TCP协议学习记录 (二) Ping程序

简单的实现了一个ping程序,没有做icmp差错报文的检查。

支持自定义字节数,支持发包个数

 #pragma pack(4)

 #define  ECHO_REQUEST        8
 #define  DATASIZE            65500
 #define  PACKETSIZE          65535

 struct iphdr
 {
     unsigned char  ip_hdr_len : ; //包头长度
     unsigned char  ip_version : ; //版本
     unsigned char  ip_tos;

     unsigned short ip_length;  //总长度
     unsigned short ip_identify;//标识
     unsigned short ip_offset;//片偏移
     unsigned char  ip_ttl;
     unsigned char  ip_protocol;
     unsigned short ip_cksum;

     struct in_addr ip_src; //源地址
     struct in_addr ip_dst; //目的地址
 };

 struct icmphdr
 {
     unsigned char  icmp_type; //8位类型
     unsigned char  icmp_code; //8位代码
     unsigned short icmp_cksum; //16位的校验和

     unsigned short icmp_identify;
     unsigned short icmp_seq;

     LONGLONG       icmp_timestamp;
     char           icmp_data[DATASIZE];
 };

 unsigned short checksum(int count,unsigned short* addr)
 {
     long sum = ;

     while(count > )
     {
         sum   +=*addr++;
         count -= sizeof(unsigned short);
     }

     if(count > )
     {
         sum  +=*(unsigned char*)addr;
     }

     while(sum >> )
     {
         sum = (sum & 0xFFFF) + (sum >> );
     }

     return (unsigned short)(~sum);
 }

 void packet_pad(char * buf,int payload)
 {
     char pad[] = "\x61\x62\x63\x64\x65\x66\x67\x68\x69\x6a\x6b\x6c\x6d\x6e\x6f\x70\x71\x7\x73\x74\x75\x76\x77";

     int size   = sizeof(pad) -;
     int count  = payload / size;
     int remain = payload % size;
     int offset = ; //偏移

     memset((void *)buf,,payload);

     for(int i = ;i < count; ++i)
     {
         memcpy((void *)(buf + offset),(void *)pad,size);
         offset += size;
     }

     memcpy((void *)(buf + offset),(void *)pad,remain);
 }

 LONGLONG getsystickcount64()
 {
     static LARGE_INTEGER tickspersecond = {};
     LARGE_INTEGER tick;

     if(!tickspersecond.QuadPart)
     {
         QueryPerformanceFrequency(&tickspersecond);
     }

     QueryPerformanceCounter(&tick);

     LONGLONG seconds     = tick.QuadPart / tickspersecond.QuadPart;
     LONGLONG leftPart    = tick.QuadPart - (tickspersecond.QuadPart * seconds);
     LONGLONG millseconds = ((leftpart << )  - ((leftpart << ) + (leftpart << )))  / tickspersecond.QuadPart;
     LONGLONG ret         = ((seconds  << )  - ((seconds  << ) + (seconds  << )))  + millseconds;

     return ret;
 };

 bool ping(char * target,int payload,int count)
 {
     WSADATA wsaData;
     WSAStartup(MAKEWORD(, ), &wsaData);

     SOCKET soc = socket(AF_INET,SOCK_RAW,IPPROTO_ICMP);
     if(soc == -)
     {
         printf("create raw socket failed!\n");
         return false;
     }

     if(payload > DATASIZE)
     {
         printf("发送的字节数有错误,有效范围从 0 到 %d",DATASIZE);
         return false;
     }

     payload = payload - sizeof(LONGLONG); 

     struct sockaddr_in  addrsrv;

     addrsrv.sin_family        = AF_INET;
     addrsrv.sin_port          = htons();
     struct hostent* phostent  = gethostbyname(target);
     if (phostent)
     {
         addrsrv.sin_addr.s_addr = *(u_long *)phostent->h_addr_list[];
     }

     printf("正在 Ping %s [%s] 具有 %d 字节的数据: \n",target,inet_ntoa(addrsrv.sin_addr),payload + sizeof(LONGLONG));

     icmphdr ihdr       = {};

     memset((void *)ihdr.icmp_data,,DATASIZE);
     packet_pad(ihdr.icmp_data,payload); //填充数据

     ihdr.icmp_type        = ECHO_REQUEST;
     ihdr.icmp_identify    = (unsigned short)GetCurrentProcessId();

     int hdr_len           = payload + sizeof(icmphdr) - DATASIZE;

     struct timeval timeout;
     struct sockaddr_in addrcli;

     char recv[PACKETSIZE]   = {};

     unsigned long interval  = ;
     unsigned long avgdelay  = ;
     unsigned long maxdelay  = ;
     unsigned long mindelay  = ~;

     unsigned int  sndcnt = count;
     unsigned int  loscnt = ;

     for(int seq = ; seq < count; ++seq)
     {
         memset((void *)recv,,PACKETSIZE);

         ihdr.icmp_seq        = seq;
         ihdr.icmp_cksum      = ;
         ihdr.icmp_timestamp  = getsystickcount64(); //时间戳
         ihdr.icmp_cksum      = checksum(hdr_len,(unsigned short *)&ihdr);

         if(sendto(soc,(char *)&ihdr,hdr_len,,(sockaddr *)&addrsrv,sizeof(addrsrv)) == -)
         {
             --sndcnt;
             continue;
         }

         int  nlength    = sizeof(addrcli);
         timeout.tv_sec  = ;
         timeout.tv_usec = ;

         setsockopt(soc, SOL_SOCKET,SO_RCVTIMEO, (char*)&timeout,sizeof(timeout));

         if(recvfrom(soc,recv,PACKETSIZE,,(sockaddr *)&addrcli,&nlength) == -)
         {
             printf("请求超时!\n");
             ++loscnt;
             continue;
         }

         iphdr* piphdr = (iphdr *)recv;
         if(checksum(piphdr->ip_hdr_len << ,(unsigned short *)piphdr) != )
         {
             printf("invalid ip packet!\n");
             continue;
         }

         icmphdr* pichdr = (icmphdr *)(piphdr + );
         if(checksum(hdr_len,(unsigned short *)pichdr) != )
         {
             printf("invalid icmp packet!\n");
             continue;
         }

         interval = getsystickcount64() - pichdr->icmp_timestamp;
         avgdelay+= interval;

         maxdelay = interval > maxdelay ? interval : maxdelay;
         mindelay = interval > mindelay ? mindelay : interval;

         printf("来自 %s 的回复: 字节=%d 时间=%dms TTL=%u\n",inet_ntoa(addrsrv.sin_addr),payload + sizeof(LONGLONG),interval,piphdr->ip_ttl);

         Sleep();
     }

     printf("\n");
     printf("%s 的 Ping 统计信息: \n",inet_ntoa(addrsrv.sin_addr));
     printf("    数据包: 已发送 = %d, 已接收 = %d, 丢失 = %d (%.2f%% 丢失),\n",sndcnt,sndcnt-loscnt,loscnt,(loscnt * ) / (double)sndcnt);
     printf("往返行程的估计时间(以毫秒为单位):\n");
     printf("    最短 = %dms, 最长 = %dms, 平均 = %dms\n",mindelay,maxdelay,avgdelay / sndcnt);
     printf("\n");
 }

 int main(int argc,char * argv[])
 {
     ping("www.baidu.com",,);
     return ;
 }