Add initial implementation of Naive client

src/net/BUILD.gn

@@ -1728,3 +1728,29 @@ static_library("preload_decoder") {
   ]
   deps = [ "//base" ]
 }
+
+executable("naive") {
+  sources = [
+    "tools/naive/naive_connection.cc",
+    "tools/naive/naive_connection.h",
+    "tools/naive/naive_proxy.cc",
+    "tools/naive/naive_proxy.h",
+    "tools/naive/naive_proxy_bin.cc",
+    "tools/naive/naive_proxy_delegate.h",
+    "tools/naive/naive_proxy_delegate.cc",
+    "tools/naive/http_proxy_socket.cc",
+    "tools/naive/http_proxy_socket.h",
+    "tools/naive/redirect_resolver.h",
+    "tools/naive/redirect_resolver.cc",
+    "tools/naive/socks5_server_socket.cc",
+    "tools/naive/socks5_server_socket.h",
+  ]
+
+  deps = [
+    ":net",
+    "//base",
+    "//build/win:default_exe_manifest",
+    "//components/version_info:version_info",
+    "//url",
+  ]
+}

src/net/log/net_log_event_type_list.h

@@ -488,6 +488,11 @@ EVENT_TYPE(SOCKS_HOSTNAME_TOO_BIG)
 EVENT_TYPE(SOCKS_UNEXPECTEDLY_CLOSED_DURING_GREETING)
 EVENT_TYPE(SOCKS_UNEXPECTEDLY_CLOSED_DURING_HANDSHAKE)
 
+EVENT_TYPE(SOCKS_NO_REQUESTED_AUTH)
+EVENT_TYPE(SOCKS_NO_ACCEPTABLE_AUTH)
+EVENT_TYPE(SOCKS_ZERO_LENGTH_DOMAIN)
+EVENT_TYPE(SOCKS_UNEXPECTED_COMMAND)
+
 // This event indicates that a bad version number was received in the
 // proxy server's response. The extra parameters show its value:
 //   {

src/net/tools/naive/http_proxy_socket.cc

@@ -0,0 +1,360 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Copyright 2018 klzgrad <kizdiv@gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/tools/naive/http_proxy_socket.h"
+
+#include <cstring>
+#include <utility>
+
+#include "base/bind.h"
+#include "base/callback_helpers.h"
+#include "base/logging.h"
+#include "base/rand_util.h"
+#include "base/sys_byteorder.h"
+#include "net/base/ip_address.h"
+#include "net/base/net_errors.h"
+#include "net/http/http_request_headers.h"
+#include "net/log/net_log.h"
+#include "net/third_party/quiche/src/spdy/core/hpack/hpack_constants.h"
+#include "net/tools/naive/naive_proxy_delegate.h"
+
+namespace net {
+
+namespace {
+constexpr int kBufferSize = 64 * 1024;
+constexpr size_t kMaxHeaderSize = 64 * 1024;
+constexpr char kResponseHeader[] = "HTTP/1.1 200 OK\r\nPadding: ";
+constexpr int kResponseHeaderSize = sizeof(kResponseHeader) - 1;
+// A plain 200 is 10 bytes. Expected 48 bytes. "Padding" uses up 7 bytes.
+constexpr int kMinPaddingSize = 30;
+constexpr int kMaxPaddingSize = kMinPaddingSize + 32;
+}  // namespace
+
+HttpProxySocket::HttpProxySocket(
+    std::unique_ptr<StreamSocket> transport_socket,
+    ClientPaddingDetectorDelegate* padding_detector_delegate,
+    const NetworkTrafficAnnotationTag& traffic_annotation)
+    : io_callback_(base::BindRepeating(&HttpProxySocket::OnIOComplete,
+                                       base::Unretained(this))),
+      transport_(std::move(transport_socket)),
+      padding_detector_delegate_(padding_detector_delegate),
+      next_state_(STATE_NONE),
+      completed_handshake_(false),
+      was_ever_used_(false),
+      header_write_size_(-1),
+      net_log_(transport_->NetLog()),
+      traffic_annotation_(traffic_annotation) {}
+
+HttpProxySocket::~HttpProxySocket() {
+  Disconnect();
+}
+
+const HostPortPair& HttpProxySocket::request_endpoint() const {
+  return request_endpoint_;
+}
+
+int HttpProxySocket::Connect(CompletionOnceCallback callback) {
+  DCHECK(transport_);
+  DCHECK_EQ(STATE_NONE, next_state_);
+  DCHECK(!user_callback_);
+
+  // If already connected, then just return OK.
+  if (completed_handshake_)
+    return OK;
+
+  next_state_ = STATE_HEADER_READ;
+  buffer_.clear();
+
+  int rv = DoLoop(OK);
+  if (rv == ERR_IO_PENDING) {
+    user_callback_ = std::move(callback);
+  }
+  return rv;
+}
+
+void HttpProxySocket::Disconnect() {
+  completed_handshake_ = false;
+  transport_->Disconnect();
+
+  // Reset other states to make sure they aren't mistakenly used later.
+  // These are the states initialized by Connect().
+  next_state_ = STATE_NONE;
+  user_callback_.Reset();
+}
+
+bool HttpProxySocket::IsConnected() const {
+  return completed_handshake_ && transport_->IsConnected();
+}
+
+bool HttpProxySocket::IsConnectedAndIdle() const {
+  return completed_handshake_ && transport_->IsConnectedAndIdle();
+}
+
+const NetLogWithSource& HttpProxySocket::NetLog() const {
+  return net_log_;
+}
+
+bool HttpProxySocket::WasEverUsed() const {
+  return was_ever_used_;
+}
+
+bool HttpProxySocket::WasAlpnNegotiated() const {
+  if (transport_) {
+    return transport_->WasAlpnNegotiated();
+  }
+  NOTREACHED();
+  return false;
+}
+
+NextProto HttpProxySocket::GetNegotiatedProtocol() const {
+  if (transport_) {
+    return transport_->GetNegotiatedProtocol();
+  }
+  NOTREACHED();
+  return kProtoUnknown;
+}
+
+bool HttpProxySocket::GetSSLInfo(SSLInfo* ssl_info) {
+  if (transport_) {
+    return transport_->GetSSLInfo(ssl_info);
+  }
+  NOTREACHED();
+  return false;
+}
+
+void HttpProxySocket::GetConnectionAttempts(ConnectionAttempts* out) const {
+  out->clear();
+}
+
+int64_t HttpProxySocket::GetTotalReceivedBytes() const {
+  return transport_->GetTotalReceivedBytes();
+}
+
+void HttpProxySocket::ApplySocketTag(const SocketTag& tag) {
+  return transport_->ApplySocketTag(tag);
+}
+
+// Read is called by the transport layer above to read. This can only be done
+// if the HTTP header is complete.
+int HttpProxySocket::Read(IOBuffer* buf,
+                          int buf_len,
+                          CompletionOnceCallback callback) {
+  DCHECK(completed_handshake_);
+  DCHECK_EQ(STATE_NONE, next_state_);
+  DCHECK(!user_callback_);
+  DCHECK(callback);
+
+  if (!buffer_.empty()) {
+    was_ever_used_ = true;
+    int data_len = buffer_.size();
+    if (data_len <= buf_len) {
+      std::memcpy(buf->data(), buffer_.data(), data_len);
+      buffer_.clear();
+      return data_len;
+    } else {
+      std::memcpy(buf->data(), buffer_.data(), buf_len);
+      buffer_ = buffer_.substr(buf_len);
+      return buf_len;
+    }
+  }
+
+  int rv = transport_->Read(
+      buf, buf_len,
+      base::BindOnce(&HttpProxySocket::OnReadWriteComplete,
+                     base::Unretained(this), std::move(callback)));
+  if (rv > 0)
+    was_ever_used_ = true;
+  return rv;
+}
+
+// Write is called by the transport layer. This can only be done if the
+// SOCKS handshake is complete.
+int HttpProxySocket::Write(
+    IOBuffer* buf,
+    int buf_len,
+    CompletionOnceCallback callback,
+    const NetworkTrafficAnnotationTag& traffic_annotation) {
+  DCHECK(completed_handshake_);
+  DCHECK_EQ(STATE_NONE, next_state_);
+  DCHECK(!user_callback_);
+  DCHECK(callback);
+
+  int rv = transport_->Write(
+      buf, buf_len,
+      base::BindOnce(&HttpProxySocket::OnReadWriteComplete,
+                     base::Unretained(this), std::move(callback)),
+      traffic_annotation);
+  if (rv > 0)
+    was_ever_used_ = true;
+  return rv;
+}
+
+int HttpProxySocket::SetReceiveBufferSize(int32_t size) {
+  return transport_->SetReceiveBufferSize(size);
+}
+
+int HttpProxySocket::SetSendBufferSize(int32_t size) {
+  return transport_->SetSendBufferSize(size);
+}
+
+void HttpProxySocket::DoCallback(int result) {
+  DCHECK_NE(ERR_IO_PENDING, result);
+  DCHECK(user_callback_);
+
+  // Since Run() may result in Read being called,
+  // clear user_callback_ up front.
+  std::move(user_callback_).Run(result);
+}
+
+void HttpProxySocket::OnIOComplete(int result) {
+  DCHECK_NE(STATE_NONE, next_state_);
+  int rv = DoLoop(result);
+  if (rv != ERR_IO_PENDING) {
+    DoCallback(rv);
+  }
+}
+
+void HttpProxySocket::OnReadWriteComplete(CompletionOnceCallback callback,
+                                          int result) {
+  DCHECK_NE(ERR_IO_PENDING, result);
+  DCHECK(callback);
+
+  if (result > 0)
+    was_ever_used_ = true;
+  std::move(callback).Run(result);
+}
+
+int HttpProxySocket::DoLoop(int last_io_result) {
+  DCHECK_NE(next_state_, STATE_NONE);
+  int rv = last_io_result;
+  do {
+    State state = next_state_;
+    next_state_ = STATE_NONE;
+    switch (state) {
+      case STATE_HEADER_READ:
+        DCHECK_EQ(OK, rv);
+        rv = DoHeaderRead();
+        break;
+      case STATE_HEADER_READ_COMPLETE:
+        rv = DoHeaderReadComplete(rv);
+        break;
+      case STATE_HEADER_WRITE:
+        DCHECK_EQ(OK, rv);
+        rv = DoHeaderWrite();
+        break;
+      case STATE_HEADER_WRITE_COMPLETE:
+        rv = DoHeaderWriteComplete(rv);
+        break;
+      default:
+        NOTREACHED() << "bad state";
+        rv = ERR_UNEXPECTED;
+        break;
+    }
+  } while (rv != ERR_IO_PENDING && next_state_ != STATE_NONE);
+  return rv;
+}
+
+int HttpProxySocket::DoHeaderRead() {
+  next_state_ = STATE_HEADER_READ_COMPLETE;
+
+  handshake_buf_ = base::MakeRefCounted<IOBuffer>(kBufferSize);
+  return transport_->Read(handshake_buf_.get(), kBufferSize, io_callback_);
+}
+
+int HttpProxySocket::DoHeaderReadComplete(int result) {
+  if (result < 0)
+    return result;
+
+  if (result == 0) {
+    return ERR_CONNECTION_CLOSED;
+  }
+
+  buffer_.append(handshake_buf_->data(), result);
+  if (buffer_.size() > kMaxHeaderSize) {
+    return ERR_MSG_TOO_BIG;
+  }
+
+  auto header_end = buffer_.find("\r\n\r\n");
+  if (header_end == std::string::npos) {
+    next_state_ = STATE_HEADER_READ;
+    return OK;
+  }
+
+  // HttpProxyClientSocket uses CONNECT for all endpoints.
+  auto first_line_end = buffer_.find("\r\n");
+  auto first_space = buffer_.find(' ');
+  if (first_space == std::string::npos || first_space + 1 >= first_line_end) {
+    return ERR_INVALID_ARGUMENT;
+  }
+  if (buffer_.compare(0, first_space, "CONNECT") != 0) {
+    return ERR_INVALID_ARGUMENT;
+  }
+  auto second_space = buffer_.find(' ', first_space + 1);
+  if (second_space == std::string::npos || second_space >= first_line_end) {
+    return ERR_INVALID_ARGUMENT;
+  }
+  request_endpoint_ = HostPortPair::FromString(
+      buffer_.substr(first_space + 1, second_space - (first_space + 1)));
+
+  auto second_line = first_line_end + 2;
+  HttpRequestHeaders headers;
+  std::string headers_str;
+  if (second_line < header_end) {
+    headers_str = buffer_.substr(second_line, header_end - second_line);
+    headers.AddHeadersFromString(headers_str);
+  }
+  if (headers.HasHeader("padding")) {
+    padding_detector_delegate_->SetClientPaddingSupport(
+        PaddingSupport::kCapable);
+  } else {
+    padding_detector_delegate_->SetClientPaddingSupport(
+        PaddingSupport::kIncapable);
+  }
+
+  buffer_ = buffer_.substr(header_end + 4);
+
+  next_state_ = STATE_HEADER_WRITE;
+  return OK;
+}
+
+int HttpProxySocket::DoHeaderWrite() {
+  next_state_ = STATE_HEADER_WRITE_COMPLETE;
+
+  // Adds padding.
+  int padding_size = base::RandInt(kMinPaddingSize, kMaxPaddingSize);
+  header_write_size_ = kResponseHeaderSize + padding_size + 4;
+  handshake_buf_ = base::MakeRefCounted<IOBuffer>(header_write_size_);
+  char* p = handshake_buf_->data();
+  std::memcpy(p, kResponseHeader, kResponseHeaderSize);
+  FillNonindexHeaderValue(base::RandUint64(), p + kResponseHeaderSize,
+                          padding_size);
+  std::memcpy(p + kResponseHeaderSize + padding_size, "\r\n\r\n", 4);
+
+  return transport_->Write(handshake_buf_.get(), header_write_size_,
+                           io_callback_, traffic_annotation_);
+}
+
+int HttpProxySocket::DoHeaderWriteComplete(int result) {
+  if (result < 0)
+    return result;
+
+  if (result != header_write_size_) {
+    return ERR_FAILED;
+  }
+
+  completed_handshake_ = true;
+  next_state_ = STATE_NONE;
+  return OK;
+}
+
+int HttpProxySocket::GetPeerAddress(IPEndPoint* address) const {
+  return transport_->GetPeerAddress(address);
+}
+
+int HttpProxySocket::GetLocalAddress(IPEndPoint* address) const {
+  return transport_->GetLocalAddress(address);
+}
+
+}  // namespace net

src/net/tools/naive/http_proxy_socket.h

@@ -0,0 +1,125 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Copyright 2018 klzgrad <kizdiv@gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef NET_TOOLS_NAIVE_HTTP_PROXY_SOCKET_H_
+#define NET_TOOLS_NAIVE_HTTP_PROXY_SOCKET_H_
+
+#include <cstddef>
+#include <cstdint>
+#include <memory>
+#include <string>
+
+#include "base/memory/scoped_refptr.h"
+#include "net/base/completion_once_callback.h"
+#include "net/base/completion_repeating_callback.h"
+#include "net/base/host_port_pair.h"
+#include "net/base/io_buffer.h"
+#include "net/base/ip_endpoint.h"
+#include "net/log/net_log_with_source.h"
+#include "net/socket/connection_attempts.h"
+#include "net/socket/next_proto.h"
+#include "net/socket/stream_socket.h"
+#include "net/ssl/ssl_info.h"
+
+namespace net {
+struct NetworkTrafficAnnotationTag;
+class ClientPaddingDetectorDelegate;
+
+// This StreamSocket is used to setup a HTTP CONNECT tunnel.
+class HttpProxySocket : public StreamSocket {
+ public:
+  HttpProxySocket(std::unique_ptr<StreamSocket> transport_socket,
+                  ClientPaddingDetectorDelegate* padding_detector_delegate,
+                  const NetworkTrafficAnnotationTag& traffic_annotation);
+  HttpProxySocket(const HttpProxySocket&) = delete;
+  HttpProxySocket& operator=(const HttpProxySocket&) = delete;
+
+  // On destruction Disconnect() is called.
+  ~HttpProxySocket() override;
+
+  const HostPortPair& request_endpoint() const;
+
+  // StreamSocket implementation.
+
+  int Connect(CompletionOnceCallback callback) override;
+  void Disconnect() override;
+  bool IsConnected() const override;
+  bool IsConnectedAndIdle() const override;
+  const NetLogWithSource& NetLog() const override;
+  bool WasEverUsed() const override;
+  bool WasAlpnNegotiated() const override;
+  NextProto GetNegotiatedProtocol() const override;
+  bool GetSSLInfo(SSLInfo* ssl_info) override;
+  void GetConnectionAttempts(ConnectionAttempts* out) const override;
+  void ClearConnectionAttempts() override {}
+  void AddConnectionAttempts(const ConnectionAttempts& attempts) override {}
+  int64_t GetTotalReceivedBytes() const override;
+  void ApplySocketTag(const SocketTag& tag) override;
+
+  // Socket implementation.
+  int Read(IOBuffer* buf,
+           int buf_len,
+           CompletionOnceCallback callback) override;
+  int Write(IOBuffer* buf,
+            int buf_len,
+            CompletionOnceCallback callback,
+            const NetworkTrafficAnnotationTag& traffic_annotation) override;
+
+  int SetReceiveBufferSize(int32_t size) override;
+  int SetSendBufferSize(int32_t size) override;
+
+  int GetPeerAddress(IPEndPoint* address) const override;
+  int GetLocalAddress(IPEndPoint* address) const override;
+
+ private:
+  enum State {
+    STATE_HEADER_READ,
+    STATE_HEADER_READ_COMPLETE,
+    STATE_HEADER_WRITE,
+    STATE_HEADER_WRITE_COMPLETE,
+    STATE_NONE,
+  };
+
+  void DoCallback(int result);
+  void OnIOComplete(int result);
+  void OnReadWriteComplete(CompletionOnceCallback callback, int result);
+
+  int DoLoop(int last_io_result);
+  int DoHeaderWrite();
+  int DoHeaderWriteComplete(int result);
+  int DoHeaderRead();
+  int DoHeaderReadComplete(int result);
+
+  CompletionRepeatingCallback io_callback_;
+
+  // Stores the underlying socket.
+  std::unique_ptr<StreamSocket> transport_;
+  ClientPaddingDetectorDelegate* padding_detector_delegate_;
+
+  State next_state_;
+
+  // Stores the callback to the layer above, called on completing Connect().
+  CompletionOnceCallback user_callback_;
+
+  // This IOBuffer is used by the class to read and write
+  // SOCKS handshake data. The length contains the expected size to
+  // read or write.
+  scoped_refptr<IOBuffer> handshake_buf_;
+
+  std::string buffer_;
+  bool completed_handshake_;
+  bool was_ever_used_;
+  int header_write_size_;
+
+  HostPortPair request_endpoint_;
+
+  NetLogWithSource net_log_;
+
+  // Traffic annotation for socket control.
+  const NetworkTrafficAnnotationTag& traffic_annotation_;
+};
+
+}  // namespace net
+#endif  // NET_TOOLS_NAIVE_HTTP_PROXY_SOCKET_H_

