// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// A binary wrapper for QuicClient.
// Connects to a host using QUIC, sends a request to the provided URL, and
// displays the response.
//
// Some usage examples:
//
// Standard request/response:
//   quic_client www.google.com
//   quic_client www.google.com --quiet
//   quic_client www.google.com --port=443
//
// Use a specific version:
//   quic_client www.google.com --quic_version=23
//
// Send a POST instead of a GET:
//   quic_client www.google.com --body="this is a POST body"
//
// Append additional headers to the request:
//   quic_client www.google.com --headers="Header-A: 1234; Header-B: 5678"
//
// Connect to a host different to the URL being requested:
//   quic_client mail.google.com --host=www.google.com
//
// Connect to a specific IP:
//   IP=`dig www.google.com +short | head -1`
//   quic_client www.google.com --host=${IP}
//
// Send repeated requests and change ephemeral port between requests
//   quic_client www.google.com --num_requests=10
//
// Try to connect to a host which does not speak QUIC:
//   quic_client www.example.com
//
// This tool is available as a built binary at:
// /google/data/ro/teams/quic/tools/quic_client
// After submitting changes to this file, you will need to follow the
// instructions at go/quic_client_binary_update

#include "quic/tools/quic_toy_client.h"

#include <iostream>
#include <memory>
#include <string>
#include <utility>
#include <vector>

#include "absl/strings/escaping.h"
#include "absl/strings/str_split.h"
#include "absl/strings/string_view.h"
#include "quic/core/quic_packets.h"
#include "quic/core/quic_server_id.h"
#include "quic/core/quic_utils.h"
#include "quic/core/quic_versions.h"
#include "quic/platform/api/quic_default_proof_providers.h"
#include "quic/platform/api/quic_ip_address.h"
#include "quic/platform/api/quic_socket_address.h"
#include "quic/platform/api/quic_system_event_loop.h"
#include "quic/tools/fake_proof_verifier.h"
#include "quic/tools/quic_url.h"
#include "common/quiche_text_utils.h"

namespace {

using quic::QuicUrl;
using quiche::QuicheTextUtils;

}  // namespace

DEFINE_QUIC_COMMAND_LINE_FLAG(
    std::string,
    host,
    "",
    "The IP or hostname to connect to. If not provided, the host "
    "will be derived from the provided URL.");

DEFINE_QUIC_COMMAND_LINE_FLAG(int32_t, port, 0, "The port to connect to.");

DEFINE_QUIC_COMMAND_LINE_FLAG(std::string,
                              ip_version_for_host_lookup,
                              "",
                              "Only used if host address lookup is needed. "
                              "4=ipv4; 6=ipv6; otherwise=don't care.");

DEFINE_QUIC_COMMAND_LINE_FLAG(std::string,
                              body,
                              "",
                              "If set, send a POST with this body.");

DEFINE_QUIC_COMMAND_LINE_FLAG(
    std::string,
    body_hex,
    "",
    "If set, contents are converted from hex to ascii, before "
    "sending as body of a POST. e.g. --body_hex=\"68656c6c6f\"");

DEFINE_QUIC_COMMAND_LINE_FLAG(
    std::string,
    headers,
    "",
    "A semicolon separated list of key:value pairs to "
    "add to request headers.");

DEFINE_QUIC_COMMAND_LINE_FLAG(bool,
                              quiet,
                              false,
                              "Set to true for a quieter output experience.");

DEFINE_QUIC_COMMAND_LINE_FLAG(
    std::string,
    quic_version,
    "",
    "QUIC version to speak, e.g. 21. If not set, then all available "
    "versions are offered in the handshake. Also supports wire versions "
    "such as Q043 or T099.");

DEFINE_QUIC_COMMAND_LINE_FLAG(
    std::string,
    connection_options,
    "",
    "Connection options as ASCII tags separated by commas, "
    "e.g. \"ABCD,EFGH\"");

