Merge pull request #4 from pythonbpf/perfbuf

Add userspace utils for Structs and maps, starting with PERF_EVENT_ARRAY
This commit is contained in:
Pragyansh Chaturvedi
2025-10-20 06:14:45 +05:30
committed by GitHub
22 changed files with 1263 additions and 383 deletions

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@ -45,7 +45,7 @@ jobs:
run: pip install --verbose .[test]
- name: Test import
run: python -c "import pylibbpf; print('Import successful')"
run: python -I -c "import pylibbpf; print('Import successful')"
- name: Test
run: python -m pytest -v
run: python -I -m pytest -v

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@ -1,17 +1,31 @@
cmake_minimum_required(VERSION 4.0)
project(pylibbpf)
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)
# pybind11
include_directories(${CMAKE_SOURCE_DIR}/src)
add_subdirectory(pybind11)
pybind11_add_module(
pylibbpf
# Core
src/core/bpf_program.h
src/core/bpf_exception.h
src/core/bpf_map.h
src/bindings/main.cpp
src/core/bpf_object.h
src/core/bpf_program.cpp
src/core/bpf_map.cpp)
src/core/bpf_map.cpp
src/core/bpf_object.cpp
# Maps
src/maps/perf_event_array.h
src/maps/perf_event_array.cpp
# Utils
src/utils/struct_parser.h
src/utils/struct_parser.cpp
# Bindings
src/bindings/main.cpp)
# --- libbpf build rules ---
set(LIBBPF_SRC_DIR ${CMAKE_CURRENT_SOURCE_DIR}/libbpf/src)

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@ -1,10 +1,11 @@
import time
from ctypes import c_int32, c_int64, c_uint64, c_void_p
from pylibbpf import BpfMap
from pythonbpf import BPF, bpf, bpfglobal, map, section
from pythonbpf.maps import HashMap
from pylibbpf import BpfMap
@bpf
@map

46
pylibbpf/__init__.py Normal file
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@ -0,0 +1,46 @@
import logging
from .ir_to_ctypes import convert_structs_to_ctypes, is_pythonbpf_structs
from .pylibbpf import (
BpfException,
BpfMap,
BpfProgram,
PerfEventArray,
StructParser,
)
from .pylibbpf import (
BpfObject as _BpfObject, # C++ object (internal)
)
from .wrappers import BpfObjectWrapper
logger = logging.getLogger(__name__)
class BpfObject(BpfObjectWrapper):
"""BpfObject with automatic struct conversion"""
def __init__(self, object_path: str, structs=None):
"""Create a BPF object"""
if structs is None:
structs = {}
elif is_pythonbpf_structs(structs):
logger.info(f"Auto-converting {len(structs)} PythonBPF structs to ctypes")
structs = convert_structs_to_ctypes(structs)
# Create C++ BpfObject with converted structs
cpp_obj = _BpfObject(object_path, structs)
# Initialize wrapper
super().__init__(cpp_obj)
__all__ = [
"BpfObject",
"BpfProgram",
"BpfMap",
"PerfEventArray",
"StructParser",
"BpfException",
]
__version__ = "0.0.6"

105
pylibbpf/ir_to_ctypes.py Normal file
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@ -0,0 +1,105 @@
import ctypes
import logging
from typing import Dict, Type
from llvmlite import ir
logger = logging.getLogger(__name__)
def ir_type_to_ctypes(ir_type):
"""Convert LLVM IR type to ctypes type."""
if isinstance(ir_type, ir.IntType):
width = ir_type.width
type_map = {
8: ctypes.c_uint8,
16: ctypes.c_uint16,
32: ctypes.c_uint32,
64: ctypes.c_uint64,
}
if width not in type_map:
raise ValueError(f"Unsupported integer width: {width}")
return type_map[width]
elif isinstance(ir_type, ir.ArrayType):
count = ir_type.count
element_type_ir = ir_type.element
if isinstance(element_type_ir, ir.IntType) and element_type_ir.width == 8:
# Use c_char for string fields (will have .decode())
return ctypes.c_char * count
else:
element_type = ir_type_to_ctypes(element_type_ir)
return element_type * count
elif isinstance(ir_type, ir.PointerType):
return ctypes.c_void_p
else:
raise TypeError(f"Unsupported IR type: {ir_type}")
def _make_repr(struct_name: str, fields: list):
"""Create a __repr__ function for a struct"""
def __repr__(self):
field_strs = []
for field_name, _ in fields:
value = getattr(self, field_name)
field_strs.append(f"{field_name}={value}")
return f"<{struct_name} {' '.join(field_strs)}>"
return __repr__
def convert_structs_to_ctypes(structs_sym_tab) -> Dict[str, Type[ctypes.Structure]]:
"""Convert PythonBPF's structs_sym_tab to ctypes.Structure classes."""
if not structs_sym_tab:
return {}
ctypes_structs = {}
for struct_name, struct_type_obj in structs_sym_tab.items():
try:
fields = []
for field_name, field_ir_type in struct_type_obj.fields.items():
field_ctypes = ir_type_to_ctypes(field_ir_type)
fields.append((field_name, field_ctypes))
repr_func = _make_repr(struct_name, fields)
struct_class = type(
struct_name,
(ctypes.Structure,),
{
"_fields_": fields,
"__module__": "pylibbpf.ir_to_ctypes",
"__doc__": f"Auto-generated ctypes structure for {struct_name}",
"__repr__": repr_func,
},
)
ctypes_structs[struct_name] = struct_class
# Pretty print field info
field_info = ", ".join(f"{name}: {typ.__name__}" for name, typ in fields)
logger.debug(f" {struct_name}({field_info})")
except Exception as e:
logger.error(f"Failed to convert struct '{struct_name}': {e}")
raise
logger.info(f"Converted struct '{struct_name}' to ctypes")
return ctypes_structs
def is_pythonbpf_structs(structs) -> bool:
"""Check if structs dict is from PythonBPF."""
if not isinstance(structs, dict) or not structs:
return False
first_value = next(iter(structs.values()))
return (
hasattr(first_value, "ir_type")
and hasattr(first_value, "fields")
and hasattr(first_value, "size")
)
__all__ = ["convert_structs_to_ctypes", "is_pythonbpf_structs"]

