1 files changed, 583 insertions, 0 deletions
diff --git a/dnsdist-lua-ffi.cc b/dnsdist-lua-ffi.cc
new file mode 100644
index 0000000..25e36c2
--- /dev/null
+++ b/dnsdist-lua-ffi.cc
@@ -0,0 +1,583 @@
+/*
+ * 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.
+ */
+
+#include "dnsdist-lua-ffi.hh"
+#include "dnsdist-lua.hh"
+#include "dnsdist-ecs.hh"
+
+uint16_t dnsdist_ffi_dnsquestion_get_qtype(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return dq->dq->qtype;
+}
+
+uint16_t dnsdist_ffi_dnsquestion_get_qclass(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return dq->dq->qclass;
+}
+
+static void dnsdist_ffi_comboaddress_to_raw(const ComboAddress& ca, const void** addr, size_t* addrSize)
+{
+  if (ca.isIPv4()) {
+    *addr = &ca.sin4.sin_addr.s_addr;
+    *addrSize = sizeof(ca.sin4.sin_addr.s_addr);
+  }
+  else {
+    *addr = &ca.sin6.sin6_addr.s6_addr;
+    *addrSize = sizeof(ca.sin6.sin6_addr.s6_addr);
+  }
+}
+
+void dnsdist_ffi_dnsquestion_get_localaddr(const dnsdist_ffi_dnsquestion_t* dq, const void** addr, size_t* addrSize)
+{
+  dnsdist_ffi_comboaddress_to_raw(*dq->dq->local, addr, addrSize);
+}
+
+void dnsdist_ffi_dnsquestion_get_remoteaddr(const dnsdist_ffi_dnsquestion_t* dq, const void** addr, size_t* addrSize)
+{
+  dnsdist_ffi_comboaddress_to_raw(*dq->dq->remote, addr, addrSize);
+}
+
+void dnsdist_ffi_dnsquestion_get_masked_remoteaddr(dnsdist_ffi_dnsquestion_t* dq, const void** addr, size_t* addrSize, uint8_t bits)
+{
+  dq->maskedRemote = Netmask(*dq->dq->remote, bits).getMaskedNetwork();
+  dnsdist_ffi_comboaddress_to_raw(dq->maskedRemote, addr, addrSize);
+}
+
+uint16_t dnsdist_ffi_dnsquestion_get_local_port(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return dq->dq->local->getPort();
+}
+
+uint16_t dnsdist_ffi_dnsquestion_get_remote_port(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return dq->dq->remote->getPort();
+}
+
+void dnsdist_ffi_dnsquestion_get_qname_raw(const dnsdist_ffi_dnsquestion_t* dq, const char** qname, size_t* qnameSize)
+{
+  const auto& storage = dq->dq->qname->getStorage();
+  *qname = storage.data();
+  *qnameSize = storage.size();
+}
+
+size_t dnsdist_ffi_dnsquestion_get_qname_hash(const dnsdist_ffi_dnsquestion_t* dq, size_t init)
+{
+  return dq->dq->qname->hash(init);
+}
+
+int dnsdist_ffi_dnsquestion_get_rcode(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return dq->dq->getHeader()->rcode;
+}
+
+void* dnsdist_ffi_dnsquestion_get_header(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return dq->dq->getHeader();
+}
+
+uint16_t dnsdist_ffi_dnsquestion_get_len(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return dq->dq->getData().size();
+}
+
+size_t dnsdist_ffi_dnsquestion_get_size(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return dq->dq->getData().size();
+}
+
+bool dnsdist_ffi_dnsquestion_set_size(dnsdist_ffi_dnsquestion_t* dq, size_t newSize)
+{
+  try {
+    dq->dq->getMutableData().resize(newSize);
+    return true;
+  }
+  catch (const std::exception& e) {
+    return false;
+  }
+}
+
+uint8_t dnsdist_ffi_dnsquestion_get_opcode(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return dq->dq->getHeader()->opcode;
