From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- fs/adfs/dir_fplus.c | 287 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 287 insertions(+) create mode 100644 fs/adfs/dir_fplus.c (limited to 'fs/adfs/dir_fplus.c') diff --git a/fs/adfs/dir_fplus.c b/fs/adfs/dir_fplus.c new file mode 100644 index 000000000..4a1592401 --- /dev/null +++ b/fs/adfs/dir_fplus.c @@ -0,0 +1,287 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/fs/adfs/dir_fplus.c + * + * Copyright (C) 1997-1999 Russell King + */ +#include "adfs.h" +#include "dir_fplus.h" + +/* Return the byte offset to directory entry pos */ +static unsigned int adfs_fplus_offset(const struct adfs_bigdirheader *h, + unsigned int pos) +{ + return offsetof(struct adfs_bigdirheader, bigdirname) + + ALIGN(le32_to_cpu(h->bigdirnamelen), 4) + + pos * sizeof(struct adfs_bigdirentry); +} + +static int adfs_fplus_validate_header(const struct adfs_bigdirheader *h) +{ + unsigned int size = le32_to_cpu(h->bigdirsize); + unsigned int len; + + if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 || + h->bigdirversion[2] != 0 || + h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME) || + !size || size & 2047 || size > SZ_4M) + return -EIO; + + size -= sizeof(struct adfs_bigdirtail) + + offsetof(struct adfs_bigdirheader, bigdirname); + + /* Check that bigdirnamelen fits within the directory */ + len = ALIGN(le32_to_cpu(h->bigdirnamelen), 4); + if (len > size) + return -EIO; + + size -= len; + + /* Check that bigdirnamesize fits within the directory */ + len = le32_to_cpu(h->bigdirnamesize); + if (len > size) + return -EIO; + + size -= len; + + /* + * Avoid division, we know that absolute maximum number of entries + * can not be so large to cause overflow of the multiplication below. + */ + len = le32_to_cpu(h->bigdirentries); + if (len > SZ_4M / sizeof(struct adfs_bigdirentry) || + len * sizeof(struct adfs_bigdirentry) > size) + return -EIO; + + return 0; +} + +static int adfs_fplus_validate_tail(const struct adfs_bigdirheader *h, + const struct adfs_bigdirtail *t) +{ + if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) || + t->bigdirendmasseq != h->startmasseq || + t->reserved[0] != 0 || t->reserved[1] != 0) + return -EIO; + + return 0; +} + +static u8 adfs_fplus_checkbyte(struct adfs_dir *dir) +{ + struct adfs_bigdirheader *h = dir->bighead; + struct adfs_bigdirtail *t = dir->bigtail; + unsigned int end, bs, bi, i; + __le32 *bp; + u32 dircheck; + + end = adfs_fplus_offset(h, le32_to_cpu(h->bigdirentries)) + + le32_to_cpu(h->bigdirnamesize); + + /* Accumulate the contents of the header, entries and names */ + for (dircheck = 0, bi = 0; end; bi++) { + bp = (void *)dir->bhs[bi]->b_data; + bs = dir->bhs[bi]->b_size; + if (bs > end) + bs = end; + + for (i = 0; i < bs; i += sizeof(u32)) + dircheck = ror32(dircheck, 13) ^ le32_to_cpup(bp++); + + end -= bs; + } + + /* Accumulate the contents of the tail except for the check byte */ + dircheck = ror32(dircheck, 13) ^ le32_to_cpu(t->bigdirendname); + dircheck = ror32(dircheck, 13) ^ t->bigdirendmasseq; + dircheck = ror32(dircheck, 13) ^ t->reserved[0]; + dircheck = ror32(dircheck, 13) ^ t->reserved[1]; + + return dircheck ^ dircheck >> 8 ^ dircheck >> 16 ^ dircheck >> 24; +} + +static int adfs_fplus_read(struct super_block *sb, u32 indaddr, + unsigned int size, struct adfs_dir *dir) +{ + struct adfs_bigdirheader *h; + struct adfs_bigdirtail *t; + unsigned int dirsize; + int ret; + + /* Read first buffer */ + ret = adfs_dir_read_buffers(sb, indaddr, sb->s_blocksize, dir); + if (ret) + return ret; + + dir->bighead = h = (void *)dir->bhs[0]->b_data; + ret = adfs_fplus_validate_header(h); + if (ret) { + adfs_error(sb, "dir %06x has malformed header", indaddr); + goto out; + } + + dirsize = le32_to_cpu(h->bigdirsize); + if (size && dirsize != size) { + adfs_msg(sb, KERN_WARNING, + "dir %06x header size %X does not match