0
pylibbpf/py.typed Normal file
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77
pylibbpf/wrappers.py Normal file
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@ -0,0 +1,77 @@
from typing import Callable, Optional
class PerfEventArrayHelper:
"""Fluent wrapper for PERF_EVENT_ARRAY maps."""
def __init__(self, bpf_map):
self._map = bpf_map
self._perf_buffer = None
def open_perf_buffer(
self,
callback: Callable,
struct_name: str = "",
page_cnt: int = 8,
lost_callback: Optional[Callable] = None,
):
"""Open perf buffer with auto-deserialization."""
from .pylibbpf import PerfEventArray
if struct_name:
self._perf_buffer = PerfEventArray(
self._map,
page_cnt,
callback,
struct_name,
lost_callback or (lambda cpu, cnt: None),
)
else:
self._perf_buffer = PerfEventArray(
self._map, page_cnt, callback, lost_callback or (lambda cpu, cnt: None)
)
return self
def poll(self, timeout_ms: int = -1) -> int:
if not self._perf_buffer:
raise RuntimeError("Call open_perf_buffer() first")
return self._perf_buffer.poll(timeout_ms)
def consume(self) -> int:
if not self._perf_buffer:
raise RuntimeError("Call open_perf_buffer() first")
return self._perf_buffer.consume()
def __getattr__(self, name):
return getattr(self._map, name)
class BpfObjectWrapper:
"""Smart wrapper that returns map-specific helpers."""
BPF_MAP_TYPE_PERF_EVENT_ARRAY = 4
BPF_MAP_TYPE_RINGBUF = 27
def __init__(self, bpf_object):
self._obj = bpf_object
self._map_helpers = {}
def __getitem__(self, name: str):
"""Return appropriate helper based on map type."""
if name in self._map_helpers:
return self._map_helpers[name]
map_obj = self._obj[name]
map_type = map_obj.get_type()
if map_type == self.BPF_MAP_TYPE_PERF_EVENT_ARRAY:
helper = PerfEventArrayHelper(map_obj)
else:
helper = map_obj
self._map_helpers[name] = helper
return helper
def __getattr__(self, name):
return getattr(self._obj, name)

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@ -4,12 +4,13 @@ requires = [
"wheel",
"ninja",
"cmake>=4.0",
"pybind11>=2.10",
]
build-backend = "setuptools.build_meta"
[project]
name = "pylibbpf"
version = "0.0.5"
version = "0.0.6"
description = "Python Bindings for Libbpf"
authors = [
{ name = "r41k0u", email = "pragyanshchaturvedi18@gmail.com" },
@ -32,14 +33,17 @@ classifiers = [
"Topic :: Software Development :: Libraries :: Python Modules",
"Topic :: System :: Operating System Kernels :: Linux",
]
dependencies = [
"llvmlite>=0.40.0",
]
[project.optional-dependencies]
test = ["pytest>=6.0"]
[project.urls]
Homepage = "https://github.com/varun-r-mallya/pylibbpf"
Repository = "https://github.com/varun-r-mallya/pylibbpf"
Issues = "https://github.com/varun-r-mallya/pylibbpf/issues"
Homepage = "https://github.com/pythonbpf/pylibbpf"
Repository = "https://github.com/pythonbpf/pylibbpf"
Issues = "https://github.com/pythonbpf/pylibbpf/issues"
[tool.mypy]
files = "setup.py"

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@ -3,7 +3,7 @@ import subprocess
import sys
from pathlib import Path
from setuptools import Extension, setup
from setuptools import Extension, find_packages, setup
from setuptools.command.build_ext import build_ext
# Convert distutils Windows platform specifiers to CMake -A arguments
@ -129,8 +129,11 @@ setup(
description="Python Bindings for Libbpf",
long_description=long_description,
long_description_content_type="text/markdown",
url="https://github.com/varun-r-mallya/pylibbpf",
ext_modules=[CMakeExtension("pylibbpf")],
url="https://github.com/pythonbpf/pylibbpf",
packages=find_packages(where="."),
package_dir={"": "."},
py_modules=[], # Empty since we use packages
ext_modules=[CMakeExtension("pylibbpf.pylibbpf")],
cmdclass={"build_ext": CMakeBuild},
zip_safe=False,
classifiers=[
@ -147,6 +150,16 @@ setup(
"Topic :: Software Development :: Libraries :: Python Modules",
"Topic :: System :: Operating System Kernels :: Linux",
],
install_requires=[
"llvmlite>=0.40.0", # Required for struct conversion
],
extras_require={"test": ["pytest>=6.0"]},
python_requires=">=3.8",
package_data={
"pylibbpf": [
"*.py",
"py.typed", # For type hints
],
},
include_package_data=True,
)

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@ -2,18 +2,17 @@
#define STRINGIFY(x) #x
#define MACRO_STRINGIFY(x) STRINGIFY(x)
extern "C" {
#include <libbpf.h>
}
#include "core/bpf_program.h"
#include "core/bpf_exception.h"
#include "core/bpf_map.h"
#include "core/bpf_object.h"
#include "core/bpf_program.h"
#include "maps/perf_event_array.h"
#include "utils/struct_parser.h"
namespace py = pybind11;
PYBIND11_MODULE(pylibbpf, m) {
m.doc() = R"pbdoc(
m.doc() = R"pbdoc(
Pylibbpf - libbpf bindings for Python
-----------------------
@ -27,41 +26,73 @@ PYBIND11_MODULE(pylibbpf, m) {
BpfException
)pbdoc";
// Register the custom exception
py::register_exception<BpfException>(m, "BpfException");
// Register the custom exception
py::register_exception<BpfException>(m, "BpfException");
py::class_<BpfProgram>(m, "BpfProgram")
.def(py::init<const std::string &>())
.def(py::init<const std::string &, const std::string &>())
.def("load", &BpfProgram::load)
.def("attach", &BpfProgram::attach)
.def("destroy", &BpfProgram::destroy)
.def("load_and_attach", &BpfProgram::load_and_attach)
.def("is_loaded", &BpfProgram::is_loaded)
.def("is_attached", &BpfProgram::is_attached);
// BpfObject
py::class_<BpfObject, std::shared_ptr<BpfObject>>(m, "BpfObject")
.def(py::init<std::string, py::dict>(), py::arg("object_path"),
py::arg("structs") = py::dict())
.def("load", &BpfObject::load)
.def("is_loaded", &BpfObject::is_loaded)
.def("get_program_names", &BpfObject::get_program_names)
.def("get_program", &BpfObject::get_program, py::arg("name"))
.def("attach_all", &BpfObject::attach_all)
.def("get_map_names", &BpfObject::get_map_names)
.def("get_map", &BpfObject::get_map, py::arg("name"))
.def("get_struct_defs", &BpfObject::get_struct_defs)
.def("__getitem__", &BpfObject::get_map, py::arg("name"));
py::class_<BpfMap>(m, "BpfMap")
.def(py::init<BpfProgram *, py::object &>())
.def("lookup", &BpfMap::lookup)
.def("update", &BpfMap::update)
.def("delete", &BpfMap::delete_elem)
.def("get_next_key", &BpfMap::get_next_key, py::arg("key") = py::none())
.def("items", &BpfMap::items)
.def("keys", &BpfMap::keys)
.def("values", &BpfMap::values)
.def("get_name", &BpfMap::get_name)
.def("get_type", &BpfMap::get_type)
.def("get_key_size", &BpfMap::get_key_size)
.def("get_value_size", &BpfMap::get_value_size)
.def("get_max_entries", &BpfMap::get_max_entries)
.def("__getitem__", &BpfMap::lookup)
.def("__setitem__", &BpfMap::update)
.def("__delitem__", &BpfMap::delete_elem);
// BpfProgram
py::class_<BpfProgram, std::shared_ptr<BpfProgram>>(m, "BpfProgram")
.def("attach", &BpfProgram::attach)
.def("detach", &BpfProgram::detach)
.def("is_attached", &BpfProgram::is_attached)
.def("get_name", &BpfProgram::get_name);
// BpfMap
py::class_<BpfMap, std::shared_ptr<BpfMap>>(m, "BpfMap")
.def("lookup", &BpfMap::lookup, py::arg("key"))
.def("update", &BpfMap::update, py::arg("key"), py::arg("value"))
.def("delete_elem", &BpfMap::delete_elem, py::arg("key"))
.def("get_next_key", &BpfMap::get_next_key, py::arg("key") = py::none())
.def("items", &BpfMap::items)
.def("keys", &BpfMap::keys)
.def("values", &BpfMap::values)
.def("get_name", &BpfMap::get_name)
.def("get_fd", &BpfMap::get_fd)
.def("get_type", &BpfMap::get_type)
.def("get_key_size", &BpfMap::get_key_size)
.def("get_value_size", &BpfMap::get_value_size)
.def("get_max_entries", &BpfMap::get_max_entries)
.def("__getitem__", &BpfMap::lookup, py::arg("key"))
.def("__setitem__", &BpfMap::update, py::arg("key"), py::arg("value"))
.def("__delitem__", &BpfMap::delete_elem, py::arg("key"));
// StructParser
py::class_<StructParser>(m, "StructParser")
.def(py::init<py::dict>(), py::arg("structs"))
.def("parse", &StructParser::parse, py::arg("struct_name"),
py::arg("data"))
.def("has_struct", &StructParser::has_struct, py::arg("struct_name"));
// PerfEventArray
py::class_<PerfEventArray, std::shared_ptr<PerfEventArray>>(m,
"PerfEventArray")
.def(py::init<std::shared_ptr<BpfMap>, int, py::function, py::object>(),
py::arg("map"), py::arg("page_cnt"), py::arg("callback"),
py::arg("lost_callback") = py::none())
.def(py::init<std::shared_ptr<BpfMap>, int, py::function, std::string,
py::object>(),
py::arg("map"), py::arg("page_cnt"), py::arg("callback"),
py::arg("struct_name"), py::arg("lost_callback") = py::none())
.def("poll", &PerfEventArray::poll, py::arg("timeout_ms"))
.def("consume", &PerfEventArray::consume)
.def("get_map", &PerfEventArray::get_map);
#ifdef VERSION_INFO
m.attr("__version__") = MACRO_STRINGIFY(VERSION_INFO);
m.attr("__version__") = MACRO_STRINGIFY(VERSION_INFO);
#else
m.attr("__version__") = "dev";
m.attr("__version__") = "dev";
#endif
}

