physicalsocketserver.cc

本人收集整理的一份c/c++跨平台网络库

#if defined(_MSC_VER) && _MSC_VER < 1300
#pragma warning(disable:4786)
#endif

#include <cassert>

#ifdef POSIX
extern "C" {
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/time.h>
#include <unistd.h>
}
#endif

#ifdef WIN32
#include <winsock2.h>
#include <ws2tcpip.h>
#define _WINSOCKAPI_
#include <windows.h>
#undef SetPort
#endif

#include <algorithm>
#include <iostream>

#include "basictypes.h"
#include "byteorder.h"
#include "common.h"
#include "logging.h"
#include "physicalsocketserver.h"
#include "time.h"
#include "winping.h"

#ifdef __linux 
#define IP_MTU 14 // Until this is integrated from linux/in.h to netinet/in.h
#endif  // __linux

#ifdef WIN32
class WinsockInitializer {
public:
  WinsockInitializer() {
    WSADATA wsaData;
    WORD wVersionRequested = MAKEWORD(1, 0);
    err_ = WSAStartup(wVersionRequested, &wsaData);
  }
  ~WinsockInitializer() {
    WSACleanup();
  }
  int error() {
    return err_;
  }
private:
  int err_;
};
WinsockInitializer g_winsockinit;
#endif

namespace utils_base {

const int kfRead  = 0x0001;
const int kfWrite = 0x0002;
const int kfConnect = 0x0004;
const int kfClose = 0x0008;

// Standard MTUs
const uint16 PACKET_MAXIMUMS[] = {
  65535,    // Theoretical maximum, Hyperchannel
  32000,    // Nothing
  17914,    // 16Mb IBM Token Ring
  8166,     // IEEE 802.4
  //4464,   // IEEE 802.5 (4Mb max)
  4352,     // FDDI
  //2048,   // Wideband Network
  2002,     // IEEE 802.5 (4Mb recommended)
  //1536,   // Expermental Ethernet Networks
  //1500,   // Ethernet, Point-to-Point (default)
  1492,     // IEEE 802.3
  1006,     // SLIP, ARPANET
  //576,    // X.25 Networks
  //544,    // DEC IP Portal
  //512,    // NETBIOS
  508,      // IEEE 802/Source-Rt Bridge, ARCNET
  296,      // Point-to-Point (low delay)
  68,       // Official minimum
  0,        // End of list marker
};

const uint32 IP_HEADER_SIZE = 20;
const uint32 ICMP_HEADER_SIZE = 8;

class PhysicalSocket : public AsyncSocket {
public:
  PhysicalSocket(PhysicalSocketServer* ss, SOCKET s = INVALID_SOCKET)
    : ss_(ss), s_(s), enabled_events_(0), error_(0),
      state_((s == INVALID_SOCKET) ? CS_CLOSED : CS_CONNECTED) {
    if (s != INVALID_SOCKET)
      enabled_events_ = kfRead | kfWrite;
  }

  virtual ~PhysicalSocket() {
    Close();
  }

  // Creates the underlying OS socket (same as the "socket" function).
  virtual bool Create(int type) {
    Close();
    s_ = ::socket(AF_INET, type, 0);
    UpdateLastError();
    if (type != SOCK_STREAM)
      enabled_events_ = kfRead | kfWrite;
    return s_ != INVALID_SOCKET;
  }

  SocketAddress GetLocalAddress() const {
    sockaddr_in addr;
    socklen_t addrlen = sizeof(addr);
    int result = ::getsockname(s_, (sockaddr*)&addr, &addrlen);
    ASSERT(addrlen == sizeof(addr));
    utils_base::SocketAddress address;
    if (result >= 0) {
      address.FromSockAddr(addr);
    } else {
      ASSERT(result >= 0);
    }
    return address;
  }

