocks_ufs2(ib_params *, ino_t,
                   int (*)(ib_params *, void *, uint64_t, uint32_t), void *);
static int      ffs_findstage2_ino(ib_params *, void *, uint64_t, uint32_t);
static int      ffs_findstage2_blocks(ib_params *, void *, uint64_t, uint32_t);

static int is_ufs2;


/* This reads a disk block from the filesystem. */
static int
ffs_read_disk_block(ib_params *params, uint64_t blkno, int size, char blk[])
{
       int     rv;

       assert(params != NULL);
       assert(params->filesystem != NULL);
       assert(params->fsfd != -1);
       assert(size > 0);
       assert(blk != NULL);

       rv = pread(params->fsfd, blk, size, blkno * params->sectorsize);
       if (rv == -1) {
               warn("Reading block %llu in `%s'",
                   (unsigned long long)blkno, params->filesystem);
               return (0);
       } else if (rv != size) {
               warnx("Reading block %llu in `%s': short read",
                   (unsigned long long)blkno, params->filesystem);
               return (0);
       }

       return (1);
}

/*
* This iterates over the data blocks belonging to an inode,
* making a callback each iteration with the disk block number
* and the size.
*/
static int
ffs_find_disk_blocks_ufs1(ib_params *params, ino_t ino,
       int (*callback)(ib_params *, void *, uint64_t, uint32_t),
       void *state)
{
       char            sbbuf[SBLOCKSIZE];
       struct fs       *fs;
       char            inodebuf[MAXBSIZE];
       struct ufs1_dinode      *inode;
       int             level_i;
       int32_t blk, lblk, nblk;
       int             rv;
#define LEVELS 4
       struct {
               int32_t         *blknums;
               unsigned long   blkcount;
               char            diskbuf[MAXBSIZE];
       } level[LEVELS];

       assert(params != NULL);
       assert(params->fstype != NULL);
       assert(callback != NULL);
       assert(state != NULL);

       /* Read the superblock. */
       if (!ffs_read_disk_block(params, params->fstype->sblockloc, SBLOCKSIZE,
           sbbuf))
               return (0);
       fs = (struct fs *)sbbuf;
#ifndef NO_FFS_SWAP
       if (params->fstype->needswap)
               ffs_sb_swap(fs, fs);
#endif

       if (fs->fs_inopb <= 0) {
               warnx("Bad inopb %d in superblock in `%s'",
                   fs->fs_inopb, params->filesystem);
               return (0);
       }

       /* Read the inode. */
       if (! ffs_read_disk_block(params,
               FFS_FSBTODB(fs, ino_to_fsba(fs, ino)) + params->fstype->offset,
               fs->fs_bsize, inodebuf))
               return (0);
       inode = (struct ufs1_dinode *)inodebuf;
       inode += ino_to_fsbo(fs, ino);
#ifndef NO_FFS_SWAP
       if (params->fstype->needswap)
               ffs_dinode1_swap(inode, inode);
#endif

       /* Get the block count and initialize for our block walk. */
       nblk = howmany(inode->di_size, fs->fs_bsize);
       lblk = 0;
       level_i = 0;
       level[0].blknums = &inode->di_db[0];
       level[0].blkcount = UFS_NDADDR;
       level[1].blknums = &inode->di_ib[0];
       level[1].blkcount = 1;
       level[2].blknums = &inode->di_ib[1];
       level[2].blkcount = 1;
       level[3].blknums = &inode->di_ib[2];
       level[3].blkcount = 1;

       /* Walk the data blocks. */
       while (nblk > 0) {

               /*
                * If there are no more blocks at this indirection
                * level, move up one indirection level and loop.
                */
               if (level[level_i].blkcount == 0) {
                       if (++level_i == LEVELS)
                               break;
                       continue;
               }

               /* Get the next block at this level. */
               blk = *(level[level_i].blknums++);
               level[level_i].blkcount--;
               if (params->fstype->needswap)
                       blk = bswap32(blk);

#if 0
               fprintf(stderr, "ino %lu blk %lu level %d\n", ino, blk,
                   level_i);
#endif

