mirror of
https://github.com/varun-r-mallya/Python-BPF.git
synced 2026-02-08 06:00:56 +00:00
Merge pull request #80 from pythonbpf/copilot/create-documentation-project
Add comprehensive Sphinx documentation with MyST-Parser
This commit is contained in:
4
.gitignore
vendored
4
.gitignore
vendored
@ -10,3 +10,7 @@ __pycache__/
|
||||
vmlinux.py
|
||||
~*
|
||||
vmlinux.h
|
||||
|
||||
# Documentation build artifacts
|
||||
docs/_build/
|
||||
docs/_templates/
|
||||
|
||||
20
docs/Makefile
Normal file
20
docs/Makefile
Normal file
@ -0,0 +1,20 @@
|
||||
# Minimal makefile for Sphinx documentation
|
||||
#
|
||||
|
||||
# You can set these variables from the command line, and also
|
||||
# from the environment for the first two.
|
||||
SPHINXOPTS ?=
|
||||
SPHINXBUILD ?= sphinx-build
|
||||
SOURCEDIR = .
|
||||
BUILDDIR = _build
|
||||
|
||||
# Put it first so that "make" without argument is like "make help".
|
||||
help:
|
||||
@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
|
||||
|
||||
.PHONY: help Makefile
|
||||
|
||||
# Catch-all target: route all unknown targets to Sphinx using the new
|
||||
# "make mode" option. $(O) is meant as a shortcut for $(SPHINXOPTS).
|
||||
%: Makefile
|
||||
@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
|
||||
52
docs/README.md
Normal file
52
docs/README.md
Normal file
@ -0,0 +1,52 @@
|
||||
# PythonBPF Documentation
|
||||
|
||||
This directory contains the Sphinx documentation for PythonBPF.
|
||||
|
||||
## Building the Documentation
|
||||
|
||||
### Prerequisites
|
||||
|
||||
Install the documentation dependencies:
|
||||
|
||||
**Using uv (recommended):**
|
||||
```bash
|
||||
uv pip install -r requirements.txt
|
||||
# Or install the optional docs dependencies
|
||||
uv pip install pythonbpf[docs]
|
||||
```
|
||||
|
||||
**Using pip:**
|
||||
```bash
|
||||
pip install -r requirements.txt
|
||||
# Or install the optional docs dependencies
|
||||
pip install pythonbpf[docs]
|
||||
```
|
||||
|
||||
### Build HTML Documentation
|
||||
|
||||
```bash
|
||||
make html
|
||||
```
|
||||
|
||||
The generated documentation will be in `_build/html/`. Open `_build/html/index.html` in a browser to view.
|
||||
|
||||
### Other Build Formats
|
||||
|
||||
```bash
|
||||
make latexpdf # Build PDF documentation
|
||||
make epub # Build ePub format
|
||||
make clean # Clean build artifacts
|
||||
```
|
||||
|
||||
## Documentation Structure
|
||||
|
||||
- `index.md` - Main landing page
|
||||
- `getting-started/` - Installation and quick start guides
|
||||
- `user-guide/` - Comprehensive user documentation
|
||||
- `api/` - API reference documentation
|
||||
- `conf.py` - Sphinx configuration
|
||||
- `_static/` - Static files (images, CSS, etc.)
|
||||
|
||||
## Writing Documentation
|
||||
|
||||
Documentation is written in Markdown using [MyST-Parser](https://myst-parser.readthedocs.io/). See the existing files for examples.
|
||||
0
docs/_static/.gitkeep
vendored
Normal file
0
docs/_static/.gitkeep
vendored
Normal file
471
docs/api/index.md
Normal file
471
docs/api/index.md
Normal file
@ -0,0 +1,471 @@
|
||||
# API Reference
|
||||
|
||||
This section provides detailed API documentation for all PythonBPF modules, classes, and functions.
|
||||
|
||||
## Module Overview
|
||||
|
||||
PythonBPF is organized into several modules:
|
||||
|
||||
* `pythonbpf` - Main module with decorators and compilation functions
|
||||
* `pythonbpf.maps` - BPF map types
|
||||
* `pythonbpf.helper` - BPF helper functions
|
||||
* `pythonbpf.structs` - Struct type handling
|
||||
* `pythonbpf.codegen` - Code generation and compilation
|
||||
|
||||
## Public API
|
||||
|
||||
The main `pythonbpf` module exports the following public API:
|
||||
|
||||
```python
|
||||
from pythonbpf import (
|
||||
# Decorators
|
||||
bpf,
|
||||
map,
|
||||
section,
|
||||
bpfglobal,
|
||||
struct,
|
||||
|
||||
# Compilation
|
||||
compile_to_ir,
|
||||
compile,
|
||||
BPF,
|
||||
|
||||
# Utilities
|
||||
trace_pipe,
|
||||
trace_fields,
|
||||
)
|
||||
```
|
||||
|
||||
## Decorators
|
||||
|
||||
```{eval-rst}
|
||||
.. automodule:: pythonbpf.decorators
|
||||
:members:
|
||||
:undoc-members:
|
||||
:show-inheritance:
|
||||
```
|
||||
|
||||
### bpf
|
||||
|
||||
```python
|
||||
@bpf
|
||||
def my_function():
|
||||
pass
|
||||
```
|
||||
|
||||
Decorator to mark a function or class for BPF compilation. Any function or class decorated with `@bpf` will be processed by the PythonBPF compiler.
|
||||
|
||||
**See also:** {doc}`../user-guide/decorators`
|
||||
|
||||
### map
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@map
|
||||
def my_map() -> HashMap:
|
||||
return HashMap(key=c_uint32, value=c_uint64, max_entries=1024)
|
||||
```
|
||||
|
||||
Decorator to mark a function as a BPF map definition. The function must return a map type.
|
||||
|
||||
**See also:** {doc}`../user-guide/maps`
|
||||
|
||||
### section
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_open")
|
||||
def trace_open(ctx: c_void_p) -> c_int64:
|
||||
return c_int64(0)
|
||||
```
|
||||
|
||||
Decorator to specify which kernel hook to attach the BPF program to.
|
||||
|
||||
**Parameters:**
|
||||
* `name` (str) - The section name (e.g., "tracepoint/...", "kprobe/...", "xdp")
|
||||
|
||||
**See also:** {doc}`../user-guide/decorators`
|
||||
|
||||
### bpfglobal
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
```
|
||||
|
||||
Decorator to mark a function as a BPF global variable definition.
|
||||
|
||||
**See also:** {doc}`../user-guide/decorators`
|
||||
|
||||
### struct
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@struct
|
||||
class Event:
|
||||
timestamp: c_uint64
|
||||
pid: c_uint32
|
||||
```
|
||||
|
||||
Decorator to mark a class as a BPF struct definition.
|
||||
|
||||
**See also:** {doc}`../user-guide/structs`
|
||||
|
||||
## Compilation Functions
|
||||
|
||||
```{eval-rst}
|
||||
.. automodule:: pythonbpf.codegen
|
||||
:members: compile_to_ir, compile, BPF
|
||||
:undoc-members:
|
||||
:show-inheritance:
|
||||
```
|
||||
|
||||
### compile_to_ir()
|
||||
|
||||
```python
|
||||
def compile_to_ir(
|
||||
filename: str,
|
||||
output: str,
|
||||
loglevel=logging.WARNING
|
||||
) -> None
|
||||
```
|
||||
|
||||
Compile Python source to LLVM Intermediate Representation.
|
||||
|
||||
**Parameters:**
|
||||
* `filename` (str) - Path to the Python source file
|
||||
* `output` (str) - Path for the output LLVM IR file (.ll)
|
||||
* `loglevel` - Logging level (default: logging.WARNING)
|
||||
|
||||
**See also:** {doc}`../user-guide/compilation`
|
||||
|
||||
### compile()
|
||||
|
||||
```python
|
||||
def compile(
|
||||
filename: str = None,
|
||||
output: str = None,
|
||||
loglevel=logging.WARNING
|
||||
) -> None
|
||||
```
|
||||
|
||||
Compile Python source to BPF object file.
|
||||
|
||||
**Parameters:**
|
||||
* `filename` (str, optional) - Path to the Python source file (default: calling file)
|
||||
* `output` (str, optional) - Path for the output object file (default: same name with .o extension)
|
||||
* `loglevel` - Logging level (default: logging.WARNING)
|
||||
|
||||
**See also:** {doc}`../user-guide/compilation`
|
||||
|
||||
### BPF
|
||||
|
||||
```python
|
||||
class BPF:
|
||||
def __init__(
|
||||
self,
|
||||
filename: str = None,
|
||||
loglevel=logging.WARNING
|
||||
)
|
||||
|
||||
def load(self) -> BpfObject
|
||||
def attach_all(self) -> None
|
||||
def load_and_attach(self) -> BpfObject
|
||||
```
|
||||
|
||||
High-level interface to compile, load, and attach BPF programs.
|
||||
|
||||
**Parameters:**
|
||||
* `filename` (str, optional) - Path to Python source file (default: calling file)
|
||||
* `loglevel` - Logging level (default: logging.WARNING)
|
||||
|
||||
**Methods:**
|
||||
* `load()` - Load the compiled BPF program into the kernel
|
||||
* `attach_all()` - Attach all BPF programs to their hooks
|
||||
* `load_and_attach()` - Convenience method that loads and attaches
|
||||
|
||||
**See also:** {doc}`../user-guide/compilation`
|
||||
|
||||
## Utilities
|
||||
|
||||
```{eval-rst}
|
||||
.. automodule:: pythonbpf.utils
|
||||
:members:
|
||||
:undoc-members:
|
||||
:show-inheritance:
|
||||
```
|
||||
|
||||
### trace_pipe()
|
||||
|
||||
```python
|
||||
def trace_pipe() -> None
|
||||
```
|
||||
|
||||
Read and display output from the kernel trace pipe.
|
||||
|
||||
Blocks until interrupted with Ctrl+C. Displays BPF program output from `print()` statements.
|
||||
|
||||
**See also:** {doc}`../user-guide/helpers`
|
||||
|
||||
### trace_fields()
|
||||
|
||||
```python
|
||||
def trace_fields() -> tuple
|
||||
```
|
||||
|
||||
Parse one line from the trace pipe into structured fields.
|
||||
|
||||
**Returns:** Tuple of `(task, pid, cpu, flags, timestamp, message)`
|
||||
* `task` (str) - Task/process name
|
||||
* `pid` (int) - Process ID
|
||||
* `cpu` (int) - CPU number
|
||||
* `flags` (bytes) - Trace flags
|
||||
* `timestamp` (float) - Timestamp in seconds
|
||||
* `message` (str) - The trace message
|
||||
|
||||
**See also:** {doc}`../user-guide/helpers`
|
||||
|
||||
## Map Types
|
||||
|
||||
```{eval-rst}
|
||||
.. automodule:: pythonbpf.maps.maps
|
||||
:members:
|
||||
:undoc-members:
|
||||
:show-inheritance:
|
||||
```
|
||||
|
||||
### HashMap
|
||||
|
||||
```python
|
||||
class HashMap:
|
||||
def __init__(
|
||||
self,
|
||||
key,
|
||||
value,
|
||||
max_entries: int
|
||||
)
|
||||
|
||||
def lookup(self, key)
|
||||
def update(self, key, value, flags=None)
|
||||
def delete(self, key)
|
||||
```
|
||||
|
||||
Hash map for efficient key-value storage.
|
||||
|
||||
**Parameters:**
|
||||
* `key` - The type of the key (ctypes type or struct)
|
||||
* `value` - The type of the value (ctypes type or struct)
|
||||
* `max_entries` (int) - Maximum number of entries
|
||||
|
||||
**Methods:**
|
||||
* `lookup(key)` - Look up a value by key
|
||||
* `update(key, value, flags=None)` - Update or insert a key-value pair
|
||||
* `delete(key)` - Remove an entry from the map
|
||||
|
||||
**See also:** {doc}`../user-guide/maps`
|
||||
|
||||
### PerfEventArray
|
||||
|
||||
```python
|
||||
class PerfEventArray:
|
||||
def __init__(
|
||||
self,
|
||||
key_size,
|
||||
value_size
|
||||
)
|
||||
|
||||
def output(self, data)
|
||||
```
|
||||
|
||||
Perf event array for sending data to userspace.
|
||||
|
||||
**Parameters:**
|
||||
* `key_size` - Type for the key
|
||||
* `value_size` - Type for the value
|
||||
|
||||
**Methods:**
|
||||
* `output(data)` - Send data to userspace
|
||||
|
||||
**See also:** {doc}`../user-guide/maps`
|
||||
|
||||
### RingBuffer
|
||||
|
||||
```python
|
||||
class RingBuffer:
|
||||
def __init__(self, max_entries: int)
|
||||
|
||||
def output(self, data, flags=0)
|
||||
def reserve(self, size: int)
|
||||
def submit(self, data, flags=0)
|
||||
def discard(self, data, flags=0)
|
||||
```
|
||||
|
||||
Ring buffer for efficient event delivery.
|
||||
|
||||
**Parameters:**
|
||||
* `max_entries` (int) - Maximum size in bytes (must be power of 2)
|
||||
|
||||
**Methods:**
|
||||
* `output(data, flags=0)` - Send data to the ring buffer
|
||||
* `reserve(size)` - Reserve space in the buffer
|
||||
* `submit(data, flags=0)` - Submit previously reserved space
|
||||
* `discard(data, flags=0)` - Discard previously reserved space
|
||||
|
||||
**See also:** {doc}`../user-guide/maps`
|
||||
|
||||
## Helper Functions
|
||||
|
||||
```{eval-rst}
|
||||
.. automodule:: pythonbpf.helper.helpers
|
||||
:members:
|
||||
:undoc-members:
|
||||
:show-inheritance:
|
||||
```
|
||||
|
||||
### Process Information
|
||||
|
||||
* `pid()` - Get current process ID
|
||||
* `comm(buf)` - Get current process command name (requires buffer parameter)
|
||||
* `uid()` - Get current user ID
|
||||
|
||||
### Time
|
||||
|
||||
* `ktime()` - Get current kernel time in nanoseconds
|
||||
|
||||
### CPU
|
||||
|
||||
* `smp_processor_id()` - Get current CPU ID
|
||||
|
||||
### Memory
|
||||
|
||||
* `probe_read(dst, size, src)` - Safely read kernel memory
|
||||
* `probe_read_str(dst, src)` - Safely read string from kernel memory
|
||||
* `deref(ptr)` - Dereference a pointer
|
||||
|
||||
### Random
|
||||
|
||||
* `random()` - Get pseudo-random number
|
||||
|
||||
**See also:** {doc}`../user-guide/helpers`
|
||||
|
||||
## Type System
|
||||
|
||||
PythonBPF uses Python's `ctypes` module for type definitions:
|
||||
|
||||
### Integer Types
|
||||
|
||||
* `c_int8`, `c_int16`, `c_int32`, `c_int64` - Signed integers
|
||||
* `c_uint8`, `c_uint16`, `c_uint32`, `c_uint64` - Unsigned integers
|
||||
|
||||
### Other Types
|
||||
|
||||
* `c_char`, `c_bool` - Characters and booleans
|
||||
* `c_void_p` - Void pointers
|
||||
* `str(N)` - Fixed-length strings
|
||||
|
||||
## Examples
|
||||
|
||||
### Basic Usage
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, section, bpfglobal, BPF, trace_pipe
|
||||
from ctypes import c_void_p, c_int64
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
def hello(ctx: c_void_p) -> c_int64:
|
||||
print("Hello, World!")
