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Stable release v32.1bitcoin/bitcoin · f0de87f04062 ↗3,020 source files · 47.5 MB stored on the server340 file guides

Release published 2026-10-28 · Snapshot fetched 2026-11-01. Latest stable release at fetch time; development branches and Git history are excluded. Only the selected code window and visible folders load here.

15,294 bytes · SHA-256 22d9c9591d1d832e… · View upstream ↗

1// Copyright (c) 2024-present The Bitcoin Core developers
2// Distributed under the MIT software license, see the accompanying
3// file COPYING or https://www.opensource.org/licenses/mit-license.php.
4
5#include <bitcoin-build-config.h> // IWYU pragma: keep
6
7#include <common/netif.h>
8
9#include <compat/compat.h>
10#include <netbase.h>
11#include <util/check.h>
12#include <util/log.h>
13#include <util/sock.h>
14
15#include <cerrno>
16#include <cstdint>
17#include <cstring>
18#include <functional>
19#include <memory>
20#include <string>
21#include <type_traits>
22
23#if defined(__linux__)
24#include <linux/netlink.h>
25#include <linux/rtnetlink.h>
26#elif defined(__FreeBSD__)
27#include <netlink/netlink.h>
28#include <netlink/netlink_route.h>
29#elif defined(WIN32)
30#include <iphlpapi.h>
31#elif defined(__APPLE__)
32#include <net/route.h>
33#include <sys/sysctl.h>
34#endif
35
36#ifdef HAVE_IFADDRS
37#include <ifaddrs.h>
38#endif
39
40namespace {
41
42//! Return CNetAddr for the specified OS-level network address.
43//! If a length is not given, it is taken to be sizeof(struct sockaddr_*) for the family.
44std::optional<CNetAddr> FromSockAddr(const struct sockaddr* addr, std::optional<socklen_t> sa_len_opt)
45{
46    socklen_t sa_len = 0;
47    if (sa_len_opt.has_value()) {
48        sa_len = *sa_len_opt;
49    } else {
50        // If sockaddr length was not specified, determine it from the family.
51        switch (addr->sa_family) {
52        case AF_INET: sa_len = sizeof(struct sockaddr_in); break;
53        case AF_INET6: sa_len = sizeof(struct sockaddr_in6); break;
54        default:
55            return std::nullopt;
56        }
57    }
58    // Fill in a CService from the sockaddr, then drop the port part.
59    CService service;
60    if (service.SetSockAddr(addr, sa_len)) {
61        return (CNetAddr)service;
62    }
63    return std::nullopt;
64}
65
66// Linux and FreeBSD.
67#if defined(__linux__) || defined(__FreeBSD__)
68
69// Good for responses containing ~ 10,000-15,000 routes.
70static constexpr ssize_t NETLINK_MAX_RESPONSE_SIZE{1'048'576};
71
72std::optional<CNetAddr> QueryDefaultGatewayImpl(sa_family_t family)
73{
74    // Create a netlink socket.
75    auto sock{CreateSock(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE)};
76    if (!sock) {
77        LogError("socket(AF_NETLINK): %s\n", NetworkErrorString(errno));
78        return std::nullopt;
79    }
80
81    // Send request.
82    struct {
83        nlmsghdr hdr; ///< Request header.
84        rtmsg data; ///< Request data, a "route message".
85        nlattr dst_hdr; ///< One attribute, conveying the route destination address.
86        char dst_data[16]; ///< Route destination address. To query the default route we use 0.0.0.0/0 or [::]/0. For IPv4 the first 4 bytes are used.
87    } request{};
88
89    // Whether to use the first 4 or 16 bytes from request.dst_data.
90    const size_t dst_data_len = family == AF_INET ? 4 : 16;
91
92    request.hdr.nlmsg_type = RTM_GETROUTE;
93    request.hdr.nlmsg_flags = NLM_F_REQUEST;
94#ifdef __linux__
