Add support for special files on UNIX

[wimlib] / src / unix_apply.c

diff --git a/src/unix_apply.c b/src/unix_apply.c
index 40dc9edf701a1a9285632f24504be666103055de..8b8d9bf5bf0480a1640d95ff1aaf76e7ac1bf049 100644 (file)
--- a/src/unix_apply.c
+++ b/src/unix_apply.c
@@ -96,6 +96,9 @@ struct unix_apply_ctx {
 
        /* Number of characters in target_abspath.  */
        size_t target_abspath_nchars;
+
+       /* Number of special files we couldn't create due to EPERM  */
+       unsigned long num_special_files_ignored;
 };
 
 /* Returns the number of characters needed to represent the path to the
@@ -373,15 +376,15 @@ unix_create_if_directory(const struct wim_dentry *dentry,
        return 0;
 }
 
-/* If @dentry represents an empty regular file, create it, set its metadata, and
- * create any needed hard links.  */
+/* If @dentry represents an empty regular file or a special file, create it, set
+ * its metadata, and create any needed hard links.  */
 static int
 unix_extract_if_empty_file(const struct wim_dentry *dentry,
                           struct unix_apply_ctx *ctx)
 {
        const struct wim_inode *inode;
+       struct wimlib_unix_data unix_data;
        const char *path;
-       int fd;
        int ret;
 
        inode = dentry->d_inode;
@@ -390,26 +393,54 @@ unix_extract_if_empty_file(const struct wim_dentry *dentry,
        if (dentry != inode_first_extraction_dentry(inode))
                return 0;
 
-       /* Not an empty regular file?  */
+       /* Is this a directory, a symbolic link, or any type of nonempty file?
+        */
        if (inode_is_directory(inode) || inode_is_symlink(inode) ||
            inode_unnamed_lte_resolved(inode))
                return 0;
 
-       path = unix_build_extraction_path(dentry, ctx);
-retry_create:
-       fd = open(path, O_TRUNC | O_CREAT | O_WRONLY | O_NOFOLLOW, 0644);
-       if (fd < 0) {
-               if (errno == EEXIST && !unlink(path))
-                       goto retry_create;
-               ERROR_WITH_ERRNO("Can't create regular file \"%s\"", path);
-               return WIMLIB_ERR_OPEN;
-       }
-       /* On empty files, we can set timestamps immediately because we don't
-        * need to write any data to them.  */
-       ret = unix_set_metadata(fd, inode, path, ctx);
-       if (close(fd) && !ret) {
-               ERROR_WITH_ERRNO("Error closing \"%s\"", path);
-               ret = WIMLIB_ERR_WRITE;
+       /* Recognize special files in UNIX_DATA mode  */
+       if ((ctx->common.extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) &&
+           inode_get_unix_data(inode, &unix_data) &&
+           !S_ISREG(unix_data.mode))
+       {
+               path = unix_build_extraction_path(dentry, ctx);
+       retry_mknod:
+               if (mknod(path, unix_data.mode, unix_data.rdev)) {
+                       if (errno == EPERM) {
+                               WARNING_WITH_ERRNO("Can't create special "
+                                                  "file \"%s\"", path);
+                               ctx->num_special_files_ignored++;
+                               return 0;
+                       }
+                       if (errno == EEXIST && !unlink(path))
+                               goto retry_mknod;
+                       ERROR_WITH_ERRNO("Can't create special file \"%s\"",
+                                        path);
+                       return WIMLIB_ERR_MKNOD;
+               }
+               /* On special files, we can set timestamps immediately because
+                * we don't need to write any data to them.  */
+               ret = unix_set_metadata(-1, inode, path, ctx);
+       } else {
+               int fd;
+
+               path = unix_build_extraction_path(dentry, ctx);
+       retry_create:
+               fd = open(path, O_TRUNC | O_CREAT | O_WRONLY | O_NOFOLLOW, 0644);
+               if (fd < 0) {
+                       if (errno == EEXIST && !unlink(path))
+                               goto retry_create;
+                       ERROR_WITH_ERRNO("Can't create regular file \"%s\"", path);
+                       return WIMLIB_ERR_OPEN;
+               }
+               /* On empty files, we can set timestamps immediately because we
+                * don't need to write any data to them.  */
+               ret = unix_set_metadata(fd, inode, path, ctx);
+               if (close(fd) && !ret) {
+                       ERROR_WITH_ERRNO("Error closing \"%s\"", path);
+                       ret = WIMLIB_ERR_WRITE;
+               }
        }
        if (ret)
                return ret;
@@ -709,6 +740,12 @@ unix_extract(struct list_head *dentry_list, struct apply_ctx *_ctx)
        /* Set directory metadata.  We do this last so that we get the right
         * directory timestamps.  */
        ret = unix_set_dir_metadata(dentry_list, ctx);
+       if (ret)
+               goto out;
+       if (ctx->num_special_files_ignored) {
+               WARNING("%lu special files were not extracted due to EPERM!",
+                       ctx->num_special_files_ignored);
+       }
 out:
        for (unsigned i = 0; i < NUM_PATHBUFS; i++)
                FREE(ctx->pathbufs[i]);