#include "source/server/admin/admin.h"

#include <algorithm>

#include <cstdint>

#include <fstream>

#include <string>

#include <utility>

#include <vector>

#include "envoy/extensions/http/header_validators/envoy_default/v3/header_validator.pb.h"

#include "envoy/http/header_validator_factory.h"

#include "envoy/server/hot_restart.h"

#include "envoy/server/instance.h"

#include "envoy/server/options.h"

#include "envoy/upstream/cluster_manager.h"

#include "envoy/upstream/outlier_detection.h"

#include "envoy/upstream/upstream.h"

#include "source/common/access_log/access_log_impl.h"

#include "source/common/buffer/buffer_impl.h"

#include "source/common/common/assert.h"

#include "source/common/common/empty_string.h"

#include "source/common/common/fmt.h"

#include "source/common/common/mutex_tracer_impl.h"

#include "source/common/common/utility.h"

#include "source/common/formatter/substitution_formatter.h"

#include "source/common/http/codes.h"

#include "source/common/http/conn_manager_utility.h"

#include "source/common/http/header_map_impl.h"

#include "source/common/http/headers.h"

#include "source/common/listener_manager/listener_impl.h"

#include "source/common/memory/utils.h"

#include "source/common/network/listen_socket_impl.h"

#include "source/common/protobuf/protobuf.h"

#include "source/common/protobuf/utility.h"

#include "source/common/router/config_impl.h"

#include "source/extensions/request_id/uuid/config.h"

#include "source/server/admin/utils.h"

#include "absl/strings/str_join.h"

#include "absl/strings/str_replace.h"

#include "absl/strings/string_view.h"

#include "spdlog/spdlog.h"

namespace Envoy {

namespace Server {

ConfigTracker& AdminImpl::getConfigTracker() { return config_tracker_; }

AdminImpl::NullRouteConfigProvider::NullRouteConfigProvider(TimeSource& time_source)

    : config_(new Router::NullConfigImpl()), time_source_(time_source) {}

void AdminImpl::startHttpListener(std::list<AccessLog::InstanceSharedPtr> access_logs,

                                  Network::Address::InstanceConstSharedPtr address,

                                  Network::Socket::OptionsSharedPtr socket_options) {

  access_logs_ = std::move(access_logs);

  socket_ = std::make_shared<Network::TcpListenSocket>(address, socket_options, true);

  RELEASE_ASSERT(0 == socket_->ioHandle().listen(ENVOY_TCP_BACKLOG_SIZE).return_value_,

                 "listen() failed on admin listener");

  socket_factories_.emplace_back(std::make_unique<AdminListenSocketFactory>(socket_));

  listener_ = std::make_unique<AdminListener>(*this, factory_context_.listenerScope());

  ENVOY_LOG(info, "admin address: {}",

            socket().connectionInfoProvider().localAddress()->asString());

  if (!server_.options().adminAddressPath().empty()) {

    std::ofstream address_out_file(server_.options().adminAddressPath());

    if (!address_out_file) {

      ENVOY_LOG(critical, "cannot open admin address output file {} for writing.",

                server_.options().adminAddressPath());

    } else {

      address_out_file << socket_->connectionInfoProvider().localAddress()->asString();

    }

  }

}

namespace {

// Prepends an element to an array, modifying it as passed in.

std::vector<absl::string_view> prepend(const absl::string_view first,

                                       std::vector<absl::string_view> strings) {

  strings.insert(strings.begin(), first);

  return strings;

}

Http::HeaderValidatorFactoryPtr createHeaderValidatorFactory(

    [[maybe_unused]] Server::Configuration::ServerFactoryContext& context) {

  Http::HeaderValidatorFactoryPtr header_validator_factory;

#ifdef ENVOY_ENABLE_UHV

  // Default UHV config matches the admin HTTP validation and normalization config

  ::envoy::extensions::http::header_validators::envoy_default::v3::HeaderValidatorConfig uhv_config;

  ::envoy::config::core::v3::TypedExtensionConfig config;

  config.set_name("default_universal_header_validator_for_admin");

  config.mutable_typed_config()->PackFrom(uhv_config);

  auto* factory = Envoy::Config::Utility::getFactory<Http::HeaderValidatorFactoryConfig>(config);

  ENVOY_BUG(factory != nullptr, "Default UHV is not linked into binary.");

  header_validator_factory = factory->createFromProto(config.typed_config(), context);

