From ae41e500a2780d8979d8da527b36b1e2c2f5d6f1 Mon Sep 17 00:00:00 2001
From: Martin Teichmann <martin.teichmann@gmail.com>
Date: Mon, 6 Feb 2023 16:38:52 +0000
Subject: [PATCH] make better use of format characters
the format characters already include the information whether they
are signed or long, no need to add this information again.
---
ebpfcat/arraymap.py | 2 +-
ebpfcat/ebpf.py | 28 ++++++++++++++--------------
ebpfcat/hashmap.py | 2 +-
3 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/ebpfcat/arraymap.py b/ebpfcat/arraymap.py
index 6f836f2..b20934c 100644
--- a/ebpfcat/arraymap.py
+++ b/ebpfcat/arraymap.py
@@ -19,7 +19,7 @@ from itertools import chain
from mmap import mmap
from struct import pack_into, unpack_from, calcsize
-from .ebpf import FuncId, Map, Memory, MemoryDesc, Opcode, SubProgram
+from .ebpf import FuncId, Map, MemoryDesc, Opcode, SubProgram
from .bpf import create_map, lookup_elem, MapType, MapFlags, update_elem
diff --git a/ebpfcat/ebpf.py b/ebpfcat/ebpf.py
index a615bcf..ebe5555 100644
--- a/ebpfcat/ebpf.py
+++ b/ebpfcat/ebpf.py
@@ -721,14 +721,13 @@ class IAdd:
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}
+ 'i': Opcode.W, 'h': Opcode.H, 'b': Opcode.B, 'q': Opcode.DW,
+ 'A': Opcode.W}
- def __init__(self, ebpf, fmt, address, signed=False, long=False):
+ def __init__(self, ebpf, fmt, address):
self.ebpf = ebpf
self.fmt = fmt
self.address = address
- self.signed = signed
- self.long = long
def __iadd__(self, value):
if self.fmt in "qQiI":
@@ -748,10 +747,10 @@ class Memory(Expression):
with self.ebpf.get_free_register(dst) as 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
+ yield dst, self.fmt in "QqA", self.fmt.islower()
else:
with super().calculate(dst, long, signed, force) as (dst, _, _):
- yield dst, self.long, self.signed
+ yield dst, self.fmt in "QqA", self.fmt.islower()
@contextmanager
def get_address(self, dst, long, signed, force=False):
@@ -761,6 +760,10 @@ class Memory(Expression):
def contains(self, no):
return self.address.contains(no)
+ @property
+ def signed(self):
+ return isinstance(self.fmt, str) and self.fmt.islower()
+
class MemoryDesc:
"""A base class used by descriptors for memory
@@ -774,8 +777,7 @@ class MemoryDesc:
return self
fmt, addr = self.fmt_addr(instance)
return Memory(instance.ebpf, fmt,
- instance.ebpf.r[self.base_register] + addr,
- fmt.islower())
+ instance.ebpf.r[self.base_register] + addr)
def __set__(self, instance, value):
ebpf = instance.ebpf
@@ -822,11 +824,9 @@ class LocalVar(MemoryDesc):
class MemoryMap:
- def __init__(self, ebpf, fmt, signed=False, long=False):
+ def __init__(self, ebpf, fmt):
self.ebpf = ebpf
self.fmt = fmt
- self.long = long
- self.signed = signed
def __setitem__(self, addr, value):
with ExitStack() as exitStack:
@@ -860,7 +860,7 @@ class MemoryMap:
def __getitem__(self, addr):
if isinstance(addr, Register):
addr = addr + 0
- return Memory(self.ebpf, self.fmt, addr, self.signed, self.long)
+ return Memory(self.ebpf, self.fmt, addr)
class Map(ABC):
@@ -1017,8 +1017,8 @@ class EBPF:
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.mA = MemoryMap(self, "A") # actually I, but treat as Q
+ self.mQ = MemoryMap(self, "Q")
self.r = RegisterArray(self, True, False)
self.sr = RegisterArray(self, True, True)
diff --git a/ebpfcat/hashmap.py b/ebpfcat/hashmap.py
index 63c9d54..76f8518 100644
--- a/ebpfcat/hashmap.py
+++ b/ebpfcat/hashmap.py
@@ -18,7 +18,7 @@
from contextlib import contextmanager
from struct import pack, unpack, unpack
-from .ebpf import AssembleError, Expression, Opcode, Map, FuncId, Memory
+from .ebpf import AssembleError, Expression, Opcode, Map, FuncId
from .bpf import create_map, lookup_elem, MapType, update_elem
--
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