src/net/tools/naive/naive_connection.cc

@@ -0,0 +1,551 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Copyright 2018 klzgrad <kizdiv@gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/tools/naive/naive_connection.h"
+
+#include <cstring>
+#include <utility>
+
+#include "base/bind.h"
+#include "base/callback_helpers.h"
+#include "base/logging.h"
+#include "base/rand_util.h"
+#include "base/strings/strcat.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "base/time/time.h"
+#include "net/base/io_buffer.h"
+#include "net/base/load_flags.h"
+#include "net/base/net_errors.h"
+#include "net/base/privacy_mode.h"
+#include "net/proxy_resolution/proxy_info.h"
+#include "net/socket/client_socket_handle.h"
+#include "net/socket/client_socket_pool_manager.h"
+#include "net/socket/stream_socket.h"
+#include "net/spdy/spdy_session.h"
+#include "net/tools/naive/http_proxy_socket.h"
+#include "net/tools/naive/redirect_resolver.h"
+#include "net/tools/naive/socks5_server_socket.h"
+
+#if defined(OS_LINUX)
+#include <linux/netfilter_ipv4.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+
+#include "net/base/ip_endpoint.h"
+#include "net/base/sockaddr_storage.h"
+#include "net/socket/tcp_client_socket.h"
+#endif
+
+namespace net {
+
+namespace {
+constexpr int kBufferSize = 64 * 1024;
+constexpr int kFirstPaddings = 8;
+constexpr int kPaddingHeaderSize = 3;
+constexpr int kMaxPaddingSize = 255;
+}  // namespace
+
+NaiveConnection::NaiveConnection(
+    unsigned int id,
+    ClientProtocol protocol,
+    std::unique_ptr<PaddingDetectorDelegate> padding_detector_delegate,
+    const ProxyInfo& proxy_info,
+    const SSLConfig& server_ssl_config,
+    const SSLConfig& proxy_ssl_config,
+    RedirectResolver* resolver,
+    HttpNetworkSession* session,
+    const NetworkIsolationKey& network_isolation_key,
+    const NetLogWithSource& net_log,
+    std::unique_ptr<StreamSocket> accepted_socket,
+    const NetworkTrafficAnnotationTag& traffic_annotation)
+    : id_(id),
+      protocol_(protocol),
+      padding_detector_delegate_(std::move(padding_detector_delegate)),
+      proxy_info_(proxy_info),
+      server_ssl_config_(server_ssl_config),
+      proxy_ssl_config_(proxy_ssl_config),
+      resolver_(resolver),
+      session_(session),
+      network_isolation_key_(network_isolation_key),
+      net_log_(net_log),
+      next_state_(STATE_NONE),
+      client_socket_(std::move(accepted_socket)),
+      server_socket_handle_(std::make_unique<ClientSocketHandle>()),
+      sockets_{client_socket_.get(), nullptr},
+      errors_{OK, OK},
+      write_pending_{false, false},
+      early_pull_pending_(false),
+      can_push_to_server_(false),
+      early_pull_result_(ERR_IO_PENDING),
+      num_paddings_{0, 0},
+      read_padding_state_(STATE_READ_PAYLOAD_LENGTH_1),
+      full_duplex_(false),
+      time_func_(&base::TimeTicks::Now),
+      traffic_annotation_(traffic_annotation) {
+  io_callback_ = base::BindRepeating(&NaiveConnection::OnIOComplete,
+                                     weak_ptr_factory_.GetWeakPtr());
+}
+
+NaiveConnection::~NaiveConnection() {
+  Disconnect();
+}
+
+int NaiveConnection::Connect(CompletionOnceCallback callback) {
+  DCHECK(client_socket_);
+  DCHECK_EQ(next_state_, STATE_NONE);
+  DCHECK(!connect_callback_);
+
+  if (full_duplex_)
+    return OK;
+
+  next_state_ = STATE_CONNECT_CLIENT;
+
+  int rv = DoLoop(OK);
+  if (rv == ERR_IO_PENDING) {
+    connect_callback_ = std::move(callback);
+  }
+  return rv;
+}
+
+void NaiveConnection::Disconnect() {
+  full_duplex_ = false;
+  // Closes server side first because latency is higher.
+  if (server_socket_handle_->socket())
+    server_socket_handle_->socket()->Disconnect();
+  client_socket_->Disconnect();
+
+  next_state_ = STATE_NONE;
+  connect_callback_.Reset();
+  run_callback_.Reset();
+}
+
+void NaiveConnection::DoCallback(int result) {
+  DCHECK_NE(result, ERR_IO_PENDING);
+  DCHECK(connect_callback_);
+
+  // Since Run() may result in Read being called,
+  // clear connect_callback_ up front.
+  std::move(connect_callback_).Run(result);
+}
+
+void NaiveConnection::OnIOComplete(int result) {
+  DCHECK_NE(next_state_, STATE_NONE);
+  int rv = DoLoop(result);
+  if (rv != ERR_IO_PENDING) {
+    DoCallback(rv);
+  }
+}
+
+int NaiveConnection::DoLoop(int last_io_result) {
+  DCHECK_NE(next_state_, STATE_NONE);
+  int rv = last_io_result;
+  do {
+    State state = next_state_;
+    next_state_ = STATE_NONE;
+    switch (state) {
+      case STATE_CONNECT_CLIENT:
+        DCHECK_EQ(rv, OK);
+        rv = DoConnectClient();
+        break;
+      case STATE_CONNECT_CLIENT_COMPLETE:
+        rv = DoConnectClientComplete(rv);
+        break;
+      case STATE_CONNECT_SERVER:
+        DCHECK_EQ(rv, OK);
+        rv = DoConnectServer();
+        break;
+      case STATE_CONNECT_SERVER_COMPLETE:
+        rv = DoConnectServerComplete(rv);
+        break;
+      default:
+        NOTREACHED() << "bad state";
+        rv = ERR_UNEXPECTED;
+        break;
+    }
+  } while (rv != ERR_IO_PENDING && next_state_ != STATE_NONE);
+  return rv;
+}
+
+int NaiveConnection::DoConnectClient() {
+  next_state_ = STATE_CONNECT_CLIENT_COMPLETE;
+
+  return client_socket_->Connect(io_callback_);
+}
+
+int NaiveConnection::DoConnectClientComplete(int result) {
+  if (result < 0)
+    return result;
+
+  // For proxy client sockets, padding support detection is finished after the
+  // first server response which means there will be one missed early pull. For
+  // proxy server sockets (HttpProxySocket), padding support detection is
+  // done during client connect, so there shouldn't be any missed early pull.
+  if (!padding_detector_delegate_->IsPaddingSupportKnown()) {
+    early_pull_pending_ = false;
+    early_pull_result_ = 0;
+    next_state_ = STATE_CONNECT_SERVER;
+    return OK;
+  }
+
+  early_pull_pending_ = true;
+  Pull(kClient, kServer);
+  if (early_pull_result_ != ERR_IO_PENDING) {
+    // Pull has completed synchronously.
+    if (early_pull_result_ <= 0) {
+      return early_pull_result_ ? early_pull_result_ : ERR_CONNECTION_CLOSED;
+    }
+  }
+
+  next_state_ = STATE_CONNECT_SERVER;
+  return OK;
+}
+
+int NaiveConnection::DoConnectServer() {
+  next_state_ = STATE_CONNECT_SERVER_COMPLETE;
+
+  HostPortPair origin;
+  if (protocol_ == ClientProtocol::kSocks5) {
+    const auto* socket =
+        static_cast<const Socks5ServerSocket*>(client_socket_.get());
+    origin = socket->request_endpoint();
+  } else if (protocol_ == ClientProtocol::kHttp) {
+    const auto* socket =
+        static_cast<const HttpProxySocket*>(client_socket_.get());
+    origin = socket->request_endpoint();
+  } else if (protocol_ == ClientProtocol::kRedir) {
+#if defined(OS_LINUX)
+    const auto* socket =
+        static_cast<const TCPClientSocket*>(client_socket_.get());
+    int sd = socket->SocketDescriptorForTesting();
+    SockaddrStorage dst;
+    int rv;
+    rv = getsockopt(sd, SOL_IP, SO_ORIGINAL_DST, dst.addr, &dst.addr_len);
+    if (rv == 0) {
+      IPEndPoint ipe;
+      if (ipe.FromSockAddr(dst.addr, dst.addr_len)) {
+        const auto& addr = ipe.address();
+        auto name = resolver_->FindNameByAddress(addr);
+        if (!name.empty()) {
+          origin = HostPortPair(name, ipe.port());
+        } else if (!resolver_->IsInResolvedRange(addr)) {
+          origin = HostPortPair::FromIPEndPoint(ipe);
+        } else {
+          LOG(ERROR) << "Connection " << id_ << " to unresolved name for "
+                     << addr.ToString();
+          return ERR_ADDRESS_INVALID;
+        }
+      }
+    }
+#else
+    static_cast<void>(resolver_);
+#endif
+  }
+
+  if (origin.IsEmpty()) {
+    LOG(ERROR) << "Connection " << id_ << " to invalid origin";
+    return ERR_ADDRESS_INVALID;
+  }
+
+  LOG(INFO) << "Connection " << id_ << " to " << origin.ToString();
+
+  // Ignores socket limit set by socket pool for this type of socket.
+  return InitSocketHandleForRawConnect2(
+      origin, session_, LOAD_IGNORE_LIMITS, MAXIMUM_PRIORITY, proxy_info_,
+      server_ssl_config_, proxy_ssl_config_, PRIVACY_MODE_DISABLED,
+      network_isolation_key_, net_log_, server_socket_handle_.get(),
+      io_callback_);
+}
+
+int NaiveConnection::DoConnectServerComplete(int result) {
+  if (result < 0)
+    return result;
+
+  DCHECK(server_socket_handle_->socket());
+  sockets_[kServer] = server_socket_handle_->socket();
+
+  full_duplex_ = true;
+  next_state_ = STATE_NONE;
+  return OK;
+}
+
+int NaiveConnection::Run(CompletionOnceCallback callback) {
+  DCHECK(sockets_[kClient]);
+  DCHECK(sockets_[kServer]);
+  DCHECK_EQ(next_state_, STATE_NONE);
+  DCHECK(!connect_callback_);
+
+  if (errors_[kClient] != OK)
+    return errors_[kClient];
+  if (errors_[kServer] != OK)
+    return errors_[kServer];
+
+  run_callback_ = std::move(callback);
+
+  bytes_passed_without_yielding_[kClient] = 0;
+  bytes_passed_without_yielding_[kServer] = 0;
+
+  yield_after_time_[kClient] =
+      time_func_() + base::Milliseconds(kYieldAfterDurationMilliseconds);
+  yield_after_time_[kServer] = yield_after_time_[kClient];
+
+  can_push_to_server_ = true;
+  // early_pull_result_ == 0 means the early pull was not started because
+  // padding support was not yet known.
+  if (!early_pull_pending_ && early_pull_result_ == 0) {
+    Pull(kClient, kServer);
+  } else if (!early_pull_pending_) {
+    DCHECK_GT(early_pull_result_, 0);
+    Push(kClient, kServer, early_pull_result_);
+  }
+  Pull(kServer, kClient);
+
+  return ERR_IO_PENDING;
+}
+
+void NaiveConnection::Pull(Direction from, Direction to) {
+  if (errors_[kClient] < 0 || errors_[kServer] < 0)
+    return;
+
+  int read_size = kBufferSize;
+  auto padding_direction = padding_detector_delegate_->GetPaddingDirection();
+  if (from == padding_direction && num_paddings_[from] < kFirstPaddings) {
+    auto buffer = base::MakeRefCounted<GrowableIOBuffer>();
+    buffer->SetCapacity(kBufferSize);
+    buffer->set_offset(kPaddingHeaderSize);
+    read_buffers_[from] = buffer;
+    read_size = kBufferSize - kPaddingHeaderSize - kMaxPaddingSize;
+  } else {
+    read_buffers_[from] = base::MakeRefCounted<IOBuffer>(kBufferSize);
+  }
+
+  DCHECK(sockets_[from]);
+  int rv = sockets_[from]->Read(
+      read_buffers_[from].get(), read_size,
+      base::BindRepeating(&NaiveConnection::OnPullComplete,
+                          weak_ptr_factory_.GetWeakPtr(), from, to));
+
+  if (from == kClient && early_pull_pending_)
+    early_pull_result_ = rv;
+
+  if (rv != ERR_IO_PENDING)
+    OnPullComplete(from, to, rv);
+}
+
+void NaiveConnection::Push(Direction from, Direction to, int size) {
+  int write_size = size;
+  int write_offset = 0;
+  auto padding_direction = padding_detector_delegate_->GetPaddingDirection();
+  if (from == padding_direction && num_paddings_[from] < kFirstPaddings) {
+    // Adds padding.
+    ++num_paddings_[from];
+    int padding_size = base::RandInt(0, kMaxPaddingSize);
+    auto* buffer = static_cast<GrowableIOBuffer*>(read_buffers_[from].get());
+    buffer->set_offset(0);
+    uint8_t* p = reinterpret_cast<uint8_t*>(buffer->data());
+    p[0] = size / 256;
+    p[1] = size % 256;
+    p[2] = padding_size;
+    std::memset(p + kPaddingHeaderSize + size, 0, padding_size);
+    write_size = kPaddingHeaderSize + size + padding_size;
+  } else if (to == padding_direction && num_paddings_[from] < kFirstPaddings) {
+    // Removes padding.
+    const char* p = read_buffers_[from]->data();
+    bool trivial_padding = false;
+    if (read_padding_state_ == STATE_READ_PAYLOAD_LENGTH_1 &&
+        size >= kPaddingHeaderSize) {
+      int payload_size =
+          static_cast<uint8_t>(p[0]) * 256 + static_cast<uint8_t>(p[1]);
+      int padding_size = static_cast<uint8_t>(p[2]);
+      if (size == kPaddingHeaderSize + payload_size + padding_size) {
+        write_size = payload_size;
+        write_offset = kPaddingHeaderSize;
+        ++num_paddings_[from];
+        trivial_padding = true;
+      }
+    }
+    if (!trivial_padding) {
+      auto unpadded_buffer = base::MakeRefCounted<IOBuffer>(kBufferSize);
+      char* unpadded_ptr = unpadded_buffer->data();
+      for (int i = 0; i < size;) {
+        if (num_paddings_[from] >= kFirstPaddings &&
+            read_padding_state_ == STATE_READ_PAYLOAD_LENGTH_1) {
+          std::memcpy(unpadded_ptr, p + i, size - i);
+          unpadded_ptr += size - i;
+          break;
+        }
+        int copy_size;
+        switch (read_padding_state_) {
+          case STATE_READ_PAYLOAD_LENGTH_1:
+            payload_length_ = static_cast<uint8_t>(p[i]);
+            ++i;
+            read_padding_state_ = STATE_READ_PAYLOAD_LENGTH_2;
+            break;
+          case STATE_READ_PAYLOAD_LENGTH_2:
+            payload_length_ =
+                payload_length_ * 256 + static_cast<uint8_t>(p[i]);
+            ++i;
+            read_padding_state_ = STATE_READ_PADDING_LENGTH;
+            break;
+          case STATE_READ_PADDING_LENGTH:
+            padding_length_ = static_cast<uint8_t>(p[i]);
+            ++i;
+            read_padding_state_ = STATE_READ_PAYLOAD;
+            break;
+          case STATE_READ_PAYLOAD:
+            if (payload_length_ <= size - i) {
+              copy_size = payload_length_;
+              read_padding_state_ = STATE_READ_PADDING;
+            } else {
+              copy_size = size - i;
+            }
+            std::memcpy(unpadded_ptr, p + i, copy_size);
+            unpadded_ptr += copy_size;
+            i += copy_size;
+            payload_length_ -= copy_size;
+            break;
+          case STATE_READ_PADDING:
+            if (padding_length_ <= size - i) {
+              copy_size = padding_length_;
+              read_padding_state_ = STATE_READ_PAYLOAD_LENGTH_1;
+              ++num_paddings_[from];
+            } else {
+              copy_size = size - i;
+            }
+            i += copy_size;
+            padding_length_ -= copy_size;
+            break;
+        }
+      }
+      write_size = unpadded_ptr - unpadded_buffer->data();
+      read_buffers_[from] = unpadded_buffer;
+    }
+    if (write_size == 0) {
+      OnPushComplete(from, to, OK);
+      return;
+    }
+  }
+
+  write_buffers_[to] = base::MakeRefCounted<DrainableIOBuffer>(
+      std::move(read_buffers_[from]), write_offset + write_size);
+  if (write_offset) {
+    write_buffers_[to]->DidConsume(write_offset);
+  }
+  write_pending_[to] = true;
+  DCHECK(sockets_[to]);
+  int rv = sockets_[to]->Write(
+      write_buffers_[to].get(), write_size,
+      base::BindRepeating(&NaiveConnection::OnPushComplete,
+                          weak_ptr_factory_.GetWeakPtr(), from, to),
+      traffic_annotation_);
+
+  if (rv != ERR_IO_PENDING)
+    OnPushComplete(from, to, rv);
+}
+
+void NaiveConnection::Disconnect(Direction side) {
+  if (sockets_[side]) {
+    sockets_[side]->Disconnect();
+    sockets_[side] = nullptr;
+    write_pending_[side] = false;
+  }
+}
+
+bool NaiveConnection::IsConnected(Direction side) {
+  return sockets_[side];
+}
+
+void NaiveConnection::OnBothDisconnected() {
+  if (run_callback_) {
+    int error = OK;
+    if (errors_[kClient] != ERR_CONNECTION_CLOSED && errors_[kClient] < 0)
+      error = errors_[kClient];
+    if (errors_[kServer] != ERR_CONNECTION_CLOSED && errors_[kClient] < 0)
+      error = errors_[kServer];
+    std::move(run_callback_).Run(error);
+  }
+}
+
+void NaiveConnection::OnPullError(Direction from, Direction to, int error) {
+  DCHECK_LT(error, 0);
+
+  errors_[from] = error;
+  Disconnect(from);
+
+  if (!write_pending_[to])
+    Disconnect(to);
+
+  if (!IsConnected(from) && !IsConnected(to))
+    OnBothDisconnected();
+}
+
+void NaiveConnection::OnPushError(Direction from, Direction to, int error) {
+  DCHECK_LE(error, 0);
+  DCHECK(!write_pending_[to]);
+
+  if (error < 0) {
+    errors_[to] = error;
+    Disconnect(kServer);
+    Disconnect(kClient);
+  } else if (!IsConnected(from)) {
+    Disconnect(to);
+  }
+
+  if (!IsConnected(from) && !IsConnected(to))
+    OnBothDisconnected();
+}
+
+void NaiveConnection::OnPullComplete(Direction from, Direction to, int result) {
+  if (from == kClient && early_pull_pending_) {
+    early_pull_pending_ = false;
+    early_pull_result_ = result ? result : ERR_CONNECTION_CLOSED;
+  }
+
+  if (result <= 0) {
+    OnPullError(from, to, result ? result : ERR_CONNECTION_CLOSED);
+    return;
+  }
+
+  if (from == kClient && !can_push_to_server_)
+    return;
+
+  Push(from, to, result);
+}
+
+void NaiveConnection::OnPushComplete(Direction from, Direction to, int result) {
+  if (result >= 0 && write_buffers_[to] != nullptr) {
+    bytes_passed_without_yielding_[from] += result;
+    write_buffers_[to]->DidConsume(result);
+    int size = write_buffers_[to]->BytesRemaining();
+    if (size > 0) {
+      int rv = sockets_[to]->Write(
+          write_buffers_[to].get(), size,
+          base::BindRepeating(&NaiveConnection::OnPushComplete,
+                              weak_ptr_factory_.GetWeakPtr(), from, to),
+          traffic_annotation_);
+      if (rv != ERR_IO_PENDING)
+        OnPushComplete(from, to, rv);
+      return;
+    }
+  }
+
+  write_pending_[to] = false;
+  // Checks for termination even if result is OK.
+  OnPushError(from, to, result >= 0 ? OK : result);
+
+  if (bytes_passed_without_yielding_[from] > kYieldAfterBytesRead ||
+      time_func_() > yield_after_time_[from]) {
+    bytes_passed_without_yielding_[from] = 0;
+    yield_after_time_[from] =
+        time_func_() + base::Milliseconds(kYieldAfterDurationMilliseconds);
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE,
+        base::BindRepeating(&NaiveConnection::Pull,
+                            weak_ptr_factory_.GetWeakPtr(), from, to));
+  } else {
+    Pull(from, to);
+  }
+}
+
+}  // namespace net

