C++博客-小明思考-随笔分类-Network/ACE

IOCP Tips

小明 — Wed, 12 Mar 2008 03:51:00 GMT

摘要: 使用完成端口的一些基本技巧阅读全文

小明 2008-03-12 11:51 发表评论

多进程服务端实现-共享socket

小明 — Mon, 10 Mar 2008 06:09:00 GMT

摘要: 多进程服务端实现-共享socket 阅读全文

小明 2008-03-10 14:09 发表评论

ACE示例3 - ACE Proactor

小明 — Tue, 19 Jun 2007 08:31:00 GMT

摘要: 阅读全文

小明 2007-06-19 16:31 发表评论

用完成端口写的echo server

小明 — Wed, 06 Jun 2007 09:44:00 GMT

摘要: 阅读全文

小明 2007-06-06 17:44 发表评论

网络包过滤的实现

小明 — Wed, 19 Apr 2006 08:53:00 GMT

最近在使用金山词霸2005,由于金山词霸2005在启动的时候会发一个UDP包到局域网，然后检测是否有相同序列号的金山词霸，如果发现则要求退出。甚为无奈。windows 2000自带有防火墙的功能，但是只有Permit all 和 Permit only两种模式，居然没有Deny only,奇怪。

所以我就查了一下MSDN,发现有Routing and Remote Access Service一类的API可以用。
于是程序的流程就是这样
1.设置临时防火墙，以阻挡发到端口11113的UDP包
2.启动金山词霸
3.删除设置

代码：

#include <stdlib.h>
#include <Iphlpapi.h>
#include <Fltdefs.h>

#pragma comment(lib, "Iphlpapi.lib")

const int XDICT_PORT = 11113;

unsigned long CharToIp(const char *sIp)
{
    int octets[4];
    int i;
    const char * auxCad = sIp;
    unsigned long lIp = 0;

    //we extract each octet of the ip address
    //atoi will get characters until it found a non numeric character(in our case '.')
    for(i = 0; i < 4; i++)
    {
        octets[i] = atoi(auxCad);

        if(octets[i] < 0 || octets[i] > 255)
            return 0;

        lIp |= (octets[i] << (i*8));

        //update auxCad to point to the next octet
        auxCad = strchr(auxCad, '.');

        if(auxCad == NULL && i!=3)
            return -1;

        auxCad++;
    }
    return lIp;
}

int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
    //first get adapter info
    PIP_ADAPTER_INFO pAdapterInfo = NULL,tmp;
    unsigned long len = 0;
     GetAdaptersInfo(pAdapterInfo,&len);
    pAdapterInfo = (PIP_ADAPTER_INFO) malloc (len);
    DWORD result = GetAdaptersInfo(pAdapterInfo, &len);
    if(result!=ERROR_SUCCESS)
    {
        MessageBox(NULL,"Fail to call GetAdaptersInfo","ERROR",MB_OK);
        return -1;
    }

    //create filters interface
    INTERFACE_HANDLE hInterface = NULL;
    result = PfCreateInterface(0,PF_ACTION_FORWARD,PF_ACTION_FORWARD,FALSE,TRUE,&hInterface);
    if(result!=NO_ERROR)
    {
        MessageBox(NULL,"Fail to call PfCreateInterface","ERROR",MB_OK);
        return -1;
    }

    //add the filter to adapter
    unsigned long dmp = 0;
    PF_FILTER_DESCRIPTOR ipFlt;
    ipFlt.dwFilterFlags     = 0;
    ipFlt.dwRule            = 0;
    ipFlt.pfatType          = PF_IPV4;
    ipFlt.dwProtocol        = FILTER_PROTO_UDP;
    ipFlt.fLateBound        = 0;
    ipFlt.wSrcPort          = 0;
    ipFlt.wSrcPortHighRange = 0;
    ipFlt.wDstPort          = XDICT_PORT;
    ipFlt.wDstPortHighRange = XDICT_PORT;
    ipFlt.SrcAddr = (PBYTE)&dmp ;
    ipFlt.SrcMask = (PBYTE)&dmp;
    ipFlt.DstAddr = (PBYTE)&dmp;
    ipFlt.DstMask = (PBYTE)&dmp;

