+#include "common.h"
+
+static int we_are_root; /* true if our effective uid == 0 */
+static mode_t newdir_umask; /* umask when creating new directories */
+static mode_t current_umask; /* current umask (which is set to 0 if -p) */
+
+/* Status of the permissions of a file that we are extracting. */
+enum permstatus
+{
+ /* This file may have existed already; its permissions are unknown. */
+ UNKNOWN_PERMSTATUS,
+
+ /* This file was created using the permissions from the archive. */
+ ARCHIVED_PERMSTATUS,
+
+ /* This is an intermediate directory; the archive did not specify
+ its permissions. */
+ INTERDIR_PERMSTATUS
+};
+
+/* List of directories whose statuses we need to extract after we've
+ finished extracting their subsidiary files. The head of the list
+ has the longest name; each non-head element in the list is an
+ ancestor (in the directory hierarchy) of the preceding element. */
+struct delayed_set_stat
+ {
+ struct delayed_set_stat *next;
+ struct stat stat_info;
+ size_t file_name_len;
+ mode_t invert_permissions;
+ enum permstatus permstatus;
+ char file_name[1];
+ };
+
+static struct delayed_set_stat *delayed_set_stat_head;
+
+/*--------------------------.
+| Set up to extract files. |
+`--------------------------*/
+
+void
+extr_init (void)
+{
+ we_are_root = geteuid () == 0;
+ same_permissions_option += we_are_root;
+ same_owner_option += we_are_root;
+ xalloc_fail_func = apply_delayed_set_stat;
+
+ /* Option -p clears the kernel umask, so it does not affect proper
+ restoration of file permissions. New intermediate directories will
+ comply with umask at start of program. */
+
+ newdir_umask = umask (0);
+ if (0 < same_permissions_option)
+ current_umask = 0;
+ else
+ {
+ umask (newdir_umask); /* restore the kernel umask */
+ current_umask = newdir_umask;
+ }
+}
+
+/* If restoring permissions, restore the mode for FILE_NAME from
+ information given in *STAT_INFO; otherwise invert the
+ INVERT_PERMISSIONS bits from the file's current permissions.
+ PERMSTATUS specifies the status of the file's permissions.
+ TYPEFLAG specifies the type of the file. */
+static void
+set_mode (char *file_name, struct stat *stat_info,
+ mode_t invert_permissions, enum permstatus permstatus,
+ char typeflag)
+{
+ mode_t mode;
+
+ if (0 < same_permissions_option
+ && permstatus != INTERDIR_PERMSTATUS)
+ {
+ mode = stat_info->st_mode;
+
+ /* If we created the file and it has a usual mode, then its mode
+ is normally set correctly already. But on many hosts, some
+ directories inherit the setgid bits from their parents, so we
+ we must set directories' modes explicitly. */
+ if (permstatus == ARCHIVED_PERMSTATUS
+ && ! (mode & ~ MODE_RWX)
+ && typeflag != DIRTYPE
+ && typeflag != GNUTYPE_DUMPDIR)
+ return;
+ }
+ else if (! invert_permissions)
+ return;
+ else
+ {
+ /* We must inspect a directory's current permissions, since the
+ directory may have inherited its setgid bit from its parent.
+
+ INVERT_PERMISSIONS happens to be nonzero only for directories
+ that we created, so there's no point optimizing this code for
+ other cases. */
+ struct stat st;
+ if (stat (file_name, &st) != 0)
+ {
+ stat_error (file_name);
+ return;
+ }
+ mode = st.st_mode ^ invert_permissions;
+ }
+
+ if (chmod (file_name, mode) != 0)
+ chmod_error_details (file_name, mode);
+}
+
+/* Restore stat attributes (owner, group, mode and times) for
+ FILE_NAME, using information given in *STAT_INFO.
+ If not restoring permissions, invert the
+ INVERT_PERMISSIONS bits from the file's current permissions.
+ PERMSTATUS specifies the status of the file's permissions.
+ TYPEFLAG specifies the type of the file. */
+
+/* FIXME: About proper restoration of symbolic link attributes, we still do
+ not have it right. Pretesters' reports tell us we need further study and
+ probably more configuration. For now, just use lchown if it exists, and
+ punt for the rest. Sigh! */
+
+static void
+set_stat (char *file_name, struct stat *stat_info,
+ mode_t invert_permissions, enum permstatus permstatus,
+ char typeflag)
+{
+ struct utimbuf utimbuf;
+
+ if (typeflag != SYMTYPE)
+ {
+ /* We do the utime before the chmod because some versions of utime are
+ broken and trash the modes of the file. */
+
+ if (! touch_option && permstatus != INTERDIR_PERMSTATUS)
+ {
+ /* We set the accessed time to `now', which is really the time we
+ started extracting files, unless incremental_option is used, in
+ which case .st_atime is used. */
+
+ /* FIXME: incremental_option should set ctime too, but how? */
+
+ if (incremental_option)
+ utimbuf.actime = stat_info->st_atime;
+ else
+ utimbuf.actime = start_time;
+
+ utimbuf.modtime = stat_info->st_mtime;
+
+ if (utime (file_name, &utimbuf) < 0)
+ utime_error (file_name);
+ }