aboutsummaryrefslogtreecommitdiff
path: root/src/netaddress.h
blob: b9beb1e3585d41f82ff034a1e10b8e851815f3ab (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
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
// Copyright (c) 2009-2020 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_NETADDRESS_H
#define BITCOIN_NETADDRESS_H

#if defined(HAVE_CONFIG_H)
#include <config/bitcoin-config.h>
#endif

#include <attributes.h>
#include <compat.h>
#include <prevector.h>
#include <serialize.h>
#include <tinyformat.h>
#include <util/strencodings.h>
#include <util/string.h>

#include <array>
#include <cstdint>
#include <ios>
#include <string>
#include <vector>

/**
 * A flag that is ORed into the protocol version to designate that addresses
 * should be serialized in (unserialized from) v2 format (BIP155).
 * Make sure that this does not collide with any of the values in `version.h`
 * or with `SERIALIZE_TRANSACTION_NO_WITNESS`.
 */
static constexpr int ADDRV2_FORMAT = 0x20000000;

/**
 * A network type.
 * @note An address may belong to more than one network, for example `10.0.0.1`
 * belongs to both `NET_UNROUTABLE` and `NET_IPV4`.
 * Keep these sequential starting from 0 and `NET_MAX` as the last entry.
 * We have loops like `for (int i = 0; i < NET_MAX; i++)` that expect to iterate
 * over all enum values and also `GetExtNetwork()` "extends" this enum by
 * introducing standalone constants starting from `NET_MAX`.
 */
enum Network
{
    /// Addresses from these networks are not publicly routable on the global Internet.
    NET_UNROUTABLE = 0,

    /// IPv4
    NET_IPV4,

    /// IPv6
    NET_IPV6,

    /// TOR (v2 or v3)
    NET_ONION,

    /// I2P
    NET_I2P,

    /// CJDNS
    NET_CJDNS,

    /// A set of addresses that represent the hash of a string or FQDN. We use
    /// them in CAddrMan to keep track of which DNS seeds were used.
    NET_INTERNAL,

    /// Dummy value to indicate the number of NET_* constants.
    NET_MAX,
};

/// Prefix of an IPv6 address when it contains an embedded IPv4 address.
/// Used when (un)serializing addresses in ADDRv1 format (pre-BIP155).
static const std::array<uint8_t, 12> IPV4_IN_IPV6_PREFIX{
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF
};

/// Prefix of an IPv6 address when it contains an embedded TORv2 address.
/// Used when (un)serializing addresses in ADDRv1 format (pre-BIP155).
/// Such dummy IPv6 addresses are guaranteed to not be publicly routable as they
/// fall under RFC4193's fc00::/7 subnet allocated to unique-local addresses.
static const std::array<uint8_t, 6> TORV2_IN_IPV6_PREFIX{
    0xFD, 0x87, 0xD8, 0x7E, 0xEB, 0x43
};

/// Prefix of an IPv6 address when it contains an embedded "internal" address.
/// Used when (un)serializing addresses in ADDRv1 format (pre-BIP155).
/// The prefix comes from 0xFD + SHA256("bitcoin")[0:5].
/// Such dummy IPv6 addresses are guaranteed to not be publicly routable as they
/// fall under RFC4193's fc00::/7 subnet allocated to unique-local addresses.
static const std::array<uint8_t, 6> INTERNAL_IN_IPV6_PREFIX{
    0xFD, 0x6B, 0x88, 0xC0, 0x87, 0x24 // 0xFD + sha256("bitcoin")[0:5].
};

/// Size of IPv4 address (in bytes).
static constexpr size_t ADDR_IPV4_SIZE = 4;

/// Size of IPv6 address (in bytes).
static constexpr size_t ADDR_IPV6_SIZE = 16;

/// Size of TORv2 address (in bytes).
static constexpr size_t ADDR_TORV2_SIZE = 10;

/// Size of TORv3 address (in bytes). This is the length of just the address
/// as used in BIP155, without the checksum and the version byte.
static constexpr size_t ADDR_TORV3_SIZE = 32;

/// Size of I2P address (in bytes).
static constexpr size_t ADDR_I2P_SIZE = 32;

