aboutsummaryrefslogtreecommitdiff
path: root/src/protocol.h
blob: fba08c6f55d8d387d8e7b9fab957a9de2411cae4 (plain)
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
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2022 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#ifndef BITCOIN_PROTOCOL_H
#define BITCOIN_PROTOCOL_H

#include <kernel/messagestartchars.h> // IWYU pragma: export
#include <netaddress.h>
#include <primitives/transaction.h>
#include <serialize.h>
#include <streams.h>
#include <uint256.h>
#include <util/time.h>

#include <array>
#include <cstdint>
#include <limits>
#include <string>

/** Message header.
 * (4) message start.
 * (12) command.
 * (4) size.
 * (4) checksum.
 */
class CMessageHeader
{
public:
    static constexpr size_t COMMAND_SIZE = 12;
    static constexpr size_t MESSAGE_SIZE_SIZE = 4;
    static constexpr size_t CHECKSUM_SIZE = 4;
    static constexpr size_t MESSAGE_SIZE_OFFSET = std::tuple_size_v<MessageStartChars> + COMMAND_SIZE;
    static constexpr size_t CHECKSUM_OFFSET = MESSAGE_SIZE_OFFSET + MESSAGE_SIZE_SIZE;
    static constexpr size_t HEADER_SIZE = std::tuple_size_v<MessageStartChars> + COMMAND_SIZE + MESSAGE_SIZE_SIZE + CHECKSUM_SIZE;

    explicit CMessageHeader() = default;

    /** Construct a P2P message header from message-start characters, a command and the size of the message.
     * @note Passing in a `pszCommand` longer than COMMAND_SIZE will result in a run-time assertion error.
     */
    CMessageHeader(const MessageStartChars& pchMessageStartIn, const char* pszCommand, unsigned int nMessageSizeIn);

    std::string GetCommand() const;
    bool IsCommandValid() const;

    SERIALIZE_METHODS(CMessageHeader, obj) { READWRITE(obj.pchMessageStart, obj.pchCommand, obj.nMessageSize, obj.pchChecksum); }

    MessageStartChars pchMessageStart{};
    char pchCommand[COMMAND_SIZE]{};
    uint32_t nMessageSize{std::numeric_limits<uint32_t>::max()};
    uint8_t pchChecksum[CHECKSUM_SIZE]{};
};

/**
 * Bitcoin protocol message types. When adding new message types, don't forget
 * to update allNetMessageTypes in protocol.cpp.
 */
namespace NetMsgType {