95    // Linux IPv4 / IPv6 - this must be present, otherwise no gateway is found
96    // FreeBSD IPv4 - does not matter, the gateway is found with or without this
97    // FreeBSD IPv6 - this must be absent, otherwise no gateway is found
98    request.hdr.nlmsg_flags |= NLM_F_DUMP;
99#endif
100    request.hdr.nlmsg_len = NLMSG_LENGTH(sizeof(rtmsg) + sizeof(nlattr) + dst_data_len);
101    request.hdr.nlmsg_seq = 0; // Sequence number, used to match which reply is to which request. Irrelevant for us because we send just one request.
102    request.data.rtm_family = family;
103    request.data.rtm_dst_len = 0; // Prefix length.
104#ifdef __FreeBSD__
105    // Linux IPv4 / IPv6 this must be absent, otherwise no gateway is found
106    // FreeBSD IPv4 - does not matter, the gateway is found with or without this
107    // FreeBSD IPv6 - this must be present, otherwise no gateway is found
108    request.data.rtm_flags = RTM_F_PREFIX;
109#endif
110    request.dst_hdr.nla_type = RTA_DST;
111    request.dst_hdr.nla_len = sizeof(nlattr) + dst_data_len;
112
113    if (sock->Send(&request, request.hdr.nlmsg_len, 0) != static_cast<ssize_t>(request.hdr.nlmsg_len)) {
114        LogError("send() to netlink socket: %s\n", NetworkErrorString(errno));
115        return std::nullopt;
116    }
117
118    // Receive response.
119    char response[4096];
120    ssize_t total_bytes_read{0};
121    bool done{false};
122    while (!done) {
123        int64_t recv_result;
124        do {
125            recv_result = sock->Recv(response, sizeof(response), 0);
126        } while (recv_result < 0 && (errno == EINTR || errno == EAGAIN));
127        if (recv_result < 0) {
128            LogError("recv() from netlink socket: %s\n", NetworkErrorString(errno));
129            return std::nullopt;
130        }
131
132        total_bytes_read += recv_result;
133        if (total_bytes_read > NETLINK_MAX_RESPONSE_SIZE) {
134            LogWarning("Netlink response exceeded size limit (%zu bytes, family=%d)\n", NETLINK_MAX_RESPONSE_SIZE, family);
135            return std::nullopt;
136        }
137
138        using recv_result_t = std::conditional_t<std::is_signed_v<decltype(NLMSG_HDRLEN)>, int64_t, decltype(NLMSG_HDRLEN)>;
139
140        for (nlmsghdr* hdr = (nlmsghdr*)response; NLMSG_OK(hdr, static_cast<recv_result_t>(recv_result)); hdr = NLMSG_NEXT(hdr, recv_result)) {
141            if (!(hdr->nlmsg_flags & NLM_F_MULTI)) {
142                done = true;
143            }
144
145            if (hdr->nlmsg_type == NLMSG_DONE) {
146                done = true;
147                break;
148            }
149
150            rtmsg* r = (rtmsg*)NLMSG_DATA(hdr);
151            int remaining_len = RTM_PAYLOAD(hdr);
152
153            if (hdr->nlmsg_type != RTM_NEWROUTE) {
154                continue; // Skip non-route messages
155            }
156
157            // Only consider default routes (destination prefix length of 0).
158            if (r->rtm_dst_len != 0) {
159                continue;
160            }
161
162            // Iterate over the attributes.
163            rtattr* rta_gateway = nullptr;
164            int scope_id = 0;
165            for (rtattr* attr = RTM_RTA(r); RTA_OK(attr, remaining_len); attr = RTA_NEXT(attr, remaining_len)) {
166                if (attr->rta_type == RTA_GATEWAY) {
167                    rta_gateway = attr;
168                } else if (attr->rta_type == RTA_OIF && sizeof(int) == RTA_PAYLOAD(attr)) {
169                    std::memcpy(&scope_id, RTA_DATA(attr), sizeof(scope_id));
170                }
171            }
172