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
|
||||
b = BPF()
|
||||
b.load_and_attach()
|
||||
trace_pipe()
|
||||
```
|
||||
|
||||
### With Maps
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, map, section, bpfglobal, BPF
|
||||
from pythonbpf.maps import HashMap
|
||||
from pythonbpf.helper import pid
|
||||
from ctypes import c_void_p, c_int64, c_uint32, c_uint64
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def counters() -> HashMap:
|
||||
return HashMap(key=c_uint32, value=c_uint64, max_entries=256)
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_clone")
|
||||
def count_clones(ctx: c_void_p) -> c_int64:
|
||||
process_id = pid()
|
||||
count = counters.lookup(process_id)
|
||||
|
||||
if count:
|
||||
counters.update(process_id, count + 1)
|
||||
else:
|
||||
counters.update(process_id, 1)
|
||||
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
|
||||
b = BPF()
|
||||
b.load_and_attach()
|
||||
```
|
||||
|
||||
### With Structs
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, struct, map, section, bpfglobal, BPF
|
||||
from pythonbpf.maps import RingBuffer
|
||||
from pythonbpf.helper import pid, ktime, comm
|
||||
from ctypes import c_void_p, c_int64, c_uint32, c_uint64
|
||||
|
||||
@bpf
|
||||
@struct
|
||||
class Event:
|
||||
timestamp: c_uint64
|
||||
pid: c_uint32
|
||||
comm: str(16)
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def events() -> RingBuffer:
|
||||
return RingBuffer(max_entries=4096)
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
def track_exec(ctx: c_void_p) -> c_int64:
|
||||
event = Event()
|
||||
event.timestamp = ktime()
|
||||
event.pid = pid()
|
||||
comm(event.comm)
|
||||
|
||||
events.output(event)
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
|
||||
b = BPF()
|
||||
b.load_and_attach()
|
||||
```
|
||||
|
||||
## See Also
|
||||
|
||||
* {doc}`../user-guide/index` - Comprehensive user guide
|
||||
* {doc}`../getting-started/quickstart` - Quick start tutorial
|
||||
* [GitHub Repository](https://github.com/pythonbpf/Python-BPF) - Source code and examples
|
||||
105
docs/conf.py
Normal file
105
docs/conf.py
Normal file
@ -0,0 +1,105 @@
|
||||
# Configuration file for the Sphinx documentation builder.
|
||||
#
|
||||
# For the full list of built-in configuration values, see the documentation:
|
||||
# https://www.sphinx-doc.org/en/master/usage/configuration.html
|
||||
|
||||
import os
|
||||
import sys
|
||||
|
||||
# Add the parent directory to the path so we can import pythonbpf
|
||||
sys.path.insert(0, os.path.abspath(".."))
|
||||
|
||||
# -- Project information -----------------------------------------------------
|
||||
# https://www.sphinx-doc.org/en/master/usage/configuration.html#project-information
|
||||
|
||||
project = "PythonBPF"
|
||||
copyright = "2026, Pragyansh Chaturvedi, Varun Mallya"
|
||||
author = "Pragyansh Chaturvedi, Varun Mallya"
|
||||
release = "0.1.8"
|
||||
version = "0.1.8"
|
||||
|
||||
# -- General configuration ---------------------------------------------------
|
||||
# https://www.sphinx-doc.org/en/master/usage/configuration.html#general-configuration
|
||||
|
||||
extensions = [
|
||||
"myst_parser",
|
||||
"sphinx.ext.autodoc",
|
||||
"sphinx.ext.napoleon",
|
||||
"sphinx.ext.viewcode",
|
||||
"sphinx.ext.intersphinx",
|
||||
"sphinx_copybutton",
|
||||
]
|
||||
|
||||
# MyST-Parser configuration
|
||||
myst_enable_extensions = [
|
||||
"colon_fence",
|
||||
"deflist",
|
||||
"fieldlist",
|
||||
]
|
||||
|
||||
# Napoleon settings for Google/NumPy style docstrings
|
||||
napoleon_google_docstring = True
|
||||
napoleon_numpy_docstring = True
|
||||
napoleon_include_init_with_doc = True
|
||||
napoleon_include_private_with_doc = False
|
||||
napoleon_include_special_with_doc = True
|
||||
napoleon_use_admonition_for_examples = True
|
||||
napoleon_use_admonition_for_notes = True
|
||||
napoleon_use_admonition_for_references = False
|
||||
napoleon_use_ivar = False
|
||||
napoleon_use_param = True
|
||||
napoleon_use_rtype = True
|
||||
napoleon_type_aliases = None
|
||||
|
||||
# Intersphinx mapping
|
||||
intersphinx_mapping = {
|
||||
"python": ("https://docs.python.org/3", None),
|
||||
"llvmlite": ("https://llvmlite.readthedocs.io/en/latest/", None),
|
||||
}
|
||||
|
||||
templates_path = ["_templates"]
|
||||
exclude_patterns = ["_build", "Thumbs.db", ".DS_Store"]
|
||||
|
||||
# Source file suffixes
|
||||
source_suffix = {
|
||||
".rst": "restructuredtext",
|
||||
".md": "markdown",
|
||||
}
|
||||
|
||||
# The master toctree document
|
||||
master_doc = "index"
|
||||
|
||||
# -- Options for HTML output -------------------------------------------------
|
||||
# https://www.sphinx-doc.org/en/master/usage/configuration.html#options-for-html-output
|
||||
|
||||
html_theme = "sphinx_rtd_theme"
|
||||
html_static_path = ["_static"]
|
||||
|
||||
# Theme options
|
||||
html_theme_options = {
|
||||
"logo_only": False,
|
||||
"display_version": True,
|
||||
"prev_next_buttons_location": "bottom",
|
||||
"style_external_links": False,
|
||||
"vcs_pageview_mode": "",
|
||||
# Toc options
|
||||
"collapse_navigation": False,
|
||||
"sticky_navigation": True,
|
||||
"navigation_depth": 4,
|
||||
"includehidden": True,
|
||||
"titles_only": False,
|
||||
}
|
||||
|
||||
# -- Options for autodoc -----------------------------------------------------
|
||||
|
||||
autodoc_default_options = {
|
||||
"members": True,
|
||||
"member-order": "bysource",
|
||||
"special-members": "__init__",
|
||||
"undoc-members": True,
|
||||
"exclude-members": "__weakref__",
|
||||
}
|
||||
|
||||
autodoc_typehints = "description"
|
||||
|
||||
exclude_patterns = ["README.md"]
|
||||
35
docs/getting-started/index.md
Normal file
35
docs/getting-started/index.md
Normal file
@ -0,0 +1,35 @@
|
||||
# Getting Started
|
||||
|
||||
Welcome to PythonBPF! This section will help you get started with writing eBPF programs in Python.
|
||||
|
||||
## What You'll Learn
|
||||
|
||||
In this section, you'll learn how to:
|
||||
|
||||
1. **Install PythonBPF** - Set up your development environment with all necessary dependencies
|
||||
2. **Write Your First Program** - Create a simple BPF program to understand the basics
|
||||
3. **Understand Core Concepts** - Learn about decorators, compilation, and program structure
|
||||
|
||||
## Prerequisites
|
||||
|
||||
Before you begin, make sure you have:
|
||||
|
||||
* A Linux system (eBPF requires Linux kernel 4.15+)
|
||||
* Python 3.10 or higher
|
||||
* Root or sudo access (required for loading BPF programs)
|
||||
|
||||
## Next Steps
|
||||
|
||||
After completing the getting started guide, you can:
|
||||
|
||||
* Explore the {doc}`../user-guide/index` for detailed information on features
|
||||
* Check out the {doc}`../api/index`
|
||||
* Browse the [examples directory](https://github.com/pythonbpf/Python-BPF/tree/master/examples) and the [BCC examples directory](https://github.com/pythonbpf/Python-BPF/tree/master/BCC-Examples)
|
||||
|
||||
## Need Help?
|
||||
|
||||
If you encounter any issues:
|
||||
|
||||
* Check the [GitHub Issues](https://github.com/pythonbpf/Python-BPF/issues) for known problems
|
||||
* Review the [README](https://github.com/pythonbpf/Python-BPF/blob/master/README.md) for additional information
|
||||
* Reach out to the maintainers: [@r41k0u](https://github.com/r41k0u) and [@varun-r-mallya](https://github.com/varun-r-mallya)
|
||||
182
docs/getting-started/installation.md
Normal file
182
docs/getting-started/installation.md
Normal file
@ -0,0 +1,182 @@
|
||||
# Installation
|
||||
|
||||
This guide will walk you through installing PythonBPF and its dependencies.
|
||||
|
||||
## Prerequisites
|
||||
|
||||
### System Requirements
|
||||
|
||||
PythonBPF requires:
|
||||
|
||||
* **Linux** - eBPF is a Linux kernel feature (kernel 4.15 or higher recommended)
|
||||
* **Python 3.10+** - Python 3.10 or higher is required
|
||||
* **Root/sudo access** - Loading BPF programs into the kernel requires elevated privileges
|
||||
|
||||
### Required System Packages
|
||||
|
||||
Before installing PythonBPF, you need to install the following system packages:
|
||||
|
||||
#### On Ubuntu/Debian:
|
||||
|
||||
```bash
|
||||
sudo apt-get update
|
||||
sudo apt-get install -y bpftool clang llvm
|
||||
```
|
||||
|
||||
#### On Fedora/RHEL/CentOS:
|
||||
|
||||
```bash
|
||||
sudo dnf install -y bpftool clang llvm
|
||||
```
|
||||
|
||||
#### On Arch Linux:
|
||||
|
||||
```bash
|
||||
sudo pacman -S bpf clang llvm
|
||||
```
|
||||
|
||||
## Installing PythonBPF
|
||||
|
||||
### From PyPI (Recommended)
|
||||
|
||||
The easiest way to install PythonBPF is using uv or pip:
|
||||
|
||||
**Using uv (recommended):**
|
||||
```bash
|
||||
uv pip install pythonbpf pylibbpf
|
||||
```
|
||||
|
||||
**Using pip:**
|
||||
```bash
|
||||
pip install pythonbpf pylibbpf
|
||||
```
|
||||
|
||||
This will install:
|
||||
* `pythonbpf` - The main package for writing and compiling BPF programs
|
||||
* `pylibbpf` - Python bindings for libbpf, used to load and attach BPF programs
|
||||
|
||||
### Development Installation
|
||||
|
||||
If you want to contribute to PythonBPF or work with the latest development version:
|
||||
|
||||
1. Clone the repository:
|
||||
|
||||
```bash
|
||||
git clone https://github.com/pythonbpf/Python-BPF.git
|
||||
cd Python-BPF
|
||||
```
|
||||
|
||||
2. Create and activate a virtual environment:
|
||||
|
||||
```bash
|
||||
python3 -m venv .venv
|
||||
source .venv/bin/activate # On Windows: .venv\Scripts\activate
|
||||
```
|
||||
|
||||
3. Install in development mode:
|
||||
|
||||
**Using uv (recommended):**
|
||||
```bash
|
||||
uv pip install -e .
|
||||
uv pip install pylibbpf
|
||||
```
|
||||
|
||||
**Using pip:**
|
||||
```bash
|
||||
pip install -e .
|
||||
pip install pylibbpf
|
||||
```
|
||||
|
||||
4. Install development dependencies:
|
||||
|
||||
```bash
|
||||
make install
|
||||
```
|
||||
|
||||
### Installing Documentation Dependencies
|
||||
|
||||
If you want to build the documentation locally:
|
||||
|
||||
**Using uv (recommended):**
|
||||
```bash
|
||||
uv pip install pythonbpf[docs]
|
||||
# Or from the repository root:
|
||||
uv pip install -e .[docs]
|
||||
```
|
||||
|
||||
**Using pip:**
|
||||
```bash
|
||||
pip install pythonbpf[docs]
|
||||
# Or from the repository root:
|
||||
pip install -e .[docs]
|
||||
```
|
||||
|
||||
## Generating vmlinux.py
|
||||
|
||||
`vmlinux.py` contains the running kernel's data structures and is analogous to `vmlinux.h` included in eBPF programs written in C. Some examples require access to it. To use these features, you need to generate a `vmlinux.py` file:
|
||||
|
||||
1. Install additional dependencies:
|
||||
|
||||
**Using uv (recommended):**
|
||||
```bash
|
||||
uv pip install ctypeslib2
|
||||
```
|
||||
|
||||
**Using pip:**
|
||||
```bash
|
||||
pip install ctypeslib2
|
||||
```
|
||||
|
||||
2. Generate the vmlinux.py file:
|
||||
|
||||
```bash
|
||||
sudo tools/vmlinux-gen.py
|
||||
```
|
||||
|
||||
3. Copy the generated file to your working directory or the examples directory as needed.
|
||||
|
||||
```{warning}
|
||||
The `vmlinux.py` file is kernel-specific. If you upgrade your kernel, you may need to regenerate this file.
|
||||
```
|
||||
|
||||
## Verifying Installation
|
||||
|
||||
To verify that PythonBPF is installed correctly, run:
|
||||
|
||||
```bash
|
||||
python3 -c "import pythonbpf; print(pythonbpf.__all__)"
|
||||
```
|
||||
|
||||
You should see output similar to:
|
||||
|
||||
```
|
||||
['bpf', 'map', 'section', 'bpfglobal', 'struct', 'compile_to_ir', 'compile', 'BPF', 'trace_pipe', 'trace_fields']
|
||||
```
|
||||
|
||||
## Troubleshooting
|
||||
|
||||
### Permission Errors
|
||||
|
||||
If you encounter permission errors when running BPF programs:
|
||||
|
||||
* Make sure you're running with `sudo` or as root
|
||||
* Check that `/sys/kernel/tracing/` is accessible
|
||||
|
||||
### LLVM/Clang Not Found
|
||||
|
||||
If you get errors about `llc` or `clang` not being found:
|
||||
|
||||
* Verify they're installed: `which llc` and `which clang`
|
||||
* Check your PATH environment variable includes the LLVM bin directory
|
||||
|
||||
### Import Errors
|
||||
|
||||
If Python can't find the `pythonbpf` module:
|
||||
|
||||
* Make sure you've activated your virtual environment
|
||||
* Verify installation with `uv pip list | grep pythonbpf` or `pip list | grep pythonbpf`
|
||||
* Try reinstalling: `uv pip install --force-reinstall pythonbpf` or `pip install --force-reinstall pythonbpf`
|
||||
|
||||
## Next Steps
|
||||
|
||||
Now that you have PythonBPF installed, continue to the {doc}`quickstart` guide to write your first BPF program!
|
||||
249
docs/getting-started/quickstart.md
Normal file
249
docs/getting-started/quickstart.md
Normal file
@ -0,0 +1,249 @@
|
||||
# Quick Start
|
||||
|
||||
This guide will walk you through creating your first BPF program with PythonBPF.
|
||||
|
||||
## Your First BPF Program
|
||||
|
||||
Let's create a simple "Hello World" program that prints a message every time a process is executed on your system.
|
||||
|
||||
### Step 1: Create the Program
|
||||
|
||||
Create a new file called `hello_world.py`:
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, section, bpfglobal, BPF, trace_pipe
|
||||
from ctypes import c_void_p, c_int64
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
def hello_world(ctx: c_void_p) -> c_int64:
|
||||
print("Hello, World!")
