From d3df05abaa8f145658873a61174a3b4454c7e00c Mon Sep 17 00:00:00 2001
From: Martin Teichmann <martin.teichmann@xfel.eu>
Date: Mon, 18 Jan 2021 16:45:49 +0000
Subject: [PATCH] make local variables work for subprograms
---
ebpf.py | 34 ++++++++++++++++++++++------------
ebpf_test.py | 24 ++++++++++++++++++++++++
xdp.py | 2 +-
3 files changed, 47 insertions(+), 13 deletions(-)
diff --git a/ebpf.py b/ebpf.py
index f19904b..19c900c 100644
--- a/ebpf.py
+++ b/ebpf.py
@@ -633,27 +633,31 @@ class MemoryDesc:
self.bits = bits
self.signed = signed
- def __get__(self, ebpf, owner):
- if ebpf is None:
+ def __get__(self, instance, owner):
+ if instance is None:
return self
- elif isinstance(ebpf, SubProgram):
- ebpf = ebpf.ebpf
+ elif isinstance(instance, SubProgram):
+ ebpf = instance.ebpf
+ else:
+ ebpf = instance
return Memory(ebpf, Memory.bits_to_opcode[self.bits],
- ebpf.r[self.base_register] + self.addr,
+ ebpf.r[self.base_register] + self.addr(instance),
self.signed)
- def __set__(self, ebpf, value):
- if isinstance(ebpf, SubProgram):
- ebpf = ebpf.ebpf
+ def __set__(self, instance, value):
+ if isinstance(instance, SubProgram):
+ ebpf = instance.ebpf
+ else:
+ ebpf = instance
bits = Memory.bits_to_opcode[self.bits]
if isinstance(value, int):
ebpf.append(Opcode.ST + bits, self.base_register, 0,
- self.addr, value)
+ self.addr(instance), value)
else:
with value.calculate(None, self.bits == 64, self.signed) \
as (src, _, _):
ebpf.append(Opcode.STX + bits, self.base_register,
- src, self.addr, 0)
+ src, self.addr(instance), 0)
class LocalVar(MemoryDesc):
@@ -663,9 +667,15 @@ class LocalVar(MemoryDesc):
size = int(self.bits // 8)
owner.stack -= size
owner.stack &= -size
- self.addr = owner.stack
+ self.relative_addr = owner.stack
self.name = name
+ def addr(self, instance):
+ if isinstance(instance, SubProgram):
+ return (instance.ebpf.stack & -8) + self.relative_addr
+ else:
+ return self.relative_addr
+
class MemoryMap:
def __init__(self, ebpf, bits):
@@ -945,4 +955,4 @@ for i in range(10):
class SubProgram:
- pass
+ stack = 0
diff --git a/ebpf_test.py b/ebpf_test.py
index 229588b..b2ac19e 100644
--- a/ebpf_test.py
+++ b/ebpf_test.py
@@ -157,6 +157,30 @@ class Tests(TestCase):
Instruction(opcode=O.REG+O.STX, dst=10, src=0, off=-4, imm=0),
Instruction(opcode=O.DW+O.STX, dst=10, src=1, off=-16, imm=0)])
+ def test_local_subprog(self):
+ class Local(EBPF):
+ a = LocalVar(32, False)
+
+ class Sub(SubProgram):
+ b = LocalVar(32, False)
+
+ def program(self):
+ self.b *= 3
+
+ s1 = Sub()
+ s2 = Sub()
+ e = Local(ProgType.XDP, "GPL", subprograms=[s1, s2])
+ e.a = 5
+ s1.b = 3
+ e.r3 = s1.b
+ s2.b = 7
+ self.assertEqual(e.opcodes, [
+ Instruction(opcode=O.W+O.ST, dst=10, src=0, off=-4, imm=5),
+ Instruction(opcode=O.W+O.ST, dst=10, src=0, off=-12, imm=3),
+ Instruction(opcode=O.W+O.LD, dst=3, src=10, off=-12, imm=0),
+ Instruction(opcode=O.W+O.ST, dst=10, src=0, off=-12, imm=7)])
+
+
def test_jump(self):
e = EBPF()
e.owners = set(range(11))
diff --git a/xdp.py b/xdp.py
index efc0998..0a9753a 100644
--- a/xdp.py
+++ b/xdp.py
@@ -4,7 +4,7 @@ from socket import AF_NETLINK, NETLINK_ROUTE, if_nametoindex
import socket
from struct import pack, unpack
-from .ebpf import EBPF, Expression, Memory, MemoryDesc, Opcode, Comparison
+from .ebpf import EBPF, Expression, Memory, Opcode, Comparison
from .bpf import ProgType
--
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