import ext2fs lib to prep for new e2fsprogs

1 files changed, 205 insertions, 0 deletions

diff --git a/e2fsprogs/ext2fs/namei.c b/e2fsprogs/ext2fs/namei.c
new file mode 100644
index 0000000..13d13ad
--- /dev/null
+++ b/e2fsprogs/ext2fs/namei.c
@@ -0,0 +1,205 @@
+/*
+ * namei.c --- ext2fs directory lookup operations
+ * 
+ * Copyright (C) 1993, 1994, 1994, 1995 Theodore Ts'o.
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Public
+ * License.
+ * %End-Header%
+ */
+
+#include <stdio.h>
+#include <string.h>
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+/* #define NAMEI_DEBUG */
+
+#include "ext2_fs.h"
+#include "ext2fs.h"
+
+static errcode_t open_namei(ext2_filsys fs, ext2_ino_t root, ext2_ino_t base,
+			    const char *pathname, size_t pathlen, int follow,
+			    int link_count, char *buf, ext2_ino_t *res_inode);
+
+static errcode_t follow_link(ext2_filsys fs, ext2_ino_t root, ext2_ino_t dir,
+			     ext2_ino_t inode, int link_count,
+			     char *buf, ext2_ino_t *res_inode)
+{
+	char *pathname;
+	char *buffer = 0;
+	errcode_t retval;
+	struct ext2_inode ei;
+
+#ifdef NAMEI_DEBUG
+	printf("follow_link: root=%lu, dir=%lu, inode=%lu, lc=%d\n",
+	       root, dir, inode, link_count);
+	
+#endif
+	retval = ext2fs_read_inode (fs, inode, &ei);
+	if (retval) return retval;
+	if (!LINUX_S_ISLNK (ei.i_mode)) {
+		*res_inode = inode;
+		return 0;
+	}
+	if (link_count++ > 5) {
+		return EXT2_ET_SYMLINK_LOOP;
+	}
+	if (ext2fs_inode_data_blocks(fs,&ei)) {
+		retval = ext2fs_get_mem(fs->blocksize, &buffer);
+		if (retval)
+			return retval;
+		retval = io_channel_read_blk(fs->io, ei.i_block[0], 1, buffer);
+		if (retval) {
+			ext2fs_free_mem(&buffer);
+			return retval;
+		}
+		pathname = buffer;
+	} else
+		pathname = (char *)&(ei.i_block[0]);
+	retval = open_namei(fs, root, dir, pathname, ei.i_size, 1,
+			    link_count, buf, res_inode);
+	if (buffer)
+		ext2fs_free_mem(&buffer);
+	return retval;
+}
+
+/*
+ * This routine interprets a pathname in the context of the current
+ * directory and the root directory, and returns the inode of the
+ * containing directory, and a pointer to the filename of the file
+ * (pointing into the pathname) and the length of the filename.
+ */
+static errcode_t dir_namei(ext2_filsys fs, ext2_ino_t root, ext2_ino_t dir,
+			   const char *pathname, int pathlen,
+			   int link_count, char *buf,
+			   const char **name, int *namelen,
+			   ext2_ino_t *res_inode)
+{
+	char c;
+	const char *thisname;
+	int len;
+	ext2_ino_t inode;
+	errcode_t retval;
+
+	if ((c = *pathname) == '/') {
+        	dir = root;
+		pathname++;
+		pathlen--;
+	}
+	while (1) {
+        	thisname = pathname;
+		for (len=0; --pathlen >= 0;len++) {
+			c = *(pathname++);
+			if (c == '/')
+				break;
+		}
+		if (pathlen < 0)
+			break;
+		retval = ext2fs_lookup (fs, dir, thisname, len, buf, &inode);
+		if (retval) return retval;
+        	retval = follow_link (fs, root, dir, inode,
+				      link_count, buf, &dir);
+        	if (retval) return retval;
+    	}
+	*name = thisname;
+	*namelen = len;
+	*res_inode = dir;
+	return 0;
+}
+
+static errcode_t open_namei(ext2_filsys fs, ext2_ino_t root, ext2_ino_t base,
+			    const char *pathname, size_t pathlen, int follow,
+			    int link_count, char *buf, ext2_ino_t *res_inode)
+{
+	const char *basename;
+	int namelen;
+	ext2_ino_t dir, inode;
+	errcode_t retval;
+
+#ifdef NAMEI_DEBUG
+	printf("open_namei: root=%lu, dir=%lu, path=%*s, lc=%d\n",
+	       root, base, pathlen, pathname, link_count);
+#endif
+	retval = dir_namei(fs, root, base, pathname, pathlen,
+			   link_count, buf, &basename, &namelen, &dir);
+	if (retval) return retval;
+	if (!namelen) {                     /* special case: '/usr/' etc */
+		*res_inode=dir;
+		return 0;
+	}
+	retval = ext2fs_lookup (fs, dir, basename, namelen, buf, &inode);
+	if (retval)
+		return retval;
+	if (follow) {
+		retval = follow_link(fs, root, dir, inode, link_count,
+				     buf, &inode);
+		if (retval)
+			return retval;
+	}
+#ifdef NAMEI_DEBUG
+	printf("open_namei: (link_count=%d) returns %lu\n",
+	       link_count, inode);
+#endif
+	*res_inode = inode;
+	return 0;
+}
+
+errcode_t ext2fs_namei(ext2_filsys fs, ext2_ino_t root, ext2_ino_t cwd,
+		       const char *name, ext2_ino_t *inode)
+{
+	char *buf;
+	errcode_t retval;
+	
+	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+	retval = ext2fs_get_mem(fs->blocksize, &buf);
+	if (retval)
+		return retval;
+	
+	retval = open_namei(fs, root, cwd, name, strlen(name), 0, 0,
+			    buf, inode);
+
+	ext2fs_free_mem(&buf);
+	return retval;
+}
+
+errcode_t ext2fs_namei_follow(ext2_filsys fs, ext2_ino_t root, ext2_ino_t cwd,
+			      const char *name, ext2_ino_t *inode)
+{
+	char *buf;
+	errcode_t retval;
+	
+	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+	retval = ext2fs_get_mem(fs->blocksize, &buf);
+	if (retval)
+		return retval;
+	
+	retval = open_namei(fs, root, cwd, name, strlen(name), 1, 0,
+			    buf, inode);
+
+	ext2fs_free_mem(&buf);
+	return retval;
+}
+
+errcode_t ext2fs_follow_link(ext2_filsys fs, ext2_ino_t root, ext2_ino_t cwd,
+			ext2_ino_t inode, ext2_ino_t *res_inode)
+{
+	char *buf;
+	errcode_t retval;
+	
+	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+	retval = ext2fs_get_mem(fs->blocksize, &buf);
+	if (retval)
+		return retval;
+
+	retval = follow_link(fs, root, cwd, inode, 0, buf, res_inode);
+
+	ext2fs_free_mem(&buf);
+	return retval;
+}
+