From f00e3c6dd544a7f0e08e3efb67055c901e88427b Mon Sep 17 00:00:00 2001
From: Martin Teichmann <martin.teichmann@xfel.eu>
Date: Wed, 3 Mar 2021 09:53:26 +0000
Subject: [PATCH] introduce a watchdog
---
ebpfcat/arraymap.py | 19 ++++++++++------
ebpfcat/devices.py | 12 ++++++++++
ebpfcat/ebpf.py | 46 +++++++++++++++++++------------------
ebpfcat/ebpfcat.py | 55 +++++++++++++++++++++------------------------
ebpfcat/hashmap.py | 2 +-
ebpfcat/xdp.py | 2 +-
6 files changed, 76 insertions(+), 60 deletions(-)
diff --git a/ebpfcat/arraymap.py b/ebpfcat/arraymap.py
index 1cf4ae8..9552eb3 100644
--- a/ebpfcat/arraymap.py
+++ b/ebpfcat/arraymap.py
@@ -1,7 +1,7 @@
from itertools import chain
from struct import pack_into, unpack_from, calcsize
-from .ebpf import FuncId, Map, Memory, MemoryDesc, Opcode
+from .ebpf import FuncId, Map, MemoryDesc
from .bpf import create_map, lookup_elem, MapType, update_elem
@@ -22,18 +22,24 @@ class ArrayGlobalVarDesc(MemoryDesc):
def __get__(self, instance, owner):
if instance is None:
return self
- fmt, addr = self.fmt_addr(instance)
if instance.ebpf.loaded:
+ fmt, addr = self.fmt_addr(instance)
data = instance.ebpf.__dict__[self.map.name].data
- return unpack_from(fmt, data, addr)[0]
+ ret = unpack_from(fmt, data, addr)
+ if len(ret) == 1:
+ return ret[0]
+ else:
+ return ret
else:
return super().__get__(instance, owner)
def __set__(self, instance, value):
- fmt, addr = self.fmt_addr(instance)
if instance.ebpf.loaded:
+ fmt, addr = self.fmt_addr(instance)
+ if not isinstance(value, tuple):
+ value = value,
pack_into(fmt, instance.ebpf.__dict__[self.map.name].data,
- addr, value)
+ addr, *value)
else:
super().__set__(instance, value)
@@ -85,7 +91,6 @@ class ArrayMap(Map):
else:
return write_size, position
-
def __set_name__(self, owner, name):
self.name = name
@@ -97,7 +102,7 @@ class ArrayMap(Map):
fd = create_map(MapType.ARRAY, 4, size, 1)
setattr(ebpf, self.name, ArrayMapAccess(fd, write_size, size))
with ebpf.save_registers(list(range(6))), ebpf.get_stack(4) as stack:
- ebpf.append(Opcode.ST, 10, 0, stack, 0)
+ ebpf.mI[ebpf.r10 + stack] = 0
ebpf.r1 = ebpf.get_fd(fd)
ebpf.r2 = ebpf.r10 + stack
ebpf.call(FuncId.map_lookup_elem)
diff --git a/ebpfcat/devices.py b/ebpfcat/devices.py
index 047610c..55e4288 100644
--- a/ebpfcat/devices.py
+++ b/ebpfcat/devices.py
@@ -184,3 +184,15 @@ class Dummy(Device):
def program(self):
pass
+
+
+class RandomDropper(Device):
+ rate = DeviceVar("I", write=True)
+
+ def program(self):
+ from .xdp import XDPExitCode
+ with self.ebpf.tmp:
+ self.ebpf.tmp = ktime(self.ebpf)
+ self.ebpf.tmp = self.ebpf.tmp * 0xcf019d85 + 1
+ with self.ebpf.tmp & 0xffff < self.rate:
+ self.ebpf.exit(XDPExitCode.DROP)
diff --git a/ebpfcat/ebpf.py b/ebpfcat/ebpf.py
index 7d3df0c..d92041d 100644
--- a/ebpfcat/ebpf.py
+++ b/ebpfcat/ebpf.py
@@ -1,6 +1,6 @@
from collections import namedtuple
from contextlib import contextmanager, ExitStack
-from struct import pack, unpack
+from struct import pack, unpack, calcsize
from enum import Enum
from . import bpf
@@ -429,8 +429,9 @@ class Expression:
@contextmanager
def calculate(self, dst, long, signed, force=False):
with self.ebpf.get_free_register(dst) as dst:
- with self.get_address(dst, long, signed) as (src, bits):
- self.ebpf.append(Opcode.LD + bits, dst, src, 0, 0)
+ with self.get_address(dst, long, signed) as (src, fmt):
+ self.ebpf.append(Opcode.LD + Memory.fmt_to_opcode[fmt],
+ dst, src, 0, 0)
yield dst, long, self.signed
@contextmanager
@@ -636,12 +637,10 @@ class Memory(Expression):
bits_to_opcode = {32: Opcode.W, 16: Opcode.H, 8: Opcode.B, 64: Opcode.DW}
