早些年學習網絡協議的時候折騰而寫的代碼，代碼在後面。
純粹代碼的意義不大，建議有興趣學習的童鞋，要想學習ping，最好能了解一下 RFC 792 ICMP協議，這個比代碼純粹的代碼有意義，當年咱學習的時候，可沒人給這樣的建議啊，這可是本人後來逐漸明白的，什麼才是最重要的，在此點出來，明白的有緣人自然能明白。
直接將以下代碼存為文件xping.cpp或xping.c，用VC直接編譯就可以（VC自己會提示生成工程），GCC編譯也可以的
// //xping //awzzz //2002/06/20 // #include#include #include #include #ifdef WIN32 #define WIN32_LEAN_AND_MEAN #include #pragma comment(lib, "Wsock32.lib") #else #include #include #include #include #include #include #include #include #include #endif #define ICMP_ECHO 8 #define ICMP_ECHOREPLY 0 //#define ICMP_MIN 8 // minimum 8 byte icmp packet (just header) #define ICMP_MIN (8 + 4) // minimum 8 byte icmp packet (just header + timestamp) // IP header typedef struct _tagX_iphdr { unsigned char h_len:4; // length of the header unsigned char 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; // ttl unsigned char proto; // protocol (TCP, UDP etc) unsigned short checksum; // IP checksum unsigned int sourceIP; unsigned int destIP; }XIpHeader; // ICMP header typedef struct _tagX_icmphdr { unsigned char i_type; unsigned char i_code; unsigned short i_cksum; unsigned short i_id; unsigned short i_seq; unsigned long i_timestamp; }XIcmpHeader; //puclic code //網際校驗和生產算法 //網際校驗和是被校驗數據16位值的反碼和(ones-complement sum) unsigned short in_cksum(unsigned short* addr, int len) { int nleft = len; int sum = 0; unsigned short* w = addr; unsigned short answer = 0; while(nleft > 1) { sum += *w++; nleft -= 2; } if(nleft == 1) { *(unsigned char*)(&answer) = *(unsigned char*)w; sum += answer; } sum = (sum >> 16) + (sum & 0xffff); sum += (sum >> 16); answer = ~sum; return (answer); } void fill_IpHeader(char *buf) { // XIpHeader *ip_hdr = (XIpHeader *)buf; } void fill_IcmpData(char *buf, int datasize) { if (buf) { char ch = 0; char* icmpdata = buf + sizeof(XIcmpHeader); fprintf(stdout, "(IcmpData)\r\n"); for (int i = 0; i < datasize; i++) { ch = 'A' + i%('z' - 'A'); *(icmpdata + i) = ch; fprintf(stdout, "%c", ch); } fprintf(stdout, "\r\n"); } } void fill_IcmpHeader(char *buf, int datasize) { static unsigned short seq_no = 0; XIcmpHeader *icmp_hdr = (XIcmpHeader *)buf; if (icmp_hdr) { icmp_hdr->i_type = ICMP_ECHO; icmp_hdr->i_code = 0; icmp_hdr->i_cksum = 0; #ifdef WIN32 icmp_hdr->i_id = (unsigned short)GetCurrentProcessId(); #else icmp_hdr->i_id = (unsigned short)getpid(); #endif icmp_hdr->i_seq = seq_no++; #ifdef WIN32 icmp_hdr->i_timestamp = (unsigned long)::GetTickCount(); #else icmp_hdr->i_timestamp = (unsigned long)time(NULL); #endif icmp_hdr->i_cksum = in_cksum((unsigned short*)buf, sizeof(XIcmpHeader) + datasize); fprintf(stdout, "(IcmpHeader)\r\n"); fprintf(stdout, "%02X%02X%04X\r\n", icmp_hdr->i_type, icmp_hdr->i_code, icmp_hdr->i_cksum); fprintf(stdout, "%04X%04X\r\n", icmp_hdr->i_id, icmp_hdr->i_seq); fprintf(stdout, "%08X\r\n", icmp_hdr->i_timestamp); } } // decode void decode_IpIcmp(char *buf, int size) { XIpHeader *ip_hdr = (XIpHeader *)buf; unsigned short iphdrlen; if (ip_hdr) { fprintf(stdout, "(IpHeader)\r\n"); fprintf(stdout, "%01X%01X%02X%04X\r\n", ip_hdr->version, ip_hdr->h_len, ip_hdr->tos, ip_hdr->total_len); fprintf(stdout, "%04X%04X\r\n", ip_hdr->ident, ip_hdr->frag_and_flags); fprintf(stdout, "%02X%02X%04X\r\n", ip_hdr->ttl, ip_hdr->proto, ip_hdr->checksum); //iphdrlen = ip_hdr->h_len * 4; // number of 32-bit words *4 = bytes iphdrlen = ip_hdr->h_len << 2; // number of 32-bit words *4 = bytes fprintf(stdout, "(IcmpHeader)\r\n"); if (size < iphdrlen + ICMP_MIN) { fprintf(stdout, "Reply %d bytes Too few\r\n", size); } else { XIcmpHeader *icmp_hdr = (XIcmpHeader *)(buf + iphdrlen); fprintf(stdout, "%02X%02X%04X\r\n", icmp_hdr->i_type, icmp_hdr->i_code, icmp_hdr->i_cksum); fprintf(stdout, "%04X%04X\r\n", icmp_hdr->i_id, icmp_hdr->i_seq); fprintf(stdout, "%08X\r\n", icmp_hdr->i_timestamp); /* fprintf(stdout, "(IcmpData)\r\n"); int iIcmpDataSize = size - iphdrlen - sizeof(XIcmpHeader); char *icmpdata = buf + iIcmpDataSize; for (int i = 0; i < iIcmpDataSize; i++) fprintf(stdout, "%c", *(icmpdata + i)); fprintf(stdout, "\r\n"); */ unsigned long timestamp = 0; #ifdef WIN32 timestamp = (unsigned long)::GetTickCount(); #else timestamp = (unsigned long)time(NULL);; #endif timestamp -= icmp_hdr->i_timestamp; struct sockaddr_in from; from.sin_addr.s_addr = ip_hdr->sourceIP; fprintf(stdout, "Reply %d bytes from: %s time<%d TTL=%d icmp_seq=%d\r\n", size, inet_ntoa(from.sin_addr), timestamp, ip_hdr->ttl, icmp_hdr->i_seq ); } } } int main(int argc, char **argv) { int ret = 0; #ifdef WIN32 WSADATA ws; WSAStartup(0x0101,&ws); //#else // ; #endif int iIcmpDataSize = 0; struct sockaddr_in dest,from; unsigned int addr = 0; struct hostent *hp; char buffer[1024]; char recv_buffer[1024]; if(argc < 2) { fprintf(stderr, "Usage: %s [host|ip] [datasize]\r\n", argv[0]); return 0; } if (argc > 2) iIcmpDataSize = atoi(argv[2]); if (iIcmpDataSize < 1 || iIcmpDataSize > 1024) iIcmpDataSize = 10; memset(&dest, 0, sizeof dest); dest.sin_family = AF_INET; hp = gethostbyname(argv[1]); if (!hp) addr = inet_addr(argv[1]); if ((!hp) && (addr == INADDR_NONE)) { fprintf(stderr,"Unable to resolve %s\r\n",argv[1]); return 0; } if (hp != NULL) memcpy(&(dest.sin_addr), hp->h_addr,hp->h_length); else dest.sin_addr.s_addr = addr; #ifdef WIN32 // ; #else setuid(getuid()); // setuid(0); #endif int sockfd; sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP); fprintf(stdout, "XPing...\r\n"); for (int i = 0; i < 3; i++) { fprintf(stdout, "Echo...\r\n"); memset(buffer, 0, 1024); fill_IcmpData(buffer, iIcmpDataSize); fill_IcmpHeader(buffer, iIcmpDataSize); XIcmpHeader *icmp_hdr = (XIcmpHeader *)buffer; int iSendSize = sendto(sockfd, buffer, sizeof(XIcmpHeader) + iIcmpDataSize, 0, (struct sockaddr*)&dest, sizeof(dest)); fprintf(stdout, "Reply...\r\n"); memset(&from, 0, sizeof from); memset(recv_buffer, 0, 1024); #ifdef WIN32 int fromlen = sizeof(from); int iRecvSize = recvfrom(sockfd, recv_buffer, 1024, 0, (struct sockaddr*)&from, &fromlen); #else socklen_t fromlen = sizeof(from); int iRecvSize = recvfrom(sockfd, recv_buffer, 1024, 0, (struct sockaddr*)&from, &fromlen); #endif if (iRecvSize > 0) decode_IpIcmp(recv_buffer, iRecvSize); } #ifdef WIN32 WSACleanup(); //#else // ; #endif return ret; }
早些年網絡不發達（現在依然很落後），沒有博客？幸好這個代碼當時也還是扔到網上了，最近發現，在這裡博客一下，算是復習記載。
