From e52eb31130d97b4ad784b6b3ea034689e469ffd4 Mon Sep 17 00:00:00 2001
From: Martin Teichmann <martin.teichmann@gmail.com>
Date: Wed, 15 Feb 2023 08:40:02 +0000
Subject: [PATCH] support huge immediate values
we were already able to use huge values in assignments, now
we can also use them in operations.
---
ebpfcat/ebpf.py | 10 ++++++++--
ebpfcat/ebpf_test.py | 11 ++++++++++-
2 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/ebpfcat/ebpf.py b/ebpfcat/ebpf.py
index d0a5d05..39abe09 100644
--- a/ebpfcat/ebpf.py
+++ b/ebpfcat/ebpf.py
@@ -579,9 +579,15 @@ class Binary(Expression):
+ Opcode.LONG * ((r_long or l_long)
if long is None else long),
dst, src, 0, 0)
- else:
+ elif -0x80000000 <= self.right < 0x100000000:
self.ebpf.append(self.operator + Opcode.LONG * long,
dst, 0, 0, self.right)
+ else:
+ with self.ebpf.get_free_register(None) as src:
+ self.ebpf._load_value(src, self.right)
+ self.ebpf.append(
+ self.operator + Opcode.REG + Opcode.LONG,
+ dst, src, 0, 0)
if orig_dst is None or orig_dst == dst:
yield dst, long
return
@@ -1203,7 +1209,7 @@ class EBPF:
raise AssembleError("not enough registers")
def _load_value(self, no, value):
- if -0x80000000 <= value < 0x80000000:
+ if -0x80000000 <= value < 0x100000000:
self.append(Opcode.MOV + Opcode.LONG, no, 0, 0, value)
else:
self.append(Opcode.DW, no, 0, 0, value & 0xffffffff)
diff --git a/ebpfcat/ebpf_test.py b/ebpfcat/ebpf_test.py
index a4c33e6..19fadf2 100644
--- a/ebpfcat/ebpf_test.py
+++ b/ebpfcat/ebpf_test.py
@@ -487,11 +487,20 @@ class Tests(TestCase):
e = EBPF()
e.r3 = 0x1234567890
e.r4 = e.get_fd(7)
+ e.r3 = e.r4 + 0x1234567890
+ e.r3 = 0x90000000
+
self.assertEqual(e.opcodes, [
Instruction(opcode=24, dst=3, src=0, off=0, imm=878082192),
Instruction(opcode=0, dst=0, src=0, off=0, imm=18),
Instruction(opcode=24, dst=4, src=1, off=0, imm=7),
- Instruction(opcode=0, dst=0, src=0, off=0, imm=0)])
+ Instruction(opcode=0, dst=0, src=0, off=0, imm=0),
+ Instruction(opcode=O.REG+O.LONG+O.MOV, dst=3, src=4, off=0, imm=0),
+ Instruction(opcode=O.DW, dst=0, src=0, off=0, imm=878082192),
+ Instruction(opcode=O.W, dst=0, src=0, off=0, imm=18),
+ Instruction(opcode=O.LONG+O.REG+O.ADD, dst=3, src=0, off=0, imm=0),
+ Instruction(opcode=O.LONG+O.MOV, dst=3, src=0, off=0, imm=2415919104),
+ ])
def test_simple_binary(self):
e = EBPF()
--
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