「Ping」WinSock实作Ping
// IP头 结构
typedef struct _iphdr
{
unsigned int h_len:4; // IP首部长度
unsigned int version:4; // IP协议版本
unsigned char tos; // 服务类型
unsigned short total_len; // 总数据包大小
unsigned short ident; // 唯一识别符
unsigned short frag_and_flags; // 旗标
unsigned char ttl; // TTL生存时间
unsigned char proto; // 协议 (TCP, UDP 等)
unsigned short checksum; // IP 检验和
unsigned int sourceIP; // 源IP地址
unsigned int destIP; // 目的IP地址
} IpHeader;
// ICMP头 结构
typedef struct _icmphdr
{
BYTE i_type; // ICMP 报文类型
BYTE i_code; // ICMP 代码
USHORT i_cksum; // 检验和
USHORT i_id; // 标识符
USHORT i_seq; // 序列号
// 预留空间
ULONG timestamp; // 时间戳
} IcmpHeader;
// 构造ICMP回应请求报头
void FillICMPData(char *icmp_data, int datasize)
{
IcmpHeader *icmp_hdr = NULL;
char *datapart = NULL;
icmp_hdr = (IcmpHeader*)icmp_data;
icmp_hdr->i_type = 8; // 请求一个ICMP回应
icmp_hdr->i_code = 0; // 代码字段 0
icmp_hdr->i_id = (USHORT)GetCurrentProcessId(); // 获取当前进程一个唯一的标识符,填充为ICMP标识符
icmp_hdr->i_cksum = 0; // 检验和置零
icmp_hdr->i_seq = 0; // 序列号
// icmp_data 加上头部大小,datapart就指向ICMP数据包中的具体内容
datapart = icmp_data + sizeof(IcmpHeader);
// 在数据包正文中填充无用字符 E
memset(datapart,'E', datasize - sizeof(IcmpHeader));
}
// 计算检验和(各字节相加,再取反)
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);
}
// 解析ICMP回应报头
INT DecodeICMPHeader(char *buf, int bytes)
{
IpHeader *iphdr = NULL;
IcmpHeader *icmphdr = NULL;
unsigned short iphdrlen;
DWORD tick;
tick = GetTickCount();
iphdr = (IpHeader *)buf;
// Number of 32-bit words * 4 = bytes
iphdrlen = iphdr->h_len * 4;
// 回应的包字节不够
if (bytes < (iphdrlen + 8)) return -1;
icmphdr = (IcmpHeader*)(buf + iphdrlen);
// 回应类型表示未成功
if (icmphdr->i_type != 0) return -1;
// 唯一标识号不匹配,别人的包
if (icmphdr->i_id != (USHORT)GetCurrentProcessId()) return -1;
// 返回耗费时间,毫秒
return tick - icmphdr->timestamp;
}
INT Ping(LPSTR IP)
{
WSADATA wsaData;
SOCKET sockRaw;
sockaddr_in dest;
INT bread,
datasize = 32, // 默认包大小
timeout = 1000; // 超时时间
CHAR *icmp_data = NULL,
*recvbuf = NULL;
USHORT seq_no = 0;
if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) return -1;
sockRaw = WSASocket (AF_INET, SOCK_RAW, IPPROTO_ICMP, NULL, 0, WSA_FLAG_OVERLAPPED);
if (sockRaw == INVALID_SOCKET)
{
if (WSAGetLastError() == 10013)
{
WSACleanup();
return -2; // 创建原始套接字权限不够
}
else{
WSACleanup();
return -3; // 未知错误
}
}
bread = setsockopt(sockRaw, SOL_SOCKET, SO_RCVTIMEO, (char*)&timeout, sizeof(timeout));
if(bread == SOCKET_ERROR)
{
closesocket(sockRaw);
WSACleanup();
return -4; // 设置套接字选项失败
}
bread = setsockopt(sockRaw, SOL_SOCKET, SO_SNDTIMEO, (char*)&timeout, sizeof(timeout));
if(bread == SOCKET_ERROR)
{
closesocket(sockRaw);
WSACleanup();
return -4; // 设置套接字选项失败
}
memset(&dest, 0, sizeof(dest));
dest.sin_family = AF_INET;
dest.sin_addr.S_un.S_addr = inet_addr(IP);
datasize += sizeof(IcmpHeader);
icmp_data = (char *)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY,1024);
recvbuf = (char *)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY,1024);
if (!icmp_data)
{
closesocket(sockRaw);
WSACleanup();
return -5; // 堆内存分配失败
}
if (!recvbuf)
{
HeapFree(GetProcessHeap(), 0, recvbuf);
closesocket(sockRaw);
WSACleanup();
return -5; // 堆内存分配失败
}
memset(icmp_data,0,1024);
FillICMPData(icmp_data,datasize);
INT nCount,utime; // 尝试 ping 4次
for (nCount = 0;nCount != 4; nCount++)
{
INT bwrote;
((IcmpHeader*)icmp_data)->i_cksum = 0; // 检验和置零
((IcmpHeader*)icmp_data)->i_seq = seq_no++; // ICMP包序列号
// 返回从操作系统启动到现在所经过的毫秒数
((IcmpHeader*)icmp_data)->timestamp = GetTickCount(); // 本地发送时间戳
// 计算检验和(注意这里,一定要最后计算,哈哈~我为了让时间更准确,就犯了这个错误)
((IcmpHeader*)icmp_data)->i_cksum = checksum((USHORT*)icmp_data, datasize);
bwrote = sendto(sockRaw, icmp_data, datasize, 0, (sockaddr*)&dest, sizeof(dest));
if (bwrote == SOCKET_ERROR)
{
if (WSAGetLastError() == WSAETIMEDOUT) // 超时
continue;
HeapFree(GetProcessHeap(), 0, recvbuf);
HeapFree(GetProcessHeap(), 0, icmp_data);
closesocket(sockRaw);
WSACleanup();
return -6; // 发送ICMP报头失败
}
bread = recv(sockRaw, recvbuf, 1024, 0);
if (bread == SOCKET_ERROR)
{
if (WSAGetLastError() == WSAETIMEDOUT) // 超时
continue;
HeapFree(GetProcessHeap(), 0, recvbuf);
HeapFree(GetProcessHeap(), 0, icmp_data);
closesocket(sockRaw);
WSACleanup();
return -7; // 接收ICMP回应失败
}
utime = DecodeICMPHeader(recvbuf,bread);
if (utime != -1)
break;
Sleep(300);
}
closesocket(sockRaw);
HeapFree(GetProcessHeap(), 0, recvbuf);
HeapFree(GetProcessHeap(), 0, icmp_data);
WSACleanup();
if(nCount == 4)
return -8; // 超时
else
return utime; // 成功,返回耗时
}
使用原始套接字需要管理员权限.不然就会返回10013错误代码.