func NewConnectionFromPacket(packet []byte) (Connection, error) {
ipheader, err := ipv4.ParseHeader(packet)
if err != nil {
return Connection{}, err
}
tcpheader, err := tcp.ParseHeader(packet[ipheader.Len:])
if err != nil {
return Connection{}, err
}
return NewConnectionFromPacketAndIPHeaderAndTCPHeader(packet, ipheader, tcpheader)
}
func (t *connectionManager) Process() error {
var wg sync.WaitGroup
for i := 0; i < t.configuration.Manager.Agents; i++ {
wg.Add(1)
go func() {
defer wg.Done()
for {
message := <-t.reader.output
ipheader, err := ipv4.ParseHeader(message)
if err != nil {
log.Println("Error: Parsing IPHeader:" + err.Error())
log.Printf("Message:%v\n", message)
continue
}
if int(ipheader.Flags) < 2 {
log.Printf("Warning: More Fragments Flag Is Set\n")
}
tcpheader, err := tcp.ParseHeader(message[ipheader.Len:])
if err != nil {
log.Println("Error: Parsing TCPHeader:" + err.Error())
log.Printf("Message:%v\n", message)
continue
}
connectionhelper, err := datastore.GetConnectionHelper()
if err != nil {
log.Printf("Error: Getting Connection Helper: %v\n", err.Error())
return
}
connectionhelper.Lock()
connection, err := connectionhelper.GetConnection(ipheader.Src, tcpheader.SourcePort, ipheader.Dst, tcpheader.DestinationPort)
if err != nil {
log.Printf("Error: Getting Connection: %v\n", err.Error())
connectionhelper.Unlock()
return
}
if bytes.Equal(connection.SourceIP(), net.IP{}) {
//No connection found
connection, err = datastore.NewConnectionFromPacketAndIPHeaderAndTCPHeader(message, ipheader, tcpheader)
if err != nil {
log.Printf("Error: Creating New Connection: %v\n", err.Error())
connectionhelper.Unlock()
continue
}
err = connectionhelper.SetConnection(connection)
if err != nil {
log.Printf("Error: Saving New Connection: %v\n", err.Error())
connectionhelper.Unlock()
continue
}
} else {
//Connection found
//We need to find out if the connection is still for this device and user
devicehelper, err := datastore.GetDeviceHelper()
if err != nil {
log.Printf("Error: Getting Device Helper: %v\n", err.Error())
connectionhelper.Unlock()
return
}
device, err := devicehelper.GetDeviceByIP(ipheader.Src)
if err != nil {
log.Printf("Error: Getting Source Device By IP(%v) \"%v\"\n", ipheader.Src.String(), err.Error())
}
if bytes.Equal(device.MACAddress, net.HardwareAddr{}) {
device, err = devicehelper.GetDeviceByIP(ipheader.Dst)
if err != nil {
log.Printf("Error: Getting Destination Device By IP(%v) \"%v\"\n", ipheader.Dst.String(), err.Error())
}
}
//If we have a device, is now or it's empty
currentuser := ""
if device.GetActiveUser() != nil {
currentuser = device.GetActiveUser().Username
}
//Device, User or Number of In Memory Packets Breached...
if !bytes.Equal(device.MACAddress, connection.DeviceID()) || (connection.Username() != currentuser) || connection.NumberOfPackets() >= t.configuration.Manager.MaxPackets {
//Device or User has changed.
err = connectionhelper.RemoveConnection(connection)
if err != nil {
log.Printf("Error: Removing Connection: %v\n", err.Error())
connectionhelper.Unlock()
continue
}
//If a channel is registered and we had no errors closing it.
if t.manager.output != nil {
select {
case t.manager.output <- connection:
default:
log.Println("Error: Manager Queue is full! Discarding Closed Connection..")
}
}
//Create A New Connection
connection, err := datastore.NewConnectionFromPacketAndIPHeaderAndTCPHeader(message, ipheader, tcpheader)
if err != nil {
log.Printf("Error: Creating New Connection After Remove: %v\n", err.Error())
connectionhelper.Unlock()
continue
}
err = connectionhelper.SetConnection(connection)
if err != nil {
log.Printf("Error: Saving New Connection After Remove: %v\n", err.Error())
connectionhelper.Unlock()
continue
}
} else {
err = connection.AddPacket(message)
if err != nil {
log.Printf("Error: Adding Packet: %v\n", err.Error())
connectionhelper.Unlock()
continue
}
err = connectionhelper.SetConnection(connection)
if err != nil {
log.Printf("Error: Saving Packet after adding packet: %v\n", err.Error())
connectionhelper.Unlock()
continue
}
}
}
connectionhelper.Unlock()
}
}()
}
wg.Wait()
log.Println("Error: We seem to be existing packet processing??")
return errors.New("Error: Packet Processing Exited?")
}