173            // Found gateway?
174            if (rta_gateway != nullptr) {
175                if (family == AF_INET && sizeof(in_addr) == RTA_PAYLOAD(rta_gateway)) {
176                    in_addr gw;
177                    std::memcpy(&gw, RTA_DATA(rta_gateway), sizeof(gw));
178                    return CNetAddr(gw);
179                } else if (family == AF_INET6 && sizeof(in6_addr) == RTA_PAYLOAD(rta_gateway)) {
180                    in6_addr gw;
181                    std::memcpy(&gw, RTA_DATA(rta_gateway), sizeof(gw));
182                    return CNetAddr(gw, scope_id);
183                }
184            }
185        }
186    }
187
188    return std::nullopt;
189}
190
191#elif defined(WIN32)
192
193std::optional<CNetAddr> QueryDefaultGatewayImpl(sa_family_t family)
194{
195    NET_LUID interface_luid = {};
196    SOCKADDR_INET destination_address = {};
197    MIB_IPFORWARD_ROW2 best_route = {};
198    SOCKADDR_INET best_source_address = {};
199    DWORD best_if_idx = 0;
200    DWORD status = 0;
201
202    // Pass empty destination address of the requested type (:: or 0.0.0.0) to get interface of default route.
203    destination_address.si_family = family;
204    status = GetBestInterfaceEx((sockaddr*)&destination_address, &best_if_idx);
205    if (status != NO_ERROR) {
206        LogError("Could not get best interface for default route: %s\n", NetworkErrorString(status));
207        return std::nullopt;
208    }
209
210    // Get best route to default gateway.
211    // Leave interface_luid at all-zeros to use interface index instead.
212    status = GetBestRoute2(&interface_luid, best_if_idx, nullptr, &destination_address, 0, &best_route, &best_source_address);
213    if (status != NO_ERROR) {
214        LogError("Could not get best route for default route for interface index %d: %s\n",
215                best_if_idx, NetworkErrorString(status));
216        return std::nullopt;
217    }
218
219    Assume(best_route.NextHop.si_family == family);
220    if (family == AF_INET) {
221        return CNetAddr(best_route.NextHop.Ipv4.sin_addr);
222    } else if(family == AF_INET6) {
223        return CNetAddr(best_route.NextHop.Ipv6.sin6_addr, best_route.InterfaceIndex);
224    }
225    return std::nullopt;
226}
227
228#elif defined(__APPLE__)
229
230#define ROUNDUP32(a) \
231    ((a) > 0 ? (1 + (((a) - 1) | (sizeof(uint32_t) - 1))) : sizeof(uint32_t))
232
233//! MacOS: Get default gateway from route table. See route(4) for the format.
234std::optional<CNetAddr> QueryDefaultGatewayImpl(sa_family_t family)
235{
236    // net.route.0.inet[6].flags.gateway
237    int mib[] = {CTL_NET, PF_ROUTE, 0, family, NET_RT_FLAGS, RTF_GATEWAY};
238    // The size of the available data is determined by calling sysctl() with oldp=nullptr. See sysctl(3).
239    size_t l = 0;
240    if (sysctl(/*name=*/mib, /*namelen=*/sizeof(mib) / sizeof(int), /*oldp=*/nullptr, /*oldlenp=*/&l, /*newp=*/nullptr, /*newlen=*/0) < 0) {
241        LogError("Could not get sysctl length of routing table: %s\n", NetworkErrorString(errno));
242        return std::nullopt;
243    }
244    std::vector<std::byte> buf(l);
245    if (sysctl(/*name=*/mib, /*namelen=*/sizeof(mib) / sizeof(int), /*oldp=*/buf.data(), /*oldlenp=*/&l, /*newp=*/nullptr, /*newlen=*/0) < 0) {
246        LogError("Could not get sysctl data of routing table: %s\n", NetworkErrorString(errno));
247        return std::nullopt;
248    }
249    // Iterate over messages (each message is a routing table entry).
250    for (size_t msg_pos = 0; msg_pos < buf.size(); ) {

