celestar@5642: /* $Id$ */
celestar@5642: 
celestar@5642: #ifdef ENABLE_NETWORK
celestar@5642: 
celestar@5642: #include "../../stdafx.h"
celestar@5642: #include "../../debug.h"
celestar@5642: #include "../../openttd.h"
celestar@5642: #include "../../variables.h"
rubidium@5643: #include "table/strings.h"
celestar@5642: #include "../../functions.h"
celestar@5642: 
celestar@5648: #include "../network_data.h"
celestar@5642: #include "packet.h"
celestar@5642: #include "tcp.h"
celestar@5650: #include "../../helpers.hpp"
celestar@5642: 
celestar@5642: /**
celestar@5642:  * @file tcp.c Basic functions to receive and send TCP packets.
celestar@5642:  */
celestar@5642: 
celestar@5642: /**
celestar@5642:  * Functions to help NetworkRecv_Packet/NetworkSend_Packet a bit
celestar@5642:  *  A socket can make errors. When that happens this handles what to do.
celestar@5642:  * For clients: close connection and drop back to main-menu
celestar@5642:  * For servers: close connection and that is it
celestar@5642:  * @param cs the client to close the connection of
celestar@5642:  * @return the new status
celestar@5642:  */
celestar@5642: NetworkRecvStatus CloseConnection(NetworkClientState *cs)
celestar@5642: {
celestar@5642: 	NetworkCloseClient(cs);
celestar@5642: 
celestar@5642: 	/* Clients drop back to the main menu */
celestar@5642: 	if (!_network_server && _networking) {
celestar@5642: 		_switch_mode = SM_MENU;
celestar@5642: 		_networking = false;
celestar@5642: 		_switch_mode_errorstr = STR_NETWORK_ERR_LOSTCONNECTION;
celestar@5642: 
celestar@5642: 		return NETWORK_RECV_STATUS_CONN_LOST;
celestar@5642: 	}
celestar@5642: 
celestar@5642: 	return NETWORK_RECV_STATUS_OKAY;
celestar@5642: }
celestar@5642: 
celestar@5642: /**
celestar@5642:  * Whether the client has quit or not (used in packet.c)
celestar@5642:  * @param cs the client to check
celestar@5642:  * @return true if the client has quit
celestar@5642:  */
celestar@5648: bool HasClientQuit(const NetworkClientState *cs)
celestar@5642: {
celestar@5642: 	return cs->has_quit;
celestar@5642: }
celestar@5642: 
celestar@5642: /**
celestar@5642:  * This function puts the packet in the send-queue and it is send as
celestar@5642:  * soon as possible. This is the next tick, or maybe one tick later
celestar@5642:  * if the OS-network-buffer is full)
celestar@5642:  * @param packet the packet to send
celestar@5642:  * @param cs     the client to send to
celestar@5642:  */
celestar@5642: void NetworkSend_Packet(Packet *packet, NetworkClientState *cs)
celestar@5642: {
celestar@5642: 	Packet *p;
celestar@5642: 	assert(packet != NULL);
celestar@5642: 
celestar@5642: 	packet->pos = 0;
celestar@5642: 	packet->next = NULL;
celestar@5642: 
celestar@5642: 	NetworkSend_FillPacketSize(packet);
celestar@5642: 
celestar@5642: 	/* Locate last packet buffered for the client */
celestar@5642: 	p = cs->packet_queue;
celestar@5642: 	if (p == NULL) {
celestar@5642: 		/* No packets yet */
celestar@5642: 		cs->packet_queue = packet;
celestar@5642: 	} else {
celestar@5642: 		/* Skip to the last packet */
celestar@5642: 		while (p->next != NULL) p = p->next;
celestar@5642: 		p->next = packet;
celestar@5642: 	}
celestar@5642: }
celestar@5642: 
celestar@5642: /**
celestar@5642:  * Sends all the buffered packets out for this client. It stops when:
celestar@5642:  *   1) all packets are send (queue is empty)
celestar@5642:  *   2) the OS reports back that it can not send any more
celestar@5642:  *      data right now (full network-buffer, it happens ;))
celestar@5642:  *   3) sending took too long
celestar@5642:  * @param cs the client to send the packets for
celestar@5642:  */
celestar@5642: bool NetworkSend_Packets(NetworkClientState *cs)
celestar@5642: {
celestar@5642: 	ssize_t res;
celestar@5642: 	Packet *p;
celestar@5642: 
celestar@5642: 	/* We can not write to this socket!! */
celestar@5642: 	if (!cs->writable) return false;
celestar@5642: 	if (cs->socket == INVALID_SOCKET) return false;
celestar@5642: 
celestar@5642: 	p = cs->packet_queue;
celestar@5642: 	while (p != NULL) {
celestar@5650: 		res = send(cs->socket, (const char*)p->buffer + p->pos, p->size - p->pos, 0);
celestar@5642: 		if (res == -1) {
celestar@5642: 			int err = GET_LAST_ERROR();
celestar@5642: 			if (err != EWOULDBLOCK) {
celestar@5642: 				/* Something went wrong.. close client! */
celestar@5642: 				DEBUG(net, 0, "send failed with error %d", err);
celestar@5642: 				CloseConnection(cs);
