path: root/dnsdist-console.cc

/*
 * 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 "config.h"

#include <fstream>
// we need this to get the home directory of the current user
#include <pwd.h>
#include <thread>

#ifdef HAVE_LIBEDIT
#if defined (__OpenBSD__) || defined(__NetBSD__)
// If this is not undeffed, __attribute__ wil be redefined by /usr/include/readline/rlstdc.h
#undef __STRICT_ANSI__
#include <readline/readline.h>
#include <readline/history.h>
#else
#include <editline/readline.h>
#endif
#endif /* HAVE_LIBEDIT */

#include "ext/json11/json11.hpp"

#include "connection-management.hh"
#include "dolog.hh"
#include "dnsdist.hh"
#include "dnsdist-console.hh"
#include "sodcrypto.hh"
#include "threadname.hh"

GlobalStateHolder<NetmaskGroup> g_consoleACL;
vector<pair<struct timeval, string> > g_confDelta;
std::string g_consoleKey;
bool g_logConsoleConnections{true};
bool g_consoleEnabled{false};
uint32_t g_consoleOutputMsgMaxSize{10000000};

static ConcurrentConnectionManager s_connManager(100);

class ConsoleConnection
{
public:
  ConsoleConnection(const ComboAddress& client, FDWrapper&& fd): d_client(client), d_fd(std::move(fd))
  {
    if (!s_connManager.registerConnection()) {
      throw std::runtime_error("Too many concurrent console connections");
    }
  }
  ConsoleConnection(ConsoleConnection&& rhs): d_client(rhs.d_client), d_fd(std::move(rhs.d_fd))
  {
  }

  ConsoleConnection(const ConsoleConnection&) = delete;
  ConsoleConnection& operator=(const ConsoleConnection&) = delete;

  ~ConsoleConnection()
  {
    if (d_fd.getHandle() != -1) {
      s_connManager.releaseConnection();
    }
  }

  int getFD() const
  {
    return d_fd.getHandle();
  }

  const ComboAddress& getClient() const
  {
    return d_client;
  }

private:
  ComboAddress d_client;
  FDWrapper d_fd;
};

void setConsoleMaximumConcurrentConnections(size_t max)
{
  s_connManager.setMaxConcurrentConnections(max);
}

// MUST BE CALLED UNDER A LOCK - right now the LuaLock
static void feedConfigDelta(const std::string& line)
{
  if(line.empty())
    return;
  struct timeval now;
  gettimeofday(&now, 0);
  g_confDelta.emplace_back(now, line);
}

#ifdef HAVE_LIBEDIT
static string historyFile(const bool &ignoreHOME = false)
{
  string ret;

  struct passwd pwd;
  struct passwd *result;
  char buf[16384];
  getpwuid_r(geteuid(), &pwd, buf, sizeof(buf), &result);

  const char *homedir = getenv("HOME");
  if (result)
    ret = string(pwd.pw_dir);
  if (homedir && !ignoreHOME) // $HOME overrides what the OS tells us
    ret = string(homedir);
  if (ret.empty())
    ret = "."; // CWD if nothing works..
  ret.append("/.dnsdist_history");
  return ret;
}
#endif /* HAVE_LIBEDIT */

enum class ConsoleCommandResult : uint8_t {
  Valid = 0,
  ConnectionClosed,
  TooLarge
};

static ConsoleCommandResult getMsgLen32(int fd, uint32_t* len)
{
  try {
    uint32_t raw;
    size_t ret = readn2(fd, &raw, sizeof(raw));

    if (ret != sizeof raw) {
      return ConsoleCommandResult::ConnectionClosed;
    }

    *len = ntohl(raw);
    if (*len > g_consoleOutputMsgMaxSize) {
      return ConsoleCommandResult::TooLarge;
    }

    return ConsoleCommandResult::Valid;
  }
  catch (...) {
    return ConsoleCommandResult::ConnectionClosed;
  }
}

static bool putMsgLen32(int fd, uint32_t len)
{
  try
  {
    uint32_t raw = htonl(len);
    size_t ret = writen2(fd, &raw, sizeof raw);
    return ret == sizeof raw;
  }
  catch(...) {
    return false;
  }
}

static ConsoleCommandResult sendMessageToServer(int fd, const std::string& line, SodiumNonce& readingNonce, SodiumNonce& writingNonce, const bool outputEmptyLine)
{
  string msg = sodEncryptSym(line, g_consoleKey, writingNonce);
  const auto msgLen = msg.length();
  if (msgLen > std::numeric_limits<uint32_t>::max()) {
    cerr << "Encrypted message is too long to be sent to the server, "<< std::to_string(msgLen) << " > " << std::numeric_limits<uint32_t>::max() << endl;
    return ConsoleCommandResult::TooLarge;
  }

  putMsgLen32(fd, static_cast<uint32_t>(msgLen));

  if (!msg.empty()) {
    writen2(fd, msg);
  }

  uint32_t len;
  auto commandResult = getMsgLen32(fd, &len);
  if (commandResult == ConsoleCommandResult::ConnectionClosed) {
    cout << "Connection closed by the server." << endl;
    return commandResult;
  }
  else if (commandResult == ConsoleCommandResult::TooLarge) {
    cerr << "Received a console message whose length (" << len << ") is exceeding the allowed one (" << g_consoleOutputMsgMaxSize << "), closing that connection" << endl;
    return commandResult;
  }

  if (len == 0) {
    if (outputEmptyLine) {
      cout << endl;
    }

    return ConsoleCommandResult::Valid;
  }

  msg.clear();
  msg.resize(len);
  readn2(fd, msg.data(), len);
  msg = sodDecryptSym(msg, g_consoleKey, readingNonce);
  cout << msg;
  cout.flush();

  return ConsoleCommandResult::Valid;
}

void doClient(ComboAddress server, const std::string& command)
{
  if (!sodIsValidKey(g_consoleKey)) {
    cerr << "The currently configured console key is not valid, please configure a valid key using the setKey() directive" << endl;
    return;
  }

  if (g_verbose) {
    cout<<"Connecting to "<<server.toStringWithPort()<<endl;
  }

  auto fd = FDWrapper(socket(server.sin4.sin_family, SOCK_STREAM, 0));
  if (fd.getHandle() < 0) {
    cerr<<"Unable to connect to "<<server.toStringWithPort()<<endl;
    return;
  }
  SConnect(fd.getHandle(), server);
  setTCPNoDelay(fd.getHandle());
  SodiumNonce theirs, ours, readingNonce, writingNonce;
  ours.init();

  writen2(fd.getHandle(), (const char*)ours.value, sizeof(ours.value));
  readn2(fd.getHandle(), (char*)theirs.value, sizeof(theirs.value));
  readingNonce.merge(ours, theirs);
  writingNonce.merge(theirs, ours);

  /* try sending an empty message, the server should send an empty
     one back. If it closes the connection instead, we are probably
     having a key mismatch issue. */
  auto commandResult = sendMessageToServer(fd.getHandle(), "", readingNonce, writingNonce, false);
  if (commandResult == ConsoleCommandResult::ConnectionClosed) {
    cerr<<"The server closed the connection right away, likely indicating a key mismatch. Please check your setKey() directive."<<endl;
    return;
  }
  else if (commandResult == ConsoleCommandResult::TooLarge) {
    return;
  }

  if (!command.empty()) {
    sendMessageToServer(fd.getHandle(), command, readingNonce, writingNonce, false);
    return;
  }

#ifdef HAVE_LIBEDIT
  string histfile = historyFile();
  {
    ifstream history(histfile);
    string line;
    while (getline(history, line)) {
      add_history(line.c_str());
    }
  }
  ofstream history(histfile, std::ios_base::app);
  string lastline;
  for (;;) {
    char* sline = readline("> ");
    rl_bind_key('\t',rl_complete);
    if (!sline) {
      break;
    }

    string line(sline);
    if (!line.empty() && line != lastline) {
      add_history(sline);
      history << sline <<endl;
      history.flush();
    }
    lastline = line;
    free(sline);

    if (line == "quit") {
      break;
    }
    if (line == "help" || line == "?") {
      line = "help()";
    }