src/wallet/receive.cpp

src/wallet/coinselection.cpp

src/consensus/validation.h

src/primitives/transaction.cpp

src/script/descriptor.cpp

src/bitcoin-cli.cpp

src/rpc/blockchain.cpp

src/rpc/rawtransaction.cpp

src/init.cpp

src/crypto/sha256.cpp

src/consensus/merkle.h

src/consensus/tx_check.h

src/consensus/tx_verify.h

src/policy/feerate.h

src/policy/feerate.cpp

src/primitives/transaction_identifier.h

src/chainparamsbase.h

src/chainparamsbase.cpp

src/util/moneystr.cpp

src/crypto/ripemd160.h

src/crypto/sha1.h

src/crypto/sha512.h

src/crypto/hmac_sha256.h

src/crypto/hmac_sha512.h

src/crypto/hmac_sha256.cpp

src/crypto/hmac_sha512.cpp

src/crypto/hkdf_sha256_32.h

src/crypto/hkdf_sha256_32.cpp

src/support/cleanse.h

src/support/cleanse.cpp

src/crypto/siphash.cpp

src/crypto/muhash.h

src/crypto/chacha20.h

src/crypto/poly1305.h

src/crypto/chacha20poly1305.h

src/crypto/chacha20poly1305.cpp

src/util/chaintype.cpp

src/util/obfuscation.h

src/util/byte_units.h

src/util/overflow.h

src/blockencodings.cpp

src/net_permissions.cpp

src/policy/packages.cpp

src/policy/rbf.cpp

src/policy/truc_policy.cpp

src/policy/ephemeral_policy.cpp

src/policy/settings.cpp

src/policy/policy.cpp

src/node/transaction.cpp

src/node/coin.cpp

src/rpc/client.cpp

src/rpc/external_signer.cpp

src/rpc/request.cpp

src/rpc/server_util.cpp

src/rpc/fees.cpp

src/rpc/output_script.cpp

src/rpc/rawtransaction_util.cpp

src/rpc/rawtransaction_util.h

src/rpc/register.h

src/rpc/request.h

src/rpc/server_util.h

src/rpc/protocol.h

src/rpc/server.h

src/rpc/signmessage.cpp

src/rpc/txoutproof.cpp

src/rpc/util.cpp

src/rpc/util.h

src/wallet/rpc/addresses.cpp

src/wallet/rpc/backup.cpp

src/wallet/rpc/coins.cpp

src/wallet/rpc/encrypt.cpp

src/wallet/rpc/signmessage.cpp

src/wallet/rpc/util.cpp

src/wallet/rpc/util.h

src/wallet/coincontrol.cpp

src/wallet/coincontrol.h

src/wallet/context.cpp

src/wallet/context.h

src/wallet/crypter.cpp

src/wallet/crypter.h

src/wallet/db.cpp

src/wallet/export.cpp

src/wallet/external_signer_scriptpubkeyman.cpp

src/wallet/rpc/spend.cpp

src/wallet/rpc/transactions.cpp

src/wallet/rpc/wallet.cpp

src/wallet/feebumper.cpp

src/wallet/feebumper.h

src/index/base.h

src/index/base.cpp

src/index/txindex.h

src/index/txindex.cpp

src/index/txindex_key.h

src/index/txospenderindex.h

src/index/txospenderindex.cpp

src/index/blockfilterindex.h

src/index/blockfilterindex.cpp

src/index/coinstatsindex.h

src/index/coinstatsindex.cpp

src/index/db_key.h

src/index/disktxpos.h

src/kernel/chain.cpp

src/kernel/chain.h

src/kernel/checks.cpp

src/kernel/checks.h

src/kernel/context.cpp

src/kernel/context.h

src/kernel/cs_main.cpp

src/kernel/cs_main.h

src/kernel/disconnected_transactions.cpp

src/kernel/disconnected_transactions.h

src/kernel/mempool_removal_reason.cpp

src/kernel/mempool_removal_reason.h

src/kernel/coinstats.cpp

src/kernel/coinstats.h

src/kernel/chainparams.cpp

src/kernel/chainparams.h

src/wallet/sqlite.cpp

src/wallet/sqlite.h

src/wallet/transaction.cpp

src/wallet/transaction.h

src/wallet/dump.cpp