+}
+
+bool dnsdist_ffi_dnsquestion_get_tcp(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return dq->dq->overTCP();
+}
+
+bool dnsdist_ffi_dnsquestion_get_skip_cache(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return dq->dq->skipCache;
+}
+
+bool dnsdist_ffi_dnsquestion_get_use_ecs(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return dq->dq->useECS;
+}
+
+bool dnsdist_ffi_dnsquestion_get_add_xpf(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return dq->dq->addXPF;
+}
+
+bool dnsdist_ffi_dnsquestion_get_ecs_override(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return dq->dq->ecsOverride;
+}
+
+uint16_t dnsdist_ffi_dnsquestion_get_ecs_prefix_length(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return dq->dq->ecsPrefixLength;
+}
+
+bool dnsdist_ffi_dnsquestion_is_temp_failure_ttl_set(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return dq->dq->tempFailureTTL != boost::none;
+}
+
+uint32_t dnsdist_ffi_dnsquestion_get_temp_failure_ttl(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  if (dq->dq->tempFailureTTL) {
+    return *dq->dq->tempFailureTTL;
+  }
+  return 0;
+}
+
+bool dnsdist_ffi_dnsquestion_get_do(const dnsdist_ffi_dnsquestion_t* dq)
+{
+  return getEDNSZ(*dq->dq) & EDNS_HEADER_FLAG_DO;
+}
+
+void dnsdist_ffi_dnsquestion_get_sni(const dnsdist_ffi_dnsquestion_t* dq, const char** sni, size_t* sniSize)
+{
+  *sniSize = dq->dq->sni.size();
+  *sni = dq->dq->sni.c_str();
+}
+
+const char* dnsdist_ffi_dnsquestion_get_tag(const dnsdist_ffi_dnsquestion_t* dq, const char* label)
+{
+  const char * result = nullptr;
+
+  if (dq->dq->qTag != nullptr) {
+    const auto it = dq->dq->qTag->find(label);
+    if (it != dq->dq->qTag->cend()) {
+      result = it->second.c_str();
+    }
+  }
+
+  return result;
+}
+
+const char* dnsdist_ffi_dnsquestion_get_http_path(dnsdist_ffi_dnsquestion_t* dq)
+{
+  if (!dq->httpPath) {
+    if (dq->dq->du == nullptr) {
+      return nullptr;
+    }
+#ifdef HAVE_DNS_OVER_HTTPS
+    dq->httpPath = dq->dq->du->getHTTPPath();
+#endif /* HAVE_DNS_OVER_HTTPS */
+  }
+  if (dq->httpPath) {
+    return dq->httpPath->c_str();
+  }
+  return nullptr;
+}
+
+const char* dnsdist_ffi_dnsquestion_get_http_query_string(dnsdist_ffi_dnsquestion_t* dq)
+{
+  if (!dq->httpQueryString) {
+    if (dq->dq->du == nullptr) {
+      return nullptr;
+    }
+#ifdef HAVE_DNS_OVER_HTTPS
+    dq->httpQueryString = dq->dq->du->getHTTPQueryString();
+#endif /* HAVE_DNS_OVER_HTTPS */
+  }
+  if (dq->httpQueryString) {
+    return dq->httpQueryString->c_str();
+  }
+  return nullptr;
+}
+
+const char* dnsdist_ffi_dnsquestion_get_http_host(dnsdist_ffi_dnsquestion_t* dq)
+{
+  if (!dq->httpHost) {
+    if (dq->dq->du == nullptr) {
+      return nullptr;
+    }
+#ifdef HAVE_DNS_OVER_HTTPS
+    dq->httpHost = dq->dq->du->getHTTPHost();
+#endif /* HAVE_DNS_OVER_HTTPS */
+  }
+  if (dq->httpHost) {
+    return dq->httpHost->c_str();
+  }
+  return nullptr;
+}
+
+const char* dnsdist_ffi_dnsquestion_get_http_scheme(dnsdist_ffi_dnsquestion_t* dq)
+{
+  if (!dq->httpScheme) {
+    if (dq->dq->du == nullptr) {