    //bind
    IP_ADDR_STRING *localIp;
    for(tmp=pAdapterInfo;tmp != NULL;tmp=tmp->Next)
    {
            // each ip of a adapter
            for(localIp=&tmp->IpAddressList;localIp!=NULL;localIp=localIp->Next)
            {
                unsigned long ul = CharToIp(localIp->IpAddress.String);
                PBYTE lIp = (PBYTE)&ul;
                PfBindInterfaceToIPAddress(hInterface, PF_IPV4, lIp);
            }
    }

    result = PfAddFiltersToInterface(hInterface,1,&ipFlt,1,&ipFlt,NULL);
    if(result!=NO_ERROR)
    {
        MessageBox(NULL,"Fail to call PfAddFiltersToInterface","ERROR",MB_OK);
        return -1;
    }

    //start XDict
    STARTUPINFO si;
    PROCESS_INFORMATION pi;
    ZeroMemory( &si, sizeof(si) );
    si.cb = sizeof(si);
    ZeroMemory( &pi, sizeof(pi) );
    ::CreateProcess(NULL,"XDICT.exe",
        NULL,             // Process handle not inheritable.
        NULL,             // Thread handle not inheritable.
        FALSE,            // Set handle inheritance to FALSE.
        0,                // No creation flags.
        NULL,             // Use parent's environment block.
        NULL,             // Use parent's starting directory.
        &si,              // Pointer to STARTUPINFO structure.
        &pi );            // Pointer to PROCESS_INFORMATION structure.

    // Wait until child process exits.
    WaitForSingleObject( pi.hProcess, INFINITE );
    // Close process and thread handles.
    CloseHandle( pi.hProcess );
    CloseHandle( pi.hThread );

    //remove filter
    for(tmp=pAdapterInfo;tmp != NULL;tmp=tmp->Next)
    {
        result = PfRemoveFiltersFromInterface(hInterface,1,&ipFlt,1,&ipFlt);
        if(result!=NO_ERROR)
        {
            MessageBox(NULL,"Fail to call PfRemoveFiltersFromInterface","ERROR",MB_OK);
            return -1;
        }
    }
    PfUnBindInterface(hInterface);
    PfDeleteInterface(hInterface);

    //free
    free(pAdapterInfo);
    return 0;
}

使用的API有
GetAdapaterInfo --- 取得网卡的信息，如ip
PfCreateInterface ----Create一个Filter Interface
PfBindInterfaceToIPAddress ----绑定Filter Interface到IP
PfAddFiltersToInterface ----增加Filter到Interface
PfRemoveFiltersFromInterface ---Remove Filter
PfUnBindInterface---取消绑定到ip
PfDeleteInterface---删除Filter Interface

附上可执行文件: http://www.cppblog.com/Files/sandy/XDictWrapper.zip
使用的时候解压放在金山词霸同一个目录就可以了，然后通过这个程序来启动金山词霸。

小明 2006-04-19 16:53 发表评论

[ACE源码分析]ACE_Reactor是如何做到事件分发的

小明 — Thu, 23 Feb 2006 13:28:00 GMT

1. ACE_Reactor的创建
ctor: ACE_Reactor (ACE_Reactor_Impl *implementation = 0, int delete_implementation = 0);
你可以自己创建一个ACE_Reactor
但是大多数时候，我们都是通过调用ACE_Reactor::instance()这个静态方法来返回唯一的实例。

