congestvpn/UdpVpnServer.cpp

#include <cstring>

#include "UdpVpnServer.hpp"
#include "ip_header.hpp"

UdpVpnServer::UdpVpnServer(in_port_t port) : UdpVpn() {
    memset(&_bind_addr, 0, sizeof(_bind_addr));
    bind(in6addr_any, port);
}

UdpVpnServer::UdpVpnServer(const struct in6_addr& bind_addr6, in_port_t port)
    : UdpVpn()
{
    memset(&_bind_addr, 0, sizeof(_bind_addr));
    bind(bind_addr6, port);
}

void UdpVpnServer::acquire_peer(
        TunnelledPacket& packet,
        const sockaddr_in6& peer_ext_addr)
{
    if(_peer)
        return;  // Refusing a connection if we already have one
    // TODO: reset state at some point/if connection broken

    if(!packet.parse_as_ipv6())
        return;
    const in6_addr& peer_inner_addr = packet.get_ipv6_header().source;
    _peer = std::make_unique<VpnPeer>(this, peer_ext_addr, peer_inner_addr);

    packet.get_packet().set_peer(_peer.get());

    debugf("Got new peer %s:%d -- %s\n",
            format_address(peer_ext_addr.sin6_addr.s6_addr),
            htons(peer_ext_addr.sin6_port),
            format_address(peer_inner_addr.s6_addr));
}

void UdpVpnServer::bind(const struct in6_addr& bind_addr6, in_port_t port) {
    int rc;

    _bind_addr.sin6_family = AF_INET6;
    _bind_addr.sin6_port = htons(port);
    _bind_addr.sin6_addr = bind_addr6;

    rc = ::bind(
            _socket, (const struct sockaddr*)&_bind_addr, sizeof(_bind_addr));
    if(rc < 0) {
        throw UdpVpn::InitializationError("Cannot bind socket", errno, true);
    }

    debugf("> Listening on port %d\n", port);
}