91 Commits

Author SHA1 Message Date
fed6af1ed6 bump version and prepare for release 2025-11-22 13:54:41 +05:30
18886816fb Merge pull request #68 from pythonbpf/request-struct
Support enough machinery to make request struct work
2025-11-22 13:48:06 +05:30
a2de15fb1e add c_int to type_deducer.py 2025-11-22 13:36:21 +05:30
9def969592 Make map val struct type allocation work by fixing pointer deref and debuginfogen: WIP 2025-11-22 13:20:09 +05:30
081ee5cb4c move requests.py to passing tests 2025-11-22 13:19:55 +05:30
a91c3158ad sort fields in debug info by offset order 2025-11-22 12:35:47 +05:30
2b3635fe20 format chore 2025-11-22 01:48:44 +05:30
6f25c554a9 fix CO-RE read for cast structs 2025-11-22 01:47:25 +05:30
84507b8b98 add btf probe read kernel helper 2025-11-22 00:57:12 +05:30
a42a75179d format chore 2025-11-22 00:37:39 +05:30
377fa4041d add regular struct field access handling in vmlinux_registry.py 2025-11-22 00:36:59 +05:30
99321c7669 add a failing C test 2025-11-21 23:01:08 +05:30
11850d16d3 field check in allocation pass 2025-11-21 21:47:58 +05:30
9ee821c7f6 make pointer allocation feasible but subverting LLC 2025-11-21 21:47:55 +05:30
25394059a6 allow casting 2025-11-21 21:47:10 +05:30
fde8eab775 allow allocation pass on vmlinux cast 2025-11-21 21:47:07 +05:30
42b8865a56 Merge branch 'master' into request-struct 2025-11-21 02:10:52 +05:30
144d9b0ab4 change c-file test structure 2025-11-20 17:24:02 +05:30
902a52a07d remove debug print statements 2025-11-20 14:39:13 +05:30
306570953b format chore 2025-11-20 14:18:45 +05:30
740eed45e1 add placeholder debug info to shut llvmlite up about NoneType 2025-11-20 14:17:57 +05:30
c8801f4c3e nonetype not parsed 2025-11-19 23:35:10 +05:30
e5b3b001ce Minor fix for PTR_TO_MAP_VALUE_OR_NULL target 2025-11-19 04:29:35 +05:30
19b42b9a19 Allocate hashmap lookup return vars based on the value type of said hashmap 2025-11-19 04:09:51 +05:30
9f5ec62383 Add get_uint8_type to DebugInfoGenerator 2025-11-19 03:24:40 +05:30
7af54df7c0 Add passing test hash_map_struct.py for using structs as hashmap key/val types 2025-11-19 00:17:01 +05:30
573bbb350e Allow structs to be key/val type for hashmaps 2025-11-19 00:08:15 +05:30
64679f8072 Add skeleton _get_key_val_dbg_type in maps_debug_info.py 2025-11-18 05:00:00 +05:30
5667facf23 Pass down structs_sym_tab to maps_debug_info, allow vmlinux enums to be used in an indexed format for map declaration 2025-11-18 04:34:51 +05:30
4f8af16a17 Pass structs_sym_tab to maps_proc 2025-11-18 04:34:42 +05:30
b84884162d Merge pull request #69 from pythonbpf/symex
Add support for userspace+kernelspace stack trace example using blazesym
2025-11-17 01:47:35 +05:30
e9bb90cb70 Add docstring for bpf_get_stack_emitter 2025-11-17 01:46:57 +05:30
49740598ea format chore 2025-11-13 09:31:10 +05:30
73bbf00e7c add tests 2025-11-13 09:29:53 +05:30
9d76502d5a Fix get_flags_val usage 2025-11-13 02:24:35 +05:30
a10da4a277 Implement bpf_get_stack handler 2025-11-13 00:59:50 +05:30
29e90601b7 Init bpf_get_stack emitter 2025-11-13 00:51:48 +05:30
56df05a93c Janitorial formatting 2025-11-12 14:38:35 +05:30
a55efc6469 Implement output helper for RingBuf maps, add a match-case based dispatch for output helper handlers for multiple map types 2025-11-12 14:06:09 +05:30
64cd2d2fc2 Set minimum supported Python version to 3.10 2025-11-12 14:06:00 +05:30
cbddc0aa96 Introduce MapSymbol to propagate map type info in map_sym_tab 2025-11-12 13:16:23 +05:30
209df33c8f Add RingBuf submit and reserve helpers 2025-11-12 03:53:16 +05:30
7a56e5d0cd Initialize required helpers for ringbuffer 2025-11-12 01:59:07 +05:30
1d7a436c9f Add linting function for RingBuf.discard 2025-11-12 01:30:15 +05:30
5eaeb3e921 Add max_entries constraints for RingBuffer 2025-11-12 01:27:41 +05:30
cd52d0d91b Rename RingBuf map to RingBuffer 2025-11-12 01:07:12 +05:30
df981be095 Janitorial format 2025-11-11 21:08:06 +05:30
316c21c428 Fix char_array to pointer/int detection fallback in helper_utils 2025-11-11 21:00:42 +05:30
