fix(anytls): deadlock in session close

[artiga033]

Fixes a deadlock case in anytls.

Currently, in

outbound/protocol/anytls/session.go

Lines 207 to 218 in 00c4fbb

	func (s *session) Close() error {
	if s.closed.CompareAndSwap(false, true) {
	s.streamLock.Lock()
	defer s.streamLock.Unlock()
	for i := range s.streams {
	s.streams[i].Close()
	}
	s.streams = make(map[uint32]*stream)
	return s.conn.Close()
	}
	return nil
	}

L212 s.streams[i].Close() calls session.removeStream, in which the streamLock is locked again and thus hangs permanently.

A unit test case to reproduce

outbound/protocol/anytls/session_test.go:

package anytls

import (
	"testing"
	"time"

	"github.com/daeuniverse/outbound/netproxy"
)

type mockConn struct {
}

// Close implements [netproxy.Conn].
func (m *mockConn) Close() error {
	println("mockConn closed")
	return nil
}

// Read implements [netproxy.Conn].
func (m *mockConn) Read(b []byte) (n int, err error) {
	println("mockConn read")
	return 0, nil
}

// SetDeadline implements [netproxy.Conn].
func (m *mockConn) SetDeadline(t time.Time) error {
	println("mockConn set deadline")
	return nil
}

// SetReadDeadline implements [netproxy.Conn].
func (m *mockConn) SetReadDeadline(t time.Time) error {
	println("mockConn set read deadline")
	return nil
}

// SetWriteDeadline implements [netproxy.Conn].
func (m *mockConn) SetWriteDeadline(t time.Time) error {
	println("mockConn set write deadline")
	return nil
}

// Write implements [netproxy.Conn].
func (m *mockConn) Write(b []byte) (n int, err error) {
	println("mockConn write")
	return len(b), nil
}

var _ netproxy.Conn = (*mockConn)(nil)

func TestCloseSession(t *testing.T) {
	sess := newSession(&mockConn{}, 0)
	_, err := sess.newStream("example.com:443")
	if err != nil {
		t.Fatalf("failed to create new stream: %v", err)
	}

	sess.Close()
}

go test -test.fullpath=true -timeout 30s -run ^TestCloseSession$ github.com/daeuniverse/outbound/protocol/anytls

panic: test timed out after 30s
	running tests:
		TestCloseSession (30s)


goroutine 21 [sync.Mutex.Lock]:
internal/sync.runtime_SemacquireMutex(0x7a391ac9bdc0?, 0x90?, 0x7f0320?)
	/usr/lib/go/src/runtime/sema.go:95 +0x25
internal/sync.(*Mutex).lockSlow(0x3fbdb00de2c0)
	/usr/lib/go/src/internal/sync/mutex.go:149 +0x15d
internal/sync.(*Mutex).Lock(...)
	/usr/lib/go/src/internal/sync/mutex.go:70
sync.(*Mutex).Lock(...)
	/usr/lib/go/src/sync/mutex.go:46
sync.(*RWMutex).Lock(0x7f0858?)
	/usr/lib/go/src/sync/rwmutex.go:150 +0x32
github.com/daeuniverse/outbound/protocol/anytls.(*session).removeStream(0x3fbdb00de2a0, 0x1)
	/redacted/outbound/protocol/anytls/session.go:95 +0x27
github.com/daeuniverse/outbound/protocol/anytls.(*stream).Close(0x4169c6?)
	/redacted/outbound/protocol/anytls/stream.go:77 +0x38
github.com/daeuniverse/outbound/protocol/anytls.(*session).Close(0x3fbdb00de2a0?)
	/redacted/outbound/protocol/anytls/session.go:212 +0xed
github.com/daeuniverse/outbound/protocol/anytls.TestCloseSession(0x3fbdb00e66c8)
	/redacted/outbound/protocol/anytls/session_test.go:58 +0x8f
testing.tRunner(0x3fbdb00e66c8, 0x6328e8)
	/usr/lib/go/src/testing/testing.go:2036 +0xea
created by testing.(*T).Run in goroutine 1
	/usr/lib/go/src/testing/testing.go:2101 +0x4c5
FAIL	github.com/daeuniverse/outbound/protocol/anytls	30.038s
FAIL