github.com/oskarth/go-ethereum@v1.6.8-0.20191013093314-dac24a9d3494/les/protocol.go (about) 1 // Copyright 2016 The go-ethereum Authors 2 // This file is part of the go-ethereum library. 3 // 4 // The go-ethereum library is free software: you can redistribute it and/or modify 5 // it under the terms of the GNU Lesser General Public License as published by 6 // the Free Software Foundation, either version 3 of the License, or 7 // (at your option) any later version. 8 // 9 // The go-ethereum library is distributed in the hope that it will be useful, 10 // but WITHOUT ANY WARRANTY; without even the implied warranty of 11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 // GNU Lesser General Public License for more details. 13 // 14 // You should have received a copy of the GNU Lesser General Public License 15 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. 16 17 // Package les implements the Light Ethereum Subprotocol. 18 package les 19 20 import ( 21 "crypto/ecdsa" 22 "errors" 23 "fmt" 24 "io" 25 "math/big" 26 27 "github.com/ethereum/go-ethereum/common" 28 "github.com/ethereum/go-ethereum/core" 29 "github.com/ethereum/go-ethereum/core/rawdb" 30 "github.com/ethereum/go-ethereum/crypto" 31 "github.com/ethereum/go-ethereum/p2p/enode" 32 "github.com/ethereum/go-ethereum/rlp" 33 ) 34 35 // Constants to match up protocol versions and messages 36 const ( 37 lpv1 = 1 38 lpv2 = 2 39 ) 40 41 // Supported versions of the les protocol (first is primary) 42 var ( 43 ClientProtocolVersions = []uint{lpv2, lpv1} 44 ServerProtocolVersions = []uint{lpv2, lpv1} 45 AdvertiseProtocolVersions = []uint{lpv2} // clients are searching for the first advertised protocol in the list 46 ) 47 48 // Number of implemented message corresponding to different protocol versions. 49 var ProtocolLengths = map[uint]uint64{lpv1: 15, lpv2: 22} 50 51 const ( 52 NetworkId = 1 53 ProtocolMaxMsgSize = 10 * 1024 * 1024 // Maximum cap on the size of a protocol message 54 ) 55 56 // les protocol message codes 57 const ( 58 // Protocol messages belonging to LPV1 59 StatusMsg = 0x00 60 AnnounceMsg = 0x01 61 GetBlockHeadersMsg = 0x02 62 BlockHeadersMsg = 0x03 63 GetBlockBodiesMsg = 0x04 64 BlockBodiesMsg = 0x05 65 GetReceiptsMsg = 0x06 66 ReceiptsMsg = 0x07 67 GetProofsV1Msg = 0x08 68 ProofsV1Msg = 0x09 69 GetCodeMsg = 0x0a 70 CodeMsg = 0x0b 71 SendTxMsg = 0x0c 72 GetHeaderProofsMsg = 0x0d 73 HeaderProofsMsg = 0x0e 74 // Protocol messages belonging to LPV2 75 GetProofsV2Msg = 0x0f 76 ProofsV2Msg = 0x10 77 GetHelperTrieProofsMsg = 0x11 78 HelperTrieProofsMsg = 0x12 79 SendTxV2Msg = 0x13 80 GetTxStatusMsg = 0x14 81 TxStatusMsg = 0x15 82 ) 83 84 type errCode int 85 86 const ( 87 ErrMsgTooLarge = iota 88 ErrDecode 89 ErrInvalidMsgCode 90 ErrProtocolVersionMismatch 91 ErrNetworkIdMismatch 92 ErrGenesisBlockMismatch 93 ErrNoStatusMsg 94 ErrExtraStatusMsg 95 ErrSuspendedPeer 96 ErrUselessPeer 97 ErrRequestRejected 98 ErrUnexpectedResponse 99 ErrInvalidResponse 100 ErrTooManyTimeouts 101 ErrMissingKey 102 ) 103 104 func (e errCode) String() string { 105 return errorToString[int(e)] 106 } 107 108 // XXX change once legacy code is out 109 var errorToString = map[int]string{ 110 ErrMsgTooLarge: "Message too long", 111 ErrDecode: "Invalid message", 112 ErrInvalidMsgCode: "Invalid message code", 113 ErrProtocolVersionMismatch: "Protocol version mismatch", 114 ErrNetworkIdMismatch: "NetworkId mismatch", 115 ErrGenesisBlockMismatch: "Genesis block mismatch", 116 ErrNoStatusMsg: "No status message", 117 ErrExtraStatusMsg: "Extra status message", 118 ErrSuspendedPeer: "Suspended peer", 119 ErrRequestRejected: "Request rejected", 120 ErrUnexpectedResponse: "Unexpected response", 121 ErrInvalidResponse: "Invalid response", 122 ErrTooManyTimeouts: "Too many request timeouts", 123 ErrMissingKey: "Key missing from list", 124 } 125 126 type announceBlock struct { 127 Hash common.Hash // Hash of one particular block being announced 128 Number uint64 // Number of one particular block being announced 129 Td *big.Int // Total difficulty of one particular block being announced 130 } 131 132 // announceData is the network packet for the block announcements. 