1 files changed, 53 insertions, 0 deletions
diff --git a/pkg/sentry/syscalls/linux/flags.go b/pkg/sentry/syscalls/linux/flags.go
new file mode 100644
index 000000000..d83e12971
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/flags.go
@@ -0,0 +1,53 @@
+// Copyright 2018 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package linux
+
+import (
+	"gvisor.googlesource.com/gvisor/pkg/abi/linux"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/fs"
+)
+
+// flagsToPermissions returns a Permissions object from Linux flags.
+// This includes truncate permission if O_TRUNC is set in the mask.
+func flagsToPermissions(mask uint) (p fs.PermMask) {
+	if mask&linux.O_TRUNC != 0 {
+		p.Write = true
+	}
+	switch mask & linux.O_ACCMODE {
+	case linux.O_WRONLY:
+		p.Write = true
+	case linux.O_RDWR:
+		p.Write = true
+		p.Read = true
+	case linux.O_RDONLY:
+		p.Read = true
+	}
+	return
+}
+
+// linuxToFlags converts Linux file flags to a FileFlags object.
+func linuxToFlags(mask uint) fs.FileFlags {
+	return fs.FileFlags{
+		Direct:      mask&linux.O_DIRECT != 0,
+		Sync:        mask&linux.O_SYNC != 0,
+		NonBlocking: mask&linux.O_NONBLOCK != 0,
+		Read:        (mask & linux.O_ACCMODE) != linux.O_WRONLY,
+		Write:       (mask & linux.O_ACCMODE) != linux.O_RDONLY,
+		Append:      mask&linux.O_APPEND != 0,
+		Directory:   mask&linux.O_DIRECTORY != 0,
+		Async:       mask&linux.O_ASYNC != 0,
+		LargeFile:   mask&linux.O_LARGEFILE != 0,
+	}
+}