Fix compiler warnings.

[openttd-joker.git] / src / network / core / udp.cpp

/* $Id: udp.cpp 26046 2013-11-22 21:41:19Z rubidium $ */

/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * @file core/udp.cpp Basic functions to receive and send UDP packets.
 */

#ifdef ENABLE_NETWORK

#include "../../stdafx.h"
#include "../../date_func.h"
#include "../../debug.h"

#include "udp.h"

#include "../../safeguards.h"

/**
 * Create an UDP socket but don't listen yet.
 * @param bind the addresses to bind to.
 */
NetworkUDPSocketHandler::NetworkUDPSocketHandler(NetworkAddressList *bind)
{
        if (bind != NULL) {
                for (NetworkAddress *addr = bind->Begin(); addr != bind->End(); addr++) {
                        *this->bind.Append() = *addr;
                }
        } else {
                /* As hostname NULL and port 0/NULL don't go well when
                 * resolving it we need to add an address for each of
                 * the address families we support. */
                *this->bind.Append() = NetworkAddress(NULL, 0, AF_INET);
                *this->bind.Append() = NetworkAddress(NULL, 0, AF_INET6);
        }
}


/**
 * Start listening on the given host and port.
 * @return true if at least one port is listening
 */
bool NetworkUDPSocketHandler::Listen()
{
        /* Make sure socket is closed */
        this->Close();

        for (NetworkAddress *addr = this->bind.Begin(); addr != this->bind.End(); addr++) {
                addr->Listen(SOCK_DGRAM, &this->sockets);
        }

        return this->sockets.Length() != 0;
}

/**
 * Close the given UDP socket
 */
void NetworkUDPSocketHandler::Close()
{
        for (SocketList::iterator s = this->sockets.Begin(); s != this->sockets.End(); s++) {
                closesocket(s->second);
        }
        this->sockets.Clear();
}

NetworkRecvStatus NetworkUDPSocketHandler::CloseConnection(bool error)
{
        NetworkSocketHandler::CloseConnection(error);
        return NETWORK_RECV_STATUS_OKAY;
}

/**
 * Send a packet over UDP
 * @param p    the packet to send
 * @param recv the receiver (target) of the packet
 * @param all  send the packet using all sockets that can send it
 * @param broadcast whether to send a broadcast message
 */
void NetworkUDPSocketHandler::SendPacket(Packet *p, NetworkAddress *recv, bool all, bool broadcast)
{
        if (this->sockets.Length() == 0) this->Listen();

        for (SocketList::iterator s = this->sockets.Begin(); s != this->sockets.End(); s++) {
                /* Make a local copy because if we resolve it we cannot
                 * easily unresolve it so we can resolve it later again. */
                NetworkAddress send(*recv);

                /* Not the same type */
                if (!send.IsFamily(s->first.GetAddress()->ss_family)) continue;

                p->PrepareToSend();

#ifndef BEOS_NET_SERVER /* will work around this, some day; maybe. */
                if (broadcast) {
                        /* Enable broadcast */
                        unsigned long val = 1;
                        if (setsockopt(s->second, SOL_SOCKET, SO_BROADCAST, (char *) &val, sizeof(val)) < 0) {
                                DEBUG(net, 1, "[udp] setting broadcast failed with: %i", GET_LAST_ERROR());
                        }
                }
#endif

                /* Send the buffer */
                int res = sendto(s->second, (const char*)p->buffer, p->size, 0, (const struct sockaddr *)send.GetAddress(), send.GetAddressLength());
                DEBUG(net, 7, "[udp] sendto(%s)", send.GetAddressAsString());

                /* Check for any errors, but ignore it otherwise */
                if (res == -1) DEBUG(net, 1, "[udp] sendto(%s) failed with: %i", send.GetAddressAsString(), GET_LAST_ERROR());

                if (!all) break;
        }
}

/**
 * Receive a packet at UDP level
 */
void NetworkUDPSocketHandler::ReceivePackets()
{
        for (SocketList::iterator s = this->sockets.Begin(); s != this->sockets.End(); s++) {
                for (int i = 0; i < 1000; i++) { // Do not infinitely loop when DoSing with UDP
                        struct sockaddr_storage client_addr;
                        memset(&client_addr, 0, sizeof(client_addr));

