func (n *NPServer) HandleConnection(conn net.Conn) {
// Close the connection after it ends its execution
defer conn.Close()
// This is the place where you should put stuff to be executed for the "connection" event
// The below code is the most non-thread-safe way to create such identifiers
// If we get enough load, servers can f**k up
TotalConnections++
LastCid++
cid := LastCid
// Here comes a struct for connection data, that we pass over to handlers
connection_data := new(structs.ConnData)
connection_data.Authenticated = false // Because we don't want session stealing
connection_data.ConnectionId = cid // Connection ID is mainly used in servers
connection_data.PresenceData = make(map[string]string) // If we don't init it here, it'll panic later
connection_data.Connection = conn
connection_data.Valid = true
for {
// Set timeout
conn.SetReadDeadline(time.Now().Add(60 * time.Second))
// First 16 bytes are defined in the structs subpackage
// It consists of four, 4-byte Little Endian unsigned 32bit integers
// in the following order: signature, length, type, id
headerBytes := make([]byte, 16)
_, err := conn.Read(headerBytes)
if err != nil {
if err != io.EOF {
logger.Warningf("Error while reading the header; %s", err)
}
break
}
// Initialize a bytes mapper
buf := bytes.NewReader(headerBytes)
// Map data to the struct
var packet_header structs.PacketHeader
err = binary.Read(buf, binary.LittleEndian, &packet_header)
if err != nil {
logger.Warningf("Error while mapping packet_header to struct; %s", err)
continue
}
// Signature check
if packet_header.Signature != packet_signature {
logger.Warningf(
"Signature doesn't match (from %s), received 0x%X",
conn.RemoteAddr().String(),
packet_header.Signature,
)
continue
}
// Length from the packet_header specifies how many of the next bytes are the content
// Pass it over to the handlers which will decode it using protobuf
contentBytes := make([]byte, packet_header.Length)
// Set timeout
conn.SetReadDeadline(time.Now().Add(60 * time.Second))
// Read the body
_, err = io.ReadFull(conn, contentBytes)
if err != nil {
logger.Warningf("Error while reading; %s", err)
break
}
// Log that we are parsing a RPC message
logger.Debugf("Received message %d (ID: %d) from %s", packet_header.Type, packet_header.Id, structs.StripPort(conn.RemoteAddr().String()))
// Generate a new PacketData struct
packet_data := new(structs.PacketData)
packet_data.Header = packet_header
packet_data.Content = contentBytes
// Pass it to the handlers. Not the best idea to do it using params, we should use
// a struct, so we will easily be able to inject more variables.
err = HandleMessage(conn, connection_data, packet_data)
if err != nil {
logger.Warningf("Error while handling message %d from %s; %s", packet_data.Header.Id, conn.RemoteAddr().String(), err)
}
}
if connection_data.Authenticated {
if connection_data.IsServer {
storage.DeleteServerConnection(connection_data.Npid)
} else {
storage.DeleteClientConnection(connection_data.Npid)
}
}
// I guess that count is going to be used by the web API
TotalConnections--
connection_data.Valid = false
}
