liteeth/core/udp.py

   1 from liteeth.common import *
   2 from liteeth.generic.depacketizer import LiteEthDepacketizer
   3 from liteeth.generic.packetizer import LiteEthPacketizer
   4
   5 class LiteEthUDPDepacketizer(LiteEthDepacketizer):
   6         def __init__(self):
   7                 LiteEthDepacketizer.__init__(self,
   8                         eth_ipv4_user_description(8),
   9                         eth_udp_description(8),
  10                         udp_header,
  11                         udp_header_len)
  12
  13 class LiteEthUDPPacketizer(LiteEthPacketizer):
  14         def __init__(self):
  15                 LiteEthPacketizer.__init__(self,
  16                         eth_udp_description(8),
  17                         eth_ipv4_user_description(8),
  18                         udp_header,
  19                         udp_header_len)
  20
  21 class LiteEthUDPTX(Module):
  22         def __init__(self, ip_address):
  23                 self.sink = Sink(eth_udp_user_description(8))
  24                 self.source = Source(eth_ipv4_user_description(8))
  25                 ###
  26                 packetizer = LiteEthUDPPacketizer()
  27                 self.submodules += packetizer
  28                 self.comb += [
  29                         packetizer.sink.stb.eq(self.sink.stb),
  30                         packetizer.sink.sop.eq(self.sink.sop),
  31                         packetizer.sink.eop.eq(self.sink.eop),
  32                         self.sink.ack.eq(packetizer.sink.ack),
  33                         packetizer.sink.source_port.eq(self.sink.source_port),
  34                         packetizer.sink.destination_port.eq(self.sink.destination_port),
  35                         packetizer.sink.length.eq(self.sink.length + udp_header_len),
  36                         packetizer.sink.checksum.eq(0),
  37                         packetizer.sink.data.eq(self.sink.data)
  38                 ]
  39                 sink = packetizer.source
  40
  41                 fsm = FSM(reset_state="IDLE")
  42                 self.submodules += fsm
  43                 fsm.act("IDLE",
  44                         sink.ack.eq(1),
  45                         If(sink.stb & sink.sop,
  46                                 sink.ack.eq(0),
  47                                 NextState("SEND")
  48                         )
  49                 )
  50                 fsm.act("SEND",
  51                         Record.connect(packetizer.source, self.source),
  52                         self.source.length.eq(packetizer.sink.length + ipv4_header_len),
  53                         self.source.protocol.eq(udp_protocol),
  54                         self.source.ip_address.eq(self.sink.ip_address),
  55                         If(self.source.stb & self.source.eop & self.source.ack,
  56                                 NextState("IDLE")
  57                         )
  58                 )
  59
  60 class LiteEthUDPRX(Module):
  61         def __init__(self, ip_address):
  62                 self.sink = Sink(eth_ipv4_user_description(8))
  63                 self.source = source = Source(eth_udp_user_description(8))
  64                 ###
  65                 depacketizer = LiteEthUDPDepacketizer()
  66                 self.submodules += depacketizer
  67                 self.comb += Record.connect(self.sink, depacketizer.sink)
  68                 sink = depacketizer.source
  69
  70                 fsm = FSM(reset_state="IDLE")
  71                 self.submodules += fsm
  72                 fsm.act("IDLE",
  73                         sink.ack.eq(1),
  74                         If(sink.stb & sink.sop,
  75                                 sink.ack.eq(0),
  76                                 NextState("CHECK")
  77                         )
  78                 )
  79                 valid = Signal()
  80                 self.comb += valid.eq(
  81                         sink.stb &
  82                         (self.sink.protocol == udp_protocol) &
  83                         (self.sink.ip_address == ip_address)
  84                 )
  85
  86                 fsm.act("CHECK",
  87                         If(valid,
  88                                 NextState("PRESENT")
  89                         ).Else(
  90                                 NextState("DROP")
  91                         )
  92                 ),
  93                 fsm.act("PRESENT",
  94                         source.stb.eq(sink.stb),
  95                         source.sop.eq(sink.sop),
  96                         source.eop.eq(sink.eop),
  97                         sink.ack.eq(source.ack),
  98                         source.source_port.eq(sink.source_port),
  99                         source.destination_port.eq(sink.destination_port),
 100                         source.ip_address.eq(0),
 101                         source.length.eq(sink.length - udp_header_len),
 102                         source.data.eq(sink.data),
 103                         source.error.eq(sink.error),
 104                         If(source.stb & source.eop & source.ack,
 105                                 NextState("IDLE")
 106                         )
 107                 )
 108                 fsm.act("DROP",
 109                         sink.ack.eq(1),
 110                         If(source.stb & source.eop & source.ack,
 111                                 NextState("IDLE")
 112                         )
 113                 )
 114
 115 class LiteEthUDP(Module):
 116         def __init__(self, ip, ip_address):
 117                 self.submodules.tx = LiteEthUDPTX(ip_address)
 118                 self.submodules.rx = LiteEthUDPRX(ip_address)
 119                 self.comb += [
 120                         Record.connect(self.tx.source, ip.sink),
 121                         Record.connect(ip.source, self.rx.sink)
 122                 ]
 123                 self.sink, self.source = self.tx.sink, self.rx.source