                        Packet p(this);
                        socklen_t client_len = sizeof(client_addr);

                        /* Try to receive anything */
                        SetNonBlocking(s->second); // Some OSes seem to lose the non-blocking status of the socket
                        int nbytes = recvfrom(s->second, (char*)p.buffer, SEND_MTU, 0, (struct sockaddr *)&client_addr, &client_len);

                        /* Did we get the bytes for the base header of the packet? */
                        if (nbytes <= 0) break;    // No data, i.e. no packet
                        if (nbytes <= 2) continue; // Invalid data; try next packet

                        NetworkAddress address(client_addr, client_len);
                        p.PrepareToRead();

                        /* If the size does not match the packet must be corrupted.
                         * Otherwise it will be marked as corrupted later on. */
                        if (nbytes != p.size) {
                                DEBUG(net, 1, "received a packet with mismatching size from %s", address.GetAddressAsString());
                                continue;
                        }

                        /* Handle the packet */
                        this->HandleUDPPacket(&p, &address);
                }
        }
}

/**
 * Serializes the NewGRF information of the NetworkGameInfo struct to several packets
 * @param p    the packet type to write the data to
 * @param info the NetworkGameInfo struct to serialize
 * @return The ready to send packets.
 */
std::list<std::shared_ptr<Packet>> NetworkUDPSocketHandler::SendNetworkGameNewGrfInfo(PacketType packet_type, const NetworkGameInfo *info)
{
        /* Only send the GRF Identification (GRF_ID and MD5 checksum) of
        * the GRFs that are needed, i.e. the ones that the server has
        * selected in the NewGRF GUI and not the ones that are used due
        * to the fact that they are in [newgrf-static] in openttd.cfg */
        uint count = 0;
        uint packet_id = 0;
        std::shared_ptr<Packet> packet = std::make_shared<Packet>(PACKET_UDP_SERVER_NEWGRF_RESPONSE);
        std::list<std::shared_ptr<Packet>> packets_to_send;
        std::list<std::pair<std::shared_ptr<Packet>, std::list<GRFIdentifier>>> packet_content_pairs;

        /* Collect GRF Identifications and split them into several packages */
        for (auto config = info->grfconfig; config != nullptr; config = config->next) {
                if (HasBit(config->flags, GCF_STATIC)) continue;

                if ((count % NETWORK_MAX_GRF_COUNT) == 0) {
                        auto new_pair = std::make_pair(std::make_shared<Packet>(PACKET_UDP_SERVER_NEWGRF_RESPONSE), std::list<GRFIdentifier>());
                        packet_content_pairs.push_back(new_pair);
                }
                
                assert(!packet_content_pairs.empty());

                packet_content_pairs.back().second.push_back(config->ident);

                ++count;
        }

        /* Send actual GRF Identifications */
        for (auto pair : packet_content_pairs) {
                auto packet = pair.first;

                packet->Send_uint8(NETWORK_NEWGRF_INFO_VERSION);
                packet->Send_uint8(packet_id++); // The id of this packet
                packet->Send_uint8((uint8)pair.second.size()); // Number of NewGRFs in this packet

                for (auto grf_ident : pair.second) {
                        this->SendGRFIdentifier(packet.get(), &grf_ident);
                }

                packets_to_send.push_back(packet);
        }

        return packets_to_send;
}


/**
 * Serializes the NetworkGameInfo struct to the packet
 * @param p    the packet to write the data to
 * @param info the NetworkGameInfo struct to serialize
 */
void NetworkUDPSocketHandler::SendNetworkGameInfo(Packet *p, const NetworkGameInfo *info)
{
        p->Send_uint8 (NETWORK_GAME_INFO_VERSION);

        /*
         *              Please observe the order.
         * The parts must be read in the same order as they are sent!
         */

        /* Update the documentation in udp.h on changes
         * to the NetworkGameInfo wire-protocol! */

