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-rw-r--r--fs/isofs/dir.c283
1 files changed, 283 insertions, 0 deletions
diff --git a/fs/isofs/dir.c b/fs/isofs/dir.c
new file mode 100644
index 000000000..eb2f8273e
--- /dev/null
+++ b/fs/isofs/dir.c
@@ -0,0 +1,283 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/isofs/dir.c
+ *
+ * (C) 1992, 1993, 1994 Eric Youngdale Modified for ISO 9660 filesystem.
+ *
+ * (C) 1991 Linus Torvalds - minix filesystem
+ *
+ * Steve Beynon : Missing last directory entries fixed
+ * (stephen@askone.demon.co.uk) : 21st June 1996
+ *
+ * isofs directory handling functions
+ */
+#include <linux/gfp.h>
+#include "isofs.h"
+
+int isofs_name_translate(struct iso_directory_record *de, char *new, struct inode *inode)
+{
+ char * old = de->name;
+ int len = de->name_len[0];
+ int i;
+
+ for (i = 0; i < len; i++) {
+ unsigned char c = old[i];
+ if (!c)
+ break;
+
+ if (c >= 'A' && c <= 'Z')
+ c |= 0x20; /* lower case */
+
+ /* Drop trailing '.;1' (ISO 9660:1988 7.5.1 requires period) */
+ if (c == '.' && i == len - 3 && old[i + 1] == ';' && old[i + 2] == '1')
+ break;
+
+ /* Drop trailing ';1' */
+ if (c == ';' && i == len - 2 && old[i + 1] == '1')
+ break;
+
+ /* Convert remaining ';' to '.' */
+ /* Also '/' to '.' (broken Acorn-generated ISO9660 images) */
+ if (c == ';' || c == '/')
+ c = '.';
+
+ new[i] = c;
+ }
+ return i;
+}
+
+/* Acorn extensions written by Matthew Wilcox <willy@infradead.org> 1998 */
+int get_acorn_filename(struct iso_directory_record *de,
+ char *retname, struct inode *inode)
+{
+ int std;
+ unsigned char *chr;
+ int retnamlen = isofs_name_translate(de, retname, inode);
+
+ if (retnamlen == 0)
+ return 0;
+ std = sizeof(struct iso_directory_record) + de->name_len[0];
+ if (std & 1)
+ std++;
+ if (de->length[0] - std != 32)
+ return retnamlen;
+ chr = ((unsigned char *) de) + std;
+ if (strncmp(chr, "ARCHIMEDES", 10))
+ return retnamlen;
+ if ((*retname == '_') && ((chr[19] & 1) == 1))
+ *retname = '!';
+ if (((de->flags[0] & 2) == 0) && (chr[13] == 0xff)
+ && ((chr[12] & 0xf0) == 0xf0)) {
+ retname[retnamlen] = ',';
+ sprintf(retname+retnamlen+1, "%3.3x",
+ ((chr[12] & 0xf) << 8) | chr[11]);
+ retnamlen += 4;
+ }
+ return retnamlen;
+}
+
+/*
+ * This should _really_ be cleaned up some day..
+ */
+static int do_isofs_readdir(struct inode *inode, struct file *file,
+ struct dir_context *ctx,
+ char *tmpname, struct iso_directory_record *tmpde)
+{
+ unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
+ unsigned char bufbits = ISOFS_BUFFER_BITS(inode);
+ unsigned long block, offset, block_saved, offset_saved;
+ unsigned long inode_number = 0; /* Quiet GCC */
+ struct buffer_head *bh = NULL;
+ int len;
+ int map;
+ int first_de = 1;
+ char *p = NULL; /* Quiet GCC */
+ struct iso_directory_record *de;
+ struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb);
+
+ offset = ctx->pos & (bufsize - 1);
+ block = ctx->pos >> bufbits;
+
+ while (ctx->pos < inode->i_size) {
+ int de_len;
+
+ if (!bh) {
+ bh = isofs_bread(inode, block);
+ if (!bh)
+ return 0;
+ }
+
+ de = (struct iso_directory_record *) (bh->b_data + offset);
+
+ de_len = *(unsigned char *)de;
+
+ /*
+ * If the length byte is zero, we should move on to the next
+ * CDROM sector. If we are at the end of the directory, we
+ * kick out of the while loop.