src/net/tools/naive/naive_connection.h

@@ -0,0 +1,142 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Copyright 2018 klzgrad <kizdiv@gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef NET_TOOLS_NAIVE_NAIVE_CONNECTION_H_
+#define NET_TOOLS_NAIVE_NAIVE_CONNECTION_H_
+
+#include <memory>
+#include <string>
+
+#include "base/memory/scoped_refptr.h"
+#include "base/memory/weak_ptr.h"
+#include "base/time/time.h"
+#include "net/base/completion_once_callback.h"
+#include "net/base/completion_repeating_callback.h"
+#include "net/tools/naive/naive_protocol.h"
+#include "net/tools/naive/naive_proxy_delegate.h"
+
+namespace net {
+
+class ClientSocketHandle;
+class DrainableIOBuffer;
+class HttpNetworkSession;
+class IOBuffer;
+class NetLogWithSource;
+class ProxyInfo;
+class StreamSocket;
+struct NetworkTrafficAnnotationTag;
+struct SSLConfig;
+class RedirectResolver;
+class NetworkIsolationKey;
+
+class NaiveConnection {
+ public:
+  using TimeFunc = base::TimeTicks (*)();
+
+  NaiveConnection(
+      unsigned int id,
+      ClientProtocol protocol,
+      std::unique_ptr<PaddingDetectorDelegate> padding_detector_delegate,
+      const ProxyInfo& proxy_info,
+      const SSLConfig& server_ssl_config,
+      const SSLConfig& proxy_ssl_config,
+      RedirectResolver* resolver,
+      HttpNetworkSession* session,
+      const NetworkIsolationKey& network_isolation_key,
+      const NetLogWithSource& net_log,
+      std::unique_ptr<StreamSocket> accepted_socket,
+      const NetworkTrafficAnnotationTag& traffic_annotation);
+  ~NaiveConnection();
+  NaiveConnection(const NaiveConnection&) = delete;
+  NaiveConnection& operator=(const NaiveConnection&) = delete;
+
+  unsigned int id() const { return id_; }
+  int Connect(CompletionOnceCallback callback);
+  void Disconnect();
+  int Run(CompletionOnceCallback callback);
+
+ private:
+  enum State {
+    STATE_CONNECT_CLIENT,
+    STATE_CONNECT_CLIENT_COMPLETE,
+    STATE_CONNECT_SERVER,
+    STATE_CONNECT_SERVER_COMPLETE,
+    STATE_NONE,
+  };
+
+  enum PaddingState {
+    STATE_READ_PAYLOAD_LENGTH_1,
+    STATE_READ_PAYLOAD_LENGTH_2,
+    STATE_READ_PADDING_LENGTH,
+    STATE_READ_PAYLOAD,
+    STATE_READ_PADDING,
+  };
+
+  void DoCallback(int result);
+  void OnIOComplete(int result);
+  int DoLoop(int last_io_result);
+  int DoConnectClient();
+  int DoConnectClientComplete(int result);
+  int DoConnectServer();
+  int DoConnectServerComplete(int result);
+  void Pull(Direction from, Direction to);
+  void Push(Direction from, Direction to, int size);
+  void Disconnect(Direction side);
+  bool IsConnected(Direction side);
+  void OnBothDisconnected();
+  void OnPullError(Direction from, Direction to, int error);
+  void OnPushError(Direction from, Direction to, int error);
+  void OnPullComplete(Direction from, Direction to, int result);
+  void OnPushComplete(Direction from, Direction to, int result);
+
+  unsigned int id_;
+  ClientProtocol protocol_;
+  std::unique_ptr<PaddingDetectorDelegate> padding_detector_delegate_;
+  const ProxyInfo& proxy_info_;
+  const SSLConfig& server_ssl_config_;
+  const SSLConfig& proxy_ssl_config_;
+  RedirectResolver* resolver_;
+  HttpNetworkSession* session_;
+  const NetworkIsolationKey& network_isolation_key_;
+  const NetLogWithSource& net_log_;
+
+  CompletionRepeatingCallback io_callback_;
+  CompletionOnceCallback connect_callback_;
+  CompletionOnceCallback run_callback_;
+
+  State next_state_;
+
+  std::unique_ptr<StreamSocket> client_socket_;
+  std::unique_ptr<ClientSocketHandle> server_socket_handle_;
+
+  StreamSocket* sockets_[kNumDirections];
+  scoped_refptr<IOBuffer> read_buffers_[kNumDirections];
+  scoped_refptr<DrainableIOBuffer> write_buffers_[kNumDirections];
+  int errors_[kNumDirections];
+  bool write_pending_[kNumDirections];
+  int bytes_passed_without_yielding_[kNumDirections];
+  base::TimeTicks yield_after_time_[kNumDirections];
+
+  bool early_pull_pending_;
+  bool can_push_to_server_;
+  int early_pull_result_;
+
+  int num_paddings_[kNumDirections];
+  PaddingState read_padding_state_;
+  int payload_length_;
+  int padding_length_;
+
+  bool full_duplex_;
+
+  TimeFunc time_func_;
+
+  // Traffic annotation for socket control.
+  const NetworkTrafficAnnotationTag& traffic_annotation_;
+
+  base::WeakPtrFactory<NaiveConnection> weak_ptr_factory_{this};
+};
+
+}  // namespace net
+#endif  // NET_TOOLS_NAIVE_NAIVE_CONNECTION_H_

src/net/tools/naive/naive_protocol.h

@@ -0,0 +1,24 @@
+// Copyright 2020 klzgrad <kizdiv@gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+#ifndef NET_TOOLS_NAIVE_NAIVE_PROTOCOL_H_
+#define NET_TOOLS_NAIVE_NAIVE_PROTOCOL_H_
+
+namespace net {
+enum class ClientProtocol {
+  kSocks5,
+  kHttp,
+  kRedir,
+};
+
+// Adds padding for traffic from this direction.
+// Removes padding for traffic from the opposite direction.
+enum Direction {
+  kClient = 0,
+  kServer = 1,
+  kNumDirections = 2,
+  kNone = 2,
+};
+
+}  // namespace net
+#endif  // NET_TOOLS_NAIVE_NAIVE_PROTOCOL_H_

src/net/tools/naive/naive_proxy.cc

@@ -0,0 +1,211 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Copyright 2018 klzgrad <kizdiv@gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/tools/naive/naive_proxy.h"
+
+#include <utility>
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/logging.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "net/base/load_flags.h"
+#include "net/base/net_errors.h"
+#include "net/http/http_network_session.h"
+#include "net/proxy_resolution/configured_proxy_resolution_service.h"
+#include "net/proxy_resolution/proxy_config.h"
+#include "net/proxy_resolution/proxy_list.h"
+#include "net/socket/client_socket_pool_manager.h"
+#include "net/socket/server_socket.h"
+#include "net/socket/stream_socket.h"
+#include "net/tools/naive/http_proxy_socket.h"
+#include "net/tools/naive/naive_proxy_delegate.h"
+#include "net/tools/naive/socks5_server_socket.h"
+
+namespace net {
+
+NaiveProxy::NaiveProxy(std::unique_ptr<ServerSocket> listen_socket,
+                       ClientProtocol protocol,
+                       const std::string& listen_user,
+                       const std::string& listen_pass,
+                       int concurrency,
+                       RedirectResolver* resolver,
+                       HttpNetworkSession* session,
+                       const NetworkTrafficAnnotationTag& traffic_annotation)
+    : listen_socket_(std::move(listen_socket)),
+      protocol_(protocol),
+      listen_user_(listen_user),
+      listen_pass_(listen_pass),
+      concurrency_(concurrency),
+      resolver_(resolver),
+      session_(session),
+      net_log_(
+          NetLogWithSource::Make(session->net_log(), NetLogSourceType::NONE)),
+      last_id_(0),
+      traffic_annotation_(traffic_annotation) {
+  const auto& proxy_config = static_cast<ConfiguredProxyResolutionService*>(
+                                 session_->proxy_resolution_service())
+                                 ->config();
+  DCHECK(proxy_config);
+  const ProxyList& proxy_list =
+      proxy_config.value().value().proxy_rules().single_proxies;
+  DCHECK(!proxy_list.IsEmpty());
+  proxy_info_.UseProxyList(proxy_list);
+  proxy_info_.set_traffic_annotation(
+      net::MutableNetworkTrafficAnnotationTag(traffic_annotation_));
+
+  // See HttpStreamFactory::Job::DoInitConnectionImpl()
+  proxy_ssl_config_.disable_cert_verification_network_fetches = true;
+  server_ssl_config_.alpn_protos = session_->GetAlpnProtos();
+  proxy_ssl_config_.alpn_protos = session_->GetAlpnProtos();
+  server_ssl_config_.application_settings = session_->GetApplicationSettings();
+  proxy_ssl_config_.application_settings = session_->GetApplicationSettings();
+  server_ssl_config_.ignore_certificate_errors =
+      session_->params().ignore_certificate_errors;
+  proxy_ssl_config_.ignore_certificate_errors =
+      session_->params().ignore_certificate_errors;
+  // TODO(https://crbug.com/964642): Also enable 0-RTT for TLS proxies.
+  server_ssl_config_.early_data_enabled = session_->params().enable_early_data;
+
+  for (int i = 0; i < concurrency_; i++) {
+    network_isolation_keys_.push_back(NetworkIsolationKey::CreateTransient());
+  }
+
+  DCHECK(listen_socket_);
+  // Start accepting connections in next run loop in case when delegate is not
+  // ready to get callbacks.
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::BindOnce(&NaiveProxy::DoAcceptLoop,
+                                weak_ptr_factory_.GetWeakPtr()));
+}
+
+NaiveProxy::~NaiveProxy() = default;
+
+void NaiveProxy::DoAcceptLoop() {
+  int result;
+  do {
+    result = listen_socket_->Accept(
+        &accepted_socket_, base::BindRepeating(&NaiveProxy::OnAcceptComplete,
+                                               weak_ptr_factory_.GetWeakPtr()));
+    if (result == ERR_IO_PENDING)
+      return;
+    HandleAcceptResult(result);
+  } while (result == OK);
+}
+
+void NaiveProxy::OnAcceptComplete(int result) {
+  HandleAcceptResult(result);
+  if (result == OK)
+    DoAcceptLoop();
+}
+
+void NaiveProxy::HandleAcceptResult(int result) {
+  if (result != OK) {
+    LOG(ERROR) << "Accept error: rv=" << result;
+    return;
+  }
+  DoConnect();
+}
+
+void NaiveProxy::DoConnect() {
+  std::unique_ptr<StreamSocket> socket;
+  auto* proxy_delegate =
+      static_cast<NaiveProxyDelegate*>(session_->context().proxy_delegate);
+  DCHECK(proxy_delegate);
+  DCHECK(!proxy_info_.is_empty());
+  const auto& proxy_server = proxy_info_.proxy_server();
+  auto padding_detector_delegate = std::make_unique<PaddingDetectorDelegate>(
+      proxy_delegate, proxy_server, protocol_);
+
+  if (protocol_ == ClientProtocol::kSocks5) {
+    socket = std::make_unique<Socks5ServerSocket>(std::move(accepted_socket_),
+                                                  listen_user_, listen_pass_,
+                                                  traffic_annotation_);
+  } else if (protocol_ == ClientProtocol::kHttp) {
+    socket = std::make_unique<HttpProxySocket>(std::move(accepted_socket_),
+                                               padding_detector_delegate.get(),
+                                               traffic_annotation_);
+  } else if (protocol_ == ClientProtocol::kRedir) {
+    socket = std::move(accepted_socket_);
+  } else {
+    return;
+  }
+
+  last_id_++;
+  const auto& nik = network_isolation_keys_[last_id_ % concurrency_];
+  auto connection_ptr = std::make_unique<NaiveConnection>(
+      last_id_, protocol_, std::move(padding_detector_delegate), proxy_info_,
+      server_ssl_config_, proxy_ssl_config_, resolver_, session_, nik, net_log_,
+      std::move(socket), traffic_annotation_);
+  auto* connection = connection_ptr.get();
+  connection_by_id_[connection->id()] = std::move(connection_ptr);
+  int result = connection->Connect(
+      base::BindRepeating(&NaiveProxy::OnConnectComplete,
+                          weak_ptr_factory_.GetWeakPtr(), connection->id()));
+  if (result == ERR_IO_PENDING)
+    return;
+  HandleConnectResult(connection, result);
+}
+
+void NaiveProxy::OnConnectComplete(unsigned int connection_id, int result) {
+  auto* connection = FindConnection(connection_id);
+  if (!connection)
+    return;
+  HandleConnectResult(connection, result);
+}
+
+void NaiveProxy::HandleConnectResult(NaiveConnection* connection, int result) {
+  if (result != OK) {
+    Close(connection->id(), result);
+    return;
+  }
+  DoRun(connection);
+}
+
+void NaiveProxy::DoRun(NaiveConnection* connection) {
+  int result = connection->Run(
+      base::BindRepeating(&NaiveProxy::OnRunComplete,
+                          weak_ptr_factory_.GetWeakPtr(), connection->id()));
+  if (result == ERR_IO_PENDING)
+    return;
+  HandleRunResult(connection, result);
+}
+
+void NaiveProxy::OnRunComplete(unsigned int connection_id, int result) {
+  auto* connection = FindConnection(connection_id);
+  if (!connection)
+    return;
+  HandleRunResult(connection, result);
+}
+
+void NaiveProxy::HandleRunResult(NaiveConnection* connection, int result) {
+  Close(connection->id(), result);
+}
+
+void NaiveProxy::Close(unsigned int connection_id, int reason) {
+  auto it = connection_by_id_.find(connection_id);
+  if (it == connection_by_id_.end())
+    return;
+
+  LOG(INFO) << "Connection " << connection_id
+            << " closed: " << ErrorToShortString(reason);
+
+  // The call stack might have callbacks which still have the pointer of
+  // connection. Instead of referencing connection with ID all the time,
+  // destroys the connection in next run loop to make sure any pending
+  // callbacks in the call stack return.
+  base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE,
+                                                  std::move(it->second));
+  connection_by_id_.erase(it);
+}
+
+NaiveConnection* NaiveProxy::FindConnection(unsigned int connection_id) {
+  auto it = connection_by_id_.find(connection_id);
+  if (it == connection_by_id_.end())
+    return nullptr;
+  return it->second.get();
+}
+
+}  // namespace net