ACE_Reactor *
ACE_Reactor::instance (void)
{
  ACE_TRACE ("ACE_Reactor::instance");

  if (ACE_Reactor::reactor_ == 0) //1
    {
      // Perform Double-Checked Locking Optimization.
      ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon,
                                *ACE_Static_Object_Lock::instance (), 0));

      if (ACE_Reactor::reactor_ == 0) //2
        {
          ACE_NEW_RETURN (ACE_Reactor::reactor_,
                          ACE_Reactor,
                          0);
          ACE_Reactor::delete_reactor_ = 1;
          ACE_REGISTER_FRAMEWORK_COMPONENT(ACE_Reactor, ACE_Reactor::reactor_)
        }
    }
  return ACE_Reactor::reactor_;
}

注意这点使用了双检测的机制(代码1和2)，为了提高效率，不用每次都加锁。

2. Impl手法的运用
ACE_Reactor有个成员变量 ACE_Reactor_Impl *implementation_;
这个implementation_才是真正做事情的东西，典型的Impl手法。
为什么要多一个这个间隔层呢，主要是为了实现跨平台。
因为不同的平台的Reactor差异很大。
在Windows平台，实现这个是ACE_WFMO_Reactor

class ACE_Export ACE_WFMO_Reactor : public ACE_Reactor_Impl

3. Event_Handle的管理
ACE_WFMO_Reactor把要管理的Handle都放在 ACE_WFMO_Reactor_Handler_Repository handler_rep_;
这里要注意的是io_handle和event_handle的区别
io_handle是真正的handle，比如socket_handle, thread_handle
而event_handle是绑定在io_handle上面的事件handle

有代码为证:

1 int
2 ACE_WFMO_Reactor::register_handler_i (ACE_HANDLE event_handle,
3                                       ACE_HANDLE io_handle,
4                                       ACE_Event_Handler *event_handler,
5                                       ACE_Reactor_Mask new_masks)
6 {
7   // If this is a Winsock 1 system, the underlying event assignment will
8   // not work, so don't try. Winsock 1 must use ACE_Select_Reactor for
9   // reacting to socket activity.
10
11   // Make sure that the  is valid
12   if (io_handle == ACE_INVALID_HANDLE)
13     io_handle = event_handler->get_handle ();
14
15   if (this->handler_rep_.invalid_handle (io_handle))
16     {
17       errno = ERROR_INVALID_HANDLE;
18       return -1;
19     }
20
21   long new_network_events = 0;
22   int delete_event = 0;
23   auto_ptr <ACE_Auto_Event> event;
24
25   // Look up the repository to see if the  is already
26   // there.
27   ACE_Reactor_Mask old_masks;
28   int found = this->handler_rep_.modify_network_events_i (io_handle,
29                                                           new_masks,
30                                                           old_masks,
31                                                           new_network_events,
32                                                           event_handle,
33                                                           delete_event,
34                                                           ACE_Reactor::ADD_MASK);
35
36   // Check to see if the user passed us a valid event; If not then we
37   // need to create one
38   if (event_handle == ACE_INVALID_HANDLE)
39     {
40       // Note: don't change this since some C++ compilers have
41       // s that don't work properly
42       auto_ptr<ACE_Auto_Event> tmp (new ACE_Auto_Event);
43       event = tmp;
44       event_handle = event->handle ();
45       delete_event = 1;
46     }
47
48   int result = ::WSAEventSelect ((SOCKET) io_handle,
49                                  event_handle,
50                                  new_network_events);

可以看到在42行create event,在44复制到event_handle,最后通过WSAEventSelect将这个io_handle和event_handle绑定在一起了

这个register_handle调用一般都在Event_Handler的open函数中，实现了注册到Reactor中去。

4. 等待事件
如何检测到要发生的socket的事件呢？比如有新的client连接，收发。ACE并不直接调用select函数来取得。
ACE调用WaitForMultipleObjectsEx来等待事件的发生。ACE这样做的好处是不但可以捕捉socket事件，也可以捕捉到其他事件。前面说过了每一个对应的socket都有一个event_handle与之对应。WaitForMultipleObjectsEx会将发生事件的socket handle的index返回。这样ACE_Reactor就可以利用这个slot来查到io_handle和event_handler( 注意:event_handle和event_handler是不同的)