               /*
                * If we're not at the direct level, descend one
                * level, read in that level's new block list,
                * and loop.
                */
               if (level_i > 0) {
                       level_i--;
                       if (blk == 0)
                               memset(level[level_i].diskbuf, 0, MAXBSIZE);
                       else if (! ffs_read_disk_block(params,
                               FFS_FSBTODB(fs, blk) + params->fstype->offset,
                               fs->fs_bsize, level[level_i].diskbuf))
                               return (0);
                       /* XXX ondisk32 */
                       level[level_i].blknums =
                               (int32_t *)level[level_i].diskbuf;
                       level[level_i].blkcount = FFS_NINDIR(fs);
                       continue;
               }

               /* blk is the next direct level block. */
#if 0
               fprintf(stderr, "ino %lu db %lu blksize %lu\n", ino,
                   FFS_FSBTODB(fs, blk), ffs_sblksize(fs, inode->di_size, lblk));
#endif
               rv = (*callback)(params, state,
                   FFS_FSBTODB(fs, blk) + params->fstype->offset,
                   ffs_sblksize(fs, (int64_t)inode->di_size, lblk));
               lblk++;
               nblk--;
               if (rv != 1)
                       return (rv);
       }

       if (nblk != 0) {
               warnx("Inode %llu in `%s' ran out of blocks?",
                   (unsigned long long)ino, params->filesystem);
               return (0);
       }

       return (1);
}

/*
* This iterates over the data blocks belonging to an inode,
* making a callback each iteration with the disk block number
* and the size.
*/
static int
ffs_find_disk_blocks_ufs2(ib_params *params, ino_t ino,
       int (*callback)(ib_params *, void *, uint64_t, uint32_t),
       void *state)
{
       char            sbbuf[SBLOCKSIZE];
       struct fs       *fs;
       char            inodebuf[MAXBSIZE];
       struct ufs2_dinode      *inode;
       int             level_i;
       int64_t         blk, lblk, nblk;
       int             rv;
#define LEVELS 4
       struct {
               int64_t         *blknums;
               unsigned long   blkcount;
               char            diskbuf[MAXBSIZE];
       } level[LEVELS];

       assert(params != NULL);
       assert(params->fstype != NULL);
       assert(callback != NULL);
       assert(state != NULL);

       /* Read the superblock. */
       if (!ffs_read_disk_block(params, params->fstype->sblockloc, SBLOCKSIZE,
           sbbuf))
               return (0);
       fs = (struct fs *)sbbuf;
#ifndef NO_FFS_SWAP
       if (params->fstype->needswap)
               ffs_sb_swap(fs, fs);
#endif

       if (fs->fs_inopb <= 0) {
               warnx("Bad inopb %d in superblock in `%s'",
                   fs->fs_inopb, params->filesystem);
               return (0);
       }

       /* Read the inode. */
       if (! ffs_read_disk_block(params,
               FFS_FSBTODB(fs, ino_to_fsba(fs, ino)) + params->fstype->offset,
               fs->fs_bsize, inodebuf))
               return (0);
       inode = (struct ufs2_dinode *)inodebuf;
       inode += ino_to_fsbo(fs, ino);
#ifndef NO_FFS_SWAP
       if (params->fstype->needswap)
               ffs_dinode2_swap(inode, inode);
#endif

       /* Get the block count and initialize for our block walk. */
       nblk = howmany(inode->di_size, fs->fs_bsize);
       lblk = 0;
       level_i = 0;
       level[0].blknums = &inode->di_db[0];
       level[0].blkcount = UFS_NDADDR;
       level[1].blknums = &inode->di_ib[0];
       level[1].blkcount = 1;
       level[2].blknums = &inode->di_ib[1];
       level[2].blkcount = 1;
       level[3].blknums = &inode->di_ib[2];
       level[3].blkcount = 1;

       /* Walk the data blocks. */
       while (nblk > 0) {

               /*
                * If there are no more blocks at this indirection
                * level, move up one indirection level and loop.
                */
               if (level[level_i].blkcount == 0) {
                       if (++level_i == LEVELS)
                               break;
                       continue;
               }