DEFINE_QUIC_COMMAND_LINE_FLAG(
    std::string,
    client_connection_options,
    "",
    "Client connection options as ASCII tags separated by commas, "
    "e.g. \"ABCD,EFGH\"");

DEFINE_QUIC_COMMAND_LINE_FLAG(bool,
                              quic_ietf_draft,
                              false,
                              "Use the IETF draft version. This also enables "
                              "required internal QUIC flags.");

DEFINE_QUIC_COMMAND_LINE_FLAG(
    bool,
    version_mismatch_ok,
    false,
    "If true, a version mismatch in the handshake is not considered a "
    "failure. Useful for probing a server to determine if it speaks "
    "any version of QUIC.");

DEFINE_QUIC_COMMAND_LINE_FLAG(
    bool,
    force_version_negotiation,
    false,
    "If true, start by proposing a version that is reserved for version "
    "negotiation.");

DEFINE_QUIC_COMMAND_LINE_FLAG(
    bool,
    multi_packet_chlo,
    false,
    "If true, add a transport parameter to make the ClientHello span two "
    "packets. Only works with QUIC+TLS.");

DEFINE_QUIC_COMMAND_LINE_FLAG(
    bool,
    redirect_is_success,
    true,
    "If true, an HTTP response code of 3xx is considered to be a "
    "successful response, otherwise a failure.");

DEFINE_QUIC_COMMAND_LINE_FLAG(int32_t,
                              initial_mtu,
                              0,
                              "Initial MTU of the connection.");

DEFINE_QUIC_COMMAND_LINE_FLAG(
    int32_t,
    num_requests,
    1,
    "How many sequential requests to make on a single connection.");

DEFINE_QUIC_COMMAND_LINE_FLAG(bool,
                              disable_certificate_verification,
                              false,
                              "If true, don't verify the server certificate.");

DEFINE_QUIC_COMMAND_LINE_FLAG(
    bool,
    drop_response_body,
    false,
    "If true, drop response body immediately after it is received.");

DEFINE_QUIC_COMMAND_LINE_FLAG(
    bool,
    disable_port_changes,
    false,
    "If true, do not change local port after each request.");

DEFINE_QUIC_COMMAND_LINE_FLAG(int32_t,
                              server_connection_id_length,
                              -1,
                              "Length of the server connection ID used.");

DEFINE_QUIC_COMMAND_LINE_FLAG(int32_t,
                              client_connection_id_length,
                              -1,
                              "Length of the client connection ID used.");

namespace quic {

QuicToyClient::QuicToyClient(ClientFactory* client_factory)
    : client_factory_(client_factory) {}

int QuicToyClient::SendRequestsAndPrintResponses(
    std::vector<std::string> urls) {
  QuicUrl url(urls[0], "https");
  std::string host = GetQuicFlag(FLAGS_host);
  if (host.empty()) {
    host = url.host();
  }
  int port = GetQuicFlag(FLAGS_port);
  if (port == 0) {
    port = url.port();
  }

  quic::ParsedQuicVersionVector versions = quic::CurrentSupportedVersions();

  if (GetQuicFlag(FLAGS_quic_ietf_draft)) {
    quic::QuicVersionInitializeSupportForIetfDraft();
    versions = {};
    for (const ParsedQuicVersion& version : AllSupportedVersions()) {
      if (version.HasIetfQuicFrames() &&
          version.handshake_protocol == quic::PROTOCOL_TLS1_3) {
        versions.push_back(version);
      }
    }
  }

  std::string quic_version_string = GetQuicFlag(FLAGS_quic_version);
  if (!quic_version_string.empty()) {
    versions = quic::ParseQuicVersionVectorString(quic_version_string);
  }

  if (versions.empty()) {
    std::cerr << "No known version selected." << std::endl;
    return 1;
  }

  for (const quic::ParsedQuicVersion& version : versions) {
    quic::QuicEnableVersion(version);
  }

  if (GetQuicFlag(FLAGS_force_version_negotiation)) {
    versions.insert(versions.begin(),
                    quic::QuicVersionReservedForNegotiation());
  }

  const int32_t num_requests(GetQuicFlag(FLAGS_num_requests));
  std::unique_ptr<quic::ProofVerifier> proof_verifier;
  if (GetQuicFlag(FLAGS_disable_certificate_verification)) {
    proof_verifier = std::make_unique<FakeProofVerifier>();
  } else {
    proof_verifier = quic::CreateDefaultProofVerifier(url.host());
  }

