VC判断目标主机是否存活，模拟系统的ping

// Module Name: Ping.c // // Description: // This sample illustrates how an ICMP ping app can be written // using the SOCK_RAW socket type and IPPROTO_ICMP protocol. // By creating a raw socket, the underlying layer does not change // the protocol header so that when we submit the ICMP header // nothing is changed so that the receiving end will see an // ICMP packet. Additionally, we use the record route IP option // to get a round trip path to the endpoint. Note that the size // of the IP option header that records the route is limited to // nine IP addresses. // // Compile: // cl -o Ping Ping.c ws2_32.lib /Zp1 // // Command Line Options/Parameters: // Ping [host] [packet-size] // // host String name of host to ping // packet-size Integer size of packet to send // (smaller than 1024 bytes) // //#pragma pack(1) #define WIN32_LEAN_AND_MEAN #include <winsock2.h> #include <ws2tcpip.h> #include <stdio.h> #include <stdlib.h> #define IP_RECORD_ROUTE 0x7 // // IP header structure // 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; // Time to live unsigned char proto; // Protocol (TCP, UDP etc) unsigned short checksum; // IP checksum unsigned int sourceIP; unsigned int destIP; } IpHeader; #define ICMP_ECHO 8 #define ICMP_ECHOREPLY 0 #define ICMP_MIN 8 // Minimum 8-byte ICMP packet (header) // // ICMP header structure // 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 standard header, but we reserve space for time ULONG timestamp; } IcmpHeader; // // IP option header - use with socket option IP_OPTIONS // typedef struct _ipoptionhdr { unsigned char code; // Option type unsigned char len; // Length of option hdr unsigned char ptr; // Offset into options unsigned long addr[9]; // List of IP addrs } IpOptionHeader; #define DEF_PACKET_SIZE 32 // Default packet size #define MAX_PACKET 1024 // Max ICMP packet size #define MAX_IP_HDR_SIZE 60 // Max IP header size w/options BOOL bRecordRoute; int datasize; char *lpdest; // // Function: usage // // Description: // Print usage information // void usage(char *progname) { printf("usage: ping -r <host> [data size]/n"); printf(" -r record route/n"); printf(" host remote machine to ping/n"); printf(" datasize can be up to 1KB/n"); ExitProcess(-1); } // // Function: FillICMPData // // Description: // Helper function to fill in various fields for our ICMP request // void FillICMPData(char *icmp_data, int datasize) { IcmpHeader *icmp_hdr = NULL; char *datapart = NULL; icmp_hdr = (IcmpHeader*)icmp_data; icmp_hdr->i_type = ICMP_ECHO; // Request an 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)); } // // Function: checksum // // Description: // This function calculates the 16-bit one's complement sum // of the supplied buffer (ICMP) header // 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); } // // Function: DecodeIPOptions // // Description: // If the IP option header is present, find the IP options // within the IP header and print the record route option // values // void DecodeIPOptions(char *buf, int bytes) { IpOptionHeader *ipopt = NULL; IN_ADDR inaddr; int i; HOSTENT *host = NULL; ipopt = (IpOptionHeader *)(buf + 20); printf("RR: "); for(i = 0; i < (ipopt->ptr / 4) - 1; i++) { inaddr.S_un.S_addr = ipopt->addr[i]; if (i != 0) printf(" "); host = gethostbyaddr((char *)&inaddr.S_un.S_addr, sizeof(inaddr.S_un.S_addr), AF_INET); if (host) printf("(%-15s) %s/n", inet_ntoa(inaddr), host->h_name); else printf("(%-15s)/n", inet_ntoa(inaddr)); } return; } // // Function: DecodeICMPHeader // // Description: // The response is an IP packet. We must decode the IP header to // locate the ICMP data. // void DecodeICMPHeader(char *buf, int bytes, struct sockaddr_in *from) { IpHeader *iphdr = NULL; IcmpHeader *icmphdr = NULL; unsigned short iphdrlen; DWORD tick; static int icmpcount = 0; iphdr = (IpHeader *)buf; // Number of 32-bit words * 4 = bytes iphdrlen = iphdr->h_len * 4; tick = GetTickCount(); if ((iphdrlen == MAX_IP_HDR_SIZE) && (!icmpcount)) DecodeIPOptions(buf, 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) { printf("nonecho type %d recvd/n", icmphdr->i_type); return; } // Make sure this is an ICMP reply to something we sent! // if (icmphdr->i_id != (USHORT)GetCurrentProcessId()) { printf("someone else's packet!/n"); return ; } printf("%d bytes from %s:", bytes, inet_ntoa(from->sin_addr)); printf(" icmp_seq = %d. ", icmphdr->i_seq); printf(" time: %d ms", tick - icmphdr->timestamp); printf("/n"); icmpcount++; return; } void ValidateArgs(int argc, char **argv) { int i; bRecordRoute = FALSE; lpdest = NULL; datasize = DEF_PACKET_SIZE; for(i = 1; i < argc; i++) { if ((argv[i][0] == '-') || (argv[i][0] == '/')) { switch (tolower(argv[i][1])) { case 'r': // Record route option bRecordRoute = TRUE; break; default: usage(argv[0]); break; } } else if (isdigit(argv[i][0])) datasize = atoi(argv[i]); else lpdest = argv[i]; } }