src/net/tools/naive/naive_proxy.h

@@ -0,0 +1,89 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Copyright 2018 klzgrad <kizdiv@gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef NET_TOOLS_NAIVE_NAIVE_PROXY_H_
+#define NET_TOOLS_NAIVE_NAIVE_PROXY_H_
+
+#include <map>
+#include <memory>
+#include <vector>
+
+#include "base/memory/weak_ptr.h"
+#include "net/base/completion_repeating_callback.h"
+#include "net/base/network_isolation_key.h"
+#include "net/log/net_log_with_source.h"
+#include "net/proxy_resolution/proxy_info.h"
+#include "net/ssl/ssl_config.h"
+#include "net/tools/naive/naive_connection.h"
+#include "net/tools/naive/naive_protocol.h"
+
+namespace net {
+
+class ClientSocketHandle;
+class HttpNetworkSession;
+class NaiveConnection;
+class ServerSocket;
+class StreamSocket;
+struct NetworkTrafficAnnotationTag;
+class RedirectResolver;
+
+class NaiveProxy {
+ public:
+  NaiveProxy(std::unique_ptr<ServerSocket> server_socket,
+             ClientProtocol protocol,
+             const std::string& listen_user,
+             const std::string& listen_pass,
+             int concurrency,
+             RedirectResolver* resolver,
+             HttpNetworkSession* session,
+             const NetworkTrafficAnnotationTag& traffic_annotation);
+  ~NaiveProxy();
+  NaiveProxy(const NaiveProxy&) = delete;
+  NaiveProxy& operator=(const NaiveProxy&) = delete;
+
+ private:
+  void DoAcceptLoop();
+  void OnAcceptComplete(int result);
+  void HandleAcceptResult(int result);
+
+  void DoConnect();
+  void OnConnectComplete(unsigned int connection_id, int result);
+  void HandleConnectResult(NaiveConnection* connection, int result);
+
+  void DoRun(NaiveConnection* connection);
+  void OnRunComplete(unsigned int connection_id, int result);
+  void HandleRunResult(NaiveConnection* connection, int result);
+
+  void Close(unsigned int connection_id, int reason);
+
+  NaiveConnection* FindConnection(unsigned int connection_id);
+
+  std::unique_ptr<ServerSocket> listen_socket_;
+  ClientProtocol protocol_;
+  std::string listen_user_;
+  std::string listen_pass_;
+  int concurrency_;
+  ProxyInfo proxy_info_;
+  SSLConfig server_ssl_config_;
+  SSLConfig proxy_ssl_config_;
+  RedirectResolver* resolver_;
+  HttpNetworkSession* session_;
+  NetLogWithSource net_log_;
+
+  unsigned int last_id_;
+
+  std::unique_ptr<StreamSocket> accepted_socket_;
+
+  std::vector<NetworkIsolationKey> network_isolation_keys_;
+
+  std::map<unsigned int, std::unique_ptr<NaiveConnection>> connection_by_id_;
+
+  const NetworkTrafficAnnotationTag& traffic_annotation_;
+
+  base::WeakPtrFactory<NaiveProxy> weak_ptr_factory_{this};
+};
+
+}  // namespace net
+#endif  // NET_TOOLS_NAIVE_NAIVE_PROXY_H_