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@ -6,13 +6,10 @@
class BpfException final : public std::runtime_error {
public:
explicit BpfException(const std::string &message)
: std::runtime_error(message) {
}
explicit BpfException(const std::string &message)
: std::runtime_error(message) {}
explicit BpfException(const char *message)
: std::runtime_error(message) {
}
explicit BpfException(const char *message) : std::runtime_error(message) {}
};
#endif // PYLIBBPF_BPF_EXCEPTION_H

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@ -1,211 +1,230 @@
#include "bpf_map.h"
#include "core/bpf_map.h"
#include "core/bpf_exception.h"
#include "core/bpf_object.h"
#include <algorithm>
#include <cerrno>
#include <cstring>
#include "bpf_exception.h"
BpfMap::BpfMap(std::shared_ptr<BpfObject> parent, struct bpf_map *raw_map,
const std::string &map_name)
: parent_obj_(parent), map_(raw_map), map_fd_(-1), map_name_(map_name),
key_size_(0), value_size_(0) {
if (!parent)
throw BpfException("Parent BpfObject is null");
if (!(parent->is_loaded()))
throw BpfException("Parent BpfObject is not loaded");
if (!raw_map)
throw BpfException("bpf_map pointer is null");
BpfMap::BpfMap(BpfProgram *program_, const py::object &map_from_python) {
if (py::isinstance<py::function>(map_from_python)) {
const auto name = map_from_python.attr("__name__").cast<std::string>();
bpf_program = program_;
map_ = bpf_object__find_map_by_name(bpf_program->get_obj(), name.c_str());
if (!map_) {
throw BpfException("Failed to find map by name");
}
map_fd = bpf_map__fd(map_);
if (map_fd == -1) {
throw BpfException("Failed to open map File Descriptor");
}
} else {
throw BpfException("Invalid map object passed to function.");
}
}
map_fd_ = bpf_map__fd(map_);
if (map_fd_ < 0)
throw BpfException("Failed to get file descriptor for map '" + map_name_ +
"'");
std::vector<uint8_t> BpfMap::python_to_bytes(const py::object &obj, size_t size) {
std::vector<uint8_t> result(size, 0);
if (py::isinstance<py::int_>(obj)) {
const auto value = obj.cast<uint64_t>();
std::memcpy(result.data(), &value, std::min(size, sizeof(uint64_t)));
} else if (py::isinstance<py::bytes>(obj)) {
const auto bytes_str = obj.cast<std::string>();
std::memcpy(result.data(), bytes_str.data(), std::min(size, bytes_str.size()));
} else if (py::isinstance<py::str>(obj)) {
const auto str_val = obj.cast<std::string>();
std::memcpy(result.data(), str_val.data(), std::min(size, str_val.size()));
}
return result;
}
py::object BpfMap::bytes_to_python(const std::vector<uint8_t> &data) {
// Try to interpret as integer if it's a common integer size
if (data.size() == 4) {
uint32_t value;
std::memcpy(&value, data.data(), 4);
return py::cast(value);
} else if (data.size() == 8) {
uint64_t value;
std::memcpy(&value, data.data(), 8);
return py::cast(value);
} else {
// Return as bytes
return py::bytes(reinterpret_cast<const char *>(data.data()), data.size());
}
}
void BpfMap::update(const py::object &key, const py::object &value) const {
const size_t key_size = bpf_map__key_size(map_);
const size_t value_size = bpf_map__value_size(map_);
const auto key_bytes = python_to_bytes(key, key_size);
const auto value_bytes = python_to_bytes(value, value_size);
const int ret = bpf_map__update_elem(
map_,
key_bytes.data(),
key_size,
value_bytes.data(),
value_size,
BPF_ANY);
if (ret != 0) {
throw BpfException("Failed to update map element");
}
}
void BpfMap::delete_elem(const py::object &key) const {
const size_t key_size = bpf_map__key_size(map_);
std::vector<uint8_t> key_bytes;
key_bytes = python_to_bytes(key, key_size);
if (const int ret = bpf_map__delete_elem(map_, key_bytes.data(), key_size, BPF_ANY); ret != 0) {
throw BpfException("Failed to delete map element");
}
}
py::list BpfMap::get_next_key(const py::object &key) const {
const size_t key_size = bpf_map__key_size(map_);
std::vector<uint8_t> next_key(key_size);
int ret;
if (key.is_none()) {
ret = bpf_map__get_next_key(map_, nullptr, next_key.data(), key_size);
} else {
const auto key_bytes = python_to_bytes(key, key_size);
ret = bpf_map__get_next_key(map_, key_bytes.data(), next_key.data(), key_size);
}
py::list result;
if (ret == 0) {
result.append(bytes_to_python(next_key));
}
return result;
}
py::list BpfMap::keys() const {
py::list result;
const size_t key_size = bpf_map__key_size(map_);
std::vector<uint8_t> key(key_size);
std::vector<uint8_t> next_key(key_size);
int ret = bpf_map__get_next_key(map_, nullptr, key.data(), key_size);
while (ret == 0) {
result.append(bytes_to_python(key));
ret = bpf_map__get_next_key(map_, key.data(), next_key.data(), key_size);
key = next_key;
}
return result;
}
py::list BpfMap::values() const {
py::list result;
const size_t key_size = bpf_map__key_size(map_);
const size_t value_size = bpf_map__value_size(map_);
std::vector<uint8_t> key(key_size);
std::vector<uint8_t> next_key(key_size);
std::vector<uint8_t> value(value_size);
int ret = bpf_map__get_next_key(map_, nullptr, key.data(), key_size);
while (ret == 0) {
if (bpf_map__lookup_elem(map_, key.data(), key_size, value.data(), value_size, BPF_ANY) == 0) {
result.append(bytes_to_python(value));
}
ret = bpf_map__get_next_key(map_, key.data(), next_key.data(), key_size);
key = next_key;
}
return result;
}
std::string BpfMap::get_name() const {
const char *name = bpf_map__name(map_);
return name ? std::string(name) : "";
}
int BpfMap::get_type() const {
return bpf_map__type(map_);
}
int BpfMap::get_key_size() const {
return bpf_map__key_size(map_);
}
int BpfMap::get_value_size() const {
return bpf_map__value_size(map_);
}
int BpfMap::get_max_entries() const {
return bpf_map__max_entries(map_);
}
py::dict BpfMap::items() const {
py::dict result;
const size_t key_size = bpf_map__key_size(map_);
const size_t value_size = bpf_map__value_size(map_);
std::vector<uint8_t> key(key_size);
std::vector<uint8_t> next_key(key_size);
std::vector<uint8_t> value(value_size);
// Get first key
int ret = bpf_map__get_next_key(map_, nullptr, key.data(), key_size);
while (ret == 0) {
// Lookup value for current key