        /* NETWORK_GAME_INFO_VERSION = 128 */
        {
                /* Only send the GRF Identification (GRF_ID and MD5 checksum) of
                 * the GRFs that are needed, i.e. the ones that the server has
                 * selected in the NewGRF GUI and not the ones that are used due
                 * to the fact that they are in [newgrf-static] in openttd.cfg */
                uint count = 0;

                /* Count number of GRFs to send information about */
                for (auto config = info->grfconfig; config != nullptr; config = config->next) {
                        if (!HasBit(config->flags, GCF_STATIC)) ++count;
                }

                uint8 num_grf_packets_to_expect = std::ceil((float)count / NETWORK_MAX_GRF_COUNT);

                // Send number of GRF info packets that will be sent
                p->Send_uint8(num_grf_packets_to_expect);

                // Actual GRF Identifications will be send in multiple PACKET_UDP_SERVER_NEWGRF_RESPONSE packages.
                // This package has not enough storage to send all that data depending on how many NewGRFs are active.
        }

        /* NETWORK_GAME_INFO_VERSION = 4 */
        {
                // This part is deprecated and is no longer sent. The version 128 part replaces it.
        }

        /* NETWORK_GAME_INFO_VERSION = 3 */
        p->Send_uint32(info->game_date);
        p->Send_uint32(info->start_date);

        /* NETWORK_GAME_INFO_VERSION = 2 */
        p->Send_uint8 (info->companies_max);
        p->Send_uint8 (info->companies_on);
        p->Send_uint8 (info->spectators_max);

        /* NETWORK_GAME_INFO_VERSION = 1 */
        p->Send_string(info->server_name);
        p->Send_string(info->server_revision);
        p->Send_uint8 (info->server_lang);
        p->Send_bool  (info->use_password);
        p->Send_uint8 (info->clients_max);
        p->Send_uint8 (info->clients_on);
        p->Send_uint8 (info->spectators_on);
        p->Send_string(info->map_name);
        p->Send_uint16(info->map_width);
        p->Send_uint16(info->map_height);
        p->Send_uint8 (info->map_set);
        p->Send_bool  (info->dedicated);
}

/**
 * Deserializes the NewGRF information of the NetworkGameInfo struct from one out of several sent packets
 * @param p    the packet to read the data from
 * @param info the NetworkGameInfo to deserialize into
 */
void NetworkUDPSocketHandler::ReceiveNetworkGameNewGrfInfo(Packet *p, NetworkGameInfo *info)
{
        auto new_grf_info_packet_version =  p->Recv_uint8();

        // For now we only handle this specific version.
        if (new_grf_info_packet_version != NETWORK_NEWGRF_INFO_VERSION) return;

        auto packet_id = p->Recv_uint8();

        // Check if we already received this one. Bail if so. No need to process it again.
        if (std::any_of(info->received_grf_identifiers.begin(), info->received_grf_identifiers.end(), [&](auto item) {
                return item.first == packet_id;
        })) return;

        auto num_grfs = p->Recv_uint8();

        /* Broken/bad data. It cannot have that many NewGRFs. */
        if (num_grfs > NETWORK_MAX_GRF_COUNT) return;

        auto received_pair = std::make_pair(packet_id, std::list<GRFIdentifier>());

        for (auto i = 0; i < num_grfs; ++i) {
                GRFIdentifier ident;
                this->ReceiveGRFIdentifier(p, &ident);

                received_pair.second.push_back(ident);
        }

        info->received_grf_identifiers.push_back(received_pair);
}

/**
 * Deserializes the NetworkGameInfo struct minus NewGRF information from the packet
 * @param p    the packet to read the data from
 * @param info the NetworkGameInfo to deserialize into
 */
void NetworkUDPSocketHandler::ReceiveNetworkGameInfo(Packet *p, NetworkGameInfo *info)
{
        static const Date MAX_DATE = ConvertYMDToDate(MAX_YEAR, 11, 31); // December is month 11

        info->game_info_version = p->Recv_uint8();

