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#include "allinc.h"
static WORD Compute16BitXSum( IN PVOID pvData, IN DWORD dwNumBytes ) /*++
Routine Description
Arguments
Return Value 16 Bit one's complement of the one's complement sum of dwNumBytes starting at pData --*/ { REGISTER PWORD pwStart; REGISTER DWORD dwNumWords,i; REGISTER DWORD dwSum = 0; pwStart = (PWORD)pvData; //
// If there are odd numbered bytes, that has to be handled differently
// However we can never have odd numbered bytes in our case so we optimize.
//
dwNumWords = dwNumBytes/2; for(i = 0; i < dwNumWords; i++) { dwSum += pwStart[i]; if(dwSum & 0x80000000) { dwSum = (dwSum & 0x0000FFFF) + (dwSum >> 16); } } return (WORD)~dwSum; }
int __cdecl main() { SOCKET Socket; DWORD dwResult,dwNumBytesSent,dwBytesRead,dwAns,dwAddrLen,dwFlags; LONG i; DWORD dwSizeOfHeader; BOOL bOption; SOCKADDR_IN sinSourceAddr, sinSockAddr; WSABUF wsaBuf; DWORD pdwIpAndIcmpBuf[ICMP_RCV_BUFFER_LEN+2]; PIP_HEADER pIpHeader; PICMP_ROUTER_ADVT_MSG pIcmpAdvt; ICMP_ROUTER_SOL_MSG icmpSolMsg; WORD wVersion = MAKEWORD(2,0); //Winsock version 2.0 minimum
WSADATA wsaData; struct ip_mreq imOption; icmpSolMsg.byType = 0x0A; icmpSolMsg.byCode = 0x00; icmpSolMsg.dwReserved = 0; icmpSolMsg.wXSum = 0x0000; icmpSolMsg.wXSum = Compute16BitXSum((PVOID)&icmpSolMsg, 8); if(WSAStartup(wVersion,&wsaData) isnot NO_ERROR) { printf("WSAStartup failed\n"); exit(1); } Socket = WSASocket(AF_INET, SOCK_RAW, IPPROTO_ICMP, NULL, 0, RTR_DISC_SOCKET_FLAGS); if(Socket is INVALID_SOCKET) { dwResult = WSAGetLastError(); printf("Couldnt create socket. Error %d\n", dwResult); exit(1); } //
// Set to SO_REUSEADDR
//
bOption = TRUE; if(setsockopt(Socket, SOL_SOCKET, SO_REUSEADDR, (const char FAR*)&bOption, sizeof(BOOL)) is SOCKET_ERROR) { printf("Couldnt set linger option. Error %d\n", WSAGetLastError()); } //
// Bind to the addresses on the interface
//
sinSourceAddr.sin_family = AF_INET; sinSourceAddr.sin_addr.s_addr = INADDR_ANY; sinSourceAddr.sin_port = 0; if(bind(Socket, (const struct sockaddr FAR*)&sinSourceAddr, sizeof(SOCKADDR_IN)) is SOCKET_ERROR) { dwResult = WSAGetLastError(); printf("Couldnt bind. Error %d\n", dwResult); exit(1); } #if 0
//
// Join the multicast session on ALL_SYSTEMS_MULTICAST
//
sinSockAddr.sin_family = AF_INET; sinSockAddr.sin_addr.s_addr = ALL_SYSTEMS_MULTICAST_GROUP; sinSockAddr.sin_port = 0; if(WSAJoinLeaf(Socket, (const struct sockaddr FAR*)&sinSockAddr, sizeof(SOCKADDR_IN), NULL, NULL, NULL, NULL, JL_BOTH) is INVALID_SOCKET) { dwResult = WSAGetLastError(); printf("Error %d joining ALL_SYSTEMS multicast group on socket for %s", dwResult, inet_ntoa(*(PIN_ADDR)&(sinSourceAddr.sin_addr)));
closesocket(Socket);
exit(1); }
#endif
if(setsockopt(Socket, IPPROTO_IP, IP_MULTICAST_IF, (PBYTE)&sinSourceAddr.sin_addr, sizeof(IN_ADDR)) is SOCKET_ERROR) { dwResult = WSAGetLastError(); printf("Couldnt join multicast group on socket for %s", inet_ntoa(*(PIN_ADDR)&(sinSourceAddr.sin_addr))); exit(1); } imOption.imr_multiaddr.s_addr = ALL_SYSTEMS_MULTICAST_GROUP; imOption.imr_interface.s_addr = sinSourceAddr.sin_addr.s_addr; if(setsockopt(Socket, IPPROTO_IP, IP_ADD_MEMBERSHIP, (PBYTE)&imOption, sizeof(imOption)) is SOCKET_ERROR) { dwResult = WSAGetLastError(); printf("Couldnt join multicast group on socket for %s", inet_ntoa(*(PIN_ADDR)&(sinSourceAddr.sin_addr))); exit(1); }
while(TRUE) { printf("Send Solicitation? (1 - yes, 0 - no) ");
scanf("%d",&dwAns); if(!dwAns) { break; } sinSourceAddr.sin_family = AF_INET; sinSourceAddr.sin_addr.s_addr = ALL_ROUTERS_MULTICAST_GROUP; sinSourceAddr.sin_port = 0; wsaBuf.buf = (PBYTE)&icmpSolMsg; wsaBuf.len = sizeof(ICMP_ROUTER_SOL_MSG);
if(WSASendTo(Socket, &wsaBuf, 1, &dwNumBytesSent, MSG_DONTROUTE, (const struct sockaddr FAR*)&sinSourceAddr, sizeof(SOCKADDR_IN), NULL, NULL ) is SOCKET_ERROR) { dwResult = WSAGetLastError(); printf("WSASendTo failed with %d\n", dwResult); break; } while(TRUE) { dwAddrLen = sizeof(SOCKADDR_IN); dwFlags = 0; pIpHeader = (PIP_HEADER)pdwIpAndIcmpBuf; wsaBuf.buf = (PBYTE)pIpHeader; wsaBuf.len = (ICMP_RCV_BUFFER_LEN+2) * sizeof(DWORD); if(WSARecvFrom(Socket, &wsaBuf, 1, &dwBytesRead, &dwFlags, (struct sockaddr FAR*)&sinSourceAddr, &dwAddrLen, NULL, NULL) is SOCKET_ERROR) { dwResult = WSAGetLastError(); printf("Error %d doing a receive\n", dwResult); break; } dwSizeOfHeader = ((pIpHeader->byVerLen)&0x0f)<<2; pIcmpAdvt = (PICMP_ROUTER_ADVT_MSG)(((PBYTE)pIpHeader) + dwSizeOfHeader); if(pIcmpAdvt->byType is 0x9) { for(i = 0; i < MAKELONG(MAKEWORD(pIcmpAdvt->byNumAddrs,0x00),0x0000); i++) { printf("Router Address %s \t Preference %d Lifetime %d\n", inet_ntoa(*(PIN_ADDR)&(pIcmpAdvt->iaAdvt[i].dwRtrIpAddr)), ntohl(pIcmpAdvt->iaAdvt[i].lPrefLevel), ntohs(pIcmpAdvt->wLifeTime)); } break; } } } return 0; }
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