linux/fs/hpfs/map.c
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   1/*
   2 *  linux/fs/hpfs/map.c
   3 *
   4 *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
   5 *
   6 *  mapping structures to memory with some minimal checks
   7 */
   8
   9#include "hpfs_fn.h"
  10
  11__le32 *hpfs_map_dnode_bitmap(struct super_block *s, struct quad_buffer_head *qbh)
  12{
  13        return hpfs_map_4sectors(s, hpfs_sb(s)->sb_dmap, qbh, 0);
  14}
  15
  16__le32 *hpfs_map_bitmap(struct super_block *s, unsigned bmp_block,
  17                         struct quad_buffer_head *qbh, char *id)
  18{
  19        secno sec;
  20        if (hpfs_sb(s)->sb_chk) if (bmp_block * 16384 > hpfs_sb(s)->sb_fs_size) {
  21                hpfs_error(s, "hpfs_map_bitmap called with bad parameter: %08x at %s", bmp_block, id);
  22                return NULL;
  23        }
  24        sec = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block]);
  25        if (!sec || sec > hpfs_sb(s)->sb_fs_size-4) {
  26                hpfs_error(s, "invalid bitmap block pointer %08x -> %08x at %s", bmp_block, sec, id);
  27                return NULL;
  28        }
  29        return hpfs_map_4sectors(s, sec, qbh, 4);
  30}
  31
  32/*
  33 * Load first code page into kernel memory, return pointer to 256-byte array,
  34 * first 128 bytes are uppercasing table for chars 128-255, next 128 bytes are
  35 * lowercasing table
  36 */
  37
  38unsigned char *hpfs_load_code_page(struct super_block *s, secno cps)
  39{
  40        struct buffer_head *bh;
  41        secno cpds;
  42        unsigned cpi;
  43        unsigned char *ptr;
  44        unsigned char *cp_table;
  45        int i;
  46        struct code_page_data *cpd;
  47        struct code_page_directory *cp = hpfs_map_sector(s, cps, &bh, 0);
  48        if (!cp) return NULL;
  49        if (le32_to_cpu(cp->magic) != CP_DIR_MAGIC) {
  50                printk("HPFS: Code page directory magic doesn't match (magic = %08x)\n", le32_to_cpu(cp->magic));
  51                brelse(bh);
  52                return NULL;
  53        }
  54        if (!le32_to_cpu(cp->n_code_pages)) {
  55                printk("HPFS: n_code_pages == 0\n");
  56                brelse(bh);
  57                return NULL;
  58        }
  59        cpds = le32_to_cpu(cp->array[0].code_page_data);
  60        cpi = le16_to_cpu(cp->array[0].index);
  61        brelse(bh);
  62
  63        if (cpi >= 3) {
  64                printk("HPFS: Code page index out of array\n");
  65                return NULL;
  66        }
  67        
  68        if (!(cpd = hpfs_map_sector(s, cpds, &bh, 0))) return NULL;
  69        if (le16_to_cpu(cpd->offs[cpi]) > 0x178) {
  70                printk("HPFS: Code page index out of sector\n");
  71                brelse(bh);
  72                return NULL;
  73        }
  74        ptr = (unsigned char *)cpd + le16_to_cpu(cpd->offs[cpi]) + 6;
  75        if (!(cp_table = kmalloc(256, GFP_KERNEL))) {
  76                printk("HPFS: out of memory for code page table\n");
  77                brelse(bh);
  78                return NULL;
  79        }
  80        memcpy(cp_table, ptr, 128);
  81        brelse(bh);
  82
  83        /* Try to build lowercasing table from uppercasing one */
  84
  85        for (i=128; i<256; i++) cp_table[i]=i;
  86        for (i=128; i<256; i++) if (cp_table[i-128]!=i && cp_table[i-128]>=128)
  87                cp_table[cp_table[i-128]] = i;
  88        
  89        return cp_table;
  90}
  91
  92__le32 *hpfs_load_bitmap_directory(struct super_block *s, secno bmp)
  93{
  94        struct buffer_head *bh;
  95        int n = (hpfs_sb(s)->sb_fs_size + 0x200000 - 1) >> 21;
  96        int i;
  97        __le32 *b;
  98        if (!(b = kmalloc(n * 512, GFP_KERNEL))) {
  99                printk("HPFS: can't allocate memory for bitmap directory\n");
 100                return NULL;
 101        }       
 102        for (i=0;i<n;i++) {
 103                __le32 *d = hpfs_map_sector(s, bmp+i, &bh, n - i - 1);
 104                if (!d) {
 105                        kfree(b);
 106                        return NULL;
 107                }
 108                memcpy((char *)b + 512 * i, d, 512);
 109                brelse(bh);
 110        }
 111        return b;
 112}
 113
 114/*
 115 * Load fnode to memory
 116 */
 117
 118struct fnode *hpfs_map_fnode(struct super_block *s, ino_t ino, struct buffer_head **bhp)
 119{
 120        struct fnode *fnode;
 121        if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ino, 1, "fnode")) {
 122                return NULL;