directory size %X", + indaddr, dirsize, size); + } + + /* Read remaining buffers */ + ret = adfs_dir_read_buffers(sb, indaddr, dirsize, dir); + if (ret) + return ret; + + dir->bigtail = t = (struct adfs_bigdirtail *) + (dir->bhs[dir->nr_buffers - 1]->b_data + (sb->s_blocksize - 8)); + + ret = adfs_fplus_validate_tail(h, t); + if (ret) { + adfs_error(sb, "dir %06x has malformed tail", indaddr); + goto out; + } + + if (adfs_fplus_checkbyte(dir) != t->bigdircheckbyte) { + adfs_error(sb, "dir %06x checkbyte mismatch\n", indaddr); + goto out; + } + + dir->parent_id = le32_to_cpu(h->bigdirparent); + return 0; + +out: + adfs_dir_relse(dir); + + return ret; +} + +static int +adfs_fplus_setpos(struct adfs_dir *dir, unsigned int fpos) +{ + int ret = -ENOENT; + + if (fpos <= le32_to_cpu(dir->bighead->bigdirentries)) { + dir->pos = fpos; + ret = 0; + } + + return ret; +} + +static int +adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj) +{ + struct adfs_bigdirheader *h = dir->bighead; + struct adfs_bigdirentry bde; + unsigned int offset; + int ret; + + if (dir->pos >= le32_to_cpu(h->bigdirentries)) + return -ENOENT; + + offset = adfs_fplus_offset(h, dir->pos); + + ret = adfs_dir_copyfrom(&bde, dir, offset, + sizeof(struct adfs_bigdirentry)); + if (ret) + return ret; + + obj->loadaddr = le32_to_cpu(bde.bigdirload); + obj->execaddr = le32_to_cpu(bde.bigdirexec); + obj->size = le32_to_cpu(bde.bigdirlen); + obj->indaddr = le32_to_cpu(bde.bigdirindaddr); + obj->attr = le32_to_cpu(bde.bigdirattr); + obj->name_len = le32_to_cpu(bde.bigdirobnamelen); + + offset = adfs_fplus_offset(h, le32_to_cpu(h->bigdirentries)); + offset += le32_to_cpu(bde.bigdirobnameptr); + + ret = adfs_dir_copyfrom(obj->name, dir, offset, obj->name_len); + if (ret) + return ret; + + adfs_object_fixup(dir, obj); + + dir->pos += 1; + + return 0; +} + +static int adfs_fplus_iterate(struct adfs_dir *dir, struct dir_context *ctx) +{ + struct object_info obj; + + if ((ctx->pos - 2) >> 32) + return 0; + + if (adfs_fplus_setpos(dir, ctx->pos - 2)) + return 0; + + while (!adfs_fplus_getnext(dir, &obj)) { + if (!dir_emit(ctx, obj.name, obj.name_len, + obj.indaddr, DT_UNKNOWN)) + break; + ctx->pos++; + } + + return 0; +} + +static int adfs_fplus_update(struct adfs_dir *dir, struct object_info *obj) +{ + struct adfs_bigdirheader *h = dir->bighead; + struct adfs_bigdirentry bde; + int offset, end, ret; + + offset = adfs_fplus_offset(h, 0) - sizeof(bde); + end = adfs_fplus_offset(h, le32_to_cpu(h->bigdirentries)); + + do { + offset += sizeof(bde); + if (offset >= end) { + adfs_error(dir->sb, "unable to locate entry to update"); + return -ENOENT; + } + ret = adfs_dir_copyfrom(&bde, dir, offset, sizeof(bde)); + if (ret) { + adfs_error(dir->sb, "error reading directory entry"); + return -ENOENT; + } + } while (le32_to_cpu(bde.bigdirindaddr) != obj->indaddr); + + bde.bigdirload = cpu_to_le32(obj->loadaddr); + bde.bigdirexec = cpu_to_le32(obj->execaddr); + bde.bigdirlen = cpu_to_le32(obj->size); + bde.bigdirindaddr = cpu_to_le32(obj->indaddr); + bde.bigdirattr = cpu_to_le32(obj->attr); + + return adfs_dir_copyto(dir, offset, &bde, sizeof(bde)); +} + +static int adfs_fplus_commit(struct adfs_dir *dir) +{ + int ret; + + /* Increment directory sequence number */ + dir->bighead->startmasseq += 1; + dir->bigtail->bigdirendmasseq += 1; + + /* Update directory check byte */ + dir->bigtail->bigdircheckbyte = adfs_fplus_checkbyte(dir); + + /* Make sure the directory still validates correctly */ + ret = adfs_fplus_validate_header(dir->bighead); + if (ret == 0) + ret = adfs_fplus_validate_tail(dir->bighead, dir->bigtail); + + return ret; +} + +const struct adfs_dir_ops adfs_fplus_dir_ops = { + .read = adfs_fplus_read, + .iterate = adfs_fplus_iterate, + .setpos = adfs_fplus_setpos, + .getnext = adfs_fplus_getnext, + .update = adfs_fplus_update, + .commit = adfs_fplus_commit, +}; -- cgit v1.2.3