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修改tcpip.sys,破除winxp�?0个网�l�连接限�?�?

CPP&&设计模式��屋 — Sun, 25 Feb 2007 06:29:00 GMT

摘要: 修改tcpip.sys,破除winxp�?0个网�l�连接限�?nbsp; 阅读全文

CPP&&设计模式��屋 2007-02-25 14:29 发表评论

CPP&&设计模式��屋 — Fri, 19 Jan 2007 08:44:00 GMT

摘要: 转脓自：http://blog.csdn.net/dylgsy/查找了很多资料都找不到select模型的详�l�用法，《Windows�|�络�~�程》这本书上也只是写了一个简单的回应服务器，��p��writefds的用法都没讲�Q�也不知道什么时候利用“可写”来发文件。这些都是我的疑问，�怿�很多研究�|�络�~�程的同路�h也碰��C��我的�q�些问题。这些疑问在�q�篇文章中都解决了！耗费了偶很多的精力去猜测��L��考！感觉一�?.. 阅读全文

CPP&&设计模式��屋 2007-01-19 16:44 发表评论

微��Yping�E�序源代码完整版(�?

CPP&&设计模式��屋 — Fri, 05 Jan 2007 05:46:00 GMT

作�?侯志�?/p>

�~�写自己的一个ping�E�序,可以说是许多��出网�l�编�E�的�W�一步吧!!�q�个ping�E�序的源代码�l�过我的修改和调�?基本上可以取代windows中自带的ping�E�序. 各个模块后都有我的详�l�注释和修改日志,希望能够对大家的学习有所帮助!!

/* 本程序的主要源代码来自MSDN�|�站, �W�者只是做了一些改�q�和注释! 另外需要注意的是在Build之前,必须加入ws2_32.lib库文�?否则会提�C?error LNK2001:"的错误！*/

/******************************************************************************\
| Version 1.1 修改记录:                                                                                                              |
|    <1> 解决了socket��d��的问�?从而能够正��地处理��时的请�?                                                        |
|----------------------------------------------------------------------------------------------------|
| Version 1.2 修改记录:                                                                                                              |
|    <1> 增加了由用户控制发送ICMP包的数目的功�?卛_��令的�W�二个参�?.                                              |
|    <2> 增加了对ping�l�果的统计功�?                                                                                           |
\******************************************************************************/

#pragma pack(4)

#include
#include
#include

#define ICMP_ECHO 8
#define ICMP_ECHOREPLY 0

#define ICMP_MIN 8 // minimum 8 byte icmp packet (just header)

/* The IP header */
typedef struct iphdr {
unsigned int h_len:4; // length of the header
unsigned int version:4; // Version of IP
unsigned char tos; // Type of service
unsigned short total_len; // total length of the packet
unsigned short ident; // unique identifier
unsigned short frag_and_flags; // flags
unsigned char ttl;
unsigned char proto; // protocol (TCP, UDP etc)
unsigned short checksum; // IP checksum

unsigned int sourceIP;
unsigned int destIP;

}IpHeader;

//
// ICMP header
//
typedef struct icmphdr {
BYTE i_type;
BYTE i_code; /* type sub code */
USHORT i_cksum;
USHORT i_id;
USHORT i_seq;
/* This is not the std header, but we reserve space for time */
ULONG timestamp;
}IcmpHeader;

#define STATUS_FAILED 0xFFFF
#define DEF_PACKET_SIZE 32
#define DEF_PACKET_NUMBER 4 /* 发送数据报的个�?*/
#define MAX_PACKET 1024

#define xmalloc(s) HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY,(s))
#define xfree(p) HeapFree (GetProcessHeap(),0,(p))

void fill_icmp_data(char *, int);
USHORT checksum(USHORT *, int);
int decode_resp(char *,int ,struct sockaddr_in *);

void Usage(char *progname){

fprintf(stderr,"Usage:\n");
fprintf(stderr,"%s [number of packets] [data_size]\n",progname);
fprintf(stderr,"datasize can be up to 1Kb\n");
ExitProcess(STATUS_FAILED);

}
int main(int argc, char **argv){

WSADATA wsaData;
SOCKET sockRaw;
struct sockaddr_in dest,from;
struct hostent * hp;
int bread,datasize,times;
int fromlen = sizeof(from);
int timeout = 1000;
int statistic = 0; /* 用于�l�计�l�果 */
char *dest_ip;
char *icmp_data;
char *recvbuf;
unsigned int addr=0;
USHORT seq_no = 0;

if (WSAStartup(MAKEWORD(2,1),&wsaData) != 0){
fprintf(stderr,"WSAStartup failed: %d\n",GetLastError());
ExitProcess(STATUS_FAILED);
}

if (argc <2 ) {
Usage(argv[0]);
}
sockRaw = WSASocket(AF_INET,SOCK_RAW,IPPROTO_ICMP,NULL, 0,WSA_FLAG_OVERLAPPED);

//
//注：��Z��使用发送接收超时设�|?卌��|�SO_RCVTIMEO, SO_SNDTIMEO)�Q?
// 必须��标志位设�ؓWSA_FLAG_OVERLAPPED !
//

if (sockRaw == INVALID_SOCKET) {
fprintf(stderr,"WSASocket() failed: %d\n",WSAGetLastError());
ExitProcess(STATUS_FAILED);
}
bread = setsockopt(sockRaw,SOL_SOCKET,SO_RCVTIMEO,(char*)&timeout,
sizeof(timeout));
if(bread == SOCKET_ERROR) {
fprintf(stderr,"failed to set recv timeout: %d\n",WSAGetLastError());
ExitProcess(STATUS_FAILED);
}
timeout = 1000;
bread = setsockopt(sockRaw,SOL_SOCKET,SO_SNDTIMEO,(char*)&timeout,
sizeof(timeout));
if(bread == SOCKET_ERROR) {
fprintf(stderr,"failed to set send timeout: %d\n",WSAGetLastError());
ExitProcess(STATUS_FAILED);
}
memset(&dest,0,sizeof(dest));

hp = gethostbyname(argv[1]);

if (!hp){
addr = inet_addr(argv[1]);
}
if ((!hp) && (addr == INADDR_NONE) ) {
fprintf(stderr,"Unable to resolve %s\n",argv[1]);
ExitProcess(STATUS_FAILED);
}

if (hp != NULL)
memcpy(&(dest.sin_addr),hp->h_addr,hp->h_length);
else
dest.sin_addr.s_addr = addr;

if (hp)
dest.sin_family = hp->h_addrtype;
else
dest.sin_family = AF_INET;

dest_ip = inet_ntoa(dest.sin_addr);

