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

#include "net/socket/socks5_client_socket.h"

#include <stdint.h>

#include <algorithm>
#include <iterator>
#include <map>
#include <memory>
#include <utility>

#include "base/containers/span.h"
#include "base/memory/ptr_util.h"
#include "base/memory/raw_ptr.h"
#include "base/strings/string_view_util.h"
#include "base/sys_byteorder.h"
#include "build/build_config.h"
#include "net/base/address_list.h"
#include "net/base/test_completion_callback.h"
#include "net/base/winsock_init.h"
#include "net/log/net_log_event_type.h"
#include "net/log/test_net_log.h"
#include "net/log/test_net_log_util.h"
#include "net/socket/client_socket_factory.h"
#include "net/socket/socket_test_util.h"
#include "net/socket/tcp_client_socket.h"
#include "net/test/gtest_util.h"
#include "net/test/test_with_task_environment.h"
#include "net/traffic_annotation/network_traffic_annotation_test_helper.h"
#include "testing/gmock/include/gmock/gmock.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "testing/platform_test.h"

using net::test::IsError;
using net::test::IsOk;

//-----------------------------------------------------------------------------

namespace net {

class NetLog;

namespace {

// Base class to test SOCKS5ClientSocket
class SOCKS5ClientSocketTest : public PlatformTest, public WithTaskEnvironment {
 public:
  SOCKS5ClientSocketTest();

  SOCKS5ClientSocketTest(const SOCKS5ClientSocketTest&) = delete;
  SOCKS5ClientSocketTest& operator=(const SOCKS5ClientSocketTest&) = delete;

  // Create a SOCKSClientSocket on top of a MockSocket.
  std::unique_ptr<SOCKS5ClientSocket> BuildMockSocket(
      base::span<const MockRead> reads,
      base::span<const MockWrite> writes,
      std::string_view hostname,
      int port,
      NetLog* net_log);

  void SetUp() override;

 protected:
  static constexpr uint16_t kNwPort = base::HostToNet16(80);
  RecordingNetLogObserver net_log_observer_;
  std::unique_ptr<SOCKS5ClientSocket> user_sock_;
  AddressList address_list_;
  // Filled in by BuildMockSocket() and owned by its return value
  // (which |user_sock| is set to).
  raw_ptr<StreamSocket> tcp_sock_;
  TestCompletionCallback callback_;
  std::unique_ptr<SocketDataProvider> data_;
};

SOCKS5ClientSocketTest::SOCKS5ClientSocketTest() {}

// Set up platform before every test case
void SOCKS5ClientSocketTest::SetUp() {
  PlatformTest::SetUp();

  // Create the "localhost" AddressList used by the TCP connection to connect.
  address_list_ =
      AddressList::CreateFromIPAddress(IPAddress::IPv4Localhost(), 1080);
}

std::unique_ptr<SOCKS5ClientSocket> SOCKS5ClientSocketTest::BuildMockSocket(
    base::span<const MockRead> reads,
    base::span<const MockWrite> writes,
    std::string_view hostname,
    int port,
    NetLog* net_log) {
  TestCompletionCallback callback;
  data_ = std::make_unique<StaticSocketDataProvider>(reads, writes);
  auto tcp_sock = std::make_unique<MockTCPClientSocket>(address_list_, net_log,
                                                        data_.get());
  tcp_sock_ = tcp_sock.get();

  int rv = tcp_sock_->Connect(callback.callback());
  EXPECT_THAT(rv, IsError(ERR_IO_PENDING));
  rv = callback.WaitForResult();
  EXPECT_THAT(rv, IsOk());
  EXPECT_TRUE(tcp_sock_->IsConnected());

  // The SOCKS5ClientSocket takes ownership of |tcp_sock_|, but keep a
  // non-owning pointer to it.
  return std::make_unique<SOCKS5ClientSocket>(std::move(tcp_sock),
                                              HostPortPair(hostname, port),
                                              TRAFFIC_ANNOTATION_FOR_TESTS);
}

