1 files changed, 205 insertions, 0 deletions

diff --git a/e2fsprogs/ext2fs/namei.c b/e2fsprogs/ext2fs/namei.c
new file mode 100644
index 000000000..13d13adfe
--- /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;
+}
+