feat: full NFSv4.2 server and client in pure Go

Assisted-by: GLM 5.3 Flash

internal/nfsclient/cb_test.go

@@ -0,0 +1,85 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
+package nfsclient
+
+import (
+	"net"
+	"testing"
+
+	"sourcedock.dev/petrbalvin/nfs/internal/nfs4"
+	"sourcedock.dev/petrbalvin/nfs/internal/rpc"
+)
+
+// The accessors answer copies of what the callback demux recorded.
+func TestNotifiedAccessors(t *testing.T) {
+	c := &Client{}
+	if got := c.Notified(); len(got) != 0 {
+		t.Fatal("notified before any delivery")
+	}
+	if got := c.NotifiedLocks(); len(got) != 0 {
+		t.Fatal("locks notified before any delivery")
+	}
+	c.recMu.Lock()
+	c.notified = append(c.notified, nfs4.CBNotify{FH: []byte("d")})
+	c.notifiedLocks = append(c.notifiedLocks, nfs4.CBNotifyLock{Clientid: 5})
+	c.recMu.Unlock()
+	if n := c.Notified(); len(n) != 1 || string(n[0].FH) != "d" {
+		t.Fatalf("notified %+v", n)
+	}
+	if n := c.NotifiedLocks(); len(n) != 1 || n[0].Clientid != 5 {
+		t.Fatalf("locks %+v", n)
+	}
+}
+
+// The callback demux answers CB_NOTIFY and CB_NOTIFY_LOCK and records
+// them for the caller.
+func TestCBCompoundNotifies(t *testing.T) {
+	// The demux answers every callback on the wire; a pipe with a
+	// draining side stands in for the connection.
+	a, b := net.Pipe()
+	defer a.Close()
+	defer b.Close()
+	go func() {
+		buf := make([]byte, 4096)
+		for {
+			if _, err := b.Read(buf); err != nil {
+				return
+			}
+		}
+	}()
+	c := &Client{conn: a, cbProgram: 0x40000000}
+	st := nfs4.Stateid{1, 'D', 'D'}
+
+	notify := nfs4.AppendCBNotifyArgs(nil, st, []byte("dir"),
+		[]nfs4.Notify4{{Mask: nfs4.OfBits(nfs4.NotifyAddEntry),
+			Vals: nfs4.AppendNotifyAdd(nil, "new", 0, true)}})
+	lock := nfs4.AppendCBNotifyLockArgs(nil, []byte("f"), 9, []byte("owner"))
+
+	c.handleCBCall(1, buildCBCall(t, [][]byte{notify, lock}))
+	notes := c.Notified()
+	if len(notes) != 1 || !notes[0].Changes[0].Mask.Has(nfs4.NotifyAddEntry) {
+		t.Fatalf("notified %+v", notes)
+	}
+	if n := c.NotifiedLocks(); len(n) != 1 || n[0].Clientid != 9 {
+		t.Fatalf("locks %+v", n)
+	}
+
+}
+
+// buildCBCall frames one CB_COMPOUND call record the way the server
+// sends it.
+func buildCBCall(t *testing.T, ops [][]byte) []byte {
+	t.Helper()
+	args := nfs4.AppendCBCompoundArgs(nil, "cb", nfs4.MinorVersion, 0, ops)
+	record, err := rpc.AppendCall(nil, rpc.Call{
+		XID: 1, Program: nfs4.CBDefaultProgram, Version: nfs4.Version,
+		Procedure: 1,
+		Cred:      rpc.Auth{Flavor: rpc.FlavorNone},
+		Verifier:  rpc.Auth{Flavor: rpc.FlavorNone},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return append(record, args...)
+}