  ENVOY_BUG(header_validator_factory != nullptr, "Unable to create default UHV.");

#endif

  return header_validator_factory;

}

} // namespace

AdminImpl::AdminImpl(const std::string& profile_path, Server::Instance& server,

                     bool ignore_global_conn_limit)

    : server_(server), listener_info_(std::make_shared<ListenerInfoImpl>()),

      factory_context_(server, listener_info_),

      request_id_extension_(Extensions::RequestId::UUIDRequestIDExtension::defaultInstance(

          server_.api().randomGenerator())),

      profile_path_(profile_path), stats_(Http::ConnectionManagerImpl::generateStats(

                                       "http.admin.", *server_.stats().rootScope())),

      null_overload_manager_(server.threadLocal(), false),

      tracing_stats_(Http::ConnectionManagerImpl::generateTracingStats("http.admin.",

                                                                       *no_op_store_.rootScope())),

      route_config_provider_(server.timeSource()),

      scoped_route_config_provider_(server.timeSource()), clusters_handler_(server),

      config_dump_handler_(config_tracker_, server), init_dump_handler_(server),

      stats_handler_(server), logs_handler_(server), profiling_handler_(profile_path),

      runtime_handler_(server), listeners_handler_(server), server_cmd_handler_(server),

      server_info_handler_(server),

      // TODO(jsedgwick) add /runtime_reset endpoint that removes all admin-set values

      handlers_{

          makeHandler("/", "Admin home page", MAKE_ADMIN_HANDLER(handlerAdminHome), false, false),

          makeHandler("/certs", "print certs on machine",

                      MAKE_ADMIN_HANDLER(server_info_handler_.handlerCerts), false, false),

          makeHandler("/clusters", "upstream cluster status",

                      MAKE_ADMIN_HANDLER(clusters_handler_.handlerClusters), false, false),

          makeHandler(

              "/config_dump", "dump current Envoy configs (experimental)",

              MAKE_ADMIN_HANDLER(config_dump_handler_.handlerConfigDump), false, false,

              {{Admin::ParamDescriptor::Type::String, "resource", "The resource to dump"},

               {Admin::ParamDescriptor::Type::String, "mask",

                "The mask to apply. When both resource and mask are specified, "

                "the mask is applied to every element in the desired repeated field so that only a "

                "subset of fields are returned. The mask is parsed as a ProtobufWkt::FieldMask"},

               {Admin::ParamDescriptor::Type::String, "name_regex",

                "Dump only the currently loaded configurations whose names match the specified "

                "regex. Can be used with both resource and mask query parameters."},

               {Admin::ParamDescriptor::Type::Boolean, "include_eds",

                "Dump currently loaded configuration including EDS. See the response definition "

                "for more information"}}),

          makeHandler("/init_dump", "dump current Envoy init manager information (experimental)",

                      MAKE_ADMIN_HANDLER(init_dump_handler_.handlerInitDump), false, false,

                      {{Admin::ParamDescriptor::Type::String, "mask",

                        "The desired component to dump unready targets. The mask is parsed as "

                        "a ProtobufWkt::FieldMask. For example, get the unready targets of "

                        "all listeners with /init_dump?mask=listener`"}}),

          makeHandler("/contention", "dump current Envoy mutex contention stats (if enabled)",

                      MAKE_ADMIN_HANDLER(stats_handler_.handlerContention), false, false),

          makeHandler("/cpuprofiler", "enable/disable the CPU profiler",

                      MAKE_ADMIN_HANDLER(profiling_handler_.handlerCpuProfiler), false, true,

                      {{Admin::ParamDescriptor::Type::Enum,

                        "enable",

                        "enables the CPU profiler",

                        {"y", "n"}}}),

          makeHandler("/heapprofiler", "enable/disable the heap profiler",

                      MAKE_ADMIN_HANDLER(profiling_handler_.handlerHeapProfiler), false, true,

                      {{Admin::ParamDescriptor::Type::Enum,

                        "enable",

                        "enable/disable the heap profiler",

                        {"y", "n"}}}),

          makeHandler("/heap_dump", "dump current Envoy heap (if supported)",

                      MAKE_ADMIN_HANDLER(tcmalloc_profiling_handler_.handlerHeapDump), false,

                      false),

          makeHandler("/healthcheck/fail", "cause the server to fail health checks",

                      MAKE_ADMIN_HANDLER(server_cmd_handler_.handlerHealthcheckFail), false, true),

          makeHandler("/healthcheck/ok", "cause the server to pass health checks",

                      MAKE_ADMIN_HANDLER(server_cmd_handler_.handlerHealthcheckOk), false, true),

          makeHandler("/help", "print out list of admin commands", MAKE_ADMIN_HANDLER(handlerHelp),

                      false, false),

          makeHandler("/hot_restart_version", "print the hot restart compatibility version",

