1 files changed, 239 insertions, 0 deletions
diff --git a/dnsdist-lua.hh b/dnsdist-lua.hh
new file mode 100644
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--- /dev/null
+++ b/dnsdist-lua.hh
@@ -0,0 +1,239 @@
+/*
+ * This file is part of PowerDNS or dnsdist.
+ * Copyright -- PowerDNS.COM B.V. and its contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * In addition, for the avoidance of any doubt, permission is granted to
+ * link this program with OpenSSL and to (re)distribute the binaries
+ * produced as the result of such linking.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#pragma once
+
+#include "dolog.hh"
+#include "dnsdist.hh"
+#include "dnsparser.hh"
+#include <random>
+
+struct ResponseConfig
+{
+  boost::optional<bool> setAA{boost::none};
+  boost::optional<bool> setAD{boost::none};
+  boost::optional<bool> setRA{boost::none};
+  uint32_t ttl{60};
+};
+void setResponseHeadersFromConfig(dnsheader& dh, const ResponseConfig& config);
+
+class SpoofAction : public DNSAction
+{
+public:
+  SpoofAction(const vector<ComboAddress>& addrs): d_addrs(addrs)
+  {
+    for (const auto& addr : d_addrs) {
+      if (addr.isIPv4()) {
+        d_types.insert(QType::A);
+      }
+      else if (addr.isIPv6()) {
+        d_types.insert(QType::AAAA);
+      }
+    }
+
+    if (!d_addrs.empty()) {
+      d_types.insert(QType::ANY);
+    }
+  }
+
+  SpoofAction(const DNSName& cname): d_cname(cname)
+  {
+  }
+
+  SpoofAction(const char* rawresponse, size_t len): d_raw(rawresponse, rawresponse + len)
+  {
+  }
+
+  SpoofAction(const vector<std::string>& raws): d_rawResponses(raws)
+  {
+  }
+
+  DNSAction::Action operator()(DNSQuestion* dq, string* ruleresult) const override;
+
+  string toString() const override
+  {
+    string ret = "spoof in ";
+    if (!d_cname.empty()) {
+      ret += d_cname.toString() + " ";
+    }
+    if (d_rawResponses.size() > 0) {
+      ret += "raw bytes ";
+    }
+    else {
+      for(const auto& a : d_addrs)
+        ret += a.toString()+" ";
+    }
+    return ret;
+  }
+
+
+  ResponseConfig d_responseConfig;
+private:
+  static thread_local std::default_random_engine t_randomEngine;
+  std::vector<ComboAddress> d_addrs;
+  std::unordered_set<uint16_t> d_types;
+  std::vector<std::string> d_rawResponses;
+  PacketBuffer d_raw;
+  DNSName d_cname;
+};
+
+class LimitTTLResponseAction : public DNSResponseAction, public boost::noncopyable
+{
+public:
+  LimitTTLResponseAction() {}
+
+  LimitTTLResponseAction(uint32_t min, uint32_t max = std::numeric_limits<uint32_t>::max(), const std::unordered_set<QType>& types = {}) : d_types(types), d_min(min), d_max(max)
+  {
+  }
+
+  DNSResponseAction::Action operator()(DNSResponse* dr, std::string* ruleresult) const override
+  {
+    auto visitor = [&](uint8_t section, uint16_t qclass, uint16_t qtype, uint32_t ttl) {
+      if (!d_types.empty() && qclass == QClass::IN && d_types.count(qtype) == 0) {
+        return ttl;
+      }
+
+      if (d_min > 0) {
+        if (ttl < d_min) {
+          ttl = d_min;
+        }
+      }
+      if (ttl > d_max) {
+        ttl = d_max;
+      }
+      return ttl;
+    };
+    editDNSPacketTTL(reinterpret_cast<char *>(dr->getMutableData().data()), dr->getData().size(), visitor);
+    return DNSResponseAction::Action::None;
+  }
+
+  std::string toString() const override
+  {
+    std::string result = "limit ttl (" + std::to_string(d_min) + " <= ttl <= " + std::to_string(d_max);
+    if (!d_types.empty()) {
+      bool first = true;
+      result += ", types in [";
+      for (const auto& type : d_types) {
+        if (first) {
+          first = false;
+        }
+        else {
