Many files:

  Checkin of e2fsprogs 0.5b

1 files changed, 207 insertions, 0 deletions

diff --git a/lib/ext2fs/namei.c b/lib/ext2fs/namei.c
new file mode 100644
index 00000000..3bb6d570
--- /dev/null
+++ b/lib/ext2fs/namei.c
@@ -0,0 +1,207 @@
+/*
+ * namei.c --- ext2fs directory lookup operations
+ * 
+ * Copyright (C) 1993, 1994 Theodore Ts'o.  This file may be
+ * redistributed under the terms of the GNU Public License.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <linux/fs.h>
+#include <linux/ext2_fs.h>
+
+#include "ext2fs.h"
+
+struct dir_context {
+	ino_t		dir;
+	int		flags;
+	char		*buf;
+	int (*func)(struct ext2_dir_entry *dirent,
+		    int	offset,
+		    int	blocksize,
+		    char	*buf,
+		    void	*private);
+	void		*private;
+	errcode_t	errcode;
+};
+
+static int process_dir_block(ext2_filsys fs,
+			     blk_t	*blocknr,
+			     int	blockcnt,
+			     void	*private);
+
+errcode_t ext2fs_dir_iterate(ext2_filsys fs,
+			     ino_t dir,
+			     int flags,
+			     char *block_buf,
+			     int (*func)(struct ext2_dir_entry *dirent,
+					 int	offset,
+					 int	blocksize,
+					 char	*buf,
+					 void	*private),
+			     void *private)
+{
+	struct		dir_context	ctx;
+	errcode_t	retval;
+	
+	retval = ext2fs_check_directory(fs, dir);
+	if (retval)
+		return retval;
+	
+	ctx.dir = dir;
+	ctx.flags = flags;
+	if (block_buf)
+		ctx.buf = block_buf;
+	else {
+		ctx.buf = malloc(fs->blocksize);
+		if (!ctx.buf)
+			return ENOMEM;
+	}
+	ctx.func = func;
+	ctx.private = private;
+	ctx.errcode = 0;
+	retval = ext2fs_block_iterate(fs, dir, 0, 0, process_dir_block, &ctx);
+	if (!block_buf)
+		free(ctx.buf);
+	if (retval)
+		return retval;
+	return ctx.errcode;
+}
+
+static int process_dir_block(ext2_filsys  fs,
+			     blk_t	*blocknr,
+			     int	blockcnt,
+			     void	*private)
+{
+	struct dir_context *ctx = (struct dir_context *) private;
+	int		offset = 0;
+	int		ret;
+	int		changed = 0;
+	int		do_abort = 0;
+	struct ext2_dir_entry *dirent;
+
+	if (blockcnt < 0)
+		return 0;
+
+	ctx->errcode = io_channel_read_blk(fs->io, *blocknr, 1, ctx->buf);
+	if (ctx->errcode)
+		return BLOCK_ABORT;
+	
+	while (offset < fs->blocksize) {
+		dirent = (struct ext2_dir_entry *) (ctx->buf + offset);
+		if (!dirent->inode &&
+		    !(ctx->flags & DIRENT_FLAG_INCLUDE_EMPTY))
+			goto next;
+
+		ret = (ctx->func)(dirent, offset, fs->blocksize,
+				  ctx->buf, ctx->private);
+		if (ret & DIRENT_CHANGED)
+			changed++;
+		if (ret & DIRENT_ABORT) {
+			do_abort++;
+			break;
+		}
+next:		
+		if (((offset + dirent->rec_len) > fs->blocksize) ||
+		    (dirent->rec_len < 8) ||
+		    ((dirent->name_len+8) > dirent->rec_len)) {
+			ctx->errcode = EXT2_ET_DIR_CORRUPTED;
+			return BLOCK_ABORT;
+		}
+		offset += dirent->rec_len;
+	}
+
+	if (changed) {
+		ctx->errcode = io_channel_write_blk(fs->io, *blocknr, 1,
+						    ctx->buf);
+		if (ctx->errcode)
+			return BLOCK_ABORT;
+	}
+	if (do_abort)
+		return BLOCK_ABORT;
+	return 0;
+}
+
+struct lookup_struct  {
+	const char	*name;
+	int		len;
+	ino_t		*inode;
+	int		found;
+};	
+
+static int lookup_proc(struct ext2_dir_entry *dirent,
+		       int	offset,
+		       int	blocksize,
+		       char	*buf,
+		       void	*private)
+{
+	struct lookup_struct *ls = (struct lookup_struct *) private;
+
+	if (ls->len != dirent->name_len)
+		return 0;
+	if (strncmp(ls->name, dirent->name, dirent->name_len))
+		return 0;
+	*ls->inode = dirent->inode;
+	ls->found++;
+	return DIRENT_ABORT;
+}
+
+
+errcode_t ext2fs_lookup(ext2_filsys fs, ino_t dir, const char *name,
+			int namelen, char *buf, ino_t *inode)
+{
+	errcode_t	retval;
+	struct lookup_struct ls;
+
+	ls.name = name;
+	ls.len = namelen;
+	ls.inode = inode;
+	ls.found = 0;
+
+	retval = ext2fs_dir_iterate(fs, dir, 0, buf, lookup_proc, &ls);
+	if (retval)
+		return retval;
+
+	return (ls.found) ? 0 : ENOENT;
+}
+
+errcode_t ext2fs_namei(ext2_filsys fs, ino_t root, ino_t cwd, const char *name,
+		       ino_t *inode)
+{
+	ino_t		dir = cwd;
+	char		*buf;
+	const char	*p = name, *q;
+	int		len;
+	errcode_t	retval;
+
+	buf = malloc(fs->blocksize);
+	if (!buf)
+		return ENOMEM;
+	if (*p == '/') {
+		p++;
+		dir = root;
+	}
+	while (*p) {
+		q = strchr(p, '/');
+		if (q)
+			len = q - p;
+		else
+			len = strlen(p);
+		if (len) {
+			retval = ext2fs_lookup(fs, dir, p, len, buf, &dir);
+			if (retval) {
+				free(buf);
+				return retval;
+			}
+		}
+		if (q)
+			p = q+1;
+		else
+			break;
+	}
+	*inode = dir;
+	free(buf);
+	return 0;
+}