if (bpf_map__lookup_elem(map_, key.data(), key_size, value.data(), value_size, BPF_ANY) == 0) {
result[bytes_to_python(key)] = bytes_to_python(value);
}
// Get next key
ret = bpf_map__get_next_key(map_, key.data(), next_key.data(), key_size);
key = next_key;
}
return result;
key_size_ = bpf_map__key_size(map_);
value_size_ = bpf_map__value_size(map_);
}
py::object BpfMap::lookup(const py::object &key) const {
const __u32 key_size = bpf_map__key_size(map_);
const __u32 value_size = bpf_map__value_size(map_);
if (map_fd_ < 0)
throw BpfException("Map '" + map_name_ + "' is not initialized properly");
const auto key_bytes = python_to_bytes(key, key_size);
std::vector<uint8_t> value_bytes(value_size);
BufferManager<> key_buf, value_buf;
auto key_span = key_buf.get_span(key_size_);
auto value_span = value_buf.get_span(value_size_);
// The flags field here matters only when spin locks are used which is close to fucking never, so fuck no,
// im not adding it
const int ret = bpf_map__lookup_elem(
map_,
key_bytes.data(),
key_size,
value_bytes.data(),
value_size,
BPF_ANY);
if (ret != 0) {
return py::none();
// Convert Python → bytes
python_to_bytes_inplace(key, key_span);
// The flags field here matters only when spin locks are used.
// Skipping it for now.
const int ret = bpf_map__lookup_elem(map_, key_span.data(), key_size_,
value_span.data(), value_size_, BPF_ANY);
if (ret < 0) {
if (ret == -ENOENT)
throw py::key_error("Key not found in map '" + map_name_ + "'");
throw BpfException("Failed to lookup key in map '" + map_name_ +
"': " + std::strerror(-ret));
}
return bytes_to_python(value_span);
}
void BpfMap::update(const py::object &key, const py::object &value) const {
if (map_fd_ < 0)
throw BpfException("Map '" + map_name_ + "' is not initialized properly");
BufferManager<> key_buf, value_buf;
auto key_span = key_buf.get_span(key_size_);
auto value_span = value_buf.get_span(value_size_);
python_to_bytes_inplace(key, key_span);
python_to_bytes_inplace(value, value_span);
const int ret = bpf_map__update_elem(map_, key_span.data(), key_size_,
value_span.data(), value_size_, BPF_ANY);
if (ret < 0) {
throw BpfException("Failed to update key in map '" + map_name_ +
"': " + std::strerror(-ret));
}
}
void BpfMap::delete_elem(const py::object &key) const {
if (map_fd_ < 0)
throw BpfException("Map '" + map_name_ + "' is not initialized properly");
BufferManager<> key_buf;
auto key_span = key_buf.get_span(key_size_);
// Convert Python → bytes
python_to_bytes_inplace(key, key_span);
const int ret =
bpf_map__delete_elem(map_, key_span.data(), key_size_, BPF_ANY);
if (ret != 0) {
if (ret == -ENOENT)
throw py::key_error("Key not found in map '" + map_name_ + "'");
throw BpfException("Failed to delete key from map '" + map_name_ +
"': " + std::strerror(-ret));
}
}
py::object BpfMap::get_next_key(const py::object &key) const {
BufferManager<> next_key_buf;
auto next_key = next_key_buf.get_span(key_size_);
int ret;
if (key.is_none()) {
ret = bpf_map__get_next_key(map_, nullptr, next_key.data(), key_size_);
} else {
BufferManager<> key_buf;
auto key_bytes = key_buf.get_span(key_size_);
python_to_bytes_inplace(key, key_bytes);
ret = bpf_map__get_next_key(map_, key_bytes.data(), next_key.data(),
key_size_);
}
if (ret < 0) {
if (ret == -ENOENT) {
// No more keys
return py::none();
}
throw BpfException("Failed to get next key in map '" + map_name_ +
"': " + std::strerror(-ret));
}
return bytes_to_python(next_key);
}
py::dict BpfMap::items() const {
py::dict result;
py::object current_key = get_next_key(py::none());
if (current_key.is_none()) {
return result;
}
while (!current_key.is_none()) {
try {
py::object value = lookup(current_key);
result[current_key] = value;
current_key = get_next_key(current_key);
} catch (const py::key_error &) {
break;
}
}
return result;
}
py::list BpfMap::keys() const {
py::list result;
py::object current_key = get_next_key(py::none());
if (current_key.is_none()) {
return result;
}
while (!current_key.is_none()) {
result.append(current_key);
current_key = get_next_key(current_key);
}
return result;
}
py::list BpfMap::values() const {
py::list result;
py::object current_key = get_next_key(py::none());
if (current_key.is_none()) {
return result;
}
while (!current_key.is_none()) {
try {
py::object value = lookup(current_key);
result.append(value);
current_key = get_next_key(current_key);
} catch (const py::key_error &) {
break;
}
}
return result;
}
int BpfMap::get_type() const { return bpf_map__type(map_); }
int BpfMap::get_max_entries() const { return bpf_map__max_entries(map_); }
// Helper functions
void BpfMap::python_to_bytes_inplace(const py::object &obj,
std::span<uint8_t> buffer) {
std::fill(buffer.begin(), buffer.end(), 0);
if (py::isinstance<py::int_>(obj)) {
if (buffer.size() <= sizeof(uint64_t)) {
uint64_t value = obj.cast<uint64_t>();
std::memcpy(buffer.data(), &value, buffer.size());
} else {
throw BpfException("Integer key/value size exceeds maximum (8 bytes)");
}
} else if (py::isinstance<py::bytes>(obj)) {
std::string bytes_str = obj.cast<std::string>();
if (bytes_str.size() > buffer.size()) {
throw BpfException("Bytes size " + std::to_string(bytes_str.size()) +
" exceeds expected size " +
std::to_string(buffer.size()));
}
return bytes_to_python(value_bytes);
std::memcpy(buffer.data(), bytes_str.data(), bytes_str.size());
} else if (py::isinstance<py::str>(obj)) {
std::string str_val = obj.cast<std::string>();
if (str_val.size() >= buffer.size()) {
throw BpfException("String size exceeds expected size");
}
std::memcpy(buffer.data(), str_val.data(), str_val.size());
buffer[str_val.size()] = '\0';
} else {
throw BpfException("Unsupported type for BPF map key/value");
}
}
py::object BpfMap::bytes_to_python(std::span<const uint8_t> data) {
if (data.size() == 4) {
uint32_t value;
std::memcpy(&value, data.data(), 4);
return py::cast(value);
} else if (data.size() == 8) {
uint64_t value;
std::memcpy(&value, data.data(), 8);
return py::cast(value);
} else {
return py::bytes(reinterpret_cast<const char *>(data.data()), data.size());
}
}