// // Function: main // // Description: // Setup the ICMP raw socket, and create the ICMP header. Add // the appropriate IP option header, and start sending ICMP // echo requests to the endpoint. For each send and receive, // we set a timeout value so that we don't wait forever for a // response in case the endpoint is not responding. When we // receive a packet decode it. // int main(int argc, char **argv) { WSADATA wsaData; SOCKET sockRaw = INVALID_SOCKET; struct sockaddr_in dest, from; int bread, fromlen = sizeof(from), timeout = 1000, ret; char *icmp_data = NULL, *recvbuf = NULL; unsigned int addr = 0; USHORT seq_no = 0; struct hostent *hp = NULL; IpOptionHeader ipopt; if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) { printf("WSAStartup() failed: %d/n", GetLastError()); return -1; } ValidateArgs(argc, argv); // // WSA_FLAG_OVERLAPPED flag is required for SO_RCVTIMEO, // SO_SNDTIMEO option. If NULL is used as last param for // WSASocket, all I/O on the socket is synchronous, the // internal user mode wait code never gets a chance to // execute, and therefore kernel-mode I/O blocks forever. // A socket created via the socket function has the over- // lapped I/O attribute set internally. But here we need // to use WSASocket to specify a raw socket. // // If you want to use timeout with a synchronous // nonoverlapped socket created by WSASocket with last // param set to NULL, you can set the timeout by using // the select function, or you can use WSAEventSelect and // set the timeout in the WSAWaitForMultipleEvents // function. // sockRaw = WSASocket (AF_INET, SOCK_RAW, IPPROTO_ICMP, NULL, 0, WSA_FLAG_OVERLAPPED); if (sockRaw == INVALID_SOCKET) { printf("WSASocket() failed: %d/n", WSAGetLastError()); return -1; } if (bRecordRoute) { // Setup the IP option header to go out on every ICMP packet // ZeroMemory(&ipopt, sizeof(ipopt)); ipopt.code = IP_RECORD_ROUTE; // Record route option ipopt.ptr = 4; // Point to the first addr offset ipopt.len = 39; // Length of option header ret = setsockopt(sockRaw, IPPROTO_IP, IP_OPTIONS, (char *)&ipopt, sizeof(ipopt)); if (ret == SOCKET_ERROR) { printf("setsockopt(IP_OPTIONS) failed: %d/n", WSAGetLastError()); } } // Set the send/recv timeout values // bread = setsockopt(sockRaw, SOL_SOCKET, SO_RCVTIMEO, (char*)&timeout, sizeof(timeout)); if(bread == SOCKET_ERROR) { printf("setsockopt(SO_RCVTIMEO) failed: %d/n", WSAGetLastError()); return -1; } timeout = 1000; bread = setsockopt(sockRaw, SOL_SOCKET, SO_SNDTIMEO, (char*)&timeout, sizeof(timeout)); if (bread == SOCKET_ERROR) { printf("setsockopt(SO_SNDTIMEO) failed: %d/n", WSAGetLastError()); return -1; } memset(&dest, 0, sizeof(dest)); // // Resolve the endpoint's name if necessary // dest.sin_family = AF_INET; if ((dest.sin_addr.s_addr = inet_addr(lpdest)) == INADDR_NONE) { if ((hp = gethostbyname(lpdest)) != NULL) { memcpy(&(dest.sin_addr), hp->h_addr, hp->h_length); dest.sin_family = hp->h_addrtype; printf("dest.sin_addr = %s/n", inet_ntoa(dest.sin_addr)); } else { printf("gethostbyname() failed: %d/n", WSAGetLastError()); return -1; } } // // Create the ICMP packet // datasize += sizeof(IcmpHeader); icmp_data = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, MAX_PACKET); recvbuf = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, MAX_PACKET); if (!icmp_data) { printf("HeapAlloc() failed: %d/n", GetLastError()); return -1; } memset(icmp_data,0,MAX_PACKET); FillICMPData(icmp_data,datasize); // // Start sending/receiving ICMP packets // while(1) { static int nCount = 0; int bwrote; if (nCount++ == 4) break; ((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("timed out/n"); continue; } printf("sendto() failed: %d/n", WSAGetLastError()); return -1; } if (bwrote < datasize) { printf("Wrote %d bytes/n", bwrote); } bread = recvfrom(sockRaw, recvbuf, MAX_PACKET, 0, (struct sockaddr*)&from, &fromlen); if (bread == SOCKET_ERROR) { if (WSAGetLastError() == WSAETIMEDOUT) { printf("timed out/n"); continue; } printf("recvfrom() failed: %d/n", WSAGetLastError()); return -1; } DecodeICMPHeader(recvbuf, bread, &from); Sleep(1000); } // Cleanup // if (sockRaw != INVALID_SOCKET) closesocket(sockRaw); HeapFree(GetProcessHeap(), 0, recvbuf); HeapFree(GetProcessHeap(), 0, icmp_data); WSACleanup(); return 0; }

<windows网络编程>第13章的例子

PS:有防火墙则无效