sendto: Invalid argument netbsd

[quant]

hi all,
I wrote a tiny client\server on raw-socket. On linux it works very well ,but on netbsd I've got this errno...
sendto: Invalid argument
sent=sendto(sock, buf, buf_siz, 0, (struct sockaddr *) &sin, sizeof(sin));
sent returns -1, but creates socket eventually without errno
if((raw = socket(PF_INET, SOCK_RAW, PPROTO_TCP))== -1) {
perror("Error creating raw socket: ");
return 0;
}