133 type announceData struct { 134 Hash common.Hash // Hash of one particular block being announced 135 Number uint64 // Number of one particular block being announced 136 Td *big.Int // Total difficulty of one particular block being announced 137 ReorgDepth uint64 138 Update keyValueList 139 } 140 141 // sign adds a signature to the block announcement by the given privKey 142 func (a *announceData) sign(privKey *ecdsa.PrivateKey) { 143 rlp, _ := rlp.EncodeToBytes(announceBlock{a.Hash, a.Number, a.Td}) 144 sig, _ := crypto.Sign(crypto.Keccak256(rlp), privKey) 145 a.Update = a.Update.add("sign", sig) 146 } 147 148 // checkSignature verifies if the block announcement has a valid signature by the given pubKey 149 func (a *announceData) checkSignature(id enode.ID) error { 150 var sig []byte 151 if err := a.Update.decode().get("sign", &sig); err != nil { 152 return err 153 } 154 rlp, _ := rlp.EncodeToBytes(announceBlock{a.Hash, a.Number, a.Td}) 155 recPubkey, err := crypto.SigToPub(crypto.Keccak256(rlp), sig) 156 if err != nil { 157 return err 158 } 159 if id == enode.PubkeyToIDV4(recPubkey) { 160 return nil 161 } 162 return errors.New("wrong signature") 163 } 164 165 type blockInfo struct { 166 Hash common.Hash // Hash of one particular block being announced 167 Number uint64 // Number of one particular block being announced 168 Td *big.Int // Total difficulty of one particular block being announced 169 } 170 171 // getBlockHeadersData represents a block header query. 172 type getBlockHeadersData struct { 173 Origin hashOrNumber // Block from which to retrieve headers 174 Amount uint64 // Maximum number of headers to retrieve 175 Skip uint64 // Blocks to skip between consecutive headers 176 Reverse bool // Query direction (false = rising towards latest, true = falling towards genesis) 177 } 178 179 // hashOrNumber is a combined field for specifying an origin block. 180 type hashOrNumber struct { 181 Hash common.Hash // Block hash from which to retrieve headers (excludes Number) 182 Number uint64 // Block hash from which to retrieve headers (excludes Hash) 183 } 184 185 // EncodeRLP is a specialized encoder for hashOrNumber to encode only one of the 186 // two contained union fields. 187 func (hn *hashOrNumber) EncodeRLP(w io.Writer) error { 188 if hn.Hash == (common.Hash{}) { 189 return rlp.Encode(w, hn.Number) 190 } 191 if hn.Number != 0 { 192 return fmt.Errorf("both origin hash (%x) and number (%d) provided", hn.Hash, hn.Number) 193 } 194 return rlp.Encode(w, hn.Hash) 195 } 196 197 // DecodeRLP is a specialized decoder for hashOrNumber to decode the contents 198 // into either a block hash or a block number. 199 func (hn *hashOrNumber) DecodeRLP(s *rlp.Stream) error { 200 _, size, _ := s.Kind() 201 origin, err := s.Raw() 202 if err == nil { 203 switch { 204 case size == 32: 205 err = rlp.DecodeBytes(origin, &hn.Hash) 206 case size <= 8: 207 err = rlp.DecodeBytes(origin, &hn.Number) 208 default: 209 err = fmt.Errorf("invalid input size %d for origin", size) 210 } 211 } 212 return err 213 } 214 215 // CodeData is the network response packet for a node data retrieval. 216 type CodeData []struct { 217 Value []byte 218 } 219 220 type proofsData [][]rlp.RawValue 221 222 type txStatus struct { 223 Status core.TxStatus 224 Lookup *rawdb.TxLookupEntry `rlp:"nil"` 225 Error string 226 }