    /* no need to send an empty line to the server */
    if (line.empty()) {
      continue;
    }

    commandResult = sendMessageToServer(fd.getHandle(), line, readingNonce, writingNonce, true);
    if (commandResult != ConsoleCommandResult::Valid) {
      break;
    }
  }
#else
  errlog("Client mode requested but libedit support is not available");
#endif /* HAVE_LIBEDIT */
}

#ifdef HAVE_LIBEDIT
static std::optional<std::string> getNextConsoleLine(ofstream& history, std::string& lastline)
{
  char* sline = readline("> ");
  rl_bind_key('\t', rl_complete);
  if (!sline) {
    return std::nullopt;
  }

  string line(sline);
  if (!line.empty() && line != lastline) {
    add_history(sline);
    history << sline <<endl;
    history.flush();
  }

  lastline = line;
  free(sline);

  return line;
}
#else /* HAVE_LIBEDIT */
static std::optional<std::string> getNextConsoleLine()
{
  std::string line;
  if (!std::getline(std::cin, line)) {
    return std::nullopt;
  }
  return line;
}
#endif /* HAVE_LIBEDIT */

void doConsole()
{
#ifdef HAVE_LIBEDIT
  string histfile = historyFile(true);
  {
    ifstream history(histfile);
    string line;
    while (getline(history, line)) {
      add_history(line.c_str());
    }
  }
  ofstream history(histfile, std::ios_base::app);
  string lastline;
#endif /* HAVE_LIBEDIT */

  for (;;) {
#ifdef HAVE_LIBEDIT
    auto line = getNextConsoleLine(history, lastline);
#else /* HAVE_LIBEDIT */
    auto line = getNextConsoleLine();
#endif /* HAVE_LIBEDIT */
    if (!line) {
      break;
    }

    if (*line == "quit") {
      break;
    }
    if (*line == "help" || *line == "?") {
      line = "help()";
    }

    string response;
    try {
      bool withReturn = true;
    retry:;
      try {
        auto lua = g_lua.lock();
        g_outputBuffer.clear();
        resetLuaSideEffect();
        auto ret = lua->executeCode<
          boost::optional<
            boost::variant<
              string,
              shared_ptr<DownstreamState>,
              ClientState*,
              std::unordered_map<string, double>
              >
            >
          >(withReturn ? ("return "+*line) : *line);
        if (ret) {
          if (const auto dsValue = boost::get<shared_ptr<DownstreamState>>(&*ret)) {
            if (*dsValue) {
              cout<<(*dsValue)->getName()<<endl;
            }
          }
          else if (const auto csValue = boost::get<ClientState*>(&*ret)) {
            if (*csValue) {
              cout<<(*csValue)->local.toStringWithPort()<<endl;
            }
          }
          else if (const auto strValue = boost::get<string>(&*ret)) {
            cout<<*strValue<<endl;
          }
          else if (const auto um = boost::get<std::unordered_map<string, double> >(&*ret)) {
            using namespace json11;
            Json::object o;
            for(const auto& v : *um)
              o[v.first]=v.second;
            Json out = o;
            cout<<out.dump()<<endl;
          }
        }
        else {
          cout << g_outputBuffer << std::flush;
        }

        if (!getLuaNoSideEffect()) {
          feedConfigDelta(*line);
        }
      }
      catch (const LuaContext::SyntaxErrorException&) {
        if (withReturn) {
          withReturn=false;
          goto retry;
        }
        throw;
      }
    }
    catch (const LuaContext::WrongTypeException& e) {
      std::cerr<<"Command returned an object we can't print: "<<std::string(e.what())<<std::endl;
      // tried to return something we don't understand
    }
    catch (const LuaContext::ExecutionErrorException& e) {
      if (!strcmp(e.what(), "invalid key to 'next'")) {
        std::cerr<<"Error parsing parameters, did you forget parameter name?";
      }
      else {
        std::cerr << e.what();
      }

      try {
        std::rethrow_if_nested(e);

        std::cerr << std::endl;
      } catch (const std::exception& ne) {
        // ne is the exception that was thrown from inside the lambda
        std::cerr << ": " << ne.what() << std::endl;
      }
      catch (const PDNSException& ne) {
        // ne is the exception that was thrown from inside the lambda
        std::cerr << ": " << ne.reason << std::endl;
      }
    }
    catch (const std::exception& e) {
      std::cerr << e.what() << std::endl;
    }
  }
}