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@ -1,55 +1,72 @@
#ifndef PYLIBBPF_MAPS_H
#define PYLIBBPF_MAPS_H
#ifndef PYLIBBPF_BPF_MAP_H
#define PYLIBBPF_BPF_MAP_H
#include <array>
#include <libbpf.h>
#include <pybind11/pybind11.h>
#include <vector>
#include <span>
#include <string>
#include <vector>
#include "bpf_program.h"
class BpfObject;
namespace py = pybind11;
class BpfMap {
class BpfMap : public std::enable_shared_from_this<BpfMap> {
private:
struct bpf_map *map_;
int map_fd = -1;
//TODO: turn below into a shared pointer and ref count it so that there is no resource leakage
BpfProgram *bpf_program;
std::weak_ptr<BpfObject> parent_obj_;
struct bpf_map *map_;
int map_fd_;
std::string map_name_;
__u32 key_size_, value_size_;
template <size_t StackSize = 64> struct BufferManager {
std::array<uint8_t, StackSize> stack_buf;
std::vector<uint8_t> heap_buf;
std::span<uint8_t> get_span(size_t size) {
if (size <= StackSize) {
return std::span<uint8_t>(stack_buf.data(), size);
} else {
heap_buf.resize(size);
return std::span<uint8_t>(heap_buf);
}
}
};
public:
BpfMap(BpfProgram *program_, const py::object &map_from_python);
BpfMap(std::shared_ptr<BpfObject> parent, struct bpf_map *raw_map,
const std::string &map_name);
~BpfMap() = default;
~BpfMap() = default;
[[nodiscard]] py::object lookup(const py::object &key) const;
BpfMap(const BpfMap &) = delete;
BpfMap &operator=(const BpfMap &) = delete;
BpfMap(BpfMap &&) noexcept = default;
BpfMap &operator=(BpfMap &&) noexcept = default;
void update(const py::object &key, const py::object &value) const;
[[nodiscard]] py::object lookup(const py::object &key) const;
void update(const py::object &key, const py::object &value) const;
void delete_elem(const py::object &key) const;
py::object get_next_key(const py::object &key = py::none()) const;
py::dict items() const;
py::list keys() const;
py::list values() const;
void delete_elem(const py::object &key) const;
py::list get_next_key(const py::object &key = py::none()) const;
py::dict items() const;
py::list keys() const;
py::list values() const;
[[nodiscard]] std::string get_name() const;
int get_type() const;
int get_key_size() const;
int get_value_size() const;
int get_max_entries() const;
[[nodiscard]] std::string get_name() const { return map_name_; }
[[nodiscard]] int get_fd() const { return map_fd_; }
[[nodiscard]] int get_type() const;
[[nodiscard]] int get_key_size() const { return key_size_; };
[[nodiscard]] int get_value_size() const { return value_size_; };
[[nodiscard]] int get_max_entries() const;
[[nodiscard]] std::shared_ptr<BpfObject> get_parent() const {
return parent_obj_.lock();
}
private:
static std::vector<uint8_t> python_to_bytes(const py::object &obj, size_t size);
static py::object bytes_to_python(const std::vector<uint8_t> &data);
static void python_to_bytes_inplace(const py::object &obj,
std::span<uint8_t> buffer);
static py::object bytes_to_python(std::span<const uint8_t> data);
};
#endif //PYLIBBPF_MAPS_H
#endif // PYLIBBPF_BPF_MAP_H