/**
 * The version message provides information about the transmitting node to the
 * receiving node at the beginning of a connection.
 */
extern const char* VERSION;
/**
 * The verack message acknowledges a previously-received version message,
 * informing the connecting node that it can begin to send other messages.
 */
extern const char* VERACK;
/**
 * The addr (IP address) message relays connection information for peers on the
 * network.
 */
extern const char* ADDR;
/**
 * The addrv2 message relays connection information for peers on the network just
 * like the addr message, but is extended to allow gossiping of longer node
 * addresses (see BIP155).
 */
extern const char *ADDRV2;
/**
 * The sendaddrv2 message signals support for receiving ADDRV2 messages (BIP155).
 * It also implies that its sender can encode as ADDRV2 and would send ADDRV2
 * instead of ADDR to a peer that has signaled ADDRV2 support by sending SENDADDRV2.
 */
extern const char *SENDADDRV2;
/**
 * The inv message (inventory message) transmits one or more inventories of
 * objects known to the transmitting peer.
 */
extern const char* INV;
/**
 * The getdata message requests one or more data objects from another node.
 */
extern const char* GETDATA;
/**
 * The merkleblock message is a reply to a getdata message which requested a
 * block using the inventory type MSG_MERKLEBLOCK.
 * @since protocol version 70001 as described by BIP37.
 */
extern const char* MERKLEBLOCK;
/**
 * The getblocks message requests an inv message that provides block header
 * hashes starting from a particular point in the block chain.
 */
extern const char* GETBLOCKS;
/**
 * The getheaders message requests a headers message that provides block
 * headers starting from a particular point in the block chain.
 * @since protocol version 31800.
 */
extern const char* GETHEADERS;
/**
 * The tx message transmits a single transaction.
 */
extern const char* TX;
/**
 * The headers message sends one or more block headers to a node which
 * previously requested certain headers with a getheaders message.
 * @since protocol version 31800.
 */
extern const char* HEADERS;
/**
 * The block message transmits a single serialized block.
 */
extern const char* BLOCK;
/**
 * The getaddr message requests an addr message from the receiving node,
 * preferably one with lots of IP addresses of other receiving nodes.
 */
extern const char* GETADDR;
/**
 * The mempool message requests the TXIDs of transactions that the receiving
 * node has verified as valid but which have not yet appeared in a block.
 * @since protocol version 60002 as described by BIP35.
 *   Only available with service bit NODE_BLOOM, see also BIP111.
 */
extern const char* MEMPOOL;
/**
 * The ping message is sent periodically to help confirm that the receiving
 * peer is still connected.
 */
extern const char* PING;
/**
 * The pong message replies to a ping message, proving to the pinging node that
 * the ponging node is still alive.
 * @since protocol version 60001 as described by BIP31.
 */
extern const char* PONG;
/**
 * The notfound message is a reply to a getdata message which requested an
 * object the receiving node does not have available for relay.
 * @since protocol version 70001.
 */
extern const char* NOTFOUND;
/**
 * The filterload message tells the receiving peer to filter all relayed
 * transactions and requested merkle blocks through the provided filter.
 * @since protocol version 70001 as described by BIP37.
 *   Only available with service bit NODE_BLOOM since protocol version
 *   70011 as described by BIP111.
 */
extern const char* FILTERLOAD;
/**
 * The filteradd message tells the receiving peer to add a single element to a
 * previously-set bloom filter, such as a new public key.
 * @since protocol version 70001 as described by BIP37.
 *   Only available with service bit NODE_BLOOM since protocol version
 *   70011 as described by BIP111.
 */
extern const char* FILTERADD;
/**
 * The filterclear message tells the receiving peer to remove a previously-set
 * bloom filter.
 * @since protocol version 70001 as described by BIP37.
 *   Only available with service bit NODE_BLOOM since protocol version
 *   70011 as described by BIP111.
 */
extern const char* FILTERCLEAR;
/**
 * Indicates that a node prefers to receive new block announcements via a
 * "headers" message rather than an "inv".
 * @since protocol version 70012 as described by BIP130.
 */
extern const char* SENDHEADERS;
/**
 * The feefilter message tells the receiving peer not to inv us any txs
 * which do not meet the specified min fee rate.
 * @since protocol version 70013 as described by BIP133
 */
extern const char* FEEFILTER;
/**
 * Contains a 1-byte bool and 8-byte LE version number.
 * Indicates that a node is willing to provide blocks via "cmpctblock" messages.
 * May indicate that a node prefers to receive new block announcements via a
 * "cmpctblock" message rather than an "inv", depending on message contents.
 * @since protocol version 70014 as described by BIP 152
 */
extern const char* SENDCMPCT;
/**
 * Contains a CBlockHeaderAndShortTxIDs object - providing a header and
 * list of "short txids".
 * @since protocol version 70014 as described by BIP 152
 */
extern const char* CMPCTBLOCK;
/**
 * Contains a BlockTransactionsRequest
 * Peer should respond with "blocktxn" message.
 * @since protocol version 70014 as described by BIP 152
 */
extern const char* GETBLOCKTXN;
/**
 * Contains a BlockTransactions.
 * Sent in response to a "getblocktxn" message.
 * @since protocol version 70014 as described by BIP 152
 */
extern const char* BLOCKTXN;
/**
 * getcfilters requests compact filters for a range of blocks.
 * Only available with service bit NODE_COMPACT_FILTERS as described by
 * BIP 157 & 158.
 */
extern const char* GETCFILTERS;
/**
 * cfilter is a response to a getcfilters request containing a single compact
 * filter.
 */
extern const char* CFILTER;
/**
 * getcfheaders requests a compact filter header and the filter hashes for a
 * range of blocks, which can then be used to reconstruct the filter headers
 * for those blocks.
 * Only available with service bit NODE_COMPACT_FILTERS as described by
 * BIP 157 & 158.
 */
extern const char* GETCFHEADERS;
/**
 * cfheaders is a response to a getcfheaders request containing a filter header
 * and a vector of filter hashes for each subsequent block in the requested range.
 */
extern const char* CFHEADERS;
/**
 * getcfcheckpt requests evenly spaced compact filter headers, enabling
 * parallelized download and validation of the headers between them.
 * Only available with service bit NODE_COMPACT_FILTERS as described by
 * BIP 157 & 158.
 */
extern const char* GETCFCHECKPT;
/**
 * cfcheckpt is a response to a getcfcheckpt request containing a vector of
 * evenly spaced filter headers for blocks on the requested chain.
 */
extern const char* CFCHECKPT;
/**
 * Indicates that a node prefers to relay transactions via wtxid, rather than
 * txid.
 * @since protocol version 70016 as described by BIP 339.
 */
extern const char* WTXIDRELAY;
/**
 * Contains a 4-byte version number and an 8-byte salt.
 * The salt is used to compute short txids needed for efficient
 * txreconciliation, as described by BIP 330.
 */
extern const char* SENDTXRCNCL;
}; // namespace NetMsgType