/// Size of CJDNS address (in bytes).
static constexpr size_t ADDR_CJDNS_SIZE = 16;

/// Size of "internal" (NET_INTERNAL) address (in bytes).
static constexpr size_t ADDR_INTERNAL_SIZE = 10;

/**
 * Network address.
 */
class CNetAddr
{
    protected:
        /**
         * Raw representation of the network address.
         * In network byte order (big endian) for IPv4 and IPv6.
         */
        prevector<ADDR_IPV6_SIZE, uint8_t> m_addr{ADDR_IPV6_SIZE, 0x0};

        /**
         * Network to which this address belongs.
         */
        Network m_net{NET_IPV6};

        /**
         * Scope id if scoped/link-local IPV6 address.
         * See https://tools.ietf.org/html/rfc4007
         */
        uint32_t m_scope_id{0};

    public:
        CNetAddr();
        explicit CNetAddr(const struct in_addr& ipv4Addr);
        void SetIP(const CNetAddr& ip);

        /**
         * Set from a legacy IPv6 address.
         * Legacy IPv6 address may be a normal IPv6 address, or another address
         * (e.g. IPv4) disguised as IPv6. This encoding is used in the legacy
         * `addr` encoding.
         */
        void SetLegacyIPv6(Span<const uint8_t> ipv6);

        bool SetInternal(const std::string& name);

        bool SetSpecial(const std::string &strName); // for Tor addresses
        bool IsBindAny() const; // INADDR_ANY equivalent
        bool IsIPv4() const;    // IPv4 mapped address (::FFFF:0:0/96, 0.0.0.0/0)
        bool IsIPv6() const;    // IPv6 address (not mapped IPv4, not Tor)
        bool IsRFC1918() const; // IPv4 private networks (10.0.0.0/8, 192.168.0.0/16, 172.16.0.0/12)
        bool IsRFC2544() const; // IPv4 inter-network communications (198.18.0.0/15)
        bool IsRFC6598() const; // IPv4 ISP-level NAT (100.64.0.0/10)
        bool IsRFC5737() const; // IPv4 documentation addresses (192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24)
        bool IsRFC3849() const; // IPv6 documentation address (2001:0DB8::/32)
        bool IsRFC3927() const; // IPv4 autoconfig (169.254.0.0/16)
        bool IsRFC3964() const; // IPv6 6to4 tunnelling (2002::/16)
        bool IsRFC4193() const; // IPv6 unique local (FC00::/7)
        bool IsRFC4380() const; // IPv6 Teredo tunnelling (2001::/32)
        bool IsRFC4843() const; // IPv6 ORCHID (deprecated) (2001:10::/28)
        bool IsRFC7343() const; // IPv6 ORCHIDv2 (2001:20::/28)
        bool IsRFC4862() const; // IPv6 autoconfig (FE80::/64)
        bool IsRFC6052() const; // IPv6 well-known prefix for IPv4-embedded address (64:FF9B::/96)
        bool IsRFC6145() const; // IPv6 IPv4-translated address (::FFFF:0:0:0/96) (actually defined in RFC2765)
        bool IsHeNet() const;   // IPv6 Hurricane Electric - https://he.net (2001:0470::/36)
        bool IsTor() const;
        bool IsI2P() const;
        bool IsCJDNS() const;
        bool IsLocal() const;
        bool IsRoutable() const;
        bool IsInternal() const;
        bool IsValid() const;

        /**
         * Check if the current object can be serialized in pre-ADDRv2/BIP155 format.
         */
        bool IsAddrV1Compatible() const;

        enum Network GetNetwork() const;
        std::string ToString() const;
        std::string ToStringIP() const;
        uint64_t GetHash() const;
        bool GetInAddr(struct in_addr* pipv4Addr) const;
        Network GetNetClass() const;

        //! For IPv4, mapped IPv4, SIIT translated IPv4, Teredo, 6to4 tunneled addresses, return the relevant IPv4 address as a uint32.
        uint32_t GetLinkedIPv4() const;
        //! Whether this address has a linked IPv4 address (see GetLinkedIPv4()).
        bool HasLinkedIPv4() const;