//
// atoi函数原型�? int atoi( const char *string );
// The return value is 0 if the input cannot be converted to an integer !
//
if(argc>2)
{
times=atoi(argv[2]);
if(times == 0)
times=DEF_PACKET_NUMBER;
}
else
times=DEF_PACKET_NUMBER;

if (argc >3)
{
datasize = atoi(argv[3]);
    if (datasize == 0)
        datasize = DEF_PACKET_SIZE;
if (datasize >1024)   /* 用户�l�出的数据包大小太大 */
{
fprintf(stderr,"WARNING : data_size is too large !\n");
datasize = DEF_PACKET_SIZE;
}
}
else
    datasize = DEF_PACKET_SIZE;

datasize += sizeof(IcmpHeader);

icmp_data = (char*)xmalloc(MAX_PACKET);
recvbuf = (char*)xmalloc(MAX_PACKET);

if (!icmp_data) {
fprintf(stderr,"HeapAlloc failed %d\n",GetLastError());
ExitProcess(STATUS_FAILED);
}

memset(icmp_data,0,MAX_PACKET);
fill_icmp_data(icmp_data,datasize);

//
//昄��提示信息
//
fprintf(stdout,"\nPinging %s ....\n\n",dest_ip);

for(int i=0;i{
int bwrote;

((IcmpHeader*)icmp_data)->i_cksum = 0;
((IcmpHeader*)icmp_data)->timestamp = GetTickCount();

((IcmpHeader*)icmp_data)->i_seq = seq_no++;
((IcmpHeader*)icmp_data)->i_cksum = checksum((USHORT*)icmp_data,datasize);

bwrote = sendto(sockRaw,icmp_data,datasize,0,(struct sockaddr*)&dest,sizeof(dest));
if (bwrote == SOCKET_ERROR){
if (WSAGetLastError() == WSAETIMEDOUT) {
printf("Request timed out.\n");
continue;
}
fprintf(stderr,"sendto failed: %d\n",WSAGetLastError());
ExitProcess(STATUS_FAILED);
}
if (bwrote < datasize ) {
fprintf(stdout,"Wrote %d bytes\n",bwrote);
}
bread = recvfrom(sockRaw,recvbuf,MAX_PACKET,0,(struct sockaddr*)&from,&fromlen);
if (bread == SOCKET_ERROR){
if (WSAGetLastError() == WSAETIMEDOUT) {
printf("Request timed out.\n");
continue;
}
fprintf(stderr,"recvfrom failed: %d\n",WSAGetLastError());
ExitProcess(STATUS_FAILED);
}
if(!decode_resp(recvbuf,bread,&from))
statistic++; /* 成功接收的数�?+ */
Sleep(1000);

}

/*
Display the statistic result
*/
fprintf(stdout,"\nPing statistics for %s \n",dest_ip);
fprintf(stdout," Packets: Sent = %d,Received = %d, Lost = %d (%2.0f%% loss)\n",times,
statistic,(times-statistic),(float)(times-statistic)/times*100);

WSACleanup();
return 0;

}
/*
The response is an IP packet. We must decode the IP header to locate
the ICMP data
*/
int decode_resp(char *buf, int bytes,struct sockaddr_in *from) {

IpHeader *iphdr;
IcmpHeader *icmphdr;
unsigned short iphdrlen;

iphdr = (IpHeader *)buf;

iphdrlen = (iphdr->h_len) * 4 ; // number of 32-bit words *4 = bytes

if (bytes < iphdrlen + ICMP_MIN) {
printf("Too few bytes from %s\n",inet_ntoa(from->sin_addr));
}

icmphdr = (IcmpHeader*)(buf + iphdrlen);

if (icmphdr->i_type != ICMP_ECHOREPLY) {
fprintf(stderr,"non-echo type %d recvd\n",icmphdr->i_type);
return 1;
}
if (icmphdr->i_id != (USHORT)GetCurrentProcessId()) {
fprintf(stderr,"someone else's packet!\n");
return 1;
}
printf("%d bytes from %s:",bytes, inet_ntoa(from->sin_addr));
printf(" icmp_seq = %d. ",icmphdr->i_seq);
printf(" time: %d ms ",GetTickCount()-icmphdr->timestamp);
printf("\n");
return 0;

}

USHORT checksum(USHORT *buffer, int size) {

unsigned long cksum=0;

while(size >1) {
cksum+=*buffer++;
size -=sizeof(USHORT);
}

if(size) {
cksum += *(UCHAR*)buffer;
}

cksum = (cksum >> 16) + (cksum & 0xffff);
cksum += (cksum >>16);
return (USHORT)(~cksum);
}
/*
Helper function to fill in various stuff in our ICMP request.
*/
void fill_icmp_data(char * icmp_data, int datasize){

