Start to address the race issue between restoring a file's contents

and restoring the metadata.  In particular, the metadata-restore
functions now all accept a file descriptor and a pathname.  If the
file descriptor is set and the platform supports the appropriate
syscall, restore the metadata through the file descriptor.  Otherwise,
restore it through the pathname.  This is complicated by varying
syscall support (FreeBSD has an fchmod(2) but no fchflags(2), for
example) and because non-file entries don't have an fd to use in
restoring attributes (for example, mknod(2) doesn't return a file
handle).

MFC after: 14 days

1 files changed, 13 insertions, 0 deletions

diff --git a/lib/libarchive/archive_platform.h b/lib/libarchive/archive_platform.h
index 770d8082c23c..4140df28e938 100644
--- a/lib/libarchive/archive_platform.h
+++ b/lib/libarchive/archive_platform.h
@@ -46,6 +46,8 @@
 #if __FreeBSD__ > 4
 #define	HAVE_ACL_CREATE_ENTRY 1
 #define	HAVE_ACL_INIT 1
+#define	HAVE_ACL_SET_FD 1
+#define	HAVE_ACL_SET_FD_NP 1
 #define	HAVE_ACL_SET_FILE 1
 #endif
 #define	HAVE_BZLIB_H 1
@@ -55,7 +57,10 @@
 #define	HAVE_EILSEQ 1
 #define	HAVE_ERRNO_H 1
 #define	HAVE_FCHDIR 1
+#define	HAVE_FCHMOD 1
+#define	HAVE_FCHOWN 1
 #define	HAVE_FCNTL_H 1
+#define	HAVE_FUTIMES 1
 #define	HAVE_INTTYPES_H 1
 #define	HAVE_LCHMOD 1
 #define	HAVE_LCHOWN 1
@@ -123,6 +128,14 @@
 #define	HAVE_POSIX_ACL	1
 #endif
 
+/*
+ * If we can't restore metadata using a file descriptor, then
+ * for compatibility's sake, close files before trying to restore metadata.
+ */
+#if defined(HAVE_FCHMOD) || defined(HAVE_FUTIMES) || defined(HAVE_ACL_SET_FD) || defined(HAVE_ACL_SET_FD_NP) || defined(HAVE_FCHOWN)
+#define CAN_RESTORE_METADATA_FD
+#endif
+
 /* Set up defaults for internal error codes. */
 #ifndef ARCHIVE_ERRNO_FILE_FORMAT
 #if HAVE_EFTYPE