From 62e764219b25f5d5a4de855e53f62c43130ec918 Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Thu, 19 Oct 2017 17:32:45 -0400 Subject: [PATCH] Fall back to oneshot for DNS Seeds which don't support filtering. This allows us to not have to update the chainparams whenever a DNS Seed changes its filtering support, as well fixes a bug introduced in 44407100f where returned nodes will never be attempted. --- src/chainparams.cpp | 20 ++++++++++---------- src/chainparams.h | 11 +++-------- src/net.cpp | 25 ++++++++----------------- 3 files changed, 21 insertions(+), 35 deletions(-) diff --git a/src/chainparams.cpp b/src/chainparams.cpp index ad648dc8df..eb8531e4b5 100644 --- a/src/chainparams.cpp +++ b/src/chainparams.cpp @@ -125,12 +125,12 @@ public: assert(genesis.hashMerkleRoot == uint256S("0x4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b")); // Note that of those with the service bits flag, most only support a subset of possible options - vSeeds.emplace_back("seed.bitcoin.sipa.be", true); // Pieter Wuille, only supports x1, x5, x9, and xd - vSeeds.emplace_back("dnsseed.bluematt.me", true); // Matt Corallo, only supports x9 - vSeeds.emplace_back("dnsseed.bitcoin.dashjr.org", false); // Luke Dashjr - vSeeds.emplace_back("seed.bitcoinstats.com", true); // Christian Decker, supports x1 - xf - vSeeds.emplace_back("seed.bitcoin.jonasschnelli.ch", true); // Jonas Schnelli, only supports x1, x5, x9, and xd - vSeeds.emplace_back("seed.btc.petertodd.org", true); // Peter Todd, only supports x1, x5, x9, and xd + vSeeds.emplace_back("seed.bitcoin.sipa.be"); // Pieter Wuille, only supports x1, x5, x9, and xd + vSeeds.emplace_back("dnsseed.bluematt.me"); // Matt Corallo, only supports x9 + vSeeds.emplace_back("dnsseed.bitcoin.dashjr.org"); // Luke Dashjr + vSeeds.emplace_back("seed.bitcoinstats.com"); // Christian Decker, supports x1 - xf + vSeeds.emplace_back("seed.bitcoin.jonasschnelli.ch"); // Jonas Schnelli, only supports x1, x5, x9, and xd + vSeeds.emplace_back("seed.btc.petertodd.org"); // Peter Todd, only supports x1, x5, x9, and xd base58Prefixes[PUBKEY_ADDRESS] = std::vector(1,0); base58Prefixes[SCRIPT_ADDRESS] = std::vector(1,5); @@ -229,10 +229,10 @@ public: vFixedSeeds.clear(); vSeeds.clear(); // nodes with support for servicebits filtering should be at the top - vSeeds.emplace_back("testnet-seed.bitcoin.jonasschnelli.ch", true); - vSeeds.emplace_back("seed.tbtc.petertodd.org", true); - vSeeds.emplace_back("seed.testnet.bitcoin.sprovoost.nl", true); - vSeeds.emplace_back("testnet-seed.bluematt.me", true); // Just a static list of stable node(s), only supports x9 + vSeeds.emplace_back("testnet-seed.bitcoin.jonasschnelli.ch"); + vSeeds.emplace_back("seed.tbtc.petertodd.org"); + vSeeds.emplace_back("seed.testnet.bitcoin.sprovoost.nl"); + vSeeds.emplace_back("testnet-seed.bluematt.me"); // Just a static list of stable node(s), only supports x9 base58Prefixes[PUBKEY_ADDRESS] = std::vector(1,111); base58Prefixes[SCRIPT_ADDRESS] = std::vector(1,196); diff --git a/src/chainparams.h b/src/chainparams.h index 0d82a998b1..4b62ca526e 100644 --- a/src/chainparams.h +++ b/src/chainparams.h @@ -14,12 +14,6 @@ #include #include -struct CDNSSeedData { - std::string host; - bool supportsServiceBitsFiltering; - CDNSSeedData(const std::string &strHost, bool supportsServiceBitsFilteringIn) : host(strHost), supportsServiceBitsFiltering(supportsServiceBitsFilteringIn) {} -}; - struct SeedSpec6 { uint8_t addr[16]; uint16_t port; @@ -71,7 +65,8 @@ public: bool MineBlocksOnDemand() const { return fMineBlocksOnDemand; } /** Return the BIP70 network string (main, test or regtest) */ std::string NetworkIDString() const { return strNetworkID; } - const std::vector& DNSSeeds() const { return vSeeds; } + /** Return the list of hostnames to look up for DNS seeds */ + const std::vector& DNSSeeds() const { return vSeeds; } const std::vector& Base58Prefix(Base58Type type) const { return base58Prefixes[type]; } const std::string& Bech32HRP() const { return bech32_hrp; } const std::vector& FixedSeeds() const { return vFixedSeeds; } @@ -85,7 +80,7 @@ protected: CMessageHeader::MessageStartChars pchMessageStart; int nDefaultPort; uint64_t nPruneAfterHeight; - std::vector vSeeds; + std::vector vSeeds; std::vector base58Prefixes[MAX_BASE58_TYPES]; std::string bech32_hrp; std::string strNetworkID; diff --git a/src/net.cpp b/src/net.cpp index 5252128400..82bae05b39 100644 --- a/src/net.cpp +++ b/src/net.cpp @@ -1577,19 +1577,6 @@ void MapPort(bool) -static std::string GetDNSHost(const CDNSSeedData& data, ServiceFlags* requiredServiceBits) -{ - //use default host for non-filter-capable seeds or if we use the default service bits (NODE_NETWORK) - if (!data.supportsServiceBitsFiltering || *requiredServiceBits == NODE_NETWORK) { - *requiredServiceBits = NODE_NETWORK; - return data.host; - } - - // See chainparams.cpp, most dnsseeds only support one or two possible servicebits hostnames - return strprintf("x%x.%s", *requiredServiceBits, data.host); -} - - void CConnman::ThreadDNSAddressSeed() { // goal: only query DNS seeds if address need is acute @@ -1612,22 +1599,22 @@ void CConnman::ThreadDNSAddressSeed() } } - const std::vector &vSeeds = Params().DNSSeeds(); + const std::vector &vSeeds = Params().DNSSeeds(); int found = 0; LogPrintf("Loading addresses from DNS seeds (could take a while)\n"); - for (const CDNSSeedData &seed : vSeeds) { + for (const std::string &seed : vSeeds) { if (interruptNet) { return; } if (HaveNameProxy()) { - AddOneShot(seed.host); + AddOneShot(seed); } else { std::vector vIPs; std::vector vAdd; ServiceFlags requiredServiceBits = GetDesirableServiceFlags(NODE_NONE); - std::string host = GetDNSHost(seed, &requiredServiceBits); + std::string host = strprintf("x%x.%s", requiredServiceBits, seed); CNetAddr resolveSource; if (!resolveSource.SetInternal(host)) { continue; @@ -1643,6 +1630,10 @@ void CConnman::ThreadDNSAddressSeed() found++; } addrman.Add(vAdd, resolveSource); + } else { + // We now avoid directly using results from DNS Seeds which do not support service bit filtering, + // instead using them as a oneshot to get nodes with our desired service bits. + AddOneShot(seed); } } }