+ */
+
+ if (de_len == 0) {
+ brelse(bh);
+ bh = NULL;
+ ctx->pos = (ctx->pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1);
+ block = ctx->pos >> bufbits;
+ offset = 0;
+ continue;
+ }
+
+ block_saved = block;
+ offset_saved = offset;
+ offset += de_len;
+
+ /* Make sure we have a full directory entry */
+ if (offset >= bufsize) {
+ int slop = bufsize - offset + de_len;
+ memcpy(tmpde, de, slop);
+ offset &= bufsize - 1;
+ block++;
+ brelse(bh);
+ bh = NULL;
+ if (offset) {
+ bh = isofs_bread(inode, block);
+ if (!bh)
+ return 0;
+ memcpy((void *) tmpde + slop, bh->b_data, offset);
+ }
+ de = tmpde;
+ }
+ /* Basic sanity check, whether name doesn't exceed dir entry */
+ if (de_len < de->name_len[0] +
+ sizeof(struct iso_directory_record)) {
+ printk(KERN_NOTICE "iso9660: Corrupted directory entry"
+ " in block %lu of inode %lu\n", block,
+ inode->i_ino);
+ brelse(bh);
+ return -EIO;
+ }
+
+ if (first_de) {
+ isofs_normalize_block_and_offset(de,
+ &block_saved,
+ &offset_saved);
+ inode_number = isofs_get_ino(block_saved,
+ offset_saved, bufbits);
+ }
+
+ if (de->flags[-sbi->s_high_sierra] & 0x80) {
+ first_de = 0;
+ ctx->pos += de_len;
+ continue;
+ }
+ first_de = 1;
+
+ /* Handle the case of the '.' directory */
+ if (de->name_len[0] == 1 && de->name[0] == 0) {
+ if (!dir_emit_dot(file, ctx))
+ break;
+ ctx->pos += de_len;
+ continue;
+ }
+
+ len = 0;
+
+ /* Handle the case of the '..' directory */
+ if (de->name_len[0] == 1 && de->name[0] == 1) {
+ if (!dir_emit_dotdot(file, ctx))
+ break;
+ ctx->pos += de_len;
+ continue;
+ }
+
+ /* Handle everything else. Do name translation if there
+ is no Rock Ridge NM field. */
+
+ /*
+ * Do not report hidden files if so instructed, or associated
+ * files unless instructed to do so
+ */
+ if ((sbi->s_hide && (de->flags[-sbi->s_high_sierra] & 1)) ||
+ (!sbi->s_showassoc &&
+ (de->flags[-sbi->s_high_sierra] & 4))) {
+ ctx->pos += de_len;
+ continue;
+ }
+
+ map = 1;
+ if (sbi->s_rock) {
+ len = get_rock_ridge_filename(de, tmpname, inode);
+ if (len != 0) { /* may be -1 */
+ p = tmpname;
+ map = 0;
+ }
+ }
+ if (map) {
+#ifdef CONFIG_JOLIET
+ if (sbi->s_joliet_level) {
+ len = get_joliet_filename(de, tmpname, inode);
+ p = tmpname;
+ } else
+#endif
+ if (sbi->s_mapping == 'a') {
+ len = get_acorn_filename(de, tmpname, inode);
+ p = tmpname;
+ } else
+ if (sbi->s_mapping == 'n') {
+ len = isofs_name_translate(de, tmpname, inode);
+ p = tmpname;
+ } else {
+ p = de->name;
+ len = de->name_len[0];
+ }
+ }
+ if (len > 0) {
+ if (!dir_emit(ctx, p, len, inode_number, DT_UNKNOWN))
+ break;
+ }
+ ctx->pos += de_len;
+ }
+ if (bh)
+ brelse(bh);
+ return 0;
+}
+
+/*
+ * Handle allocation of temporary space for name translation and
+ * handling split directory entries.. The real work is done by
+ * "do_isofs_readdir()".
+ */
+static int isofs_readdir(struct file *file, struct dir_context *ctx)
+{
+ int result;
+ char *tmpname;
+ struct iso_directory_record *tmpde;
+ struct inode *inode = file_inode(file);
+
+ tmpname = (char *)__get_free_page(GFP_KERNEL);
+ if (tmpname == NULL)
+ return -ENOMEM;
+
+ tmpde = (struct iso_directory_record *) (tmpname+1024);
+
+ result = do_isofs_readdir(inode, file, ctx, tmpname, tmpde);
+
+ free_page((unsigned long) tmpname);
+ return result;
+}
+
+const struct file_operations isofs_dir_operations =
+{
+ .llseek = generic_file_llseek,
+ .read = generic_read_dir,
+ .iterate_shared = isofs_readdir,
+};
+
+/*
+ * directories can handle most operations...
+ */
+const struct inode_operations isofs_dir_inode_operations =
+{
+ .lookup = isofs_lookup,
+};
+
+
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