void Connection::add_option(TCP::Option::Kind kind, TCP::Packet_ptr packet) {
switch(kind) {
case Option::MSS: {
packet->add_tcp_option<Option::opt_mss>(host_.MSS());
debug2("<TCP::Connection::add_option@Option::MSS> Packet: %s - MSS: %u\n",
packet->to_string().c_str(), ntohs(*(uint16_t*)(packet->tcp_options()+2)));
break;
}
default:
break;
}
}
void Connection::parse_options(TCP::Packet_ptr packet) {
assert(packet->has_tcp_options());
debug("<TCP::parse_options> Parsing options. Offset: %u, Options: %u \n",
packet->offset(), packet->tcp_options_length());
auto* opt = packet->tcp_options();
while((char*)opt < packet->tcp_data()) {
auto* option = (TCP::Option*)opt;
switch(option->kind) {
case Option::END: {
return;
}
case Option::NOP: {
opt++;
break;
}
case Option::MSS: {
// unlikely
if(option->length != 4)
throw TCPBadOptionException{Option::MSS, "length != 4"};
// unlikely
if(!packet->isset(SYN))
throw TCPBadOptionException{Option::MSS, "Non-SYN packet"};
auto* opt_mss = (Option::opt_mss*)option;
uint16_t mss = ntohs(opt_mss->mss);
cb.SND.MSS = mss;
debug2("<TCP::parse_options@Option:MSS> MSS: %u \n", mss);
opt += option->length;
break;
}
default:
return;
}
}
}