  QuicConfig config;
  std::string connection_options_string = GetQuicFlag(FLAGS_connection_options);
  if (!connection_options_string.empty()) {
    config.SetConnectionOptionsToSend(
        ParseQuicTagVector(connection_options_string));
  }
  std::string client_connection_options_string =
      GetQuicFlag(FLAGS_client_connection_options);
  if (!client_connection_options_string.empty()) {
    config.SetClientConnectionOptions(
        ParseQuicTagVector(client_connection_options_string));
  }
  if (GetQuicFlag(FLAGS_multi_packet_chlo)) {
    // Make the ClientHello span multiple packets by adding a custom transport
    // parameter.
    constexpr auto kCustomParameter =
        static_cast<TransportParameters::TransportParameterId>(0x173E);
    std::string custom_value(2000, '?');
    config.custom_transport_parameters_to_send()[kCustomParameter] =
        custom_value;
  }

  int address_family_for_lookup = AF_UNSPEC;
  if (GetQuicFlag(FLAGS_ip_version_for_host_lookup) == "4") {
    address_family_for_lookup = AF_INET;
  } else if (GetQuicFlag(FLAGS_ip_version_for_host_lookup) == "6") {
    address_family_for_lookup = AF_INET6;
  }

  // Build the client, and try to connect.
  std::unique_ptr<QuicSpdyClientBase> client = client_factory_->CreateClient(
      url.host(), host, address_family_for_lookup, port, versions, config,
      std::move(proof_verifier));

  if (client == nullptr) {
    std::cerr << "Failed to create client." << std::endl;
    return 1;
  }

  int32_t initial_mtu = GetQuicFlag(FLAGS_initial_mtu);
  client->set_initial_max_packet_length(
      initial_mtu != 0 ? initial_mtu : quic::kDefaultMaxPacketSize);
  client->set_drop_response_body(GetQuicFlag(FLAGS_drop_response_body));
  const int32_t server_connection_id_length =
      GetQuicFlag(FLAGS_server_connection_id_length);
  if (server_connection_id_length >= 0) {
    client->set_server_connection_id_length(server_connection_id_length);
  }
  const int32_t client_connection_id_length =
      GetQuicFlag(FLAGS_client_connection_id_length);
  if (client_connection_id_length >= 0) {
    client->set_client_connection_id_length(client_connection_id_length);
  }
  if (!client->Initialize()) {
    std::cerr << "Failed to initialize client." << std::endl;
    return 1;
  }
  if (!client->Connect()) {
    quic::QuicErrorCode error = client->session()->error();
    if (error == quic::QUIC_INVALID_VERSION) {
      std::cerr << "Failed to negotiate version with " << host << ":" << port
                << ". " << client->session()->error_details() << std::endl;
      // 0: No error.
      // 20: Failed to connect due to QUIC_INVALID_VERSION.
      return GetQuicFlag(FLAGS_version_mismatch_ok) ? 0 : 20;
    }
    std::cerr << "Failed to connect to " << host << ":" << port << ". "
              << quic::QuicErrorCodeToString(error) << " "
              << client->session()->error_details() << std::endl;
    return 1;
  }
  std::cerr << "Connected to " << host << ":" << port << std::endl;

  // Construct the string body from flags, if provided.
  std::string body = GetQuicFlag(FLAGS_body);
  if (!GetQuicFlag(FLAGS_body_hex).empty()) {
    QUICHE_DCHECK(GetQuicFlag(FLAGS_body).empty())
        << "Only set one of --body and --body_hex.";
    body = absl::HexStringToBytes(GetQuicFlag(FLAGS_body_hex));
  }

