litex/liteeth/core/ip.py

184 lines
5.1 KiB
Python

from liteeth.common import *
from liteeth.generic.depacketizer import LiteEthDepacketizer
from liteeth.generic.packetizer import LiteEthPacketizer
class LiteEthIPV4Depacketizer(LiteEthDepacketizer):
def __init__(self):
LiteEthDepacketizer.__init__(self,
eth_mac_description(8),
eth_ipv4_description(8),
ipv4_header,
ipv4_header_len)
class LiteEthIPV4Packetizer(LiteEthPacketizer):
def __init__(self):
LiteEthPacketizer.__init__(self,
eth_ipv4_description(8),
eth_mac_description(8),
ipv4_header,
ipv4_header_len)
class LiteEthIPV4Checksum(Module):
def __init__(self, skip_header=False):
self.header = Signal(ipv4_header_len*8)
self.value = Signal(16)
s = Signal(17)
r = Signal(17)
for i in range(ipv4_header_len//2):
if skip_header and i == 5:
pass
else:
s_next = Signal(17)
r_next = Signal(17)
self.comb += [
s_next.eq(r + self.header[i*16:(i+1)*16]),
r_next.eq(Cat(s_next[:16]+s_next[16], Signal()))
]
s, r = s_next, r_next
self.comb += self.value.eq(~Cat(r[8:16], r[:8]))
class LiteEthIPTX(Module):
def __init__(self, mac_address, ip_address, arp_table):
self.sink = Sink(eth_ipv4_user_description(8))
self.source = Source(eth_mac_description(8))
###
packetizer = LiteEthIPV4Packetizer()
self.submodules += packetizer
self.comb += [
packetizer.sink.stb.eq(self.sink.stb),
packetizer.sink.sop.eq(self.sink.sop),
packetizer.sink.eop.eq(self.sink.eop),
self.sink.ack.eq(packetizer.sink.ack),
packetizer.sink.target_ip.eq(ip_address),
packetizer.sink.protocol.eq(self.sink.protocol),
packetizer.sink.total_length.eq(self.sink.length + (0x5*4)),
packetizer.sink.version.eq(0x4), # ipv4
packetizer.sink.ihl.eq(0x5), # 20 bytes
packetizer.sink.diff_services.eq(0),
packetizer.sink.ecn.eq(0),
packetizer.sink.identification.eq(0),
packetizer.sink.flags.eq(0),
packetizer.sink.fragment_offset.eq(0),
packetizer.sink.ttl.eq(0x80),
packetizer.sink.sender_ip.eq(ip_address),
packetizer.sink.data.eq(self.sink.data)
]
sink = packetizer.source
checksum = LiteEthIPV4Checksum(skip_header=True)
self.submodules += checksum
self.comb += [
checksum.header.eq(packetizer.header),
packetizer.sink.checksum.eq(checksum.value)
]
target_mac = Signal(48)
fsm = FSM(reset_state="IDLE")
self.submodules += fsm
fsm.act("IDLE",
sink.ack.eq(1),
If(sink.stb & sink.sop,
sink.ack.eq(0),
NextState("SEND_MAC_ADDRESS_REQUEST")
)
)
fsm.act("SEND_MAC_ADDRESS_REQUEST",
arp_table.request.stb.eq(1),
arp_table.request.ip_address.eq(self.sink.ip_address),
If(arp_table.request.stb & arp_table.request.ack,
NextState("WAIT_MAC_ADDRESS_RESPONSE")
)
)
fsm.act("WAIT_MAC_ADDRESS_RESPONSE",
# XXX add timeout
If(arp_table.response.stb,
arp_table.response.ack.eq(1),
# XXX manage failed
NextState("SEND")
)
)
self.sync += If(arp_table.response.stb, target_mac.eq(arp_table.response.mac_address))
fsm.act("SEND",
Record.connect(packetizer.source, self.source),
self.source.ethernet_type.eq(ethernet_type_ip),
self.source.target_mac.eq(target_mac),
self.source.sender_mac.eq(mac_address),
If(self.source.stb & self.source.eop & self.source.ack,
# XXX manage failed
NextState("IDLE")
)
)
class LiteEthIPRX(Module):
def __init__(self, mac_address, ip_address):
self.sink = Sink(eth_mac_description(8))
self.source = source = Source(eth_ipv4_user_description(8))
###
depacketizer = LiteEthIPV4Depacketizer()
self.submodules += depacketizer
self.comb += Record.connect(self.sink, depacketizer.sink)
sink = depacketizer.source
checksum = LiteEthIPV4Checksum(skip_header=False)
self.submodules += checksum
self.comb += checksum.header.eq(depacketizer.header)
fsm = FSM(reset_state="IDLE")
self.submodules += fsm
fsm.act("IDLE",
sink.ack.eq(1),
If(sink.stb & sink.sop,
sink.ack.eq(0),
NextState("CHECK")
)
)
valid = Signal()
self.comb += valid.eq(
sink.stb &
(sink.target_ip == ip_address) &
(sink.version == 0x4) &
(sink.ihl == 0x5) &
(checksum.value == 0)
)
fsm.act("CHECK",
If(valid,
NextState("PRESENT")
).Else(
NextState("DROP")
)
),
fsm.act("PRESENT",
source.stb.eq(sink.stb),
source.sop.eq(sink.sop),
source.eop.eq(sink.eop),
sink.ack.eq(source.ack),
source.length.eq(sink.total_length - (sink.ihl*4)),
source.protocol.eq(sink.protocol),
source.ip_address.eq(sink.target_ip),
source.data.eq(sink.data),
source.error.eq(sink.error),
If(source.stb & source.eop & source.ack,
NextState("IDLE")
)
)
fsm.act("DROP",
sink.ack.eq(1),
If(source.stb & source.eop & source.ack,
NextState("IDLE")
)
)
class LiteEthIP(Module):
def __init__(self, mac, mac_address, ip_address, arp_table):
self.submodules.tx = LiteEthIPTX(mac_address, ip_address, arp_table)
self.submodules.rx = LiteEthIPRX(mac_address, ip_address)
mac_port = mac.crossbar.get_port(ethernet_type_ip)
self.comb += [
Record.connect(self.tx.source, mac_port.sink),
Record.connect(mac_port.source, self.rx.sink)
]
self.sink, self.source = self.tx.sink, self.rx.source