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
|
||||
b = BPF()
|
||||
b.load()
|
||||
b.attach_all()
|
||||
trace_pipe()
|
||||
```
|
||||
|
||||
### Step 2: Run the Program
|
||||
|
||||
Run the program with sudo (required for BPF operations):
|
||||
|
||||
```bash
|
||||
sudo python3 hello_world.py
|
||||
```
|
||||
|
||||
### Step 3: See it in Action
|
||||
|
||||
Open another terminal and run any command:
|
||||
|
||||
```bash
|
||||
ls
|
||||
echo "test"
|
||||
date
|
||||
```
|
||||
|
||||
You should see "Hello, World!" printed in the first terminal for each command executed!
|
||||
|
||||
Press `Ctrl+C` to stop the program.
|
||||
|
||||
## Understanding the Code
|
||||
|
||||
Let's break down what each part does:
|
||||
|
||||
### Imports
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, section, bpfglobal, BPF, trace_pipe
|
||||
from ctypes import c_void_p, c_int64
|
||||
```
|
||||
|
||||
* `bpf` - Decorator to mark functions for BPF compilation
|
||||
* `section` - Decorator to specify which kernel event to attach to
|
||||
* `bpfglobal` - Decorator for BPF global variables
|
||||
* `BPF` - Class to compile, load, and attach BPF programs
|
||||
* `trace_pipe` - Utility to read kernel trace output (similar to BCC)
|
||||
* `c_void_p`, `c_int64` - C types for function signatures
|
||||
|
||||
### The BPF Function
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
def hello_world(ctx: c_void_p) -> c_int64:
|
||||
print("Hello, World!")
|
||||
return 0
|
||||
```
|
||||
|
||||
* `@bpf` - Marks this function to be compiled to BPF bytecode
|
||||
* `@section("tracepoint/syscalls/sys_enter_execve")` - Attaches to the execve syscall tracepoint (called when processes start)
|
||||
* `ctx: c_void_p` - Context parameter (required for all BPF functions)
|
||||
* `print()` - the PythonBPF API for `bpf_printk` helper function
|
||||
* `return 0` - BPF functions must return an integer
|
||||
|
||||
### License Declaration
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
```
|
||||
|
||||
* The Linux kernel requires BPF programs to declare a license
|
||||
* Most kernel features require GPL-compatible licenses
|
||||
* This is defined as a BPF global variable
|
||||
|
||||
### Compilation and Execution
|
||||
|
||||
```python
|
||||
b = BPF()
|
||||
b.load()
|
||||
b.attach_all()
|
||||
trace_pipe()
|
||||
```
|
||||
|
||||
* `BPF()` - Creates a BPF object and compiles the current file
|
||||
* `b.load()` - Loads the compiled BPF program into the kernel
|
||||
* `b.attach_all()` - Attaches all BPF programs to their specified hooks
|
||||
* `trace_pipe()` - Reads and displays output from the kernel trace buffer
|
||||
|
||||
Alternatively, you can also use the `compile()` function to compile the BPF code to an object file:
|
||||
|
||||
```python
|
||||
from pythonbpf import compile
|
||||
```
|
||||
|
||||
This object file can then be loaded using any other userspace library in any language.
|
||||
|
||||
## Next Example: Tracking Process IDs
|
||||
|
||||
Let's make a more interesting program that tracks which processes are being created:
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, section, bpfglobal, BPF, trace_pipe
|
||||
from pythonbpf.helper import pid
|
||||
from ctypes import c_void_p, c_int64
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
def track_exec(ctx: c_void_p) -> c_int64:
|
||||
process_id = pid()
|
||||
print(f"Process with PID: {process_id} is starting")
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
|
||||
b = BPF()
|
||||
b.load()
|
||||
b.attach_all()
|
||||
trace_pipe()
|
||||
```
|
||||
|
||||
This program uses BPF helper functions:
|
||||
|
||||
* `pid()` - Gets the current process ID
|
||||
|
||||
Run it with `sudo python3 track_exec.py` and watch processes being created!
|
||||
|
||||
## Common Patterns
|
||||
|
||||
### Tracepoints
|
||||
|
||||
Tracepoints are predefined hooks in the kernel. Common ones include:
|
||||
|
||||
```python
|
||||
# System calls
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
@section("tracepoint/syscalls/sys_enter_clone")
|
||||
@section("tracepoint/syscalls/sys_enter_open")
|
||||
|
||||
# Scheduler events
|
||||
@section("tracepoint/sched/sched_process_fork")
|
||||
@section("tracepoint/sched/sched_switch")
|
||||
```
|
||||
|
||||
### Kprobes
|
||||
|
||||
Kprobes allow you to attach to any kernel function:
|
||||
|
||||
```python
|
||||
@section("kprobe/do_sys_open")
|
||||
def trace_open(ctx: c_void_p) -> c_int64:
|
||||
print("File is being opened")
|
||||
return 0
|
||||
```
|
||||
|
||||
### XDP (eXpress Data Path)
|
||||
|
||||
For network packet processing:
|
||||
|
||||
```python
|
||||
from pythonbpf.helper import XDP_PASS
|
||||
|
||||
@section("xdp")
|
||||
def xdp_pass(ctx: c_void_p) -> c_int64:
|
||||
return XDP_PASS
|
||||
```
|
||||
|
||||
## Best Practices
|
||||
|
||||
1. **Always include a LICENSE** - Required by the kernel
|
||||
2. **Use type hints** - Required by PythonBPF to generate correct code
|
||||
3. **Return the correct type** - Match the expected return type for your program type
|
||||
4. **Test incrementally** - Start simple and add complexity gradually
|
||||
5. **Check kernel logs** - Use `dmesg` to see BPF verifier messages if loading fails
|
||||
|
||||
## Common Issues
|
||||
|
||||
### Program Won't Load
|
||||
|
||||
If your BPF program fails to load:
|
||||
|
||||
* Check `dmesg` for verifier error messages
|
||||
* Ensure your LICENSE is GPL-compatible
|
||||
* Verify you're using supported BPF features
|
||||
* Make sure return types match function signatures
|
||||
|
||||
### No Output
|
||||
|
||||
If you don't see output:
|
||||
|
||||
* Verify the tracepoint/kprobe is being triggered
|
||||
* Check that you're running with sudo
|
||||
* Ensure `/sys/kernel/tracing/trace_pipe` is accessible
|
||||
|
||||
### Compilation Errors
|
||||
|
||||
If compilation fails:
|
||||
|
||||
* Check that `llc` is installed and in your PATH
|
||||
* Verify your Python syntax is correct
|
||||
* Ensure all imported types are from `ctypes`
|
||||
* In the worst case, compile object files manually using `compile_to_ir()` and `llc` to get detailed errors
|
||||
|
||||
### Verification Failure
|
||||
|
||||
If verification fails:
|
||||
|
||||
* Compile the object files using `compile()` function instead of loading directly
|
||||
* Run `sudo check.sh check <bpf>.o` to get detailed verification output
|
||||
|
||||
## Next Steps
|
||||
|
||||
Now that you understand the basics, explore:
|
||||
|
||||
* {doc}`../user-guide/decorators` - Learn about all available decorators
|
||||
* {doc}`../user-guide/maps` - Use BPF maps for data storage and communication
|
||||
* {doc}`../user-guide/structs` - Define custom data structures
|
||||
* {doc}`../user-guide/helpers` - Discover all available BPF helper functions
|
||||
* [Examples directory](https://github.com/pythonbpf/Python-BPF/tree/master/examples) - See more complex examples
|
||||
95
docs/index.md
Normal file
95
docs/index.md
Normal file
@ -0,0 +1,95 @@
|
||||
# PythonBPF Documentation
|
||||
|
||||
Welcome to **PythonBPF** - a Python frontend for writing eBPF programs without embedding C code. PythonBPF uses [llvmlite](https://github.com/numba/llvmlite) to generate LLVM IR and compiles directly to eBPF object files that can be loaded into the Linux kernel.
|
||||
|
||||
```{note}
|
||||
This project is under active development.
|
||||
```
|
||||
|
||||
## What is PythonBPF?
|
||||
|
||||
PythonBPF is an LLVM IR generator for eBPF programs written in Python. It provides:
|
||||
|
||||
* **Pure Python syntax** - Write eBPF programs in Python using familiar decorators and type annotations
|
||||
* **Direct compilation** - Compile to LLVM object files without relying on BCC
|
||||
* **Full eBPF features** - Support for maps, helpers, global definitions, and more
|
||||
* **Integration with libbpf** - Works with [pylibbpf](https://github.com/pythonbpf/pylibbpf) for object loading and execution
|
||||
|
||||
## Quick Example
|
||||
|
||||
Here's a simple "Hello World" BPF program that traces process creation:
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, section, bpfglobal, BPF, trace_pipe
|
||||
from ctypes import c_void_p, c_int64
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
def hello_world(ctx: c_void_p) -> c_int64:
|
||||
print("Hello, World!")
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
|
||||
b = BPF()
|
||||
b.load()
|
||||
b.attach_all()
|
||||
trace_pipe()
|
||||
```
|
||||
|
||||
## Features
|
||||
|
||||
* Generate eBPF programs directly using Python syntax
|
||||
* Compile to LLVM object files for kernel execution
|
||||
* Built with `llvmlite` for IR generation
|
||||
* Supports maps, helpers, and global definitions for BPF
|
||||
* Companion project: [pylibbpf](https://github.com/pythonbpf/pylibbpf), which provides bindings for libbpf
|
||||
|
||||
## Table of Contents
|
||||
|
||||
```{toctree}
|
||||
:maxdepth: 2
|
||||
:caption: Getting Started
|
||||
|
||||
getting-started/index
|
||||
getting-started/installation
|
||||
getting-started/quickstart
|
||||
```
|
||||
|
||||
```{toctree}
|
||||
:maxdepth: 2
|
||||
:caption: User Guide
|
||||
|
||||
user-guide/index
|
||||
user-guide/decorators
|
||||
user-guide/maps
|
||||
user-guide/structs
|
||||
user-guide/compilation
|
||||
user-guide/helpers
|
||||
```
|
||||
|
||||
```{toctree}
|
||||
:maxdepth: 2
|
||||
:caption: API Reference
|
||||
|
||||
api/index
|
||||
```
|
||||
|
||||
## Links
|
||||
|
||||
* **GitHub Repository**: [pythonbpf/Python-BPF](https://github.com/pythonbpf/Python-BPF)
|
||||
* **PyPI Package**: [pythonbpf](https://pypi.org/project/pythonbpf/)
|
||||
* **Video Demo**: [YouTube](https://www.youtube.com/watch?v=eFVhLnWFxtE)
|
||||
|
||||
## License
|
||||
|
||||
PythonBPF is licensed under the Apache License 2.0.
|
||||
|
||||
## Indices and tables
|
||||
|
||||
* {ref}`genindex`
|
||||
* {ref}`modindex`
|
||||
* {ref}`search`
|
||||
4
docs/requirements.txt
Normal file
4
docs/requirements.txt
Normal file
@ -0,0 +1,4 @@
|
||||
myst-parser>=2.0
|
||||
sphinx>=7.0
|
||||
sphinx-copybutton
|
||||
sphinx-rtd-theme>=2.0
|
||||
432
docs/user-guide/compilation.md
Normal file
432
docs/user-guide/compilation.md
Normal file
@ -0,0 +1,432 @@
|
||||
# Compilation
|
||||
|
||||
PythonBPF provides several functions and classes for compiling Python code into BPF bytecode and loading it into the kernel.
|
||||
|
||||
## Overview
|
||||
|
||||
The compilation process transforms Python code into executable BPF programs:
|
||||
|
||||
1. **Python AST** → LLVM IR generation (using llvmlite)
|
||||
2. **LLVM IR** → BPF bytecode (using llc)
|
||||
3. **BPF Object** → Kernel loading (using libbpf)
|
||||
|
||||
## Compilation Functions
|
||||
|
||||
### compile_to_ir()
|
||||
|
||||
Compile Python source to LLVM Intermediate Representation.