IcmpHeader *icmp_hdr;
char *datapart;

icmp_hdr = (IcmpHeader*)icmp_data;

icmp_hdr->i_type = ICMP_ECHO;
icmp_hdr->i_code = 0;
icmp_hdr->i_id = (USHORT)GetCurrentProcessId();
icmp_hdr->i_cksum = 0;
icmp_hdr->i_seq = 0;

datapart = icmp_data + sizeof(IcmpHeader);
//
// Place some junk in the buffer.
//
memset(datapart,'E', datasize - sizeof(IcmpHeader));

}

/******************* �? ping命��o执行时显�C�的画面 ***************\
* C:\Documents and Settings\houzhijiang>ping 236.56.54.12               *
*                                                                                                      *
* Pinging 236.56.54.12 with 32 bytes of data:                                      *
*                                                                                                      *
* Request timed out.                                                                         *
* Request timed out.                                                                         *
* Request timed out.                                                                         *
* Request timed out.                                                                         *
*                                                                                                      *
* Ping statistics for 236.56.54.12:                                                      *
*     Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),                  *
*                                                                                                      *
\*********************************************************/

/*********************************************************\
* C:\Documents and Settings\houzhijiang>ping 127.0.0.1                    *
*                                                                                                     *
* Pinging 127.0.0.1 with 32 bytes of data:                                          *
*                                                                                                     *
* Reply from 127.0.0.1: bytes=32 time<1ms TTL=128                        *
* Reply from 127.0.0.1: bytes=32 time<1ms TTL=128                        *
* Reply from 127.0.0.1: bytes=32 time<1ms TTL=128                        *
* Reply from 127.0.0.1: bytes=32 time<1ms TTL=128                        *
*                                                                                                     *
* Ping statistics for 127.0.0.1:                                                          *
*     Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),                    *
* Approximate round trip times in milli-seconds:                                 *
*     Minimum = 0ms, Maximum = 0ms, Average = 0ms                        *
*                                                                                                    *
\********************************************************/

CPP&&设计模式��屋 2007-01-05 13:46 发表评论

CPP&&设计模式��屋 — Thu, 04 Jan 2007 05:37:00 GMT

P2P之UDP�I�K��NAT的原理与实现�Q�附源代码）

作者：shootingstars | 日期�Q?span id="TimeLabel">2004-05-25 | 字体�Q?a href="javascript:ContentSize(16)">�?/a>�?/a>��?/a>

P2P �?UDP�I�K��NAT的原理与实现�Q�附源代码）
原创�Q�shootingstars
参考：http://midcom-p2p.sourceforge.net/draft-ford-midcom-p2p-01.txt

论坛上经常有对P2P原理的讨论，但是讨论归讨论，很少有实质的东西产生�Q�源代码�Q�。呵呵，在这里我��q��自己实现的一个源代码来说明UDP�I�越NAT的原理�?/p>

首先先介�l�一些基本概念：
    NAT(Network Address Translators)�Q�网�l�地址转换�Q�网�l�地址转换是在IP地址日益�~�Z��的情况下产生的，它的主要目的��是��Z��能够地址重用。NAT分�ؓ两大�c�，基本的NAT和NAPT(Network Address/Port Translator)�?br />    最开始NAT是运行在路由器上的一个功能模块�?br />
    最先提出的是基本的NAT�Q�它的��生基于如下事实：一个私有网�l�（域）中的节点中只有很��的节点需要与外网�q�接�Q�呵呵，�q�是在上世纪90�q�代中期提出的）。那么这个子�|�中其实只有��数的节炚w��要全球唯一的IP地址�Q�其他的节点的IP地址应该是可以重用的�?br />    因此�Q�基本的NAT实现的功能很��单，在子�|�内使用一个保留的IP子网�D�，�q�些IP对外是不可见的。子�|�内只有��数一些IP地址可以对应到真正全球唯一的IP地址。如果这些节炚w��要访问外部网�l�，那么基本NAT��p��责将�q�个节点的子�|�内IP转化��Z��个全球唯一的IP然后发送出厅R�?基本的NAT会改变IP包中的原IP地址�Q�但是不会改变IP包中的端�?
    关于基本的NAT可以参看RFC 1631

    另外一�U�NAT叫做NAPT�Q�从名称上我们也可以看得出，NAPT不但会改变经�q�这个NAT讑֤�的IP数据报的IP地址�Q�还会改变IP数据报的TCP/UDP端口。基本NAT的设备可能我们见的不多（呵呵�Q�我没有见到�q�）�Q�NAPT才是我们真正讨论的主角。看下图�Q?br />                                Server S1
                         18.181.0.31:1235
                                      |
          ^ Session 1 (A-S1) ^      |
          | 18.181.0.31:1235 |      |
          v 155.99.25.11:62000 v      |
                                      |
                                     NAT
                                 155.99.25.11
                                      |
          ^ Session 1 (A-S1) ^      |
          | 18.181.0.31:1235 |      |
          v   10.0.0.1:1234    v      |
                                      |
                                   Client A
                                10.0.0.1:1234
    有一个私有网�l?0.*.*.*�Q�Client A是其中的一台计��机�Q�这个网�l�的�|�关�Q�一个NAT讑֤��Q�的外网IP�?55.99.25.11(应该�q�有一个内�|�的IP地址�Q�比�?0.0.0.10)。如果Client A中的某个�q�程�Q�这个进�E�创��Z��一个UDP Socket,�q�个Socket�l�定1234端口�Q�想讉K��外网��L��18.181.0.31�?235端口�Q�那么当数据包通过NAT时会发生什么事情呢�Q?br />    首先NAT会改变这个数据包的原IP地址�Q�改�?55.99.25.11。接着NAT会�ؓ�q�个传输创徏一个Session�Q�Session是一个抽象的概念�Q�如果是TCP�Q�也许Session是由一个SYN包开始，以一个FIN包结束。而UDP呢，以这个IP的这个端口的�W�一个UDP开始，�l�束呢，呵呵�Q�也许是几分钟，也许是几��时�Q�这要看具体的实��C��Q��ƈ且给�q�个Session分配一个端口，比如62000�Q�然后改变这个数据包的源端口�?2000。所以本来是�Q?0.0.0.1:1234->18.181.0.31:1235�Q�的数据包到了互联网上变��Z��Q?55.99.25.11:62000->18.181.0.31:1235�Q��?br />    一旦NAT创徏了一个Session后，NAT会记�?2000端口对应的是10.0.0.1�?234端口�Q�以后从18.181.0.31发送到62000端口的数据会被NAT自动的�{发到10.0.0.1上。（注意�Q�这里是�?8.181.0.31发送到62000端口的数据会被�{发，其他的IP发送到�q�个端口的数据将被NAT抛弃�Q�这样Client A��׃��Server S1建立以了一个连接�?/p>