  SocketAddress GetRemoteAddress() const {
    sockaddr_in addr;
    socklen_t addrlen = sizeof(addr);
    int result = ::getpeername(s_, (sockaddr*)&addr, &addrlen);
    ASSERT(addrlen == sizeof(addr));
    utils_base::SocketAddress address;
    if (result >= 0) {
      address.FromSockAddr(addr);
    } else {
      ASSERT(errno == ENOTCONN);
    }
    return address;
  }

  int Bind(const SocketAddress& addr) {
    sockaddr_in saddr;
    addr.ToSockAddr(&saddr);
    int err = ::bind(s_, (sockaddr*)&saddr, sizeof(saddr));
    UpdateLastError();
    return err;
  }

  int Connect(const SocketAddress& addr) {
    // TODO: Implicit creation is required to reconnect...
    // ...but should we make it more explicit?
    if ((s_ == INVALID_SOCKET) && !Create(SOCK_STREAM))
      return SOCKET_ERROR;
    SocketAddress addr2(addr);
    if (addr2.IsUnresolved()) {
      LOG(INFO) << "Resolving addr in PhysicalSocket::Connect";
      addr2.Resolve(); // TODO: Do this async later?
    }
    sockaddr_in saddr;
    addr2.ToSockAddr(&saddr);
    int err = ::connect(s_, (sockaddr*)&saddr, sizeof(saddr));
    UpdateLastError();
    //LOG(INFO) << "SOCK[" << static_cast<int>(s_) << "] Connect(" << addr2.ToString() << ") Ret: " << err << " Error: " << error_;
    if (err == 0) {
      state_ = CS_CONNECTED;
    } else if (IsBlockingError(error_)) {
      state_ = CS_CONNECTING;
      enabled_events_ |= kfConnect;
    }
    enabled_events_ |= kfRead | kfWrite;
    return err;
  }

  int GetError() const {
    return error_;
  }

  void SetError(int error) {
    error_ = error;
  }

  ConnState GetState() const {
    return state_;
  }

  int SetOption(Option opt, int value) {
    assert(opt == OPT_DONTFRAGMENT);
#ifdef WIN32
    value = (value == 0) ? 0 : 1;
    return ::setsockopt(
        s_, IPPROTO_IP, IP_DONTFRAGMENT, reinterpret_cast<char*>(&value),
        sizeof(value));
#endif
#ifdef __linux 
    value = (value == 0) ? IP_PMTUDISC_DONT : IP_PMTUDISC_DO;
    return ::setsockopt(
        s_, IPPROTO_IP, IP_MTU_DISCOVER, &value, sizeof(value));
#endif
#ifdef OSX
    // This is not possible on OSX.
    return -1;
#endif
  }

  int Send(const void *pv, size_t cb) {
    int sent = ::send(s_, reinterpret_cast<const char *>(pv), (int)cb, 0);
    UpdateLastError();
    //LOG(INFO) << "SOCK[" << static_cast<int>(s_) << "] Send(" << cb << ") Ret: " << sent << " Error: " << error_;
    ASSERT(sent <= static_cast<int>(cb));  // We have seen minidumps where this may be false
    if ((sent < 0) && IsBlockingError(error_)) {
      enabled_events_ |= kfWrite;
    }
    return sent;
  }

  int SendTo(const void *pv, size_t cb, const SocketAddress& addr) {
    sockaddr_in saddr;
    addr.ToSockAddr(&saddr);
    int sent = ::sendto(
        s_, (const char *)pv, (int)cb, 0, (sockaddr*)&saddr,
        sizeof(saddr));
    UpdateLastError();
    ASSERT(sent <= static_cast<int>(cb));  // We have seen minidumps where this may be false
    if ((sent < 0) && IsBlockingError(error_)) {
      enabled_events_ |= kfWrite;
    }
    return sent;
  }

  int Recv(void *pv, size_t cb) {
    int received = ::recv(s_, (char *)pv, (int)cb, 0);
    if ((received == 0) && (cb != 0)) {
      // Note: on graceful shutdown, recv can return 0.  In this case, we
      // pretend it is blocking, and then signal close, so that simplifying
      // assumptions can be made about Recv.
      error_ = EWOULDBLOCK;
      return SOCKET_ERROR;
    }
    UpdateLastError();
    if ((received >= 0) || IsBlockingError(error_)) {
      enabled_events_ |= kfRead;
    }
    return received;
  }