+      return nullptr;
+    }
+#ifdef HAVE_DNS_OVER_HTTPS
+    dq->httpScheme = dq->dq->du->getHTTPScheme();
+#endif /* HAVE_DNS_OVER_HTTPS */
+  }
+  if (dq->httpScheme) {
+    return dq->httpScheme->c_str();
+  }
+  return nullptr;
+}
+
+static void fill_edns_option(const EDNSOptionViewValue& value, dnsdist_ffi_ednsoption_t& option)
+{
+  option.len = value.size;
+  option.data = nullptr;
+
+  if (value.size > 0) {
+    option.data = value.content;
+  }
+}
+
+// returns the length of the resulting 'out' array. 'out' is not set if the length is 0
+size_t dnsdist_ffi_dnsquestion_get_edns_options(dnsdist_ffi_dnsquestion_t* dq, const dnsdist_ffi_ednsoption_t** out)
+{
+  if (dq->dq->ednsOptions == nullptr) {
+    parseEDNSOptions(*(dq->dq));
+
+    if (dq->dq->ednsOptions == nullptr) {
+      return 0;
+    }
+  }
+
+  size_t totalCount = 0;
+  for (const auto& option : *dq->dq->ednsOptions) {
+    totalCount += option.second.values.size();
+  }
+
+  dq->ednsOptionsVect.clear();
+  dq->ednsOptionsVect.resize(totalCount);
+  size_t pos = 0;
+  for (const auto& option : *dq->dq->ednsOptions) {
+    for (const auto& entry : option.second.values) {
+      fill_edns_option(entry, dq->ednsOptionsVect.at(pos));
+      dq->ednsOptionsVect.at(pos).optionCode = option.first;
+      pos++;
+    }
+  }
+
+  if (totalCount > 0) {
+    *out = dq->ednsOptionsVect.data();
+  }
+
+  return totalCount;
+}
+
+size_t dnsdist_ffi_dnsquestion_get_http_headers(dnsdist_ffi_dnsquestion_t* dq, const dnsdist_ffi_http_header_t** out)
+{
+  if (dq->dq->du == nullptr) {
+    return 0;
+  }
+
+#ifdef HAVE_DNS_OVER_HTTPS
+  dq->httpHeaders = dq->dq->du->getHTTPHeaders();
+  dq->httpHeadersVect.clear();
+  dq->httpHeadersVect.resize(dq->httpHeaders.size());
+  size_t pos = 0;
+  for (const auto& header : dq->httpHeaders) {
+    dq->httpHeadersVect.at(pos).name = header.first.c_str();
+    dq->httpHeadersVect.at(pos).value = header.second.c_str();
+    ++pos;
+  }
+
+  if (!dq->httpHeadersVect.empty()) {
+    *out = dq->httpHeadersVect.data();
+  }
+
+  return dq->httpHeadersVect.size();
+#else
+  return 0;
+#endif
+}
+
+size_t dnsdist_ffi_dnsquestion_get_tag_array(dnsdist_ffi_dnsquestion_t* dq, const dnsdist_ffi_tag_t** out)
+{
+  if (dq->dq->qTag == nullptr || dq->dq->qTag->size() == 0) {
+    return 0;
+  }
+
+  dq->tagsVect.clear();
+  dq->tagsVect.resize(dq->dq->qTag->size());
+  size_t pos = 0;
+
+  for (const auto& tag : *dq->dq->qTag) {
+    auto& entry = dq->tagsVect.at(pos);
+    entry.name = tag.first.c_str();
+    entry.value = tag.second.c_str();
+    ++pos;
+  }
+
+
+  if (!dq->tagsVect.empty()) {
+    *out = dq->tagsVect.data();
+  }
+
+  return dq->tagsVect.size();
+}
+
+void dnsdist_ffi_dnsquestion_set_result(dnsdist_ffi_dnsquestion_t* dq, const char* str, size_t strSize)
+{
+  dq->result = std::string(str, strSize);
+}
+
+void dnsdist_ffi_dnsquestion_set_http_response(dnsdist_ffi_dnsquestion_t* dq, uint16_t statusCode, const char* body, size_t bodyLen, const char* contentType)
+{
+  if (dq->dq->du == nullptr) {
+    return;
+  }
+
+#ifdef HAVE_DNS_OVER_HTTPS
+  PacketBuffer bodyVect(body, body + bodyLen);