src/net/tools/naive/naive_proxy_bin.cc

@@ -0,0 +1,592 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Copyright 2018 klzgrad <kizdiv@gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <cstdlib>
+#include <iostream>
+#include <limits>
+#include <memory>
+#include <string>
+
+#include "base/at_exit.h"
+#include "base/command_line.h"
+#include "base/feature_list.h"
+#include "base/files/file_path.h"
+#include "base/json/json_file_value_serializer.h"
+#include "base/json/json_writer.h"
+#include "base/logging.h"
+#include "base/rand_util.h"
+#include "base/run_loop.h"
+#include "base/strings/escape.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/stringprintf.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/system/sys_info.h"
+#include "base/task/single_thread_task_executor.h"
+#include "base/task/thread_pool/thread_pool_instance.h"
+#include "base/values.h"
+#include "build/build_config.h"
+#include "components/version_info/version_info.h"
+#include "net/base/auth.h"
+#include "net/base/network_isolation_key.h"
+#include "net/base/url_util.h"
+#include "net/cert/cert_verifier.h"
+#include "net/cert_net/cert_net_fetcher_url_request.h"
+#include "net/dns/host_resolver.h"
+#include "net/dns/mapped_host_resolver.h"
+#include "net/http/http_auth.h"
+#include "net/http/http_auth_cache.h"
+#include "net/http/http_network_session.h"
+#include "net/http/http_request_headers.h"
+#include "net/http/http_transaction_factory.h"
+#include "net/log/file_net_log_observer.h"
+#include "net/log/net_log.h"
+#include "net/log/net_log_capture_mode.h"
+#include "net/log/net_log_entry.h"
+#include "net/log/net_log_event_type.h"
+#include "net/log/net_log_source.h"
+#include "net/log/net_log_util.h"
+#include "net/proxy_resolution/configured_proxy_resolution_service.h"
+#include "net/proxy_resolution/proxy_config.h"
+#include "net/proxy_resolution/proxy_config_service_fixed.h"
+#include "net/proxy_resolution/proxy_config_with_annotation.h"
+#include "net/socket/client_socket_pool_manager.h"
+#include "net/socket/ssl_client_socket.h"
+#include "net/socket/tcp_server_socket.h"
+#include "net/socket/udp_server_socket.h"
+#include "net/ssl/ssl_key_logger_impl.h"
+#include "net/third_party/quiche/src/quic/core/quic_versions.h"
+#include "net/tools/naive/naive_protocol.h"
+#include "net/tools/naive/naive_proxy.h"
+#include "net/tools/naive/naive_proxy_delegate.h"
+#include "net/tools/naive/redirect_resolver.h"
+#include "net/traffic_annotation/network_traffic_annotation.h"
+#include "net/url_request/url_request_context.h"
+#include "net/url_request/url_request_context_builder.h"
+#include "url/gurl.h"
+#include "url/scheme_host_port.h"
+#include "url/url_util.h"
+
+#if defined(OS_MACOSX)
+#include "base/mac/scoped_nsautorelease_pool.h"
+#endif
+
+namespace {
+
+constexpr int kListenBackLog = 512;
+constexpr int kDefaultMaxSocketsPerPool = 256;
+constexpr int kDefaultMaxSocketsPerGroup = 255;
+constexpr int kExpectedMaxUsers = 8;
+constexpr net::NetworkTrafficAnnotationTag kTrafficAnnotation =
+    net::DefineNetworkTrafficAnnotation("naive", "");
+
+struct CommandLine {
+  std::string listen;
+  std::string proxy;
+  std::string concurrency;
+  std::string extra_headers;
+  std::string host_resolver_rules;
+  std::string resolver_range;
+  bool no_log;
+  base::FilePath log;
+  base::FilePath log_net_log;
+  base::FilePath ssl_key_log_file;
+};
+
+struct Params {
+  net::ClientProtocol protocol;
+  std::string listen_user;
+  std::string listen_pass;
+  std::string listen_addr;
+  int listen_port;
+  int concurrency;
+  net::HttpRequestHeaders extra_headers;
+  std::string proxy_url;
+  std::u16string proxy_user;
+  std::u16string proxy_pass;
+  std::string host_resolver_rules;
+  net::IPAddress resolver_range;
+  size_t resolver_prefix;
+  logging::LoggingSettings log_settings;
+  base::FilePath net_log_path;
+  base::FilePath ssl_key_path;
+};
+
+std::unique_ptr<base::Value> GetConstants() {
+  auto constants_dict = std::make_unique<base::Value>(net::GetNetConstants());
+  base::DictionaryValue dict;
+  std::string os_type = base::StringPrintf(
+      "%s: %s (%s)", base::SysInfo::OperatingSystemName().c_str(),
+      base::SysInfo::OperatingSystemVersion().c_str(),
+      base::SysInfo::OperatingSystemArchitecture().c_str());
+  dict.SetStringPath("os_type", os_type);
+  constants_dict->SetKey("clientInfo", std::move(dict));
+  return constants_dict;
+}
+
+void GetCommandLine(const base::CommandLine& proc, CommandLine* cmdline) {
+  if (proc.HasSwitch("h") || proc.HasSwitch("help")) {
+    std::cout << "Usage: naive { OPTIONS | config.json }\n"
+                 "\n"
+                 "Options:\n"
+                 "-h, --help                 Show this message\n"
+                 "--version                  Print version\n"
+                 "--listen=<proto>://[addr][:port]\n"
+                 "                           proto: socks, http\n"
+                 "                                  redir (Linux only)\n"
+                 "--proxy=<proto>://[<user>:<pass>@]<hostname>[:<port>]\n"
+                 "                           proto: https, quic\n"
+                 "--insecure-concurrency=<N> Use N connections, insecure\n"
+                 "--extra-headers=...        Extra headers split by CRLF\n"
+                 "--host-resolver-rules=...  Resolver rules\n"
+                 "--resolver-range=...       Redirect resolver range\n"
+                 "--log[=<path>]             Log to stderr, or file\n"
+                 "--log-net-log=<path>       Save NetLog\n"
+                 "--ssl-key-log-file=<path>  Save SSL keys for Wireshark\n"
+              << std::endl;
+    exit(EXIT_SUCCESS);
+  }
+
+  if (proc.HasSwitch("version")) {
+    std::cout << "naive " << version_info::GetVersionNumber() << std::endl;
+    exit(EXIT_SUCCESS);
+  }
+
+  cmdline->listen = proc.GetSwitchValueASCII("listen");
+  cmdline->proxy = proc.GetSwitchValueASCII("proxy");
+  cmdline->concurrency = proc.GetSwitchValueASCII("insecure-concurrency");
+  cmdline->extra_headers = proc.GetSwitchValueASCII("extra-headers");
+  cmdline->host_resolver_rules =
+      proc.GetSwitchValueASCII("host-resolver-rules");
+  cmdline->resolver_range = proc.GetSwitchValueASCII("resolver-range");
+  cmdline->no_log = !proc.HasSwitch("log");
+  cmdline->log = proc.GetSwitchValuePath("log");
+  cmdline->log_net_log = proc.GetSwitchValuePath("log-net-log");
+  cmdline->ssl_key_log_file = proc.GetSwitchValuePath("ssl-key-log-file");
+}
+
+void GetCommandLineFromConfig(const base::FilePath& config_path,
+                              CommandLine* cmdline) {
+  JSONFileValueDeserializer reader(config_path);
+  int error_code;
+  std::string error_message;
+  auto value = reader.Deserialize(&error_code, &error_message);
+  if (value == nullptr) {
+    std::cerr << "Error reading " << config_path << ": (" << error_code << ") "
+              << error_message << std::endl;
+    exit(EXIT_FAILURE);
+  }
+  if (!value->is_dict()) {
+    std::cerr << "Invalid config format" << std::endl;
+    exit(EXIT_FAILURE);
+  }
+  const auto* listen = value->FindStringKey("listen");
+  if (listen) {
+    cmdline->listen = *listen;
+  }
+  const auto* proxy = value->FindStringKey("proxy");
+  if (proxy) {
+    cmdline->proxy = *proxy;
+  }
+  const auto* concurrency = value->FindStringKey("insecure-concurrency");
+  if (concurrency) {
+    cmdline->concurrency = *concurrency;
+  }
+  const auto* extra_headers = value->FindStringKey("extra-headers");
+  if (extra_headers) {
+    cmdline->extra_headers = *extra_headers;
+  }
+  const auto* host_resolver_rules = value->FindStringKey("host-resolver-rules");
+  if (host_resolver_rules) {
+    cmdline->host_resolver_rules = *host_resolver_rules;
+  }
+  const auto* resolver_range = value->FindStringKey("resolver-range");
+  if (resolver_range) {
+    cmdline->resolver_range = *resolver_range;
+  }
+  cmdline->no_log = true;
+  const auto* log = value->FindStringKey("log");
+  if (log) {
+    cmdline->no_log = false;
+    cmdline->log = base::FilePath::FromUTF8Unsafe(*log);
+  }
+  const auto* log_net_log = value->FindStringKey("log-net-log");
+  if (log_net_log) {
+    cmdline->log_net_log = base::FilePath::FromUTF8Unsafe(*log_net_log);
+  }
+  const auto* ssl_key_log_file = value->FindStringKey("ssl-key-log-file");
+  if (ssl_key_log_file) {
+    cmdline->ssl_key_log_file =
+        base::FilePath::FromUTF8Unsafe(*ssl_key_log_file);
+  }
+}
+
+std::string GetProxyFromURL(const GURL& url) {
+  std::string str = url.GetWithEmptyPath().spec();
+  if (str.size() && str.back() == '/') {
+    str.pop_back();
+  }
+  return str;
+}
+
+bool ParseCommandLine(const CommandLine& cmdline, Params* params) {
+  params->protocol = net::ClientProtocol::kSocks5;
+  params->listen_addr = "0.0.0.0";
+  params->listen_port = 1080;
+  url::AddStandardScheme("socks",
+                         url::SCHEME_WITH_HOST_PORT_AND_USER_INFORMATION);
+  url::AddStandardScheme("redir", url::SCHEME_WITH_HOST_AND_PORT);
+  if (!cmdline.listen.empty()) {
+    GURL url(cmdline.listen);
+    if (url.scheme() == "socks") {
+      params->protocol = net::ClientProtocol::kSocks5;
+      params->listen_port = 1080;
+    } else if (url.scheme() == "http") {
+      params->protocol = net::ClientProtocol::kHttp;
+      params->listen_port = 8080;
+    } else if (url.scheme() == "redir") {
+#if defined(OS_LINUX)
+      params->protocol = net::ClientProtocol::kRedir;
+      params->listen_port = 1080;
+#else
+      std::cerr << "Redir protocol only supports Linux." << std::endl;
+      return false;
+#endif
+    } else {
+      std::cerr << "Invalid scheme in --listen" << std::endl;
+      return false;
+    }
+    if (!url.username().empty()) {
+      params->listen_user = base::UnescapeBinaryURLComponent(url.username());
+    }
+    if (!url.password().empty()) {
+      params->listen_pass = base::UnescapeBinaryURLComponent(url.password());
+    }
+    if (!url.host().empty()) {
+      params->listen_addr = url.host();
+    }
+    if (!url.port().empty()) {
+      if (!base::StringToInt(url.port(), &params->listen_port)) {
+        std::cerr << "Invalid port in --listen" << std::endl;
+        return false;
+      }
+      if (params->listen_port <= 0 ||
+          params->listen_port > std::numeric_limits<uint16_t>::max()) {
+        std::cerr << "Invalid port in --listen" << std::endl;
+        return false;
+      }
+    }
+  }
+
+  params->proxy_url = "direct://";
+  GURL url(cmdline.proxy);
+  GURL::Replacements remove_auth;
+  remove_auth.ClearUsername();
+  remove_auth.ClearPassword();
+  GURL url_no_auth = url.ReplaceComponents(remove_auth);
+  if (!cmdline.proxy.empty()) {
+    if (!url.is_valid()) {
+      std::cerr << "Invalid proxy URL" << std::endl;
+      return false;
+    }
+    params->proxy_url = GetProxyFromURL(url_no_auth);
+    net::GetIdentityFromURL(url, &params->proxy_user, &params->proxy_pass);
+  }
+
+  if (!cmdline.concurrency.empty()) {
+    if (!base::StringToInt(cmdline.concurrency, &params->concurrency) ||
+        params->concurrency < 1) {
+      std::cerr << "Invalid concurrency" << std::endl;
+      return false;
+    }
+  } else {
+    params->concurrency = 1;
+  }
+
+  params->extra_headers.AddHeadersFromString(cmdline.extra_headers);
+
+  params->host_resolver_rules = cmdline.host_resolver_rules;
+
+  if (params->protocol == net::ClientProtocol::kRedir) {
+    std::string range = "100.64.0.0/10";
+    if (!cmdline.resolver_range.empty())
+      range = cmdline.resolver_range;
+
+    if (!net::ParseCIDRBlock(range, &params->resolver_range,
+                             &params->resolver_prefix)) {
+      std::cerr << "Invalid resolver range" << std::endl;
+      return false;
+    }
+    if (params->resolver_range.IsIPv6()) {
+      std::cerr << "IPv6 resolver range not supported" << std::endl;
+      return false;
+    }
+  }
+
+  if (!cmdline.no_log) {
+    if (!cmdline.log.empty()) {
+      params->log_settings.logging_dest = logging::LOG_TO_FILE;
+      params->log_settings.log_file_path = cmdline.log.value().c_str();
+    } else {
+      params->log_settings.logging_dest = logging::LOG_TO_STDERR;
+    }
+  } else {
+    params->log_settings.logging_dest = logging::LOG_NONE;
+  }
+
+  params->net_log_path = cmdline.log_net_log;
+  params->ssl_key_path = cmdline.ssl_key_log_file;
+
+  return true;
+}
+}  // namespace
+
+namespace net {
+namespace {
+// NetLog::ThreadSafeObserver implementation that simply prints events
+// to the logs.
+class PrintingLogObserver : public NetLog::ThreadSafeObserver {
+ public:
+  PrintingLogObserver() = default;
+  PrintingLogObserver(const PrintingLogObserver&) = delete;
+  PrintingLogObserver& operator=(const PrintingLogObserver&) = delete;
+
+  ~PrintingLogObserver() override {
+    // This is guaranteed to be safe as this program is single threaded.
+    net_log()->RemoveObserver(this);
+  }
+
+  // NetLog::ThreadSafeObserver implementation:
+  void OnAddEntry(const NetLogEntry& entry) override {
+    switch (entry.type) {
+      case NetLogEventType::SOCKET_POOL_STALLED_MAX_SOCKETS:
+      case NetLogEventType::SOCKET_POOL_STALLED_MAX_SOCKETS_PER_GROUP:
+      case NetLogEventType::HTTP2_SESSION_STREAM_STALLED_BY_SESSION_SEND_WINDOW:
+      case NetLogEventType::HTTP2_SESSION_STREAM_STALLED_BY_STREAM_SEND_WINDOW:
+      case NetLogEventType::HTTP2_SESSION_STALLED_MAX_STREAMS:
+      case NetLogEventType::HTTP2_STREAM_FLOW_CONTROL_UNSTALLED:
+        break;
+      default:
+        return;
+    }
+    const char* source_type = NetLog::SourceTypeToString(entry.source.type);
+    const char* event_type = NetLogEventTypeToString(entry.type);
+    const char* event_phase = NetLog::EventPhaseToString(entry.phase);
+    base::Value params(entry.ToValue());
+    std::string params_str;
+    base::JSONWriter::Write(params, &params_str);
+    params_str.insert(0, ": ");
+
+    VLOG(1) << source_type << "(" << entry.source.id << "): " << event_type
+            << ": " << event_phase << params_str;
+  }
+};
+}  // namespace
+
+namespace {
+std::unique_ptr<URLRequestContext> BuildCertURLRequestContext(NetLog* net_log) {
+  URLRequestContextBuilder builder;
+
+  builder.DisableHttpCache();
+  builder.set_net_log(net_log);
+
+  ProxyConfig proxy_config;
+  auto proxy_service =
+      ConfiguredProxyResolutionService::CreateWithoutProxyResolver(
+          std::make_unique<ProxyConfigServiceFixed>(
+              ProxyConfigWithAnnotation(proxy_config, kTrafficAnnotation)),
+          net_log);
+  proxy_service->ForceReloadProxyConfig();
+  builder.set_proxy_resolution_service(std::move(proxy_service));
+
+  return builder.Build();
+}
+
+// Builds a URLRequestContext assuming there's only a single loop.
+std::unique_ptr<URLRequestContext> BuildURLRequestContext(
+    const Params& params,
+    scoped_refptr<CertNetFetcherURLRequest> cert_net_fetcher,
+    NetLog* net_log) {
+  URLRequestContextBuilder builder;
+
+  builder.DisableHttpCache();
+  builder.set_net_log(net_log);
+
+  ProxyConfig proxy_config;
+  proxy_config.proxy_rules().ParseFromString(params.proxy_url);
+  LOG(INFO) << "Proxying via " << params.proxy_url;
+  auto proxy_service =
+      ConfiguredProxyResolutionService::CreateWithoutProxyResolver(
+          std::make_unique<ProxyConfigServiceFixed>(
+              ProxyConfigWithAnnotation(proxy_config, kTrafficAnnotation)),
+          net_log);
+  proxy_service->ForceReloadProxyConfig();
+  builder.set_proxy_resolution_service(std::move(proxy_service));
+
+  if (!params.host_resolver_rules.empty()) {
+    builder.set_host_mapping_rules(params.host_resolver_rules);
+  }
+
+  builder.SetCertVerifier(
+      CertVerifier::CreateDefault(std::move(cert_net_fetcher)));
+
+  builder.set_proxy_delegate(
+      std::make_unique<NaiveProxyDelegate>(params.extra_headers));
+
+  auto context = builder.Build();
+
+  if (!params.proxy_url.empty() && !params.proxy_user.empty() &&
+      !params.proxy_pass.empty()) {
+    auto* session = context->http_transaction_factory()->GetSession();
+    auto* auth_cache = session->http_auth_cache();
+    std::string proxy_url = params.proxy_url;
+    GURL proxy_gurl(proxy_url);
+    if (proxy_url.compare(0, 7, "quic://") == 0) {
+      proxy_url.replace(0, 4, "https");
+      proxy_gurl = GURL(proxy_url);
+      auto* quic = context->quic_context()->params();
+      quic->supported_versions = {quic::ParsedQuicVersion::RFCv1()};
+      quic->origins_to_force_quic_on.insert(
+          net::HostPortPair::FromURL(proxy_gurl));
+    }
+    url::SchemeHostPort auth_origin(proxy_gurl);
+    AuthCredentials credentials(params.proxy_user, params.proxy_pass);
+    auth_cache->Add(auth_origin, HttpAuth::AUTH_PROXY,
+                    /*realm=*/{}, HttpAuth::AUTH_SCHEME_BASIC, {},
+                    /*challenge=*/"Basic", credentials, /*path=*/"/");
+  }
+
+  return context;
+}
+}  // namespace
+}  // namespace net
+
+int main(int argc, char* argv[]) {
+  url::AddStandardScheme("quic",
+                         url::SCHEME_WITH_HOST_PORT_AND_USER_INFORMATION);
+  base::FeatureList::InitializeInstance(
+      "PartitionConnectionsByNetworkIsolationKey", std::string());
+  base::SingleThreadTaskExecutor io_task_executor(base::MessagePumpType::IO);
+  base::ThreadPoolInstance::CreateAndStartWithDefaultParams("naive");
+  base::AtExitManager exit_manager;
+
+#if defined(OS_MACOSX)
+  base::mac::ScopedNSAutoreleasePool pool;
+#endif
+
+  base::CommandLine::Init(argc, argv);
+
+  CommandLine cmdline;
+  Params params;
+  const auto& proc = *base::CommandLine::ForCurrentProcess();
+  const auto& args = proc.GetArgs();
+  if (args.empty()) {
+    if (proc.argv().size() >= 2) {
+      GetCommandLine(proc, &cmdline);
+    } else {
+      auto path = base::FilePath::FromUTF8Unsafe("config.json");
+      GetCommandLineFromConfig(path, &cmdline);
+    }
+  } else {
+    base::FilePath path(args[0]);
+    GetCommandLineFromConfig(path, &cmdline);
+  }
+  if (!ParseCommandLine(cmdline, &params)) {
+    return EXIT_FAILURE;
+  }
+
+  net::ClientSocketPoolManager::set_max_sockets_per_pool(
+      net::HttpNetworkSession::NORMAL_SOCKET_POOL,
+      kDefaultMaxSocketsPerPool * kExpectedMaxUsers);
+  net::ClientSocketPoolManager::set_max_sockets_per_proxy_server(
+      net::HttpNetworkSession::NORMAL_SOCKET_POOL,
+      kDefaultMaxSocketsPerPool * kExpectedMaxUsers);
+  net::ClientSocketPoolManager::set_max_sockets_per_group(
+      net::HttpNetworkSession::NORMAL_SOCKET_POOL,
+      kDefaultMaxSocketsPerGroup * kExpectedMaxUsers);
+
+  CHECK(logging::InitLogging(params.log_settings));
+
+  if (!params.ssl_key_path.empty()) {
+    net::SSLClientSocket::SetSSLKeyLogger(
+        std::make_unique<net::SSLKeyLoggerImpl>(params.ssl_key_path));
+  }
+
+  // The declaration order for net_log and printing_log_observer is
+  // important. The destructor of PrintingLogObserver removes itself
+  // from net_log, so net_log must be available for entire lifetime of
+  // printing_log_observer.
+  net::NetLog* net_log = net::NetLog::Get();
+  std::unique_ptr<net::FileNetLogObserver> observer;
+  if (!params.net_log_path.empty()) {
+    observer = net::FileNetLogObserver::CreateUnbounded(
+        params.net_log_path, net::NetLogCaptureMode::kDefault, GetConstants());
+    observer->StartObserving(net_log);
+  }
+
+  // Avoids net log overhead if verbose logging is disabled.
+  std::unique_ptr<net::PrintingLogObserver> printing_log_observer;
+  if (params.log_settings.logging_dest != logging::LOG_NONE && VLOG_IS_ON(1)) {
+    printing_log_observer = std::make_unique<net::PrintingLogObserver>();
+    net_log->AddObserver(printing_log_observer.get(),
+                         net::NetLogCaptureMode::kDefault);
+  }
+
+  auto cert_context = net::BuildCertURLRequestContext(net_log);
+  scoped_refptr<net::CertNetFetcherURLRequest> cert_net_fetcher;
+  // The builtin verifier is supported but not enabled by default on Mac,
+  // falling back to CreateSystemVerifyProc() which drops the net fetcher.
+  // Skips defined(OS_MAC) for now, until it is enabled by default.
+#if defined(OS_LINUX) || defined(OS_ANDROID)
+  cert_net_fetcher = base::MakeRefCounted<net::CertNetFetcherURLRequest>();
+  cert_net_fetcher->SetURLRequestContext(cert_context.get());
+#endif
+  auto context =
+      net::BuildURLRequestContext(params, std::move(cert_net_fetcher), net_log);
+  auto* session = context->http_transaction_factory()->GetSession();
+
+  auto listen_socket =
+      std::make_unique<net::TCPServerSocket>(net_log, net::NetLogSource());
+
+  int result = listen_socket->ListenWithAddressAndPort(
+      params.listen_addr, params.listen_port, kListenBackLog);
+  if (result != net::OK) {
+    LOG(ERROR) << "Failed to listen: " << result;
+    return EXIT_FAILURE;
+  }
+  LOG(INFO) << "Listening on " << params.listen_addr << ":"
+            << params.listen_port;
+
+  std::unique_ptr<net::RedirectResolver> resolver;
+  if (params.protocol == net::ClientProtocol::kRedir) {
+    auto resolver_socket =
+        std::make_unique<net::UDPServerSocket>(net_log, net::NetLogSource());
+    resolver_socket->AllowAddressReuse();
+    net::IPAddress listen_addr;
+    if (!listen_addr.AssignFromIPLiteral(params.listen_addr)) {
+      LOG(ERROR) << "Failed to open resolver: " << net::ERR_ADDRESS_INVALID;
+      return EXIT_FAILURE;
+    }
+
+    result = resolver_socket->Listen(
+        net::IPEndPoint(listen_addr, params.listen_port));
+    if (result != net::OK) {
+      LOG(ERROR) << "Failed to open resolver: " << result;
+      return EXIT_FAILURE;
+    }
+
+    resolver = std::make_unique<net::RedirectResolver>(
+        std::move(resolver_socket), params.resolver_range,
+        params.resolver_prefix);
+  }
+
+  net::NaiveProxy naive_proxy(std::move(listen_socket), params.protocol,
+                              params.listen_user, params.listen_pass,
+                              params.concurrency, resolver.get(), session,
+                              kTrafficAnnotation);
+
+  base::RunLoop().Run();
+
+  return EXIT_SUCCESS;
+}