272
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#include "core/bpf_object.h"
#include "core/bpf_exception.h"
#include "core/bpf_map.h"
#include "core/bpf_program.h"
#include "utils/struct_parser.h"
#include <cerrno>
#include <cstring>
#include <utility>
BpfObject::BpfObject(std::string object_path, py::dict structs)
: obj_(nullptr), object_path_(std::move(object_path)), loaded_(false),
struct_defs_(structs), struct_parser_(nullptr) {}
BpfObject::~BpfObject() {
// Clear caches first (order matters!)
prog_cache_.clear(); // Detaches programs
maps_cache_.clear(); // Closes maps
// Then close object
if (obj_) {
bpf_object__close(obj_);
obj_ = nullptr;
}
}
BpfObject::BpfObject(BpfObject &&other) noexcept
: obj_(std::exchange(other.obj_, nullptr)),
object_path_(std::move(other.object_path_)),
loaded_(std::exchange(other.loaded_, false)),
maps_cache_(std::move(other.maps_cache_)),
prog_cache_(std::move(other.prog_cache_)),
struct_defs_(std::move(other.struct_defs_)),
struct_parser_(std::move(other.struct_parser_)) {
other.obj_ = nullptr;
other.loaded_ = false;
}
BpfObject &BpfObject::operator=(BpfObject &&other) noexcept {
if (this != &other) {
prog_cache_.clear();
maps_cache_.clear();
if (obj_) {
bpf_object__close(obj_);
}
obj_ = std::exchange(other.obj_, nullptr);
object_path_ = std::move(other.object_path_);
loaded_ = std::exchange(other.loaded_, false);
maps_cache_ = std::move(other.maps_cache_);
prog_cache_ = std::move(other.prog_cache_);
struct_defs_ = std::move(other.struct_defs_);
struct_parser_ = std::move(other.struct_parser_);
}
return *this;
}
void BpfObject::load() {
if (loaded_) {
throw BpfException("BPF object already loaded");
}
std::string error_msg = "Failed to open BPF object";
obj_ = bpf_object__open_file(object_path_.c_str(), nullptr);
if (!obj_) {
error_msg += " file '" + object_path_ + "': " + std::strerror(errno);
throw BpfException(error_msg);
}
if (bpf_object__load(obj_)) {
error_msg +=
" object from file '" + object_path_ + "': " + std::strerror(errno);
bpf_object__close(obj_);
obj_ = nullptr;
throw BpfException(error_msg);
}
loaded_ = true;
}
// ==================== Program Methods ====================
py::list BpfObject::get_program_names() {
if (!loaded_) {
throw BpfException("BPF object not loaded");
}
py::list names;
struct bpf_program *prog = nullptr;
bpf_object__for_each_program(prog, obj_) {
_get_or_create_program(prog); // Ensure cached
names.append(bpf_program__name(prog));
}
return names;
}
std::shared_ptr<BpfProgram>
BpfObject::_get_or_create_program(struct bpf_program *prog) {
if (!prog) {
throw BpfException("bpf_program pointer is null");
}
const char *name = bpf_program__name(prog);
std::string prog_name(name ? name : "");
// Check cache
auto it = prog_cache_.find(prog_name);
if (it != prog_cache_.end()) {
return it->second;
}
// Create and cache
auto bpf_prog =
std::make_shared<BpfProgram>(shared_from_this(), prog, prog_name);
prog_cache_[prog_name] = bpf_prog;
return bpf_prog;
}
std::shared_ptr<BpfProgram> BpfObject::get_program(const std::string &name) {
if (!loaded_) {
throw BpfException("BPF object not loaded");
}
// Check cache
auto it = prog_cache_.find(name);
if (it != prog_cache_.end()) {
return it->second;
}
// Create and cache
struct bpf_program *raw_prog = find_program_by_name(name);
auto prog = std::make_shared<BpfProgram>(shared_from_this(), raw_prog, name);
prog_cache_[name] = prog;
return prog;
}
struct bpf_program *
BpfObject::find_program_by_name(const std::string &name) const {
if (!loaded_) {
throw BpfException("BPF object not loaded");
}
struct bpf_program *prog =
bpf_object__find_program_by_name(obj_, name.c_str());
if (!prog) {
throw BpfException("Program '" + name + "' not found");
}
return prog;
}
py::dict BpfObject::get_cached_programs() const {
py::dict programs;
for (const auto &entry : prog_cache_) {
programs[entry.first.c_str()] = entry.second;
}
return programs;
}
py::dict BpfObject::attach_all() {
if (!loaded_) {
throw BpfException("BPF object not loaded");
}
py::dict attached_programs;
struct bpf_program *prog = nullptr;
bpf_object__for_each_program(prog, obj_) {
auto bpf_prog = _get_or_create_program(prog);
if (!bpf_prog->is_attached()) {
bpf_prog->attach();
}
const char *name = bpf_program__name(prog);
attached_programs[name] = bpf_prog;
}
return attached_programs;
}
// ==================== Map Methods ====================
py::list BpfObject::get_map_names() {
if (!loaded_) {
throw BpfException("BPF object not loaded");
}
py::list names;
struct bpf_map *map = nullptr;
bpf_object__for_each_map(map, obj_) {
_get_or_create_map(map); // Ensure cached
names.append(bpf_map__name(map));
}
return names;
}
std::shared_ptr<BpfMap> BpfObject::get_map(const std::string &name) {
if (!loaded_) {
throw BpfException("BPF object not loaded");
}
// Check cache
auto it = maps_cache_.find(name);
if (it != maps_cache_.end()) {
return it->second;
}
// Create and cache
struct bpf_map *raw_map = find_map_by_name(name);
auto map = std::make_shared<BpfMap>(shared_from_this(), raw_map, name);
maps_cache_[name] = map;
return map;
}
std::shared_ptr<BpfMap> BpfObject::_get_or_create_map(struct bpf_map *map) {
if (!map) {
throw BpfException("bpf_map pointer is null");
}
const char *name = bpf_map__name(map);
std::string map_name(name ? name : "");
// Check cache
auto it = maps_cache_.find(map_name);
if (it != maps_cache_.end()) {
return it->second;
}
// Create and cache
auto bpf_map = std::make_shared<BpfMap>(shared_from_this(), map, map_name);
maps_cache_[map_name] = bpf_map;
return bpf_map;
}
struct bpf_map *BpfObject::find_map_by_name(const std::string &name) const {
if (!loaded_) {
throw BpfException("BPF object not loaded");
}
struct bpf_map *map = bpf_object__find_map_by_name(obj_, name.c_str());
if (!map) {
throw BpfException("Map '" + name + "' not found");
}
return map;
}
py::dict BpfObject::get_cached_maps() const {
py::dict maps;
for (const auto &entry : maps_cache_) {
maps[entry.first.c_str()] = entry.second;
}
return maps;
}
std::shared_ptr<StructParser> BpfObject::get_struct_parser() const {
if (!struct_parser_ && !struct_defs_.empty()) {
// Create parser on first access
struct_parser_ = std::make_shared<StructParser>(struct_defs_);
}
return struct_parser_;
}