#ifndef DISABLE_COMPLETION
/**** CARGO CULT CODE AHEAD ****/
const std::vector<ConsoleKeyword> g_consoleKeywords{
  /* keyword, function, parameters, description */
  { "addACL", true, "netmask", "add to the ACL set who can use this server" },
  { "addAction", true, "DNS rule, DNS action [, {uuid=\"UUID\", name=\"name\"}]", "add a rule" },
  { "addBPFFilterDynBlocks", true, "addresses, dynbpf[[, seconds=10], msg]", "This is the eBPF equivalent of addDynBlocks(), blocking a set of addresses for (optionally) a number of seconds, using an eBPF dynamic filter" },
  { "addCapabilitiesToRetain", true, "capability or list of capabilities", "Linux capabilities to retain after startup, like CAP_BPF" },
  { "addConsoleACL", true, "netmask", "add a netmask to the console ACL" },
  { "addDNSCryptBind", true, "\"127.0.0.1:8443\", \"provider name\", \"/path/to/resolver.cert\", \"/path/to/resolver.key\", {reusePort=false, tcpFastOpenQueueSize=0, interface=\"\", cpus={}}", "listen to incoming DNSCrypt queries on 127.0.0.1 port 8443, with a provider name of `provider name`, using a resolver certificate and associated key stored respectively in the `resolver.cert` and `resolver.key` files. The fifth optional parameter is a table of parameters" },
  { "addDOHLocal", true, "addr, certFile, keyFile [, urls [, vars]]", "listen to incoming DNS over HTTPS queries on the specified address using the specified certificate and key. The last two parameters are tables" },
  { "addDynBlocks", true, "addresses, message[, seconds[, action]]", "block the set of addresses with message `msg`, for `seconds` seconds (10 by default), applying `action` (default to the one set with `setDynBlocksAction()`)" },
  { "addDynBlockSMT", true, "names, message[, seconds [, action]]", "block the set of names with message `msg`, for `seconds` seconds (10 by default), applying `action` (default to the one set with `setDynBlocksAction()`)" },
  { "addLocal", true, "addr [, {doTCP=true, reusePort=false, tcpFastOpenQueueSize=0, interface=\"\", cpus={}}]", "add `addr` to the list of addresses we listen on" },
  { "addCacheHitResponseAction", true, "DNS rule, DNS response action [, {uuid=\"UUID\", name=\"name\"}}]", "add a cache hit response rule" },
  { "addCacheInsertedResponseAction", true, "DNS rule, DNS response action [, {uuid=\"UUID\", name=\"name\"}}]", "add a cache inserted response rule" },
  { "addResponseAction", true, "DNS rule, DNS response action [, {uuid=\"UUID\", name=\"name\"}}]", "add a response rule" },
  { "addSelfAnsweredResponseAction", true, "DNS rule, DNS response action [, {uuid=\"UUID\", name=\"name\"}}]", "add a self-answered response rule" },
  { "addTLSLocal", true, "addr, certFile(s), keyFile(s) [,params]", "listen to incoming DNS over TLS queries on the specified address using the specified certificate (or list of) and key (or list of). The last parameter is a table" },
  { "AllowAction", true, "", "let these packets go through" },
  { "AllowResponseAction", true, "", "let these packets go through" },
  { "AllRule", true, "", "matches all traffic" },
  { "AndRule", true, "list of DNS rules", "matches if all sub-rules matches" },
  { "benchRule", true, "DNS Rule [, iterations [, suffix]]", "bench the specified DNS rule" },
  { "carbonServer", true, "serverIP, [ourname], [interval]", "report statistics to serverIP using our hostname, or 'ourname' if provided, every 'interval' seconds" },
  { "clearConsoleHistory", true, "", "clear the internal (in-memory) history of console commands" },
  { "clearDynBlocks", true, "", "clear all dynamic blocks" },
  { "clearQueryCounters", true, "", "clears the query counter buffer" },
  { "clearRules", true, "", "remove all current rules" },
  { "controlSocket", true, "addr", "open a control socket on this address / connect to this address in client mode" },
  { "ContinueAction", true, "action", "execute the specified action and continue the processing of the remaining rules, regardless of the return of the action" },
  { "declareMetric", true, "name, type, description [, prometheusName]", "Declare a custom metric" },
  { "decMetric", true, "name", "Decrement a custom metric" },
  { "DelayAction", true, "milliseconds", "delay the response by the specified amount of milliseconds (UDP-only)" },
  { "DelayResponseAction", true, "milliseconds", "delay the response by the specified amount of milliseconds (UDP-only)" },
  { "delta", true, "", "shows all commands entered that changed the configuration" },
  { "DNSSECRule", true, "", "matches queries with the DO bit set" },
  { "DnstapLogAction", true, "identity, FrameStreamLogger [, alterFunction]", "send the contents of this query to a FrameStreamLogger or RemoteLogger as dnstap. `alterFunction` is a callback, receiving a DNSQuestion and a DnstapMessage, that can be used to modify the dnstap message" },
  { "DnstapLogResponseAction", true, "identity, FrameStreamLogger [, alterFunction]", "send the contents of this response to a remote or FrameStreamLogger or RemoteLogger as dnstap. `alterFunction` is a callback, receiving a DNSResponse and a DnstapMessage, that can be used to modify the dnstap message" },
  { "DropAction", true, "", "drop these packets" },
  { "DropResponseAction", true, "", "drop these packets" },
  { "DSTPortRule", true, "port", "matches questions received to the destination port specified" },
  { "dumpStats", true, "", "print all statistics we gather" },
  { "dynBlockRulesGroup", true, "", "return a new DynBlockRulesGroup object" },
  { "EDNSVersionRule", true, "version", "matches queries with the specified EDNS version" },
  { "EDNSOptionRule", true, "optcode", "matches queries with the specified EDNS0 option present" },
  { "ERCodeAction", true, "ercode", "Reply immediately by turning the query into a response with the specified EDNS extended rcode" },
  { "ERCodeRule", true, "rcode", "matches responses with the specified extended rcode (EDNS0)" },
  { "exceedNXDOMAINs", true, "rate, seconds", "get set of addresses that exceed `rate` NXDOMAIN/s over `seconds` seconds" },
  { "exceedQRate", true, "rate, seconds", "get set of address that exceed `rate` queries/s over `seconds` seconds" },
  { "exceedQTypeRate", true, "type, rate, seconds", "get set of address that exceed `rate` queries/s for queries of type `type` over `seconds` seconds" },
  { "exceedRespByterate", true, "rate, seconds", "get set of addresses that exceeded `rate` bytes/s answers over `seconds` seconds" },
  { "exceedServFails", true, "rate, seconds", "get set of addresses that exceed `rate` servfails/s over `seconds` seconds" },
  { "firstAvailable", false, "", "picks the server with the lowest `order` that has not exceeded its QPS limit" },
  { "fixupCase", true, "bool", "if set (default to no), rewrite the first qname of the question part of the answer to match the one from the query. It is only useful when you have a downstream server that messes up the case of the question qname in the answer" },
  { "generateDNSCryptCertificate", true, "\"/path/to/providerPrivate.key\", \"/path/to/resolver.cert\", \"/path/to/resolver.key\", serial, validFrom, validUntil", "generate a new resolver private key and related certificate, valid from the `validFrom` timestamp until the `validUntil` one, signed with the provider private key" },
  { "generateDNSCryptProviderKeys", true, "\"/path/to/providerPublic.key\", \"/path/to/providerPrivate.key\"", "generate a new provider keypair" },
  { "getAction", true, "n", "Returns the Action associated with rule n" },
  { "getBind", true, "n", "returns the listener at index n" },
  { "getBindCount", true, "", "returns the number of listeners all kinds" },
  { "getCurrentTime", true, "", "returns the current time" },
  { "getDNSCryptBind", true, "n", "return the `DNSCryptContext` object corresponding to the bind `n`" },
  { "getDNSCryptBindCount", true, "", "returns the number of DNSCrypt listeners" },
  { "getDOHFrontend", true, "n", "returns the DOH frontend with index n" },
  { "getDOHFrontendCount", true, "", "returns the number of DoH listeners" },
  { "getListOfAddressesOfNetworkInterface", true, "itf", "returns the list of addresses configured on a given network interface, as strings" },
  { "getListOfNetworkInterfaces", true, "", "returns the list of network interfaces present on the system, as strings" },
  { "getListOfRangesOfNetworkInterface", true, "itf", "returns the list of network ranges configured on a given network interface, as strings" },
  { "getMACAddress", true, "IP addr", "return the link-level address (MAC) corresponding to the supplied neighbour  IP address, if known by the kernel" },
  { "getMetric", true, "name", "Get the value of a custom metric" },
  { "getOutgoingTLSSessionCacheSize", true, "", "returns the number of TLS sessions (for outgoing connections) currently cached" },
  { "getPool", true, "name", "return the pool named `name`, or \"\" for the default pool" },
  { "getPoolServers", true, "pool", "return servers part of this pool" },
  { "getPoolNames", true, "", "returns a table with all the pool names" },