|
||||
|
||||
#### Signature
|
||||
|
||||
```python
|
||||
def compile_to_ir(filename: str, output: str, loglevel=logging.WARNING)
|
||||
```
|
||||
|
||||
#### Parameters
|
||||
|
||||
* `filename` - Path to the Python source file to compile
|
||||
* `output` - Path where the LLVM IR file (.ll) should be written
|
||||
* `loglevel` - Logging level (default: `logging.WARNING`)
|
||||
|
||||
#### Usage
|
||||
|
||||
```python
|
||||
from pythonbpf import compile_to_ir
|
||||
import logging
|
||||
|
||||
# Compile to LLVM IR
|
||||
compile_to_ir(
|
||||
filename="my_bpf_program.py",
|
||||
output="my_bpf_program.ll",
|
||||
loglevel=logging.DEBUG
|
||||
)
|
||||
```
|
||||
|
||||
#### Output
|
||||
|
||||
This function generates an `.ll` file containing LLVM IR, which is human-readable assembly-like code. This is useful for:
|
||||
|
||||
* Debugging compilation issues
|
||||
* Understanding code generation
|
||||
|
||||
### compile()
|
||||
|
||||
Compile Python source to BPF object file.
|
||||
|
||||
#### Signature
|
||||
|
||||
```python
|
||||
def compile(filename: str = None, output: str = None, loglevel=logging.WARNING)
|
||||
```
|
||||
|
||||
#### Parameters
|
||||
|
||||
* `filename` - Path to the Python source file (default: calling file)
|
||||
* `output` - Path for the output object file (default: same name with `.o` extension)
|
||||
* `loglevel` - Logging level (default: `logging.WARNING`)
|
||||
|
||||
#### Usage
|
||||
|
||||
```python
|
||||
from pythonbpf import compile
|
||||
import logging
|
||||
|
||||
# Compile current file
|
||||
compile()
|
||||
|
||||
# Compile specific file
|
||||
compile(filename="my_program.py", output="my_program.o")
|
||||
|
||||
# Compile with debug logging
|
||||
compile(loglevel=logging.DEBUG)
|
||||
```
|
||||
|
||||
#### Output
|
||||
|
||||
This function generates a `.o` file containing BPF bytecode that can be:
|
||||
|
||||
* Loaded into the kernel
|
||||
* Inspected with `bpftool`
|
||||
* Verified with the BPF verifier
|
||||
* Distributed as a compiled binary
|
||||
|
||||
### BPF Class
|
||||
|
||||
The `BPF` class provides a high-level interface to compile, load, and attach BPF programs.
|
||||
|
||||
#### Signature
|
||||
|
||||
```python
|
||||
class BPF:
|
||||
def __init__(self, filename: str = None, loglevel=logging.WARNING)
|
||||
def load(self)
|
||||
def attach_all(self)
|
||||
def load_and_attach(self)
|
||||
```
|
||||
|
||||
#### Parameters
|
||||
|
||||
* `filename` - Path to Python source file (default: calling file)
|
||||
* `loglevel` - Logging level (default: `logging.WARNING`)
|
||||
|
||||
#### Methods
|
||||
|
||||
##### __init__()
|
||||
|
||||
Create a BPF object and compile the source.
|
||||
|
||||
```python
|
||||
from pythonbpf import BPF
|
||||
|
||||
# Compile current file
|
||||
b = BPF()
|
||||
|
||||
# Compile specific file
|
||||
b = BPF(filename="my_program.py")
|
||||
```
|
||||
|
||||
##### load()
|
||||
|
||||
Load the compiled BPF program into the kernel.
|
||||
|
||||
```python
|
||||
b = BPF()
|
||||
b.load()
|
||||
```
|
||||
|
||||
This method:
|
||||
* Loads the BPF object file into the kernel
|
||||
* Creates maps
|
||||
* Verifies the BPF program
|
||||
* Returns a `BpfObject` instance
|
||||
|
||||
##### attach_all()
|
||||
|
||||
Attach all BPF programs to their specified hooks.
|
||||
|
||||
```python
|
||||
b = BPF()
|
||||
b.load()
|
||||
b.attach_all()
|
||||
```
|
||||
|
||||
This method:
|
||||
* Attaches tracepoints
|
||||
* Attaches kprobes/kretprobes
|
||||
* Attaches XDP programs
|
||||
* Enables all hooks
|
||||
|
||||
##### load_and_attach()
|
||||
|
||||
Convenience method that loads and attaches in one call.
|
||||
|
||||
```python
|
||||
b = BPF()
|
||||
b.load_and_attach()
|
||||
```
|
||||
|
||||
Equivalent to:
|
||||
```python
|
||||
b = BPF()
|
||||
b.load()
|
||||
b.attach_all()
|
||||
```
|
||||
|
||||
## Complete Example
|
||||
|
||||
Here's a complete example showing the compilation workflow:
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, section, bpfglobal, BPF, trace_pipe
|
||||
from ctypes import c_void_p, c_int64
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
def trace_exec(ctx: c_void_p) -> c_int64:
|
||||
print("Process started")
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
|
||||
if __name__ == "__main__":
|
||||
# Method 1: Simple compilation and loading
|
||||
b = BPF()
|
||||
b.load_and_attach()
|
||||
trace_pipe()
|
||||
|
||||
# Method 2: Step-by-step
|
||||
# b = BPF()
|
||||
# b.load()
|
||||
# b.attach_all()
|
||||
# trace_pipe()
|
||||
|
||||
# Method 3: Manual compilation
|
||||
# from pythonbpf import compile
|
||||
# compile(filename="my_program.py", output="my_program.o")
|
||||
# # Then load with pylibbpf directly
|
||||
```
|
||||
|
||||
## Compilation Pipeline Details
|
||||
|
||||
### AST Parsing
|
||||
|
||||
The Python `ast` module parses your source code:
|
||||
|
||||
```python
|
||||
import ast
|
||||
tree = ast.parse(source_code, filename)
|
||||
```
|
||||
|
||||
The AST is then walked to find:
|
||||
* Functions decorated with `@bpf`
|
||||
* Classes decorated with `@struct`
|
||||
* Map definitions with `@map`
|
||||
* Global variables with `@bpfglobal`
|
||||
|
||||
### IR Generation
|
||||
|
||||
PythonBPF uses `llvmlite` to generate LLVM IR:
|
||||
|
||||
```python
|
||||
from llvmlite import ir
|
||||
|
||||
# Create module
|
||||
module = ir.Module(name='bpf_module')
|
||||
module.triple = 'bpf'
|
||||
|
||||
# Generate IR for each BPF function
|
||||
# ...
|
||||
```
|
||||
|
||||
Key aspects of IR generation:
|
||||
|
||||
* Type conversion (Python types → LLVM types)
|
||||
* Function definitions
|
||||
* Map declarations
|
||||
* Global variable initialization
|
||||
* Debug information
|
||||
|
||||
### BPF Compilation
|
||||
|
||||
The LLVM IR is compiled to BPF bytecode using `llc`:
|
||||
|
||||
```bash
|
||||
llc -march=bpf -filetype=obj input.ll -o output.o
|
||||
```
|
||||
|
||||
### Kernel Loading
|
||||
|
||||
The compiled object is loaded using `pylibbpf`:
|
||||
|
||||
```python
|
||||
from pylibbpf import BpfObject
|
||||
|
||||
obj = BpfObject(path="program.o")
|
||||
obj.load()
|
||||
```
|
||||
|
||||
## Debugging Compilation
|
||||
|
||||
### Logging
|
||||
|
||||
Enable debug logging to see compilation details:
|
||||
|
||||
```python
|
||||
import logging
|
||||
from pythonbpf import BPF
|
||||
|
||||
b = BPF(loglevel=logging.DEBUG)
|
||||
```
|
||||
|
||||
This will show:
|
||||
* AST parsing details
|
||||
* IR generation steps
|
||||
* Compilation commands
|
||||
* Loading status
|
||||
|
||||
### Inspecting LLVM IR
|
||||
|
||||
Generate and inspect the IR file:
|
||||
|
||||
```python
|
||||
from pythonbpf import compile_to_ir
|
||||
|
||||
compile_to_ir("program.py", "program.ll")
|
||||
```
|
||||
|
||||
Then examine `program.ll` to understand the generated code.
|
||||
|
||||
### Using bpftool
|
||||
|
||||
Inspect compiled objects with `bpftool`:
|
||||
|
||||
```bash
|
||||
# Show program info
|
||||
bpftool prog show
|
||||
|
||||
# Dump program instructions
|
||||
bpftool prog dump xlated id <ID>
|
||||
|
||||
# Dump program JIT code
|
||||
bpftool prog dump jited id <ID>
|
||||
|
||||
# Show maps
|
||||
bpftool map show
|
||||
|
||||
# Dump map contents
|
||||
bpftool map dump id <ID>
|
||||
```
|
||||
|
||||
### Verifier Errors
|
||||
|
||||
If the kernel verifier rejects your program:
|
||||
|
||||
* Check `dmesg` for detailed error messages:
|
||||
```bash
|
||||
sudo dmesg | tail -50
|
||||
```
|
||||
|
||||
## Compilation Options
|
||||
|
||||
### Optimization Levels
|
||||
|
||||
While PythonBPF doesn't expose optimization flags directly, you can:
|
||||
|
||||
1. Manually compile IR with specific flags:
|
||||
```bash
|
||||
llc -march=bpf -O2 -filetype=obj program.ll -o program.o
|
||||
```
|
||||
|
||||
2. Modify the compilation pipeline in your code
|
||||
|
||||
### Debug Information
|
||||
|
||||
PythonBPF automatically generates debug information (DWARF) for:
|
||||
|
||||
* Function names
|
||||
* Variable names
|
||||
* Type information
|
||||
|
||||
This helps with:
|
||||
* Stack traces
|
||||
* Debugging with `bpftool`
|
||||
* Source-level debugging
|
||||
|
||||
## Working with Compiled Objects
|
||||
|
||||
### Loading Pre-compiled Objects
|
||||
|
||||
You can load previously compiled objects:
|
||||
|
||||
```python
|
||||
from pylibbpf import BpfObject
|
||||
|
||||
# Load object file
|
||||
obj = BpfObject(path="my_program.o")
|
||||
obj.load()
|
||||
|
||||
# Attach programs
|
||||
# (specific attachment depends on program type)
|
||||
```
|
||||
|
||||
### Distribution
|
||||
|
||||
Distribute compiled BPF objects:
|
||||
|
||||
1. Compile once:
|
||||
```python
|
||||
from pythonbpf import compile
|
||||
compile(filename="program.py", output="program.o")
|
||||
```
|
||||
|
||||
2. Ship `program.o` file
|
||||
|
||||
3. Load on target systems:
|
||||
```python
|
||||
from pylibbpf import BpfObject
|
||||
obj = BpfObject(path="program.o")
|
||||
obj.load()
|
||||
```
|
||||
|
||||
### Version Compatibility
|
||||
|
||||
BPF objects are generally compatible across kernel versions, but:
|
||||
|
||||
* Some features require specific kernel versions
|
||||
* Helper functions may not be available on older kernels
|
||||
* BTF (BPF Type Format) requirements vary
|
||||
|
||||
## Troubleshooting
|
||||
|
||||
### Compilation Fails
|
||||
|
||||
If compilation fails:
|
||||
* Check Python syntax
|
||||
* Verify all decorators are correct
|
||||
* Ensure type hints are present
|
||||
* Check for unsupported Python features
|
||||
|
||||
### Loading Fails
|
||||
|
||||
If loading fails:
|
||||
* Check `dmesg` for verifier errors
|
||||
* Verify LICENSE is set correctly
|
||||
* Ensure helper functions are valid
|
||||
* Check map definitions
|
||||
|
||||
### Programs Don't Attach
|
||||
|
||||
If attachment fails:
|
||||
* Verify section names are correct
|
||||
* Check that hooks exist on your kernel
|
||||
* Ensure you have sufficient permissions
|
||||
* Verify kernel version supports the feature
|
||||
|
||||
## Next Steps
|
||||
|
||||
* Learn about {doc}`helpers` for available BPF helper functions
|
||||
* Explore {doc}`maps` for data storage
|
||||
* See {doc}`decorators` for compilation markers
|
||||
448
docs/user-guide/decorators.md
Normal file
448
docs/user-guide/decorators.md
Normal file
@ -0,0 +1,448 @@
|
||||
# Decorators
|
||||
|
||||
Decorators are the primary way to mark Python code for BPF compilation. PythonBPF provides five core decorators that control how your code is transformed into eBPF bytecode.
|
||||
|
||||
## @bpf
|
||||
|
||||
The `@bpf` decorator marks functions or classes for BPF compilation.
|
||||
|
||||
### Usage
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf
|
||||
|
||||
@bpf
|
||||
def my_function(ctx):
|
||||
# This function will be compiled to BPF bytecode
|
||||
pass
|
||||
```
|
||||
|
||||
### Description
|
||||
|
||||
Any function or class decorated with `@bpf` will be processed by the PythonBPF compiler and transformed into LLVM IR, then compiled to BPF bytecode. This is the fundamental decorator that enables BPF compilation.
|
||||
|
||||
### Rules
|
||||
|
||||
* Must be used on top-level functions or classes
|
||||
* The function must have proper type hints
|
||||
* Return types must be BPF-compatible
|
||||
* Only BPF-compatible operations are allowed inside
|
||||
|
||||
### Example
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, section
|
||||
from ctypes import c_void_p, c_int64
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
def trace_exec(ctx: c_void_p) -> c_int64:
|
||||
print("Process started")
|
||||
return c_int64(0)
|
||||
```
|
||||
|
||||
## @section
|
||||
|
||||
The `@section(name)` decorator specifies which kernel hook to attach the BPF program to.
