Sending UDP Raw socket

Posted on 16th Feb 2014 by admin

I truly need help on this. I am trying to write a test program that simulate a network environment that have 5 clients and 1 server. To do so, I need to be able to edit IP header to change it's source address and various other values in the header. To change it, I need to use socket raw and IP_HRINCL socket option.

However, it doesn't work during the send with error 10049, "Address not available" from WSAGetLastError(). I am wondering how would I do so, and can I please look at a simple example on how to change your IP header and send it. By the way, I am using winsock with VC++, and my os is XP. I know there are some issues regarding XP's compatibility with Raw socket. In addition, if winsock is not a viable option, is there anyway for me to write in lower socket?

Here's my code

Code: #include #include #include using namespace std; int initialize(); void main() { initialize(); SOCKET sock = socket(AF_INET,SOCK_RAW,IPPROTO_IP); int error; char on = 1; setsockopt(sock,IPPROTO_IP,IP_HDRINCL,&on,sizeof(on)); if(sock == INVALID_SOCKET) cout << "Crap raw socket " << endl; /* Header data */ unsigned char header[32] = {0x45,0x00,0x00,0x20,0x01,0xf1,0x00,0x00,0x05,0x11,0x9c,0x0a,0x05,0x3a,0x38,0x02,0xe0, 0x02,0xfa,0x93}; memset(header+20,0,12); SOCKADDR_IN sock_add; sock_add.sin_family = AF_INET; sock_add.sin_port = htons(1542); sock_add.sin_addr.s_addr = inet_addr("192.168.1.1"); error = sendto(sock,(char*)header,32,0,(LPSOCKADDR)&sock_add,sizeof(SOCKADDR_IN)); } int initialize() { int t; /* Before any Winsock function to work, we need to call to wsock.dll to initialize those functions */ WSADATA wsa_data; t = WSAStartup(MAKEWORD(1,1), &wsa_data); if(t != 0) return -1; else return 0; }