1 files changed, 30 insertions, 0 deletions
diff --git a/runsc/fsgofer/fsgofer_unsafe.go b/runsc/fsgofer/fsgofer_unsafe.go
index f11fea40d..fb4fbe0d2 100644
--- a/runsc/fsgofer/fsgofer_unsafe.go
+++ b/runsc/fsgofer/fsgofer_unsafe.go
@@ -21,6 +21,8 @@ import (
 	"gvisor.dev/gvisor/pkg/syserr"
 )
 
+var unixDirentMaxSize uint32 = uint32(unsafe.Sizeof(unix.Dirent{}))
+
 func utimensat(dirFd int, name string, times [2]unix.Timespec, flags int) error {
 	// utimensat(2) doesn't accept empty name, instead name must be nil to make it
 	// operate directly on 'dirFd' unlike other *at syscalls.
@@ -80,3 +82,31 @@ func renameat(oldDirFD int, oldName string, newDirFD int, newName string) error
 	}
 	return nil
 }
+
+func parseDirents(buf []byte, handleDirent func(ino uint64, off int64, ftype uint8, name string) bool) {
+	for len(buf) > 0 {
+		// Interpret the buf populated by unix.Getdents as unix.Dirent.
+		dirent := *(*unix.Dirent)(unsafe.Pointer(&buf[0]))
+
+		// Extracting the name is pretty tedious...
+		var nameBuf [unix.NAME_MAX]byte
+		var nameLen int
+		for i := 0; i < len(dirent.Name); i++ {
+			// The name is null terminated.
+			if dirent.Name[i] == 0 {
+				nameLen = i
+				break
+			}
+			nameBuf[i] = byte(dirent.Name[i])
+		}
+		name := string(nameBuf[:nameLen])
+
+		// Deliver results to caller.
+		if !handleDirent(dirent.Ino, dirent.Off, dirent.Type, name) {
+			return
+		}
+
+		// Advance buf for the next dirent.
+		buf = buf[dirent.Reclen:]
+	}
+}