1 DWORD
2 ACE_WFMO_Reactor::wait_for_multiple_events (int timeout,
3                                             int alertable)
4 {
5   // Wait for any of handles_ to be active, or until timeout expires.
6   // If  is enabled allow asynchronous completion of
7   // ReadFile and WriteFile operations.
8
9   return ::WaitForMultipleObjectsEx (this->handler_rep_.max_handlep1 (),
10                                      this->handler_rep_.handles (),
11                                      FALSE,
12                                      timeout,
13                                      alertable);
14 }

5.分发事件
根据WaitForMultiObjectEx返回的slot就可以查询到event_handler来调用用户的处理函数了

1 int
2 ACE_WFMO_Reactor::complex_dispatch_handler (DWORD slot,
3                                             ACE_HANDLE event_handle)
4 {
5   // This dispatch is used for I/O entires.
6
7   ACE_WFMO_Reactor_Handler_Repository::Current_Info &current_info =
8     this->handler_rep_.current_info ()[slot];
9
10   WSANETWORKEVENTS events;
11   ACE_Reactor_Mask problems = ACE_Event_Handler::NULL_MASK;
12   if (::WSAEnumNetworkEvents ((SOCKET) current_info.io_handle_,
13                               event_handle,
14                               &events) == SOCKET_ERROR)
15     problems = ACE_Event_Handler::ALL_EVENTS_MASK;
16   else
17     {
18       // Prepare for upcalls. Clear the bits from  representing
19       // events the handler is not interested in. If there are any left,
20       // do the upcall(s). upcall will replace events.lNetworkEvents
21       // with bits representing any functions that requested a repeat
22       // callback before checking handles again. In this case, continue
23       // to call back unless the handler is unregistered as a result of
24       // one of the upcalls. The way this is written, the upcalls will
25       // keep being done even if one or more upcalls reported problems.
26       // In practice this may turn out not so good, but let's see. If any
27       // problems, please notify Steve Huston
28       // before or after you change this code.
29       events.lNetworkEvents &= current_info.network_events_;
30       while (events.lNetworkEvents != 0)
31         {
32           ACE_Event_Handler *event_handler =
33             current_info.event_handler_;
34
35           int reference_counting_required =
36             event_handler->reference_counting_policy ().value () ==
37             ACE_Event_Handler::Reference_Counting_Policy::ENABLED;
38
39           // Call add_reference() if needed.
40           if (reference_counting_required)
41             {
42               event_handler->add_reference ();
43             }
44
45           // Upcall
46           problems |= this->upcall (current_info.event_handler_,
47                                     current_info.io_handle_,
48                                     events);
49
50           // Call remove_reference() if needed.
51           if (reference_counting_required)
52             {
53               event_handler->remove_reference ();
54             }
55
56           if (this->handler_rep_.scheduled_for_deletion (slot))
57             break;
58         }
59     }
60
61   if (problems != ACE_Event_Handler::NULL_MASK
62       && !this->handler_rep_.scheduled_for_deletion (slot)  )
63     this->handler_rep_.unbind (event_handle, problems);
64
65   return 0;
66 }

这里值得注意的是ACE通过调用WSAEnumNetworkEvents来重置event_handle。

讲的比较概要，更具体的细节请自己阅读源码。
关于ACE_Reactor的用法请参见前一篇我的示例。

小明 2006-02-23 21:28 发表评论

ACE 示例2 --- Echo Server

小明 — Fri, 17 Feb 2006 07:33:00 GMT

Echo server就是那种提供回显服务的程序，就是收到什么，然后就发送什么的程序。

两种实现方法

1.Per client Per Thread (每个连接每个线程来处理)