    呵呵�Q�上面的基础知识可能很多人都知道了，那么下面是关键的部分了�?br />    看看下面的情况：
    Server S1                                     Server S2
18.181.0.31:1235                              138.76.29.7:1235
        |                                             |
        |                                             |
        +----------------------+----------------------+
                               |
   ^ Session 1 (A-S1) ^      |      ^ Session 2 (A-S2) ^
   | 18.181.0.31:1235 |      |      | 138.76.29.7:1235 |
   v 155.99.25.11:62000 v      |      v 155.99.25.11:62000 v
                               |
                            Cone NAT
                          155.99.25.11
                               |
   ^ Session 1 (A-S1) ^      |      ^ Session 2 (A-S2) ^
   | 18.181.0.31:1235 |      |      | 138.76.29.7:1235 |
   v   10.0.0.1:1234    v      |      v   10.0.0.1:1234    v
                               |
                            Client A
                         10.0.0.1:1234
    接上面的例子�Q�如果Client A的原来那个Socket(�l�定�?234端口的那个UDP Socket)又接着向另外一个Server S2发送了一个UDP包，那么�q�个UDP包在通过NAT时会怎么样呢�Q?br />    �q�时可能会有两种情况发生�Q�一�U�是NAT再次创徏一个Session�Q��ƈ且再�ơ�ؓ�q�个Session分配一个端口号�Q�比如：62001�Q�。另外一�U�是NAT再次创徏一个Session�Q�但是不会新分配一个端口号�Q�而是用原来分配的端口�?2000。前一�U�NAT叫做Symmetric NAT�Q�后一�U�叫做Cone NAT。我们期望我们的NAT是第二种�Q�呵呵，如果你的NAT刚好是第一�U�，那么很可能会有很多P2P软�g��q��。（可以庆幸的是�Q�现在绝大多数的NAT属于后者，即Cone NAT�Q?br />
    好了�Q�我们看刎ͼ�通过NAT,子网内的计算机向外连�l�是很容易的�Q�NAT相当于透明的，子网内的和外�|�的计算��Z��用知道NAT的情况）�?br />    但是如果外部的计��机惌��问子�|�内的计��机��比较困难了�Q�而这正是P2P所需要的�Q��?br />    那么我们如果想从外部发送一个数据报�l�内�|�的计算机有什么办法呢�Q�首先，我们必须在内�|�的NAT上打上一个“洞”（也就是前面我们说的在NAT上徏立一个Session�Q�，�q�个�z�不能由外部来打�Q�只能由内网内的��L��来打。而且�q�个�z�是有方向的�Q�比如从内部某台��L��Q�比如：192.168.0.10�Q�向外部的某个IP(比如�Q?19.237.60.1)发送一个UDP包，那么��在�q�个内网的NAT讑֤�上打了一个方向�ؓ219.237.60.1的“洞”，�Q�这��是�U�CؓUDP Hole Punching的技术）以后219.237.60.1��可以通过�q�个�z�与内网�?92.168.0.10联系了。（但是其他的IP不能利用�q�个�z�）�?/p>

呵呵�Q�现在该轮到我们的正题P2P了。有了上面的理论�Q�实��C��个内�|�的��L��通讯��差最后一步了�Q�那��是鸡生蛋还是蛋生鸡的问题了�Q�两辚w��无法��d��发出�q�接��h��Q�谁也不知道谁的公网地址�Q�那我们如何来打�q�个�z�呢�Q�我们需要一个中间�h来联�p�这两个内网��L��?br /> 现在我们来看看一个P2P软�g的流�E�，以下图�ؓ例：

                       Server S �Q?19.237.60.1�Q?br />                          |
                          |
   +----------------------+----------------------+
   |                                             |
NAT A (外网IP:202.187.45.3)                 NAT B (外网IP:187.34.1.56)
   |   (内网IP:192.168.0.1)                      | (内网IP:192.168.0.1)
   |                                             |
Client A (192.168.0.20:4000)             Client B (192.168.0.10:40000)

