nebula/overlay/tun_file_linux_test.go

120 lines
2.6 KiB
Go

//go:build linux && !android && !e2e_testing
// +build linux,!android,!e2e_testing
package overlay
import (
"errors"
"os"
"sync"
"testing"
"time"
"golang.org/x/sys/unix"
)
// newReadPipe returns a read fd. The matching write fd is registered for cleanup.
// The caller takes ownership of the read fd (pass it to newTunFd / newFriend).
func newReadPipe(t *testing.T) int {
t.Helper()
var fds [2]int
if err := unix.Pipe2(fds[:], unix.O_CLOEXEC); err != nil {
t.Fatalf("pipe2: %v", err)
}
t.Cleanup(func() { _ = unix.Close(fds[1]) })
return fds[0]
}
func TestTunFile_WakeForShutdown_UnblocksRead(t *testing.T) {
tf, err := newTunFd(newReadPipe(t))
if err != nil {
t.Fatalf("newTunFd: %v", err)
}
t.Cleanup(func() { _ = tf.Close() })
done := make(chan error, 1)
go func() {
_, err := tf.Read(make([]byte, 64))
done <- err
}()
// Verify Read is actually blocked in poll.
select {
case err := <-done:
t.Fatalf("Read returned before shutdown signal: %v", err)
case <-time.After(50 * time.Millisecond):
}
if err := tf.wakeForShutdown(); err != nil {
t.Fatalf("wakeForShutdown: %v", err)
}
select {
case err := <-done:
if !errors.Is(err, os.ErrClosed) {
t.Fatalf("expected os.ErrClosed, got %v", err)
}
case <-time.After(2 * time.Second):
t.Fatal("Read did not wake on shutdown")
}
}
func TestTunFile_WakeForShutdown_WakesFriends(t *testing.T) {
parent, err := newTunFd(newReadPipe(t))
if err != nil {
t.Fatalf("newTunFd: %v", err)
}
friend, err := parent.newFriend(newReadPipe(t))
if err != nil {
_ = parent.Close()
t.Fatalf("newFriend: %v", err)
}
t.Cleanup(func() {
_ = friend.Close()
_ = parent.Close()
})
readers := []*tunFile{parent, friend}
errs := make([]error, len(readers))
var wg sync.WaitGroup
for i, r := range readers {
wg.Add(1)
go func(i int, r *tunFile) {
defer wg.Done()
_, errs[i] = r.Read(make([]byte, 64))
}(i, r)
}
time.Sleep(50 * time.Millisecond)
if err := parent.wakeForShutdown(); err != nil {
t.Fatalf("wakeForShutdown: %v", err)
}
done := make(chan struct{})
go func() { wg.Wait(); close(done) }()
select {
case <-done:
case <-time.After(2 * time.Second):
t.Fatal("readers did not wake")
}
for i, err := range errs {
if !errors.Is(err, os.ErrClosed) {
t.Errorf("reader %d: expected os.ErrClosed, got %v", i, err)
}
}
}
func TestTunFile_Close_Idempotent(t *testing.T) {
tf, err := newTunFd(newReadPipe(t))
if err != nil {
t.Fatalf("newTunFd: %v", err)
}
if err := tf.Close(); err != nil {
t.Fatalf("first Close: %v", err)
}
if err := tf.Close(); err != nil {
t.Fatalf("second Close should be a no-op, got %v", err)
}
}