Add lsattr/chattr support to --xattrs

lib/sysxattrs.c

@@ -30,29 +30,186 @@
 
 #if defined HAVE_LINUX_XATTRS
 
+#include <linux/fs.h>
+#define FS_FL_ATTR "user.rsync.lsattr"
+#define FS_FL_ATTR_BUF_SIZE sizeof("-2147483648")
+
+#ifdef FS_IOC_GETFLAGS
+
+#define FS_FL_SETTABLE (FS_APPEND_FL|FS_COMPR_FL|FS_DIRSYNC_FL|FS_IMMUTABLE_FL|FS_JOURNAL_DATA_FL|FS_NOATIME_FL|\
+	FS_NOCOW_FL|FS_NODUMP_FL|FS_NOTAIL_FL|FS_PROJINHERIT_FL|FS_SECRM_FL|FS_SYNC_FL|FS_TOPDIR_FL|FS_UNRM_FL|\
+	FS_CASEFOLD_FL|FS_NOCOMP_FL|FS_PROJINHERIT_FL|FS_DAX_FL)
+
+static int handle_fs_fl_impl(int lsattr_fd, const char *source, const char *dest, int open_flags, int *lsattr_flags) {
+	int ret;
+	struct stat st;
+	if (source) {
+		int lsattr_fd_owned = 0;
+		if (lsattr_fd == -1) {
+			if ((open_flags & O_NOFOLLOW ? lstat : stat)(source, &st)) {
+				rsyserr(FERROR_XFER, errno,
+					"handle_fs_fl_impl: stat(%s) for source failed",
+					full_fname(source));
+				return -1;
+			}
+			if (!S_ISREG(st.st_mode) && !S_ISDIR(st.st_mode)) {
+				return 0;
+			}
+			lsattr_fd_owned = 1;
+			lsattr_fd = open(source, open_flags);
+			if (lsattr_fd == -1) {
+				rsyserr(FERROR_XFER, errno,
+					"handle_fs_fl_impl: open(%s) for source failed",
+					full_fname(source));
+				return -1;
+			}
+		}
+		ret = ioctl(lsattr_fd, FS_IOC_GETFLAGS, lsattr_flags);
+		if (ret) {
+			rsyserr(FERROR_XFER, ret,
+				"handle_fs_fl_impl: FS_IOC_GETFLAGS(%s) for source failed",
+				full_fname(source));
+			if (lsattr_fd_owned)
+				close(lsattr_fd);
+			assert(ret < 0);
+			return ret;
+		}
+		*lsattr_flags &= FS_FL_SETTABLE;
+		if (lsattr_fd_owned)
+			close(lsattr_fd);
+	}
+	if (dest) {
+		if ((open_flags & O_NOFOLLOW ? lstat : stat)(dest, &st)) {
+			rsyserr(FERROR_XFER, errno,
+				"handle_fs_fl_impl: stat(%s) for dest failed",
+				full_fname(dest));
+			return -1;
+		}
+		if (!S_ISREG(st.st_mode) && !S_ISDIR(st.st_mode)) {
+			return 0;
+		}
+		const int chattr_fd = open(dest, open_flags);
+		if (chattr_fd == -1) {
+			rsyserr(FERROR_XFER, errno,
+				"handle_fs_fl_impl: open(%s) for dest failed",
+				full_fname(dest));
+			return -1;
+		}
+		int chattr_flags = 0;
+		ret = ioctl(chattr_fd, FS_IOC_GETFLAGS, &chattr_flags);
+		if (ret) {
+			rsyserr(FERROR_XFER, ret,
+				"handle_fs_fl_impl: FS_IOC_GETFLAGS(%s) for dest failed",
+				full_fname(dest));
+			close(chattr_fd);
+			assert(ret < 0);
+			return ret;
+		}
+		chattr_flags &= ~FS_FL_SETTABLE;
+		chattr_flags |= *lsattr_flags;
+		ret = ioctl(chattr_fd, FS_IOC_SETFLAGS, &chattr_flags);
+		if (ret) {
+			rsyserr(FERROR_XFER, ret,
+				"handle_fs_fl_impl: FS_IOC_SETFLAGS(%s) for dest failed",
+				full_fname(dest));
+			close(chattr_fd);
+			assert(ret < 0);
+			return ret;
+		}
+		close(chattr_fd);
+	}
+	return 0;
+}
+
+static int handle_fs_fl(int source_fd, const char *source, const char *dest, int nofollow, char *rsync_lsattr, size_t buf_size) {
+	if (dest && !rsync_lsattr)
+		return -1;
+	int lsattr_flags = 0;
+	if (dest)
+		lsattr_flags = atoi(rsync_lsattr); // NOLINT(*-err34-c)
+	int open_flags = O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NONBLOCK;
+	if (nofollow)
+		open_flags |= O_NOFOLLOW;
+	int ret = handle_fs_fl_impl(source_fd, source, dest, open_flags, &lsattr_flags);
+	if (ret)
+		return ret;
+	if (!source)
+		return 0;
+	char rsync_lsattr_tmp[FS_FL_ATTR_BUF_SIZE];
+	ret = sprintf(rsync_lsattr_tmp, "%d", lsattr_flags) + 1;
+	if (ret < 0)
+		return ret;
+	if (rsync_lsattr) {
+		if (buf_size < (size_t) ret)
+			return -ERANGE;
+		memcpy(rsync_lsattr, rsync_lsattr_tmp, ret);
+	}
+	return ret;
+}
+#endif
+
 ssize_t sys_lgetxattr(const char *path, const char *name, void *value, size_t size)
 {
+#ifdef FS_IOC_GETFLAGS
+	if (!strcmp(name, FS_FL_ATTR))
+		return handle_fs_fl(-1, path, NULL, 1, value, size);
+#endif
 	return lgetxattr(path, name, value, size);
 }
 