celestar@5642: 				return false;
celestar@5642: 			}
celestar@5642: 			return true;
celestar@5642: 		}
celestar@5642: 		if (res == 0) {
celestar@5642: 			/* Client/server has left us :( */
celestar@5642: 			CloseConnection(cs);
celestar@5642: 			return false;
celestar@5642: 		}
celestar@5642: 
celestar@5642: 		p->pos += res;
celestar@5642: 
celestar@5642: 		/* Is this packet sent? */
celestar@5642: 		if (p->pos == p->size) {
celestar@5642: 			/* Go to the next packet */
celestar@5642: 			cs->packet_queue = p->next;
celestar@5642: 			free(p);
celestar@5642: 			p = cs->packet_queue;
celestar@5642: 		} else {
celestar@5642: 			return true;
celestar@5642: 		}
celestar@5642: 	}
celestar@5642: 
celestar@5642: 	return true;
celestar@5642: }
celestar@5642: 
celestar@5642: /**
celestar@5642:  * Receives a packet for the given client
celestar@5642:  * @param cs     the client to (try to) receive a packet for
celestar@5642:  * @param status the variable to store the status into
celestar@5642:  * @return the received packet (or NULL when it didn't receive one)
celestar@5642:  */
celestar@5642: Packet *NetworkRecv_Packet(NetworkClientState *cs, NetworkRecvStatus *status)
celestar@5642: {
celestar@5642: 	ssize_t res;
celestar@5642: 	Packet *p;
celestar@5642: 
celestar@5642: 	*status = NETWORK_RECV_STATUS_OKAY;
celestar@5642: 
celestar@5642: 	if (cs->socket == INVALID_SOCKET) return NULL;
celestar@5642: 
celestar@5642: 	if (cs->packet_recv == NULL) {
celestar@5650: 		MallocT(&cs->packet_recv, 1);
celestar@5642: 		if (cs->packet_recv == NULL) error("Failed to allocate packet");
celestar@5642: 		/* Set pos to zero! */
celestar@5642: 		cs->packet_recv->pos = 0;
celestar@5642: 		cs->packet_recv->size = 0; // Can be ommited, just for safety reasons
celestar@5642: 	}
celestar@5642: 
celestar@5642: 	p = cs->packet_recv;
celestar@5642: 
celestar@5642: 	/* Read packet size */
celestar@5642: 	if (p->pos < sizeof(PacketSize)) {
celestar@5642: 		while (p->pos < sizeof(PacketSize)) {
celestar@5642: 			/* Read the size of the packet */
celestar@5650: 			res = recv(cs->socket, (char*)p->buffer + p->pos, sizeof(PacketSize) - p->pos, 0);
celestar@5642: 			if (res == -1) {
celestar@5642: 				int err = GET_LAST_ERROR();
celestar@5642: 				if (err != EWOULDBLOCK) {
celestar@5642: 					/* Something went wrong... (104 is connection reset by peer) */
celestar@5642: 					if (err != 104) DEBUG(net, 0, "recv failed with error %d", err);
celestar@5642: 					*status = CloseConnection(cs);
celestar@5642: 					return NULL;
celestar@5642: 				}
celestar@5642: 				/* Connection would block, so stop for now */
celestar@5642: 				return NULL;
celestar@5642: 			}
celestar@5642: 			if (res == 0) {
celestar@5642: 				/* Client/server has left */
celestar@5642: 				*status = CloseConnection(cs);
celestar@5642: 				return NULL;
celestar@5642: 			}
celestar@5642: 			p->pos += res;
celestar@5642: 		}
celestar@5642: 
celestar@5642: 		NetworkRecv_ReadPacketSize(p);
celestar@5642: 
celestar@5642: 		if (p->size > SEND_MTU) {
celestar@5642: 			*status = CloseConnection(cs);
celestar@5642: 			return NULL;
celestar@5642: 		}
celestar@5642: 	}
celestar@5642: 
celestar@5642: 	/* Read rest of packet */
celestar@5642: 	while (p->pos < p->size) {
celestar@5650: 		res = recv(cs->socket, (char*)p->buffer + p->pos, p->size - p->pos, 0);
celestar@5642: 		if (res == -1) {
celestar@5642: 			int err = GET_LAST_ERROR();
celestar@5642: 			if (err != EWOULDBLOCK) {
celestar@5642: 				/* Something went wrong... (104 is connection reset by peer) */
celestar@5642: 				if (err != 104) DEBUG(net, 0, "recv failed with error %d", err);
celestar@5642: 				*status = CloseConnection(cs);
celestar@5642: 				return NULL;
celestar@5642: 			}
celestar@5642: 			/* Connection would block */
celestar@5642: 			return NULL;
celestar@5642: 		}
celestar@5642: 		if (res == 0) {
celestar@5642: 			/* Client/server has left */
celestar@5642: 			*status = CloseConnection(cs);
celestar@5642: 			return NULL;
celestar@5642: 		}
celestar@5642: 
celestar@5642: 		p->pos += res;
celestar@5642: 	}
celestar@5642: 
celestar@5642: 	/* We have a complete packet, return it! */
celestar@5642: 	p->pos = 2;
celestar@5642: 	p->next = NULL; // Should not be needed, but who knows...
celestar@5642: 
celestar@5642: 	/* Prepare for receiving a new packet */
celestar@5642: 	cs->packet_recv = NULL;
celestar@5642: 
celestar@5642: 	return p;
celestar@5642: }
celestar@5642: 
celestar@5642: #endif /* ENABLE_NETWORK */