+          result += " ";
+        }
+        result += type.toString();
+      }
+      result += "]";
+    }
+    result += + ")";
+    return result;
+  }
+
+private:
+  std::unordered_set<QType> d_types;
+  uint32_t d_min{0};
+  uint32_t d_max{std::numeric_limits<uint32_t>::max()};
+};
+
+template <class T> using LuaArray = std::vector<std::pair<int, T>>;
+template <class T> using LuaAssociativeTable = std::unordered_map<std::string, T>;
+template <class T> using LuaTypeOrArrayOf = boost::variant<T, LuaArray<T>>;
+
+using luadnsrule_t = boost::variant<string, LuaArray<std::string>, std::shared_ptr<DNSRule>, DNSName, LuaArray<DNSName>>;
+using luaruleparams_t = LuaAssociativeTable<std::string>;
+using nmts_t = NetmaskTree<DynBlock, AddressAndPortRange>;
+
+std::shared_ptr<DNSRule> makeRule(const luadnsrule_t& var);
+void parseRuleParams(boost::optional<luaruleparams_t>& params, boost::uuids::uuid& uuid, std::string& name, uint64_t& creationOrder);
+void checkParameterBound(const std::string& parameter, uint64_t value, size_t max = std::numeric_limits<uint16_t>::max());
+
+vector<std::function<void(void)>> setupLua(LuaContext& luaCtx, bool client, bool configCheck, const std::string& config);
+void setupLuaActions(LuaContext& luaCtx);
+void setupLuaBindings(LuaContext& luaCtx, bool client);
+void setupLuaBindingsDNSCrypt(LuaContext& luaCtx, bool client);
+void setupLuaBindingsDNSParser(LuaContext& luaCtx);
+void setupLuaBindingsDNSQuestion(LuaContext& luaCtx);
+void setupLuaBindingsKVS(LuaContext& luaCtx, bool client);
+void setupLuaBindingsNetwork(LuaContext& luaCtx, bool client);
+void setupLuaBindingsPacketCache(LuaContext& luaCtx, bool client);
+void setupLuaBindingsProtoBuf(LuaContext& luaCtx, bool client, bool configCheck);
+void setupLuaBindingsRings(LuaContext& luaCtx, bool client);
+void setupLuaRules(LuaContext& luaCtx);
+void setupLuaInspection(LuaContext& luaCtx);
+void setupLuaVars(LuaContext& luaCtx);
+void setupLuaWeb(LuaContext& luaCtx);
+void setupLuaLoadBalancingContext(LuaContext& luaCtx);
+
+/**
+ * getOptionalValue(vars, key, value)
+ *
+ * Attempts to extract value for key in vars.
+ * Erases the key from vars.
+ *
+ * returns: -1 if type wasn't compatible, 0 if not found or number of element(s) found
+ */
+template<class G, class T, class V>
+static inline int getOptionalValue(boost::optional<V>& vars, const std::string& key, T& value, bool warnOnWrongType = true) {
+  /* nothing found, nothing to return */
+  if (!vars) {
+    return 0;
+  }
+
+  if (vars->count(key)) {
+    try {
+      value = boost::get<G>((*vars)[key]);
+    } catch (const boost::bad_get& e) {
+      /* key is there but isn't compatible */
+      if (warnOnWrongType) {
+        warnlog("Invalid type for key '%s' - ignored", key);
+        vars->erase(key);
+      }
+      return -1;
+    }
+  }
+  return vars->erase(key);
+}
+
+template<class T, class V>
+static inline int getOptionalIntegerValue(const std::string& func, boost::optional<V>& vars, const std::string& key, T& value) {
+  std::string valueStr;
+  auto ret = getOptionalValue<std::string>(vars, key, valueStr, true);
+  if (ret == 1) {
+    try {
+      value = std::stoi(valueStr);
+    }
+    catch (const std::exception& e) {
+      warnlog("Parameter '%s' of '%s' must be integer, not '%s' - ignoring", func, key, valueStr);
+      return -1;
+    }
+  }
+  return ret;
+}
+
+template<class V>
+static inline void checkAllParametersConsumed(const std::string& func, const boost::optional<V>& vars) {
+  /* no vars */
+  if (!vars) {
+    return;
+  }
+  for (const auto& [key, value] : *vars) {
+    warnlog("%s: Unknown key '%s' given - ignored", func, key);
+  }
+}