 ssize_t sys_fgetxattr(int filedes, const char *name, void *value, size_t size)
 {
+#ifdef FS_IOC_GETFLAGS
+	if (!strcmp(name, FS_FL_ATTR))
+		return handle_fs_fl(filedes, "(fd)", NULL, 0, value, size);
+#endif
 	return fgetxattr(filedes, name, value, size);
 }
 
 int sys_lsetxattr(const char *path, const char *name, const void *value, size_t size)
 {
+#ifdef FS_IOC_GETFLAGS
+	if (!strcmp(name, FS_FL_ATTR))
+		return handle_fs_fl(-1, NULL, path, 1, (void *) value, size);
+#endif
 	return lsetxattr(path, name, value, size, 0);
 }
 
+#ifdef FS_IOC_GETFLAGS
+static const char FS_FL_ZERO[FS_FL_ATTR_BUF_SIZE] = "0";
+#endif
+
 int sys_lremovexattr(const char *path, const char *name)
 {
+#ifdef FS_IOC_GETFLAGS
+	if (!strcmp(name, FS_FL_ATTR))
+		return handle_fs_fl(-1, NULL, path, 1, (char *) FS_FL_ZERO, strlen(FS_FL_ZERO));
+#endif
 	return lremovexattr(path, name);
 }
 
-ssize_t sys_llistxattr(const char *path, char *list, size_t size)
-{
-	return llistxattr(path, list, size);
+ssize_t sys_llistxattr(const char *path, char *list, size_t size) {
+	ssize_t ret;
+#ifdef FS_IOC_GETFLAGS
+	char fs_fl_attr_buf[FS_FL_ATTR_BUF_SIZE];
+	ret = handle_fs_fl(-1, path, NULL, 1, fs_fl_attr_buf, FS_FL_ATTR_BUF_SIZE);
+	if (ret < 0)
+		return ret;
+#endif
+	ret = llistxattr(path, list, size);
+#ifdef FS_IOC_GETFLAGS
+	if (ret < 0)
+		return ret;
+	if (strcmp(fs_fl_attr_buf, FS_FL_ZERO) != 0) {
+		if (list) {
+			if (ret + sizeof(FS_FL_ATTR) > size)
+				return -ERANGE;
+			memcpy(&list[ret], FS_FL_ATTR, sizeof(FS_FL_ATTR));
+		}
+		ret += sizeof(FS_FL_ATTR);
+	}
+#endif
+	return ret;
 }
 
 #elif HAVE_OSX_XATTRS

rsync.1.md

@@ -449,7 +449,7 @@ has its own detailed description later in this manpage.
 --executability, -E      preserve executability
 --chmod=CHMOD            affect file and/or directory permissions
 --acls, -A               preserve ACLs (implies --perms)
---xattrs, -X             preserve extended attributes
+--xattrs, -X             preserve file attributes (including extended attributes)
 --owner, -o              preserve owner (super-user only)
 --group, -g              preserve group
 --devices                preserve device files (super-user only)