94 lines
2.9 KiB
Go
94 lines
2.9 KiB
Go
// Copyright 2014 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package p2p
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import (
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"fmt"
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"strings"
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"github.com/ethereum/go-ethereum/p2p/enode"
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"github.com/ethereum/go-ethereum/p2p/enr"
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)
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// Protocol represents a P2P subprotocol implementation.
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type Protocol struct {
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// Name should contain the official protocol name,
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// often a three-letter word.
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Name string
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// Version should contain the version number of the protocol.
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Version uint
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// Length should contain the number of message codes used
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// by the protocol.
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Length uint64
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// Run is called in a new goroutine when the protocol has been
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// negotiated with a peer. It should read and write messages from
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// rw. The Payload for each message must be fully consumed.
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//
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// The peer connection is closed when Start returns. It should return
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// any protocol-level error (such as an I/O error) that is
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// encountered.
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Run func(peer *Peer, rw MsgReadWriter) error
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// NodeInfo is an optional helper method to retrieve protocol specific metadata
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// about the host node.
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NodeInfo func() interface{}
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// PeerInfo is an optional helper method to retrieve protocol specific metadata
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// about a certain peer in the network. If an info retrieval function is set,
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// but returns nil, it is assumed that the protocol handshake is still running.
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PeerInfo func(id enode.ID) interface{}
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// DialCandidates, if non-nil, is a way to tell Server about protocol-specific nodes
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// that should be dialed. The server continuously reads nodes from the iterator and
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// attempts to create connections to them.
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DialCandidates enode.Iterator
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// Attributes contains protocol specific information for the node record.
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Attributes []enr.Entry
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}
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func (p Protocol) cap() Cap {
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return Cap{p.Name, p.Version}
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}
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// Cap is the structure of a peer capability.
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type Cap struct {
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Name string
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Version uint
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}
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func (cap Cap) String() string {
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return fmt.Sprintf("%s/%d", cap.Name, cap.Version)
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}
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// Cmp defines the canonical sorting order of capabilities.
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func (cap Cap) Cmp(other Cap) int {
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if cap.Name == other.Name {
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if cap.Version < other.Version {
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return -1
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}
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if cap.Version > other.Version {
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return 1
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}
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return 0
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}
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return strings.Compare(cap.Name, other.Name)
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}
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