// Tests a complete SOCKS5 handshake and the disconnection.
TEST_F(SOCKS5ClientSocketTest, CompleteHandshake) {
  const std::string payload_write = "random data";
  const std::string payload_read = "moar random data";

  const char kOkRequest[] = {
    0x05,  // Version
    0x01,  // Command (CONNECT)
    0x00,  // Reserved.
    0x03,  // Address type (DOMAINNAME).
    0x09,  // Length of domain (9)
    // Domain string:
    'l', 'o', 'c', 'a', 'l', 'h', 'o', 's', 't',
    0x00, 0x50,  // 16-bit port (80)
  };

  MockWrite data_writes[] = {MockWrite(ASYNC, kSOCKS5GreetRequest),
                             MockWrite(ASYNC, base::as_byte_span(kOkRequest)),
                             MockWrite(ASYNC, payload_write)};
  MockRead data_reads[] = {MockRead(ASYNC, kSOCKS5GreetResponse),
                           MockRead(ASYNC, kSOCKS5OkResponse),
                           MockRead(ASYNC, payload_read)};

  user_sock_ =
      BuildMockSocket(data_reads, data_writes, "localhost", 80, NetLog::Get());

  // At this state the TCP connection is completed but not the SOCKS handshake.
  EXPECT_TRUE(tcp_sock_->IsConnected());
  EXPECT_FALSE(user_sock_->IsConnected());

  int rv = user_sock_->Connect(callback_.callback());
  EXPECT_THAT(rv, IsError(ERR_IO_PENDING));
  EXPECT_FALSE(user_sock_->IsConnected());

  auto net_log_entries = net_log_observer_.GetEntries();
  EXPECT_TRUE(LogContainsBeginEvent(net_log_entries, 0,
                                    NetLogEventType::SOCKS5_CONNECT));

  rv = callback_.WaitForResult();

  EXPECT_THAT(rv, IsOk());
  EXPECT_TRUE(user_sock_->IsConnected());

  net_log_entries = net_log_observer_.GetEntries();
  EXPECT_TRUE(LogContainsEndEvent(net_log_entries, -1,
                                  NetLogEventType::SOCKS5_CONNECT));

  auto write_buffer = base::MakeRefCounted<StringIOBuffer>(payload_write);
  rv = user_sock_->Write(write_buffer.get(), payload_write.size(),
                         callback_.callback(), TRAFFIC_ANNOTATION_FOR_TESTS);
  EXPECT_THAT(rv, IsError(ERR_IO_PENDING));
  rv = callback_.WaitForResult();
  EXPECT_EQ(static_cast<int>(payload_write.size()), rv);

  auto read_buffer =
      base::MakeRefCounted<IOBufferWithSize>(payload_read.size());
  rv = user_sock_->Read(read_buffer.get(), payload_read.size(),
                        callback_.callback());
  EXPECT_THAT(rv, IsError(ERR_IO_PENDING));
  rv = callback_.WaitForResult();
  EXPECT_EQ(static_cast<int>(payload_read.size()), rv);
  EXPECT_EQ(payload_read, base::as_string_view(read_buffer->span()));

  user_sock_->Disconnect();
  EXPECT_FALSE(tcp_sock_->IsConnected());
  EXPECT_FALSE(user_sock_->IsConnected());
}

// Test that you can call Connect() again after having called Disconnect().
TEST_F(SOCKS5ClientSocketTest, ConnectAndDisconnectTwice) {
  const std::string_view kHostname = "my-host-name";
  const char kSOCKS5DomainRequest[] = {
      0x05,  // VER
      0x01,  // CMD
      0x00,  // RSV
      0x03,  // ATYPE
  };

  std::string request(kSOCKS5DomainRequest, std::size(kSOCKS5DomainRequest));
  request.push_back(static_cast<char>(kHostname.size()));
  request.append(kHostname);
  request.append(base::as_string_view(base::byte_span_from_ref(kNwPort)));

  for (int i = 0; i < 2; ++i) {
    MockWrite data_writes[] = {MockWrite(SYNCHRONOUS, kSOCKS5GreetRequest),
                               MockWrite(SYNCHRONOUS, request)};
    MockRead data_reads[] = {MockRead(SYNCHRONOUS, kSOCKS5GreetResponse),
                             MockRead(SYNCHRONOUS, kSOCKS5OkResponse)};

    user_sock_ =
        BuildMockSocket(data_reads, data_writes, kHostname, 80, nullptr);

    int rv = user_sock_->Connect(callback_.callback());
    EXPECT_THAT(rv, IsOk());
    EXPECT_TRUE(user_sock_->IsConnected());

    user_sock_->Disconnect();
    EXPECT_FALSE(user_sock_->IsConnected());
  }
}

// Test that we fail trying to connect to a hostname longer than 255 bytes.
TEST_F(SOCKS5ClientSocketTest, LargeHostNameFails) {
  // Create a string of length 256, where each character is 'x'.
  std::string large_host_name;
  std::fill_n(std::back_inserter(large_host_name), 256, 'x');