                      MAKE_ADMIN_HANDLER(server_info_handler_.handlerHotRestartVersion), false,

                      false),

          // The logging "level" parameter, if specified as a non-blank entry,

          // changes all the logging-paths to that level. So the enum parameter

          // needs to include a an empty string as the default (first) option.

          // Thus we prepend an empty string to the logging-levels list.

          makeHandler("/logging", "query/change logging levels",

                      MAKE_ADMIN_HANDLER(logs_handler_.handlerLogging), false, true,

                      {{Admin::ParamDescriptor::Type::String, "paths",

                        "Change multiple logging levels by setting to "

                        "<logger_name1>:<desired_level1>,<logger_name2>:<desired_level2>. "

                        "If fine grain logging is enabled, use __FILE__ or a glob experision as "

                        "the logger name. "

                        "For example, source/common*:warning"},

                       {Admin::ParamDescriptor::Type::Enum, "level",

                        "desired logging level, this will change all loggers's level",

                        prepend("", LogsHandler::levelStrings())}}),

          makeHandler("/memory", "print current allocation/heap usage",

                      MAKE_ADMIN_HANDLER(server_info_handler_.handlerMemory), false, false),

          makeHandler("/quitquitquit", "exit the server",

                      MAKE_ADMIN_HANDLER(server_cmd_handler_.handlerQuitQuitQuit), false, true),

          makeHandler("/reset_counters", "reset all counters to zero",

                      MAKE_ADMIN_HANDLER(stats_handler_.handlerResetCounters), false, true),

          makeHandler(

              "/drain_listeners", "drain listeners",

              MAKE_ADMIN_HANDLER(listeners_handler_.handlerDrainListeners), false, true,

              {{ParamDescriptor::Type::Boolean, "graceful",

                "When draining listeners, enter a graceful drain period prior to closing "

                "listeners. This behaviour and duration is configurable via server options "

                "or CLI"},

               {ParamDescriptor::Type::Boolean, "skip_exit",

                "When draining listeners, do not exit after the drain period. "

                "This must be used with graceful"},

               {ParamDescriptor::Type::Boolean, "inboundonly",

                "Drains all inbound listeners. traffic_direction field in "

                "envoy_v3_api_msg_config.listener.v3.Listener is used to determine whether a "

                "listener is inbound or outbound."}}),

          makeHandler("/server_info", "print server version/status information",

                      MAKE_ADMIN_HANDLER(server_info_handler_.handlerServerInfo), false, false),

          makeHandler("/ready", "print server state, return 200 if LIVE, otherwise return 503",

                      MAKE_ADMIN_HANDLER(server_info_handler_.handlerReady), false, false),

          stats_handler_.statsHandler(false /* not active mode */),

          makeHandler("/stats/prometheus", "print server stats in prometheus format",

                      MAKE_ADMIN_HANDLER(stats_handler_.handlerPrometheusStats), false, false,

                      {{ParamDescriptor::Type::Boolean, "usedonly",

                        "Only include stats that have been written by system since restart"},

                       {ParamDescriptor::Type::Boolean, "text_readouts",

                        "Render text_readouts as new gaugues with value 0 (increases Prometheus "

                        "data size)"},

                       {ParamDescriptor::Type::String, "filter",

                        "Regular expression (Google re2) for filtering stats"},

                       {ParamDescriptor::Type::Enum,

                        "histogram_buckets",

                        "Histogram bucket display mode",

                        {"cumulative", "summary"}}}),

          makeHandler("/stats/recentlookups", "Show recent stat-name lookups",

                      MAKE_ADMIN_HANDLER(stats_handler_.handlerStatsRecentLookups), false, false),

          makeHandler("/stats/recentlookups/clear", "clear list of stat-name lookups and counter",

                      MAKE_ADMIN_HANDLER(stats_handler_.handlerStatsRecentLookupsClear), false,

                      true),

          makeHandler(

              "/stats/recentlookups/disable", "disable recording of reset stat-name lookup names",

