path: root/p2p/peer_error.go

// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package p2p

import (
    "errors"
    "fmt"
)

const (
    errInvalidMsgCode = iota
    errInvalidMsg
)

var errorToString = map[int]string{
    errInvalidMsgCode: "invalid message code",
    errInvalidMsg:     "invalid message",
}

type peerError struct {
    code    int
    message string
}

func newPeerError(code int, format string, v ...interface{}) *peerError {
    desc, ok := errorToString[code]
    if !ok {
        panic("invalid error code")
    }
    err := &peerError{code, desc}
    if format != "" {
        err.message += ": " + fmt.Sprintf(format, v...)
    }
    return err
}

func (self *peerError) Error() string {
    return self.message
}

var errProtocolReturned = errors.New("protocol returned")

type DiscReason uint

const (
    DiscRequested DiscReason = iota
    DiscNetworkError
    DiscProtocolError
    DiscUselessPeer
    DiscTooManyPeers
    DiscAlreadyConnected
    DiscIncompatibleVersion
    DiscInvalidIdentity
    DiscQuitting
    DiscUnexpectedIdentity
    DiscSelf
    DiscReadTimeout
    DiscSubprotocolError = 0x10
)

var discReasonToString = [...]string{
    DiscRequested:           "disconnect requested",
    DiscNetworkError:        "network error",
    DiscProtocolError:       "breach of protocol",
    DiscUselessPeer:         "useless peer",
    DiscTooManyPeers:        "too many peers",
    DiscAlreadyConnected:    "already connected",
    DiscIncompatibleVersion: "incompatible p2p protocol version",
    DiscInvalidIdentity:     "invalid node identity",
    DiscQuitting:            "client quitting",
    DiscUnexpectedIdentity:  "unexpected identity",
    DiscSelf:                "connected to self",
    DiscReadTimeout:         "read timeout",
    DiscSubprotocolError:    "subprotocol error",
}

func (d DiscReason) String() string {
    if len(discReasonToString) < int(d) {
        return fmt.Sprintf("unknown disconnect reason %d", d)
    }
    return discReasonToString[d]
}

func (d DiscReason) Error() string {
    return d.String()
}

func discReasonForError(err error) DiscReason {
    if reason, ok := err.(DiscReason); ok {
        return reason
    }
    if err == errProtocolReturned {
        return DiscQuitting
    }
    peerError, ok := err.(*peerError)
    if ok {
        switch peerError.code {
        case errInvalidMsgCode, errInvalidMsg:
            return DiscProtocolError
        default:
            return DiscSubprotocolError
        }
    }
    return DiscSubprotocolError
}