  { "getQueryCounters", true, "[max=10]", "show current buffer of query counters, limited by 'max' if provided" },
  { "getResponseRing", true, "", "return the current content of the response ring" },
  { "getRespRing", true, "", "return the qname/rcode content of the response ring" },
  { "getServer", true, "id", "returns server with index 'n' or whose uuid matches if 'id' is an UUID string" },
  { "getServers", true, "", "returns a table with all defined servers" },
  { "getStatisticsCounters", true, "", "returns a map of statistic counters" },
  { "getTopCacheHitResponseRules", true, "[top]", "return the `top` cache-hit response rules" },
  { "getTopCacheInsertedResponseRules", true, "[top]", "return the `top` cache-inserted response rules" },
  { "getTopResponseRules", true, "[top]", "return the `top` response rules" },
  { "getTopRules", true, "[top]", "return the `top` rules" },
  { "getTopSelfAnsweredResponseRules", true, "[top]", "return the `top` self-answered response rules" },
  { "getTLSContext", true, "n", "returns the TLS context with index n" },
  { "getTLSFrontend", true, "n", "returns the TLS frontend with index n" },
  { "getTLSFrontendCount", true, "", "returns the number of DoT listeners" },
  { "getVerbose", true, "", "get whether log messages at the verbose level will be logged" },
  { "grepq", true, "Netmask|DNS Name|100ms|{\"::1\", \"powerdns.com\", \"100ms\"} [, n]", "shows the last n queries and responses matching the specified client address or range (Netmask), or the specified DNS Name, or slower than 100ms" },
  { "hashPassword", true, "password [, workFactor]", "Returns a hashed and salted version of the supplied password, usable with 'setWebserverConfig()'"},
  { "HTTPHeaderRule", true, "name, regex", "matches DoH queries with a HTTP header 'name' whose content matches the regular expression 'regex'"},
  { "HTTPPathRegexRule", true, "regex", "matches DoH queries whose HTTP path matches 'regex'"},
  { "HTTPPathRule", true, "path", "matches DoH queries whose HTTP path is an exact match to 'path'"},
  { "HTTPStatusAction", true, "status, reason, body", "return an HTTP response"},
  { "inClientStartup", true, "", "returns true during console client parsing of configuration" },
  { "includeDirectory", true, "path", "include configuration files from `path`" },
  { "incMetric", true, "name", "Increment a custom metric" },
  { "KeyValueLookupKeyQName", true, "[wireFormat]", "Return a new KeyValueLookupKey object that, when passed to KeyValueStoreLookupAction or KeyValueStoreLookupRule, will return the qname of the query, either in wire format (default) or in plain text if 'wireFormat' is false" },
  { "KeyValueLookupKeySourceIP", true, "[v4Mask [, v6Mask [, includePort]]]", "Return a new KeyValueLookupKey object that, when passed to KeyValueStoreLookupAction or KeyValueStoreLookupRule, will return the (possibly bitmasked) source IP of the client in network byte-order." },
  { "KeyValueLookupKeySuffix", true, "[minLabels [,wireFormat]]", "Return a new KeyValueLookupKey object that, when passed to KeyValueStoreLookupAction or KeyValueStoreLookupRule, will return a vector of keys based on the labels of the qname in DNS wire format or plain text" },
  { "KeyValueLookupKeyTag", true, "tag", "Return a new KeyValueLookupKey object that, when passed to KeyValueStoreLookupAction or KeyValueStoreLookupRule, will return the value of the corresponding tag for this query, if it exists" },
  { "KeyValueStoreLookupAction", true, "kvs, lookupKey, destinationTag", "does a lookup into the key value store referenced by 'kvs' using the key returned by 'lookupKey', and storing the result if any into the tag named 'destinationTag'" },
  { "KeyValueStoreRangeLookupAction", true, "kvs, lookupKey, destinationTag", "does a range-based lookup into the key value store referenced by 'kvs' using the key returned by 'lookupKey', and storing the result if any into the tag named 'destinationTag'" },
  { "KeyValueStoreLookupRule", true, "kvs, lookupKey", "matches queries if the key is found in the specified Key Value store" },
  { "KeyValueStoreRangeLookupRule", true, "kvs, lookupKey", "matches queries if the key is found in the specified Key Value store" },
  { "leastOutstanding", false, "", "Send traffic to downstream server with least outstanding queries, with the lowest 'order', and within that the lowest recent latency"},
#if defined(HAVE_LIBSSL) && !defined(HAVE_TLS_PROVIDERS)
  { "loadTLSEngine", true, "engineName [, defaultString]", "Load the OpenSSL engine named 'engineName', setting the engine default string to 'defaultString' if supplied"},
#endif
#if defined(HAVE_LIBSSL) && OPENSSL_VERSION_MAJOR >= 3 && defined(HAVE_TLS_PROVIDERS)
  { "loadTLSProvider", true, "providerName", "Load the OpenSSL provider named 'providerName'"},
#endif
  { "LogAction", true, "[filename], [binary], [append], [buffered]", "Log a line for each query, to the specified file if any, to the console (require verbose) otherwise. When logging to a file, the `binary` optional parameter specifies whether we log in binary form (default) or in textual form, the `append` optional parameter specifies whether we open the file for appending or truncate each time (default), and the `buffered` optional parameter specifies whether writes to the file are buffered (default) or not." },
  { "LogResponseAction", true, "[filename], [append], [buffered]", "Log a line for each response, to the specified file if any, to the console (require verbose) otherwise. The `append` optional parameter specifies whether we open the file for appending or truncate each time (default), and the `buffered` optional parameter specifies whether writes to the file are buffered (default) or not." },
  { "LuaAction", true, "function", "Invoke a Lua function that accepts a DNSQuestion" },
  { "LuaFFIAction", true, "function", "Invoke a Lua FFI function that accepts a DNSQuestion" },
  { "LuaFFIPerThreadAction", true, "function", "Invoke a Lua FFI function that accepts a DNSQuestion, with a per-thread Lua context" },
  { "LuaFFIPerThreadResponseAction", true, "function", "Invoke a Lua FFI function that accepts a DNSResponse, with a per-thread Lua context" },
  { "LuaFFIResponseAction", true, "function", "Invoke a Lua FFI function that accepts a DNSResponse" },
  { "LuaFFIRule", true, "function", "Invoke a Lua FFI function that filters DNS questions" },
  { "LuaResponseAction", true, "function", "Invoke a Lua function that accepts a DNSResponse" },
  { "LuaRule", true, "function", "Invoke a Lua function that filters DNS questions" },
#ifdef HAVE_IPCIPHER
  { "makeIPCipherKey", true, "password", "generates a 16-byte key that can be used to pseudonymize IP addresses with IP cipher" },
#endif /* HAVE_IPCIPHER */
  { "makeKey", true, "", "generate a new server access key, emit configuration line ready for pasting" },
  { "makeRule", true, "rule", "Make a NetmaskGroupRule() or a SuffixMatchNodeRule(), depending on how it is called" }  ,
  { "MaxQPSIPRule", true, "qps, [v4Mask=32 [, v6Mask=64 [, burst=qps [, expiration=300 [, cleanupDelay=60 [, scanFraction=10 [, shards=10]]]]]]]", "matches traffic exceeding the qps limit per subnet" },
  { "MaxQPSRule", true, "qps", "matches traffic **not** exceeding this qps limit" },
  { "mvCacheHitResponseRule", true, "from, to", "move cache hit response rule 'from' to a position where it is in front of 'to'. 'to' can be one larger than the largest rule" },
  { "mvCacheHitResponseRuleToTop", true, "", "move the last cache hit response rule to the first position" },
  { "mvCacheInsertedResponseRule", true, "from, to", "move cache inserted response rule 'from' to a position where it is in front of 'to'. 'to' can be one larger than the largest rule" },
  { "mvCacheInsertedResponseRuleToTop", true, "", "move the last cache inserted response rule to the first position" },
  { "mvResponseRule", true, "from, to", "move response rule 'from' to a position where it is in front of 'to'. 'to' can be one larger than the largest rule" },
  { "mvResponseRuleToTop", true, "", "move the last response rule to the first position" },
  { "mvRule", true, "from, to", "move rule 'from' to a position where it is in front of 'to'. 'to' can be one larger than the largest rule, in which case the rule will be moved to the last position" },
  { "mvRuleToTop", true, "", "move the last rule to the first position" },
  { "mvSelfAnsweredResponseRule", true, "from, to", "move self-answered response rule 'from' to a position where it is in front of 'to'. 'to' can be one larger than the largest rule" },
  { "mvSelfAnsweredResponseRuleToTop", true, "", "move the last self-answered response rule to the first position" },
  { "NetmaskGroupRule", true, "nmg[, src]", "Matches traffic from/to the network range specified in nmg. Set the src parameter to false to match nmg against destination address instead of source address. This can be used to differentiate between clients" },