c883d95655 Minor fix - check expr type before sending to char_array handler in printk_formatter 2025-11-11 17:43:20 +05:30
f7dee329cb fix nested pointers issue in array generation and also fix zero length array IR generation 2025-11-10 20:29:28 +05:30
5031f90377 fix stacked vmlinux struct parsing issue 2025-11-10 20:06:04 +05:30
95a624044a fix type error 2025-11-08 20:28:56 +05:30
c5bef26b88 add multi imports to single import line. 2025-11-08 18:08:04 +05:30
5a8b64f1d9 Merge pull request #64 from pythonbpf/all_helpers
Add support for all eBPF helpers
2025-11-07 19:26:55 +05:30
cf99b3bb9a Fix call to get_or_create_ptr_from_arg for probe_read_str 2025-11-07 19:16:48 +05:30
6c85b248ce Init sz in get_or_create_ptr_from_arg 2025-11-07 19:03:21 +05:30
b5a3494cc6 Fix typo in get_or_create_ptr_from_arg 2025-11-07 19:01:40 +05:30
be62972974 Fix ScratchPoolManager::counter 2025-11-07 19:00:57 +05:30
2f4a7d2f90 Remove get_struct_char_array_ptr in favour of get_char_array_ptr_and_size, wrap it in get_or_crate_ptr_from_arg to use in bpf_helper_handler 2025-11-07 18:54:59 +05:30
3ccd3f767e Add expected types for pointer creation of args in probe_read handler 2025-11-06 19:59:04 +05:30
2e37726922 Add signature relection for all helper handlers except print 2025-11-06 19:47:57 +05:30
5b36726b7d Make bpf_skb_store_bytes work 2025-11-05 20:02:39 +05:30
faad3555dc Merge pull request #67 from pythonbpf/32int_support
add i32 support and special support for xdp_md with zext
2025-11-05 19:42:05 +05:30
3e6cea2b67 Move get_struct_char_array_ptr from helper/printk_formatter to helper/helper_utils, enable array to ptr conversion in skb_store_bytes 2025-11-05 19:10:58 +05:30
338d4994d8 Fix count_temps_in_call to only look for Pointer args of a helper_sig 2025-11-05 17:36:37 +05:30
3078d4224d Add typed scratch space support to the bpf_skb_store_bytes helper 2025-11-04 16:09:11 +05:30
7d29790f00 Make use of new get_next_temp in helpers 2025-11-04 16:02:56 +05:30
963e2a8171 Change ScratchPoolManager to use typed scratch space 2025-11-04 14:16:44 +05:30
123a92af1d Change allocation pass to generate typed temp variables 2025-11-04 06:20:39 +05:30
752f564d3f Change count_temps_in_call to return hashmap of types 2025-11-04 05:40:22 +05:30
d8cddb9799 Add signature extraction to HelperHandlerRegistry 2025-11-04 05:19:22 +05:30
33e18f6d6d Introduce HelperSignature in HelperHandlerRegistry 2025-11-03 21:21:13 +05:30
5e371787eb Fix the number of args for skb_store_bytes by making the first arg implicit 2025-11-03 21:11:16 +05:30
67c9d9b932 Fix imports for bpf_skb_store_bytes 2025-11-02 04:33:45 +05:30
f757a32a63 Implement bpf_skb_store_bytes_emitter 2025-11-02 04:32:05 +05:30
c5de92b9d0 Add BPF_SKB_STORE_BYTES to HelperIDs 2025-11-02 04:17:15 +05:30
4efd3223cd Add passing uid_gid helper test 2025-11-02 03:47:26 +05:30
4884ed7577 Fix imports for bpf_get_current_uid_gid 2025-11-02 03:35:41 +05:30
5b7769dd38 Implement bpf_get_current_uid_gid_emitter 2025-11-02 03:34:04 +05:30
b7c1e92f05 Add BPF_GET_CURRENT_UID_GID to HelperIDs 2025-11-02 03:29:02 +05:30
8b28a927c3 Add helpful TODO to PID_TGID emitter 2025-11-02 03:27:27 +05:30
f9ee43e7ef Add passing test smp_processor_id.py for helpers 2025-11-01 14:13:52 +05:30
dabb8bf0df Fix imports for BPF_GET_SMP_PROCESSOR_ID 2025-11-01 14:07:47 +05:30
19dedede53 Implement BPF_GET_SMP_PROCESSOR_ID helper 2025-11-01 14:05:50 +05:30
82cac8f8ef Add BPF_GET_SMP_PROCESSOR_ID to HelperIDs 2025-11-01 14:02:07 +05:30
70a04f54d1 Add passing test for bpf_probe_read helper 2025-11-01 13:51:08 +05:30
ec2ea835e5 Fix imports and type issues for bpf_probe_read 2025-11-01 13:50:23 +05:30
2257c175ed Implement BPF_PROBE_READ helper 2025-11-01 13:14:50 +05:30
5bf60d69b8 Add BPF_PROBE_READ to HelperIDs 2025-11-01 12:52:15 +05:30
0006e26b08 Add passing test for bpf_get_prandom_u32 implementation 2025-10-27 01:09:27 +05:30
5cbd9a531e Add bpf_get_prandom_u32 helper 2025-10-27 01:08:56 +05:30
36 changed files with 2061 additions and 320 deletions

