Forwarder 2 implementation

tools/android/forwarder2/socket.h

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef TOOLS_ANDROID_FORWARDER2_SOCKET_H_
+#define TOOLS_ANDROID_FORWARDER2_SOCKET_H_
+
+#include <fcntl.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include <string>
+
+#include "base/basictypes.h"
+
+namespace forwarder2 {
+
+// Wrapper class around unix socket api.  Can be used to create, bind or
+// connect to both Unix domain sockets and TCP sockets.
+class Socket {
+ public:
+  Socket();
+  ~Socket();
+
+  bool BindUnix(const std::string& path, bool abstract);
+  bool BindTcp(const std::string& host, int port);
+  bool ConnectUnix(const std::string& path, bool abstract);
+  bool ConnectTcp(const std::string& host, int port);
+
+  // Just a wrapper around unix socket shutdown(), see man 2 shutdown.
+  void Shutdown();
+
+  // Just a wrapper around unix socket close(), see man 2 close.
+  void Close();
+  bool IsClosed() const { return socket_ < 0; }
+
+  bool Accept(Socket* new_socket);
+
+  bool IsFdInSet(const fd_set& fds) const;
+  bool AddFdToSet(fd_set* fds) const;
+
+  // Just a wrapper around unix read() function.
+  // Reads up to buffer_size, but may read less then buffer_size.
+  // Returns the number of bytes read.
+  int Read(char* buffer, size_t buffer_size);
+
+  // Same as Read(), just a wrapper around write().
+  int Write(const char* buffer, size_t count);
+
+  // Calls Read() multiple times until num_bytes is written to the provided
+  // buffer. No bounds checking is performed.
+  // Returns number of bytes read, which can be different from num_bytes in case
+  // of errror.
+  int ReadNumBytes(char* buffer, size_t num_bytes);
+
+  // Calls Write() multiple times until num_bytes is written. No bounds checking
+  // is performed. Returns number of bytes written, which can be different from
+  // num_bytes in case of errror.
+  int WriteNumBytes(const char* buffer, size_t num_bytes);
+
+  // Calls WriteNumBytes for the given std::string.
+  int WriteString(const std::string& buffer);
+
+  bool has_error() const { return socket_error_; }
+
+  // |notifier_fd| must be a valid pipe file descriptor created from the
+  // PipeNotifier and must live (not be closed) at least as long as this socket
+  // is alive.
+  void set_notifier_fd(int notifier_fd) { exit_notifier_fd_ = notifier_fd; }
+  // Unset the |exit_notifier_fd_| so that it will not receive notifications
+  // anymore.
+  void reset_notifier_fd() { exit_notifier_fd_ = -1; }
+
+  static int GetHighestFileDescriptor(const Socket& s1, const Socket& s2);
+
+ private:
+  union SockAddr {
+    // IPv4 sockaddr
+    sockaddr_in addr4;
+    // IPv6 sockaddr
+    sockaddr_in6 addr6;
+    // Unix Domain sockaddr
+    sockaddr_un addr_un;
+  };
+
+  // If |host| is empty, use localhost.
+  bool InitTcpSocket(const std::string& host, int port);
+  bool InitUnixSocket(const std::string& path, bool abstract);
+  bool BindAndListen();
+  bool Connect();
+
+  bool Resolve(const std::string& host);
+  bool InitSocketInternal();
+  void SetSocketError();
+
+  // Waits until either the Socket or the |exit_notifier_fd_| has received a
+  // read event (accept or read). Returns false iff an exit notification was
+  // received.
+  bool WaitForEvent() const;
+
+  int socket_;
+  int port_;
+  bool socket_error_;
+
+  // Family of the socket (IF_INET, IF_INET6 or PF_UNIX).

[digit, 2012/09/07 13:47:12]

Nit: IF_INET/IF_INET6 do not exist, you probably mean PF_INET/PF_INET6 which are
the values expected by the socket() call, even though most code uses the
equivalent AF_INET/AF_INET6 values.

In theory, PF_XX is for socket/protocols, and AF_XX is for address families,
it's all confusing isn't it :-)

[felipeg, 2012/09/07 13:56:57]

Done.

+  int family_;
+
+  // True if this is an abstract unix domain socket.
+  bool abstract_;
+
+  SockAddr addr_;
+
+  // Points to one of the members of the above union depending on the family.
+  sockaddr* addr_ptr_;
+  // Length of one of the members of the above union depending on the family.
+  socklen_t addr_len_;
+
+  // File descriptor from PipeNotifier (see pipe_notifier.h) to send application
+  // exit notifications before calling socket blocking operations such as Read
+  // and Accept.
+  int exit_notifier_fd_;
+
+  DISALLOW_COPY_AND_ASSIGN(Socket);
+};
+
+}  // namespace forwarder
+
+#endif  // TOOLS_ANDROID_FORWARDER2_SOCKET_H_