88
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#ifndef PYLIBBPF_BPF_OBJECT_H
#define PYLIBBPF_BPF_OBJECT_H
#include <libbpf.h>
#include <memory>
#include <pybind11/pybind11.h>
#include <string>
#include <unordered_map>
namespace py = pybind11;
class BpfProgram;
class BpfMap;
class StructParser;
/**
* BpfObject - Represents a loaded BPF object file.
*
* This is the main entry point for loading BPF programs.
* Owns the bpf_object* and manages all programs and maps within it.
*/
class BpfObject : public std::enable_shared_from_this<BpfObject> {
private:
struct bpf_object *obj_;
std::string object_path_;
bool loaded_;
mutable std::unordered_map<std::string, std::shared_ptr<BpfMap>> maps_cache_;
mutable std::unordered_map<std::string, std::shared_ptr<BpfProgram>>
prog_cache_;
py::dict struct_defs_;
mutable std::shared_ptr<StructParser> struct_parser_;
std::shared_ptr<BpfProgram> _get_or_create_program(struct bpf_program *prog);
std::shared_ptr<BpfMap> _get_or_create_map(struct bpf_map *map);
public:
explicit BpfObject(std::string object_path, py::dict structs = py::dict());
~BpfObject();
// Disable copy, allow move
BpfObject(const BpfObject &) = delete;
BpfObject &operator=(const BpfObject &) = delete;
BpfObject(BpfObject &&) noexcept;
BpfObject &operator=(BpfObject &&) noexcept;
/**
* Load the BPF object into the kernel.
* Must be called before accessing programs or maps.
*/
void load();
/**
* Check if object is loaded.
*/
[[nodiscard]] bool is_loaded() const { return loaded_; }
/**
* Get the underlying bpf_object pointer.
* Only for internal use by BpfProgram and BpfMap.
*/
[[nodiscard]] struct bpf_object *get_obj() const { return obj_; }
/**
* Attach all programs in the object.
*/
py::dict attach_all();
// Program access
[[nodiscard]] py::list get_program_names();
[[nodiscard]] std::shared_ptr<BpfProgram>
get_program(const std::string &name);
[[nodiscard]] struct bpf_program *
find_program_by_name(const std::string &name) const;
[[nodiscard]] py::dict get_cached_programs() const;
// Map access
[[nodiscard]] py::list get_map_names();
[[nodiscard]] std::shared_ptr<BpfMap> get_map(const std::string &name);
[[nodiscard]] struct bpf_map *find_map_by_name(const std::string &name) const;
[[nodiscard]] py::dict get_cached_maps() const;
// Struct parsing
[[nodiscard]] py::dict get_struct_defs() const { return struct_defs_; }
[[nodiscard]] std::shared_ptr<StructParser> get_struct_parser() const;
};
#endif // PYLIBBPF_BPF_OBJECT_H

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@ -1,84 +1,74 @@
#include "bpf_program.h"
#include "bpf_exception.h"
#include <filesystem>
#include "core/bpf_program.h"
#include "core/bpf_exception.h"
#include "core/bpf_object.h"
#include <cerrno>
#include <cstring>
#include <utility>
BpfProgram::BpfProgram(std::string object_path, std::string program_name)
: obj_(nullptr), prog_(nullptr), link_(nullptr),
object_path_(std::move(object_path)), program_name_(std::move(program_name)) {
BpfProgram::BpfProgram(std::shared_ptr<BpfObject> parent,
struct bpf_program *raw_prog,
const std::string &program_name)
: parent_obj_(parent), prog_(raw_prog), link_(nullptr),
program_name_(program_name) {
if (!parent)
throw BpfException("Parent BpfObject is null");
if (!(parent->is_loaded()))
throw BpfException("Parent BpfObject is not loaded");
if (!raw_prog)
throw BpfException("bpf_program pointer is null");
}
BpfProgram::~BpfProgram() {
destroy();
if (obj_) {
bpf_object__close(obj_);
}
BpfProgram::~BpfProgram() { detach(); }
BpfProgram::BpfProgram(BpfProgram &&other) noexcept
: parent_obj_(std::move(other.parent_obj_)), prog_(other.prog_),
link_(other.link_), program_name_(std::move(other.program_name_)) {
other.prog_ = nullptr;
other.link_ = nullptr;
}
struct bpf_object * BpfProgram::get_obj() const {
return obj_;
BpfProgram &BpfProgram::operator=(BpfProgram &&other) noexcept {
if (this != &other) {
detach();
parent_obj_ = std::move(other.parent_obj_);
prog_ = other.prog_;
link_ = other.link_;
program_name_ = std::move(other.program_name_);
other.prog_ = nullptr;
other.link_ = nullptr;
}
return *this;
}
bool BpfProgram::load() {
// Open the eBPF object file
obj_ = bpf_object__open_file(object_path_.c_str(), nullptr);
if (libbpf_get_error(obj_)) {
throw BpfException("Failed to open BPF object file: " + object_path_);
}
void BpfProgram::attach() {
// Check if parent is still alive
auto parent = parent_obj_.lock();
if (!parent) {
throw BpfException("Parent BpfObject has been destroyed");
}
// Find the program by name (if specified)
if (!program_name_.empty()) {
prog_ = bpf_object__find_program_by_name(obj_, program_name_.c_str());
if (!prog_) {
throw BpfException("Program '" + program_name_ + "' not found in object");
}
} else {
while ((prog_ = bpf_object__next_program(obj_, prog_)) != nullptr) {
programs.emplace_back(prog_, nullptr);
}
if (link_) {
throw BpfException("Program '" + program_name_ + "' already attached");
}
// throw if no programs found
if (programs.empty()) {
throw BpfException("No programs found in object file");
}
}
if (!prog_) {
throw BpfException("Program '" + program_name_ + "' not initialized");
}
// Load the eBPF object into the kernel
if (bpf_object__load(obj_)) {
throw BpfException("Failed to load BPF object into kernel");
}
return true;
link_ = bpf_program__attach(prog_);
if (!link_) {
std::string err_msg = "bpf_program__attach failed for program '" +
program_name_ + "': " + std::strerror(errno);
throw BpfException(err_msg);
}
}
bool BpfProgram::attach() {
for (auto [prog, link]: programs) {
if (!prog) {
throw BpfException("Program not loaded");
}
link = bpf_program__attach(prog);
if (libbpf_get_error(link)) {
link = nullptr;
throw BpfException("Failed to attach BPF program");
}
}
return true;
}
bool BpfProgram::destroy() {
bool success = true;
for (auto [prog, link]: programs) {
if (!prog) {
throw BpfException("Program not loaded");
}
success = success & bpf_link__destroy(link);
}
return success;
}
void BpfProgram::load_and_attach() {
load();
attach();
void BpfProgram::detach() {
if (link_) {
bpf_link__destroy(link_);
link_ = nullptr;
}
}

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@ -2,37 +2,35 @@
#define PYLIBBPF_BPF_PROGRAM_H
#include <libbpf.h>
#include <pybind11/stl.h>
#include <memory>
#include <string>
namespace py = pybind11;
class BpfObject;
class BpfProgram {
private:
struct bpf_object *obj_;
struct bpf_program *prog_;
struct bpf_link *link_;
std::string object_path_;
std::string program_name_;
std::vector<std::pair<bpf_program *, bpf_link *> > programs;
std::weak_ptr<BpfObject> parent_obj_;
struct bpf_program *prog_;
struct bpf_link *link_;
std::string program_name_;
public:
explicit BpfProgram(std::string object_path, std::string program_name = "");
explicit BpfProgram(std::shared_ptr<BpfObject> parent,
struct bpf_program *raw_prog,
const std::string &program_name);
~BpfProgram();
~BpfProgram();
struct bpf_object *get_obj() const;
BpfProgram(const BpfProgram &) = delete;
BpfProgram &operator=(const BpfProgram &) = delete;
BpfProgram(BpfProgram &&) noexcept;
BpfProgram &operator=(BpfProgram &&) noexcept;
bool load();
void attach();
void detach();
bool attach();
bool destroy();
void load_and_attach();
[[nodiscard]] bool is_loaded() const { return obj_ != nullptr; }
[[nodiscard]] bool is_attached() const { return link_ != nullptr; }
[[nodiscard]] bool is_attached() const { return link_ != nullptr; }
[[nodiscard]] std::string get_name() const { return program_name_; }
};
#endif //PYLIBBPF_BPF_PROGRAM_H
#endif // PYLIBBPF_BPF_PROGRAM_H

