rubidium@5469: /* $Id$ */
rubidium@5469: 
rubidium@5469: #ifdef ENABLE_NETWORK
rubidium@5469: 
rubidium@5469: #include "../../stdafx.h"
rubidium@5469: #include "../../debug.h"
rubidium@5469: #include "../../openttd.h"
rubidium@5469: #include "../../variables.h"
rubidium@5475: #include "table/strings.h"
rubidium@5469: #include "../../functions.h"
rubidium@5469: 
rubidium@5527: #include "../network_data.h"
rubidium@5469: #include "packet.h"
rubidium@5469: #include "tcp.h"
rubidium@5469: 
rubidium@5469: /**
rubidium@5469:  * @file tcp.c Basic functions to receive and send TCP packets.
rubidium@5469:  */
rubidium@5469: 
rubidium@5469: /**
rubidium@5469:  * Functions to help NetworkRecv_Packet/NetworkSend_Packet a bit
rubidium@5469:  *  A socket can make errors. When that happens this handles what to do.
rubidium@5469:  * For clients: close connection and drop back to main-menu
rubidium@5469:  * For servers: close connection and that is it
rubidium@5469:  * @param cs the client to close the connection of
rubidium@5469:  * @return the new status
rubidium@5469:  */
rubidium@5469: NetworkRecvStatus CloseConnection(NetworkClientState *cs)
rubidium@5469: {
rubidium@5469: 	NetworkCloseClient(cs);
rubidium@5469: 
rubidium@5469: 	/* Clients drop back to the main menu */
rubidium@5469: 	if (!_network_server && _networking) {
rubidium@5469: 		_switch_mode = SM_MENU;
rubidium@5469: 		_networking = false;
rubidium@5469: 		_switch_mode_errorstr = STR_NETWORK_ERR_LOSTCONNECTION;
rubidium@5469: 
rubidium@5469: 		return NETWORK_RECV_STATUS_CONN_LOST;
rubidium@5469: 	}
rubidium@5469: 
rubidium@5469: 	return NETWORK_RECV_STATUS_OKAY;
rubidium@5469: }
rubidium@5469: 
rubidium@5469: /**
rubidium@5469:  * Whether the client has quit or not (used in packet.c)
rubidium@5469:  * @param cs the client to check
rubidium@5469:  * @return true if the client has quit
rubidium@5469:  */
rubidium@5528: bool HasClientQuit(const NetworkClientState *cs)
rubidium@5469: {
rubidium@5469: 	return cs->has_quit;
rubidium@5469: }
rubidium@5469: 
rubidium@5469: /**
rubidium@5469:  * This function puts the packet in the send-queue and it is send as
rubidium@5469:  * soon as possible. This is the next tick, or maybe one tick later
rubidium@5469:  * if the OS-network-buffer is full)
rubidium@5469:  * @param packet the packet to send
rubidium@5469:  * @param cs     the client to send to
rubidium@5469:  */
rubidium@5469: void NetworkSend_Packet(Packet *packet, NetworkClientState *cs)
rubidium@5469: {
rubidium@5469: 	Packet *p;
rubidium@5469: 	assert(packet != NULL);
rubidium@5469: 
rubidium@5469: 	packet->pos = 0;
rubidium@5469: 	packet->next = NULL;
rubidium@5469: 
rubidium@5469: 	NetworkSend_FillPacketSize(packet);
rubidium@5469: 
rubidium@5469: 	/* Locate last packet buffered for the client */
rubidium@5469: 	p = cs->packet_queue;
rubidium@5469: 	if (p == NULL) {
rubidium@5469: 		/* No packets yet */
rubidium@5469: 		cs->packet_queue = packet;
rubidium@5469: 	} else {
rubidium@5469: 		/* Skip to the last packet */
rubidium@5469: 		while (p->next != NULL) p = p->next;
rubidium@5469: 		p->next = packet;
rubidium@5469: 	}
rubidium@5469: }
rubidium@5469: 
rubidium@5469: /**
rubidium@5469:  * Sends all the buffered packets out for this client. It stops when:
rubidium@5469:  *   1) all packets are send (queue is empty)
rubidium@5469:  *   2) the OS reports back that it can not send any more
rubidium@5469:  *      data right now (full network-buffer, it happens ;))
rubidium@5469:  *   3) sending took too long
rubidium@5469:  * @param cs the client to send the packets for
rubidium@5469:  */
rubidium@5469: bool NetworkSend_Packets(NetworkClientState *cs)
rubidium@5469: {
rubidium@5469: 	ssize_t res;
rubidium@5469: 	Packet *p;
rubidium@5469: 
rubidium@5469: 	/* We can not write to this socket!! */
rubidium@5469: 	if (!cs->writable) return false;
rubidium@5469: 	if (cs->socket == INVALID_SOCKET) return false;
rubidium@5469: 
rubidium@5469: 	p = cs->packet_queue;
rubidium@5469: 	while (p != NULL) {
rubidium@5469: 		res = send(cs->socket, p->buffer + p->pos, p->size - p->pos, 0);
rubidium@5469: 		if (res == -1) {
rubidium@5469: 			int err = GET_LAST_ERROR();
rubidium@5469: 			if (err != EWOULDBLOCK) {
rubidium@5469: 				/* Something went wrong.. close client! */
rubidium@5469: 				DEBUG(net, 0, "send failed with error %d", err);
rubidium@5469: 				CloseConnection(cs);
rubidium@5469: 				return false;
