aboutsummaryrefslogtreecommitdiffstats
path: root/eth/peer.go
blob: db7fea7a734f7d465248aebf954ad0f73f0771d5 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
package eth

import (
    "fmt"
    "math/big"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/core/types"
    "github.com/ethereum/go-ethereum/p2p"
    "gopkg.in/fatih/set.v0"
)

type statusMsgData struct {
    ProtocolVersion uint32
    NetworkId       uint32
    TD              *big.Int
    CurrentBlock    common.Hash
    GenesisBlock    common.Hash
}

type getBlockHashesMsgData struct {
    Hash   common.Hash
    Amount uint64
}

type peer struct {
    *p2p.Peer

    rw p2p.MsgReadWriter

    protv, netid int

    currentHash common.Hash
    id          string
    td          *big.Int

    genesis, ourHash common.Hash
    ourTd            *big.Int

    txHashes    *set.Set
    blockHashes *set.Set
}

func newPeer(protv, netid int, genesis, currentHash common.Hash, td *big.Int, p *p2p.Peer, rw p2p.MsgReadWriter) *peer {
    id := p.ID()

    return &peer{
        Peer:        p,
        rw:          rw,
        genesis:     genesis,
        ourHash:     currentHash,
        ourTd:       td,
        protv:       protv,
        netid:       netid,
        id:          fmt.Sprintf("%x", id[:8]),
        txHashes:    set.New(),
        blockHashes: set.New(),
    }
}

// sendTransactions sends transactions to the peer and includes the hashes
// in it's tx hash set for future reference. The tx hash will allow the
// manager to check whether the peer has already received this particular
// transaction
func (p *peer) sendTransactions(txs types.Transactions) error {
    for _, tx := range txs {
        p.txHashes.Add(tx.Hash())
    }

    return p2p.Send(p.rw, TxMsg, txs)
}

func (p *peer) sendBlockHashes(hashes []common.Hash) error {
    return p2p.Send(p.rw, BlockHashesMsg, hashes)
}

func (p *peer) sendBlocks(blocks []*types.Block) error {
    return p2p.Send(p.rw, BlocksMsg, blocks)
}

func (p *peer) requestHashes(from common.Hash) error {
    p.Debugf("fetching hashes (%d) %x...\n", maxHashes, from[0:4])
    return p2p.Send(p.rw, GetBlockHashesMsg, getBlockHashesMsgData{from, maxHashes})
}

func (p *peer) requestBlocks(hashes []common.Hash) error {
    p.Debugf("fetching %v blocks", len(hashes))
    return p2p.Send(p.rw, GetBlocksMsg, hashes)
}

func (p *peer) handleStatus() error {
    errc := make(chan error, 1)
    go func() {
        errc <- p2p.Send(p.rw, StatusMsg, &statusMsgData{
            ProtocolVersion: uint32(p.protv),
            NetworkId:       uint32(p.netid),
            TD:              p.ourTd,
            CurrentBlock:    p.ourHash,
            GenesisBlock:    p.genesis,
        })
    }()

    // read and handle remote status
    msg, err := p.rw.ReadMsg()
    if err != nil {
        return err
    }
    if msg.Code != StatusMsg {
        return errResp(ErrNoStatusMsg, "first msg has code %x (!= %x)", msg.Code, StatusMsg)
    }
    if msg.Size > ProtocolMaxMsgSize {
        return errResp(ErrMsgTooLarge, "%v > %v", msg.Size, ProtocolMaxMsgSize)
    }

    var status statusMsgData
    if err := msg.Decode(&status); err != nil {
        return errResp(ErrDecode, "msg %v: %v", msg, err)
    }

    if status.GenesisBlock != p.genesis {
        return errResp(ErrGenesisBlockMismatch, "%x (!= %x)", status.GenesisBlock, p.genesis)
    }

    if int(status.NetworkId) != p.netid {
        return errResp(ErrNetworkIdMismatch, "%d (!= %d)", status.NetworkId, p.netid)
    }

    if int(status.ProtocolVersion) != p.protv {
        return errResp(ErrProtocolVersionMismatch, "%d (!= %d)", status.ProtocolVersion, p.protv)
    }
    // Set the total difficulty of the peer
    p.td = status.TD
    // set the best hash of the peer
    p.currentHash = status.CurrentBlock

    return <-errc
}