/* Get a vector of all valid message types (see above) */
const std::vector<std::string>& getAllNetMessageTypes();

/** nServices flags */
enum ServiceFlags : uint64_t {
    // NOTE: When adding here, be sure to update serviceFlagToStr too
    // Nothing
    NODE_NONE = 0,
    // NODE_NETWORK means that the node is capable of serving the complete block chain. It is currently
    // set by all Bitcoin Core non pruned nodes, and is unset by SPV clients or other light clients.
    NODE_NETWORK = (1 << 0),
    // NODE_BLOOM means the node is capable and willing to handle bloom-filtered connections.
    NODE_BLOOM = (1 << 2),
    // NODE_WITNESS indicates that a node can be asked for blocks and transactions including
    // witness data.
    NODE_WITNESS = (1 << 3),
    // NODE_COMPACT_FILTERS means the node will service basic block filter requests.
    // See BIP157 and BIP158 for details on how this is implemented.
    NODE_COMPACT_FILTERS = (1 << 6),
    // NODE_NETWORK_LIMITED means the same as NODE_NETWORK with the limitation of only
    // serving the last 288 (2 day) blocks
    // See BIP159 for details on how this is implemented.
    NODE_NETWORK_LIMITED = (1 << 10),

    // NODE_P2P_V2 means the node supports BIP324 transport
    NODE_P2P_V2 = (1 << 11),

    // Bits 24-31 are reserved for temporary experiments. Just pick a bit that
    // isn't getting used, or one not being used much, and notify the
    // bitcoin-development mailing list. Remember that service bits are just
    // unauthenticated advertisements, so your code must be robust against
    // collisions and other cases where nodes may be advertising a service they
    // do not actually support. Other service bits should be allocated via the
    // BIP process.
};

/**
 * Convert service flags (a bitmask of NODE_*) to human readable strings.
 * It supports unknown service flags which will be returned as "UNKNOWN[...]".
 * @param[in] flags multiple NODE_* bitwise-OR-ed together
 */
std::vector<std::string> serviceFlagsToStr(uint64_t flags);

/**
 * State independent service flags.
 * If the return value is changed, contrib/seeds/makeseeds.py
 * should be updated appropriately to filter for nodes with
 * desired service flags (compatible with our new flags).
 */
constexpr ServiceFlags SeedsServiceFlags() { return ServiceFlags(NODE_NETWORK | NODE_WITNESS); }

/**
 * Checks if a peer with the given service flags may be capable of having a
 * robust address-storage DB.
 */
static inline bool MayHaveUsefulAddressDB(ServiceFlags services)
{
    return (services & NODE_NETWORK) || (services & NODE_NETWORK_LIMITED);
}

/** A CService with information about it as peer */
class CAddress : public CService
{
    static constexpr std::chrono::seconds TIME_INIT{100000000};

