Files
netbird/relay/server/handshake.go

97 lines
2.4 KiB
Go

package server
import (
"context"
"fmt"
"time"
"github.com/netbirdio/netbird/relay/server/listener"
"github.com/netbirdio/netbird/shared/relay/messages"
)
const (
// handshakeTimeout bounds how long a connection may remain in the
// pre-authentication handshake phase before being closed.
handshakeTimeout = 10 * time.Second
)
type Validator interface {
Validate(any) error
}
// preparedMsg contains the marshalled success response message
type preparedMsg struct {
responseAuthMsg []byte
}
func newPreparedMsg(instanceURL string) (*preparedMsg, error) {
ram, err := messages.MarshalAuthResponse(instanceURL)
if err != nil {
return nil, fmt.Errorf("failed to marshal auth response msg: %w", err)
}
return &preparedMsg{
responseAuthMsg: ram,
}, nil
}
type handshake struct {
conn listener.Conn
validator Validator
preparedMsg *preparedMsg
peerID *messages.PeerID
}
func (h *handshake) handshakeReceive(ctx context.Context) (*messages.PeerID, error) {
buf := make([]byte, messages.MaxHandshakeSize)
n, err := h.conn.Read(ctx, buf)
if err != nil {
return nil, fmt.Errorf("read from %s: %w", h.conn.RemoteAddr(), err)
}
buf = buf[:n]
_, err = messages.ValidateVersion(buf)
if err != nil {
return nil, fmt.Errorf("validate version from %s: %w", h.conn.RemoteAddr(), err)
}
msgType, err := messages.DetermineClientMessageType(buf)
if err != nil {
return nil, fmt.Errorf("determine message type from %s: %w", h.conn.RemoteAddr(), err)
}
if msgType != messages.MsgTypeAuth {
return nil, fmt.Errorf("invalid message type %d from %s", msgType, h.conn.RemoteAddr())
}
peerID, err := h.handleAuthMsg(buf)
if err != nil {
return peerID, err
}
h.peerID = peerID
return peerID, nil
}
func (h *handshake) handshakeResponse(ctx context.Context) error {
if _, err := h.conn.Write(ctx, h.preparedMsg.responseAuthMsg); err != nil {
return fmt.Errorf("handshake response write to %s (%s): %w", h.peerID, h.conn.RemoteAddr(), err)
}
return nil
}
func (h *handshake) handleAuthMsg(buf []byte) (*messages.PeerID, error) {
rawPeerID, authPayload, err := messages.UnmarshalAuthMsg(buf)
if err != nil {
return nil, fmt.Errorf("unmarshal auth message: %w", err)
}
if err := h.validator.Validate(authPayload); err != nil {
return rawPeerID, fmt.Errorf("validate %s (%s): %w", rawPeerID.String(), h.conn.RemoteAddr(), err)
}
return rawPeerID, nil
}