/** @file host.c @brief ENet host management functions */ #define ENET_BUILDING_LIB 1 #include <string.h> #include <time.h> #include "enet/enet.h" /** @defgroup host ENet host functions @{ */ /** Creates a host for communicating to peers. @param address the address at which other peers may connect to this host. If NULL, then no peers may connect to the host. @param peerCount the maximum number of peers that should be allocated for the host. @param channelLimit the maximum number of channels allowed; if 0, then this is equivalent to ENET_PROTOCOL_MAXIMUM_CHANNEL_COUNT @param incomingBandwidth downstream bandwidth of the host in bytes/second; if 0, ENet will assume unlimited bandwidth. @param outgoingBandwidth upstream bandwidth of the host in bytes/second; if 0, ENet will assume unlimited bandwidth. @returns the host on success and NULL on failure @remarks ENet will strategically drop packets on specific sides of a connection between hosts to ensure the host's bandwidth is not overwhelmed. The bandwidth parameters also determine the window size of a connection which limits the amount of reliable packets that may be in transit at any given time. */ ENetHost * enet_host_create (const ENetAddress * address, size_t peerCount, size_t channelLimit, enet_uint32 incomingBandwidth, enet_uint32 outgoingBandwidth) { ENetHost * host; ENetPeer * currentPeer; if (peerCount > ENET_PROTOCOL_MAXIMUM_PEER_ID) return NULL; host = (ENetHost *) enet_malloc (sizeof (ENetHost)); if (host == NULL) return NULL; host -> peers = (ENetPeer *) enet_malloc (peerCount * sizeof (ENetPeer)); if (host -> peers == NULL) { enet_free (host); return NULL; } memset (host -> peers, 0, peerCount * sizeof (ENetPeer)); host -> socket = enet_socket_create (ENET_SOCKET_TYPE_DATAGRAM); if (host -> socket == ENET_SOCKET_NULL || (address != NULL && enet_socket_bind (host -> socket, address) < 0)) { if (host -> socket != ENET_SOCKET_NULL) enet_socket_destroy (host -> socket); enet_free (host -> peers); enet_free (host); return NULL; } enet_socket_set_option (host -> socket, ENET_SOCKOPT_NONBLOCK, 1); enet_socket_set_option (host -> socket, ENET_SOCKOPT_BROADCAST, 1); enet_socket_set_option (host -> socket, ENET_SOCKOPT_RCVBUF, ENET_HOST_RECEIVE_BUFFER_SIZE); enet_socket_set_option (host -> socket, ENET_SOCKOPT_SNDBUF, ENET_HOST_SEND_BUFFER_SIZE); if (address != NULL) host -> address = * address; if (! channelLimit || channelLimit > ENET_PROTOCOL_MAXIMUM_CHANNEL_COUNT) channelLimit = ENET_PROTOCOL_MAXIMUM_CHANNEL_COUNT; else if (channelLimit < ENET_PROTOCOL_MINIMUM_CHANNEL_COUNT) channelLimit = ENET_PROTOCOL_MINIMUM_CHANNEL_COUNT; host -> randomSeed = (enet_uint32) time(NULL) + (enet_uint32) (size_t) host; host -> randomSeed = (host -> randomSeed << 16) | (host -> randomSeed >> 16); host -> channelLimit = channelLimit; host -> incomingBandwidth = incomingBandwidth; host -> outgoingBandwidth = outgoingBandwidth; host -> bandwidthThrottleEpoch = 0; host -> recalculateBandwidthLimits = 0; host -> mtu = ENET_HOST_DEFAULT_MTU; host -> peerCount = peerCount; host -> commandCount = 0; host -> bufferCount = 0; host -> checksum = NULL; host -> receivedAddress.host = ENET_HOST_ANY; host -> receivedAddress.port = 0; host -> receivedData = NULL; host -> receivedDataLength = 0; host -> totalSentData = 0; host -> totalSentPackets = 0; host -> totalReceivedData = 0; host -> totalReceivedPackets = 0; host -> compressor.context = NULL; host -> compressor.compress = NULL; host -> compressor.decompress = NULL; host -> compressor.destroy = NULL; enet_list_clear (& host -> dispatchQueue); for (currentPeer = host -> peers; currentPeer < & host -> peers [host -> peerCount]; ++ currentPeer) { currentPeer -> host = host; currentPeer -> incomingPeerID = currentPeer - host -> peers; currentPeer -> outgoingSessionID = currentPeer -> incomingSessionID = 0xFF; currentPeer -> data = NULL; enet_list_clear (& currentPeer -> acknowledgements); enet_list_clear (& currentPeer -> sentReliableCommands); enet_list_clear (& currentPeer -> sentUnreliableCommands); enet_list_clear (& currentPeer -> outgoingReliableCommands); enet_list_clear (& currentPeer -> outgoingUnreliableCommands); enet_list_clear (& currentPeer -> dispatchedCommands); enet_peer_reset (currentPeer); } return host; } /** Destroys the host and all resources associated with it. @param host pointer to the host to destroy */ void enet_host_destroy (ENetHost * host) { ENetPeer * currentPeer; enet_socket_destroy (host -> socket); for (currentPeer = host -> peers; currentPeer < & host -> peers [host -> peerCount]; ++ currentPeer) { enet_peer_reset (currentPeer); } if (host -> compressor.context != NULL && host -> compressor.destroy) (* host -> compressor.destroy) (host -> compressor.context); enet_free (host -> peers); enet_free (host); } /** Initiates a connection to a foreign host. @param host host seeking the connection @param address destination for the connection @param channelCount number of channels to allocate @param data user data supplied to the receiving host @returns a peer representing the foreign host on success, NULL on failure @remarks The peer returned will have not completed the connection until enet_host_service() notifies of an ENET_EVENT_TYPE_CONNECT event for the peer. */ ENetPeer * enet_host_connect (ENetHost * host, const ENetAddress * address, size_t channelCount, enet_uint32 data) { ENetPeer * currentPeer; ENetChannel * channel; ENetProtocol command; if (channelCount < ENET_PROTOCOL_MINIMUM_CHANNEL_COUNT) channelCount = ENET_PROTOCOL_MINIMUM_CHANNEL_COUNT; else if (channelCount > ENET_PROTOCOL_MAXIMUM_CHANNEL_COUNT) channelCount = ENET_PROTOCOL_MAXIMUM_CHANNEL_COUNT; for (currentPeer = host -> peers; currentPeer < & host -> peers [host -> peerCount]; ++ currentPeer) { if (currentPeer -> state == ENET_PEER_STATE_DISCONNECTED) break; } if (currentPeer >= & host -> peers [host -> peerCount]) return NULL; currentPeer -> channels = (ENetChannel *) enet_malloc (channelCount * sizeof (ENetChannel)); if (currentPeer -> channels == NULL) return NULL; currentPeer -> channelCount = channelCount; currentPeer -> state = ENET_PEER_STATE_CONNECTING; currentPeer -> address = * address; currentPeer -> connectID = ++ host -> randomSeed; if (host -> outgoingBandwidth == 0) currentPeer -> windowSize = ENET_PROTOCOL_MAXIMUM_WINDOW_SIZE; else currentPeer -> windowSize = (host -> outgoingBandwidth / ENET_PEER_WINDOW_SIZE_SCALE) * ENET_PROTOCOL_MINIMUM_WINDOW_SIZE; if (currentPeer -> windowSize < ENET_PROTOCOL_MINIMUM_WINDOW_SIZE) currentPeer -> windowSize = ENET_PROTOCOL_MINIMUM_WINDOW_SIZE; else if (currentPeer -> windowSize > ENET_PROTOCOL_MAXIMUM_WINDOW_SIZE) currentPeer -> windowSize = ENET_PROTOCOL_MAXIMUM_WINDOW_SIZE; for (channel = currentPeer -> channels; channel < & currentPeer -> channels [channelCount]; ++ channel) { channel -> outgoingReliableSequenceNumber = 0; channel -> outgoingUnreliableSequenceNumber = 0; channel -> incomingReliableSequenceNumber = 0; enet_list_clear (& channel -> incomingReliableCommands); enet_list_clear (& channel -> incomingUnreliableCommands); channel -> usedReliableWindows = 0; memset (channel -> reliableWindows, 0, sizeof (channel -> reliableWindows)); } command.header.command = ENET_PROTOCOL_COMMAND_CONNECT | ENET_PROTOCOL_COMMAND_FLAG_ACKNOWLEDGE; command.header.channelID = 0xFF; command.connect.outgoingPeerID = ENET_HOST_TO_NET_16 (currentPeer -> incomingPeerID); command.connect.incomingSessionID = currentPeer -> incomingSessionID; command.connect.outgoingSessionID = currentPeer -> outgoingSessionID; command.connect.mtu = ENET_HOST_TO_NET_32 (currentPeer -> mtu); command.connect.windowSize = ENET_HOST_TO_NET_32 (currentPeer -> windowSize); command.connect.channelCount = ENET_HOST_TO_NET_32 (channelCount); command.connect.incomingBandwidth = ENET_HOST_TO_NET_32 (host -> incomingBandwidth); command.connect.outgoingBandwidth = ENET_HOST_TO_NET_32 (host -> outgoingBandwidth); command.connect.packetThrottleInterval = ENET_HOST_TO_NET_32 (currentPeer -> packetThrottleInterval); command.connect.packetThrottleAcceleration = ENET_HOST_TO_NET_32 (currentPeer -> packetThrottleAcceleration); command.connect.packetThrottleDeceleration = ENET_HOST_TO_NET_32 (currentPeer -> packetThrottleDeceleration); command.connect.connectID = currentPeer -> connectID; command.connect.data = ENET_HOST_TO_NET_32 (data); enet_peer_queue_outgoing_command (currentPeer, & command, NULL, 0, 0); return currentPeer; } /** Queues a packet to be sent to all peers associated with the host. @param host host on which to broadcast the packet @param channelID channel on which to broadcast @param packet packet to broadcast */ void enet_host_broadcast (ENetHost * host, enet_uint8 channelID, ENetPacket * packet) { ENetPeer * currentPeer; for (currentPeer = host -> peers; currentPeer < & host -> peers [host -> peerCount]; ++ currentPeer) { if (currentPeer -> state != ENET_PEER_STATE_CONNECTED) continue; enet_peer_send (currentPeer, channelID, packet); } if (packet -> referenceCount == 0) enet_packet_destroy (packet); } /** Sets the packet compressor the host should use to compress and decompress packets. @param host host to enable or disable compression for @param compressor callbacks for for the packet compressor; if NULL, then compression is disabled */ void enet_host_compress (ENetHost * host, const ENetCompressor * compressor) { if (host -> compressor.context != NULL && host -> compressor.destroy) (* host -> compressor.destroy) (host -> compressor.context); if (compressor) host -> compressor = * compressor; else host -> compressor.context = NULL; } /** Limits the maximum allowed channels of future incoming connections. @param host host to limit @param channelLimit the maximum number of channels allowed; if 0, then this is equivalent to ENET_PROTOCOL_MAXIMUM_CHANNEL_COUNT */ void enet_host_channel_limit (ENetHost * host, size_t channelLimit) { if (! channelLimit || channelLimit > ENET_PROTOCOL_MAXIMUM_CHANNEL_COUNT) channelLimit = ENET_PROTOCOL_MAXIMUM_CHANNEL_COUNT; else if (channelLimit < ENET_PROTOCOL_MINIMUM_CHANNEL_COUNT) channelLimit = ENET_PROTOCOL_MINIMUM_CHANNEL_COUNT; host -> channelLimit = channelLimit; } /** Adjusts the bandwidth limits of a host. @param host host to adjust @param incomingBandwidth new incoming bandwidth @param outgoingBandwidth new outgoing bandwidth @remarks the incoming and outgoing bandwidth parameters are identical in function to those specified in enet_host_create(). */ void enet_host_bandwidth_limit (ENetHost * host, enet_uint32 incomingBandwidth, enet_uint32 outgoingBandwidth) { host -> incomingBandwidth = incomingBandwidth; host -> outgoingBandwidth = outgoingBandwidth; host -> recalculateBandwidthLimits = 1; } void enet_host_bandwidth_throttle (ENetHost * host) { enet_uint32 timeCurrent = enet_time_get (), elapsedTime = timeCurrent - host -> bandwidthThrottleEpoch, peersTotal = 0, dataTotal = 0, peersRemaining, bandwidth, throttle = 0, bandwidthLimit = 0; int needsAdjustment; ENetPeer * peer; ENetProtocol command; if (elapsedTime < ENET_HOST_BANDWIDTH_THROTTLE_INTERVAL) return; for (peer = host -> peers; peer < & host -> peers [host -> peerCount]; ++ peer) { if (peer -> state != ENET_PEER_STATE_CONNECTED && peer -> state != ENET_PEER_STATE_DISCONNECT_LATER) continue; ++ peersTotal; dataTotal += peer -> outgoingDataTotal; } if (peersTotal == 0) return; peersRemaining = peersTotal; needsAdjustment = 1; if (host -> outgoingBandwidth == 0) bandwidth = ~0; else bandwidth = (host -> outgoingBandwidth * elapsedTime) / 1000; while (peersRemaining > 0 && needsAdjustment != 0) { needsAdjustment = 0; if (dataTotal < bandwidth) throttle = ENET_PEER_PACKET_THROTTLE_SCALE; else throttle = (bandwidth * ENET_PEER_PACKET_THROTTLE_SCALE) / dataTotal; for (peer = host -> peers; peer < & host -> peers [host -> peerCount]; ++ peer) { enet_uint32 peerBandwidth; if ((peer -> state != ENET_PEER_STATE_CONNECTED && peer -> state != ENET_PEER_STATE_DISCONNECT_LATER) || peer -> incomingBandwidth == 0 || peer -> outgoingBandwidthThrottleEpoch == timeCurrent) continue; peerBandwidth = (peer -> incomingBandwidth * elapsedTime) / 1000; if ((throttle * peer -> outgoingDataTotal) / ENET_PEER_PACKET_THROTTLE_SCALE <= peerBandwidth) continue; peer -> packetThrottleLimit = (peerBandwidth * ENET_PEER_PACKET_THROTTLE_SCALE) / peer -> outgoingDataTotal; if (peer -> packetThrottleLimit == 0) peer -> packetThrottleLimit = 1; if (peer -> packetThrottle > peer -> packetThrottleLimit) peer -> packetThrottle = peer -> packetThrottleLimit; peer -> outgoingBandwidthThrottleEpoch = timeCurrent; needsAdjustment = 1; -- peersRemaining; bandwidth -= peerBandwidth; dataTotal -= peerBandwidth; } } if (peersRemaining > 0) for (peer = host -> peers; peer < & host -> peers [host -> peerCount]; ++ peer) { if ((peer -> state != ENET_PEER_STATE_CONNECTED && peer -> state != ENET_PEER_STATE_DISCONNECT_LATER) || peer -> outgoingBandwidthThrottleEpoch == timeCurrent) continue; peer -> packetThrottleLimit = throttle; if (peer -> packetThrottle > peer -> packetThrottleLimit) peer -> packetThrottle = peer -> packetThrottleLimit; } if (host -> recalculateBandwidthLimits) { host -> recalculateBandwidthLimits = 0; peersRemaining = peersTotal; bandwidth = host -> incomingBandwidth; needsAdjustment = 1; if (bandwidth == 0) bandwidthLimit = 0; else while (peersRemaining > 0 && needsAdjustment != 0) { needsAdjustment = 0; bandwidthLimit = bandwidth / peersRemaining; for (peer = host -> peers; peer < & host -> peers [host -> peerCount]; ++ peer) { if ((peer -> state != ENET_PEER_STATE_CONNECTED && peer -> state != ENET_PEER_STATE_DISCONNECT_LATER) || peer -> incomingBandwidthThrottleEpoch == timeCurrent) continue; if (peer -> outgoingBandwidth > 0 && peer -> outgoingBandwidth >= bandwidthLimit) continue; peer -> incomingBandwidthThrottleEpoch = timeCurrent; needsAdjustment = 1; -- peersRemaining; bandwidth -= peer -> outgoingBandwidth; } } for (peer = host -> peers; peer < & host -> peers [host -> peerCount]; ++ peer) { if (peer -> state != ENET_PEER_STATE_CONNECTED && peer -> state != ENET_PEER_STATE_DISCONNECT_LATER) continue; command.header.command = ENET_PROTOCOL_COMMAND_BANDWIDTH_LIMIT | ENET_PROTOCOL_COMMAND_FLAG_ACKNOWLEDGE; command.header.channelID = 0xFF; command.bandwidthLimit.outgoingBandwidth = ENET_HOST_TO_NET_32 (host -> outgoingBandwidth); if (peer -> incomingBandwidthThrottleEpoch == timeCurrent) command.bandwidthLimit.incomingBandwidth = ENET_HOST_TO_NET_32 (peer -> outgoingBandwidth); else command.bandwidthLimit.incomingBandwidth = ENET_HOST_TO_NET_32 (bandwidthLimit); enet_peer_queue_outgoing_command (peer, & command, NULL, 0, 0); } } host -> bandwidthThrottleEpoch = timeCurrent; for (peer = host -> peers; peer < & host -> peers [host -> peerCount]; ++ peer) { peer -> incomingDataTotal = 0; peer -> outgoingDataTotal = 0; } } /** @} */