        /*
         *              Please observe the order.
         * The parts must be read in the same order as they are sent!
         */

        /* Update the documentation in udp.h on changes
         * to the NetworkGameInfo wire-protocol! */

        switch (info->game_info_version) {
                case 128: FALLTHROUGH;
                case 4: {
                        if (info->game_info_version == 4) {
                                GRFConfig **dst = &info->grfconfig;
                                uint i;
                                uint num_grfs = p->Recv_uint8();

                                /* Broken/bad data. It cannot have that many NewGRFs. */
                                if (num_grfs > NETWORK_MAX_GRF_COUNT) return;

                                for (i = 0; i < num_grfs; i++) {
                                        GRFConfig *c = new GRFConfig();
                                        this->ReceiveGRFIdentifier(p, &c->ident);
                                        this->HandleIncomingNetworkGameInfoGRFConfig(c);

                                        /* Append GRFConfig to the list */
                                        *dst = c;
                                        dst = &c->next;
                                }
                        } else if (info->game_info_version == 128) {
                                // In NETWORK_GAME_INFO_VERSION 128 the actual newGRF information is sent via a different package type.
                                // Check ReceiveNetworkGameNewGrfInfo().
                                info->new_grf_packages_to_expect = p->Recv_uint8();
                        }
                }
                FALLTHROUGH;

                case 3:
                        info->game_date      = Clamp(p->Recv_uint32(), 0, MAX_DATE);
                        info->start_date     = Clamp(p->Recv_uint32(), 0, MAX_DATE);
                        FALLTHROUGH;

                case 2:
                        info->companies_max  = p->Recv_uint8 ();
                        info->companies_on   = p->Recv_uint8 ();
                        info->spectators_max = p->Recv_uint8 ();
                        FALLTHROUGH;

                case 1:
                        p->Recv_string(info->server_name,     sizeof(info->server_name));
                        p->Recv_string(info->server_revision, sizeof(info->server_revision));
                        info->server_lang    = p->Recv_uint8 ();
                        info->use_password   = p->Recv_bool  ();
                        info->clients_max    = p->Recv_uint8 ();
                        info->clients_on     = p->Recv_uint8 ();
                        info->spectators_on  = p->Recv_uint8 ();
                        if (info->game_info_version < 3) { // 16 bits dates got scrapped and are read earlier
                                info->game_date    = p->Recv_uint16() + DAYS_TILL_ORIGINAL_BASE_YEAR;
                                info->start_date   = p->Recv_uint16() + DAYS_TILL_ORIGINAL_BASE_YEAR;
                        }
                        p->Recv_string(info->map_name, sizeof(info->map_name));
                        info->map_width      = p->Recv_uint16();
                        info->map_height     = p->Recv_uint16();
                        info->map_set        = p->Recv_uint8 ();
                        info->dedicated      = p->Recv_bool  ();

                        if (info->server_lang >= NETWORK_NUM_LANGUAGES)  info->server_lang = 0;
                        if (info->map_set     >= NETWORK_NUM_LANDSCAPES) info->map_set     = 0;
        }
}

/**
 * Handle an incoming packets by sending it to the correct function.
 * @param p the received packet
 * @param client_addr the sender of the packet
 */
void NetworkUDPSocketHandler::HandleUDPPacket(Packet *p, NetworkAddress *client_addr)
{
        PacketUDPType type;

        /* New packet == new client, which has not quit yet */
        this->Reopen();

        type = (PacketUDPType)p->Recv_uint8();