 123        }
 124        if ((fnode = hpfs_map_sector(s, ino, bhp, FNODE_RD_AHEAD))) {
 125                if (hpfs_sb(s)->sb_chk) {
 126                        struct extended_attribute *ea;
 127                        struct extended_attribute *ea_end;
 128                        if (le32_to_cpu(fnode->magic) != FNODE_MAGIC) {
 129                                hpfs_error(s, "bad magic on fnode %08lx",
 130                                        (unsigned long)ino);
 131                                goto bail;
 132                        }
 133                        if (!fnode_is_dir(fnode)) {
 134                                if ((unsigned)fnode->btree.n_used_nodes + (unsigned)fnode->btree.n_free_nodes !=
 135                                    (bp_internal(&fnode->btree) ? 12 : 8)) {
 136                                        hpfs_error(s,
 137                                           "bad number of nodes in fnode %08lx",
 138                                            (unsigned long)ino);
 139                                        goto bail;
 140                                }
 141                                if (le16_to_cpu(fnode->btree.first_free) !=
 142                                    8 + fnode->btree.n_used_nodes * (bp_internal(&fnode->btree) ? 8 : 12)) {
 143                                        hpfs_error(s,
 144                                            "bad first_free pointer in fnode %08lx",
 145                                            (unsigned long)ino);
 146                                        goto bail;
 147                                }
 148                        }
 149                        if (le16_to_cpu(fnode->ea_size_s) && (le16_to_cpu(fnode->ea_offs) < 0xc4 ||
 150                           le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s) + le16_to_cpu(fnode->ea_size_s) > 0x200)) {
 151                                hpfs_error(s,
 152                                        "bad EA info in fnode %08lx: ea_offs == %04x ea_size_s == %04x",
 153                                        (unsigned long)ino,
 154                                        le16_to_cpu(fnode->ea_offs), le16_to_cpu(fnode->ea_size_s));
 155                                goto bail;
 156                        }
 157                        ea = fnode_ea(fnode);
 158                        ea_end = fnode_end_ea(fnode);
 159                        while (ea != ea_end) {
 160                                if (ea > ea_end) {
 161                                        hpfs_error(s, "bad EA in fnode %08lx",
 162                                                (unsigned long)ino);
 163                                        goto bail;
 164                                }
 165                                ea = next_ea(ea);
 166                        }
 167                }
 168        }
 169        return fnode;
 170        bail:
 171        brelse(*bhp);
 172        return NULL;
 173}
 174
 175struct anode *hpfs_map_anode(struct super_block *s, anode_secno ano, struct buffer_head **bhp)
 176{
 177        struct anode *anode;
 178        if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ano, 1, "anode")) return NULL;
 179        if ((anode = hpfs_map_sector(s, ano, bhp, ANODE_RD_AHEAD)))
 180                if (hpfs_sb(s)->sb_chk) {
 181                        if (le32_to_cpu(anode->magic) != ANODE_MAGIC) {
 182                                hpfs_error(s, "bad magic on anode %08x", ano);
 183                                goto bail;
 184                        }
 185                        if (le32_to_cpu(anode->self) != ano) {
 186                                hpfs_error(s, "self pointer invalid on anode %08x", ano);
 187                                goto bail;
 188                        }
 189                        if ((unsigned)anode->btree.n_used_nodes + (unsigned)anode->btree.n_free_nodes !=
 190                            (bp_internal(&anode->btree) ? 60 : 40)) {
 191                                hpfs_error(s, "bad number of nodes in anode %08x", ano);
 192                                goto bail;
 193                        }
 194                        if (le16_to_cpu(anode->btree.first_free) !=
 195                            8 + anode->btree.n_used_nodes * (bp_internal(&anode->btree) ? 8 : 12)) {
 196                                hpfs_error(s, "bad first_free pointer in anode %08x", ano);
 197                                goto bail;
 198                        }
 199                }
 200        return anode;
 201        bail:
 202        brelse(*bhp);