    首先�Q�Client A��d��服务器，NAT A��ơ的Session分配了一个端�?0000�Q�那么Server S收到的Client A的地址�?02.187.45.3:60000�Q�这��是Client A的外�|�地址了。同��P��Client B��d��Server S�Q�NAT B�l�此�ơSession分配的端口是40000�Q�那么Server S收到的B的地址�?87.34.1.56:40000�?br />    此时�Q�Client A与Client B都可以与Server S通信了。如果Client A此时想直接发送信息给Client B�Q�那么他可以从Server S那儿获得B的公�|�地址187.34.1.56:40000�Q�是不是Client A向这个地址发送信息Client B��p��收到了呢�Q�答案是不行�Q�因为如果这样发送信息，NAT B会将�q�个信息丢弃�Q�因��L��信息是不误��来的�Q��ؓ了安全，大多数NAT都会执行丢弃动作�Q�。现在我们需要的是在NAT B上打一个方向�ؓ202.187.45.3�Q�即Client A的外�|�地址�Q�的�z�，那么Client A发送到187.34.1.56:40000的信�?Client B��p��收到了。这个打�z�命令由谁来发呢�Q�呵呵，当然是Server S�?br />    �ȝ��一下这个过�E�：如果Client A惛_��Client B发送信息，那么Client A发送命令给Server S�Q�请求Server S命��oClient B向Client A方向打洞。呵呵，是不是很�l�口�Q�不�q�没关系�Q�想一惛_��很清楚了�Q�何况还有源代码呢（侯老师说过�Q�在源代码面前没有秘�?8�Q�）�Q�然后Client A��可以通过Client B的外�|�地址与Client B通信了�?br />
    注意�Q�以上过�E�只适合于Cone NAT的情况，如果是Symmetric NAT�Q�那么当Client B向Client A打洞的端口已�l�重新分配了�Q�Client B��无法知道这个端口（如果Symmetric NAT的端口是��序分配的，那么我们或许可以猜测�q�个端口��P��可是�׃��可能��D��p�|的因素太多，我们不推荐这�U�猜��端口的�Ҏ��Q��?br />
    下面是一个模拟P2P聊天的过�E�的源代码，�q�程很简单，P2PServer�q�行在一个拥有公�|�IP的计��机上，P2PClient�q�行在两个不同的NAT后（注意�Q�如果两个客��L��q�行在一个NAT后，本程序很可能不能�q�行正常�Q�这取决于你的NAT是否支持loopback translation�Q�详�?a >http://midcom-p2p.sourceforge.net/draft-ford-midcom-p2p-01.txt�Q�当�Ӟ��此问题可以通过双方先尝试连接对方的内网IP来解冻I��但是�q�个代码只是��Z��验证原理�Q��ƈ没有处理�q�些问题�Q�，后登录的计算机可以获得先��d��计算机的用户名，后登录的计算机通过send username message的格式来发送消息。如果发送成功，说明你已取得了直接与�Ҏ��q�接的成功�?br />    �E�序现在支持三个命��o�Q�send , getu , exit

    send格式�Q�send username message
    功能�Q�发送信息给username

    getu格式�Q�getu
    功能�Q�获得当前服务器用户列表

    exit格式�Q�exit
    功能�Q�注销与服务器的连接（服务器不会自动监��客��h��否吊�U�）

    代码很短�Q�相信很�Ҏ��懂，如果有什么问题，可以�l�我发邮�?a href="mailto:zhouhuis22@sina.com">zhouhuis22@sina.com 或者在CSDN上发送短消息。同�Ӟ��Ƣ迎转发此文�Q�但希望保留作者版�?-�Q��?br />
    最后感谢CSDN�|�友 PiggyXP �?Seilfer的测试帮�?/p>

P2PServer.c

/* P2P �E�序服务�?br /> *
* 文�g名：P2PServer.c
*
* 日期�Q?004-5-21
*
* 作者：shootingstars(zhouhuis22@sina.com)
*
*/
#pragma comment(lib, "ws2_32.lib")

#include "windows.h"
#include "..\proto.h"
#include "..\Exception.h"

UserList ClientList;

void InitWinSock()
{
WSADATA wsaData;

if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
{
  printf("Windows sockets 2.2 startup");
  throw Exception("");
}
else{
  printf("Using %s (Status: %s)\n",
   wsaData.szDescription, wsaData.szSystemStatus);
  printf("with API versions %d.%d to %d.%d\n\n",
   LOBYTE(wsaData.wVersion), HIBYTE(wsaData.wVersion),
   LOBYTE(wsaData.wHighVersion), HIBYTE(wsaData.wHighVersion));

}
}

SOCKET mksock(int type)
{
SOCKET sock = socket(AF_INET, type, 0);
if (sock < 0)
{
printf("create socket error");
throw Exception("");
}
return sock;
}

stUserListNode GetUser(char *username)
{
for(UserList::iterator UserIterator=ClientList.begin();
      UserIterator!=ClientList.end();
       ++UserIterator)
{
  if( strcmp( ((*UserIterator)->userName), username) == 0 )
   return *(*UserIterator);
}
throw Exception("not find this user");
}

int main(int argc, char* argv[])
{
try{
  InitWinSock();

  SOCKET PrimaryUDP;
  PrimaryUDP = mksock(SOCK_DGRAM);

  sockaddr_in local;
  local.sin_family=AF_INET;
  local.sin_port= htons(SERVER_PORT);
  local.sin_addr.s_addr = htonl(INADDR_ANY);
  int nResult=bind(PrimaryUDP,(sockaddr*)&local,sizeof(sockaddr));
  if(nResult==SOCKET_ERROR)
   throw Exception("bind error");

  sockaddr_in sender;
  stMessage recvbuf;
  memset(&recvbuf,0,sizeof(stMessage));

  // 开始主循环.
  // ��d�@环负责下面几件事�?
  // 一:��d��客户端登陆和��d��消息,记录客户列表
  // �?转发客户p2p��h��
  for(;;)
  {
   int dwSender = sizeof(sender);
   int ret = recvfrom(PrimaryUDP, (char *)&recvbuf, sizeof(stMessage), 0, (sockaddr *)&sender, &dwSender);
   if(ret <= 0)
   {
    printf("recv error");
    continue;
   }
   else
   {
    int messageType = recvbuf.iMessageType;
    switch(messageType){
    case LOGIN:
     {
      // ��这个用��L��信息记录到用户列表中
      printf("has a user login : %s\n", recvbuf.message.loginmember.userName);
      stUserListNode *currentuser = new stUserListNode();
      strcpy(currentuser->userName, recvbuf.message.loginmember.userName);
      currentuser->ip = ntohl(sender.sin_addr.S_un.S_addr);
      currentuser->port = ntohs(sender.sin_port);