    /** Historically, CAddress disk serialization stored the CLIENT_VERSION, optionally OR'ed with
     *  the ADDRV2_FORMAT flag to indicate V2 serialization. The first field has since been
     *  disentangled from client versioning, and now instead:
     *  - The low bits (masked by DISK_VERSION_IGNORE_MASK) store the fixed value DISK_VERSION_INIT,
     *    (in case any code exists that treats it as a client version) but are ignored on
     *    deserialization.
     *  - The high bits (masked by ~DISK_VERSION_IGNORE_MASK) store actual serialization information.
     *    Only 0 or DISK_VERSION_ADDRV2 (equal to the historical ADDRV2_FORMAT) are valid now, and
     *    any other value triggers a deserialization failure. Other values can be added later if
     *    needed.
     *
     *  For disk deserialization, ADDRV2_FORMAT in the stream version signals that ADDRV2
     *  deserialization is permitted, but the actual format is determined by the high bits in the
     *  stored version field. For network serialization, the stream version having ADDRV2_FORMAT or
     *  not determines the actual format used (as it has no embedded version number).
     */
    static constexpr uint32_t DISK_VERSION_INIT{220000};
    static constexpr uint32_t DISK_VERSION_IGNORE_MASK{0b00000000'00000111'11111111'11111111};
    /** The version number written in disk serialized addresses to indicate V2 serializations.
     * It must be exactly 1<<29, as that is the value that historical versions used for this
     * (they used their internal ADDRV2_FORMAT flag here). */
    static constexpr uint32_t DISK_VERSION_ADDRV2{1 << 29};
    static_assert((DISK_VERSION_INIT & ~DISK_VERSION_IGNORE_MASK) == 0, "DISK_VERSION_INIT must be covered by DISK_VERSION_IGNORE_MASK");
    static_assert((DISK_VERSION_ADDRV2 & DISK_VERSION_IGNORE_MASK) == 0, "DISK_VERSION_ADDRV2 must not be covered by DISK_VERSION_IGNORE_MASK");

public:
    CAddress() : CService{} {};
    CAddress(CService ipIn, ServiceFlags nServicesIn) : CService{ipIn}, nServices{nServicesIn} {};
    CAddress(CService ipIn, ServiceFlags nServicesIn, NodeSeconds time) : CService{ipIn}, nTime{time}, nServices{nServicesIn} {};

    enum class Format {
        Disk,
        Network,
    };
    struct SerParams : CNetAddr::SerParams {
        const Format fmt;
        SER_PARAMS_OPFUNC
    };
    static constexpr SerParams V1_NETWORK{{CNetAddr::Encoding::V1}, Format::Network};
    static constexpr SerParams V2_NETWORK{{CNetAddr::Encoding::V2}, Format::Network};
    static constexpr SerParams V1_DISK{{CNetAddr::Encoding::V1}, Format::Disk};
    static constexpr SerParams V2_DISK{{CNetAddr::Encoding::V2}, Format::Disk};

    SERIALIZE_METHODS(CAddress, obj)
    {
        bool use_v2;
        auto& params = SER_PARAMS(SerParams);
        if (params.fmt == Format::Disk) {
            // In the disk serialization format, the encoding (v1 or v2) is determined by a flag version
            // that's part of the serialization itself. ADDRV2_FORMAT in the stream version only determines
            // whether V2 is chosen/permitted at all.
            uint32_t stored_format_version = DISK_VERSION_INIT;
            if (params.enc == Encoding::V2) stored_format_version |= DISK_VERSION_ADDRV2;
            READWRITE(stored_format_version);
            stored_format_version &= ~DISK_VERSION_IGNORE_MASK; // ignore low bits
            if (stored_format_version == 0) {
                use_v2 = false;
            } else if (stored_format_version == DISK_VERSION_ADDRV2 && params.enc == Encoding::V2) {
                // Only support v2 deserialization if V2 is set.
                use_v2 = true;
            } else {
                throw std::ios_base::failure("Unsupported CAddress disk format version");
            }
        } else {
            assert(params.fmt == Format::Network);
            // In the network serialization format, the encoding (v1 or v2) is determined directly by
            // the value of enc in the stream params, as no explicitly encoded version
            // exists in the stream.
            use_v2 = params.enc == Encoding::V2;
        }

