Web2socket proxy.

net/web2socket_proxy/web2socket_conn.h

+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_WEB2SOCKET_PROXY_WEB2SOCKET_CONN_H_
+#define CHROME_WEB2SOCKET_PROXY_WEB2SOCKET_CONN_H_
+
+#include <sys/socket.h>
+
+#include "base/md5.h"
+#include "net/web2socket_proxy/web2socket_serv.h"
+#include "third_party/libevent/event.h"
+
+class Conn {
+ public:
+  Web2SocketServ* master_;
+
+  enum Phase {
+    // Initial stage of connection.
+    PHASE_WAIT_HANDSHAKE,
+    PHASE_WAIT_DESTFRAME,
+    PHASE_WAIT_DESTCONNECT,
+
+    // Operational stage of connection.
+    PHASE_OUTSIDE_FRAME,
+    PHASE_INSIDE_FRAME_BASE64,
+    PHASE_INSIDE_FRAME_SKIP,
+
+    // Terminal stage of connection.
+    PHASE_SHUT, // Closing handshake was emitted, buffers may pending.
+    PHASE_DEFUNCT // Connection was nuked.
+  } phase_;
+
+  // We maintain two channels per Conn:
+  // primary channel is websocket connection,
+  // destination channel is a proxied connection.
+  class Chan {
+   public:
+    int sock_;
+    struct bufferevent* bev_;
+
+    Chan() : sock_(-1), bev_(NULL) {}
+
+    ~Chan() {
+      if (bev_) {
+        bufferevent_disable(bev_, EV_READ | EV_WRITE);
+        bufferevent_free(bev_);
+        bev_ = NULL;
+      }
+      if (sock_ >= 0) {
+        shutdown(sock_, SHUT_RDWR);
+        close(sock_);
+        sock_ = -1;
+      }
+    }
+  } primchan_, destchan_;
+
+  // Unfortunately evdns callbacks are uncancellable,
+  // so potentially we can receive callback for a deleted Conn.
+  // Even worse, storage of deleted Conn may be reused
+  // for a new connection and new connection can receive callback
+  // destined for deleted Conn.
+  // Conn::Token is introduced in order to prevent that.
+  typedef void* Token;
+  Token token_;
+  typedef std::map<Token, Conn*> TokenMap;
+  static TokenMap token_map_;
+  static Token last_token_;
+  static Conn* Get(Token token);
+
+  // Header fields supplied by client at initial websocket handshake.
+  std::map<std::string, std::string> header_fields_;
+
+  // Cryptohashed answer for websocket handshake.
+  MD5Digest handshake_response_;
+
+  // Hostname and port of destination socket.
+  // Websocket client supplies them in first data frame (destframe).
+  std::string destname_;
+  uint32_t destport_;
+
+  // We try to DNS resolve hostname in both IPv4 and IPv6 domains.
+  // Track resolution failures here.
+  bool destresolution_ipv4_failure_;
+  bool destresolution_ipv6_failure_;
+
+  // Used to schedule a timeout for an initial phase of connection.
+  struct event destconnect_timeout_event_;
+
+  explicit Conn(Web2SocketServ* master);
+  ~Conn();
+
+  enum Status {
+    STATUS_OK,
+    STATUS_INCOMPLETE,
+    STATUS_SKIP,
+    STATUS_ABORT
+  };
+
+  void Shut();
+  Status ConsumeHeader(struct evbuffer*);
+  Status ConsumeDestframe(struct evbuffer*);
+  Status ConsumeFrameHeader(struct evbuffer*);
+  Status ProcessFrameData(struct evbuffer*);
+
+  // return true on success.
+  bool EmitHandshake(struct bufferevent*);
+  bool TryConnectDest(const struct sockaddr*, socklen_t);
+
+  static void OnDestConnectTimeout(int, short, Token);
+  static void OnPrimchanRead(struct bufferevent*, Token);
+  static void OnPrimchanWrite(struct bufferevent*, Token);
+  static void OnPrimchanError(struct bufferevent*, short what, Token);
+  static void OnDestResolutionIPv4(int result, char type, int count,
+                                   int ttl, void* addr_list, Token);
+  static void OnDestResolutionIPv6(int result, char type, int count,
+                                   int ttl, void* addr_list, Token);
+  static void OnDestchanRead(struct bufferevent*, Token);
+  static void OnDestchanWrite(struct bufferevent*, Token);
+  static void OnDestchanError(struct bufferevent*, short what, Token);
+
+  DISALLOW_COPY_AND_ASSIGN(Conn);
+};
+
+#endif  // CHROME_WEB2SOCKET_PROXY_WEB2SOCKET_CONN_H_