|
||||
|
||||
### Usage
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, section
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_open")
|
||||
def trace_open(ctx):
|
||||
pass
|
||||
```
|
||||
|
||||
### Section Types
|
||||
|
||||
#### Tracepoints
|
||||
|
||||
Tracepoints are stable kernel hooks defined in `/sys/kernel/tracing/events/`:
|
||||
|
||||
```python
|
||||
# System call tracepoints
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
@section("tracepoint/syscalls/sys_enter_clone")
|
||||
@section("tracepoint/syscalls/sys_enter_open")
|
||||
@section("tracepoint/syscalls/sys_exit_read")
|
||||
|
||||
# Scheduler tracepoints
|
||||
@section("tracepoint/sched/sched_process_fork")
|
||||
@section("tracepoint/sched/sched_process_exit")
|
||||
@section("tracepoint/sched/sched_switch")
|
||||
|
||||
# Block I/O tracepoints
|
||||
@section("tracepoint/block/block_rq_insert")
|
||||
@section("tracepoint/block/block_rq_complete")
|
||||
```
|
||||
|
||||
#### Kprobes
|
||||
|
||||
Kprobes allow attaching to any kernel function:
|
||||
|
||||
```python
|
||||
@section("kprobe/do_sys_open")
|
||||
def trace_sys_open(ctx):
|
||||
pass
|
||||
|
||||
@section("kprobe/__x64_sys_write")
|
||||
def trace_write(ctx):
|
||||
pass
|
||||
```
|
||||
|
||||
#### Kretprobes
|
||||
|
||||
Kretprobes trigger when a kernel function returns:
|
||||
|
||||
```python
|
||||
@section("kretprobe/do_sys_open")
|
||||
def trace_open_return(ctx):
|
||||
pass
|
||||
```
|
||||
|
||||
#### XDP (eXpress Data Path)
|
||||
|
||||
For network packet processing at the earliest point:
|
||||
|
||||
```python
|
||||
from pythonbpf.helper import XDP_PASS
|
||||
from ctypes import c_void_p, c_int64
|
||||
|
||||
@section("xdp")
|
||||
def xdp_prog(ctx: c_void_p) -> c_int64:
|
||||
# XDP_PASS, XDP_DROP, XDP_ABORTED constants available from pythonbpf.helper
|
||||
return XDP_PASS
|
||||
```
|
||||
|
||||
### Finding Tracepoints
|
||||
|
||||
To find available tracepoints on your system:
|
||||
|
||||
```bash
|
||||
# List all tracepoints
|
||||
ls /sys/kernel/tracing/events/
|
||||
|
||||
# List syscall tracepoints
|
||||
ls /sys/kernel/tracing/events/syscalls/
|
||||
|
||||
# View tracepoint format
|
||||
cat /sys/kernel/tracing/events/syscalls/sys_enter_open/format
|
||||
```
|
||||
|
||||
## @map
|
||||
|
||||
The `@map` decorator marks a function as a BPF map definition.
|
||||
|
||||
### Usage
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, map
|
||||
from pythonbpf.maps import HashMap
|
||||
from ctypes import c_uint32, c_uint64
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def my_map() -> HashMap:
|
||||
return HashMap(key=c_uint32, value=c_uint64, max_entries=1024)
|
||||
```
|
||||
|
||||
### Description
|
||||
|
||||
Maps are BPF data structures used to:
|
||||
|
||||
* Store state between BPF program invocations
|
||||
* Communicate data between BPF programs
|
||||
* Share data with userspace
|
||||
|
||||
The function must return a map type (HashMap, PerfEventArray, RingBuffer) and the return type must be annotated.
|
||||
|
||||
### Example
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, map, section
|
||||
from pythonbpf.maps import HashMap
|
||||
from pythonbpf.helper import pid
|
||||
from ctypes import c_void_p, c_int64, c_uint32, c_uint64
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def process_count() -> HashMap:
|
||||
return HashMap(key=c_uint32, value=c_uint64, max_entries=4096)
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_clone")
|
||||
def count_clones(ctx: c_void_p) -> c_int64:
|
||||
process_id = pid()
|
||||
count = process_count.lookup(process_id)
|
||||
if count:
|
||||
process_count.update(process_id, count + 1)
|
||||
else:
|
||||
process_count.update(process_id, c_uint64(1))
|
||||
return 0
|
||||
```
|
||||
|
||||
See {doc}`maps` for more details on available map types.
|
||||
|
||||
## @struct
|
||||
|
||||
The `@struct` decorator marks a class as a BPF struct definition.
|
||||
|
||||
### Usage
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, struct
|
||||
from ctypes import c_uint64, c_uint32
|
||||
|
||||
@bpf
|
||||
@struct
|
||||
class Event:
|
||||
timestamp: c_uint64
|
||||
pid: c_uint32
|
||||
cpu: c_uint32
|
||||
```
|
||||
|
||||
### Description
|
||||
|
||||
Structs allow you to define custom data types for use in BPF programs. They can be used:
|
||||
|
||||
* As map keys and values
|
||||
* For perf event output
|
||||
* In ring buffer submissions
|
||||
* As local variables
|
||||
|
||||
### Field Types
|
||||
|
||||
Supported field types include:
|
||||
|
||||
* **Integer types**: `c_int8`, `c_int16`, `c_int32`, `c_int64`, `c_uint8`, `c_uint16`, `c_uint32`, `c_uint64`
|
||||
* **Pointers**: `c_void_p`, `c_char_p`
|
||||
* **Fixed strings**: `str(N)` where N is the size (e.g., `str(16)`)
|
||||
* **Nested structs**: Other `@struct` decorated classes
|
||||
|
||||
### Example
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, struct, map, section
|
||||
from pythonbpf.maps import RingBuffer
|
||||
from pythonbpf.helper import pid, ktime
|
||||
from ctypes import c_void_p, c_int64, c_uint64, c_uint32
|
||||
|
||||
@bpf
|
||||
@struct
|
||||
class ProcessEvent:
|
||||
timestamp: c_uint64
|
||||
pid: c_uint32
|
||||
comm: str(16)
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def events() -> RingBuffer:
|
||||
return RingBuffer(max_entries=4096)
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
def track_processes(ctx: c_void_p) -> c_int64:
|
||||
event = ProcessEvent()
|
||||
event.timestamp = ktime()
|
||||
event.pid = pid()
|
||||
comm(event.comm) # Fills event.comm with process name
|
||||
|
||||
events.output(event)
|
||||
return 0
|
||||
```
|
||||
|
||||
See {doc}`structs` for more details on working with structs.
|
||||
|
||||
## @bpfglobal
|
||||
|
||||
The `@bpfglobal` decorator marks a function as a BPF global variable definition.
|
||||
|
||||
### Usage
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, bpfglobal
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
```
|
||||
|
||||
### Description
|
||||
|
||||
BPF global variables are values that:
|
||||
|
||||
* Are initialized when the program loads
|
||||
* Can be read by all BPF functions
|
||||
* Must be constant (cannot be modified at runtime in current implementation)
|
||||
|
||||
### Common Global Variables
|
||||
|
||||
#### LICENSE (Required)
|
||||
|
||||
Every BPF program must declare a license:
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
```
|
||||
|
||||
Valid licenses include:
|
||||
* `"GPL"` - GNU General Public License
|
||||
* `"GPL v2"` - GPL version 2
|
||||
* `"Dual BSD/GPL"` - Dual licensed
|
||||
* `"Dual MIT/GPL"` - Dual licensed
|
||||
|
||||
```{warning}
|
||||
Many BPF features require a GPL-compatible license. Using a non-GPL license may prevent your program from loading or accessing certain kernel features.
|
||||
```
|
||||
|
||||
#### Custom Global Variables
|
||||
|
||||
You can define other global variables:
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def DEBUG_MODE() -> int:
|
||||
return 1
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def MAX_EVENTS() -> int:
|
||||
return 1000
|
||||
```
|
||||
|
||||
These can be referenced in your BPF functions, though modifying them at runtime is currently not supported.
|
||||
|
||||
## Combining Decorators
|
||||
|
||||
Decorators are often used together. The order matters:
|
||||
|
||||
### Correct Order
|
||||
|
||||
```python
|
||||
@bpf # Always first
|
||||
@section("...") # Section before other decorators
|
||||
def my_function():
|
||||
pass
|
||||
|
||||
@bpf # Always first
|
||||
@map # Map/struct/bpfglobal after @bpf
|
||||
def my_map():
|
||||
pass
|
||||
|
||||
@bpf # Always first
|
||||
@struct # Map/struct/bpfglobal after @bpf
|
||||
class MyStruct:
|
||||
pass
|
||||
|
||||
@bpf # Always first
|
||||
@bpfglobal # Map/struct/bpfglobal after @bpf
|
||||
def LICENSE():
|
||||
return "GPL"
|
||||
```
|
||||
|
||||
### Examples by Use Case
|
||||
|
||||
#### Simple Tracepoint
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_open")
|
||||
def trace_open(ctx: c_void_p) -> c_int64:
|
||||
return c_int64(0)
|
||||
```
|
||||
|
||||
#### Map Definition
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@map
|
||||
def counters() -> HashMap:
|
||||
return HashMap(key=c_uint32, value=c_uint64, max_entries=256)
|
||||
```
|
||||
|
||||
#### Struct Definition
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@struct
|
||||
class Event:
|
||||
timestamp: c_uint64
|
||||
value: c_uint32
|
||||
```
|
||||
|
||||
#### Global Variable
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
```
|
||||
|
||||
## Best Practices
|
||||
|
||||
1. **Always use @bpf first** - It must be the outermost decorator
|
||||
2. **Provide type hints** - Required for proper code generation
|
||||
3. **Test incrementally** - Verify each component works before combining
|
||||
|
||||
## Common Errors
|
||||
|
||||
### Missing @bpf Decorator
|
||||
|
||||
```python
|
||||
# Wrong - missing @bpf
|
||||
@section("tracepoint/syscalls/sys_enter_open")
|
||||
def my_func(ctx):
|
||||
pass
|
||||
|
||||
# Correct
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_open")
|
||||
def my_func(ctx):
|
||||
pass
|
||||
```
|
||||
|
||||
### Wrong Decorator Order
|
||||
|
||||
```python
|
||||
# Wrong - @section before @bpf
|
||||
@section("tracepoint/syscalls/sys_enter_open")
|
||||
@bpf
|
||||
def my_func(ctx):
|
||||
pass
|
||||
|
||||
# Correct
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_open")
|
||||
def my_func(ctx):
|
||||
pass
|
||||
```
|
||||
|
||||
### Missing Type Hints
|
||||
|
||||
```python
|
||||
# Wrong - no type hints
|
||||
@bpf
|
||||
def my_func(ctx):
|
||||
pass
|
||||
|
||||
# Correct
|
||||
@bpf
|
||||
def my_func(ctx: c_void_p) -> c_int64:
|
||||
pass
|
||||
```
|
||||
|
||||
## Next Steps
|
||||
|
||||
* Learn about {doc}`maps` for data storage and communication
|
||||
* Explore {doc}`structs` for defining custom data types
|
||||
* Understand {doc}`compilation` to see how code is transformed
|
||||
* Check out {doc}`helpers` for available BPF helper functions
|
||||
503
docs/user-guide/helpers.md
Normal file
503
docs/user-guide/helpers.md
Normal file
@ -0,0 +1,503 @@
|
||||
# Helper Functions and Utilities
|
||||
|
||||
PythonBPF provides helper functions and utilities for BPF programs and userspace code.
|
||||
|
||||
```{note}
|
||||
**Work in Progress:** PythonBPF is under active development. We are constantly adding support for more helpers, kfuncs, and map types. Check back for updates!
|
||||
```
|
||||
For comprehensive documentation on BPF helpers, see the [eBPF Helper Functions documentation on ebpf.io](https://ebpf.io/what-is-ebpf/#helper-calls).
|
||||
|
||||
## BPF Helper Functions
|
||||
|
||||
BPF helper functions are kernel-provided functions that BPF programs can call to interact with the system. PythonBPF exposes these through the `pythonbpf.helper` module.
|
||||
|
||||
```python
|
||||
from pythonbpf.helper import pid, ktime, comm
|
||||
```
|
||||
|
||||
### Process and Task Information
|
||||
|
||||
#### pid()
|
||||
|
||||
Get the current process ID.
|
||||
|
||||
> **Linux Kernel Helper:** `bpf_get_current_pid_tgid()`
|
||||
|
||||
```python
|
||||
from pythonbpf.helper import pid
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_open")
|
||||
def trace_open(ctx: c_void_p) -> c_int64:
|
||||
process_id = pid()
|
||||
print(f"Process {process_id} opened a file")
|
||||
return 0
|
||||
```
|
||||
|
||||
**Returns:** `c_int32` - The process ID of the current task
|
||||
|
||||
#### comm()
|
||||
|
||||
Get the current process command name.
|
||||
|
||||
> **Linux Kernel Helper:** `bpf_get_current_comm()`
|
||||
|
||||
**Parameters:**
|
||||
* `buf` - Buffer to fill with the process command name
|
||||
|
||||
**Returns:** `c_int64` - 0 on success, negative on error
|
||||
|
||||
#### uid()
|
||||
|
||||
Get the current user ID.
|
||||
|
||||
> **Linux Kernel Helper:** `bpf_get_current_uid_gid()`
|
||||
|
||||
```python
|
||||
from pythonbpf.helper import uid
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_open")
|
||||
def trace_open(ctx: c_void_p) -> c_int64:
|
||||
user_id = uid()
|
||||
if user_id == 0:
|
||||
print("Root user opened a file")
|
||||
return 0
|
||||
```
|
||||
|
||||
**Returns:** `c_int32` - The user ID of the current task
|
||||
|
||||
### Time and Timing
|
||||
|
||||
#### ktime()
|
||||
|
||||
Get the current kernel time in nanoseconds since system boot.
|
||||
|
||||
> **Linux Kernel Helper:** `bpf_ktime_get_ns()`
|
||||
|
||||
```python
|
||||
from pythonbpf.helper import ktime
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_read")
|
||||
def measure_latency(ctx: c_void_p) -> c_int64:
|
||||
start_time = ktime()
|
||||
# Store for later comparison
|
||||
return 0
|
||||
```
|
||||
|
||||
**Returns:** `c_int64` - Current time in nanoseconds
|
||||
|
||||
**Use cases:**
|
||||
* Measuring latency
|
||||
* Timestamping events
|
||||
* Rate limiting
|
||||
* Timeout detection
|
||||
|
||||
### CPU Information
|
||||
|
||||
#### smp_processor_id()
|
||||
|
||||
Get the ID of the CPU on which the BPF program is running.
|
||||
|
||||
> **Linux Kernel Helper:** `bpf_get_smp_processor_id()`
|
||||
|
||||
```python
|
||||
from pythonbpf.helper import smp_processor_id
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/sched/sched_switch")
|
||||
def track_cpu(ctx: c_void_p) -> c_int64:
|
||||
cpu = smp_processor_id()
|
||||
print(f"Running on CPU {cpu}")
|
||||
return 0
|
||||
```
|
||||
|
||||
**Returns:** `c_int32` - The current CPU ID
|
||||
|
||||
**Use cases:**
|
||||
* Per-CPU statistics
|
||||
* Load balancing analysis
|
||||
* CPU affinity tracking
|
||||
|
||||
### Memory Operations
|
||||
|
||||
#### probe_read()
|
||||
|
||||
Safely read data from kernel memory.