        // The AS on the BGP path to the node we use to diversify
        // peers in AddrMan bucketing based on the AS infrastructure.
        // The ip->AS mapping depends on how asmap is constructed.
        uint32_t GetMappedAS(const std::vector<bool> &asmap) const;

        std::vector<unsigned char> GetGroup(const std::vector<bool> &asmap) const;
        std::vector<unsigned char> GetAddrBytes() const;
        int GetReachabilityFrom(const CNetAddr *paddrPartner = nullptr) const;

        explicit CNetAddr(const struct in6_addr& pipv6Addr, const uint32_t scope = 0);
        bool GetIn6Addr(struct in6_addr* pipv6Addr) const;

        friend bool operator==(const CNetAddr& a, const CNetAddr& b);
        friend bool operator!=(const CNetAddr& a, const CNetAddr& b) { return !(a == b); }
        friend bool operator<(const CNetAddr& a, const CNetAddr& b);

        /**
         * Whether this address should be relayed to other peers even if we can't reach it ourselves.
         */
        bool IsRelayable() const
        {
            return IsIPv4() || IsIPv6() || IsTor();
        }

        /**
         * Serialize to a stream.
         */
        template <typename Stream>
        void Serialize(Stream& s) const
        {
            if (s.GetVersion() & ADDRV2_FORMAT) {
                SerializeV2Stream(s);
            } else {
                SerializeV1Stream(s);
            }
        }

        /**
         * Unserialize from a stream.
         */
        template <typename Stream>
        void Unserialize(Stream& s)
        {
            if (s.GetVersion() & ADDRV2_FORMAT) {
                UnserializeV2Stream(s);
            } else {
                UnserializeV1Stream(s);
            }
        }

        friend class CSubNet;

    private:
        /**
         * BIP155 network ids recognized by this software.
         */
        enum BIP155Network : uint8_t {
            IPV4 = 1,
            IPV6 = 2,
            TORV2 = 3,
            TORV3 = 4,
            I2P = 5,
            CJDNS = 6,
        };

        /**
         * Size of CNetAddr when serialized as ADDRv1 (pre-BIP155) (in bytes).
         */
        static constexpr size_t V1_SERIALIZATION_SIZE = ADDR_IPV6_SIZE;

        /**
         * Maximum size of an address as defined in BIP155 (in bytes).
         * This is only the size of the address, not the entire CNetAddr object
         * when serialized.
         */
        static constexpr size_t MAX_ADDRV2_SIZE = 512;

        /**
         * Get the BIP155 network id of this address.
         * Must not be called for IsInternal() objects.
         * @returns BIP155 network id
         */
        BIP155Network GetBIP155Network() const;

        /**
         * Set `m_net` from the provided BIP155 network id and size after validation.
         * @retval true the network was recognized, is valid and `m_net` was set
         * @retval false not recognised (from future?) and should be silently ignored
         * @throws std::ios_base::failure if the network is one of the BIP155 founding
         * networks (id 1..6) with wrong address size.
         */
        bool SetNetFromBIP155Network(uint8_t possible_bip155_net, size_t address_size);

        /**
         * Serialize in pre-ADDRv2/BIP155 format to an array.
         */
        void SerializeV1Array(uint8_t (&arr)[V1_SERIALIZATION_SIZE]) const
        {
            size_t prefix_size;

            switch (m_net) {
            case NET_IPV6:
                assert(m_addr.size() == sizeof(arr));
                memcpy(arr, m_addr.data(), m_addr.size());
                return;
            case NET_IPV4:
                prefix_size = sizeof(IPV4_IN_IPV6_PREFIX);
                assert(prefix_size + m_addr.size() == sizeof(arr));
                memcpy(arr, IPV4_IN_IPV6_PREFIX.data(), prefix_size);
                memcpy(arr + prefix_size, m_addr.data(), m_addr.size());
                return;
            case NET_ONION:
                if (m_addr.size() == ADDR_TORV3_SIZE) {
                    break;
                }
                prefix_size = sizeof(TORV2_IN_IPV6_PREFIX);
                assert(prefix_size + m_addr.size() == sizeof(arr));
                memcpy(arr, TORV2_IN_IPV6_PREFIX.data(), prefix_size);
                memcpy(arr + prefix_size, m_addr.data(), m_addr.size());
                return;
            case NET_INTERNAL:
                prefix_size = sizeof(INTERNAL_IN_IPV6_PREFIX);
                assert(prefix_size + m_addr.size() == sizeof(arr));
                memcpy(arr, INTERNAL_IN_IPV6_PREFIX.data(), prefix_size);
                memcpy(arr + prefix_size, m_addr.data(), m_addr.size());
                return;
            case NET_I2P:
                break;
            case NET_CJDNS:
                break;
            case NET_UNROUTABLE:
            case NET_MAX:
                assert(false);
            } // no default case, so the compiler can warn about missing cases