              MAKE_ADMIN_HANDLER(stats_handler_.handlerStatsRecentLookupsDisable), false, true),

          makeHandler(

              "/stats/recentlookups/enable", "enable recording of reset stat-name lookup names",

              MAKE_ADMIN_HANDLER(stats_handler_.handlerStatsRecentLookupsEnable), false, true),

          makeHandler("/listeners", "print listener info",

                      MAKE_ADMIN_HANDLER(listeners_handler_.handlerListenerInfo), false, false,

                      {{Admin::ParamDescriptor::Type::Enum,

                        "format",

                        "File format to use",

                        {"text", "json"}}}),

          makeHandler("/runtime", "print runtime values",

                      MAKE_ADMIN_HANDLER(runtime_handler_.handlerRuntime), false, false),

          makeHandler("/runtime_modify",

                      "Adds or modifies runtime values as passed in query parameters. To delete a "

                      "previously added key, use an empty string as the value. Note that deletion "

                      "only applies to overrides added via this endpoint; values loaded from disk "

                      "can be modified via override but not deleted. E.g. "

                      "?key1=value1&key2=value2...",

                      MAKE_ADMIN_HANDLER(runtime_handler_.handlerRuntimeModify), false, true),

          makeHandler("/reopen_logs", "reopen access logs",

                      MAKE_ADMIN_HANDLER(logs_handler_.handlerReopenLogs), false, true),

      },

      date_provider_(server.dispatcher().timeSource()),

      admin_filter_chain_(std::make_shared<AdminFilterChain>()),

      local_reply_(LocalReply::Factory::createDefault()),

      ignore_global_conn_limit_(ignore_global_conn_limit),

      header_validator_factory_(createHeaderValidatorFactory(server.serverFactoryContext())) {

#ifndef NDEBUG

  // Verify that no duplicate handlers exist.

  absl::flat_hash_set<absl::string_view> handlers;

  for (const UrlHandler& handler : handlers_) {

    ASSERT(handlers.insert(handler.prefix_).second);

  }

#endif

}

Http::ServerConnectionPtr AdminImpl::createCodec(Network::Connection& connection,

                                                 const Buffer::Instance& data,

                                                 Http::ServerConnectionCallbacks& callbacks,

                                                 Server::OverloadManager& overload_manager) {

  return Http::ConnectionManagerUtility::autoCreateCodec(

      connection, data, callbacks, *server_.stats().rootScope(), server_.api().randomGenerator(),

      http1_codec_stats_, http2_codec_stats_, Http::Http1Settings(),

      ::Envoy::Http2::Utility::initializeAndValidateOptions(

          envoy::config::core::v3::Http2ProtocolOptions())

          .value(),

      maxRequestHeadersKb(), maxRequestHeadersCount(), headersWithUnderscoresAction(),

      overload_manager);

}

bool AdminImpl::createNetworkFilterChain(Network::Connection& connection,

                                         const Filter::NetworkFilterFactoriesList&) {

  // Pass in the null overload manager so that the admin interface is accessible even when Envoy

  // is overloaded.

  connection.addReadFilter(Network::ReadFilterSharedPtr{new Http::ConnectionManagerImpl(

      shared_from_this(), server_.drainManager(), server_.api().randomGenerator(),

      server_.httpContext(), server_.runtime(), server_.localInfo(), server_.clusterManager(),

      server_.nullOverloadManager(), server_.timeSource())});

  return true;

}

bool AdminImpl::createFilterChain(Http::FilterChainManager& manager, bool,

                                  const Http::FilterChainOptions&) const {

  Http::FilterFactoryCb factory = [this](Http::FilterChainFactoryCallbacks& callbacks) {

    callbacks.addStreamFilter(std::make_shared<AdminFilter>(*this));

  };

  manager.applyFilterFactoryCb({}, factory);

  return true;

}

namespace {

// Implements a chunked request for static text.

class StaticTextRequest : public Admin::Request {

public:

  StaticTextRequest(absl::string_view response_text, Http::Code code) : code_(code) {

    response_text_.add(response_text);

  }

  StaticTextRequest(Buffer::Instance& response_text, Http::Code code) : code_(code) {

    response_text_.move(response_text);

  }

  Http::Code start(Http::ResponseHeaderMap&) override { return code_; }

  bool nextChunk(Buffer::Instance& response) override {

    response.move(response_text_);

    return false;

  }

private:

  Buffer::OwnedImpl response_text_;

  const Http::Code code_;

};