这种方式比较简单，易于实现。缺点是如果有大量的连接，必然占用过量的系统资源。

代码:

#ifdef _DEBUG
#pragma comment(lib,"ACED.lib")
#else
#pragma comment(lib,"ACE.lib")
#endif

#include <ace/OS_main.h>
#include <ace/ACE.h>
#include <ace/Log_Msg.h>
#include <ace/SOCK_Acceptor.h>
#include <ace/Thread.h>

DWORD worker(void *arg)
{
    ACE_SOCK_Stream *pStream =(ACE_SOCK_Stream *) arg;

    char buffer[32] = {0};

    int len;

    while( (len = pStream->recv(buffer,sizeof(buffer)-1)) >0)
    {
        if(pStream->send_n(buffer,len)<=0)
        {
            ACE_DEBUG ((LM_DEBUG,
            ACE_TEXT ("(%P|%t) %p\n"),
            ACE_TEXT ("send failed")));
            break;
        }
    }

    ACE_INET_Addr raddr;
    pStream->get_remote_addr(raddr);
    ACE_DEBUG ((LM_DEBUG,ACE_TEXT ("(%P|%t) close:%s %d\n"),raddr.get_host_addr(),raddr.get_port_number()));

    pStream->close();
    delete pStream;
    return 0;
}

int main(int argc, char *argv[])
{
    ACE_INET_Addr addr(1500);
    ACE_SOCK_Acceptor server;

    if(server.open(addr)==-1)
    {
        ACE_DEBUG ((LM_DEBUG,
            ACE_TEXT ("(%P|%t) %p\n"),
            ACE_TEXT ("bind failed")));
        return 1;
    }

    ACE_SOCK_Stream *pStream = 0;
    while((pStream =new ACE_SOCK_Stream()) &&  server.accept(*pStream)!=-1)
    {
        ACE_INET_Addr raddr;
        pStream->get_remote_addr(raddr);
        ACE_DEBUG ((LM_DEBUG,ACE_TEXT ("(%P|%t) connect:%s %d\n"),raddr.get_host_addr(),raddr.get_port_number()));
        ACE_Thread::spawn(worker,pStream);
    }

    server.close();
    return 0;
}

说明:
ACE_Thread用来启动thread，当有client连上来的时候，启动worker thread来处理。

2.事件模型
socket里面是有select机制，ACE也提供了这种方式。
概念:
Event_Handler:有事件来临的时候的处理器
Reactor:事件管理，负责管理Event_Hanlde和分发事件
Acceptor负责连接Event_Handle,Reactor和Sock_Acceptor

代码:

#ifdef _DEBUG
#pragma comment(lib,"ACED.lib")
#else
#pragma comment(lib,"ACE.lib")
#endif

#include <ace/OS_main.h>
#include <ace/ACE.h>
#include <ace/Svc_Handler.h>
#include <ace/Acceptor.h>
#include <ace/Log_Msg.h>
#include <ace/SOCK_Acceptor.h>
#include <ace/Thread.h>

class My_Svc_Handler:
    public ACE_Svc_Handler <ACE_SOCK_STREAM,ACE_NULL_SYNCH>
{
public:
    int open(void*)
    {
        ACE_INET_Addr raddr;
        peer().get_remote_addr(raddr);
        ACE_DEBUG ((LM_DEBUG,ACE_TEXT ("(%P|%t) connect:%s %d %d\n"),raddr.get_host_addr(),raddr.get_port_number(),this));

        reactor()->register_handler(this,ACE_Event_Handler::READ_MASK);
        return 0;
    }

    int handle_input(ACE_HANDLE)
    {
        char buffer[32] = {0};
        int len = peer().recv(buffer,sizeof(buffer)-1);
        if(len>0)
        {
            if(peer().send_n(buffer,len)<=0)
            {
                ACE_DEBUG ((LM_DEBUG,
                    ACE_TEXT ("(%P|%t) %p\n"),
                    ACE_TEXT ("send failed")));
                return -1; //must return -1 to call handle_close
            }
            return 0;
        }
        else
        {
            return -1; //must return -1 to call handle_close
        }
    }