src/net/tools/naive/naive_proxy_delegate.cc

@@ -0,0 +1,159 @@
+// Copyright 2020 klzgrad <kizdiv@gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+#include "net/tools/naive/naive_proxy_delegate.h"
+
+#include <string>
+
+#include "base/logging.h"
+#include "base/rand_util.h"
+#include "net/base/proxy_string_util.h"
+#include "net/http/http_request_headers.h"
+#include "net/http/http_response_headers.h"
+#include "net/third_party/quiche/src/spdy/core/hpack/hpack_constants.h"
+
+namespace net {
+namespace {
+bool g_nonindex_codes_initialized;
+uint8_t g_nonindex_codes[17];
+}  // namespace
+
+void InitializeNonindexCodes() {
+  if (g_nonindex_codes_initialized)
+    return;
+  g_nonindex_codes_initialized = true;
+  unsigned i = 0;
+  for (const auto& symbol : spdy::HpackHuffmanCodeVector()) {
+    if (symbol.id >= 0x20 && symbol.id <= 0x7f && symbol.length >= 8) {
+      g_nonindex_codes[i++] = symbol.id;
+      if (i >= sizeof(g_nonindex_codes))
+        break;
+    }
+  }
+  CHECK(i == sizeof(g_nonindex_codes));
+}
+
+void FillNonindexHeaderValue(uint64_t unique_bits, char* buf, int len) {
+  DCHECK(g_nonindex_codes_initialized);
+  int first = len < 16 ? len : 16;
+  for (int i = 0; i < first; i++) {
+    buf[i] = g_nonindex_codes[unique_bits & 0b1111];
+    unique_bits >>= 4;
+  }
+  for (int i = first; i < len; i++) {
+    buf[i] = g_nonindex_codes[16];
+  }
+}
+
+NaiveProxyDelegate::NaiveProxyDelegate(const HttpRequestHeaders& extra_headers)
+    : extra_headers_(extra_headers) {
+  InitializeNonindexCodes();
+}
+
+NaiveProxyDelegate::~NaiveProxyDelegate() = default;
+
+void NaiveProxyDelegate::OnBeforeTunnelRequest(
+    const ProxyServer& proxy_server,
+    HttpRequestHeaders* extra_headers) {
+  if (proxy_server.is_direct() || proxy_server.is_socks())
+    return;
+
+  // Sends client-side padding header regardless of server support
+  std::string padding(base::RandInt(16, 32), '~');
+  FillNonindexHeaderValue(base::RandUint64(), &padding[0], padding.size());
+  extra_headers->SetHeader("padding", padding);
+
+  // Enables Fast Open in H2/H3 proxy client socket once the state of server
+  // padding support is known.
+  if (padding_state_by_server_[proxy_server] != PaddingSupport::kUnknown) {
+    extra_headers->SetHeader("fastopen", "1");
+  }
+  extra_headers->MergeFrom(extra_headers_);
+}
+
+Error NaiveProxyDelegate::OnTunnelHeadersReceived(
+    const ProxyServer& proxy_server,
+    const HttpResponseHeaders& response_headers) {
+  if (proxy_server.is_direct() || proxy_server.is_socks())
+    return OK;
+
+  // Detects server padding support, even if it changes dynamically.
+  bool padding = response_headers.HasHeader("padding");
+  auto new_state =
+      padding ? PaddingSupport::kCapable : PaddingSupport::kIncapable;
+  auto& padding_state = padding_state_by_server_[proxy_server];
+  if (padding_state == PaddingSupport::kUnknown || padding_state != new_state) {
+    LOG(INFO) << "Padding capability of " << ProxyServerToProxyUri(proxy_server)
+              << (padding ? " detected" : " undetected");
+  }
+  padding_state = new_state;
+  return OK;
+}
+
+PaddingSupport NaiveProxyDelegate::GetProxyServerPaddingSupport(
+    const ProxyServer& proxy_server) {
+  // Not possible to detect padding capability given underlying protocol.
+  if (proxy_server.is_direct() || proxy_server.is_socks())
+    return PaddingSupport::kIncapable;
+
+  return padding_state_by_server_[proxy_server];
+}
+
+PaddingDetectorDelegate::PaddingDetectorDelegate(
+    NaiveProxyDelegate* naive_proxy_delegate,
+    const ProxyServer& proxy_server,
+    ClientProtocol client_protocol)
+    : naive_proxy_delegate_(naive_proxy_delegate),
+      proxy_server_(proxy_server),
+      client_protocol_(client_protocol),
+      detected_client_padding_support_(PaddingSupport::kUnknown),
+      cached_server_padding_support_(PaddingSupport::kUnknown) {}
+
+PaddingDetectorDelegate::~PaddingDetectorDelegate() = default;
+
+bool PaddingDetectorDelegate::IsPaddingSupportKnown() {
+  auto c = GetClientPaddingSupport();
+  auto s = GetServerPaddingSupport();
+  return c != PaddingSupport::kUnknown && s != PaddingSupport::kUnknown;
+}
+
+Direction PaddingDetectorDelegate::GetPaddingDirection() {
+  auto c = GetClientPaddingSupport();
+  auto s = GetServerPaddingSupport();
+  // Padding support must be already detected at this point.
+  CHECK_NE(c, PaddingSupport::kUnknown);
+  CHECK_NE(s, PaddingSupport::kUnknown);
+  if (c == PaddingSupport::kCapable && s == PaddingSupport::kIncapable) {
+    return kServer;
+  }
+  if (c == PaddingSupport::kIncapable && s == PaddingSupport::kCapable) {
+    return kClient;
+  }
+  return kNone;
+}
+
+void PaddingDetectorDelegate::SetClientPaddingSupport(
+    PaddingSupport padding_support) {
+  detected_client_padding_support_ = padding_support;
+}
+
+PaddingSupport PaddingDetectorDelegate::GetClientPaddingSupport() {
+  // Not possible to detect padding capability given underlying protocol.
+  if (client_protocol_ == ClientProtocol::kSocks5) {
+    return PaddingSupport::kIncapable;
+  } else if (client_protocol_ == ClientProtocol::kRedir) {
+    return PaddingSupport::kIncapable;
+  }
+
+  return detected_client_padding_support_;
+}
+
+PaddingSupport PaddingDetectorDelegate::GetServerPaddingSupport() {
+  if (cached_server_padding_support_ != PaddingSupport::kUnknown)
+    return cached_server_padding_support_;
+  cached_server_padding_support_ =
+      naive_proxy_delegate_->GetProxyServerPaddingSupport(proxy_server_);
+  return cached_server_padding_support_;
+}
+
+}  // namespace net

src/net/tools/naive/naive_proxy_delegate.h

@@ -0,0 +1,94 @@
+// Copyright 2020 klzgrad <kizdiv@gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+#ifndef NET_TOOLS_NAIVE_NAIVE_PROXY_DELEGATE_H_
+#define NET_TOOLS_NAIVE_NAIVE_PROXY_DELEGATE_H_
+
+#include <cstdint>
+#include <map>
+#include <string>
+
+#include "base/strings/string_piece.h"
+#include "net/base/net_errors.h"
+#include "net/base/proxy_delegate.h"
+#include "net/base/proxy_server.h"
+#include "net/proxy_resolution/proxy_retry_info.h"
+#include "net/tools/naive/naive_protocol.h"
+#include "url/gurl.h"
+
+namespace net {
+
+void InitializeNonindexCodes();
+// |unique_bits| SHOULD have relatively unique values.
+void FillNonindexHeaderValue(uint64_t unique_bits, char* buf, int len);
+
+class ProxyInfo;
+class HttpRequestHeaders;
+class HttpResponseHeaders;
+
+enum class PaddingSupport {
+  kUnknown = 0,
+  kCapable,
+  kIncapable,
+};
+
+class NaiveProxyDelegate : public ProxyDelegate {
+ public:
+  explicit NaiveProxyDelegate(const HttpRequestHeaders& extra_headers);
+  ~NaiveProxyDelegate() override;
+
+  void OnResolveProxy(const GURL& url,
+                      const std::string& method,
+                      const ProxyRetryInfoMap& proxy_retry_info,
+                      ProxyInfo* result) override {}
+  void OnFallback(const ProxyServer& bad_proxy, int net_error) override {}
+
+  // This only affects h2 proxy client socket.
+  void OnBeforeTunnelRequest(const ProxyServer& proxy_server,
+                             HttpRequestHeaders* extra_headers) override;
+
+  Error OnTunnelHeadersReceived(
+      const ProxyServer& proxy_server,
+      const HttpResponseHeaders& response_headers) override;
+
+  PaddingSupport GetProxyServerPaddingSupport(const ProxyServer& proxy_server);
+
+ private:
+  const HttpRequestHeaders& extra_headers_;
+  std::map<ProxyServer, PaddingSupport> padding_state_by_server_;
+};
+
+class ClientPaddingDetectorDelegate {
+ public:
+  virtual ~ClientPaddingDetectorDelegate() = default;
+
+  virtual void SetClientPaddingSupport(PaddingSupport padding_support) = 0;
+};
+
+class PaddingDetectorDelegate : public ClientPaddingDetectorDelegate {
+ public:
+  PaddingDetectorDelegate(NaiveProxyDelegate* naive_proxy_delegate,
+                          const ProxyServer& proxy_server,
+                          ClientProtocol client_protocol);
+  ~PaddingDetectorDelegate() override;
+
+  bool IsPaddingSupportKnown();
+  Direction GetPaddingDirection();
+  void SetClientPaddingSupport(PaddingSupport padding_support) override;
+
+ private:
+  PaddingSupport GetClientPaddingSupport();
+  PaddingSupport GetServerPaddingSupport();
+
+  NaiveProxyDelegate* naive_proxy_delegate_;
+  const ProxyServer& proxy_server_;
+  ClientProtocol client_protocol_;
+
+  PaddingSupport detected_client_padding_support_;
+  // The result is only cached during one connection, so it's still dynamically
+  // updated in the following connections after server changes support.
+  PaddingSupport cached_server_padding_support_;
+};
+
+}  // namespace net
+#endif  // NET_TOOLS_NAIVE_NAIVE_PROXY_DELEGATE_H_

src/net/tools/naive/redirect_resolver.cc

@@ -0,0 +1,246 @@
+// Copyright 2019 klzgrad <kizdiv@gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/tools/naive/redirect_resolver.h"
+
+#include <cstring>
+#include <iterator>
+#include <utility>
+
+#include "base/logging.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "net/base/io_buffer.h"
+#include "net/base/net_errors.h"
+#include "net/dns/dns_query.h"
+#include "net/dns/dns_response.h"
+#include "net/dns/dns_util.h"
+#include "net/socket/datagram_server_socket.h"
+#include "third_party/abseil-cpp/absl/types/optional.h"
+
+namespace {
+constexpr int kUdpReadBufferSize = 1024;
+constexpr int kResolutionTtl = 60;
+constexpr int kResolutionRecycleTime = 60 * 5;
+
+std::string PackedIPv4ToString(uint32_t addr) {
+  return net::IPAddress(addr >> 24, addr >> 16, addr >> 8, addr).ToString();
+}
+}  // namespace
+
+namespace net {
+
+Resolution::Resolution() = default;
+
+Resolution::~Resolution() = default;
+
+RedirectResolver::RedirectResolver(std::unique_ptr<DatagramServerSocket> socket,
+                                   const IPAddress& range,
+                                   size_t prefix)
+    : socket_(std::move(socket)),
+      range_(range),
+      prefix_(prefix),
+      offset_(0),
+      buffer_(base::MakeRefCounted<IOBufferWithSize>(kUdpReadBufferSize)) {
+  DCHECK(socket_);
+  // Start accepting connections in next run loop in case when delegate is not
+  // ready to get callbacks.
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::BindOnce(&RedirectResolver::DoRead,
+                                weak_ptr_factory_.GetWeakPtr()));
+}
+
+RedirectResolver::~RedirectResolver() = default;
+
+void RedirectResolver::DoRead() {
+  for (;;) {
+    int rv = socket_->RecvFrom(
+        buffer_.get(), kUdpReadBufferSize, &recv_address_,
+        base::BindOnce(&RedirectResolver::OnRecv, base::Unretained(this)));
+    if (rv == ERR_IO_PENDING)
+      return;
+    rv = HandleReadResult(rv);
+    if (rv == ERR_IO_PENDING)
+      return;
+    if (rv < 0) {
+      LOG(INFO) << "DoRead: ignoring error " << rv;
+    }
+  }
+}
+
+void RedirectResolver::OnRecv(int result) {
+  int rv;
+  rv = HandleReadResult(result);
+  if (rv == ERR_IO_PENDING)
+    return;
+  if (rv < 0) {
+    LOG(INFO) << "OnRecv: ignoring error " << result;
+  }
+
+  DoRead();
+}
+
+void RedirectResolver::OnSend(int result) {
+  if (result < 0) {
+    LOG(INFO) << "OnSend: ignoring error " << result;
+  }
+
+  DoRead();
+}
+
+int RedirectResolver::HandleReadResult(int result) {
+  if (result < 0)
+    return result;
+
+  DnsQuery query(buffer_.get());
+  if (!query.Parse(result)) {
+    LOG(INFO) << "Malformed DNS query from " << recv_address_.ToString();
+    return ERR_INVALID_ARGUMENT;
+  }
+
+  int size;
+  if (query.qtype() == dns_protocol::kTypeA) {
+    Resolution res;
+
+    auto name_or = DnsDomainToString(query.qname());
+    if (!name_or) {
+      LOG(INFO) << "Malformed DNS query from " << recv_address_.ToString();
+      return ERR_INVALID_ARGUMENT;
+    }
+    const auto& name = name_or.value();
+
+    auto by_name_lookup = resolution_by_name_.emplace(name, resolutions_.end());
+    auto by_name = by_name_lookup.first;
+    bool has_name = !by_name_lookup.second;
+    if (has_name) {
+      auto res_it = by_name->second;
+      auto by_addr = res_it->by_addr;
+      uint32_t addr = res_it->addr;
+
+      resolutions_.erase(res_it);
+      resolutions_.emplace_back();
+      res_it = std::prev(resolutions_.end());
+
+      by_name->second = res_it;
+      by_addr->second = res_it;
+      res_it->addr = addr;
+      res_it->name = name;
+      res_it->time = base::TimeTicks::Now();
+      res_it->by_name = by_name;
+      res_it->by_addr = by_addr;
+    } else {
+      uint32_t addr = (range_.bytes()[0] << 24) | (range_.bytes()[1] << 16) |
+                      (range_.bytes()[2] << 8) | range_.bytes()[3];
+      uint32_t subnet = ~0U >> prefix_;
+      addr &= ~subnet;
+      addr += offset_;
+      offset_ = (offset_ + 1) & subnet;
+
+      auto by_addr_lookup =
+          resolution_by_addr_.emplace(addr, resolutions_.end());
+      auto by_addr = by_addr_lookup.first;
+      bool has_addr = !by_addr_lookup.second;
+      if (has_addr) {
+        // Too few available addresses. Overwrites old one.
+        auto res_it = by_addr->second;
+
+        LOG(INFO) << "Overwrite " << res_it->name << " "
+                  << PackedIPv4ToString(res_it->addr) << " with " << name << " "
+                  << PackedIPv4ToString(addr);
+        resolution_by_name_.erase(res_it->by_name);
+        resolutions_.erase(res_it);
+        resolutions_.emplace_back();
+        res_it = std::prev(resolutions_.end());
+
+        by_name->second = res_it;
+        by_addr->second = res_it;
+        res_it->addr = addr;
+        res_it->name = name;
+        res_it->time = base::TimeTicks::Now();
+        res_it->by_name = by_name;
+        res_it->by_addr = by_addr;
+      } else {
+        LOG(INFO) << "Add " << name << " " << PackedIPv4ToString(addr);
+        resolutions_.emplace_back();
+        auto res_it = std::prev(resolutions_.end());
+
+        by_name->second = res_it;
+        by_addr->second = res_it;
+        res_it->addr = addr;
+        res_it->name = name;
+        res_it->time = base::TimeTicks::Now();
+        res_it->by_name = by_name;
+        res_it->by_addr = by_addr;
+
+        // Collects garbage.
+        auto now = base::TimeTicks::Now();
+        for (auto it = resolutions_.begin();
+             it != resolutions_.end() &&
+             (now - it->time).InSeconds() > kResolutionRecycleTime;) {
+          auto next = std::next(it);
+          LOG(INFO) << "Drop " << it->name << " "
+                    << PackedIPv4ToString(it->addr);
+          resolution_by_name_.erase(it->by_name);
+          resolution_by_addr_.erase(it->by_addr);
+          resolutions_.erase(it);
+          it = next;
+        }
+      }
+    }
+
+    DnsResourceRecord record;
+    record.name = name;
+    record.type = dns_protocol::kTypeA;
+    record.klass = dns_protocol::kClassIN;
+    record.ttl = kResolutionTtl;
+    uint32_t addr = by_name->second->addr;
+    record.SetOwnedRdata(IPAddressToPackedString(
+        IPAddress(addr >> 24, addr >> 16, addr >> 8, addr)));
+    absl::optional<DnsQuery> query_opt;
+    query_opt.emplace(query.id(), query.qname(), query.qtype());
+    DnsResponse response(query.id(), /*is_authoritative=*/false,
+                         /*answers=*/{std::move(record)},
+                         /*authority_records=*/{}, /*additional_records=*/{},
+                         query_opt);
+    size = response.io_buffer_size();
+    if (size > buffer_->size() || !response.io_buffer()) {
+      return ERR_NO_BUFFER_SPACE;
+    }
+    std::memcpy(buffer_->data(), response.io_buffer()->data(), size);
+  } else {
+    absl::optional<DnsQuery> query_opt;
+    query_opt.emplace(query.id(), query.qname(), query.qtype());
+    DnsResponse response(query.id(), /*is_authoritative=*/false, /*answers=*/{},
+                         /*authority_records=*/{}, /*additional_records=*/{},
+                         query_opt, dns_protocol::kRcodeSERVFAIL);
+    size = response.io_buffer_size();
+    if (size > buffer_->size() || !response.io_buffer()) {
+      return ERR_NO_BUFFER_SPACE;
+    }
+    std::memcpy(buffer_->data(), response.io_buffer()->data(), size);
+  }
+
+  return socket_->SendTo(
+      buffer_.get(), size, recv_address_,
+      base::BindOnce(&RedirectResolver::OnSend, base::Unretained(this)));
+}
+
+bool RedirectResolver::IsInResolvedRange(const IPAddress& address) const {
+  if (!address.IsIPv4())
+    return false;
+  return IPAddressMatchesPrefix(address, range_, prefix_);
+}
+
+std::string RedirectResolver::FindNameByAddress(
+    const IPAddress& address) const {
+  if (!address.IsIPv4())
+    return {};
+  uint32_t addr = (address.bytes()[0] << 24) | (address.bytes()[1] << 16) |
+                  (address.bytes()[2] << 8) | address.bytes()[3];
+  auto by_addr = resolution_by_addr_.find(addr);
+  if (by_addr == resolution_by_addr_.end())
+    return {};
+  return by_addr->second->name;
+}
+
+}  // namespace net

