/* * linux/fs/hpfs/map.c * * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999 * * mapping structures to memory with some minimal checks */ #include "hpfs_fn.h" unsigned *hpfs_map_dnode_bitmap(struct super_block *s, struct quad_buffer_head *qbh) { return hpfs_map_4sectors(s, hpfs_sb(s)->sb_dmap, qbh, 0); } unsigned int *hpfs_map_bitmap(struct super_block *s, unsigned bmp_block, struct quad_buffer_head *qbh, char *id) { secno sec; if (hpfs_sb(s)->sb_chk) if (bmp_block * 16384 > hpfs_sb(s)->sb_fs_size) { hpfs_error(s, "hpfs_map_bitmap called with bad parameter: %08x at %s", bmp_block, id); return NULL; } sec = hpfs_sb(s)->sb_bmp_dir[bmp_block]; if (!sec || sec > hpfs_sb(s)->sb_fs_size-4) { hpfs_error(s, "invalid bitmap block pointer %08x -> %08x at %s", bmp_block, sec, id); return NULL; } return hpfs_map_4sectors(s, sec, qbh, 4); } /* * Load first code page into kernel memory, return pointer to 256-byte array, * first 128 bytes are uppercasing table for chars 128-255, next 128 bytes are * lowercasing table */ char *hpfs_load_code_page(struct super_block *s, secno cps) { struct buffer_head *bh; secno cpds; unsigned cpi; unsigned char *ptr; unsigned char *cp_table; int i; struct code_page_data *cpd; struct code_page_directory *cp = hpfs_map_sector(s, cps, &bh, 0); if (!cp) return NULL; if (cp->magic != CP_DIR_MAGIC) { printk("HPFS: Code page directory magic doesn't match (magic = %08x)\n", cp->magic); brelse(bh); return NULL; } if (!cp->n_code_pages) { printk("HPFS: n_code_pages == 0\n"); brelse(bh); return NULL; } cpds = cp->array[0].code_page_data; cpi = cp->array[0].index; brelse(bh); if (cpi >= 3) { printk("HPFS: Code page index out of array\n"); return NULL; } if (!(cpd = hpfs_map_sector(s, cpds, &bh, 0))) return NULL; if ((unsigned)cpd->offs[cpi] > 0x178) { printk("HPFS: Code page index out of sector\n"); brelse(bh); return NULL; } ptr = (char *)cpd + cpd->offs[cpi] + 6; if (!(cp_table = kmalloc(256, GFP_KERNEL))) { printk("HPFS: out of memory for code page table\n"); brelse(bh); return NULL; } memcpy(cp_table, ptr, 128); brelse(bh); /* Try to build lowercasing table from uppercasing one */ for (i=128; i<256; i++) cp_table[i]=i; for (i=128; i<256; i++) if (cp_table[i-128]!=i && cp_table[i-128]>=128) cp_table[cp_table[i-128]] = i; return cp_table; } secno *hpfs_load_bitmap_directory(struct super_block *s, secno bmp) { struct buffer_head *bh; int n = (hpfs_sb(s)->sb_fs_size + 0x200000 - 1) >> 21; int i; secno *b; if (!(b = kmalloc(n * 512, GFP_KERNEL))) { printk("HPFS: can't allocate memory for bitmap directory\n"); return NULL; } for (i=0;i<n;i++) { secno *d = hpfs_map_sector(s, bmp+i, &bh, n - i - 1); if (!d) { kfree(b); return NULL; } memcpy((char *)b + 512 * i, d, 512); brelse(bh); } return b; } /* * Load fnode to memory */ struct fnode *hpfs_map_fnode(struct super_block *s, ino_t ino, struct buffer_head **bhp) { struct fnode *fnode; if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ino, 1, "fnode")) { return NULL; } if ((fnode = hpfs_map_sector(s, ino, bhp, FNODE_RD_AHEAD))) { if (hpfs_sb(s)->sb_chk) { struct extended_attribute *ea; struct extended_attribute *ea_end; if (fnode->magic != FNODE_MAGIC) { hpfs_error(s, "bad magic on fnode %08x", ino); goto bail; } if (!fnode->dirflag) { if ((unsigned)fnode->btree.n_used_nodes + (unsigned)fnode->btree.n_free_nodes != (fnode->btree.internal ? 12 : 8)) { hpfs_error(s, "bad number of nodes in fnode %08x", ino); goto bail; } if (fnode->btree.first_free != 8 + fnode->btree.n_used_nodes * (fnode->btree.internal ? 