// Implements a streaming Request based on a non-streaming callback that

// generates the entire admin output in one shot.

class RequestGasket : public Admin::Request {

public:

  RequestGasket(Admin::HandlerCb handler_cb, AdminStream& admin_stream)

      : handler_cb_(handler_cb), admin_stream_(admin_stream) {}

  static Admin::GenRequestFn makeGen(Admin::HandlerCb callback) {

    return [callback](AdminStream& admin_stream) -> Server::Admin::RequestPtr {

      return std::make_unique<RequestGasket>(callback, admin_stream);

    };

  }

  Http::Code start(Http::ResponseHeaderMap& response_headers) override {

    return handler_cb_(response_headers, response_, admin_stream_);

  }

  bool nextChunk(Buffer::Instance& response) override {

    response.move(response_);

    return false;

  }

private:

  Admin::HandlerCb handler_cb_;

  AdminStream& admin_stream_;

  Buffer::OwnedImpl response_;

};

} // namespace

Admin::RequestPtr Admin::makeStaticTextRequest(absl::string_view response, Http::Code code) {

  return std::make_unique<StaticTextRequest>(response, code);

}

Admin::RequestPtr Admin::makeStaticTextRequest(Buffer::Instance& response, Http::Code code) {

  return std::make_unique<StaticTextRequest>(response, code);

}

Http::Code AdminImpl::runCallback(Http::ResponseHeaderMap& response_headers,

                                  Buffer::Instance& response, AdminStream& admin_stream) {

  RequestPtr request = makeRequest(admin_stream);

  Http::Code code = request->start(response_headers);

  bool more_data;

  do {

    more_data = request->nextChunk(response);

  } while (more_data);

  Memory::Utils::tryShrinkHeap();

  return code;

}

Admin::RequestPtr AdminImpl::makeRequest(AdminStream& admin_stream) const {

  absl::string_view path_and_query = admin_stream.getRequestHeaders().getPathValue();

  std::string::size_type query_index = path_and_query.find('?');

  if (query_index == std::string::npos) {

    query_index = path_and_query.size();

  }

  for (const UrlHandler& handler : handlers_) {

    if (path_and_query.compare(0, query_index, handler.prefix_) == 0) {

      if (handler.mutates_server_state_) {

        const absl::string_view method = admin_stream.getRequestHeaders().getMethodValue();

        if (method != Http::Headers::get().MethodValues.Post) {

          ENVOY_LOG(error, "admin path \"{}\" mutates state, method={} rather than POST",

                    handler.prefix_, method);

          return Admin::makeStaticTextRequest(

              fmt::format("Method {} not allowed, POST required.", method),

              Http::Code::MethodNotAllowed);

        }

      }

      ASSERT(admin_stream.getRequestHeaders().getPathValue() == path_and_query);

      return handler.handler_(admin_stream);

    }

  }

  // Extra space is emitted below to have "invalid path." be a separate sentence in the

  // 404 output from "admin commands are:" in handlerHelp.

  Buffer::OwnedImpl error_response;

  error_response.add("invalid path. ");

  getHelp(error_response);

  return Admin::makeStaticTextRequest(error_response, Http::Code::NotFound);

}

std::vector<const AdminImpl::UrlHandler*> AdminImpl::sortedHandlers() const {

  std::vector<const UrlHandler*> sorted_handlers;

  for (const UrlHandler& handler : handlers_) {

    sorted_handlers.push_back(&handler);

  }

  // Note: it's generally faster to sort a vector with std::vector than to construct a std::map.

  std::sort(sorted_handlers.begin(), sorted_handlers.end(),

            [](const UrlHandler* h1, const UrlHandler* h2) { return h1->prefix_ < h2->prefix_; });

  return sorted_handlers;

}

Http::Code AdminImpl::handlerHelp(Http::ResponseHeaderMap&, Buffer::Instance& response,

                                  AdminStream&) {

  getHelp(response);

  return Http::Code::OK;

}

void AdminImpl::getHelp(Buffer::Instance& response) const {

  response.add("admin commands are:\n");

  // Prefix order is used during searching, but for printing do them in alpha order.

  for (const UrlHandler* handler : sortedHandlers()) {

    const absl::string_view method = handler->mutates_server_state_ ? " (POST)" : "";

    response.add(fmt::format("  {}{}: {}\n", handler->prefix_, method, handler->help_text_));

    for (const ParamDescriptor& param : handler->params_) {

      response.add(fmt::format("      {}: {}", param.id_, param.help_));

      if (param.type_ == ParamDescriptor::Type::Enum) {

        response.addFragments({"; One of (", absl::StrJoin(param.enum_choices_, ", "), ")"});