  // Create a SOCKS socket, with mock transport socket.
  MockWrite data_writes[] = {MockWrite()};
  MockRead data_reads[] = {MockRead()};
  user_sock_ =
      BuildMockSocket(data_reads, data_writes, large_host_name, 80, nullptr);

  // Try to connect -- should fail (without having read/written anything to
  // the transport socket first) because the hostname is too long.
  TestCompletionCallback callback;
  int rv = user_sock_->Connect(callback.callback());
  EXPECT_THAT(rv, IsError(ERR_SOCKS_CONNECTION_FAILED));
}

TEST_F(SOCKS5ClientSocketTest, PartialReadWrites) {
  const std::string_view kHostname = "www.google.com";

  static constexpr uint8_t kOkRequestData[] = {
      0x05,  // Version
      0x01,  // Command (CONNECT)
      0x00,  // Reserved.
      0x03,  // Address type (DOMAINNAME).
      0x0E,  // Length of domain (14)
      // Domain string:
      'w', 'w', 'w', '.', 'g', 'o', 'o', 'g', 'l', 'e', '.', 'c', 'o', 'm',
      0x00, 0x50,  // 16-bit port (80)
  };
  static constexpr base::span<const uint8_t> kOkRequest(kOkRequestData);

  // Test for partial greet request write
  {
    const uint8_t kPartial1[] = {0x05, 0x01};
    const uint8_t kPartial2[] = {0x00};
    MockWrite data_writes[] = {MockWrite(ASYNC, base::span(kPartial1)),
                               MockWrite(ASYNC, base::span(kPartial2)),
                               MockWrite(ASYNC, kOkRequest)};
    MockRead data_reads[] = {MockRead(ASYNC, kSOCKS5GreetResponse),
                             MockRead(ASYNC, kSOCKS5OkResponse)};
    user_sock_ =
        BuildMockSocket(data_reads, data_writes, kHostname, 80, NetLog::Get());
    int rv = user_sock_->Connect(callback_.callback());
    EXPECT_THAT(rv, IsError(ERR_IO_PENDING));

    auto net_log_entries = net_log_observer_.GetEntries();
    EXPECT_TRUE(LogContainsBeginEvent(net_log_entries, 0,
                                      NetLogEventType::SOCKS5_CONNECT));

    rv = callback_.WaitForResult();
    EXPECT_THAT(rv, IsOk());
    EXPECT_TRUE(user_sock_->IsConnected());

    net_log_entries = net_log_observer_.GetEntries();
    EXPECT_TRUE(LogContainsEndEvent(net_log_entries, -1,
                                    NetLogEventType::SOCKS5_CONNECT));
  }

  // Test for partial greet response read
  {
    const uint8_t kPartial1[] = {0x05};
    const uint8_t kPartial2[] = {0x00};
    MockWrite data_writes[] = {MockWrite(ASYNC, kSOCKS5GreetRequest),
                               MockWrite(ASYNC, kOkRequest)};
    MockRead data_reads[] = {MockRead(ASYNC, base::span(kPartial1)),
                             MockRead(ASYNC, base::span(kPartial2)),
                             MockRead(ASYNC, kSOCKS5OkResponse)};
    user_sock_ =
        BuildMockSocket(data_reads, data_writes, kHostname, 80, NetLog::Get());
    int rv = user_sock_->Connect(callback_.callback());
    EXPECT_THAT(rv, IsError(ERR_IO_PENDING));

    auto net_log_entries = net_log_observer_.GetEntries();
    EXPECT_TRUE(LogContainsBeginEvent(net_log_entries, 0,
                                      NetLogEventType::SOCKS5_CONNECT));
    rv = callback_.WaitForResult();
    EXPECT_THAT(rv, IsOk());
    EXPECT_TRUE(user_sock_->IsConnected());
    net_log_entries = net_log_observer_.GetEntries();
    EXPECT_TRUE(LogContainsEndEvent(net_log_entries, -1,
                                    NetLogEventType::SOCKS5_CONNECT));
  }