        switch (this->HasClientQuit() ? PACKET_UDP_END : type) {
                case PACKET_UDP_CLIENT_FIND_SERVER:             this->Receive_CLIENT_FIND_SERVER(p, client_addr);               break;
                case PACKET_UDP_SERVER_RESPONSE:                this->Receive_SERVER_RESPONSE(p, client_addr);                  break;
                case PACKET_UDP_SERVER_NEWGRF_RESPONSE: this->Receive_SERVER_NEWGRF_RESPONSE(p, client_addr);   break;
                case PACKET_UDP_CLIENT_DETAIL_INFO:             this->Receive_CLIENT_DETAIL_INFO(p, client_addr);               break;
                case PACKET_UDP_SERVER_DETAIL_INFO:             this->Receive_SERVER_DETAIL_INFO(p, client_addr);               break;
                case PACKET_UDP_SERVER_REGISTER:                this->Receive_SERVER_REGISTER(p, client_addr);                  break;
                case PACKET_UDP_MASTER_ACK_REGISTER:    this->Receive_MASTER_ACK_REGISTER(p, client_addr);              break;
                case PACKET_UDP_CLIENT_GET_LIST:                this->Receive_CLIENT_GET_LIST(p, client_addr);                  break;
                case PACKET_UDP_MASTER_RESPONSE_LIST:   this->Receive_MASTER_RESPONSE_LIST(p, client_addr);             break;
                case PACKET_UDP_SERVER_UNREGISTER:              this->Receive_SERVER_UNREGISTER(p, client_addr);                break;
                case PACKET_UDP_CLIENT_GET_NEWGRFS:             this->Receive_CLIENT_GET_NEWGRFS(p, client_addr);               break;
                case PACKET_UDP_SERVER_NEWGRFS:                 this->Receive_SERVER_NEWGRFS(p, client_addr);                   break;
                case PACKET_UDP_MASTER_SESSION_KEY:             this->Receive_MASTER_SESSION_KEY(p, client_addr);               break;

                default:
                        if (this->HasClientQuit()) {
                                DEBUG(net, 0, "[udp] received invalid packet type %d from %s", type, client_addr->GetAddressAsString());
                        } else {
                                DEBUG(net, 0, "[udp] received illegal packet from %s", client_addr->GetAddressAsString());
                        }
                        break;
        }
}

/**
 * Helper for logging receiving invalid packets.
 * @param type The received packet type.
 * @param client_addr The address we received the packet from.
 */
void NetworkUDPSocketHandler::ReceiveInvalidPacket(PacketUDPType type, NetworkAddress *client_addr)
{
        DEBUG(net, 0, "[udp] received packet type %d on wrong port from %s", type, client_addr->GetAddressAsString());
}

void NetworkUDPSocketHandler::Receive_CLIENT_FIND_SERVER(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_CLIENT_FIND_SERVER, client_addr); }
void NetworkUDPSocketHandler::Receive_SERVER_RESPONSE(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_SERVER_RESPONSE, client_addr); }
void NetworkUDPSocketHandler::Receive_SERVER_NEWGRF_RESPONSE(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_SERVER_NEWGRF_RESPONSE, client_addr); }
void NetworkUDPSocketHandler::Receive_CLIENT_DETAIL_INFO(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_CLIENT_DETAIL_INFO, client_addr); }
void NetworkUDPSocketHandler::Receive_SERVER_DETAIL_INFO(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_SERVER_DETAIL_INFO, client_addr); }
void NetworkUDPSocketHandler::Receive_SERVER_REGISTER(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_SERVER_REGISTER, client_addr); }
void NetworkUDPSocketHandler::Receive_MASTER_ACK_REGISTER(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_MASTER_ACK_REGISTER, client_addr); }
void NetworkUDPSocketHandler::Receive_CLIENT_GET_LIST(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_CLIENT_GET_LIST, client_addr); }
void NetworkUDPSocketHandler::Receive_MASTER_RESPONSE_LIST(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_MASTER_RESPONSE_LIST, client_addr); }
void NetworkUDPSocketHandler::Receive_SERVER_UNREGISTER(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_SERVER_UNREGISTER, client_addr); }
void NetworkUDPSocketHandler::Receive_CLIENT_GET_NEWGRFS(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_CLIENT_GET_NEWGRFS, client_addr); }
void NetworkUDPSocketHandler::Receive_SERVER_NEWGRFS(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_SERVER_NEWGRFS, client_addr); }
void NetworkUDPSocketHandler::Receive_MASTER_SESSION_KEY(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_MASTER_SESSION_KEY, client_addr); }

#endif /* ENABLE_NETWORK */