               /* Get the next block at this level. */
               blk = *(level[level_i].blknums++);
               level[level_i].blkcount--;
               if (params->fstype->needswap)
                       blk = bswap64(blk);

#if 0
               fprintf(stderr, "ino %lu blk %llu level %d\n", ino,
                   (unsigned long long)blk, level_i);
#endif

               /*
                * If we're not at the direct level, descend one
                * level, read in that level's new block list,
                * and loop.
                */
               if (level_i > 0) {
                       level_i--;
                       if (blk == 0)
                               memset(level[level_i].diskbuf, 0, MAXBSIZE);
                       else if (! ffs_read_disk_block(params,
                               FFS_FSBTODB(fs, blk) + params->fstype->offset,
                               fs->fs_bsize, level[level_i].diskbuf))
                               return (0);
                       level[level_i].blknums =
                               (int64_t *)level[level_i].diskbuf;
                       level[level_i].blkcount = FFS_NINDIR(fs);
                       continue;
               }

               /* blk is the next direct level block. */
#if 0
               fprintf(stderr, "ino %lu db %llu blksize %lu\n", ino,
                   FFS_FSBTODB(fs, blk), ffs_sblksize(fs, inode->di_size, lblk));
#endif
               rv = (*callback)(params, state,
                   FFS_FSBTODB(fs, blk) + params->fstype->offset,
                   ffs_sblksize(fs, (int64_t)inode->di_size, lblk));
               lblk++;
               nblk--;
               if (rv != 1)
                       return (rv);
       }

       if (nblk != 0) {
               warnx("Inode %llu in `%s' ran out of blocks?",
                   (unsigned long long)ino, params->filesystem);
               return (0);
       }

       return (1);
}

/*
* This callback reads a block of the root directory,
* searches for an entry for the secondary bootstrap,
* and saves the inode number if one is found.
*/
static int
ffs_findstage2_ino(ib_params *params, void *_ino,
       uint64_t blk, uint32_t blksize)
{
       char            dirbuf[MAXBSIZE];
       struct direct   *de, *ede;
       uint32_t        ino;

       assert(params != NULL);
       assert(params->fstype != NULL);
       assert(params->stage2 != NULL);
       assert(_ino != NULL);

       /* Skip directory holes. */
       if (blk == 0)
               return (1);

       /* Read the directory block. */
       if (! ffs_read_disk_block(params, blk, blksize, dirbuf))
               return (0);

       /* Loop over the directory entries. */
       de = (struct direct *)&dirbuf[0];
       ede = (struct direct *)&dirbuf[blksize];
       while (de < ede) {
               ino = de->d_fileno;
               if (params->fstype->needswap) {
                       ino = bswap32(ino);
                       de->d_reclen = bswap16(de->d_reclen);
               }
               if (ino != 0 && strcmp(de->d_name, params->stage2) == 0) {
                       *((uint32_t *)_ino) = ino;
                       return (2);
               }
               if (de->d_reclen == 0)
                       break;
               de = (struct direct *)((char *)de + de->d_reclen);
       }

       return (1);
}

struct findblks_state {
       uint32_t        maxblk;
       uint32_t        nblk;
       ib_block        *blocks;
};

/* This callback records the blocks of the secondary bootstrap. */
static int
ffs_findstage2_blocks(ib_params *params, void *_state,
       uint64_t blk, uint32_t blksize)
{
       struct findblks_state *state = _state;

       assert(params != NULL);
       assert(params->stage2 != NULL);
       assert(_state != NULL);

       if (state->nblk == state->maxblk) {
               warnx("Secondary bootstrap `%s' has too many blocks (max %d)",
                   params->stage2, state->maxblk);
               return (0);
       }
       state->blocks[state->nblk].block = blk;
       state->blocks[state->nblk].blocksize = blksize;
       state->nblk++;
       return (1);
}