      }

      response.add("\n");

    }

  }

}

const Network::Address::Instance& AdminImpl::localAddress() {

  return *server_.localInfo().address();

}

AdminImpl::UrlHandler AdminImpl::makeHandler(const std::string& prefix,

                                             const std::string& help_text, HandlerCb callback,

                                             bool removable, bool mutates_state,

                                             const ParamDescriptorVec& params) {

  return UrlHandler{prefix,    help_text,     RequestGasket::makeGen(callback),

                    removable, mutates_state, params};

}

bool AdminImpl::addStreamingHandler(const std::string& prefix, const std::string& help_text,

                                    GenRequestFn callback, bool removable, bool mutates_state,

                                    const ParamDescriptorVec& params) {

  ASSERT(prefix.size() > 1);

  ASSERT(prefix[0] == '/');

  // Sanitize prefix and help_text to ensure no XSS can be injected, as

  // we are injecting these strings into HTML that runs in a domain that

  // can mutate Envoy server state. Also rule out some characters that

  // make no sense as part of a URL path: ? and :.

  const std::string::size_type pos = prefix.find_first_of("&\"'<>?:");

  if (pos != std::string::npos) {

    ENVOY_LOG(error, "filter \"{}\" contains invalid character '{}'", prefix, prefix[pos]);

    return false;

  }

  auto it = std::find_if(handlers_.cbegin(), handlers_.cend(),

                         [&prefix](const UrlHandler& entry) { return prefix == entry.prefix_; });

  if (it == handlers_.end()) {

    handlers_.push_back({prefix, help_text, callback, removable, mutates_state, params});

    return true;

  }

  return false;

}

bool AdminImpl::addHandler(const std::string& prefix, const std::string& help_text,

                           HandlerCb callback, bool removable, bool mutates_state,

                           const ParamDescriptorVec& params) {

  return addStreamingHandler(prefix, help_text, RequestGasket::makeGen(callback), removable,

                             mutates_state, params);

}

bool AdminImpl::removeHandler(const std::string& prefix) {

  const size_t size_before_removal = handlers_.size();

  handlers_.remove_if(

      [&prefix](const UrlHandler& entry) { return prefix == entry.prefix_ && entry.removable_; });

  if (handlers_.size() != size_before_removal) {

    return true;

  }

  return false;

}

Http::Code AdminImpl::request(absl::string_view path_and_query, absl::string_view method,

                              Http::ResponseHeaderMap& response_headers, std::string& body) {

  AdminFilter filter(*this);

  auto request_headers = Http::RequestHeaderMapImpl::create();

  request_headers->setMethod(method);

  request_headers->setPath(path_and_query);

  filter.decodeHeaders(*request_headers, false);

  Buffer::OwnedImpl response;

  Http::Code code = runCallback(response_headers, response, filter);

  Utility::populateFallbackResponseHeaders(code, response_headers);

  body = response.toString();

  return code;

}

void AdminImpl::closeSocket() {

  if (socket_) {

    socket_->close();

  }

}

void AdminImpl::addListenerToHandler(Network::ConnectionHandler* handler) {

  if (listener_) {

    handler->addListener(absl::nullopt, *listener_, server_.runtime(),

                         server_.api().randomGenerator());

  }

}

#ifdef ENVOY_ENABLE_UHV

::Envoy::Http::HeaderValidatorStats&

AdminImpl::getHeaderValidatorStats([[maybe_unused]] Http::Protocol protocol) {

  switch (protocol) {

  case Http::Protocol::Http10:

  case Http::Protocol::Http11:

    return Http::Http1::CodecStats::atomicGet(http1_codec_stats_, *server_.stats().rootScope());

  case Http::Protocol::Http3:

    IS_ENVOY_BUG("HTTP/3 is not supported for admin UI");

    // Return H/2 stats object, since we do not have H/3 stats.

    ABSL_FALLTHROUGH_INTENDED;

  case Http::Protocol::Http2:

    return Http::Http2::CodecStats::atomicGet(http2_codec_stats_, *server_.stats().rootScope());

  }

  PANIC_DUE_TO_CORRUPT_ENUM;

}

#endif

} // namespace Server

} // namespace Envoy