rubidium@5469: 			}
rubidium@5469: 			return true;
rubidium@5469: 		}
rubidium@5469: 		if (res == 0) {
rubidium@5469: 			/* Client/server has left us :( */
rubidium@5469: 			CloseConnection(cs);
rubidium@5469: 			return false;
rubidium@5469: 		}
rubidium@5469: 
rubidium@5469: 		p->pos += res;
rubidium@5469: 
rubidium@5469: 		/* Is this packet sent? */
rubidium@5469: 		if (p->pos == p->size) {
rubidium@5469: 			/* Go to the next packet */
rubidium@5469: 			cs->packet_queue = p->next;
rubidium@5469: 			free(p);
rubidium@5469: 			p = cs->packet_queue;
rubidium@5469: 		} else {
rubidium@5469: 			return true;
rubidium@5469: 		}
rubidium@5469: 	}
rubidium@5469: 
rubidium@5469: 	return true;
rubidium@5469: }
rubidium@5469: 
rubidium@5469: /**
rubidium@5469:  * Receives a packet for the given client
rubidium@5469:  * @param cs     the client to (try to) receive a packet for
rubidium@5469:  * @param status the variable to store the status into
rubidium@5469:  * @return the received packet (or NULL when it didn't receive one)
rubidium@5469:  */
rubidium@5469: Packet *NetworkRecv_Packet(NetworkClientState *cs, NetworkRecvStatus *status)
rubidium@5469: {
rubidium@5469: 	ssize_t res;
rubidium@5469: 	Packet *p;
rubidium@5469: 
rubidium@5469: 	*status = NETWORK_RECV_STATUS_OKAY;
rubidium@5469: 
rubidium@5469: 	if (cs->socket == INVALID_SOCKET) return NULL;
rubidium@5469: 
rubidium@5469: 	if (cs->packet_recv == NULL) {
rubidium@5469: 		cs->packet_recv = malloc(sizeof(Packet));
rubidium@5469: 		if (cs->packet_recv == NULL) error("Failed to allocate packet");
rubidium@5469: 		/* Set pos to zero! */
rubidium@5469: 		cs->packet_recv->pos = 0;
rubidium@5469: 		cs->packet_recv->size = 0; // Can be ommited, just for safety reasons
rubidium@5469: 	}
rubidium@5469: 
rubidium@5469: 	p = cs->packet_recv;
rubidium@5469: 
rubidium@5469: 	/* Read packet size */
rubidium@5469: 	if (p->pos < sizeof(PacketSize)) {
rubidium@5469: 		while (p->pos < sizeof(PacketSize)) {
rubidium@5469: 			/* Read the size of the packet */
rubidium@5469: 			res = recv(cs->socket, p->buffer + p->pos, sizeof(PacketSize) - p->pos, 0);
rubidium@5469: 			if (res == -1) {
rubidium@5469: 				int err = GET_LAST_ERROR();
rubidium@5469: 				if (err != EWOULDBLOCK) {
rubidium@5469: 					/* Something went wrong... (104 is connection reset by peer) */
rubidium@5469: 					if (err != 104) DEBUG(net, 0, "recv failed with error %d", err);
rubidium@5469: 					*status = CloseConnection(cs);
rubidium@5469: 					return NULL;
rubidium@5469: 				}
rubidium@5469: 				/* Connection would block, so stop for now */
rubidium@5469: 				return NULL;
rubidium@5469: 			}
rubidium@5469: 			if (res == 0) {
rubidium@5469: 				/* Client/server has left */
rubidium@5469: 				*status = CloseConnection(cs);
rubidium@5469: 				return NULL;
rubidium@5469: 			}
rubidium@5469: 			p->pos += res;
rubidium@5469: 		}
rubidium@5469: 
rubidium@5469: 		NetworkRecv_ReadPacketSize(p);
rubidium@5469: 
rubidium@5469: 		if (p->size > SEND_MTU) {
rubidium@5469: 			*status = CloseConnection(cs);
rubidium@5469: 			return NULL;
rubidium@5469: 		}
rubidium@5469: 	}
rubidium@5469: 
rubidium@5469: 	/* Read rest of packet */
rubidium@5469: 	while (p->pos < p->size) {
rubidium@5469: 		res = recv(cs->socket, p->buffer + p->pos, p->size - p->pos, 0);
rubidium@5469: 		if (res == -1) {
rubidium@5469: 			int err = GET_LAST_ERROR();
rubidium@5469: 			if (err != EWOULDBLOCK) {
rubidium@5469: 				/* Something went wrong... (104 is connection reset by peer) */
rubidium@5469: 				if (err != 104) DEBUG(net, 0, "recv failed with error %d", err);
rubidium@5469: 				*status = CloseConnection(cs);
rubidium@5469: 				return NULL;
rubidium@5469: 			}
rubidium@5469: 			/* Connection would block */
rubidium@5469: 			return NULL;
rubidium@5469: 		}
rubidium@5469: 		if (res == 0) {
rubidium@5469: 			/* Client/server has left */
rubidium@5469: 			*status = CloseConnection(cs);
rubidium@5469: 			return NULL;
rubidium@5469: 		}
rubidium@5469: 
rubidium@5469: 		p->pos += res;
rubidium@5469: 	}
rubidium@5469: 
rubidium@5469: 	/* We have a complete packet, return it! */
rubidium@5469: 	p->pos = 2;
rubidium@5469: 	p->next = NULL; // Should not be needed, but who knows...
rubidium@5469: 
rubidium@5469: 	/* Prepare for receiving a new packet */
rubidium@5469: 	cs->packet_recv = NULL;
rubidium@5469: 
rubidium@5469: 	return p;
rubidium@5469: }
rubidium@5469: 
rubidium@5469: #endif /* ENABLE_NETWORK */