/*
*      publicly visible functions
*/

static off_t sblock_try[] = SBLOCKSEARCH;

int
ffs_match(ib_params *params)
{
       return ffs_match_common(params, (off_t) 0);
}

int
raid_match(ib_params *params)
{
       /* XXX Assumes 512 bytes / sector */
       if (params->sectorsize != 512) {
               warnx("Media is %d bytes/sector."
                       "  RAID is only supported on 512 bytes/sector media.",
                       params->sectorsize);
               return 0;
       }
       return ffs_match_common(params, (off_t) RF_PROTECTED_SECTORS);
}

int
ffs_match_common(ib_params *params, off_t offset)
{
       char            sbbuf[SBLOCKSIZE];
       struct fs       *fs;
       int i;
       off_t loc;

       assert(params != NULL);
       assert(params->fstype != NULL);

       fs = (struct fs *)sbbuf;
       for (i = 0; sblock_try[i] != -1; i++) {
               loc = sblock_try[i] / params->sectorsize + offset;
               if (!ffs_read_disk_block(params, loc, SBLOCKSIZE, sbbuf))
                       continue;
               switch (fs->fs_magic) {
               case FS_UFS2_MAGIC:
               case FS_UFS2EA_MAGIC:
                       is_ufs2 = 1;
                       /* FALLTHROUGH */
               case FS_UFS1_MAGIC:
                       params->fstype->needswap = 0;
                       params->fstype->blocksize = fs->fs_bsize;
                       params->fstype->sblockloc = loc;
                       params->fstype->offset = offset;
                       break;
#ifndef FFS_NO_SWAP
               case FS_UFS2_MAGIC_SWAPPED:
               case FS_UFS2EA_MAGIC_SWAPPED:
                       is_ufs2 = 1;
                       /* FALLTHROUGH */
               case FS_UFS1_MAGIC_SWAPPED:
                       params->fstype->needswap = 1;
                       params->fstype->blocksize = bswap32(fs->fs_bsize);
                       params->fstype->sblockloc = loc;
                       params->fstype->offset = offset;
                       break;
#endif
               default:
                       continue;
               }
               if (!is_ufs2 && sblock_try[i] == SBLOCK_UFS2)
                       continue;
               return 1;
       }

       return (0);
}

int
ffs_findstage2(ib_params *params, uint32_t *maxblk, ib_block *blocks)
{
       int                     rv;
       uint32_t                ino;
       struct findblks_state   state;

       assert(params != NULL);
       assert(params->stage2 != NULL);
       assert(maxblk != NULL);
       assert(blocks != NULL);

       if (params->flags & IB_STAGE2START)
               return (hardcode_stage2(params, maxblk, blocks));

       /* The secondary bootstrap must be clearly in /. */
       if (params->stage2[0] == '/')
               params->stage2++;
       if (strchr(params->stage2, '/') != NULL) {
               warnx("The secondary bootstrap `%s' must be in /",
                   params->stage2);
               warnx("(Path must be relative to the file system in `%s')",
                   params->filesystem);
               return (0);
       }

       /* Get the inode number of the secondary bootstrap. */
       if (is_ufs2)
               rv = ffs_find_disk_blocks_ufs2(params, UFS_ROOTINO,
                   ffs_findstage2_ino, &ino);
       else
               rv = ffs_find_disk_blocks_ufs1(params, UFS_ROOTINO,
                   ffs_findstage2_ino, &ino);
       if (rv != 2) {
               warnx("Could not find secondary bootstrap `%s' in `%s'",
                   params->stage2, params->filesystem);
               warnx("(Path must be relative to the file system in `%s')",
                   params->filesystem);
               return (0);
       }

       /* Record the disk blocks of the secondary bootstrap. */
       state.maxblk = *maxblk;
       state.nblk = 0;
       state.blocks = blocks;
       if (is_ufs2)
               rv = ffs_find_disk_blocks_ufs2(params, ino,
                   ffs_findstage2_blocks, &state);
       else
               rv = ffs_find_disk_blocks_ufs1(params, ino,
                   ffs_findstage2_blocks, &state);
       if (! rv) {
               return (0);
       }

       *maxblk = state.nblk;
       return (1);
}

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