Marshallable socket opitons.

Socket option values are now required to implement marshal.Marshallable.

Co-authored-by: Rahat Mahmood <rahat@google.com>
PiperOrigin-RevId: 322831612

2 files changed, 75 insertions, 5 deletions

diff --git a/tools/go_marshal/README.md b/tools/go_marshal/README.md
index 4886efddf..68d759083 100644
--- a/tools/go_marshal/README.md
+++ b/tools/go_marshal/README.md
@@ -9,11 +9,9 @@ automatically generating code to marshal go data structures to memory.
 `binary.Marshal` by moving the go runtime reflection necessary to marshal a
 struct to compile-time.
 
-`go_marshal` automatically generates implementations for `abi.Marshallable` and
-`safemem.{Reader,Writer}`. Call-sites for serialization (typically syscall
-implementations) can directly invoke `safemem.Reader.ReadToBlocks` and
-`safemem.Writer.WriteFromBlocks`. Data structures that require custom
-serialization will have manual implementations for these interfaces.
+`go_marshal` automatically generates implementations for `marshal.Marshallable`
+and `safemem.{Reader,Writer}`. Data structures that require custom serialization
+will have manual implementations for these interfaces.
 
 Data structures can be flagged for code generation by adding a struct-level
 comment `// +marshal`.
diff --git a/tools/go_marshal/primitive/primitive.go b/tools/go_marshal/primitive/primitive.go
index ebcf130ae..d93edda8b 100644
--- a/tools/go_marshal/primitive/primitive.go
+++ b/tools/go_marshal/primitive/primitive.go
@@ -17,10 +17,22 @@
 package primitive
 
 import (
+	"io"
+
 	"gvisor.dev/gvisor/pkg/usermem"
 	"gvisor.dev/gvisor/tools/go_marshal/marshal"
 )
 
+// Int8 is a marshal.Marshallable implementation for int8.
+//
+// +marshal slice:Int8Slice:inner
+type Int8 int8
+
+// Uint8 is a marshal.Marshallable implementation for uint8.
+//
+// +marshal slice:Uint8Slice:inner
+type Uint8 uint8
+
 // Int16 is a marshal.Marshallable implementation for int16.
 //
 // +marshal slice:Int16Slice:inner
@@ -51,6 +63,66 @@ type Int64 int64
 // +marshal slice:Uint64Slice:inner
 type Uint64 uint64
 
+// ByteSlice is a marshal.Marshallable implementation for []byte.
+// This is a convenience wrapper around a dynamically sized type, and can't be
+// embedded in other marshallable types because it breaks assumptions made by
+// go-marshal internals. It violates the "no dynamically-sized types"
+// constraint of the go-marshal library.
+type ByteSlice []byte
+
+// SizeBytes implements marshal.Marshallable.SizeBytes.
+func (b *ByteSlice) SizeBytes() int {
+	return len(*b)
+}
+
+// MarshalBytes implements marshal.Marshallable.MarshalBytes.
+func (b *ByteSlice) MarshalBytes(dst []byte) {
+	copy(dst, *b)
+}
+
+// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.
+func (b *ByteSlice) UnmarshalBytes(src []byte) {
+	copy(*b, src)
+}
+
+// Packed implements marshal.Marshallable.Packed.
+func (b *ByteSlice) Packed() bool {
+	return false
+}
+
+// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
+func (b *ByteSlice) MarshalUnsafe(dst []byte) {
+	b.MarshalBytes(dst)
+}
+
+// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
+func (b *ByteSlice) UnmarshalUnsafe(src []byte) {
+	b.UnmarshalBytes(src)
+}
+
+// CopyIn implements marshal.Marshallable.CopyIn.
+func (b *ByteSlice) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) {
+	return task.CopyInBytes(addr, *b)
+}
+
+// CopyOut implements marshal.Marshallable.CopyOut.
+func (b *ByteSlice) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) {
+	return task.CopyOutBytes(addr, *b)
+}
+
+// CopyOutN implements marshal.Marshallable.CopyOutN.
+func (b *ByteSlice) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) {
+	return task.CopyOutBytes(addr, (*b)[:limit])
+}
+
+// WriteTo implements io.WriterTo.WriteTo.
+func (b *ByteSlice) WriteTo(w io.Writer) (int64, error) {
+	n, err := w.Write(*b)
+	return int64(n), err
+}
+
+var _ marshal.Marshallable = (*ByteSlice)(nil)
+
 // Below, we define some convenience functions for marshalling primitive types
 // using the newtypes above, without requiring superfluous casts.