read_dentry_tree(): Check for presence of long names here

[wimlib] / src / extract.c

diff --git a/src/extract.c b/src/extract.c
index d4029ef61375ffe751fde3e5267fd807e2b2014d..cfeb48982392c62893f9718c8f3e3a200a8fe6a1 100644 (file)
--- a/src/extract.c
+++ b/src/extract.c
@@ -28,6 +28,10 @@
 #  include "config.h"
 #endif
 
+#ifdef __WIN32__
+#  include "wimlib/win32_common.h" /* For GetFullPathName() */
+#endif
+
 #include "wimlib/apply.h"
 #include "wimlib/dentry.h"
 #include "wimlib/encoding.h"
@@ -51,6 +55,8 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
+#define MAX_EXTRACT_LONG_PATH_WARNINGS 5
+
 static int
 do_apply_op(struct wim_dentry *dentry, struct apply_args *args,
            int (*apply_dentry_func)(const tchar *, size_t,
@@ -60,8 +66,21 @@ do_apply_op(struct wim_dentry *dentry, struct apply_args *args,
        size_t extraction_path_nchars;
        struct wim_dentry *d;
        LIST_HEAD(ancestor_list);
+       const tchar *target;
+       size_t target_nchars;
+
+#ifdef __WIN32__
+       if (args->target_lowlevel_path) {
+               target = args->target_lowlevel_path;
+               target_nchars = args->target_lowlevel_path_nchars;
+       } else
+#endif
+       {
+               target = args->target;
+               target_nchars = args->target_nchars;
+       }
 
-       extraction_path_nchars = args->target_nchars;
+       extraction_path_nchars = target_nchars;
 
        for (d = dentry; d != args->extract_root; d = d->parent) {
                if (d->not_extracted)
@@ -71,13 +90,30 @@ do_apply_op(struct wim_dentry *dentry, struct apply_args *args,
        }
 
        tchar extraction_path[extraction_path_nchars + 1];
-       p = tmempcpy(extraction_path, args->target, args->target_nchars);
+       p = tmempcpy(extraction_path, target, target_nchars);
+
 
        list_for_each_entry(d, &ancestor_list, tmp_list) {
                *p++ = OS_PREFERRED_PATH_SEPARATOR;
                p = tmempcpy(p, d->extraction_name, d->extraction_name_nchars);
        }
        *p = T('\0');
+
+#ifdef __WIN32__
+       /* Warn the user if the path exceeds MAX_PATH */
+
+       /* + 1 for '\0', -4 for \\?\.  */
+       if (extraction_path_nchars + 1 - 4 > MAX_PATH) {
+               if (dentry->needs_extraction &&
+                   args->num_long_paths < MAX_EXTRACT_LONG_PATH_WARNINGS)
+               {
+                       WARNING("Path \"%ls\" exceeds MAX_PATH and will not be accessible "
+                               "to most Windows software", extraction_path);
+                       if (++args->num_long_paths == MAX_EXTRACT_LONG_PATH_WARNINGS)
+                               WARNING("Suppressing further warnings about long paths");
+               }
+       }
+#endif
        return (*apply_dentry_func)(extraction_path, extraction_path_nchars,
                                    dentry, args);
 }
@@ -604,6 +640,8 @@ dentry_reset_needs_extraction(struct wim_dentry *dentry, void *_ignore)
        return 0;
 }
 
+#define WINDOWS_NT_MAX_PATH 32768
+
 /*
  * extract_tree - Extract a file or directory tree from the currently selected
  *               WIM image.
@@ -651,11 +689,38 @@ extract_tree(WIMStruct *wim, const tchar *wim_source_path, const tchar *target,
 
        memset(&args, 0, sizeof(args));
 
+
        args.w                      = wim;
        args.target                 = target;
+       args.target_nchars          = tstrlen(target);
        args.extract_flags          = extract_flags;
        args.progress_func          = progress_func;
-       args.target_nchars          = tstrlen(target);
+
+#ifdef __WIN32__
+       /* Work around defective behavior in Windows where paths longer than 260
+        * characters are not supported by default; instead they need to be
+        * turned into absolute paths and prefixed with "\\?\".  */
+       args.target_lowlevel_path = MALLOC(WINDOWS_NT_MAX_PATH * sizeof(wchar_t));
+       if (!args.target_lowlevel_path)
+       {
+               ret = WIMLIB_ERR_NOMEM;
+               goto out;
+       }
+       args.target_lowlevel_path_nchars =
+               GetFullPathName(args.target, WINDOWS_NT_MAX_PATH - 4,
+                               &args.target_lowlevel_path[4], NULL);
+
+       if (args.target_lowlevel_path_nchars == 0 ||
+           args.target_lowlevel_path_nchars >= WINDOWS_NT_MAX_PATH - 4)
+       {
+               WARNING("Can't get full path name for \"%ls\"", args.target);
+               FREE(args.target_lowlevel_path);
+               args.target_lowlevel_path = NULL;
+       } else {
+               wmemcpy(args.target_lowlevel_path, L"\\\\?\\", 4);
+               args.target_lowlevel_path_nchars += 4;
+       }
+#endif
 
        if (progress_func) {
                args.progress.extract.wimfile_name = wim->filename;
@@ -675,7 +740,7 @@ extract_tree(WIMStruct *wim, const tchar *wim_source_path, const tchar *target,
                        ERROR_WITH_ERRNO("Failed to mount NTFS volume `%"TS"'",
                                         target);
                        ret = WIMLIB_ERR_NTFS_3G;
-                       goto out;
+                       goto out_free_target_lowlevel_path;
                }
                ops = &ntfs_apply_operations;
        } else
@@ -793,6 +858,10 @@ out_ntfs_umount:
                }
        }
 #endif
+out_free_target_lowlevel_path:
+#ifdef __WIN32__
+       FREE(args.target_lowlevel_path);
+#endif
 out:
        return ret;
 }
@@ -1108,7 +1177,7 @@ extract_all_images(WIMStruct *wim,
        }
 
        tmemcpy(buf, target, output_path_len);
-       buf[output_path_len] = T('/');
+       buf[output_path_len] = OS_PREFERRED_PATH_SEPARATOR;
        for (image = 1; image <= wim->hdr.image_count; image++) {
                image_name = wimlib_get_image_name(wim, image);
                if (image_name_ok_as_dir(image_name)) {