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@ -68,8 +68,6 @@ def callback(cpu, event):
perf = b["events"].open_perf_buffer(callback, struct_name="data_t")
print("Starting to poll... (Ctrl+C to stop)")
print("Try running: fork() or clone() system calls to trigger events")
try:
while True:
b["events"].poll(1000)

View File

@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
[project]
name = "pythonbpf"
version = "0.1.6"
version = "0.1.7"
description = "Reduced Python frontend for eBPF"
authors = [
{ name = "r41k0u", email="pragyanshchaturvedi18@gmail.com" },
@ -26,10 +26,10 @@ classifiers = [
]
readme = "README.md"
license = {text = "Apache-2.0"}
requires-python = ">=3.8"
requires-python = ">=3.10"
dependencies = [
"llvmlite",
"llvmlite>=0.45",
"astpretty",
"pylibbpf"
]

View File

@ -7,6 +7,7 @@ from pythonbpf.helper import HelperHandlerRegistry
from pythonbpf.vmlinux_parser.dependency_node import Field
from .expr import VmlinuxHandlerRegistry
from pythonbpf.type_deducer import ctypes_to_ir
from pythonbpf.maps import BPFMapType
logger = logging.getLogger(__name__)
@ -25,7 +26,9 @@ def create_targets_and_rvals(stmt):
return stmt.targets, [stmt.value]
def handle_assign_allocation(builder, stmt, local_sym_tab, structs_sym_tab):
def handle_assign_allocation(
builder, stmt, local_sym_tab, map_sym_tab, structs_sym_tab
):
"""Handle memory allocation for assignment statements."""
logger.info(f"Handling assignment for allocation: {ast.dump(stmt)}")
@ -55,7 +58,9 @@ def handle_assign_allocation(builder, stmt, local_sym_tab, structs_sym_tab):
# Determine type and allocate based on rval
if isinstance(rval, ast.Call):
_allocate_for_call(builder, var_name, rval, local_sym_tab, structs_sym_tab)
_allocate_for_call(
builder, var_name, rval, local_sym_tab, map_sym_tab, structs_sym_tab
)
elif isinstance(rval, ast.Constant):
_allocate_for_constant(builder, var_name, rval, local_sym_tab)
elif isinstance(rval, ast.BinOp):
@ -74,7 +79,9 @@ def handle_assign_allocation(builder, stmt, local_sym_tab, structs_sym_tab):
)
def _allocate_for_call(builder, var_name, rval, local_sym_tab, structs_sym_tab):
def _allocate_for_call(
builder, var_name, rval, local_sym_tab, map_sym_tab, structs_sym_tab
):
"""Allocate memory for variable assigned from a call."""
if isinstance(rval.func, ast.Name):
@ -111,20 +118,91 @@ def _allocate_for_call(builder, var_name, rval, local_sym_tab, structs_sym_tab):
local_sym_tab[var_name] = LocalSymbol(var, struct_info.ir_type, call_type)
logger.info(f"Pre-allocated {var_name} for struct {call_type}")
elif VmlinuxHandlerRegistry.is_vmlinux_struct(call_type):
# When calling struct_name(pointer), we're doing a cast, not construction
# So we allocate as a pointer (i64) not as the actual struct
var = builder.alloca(ir.IntType(64), name=var_name)
var.align = 8
local_sym_tab[var_name] = LocalSymbol(
var, ir.IntType(64), VmlinuxHandlerRegistry.get_struct_type(call_type)
)
logger.info(
f"Pre-allocated {var_name} for vmlinux struct pointer cast to {call_type}"
)
else:
logger.warning(f"Unknown call type for allocation: {call_type}")
elif isinstance(rval.func, ast.Attribute):
# Map method calls - need double allocation for ptr handling
_allocate_for_map_method(builder, var_name, local_sym_tab)
_allocate_for_map_method(
builder, var_name, rval, local_sym_tab, map_sym_tab, structs_sym_tab
)
else:
logger.warning(f"Unsupported call function type for {var_name}")
def _allocate_for_map_method(builder, var_name, local_sym_tab):
def _allocate_for_map_method(
builder, var_name, rval, local_sym_tab, map_sym_tab, structs_sym_tab
):
"""Allocate memory for variable assigned from map method (double alloc)."""
map_name = rval.func.value.id
method_name = rval.func.attr
# NOTE: We will have to special case HashMap.lookup which returns a pointer to value type
# The value type can be a struct as well, so we need to handle that properly
# This special casing is not ideal, as over time other map methods may need similar handling
# But for now, we will just handle lookup specifically
if map_name not in map_sym_tab:
logger.error(f"Map '{map_name}' not found for allocation")
return
if method_name != "lookup":
# Fallback allocation for other map methods
_allocate_for_map_method_fallback(builder, var_name, local_sym_tab)
return
map_params = map_sym_tab[map_name].params
if map_params["type"] != BPFMapType.HASH:
logger.warning(
"Map method lookup used on non-hash map, using fallback allocation"
)
