rpfix extract on UNIX

[wimlib] / src / symlink.c

diff --git a/src/symlink.c b/src/symlink.c
index 9eaf6b4b0e2f4457d6b084f9467b33e1fd78d0b4..dc365e8cf5787a9b335e3ac77bce214f6ac853d3 100644 (file)
--- a/src/symlink.c
+++ b/src/symlink.c
@@ -57,9 +57,7 @@ get_symlink_name(const void *resource, size_t resource_len, char *buf,
        size_t link_target_len;
        ssize_t ret;
        unsigned header_size;
-       char *translated_target;
-       bool is_absolute;
-       u32 flags;
+       bool translate_slashes;
 
        if (resource_len < 12)
                return -EIO;
@@ -67,15 +65,13 @@ get_symlink_name(const void *resource, size_t resource_len, char *buf,
        p = get_u16(p, &substitute_name_len);
        p = get_u16(p, &print_name_offset);
        p = get_u16(p, &print_name_len);
-       get_u32(p, &flags);
 
        wimlib_assert(reparse_tag == WIM_IO_REPARSE_TAG_SYMLINK ||
                      reparse_tag == WIM_IO_REPARSE_TAG_MOUNT_POINT);
 
-       if (reparse_tag == WIM_IO_REPARSE_TAG_MOUNT_POINT) {
+       if (reparse_tag == WIM_IO_REPARSE_TAG_MOUNT_POINT)
                header_size = 8;
-       } else {
-               is_absolute = (flags & 1) ? false : true;
+       else {
                header_size = 12;
                p += 4;
        }
@@ -93,32 +89,57 @@ get_symlink_name(const void *resource, size_t resource_len, char *buf,
                goto out;
        }
 
-       translated_target = link_target;
-       if (reparse_tag == WIM_IO_REPARSE_TAG_MOUNT_POINT || is_absolute) {
-               if (link_target_len < 7
-                     || memcmp(translated_target, "\\??\\", 4) != 0
-                     || translated_target[4] == '\0'
-                     || translated_target[5] != ':'
-                     || translated_target[6] != '\\') {
-                       ret = -EIO;
-                       goto out;
-               }
-               translated_target += 4;
-               link_target_len -= 4;
-               /* There's a drive letter, so just leave the backslashes since
-                * it won't go anyhwere on UNIX anyway...
-                *
-                * XXX
-                * NTFS-3g tries to re-map these links to actually point to
-                * something, so maybe we could do something like that here
-                * XXX*/
+       DEBUG("Interpeting substitute name \"%s\" (ReparseTag=0x%x)",
+             link_target, reparse_tag);
+       translate_slashes = true;
+       if (link_target_len >= 7 &&
+           link_target[0] == '\\' &&
+           link_target[1] == '?' &&
+           link_target[2] == '?' &&
+           link_target[3] == '\\' &&
+           link_target[4] != '\0' &&
+           link_target[5] == ':' &&
+           link_target[6] == '\\')
+       {
+               /* "Full" symlink or junction (\??\x:\ prefixed path) */
+               link_target += 6;
+               link_target_len -= 6;
+       } else if (reparse_tag == WIM_IO_REPARSE_TAG_MOUNT_POINT &&
+                  link_target_len >= 12 &&
+                  memcmp(link_target, "\\\\?\\Volume{", 11) == 0 &&
+                  link_target[link_target_len - 1] == '\\')
+       {
+               /* Volume junction.  Can't really do anything with it. */
+               translate_slashes = false;
+       } else if (reparse_tag == WIM_IO_REPARSE_TAG_SYMLINK &&
+                  link_target_len >= 3 &&
+                  link_target[0] != '\0' &&
+                  link_target[1] == ':' &&
+                  link_target[2] == '/')
+       {
+               /* "Absolute" symlink, with drive letter */
+               link_target += 2;
+               link_target_len -= 2;
+       } else if (reparse_tag == WIM_IO_REPARSE_TAG_SYMLINK &&
+                  link_target_len >= 1)
+       {
+               if (link_target[0] == '/')
+                       /* "Absolute" symlink, without drive letter */
+                       ;
+               else
+                       /* "Relative" symlink, without drive letter */
+                       ;
        } else {
-               for (size_t i = 0; i < link_target_len; i++)
-                       if (translated_target[i] == '\\')
-                               translated_target[i] = '/';
+               ERROR("Invalid reparse point: \"%s\"", link_target);
+               ret = -EIO;
+               goto out;
        }
 
-       memcpy(buf, translated_target, link_target_len + 1);
+       if (translate_slashes)
+               for (size_t i = 0; i < link_target_len; i++)
+                       if (link_target[i] == '\\')
+                               link_target[i] = '/';
+       memcpy(buf, link_target, link_target_len + 1);
        ret = link_target_len;
 out:
        FREE(link_target);
@@ -187,7 +208,7 @@ inode_readlink(const struct wim_inode *inode, char *buf, size_t buf_len,
 
        u8 res_buf[wim_resource_size(lte)];
        ret = read_full_resource_into_buf(lte, res_buf, threadsafe);
-       if (ret != 0)
+       if (ret)
                return -EIO;
        return get_symlink_name(res_buf, wim_resource_size(lte), buf,
                                buf_len, inode->i_reparse_tag);