 203        return NULL;
 204}
 205
 206/*
 207 * Load dnode to memory and do some checks
 208 */
 209
 210struct dnode *hpfs_map_dnode(struct super_block *s, unsigned secno,
 211                             struct quad_buffer_head *qbh)
 212{
 213        struct dnode *dnode;
 214        if (hpfs_sb(s)->sb_chk) {
 215                if (hpfs_chk_sectors(s, secno, 4, "dnode")) return NULL;
 216                if (secno & 3) {
 217                        hpfs_error(s, "dnode %08x not byte-aligned", secno);
 218                        return NULL;
 219                }       
 220        }
 221        if ((dnode = hpfs_map_4sectors(s, secno, qbh, DNODE_RD_AHEAD)))
 222                if (hpfs_sb(s)->sb_chk) {
 223                        unsigned p, pp = 0;
 224                        unsigned char *d = (unsigned char *)dnode;
 225                        int b = 0;
 226                        if (le32_to_cpu(dnode->magic) != DNODE_MAGIC) {
 227                                hpfs_error(s, "bad magic on dnode %08x", secno);
 228                                goto bail;
 229                        }
 230                        if (le32_to_cpu(dnode->self) != secno)
 231                                hpfs_error(s, "bad self pointer on dnode %08x self = %08x", secno, le32_to_cpu(dnode->self));
 232                        /* Check dirents - bad dirents would cause infinite
 233                           loops or shooting to memory */
 234                        if (le32_to_cpu(dnode->first_free) > 2048) {
 235                                hpfs_error(s, "dnode %08x has first_free == %08x", secno, le32_to_cpu(dnode->first_free));
 236                                goto bail;
 237                        }
 238                        for (p = 20; p < le32_to_cpu(dnode->first_free); p += d[p] + (d[p+1] << 8)) {
 239                                struct hpfs_dirent *de = (struct hpfs_dirent *)((char *)dnode + p);
 240                                if (le16_to_cpu(de->length) > 292 || (le16_to_cpu(de->length) < 32) || (le16_to_cpu(de->length) & 3) || p + le16_to_cpu(de->length) > 2048) {
 241                                        hpfs_error(s, "bad dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp);
 242                                        goto bail;
 243                                }
 244                                if (((31 + de->namelen + de->down*4 + 3) & ~3) != le16_to_cpu(de->length)) {
 245                                        if (((31 + de->namelen + de->down*4 + 3) & ~3) < le16_to_cpu(de->length) && s->s_flags & MS_RDONLY) goto ok;
 246                                        hpfs_error(s, "namelen does not match dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp);
 247                                        goto bail;
 248                                }
 249                                ok:
 250                                if (hpfs_sb(s)->sb_chk >= 2) b |= 1 << de->down;
 251                                if (de->down) if (de_down_pointer(de) < 0x10) {
 252                                        hpfs_error(s, "bad down pointer in dnode %08x, dirent %03x, last %03x", secno, p, pp);
 253                                        goto bail;
 254                                }
 255                                pp = p;
 256                                
 257                        }
 258                        if (p != le32_to_cpu(dnode->first_free)) {
 259                                hpfs_error(s, "size on last dirent does not match first_free; dnode %08x", secno);
 260                                goto bail;
 261                        }
 262                        if (d[pp + 30] != 1 || d[pp + 31] != 255) {
 263                                hpfs_error(s, "dnode %08x does not end with \\377 entry", secno);
 264                                goto bail;
 265                        }
 266                        if (b == 3) printk("HPFS: warning: unbalanced dnode tree, dnode %08x; see hpfs.txt 4 more info\n", secno);
 267                }
 268        return dnode;
 269        bail:
 270        hpfs_brelse4(qbh);
 271        return NULL;
 272}
 273
 274dnode_secno hpfs_fnode_dno(struct super_block *s, ino_t ino)
 275{
 276        struct buffer_head *bh;
 277        struct fnode *fnode;
 278        dnode_secno dno;
 279
 280        fnode = hpfs_map_fnode(s, ino, &bh);
 281        if (!fnode)
 282                return 0;
 283
 284        dno = le32_to_cpu(fnode->u.external[0].disk_secno);
 285        brelse(bh);
 286        return dno;
 287}
 288
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