  { "newBPFFilter", true, "{ipv4MaxItems=int, ipv4PinnedPath=string, ipv6MaxItems=int, ipv6PinnedPath=string, cidr4MaxItems=int, cidr4PinnedPath=string, cidr6MaxItems=int, cidr6PinnedPath=string, qnamesMaxItems=int, qnamesPinnedPath=string, external=bool}", "Return a new eBPF socket filter with specified options." },
  { "newCA", true, "address", "Returns a ComboAddress based on `address`" },
#ifdef HAVE_CDB
  { "newCDBKVStore", true, "fname, refreshDelay", "Return a new KeyValueStore object associated to the corresponding CDB database" },
#endif
  { "newDNSName", true, "name", "make a DNSName based on this .-terminated name" },
  { "newDNSNameSet", true, "", "returns a new DNSNameSet" },
  { "newDynBPFFilter", true, "bpf", "Return a new dynamic eBPF filter associated to a given BPF Filter" },
  { "newFrameStreamTcpLogger", true, "addr [, options]", "create a FrameStream logger object writing to a TCP address (addr should be ip:port), to use with `DnstapLogAction()` and `DnstapLogResponseAction()`" },
  { "newFrameStreamUnixLogger", true, "socket [, options]", "create a FrameStream logger object writing to a local unix socket, to use with `DnstapLogAction()` and `DnstapLogResponseAction()`" },
#ifdef HAVE_LMDB
  { "newLMDBKVStore", true, "fname, dbName [, noLock]", "Return a new KeyValueStore object associated to the corresponding LMDB database" },
#endif
  { "newNMG", true, "", "Returns a NetmaskGroup" },
  { "newPacketCache", true, "maxEntries[, maxTTL=86400, minTTL=0, temporaryFailureTTL=60, staleTTL=60, dontAge=false, numberOfShards=1, deferrableInsertLock=true, options={}]", "return a new Packet Cache" },
  { "newQPSLimiter", true, "rate, burst", "configure a QPS limiter with that rate and that burst capacity" },
  { "newRemoteLogger", true, "address:port [, timeout=2, maxQueuedEntries=100, reconnectWaitTime=1]", "create a Remote Logger object, to use with `RemoteLogAction()` and `RemoteLogResponseAction()`" },
  { "newRuleAction", true, "DNS rule, DNS action [, {uuid=\"UUID\", name=\"name\"}]", "return a pair of DNS Rule and DNS Action, to be used with `setRules()`" },
  { "newServer", true, "{address=\"ip:port\", qps=1000, order=1, weight=10, pool=\"abuse\", retries=5, tcpConnectTimeout=5, tcpSendTimeout=30, tcpRecvTimeout=30, checkName=\"a.root-servers.net.\", checkType=\"A\", maxCheckFailures=1, mustResolve=false, useClientSubnet=true, source=\"address|interface name|address@interface\", sockets=1, reconnectOnUp=false}", "instantiate a server" },
  { "newServerPolicy", true, "name, function", "create a policy object from a Lua function" },
  { "newSuffixMatchNode", true, "", "returns a new SuffixMatchNode" },
  { "newSVCRecordParameters", true, "priority, target, mandatoryParams, alpns, noDefaultAlpn [, port [, ech [, ipv4hints [, ipv6hints [, additionalParameters ]]]]]", "return a new SVCRecordParameters object, to use with SpoofSVCAction" },
  { "NegativeAndSOAAction", true, "nxd, zone, ttl, mname, rname, serial, refresh, retry, expire, minimum [, options]", "Turn a query into a NXDomain or NoData answer and sets a SOA record in the additional section" },
  { "NoneAction", true, "", "Does nothing. Subsequent rules are processed after this action" },
  { "NotRule", true, "selector", "Matches the traffic if the selector rule does not match" },
  { "OpcodeRule", true, "code", "Matches queries with opcode code. code can be directly specified as an integer, or one of the built-in DNSOpcodes" },
  { "OrRule", true, "selectors", "Matches the traffic if one or more of the the selectors rules does match" },
  { "PoolAction", true, "poolname [, stop]", "set the packet into the specified pool" },
  { "PoolAvailableRule", true, "poolname", "Check whether a pool has any servers available to handle queries" },
  { "PoolOutstandingRule", true, "poolname, limit", "Check whether a pool has outstanding queries above limit" },
  { "printDNSCryptProviderFingerprint", true, "\"/path/to/providerPublic.key\"", "display the fingerprint of the provided resolver public key" },
  { "ProbaRule", true, "probability", "Matches queries with a given probability. 1.0 means always" },
  { "ProxyProtocolValueRule", true, "type [, value]", "matches queries with a specified Proxy Protocol TLV value of that type, optionally matching the content of the option as well" },
  { "QClassRule", true, "qclass", "Matches queries with the specified qclass. class can be specified as an integer or as one of the built-in DNSClass" },
  { "QNameLabelsCountRule", true, "min, max", "matches if the qname has less than `min` or more than `max` labels" },
  { "QNameRule", true, "qname", "matches queries with the specified qname" },
  { "QNameSetRule", true, "set", "Matches if the set contains exact qname" },
  { "QNameWireLengthRule", true, "min, max", "matches if the qname's length on the wire is less than `min` or more than `max` bytes" },
  { "QPSAction", true, "maxqps", "Drop a packet if it does exceed the maxqps queries per second limits. Letting the subsequent rules apply otherwise" },
  { "QPSPoolAction", true, "maxqps, poolname [, stop]", "Send the packet into the specified pool only if it does not exceed the maxqps queries per second limits. Letting the subsequent rules apply otherwise" },
  { "QTypeRule", true, "qtype", "matches queries with the specified qtype" },
  { "RCodeAction", true, "rcode", "Reply immediately by turning the query into a response with the specified rcode" },
  { "RCodeRule", true, "rcode", "matches responses with the specified rcode" },
  { "RDRule", true, "", "Matches queries with the RD flag set" },
  { "RecordsCountRule", true, "section, minCount, maxCount", "Matches if there is at least minCount and at most maxCount records in the section section. section can be specified as an integer or as a DNS Packet Sections" },
  { "RecordsTypeCountRule", true, "section, qtype, minCount, maxCount", "Matches if there is at least minCount and at most maxCount records of type type in the section section" },
  { "RegexRule", true, "regex", "matches the query name against the supplied regex" },
  { "registerDynBPFFilter", true, "DynBPFFilter", "register this dynamic BPF filter into the web interface so that its counters are displayed" },
  { "reloadAllCertificates", true, "", "reload all DNSCrypt and TLS certificates, along with their associated keys" },
  { "RemoteLogAction", true, "RemoteLogger [, alterFunction [, serverID]]", "send the content of this query to a remote logger via Protocol Buffer. `alterFunction` is a callback, receiving a DNSQuestion and a DNSDistProtoBufMessage, that can be used to modify the Protocol Buffer content, for example for anonymization purposes. `serverID` is the server identifier." },
  { "RemoteLogResponseAction", true, "RemoteLogger [,alterFunction [,includeCNAME [, serverID]]]", "send the content of this response to a remote logger via Protocol Buffer. `alterFunction` is the same callback than the one in `RemoteLogAction` and `includeCNAME` indicates whether CNAME records inside the response should be parsed and exported. The default is to only exports A and AAAA records. `serverID` is the server identifier." },
  { "requestTCPStatesDump", true, "", "Request a dump of the TCP states (incoming connections, outgoing connections) during the next scan. Useful for debugging purposes only" },
  { "rmACL", true, "netmask", "remove netmask from ACL" },
  { "rmCacheHitResponseRule", true, "id", "remove cache hit response rule in position 'id', or whose uuid matches if 'id' is an UUID string, or finally whose name matches if 'id' is a string but not a valid UUID" },
  { "rmCacheInsertedResponseRule", true, "id", "remove cache inserted response rule in position 'id', or whose uuid matches if 'id' is an UUID string, or finally whose name matches if 'id' is a string but not a valid UUID" },
  { "rmResponseRule", true, "id", "remove response rule in position 'id', or whose uuid matches if 'id' is an UUID string, or finally whose name matches if 'id' is a string but not a valid UUID" },
  { "rmRule", true, "id", "remove rule in position 'id', or whose uuid matches if 'id' is an UUID string, or finally whose name matches if 'id' is a string but not a valid UUID" },
  { "rmSelfAnsweredResponseRule", true, "id", "remove self-answered response rule in position 'id', or whose uuid matches if 'id' is an UUID string, or finally whose name matches if 'id' is a string but not a valid UUID" },
  { "rmServer", true, "id", "remove server with index 'id' or whose uuid matches if 'id' is an UUID string" },
  { "roundrobin", false, "", "Simple round robin over available servers" },
  { "sendCustomTrap", true, "str", "send a custom `SNMP` trap from Lua, containing the `str` string"},
  { "setACL", true, "{netmask, netmask}", "replace the ACL set with these netmasks. Use `setACL({})` to reset the list, meaning no one can use us" },
  { "setACLFromFile", true, "file", "replace the ACL set with netmasks in this file" },
  { "setAddEDNSToSelfGeneratedResponses", true, "add", "set whether to add EDNS to self-generated responses, provided that the initial query had EDNS" },