  int RecvFrom(void *pv, size_t cb, SocketAddress *paddr) {
    sockaddr_in saddr;
    socklen_t cbAddr = sizeof(saddr);
    int received = ::recvfrom(s_, (char *)pv, (int)cb, 0, (sockaddr*)&saddr,
                              &cbAddr);
    UpdateLastError();
    if ((received >= 0) && (paddr != NULL))
      paddr->FromSockAddr(saddr);
    if ((received >= 0) || IsBlockingError(error_)) {
      enabled_events_ |= kfRead;
    }
    return received;
  }

  int Listen(int backlog) {
    int err = ::listen(s_, backlog);
    UpdateLastError();
    if (err == 0)
      state_ = CS_CONNECTING;
    enabled_events_ |= kfRead;

    return err;
  }

  Socket* Accept(SocketAddress *paddr) {
    sockaddr_in saddr;
    socklen_t cbAddr = sizeof(saddr);
    SOCKET s = ::accept(s_, (sockaddr*)&saddr, &cbAddr);
    UpdateLastError();
    if (s == INVALID_SOCKET)
      return NULL;
    if (paddr != NULL)
      paddr->FromSockAddr(saddr);
    enabled_events_ |= kfRead | kfWrite;
    return ss_->WrapSocket(s);
  }

  int Close() {
    if (s_ == INVALID_SOCKET)
      return 0;
    int err = ::closesocket(s_);
    UpdateLastError();
    //LOG(INFO) << "SOCK[" << static_cast<int>(s_) << "] Close() Ret: " << err << " Error: " << error_;
    s_ = INVALID_SOCKET;
    state_ = CS_CLOSED;
    enabled_events_ = 0;
    return err;
  }

  int EstimateMTU(uint16* mtu) {
    SocketAddress addr = GetRemoteAddress();
    if (addr.IsAny()) {
      error_ = ENOTCONN;
      return -1;
    }

#ifdef WIN32

    WinPing ping;
    if (!ping.IsValid()) {
      error_ = EINVAL; // can't think of a better error ID
      return -1;
    }

    for (int level = 0; PACKET_MAXIMUMS[level + 1] > 0; ++level) {
      int32 size = PACKET_MAXIMUMS[level] - IP_HEADER_SIZE - ICMP_HEADER_SIZE;
      WinPing::PingResult result = ping.Ping(addr.ip(), size, 0, 1, false);
      if (result == WinPing::PING_FAIL) {
        error_ = EINVAL; // can't think of a better error ID
        return -1;
      }
      if (result != WinPing::PING_TOO_LARGE) {
        *mtu = PACKET_MAXIMUMS[level];
        return 0;
      }
    }

    assert(false);
    return 0;

#endif // WIN32

#ifdef __linux 

    int value;
    socklen_t vlen = sizeof(value);
    int err = getsockopt(s_, IPPROTO_IP, IP_MTU, &value, &vlen);
    if (err < 0) {
      UpdateLastError();
      return err;
    }

    assert((0 <= value) && (value <= 65536));
    *mtu = uint16(value);
    return 0;

#endif   // __linux

    // TODO: OSX support
  }

  SocketServer* socketserver() { return ss_; }
 
protected:
  PhysicalSocketServer* ss_;
  SOCKET s_;
  uint32 enabled_events_;
  int error_;
  ConnState state_;

  void UpdateLastError() {
#ifdef WIN32
    error_ = WSAGetLastError();
#endif
#ifdef POSIX
    error_ = errno;
#endif
  }
};

#ifdef POSIX
class Dispatcher {
public:
  virtual uint32 GetRequestedEvents() = 0;
  virtual void OnPreEvent(uint32 ff) = 0;    
  virtual void OnEvent(uint32 ff, int err) = 0;
  virtual int GetDescriptor() = 0;
};

class EventDispatcher : public Dispatcher {
public:
  EventDispatcher(PhysicalSocketServer* ss) : ss_(ss), fSignaled_(false) {
    if (pipe(afd_) < 0)
      LOG(LERROR) << "pipe failed";
    ss_->Add(this);
  }

  virtual ~EventDispatcher() {
    ss_->Remove(this);
    close(afd_[0]);
    close(afd_[1]);
  }
  
  virtual void Signal() {
    CritScope cs(&crit_);
    if (!fSignaled_) {
      uint8 b = 0;
      if (write(afd_[1], &b, sizeof(b)) < 0)
        LOG(LERROR) << "write failed";
      fSignaled_ = true;
    }
  }
  
  virtual uint32 GetRequestedEvents() {
    return kfRead;
  }

  virtual void OnPreEvent(uint32 ff) {
    // It is not possible to perfectly emulate an auto-resetting event with
    // pipes.  This simulates it by resetting before the event is handled.
  
