diff options
Diffstat (limited to 'protocol.c')
| -rw-r--r-- | protocol.c | 1296 |
1 files changed, 1296 insertions, 0 deletions
diff --git a/protocol.c b/protocol.c new file mode 100644 index 0000000..ef8e954 --- /dev/null +++ b/protocol.c @@ -0,0 +1,1296 @@ +/** + @file protocol.c + @brief ENet protocol functions +*/ +#include <stdio.h> +#include <string.h> +#define ENET_BUILDING_LIB 1 +#include "enet/utility.h" +#include "enet/time.h" +#include "enet/enet.h" + +static enet_uint32 timeCurrent; + +static int +enet_protocol_dispatch_incoming_commands (ENetHost * host, ENetEvent * event) +{ + ENetPeer * currentPeer = host -> lastServicedPeer; + ENetChannel * channel; + + do + { + ++ currentPeer; + + if (currentPeer >= & host -> peers [host -> peerCount]) + currentPeer = host -> peers; + + if (currentPeer -> state == ENET_PEER_STATE_ZOMBIE) + { + host -> recalculateBandwidthLimits = 1; + + event -> type = ENET_EVENT_TYPE_DISCONNECT; + event -> peer = currentPeer; + + enet_peer_reset (currentPeer); + + host -> lastServicedPeer = currentPeer; + + return 1; + } + + if (currentPeer -> state != ENET_PEER_STATE_CONNECTED) + continue; + + for (channel = currentPeer -> channels; + channel < & currentPeer -> channels [currentPeer -> channelCount]; + ++ channel) + { + if (enet_list_empty (& channel -> incomingReliableCommands) && + enet_list_empty (& channel -> incomingUnreliableCommands)) + continue; + + event -> packet = enet_peer_receive (currentPeer, channel - currentPeer -> channels); + if (event -> packet == NULL) + continue; + + event -> type = ENET_EVENT_TYPE_RECEIVE; + event -> peer = currentPeer; + event -> channelID = (enet_uint8) (channel - currentPeer -> channels); + + host -> lastServicedPeer = currentPeer; + + return 1; + } + } while (currentPeer != host -> lastServicedPeer); + + return 0; +} + +static void +enet_protocol_remove_sent_unreliable_commands (ENetPeer * peer) +{ + ENetOutgoingCommand * outgoingCommand; + + while (enet_list_empty (& peer -> sentUnreliableCommands) == 0) + { + outgoingCommand = (ENetOutgoingCommand *) enet_list_front (& peer -> sentUnreliableCommands); + + enet_list_remove (& outgoingCommand -> outgoingCommandList); + + if (outgoingCommand -> packet != NULL) + { + -- outgoingCommand -> packet -> referenceCount; + + if (outgoingCommand -> packet -> referenceCount == 0) + enet_packet_destroy (outgoingCommand -> packet); + } + + enet_free (outgoingCommand); + } +} + +static ENetProtocolCommand +enet_protocol_remove_sent_reliable_command (ENetPeer * peer, enet_uint32 reliableSequenceNumber, enet_uint8 channelID) +{ + ENetOutgoingCommand * outgoingCommand; + ENetListIterator currentCommand; + ENetProtocolCommand commandNumber; + + for (currentCommand = enet_list_begin (& peer -> sentReliableCommands); + currentCommand != enet_list_end (& peer -> sentReliableCommands); + currentCommand = enet_list_next (currentCommand)) + { + outgoingCommand = (ENetOutgoingCommand *) currentCommand; + + if (outgoingCommand -> reliableSequenceNumber == reliableSequenceNumber && + outgoingCommand -> command.header.channelID == channelID) + break; + } + + if (currentCommand == enet_list_end (& peer -> sentReliableCommands)) + return ENET_PROTOCOL_COMMAND_NONE; + + commandNumber = outgoingCommand -> command.header.command; + + enet_list_remove (& outgoingCommand -> outgoingCommandList); + + if (outgoingCommand -> packet != NULL) + { + peer -> reliableDataInTransit -= outgoingCommand -> fragmentLength; + + -- outgoingCommand -> packet -> referenceCount; + + if (outgoingCommand -> packet -> referenceCount == 0) + enet_packet_destroy (outgoingCommand -> packet); + } + + enet_free (outgoingCommand); + + if (enet_list_empty (& peer -> sentReliableCommands)) + return commandNumber; + + outgoingCommand = (ENetOutgoingCommand *) enet_list_front (& peer -> sentReliableCommands); + + peer -> nextTimeout = outgoingCommand -> sentTime + outgoingCommand -> roundTripTimeout; + + return commandNumber; +} + +static ENetPeer * +enet_protocol_handle_connect (ENetHost * host, const ENetProtocolHeader * header, const ENetProtocol * command) +{ + enet_uint16 mtu; + enet_uint32 windowSize; + ENetChannel * channel; + size_t channelCount; + ENetPeer * currentPeer; + ENetProtocol verifyCommand; + + if (command -> header.commandLength < sizeof (ENetProtocolConnect)) + return NULL; + + channelCount = ENET_NET_TO_HOST_32 (command -> connect.channelCount); + + if (channelCount < ENET_PROTOCOL_MINIMUM_CHANNEL_COUNT || + channelCount > ENET_PROTOCOL_MAXIMUM_CHANNEL_COUNT) + return NULL; + + for (currentPeer = host -> peers; + currentPeer < & host -> peers [host -> peerCount]; + ++ currentPeer) + { + if (currentPeer -> state != ENET_PEER_STATE_DISCONNECTED && + currentPeer -> address.host == host -> receivedAddress.host && + currentPeer -> address.port == host -> receivedAddress.port && + currentPeer -> challenge == header -> challenge) + return NULL; + } + + 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 -> state = ENET_PEER_STATE_ACKNOWLEDGING_CONNECT; + currentPeer -> challenge = header -> challenge; + currentPeer -> address = host -> receivedAddress; + currentPeer -> outgoingPeerID = ENET_NET_TO_HOST_16 (command -> connect.outgoingPeerID); + currentPeer -> incomingBandwidth = ENET_NET_TO_HOST_32 (command -> connect.incomingBandwidth); + currentPeer -> outgoingBandwidth = ENET_NET_TO_HOST_32 (command -> connect.outgoingBandwidth); + currentPeer -> packetThrottleInterval = ENET_NET_TO_HOST_32 (command -> connect.packetThrottleInterval); + currentPeer -> packetThrottleAcceleration = ENET_NET_TO_HOST_32 (command -> connect.packetThrottleAcceleration); + currentPeer -> packetThrottleDeceleration = ENET_NET_TO_HOST_32 (command -> connect.packetThrottleDeceleration); + currentPeer -> channels = (ENetChannel *) enet_malloc (channelCount * sizeof (ENetChannel)); + currentPeer -> channelCount = channelCount; + + for (channel = currentPeer -> channels; + channel < & currentPeer -> channels [channelCount]; + ++ channel) + { + channel -> outgoingReliableSequenceNumber = 0; + channel -> outgoingUnreliableSequenceNumber = 0; + channel -> incomingReliableSequenceNumber = 0; + channel -> incomingUnreliableSequenceNumber = 0; + + enet_list_clear (& channel -> incomingReliableCommands); + enet_list_clear (& channel -> incomingUnreliableCommands); + } + + mtu = ENET_NET_TO_HOST_16 (command -> connect.mtu); + + if (mtu < ENET_PROTOCOL_MINIMUM_MTU) + mtu = ENET_PROTOCOL_MINIMUM_MTU; + else + if (mtu > ENET_PROTOCOL_MAXIMUM_MTU) + mtu = ENET_PROTOCOL_MAXIMUM_MTU; + + currentPeer -> mtu = mtu; + + if (host -> outgoingBandwidth == 0 && + currentPeer -> incomingBandwidth == 0) + currentPeer -> windowSize = ENET_PROTOCOL_MAXIMUM_WINDOW_SIZE; + else + currentPeer -> windowSize = (ENET_MIN (host -> outgoingBandwidth, currentPeer -> incomingBandwidth) / + 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; + + if (host -> incomingBandwidth == 0) + windowSize = ENET_PROTOCOL_MAXIMUM_WINDOW_SIZE; + else + windowSize = (host -> incomingBandwidth / ENET_PEER_WINDOW_SIZE_SCALE) * + ENET_PROTOCOL_MINIMUM_WINDOW_SIZE; + + if (windowSize > ENET_NET_TO_HOST_32 (command -> connect.windowSize)) + windowSize = ENET_NET_TO_HOST_32 (command -> connect.windowSize); + + if (windowSize < ENET_PROTOCOL_MINIMUM_WINDOW_SIZE) + windowSize = ENET_PROTOCOL_MINIMUM_WINDOW_SIZE; + else + if (windowSize > ENET_PROTOCOL_MAXIMUM_WINDOW_SIZE) + windowSize = ENET_PROTOCOL_MAXIMUM_WINDOW_SIZE; + + verifyCommand.header.command = ENET_PROTOCOL_COMMAND_VERIFY_CONNECT; + verifyCommand.header.channelID = 0xFF; + verifyCommand.header.flags = ENET_PROTOCOL_FLAG_ACKNOWLEDGE; + verifyCommand.header.commandLength = sizeof (ENetProtocolVerifyConnect); + verifyCommand.verifyConnect.outgoingPeerID = ENET_HOST_TO_NET_16 (currentPeer -> incomingPeerID); + verifyCommand.verifyConnect.mtu = ENET_HOST_TO_NET_16 (currentPeer -> mtu); + verifyCommand.verifyConnect.windowSize = ENET_HOST_TO_NET_32 (windowSize); + verifyCommand.verifyConnect.channelCount = ENET_HOST_TO_NET_32 (channelCount); + verifyCommand.verifyConnect.incomingBandwidth = ENET_HOST_TO_NET_32 (host -> incomingBandwidth); + verifyCommand.verifyConnect.outgoingBandwidth = ENET_HOST_TO_NET_32 (host -> outgoingBandwidth); + verifyCommand.verifyConnect.packetThrottleInterval = ENET_HOST_TO_NET_32 (currentPeer -> packetThrottleInterval); + verifyCommand.verifyConnect.packetThrottleAcceleration = ENET_HOST_TO_NET_32 (currentPeer -> packetThrottleAcceleration); + verifyCommand.verifyConnect.packetThrottleDeceleration = ENET_HOST_TO_NET_32 (currentPeer -> packetThrottleDeceleration); + + enet_peer_queue_outgoing_command (currentPeer, & verifyCommand, NULL, 0, 0); + + return currentPeer; +} + +static void +enet_protocol_handle_send_reliable (ENetHost * host, ENetPeer * peer, const ENetProtocol * command) +{ + ENetPacket * packet; + + if (command -> header.commandLength <= sizeof (ENetProtocolSendReliable) || + command -> header.channelID >= peer -> channelCount || + peer -> state != ENET_PEER_STATE_CONNECTED) + return; + + packet = enet_packet_create ((const enet_uint8 *) command + sizeof (ENetProtocolSendReliable), + command -> header.commandLength - sizeof (ENetProtocolSendReliable), + ENET_PACKET_FLAG_RELIABLE); + + enet_peer_queue_incoming_command (peer, command, packet, 0); +} + +static void +enet_protocol_handle_send_unsequenced (ENetHost * host, ENetPeer * peer, const ENetProtocol * command) +{ + ENetPacket * packet; + enet_uint32 unsequencedGroup, index; + + if (command -> header.commandLength <= sizeof (ENetProtocolSendUnsequenced) || + command -> header.channelID >= peer -> channelCount || + peer -> state != ENET_PEER_STATE_CONNECTED) + return; + + unsequencedGroup = ENET_NET_TO_HOST_32 (command -> sendUnsequenced.unsequencedGroup); + index = unsequencedGroup % ENET_PEER_UNSEQUENCED_WINDOW_SIZE; + + if (unsequencedGroup >= peer -> incomingUnsequencedGroup + ENET_PEER_UNSEQUENCED_WINDOW_SIZE) + { + peer -> incomingUnsequencedGroup = unsequencedGroup - index; + + memset (peer -> unsequencedWindow, 0, sizeof (peer -> unsequencedWindow)); + } + else + if (unsequencedGroup < peer -> incomingUnsequencedGroup || + peer -> unsequencedWindow [index / 32] & (1 << (index % 32))) + return; + + peer -> unsequencedWindow [index / 32] |= 1 << (index % 32); + + + packet = enet_packet_create ((const enet_uint8 *) command + sizeof (ENetProtocolSendUnsequenced), + command -> header.commandLength - sizeof (ENetProtocolSendUnsequenced), + ENET_PACKET_FLAG_UNSEQUENCED); + + enet_peer_queue_incoming_command (peer, command, packet, 0); +} + +static void +enet_protocol_handle_send_unreliable (ENetHost * host, ENetPeer * peer, const ENetProtocol * command) +{ + ENetPacket * packet; + + if (command -> header.commandLength <= sizeof (ENetProtocolSendUnreliable) || + command -> header.channelID >= peer -> channelCount || + peer -> state != ENET_PEER_STATE_CONNECTED) + return; + + packet = enet_packet_create ((const enet_uint8 *) command + sizeof (ENetProtocolSendUnreliable), + command -> header.commandLength - sizeof (ENetProtocolSendUnreliable), + 0); + + enet_peer_queue_incoming_command (peer, command, packet, 0); +} + +static void +enet_protocol_handle_send_fragment (ENetHost * host, ENetPeer * peer, const ENetProtocol * command) +{ + enet_uint32 fragmentNumber, + fragmentCount, + fragmentOffset, + fragmentLength, + startSequenceNumber, + totalLength; + ENetChannel * channel; + ENetListIterator currentCommand; + ENetIncomingCommand * startCommand; + + if (command -> header.commandLength <= sizeof (ENetProtocolSendFragment) || + command -> header.channelID >= peer -> channelCount || + peer -> state != ENET_PEER_STATE_CONNECTED) + return; + + startSequenceNumber = ENET_NET_TO_HOST_32 (command -> sendFragment.startSequenceNumber); + fragmentNumber = ENET_NET_TO_HOST_32 (command -> sendFragment.fragmentNumber); + fragmentCount = ENET_NET_TO_HOST_32 (command -> sendFragment.fragmentCount); + fragmentOffset = ENET_NET_TO_HOST_32 (command -> sendFragment.fragmentOffset); + totalLength = ENET_NET_TO_HOST_32 (command -> sendFragment.totalLength); + fragmentLength = command -> header.commandLength - sizeof (ENetProtocolSendFragment); + + if (fragmentOffset >= totalLength || + fragmentOffset + fragmentLength > totalLength || + fragmentNumber >= fragmentCount) + return; + + channel = & peer -> channels [command -> header.channelID]; + + if (startSequenceNumber <= channel -> incomingReliableSequenceNumber) + return; + + for (currentCommand = enet_list_previous (enet_list_end (& channel -> incomingReliableCommands)); + currentCommand != enet_list_end (& channel -> incomingReliableCommands); + currentCommand = enet_list_previous (currentCommand)) + { + startCommand = (ENetIncomingCommand *) currentCommand; + + if (startCommand -> command.header.command == ENET_PROTOCOL_COMMAND_SEND_FRAGMENT && + startCommand -> command.sendFragment.startSequenceNumber == startSequenceNumber) + break; + } + + if (currentCommand == enet_list_end (& channel -> incomingReliableCommands)) + { + ENetProtocol hostCommand = * command; + + hostCommand.header.reliableSequenceNumber = startSequenceNumber; + hostCommand.sendFragment.startSequenceNumber = startSequenceNumber; + hostCommand.sendFragment.fragmentNumber = fragmentNumber; + hostCommand.sendFragment.fragmentCount = fragmentCount; + hostCommand.sendFragment.fragmentOffset = fragmentOffset; + hostCommand.sendFragment.totalLength = totalLength; + + startCommand = enet_peer_queue_incoming_command (peer, + & hostCommand, + enet_packet_create (NULL, totalLength, ENET_PACKET_FLAG_RELIABLE), + fragmentCount); + } + else + if (totalLength != startCommand -> packet -> dataLength || + fragmentCount != startCommand -> fragmentCount) + return; + + if ((startCommand -> fragments [fragmentNumber / 32] & (1 << fragmentNumber)) == 0) + -- startCommand -> fragmentsRemaining; + + startCommand -> fragments [fragmentNumber / 32] |= (1 << fragmentNumber); + + if (fragmentOffset + fragmentLength > startCommand -> packet -> dataLength) + fragmentLength = startCommand -> packet -> dataLength - fragmentOffset; + + memcpy (startCommand -> packet -> data + fragmentOffset, + (enet_uint8 *) command + sizeof (ENetProtocolSendFragment), + fragmentLength); +} + +static void +enet_protocol_handle_ping (ENetHost * host, ENetPeer * peer, const ENetProtocol * command) +{ + if (command -> header.commandLength < sizeof (ENetProtocolPing)) + return; +} + +static void +enet_protocol_handle_bandwidth_limit (ENetHost * host, ENetPeer * peer, const ENetProtocol * command) +{ + if (command -> header.commandLength < sizeof (ENetProtocolBandwidthLimit)) + return; + + peer -> incomingBandwidth = ENET_NET_TO_HOST_32 (command -> bandwidthLimit.incomingBandwidth); + peer -> outgoingBandwidth = ENET_NET_TO_HOST_32 (command -> bandwidthLimit.outgoingBandwidth); + + if (peer -> incomingBandwidth == 0 && + host -> outgoingBandwidth == 0) + peer -> windowSize = ENET_PROTOCOL_MAXIMUM_WINDOW_SIZE; + else + peer -> windowSize = (ENET_MIN (peer -> incomingBandwidth, host -> outgoingBandwidth) / + ENET_PEER_WINDOW_SIZE_SCALE) * ENET_PROTOCOL_MINIMUM_WINDOW_SIZE; + + if (peer -> windowSize < ENET_PROTOCOL_MINIMUM_WINDOW_SIZE) + peer -> windowSize = ENET_PROTOCOL_MINIMUM_WINDOW_SIZE; + else + if (peer -> windowSize > ENET_PROTOCOL_MAXIMUM_WINDOW_SIZE) + peer -> windowSize = ENET_PROTOCOL_MAXIMUM_WINDOW_SIZE; +} + +static void +enet_protocol_handle_throttle_configure (ENetHost * host, ENetPeer * peer, const ENetProtocol * command) +{ + if (command -> header.commandLength < sizeof (ENetProtocolThrottleConfigure)) + return; + + peer -> packetThrottleInterval = ENET_NET_TO_HOST_32 (command -> throttleConfigure.packetThrottleInterval); + peer -> packetThrottleAcceleration = ENET_NET_TO_HOST_32 (command -> throttleConfigure.packetThrottleAcceleration); + peer -> packetThrottleDeceleration = ENET_NET_TO_HOST_32 (command -> throttleConfigure.packetThrottleDeceleration); +} + +static void +enet_protocol_handle_disconnect (ENetHost * host, ENetPeer * peer, const ENetProtocol * command) +{ + if (command -> header.commandLength < sizeof (ENetProtocolDisconnect)) + return; + + enet_peer_reset_queues (peer); + + if (peer -> state != ENET_PEER_STATE_CONNECTED) + enet_peer_reset (peer); + else + if (command -> header.flags & ENET_PROTOCOL_FLAG_ACKNOWLEDGE) + peer -> state = ENET_PEER_STATE_ACKNOWLEDGING_DISCONNECT; + else + peer -> state = ENET_PEER_STATE_ZOMBIE; +} + +static int +enet_protocol_handle_acknowledge (ENetHost * host, ENetEvent * event, ENetPeer * peer, const ENetProtocol * command) +{ + enet_uint32 roundTripTime, + receivedSentTime, + receivedReliableSequenceNumber; + ENetProtocolCommand commandNumber; + + if (command -> header.commandLength < sizeof (ENetProtocolAcknowledge)) + return 0; + + receivedSentTime = ENET_NET_TO_HOST_32 (command -> acknowledge.receivedSentTime); + + if (ENET_TIME_LESS (timeCurrent, receivedSentTime)) + return 0; + + peer -> lastReceiveTime = timeCurrent; + + roundTripTime = ENET_TIME_DIFFERENCE (timeCurrent, receivedSentTime); + + enet_peer_throttle (peer, roundTripTime); + + peer -> roundTripTimeVariance -= peer -> roundTripTimeVariance / 4; + + if (roundTripTime >= peer -> roundTripTime) + { + peer -> roundTripTime += (roundTripTime - peer -> roundTripTime) / 8; + peer -> roundTripTimeVariance += (roundTripTime - peer -> roundTripTime) / 4; + } + else + { + peer -> roundTripTime -= (peer -> roundTripTime - roundTripTime) / 8; + peer -> roundTripTimeVariance += (peer -> roundTripTime - roundTripTime) / 4; + } + + if (peer -> roundTripTime < peer -> lowestRoundTripTime) + peer -> lowestRoundTripTime = peer -> roundTripTime; + + if (peer -> roundTripTimeVariance > peer -> highestRoundTripTimeVariance) + peer -> highestRoundTripTimeVariance = peer -> roundTripTimeVariance; + + if (peer -> packetThrottleEpoch == 0 || + ENET_TIME_DIFFERENCE(timeCurrent, peer -> packetThrottleEpoch) >= peer -> packetThrottleInterval) + { + peer -> lastRoundTripTime = peer -> lowestRoundTripTime; + peer -> lastRoundTripTimeVariance = peer -> highestRoundTripTimeVariance; + peer -> lowestRoundTripTime = peer -> roundTripTime; + peer -> highestRoundTripTimeVariance = peer -> roundTripTimeVariance; + peer -> packetThrottleEpoch = timeCurrent; + } + + receivedReliableSequenceNumber = ENET_NET_TO_HOST_32 (command -> acknowledge.receivedReliableSequenceNumber); + + commandNumber = enet_protocol_remove_sent_reliable_command (peer, receivedReliableSequenceNumber, command -> header.channelID); + + switch (peer -> state) + { + case ENET_PEER_STATE_ACKNOWLEDGING_CONNECT: + if (commandNumber != ENET_PROTOCOL_COMMAND_VERIFY_CONNECT) + return 0; + + host -> recalculateBandwidthLimits = 1; + + peer -> state = ENET_PEER_STATE_CONNECTED; + + event -> type = ENET_EVENT_TYPE_CONNECT; + event -> peer = peer; + + return 1; + + case ENET_PEER_STATE_DISCONNECTING: + if (commandNumber != ENET_PROTOCOL_COMMAND_DISCONNECT) + return 0; + + host -> recalculateBandwidthLimits = 1; + + event -> type = ENET_EVENT_TYPE_DISCONNECT; + event -> peer = peer; + + enet_peer_reset (peer); + + return 1; + + default: + break; + } + + return 0; +} + +static void +enet_protocol_handle_verify_connect (ENetHost * host, ENetEvent * event, ENetPeer * peer, const ENetProtocol * command) +{ + enet_uint16 mtu; + enet_uint32 windowSize; + + if (command -> header.commandLength < sizeof (ENetProtocolVerifyConnect) || + peer -> state != ENET_PEER_STATE_CONNECTING) + return; + + if (ENET_NET_TO_HOST_32 (command -> verifyConnect.channelCount) != peer -> channelCount || + ENET_NET_TO_HOST_32 (command -> verifyConnect.packetThrottleInterval) != peer -> packetThrottleInterval || + ENET_NET_TO_HOST_32 (command -> verifyConnect.packetThrottleAcceleration) != peer -> packetThrottleAcceleration || + ENET_NET_TO_HOST_32 (command -> verifyConnect.packetThrottleDeceleration) != peer -> packetThrottleDeceleration) + { + peer -> state = ENET_PEER_STATE_ZOMBIE; + + return; + } + + peer -> outgoingPeerID = ENET_NET_TO_HOST_16 (command -> verifyConnect.outgoingPeerID); + + mtu = ENET_NET_TO_HOST_16 (command -> verifyConnect.mtu); + + if (mtu < ENET_PROTOCOL_MINIMUM_MTU) + mtu = ENET_PROTOCOL_MINIMUM_MTU; + else + if (mtu > ENET_PROTOCOL_MAXIMUM_MTU) + mtu = ENET_PROTOCOL_MAXIMUM_MTU; + + if (mtu < peer -> mtu) + peer -> mtu = mtu; + + windowSize = ENET_NET_TO_HOST_32 (command -> verifyConnect.windowSize); + + if (windowSize < ENET_PROTOCOL_MINIMUM_WINDOW_SIZE) + windowSize = ENET_PROTOCOL_MINIMUM_WINDOW_SIZE; + + if (windowSize > ENET_PROTOCOL_MAXIMUM_WINDOW_SIZE) + windowSize = ENET_PROTOCOL_MAXIMUM_WINDOW_SIZE; + + if (windowSize < peer -> windowSize) + peer -> windowSize = windowSize; + + peer -> incomingBandwidth = ENET_NET_TO_HOST_32 (command -> verifyConnect.incomingBandwidth); + peer -> outgoingBandwidth = ENET_NET_TO_HOST_32 (command -> verifyConnect.outgoingBandwidth); + + host -> recalculateBandwidthLimits = 1; + + peer -> state = ENET_PEER_STATE_CONNECTED; + + event -> type = ENET_EVENT_TYPE_CONNECT; + event -> peer = peer; +} + +static int +enet_protocol_handle_incoming_commands (ENetHost * host, ENetEvent * event) +{ + ENetProtocolHeader * header; + ENetProtocol * command; + ENetPeer * peer; + enet_uint8 * currentData; + size_t commandCount; + + if (host -> receivedDataLength < sizeof (ENetProtocolHeader)) + return 0; + + header = (ENetProtocolHeader *) host -> receivedData; + + header -> peerID = ENET_NET_TO_HOST_16 (header -> peerID); + header -> sentTime = ENET_NET_TO_HOST_32 (header -> sentTime); + + if (header -> peerID == 0xFFFF) + peer = NULL; + else + if (header -> peerID >= host -> peerCount) + return 0; + else + { + peer = & host -> peers [header -> peerID]; + + if (peer -> state == ENET_PEER_STATE_DISCONNECTED || + peer -> state == ENET_PEER_STATE_ZOMBIE || + host -> receivedAddress.host != peer -> address.host || + header -> challenge != peer -> challenge) + return 0; + else + peer -> address.port = host -> receivedAddress.port; + } + + if (peer != NULL) + peer -> incomingDataTotal += host -> receivedDataLength; + + commandCount = header -> commandCount; + currentData = host -> receivedData + sizeof (ENetProtocolHeader); + + while (commandCount > 0 && + currentData < & host -> receivedData [host -> receivedDataLength]) + { + command = (ENetProtocol *) currentData; + + if (currentData + sizeof (ENetProtocolCommandHeader) > & host -> receivedData [host -> receivedDataLength]) + return 0; + + command -> header.commandLength = ENET_NET_TO_HOST_32 (command -> header.commandLength); + + if (currentData + command -> header.commandLength > & host -> receivedData [host -> receivedDataLength]) + return 0; + + -- commandCount; + currentData += command -> header.commandLength; + + if (peer == NULL) + { + if (command -> header.command != ENET_PROTOCOL_COMMAND_CONNECT) + return 0; + } + + command -> header.reliableSequenceNumber = ENET_NET_TO_HOST_32 (command -> header.reliableSequenceNumber); + + switch (command -> header.command) + { + case ENET_PROTOCOL_COMMAND_ACKNOWLEDGE: + enet_protocol_handle_acknowledge (host, event, peer, command); + + break; + + case ENET_PROTOCOL_COMMAND_CONNECT: + peer = enet_protocol_handle_connect (host, header, command); + + break; + + case ENET_PROTOCOL_COMMAND_VERIFY_CONNECT: + enet_protocol_handle_verify_connect (host, event, peer, command); + + break; + + case ENET_PROTOCOL_COMMAND_DISCONNECT: + enet_protocol_handle_disconnect (host, peer, command); + + break; + + case ENET_PROTOCOL_COMMAND_PING: + enet_protocol_handle_ping (host, peer, command); + + break; + + case ENET_PROTOCOL_COMMAND_SEND_RELIABLE: + enet_protocol_handle_send_reliable (host, peer, command); + + break; + + case ENET_PROTOCOL_COMMAND_SEND_UNRELIABLE: + enet_protocol_handle_send_unreliable (host, peer, command); + + break; + + case ENET_PROTOCOL_COMMAND_SEND_UNSEQUENCED: + enet_protocol_handle_send_unsequenced (host, peer, command); + + break; + + case ENET_PROTOCOL_COMMAND_SEND_FRAGMENT: + enet_protocol_handle_send_fragment (host, peer, command); + + break; + + case ENET_PROTOCOL_COMMAND_BANDWIDTH_LIMIT: + enet_protocol_handle_bandwidth_limit (host, peer, command); + + break; + + case ENET_PROTOCOL_COMMAND_THROTTLE_CONFIGURE: + enet_protocol_handle_throttle_configure (host, peer, command); + + break; + + default: + break; + } + + if (peer != NULL && + (command -> header.flags & ENET_PROTOCOL_FLAG_ACKNOWLEDGE) != 0) + { + switch (peer -> state) + { + case ENET_PEER_STATE_DISCONNECTING: + break; + + case ENET_PEER_STATE_ACKNOWLEDGING_DISCONNECT: + if (command -> header.command != ENET_PROTOCOL_COMMAND_DISCONNECT) + break; + + default: + enet_peer_queue_acknowledgement (peer, command, header -> sentTime); + + break; + } + } + } + + if (event -> type != ENET_EVENT_TYPE_NONE) + return 1; + + return 0; +} + +static int +enet_protocol_receive_incoming_commands (ENetHost * host, ENetEvent * event) +{ + for (;;) + { + int receivedLength; + ENetBuffer buffer; + + buffer.data = host -> receivedData; + buffer.dataLength = sizeof (host -> receivedData); + + receivedLength = enet_socket_receive (host -> socket, + & host -> receivedAddress, + & buffer, + 1); + + if (receivedLength < 0) + return -1; + + if (receivedLength == 0) + return 0; + + host -> receivedDataLength = receivedLength; + + switch (enet_protocol_handle_incoming_commands (host, event)) + { + case 1: + return 1; + + case -1: + return -1; + + default: + break; + } + } + + return -1; +} + +static void +enet_protocol_send_acknowledgements (ENetHost * host, ENetPeer * peer) +{ + ENetProtocol * command = & host -> commands [host -> commandCount]; + ENetBuffer * buffer = & host -> buffers [host -> bufferCount]; + ENetAcknowledgement * acknowledgement; + ENetListIterator currentAcknowledgement; + + currentAcknowledgement = enet_list_begin (& peer -> acknowledgements); + + while (currentAcknowledgement != enet_list_end (& peer -> acknowledgements)) + { + if (command >= & host -> commands [sizeof (host -> commands) / sizeof (ENetProtocol)] || + buffer >= & host -> buffers [sizeof (host -> buffers) / sizeof (ENetBuffer)] || + peer -> mtu - host -> packetSize < sizeof (ENetProtocolAcknowledge)) + break; + + acknowledgement = (ENetAcknowledgement *) currentAcknowledgement; + + currentAcknowledgement = enet_list_next (currentAcknowledgement); + + buffer -> data = command; + buffer -> dataLength = sizeof (ENetProtocolAcknowledge); + + host -> packetSize += buffer -> dataLength; + + command -> header.command = ENET_PROTOCOL_COMMAND_ACKNOWLEDGE; + command -> header.channelID = acknowledgement -> command.header.channelID; + command -> header.flags = 0; + command -> header.commandLength = ENET_HOST_TO_NET_32 (sizeof (ENetProtocolAcknowledge)); + command -> acknowledge.receivedReliableSequenceNumber = ENET_HOST_TO_NET_32 (acknowledgement -> command.header.reliableSequenceNumber); + command -> acknowledge.receivedSentTime = ENET_HOST_TO_NET_32 (acknowledgement -> sentTime); + + if (acknowledgement -> command.header.command == ENET_PROTOCOL_COMMAND_DISCONNECT) + peer -> state = ENET_PEER_STATE_ZOMBIE; + + enet_list_remove (& acknowledgement -> acknowledgementList); + enet_free (acknowledgement); + + ++ command; + ++ buffer; + } + + host -> commandCount = command - host -> commands; + host -> bufferCount = buffer - host -> buffers; +} + +static void +enet_protocol_send_unreliable_outgoing_commands (ENetHost * host, ENetPeer * peer) +{ + ENetProtocol * command = & host -> commands [host -> commandCount]; + ENetBuffer * buffer = & host -> buffers [host -> bufferCount]; + ENetOutgoingCommand * outgoingCommand; + ENetListIterator currentCommand; + + currentCommand = enet_list_begin (& peer -> outgoingUnreliableCommands); + + while (currentCommand != enet_list_end (& peer -> outgoingUnreliableCommands)) + { + outgoingCommand = (ENetOutgoingCommand *) currentCommand; + + if (command >= & host -> commands [sizeof (host -> commands) / sizeof (ENetProtocol)] || + buffer + 1 >= & host -> buffers [sizeof (host -> buffers) / sizeof (ENetBuffer)] || + peer -> mtu - host -> packetSize < outgoingCommand -> command.header.commandLength || + (outgoingCommand -> packet != NULL && + peer -> mtu - host -> packetSize < outgoingCommand -> command.header.commandLength + + outgoingCommand -> packet -> dataLength)) + break; + + currentCommand = enet_list_next (currentCommand); + + if (outgoingCommand -> packet != NULL) + { + peer -> packetThrottleCounter += ENET_PEER_PACKET_THROTTLE_COUNTER; + peer -> packetThrottleCounter %= ENET_PEER_PACKET_THROTTLE_SCALE; + + if (peer -> packetThrottleCounter > peer -> packetThrottle) + { + -- outgoingCommand -> packet -> referenceCount; + + if (outgoingCommand -> packet -> referenceCount == 0) + enet_packet_destroy (outgoingCommand -> packet); + + enet_list_remove (& outgoingCommand -> outgoingCommandList); + enet_free (outgoingCommand); + + continue; + } + } + + buffer -> data = command; + buffer -> dataLength = outgoingCommand -> command.header.commandLength; + + host -> packetSize += buffer -> dataLength; + + * command = outgoingCommand -> command; + + enet_list_remove (& outgoingCommand -> outgoingCommandList); + + if (outgoingCommand -> packet != NULL) + { + ++ buffer; + + buffer -> data = outgoingCommand -> packet -> data; + buffer -> dataLength = outgoingCommand -> packet -> dataLength; + + command -> header.commandLength += buffer -> dataLength; + + host -> packetSize += buffer -> dataLength; + + enet_list_insert (enet_list_end (& peer -> sentUnreliableCommands), outgoingCommand); + } + else + enet_free (outgoingCommand); + + command -> header.commandLength = ENET_HOST_TO_NET_32 (command -> header.commandLength); + + ++ command; + ++ buffer; + } + + host -> commandCount = command - host -> commands; + host -> bufferCount = buffer - host -> buffers; +} + +static int +enet_protocol_check_timeouts (ENetHost * host, ENetPeer * peer, ENetEvent * event) +{ + ENetOutgoingCommand * outgoingCommand; + ENetListIterator currentCommand; + + currentCommand = enet_list_begin (& peer -> sentReliableCommands); + + while (currentCommand != enet_list_end (& peer -> sentReliableCommands)) + { + outgoingCommand = (ENetOutgoingCommand *) currentCommand; + + currentCommand = enet_list_next (currentCommand); + + if (ENET_TIME_DIFFERENCE (timeCurrent, outgoingCommand -> sentTime) < outgoingCommand -> roundTripTimeout) + continue; + + if (outgoingCommand -> roundTripTimeout >= outgoingCommand -> roundTripTimeoutLimit) + { + event -> type = ENET_EVENT_TYPE_DISCONNECT; + event -> peer = peer; + + enet_peer_reset (peer); + + return 1; + } + + if (outgoingCommand -> packet != NULL) + peer -> reliableDataInTransit -= outgoingCommand -> fragmentLength; + + ++ peer -> packetsLost; + + outgoingCommand -> roundTripTimeout *= 2; + + enet_list_insert (enet_list_begin (& peer -> outgoingReliableCommands), + enet_list_remove (& outgoingCommand -> outgoingCommandList)); + + if (currentCommand == enet_list_begin (& peer -> sentReliableCommands) && + enet_list_empty (& peer -> sentReliableCommands) == 0) + { + outgoingCommand = (ENetOutgoingCommand *) currentCommand; + + peer -> nextTimeout = outgoingCommand -> sentTime + outgoingCommand -> roundTripTimeout; + } + } + + return 0; +} + +static void +enet_protocol_send_reliable_outgoing_commands (ENetHost * host, ENetPeer * peer) +{ + ENetProtocol * command = & host -> commands [host -> commandCount]; + ENetBuffer * buffer = & host -> buffers [host -> bufferCount]; + ENetOutgoingCommand * outgoingCommand; + ENetListIterator currentCommand; + + currentCommand = enet_list_begin (& peer -> outgoingReliableCommands); + + while (currentCommand != enet_list_end (& peer -> outgoingReliableCommands)) + { + outgoingCommand = (ENetOutgoingCommand *) currentCommand; + + if (command >= & host -> commands [sizeof (host -> commands) / sizeof (ENetProtocol)] || + buffer + 1 >= & host -> buffers [sizeof (host -> buffers) / sizeof (ENetBuffer)] || + peer -> mtu - host -> packetSize < outgoingCommand -> command.header.commandLength) + break; + + currentCommand = enet_list_next (currentCommand); + + if (outgoingCommand -> packet != NULL) + { + if ((enet_uint16) (peer -> mtu - host -> packetSize) < + (enet_uint16) (outgoingCommand -> command.header.commandLength + + outgoingCommand -> fragmentLength) || + peer -> reliableDataInTransit + outgoingCommand -> fragmentLength > peer -> windowSize) + break; + } + + if (outgoingCommand -> roundTripTimeout == 0) + { + outgoingCommand -> roundTripTimeout = peer -> roundTripTime + 4 * peer -> roundTripTimeVariance; + outgoingCommand -> roundTripTimeoutLimit = ENET_PEER_TIMEOUT_LIMIT * outgoingCommand -> roundTripTimeout; + } + + if (enet_list_empty (& peer -> sentReliableCommands)) + peer -> nextTimeout = timeCurrent + outgoingCommand -> roundTripTimeout; + + enet_list_insert (enet_list_end (& peer -> sentReliableCommands), + enet_list_remove (& outgoingCommand -> outgoingCommandList)); + + outgoingCommand -> sentTime = timeCurrent; + + buffer -> data = command; + buffer -> dataLength = outgoingCommand -> command.header.commandLength; + + host -> packetSize += buffer -> dataLength; + + * command = outgoingCommand -> command; + + if (outgoingCommand -> packet != NULL) + { + ++ buffer; + + buffer -> data = outgoingCommand -> packet -> data + outgoingCommand -> fragmentOffset; + buffer -> dataLength = outgoingCommand -> fragmentLength; + + command -> header.commandLength += outgoingCommand -> fragmentLength; + + host -> packetSize += outgoingCommand -> fragmentLength; + + peer -> reliableDataInTransit += outgoingCommand -> fragmentLength; + } + + command -> header.commandLength = ENET_HOST_TO_NET_32 (command -> header.commandLength); + + ++ peer -> packetsSent; + + ++ command; + ++ buffer; + } + + host -> commandCount = command - host -> commands; + host -> bufferCount = buffer - host -> buffers; +} + +static int +enet_protocol_send_outgoing_commands (ENetHost * host, ENetEvent * event, int checkForTimeouts) +{ + size_t packetsSent = 1; + ENetProtocolHeader header; + ENetPeer * currentPeer; + int sentLength; + + while (packetsSent > 0) + for (currentPeer = host -> peers, + packetsSent = 0; + currentPeer < & host -> peers [host -> peerCount]; + ++ currentPeer) + { + if (currentPeer -> state == ENET_PEER_STATE_DISCONNECTED || + currentPeer -> state == ENET_PEER_STATE_ZOMBIE) + continue; + + host -> commandCount = 0; + host -> bufferCount = 1; + host -> packetSize = sizeof (ENetProtocolHeader); + + if (enet_list_empty (& currentPeer -> acknowledgements) == 0) + enet_protocol_send_acknowledgements (host, currentPeer); + + if (host -> commandCount < sizeof (host -> commands) / sizeof (ENetProtocol)) + { + if (checkForTimeouts != 0 && + enet_list_empty (& currentPeer -> sentReliableCommands) == 0 && + ENET_TIME_GREATER_EQUAL (timeCurrent, currentPeer -> nextTimeout) && + enet_protocol_check_timeouts (host, currentPeer, event) == 1) + return 1; + } + if (enet_list_empty (& currentPeer -> outgoingReliableCommands) == 0) + enet_protocol_send_reliable_outgoing_commands (host, currentPeer); + else + if (enet_list_empty (& currentPeer -> sentReliableCommands) && + ENET_TIME_DIFFERENCE (timeCurrent, currentPeer -> lastReceiveTime) >= ENET_PEER_PING_INTERVAL && + currentPeer -> mtu - host -> packetSize >= sizeof (ENetProtocolPing)) + { + enet_peer_ping (currentPeer); + enet_protocol_send_reliable_outgoing_commands (host, currentPeer); + } + + if (host -> commandCount < sizeof (host -> commands) / sizeof (ENetProtocol) && + enet_list_empty (& currentPeer -> outgoingUnreliableCommands) == 0) + enet_protocol_send_unreliable_outgoing_commands (host, currentPeer); + + if (host -> commandCount == 0) + continue; + + if (currentPeer -> packetLossEpoch == 0) + currentPeer -> packetLossEpoch = timeCurrent; + else + if (ENET_TIME_DIFFERENCE (timeCurrent, currentPeer -> packetLossEpoch) >= ENET_PEER_PACKET_LOSS_INTERVAL && + currentPeer -> packetsSent > 0) + { + enet_uint32 packetLoss = currentPeer -> packetsLost * ENET_PEER_PACKET_LOSS_SCALE / currentPeer -> packetsSent; + +#ifdef ENET_DEBUG +#ifdef WIN32 + printf ("peer %u: %f%%+-%f%% packet loss, %u+-%u ms round trip time, %f%% throttle, %u/%u outgoing, %u/%u incoming\n", currentPeer -> incomingPeerID, currentPeer -> packetLoss / (float) ENET_PEER_PACKET_LOSS_SCALE, currentPeer -> packetLossVariance / (float) ENET_PEER_PACKET_LOSS_SCALE, currentPeer -> roundTripTime, currentPeer -> roundTripTimeVariance, currentPeer -> packetThrottle / (float) ENET_PEER_PACKET_THROTTLE_SCALE, enet_list_size (& currentPeer -> outgoingReliableCommands), enet_list_size (& currentPeer -> outgoingUnreliableCommands), currentPeer -> channels != NULL ? enet_list_size (& currentPeer -> channels -> incomingReliableCommands) : 0, enet_list_size (& currentPeer -> channels -> incomingUnreliableCommands)); +#else + fprintf (stderr, "peer %u: %f%%+-%f%% packet loss, %u+-%u ms round trip time, %f%% throttle, %u/%u outgoing, %u/%u incoming\n", currentPeer -> incomingPeerID, currentPeer -> packetLoss / (float) ENET_PEER_PACKET_LOSS_SCALE, currentPeer -> packetLossVariance / (float) ENET_PEER_PACKET_LOSS_SCALE, currentPeer -> roundTripTime, currentPeer -> roundTripTimeVariance, currentPeer -> packetThrottle / (float) ENET_PEER_PACKET_THROTTLE_SCALE, enet_list_size (& currentPeer -> outgoingReliableCommands), enet_list_size (& currentPeer -> outgoingUnreliableCommands), currentPeer -> channels != NULL ? enet_list_size (& currentPeer -> channels -> incomingReliableCommands) : 0, enet_list_size (& currentPeer -> channels -> incomingUnreliableCommands)); +#endif +#endif + + currentPeer -> packetLossVariance -= currentPeer -> packetLossVariance / 4; + + if (packetLoss >= currentPeer -> packetLoss) + { + currentPeer -> packetLoss += (packetLoss - currentPeer -> packetLoss) / 8; + currentPeer -> packetLossVariance += (packetLoss - currentPeer -> packetLoss) / 4; + } + else + { + currentPeer -> packetLoss -= (currentPeer -> packetLoss - packetLoss) / 8; + currentPeer -> packetLossVariance += (currentPeer -> packetLoss - packetLoss) / 4; + } + + currentPeer -> packetLossEpoch = timeCurrent; + currentPeer -> packetsSent = 0; + currentPeer -> packetsLost = 0; + } + + header.peerID = ENET_HOST_TO_NET_16 (currentPeer -> outgoingPeerID); + header.flags = 0; + header.commandCount = host -> commandCount; + header.sentTime = ENET_HOST_TO_NET_32 (timeCurrent); + header.challenge = currentPeer -> challenge; + + host -> buffers -> data = & header; + host -> buffers -> dataLength = sizeof (ENetProtocolHeader); + + currentPeer -> lastSendTime = timeCurrent; + + ++ packetsSent; + + sentLength = enet_socket_send (host -> socket, & currentPeer -> address, host -> buffers, host -> bufferCount); + + enet_protocol_remove_sent_unreliable_commands (currentPeer); + + if (sentLength < 0) + return -1; + } + + return 0; +} + +/** Sends any queued packets on the host specified to its designated peers. + + @param host host to flush + @remarks this function need only be used in circumstances where one wishes to send queued packets earlier than in a call to enet_host_service(). + @ingroup host +*/ +void +enet_host_flush (ENetHost * host) +{ + timeCurrent = enet_time_get (); + + enet_protocol_send_outgoing_commands (host, NULL, 0); +} + +/** Waits for events on the host specified and shuttles packets between + the host and its peers. + + @param host host to service + @param event an event structure where event details will be placed if one occurs + @param timeout number of milliseconds that ENet should wait for events + @retval > 1 if an event occurred within the specified time limit + @retval 0 if no event occurred + @retval < 1 on failure + @remarks enet_host_service should be called fairly regularly for adequate performance + @ingroup host +*/ +int +enet_host_service (ENetHost * host, ENetEvent * event, enet_uint32 timeout) +{ + enet_uint32 waitCondition; + + event -> type = ENET_EVENT_TYPE_NONE; + event -> peer = NULL; + event -> packet = NULL; + + switch (enet_protocol_dispatch_incoming_commands (host, event)) + { + case 1: + return 1; + + case -1: + perror ("Error dispatching incoming packets"); + + return -1; + + default: + break; + } + + timeCurrent = enet_time_get (); + + timeout += timeCurrent; + + do + { + if (ENET_TIME_DIFFERENCE (timeCurrent, host -> bandwidthThrottleEpoch) >= ENET_HOST_BANDWIDTH_THROTTLE_INTERVAL) + enet_host_bandwidth_throttle (host); + + switch (enet_protocol_send_outgoing_commands (host, event, 1)) + { + case 1: + return 1; + + case -1: + perror ("Error sending outgoing packets"); + + return -1; + + default: + break; + } + + switch (enet_protocol_receive_incoming_commands (host, event)) + { + case 1: + return 1; + + case -1: + perror ("Error receiving incoming packets"); + + return -1; + + default: + break; + } + + switch (enet_protocol_send_outgoing_commands (host, event, 1)) + { + case 1: + return 1; + + case -1: + perror ("Error sending outgoing packets"); + + return -1; + + default: + break; + } + + switch (enet_protocol_dispatch_incoming_commands (host, event)) + { + case 1: + return 1; + + case -1: + perror ("Error dispatching incoming packets"); + + return -1; + + default: + break; + } + + timeCurrent = enet_time_get (); + + if (ENET_TIME_GREATER_EQUAL (timeCurrent, timeout)) + return 0; + + waitCondition = ENET_SOCKET_WAIT_RECEIVE; + + if (enet_socket_wait (host -> socket, & waitCondition, ENET_TIME_DIFFERENCE (timeout, timeCurrent)) != 0) + return -1; + + timeCurrent = enet_time_get (); + } while (waitCondition == ENET_SOCKET_WAIT_RECEIVE); + + return 0; +} + |