  { "setAllowEmptyResponse", true, "allow", "Set to true (defaults to false) to allow empty responses (qdcount=0) with a NoError or NXDomain rcode (default) from backends" },
  { "setAPIWritable", true, "bool, dir", "allow modifications via the API. if `dir` is set, it must be a valid directory where the configuration files will be written by the API" },
  { "setCacheCleaningDelay", true, "num", "Set the interval in seconds between two runs of the cache cleaning algorithm, removing expired entries" },
  { "setCacheCleaningPercentage", true, "num", "Set the percentage of the cache that the cache cleaning algorithm will try to free by removing expired entries. By default (100), all expired entries are remove" },
  { "setConsistentHashingBalancingFactor", true, "factor", "Set the balancing factor for bounded-load consistent hashing" },
  { "setConsoleACL", true, "{netmask, netmask}", "replace the console ACL set with these netmasks" },
  { "setConsoleConnectionsLogging", true, "enabled", "whether to log the opening and closing of console connections" },
  { "setConsoleMaximumConcurrentConnections", true, "max", "Set the maximum number of concurrent console connections" },
  { "setConsoleOutputMaxMsgSize", true, "messageSize", "set console message maximum size in bytes, default is 10 MB" },
  { "setDefaultBPFFilter", true, "filter", "When used at configuration time, the corresponding BPFFilter will be attached to every bind" },
  { "setDoHDownstreamCleanupInterval", true, "interval", "minimum interval in seconds between two cleanups of the idle DoH downstream connections" },
  { "setDoHDownstreamMaxIdleTime", true, "time", "Maximum time in seconds that a downstream DoH connection to a backend might stay idle" },
  { "setDynBlocksAction", true, "action", "set which action is performed when a query is blocked. Only DNSAction.Drop (the default) and DNSAction.Refused are supported" },
  { "setDynBlocksPurgeInterval", true, "sec", "set how often the expired dynamic block entries should be removed" },
  { "setDropEmptyQueries", true, "drop", "Whether to drop empty queries right away instead of sending a NOTIMP response" },
  { "setECSOverride", true, "bool", "whether to override an existing EDNS Client Subnet value in the query" },
  { "setECSSourcePrefixV4", true, "prefix-length", "the EDNS Client Subnet prefix-length used for IPv4 queries" },
  { "setECSSourcePrefixV6", true, "prefix-length", "the EDNS Client Subnet prefix-length used for IPv6 queries" },
  { "setKey", true, "key", "set access key to that key" },
  { "setLocal", true, "addr [, {doTCP=true, reusePort=false, tcpFastOpenQueueSize=0, interface=\"\", cpus={}}]", "reset the list of addresses we listen on to this address" },
  { "setMaxCachedDoHConnectionsPerDownstream", true, "max", "Set the maximum number of inactive DoH connections to a backend cached by each worker DoH thread" },
  { "setMaxCachedTCPConnectionsPerDownstream", true, "max", "Set the maximum number of inactive TCP connections to a backend cached by each worker TCP thread" },
  { "setMaxTCPClientThreads", true, "n", "set the maximum of TCP client threads, handling TCP connections" },
  { "setMaxTCPConnectionDuration", true, "n", "set the maximum duration of an incoming TCP connection, in seconds. 0 means unlimited" },
  { "setMaxTCPConnectionsPerClient", true, "n", "set the maximum number of TCP connections per client. 0 means unlimited" },
  { "setMaxTCPQueriesPerConnection", true, "n", "set the maximum number of queries in an incoming TCP connection. 0 means unlimited" },
  { "setMaxTCPQueuedConnections", true, "n", "set the maximum number of TCP connections queued (waiting to be picked up by a client thread)" },
  { "setMaxUDPOutstanding", true, "n", "set the maximum number of outstanding UDP queries to a given backend server. This can only be set at configuration time and defaults to 65535" },
  { "setMetric", true, "name, value", "Set the value of a custom metric to the supplied value" },
  { "setPayloadSizeOnSelfGeneratedAnswers", true, "payloadSize", "set the UDP payload size advertised via EDNS on self-generated responses" },
  { "setPoolServerPolicy", true, "policy, pool", "set the server selection policy for this pool to that policy" },
  { "setPoolServerPolicyLua", true, "name, function, pool", "set the server selection policy for this pool to one named 'name' and provided by 'function'" },
  { "setPoolServerPolicyLuaFFI", true, "name, function, pool", "set the server selection policy for this pool to one named 'name' and provided by 'function'" },
  { "setPoolServerPolicyLuaFFIPerThread", true, "name, code", "set server selection policy for this pool to one named 'name' and returned by the Lua FFI code passed in 'code'" },
  { "setProxyProtocolACL", true, "{netmask, netmask}", "Set the netmasks who are allowed to send Proxy Protocol headers in front of queries/connections" },
  { "setProxyProtocolApplyACLToProxiedClients", true, "apply", "Whether the general ACL should be applied to the source IP address gathered from a Proxy Protocol header, in addition to being first applied to the source address seen by dnsdist" },
  { "setProxyProtocolMaximumPayloadSize", true, "max", "Set the maximum size of a Proxy Protocol payload, in bytes" },
  { "setQueryCount", true, "bool", "set whether queries should be counted" },
  { "setQueryCountFilter", true, "func", "filter queries that would be counted, where `func` is a function with parameter `dq` which decides whether a query should and how it should be counted" },
  { "SetReducedTTLResponseAction", true, "percentage", "Reduce the TTL of records in a response to a given percentage" },
  { "setRingBuffersLockRetries", true, "n", "set the number of attempts to get a non-blocking lock to a ringbuffer shard before blocking" },
  { "setRingBuffersOptions", true, "{ lockRetries=int, recordQueries=true, recordResponses=true }", "set ringbuffer options" },
  { "setRingBuffersSize", true, "n [, numberOfShards]", "set the capacity of the ringbuffers used for live traffic inspection to `n`, and optionally the number of shards to use to `numberOfShards`" },
  { "setRoundRobinFailOnNoServer", true, "value", "By default the roundrobin load-balancing policy will still try to select a backend even if all backends are currently down. Setting this to true will make the policy fail and return that no server is available instead" },
  { "setRules", true, "list of rules", "replace the current rules with the supplied list of pairs of DNS Rules and DNS Actions (see `newRuleAction()`)" },
  { "setSecurityPollInterval", true, "n", "set the security polling interval to `n` seconds" },
  { "setSecurityPollSuffix", true, "suffix", "set the security polling suffix to the specified value" },
  { "setServerPolicy", true, "policy", "set server selection policy to that policy" },
  { "setServerPolicyLua", true, "name, function", "set server selection policy to one named 'name' and provided by 'function'" },
  { "setServerPolicyLuaFFI", true, "name, function", "set server selection policy to one named 'name' and provided by the Lua FFI 'function'" },
  { "setServerPolicyLuaFFIPerThread", true, "name, code", "set server selection policy to one named 'name' and returned by the Lua FFI code passed in 'code'" },
  { "setServFailWhenNoServer", true, "bool", "if set, return a ServFail when no servers are available, instead of the default behaviour of dropping the query" },
  { "setStaleCacheEntriesTTL", true, "n", "allows using cache entries expired for at most n seconds when there is no backend available to answer for a query" },
  { "setSyslogFacility", true, "facility", "set the syslog logging facility to 'facility'. Defaults to LOG_DAEMON" },
  { "setTCPDownstreamCleanupInterval", true, "interval", "minimum interval in seconds between two cleanups of the idle TCP downstream connections" },
  { "setTCPFastOpenKey", true, "string", "TCP Fast Open Key" },
  { "setTCPDownstreamMaxIdleTime", true, "time", "Maximum time in seconds that a downstream TCP connection to a backend might stay idle" },
  { "setTCPInternalPipeBufferSize", true, "size", "Set the size in bytes of the internal buffer of the pipes used internally to distribute connections to TCP (and DoT) workers threads" },
  { "setTCPRecvTimeout", true, "n", "set the read timeout on TCP connections from the client, in seconds" },
  { "setTCPSendTimeout", true, "n", "set the write timeout on TCP connections from the client, in seconds" },
  { "setUDPMultipleMessagesVectorSize", true, "n", "set the size of the vector passed to recvmmsg() to receive UDP messages. Default to 1 which means that the feature is disabled and recvmsg() is used instead" },
  { "setUDPSocketBufferSizes", true, "recv, send", "Set the size of the receive (SO_RCVBUF) and send (SO_SNDBUF) buffers for incoming UDP sockets" },
  { "setUDPTimeout", true, "n", "set the maximum time dnsdist will wait for a response from a backend over UDP, in seconds" },
  { "setVerbose", true, "bool", "set whether log messages at the verbose level will be logged" },