        READWRITE(Using<LossyChronoFormatter<uint32_t>>(obj.nTime));
        // nServices is serialized as CompactSize in V2; as uint64_t in V1.
        if (use_v2) {
            uint64_t services_tmp;
            SER_WRITE(obj, services_tmp = obj.nServices);
            READWRITE(Using<CompactSizeFormatter<false>>(services_tmp));
            SER_READ(obj, obj.nServices = static_cast<ServiceFlags>(services_tmp));
        } else {
            READWRITE(Using<CustomUintFormatter<8>>(obj.nServices));
        }
        // Invoke V1/V2 serializer for CService parent object.
        const auto ser_params{use_v2 ? CNetAddr::V2 : CNetAddr::V1};
        READWRITE(ser_params(AsBase<CService>(obj)));
    }

    //! Always included in serialization. The behavior is unspecified if the value is not representable as uint32_t.
    NodeSeconds nTime{TIME_INIT};
    //! Serialized as uint64_t in V1, and as CompactSize in V2.
    ServiceFlags nServices{NODE_NONE};

    friend bool operator==(const CAddress& a, const CAddress& b)
    {
        return a.nTime == b.nTime &&
               a.nServices == b.nServices &&
               static_cast<const CService&>(a) == static_cast<const CService&>(b);
    }
};

/** getdata message type flags */
const uint32_t MSG_WITNESS_FLAG = 1 << 30;
const uint32_t MSG_TYPE_MASK = 0xffffffff >> 2;

/** getdata / inv message types.
 * These numbers are defined by the protocol. When adding a new value, be sure
 * to mention it in the respective BIP.
 */
enum GetDataMsg : uint32_t {
    UNDEFINED = 0,
    MSG_TX = 1,
    MSG_BLOCK = 2,
    MSG_WTX = 5,                                      //!< Defined in BIP 339
    // The following can only occur in getdata. Invs always use TX/WTX or BLOCK.
    MSG_FILTERED_BLOCK = 3,                           //!< Defined in BIP37
    MSG_CMPCT_BLOCK = 4,                              //!< Defined in BIP152
    MSG_WITNESS_BLOCK = MSG_BLOCK | MSG_WITNESS_FLAG, //!< Defined in BIP144
    MSG_WITNESS_TX = MSG_TX | MSG_WITNESS_FLAG,       //!< Defined in BIP144
    // MSG_FILTERED_WITNESS_BLOCK is defined in BIP144 as reserved for future
    // use and remains unused.
    // MSG_FILTERED_WITNESS_BLOCK = MSG_FILTERED_BLOCK | MSG_WITNESS_FLAG,
};

/** inv message data */
class CInv
{
public:
    CInv();
    CInv(uint32_t typeIn, const uint256& hashIn);

    SERIALIZE_METHODS(CInv, obj) { READWRITE(obj.type, obj.hash); }

    friend bool operator<(const CInv& a, const CInv& b);

    std::string GetCommand() const;
    std::string ToString() const;

    // Single-message helper methods
    bool IsMsgTx() const { return type == MSG_TX; }
    bool IsMsgBlk() const { return type == MSG_BLOCK; }
    bool IsMsgWtx() const { return type == MSG_WTX; }
    bool IsMsgFilteredBlk() const { return type == MSG_FILTERED_BLOCK; }
    bool IsMsgCmpctBlk() const { return type == MSG_CMPCT_BLOCK; }
    bool IsMsgWitnessBlk() const { return type == MSG_WITNESS_BLOCK; }

    // Combined-message helper methods
    bool IsGenTxMsg() const
    {
        return type == MSG_TX || type == MSG_WTX || type == MSG_WITNESS_TX;
    }
    bool IsGenBlkMsg() const
    {
        return type == MSG_BLOCK || type == MSG_FILTERED_BLOCK || type == MSG_CMPCT_BLOCK || type == MSG_WITNESS_BLOCK;
    }

    uint32_t type;
    uint256 hash;
};

/** Convert a TX/WITNESS_TX/WTX CInv to a GenTxid. */
GenTxid ToGenTxid(const CInv& inv);

#endif // BITCOIN_PROTOCOL_H