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@ -0,0 +1,117 @@
#include "maps/perf_event_array.h"
#include "core/bpf_exception.h"
#include "core/bpf_map.h"
#include "core/bpf_object.h"
#include "utils/struct_parser.h"
#include <cerrno>
#include <cstring>
PerfEventArray::PerfEventArray(std::shared_ptr<BpfMap> map, int page_cnt,
py::function callback, py::object lost_callback)
: map_(map), pb_(nullptr), callback_(std::move(callback)),
lost_callback_(std::move(lost_callback)) {
if (map->get_type() != BPF_MAP_TYPE_PERF_EVENT_ARRAY) {
throw BpfException("Map '" + map->get_name() +
"' is not a PERF_EVENT_ARRAY");
}
if (page_cnt <= 0 || (page_cnt & (page_cnt - 1)) != 0) {
throw BpfException("page_cnt must be a positive power of 2");
}
struct perf_buffer_opts pb_opts = {};
pb_opts.sz = sizeof(pb_opts); // Required for forward compatibility
pb_ = perf_buffer__new(
map->get_fd(), page_cnt,
sample_callback_wrapper, // sample_cb
lost_callback.is_none() ? nullptr : lost_callback_wrapper, // lost_cb
this, // ctx
&pb_opts // opts
);
if (!pb_) {
throw BpfException("Failed to create perf buffer: " +
std::string(std::strerror(errno)));
}
}
PerfEventArray::PerfEventArray(std::shared_ptr<BpfMap> map, int page_cnt,
py::function callback,
const std::string &struct_name,
py::object lost_callback)
: PerfEventArray(map, page_cnt, callback, lost_callback) {
auto parent = map->get_parent();
if (!parent) {
throw BpfException("Parent BpfObject has been destroyed");
}
parser_ = parent->get_struct_parser();
struct_name_ = struct_name;
if (!parser_) {
throw BpfException("No struct definitions available");
}
}
PerfEventArray::~PerfEventArray() {
if (pb_) {
perf_buffer__free(pb_);
}
}
void PerfEventArray::sample_callback_wrapper(void *ctx, int cpu, void *data,
unsigned int size) {
auto *self = static_cast<PerfEventArray *>(ctx);
// Acquire GIL for Python calls
py::gil_scoped_acquire acquire;
try {
// Convert data to Python bytes
py::bytes py_data(static_cast<const char *>(data), size);
if (self->parser_ && !self->struct_name_.empty()) {
py::object event = self->parser_->parse(self->struct_name_, py_data);
self->callback_(cpu, event);
} else {
self->callback_(cpu, py_data);
}
} catch (const py::error_already_set &e) {
PyErr_Print();
} catch (const std::exception &e) {
py::print("C++ error in perf callback:", e.what());
}
}
void PerfEventArray::lost_callback_wrapper(void *ctx, int cpu,
unsigned long long cnt) {
auto *self = static_cast<PerfEventArray *>(ctx);
py::gil_scoped_acquire acquire;
try {
if (!self->lost_callback_.is_none()) {
py::function lost_fn = py::cast<py::function>(self->lost_callback_);
lost_fn(cpu, cnt);
} else {
py::print("Lost", cnt, "events on CPU", cpu);
}
} catch (const py::error_already_set &e) {
PyErr_Print();
}
}
int PerfEventArray::poll(int timeout_ms) {
// Release GIL during blocking poll
py::gil_scoped_release release;
return perf_buffer__poll(pb_, timeout_ms);
}
int PerfEventArray::consume() {
py::gil_scoped_release release;
return perf_buffer__consume(pb_);
}

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@ -0,0 +1,46 @@
#ifndef PYLIBBPF_PERF_EVENT_ARRAY_H
#define PYLIBBPF_PERF_EVENT_ARRAY_H
#include <libbpf.h>
#include <memory>
#include <pybind11/pybind11.h>
#include <string>
class StructParser;
class BpfMap;
namespace py = pybind11;
class PerfEventArray {
private:
std::shared_ptr<BpfMap> map_;
struct perf_buffer *pb_;
py::function callback_;
py::object lost_callback_;
std::shared_ptr<StructParser> parser_;
std::string struct_name_;
// Static callback wrappers for C API
static void sample_callback_wrapper(void *ctx, int cpu, void *data,
unsigned int size);
static void lost_callback_wrapper(void *ctx, int cpu, unsigned long long cnt);
public:
PerfEventArray(std::shared_ptr<BpfMap> map, int page_cnt,
py::function callback, py::object lost_callback = py::none());
PerfEventArray(std::shared_ptr<BpfMap> map, int page_cnt,
py::function callback, const std::string &struct_name,
py::object lost_callback = py::none());
~PerfEventArray();
PerfEventArray(const PerfEventArray &) = delete;
PerfEventArray &operator=(const PerfEventArray &) = delete;
int poll(int timeout_ms);
int consume();
[[nodiscard]] std::shared_ptr<BpfMap> get_map() const { return map_; }
};
#endif // PYLIBBPF_PERF_EVENT_ARRAY_H

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@ -0,0 +1,25 @@
#include "struct_parser.h"
#include "core/bpf_exception.h"
StructParser::StructParser(py::dict structs) {
for (auto item : structs) {
std::string name = py::str(item.first);
struct_types_[name] = py::reinterpret_borrow<py::object>(item.second);
}
}
py::object StructParser::parse(const std::string &struct_name, py::bytes data) {
auto it = struct_types_.find(struct_name);
if (it == struct_types_.end()) {
throw BpfException("Unknown struct: " + struct_name);
}
py::object struct_type = it->second;
// Use ctypes.from_buffer_copy() to create struct from bytes
return struct_type.attr("from_buffer_copy")(data);
}
bool StructParser::has_struct(const std::string &struct_name) const {
return struct_types_.find(struct_name) != struct_types_.end();
}

20
src/utils/struct_parser.h Normal file
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@ -0,0 +1,20 @@
#ifndef PYLIBBPF_STRUCT_PARSER_H
#define PYLIBBPF_STRUCT_PARSER_H
#include <pybind11/pybind11.h>
#include <string>
#include <unordered_map>
namespace py = pybind11;
class StructParser {
private:
std::unordered_map<std::string, py::object> struct_types_;
public:
explicit StructParser(py::dict structs);
py::object parse(const std::string &struct_name, py::bytes data);
bool has_struct(const std::string &struct_name) const;
};
#endif

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@ -2,6 +2,6 @@ import pylibbpf as m
def test_main():
assert m.__version__ == "0.0.5"
prog = m.BpfProgram("tests/execve2.o")
assert m.__version__ == "0.0.6"
prog = m.BpfObject("tests/execve2.o", structs={})
print(prog)