src/net/tools/naive/redirect_resolver.h

@@ -0,0 +1,69 @@
+// Copyright 2019 klzgrad <kizdiv@gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef NET_TOOLS_NAIVE_REDIRECT_RESOLVER_H_
+#define NET_TOOLS_NAIVE_REDIRECT_RESOLVER_H_
+
+#include <cstdint>
+#include <list>
+#include <map>
+#include <memory>
+#include <string>
+
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "base/time/time.h"
+#include "net/base/ip_address.h"
+#include "net/base/ip_endpoint.h"
+
+namespace net {
+
+class DatagramServerSocket;
+class IOBufferWithSize;
+
+struct Resolution {
+  Resolution();
+  ~Resolution();
+
+  uint32_t addr;
+  std::string name;
+  base::TimeTicks time;
+  std::map<std::string, std::list<Resolution>::iterator>::iterator by_name;
+  std::map<uint32_t, std::list<Resolution>::iterator>::iterator by_addr;
+};
+
+class RedirectResolver {
+ public:
+  RedirectResolver(std::unique_ptr<DatagramServerSocket> socket,
+                   const IPAddress& range,
+                   size_t prefix);
+  ~RedirectResolver();
+  RedirectResolver(const RedirectResolver&) = delete;
+  RedirectResolver& operator=(const RedirectResolver&) = delete;
+
+  bool IsInResolvedRange(const IPAddress& address) const;
+  std::string FindNameByAddress(const IPAddress& address) const;
+
+ private:
+  void DoRead();
+  void OnRecv(int result);
+  void OnSend(int result);
+  int HandleReadResult(int result);
+
+  std::unique_ptr<DatagramServerSocket> socket_;
+  IPAddress range_;
+  size_t prefix_;
+  uint32_t offset_;
+  scoped_refptr<IOBufferWithSize> buffer_;
+  IPEndPoint recv_address_;
+
+  std::map<std::string, std::list<Resolution>::iterator> resolution_by_name_;
+  std::map<uint32_t, std::list<Resolution>::iterator> resolution_by_addr_;
+  std::list<Resolution> resolutions_;
+
+  base::WeakPtrFactory<RedirectResolver> weak_ptr_factory_{this};
+};
+
+}  // namespace net
+#endif  // NET_TOOLS_NAIVE_REDIRECT_RESOLVER_H_

src/net/tools/naive/socks5_server_socket.cc

@@ -0,0 +1,673 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Copyright 2018 klzgrad <kizdiv@gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/tools/naive/socks5_server_socket.h"
+
+#include <cstring>
+#include <utility>
+
+#include "base/bind.h"
+#include "base/callback_helpers.h"
+#include "base/cxx17_backports.h"
+#include "base/logging.h"
+#include "base/sys_byteorder.h"
+#include "net/base/ip_address.h"
+#include "net/base/net_errors.h"
+#include "net/base/sys_addrinfo.h"
+#include "net/log/net_log.h"
+#include "net/log/net_log_event_type.h"
+
+namespace net {
+
+enum SocksCommandType {
+  kCommandConnect = 0x01,
+  kCommandBind = 0x02,
+  kCommandUDPAssociate = 0x03,
+};
+
+static constexpr unsigned int kGreetReadHeaderSize = 2;
+static constexpr unsigned int kAuthReadHeaderSize = 2;
+static constexpr unsigned int kReadHeaderSize = 5;
+static constexpr char kSOCKS5Version = '\x05';
+static constexpr char kSOCKS5Reserved = '\x00';
+static constexpr char kAuthMethodNone = '\x00';
+static constexpr char kAuthMethodUserPass = '\x02';
+static constexpr char kAuthMethodNoAcceptable = '\xff';
+static constexpr char kSubnegotiationVersion = '\x01';
+static constexpr char kAuthStatusSuccess = '\x00';
+static constexpr char kAuthStatusFailure = '\xff';
+static constexpr char kReplySuccess = '\x00';
+static constexpr char kReplyCommandNotSupported = '\x07';
+
+static_assert(sizeof(struct in_addr) == 4, "incorrect system size of IPv4");
+static_assert(sizeof(struct in6_addr) == 16, "incorrect system size of IPv6");
+
+Socks5ServerSocket::Socks5ServerSocket(
+    std::unique_ptr<StreamSocket> transport_socket,
+    const std::string& user,
+    const std::string& pass,
+    const NetworkTrafficAnnotationTag& traffic_annotation)
+    : io_callback_(base::BindRepeating(&Socks5ServerSocket::OnIOComplete,
+                                       base::Unretained(this))),
+      transport_(std::move(transport_socket)),
+      next_state_(STATE_NONE),
+      completed_handshake_(false),
+      bytes_sent_(0),
+      was_ever_used_(false),
+      user_(user),
+      pass_(pass),
+      net_log_(transport_->NetLog()),
+      traffic_annotation_(traffic_annotation) {}
+
+Socks5ServerSocket::~Socks5ServerSocket() {
+  Disconnect();
+}
+
+const HostPortPair& Socks5ServerSocket::request_endpoint() const {
+  return request_endpoint_;
+}
+
+int Socks5ServerSocket::Connect(CompletionOnceCallback callback) {
+  DCHECK(transport_);
+  DCHECK_EQ(STATE_NONE, next_state_);
+  DCHECK(!user_callback_);
+
+  // If already connected, then just return OK.
+  if (completed_handshake_)
+    return OK;
+
+  net_log_.BeginEvent(NetLogEventType::SOCKS5_CONNECT);
+
+  next_state_ = STATE_GREET_READ;
+  buffer_.clear();
+
+  int rv = DoLoop(OK);
+  if (rv == ERR_IO_PENDING) {
+    user_callback_ = std::move(callback);
+  } else {
+    net_log_.EndEventWithNetErrorCode(NetLogEventType::SOCKS5_CONNECT, rv);
+  }
+  return rv;
+}
+
+void Socks5ServerSocket::Disconnect() {
+  completed_handshake_ = false;
+  transport_->Disconnect();
+
+  // Reset other states to make sure they aren't mistakenly used later.
+  // These are the states initialized by Connect().
+  next_state_ = STATE_NONE;
+  user_callback_.Reset();
+}
+
+bool Socks5ServerSocket::IsConnected() const {
+  return completed_handshake_ && transport_->IsConnected();
+}
+
+bool Socks5ServerSocket::IsConnectedAndIdle() const {
+  return completed_handshake_ && transport_->IsConnectedAndIdle();
+}
+
+const NetLogWithSource& Socks5ServerSocket::NetLog() const {
+  return net_log_;
+}
+
+bool Socks5ServerSocket::WasEverUsed() const {
+  return was_ever_used_;
+}
+
+bool Socks5ServerSocket::WasAlpnNegotiated() const {
+  if (transport_) {
+    return transport_->WasAlpnNegotiated();
+  }
+  NOTREACHED();
+  return false;
+}
+
+NextProto Socks5ServerSocket::GetNegotiatedProtocol() const {
+  if (transport_) {
+    return transport_->GetNegotiatedProtocol();
+  }
+  NOTREACHED();
+  return kProtoUnknown;
+}
+
+bool Socks5ServerSocket::GetSSLInfo(SSLInfo* ssl_info) {
+  if (transport_) {
+    return transport_->GetSSLInfo(ssl_info);
+  }
+  NOTREACHED();
+  return false;
+}
+
+void Socks5ServerSocket::GetConnectionAttempts(ConnectionAttempts* out) const {
+  out->clear();
+}
+
+int64_t Socks5ServerSocket::GetTotalReceivedBytes() const {
+  return transport_->GetTotalReceivedBytes();
+}
+
+void Socks5ServerSocket::ApplySocketTag(const SocketTag& tag) {
+  return transport_->ApplySocketTag(tag);
+}
+
+// Read is called by the transport layer above to read. This can only be done
+// if the SOCKS handshake is complete.
+int Socks5ServerSocket::Read(IOBuffer* buf,
+                             int buf_len,
+                             CompletionOnceCallback callback) {
+  DCHECK(completed_handshake_);
+  DCHECK_EQ(STATE_NONE, next_state_);
+  DCHECK(!user_callback_);
+  DCHECK(callback);
+
+  int rv = transport_->Read(
+      buf, buf_len,
+      base::BindOnce(&Socks5ServerSocket::OnReadWriteComplete,
+                     base::Unretained(this), std::move(callback)));
+  if (rv > 0)
+    was_ever_used_ = true;
+  return rv;
+}
+
+// Write is called by the transport layer. This can only be done if the
+// SOCKS handshake is complete.
+int Socks5ServerSocket::Write(
+    IOBuffer* buf,
+    int buf_len,
+    CompletionOnceCallback callback,
+    const NetworkTrafficAnnotationTag& traffic_annotation) {
+  DCHECK(completed_handshake_);
+  DCHECK_EQ(STATE_NONE, next_state_);
+  DCHECK(!user_callback_);
+  DCHECK(callback);
+
+  int rv = transport_->Write(
+      buf, buf_len,
+      base::BindOnce(&Socks5ServerSocket::OnReadWriteComplete,
+                     base::Unretained(this), std::move(callback)),
+      traffic_annotation);
+  if (rv > 0)
+    was_ever_used_ = true;
+  return rv;
+}
+
+int Socks5ServerSocket::SetReceiveBufferSize(int32_t size) {
+  return transport_->SetReceiveBufferSize(size);
+}
+
+int Socks5ServerSocket::SetSendBufferSize(int32_t size) {
+  return transport_->SetSendBufferSize(size);
+}
+
+void Socks5ServerSocket::DoCallback(int result) {
+  DCHECK_NE(ERR_IO_PENDING, result);
+  DCHECK(user_callback_);
+
+  // Since Run() may result in Read being called,
+  // clear user_callback_ up front.
+  std::move(user_callback_).Run(result);
+}
+
+void Socks5ServerSocket::OnIOComplete(int result) {
+  DCHECK_NE(STATE_NONE, next_state_);
+  int rv = DoLoop(result);
+  if (rv != ERR_IO_PENDING) {
+    net_log_.EndEvent(NetLogEventType::SOCKS5_CONNECT);
+    DoCallback(rv);
+  }
+}
+
+void Socks5ServerSocket::OnReadWriteComplete(CompletionOnceCallback callback,
+                                             int result) {
+  DCHECK_NE(ERR_IO_PENDING, result);
+  DCHECK(callback);
+
+  if (result > 0)
+    was_ever_used_ = true;
+  std::move(callback).Run(result);
+}
+
+int Socks5ServerSocket::DoLoop(int last_io_result) {
+  DCHECK_NE(next_state_, STATE_NONE);
+  int rv = last_io_result;
+  do {
+    State state = next_state_;
+    next_state_ = STATE_NONE;
+    switch (state) {
+      case STATE_GREET_READ:
+        DCHECK_EQ(OK, rv);
+        net_log_.BeginEvent(NetLogEventType::SOCKS5_GREET_READ);
+        rv = DoGreetRead();
+        break;
+      case STATE_GREET_READ_COMPLETE:
+        rv = DoGreetReadComplete(rv);
+        net_log_.EndEventWithNetErrorCode(NetLogEventType::SOCKS5_GREET_READ,
+                                          rv);
+        break;
+      case STATE_GREET_WRITE:
+        DCHECK_EQ(OK, rv);
+        net_log_.BeginEvent(NetLogEventType::SOCKS5_GREET_WRITE);
+        rv = DoGreetWrite();
+        break;
+      case STATE_GREET_WRITE_COMPLETE:
+        rv = DoGreetWriteComplete(rv);
+        net_log_.EndEventWithNetErrorCode(NetLogEventType::SOCKS5_GREET_WRITE,
+                                          rv);
+        break;
+      case STATE_AUTH_READ:
+        DCHECK_EQ(OK, rv);
+        rv = DoAuthRead();
+        break;
+      case STATE_AUTH_READ_COMPLETE:
+        rv = DoAuthReadComplete(rv);
+        break;
+      case STATE_AUTH_WRITE:
+        DCHECK_EQ(OK, rv);
+        rv = DoAuthWrite();
+        break;
+      case STATE_AUTH_WRITE_COMPLETE:
+        rv = DoAuthWriteComplete(rv);
+        break;
+      case STATE_HANDSHAKE_READ:
+        DCHECK_EQ(OK, rv);
+        net_log_.BeginEvent(NetLogEventType::SOCKS5_HANDSHAKE_READ);
+        rv = DoHandshakeRead();
+        break;
+      case STATE_HANDSHAKE_READ_COMPLETE:
+        rv = DoHandshakeReadComplete(rv);
+        net_log_.EndEventWithNetErrorCode(
+            NetLogEventType::SOCKS5_HANDSHAKE_READ, rv);
+        break;
+      case STATE_HANDSHAKE_WRITE:
+        DCHECK_EQ(OK, rv);
+        net_log_.BeginEvent(NetLogEventType::SOCKS5_HANDSHAKE_WRITE);
+        rv = DoHandshakeWrite();
+        break;
+      case STATE_HANDSHAKE_WRITE_COMPLETE:
+        rv = DoHandshakeWriteComplete(rv);
+        net_log_.EndEventWithNetErrorCode(
+            NetLogEventType::SOCKS5_HANDSHAKE_WRITE, rv);
+        break;
+      default:
+        NOTREACHED() << "bad state";
+        rv = ERR_UNEXPECTED;
+        break;
+    }
+  } while (rv != ERR_IO_PENDING && next_state_ != STATE_NONE);
+  return rv;
+}
+
+int Socks5ServerSocket::DoGreetRead() {
+  next_state_ = STATE_GREET_READ_COMPLETE;
+
+  if (buffer_.empty()) {
+    read_header_size_ = kGreetReadHeaderSize;
+  }
+
+  int handshake_buf_len = read_header_size_ - buffer_.size();
+  DCHECK_LT(0, handshake_buf_len);
+  handshake_buf_ = base::MakeRefCounted<IOBuffer>(handshake_buf_len);
+  return transport_->Read(handshake_buf_.get(), handshake_buf_len,
+                          io_callback_);
+}
+
+int Socks5ServerSocket::DoGreetReadComplete(int result) {
+  if (result < 0)
+    return result;
+
+  if (result == 0) {
+    net_log_.AddEvent(
+        NetLogEventType::SOCKS_UNEXPECTEDLY_CLOSED_DURING_GREETING);
+    return ERR_SOCKS_CONNECTION_FAILED;
+  }
+
+  buffer_.append(handshake_buf_->data(), result);
+
+  // When the first few bytes are read, check how many more are required
+  // and accordingly increase them
+  if (buffer_.size() == kGreetReadHeaderSize) {
+    if (buffer_[0] != kSOCKS5Version) {
+      net_log_.AddEventWithIntParams(NetLogEventType::SOCKS_UNEXPECTED_VERSION,
+                                     "version", buffer_[0]);
+      return ERR_SOCKS_CONNECTION_FAILED;
+    }
+    int nmethods = buffer_[1];
+    if (nmethods == 0) {
+      net_log_.AddEvent(NetLogEventType::SOCKS_NO_REQUESTED_AUTH);
+      return ERR_SOCKS_CONNECTION_FAILED;
+    }
+
+    read_header_size_ += nmethods;
+    next_state_ = STATE_GREET_READ;
+    return OK;
+  }
+
+  if (buffer_.size() == read_header_size_) {
+    int nmethods = buffer_[1];
+    char expected_method = kAuthMethodNone;
+    if (!user_.empty() || !pass_.empty()) {
+      expected_method = kAuthMethodUserPass;
+    }
+    void* match =
+        std::memchr(&buffer_[kGreetReadHeaderSize], expected_method, nmethods);
+    if (match) {
+      auth_method_ = expected_method;
+    } else {
+      auth_method_ = kAuthMethodNoAcceptable;
+    }
+    buffer_.clear();
+    next_state_ = STATE_GREET_WRITE;
+    return OK;
+  }
+
+  next_state_ = STATE_GREET_READ;
+  return OK;
+}
+
+int Socks5ServerSocket::DoGreetWrite() {
+  if (buffer_.empty()) {
+    const char write_data[] = {kSOCKS5Version, auth_method_};
+    buffer_ = std::string(write_data, std::size(write_data));
+    bytes_sent_ = 0;
+  }
+
+  next_state_ = STATE_GREET_WRITE_COMPLETE;
+  int handshake_buf_len = buffer_.size() - bytes_sent_;
+  DCHECK_LT(0, handshake_buf_len);
+  handshake_buf_ = base::MakeRefCounted<IOBuffer>(handshake_buf_len);
+  std::memcpy(handshake_buf_->data(), &buffer_.data()[bytes_sent_],
+              handshake_buf_len);
+  return transport_->Write(handshake_buf_.get(), handshake_buf_len,
+                           io_callback_, traffic_annotation_);
+}
+
+int Socks5ServerSocket::DoGreetWriteComplete(int result) {
+  if (result < 0)
+    return result;
+
+  bytes_sent_ += result;
+  if (bytes_sent_ == buffer_.size()) {
+    buffer_.clear();
+    if (auth_method_ == kAuthMethodNone) {
+      next_state_ = STATE_HANDSHAKE_READ;
+    } else if (auth_method_ == kAuthMethodUserPass) {
+      next_state_ = STATE_AUTH_READ;
+    } else {
+      net_log_.AddEvent(NetLogEventType::SOCKS_NO_ACCEPTABLE_AUTH);
+      return ERR_SOCKS_CONNECTION_FAILED;
+    }
+  } else {
+    next_state_ = STATE_GREET_WRITE;
+  }
+  return OK;
+}
+
+int Socks5ServerSocket::DoAuthRead() {
+  next_state_ = STATE_AUTH_READ_COMPLETE;
+
+  if (buffer_.empty()) {
+    read_header_size_ = kAuthReadHeaderSize;
+  }
+
+  int handshake_buf_len = read_header_size_ - buffer_.size();
+  DCHECK_LT(0, handshake_buf_len);
+  handshake_buf_ = base::MakeRefCounted<IOBuffer>(handshake_buf_len);
+  return transport_->Read(handshake_buf_.get(), handshake_buf_len,
+                          io_callback_);
+}
+
+int Socks5ServerSocket::DoAuthReadComplete(int result) {
+  if (result < 0)
+    return result;
+
+  if (result == 0) {
+    return ERR_SOCKS_CONNECTION_FAILED;
+  }
+
+  buffer_.append(handshake_buf_->data(), result);
+
+  // When the first few bytes are read, check how many more are required
+  // and accordingly increase them
+  if (buffer_.size() == kAuthReadHeaderSize) {
+    if (buffer_[0] != kSubnegotiationVersion) {
+      net_log_.AddEventWithIntParams(NetLogEventType::SOCKS_UNEXPECTED_VERSION,
+                                     "version", buffer_[0]);
+      return ERR_SOCKS_CONNECTION_FAILED;
+    }
+    int username_len = buffer_[1];
+    read_header_size_ += username_len + 1;
+    next_state_ = STATE_AUTH_READ;
+    return OK;
+  }
+
+  if (buffer_.size() == read_header_size_) {
+    int username_len = buffer_[1];
+    int password_len = buffer_[kAuthReadHeaderSize + username_len];
+    size_t password_offset = kAuthReadHeaderSize + username_len + 1;
+    if (buffer_.size() == password_offset && password_len != 0) {
+      read_header_size_ += password_len;
+      next_state_ = STATE_AUTH_READ;
+      return OK;
+    }
+
+    if (buffer_.compare(kAuthReadHeaderSize, username_len, user_) == 0 &&
+        buffer_.compare(password_offset, password_len, pass_) == 0) {
+      auth_status_ = kAuthStatusSuccess;
+    } else {
+      auth_status_ = kAuthStatusFailure;
+    }
+    buffer_.clear();
+    next_state_ = STATE_AUTH_WRITE;
+    return OK;
+  }
+
+  next_state_ = STATE_AUTH_READ;
+  return OK;
+}
+
+int Socks5ServerSocket::DoAuthWrite() {
+  if (buffer_.empty()) {
+    const char write_data[] = {kSubnegotiationVersion, auth_status_};
+    buffer_ = std::string(write_data, std::size(write_data));
+    bytes_sent_ = 0;
+  }
+
+  next_state_ = STATE_AUTH_WRITE_COMPLETE;
+  int handshake_buf_len = buffer_.size() - bytes_sent_;
+  DCHECK_LT(0, handshake_buf_len);
+  handshake_buf_ = base::MakeRefCounted<IOBuffer>(handshake_buf_len);
+  std::memcpy(handshake_buf_->data(), &buffer_.data()[bytes_sent_],
+              handshake_buf_len);
+  return transport_->Write(handshake_buf_.get(), handshake_buf_len,
+                           io_callback_, traffic_annotation_);
+}
+
+int Socks5ServerSocket::DoAuthWriteComplete(int result) {
+  if (result < 0)
+    return result;
+
+  bytes_sent_ += result;
+  if (bytes_sent_ == buffer_.size()) {
+    buffer_.clear();
+    if (auth_status_ == kAuthStatusSuccess) {
+      next_state_ = STATE_HANDSHAKE_READ;
+    } else {
+      return ERR_SOCKS_CONNECTION_FAILED;
+    }
+  } else {
+    next_state_ = STATE_AUTH_WRITE;
+  }
+  return OK;
+}
+
+int Socks5ServerSocket::DoHandshakeRead() {
+  next_state_ = STATE_HANDSHAKE_READ_COMPLETE;
+
+  if (buffer_.empty()) {
+    read_header_size_ = kReadHeaderSize;
+  }
+
+  int handshake_buf_len = read_header_size_ - buffer_.size();
+  DCHECK_LT(0, handshake_buf_len);
+  handshake_buf_ = base::MakeRefCounted<IOBuffer>(handshake_buf_len);
+  return transport_->Read(handshake_buf_.get(), handshake_buf_len,
+                          io_callback_);
+}
+
+int Socks5ServerSocket::DoHandshakeReadComplete(int result) {
+  if (result < 0)
+    return result;
+
+  // The underlying socket closed unexpectedly.
+  if (result == 0) {
+    net_log_.AddEvent(
+        NetLogEventType::SOCKS_UNEXPECTEDLY_CLOSED_DURING_HANDSHAKE);
+    return ERR_SOCKS_CONNECTION_FAILED;
+  }
+
+  buffer_.append(handshake_buf_->data(), result);
+
+  // When the first few bytes are read, check how many more are required
+  // and accordingly increase them
+  if (buffer_.size() == kReadHeaderSize) {
+    if (buffer_[0] != kSOCKS5Version || buffer_[2] != kSOCKS5Reserved) {
+      net_log_.AddEventWithIntParams(NetLogEventType::SOCKS_UNEXPECTED_VERSION,
+                                     "version", buffer_[0]);
+      return ERR_SOCKS_CONNECTION_FAILED;
+    }
+    SocksCommandType command = static_cast<SocksCommandType>(buffer_[1]);
+    if (command == kCommandConnect) {
+      // The proxy replies with success immediately without first connecting
+      // to the requested endpoint.
+      reply_ = kReplySuccess;
+    } else if (command == kCommandBind || command == kCommandUDPAssociate) {
+      reply_ = kReplyCommandNotSupported;
+    } else {
+      net_log_.AddEventWithIntParams(NetLogEventType::SOCKS_UNEXPECTED_COMMAND,
+                                     "commmand", buffer_[1]);
+      return ERR_SOCKS_CONNECTION_FAILED;
+    }
+
+    // We check the type of IP/Domain the server returns and accordingly
+    // increase the size of the request. For domains, we need to read the
+    // size of the domain, so the initial request size is upto the domain
+    // size. Since for IPv4/IPv6 the size is fixed and hence no 'size' is
+    // read, we substract 1 byte from the additional request size.
+    address_type_ = static_cast<SocksEndPointAddressType>(buffer_[3]);
+    if (address_type_ == kEndPointDomain) {
+      address_size_ = static_cast<uint8_t>(buffer_[4]);
+      if (address_size_ == 0) {
+        net_log_.AddEvent(NetLogEventType::SOCKS_ZERO_LENGTH_DOMAIN);
+        return ERR_SOCKS_CONNECTION_FAILED;
+      }
+    } else if (address_type_ == kEndPointResolvedIPv4) {
+      address_size_ = sizeof(struct in_addr);
+      --read_header_size_;
+    } else if (address_type_ == kEndPointResolvedIPv6) {
+      address_size_ = sizeof(struct in6_addr);
+      --read_header_size_;
+    } else {
+      // Aborts connection on unspecified address type.
+      net_log_.AddEventWithIntParams(
+          NetLogEventType::SOCKS_UNKNOWN_ADDRESS_TYPE, "address_type",
+          buffer_[3]);
+      return ERR_SOCKS_CONNECTION_FAILED;
+    }
+
+    read_header_size_ += address_size_ + sizeof(uint16_t);
+    next_state_ = STATE_HANDSHAKE_READ;
+    return OK;
+  }
+
+  // When the final bytes are read, setup handshake.
+  if (buffer_.size() == read_header_size_) {
+    size_t port_start = read_header_size_ - sizeof(uint16_t);
+    uint16_t port_net;
+    std::memcpy(&port_net, &buffer_[port_start], sizeof(uint16_t));
+    uint16_t port_host = base::NetToHost16(port_net);
+
+    size_t address_start = port_start - address_size_;
+    if (address_type_ == kEndPointDomain) {
+      std::string domain(&buffer_[address_start], address_size_);
+      request_endpoint_ = HostPortPair(domain, port_host);
+    } else {
+      IPAddress ip_addr(
+          reinterpret_cast<const uint8_t*>(&buffer_[address_start]),
+          address_size_);
+      IPEndPoint endpoint(ip_addr, port_host);
+      request_endpoint_ = HostPortPair::FromIPEndPoint(endpoint);
+    }
+    buffer_.clear();
+    next_state_ = STATE_HANDSHAKE_WRITE;
+    return OK;
+  }
+
+  next_state_ = STATE_HANDSHAKE_READ;
+  return OK;
+}
+
+// Writes the SOCKS handshake data to the underlying socket connection.
+int Socks5ServerSocket::DoHandshakeWrite() {
+  next_state_ = STATE_HANDSHAKE_WRITE_COMPLETE;
+
+  if (buffer_.empty()) {
+    const char write_data[] = {
+        // clang-format off
+        kSOCKS5Version,
+        reply_,
+        kSOCKS5Reserved,
+        kEndPointResolvedIPv4,
+        0x00, 0x00, 0x00, 0x00,  // BND.ADDR
+        0x00, 0x00,  // BND.PORT
+        // clang-format on
+    };
+    buffer_ = std::string(write_data, std::size(write_data));
+    bytes_sent_ = 0;
+  }
+
+  int handshake_buf_len = buffer_.size() - bytes_sent_;
+  DCHECK_LT(0, handshake_buf_len);
+  handshake_buf_ = base::MakeRefCounted<IOBuffer>(handshake_buf_len);
+  std::memcpy(handshake_buf_->data(), &buffer_[bytes_sent_], handshake_buf_len);
+  return transport_->Write(handshake_buf_.get(), handshake_buf_len,
+                           io_callback_, traffic_annotation_);
+}
+
+int Socks5ServerSocket::DoHandshakeWriteComplete(int result) {
+  if (result < 0)
+    return result;
+
+  // We ignore the case when result is 0, since the underlying Write
+  // may return spurious writes while waiting on the socket.
+
+  bytes_sent_ += result;
+  if (bytes_sent_ == buffer_.size()) {
+    buffer_.clear();
+    if (reply_ == kReplySuccess) {
+      completed_handshake_ = true;
+      next_state_ = STATE_NONE;
+    } else {
+      net_log_.AddEventWithIntParams(NetLogEventType::SOCKS_SERVER_ERROR,
+                                     "error_code", reply_);
+      return ERR_SOCKS_CONNECTION_FAILED;
+    }
+  } else {
+    next_state_ = STATE_HANDSHAKE_WRITE;
+  }
+
+  return OK;
+}
+
+int Socks5ServerSocket::GetPeerAddress(IPEndPoint* address) const {
+  return transport_->GetPeerAddress(address);
+}
+
+int Socks5ServerSocket::GetLocalAddress(IPEndPoint* address) const {
+  return transport_->GetLocalAddress(address);
+}
+
+}  // namespace net