      ClientList.push_back(currentuser);

      // 发送已�l�登陆的客户信息
      int nodecount = (int)ClientList.size();
      sendto(PrimaryUDP, (const char*)&nodecount, sizeof(int), 0, (const sockaddr*)&sender, sizeof(sender));
      for(UserList::iterator UserIterator=ClientList.begin();
        UserIterator!=ClientList.end();
        ++UserIterator)
      {
       sendto(PrimaryUDP, (const char*)(*UserIterator), sizeof(stUserListNode), 0, (const sockaddr*)&sender, sizeof(sender));
      }

      break;
     }
    case LOGOUT:
     {
      // ��此客户信息删除
      printf("has a user logout : %s\n", recvbuf.message.logoutmember.userName);
      UserList::iterator removeiterator = NULL;
      for(UserList::iterator UserIterator=ClientList.begin();
       UserIterator!=ClientList.end();
       ++UserIterator)
      {
       if( strcmp( ((*UserIterator)->userName), recvbuf.message.logoutmember.userName) == 0 )
       {
        removeiterator = UserIterator;
        break;
       }
      }
      if(removeiterator != NULL)
       ClientList.remove(*removeiterator);
      break;
     }
    case P2PTRANS:
     {
      // 某个客户希望服务端向另外一个客户发送一个打�z�消�?br />      printf("%s wants to p2p %s\n",inet_ntoa(sender.sin_addr),recvbuf.message.translatemessage.userName);
      stUserListNode node = GetUser(recvbuf.message.translatemessage.userName);
      sockaddr_in remote;
      remote.sin_family=AF_INET;
      remote.sin_port= htons(node.port);
      remote.sin_addr.s_addr = htonl(node.ip);

      in_addr tmp;
      tmp.S_un.S_addr = htonl(node.ip);
      printf("the address is %s,and port is %d\n",inet_ntoa(tmp), node.port);

      stP2PMessage transMessage;
      transMessage.iMessageType = P2PSOMEONEWANTTOCALLYOU;
      transMessage.iStringLen = ntohl(sender.sin_addr.S_un.S_addr);
      transMessage.Port = ntohs(sender.sin_port);

      sendto(PrimaryUDP,(const char*)&transMessage, sizeof(transMessage), 0, (const sockaddr *)&remote, sizeof(remote));

      break;
     }

    case GETALLUSER:
     {
      int command = GETALLUSER;
      sendto(PrimaryUDP, (const char*)&command, sizeof(int), 0, (const sockaddr*)&sender, sizeof(sender));

int nodecount = (int)ClientList.size();
sendto(PrimaryUDP, (const char*)&nodecount, sizeof(int), 0, (const sockaddr*)&sender, sizeof(sender));

      for(UserList::iterator UserIterator=ClientList.begin();
        UserIterator!=ClientList.end();
        ++UserIterator)
      {
       sendto(PrimaryUDP, (const char*)(*UserIterator), sizeof(stUserListNode), 0, (const sockaddr*)&sender, sizeof(sender));
      }
      break;
     }
    }
   }
  }

}
catch(Exception &e)
{
printf(e.GetMessage());
return 1;
}

return 0;
}

/* P2P �E�序客户�?br /> *
* 文�g名：P2PClient.c
*
* 日期�Q?004-5-21
*
* 作者：shootingstars(zhouhuis22@sina.com)
*
*/

#pragma comment(lib,"ws2_32.lib")

#include "windows.h"
#include "..\proto.h"
#include "..\Exception.h"
#include
using namespace std;

UserList ClientList;

#define COMMANDMAXC 256
#define MAXRETRY 5

SOCKET PrimaryUDP;
char UserName[10];
char ServerIP[20];

bool RecvedACK;

void InitWinSock()
{
WSADATA wsaData;

SOCKET mksock(int type)
{
SOCKET sock = socket(AF_INET, type, 0);
if (sock < 0)
{
printf("create socket error");
throw Exception("");
}
return sock;
}

void BindSock(SOCKET sock)
{
sockaddr_in sin;
sin.sin_addr.S_un.S_addr = INADDR_ANY;
sin.sin_family = AF_INET;
sin.sin_port = 0;

if (bind(sock, (struct sockaddr*)&sin, sizeof(sin)) < 0)
throw Exception("bind error");
}

void ConnectToServer(SOCKET sock,char *username, char *serverip)
{
sockaddr_in remote;
remote.sin_addr.S_un.S_addr = inet_addr(serverip);
remote.sin_family = AF_INET;
remote.sin_port = htons(SERVER_PORT);

stMessage sendbuf;
sendbuf.iMessageType = LOGIN;
strncpy(sendbuf.message.loginmember.userName, username, 10);

sendto(sock, (const char*)&sendbuf, sizeof(sendbuf), 0, (const sockaddr*)&remote,sizeof(remote));

int usercount;
int fromlen = sizeof(remote);
int iread = recvfrom(sock, (char *)&usercount, sizeof(int), 0, (sockaddr *)&remote, &fromlen);
if(iread<=0)
{
throw Exception("Login error\n");
}

// ��d��到服务端后，接收服务端发来的已经��d��的用��L��信息
cout<<"Have "< for(int i = 0;i {
  stUserListNode *node = new stUserListNode;
  recvfrom(sock, (char*)node, sizeof(stUserListNode), 0, (sockaddr *)&remote, &fromlen);
  ClientList.push_back(node);
  cout<<"Username:"<userName<  in_addr tmp;
  tmp.S_un.S_addr = htonl(node->ip);
  cout<<"UserIP:"<  cout<<"UserPort:"<port<  cout<<""< }
}

void OutputUsage()
{
cout<<"You can input you command:\n"
  <<"Command Type:\"send\",\"exit\",\"getu\"\n"
  <<"Example : send Username Message\n"
  <<"          exit\n"
  <<"          getu\n"
  <}