+  dq->dq->du->setHTTPResponse(statusCode, std::move(bodyVect), contentType);
+  dq->dq->getHeader()->qr = true;
+#endif
+}
+
+void dnsdist_ffi_dnsquestion_set_rcode(dnsdist_ffi_dnsquestion_t* dq, int rcode)
+{
+  dq->dq->getHeader()->rcode = rcode;
+  dq->dq->getHeader()->qr = true;
+}
+
+void dnsdist_ffi_dnsquestion_set_len(dnsdist_ffi_dnsquestion_t* dq, uint16_t len)
+{
+  dq->dq->getMutableData().resize(len);
+}
+
+void dnsdist_ffi_dnsquestion_set_skip_cache(dnsdist_ffi_dnsquestion_t* dq, bool skipCache)
+{
+  dq->dq->skipCache = skipCache;
+}
+
+void dnsdist_ffi_dnsquestion_set_use_ecs(dnsdist_ffi_dnsquestion_t* dq, bool useECS)
+{
+  dq->dq->useECS = useECS;
+}
+
+void dnsdist_ffi_dnsquestion_set_ecs_override(dnsdist_ffi_dnsquestion_t* dq, bool ecsOverride)
+{
+  dq->dq->ecsOverride = ecsOverride;
+}
+
+void dnsdist_ffi_dnsquestion_set_ecs_prefix_length(dnsdist_ffi_dnsquestion_t* dq, uint16_t ecsPrefixLength)
+{
+  dq->dq->ecsPrefixLength = ecsPrefixLength;
+}
+
+void dnsdist_ffi_dnsquestion_set_temp_failure_ttl(dnsdist_ffi_dnsquestion_t* dq, uint32_t tempFailureTTL)
+{
+  dq->dq->tempFailureTTL = tempFailureTTL;
+}
+
+void dnsdist_ffi_dnsquestion_unset_temp_failure_ttl(dnsdist_ffi_dnsquestion_t* dq)
+{
+  dq->dq->tempFailureTTL = boost::none;
+}
+
+void dnsdist_ffi_dnsquestion_set_tag(dnsdist_ffi_dnsquestion_t* dq, const char* label, const char* value)
+{
+  dq->dq->setTag(label, value);
+}
+
+size_t dnsdist_ffi_dnsquestion_get_trailing_data(dnsdist_ffi_dnsquestion_t* dq, const char** out)
+{
+  dq->trailingData = dq->dq->getTrailingData();
+  if (!dq->trailingData.empty()) {
+    *out = dq->trailingData.data();
+  }
+
+  return dq->trailingData.size();
+}
+
+bool dnsdist_ffi_dnsquestion_set_trailing_data(dnsdist_ffi_dnsquestion_t* dq, const char* data, size_t dataLen)
+{
+  return dq->dq->setTrailingData(std::string(data, dataLen));
+}
+
+void dnsdist_ffi_dnsquestion_send_trap(dnsdist_ffi_dnsquestion_t* dq, const char* reason, size_t reasonLen)
+{
+  if (g_snmpAgent && g_snmpTrapsEnabled) {
+    g_snmpAgent->sendDNSTrap(*dq->dq, std::string(reason, reasonLen));
+  }
+}
+
+void dnsdist_ffi_dnsquestion_spoof_raw(dnsdist_ffi_dnsquestion_t* dq, const dnsdist_ffi_raw_value_t* values, size_t valuesCount)
+{
+  std::vector<std::string> data;
+  data.reserve(valuesCount);
+
+  for (size_t idx = 0; idx < valuesCount; idx++) {
+    data.emplace_back(values[idx].value, values[idx].size);
+  }
+
+  std::string result;
+  SpoofAction sa(data);
+  sa(dq->dq, &result);
+}
+
+void dnsdist_ffi_dnsquestion_spoof_addrs(dnsdist_ffi_dnsquestion_t* dq, const dnsdist_ffi_raw_value_t* values, size_t valuesCount)
+{
+  std::vector<ComboAddress> data;
+  data.reserve(valuesCount);
+
+  for (size_t idx = 0; idx < valuesCount; idx++) {
+    if (values[idx].size == 4) {
+      sockaddr_in sin;
+      sin.sin_family = AF_INET;
+      sin.sin_port = 0;
+      memcpy(&sin.sin_addr.s_addr, values[idx].value, sizeof(sin.sin_addr.s_addr));
+      data.emplace_back(&sin);
+    }
+    else if (values[idx].size == 16) {
+      sockaddr_in6 sin6;
+      sin6.sin6_family = AF_INET6;