  // Construct a GET or POST request for supplied URL.
  spdy::Http2HeaderBlock header_block;
  header_block[":method"] = body.empty() ? "GET" : "POST";
  header_block[":scheme"] = url.scheme();
  header_block[":authority"] = url.HostPort();
  header_block[":path"] = url.PathParamsQuery();

  // Append any additional headers supplied on the command line.
  const std::string headers = GetQuicFlag(FLAGS_headers);
  for (absl::string_view sp : absl::StrSplit(headers, ';')) {
    QuicheTextUtils::RemoveLeadingAndTrailingWhitespace(&sp);
    if (sp.empty()) {
      continue;
    }
    std::vector<absl::string_view> kv =
        absl::StrSplit(sp, absl::MaxSplits(':', 1));
    QuicheTextUtils::RemoveLeadingAndTrailingWhitespace(&kv[0]);
    QuicheTextUtils::RemoveLeadingAndTrailingWhitespace(&kv[1]);
    header_block[kv[0]] = kv[1];
  }

  // Make sure to store the response, for later output.
  client->set_store_response(true);

  for (int i = 0; i < num_requests; ++i) {
    // Send the request.
    client->SendRequestAndWaitForResponse(header_block, body, /*fin=*/true);

    // Print request and response details.
    if (!GetQuicFlag(FLAGS_quiet)) {
      std::cout << "Request:" << std::endl;
      std::cout << "headers:" << header_block.DebugString();
      if (!GetQuicFlag(FLAGS_body_hex).empty()) {
        // Print the user provided hex, rather than binary body.
        std::cout << "body:\n"
                  << QuicheTextUtils::HexDump(
                         absl::HexStringToBytes(GetQuicFlag(FLAGS_body_hex)))
                  << std::endl;
      } else {
        std::cout << "body: " << body << std::endl;
      }
      std::cout << std::endl;

      if (!client->preliminary_response_headers().empty()) {
        std::cout << "Preliminary response headers: "
                  << client->preliminary_response_headers() << std::endl;
        std::cout << std::endl;
      }

      std::cout << "Response:" << std::endl;
      std::cout << "headers: " << client->latest_response_headers()
                << std::endl;
      std::string response_body = client->latest_response_body();
      if (!GetQuicFlag(FLAGS_body_hex).empty()) {
        // Assume response is binary data.
        std::cout << "body:\n"
                  << QuicheTextUtils::HexDump(response_body) << std::endl;
      } else {
        std::cout << "body: " << response_body << std::endl;
      }
      std::cout << "trailers: " << client->latest_response_trailers()
                << std::endl;
    }

    if (!client->connected()) {
      std::cerr << "Request caused connection failure. Error: "
                << quic::QuicErrorCodeToString(client->session()->error())
                << std::endl;
      return 1;
    }

    int response_code = client->latest_response_code();
    if (response_code >= 200 && response_code < 300) {
      std::cout << "Request succeeded (" << response_code << ")." << std::endl;
    } else if (response_code >= 300 && response_code < 400) {
      if (GetQuicFlag(FLAGS_redirect_is_success)) {
        std::cout << "Request succeeded (redirect " << response_code << ")."
                  << std::endl;
      } else {
        std::cout << "Request failed (redirect " << response_code << ")."
                  << std::endl;
        return 1;
      }
    } else {
      std::cout << "Request failed (" << response_code << ")." << std::endl;
      return 1;
    }

    // Change the ephemeral port if there are more requests to do.
    if (!GetQuicFlag(FLAGS_disable_port_changes) && i + 1 < num_requests) {
      if (!client->ChangeEphemeralPort()) {
        std::cerr << "Failed to change ephemeral port." << std::endl;
        return 1;
      }
    }
  }

  return 0;
}

}  // namespace quic