            // Serialize TORv3, I2P and CJDNS as all-zeros.
            memset(arr, 0x0, V1_SERIALIZATION_SIZE);
        }

        /**
         * Serialize in pre-ADDRv2/BIP155 format to a stream.
         */
        template <typename Stream>
        void SerializeV1Stream(Stream& s) const
        {
            uint8_t serialized[V1_SERIALIZATION_SIZE];

            SerializeV1Array(serialized);

            s << serialized;
        }

        /**
         * Serialize as ADDRv2 / BIP155.
         */
        template <typename Stream>
        void SerializeV2Stream(Stream& s) const
        {
            if (IsInternal()) {
                // Serialize NET_INTERNAL as embedded in IPv6. We need to
                // serialize such addresses from addrman.
                s << static_cast<uint8_t>(BIP155Network::IPV6);
                s << COMPACTSIZE(ADDR_IPV6_SIZE);
                SerializeV1Stream(s);
                return;
            }

            s << static_cast<uint8_t>(GetBIP155Network());
            s << m_addr;
        }

        /**
         * Unserialize from a pre-ADDRv2/BIP155 format from an array.
         */
        void UnserializeV1Array(uint8_t (&arr)[V1_SERIALIZATION_SIZE])
        {
            // Use SetLegacyIPv6() so that m_net is set correctly. For example
            // ::FFFF:0102:0304 should be set as m_net=NET_IPV4 (1.2.3.4).
            SetLegacyIPv6(arr);
        }

        /**
         * Unserialize from a pre-ADDRv2/BIP155 format from a stream.
         */
        template <typename Stream>
        void UnserializeV1Stream(Stream& s)
        {
            uint8_t serialized[V1_SERIALIZATION_SIZE];

            s >> serialized;

            UnserializeV1Array(serialized);
        }

        /**
         * Unserialize from a ADDRv2 / BIP155 format.
         */
        template <typename Stream>
        void UnserializeV2Stream(Stream& s)
        {
            uint8_t bip155_net;
            s >> bip155_net;

            size_t address_size;
            s >> COMPACTSIZE(address_size);

            if (address_size > MAX_ADDRV2_SIZE) {
                throw std::ios_base::failure(strprintf(
                    "Address too long: %u > %u", address_size, MAX_ADDRV2_SIZE));
            }

            m_scope_id = 0;

            if (SetNetFromBIP155Network(bip155_net, address_size)) {
                m_addr.resize(address_size);
                s >> MakeSpan(m_addr);

                if (m_net != NET_IPV6) {
                    return;
                }

                // Do some special checks on IPv6 addresses.

                // Recognize NET_INTERNAL embedded in IPv6, such addresses are not
                // gossiped but could be coming from addrman, when unserializing from
                // disk.
                if (HasPrefix(m_addr, INTERNAL_IN_IPV6_PREFIX)) {
                    m_net = NET_INTERNAL;
                    memmove(m_addr.data(), m_addr.data() + INTERNAL_IN_IPV6_PREFIX.size(),
                            ADDR_INTERNAL_SIZE);
                    m_addr.resize(ADDR_INTERNAL_SIZE);
                    return;
                }

                if (!HasPrefix(m_addr, IPV4_IN_IPV6_PREFIX) &&
                    !HasPrefix(m_addr, TORV2_IN_IPV6_PREFIX)) {
                    return;
                }

                // IPv4 and TORv2 are not supposed to be embedded in IPv6 (like in V1
                // encoding). Unserialize as !IsValid(), thus ignoring them.
            } else {
                // If we receive an unknown BIP155 network id (from the future?) then
                // ignore the address - unserialize as !IsValid().
                s.ignore(address_size);
            }

