Add support for dnsseeds with option to filter by servicebits

jonasschnelli · Fuzzbawls · commit 9a364e106ef4 · 2020-03-23T16:56:32.000-07:00
diff --git a/src/chainparams.cpp b/src/chainparams.cpp
@@ -19,6 +19,14 @@
 
 #include "chainparamsseeds.h"
 
+std::string CDNSSeedData::getHost(uint64_t requiredServiceBits) const {
+    //use default host for non-filter-capable seeds or if we use the default service bits (NODE_NETWORK)
+    if (!supportsServiceBitsFiltering || requiredServiceBits == NODE_NETWORK)
+        return host;
+
+    return strprintf("x%x.%s", requiredServiceBits, host);
+}
+
 static CBlock CreateGenesisBlock(const char* pszTimestamp, const CScript& genesisOutputScript, uint32_t nTime, uint32_t nNonce, uint32_t nBits, int32_t nVersion, const CAmount& genesisReward)
 {
     CMutableTransaction txNew;
@@ -222,8 +230,8 @@ class CMainParams : public CChainParams
         nDefaultPort = 51472;
 
         // Note that of those with the service bits flag, most only support a subset of possible options
-        vSeeds.push_back(CDNSSeedData("fuzzbawls.pw", "pivx.seed.fuzzbawls.pw"));     // Primary DNS Seeder from Fuzzbawls
-        vSeeds.push_back(CDNSSeedData("fuzzbawls.pw", "pivx.seed2.fuzzbawls.pw"));    // Secondary DNS Seeder from Fuzzbawls
+        vSeeds.push_back(CDNSSeedData("fuzzbawls.pw", "pivx.seed.fuzzbawls.pw", true));     // Primary DNS Seeder from Fuzzbawls
+        vSeeds.push_back(CDNSSeedData("fuzzbawls.pw", "pivx.seed2.fuzzbawls.pw", true));    // Secondary DNS Seeder from Fuzzbawls
         vSeeds.push_back(CDNSSeedData("warrows.dev", "dnsseed.pivx.warrows.dev"));    // Primery DNS Seeder from warrows
 
         base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1, 30);
@@ -339,8 +347,9 @@ class CTestNetParams : public CMainParams
 
         vFixedSeeds.clear();
         vSeeds.clear();
-        vSeeds.push_back(CDNSSeedData("fuzzbawls.pw", "pivx-testnet.seed.fuzzbawls.pw"));
-        vSeeds.push_back(CDNSSeedData("fuzzbawls.pw", "pivx-testnet.seed2.fuzzbawls.pw"));
+        // nodes with support for servicebits filtering should be at the top
+        vSeeds.push_back(CDNSSeedData("fuzzbawls.pw", "pivx-testnet.seed.fuzzbawls.pw", true));
+        vSeeds.push_back(CDNSSeedData("fuzzbawls.pw", "pivx-testnet.seed2.fuzzbawls.pw", true));
         vSeeds.push_back(CDNSSeedData("warrows.dev", "testnet.dnsseed.pivx.warrows.dev"));
 
         base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1, 139); // Testnet pivx addresses start with 'x' or 'y'
diff --git a/src/chainparams.h b/src/chainparams.h
@@ -19,9 +19,12 @@
 
 typedef unsigned char MessageStartChars[MESSAGE_START_SIZE];
 
-struct CDNSSeedData {
+class CDNSSeedData {
+public:
     std::string name, host;
-    CDNSSeedData(const std::string& strName, const std::string& strHost) : name(strName), host(strHost) {}
+    bool supportsServiceBitsFiltering;
+    std::string getHost(uint64_t requiredServiceBits) const;
+    CDNSSeedData(const std::string& strName, const std::string& strHost, bool supportsServiceBitsFilteringIn = false) : name(strName), host(strHost), supportsServiceBitsFiltering(supportsServiceBitsFilteringIn) {}
 };
 
 struct SeedSpec6 {
diff --git a/src/net.cpp b/src/net.cpp
@@ -1283,10 +1283,11 @@ void ThreadDNSAddressSeed()
         } else {
             std::vector<CNetAddr> vIPs;
             std::vector<CAddress> vAdd;
-            if (LookupHost(seed.host.c_str(), vIPs, 0, true)) {
+            uint64_t requiredServiceBits = NODE_NETWORK;
+            if (LookupHost(seed.getHost(requiredServiceBits).c_str(), vIPs, 0, true)) {
                 for (CNetAddr& ip : vIPs) {
                     int nOneDay = 24 * 3600;
-                    CAddress addr = CAddress(CService(ip, Params().GetDefaultPort()));
+                    CAddress addr = CAddress(CService(ip, Params().GetDefaultPort()), requiredServiceBits);
                     addr.nTime = GetTime() - 3 * nOneDay - GetRand(4 * nOneDay); // use a random age between 3 and 7 days old
                     vAdd.push_back(addr);
                     found++;