|
||||
|
||||
> **Linux Kernel Helper:** `bpf_probe_read()`
|
||||
|
||||
```python
|
||||
from pythonbpf.helper import probe_read
|
||||
|
||||
@bpf
|
||||
def read_kernel_data(ctx: c_void_p) -> c_int64:
|
||||
dst = 0
|
||||
size = 8
|
||||
src = ctx # kernel address
|
||||
|
||||
result = probe_read(dst, size, src)
|
||||
if result == 0:
|
||||
print(f"Read value: {dst}")
|
||||
return 0
|
||||
```
|
||||
|
||||
**Parameters:**
|
||||
* `dst` - Destination buffer
|
||||
* `size` - Number of bytes to read
|
||||
* `src` - Source kernel address
|
||||
|
||||
**Returns:** `c_int64` - 0 on success, negative on error
|
||||
|
||||
**Safety:** This function performs bounds checking and prevents invalid memory access.
|
||||
|
||||
#### probe_read_str()
|
||||
|
||||
Safely read a null-terminated string from kernel memory.
|
||||
|
||||
> **Linux Kernel Helper:** `bpf_probe_read_str()`
|
||||
|
||||
**Parameters:**
|
||||
* `dst` - Destination buffer (string)
|
||||
* `src` - Source kernel address
|
||||
|
||||
**Returns:** `c_int64` - Length of string on success, negative on error
|
||||
|
||||
### Random Numbers
|
||||
|
||||
#### random()
|
||||
|
||||
Generate a pseudo-random 32-bit number.
|
||||
|
||||
> **Linux Kernel Helper:** `bpf_get_prandom_u32()`
|
||||
|
||||
```python
|
||||
from pythonbpf.helper import random
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_open")
|
||||
def sample_events(ctx: c_void_p) -> c_int64:
|
||||
# Sample 1% of events
|
||||
if (random() % 100) == 0:
|
||||
print("Sampled event")
|
||||
return 0
|
||||
```
|
||||
|
||||
**Returns:** `c_int32` - A pseudo-random number
|
||||
|
||||
### Network Helpers
|
||||
|
||||
#### skb_store_bytes()
|
||||
|
||||
Store bytes into a socket buffer (for network programs).
|
||||
|
||||
> **Linux Kernel Helper:** `bpf_skb_store_bytes()`
|
||||
|
||||
```python
|
||||
from pythonbpf.helper import skb_store_bytes
|
||||
|
||||
@bpf
|
||||
@section("classifier")
|
||||
def modify_packet(ctx: c_void_p) -> c_int32:
|
||||
offset = 14 # Skip Ethernet header
|
||||
data = b"\x00\x01\x02\x03"
|
||||
size = len(data)
|
||||
|
||||
result = skb_store_bytes(offset, data, size)
|
||||
return 0
|
||||
```
|
||||
|
||||
**Parameters:**
|
||||
* `offset` - Offset in the socket buffer
|
||||
* `from_buf` - Data to write
|
||||
* `size` - Number of bytes to write
|
||||
* `flags` - Optional flags
|
||||
|
||||
**Returns:** `c_int64` - 0 on success, negative on error
|
||||
|
||||
## Userspace Utilities
|
||||
|
||||
PythonBPF provides utilities for working with BPF programs from Python userspace code.
|
||||
|
||||
### trace_pipe()
|
||||
|
||||
Read and display output from the kernel trace pipe.
|
||||
|
||||
```python
|
||||
from pythonbpf import trace_pipe
|
||||
|
||||
# After loading and attaching BPF programs
|
||||
trace_pipe()
|
||||
```
|
||||
|
||||
**Description:**
|
||||
|
||||
The `trace_pipe()` function reads from `/sys/kernel/tracing/trace_pipe` and displays BPF program output to stdout. This is the output from `print()` statements in BPF programs.
|
||||
|
||||
**Usage:**
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, section, bpfglobal, BPF, trace_pipe
|
||||
from ctypes import c_void_p, c_int64
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
def trace_exec(ctx: c_void_p) -> c_int64:
|
||||
print("Process started") # This goes to trace_pipe
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
|
||||
b = BPF()
|
||||
b.load_and_attach()
|
||||
trace_pipe() # Display BPF output
|
||||
```
|
||||
|
||||
**Behavior:**
|
||||
|
||||
* Blocks until Ctrl+C is pressed
|
||||
* Displays output in real-time
|
||||
* Shows task name, PID, CPU, timestamp, and message
|
||||
* Automatically handles trace pipe access errors
|
||||
|
||||
**Requirements:**
|
||||
|
||||
* Root or sudo access
|
||||
* Accessible `/sys/kernel/tracing/trace_pipe`
|
||||
|
||||
### trace_fields()
|
||||
|
||||
Parse one line from the trace pipe into structured fields.
|
||||
|
||||
```python
|
||||
from pythonbpf import trace_fields
|
||||
|
||||
# Read and parse trace output
|
||||
task, pid, cpu, flags, ts, msg = trace_fields()
|
||||
print(f"Task: {task}, PID: {pid}, CPU: {cpu}, Time: {ts}, Message: {msg}")
|
||||
```
|
||||
|
||||
**Returns:** Tuple of `(task, pid, cpu, flags, timestamp, message)`
|
||||
|
||||
* `task` - String: Task/process name (up to 16 chars)
|
||||
* `pid` - Integer: Process ID
|
||||
* `cpu` - Integer: CPU number
|
||||
* `flags` - Bytes: Trace flags
|
||||
* `timestamp` - Float: Timestamp in seconds
|
||||
* `message` - String: The actual trace message
|
||||
|
||||
**Description:**
|
||||
|
||||
The `trace_fields()` function reads one line from the trace pipe and parses it into individual fields. This is useful when you need programmatic access to trace data rather than just displaying it.
|
||||
|
||||
**Usage:**
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, section, bpfglobal, BPF, trace_fields
|
||||
from ctypes import c_void_p, c_int64
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
def trace_exec(ctx: c_void_p) -> c_int64:
|
||||
print(f"PID:{pid()}")
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
|
||||
b = BPF()
|
||||
b.load_and_attach()
|
||||
|
||||
# Process trace events
|
||||
try:
|
||||
while True:
|
||||
task, pid, cpu, flags, ts, msg = trace_fields()
|
||||
print(f"[{ts:.6f}] {task}({pid}) on CPU{cpu}: {msg}")
|
||||
except KeyboardInterrupt:
|
||||
print("Stopped")
|
||||
```
|
||||
|
||||
**Error Handling:**
|
||||
|
||||
* Raises `ValueError` if line cannot be parsed
|
||||
* Skips lines about lost events
|
||||
* Blocks waiting for next line
|
||||
|
||||
## Helper Function Examples
|
||||
|
||||
### Example 1: Latency Measurement
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, map, section, bpfglobal, BPF, trace_pipe
|
||||
from pythonbpf.maps import HashMap
|
||||
from pythonbpf.helper import pid, ktime
|
||||
from ctypes import c_void_p, c_int64, c_uint32, c_uint64
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def start_times() -> HashMap:
|
||||
return HashMap(key=c_uint32, value=c_uint64, max_entries=4096)
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_read")
|
||||
def read_start(ctx: c_void_p) -> c_int64:
|
||||
process_id = pid()
|
||||
start = ktime()
|
||||
start_times.update(process_id, start)
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_exit_read")
|
||||
def read_end(ctx: c_void_p) -> c_int64:
|
||||
process_id = pid()
|
||||
start = start_times.lookup(process_id)
|
||||
|
||||
if start:
|
||||
latency = ktime() - start
|
||||
print(f"Read latency: {latency} ns")
|
||||
start_times.delete(process_id)
|
||||
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
|
||||
b = BPF()
|
||||
b.load_and_attach()
|
||||
trace_pipe()
|
||||
```
|
||||
|
||||
### Example 2: Process Tracking
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, section, bpfglobal, BPF, trace_pipe
|
||||
from pythonbpf.helper import pid, uid
|
||||
from ctypes import c_void_p, c_int64
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
def track_exec(ctx: c_void_p) -> c_int64:
|
||||
process_id = pid()
|
||||
user_id = uid()
|
||||
|
||||
print(f"User {user_id} started process (PID: {process_id})")
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
|
||||
b = BPF()
|
||||
b.load_and_attach()
|
||||
trace_pipe()
|
||||
```
|
||||
|
||||
### Example 3: CPU Load Monitoring
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, map, section, bpfglobal, BPF
|
||||
from pythonbpf.maps import HashMap
|
||||
from pythonbpf.helper import smp_processor_id
|
||||
from ctypes import c_void_p, c_int64, c_uint32, c_uint64
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def cpu_counts() -> HashMap:
|
||||
return HashMap(key=c_uint32, value=c_uint64, max_entries=256)
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/sched/sched_switch")
|
||||
def count_switches(ctx: c_void_p) -> c_int64:
|
||||
cpu = smp_processor_id()
|
||||
count = cpu_counts.lookup(cpu)
|
||||
|
||||
if count:
|
||||
cpu_counts.update(cpu, count + 1)
|
||||
else:
|
||||
cpu_counts.update(cpu, 1)
|
||||
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
|
||||
b = BPF()
|
||||
b.load_and_attach()
|
||||
|
||||
import time
|
||||
time.sleep(5)
|
||||
|
||||
# Read results
|
||||
from pylibbpf import BpfMap
|
||||
map_obj = BpfMap(b, cpu_counts)
|
||||
for cpu, count in map_obj.items():
|
||||
print(f"CPU {cpu}: {count} context switches")
|
||||
```
|
||||
|
||||
### Example 4: Event Sampling
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, section, bpfglobal, BPF, trace_pipe
|
||||
from pythonbpf.helper import random, pid
|
||||
from ctypes import c_void_p, c_int64
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_open")
|
||||
def sample_opens(ctx: c_void_p) -> c_int64:
|
||||
# Sample 5% of events
|
||||
if (random() % 100) < 5:
|
||||
process_id = pid()
|
||||
print(f"Sampled: PID {process_id} opening file")
|
||||
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
|
||||
b = BPF()
|
||||
b.load_and_attach()
|
||||
trace_pipe()
|
||||
```
|
||||
|
||||
## Troubleshooting
|
||||
|
||||
### Helper Not Available
|
||||
|
||||
If a helper function doesn't work:
|
||||
* Check your kernel version (some helpers are newer)
|
||||
* Ensure your LICENSE is GPL-compatible
|
||||
|
||||
### Trace Pipe Access Denied
|
||||
|
||||
If `trace_pipe()` fails:
|
||||
* Run with sudo/root
|
||||
* Check `/sys/kernel/tracing/` is accessible
|
||||
* Verify tracing is enabled in kernel config
|
||||
|
||||
## Examples
|
||||
|
||||
Check out these examples in the `BCC-Examples/` directory that demonstrate helper functions:
|
||||
|
||||
* [hello_world.py](https://github.com/pythonbpf/Python-BPF/blob/main/BCC-Examples/hello_world.py) - Basic tracing with `print()`
|
||||
* [sync_timing.py](https://github.com/pythonbpf/Python-BPF/blob/main/BCC-Examples/sync_timing.py) - Using `ktime()` for timing measurements
|
||||
* [hello_perf_output.py](https://github.com/pythonbpf/Python-BPF/blob/main/BCC-Examples/hello_perf_output.py) - Using `pid()`, `ktime()`, and `comm()` with perf events
|
||||
* [vfsreadlat.py](https://github.com/pythonbpf/Python-BPF/blob/main/BCC-Examples/vfsreadlat.py) - Latency measurement with `ktime()` in kprobes
|
||||
|
||||
## Next Steps
|
||||
|
||||
* Explore {doc}`maps` for data storage with helpers
|
||||
* Learn about {doc}`compilation` to understand helper implementation
|
||||
* See {doc}`decorators` for marking BPF functions
|
||||
87
docs/user-guide/index.md
Normal file
87
docs/user-guide/index.md
Normal file
@ -0,0 +1,87 @@
|
||||
# User Guide
|
||||
|
||||
This user guide provides comprehensive documentation for all PythonBPF features. Whether you're building simple tracing tools or complex performance monitoring systems, this guide will help you master PythonBPF.
|
||||
|
||||
## Overview
|
||||
|
||||
PythonBPF transforms Python code into eBPF bytecode that runs in the Linux kernel. It provides a Pythonic interface to eBPF features through decorators, type annotations, and familiar programming patterns.
|
||||
|
||||
## Core Concepts
|
||||
|
||||
### Decorators
|
||||
|
||||
PythonBPF uses decorators to mark code for BPF compilation:
|
||||
|
||||
* `@bpf` - Mark functions and classes for BPF compilation
|
||||
* `@map` - Define BPF maps for data storage
|
||||
* `@struct` - Define custom data structures
|
||||
* `@section(name)` - Specify attachment points
|
||||
* `@bpfglobal` - Define global variables
|
||||
|
||||
### Compilation Pipeline
|
||||
|
||||
Your Python code goes through several stages:
|
||||
|
||||
1. **IR Generation** - The Python AST is transformed into LLVM IR using llvmlite
|
||||
2. **BPF Compilation** - LLVM IR is compiled to BPF bytecode using `llc`
|
||||
3. **Loading** - The BPF object is loaded into the kernel using libbpf
|
||||
4. **Attachment** - Programs are attached to kernel hooks (tracepoints, kprobes, etc.)
|
||||
|
||||
## Code Organization
|
||||
|
||||
When writing BPF programs with PythonBPF, we recommend:
|
||||
|
||||
1. **Use type hints** - Required for proper code generation
|
||||
2. **Test incrementally** - Verify each component works before adding complexity
|
||||
|
||||
## Type System
|
||||
|
||||
PythonBPF uses Python's `ctypes` module for type definitions:
|
||||
|
||||
* `c_int8`, `c_int16`, `c_int32`, `c_int64` - Signed integers
|
||||
* `c_uint8`, `c_uint16`, `c_uint32`, `c_uint64` - Unsigned integers
|
||||
* `c_char`, `c_bool` - Characters and booleans
|
||||
* `c_void_p` - Void pointers
|
||||
* `str(N)` - Fixed-length strings (e.g., `str(16)` for 16-byte string)
|
||||
|
||||
## Example Structure
|
||||
|
||||
A typical PythonBPF program follows this structure:
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, map, section, bpfglobal, BPF, compile
|
||||
from pythonbpf.maps import HashMap
|
||||
from ctypes import c_void_p, c_int64, c_uint32
|
||||
|
||||
# Define maps
|
||||
@bpf
|
||||
@map
|
||||
def my_map() -> HashMap:
|
||||
return HashMap(key=c_uint32, value=c_uint64, max_entries=1024)
|
||||
|
||||
# Define BPF function
|
||||
@bpf
|
||||
@section("tracepoint/...")
