dnscrypt-proxy/vendor/github.com/quic-go/quic-go/internal/wire/connection_close_frame.go

79 lines
2.2 KiB
Go

package wire
import (
"bytes"
"io"
"github.com/quic-go/quic-go/internal/protocol"
"github.com/quic-go/quic-go/quicvarint"
)
// A ConnectionCloseFrame is a CONNECTION_CLOSE frame
type ConnectionCloseFrame struct {
IsApplicationError bool
ErrorCode uint64
FrameType uint64
ReasonPhrase string
}
func parseConnectionCloseFrame(r *bytes.Reader, typ uint64, _ protocol.Version) (*ConnectionCloseFrame, error) {
f := &ConnectionCloseFrame{IsApplicationError: typ == applicationCloseFrameType}
ec, err := quicvarint.Read(r)
if err != nil {
return nil, err
}
f.ErrorCode = ec
// read the Frame Type, if this is not an application error
if !f.IsApplicationError {
ft, err := quicvarint.Read(r)
if err != nil {
return nil, err
}
f.FrameType = ft
}
var reasonPhraseLen uint64
reasonPhraseLen, err = quicvarint.Read(r)
if err != nil {
return nil, err
}
// shortcut to prevent the unnecessary allocation of dataLen bytes
// if the dataLen is larger than the remaining length of the packet
// reading the whole reason phrase would result in EOF when attempting to READ
if int(reasonPhraseLen) > r.Len() {
return nil, io.EOF
}
reasonPhrase := make([]byte, reasonPhraseLen)
if _, err := io.ReadFull(r, reasonPhrase); err != nil {
// this should never happen, since we already checked the reasonPhraseLen earlier
return nil, err
}
f.ReasonPhrase = string(reasonPhrase)
return f, nil
}
// Length of a written frame
func (f *ConnectionCloseFrame) Length(protocol.Version) protocol.ByteCount {
length := 1 + quicvarint.Len(f.ErrorCode) + quicvarint.Len(uint64(len(f.ReasonPhrase))) + protocol.ByteCount(len(f.ReasonPhrase))
if !f.IsApplicationError {
length += quicvarint.Len(f.FrameType) // for the frame type
}
return length
}
func (f *ConnectionCloseFrame) Append(b []byte, _ protocol.Version) ([]byte, error) {
if f.IsApplicationError {
b = append(b, applicationCloseFrameType)
} else {
b = append(b, connectionCloseFrameType)
}
b = quicvarint.Append(b, f.ErrorCode)
if !f.IsApplicationError {
b = quicvarint.Append(b, f.FrameType)
}
b = quicvarint.Append(b, uint64(len(f.ReasonPhrase)))
b = append(b, []byte(f.ReasonPhrase)...)
return b, nil
}