c 实现ip是否在同一个网段的判断-ag真人游戏

废话不说直接贴代码：

ip的数据结构

typedef struct ip_struct{
	//ip地址划分后各个域的值
	struct ipadress_struct
	{
		int first;  
		int second;  
		int third;  
		int forth;
	}ipadress,*pipadress;
	//ip地址
	char szipadress[max_path];
	//子网掩码
	char szipmask[max_path];
	ip_struct()
	{
		strcpy(szipadress,"");
		strcpy(szipmask,"");
	}
	ip_struct(char szipadress[],char szipmask[])
	{
		strcpy(this->szipadress,szipadress);
		strcpy(this->szipmask,szipmask);
	}
}ip,*pip;

判断ip是否合理及获取ip各个域的值

bool judgeip(char *szip,ip_struct::ipadress_struct *ipadress)
{
	if (!szip) return false;
	int index=0;
	int first=0,second=0,third=0,forth=0;   
	std::string ip=std::string(szip);
    first=atoi(&ip[index]);  
    if (first>255)  
        return false;
	if (ipadress)
		ipadress->first=first;
    
    index  ;  
    index=ip.find_first_of('.',index);  
    second=atoi(&ip[  index]);  
    if(second>255)  
        return false;  
	if (ipadress)
		ipadress->second=second;
    
    index  ;  
    index=ip.find_first_of('.',index);  
    third=atoi(&ip[  index]);  
    if(third>255)  
        return false;  
	if (ipadress)
		ipadress->third=third;
    index  ;  
    index=ip.find_first_of('.',index);  
    forth=atoi(&ip[  index]);  
    if(forth>255)  
        return false;  
	if (ipadress)
		ipadress->forth=forth;
    
    return true;  
}

判断是否同一网段

//-1 indicates ip格式错误，0表示不同网段，1表示同网段
int issamenetworksegment(char *szipadress,char *szmask,char *szipadresss1)
{
	if (!szipadress||!szmask||!szipadresss1) return false;
    ip_struct::ipadress_struct ip,ip1,mask;
    if (judgeip(szipadress,&ip)&&judgeip(szipadresss1,&ip1)&&judgeip(szmask,&mask))
    {
    	    ip.first=ip.first & mask.first;  
            ip.second=ip.second & mask.second;  
            ip.third=ip.third & mask.third;  
            ip.forth=ip.forth & mask.forth;  
  
            ip1.first=ip1.first & mask.first;  
            ip1.second=ip1.second & mask.second;  
            ip1.third=ip1.third & mask.third;  
            ip1.forth=ip1.forth & mask.forth;  
  
            if(ip.first==ip1.first&&ip.second==ip1.second&&ip.third==ip1.third&&ip.forth==ip1.forth)  
                return 1;
            else  
                return 0;
	}
	else
	    return -1;
}