|
||||
def my_function(ctx: c_void_p) -> c_int64:
|
||||
# BPF logic here
|
||||
return 0
|
||||
|
||||
# License (required)
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
|
||||
# Compile, load, and run
|
||||
if __name__ == "__main__":
|
||||
b = BPF()
|
||||
b.load_and_attach()
|
||||
# Use the program...
|
||||
|
||||
# Or, compile to an object file
|
||||
compile()
|
||||
```
|
||||
|
||||
## Next Steps
|
||||
|
||||
Start with {doc}`decorators` to learn about all available decorators, then explore the other sections to master specific features.
|
||||
476
docs/user-guide/maps.md
Normal file
476
docs/user-guide/maps.md
Normal file
@ -0,0 +1,476 @@
|
||||
# BPF Maps
|
||||
|
||||
Maps are BPF data structures that provide storage and communication mechanisms. They allow BPF programs to:
|
||||
|
||||
* Store state between invocations
|
||||
* Share data between multiple BPF programs
|
||||
* Communicate with userspace applications
|
||||
|
||||
```{note}
|
||||
**Work in Progress:** PythonBPF is under active development. We are constantly adding support for more map types, helpers, and kfuncs. Check back for updates!
|
||||
```
|
||||
For comprehensive documentation on BPF maps, see the [eBPF Maps documentation on ebpf.io](https://ebpf.io/what-is-ebpf/#maps).
|
||||
|
||||
## Map Types
|
||||
|
||||
PythonBPF supports several map types, each optimized for different use cases.
|
||||
|
||||
### HashMap
|
||||
|
||||
Hash maps provide efficient key-value storage with O(1) lookup time.
|
||||
|
||||
> **Linux Kernel Map Type:** `BPF_MAP_TYPE_HASH`
|
||||
|
||||
#### Definition
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, map
|
||||
from pythonbpf.maps import HashMap
|
||||
from ctypes import c_uint32, c_uint64
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def my_map() -> HashMap:
|
||||
return HashMap(
|
||||
key=c_uint32,
|
||||
value=c_uint64,
|
||||
max_entries=1024
|
||||
)
|
||||
```
|
||||
|
||||
#### Parameters
|
||||
|
||||
* `key` - The type of the key (must be a ctypes type or struct)
|
||||
* `value` - The type of the value (must be a ctypes type or struct)
|
||||
* `max_entries` - Maximum number of entries the map can hold
|
||||
|
||||
#### Operations
|
||||
|
||||
##### lookup(key)
|
||||
|
||||
Look up a value by key. Returns the value if found, `None` otherwise.
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_open")
|
||||
def trace_open(ctx: c_void_p) -> c_int64:
|
||||
value = my_map.lookup(1)
|
||||
if value:
|
||||
print(f"Found value: {value}")
|
||||
return 0
|
||||
```
|
||||
|
||||
##### update(key, value, flags=None)
|
||||
|
||||
Update or insert a key-value pair.
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_open")
|
||||
def track_opens(ctx: c_void_p) -> c_int64:
|
||||
key = pid()
|
||||
count = my_map.lookup(key)
|
||||
if count:
|
||||
my_map.update(key, count + 1)
|
||||
else:
|
||||
my_map.update(key, 1)
|
||||
return 0
|
||||
```
|
||||
|
||||
##### delete(key)
|
||||
|
||||
Remove an entry from the map.
|
||||
|
||||
```python
|
||||
@bpf
|
||||
def cleanup(ctx: c_void_p) -> c_int64:
|
||||
my_map.delete(1)
|
||||
return 0
|
||||
```
|
||||
|
||||
#### Use Cases
|
||||
|
||||
* Counting events per process/CPU
|
||||
* Storing timestamps for latency calculations
|
||||
* Caching lookup results
|
||||
* Implementing rate limiters
|
||||
|
||||
#### Example: Process Counter
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, map, section, bpfglobal, BPF
|
||||
from pythonbpf.maps import HashMap
|
||||
from pythonbpf.helper import pid
|
||||
from ctypes import c_void_p, c_int64, c_uint32, c_uint64
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def process_count() -> HashMap:
|
||||
return HashMap(key=c_uint32, value=c_uint64, max_entries=4096)
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_clone")
|
||||
def count_processes(ctx: c_void_p) -> c_int64:
|
||||
process_id = pid()
|
||||
count = process_count.lookup(process_id)
|
||||
|
||||
if count:
|
||||
new_count = count + 1
|
||||
process_count.update(process_id, new_count)
|
||||
else:
|
||||
process_count.update(process_id, 1)
|
||||
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
|
||||
if __name__ == "__main__":
|
||||
b = BPF()
|
||||
b.load_and_attach()
|
||||
# Access map from userspace
|
||||
from pylibbpf import BpfMap
|
||||
map_obj = BpfMap(b, process_count)
|
||||
# Read values...
|
||||
```
|
||||
|
||||
### PerfEventArray
|
||||
|
||||
Perf event arrays are used to send data from BPF programs to userspace with high throughput.
|
||||
|
||||
> **Linux Kernel Map Type:** `BPF_MAP_TYPE_PERF_EVENT_ARRAY`
|
||||
|
||||
#### Definition
|
||||
|
||||
```python
|
||||
from pythonbpf.maps import PerfEventArray
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def events() -> PerfEventArray:
|
||||
return PerfEventArray(
|
||||
key_size=c_uint32,
|
||||
value_size=c_uint32
|
||||
)
|
||||
```
|
||||
|
||||
#### Parameters
|
||||
|
||||
* `key_size` - Type for the key (typically `c_uint32`)
|
||||
* `value_size` - Type for the value (typically `c_uint32`)
|
||||
|
||||
#### Operations
|
||||
|
||||
##### output(data)
|
||||
|
||||
Send data to userspace. The data can be a struct or basic type.
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@struct
|
||||
class Event:
|
||||
pid: c_uint32
|
||||
timestamp: c_uint64
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def events() -> PerfEventArray:
|
||||
return PerfEventArray(key_size=c_uint32, value_size=c_uint32)
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
def send_event(ctx: c_void_p) -> c_int64:
|
||||
event = Event()
|
||||
event.pid = pid()
|
||||
event.timestamp = ktime()
|
||||
events.output(event)
|
||||
return 0
|
||||
```
|
||||
|
||||
#### Use Cases
|
||||
|
||||
* Sending detailed event data to userspace
|
||||
* Real-time monitoring and alerting
|
||||
* Collecting samples for analysis
|
||||
* High-throughput data collection
|
||||
|
||||
#### Example: Event Logging
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, map, struct, section, bpfglobal, BPF
|
||||
from pythonbpf.maps import PerfEventArray
|
||||
from pythonbpf.helper import pid, ktime, comm
|
||||
from ctypes import c_void_p, c_int64, c_uint32, c_uint64
|
||||
|
||||
@bpf
|
||||
@struct
|
||||
class ProcessEvent:
|
||||
timestamp: c_uint64
|
||||
pid: c_uint32
|
||||
comm: str(16)
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def events() -> PerfEventArray:
|
||||
return PerfEventArray(key_size=c_uint32, value_size=c_uint32)
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
def log_exec(ctx: c_void_p) -> c_int64:
|
||||
event = ProcessEvent()
|
||||
event.timestamp = ktime()
|
||||
event.pid = pid()
|
||||
comm(event.comm) # Fills event.comm with process name
|
||||
events.output(event)
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@bpfglobal
|
||||
def LICENSE() -> str:
|
||||
return "GPL"
|
||||
```
|
||||
|
||||
### RingBuffer
|
||||
|
||||
Ring buffers provide efficient, ordered event delivery with lower overhead than perf event arrays.
|
||||
|
||||
> **Linux Kernel Map Type:** `BPF_MAP_TYPE_RINGBUF`
|
||||
|
||||
#### Definition
|
||||
|
||||
```python
|
||||
from pythonbpf.maps import RingBuffer
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def events() -> RingBuffer:
|
||||
return RingBuffer(max_entries=4096)
|
||||
```
|
||||
|
||||
#### Parameters
|
||||
|
||||
* `max_entries` - Maximum size of the ring buffer in bytes (must be power of 2)
|
||||
|
||||
#### Operations
|
||||
|
||||
##### output(data, flags=0)
|
||||
|
||||
Send data to the ring buffer.
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_open")
|
||||
def log_event(ctx: c_void_p) -> c_int64:
|
||||
event = Event()
|
||||
event.pid = pid()
|
||||
events.output(event)
|
||||
return 0
|
||||
```
|
||||
|
||||
##### reserve(size)
|
||||
|
||||
Reserve space in the ring buffer. Returns a pointer to the reserved space or 0 if no space available.
|
||||
|
||||
```python
|
||||
@bpf
|
||||
def reserve_space(ctx: c_void_p) -> c_int64:
|
||||
ptr = events.reserve(64) # Reserve 64 bytes
|
||||
if ptr:
|
||||
# Use the reserved space
|
||||
events.submit(ptr)
|
||||
return 0
|
||||
```
|
||||
|
||||
##### submit(data, flags=0)
|
||||
|
||||
Submit previously reserved space.
|
||||
|
||||
##### discard(data, flags=0)
|
||||
|
||||
Discard previously reserved space without submitting.
|
||||
|
||||
#### Use Cases
|
||||
|
||||
* Modern event streaming (preferred over PerfEventArray)
|
||||
* Lower overhead event delivery
|
||||
* Ordered event processing
|
||||
* Kernel 5.8+ systems
|
||||
|
||||
#### Advantages over PerfEventArray
|
||||
|
||||
* Lower memory overhead
|
||||
* Better performance
|
||||
* Simpler API
|
||||
* Ordered delivery guarantees
|
||||
|
||||
### BPFMapType Enum
|
||||
|
||||
PythonBPF supports various BPF map types through the `BPFMapType` enum:
|
||||
|
||||
```python
|
||||
from pythonbpf.maps import BPFMapType
|
||||
|
||||
# Common map types
|
||||
BPFMapType.BPF_MAP_TYPE_HASH # Hash map
|
||||
BPFMapType.BPF_MAP_TYPE_ARRAY # Array map
|
||||
BPFMapType.BPF_MAP_TYPE_PERF_EVENT_ARRAY # Perf event array
|
||||
BPFMapType.BPF_MAP_TYPE_RINGBUF # Ring buffer
|
||||
BPFMapType.BPF_MAP_TYPE_STACK_TRACE # Stack trace storage
|
||||
BPFMapType.BPF_MAP_TYPE_LRU_HASH # LRU hash map
|
||||
```
|
||||
|
||||
## Using Maps with Structs
|
||||
|
||||
Maps can store complex data types using structs as values:
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, map, struct, section
|
||||
from pythonbpf.maps import HashMap
|
||||
from ctypes import c_uint32, c_uint64
|
||||
|
||||
@bpf
|
||||
@struct
|
||||
class Stats:
|
||||
count: c_uint64
|
||||
total_time: c_uint64
|
||||
max_time: c_uint64
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def process_stats() -> HashMap:
|
||||
return HashMap(
|
||||
key=c_uint32, # PID as key
|
||||
value=Stats, # Struct as value
|
||||
max_entries=1024
|
||||
)
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_read")
|
||||
def track_stats(ctx: c_void_p) -> c_int64:
|
||||
process_id = pid()
|
||||
stats = process_stats.lookup(process_id)
|
||||
|
||||
if stats:
|
||||
stats.count = stats.count + 1
|
||||
process_stats.update(process_id, stats)
|
||||
else:
|
||||
new_stats = Stats()
|
||||
new_stats.count = 1
|
||||
new_stats.total_time = 0
|
||||
new_stats.max_time = 0
|
||||
process_stats.update(process_id, new_stats)
|
||||
|
||||
return 0
|
||||
```
|
||||
|
||||
## Accessing Maps from Userspace
|
||||
|
||||
After loading a BPF program, you can access maps from Python using `pylibbpf`:
|
||||
|
||||
```python
|
||||
from pythonbpf import BPF
|
||||
from pylibbpf import BpfMap
|
||||
|
||||
# Load BPF program
|
||||
b = BPF()
|
||||
b.load_and_attach()
|
||||
|
||||
# Get map reference
|
||||
map_obj = BpfMap(b, my_map)
|
||||
|
||||
# Read all key-value pairs
|
||||
for key, value in map_obj.items():
|
||||
print(f"Key: {key}, Value: {value}")
|
||||
|
||||
# Get all keys
|
||||
keys = list(map_obj.keys())
|
||||
|
||||
# Get all values
|
||||
values = list(map_obj.values())
|
||||
|
||||
# Lookup specific key
|
||||
value = map_obj[key]
|
||||
|
||||
# Update from userspace
|
||||
map_obj[key] = new_value
|
||||
|
||||
# Delete from userspace
|
||||
del map_obj[key]
|
||||
```
|
||||
|
||||
## Common Patterns
|
||||
|
||||
### Counter Pattern
|
||||
|
||||
```python
|
||||
count = my_map.lookup(key)
|
||||
if count:
|
||||
my_map.update(key, count + 1)
|
||||
else:
|
||||
my_map.update(key, 1)
|
||||
```
|
||||
|
||||
### Latency Tracking
|
||||
|
||||
```python
|
||||
# Store start time
|
||||
start = ktime()
|
||||
start_map.update(key, start)
|
||||
|
||||
# Later: calculate latency
|
||||
start_time = start_map.lookup(key)
|
||||
if start_time:
|
||||
latency = ktime() - start_time
|
||||
latency_map.update(key, latency)
|
||||
start_map.delete(key)
|
||||
```
|
||||
|
||||
### Event Sampling
|
||||
|
||||
```python
|
||||
# Only process every Nth event
|
||||
count = counter.lookup(key)
|
||||
if count and (count % 100) == 0:
|
||||
events.output(data)
|
||||
counter.update(key, count + 1 if count else 1)
|
||||
```
|
||||
|
||||
## Troubleshooting
|
||||
|
||||
### Map Not Found
|
||||
|
||||
If you get "map not found" errors:
|
||||
* Ensure the map is defined with `@bpf` and `@map`
|
||||
* Check that the map name matches exactly
|
||||
* Verify the BPF program loaded successfully
|
||||
|
||||
### Map Full
|
||||
|
||||
If updates fail due to map being full:
|
||||
* Increase `max_entries`
|
||||
* Use LRU maps for automatic eviction
|
||||
* Add cleanup logic to delete old entries
|
||||
|
||||
### Type Errors
|
||||
|
||||
If you get type-related errors:
|
||||
* Verify key and value types match the definition
|
||||
* Check that structs are properly defined
|
||||
|
||||
## Examples
|
||||
|
||||
Check out these examples in the `BCC-Examples/` directory that demonstrate map usage:
|
||||
|
||||
* [sync_timing.py](https://github.com/pythonbpf/Python-BPF/blob/main/BCC-Examples/sync_timing.py) - HashMap for storing timestamps
|
||||
* [sync_count.py](https://github.com/pythonbpf/Python-BPF/blob/main/BCC-Examples/sync_count.py) - HashMap for counting events
|
||||
* [hello_perf_output.py](https://github.com/pythonbpf/Python-BPF/blob/main/BCC-Examples/hello_perf_output.py) - PerfEventArray for sending structs to userspace
|
||||
* [sync_perf_output.py](https://github.com/pythonbpf/Python-BPF/blob/main/BCC-Examples/sync_perf_output.py) - PerfEventArray with timing data
|
||||
* [disksnoop.py](https://github.com/pythonbpf/Python-BPF/blob/main/BCC-Examples/disksnoop.py) - HashMap for tracking disk I/O
|
||||
|
||||
## Next Steps
|
||||
|
||||
* Learn about {doc}`structs` for defining custom value types
|
||||
* Explore {doc}`helpers` for BPF helper functions
|
||||
* See {doc}`compilation` to understand how maps are compiled
|
||||
413
docs/user-guide/structs.md
Normal file
413
docs/user-guide/structs.md
Normal file
@ -0,0 +1,413 @@
|
||||
# BPF Structs
|
||||
|
||||
Structs allow you to define custom data types for use in BPF programs. They provide a way to group related fields together and can be used as map values, event payloads, or local variables.