  // Test for partial handshake request write.
  {
    // Break handshake write into two parts.
    const auto [kPart1, kPart2] = kOkRequest.split_at<3>();
    MockWrite data_writes[] = {MockWrite(ASYNC, kSOCKS5GreetRequest),
                               MockWrite(ASYNC, kPart1),
                               MockWrite(ASYNC, kPart2)};
    MockRead data_reads[] = {MockRead(ASYNC, kSOCKS5GreetResponse),
                             MockRead(ASYNC, kSOCKS5OkResponse)};
    user_sock_ =
        BuildMockSocket(data_reads, data_writes, kHostname, 80, NetLog::Get());
    int rv = user_sock_->Connect(callback_.callback());
    EXPECT_THAT(rv, IsError(ERR_IO_PENDING));
    auto net_log_entries = net_log_observer_.GetEntries();
    EXPECT_TRUE(LogContainsBeginEvent(net_log_entries, 0,
                                      NetLogEventType::SOCKS5_CONNECT));
    rv = callback_.WaitForResult();
    EXPECT_THAT(rv, IsOk());
    EXPECT_TRUE(user_sock_->IsConnected());
    net_log_entries = net_log_observer_.GetEntries();
    EXPECT_TRUE(LogContainsEndEvent(net_log_entries, -1,
                                    NetLogEventType::SOCKS5_CONNECT));
  }

  // Test for partial handshake response read
  {
    const size_t kSplitPoint = 6;  // Break the handshake read into two parts.
    MockWrite data_writes[] = {MockWrite(ASYNC, kSOCKS5GreetRequest),
                               MockWrite(ASYNC, kOkRequest)};
    MockRead data_reads[] = {
        MockRead(ASYNC, kSOCKS5GreetResponse),
        MockRead(ASYNC, kSOCKS5OkResponse.substr(0, kSplitPoint)),
        MockRead(ASYNC, kSOCKS5OkResponse.substr(kSplitPoint))};

    user_sock_ =
        BuildMockSocket(data_reads, data_writes, kHostname, 80, NetLog::Get());
    int rv = user_sock_->Connect(callback_.callback());
    EXPECT_THAT(rv, IsError(ERR_IO_PENDING));
    auto net_log_entries = net_log_observer_.GetEntries();
    EXPECT_TRUE(LogContainsBeginEvent(net_log_entries, 0,
                                      NetLogEventType::SOCKS5_CONNECT));
    rv = callback_.WaitForResult();
    EXPECT_THAT(rv, IsOk());
    EXPECT_TRUE(user_sock_->IsConnected());
    net_log_entries = net_log_observer_.GetEntries();
    EXPECT_TRUE(LogContainsEndEvent(net_log_entries, -1,
                                    NetLogEventType::SOCKS5_CONNECT));
  }
}

TEST_F(SOCKS5ClientSocketTest, Tag) {
  StaticSocketDataProvider data;
  auto tagging_sock = std::make_unique<MockTaggingStreamSocket>(
      std::make_unique<MockTCPClientSocket>(address_list_, NetLog::Get(),
                                            &data));
  auto* tagging_sock_ptr = tagging_sock.get();

  // |socket| takes ownership of |tagging_sock|, but keep a non-owning pointer
  // to it.
  SOCKS5ClientSocket socket(std::move(tagging_sock),
                            HostPortPair("localhost", 80),
                            TRAFFIC_ANNOTATION_FOR_TESTS);

  EXPECT_EQ(tagging_sock_ptr->tag(), SocketTag());
#if BUILDFLAG(IS_ANDROID)
  SocketTag tag(0x12345678, 0x87654321);
  socket.ApplySocketTag(tag);
  EXPECT_EQ(tagging_sock_ptr->tag(), tag);
#endif  // BUILDFLAG(IS_ANDROID)
}

}  // namespace

}  // namespace net