src/wallet/dump.h

src/wallet/init.cpp

src/wallet/walletutil.cpp

src/wallet/walletutil.h

src/wallet/wallettool.cpp

src/wallet/wallettool.h

src/wallet/export.h

src/wallet/migrate.cpp

src/wallet/migrate.h

src/wallet/db.h

src/wallet/walletdb.cpp

src/wallet/interfaces.cpp

src/wallet/scriptpubkeyman.cpp

src/wallet/scriptpubkeyman.h

src/kernel/bitcoinkernel.cpp

src/kernel/bitcoinkernel.h

src/kernel/bitcoinkernel_wrapper.h

src/node/chainstate.cpp

src/node/chainstate.h

src/node/blockstorage.cpp

src/node/blockstorage.h

src/node/mempool_persist.cpp

src/node/mempool_persist.h

src/node/utxo_snapshot.cpp

src/node/utxo_snapshot.h

src/node/kernel_notifications.cpp

src/node/kernel_notifications.h

src/node/blockmanager_args.cpp

src/kernel/blockmanager_opts.h

src/util/expected.cpp

src/policy/settings.h

src/util/types.h

src/kernel/messagestartchars.h

src/kernel/warning.h

src/util/exception.h

src/common/license_info.h

src/node/coins_view_args.h

src/node/database_args.h

src/util/batchpriority.h

src/util/ui_change_type.h

src/node/coins_view_args.cpp

src/node/peerman_args.h

src/util/serfloat.h

src/node/blockmanager_args.h

src/node/database_args.cpp

src/util/overloaded.h

src/interfaces/types.h

src/node/chainstatemanager_args.h

src/node/minisketchwrapper.h

src/util/macros.h

src/util/syserror.h

src/common/run_command.h

src/util/bytevectorhash.cpp

src/node/mempool_persist_args.cpp

src/util/exec.h

src/util/rbf.h

src/crypto/hex_base.h

src/node/mempool_persist_args.h

src/interfaces/echo.h

src/util/any.h

src/util/batchpriority.cpp

src/util/threadnames.h

src/node/coin.h

src/node/mempool_args.h

src/util/asmap.h

src/util/bytevectorhash.h

src/node/context.cpp

src/util/insert.h

src/util/readwritefile.h

src/node/peerman_args.cpp

src/node/interface_ui.cpp

src/interfaces/handler.h

src/node/mining_args.h

src/util/hasher.cpp

src/common/init.h

src/kernel/mempool_limits.h

src/common/system.h

src/crypto/sha3.h

src/util/threadinterrupt.cpp

src/node/protocol_version.h

src/util/exception.cpp

src/common/messages.h

src/node/connection_types.cpp

src/util/bip32.h

src/common/license_info.cpp

src/util/stdmutex.h

src/common/run_command.cpp

src/util/check.cpp

src/util/golombrice.h

src/node/types.h

src/node/timeoffsets.h

src/util/readwritefile.cpp

src/util/fastrange.h

src/util/signalinterrupt.h

src/util/task_runner.h

src/util/syserror.cpp

src/common/interfaces.cpp

src/common/types.h

src/util/threadinterrupt.h

src/kernel/chainstatemanager_opts.h

src/node/psbt.h

src/policy/ephemeral_policy.h

src/util/trace.h

src/common/url.cpp

src/kernel/mempool_options.h

src/util/serfloat.cpp

src/kernel/notifications_interface.h

src/node/timeoffsets.cpp

src/node/warnings.cpp

src/util/hash_type.h

src/crypto/hex_base.cpp

src/node/eviction.h

src/util/tokenbucket.h

src/crypto/aes.h

src/common/pcp.h

src/util/feefrac.cpp

src/node/transaction.h

src/util/threadnames.cpp

src/common/signmessage.h

src/util/exec.cpp

src/util/signalinterrupt.cpp

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