fmt_to_opcode = {'I': Opcode.W, 'H': Opcode.H, 'B': Opcode.B, 'Q': Opcode.DW,
'i': Opcode.W, 'h': Opcode.H, 'b': Opcode.B, 'q': Opcode.DW}
- fmt_to_size = {'I': 4, 'H': 2, 'B': 1, 'Q': 8,
- 'i': 4, 'h': 2, 'b': 1, 'q': 8}
- def __init__(self, ebpf, bits, address, signed=False, long=False):
+ def __init__(self, ebpf, fmt, address, signed=False, long=False):
self.ebpf = ebpf
- self.bits = bits
+ self.fmt = fmt
self.address = address
self.signed = signed
self.long = long
@@ -656,7 +655,7 @@ class Memory(Expression):
def calculate(self, dst, long, signed, force=False):
if isinstance(self.address, Sum):
with self.ebpf.get_free_register(dst) as dst:
- self.ebpf.append(Opcode.LD + self.bits, dst,
+ self.ebpf.append(Opcode.LD + self.fmt_to_opcode[self.fmt], dst,
self.address.left.no, self.address.right, 0)
yield dst, self.long, self.signed
else:
@@ -666,7 +665,7 @@ class Memory(Expression):
@contextmanager
def get_address(self, dst, long, signed, force=False):
with self.address.calculate(dst, True, None) as (src, _, _):
- yield src, self.bits
+ yield src, self.fmt
def contains(self, no):
return self.address.contains(no)
@@ -677,7 +676,7 @@ class MemoryDesc:
if instance is None:
return self
fmt, addr = self.fmt_addr(instance)
- return Memory(instance.ebpf, Memory.fmt_to_opcode[fmt],
+ return Memory(instance.ebpf, fmt,
instance.ebpf.r[self.base_register] + addr,
fmt.islower())
@@ -711,7 +710,7 @@ class LocalVar(MemoryDesc):
self.fmt = fmt
def __set_name__(self, owner, name):
- size = Memory.fmt_to_size[self.fmt]
+ size = calcsize(self.fmt)
owner.stack -= size
owner.stack &= -size
self.relative_addr = owner.stack
@@ -725,9 +724,9 @@ class LocalVar(MemoryDesc):
class MemoryMap:
- def __init__(self, ebpf, bits, signed=False, long=False):
+ def __init__(self, ebpf, fmt, signed=False, long=False):
self.ebpf = ebpf
- self.bits = bits
+ self.fmt = fmt
self.long = long
self.signed = signed
@@ -741,7 +740,8 @@ class MemoryMap:
addr.calculate(None, True, None))
offset = 0
if isinstance(value, int):
- self.ebpf.append(Opcode.ST + self.bits, dst, 0, offset, value)
+ self.ebpf.append(Opcode.ST + Memory.fmt_to_opcode[self.fmt],
+ dst, 0, offset, value)
return
elif isinstance(value, IAdd):
value = value.value
@@ -749,18 +749,20 @@ class MemoryMap:
with self.ebpf.get_free_register(None) as src:
self.ebpf.r[src] = value
self.ebpf.append(
- Opcode.XADD + self.bits, dst, src, offset, 0)
+ Opcode.XADD + Memory.fmt_to_opcode[self.fmt],
+ dst, src, offset, 0)
return
opcode = Opcode.XADD
else:
opcode = Opcode.STX
with value.calculate(None, None, None) as (src, _, _):
- self.ebpf.append(opcode + self.bits, dst, src, offset, 0)
+ self.ebpf.append(opcode + Memory.fmt_to_opcode[self.fmt],
+ dst, src, offset, 0)
def __getitem__(self, addr):
if isinstance(addr, Register):
addr = addr + 0
- return Memory(self.ebpf, self.bits, addr, self.signed, self.long)
+ return Memory(self.ebpf, self.fmt, addr, self.signed, self.long)
class Map:
@@ -890,11 +892,11 @@ class EBPF:
self.name = name
self.loaded = False
- self.mB = MemoryMap(self, Opcode.B)
- self.mH = MemoryMap(self, Opcode.H)
- self.mI = MemoryMap(self, Opcode.W)
- self.mA = MemoryMap(self, Opcode.W, False, True)
- self.mQ = MemoryMap(self, Opcode.DW, False, True)
+ self.mB = MemoryMap(self, "B")
+ self.mH = MemoryMap(self, "H")
+ self.mI = MemoryMap(self, "I")
+ self.mA = MemoryMap(self, "I", False, True)
+ self.mQ = MemoryMap(self, "Q", False, True)
self.r = RegisterArray(self, True, False)
self.sr = RegisterArray(self, True, True)
diff --git a/ebpfcat/ebpfcat.py b/ebpfcat/ebpfcat.py
index d10ca31..62d2ea0 100644