src/net/tools/naive/socks5_server_socket.h

@@ -0,0 +1,169 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Copyright 2018 klzgrad <kizdiv@gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef NET_TOOLS_NAIVE_SOCKS5_SERVER_SOCKET_H_
+#define NET_TOOLS_NAIVE_SOCKS5_SERVER_SOCKET_H_
+
+#include <cstddef>
+#include <cstdint>
+#include <memory>
+#include <string>
+
+#include "base/memory/scoped_refptr.h"
+#include "net/base/completion_once_callback.h"
+#include "net/base/completion_repeating_callback.h"
+#include "net/base/host_port_pair.h"
+#include "net/base/io_buffer.h"
+#include "net/base/ip_endpoint.h"
+#include "net/log/net_log_with_source.h"
+#include "net/socket/connection_attempts.h"
+#include "net/socket/next_proto.h"
+#include "net/socket/stream_socket.h"
+#include "net/ssl/ssl_info.h"
+
+namespace net {
+struct NetworkTrafficAnnotationTag;
+
+// This StreamSocket is used to setup a SOCKSv5 handshake with a socks client.
+// Currently no SOCKSv5 authentication is supported.
+class Socks5ServerSocket : public StreamSocket {
+ public:
+  Socks5ServerSocket(std::unique_ptr<StreamSocket> transport_socket,
+                     const std::string& user,
+                     const std::string& pass,
+                     const NetworkTrafficAnnotationTag& traffic_annotation);
+
+  // On destruction Disconnect() is called.
+  ~Socks5ServerSocket() override;
+
+  Socks5ServerSocket(const Socks5ServerSocket&) = delete;
+  Socks5ServerSocket& operator=(const Socks5ServerSocket&) = delete;
+
+  const HostPortPair& request_endpoint() const;
+
+  // StreamSocket implementation.
+
+  // Does the SOCKS handshake and completes the protocol.
+  int Connect(CompletionOnceCallback callback) override;
+  void Disconnect() override;
+  bool IsConnected() const override;
+  bool IsConnectedAndIdle() const override;
+  const NetLogWithSource& NetLog() const override;
+  bool WasEverUsed() const override;
+  bool WasAlpnNegotiated() const override;
+  NextProto GetNegotiatedProtocol() const override;
+  bool GetSSLInfo(SSLInfo* ssl_info) override;
+  void GetConnectionAttempts(ConnectionAttempts* out) const override;
+  void ClearConnectionAttempts() override {}
+  void AddConnectionAttempts(const ConnectionAttempts& attempts) override {}
+  int64_t GetTotalReceivedBytes() const override;
+  void ApplySocketTag(const SocketTag& tag) override;
+
+  // Socket implementation.
+  int Read(IOBuffer* buf,
+           int buf_len,
+           CompletionOnceCallback callback) override;
+  int Write(IOBuffer* buf,
+            int buf_len,
+            CompletionOnceCallback callback,
+            const NetworkTrafficAnnotationTag& traffic_annotation) override;
+
+  int SetReceiveBufferSize(int32_t size) override;
+  int SetSendBufferSize(int32_t size) override;
+
+  int GetPeerAddress(IPEndPoint* address) const override;
+  int GetLocalAddress(IPEndPoint* address) const override;
+
+ private:
+  enum State {
+    STATE_GREET_READ,
+    STATE_GREET_READ_COMPLETE,
+    STATE_GREET_WRITE,
+    STATE_GREET_WRITE_COMPLETE,
+    STATE_AUTH_READ,
+    STATE_AUTH_READ_COMPLETE,
+    STATE_AUTH_WRITE,
+    STATE_AUTH_WRITE_COMPLETE,
+    STATE_HANDSHAKE_WRITE,
+    STATE_HANDSHAKE_WRITE_COMPLETE,
+    STATE_HANDSHAKE_READ,
+    STATE_HANDSHAKE_READ_COMPLETE,
+    STATE_NONE,
+  };
+
+  // Addressing type that can be specified in requests or responses.
+  enum SocksEndPointAddressType {
+    kEndPointDomain = 0x03,
+    kEndPointResolvedIPv4 = 0x01,
+    kEndPointResolvedIPv6 = 0x04,
+  };
+
+  void DoCallback(int result);
+  void OnIOComplete(int result);
+  void OnReadWriteComplete(CompletionOnceCallback callback, int result);
+
+  int DoLoop(int last_io_result);
+  int DoGreetRead();
+  int DoGreetReadComplete(int result);
+  int DoGreetWrite();
+  int DoGreetWriteComplete(int result);
+  int DoAuthRead();
+  int DoAuthReadComplete(int result);
+  int DoAuthWrite();
+  int DoAuthWriteComplete(int result);
+  int DoHandshakeRead();
+  int DoHandshakeReadComplete(int result);
+  int DoHandshakeWrite();
+  int DoHandshakeWriteComplete(int result);
+
+  CompletionRepeatingCallback io_callback_;
+
+  // Stores the underlying socket.
+  std::unique_ptr<StreamSocket> transport_;
+
+  State next_state_;
+
+  // Stores the callback to the layer above, called on completing Connect().
+  CompletionOnceCallback user_callback_;
+
+  // This IOBuffer is used by the class to read and write
+  // SOCKS handshake data. The length contains the expected size to
+  // read or write.
+  scoped_refptr<IOBuffer> handshake_buf_;
+
+  // While writing, this buffer stores the complete write handshake data.
+  // While reading, it stores the handshake information received so far.
+  std::string buffer_;
+
+  // This becomes true when the SOCKS handshake has completed and the
+  // overlying connection is free to communicate.
+  bool completed_handshake_;
+
+  // Contains the bytes sent by the SOCKS handshake.
+  size_t bytes_sent_;
+
+  size_t read_header_size_;
+
+  bool was_ever_used_;
+
+  SocksEndPointAddressType address_type_;
+  int address_size_;
+
+  std::string user_;
+  std::string pass_;
+  char auth_method_;
+  char auth_status_;
+  char reply_;
+
+  HostPortPair request_endpoint_;
+
+  NetLogWithSource net_log_;
+
+  // Traffic annotation for socket control.
+  const NetworkTrafficAnnotationTag& traffic_annotation_;
+};
+
+}  // namespace net
+#endif  // NET_TOOLS_NAIVE_SOCKS5_SERVER_SOCKET_H_