cloudflared-mirror/vendor/nhooyr.io/websocket/close_notjs.go

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// +build !js
package websocket
import (
"context"
"encoding/binary"
"errors"
"fmt"
"log"
"time"
"nhooyr.io/websocket/internal/errd"
)
// Close performs the WebSocket close handshake with the given status code and reason.
//
// It will write a WebSocket close frame with a timeout of 5s and then wait 5s for
// the peer to send a close frame.
// All data messages received from the peer during the close handshake will be discarded.
//
// The connection can only be closed once. Additional calls to Close
// are no-ops.
//
// The maximum length of reason must be 125 bytes. Avoid
// sending a dynamic reason.
//
// Close will unblock all goroutines interacting with the connection once
// complete.
func (c *Conn) Close(code StatusCode, reason string) error {
return c.closeHandshake(code, reason)
}
func (c *Conn) closeHandshake(code StatusCode, reason string) (err error) {
defer errd.Wrap(&err, "failed to close WebSocket")
writeErr := c.writeClose(code, reason)
closeHandshakeErr := c.waitCloseHandshake()
if writeErr != nil {
return writeErr
}
if CloseStatus(closeHandshakeErr) == -1 {
return closeHandshakeErr
}
return nil
}
var errAlreadyWroteClose = errors.New("already wrote close")
func (c *Conn) writeClose(code StatusCode, reason string) error {
c.closeMu.Lock()
wroteClose := c.wroteClose
c.wroteClose = true
c.closeMu.Unlock()
if wroteClose {
return errAlreadyWroteClose
}
ce := CloseError{
Code: code,
Reason: reason,
}
var p []byte
var marshalErr error
if ce.Code != StatusNoStatusRcvd {
p, marshalErr = ce.bytes()
if marshalErr != nil {
log.Printf("websocket: %v", marshalErr)
}
}
writeErr := c.writeControl(context.Background(), opClose, p)
if CloseStatus(writeErr) != -1 {
// Not a real error if it's due to a close frame being received.
writeErr = nil
}
// We do this after in case there was an error writing the close frame.
c.setCloseErr(fmt.Errorf("sent close frame: %w", ce))
if marshalErr != nil {
return marshalErr
}
return writeErr
}
func (c *Conn) waitCloseHandshake() error {
defer c.close(nil)
ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
defer cancel()
err := c.readMu.lock(ctx)
if err != nil {
return err
}
defer c.readMu.unlock()
if c.readCloseFrameErr != nil {
return c.readCloseFrameErr
}
for {
h, err := c.readLoop(ctx)
if err != nil {
return err
}
for i := int64(0); i < h.payloadLength; i++ {
_, err := c.br.ReadByte()
if err != nil {
return err
}
}
}
}
func parseClosePayload(p []byte) (CloseError, error) {
if len(p) == 0 {
return CloseError{
Code: StatusNoStatusRcvd,
}, nil
}
if len(p) < 2 {
return CloseError{}, fmt.Errorf("close payload %q too small, cannot even contain the 2 byte status code", p)
}
ce := CloseError{
Code: StatusCode(binary.BigEndian.Uint16(p)),
Reason: string(p[2:]),
}
if !validWireCloseCode(ce.Code) {
return CloseError{}, fmt.Errorf("invalid status code %v", ce.Code)
}
return ce, nil
}
// See http://www.iana.org/assignments/websocket/websocket.xhtml#close-code-number
// and https://tools.ietf.org/html/rfc6455#section-7.4.1
func validWireCloseCode(code StatusCode) bool {
switch code {
case statusReserved, StatusNoStatusRcvd, StatusAbnormalClosure, StatusTLSHandshake:
return false
}
if code >= StatusNormalClosure && code <= StatusBadGateway {
return true
}
if code >= 3000 && code <= 4999 {
return true
}
return false
}
func (ce CloseError) bytes() ([]byte, error) {
p, err := ce.bytesErr()
if err != nil {
err = fmt.Errorf("failed to marshal close frame: %w", err)
ce = CloseError{
Code: StatusInternalError,
}
p, _ = ce.bytesErr()
}
return p, err
}
const maxCloseReason = maxControlPayload - 2
func (ce CloseError) bytesErr() ([]byte, error) {
if len(ce.Reason) > maxCloseReason {
return nil, fmt.Errorf("reason string max is %v but got %q with length %v", maxCloseReason, ce.Reason, len(ce.Reason))
}
if !validWireCloseCode(ce.Code) {
return nil, fmt.Errorf("status code %v cannot be set", ce.Code)
}
buf := make([]byte, 2+len(ce.Reason))
binary.BigEndian.PutUint16(buf, uint16(ce.Code))
copy(buf[2:], ce.Reason)
return buf, nil
}
func (c *Conn) setCloseErr(err error) {
c.closeMu.Lock()
c.setCloseErrLocked(err)
c.closeMu.Unlock()
}
func (c *Conn) setCloseErrLocked(err error) {
if c.closeErr == nil {
c.closeErr = fmt.Errorf("WebSocket closed: %w", err)
}
}
func (c *Conn) isClosed() bool {
select {
case <-c.closed:
return true
default:
return false
}
}