--- a/ebpfcat/ebpfcat.py
+++ b/ebpfcat/ebpfcat.py
@@ -6,7 +6,6 @@ from .arraymap import ArrayMap, ArrayGlobalVarDesc
from .ethercat import ECCmd, EtherCat, Packet, Terminal
from .ebpf import FuncId, MemoryDesc, SubProgram
from .xdp import XDP, XDPExitCode
-from .hashmap import HashMap
from .bpf import (
ProgType, MapType, create_map, update_elem, prog_test_run, lookup_elem)
@@ -224,36 +223,21 @@ class EBPFTerminal(Terminal):
pass
-class EBPFCat(XDP):
- vars = HashMap()
-
- count = vars.globalVar()
- ptype = vars.globalVar()
-
- def program(self):
- #with self.If(self.packet16[12] != 0xA488):
- # self.exit(2)
- self.count += 1
- #self.ptype = self.packet32[18]
- self.exit(2)
-
-
class EtherXDP(XDP):
license = "GPL"
- variables = HashMap()
- count = variables.globalVar()
- allcount = variables.globalVar()
+ variables = ArrayMap()
+ counters = variables.globalVar("64I", write=True)
def program(self):
- e = self
- with e.packetSize > 24 as p, p.pH[12] == 0xA488, p.pB[16] == 0:
- e.count += 1
- e.r2 = e.get_fd(self.programs)
- e.r3 = p.pI[18]
- e.call(FuncId.tail_call)
- e.allcount += 1
- e.exit(XDPExitCode.PASS)
+ with self.packetSize > 24 as p, p.pH[12] == 0xA488, p.pB[16] == 0:
+ self.r3 = p.pI[18]
+ with self.counters.get_address(None, False, False) as (dst, _), \
+ self.r3 < FastEtherCat.MAX_PROGS:
+ self.mI[self.r[dst] + 4 * self.r3] += 1
+ self.r2 = self.get_fd(self.programs)
+ self.call(FuncId.tail_call)
+ self.exit(XDPExitCode.PASS)
class SimpleEtherCat(EtherCat):
@@ -275,20 +259,34 @@ class FastEtherCat(SimpleEtherCat):
self.programs = create_map(MapType.PROG_ARRAY, 4, 4, self.MAX_PROGS)
self.sync_groups = {}
- def register_sync_group(self, sg):
+ def register_sync_group(self, sg, packet):
index = len(self.sync_groups)
while index in self.sync_groups:
index = (index + 1) % self.MAX_PROGS
fd, _ = sg.load(log_level=1)
update_elem(self.programs, pack("<I", index), pack("<I", fd), 0)
self.sync_groups[index] = sg
+ sg.assembled = packet.assemble(index)
return index
+ async def watchdog(self):
+ while True:
+ t0 = time()
+ self.ebpf.counters = (0,) * self.MAX_PROGS
+ self.ebpf.variables.readwrite()
+ counts = self.ebpf.counters
+ for i, sg in self.sync_groups.items():
+ if counts[i] == 0:
+ self.send_packet(sg.assembled)
+ await sleep(0.001)
+
async def connect(self):
await super().connect()
self.ebpf = EtherXDP()
self.ebpf.programs = self.programs
self.fd = await self.ebpf.attach(self.addr[0])
+ ensure_future(self.watchdog())
+
class SyncGroupBase:
def __init__(self, ec, devices, **kwargs):
@@ -353,8 +351,7 @@ class FastSyncGroup(SyncGroupBase, XDP):
def start(self):
self.allocate()
- index = self.ec.register_sync_group(self)
- self.ec.send_packet(self.packet.assemble(index))
+ self.ec.register_sync_group(self, self.packet)
self.monitor = ensure_future(gather(*[t.to_operational()
for t in self.terminals]))
return self.monitor
diff --git a/ebpfcat/hashmap.py b/ebpfcat/hashmap.py
index 3221b6c..963afdc 100644
--- a/ebpfcat/hashmap.py
+++ b/ebpfcat/hashmap.py
@@ -29,7 +29,7 @@ class HashGlobalVar(Expression):
0, 0, 0)
else:
dst = 0
- yield dst, Memory.fmt_to_opcode[self.fmt]
+ yield dst, self.fmt
class HashGlobalVarDesc:
diff --git a/ebpfcat/xdp.py b/ebpfcat/xdp.py
index d61ab1d..53304d4 100644
--- a/ebpfcat/xdp.py
+++ b/ebpfcat/xdp.py
@@ -5,7 +5,7 @@ from socket import AF_NETLINK, NETLINK_ROUTE, if_nametoindex
import socket
from struct import pack, unpack
-from .ebpf import EBPF, Expression, Memory, Opcode, Comparison
+from .ebpf import EBPF
from .bpf import ProgType
--
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