            // Mimic a default-constructed CNetAddr object which is !IsValid() and thus
            // will not be gossiped, but continue reading next addresses from the stream.
            m_net = NET_IPV6;
            m_addr.assign(ADDR_IPV6_SIZE, 0x0);
        }
};

class CSubNet
{
    protected:
        /// Network (base) address
        CNetAddr network;
        /// Netmask, in network byte order
        uint8_t netmask[16];
        /// Is this value valid? (only used to signal parse errors)
        bool valid;

        bool SanityCheck() const;

    public:
        /**
         * Construct an invalid subnet (empty, `Match()` always returns false).
         */
        CSubNet();

        /**
         * Construct from a given network start and number of bits (CIDR mask).
         * @param[in] addr Network start. Must be IPv4 or IPv6, otherwise an invalid subnet is
         * created.
         * @param[in] mask CIDR mask, must be in [0, 32] for IPv4 addresses and in [0, 128] for
         * IPv6 addresses. Otherwise an invalid subnet is created.
         */
        CSubNet(const CNetAddr& addr, uint8_t mask);

        /**
         * Construct from a given network start and mask.
         * @param[in] addr Network start. Must be IPv4 or IPv6, otherwise an invalid subnet is
         * created.
         * @param[in] mask Network mask, must be of the same type as `addr` and not contain 0-bits
         * followed by 1-bits. Otherwise an invalid subnet is created.
         */
        CSubNet(const CNetAddr& addr, const CNetAddr& mask);

        /**
         * Construct a single-host subnet.
         * @param[in] addr The sole address to be contained in the subnet, can also be non-IPv[46].
         */
        explicit CSubNet(const CNetAddr& addr);

        bool Match(const CNetAddr &addr) const;

        std::string ToString() const;
        bool IsValid() const;

        friend bool operator==(const CSubNet& a, const CSubNet& b);
        friend bool operator!=(const CSubNet& a, const CSubNet& b) { return !(a == b); }
        friend bool operator<(const CSubNet& a, const CSubNet& b);

        SERIALIZE_METHODS(CSubNet, obj)
        {
            READWRITE(obj.network);
            if (obj.network.IsIPv4()) {
                // Before commit 102867c587f5f7954232fb8ed8e85cda78bb4d32, CSubNet used the last 4 bytes of netmask
                // to store the relevant bytes for an IPv4 mask. For compatiblity reasons, keep doing so in
                // serialized form.
                unsigned char dummy[12] = {0};
                READWRITE(dummy);
                READWRITE(MakeSpan(obj.netmask).first(4));
            } else {
                READWRITE(obj.netmask);
            }
            READWRITE(obj.valid);
            // Mark invalid if the result doesn't pass sanity checking.
            SER_READ(obj, if (obj.valid) obj.valid = obj.SanityCheck());
        }
};

/** A combination of a network address (CNetAddr) and a (TCP) port */
class CService : public CNetAddr
{
    protected:
        uint16_t port; // host order

    public:
        CService();
        CService(const CNetAddr& ip, uint16_t port);
        CService(const struct in_addr& ipv4Addr, uint16_t port);
        explicit CService(const struct sockaddr_in& addr);
        uint16_t GetPort() const;
        bool GetSockAddr(struct sockaddr* paddr, socklen_t *addrlen) const;
        bool SetSockAddr(const struct sockaddr* paddr);
        friend bool operator==(const CService& a, const CService& b);
        friend bool operator!=(const CService& a, const CService& b) { return !(a == b); }
        friend bool operator<(const CService& a, const CService& b);
        std::vector<unsigned char> GetKey() const;
        std::string ToString() const;
        std::string ToStringPort() const;
        std::string ToStringIPPort() const;

        CService(const struct in6_addr& ipv6Addr, uint16_t port);
        explicit CService(const struct sockaddr_in6& addr);

        SERIALIZE_METHODS(CService, obj)
        {
            READWRITEAS(CNetAddr, obj);
            READWRITE(Using<BigEndianFormatter<2>>(obj.port));
        }
};

bool SanityCheckASMap(const std::vector<bool>& asmap);

#endif // BITCOIN_NETADDRESS_H