/* �q�是主要的函敎ͼ�发送一个消息给某个用户(C)
*��程�Q�直接向某个用户的外�|�IP发送消息，如果此前没有联系�q?br /> *      那么此消息将无法发送，发送端�{�待��时�?br /> *      ��时后，发送端��发送一个请求信息到服务端，
*      要求服务端发送给客户C一个请求，��h��C�l�本机发送打�z�消�?br /> *      以上��程��重复MAXRETRY��?br /> */
bool SendMessageTo(char *UserName, char *Message)
{
char realmessage[256];
unsigned int UserIP;
unsigned short UserPort;
bool FindUser = false;
for(UserList::iterator UserIterator=ClientList.begin();
      UserIterator!=ClientList.end();
      ++UserIterator)
{
  if( strcmp( ((*UserIterator)->userName), UserName) == 0 )
  {
   UserIP = (*UserIterator)->ip;
   UserPort = (*UserIterator)->port;
   FindUser = true;
  }
}

if(!FindUser)
return false;

strcpy(realmessage, Message);
for(int i=0;i {
RecvedACK = false;

  sockaddr_in remote;
  remote.sin_addr.S_un.S_addr = htonl(UserIP);
  remote.sin_family = AF_INET;
  remote.sin_port = htons(UserPort);
  stP2PMessage MessageHead;
  MessageHead.iMessageType = P2PMESSAGE;
  MessageHead.iStringLen = (int)strlen(realmessage)+1;
  int isend = sendto(PrimaryUDP, (const char *)&MessageHead, sizeof(MessageHead), 0, (const sockaddr*)&remote, sizeof(remote));
  isend = sendto(PrimaryUDP, (const char *)&realmessage, MessageHead.iStringLen, 0, (const sockaddr*)&remote, sizeof(remote));

  // �{�待接收�U�程��此标记修改
  for(int j=0;j<10;j++)
  {
   if(RecvedACK)
    return true;
   else
    Sleep(300);
  }

  // 没有接收到目标主机的回应�Q�认为目标主机的端口映射没有
  // 打开�Q�那么发送请求信息给服务器，要服务器告诉目标��L��
  // 打开映射端口�Q�UDP打洞�Q?br />  sockaddr_in server;
  server.sin_addr.S_un.S_addr = inet_addr(ServerIP);
  server.sin_family = AF_INET;
  server.sin_port = htons(SERVER_PORT);

  stMessage transMessage;
  transMessage.iMessageType = P2PTRANS;
  strcpy(transMessage.message.translatemessage.userName, UserName);

sendto(PrimaryUDP, (const char*)&transMessage, sizeof(transMessage), 0, (const sockaddr*)&server, sizeof(server));
Sleep(100);// �{�待�Ҏ��先发送信息�?br /> }
return false;
}

// 解析命��o�Q�暂时只有exit和send命��o
// 新增getu命��o�Q�获取当前服务器的所有用�?br />void ParseCommand(char * CommandLine)
{
if(strlen(CommandLine)<4)
return;
char Command[10];
strncpy(Command, CommandLine, 4);
Command[4]='\0';

if(strcmp(Command,"exit")==0)
{
  stMessage sendbuf;
  sendbuf.iMessageType = LOGOUT;
  strncpy(sendbuf.message.logoutmember.userName, UserName, 10);
  sockaddr_in server;
  server.sin_addr.S_un.S_addr = inet_addr(ServerIP);
  server.sin_family = AF_INET;
  server.sin_port = htons(SERVER_PORT);

  sendto(PrimaryUDP,(const char*)&sendbuf, sizeof(sendbuf), 0, (const sockaddr *)&server, sizeof(server));
  shutdown(PrimaryUDP, 2);
  closesocket(PrimaryUDP);
  exit(0);
}
else if(strcmp(Command,"send")==0)
{
  char sendname[20];
  char message[COMMANDMAXC];
  int i;
  for(i=5;;i++)
  {
   if(CommandLine[i]!=' ')
    sendname[i-5]=CommandLine[i];
   else
   {
    sendname[i-5]='\0';
    break;
   }
  }
  strcpy(message, &(CommandLine[i+1]));
  if(SendMessageTo(sendname, message))
   printf("Send OK!\n");
  else
   printf("Send Failure!\n");
}
else if(strcmp(Command,"getu")==0)
{
  int command = GETALLUSER;
  sockaddr_in server;
  server.sin_addr.S_un.S_addr = inet_addr(ServerIP);
  server.sin_family = AF_INET;
  server.sin_port = htons(SERVER_PORT);

sendto(PrimaryUDP,(const char*)&command, sizeof(command), 0, (const sockaddr *)&server, sizeof(server));
}
}

// 接受消息�U�程
DWORD WINAPI RecvThreadProc(LPVOID lpParameter)
{
sockaddr_in remote;
int sinlen = sizeof(remote);
stP2PMessage recvbuf;
for(;;)
{
  int iread = recvfrom(PrimaryUDP, (char *)&recvbuf, sizeof(recvbuf), 0, (sockaddr *)&remote, &sinlen);
  if(iread<=0)
  {
   printf("recv error\n");
   continue;
  }
  switch(recvbuf.iMessageType)
  {
  case P2PMESSAGE:
   {
    // 接收到P2P的消�?br />    char *comemessage= new char[recvbuf.iStringLen];
    int iread1 = recvfrom(PrimaryUDP, comemessage, 256, 0, (sockaddr *)&remote, &sinlen);
    comemessage[iread1-1] = '\0';
    if(iread1<=0)
     throw Exception("Recv Message Error\n");
    else
    {
     printf("Recv a Message:%s\n",comemessage);

     stP2PMessage sendbuf;
     sendbuf.iMessageType = P2PMESSAGEACK;
     sendto(PrimaryUDP, (const char*)&sendbuf, sizeof(sendbuf), 0, (const sockaddr*)&remote, sizeof(remote));
    }

delete []comemessage;
break;