8 : 12)) { hpfs_error(s, "bad first_free pointer in fnode %08x", ino); goto bail; } } if (fnode->ea_size_s && ((signed int)fnode->ea_offs < 0xc4 || (signed int)fnode->ea_offs + fnode->acl_size_s + fnode->ea_size_s > 0x200)) { hpfs_error(s, "bad EA info in fnode %08x: ea_offs == %04x ea_size_s == %04x", ino, fnode->ea_offs, fnode->ea_size_s); goto bail; } ea = fnode_ea(fnode); ea_end = fnode_end_ea(fnode); while (ea != ea_end) { if (ea > ea_end) { hpfs_error(s, "bad EA in fnode %08x", ino); goto bail; } ea = next_ea(ea); } } } return fnode; bail: brelse(*bhp); return NULL; } struct anode *hpfs_map_anode(struct super_block *s, anode_secno ano, struct buffer_head **bhp) { struct anode *anode; if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ano, 1, "anode")) return NULL; if ((anode = hpfs_map_sector(s, ano, bhp, ANODE_RD_AHEAD))) if (hpfs_sb(s)->sb_chk) { if (anode->magic != ANODE_MAGIC || anode->self != ano) { hpfs_error(s, "bad magic on anode %08x", ano); goto bail; } if ((unsigned)anode->btree.n_used_nodes + (unsigned)anode->btree.n_free_nodes != (anode->btree.internal ? 60 : 40)) { hpfs_error(s, "bad number of nodes in anode %08x", ano); goto bail; } if (anode->btree.first_free != 8 + anode->btree.n_used_nodes * (anode->btree.internal ? 8 : 12)) { hpfs_error(s, "bad first_free pointer in anode %08x", ano); goto bail; } } return anode; bail: brelse(*bhp); return NULL; } /* * Load dnode to memory and do some checks */ struct dnode *hpfs_map_dnode(struct super_block *s, unsigned secno, struct quad_buffer_head *qbh) { struct dnode *dnode; if (hpfs_sb(s)->sb_chk) { if (hpfs_chk_sectors(s, secno, 4, "dnode")) return NULL; if (secno & 3) { hpfs_error(s, "dnode %08x not byte-aligned", secno); return NULL; } } if ((dnode = hpfs_map_4sectors(s, secno, qbh, DNODE_RD_AHEAD))) if (hpfs_sb(s)->sb_chk) { unsigned p, pp = 0; unsigned char *d = (char *)dnode; int b = 0; if (dnode->magic != DNODE_MAGIC) { hpfs_error(s, "bad magic on dnode %08x", secno); goto bail; } if (dnode->self != secno) hpfs_error(s, "bad self pointer on dnode %08x self = %08x", secno, dnode->self); /* Check dirents - bad dirents would cause infinite loops or shooting to memory */ if (dnode->first_free > 2048/* || dnode->first_free < 84*/) { hpfs_error(s, "dnode %08x has first_free == %08x", secno, dnode->first_free); goto bail; } for (p = 20; p < dnode->first_free; p += d[p] + (d[p+1] << 8)) { struct hpfs_dirent *de = (struct hpfs_dirent *)((char *)dnode + p); if (de->length > 292 || (de->length < 32) || (de->length & 3) || p + de->length > 2048) { hpfs_error(s, "bad dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp); goto bail; } if (((31 + de->namelen + de->down*4 + 3) & ~3) != de->length) { if (((31 + de->namelen + de->down*4 + 3) & ~3) < de->length && s->s_flags & MS_RDONLY) goto ok; hpfs_error(s, "namelen does not match dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp); goto bail; } ok: if (hpfs_sb(s)->sb_chk >= 2) b |= 1 << de->down; if (de->down) if (de_down_pointer(de) < 0x10) { hpfs_error(s, "bad down pointer in dnode %08x, dirent %03x, last %03x", secno, p, pp); goto bail; } pp = p; } if (p != dnode->first_free) { hpfs_error(s, "size on last dirent does not match first_free; dnode %08x", secno); goto bail; } if (d[pp + 30] != 1 || d[pp + 31] != 255) { hpfs_error(s, "dnode %08x does not end with \\377 entry", secno); goto bail; } if (b == 3) printk("HPFS: warning: unbalanced dnode tree, dnode %08x; see hpfs.txt 4 more info\n", secno); } return dnode; bail: hpfs_brelse4(qbh); return NULL; } dnode_secno hpfs_fnode_dno(struct super_block *s, ino_t ino) { struct buffer_head *bh; struct fnode *fnode; dnode_secno dno; fnode = hpfs_map_fnode(s, ino, &bh); if (!fnode) return 0; dno = fnode->u.external[0].disk_secno; brelse(bh); return dno; }