  { "setVerboseHealthChecks", true, "bool", "set whether health check errors will be logged" },
  { "setVerboseLogDestination", true, "destination file", "Set a destination file to write the 'verbose' log messages to, instead of sending them to syslog and/or the standard output" },
  { "setWebserverConfig", true, "[{password=string, apiKey=string, customHeaders, statsRequireAuthentication}]", "Updates webserver configuration" },
  { "setWeightedBalancingFactor", true, "factor", "Set the balancing factor for bounded-load weighted policies (whashed, wrandom)" },
  { "setWHashedPertubation", true, "value", "Set the hash perturbation value to be used in the whashed policy instead of a random one, allowing to have consistent whashed results on different instance" },
  { "show", true, "string", "outputs `string`" },
  { "showACL", true, "", "show our ACL set" },
  { "showBinds", true, "", "show listening addresses (frontends)" },
  { "showCacheHitResponseRules", true, "[{showUUIDs=false, truncateRuleWidth=-1}]", "show all defined cache hit response rules, optionally with their UUIDs and optionally truncated to a given width" },
  { "showConsoleACL", true, "", "show our current console ACL set" },
  { "showDNSCryptBinds", true, "", "display the currently configured DNSCrypt binds" },
  { "showDOHFrontends", true, "", "list all the available DOH frontends" },
  { "showDOHResponseCodes", true, "", "show the HTTP response code statistics for the DoH frontends"},
  { "showDynBlocks", true, "", "show dynamic blocks in force" },
  { "showPools", true, "", "show the available pools" },
  { "showPoolServerPolicy", true, "pool", "show server selection policy for this pool" },
  { "showResponseLatency", true, "", "show a plot of the response time latency distribution" },
  { "showResponseRules", true, "[{showUUIDs=false, truncateRuleWidth=-1}]", "show all defined response rules, optionally with their UUIDs and optionally truncated to a given width" },
  { "showRules", true, "[{showUUIDs=false, truncateRuleWidth=-1}]", "show all defined rules, optionally with their UUIDs and optionally truncated to a given width" },
  { "showSecurityStatus", true, "", "Show the security status"},
  { "showSelfAnsweredResponseRules", true, "[{showUUIDs=false, truncateRuleWidth=-1}]", "show all defined self-answered response rules, optionally with their UUIDs and optionally truncated to a given width" },
  { "showServerPolicy", true, "", "show name of currently operational server selection policy" },
  { "showServers", true, "[{showUUIDs=false}]", "output all servers, optionally with their UUIDs" },
  { "showTCPStats", true, "", "show some statistics regarding TCP" },
  { "showTLSContexts", true, "", "list all the available TLS contexts" },
  { "showTLSErrorCounters", true, "", "show metrics about TLS handshake failures" },
  { "showVersion", true, "", "show the current version" },
  { "showWebserverConfig", true, "", "Show the current webserver configuration" },
  { "shutdown", true, "", "shut down `dnsdist`" },
  { "snmpAgent", true, "enableTraps [, daemonSocket]", "enable `SNMP` support. `enableTraps` is a boolean indicating whether traps should be sent and `daemonSocket` an optional string specifying how to connect to the daemon agent"},
  { "SetAdditionalProxyProtocolValueAction", true, "type, value", "Add a Proxy Protocol TLV value of this type" },
  { "SetDisableECSAction", true, "", "Disable the sending of ECS to the backend. Subsequent rules are processed after this action." },
  { "SetDisableValidationAction", true, "", "set the CD bit in the question, let it go through" },
  { "SetECSAction", true, "v4[, v6]", "Set the ECS prefix and prefix length sent to backends to an arbitrary value" },
  { "SetECSOverrideAction", true, "override", "Whether an existing EDNS Client Subnet value should be overridden (true) or not (false). Subsequent rules are processed after this action" },
  { "SetECSPrefixLengthAction", true, "v4, v6", "Set the ECS prefix length. Subsequent rules are processed after this action" },
  { "SetMacAddrAction", true, "option", "Add the source MAC address to the query as EDNS0 option option. This action is currently only supported on Linux. Subsequent rules are processed after this action" },
  { "SetEDNSOptionAction", true, "option, data", "Add arbitrary EDNS option and data to the query. Subsequent rules are processed after this action" },
  { "SetNoRecurseAction", true, "", "strip RD bit from the question, let it go through" },
  { "setOutgoingDoHWorkerThreads", true, "n", "Number of outgoing DoH worker threads" },
  { "SetProxyProtocolValuesAction", true, "values", "Set the Proxy-Protocol values for this queries to 'values'" },
  { "SetSkipCacheAction", true, "", "Don’t lookup the cache for this query, don’t store the answer" },
  { "SetSkipCacheResponseAction", true, "", "Don’t store this response into the cache" },
  { "SetTagAction", true, "name, value", "set the tag named 'name' to the given value" },
  { "SetTagResponseAction", true, "name, value", "set the tag named 'name' to the given value" },
  { "SetTempFailureCacheTTLAction", true, "ttl", "set packetcache TTL for temporary failure replies" },
  { "SNIRule", true, "name", "Create a rule which matches on the incoming TLS SNI value, if any (DoT or DoH)" },
  { "SNMPTrapAction", true, "[reason]", "send an SNMP trap, adding the optional `reason` string as the query description"},
  { "SNMPTrapResponseAction", true, "[reason]", "send an SNMP trap, adding the optional `reason` string as the response description"},
  { "SpoofAction", true, "ip|list of ips [, options]", "forge a response with the specified IPv4 (for an A query) or IPv6 (for an AAAA). If you specify multiple addresses, all that match the query type (A, AAAA or ANY) will get spoofed in" },
  { "SpoofCNAMEAction", true, "cname [, options]", "Forge a response with the specified CNAME value" },
  { "SpoofRawAction", true, "raw|list of raws [, options]", "Forge a response with the specified record data as raw bytes. If you specify multiple raws (it is assumed they match the query type), all will get spoofed in" },
  { "SpoofSVCAction", true, "list of svcParams [, options]", "Forge a response with the specified SVC record data" } ,
  { "SuffixMatchNodeRule", true, "smn[, quiet]", "Matches based on a group of domain suffixes for rapid testing of membership. Pass true as second parameter to prevent listing of all domains matched" },
  { "TagRule", true, "name [, value]", "matches if the tag named 'name' is present, with the given 'value' matching if any" },
  { "TCAction", true, "", "create answer to query with TC and RD bits set, to move to TCP" },
  { "TCPRule", true, "[tcp]", "Matches question received over TCP if tcp is true, over UDP otherwise" },
  { "TeeAction", true, "remote [, addECS [, local]]", "send copy of query to remote, optionally adding ECS info, optionally set local address" },
  { "testCrypto", true, "", "test of the crypto all works" },
  { "TimedIPSetRule", true, "", "Create a rule which matches a set of IP addresses which expire"},
  { "topBandwidth", true, "top", "show top-`top` clients that consume the most bandwidth over length of ringbuffer" },
  { "topCacheHitResponseRules", true, "[top][, vars]", "show `top` cache-hit response rules" },
  { "topCacheInsertedResponseRules", true, "[top][, vars]", "show `top` cache-inserted response rules" },
  { "topClients", true, "n", "show top-`n` clients sending the most queries over length of ringbuffer" },
  { "topQueries", true, "n[, labels]", "show top 'n' queries, as grouped when optionally cut down to 'labels' labels" },
  { "topResponses", true, "n, kind[, labels]", "show top 'n' responses with RCODE=kind (0=NO Error, 2=ServFail, 3=NXDomain), as grouped when optionally cut down to 'labels' labels" },
  { "topResponseRules", true, "[top][, vars]", "show `top` response rules" },
  { "topRules", true, "[top][, vars]", "show `top` rules" },
  { "topSelfAnsweredResponseRules", true, "[top][, vars]", "show `top` self-answered response rules" },
  { "topSlow", true, "[top][, limit][, labels]", "show `top` queries slower than `limit` milliseconds, grouped by last `labels` labels" },
  { "TrailingDataRule", true, "", "Matches if the query has trailing data" },
  { "truncateTC", true, "bool", "if set (defaults to no starting with dnsdist 1.2.0) truncate TC=1 answers so they are actually empty. Fixes an issue for PowerDNS Authoritative Server 2.9.22. Note: turning this on breaks compatibility with RFC 6891." },
  { "unregisterDynBPFFilter", true, "DynBPFFilter", "unregister this dynamic BPF filter" },
  { "webserver", true, "address:port", "launch a webserver with stats on that address" },
  { "whashed", false, "", "Weighted hashed ('sticky') distribution over available servers, based on the server 'weight' parameter" },
  { "chashed", false, "", "Consistent hashed ('sticky') distribution over available servers, also based on the server 'weight' parameter" },
  { "wrandom", false, "", "Weighted random over available servers, based on the server 'weight' parameter" },
};