   }
  case P2PSOMEONEWANTTOCALLYOU:
   {
    // 接收到打�z�命令，向指定的IP地址打洞
    printf("Recv p2someonewanttocallyou data\n");
    sockaddr_in remote;
    remote.sin_addr.S_un.S_addr = htonl(recvbuf.iStringLen);
    remote.sin_family = AF_INET;
    remote.sin_port = htons(recvbuf.Port);

    // UDP hole punching
    stP2PMessage message;
    message.iMessageType = P2PTRASH;
    sendto(PrimaryUDP, (const char *)&message, sizeof(message), 0, (const sockaddr*)&remote, sizeof(remote));

    break;
   }
  case P2PMESSAGEACK:
   {
    // 发送消息的应答
    RecvedACK = true;
    break;
   }
  case P2PTRASH:
   {
    // �Ҏ��发送的打洞消息�Q�忽略掉�?br />    //do nothing ...
    printf("Recv p2ptrash data\n");
    break;
   }
  case GETALLUSER:
   {
    int usercount;
    int fromlen = sizeof(remote);
    int iread = recvfrom(PrimaryUDP, (char *)&usercount, sizeof(int), 0, (sockaddr *)&remote, &fromlen);
    if(iread<=0)
    {
     throw Exception("Login error\n");
    }

    ClientList.clear();

    cout<<"Have "<    for(int i = 0;i    {
     stUserListNode *node = new stUserListNode;
     recvfrom(PrimaryUDP, (char*)node, sizeof(stUserListNode), 0, (sockaddr *)&remote, &fromlen);
     ClientList.push_back(node);
     cout<<"Username:"<userName<     in_addr tmp;
     tmp.S_un.S_addr = htonl(node->ip);
     cout<<"UserIP:"<     cout<<"UserPort:"<port<     cout<<""<    }
    break;
   }
  }
}
}

int main(int argc, char* argv[])
{
try
{
  InitWinSock();

  PrimaryUDP = mksock(SOCK_DGRAM);
  BindSock(PrimaryUDP);

cout<<"Please input server ip:";
cin>>ServerIP;

cout<<"Please input your name:";
cin>>UserName;

ConnectToServer(PrimaryUDP, UserName, ServerIP);

  HANDLE threadhandle = CreateThread(NULL, 0, RecvThreadProc, NULL, NULL, NULL);
  CloseHandle(threadhandle);
  OutputUsage();

  for(;;)
  {
   char Command[COMMANDMAXC];
   gets(Command);
   ParseCommand(Command);
  }
}
catch(Exception &e)
{
  printf(e.GetMessage());
  return 1;
}
return 0;
}

/* 异常�c?br /> *
* 文�g名：Exception.h
*
* 日期�Q?004.5.5
*
* 作者：shootingstars(zhouhuis22@sina.com)
*/

#ifndef __HZH_Exception__
#define __HZH_Exception__

#define EXCEPTION_MESSAGE_MAXLEN 256
#include "string.h"

class Exception
{
private:
char m_ExceptionMessage[EXCEPTION_MESSAGE_MAXLEN];
public:
Exception(char *msg)
{
strncpy(m_ExceptionMessage, msg, EXCEPTION_MESSAGE_MAXLEN);
}

char *GetMessage()
{
return m_ExceptionMessage;
}
};

#endif

/* P2P �E�序传输协议
*
* 日期�Q?004-5-21
*
* 作者：shootingstars(zhouhuis22@sina.com)
*
*/

#pragma once
#include

// 定义iMessageType的�?br />#define LOGIN 1
#define LOGOUT 2
#define P2PTRANS 3
#define GETALLUSER 4

// 服务器端�?br />#define SERVER_PORT 2280

// Client��d��时向服务器发送的消息
struct stLoginMessage
{
char userName[10];
char password[10];
};

// Client注销时发送的消息
struct stLogoutMessage
{
char userName[10];
};

// Client向服务器��h��另外一个Client(userName)向自己方向发送UDP打洞消息
struct stP2PTranslate
{
char userName[10];
};

// Client向服务器发送的消息格式
struct stMessage
{
int iMessageType;
union _message
{
  stLoginMessage loginmember;
  stLogoutMessage logoutmember;
  stP2PTranslate translatemessage;
}message;
};

// 客户节点信息
struct stUserListNode
{
char userName[10];
unsigned int ip;
unsigned short port;
};

// Server向Client发送的消息
struct stServerToClient
{
int iMessageType;
union _message
{
stUserListNode user;
}message;

};

//======================================
// 下面的协议用于客��L��之间的通信
//======================================
#define P2PMESSAGE 100 // 发送消�?br />#define P2PMESSAGEACK 101 // 收到消息的应�{?br />#define P2PSOMEONEWANTTOCALLYOU 102 // 服务器向客户端发送的消息
// 希望此客��L��发送一个UDP打洞�?br />#define P2PTRASH 103 // 客户端发送的打洞包，接收端应该忽略此消息

// 客户端之间发送消息格�?br />struct stP2PMessage
{
int iMessageType;
int iStringLen; // or IP address
unsigned short Port;
};

using namespace std;
typedef list UserList;

CPP&&设计模式��屋 2007-01-04 13:37 发表评论

Peer-to-Peer (P2P) communication across middleboxes(�?

CPP&&设计模式��屋 — Thu, 04 Jan 2007 05:35:00 GMT

摘要: Internet Draft B. FordDocument: draft-ford-midcom-p2p-01.txt M.I.T.Expires: April 27, 2004 ... 阅读全文

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