    int handle_close(ACE_HANDLE handle,ACE_Reactor_Mask close_mask)
    {
        ACE_INET_Addr raddr;
        peer().get_remote_addr(raddr);
        ACE_DEBUG ((LM_DEBUG,ACE_TEXT ("(%P|%t) close:%s %d\n"),raddr.get_host_addr(),raddr.get_port_number()));
        peer().close();
        return 0;
    }
};

typedef ACE_Acceptor<My_Svc_Handler,ACE_SOCK_ACCEPTOR> MyAcceptor;
int main(int argc, char *argv[])
{
    ACE_INET_Addr addr(1500);
    MyAcceptor server;

    if(server.open(addr)==-1)
    {
        ACE_DEBUG ((LM_DEBUG,
            ACE_TEXT ("(%P|%t) %p\n"),
            ACE_TEXT ("bind failed")));
        return 1;
    }

    while(1){
        ACE_Reactor::instance()->handle_events();
    }
    server.close();
    return 0;
}

说明：
1.使用ACE_Acceptor模板类来定义自己的Acceptor
2.ACE_Reactor::instance()->handle_events()来实现事件分发
3.在Event_Handle里面使用reactor()->register_handler(this,ACE_Event_Handler::READ_MASK);来注册要关心的事件
4.在Event_Handle中使用peer()来获得Sock_Stream来发送接受数据。

小明 2006-02-17 15:33 发表评论

ACE 示例1 --- Time Server

小明 — Thu, 16 Feb 2006 09:48:00 GMT

摘要: ACE示例1-Time Server 阅读全文

小明 2006-02-16 17:48 发表评论

ACE Beginner

小明 — Thu, 24 Nov 2005 03:28:00 GMT

1.download ACE from: www.cs.wustl.edu/~schmidt/ACE.html

2.build ACE in Visual Studio,generate ACE.lib(dll)[for release] & ACEd.lib(dll)[for debug]

3.create a empty project named: ACETest

4.add ACE path into Project Include Path and add ACE/lib into project lib path

5.create a file(hello.cpp)

#ifdef _DEBUG
#pragma comment(lib,"ACED.lib")
#else
#pragma comment(lib,"ACE.lib")
#endif

#include <ace/OS_main.h>
#include <ace/ACE.h>
#include <ace/Log_Msg.h>
#include <ace/SOCK_Connector.h>

int main(int argc, char *argv[])
{
ACE_INET_Addr addr(1500,"127.0.0.1"); //remote address
ACE_SOCK_Connector con; // connetor for socket client
ACE_SOCK_Stream stream; // stream is for socket read/write

if(con.connect(stream,addr)==-1) //connect to remote address
{
  ACE_DEBUG ((LM_DEBUG,
   ACE_TEXT ("(%P|%t) %p\n"),
   ACE_TEXT ("connection failed")));
  return 1;
}

const char msg[] = "Hello,ACE!";

stream.send_n(msg,sizeof(msg)); // send_n function send exactly n bytes

char buffer[1024] = {0};

if(stream.recv(buffer,sizeof(buffer)-1)==-1) // just call socket recv
{
  ACE_DEBUG ((LM_DEBUG,
   ACE_TEXT ("(%P|%t) %p\n"),
   ACE_TEXT ("recv failed")));
  return 1;
}
ACE_DEBUG ((LM_DEBUG,
  ACE_TEXT ("(%P|%t) recv:%s\n"),
  buffer));

if (stream.close () == -1) //close the connection
{
  ACE_ERROR ((LM_ERROR,
   ACE_TEXT ("(%P|%t) %p\n"),
   ACE_TEXT ("close")));
  return 1;
}

return 0;
}

6.build & execute

小明 2005-11-24 11:28 发表评论