#if defined(HAVE_LIBEDIT)
extern "C" {
static char* my_generator(const char* text, int state)
{
  string t(text);
  /* to keep it readable, we try to keep only 4 keywords per line
     and to start a new line when the first letter changes */
  static int s_counter = 0;
  int counter=0;
  if (!state) {
    s_counter = 0;
  }

  for (const auto& keyword : g_consoleKeywords) {
    if (boost::starts_with(keyword.name, t) && counter++ == s_counter)  {
      std::string value(keyword.name);
      s_counter++;
      if (keyword.function) {
        value += "(";
        if (keyword.parameters.empty()) {
          value += ")";
        }
      }
      return strdup(value.c_str());
    }
  }
  return 0;
}

char** my_completion( const char * text , int start,  int end)
{
  char **matches=0;
  if (start == 0) {
    matches = rl_completion_matches ((char*)text, &my_generator);
  }

  // skip default filename completion.
  rl_attempted_completion_over = 1;

  return matches;
}
}
#endif /* HAVE_LIBEDIT */
#endif /* DISABLE_COMPLETION */

static void controlClientThread(ConsoleConnection&& conn)
{
  try {
    setThreadName("dnsdist/conscli");

    setTCPNoDelay(conn.getFD());

    SodiumNonce theirs, ours, readingNonce, writingNonce;
    ours.init();
    readn2(conn.getFD(), (char*)theirs.value, sizeof(theirs.value));
    writen2(conn.getFD(), (char*)ours.value, sizeof(ours.value));
    readingNonce.merge(ours, theirs);
    writingNonce.merge(theirs, ours);

    for (;;) {
      uint32_t len;
      if (getMsgLen32(conn.getFD(), &len) != ConsoleCommandResult::Valid) {
        break;
      }

      if (len == 0) {
        /* just ACK an empty message
           with an empty response */
        putMsgLen32(conn.getFD(), 0);
        continue;
      }

      std::string line;
      line.resize(len);
      readn2(conn.getFD(), line.data(), len);

      line = sodDecryptSym(line, g_consoleKey, readingNonce);

      string response;
      try {
        bool withReturn = true;
      retry:;
        try {
          auto lua = g_lua.lock();

          g_outputBuffer.clear();
          resetLuaSideEffect();
          auto ret = lua->executeCode<
            boost::optional<
              boost::variant<
                string,
                shared_ptr<DownstreamState>,
                ClientState*,
                std::unordered_map<string, double>
                >
              >
            >(withReturn ? ("return "+line) : line);

          if (ret) {
            if (const auto dsValue = boost::get<shared_ptr<DownstreamState>>(&*ret)) {
              if (*dsValue) {
                response = (*dsValue)->getName()+"\n";
              } else {
                response = "";
              }
            }
            else if (const auto csValue = boost::get<ClientState*>(&*ret)) {
              if (*csValue) {
                response = (*csValue)->local.toStringWithPort()+"\n";
              } else {
                response = "";
              }
            }
            else if (const auto strValue = boost::get<string>(&*ret)) {
              response = *strValue+"\n";
            }
            else if (const auto um = boost::get<std::unordered_map<string, double> >(&*ret)) {
              using namespace json11;
              Json::object o;
              for(const auto& v : *um) {
                o[v.first] = v.second;
              }
              Json out = o;
              response = out.dump()+"\n";
            }
          }
          else {
            response = g_outputBuffer;
          }
          if (!getLuaNoSideEffect()) {
            feedConfigDelta(line);
          }
        }
        catch (const LuaContext::SyntaxErrorException&) {
          if(withReturn) {
            withReturn=false;
            goto retry;
          }
          throw;
        }
      }
      catch(const LuaContext::WrongTypeException& e) {
        response = "Command returned an object we can't print: " +std::string(e.what()) + "\n";
        // tried to return something we don't understand
      }
      catch (const LuaContext::ExecutionErrorException& e) {
        if (!strcmp(e.what(),"invalid key to 'next'")) {
          response = "Error: Parsing function parameters, did you forget parameter name?";
        }
        else {
          response = "Error: " + string(e.what());
        }

        try {
          std::rethrow_if_nested(e);
        } catch (const std::exception& ne) {
          // ne is the exception that was thrown from inside the lambda
          response+= ": " + string(ne.what());
        }
        catch (const PDNSException& ne) {
          // ne is the exception that was thrown from inside the lambda
          response += ": " + string(ne.reason);
        }
      }
      catch (const LuaContext::SyntaxErrorException& e) {
        response = "Error: " + string(e.what()) + ": ";
      }
      response = sodEncryptSym(response, g_consoleKey, writingNonce);
      putMsgLen32(conn.getFD(), response.length());
      writen2(conn.getFD(), response.c_str(), response.length());
    }
    if (g_logConsoleConnections) {
      infolog("Closed control connection from %s", conn.getClient().toStringWithPort());
    }
  }
  catch (const std::exception& e) {
    errlog("Got an exception in client connection from %s: %s", conn.getClient().toStringWithPort(), e.what());
  }
}

void controlThread(int fd, ComboAddress local)
{
  FDWrapper acceptFD(fd);
  try
  {
    setThreadName("dnsdist/control");
    ComboAddress client;
    int sock;
    auto localACL = g_consoleACL.getLocal();
    infolog("Accepting control connections on %s", local.toStringWithPort());

    while ((sock = SAccept(acceptFD.getHandle(), client)) >= 0) {

      FDWrapper socket(sock);
      if (!sodIsValidKey(g_consoleKey)) {
        vinfolog("Control connection from %s dropped because we don't have a valid key configured, please configure one using setKey()", client.toStringWithPort());
        continue;
      }

      if (!localACL->match(client)) {
        vinfolog("Control connection from %s dropped because of ACL", client.toStringWithPort());
        continue;
      }

      try {
        ConsoleConnection conn(client, std::move(socket));
        if (g_logConsoleConnections) {
          warnlog("Got control connection from %s", client.toStringWithPort());
        }

        std::thread t(controlClientThread, std::move(conn));
        t.detach();
      }
      catch (const std::exception& e) {
        errlog("Control connection died: %s", e.what());
      }
    }
  }
  catch (const std::exception& e) {
    errlog("Control thread died: %s", e.what());
  }
}

void clearConsoleHistory()
{
#ifdef HAVE_LIBEDIT
  clear_history();
#endif /* HAVE_LIBEDIT */
  g_confDelta.clear();
}