|
||||
|
||||
## Defining Structs
|
||||
|
||||
Use the `@bpf` and `@struct` decorators to define a BPF struct:
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, struct
|
||||
from ctypes import c_uint64, c_uint32
|
||||
|
||||
@bpf
|
||||
@struct
|
||||
class Event:
|
||||
timestamp: c_uint64
|
||||
pid: c_uint32
|
||||
cpu: c_uint32
|
||||
```
|
||||
|
||||
## Field Types
|
||||
|
||||
Structs support various field types from Python's `ctypes` module.
|
||||
|
||||
### Integer Types
|
||||
|
||||
```python
|
||||
from ctypes import (
|
||||
c_int8, c_int16, c_int32, c_int64,
|
||||
c_uint8, c_uint16, c_uint32, c_uint64
|
||||
)
|
||||
|
||||
@bpf
|
||||
@struct
|
||||
class Numbers:
|
||||
small_int: c_int8 # -128 to 127
|
||||
short_int: c_int16 # -32768 to 32767
|
||||
int_val: c_int32 # -2^31 to 2^31-1
|
||||
long_int: c_int64 # -2^63 to 2^63-1
|
||||
|
||||
byte: c_uint8 # 0 to 255
|
||||
word: c_uint16 # 0 to 65535
|
||||
dword: c_uint32 # 0 to 2^32-1
|
||||
qword: c_uint64 # 0 to 2^64-1
|
||||
```
|
||||
|
||||
### String Types
|
||||
|
||||
Fixed-length strings are defined using `str(N)` where N is the size:
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@struct
|
||||
class ProcessInfo:
|
||||
name: str(16) # 16-byte string
|
||||
path: str(256) # 256-byte string
|
||||
```
|
||||
|
||||
```{note}
|
||||
Strings in BPF are fixed-length and null-terminated. The size includes the null terminator.
|
||||
```
|
||||
|
||||
### Pointer Types
|
||||
|
||||
```python
|
||||
from ctypes import c_void_p, c_char_p
|
||||
|
||||
@bpf
|
||||
@struct
|
||||
class Pointers:
|
||||
ptr: c_void_p # Generic pointer
|
||||
str_ptr: c_char_p # Character pointer
|
||||
```
|
||||
|
||||
### Nested Structs
|
||||
|
||||
Structs can contain other structs as fields:
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@struct
|
||||
class Address:
|
||||
street: str(64)
|
||||
city: str(32)
|
||||
zip_code: c_uint32
|
||||
|
||||
@bpf
|
||||
@struct
|
||||
class Person:
|
||||
name: str(32)
|
||||
age: c_uint32
|
||||
address: Address # Nested struct
|
||||
```
|
||||
|
||||
## Using Structs
|
||||
|
||||
### As Local Variables
|
||||
|
||||
Create and use struct instances within BPF functions:
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, struct, section
|
||||
from pythonbpf.helper import pid, ktime, comm
|
||||
from ctypes import c_void_p, c_int64, c_uint64, c_uint32
|
||||
|
||||
@bpf
|
||||
@struct
|
||||
class Event:
|
||||
timestamp: c_uint64
|
||||
pid: c_uint32
|
||||
comm: str(16)
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_execve")
|
||||
def capture_event(ctx: c_void_p) -> c_int64:
|
||||
# Create an instance
|
||||
event = Event()
|
||||
|
||||
# Set fields
|
||||
event.timestamp = ktime()
|
||||
event.pid = pid()
|
||||
comm(event.comm) # Fills event.comm with process name
|
||||
|
||||
# Use the struct
|
||||
print(f"Process with PID {event.pid}")
|
||||
|
||||
return 0
|
||||
```
|
||||
|
||||
### As Map Keys and Values
|
||||
|
||||
Use structs as keys and values in maps for complex state storage:
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, struct, map, section
|
||||
from pythonbpf.maps import HashMap
|
||||
from ctypes import c_uint32, c_uint64
|
||||
|
||||
@bpf
|
||||
@struct
|
||||
class ProcessStats:
|
||||
syscall_count: c_uint64
|
||||
total_time: c_uint64
|
||||
max_latency: c_uint64
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def stats() -> HashMap:
|
||||
return HashMap(
|
||||
key=c_uint32,
|
||||
value=ProcessStats,
|
||||
max_entries=1024
|
||||
)
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_read")
|
||||
def track_syscalls(ctx: c_void_p) -> c_int64:
|
||||
process_id = pid()
|
||||
|
||||
# Lookup existing stats
|
||||
s = stats.lookup(process_id)
|
||||
|
||||
if s:
|
||||
# Update existing stats
|
||||
s.syscall_count = s.syscall_count + 1
|
||||
stats.update(process_id, s)
|
||||
else:
|
||||
# Create new stats
|
||||
new_stats = ProcessStats()
|
||||
new_stats.syscall_count = 1
|
||||
new_stats.total_time = 0
|
||||
new_stats.max_latency = 0
|
||||
stats.update(process_id, new_stats)
|
||||
|
||||
return 0
|
||||
```
|
||||
|
||||
### With Perf Events
|
||||
|
||||
Send struct data to userspace using PerfEventArray:
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, struct, map, section
|
||||
from pythonbpf.maps import PerfEventArray
|
||||
from pythonbpf.helper import pid, ktime, comm
|
||||
from ctypes import c_void_p, c_int64, c_uint32, c_uint64
|
||||
|
||||
@bpf
|
||||
@struct
|
||||
class ProcessEvent:
|
||||
timestamp: c_uint64
|
||||
pid: c_uint32
|
||||
ppid: c_uint32
|
||||
comm: str(16)
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def events() -> PerfEventArray:
|
||||
return PerfEventArray(key_size=c_uint32, value_size=c_uint32)
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/sched/sched_process_fork")
|
||||
def trace_fork(ctx: c_void_p) -> c_int64:
|
||||
event = ProcessEvent()
|
||||
event.timestamp = ktime()
|
||||
event.pid = pid()
|
||||
comm(event.comm) # Fills event.comm with process name
|
||||
|
||||
# Send to userspace
|
||||
events.output(event)
|
||||
|
||||
return 0
|
||||
```
|
||||
|
||||
### With Ring Buffers
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, struct, map, section
|
||||
from pythonbpf.maps import RingBuffer
|
||||
|
||||
@bpf
|
||||
@struct
|
||||
class FileEvent:
|
||||
timestamp: c_uint64
|
||||
pid: c_uint32
|
||||
filename: str(256)
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def events() -> RingBuffer:
|
||||
return RingBuffer(max_entries=4096)
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/syscalls/sys_enter_openat")
|
||||
def trace_open(ctx: c_void_p) -> c_int64:
|
||||
event = FileEvent()
|
||||
event.timestamp = ktime()
|
||||
event.pid = pid()
|
||||
|
||||
events.output(event)
|
||||
|
||||
return 0
|
||||
```
|
||||
|
||||
## Field Access and Modification
|
||||
|
||||
### Reading Fields
|
||||
|
||||
Access struct fields using dot notation:
|
||||
|
||||
```python
|
||||
event = Event()
|
||||
ts = event.timestamp
|
||||
process_id = event.pid
|
||||
```
|
||||
|
||||
### Writing Fields
|
||||
|
||||
Assign values to fields:
|
||||
|
||||
```python
|
||||
event = Event()
|
||||
event.timestamp = ktime()
|
||||
event.pid = pid()
|
||||
comm(event.comm)
|
||||
```
|
||||
|
||||
## StructType Class
|
||||
|
||||
PythonBPF provides a `StructType` class for working with struct metadata:
|
||||
|
||||
```python
|
||||
from pythonbpf.structs import StructType
|
||||
|
||||
# Define a struct
|
||||
@bpf
|
||||
@struct
|
||||
class MyStruct:
|
||||
field1: c_uint64
|
||||
field2: c_uint32
|
||||
|
||||
# Access struct information (from userspace)
|
||||
# This is typically used internally by the compiler
|
||||
```
|
||||
|
||||
## Complex Examples
|
||||
|
||||
### Network Packet Event
|
||||
|
||||
```python
|
||||
from pythonbpf import bpf, struct, map, section
|
||||
from pythonbpf.maps import RingBuffer
|
||||
from pythonbpf.helper import ktime, XDP_PASS
|
||||
from ctypes import c_void_p, c_int64, c_uint8, c_uint16, c_uint32, c_uint64
|
||||
|
||||
@bpf
|
||||
@struct
|
||||
class PacketEvent:
|
||||
timestamp: c_uint64
|
||||
src_ip: c_uint32
|
||||
dst_ip: c_uint32
|
||||
src_port: c_uint16
|
||||
dst_port: c_uint16
|
||||
protocol: c_uint8
|
||||
length: c_uint16
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def packets() -> RingBuffer:
|
||||
return RingBuffer(max_entries=8192)
|
||||
|
||||
@bpf
|
||||
@section("xdp")
|
||||
def capture_packets(ctx: c_void_p) -> c_int64:
|
||||
pkt = PacketEvent()
|
||||
pkt.timestamp = ktime()
|
||||
# Parse packet data from ctx...
|
||||
|
||||
packets.output(pkt)
|
||||
|
||||
return XDP_PASS
|
||||
```
|
||||
|
||||
### Process Lifecycle Tracking
|
||||
|
||||
```python
|
||||
@bpf
|
||||
@struct
|
||||
class ProcessLifecycle:
|
||||
pid: c_uint32
|
||||
ppid: c_uint32
|
||||
start_time: c_uint64
|
||||
exit_time: c_uint64
|
||||
exit_code: c_int32
|
||||
comm: str(16)
|
||||
|
||||
@bpf
|
||||
@map
|
||||
def process_info() -> HashMap:
|
||||
return HashMap(
|
||||
key=c_uint32,
|
||||
value=ProcessLifecycle,
|
||||
max_entries=4096
|
||||
)
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/sched/sched_process_fork")
|
||||
def track_fork(ctx: c_void_p) -> c_int64:
|
||||
process_id = pid()
|
||||
|
||||
info = ProcessLifecycle()
|
||||
info.pid = process_id
|
||||
info.start_time = ktime()
|
||||
|
||||
process_info.update(process_id, info)
|
||||
|
||||
return 0
|
||||
|
||||
@bpf
|
||||
@section("tracepoint/sched/sched_process_exit")
|
||||
def track_exit(ctx: c_void_p) -> c_int64:
|
||||
process_id = pid()
|
||||
|
||||
info = process_info.lookup(process_id)
|
||||
if info:
|
||||
info.exit_time = ktime()
|
||||
process_info.update(process_id, info)
|
||||
|
||||
return 0
|
||||
```
|
||||
|
||||
## Troubleshooting
|
||||
|
||||
### Struct Size Issues
|
||||
|
||||
If you encounter size-related errors:
|
||||
* Check for excessive padding
|
||||
* Verify field types are correct
|
||||
* Consider reordering fields
|
||||
|
||||
### Initialization Problems
|
||||
|
||||
If fields aren't initialized correctly:
|
||||
* Always initialize all fields explicitly
|
||||
* Set default values where appropriate
|
||||
* Use helper functions for dynamic values
|
||||
|
||||
### Type Mismatch Errors
|
||||
|
||||
If you get type errors:
|
||||
* Ensure field types match assignments
|
||||
* Check that imported types are from `ctypes`
|
||||
* Verify nested struct definitions
|
||||
|
||||
## Reading Struct Data in Userspace
|
||||
|
||||
After capturing struct data, read it in Python:
|
||||
|
||||
```python
|
||||
from pylibbpf import BpfMap
|
||||
|
||||
# Read from map
|
||||
map_obj = BpfMap(b, stats)
|
||||
for key, value_bytes in map_obj.items():
|
||||
value = Event.from_buffer_copy(value_bytes)
|
||||
print(f"PID: {value.pid}, Comm: {value.comm.decode()}")
|
||||
```
|
||||
|
||||
## Next Steps
|
||||
|
||||
* Learn about {doc}`maps` for storing struct data
|
||||
* Explore {doc}`helpers` for populating struct fields
|
||||
* See {doc}`compilation` to understand how structs are compiled
|
||||
@ -34,6 +34,14 @@ dependencies = [
|
||||
"pylibbpf"
|
||||
]
|
||||
|
||||
[project.optional-dependencies]
|
||||
docs = [
|
||||
"sphinx>=7.0",
|
||||
"myst-parser>=2.0",
|
||||
"sphinx-rtd-theme>=2.0",
|
||||
"sphinx-copybutton",
|
||||
]
|
||||
|
||||
[tool.setuptools.packages.find]
|
||||
where = ["."]
|
||||
include = ["pythonbpf*"]
|
||||
|
||||
Reference in New Issue
Block a user