    CritScope cs(&crit_);
    if (fSignaled_) {
      uint8 b;
      read(afd_[0], &b, sizeof(b));
      fSignaled_ = false;
    }
  }

  virtual void OnEvent(uint32 ff, int err) {
    assert(false);
  }

  virtual int GetDescriptor() {
    return afd_[0];
  }

private:
  PhysicalSocketServer *ss_;
  int afd_[2];
  bool fSignaled_;
  CriticalSection crit_;
};

class SocketDispatcher : public Dispatcher, public PhysicalSocket {
public:
  SocketDispatcher(PhysicalSocketServer *ss) : PhysicalSocket(ss) {
    ss_->Add(this);
  }
  SocketDispatcher(SOCKET s, PhysicalSocketServer *ss) : PhysicalSocket(ss, s) {
    ss_->Add(this);
  }

  virtual ~SocketDispatcher() {
    Close();
  }

  bool Initialize() {
    ss_->Add(this);
    fcntl(s_, F_SETFL, fcntl(s_, F_GETFL, 0) | O_NONBLOCK);
    return true;
  }

  virtual bool Create(int type) {
    // Change the socket to be non-blocking.
    if (!PhysicalSocket::Create(type))
      return false;

    return Initialize();
  }
  
  virtual int GetDescriptor() {
    return s_;
  }

  virtual uint32 GetRequestedEvents() {
    return enabled_events_;
  }

  virtual void OnPreEvent(uint32 ff) {
    if ((ff & kfConnect) != 0)
      state_ = CS_CONNECTED;
  }

  virtual void OnEvent(uint32 ff, int err) {
    if ((ff & kfRead) != 0) {
      enabled_events_ &= ~kfRead;
      SignalReadEvent(this);
    }
    if ((ff & kfWrite) != 0) {
      enabled_events_ &= ~kfWrite;
      SignalWriteEvent(this);
    }
    if ((ff & kfConnect) != 0) {
      enabled_events_ &= ~kfConnect;
      SignalConnectEvent(this);
    }
    if ((ff & kfClose) != 0)
      SignalCloseEvent(this, err);
  }

  virtual int Close() {
    if (s_ == INVALID_SOCKET)
      return 0;

    ss_->Remove(this);
    return PhysicalSocket::Close();
  }
    
};

class FileDispatcher: public Dispatcher, public AsyncFile {
public:
  FileDispatcher(int fd, PhysicalSocketServer *ss) : ss_(ss), fd_(fd) {
    set_readable(true);

    ss_->Add(this);

    fcntl(fd_, F_SETFL, fcntl(fd_, F_GETFL, 0) | O_NONBLOCK);
  }

  virtual ~FileDispatcher() {
    ss_->Remove(this);
  }

  SocketServer* socketserver() { return ss_; }

  virtual int GetDescriptor() {
    return fd_;
  }

  virtual uint32 GetRequestedEvents() {
    return flags_;
  }

  virtual void OnPreEvent(uint32 ff) {
  }

  virtual void OnEvent(uint32 ff, int err) {
    if ((ff & kfRead) != 0)
      SignalReadEvent(this);
    if ((ff & kfWrite) != 0)
      SignalWriteEvent(this);
    if ((ff & kfClose) != 0)
      SignalCloseEvent(this, err);
  }

  virtual bool readable() {
    return (flags_ & kfRead) != 0;
  }

  virtual void set_readable(bool value) {
    flags_ = value ? (flags_ | kfRead) : (flags_ & ~kfRead);
  }

  virtual bool writable() {
    return (flags_ & kfWrite) != 0;
  }

  virtual void set_writable(bool value) {
    flags_ = value ? (flags_ | kfWrite) : (flags_ & ~kfWrite);
  }

private:
  PhysicalSocketServer* ss_;