+      sin6.sin6_port = 0;
+      sin6.sin6_scope_id = 0;
+      sin6.sin6_flowinfo = 0;
+      memcpy(&sin6.sin6_addr.s6_addr, values[idx].value, sizeof(sin6.sin6_addr.s6_addr));
+      data.emplace_back(&sin6);
+    }
+  }
+
+  std::string result;
+  SpoofAction sa(data);
+  sa(dq->dq, &result);
+}
+
+size_t dnsdist_ffi_servers_list_get_count(const dnsdist_ffi_servers_list_t* list)
+{
+  return list->ffiServers.size();
+}
+
+void dnsdist_ffi_servers_list_get_server(const dnsdist_ffi_servers_list_t* list, size_t idx, const dnsdist_ffi_server_t** out)
+{
+  *out = &list->ffiServers.at(idx);
+}
+
+static size_t dnsdist_ffi_servers_get_index_from_server(const ServerPolicy::NumberedServerVector& servers, const std::shared_ptr<DownstreamState>& server)
+{
+  for (const auto& pair : servers) {
+    if (pair.second == server) {
+      return pair.first - 1;
+    }
+  }
+  throw std::runtime_error("Unable to find servers in server list");
+}
+
+size_t dnsdist_ffi_servers_list_chashed(const dnsdist_ffi_servers_list_t* list, const dnsdist_ffi_dnsquestion_t* dq, size_t hash)
+{
+  auto server = chashedFromHash(list->servers, hash);
+  return dnsdist_ffi_servers_get_index_from_server(list->servers, server);
+}
+
+size_t dnsdist_ffi_servers_list_whashed(const dnsdist_ffi_servers_list_t* list, const dnsdist_ffi_dnsquestion_t* dq, size_t hash)
+{
+  auto server = whashedFromHash(list->servers, hash);
+  return dnsdist_ffi_servers_get_index_from_server(list->servers, server);
+}
+
+uint64_t dnsdist_ffi_server_get_outstanding(const dnsdist_ffi_server_t* server)
+{
+  return server->server->outstanding;
+}
+
+int dnsdist_ffi_server_get_weight(const dnsdist_ffi_server_t* server)
+{
+  return server->server->weight;
+}
+
+int dnsdist_ffi_server_get_order(const dnsdist_ffi_server_t* server)
+{
+  return server->server->order;
+}
+
+double dnsdist_ffi_server_get_latency(const dnsdist_ffi_server_t* server)
+{
+  return server->server->latencyUsec;
+}
+
+bool dnsdist_ffi_server_is_up(const dnsdist_ffi_server_t* server)
+{
+  return server->server->isUp();
+}
+
+const char* dnsdist_ffi_server_get_name(const dnsdist_ffi_server_t* server)
+{
+  return server->server->getName().c_str();
+}
+
+const char* dnsdist_ffi_server_get_name_with_addr(const dnsdist_ffi_server_t* server)
+{
+  return server->server->getNameWithAddr().c_str();
+}
+
+const std::string& getLuaFFIWrappers()
+{
+  static const std::string interface =
+#include "dnsdist-lua-ffi-interface.inc"
+    ;
+  static const std::string code = R"FFICodeContent(
+  local ffi = require("ffi")
+  local C = ffi.C
+
+  ffi.cdef[[
+)FFICodeContent" + interface + R"FFICodeContent(
+  ]]
+
+)FFICodeContent";
+  return code;
+}
+
+void setupLuaLoadBalancingContext(LuaContext& luaCtx)
+{
+  setupLuaBindings(luaCtx, true);
+  setupLuaBindingsDNSQuestion(luaCtx);
+  setupLuaBindingsKVS(luaCtx, true);
+  setupLuaVars(luaCtx);
+
+#ifdef LUAJIT_VERSION
+  luaCtx.executeCode(getLuaFFIWrappers());
+#endif
+}
+
+void setupLuaFFIPerThreadContext(LuaContext& luaCtx)
+{
+  setupLuaVars(luaCtx);
+
+#ifdef LUAJIT_VERSION
+  luaCtx.executeCode(getLuaFFIWrappers());
+#endif
+}