_allocate_for_map_method_fallback(builder, var_name, local_sym_tab)
return
value_type = map_params["value"]
# Determine IR type for value
if isinstance(value_type, str) and value_type in structs_sym_tab:
struct_info = structs_sym_tab[value_type]
value_ir_type = struct_info.ir_type
else:
value_ir_type = ctypes_to_ir(value_type)
if value_ir_type is None:
logger.warning(
f"Could not determine IR type for map value '{value_type}', using fallback allocation"
)
_allocate_for_map_method_fallback(builder, var_name, local_sym_tab)
return
# Main variable (pointer to pointer)
ir_type = ir.PointerType(ir.IntType(64))
var = builder.alloca(ir_type, name=var_name)
local_sym_tab[var_name] = LocalSymbol(var, ir_type, value_type)
# Temporary variable for computed values
tmp_ir_type = value_ir_type
var_tmp = builder.alloca(tmp_ir_type, name=f"{var_name}_tmp")
local_sym_tab[f"{var_name}_tmp"] = LocalSymbol(var_tmp, tmp_ir_type)
logger.info(
f"Pre-allocated {var_name} and {var_name}_tmp for map method lookup of type {value_ir_type}"
)
def _allocate_for_map_method_fallback(builder, var_name, local_sym_tab):
"""Fallback allocation for map method variable (i64* and i64**)."""
# Main variable (pointer to pointer)
ir_type = ir.PointerType(ir.IntType(64))
var = builder.alloca(ir_type, name=var_name)
@ -135,7 +213,9 @@ def _allocate_for_map_method(builder, var_name, local_sym_tab):
var_tmp = builder.alloca(tmp_ir_type, name=f"{var_name}_tmp")
local_sym_tab[f"{var_name}_tmp"] = LocalSymbol(var_tmp, tmp_ir_type)
logger.info(f"Pre-allocated {var_name} and {var_name}_tmp for map method")
logger.info(
f"Pre-allocated {var_name} and {var_name}_tmp for map method (fallback)"
)
def _allocate_for_constant(builder, var_name, rval, local_sym_tab):
@ -177,17 +257,33 @@ def _allocate_for_binop(builder, var_name, local_sym_tab):
logger.info(f"Pre-allocated {var_name} for binop result")
def _get_type_name(ir_type):
"""Get a string representation of an IR type."""
if isinstance(ir_type, ir.IntType):
return f"i{ir_type.width}"
elif isinstance(ir_type, ir.PointerType):
return "ptr"
elif isinstance(ir_type, ir.ArrayType):
return f"[{ir_type.count}x{_get_type_name(ir_type.element)}]"
else:
return str(ir_type).replace(" ", "")
def allocate_temp_pool(builder, max_temps, local_sym_tab):
"""Allocate the temporary scratch space pool for helper arguments."""
if max_temps == 0:
if not max_temps:
logger.info("No temp pool allocation needed")
return
logger.info(f"Allocating temp pool of {max_temps} variables")
for i in range(max_temps):
temp_name = f"__helper_temp_{i}"
temp_var = builder.alloca(ir.IntType(64), name=temp_name)
temp_var.align = 8
local_sym_tab[temp_name] = LocalSymbol(temp_var, ir.IntType(64))
for tmp_type, cnt in max_temps.items():
type_name = _get_type_name(tmp_type)
logger.info(f"Allocating temp pool of {cnt} variables of type {type_name}")
for i in range(cnt):
temp_name = f"__helper_temp_{type_name}_{i}"
temp_var = builder.alloca(tmp_type, name=temp_name)
temp_var.align = _get_alignment(tmp_type)
local_sym_tab[temp_name] = LocalSymbol(temp_var, tmp_type)
logger.debug(f"Allocated temp variable: {temp_name}")
def _allocate_for_name(builder, var_name, rval, local_sym_tab):
@ -241,13 +337,6 @@ def _allocate_for_attribute(builder, var_name, rval, local_sym_tab, structs_sym_
VmlinuxHandlerRegistry.get_field_type(vmlinux_struct_name, field_name)
)
field_ir, field = field_type
# TODO: For now, we only support integer type allocations.
# This always assumes first argument of function to be the context struct
base_ptr = builder.function.args[0]
local_sym_tab[
struct_var
].var = base_ptr # This is repurposing of var to store the pointer of the base type
local_sym_tab[struct_var].ir_type = field_ir
# Determine the actual IR type based on the field's type
actual_ir_type = None
@ -302,12 +391,14 @@ def _allocate_for_attribute(builder, var_name, rval, local_sym_tab, structs_sym_
)
actual_ir_type = ir.IntType(64)
# Allocate with the actual IR type, not the GlobalVariable
# Allocate with the actual IR type
var = _allocate_with_type(builder, var_name, actual_ir_type)
local_sym_tab[var_name] = LocalSymbol(var, actual_ir_type, field)
local_sym_tab[var_name] = LocalSymbol(
var, actual_ir_type, field
) # <-- Store Field metadata
logger.info(
f"Pre-allocated {var_name} from vmlinux struct {vmlinux_struct_name}.{field_name}"
f"Pre-allocated {var_name} as {actual_ir_type} from vmlinux struct {vmlinux_struct_name}.{field_name}"
)
return
else:

View File

@ -1,5 +1,7 @@
import ast
import logging
from inspect import isclass
from llvmlite import ir
from pythonbpf.expr import eval_expr
from pythonbpf.helper import emit_probe_read_kernel_str_call
@ -148,8 +150,30 @@ def handle_variable_assignment(
return False
val, val_type = val_result
logger.info(f"Evaluated value for {var_name}: {val} of type {val_type}, {var_type}")
logger.info(
f"Evaluated value for {var_name}: {val} of type {val_type}, expected {var_type}"
)
if val_type != var_type:
# Handle vmlinux struct pointers - they're represented as Python classes but are i64 pointers
if isclass(val_type) and (val_type.__module__ == "vmlinux"):
logger.info("Handling vmlinux struct pointer assignment")
# vmlinux struct pointers: val is a pointer, need to convert to i64
if isinstance(var_type, ir.IntType) and var_type.width == 64:
# Convert pointer to i64 using ptrtoint
if isinstance(val.type, ir.PointerType):
val = builder.ptrtoint(val, ir.IntType(64))
logger.info(
"Converted vmlinux struct pointer to i64 using ptrtoint"
)
builder.store(val, var_ptr)
logger.info(f"Assigned vmlinux struct pointer to {var_name} (i64)")
return True
else:
logger.error(
f"Type mismatch: vmlinux struct pointer requires i64, got {var_type}"
)
return False
if isinstance(val_type, Field):
logger.info("Handling assignment to struct field")
# Special handling for struct_xdp_md i32 fields that are zero-extended to i64

View File

@ -25,7 +25,7 @@ import re
logger: Logger = logging.getLogger(__name__)
VERSION = "v0.1.6"
VERSION = "v0.1.7"
def finalize_module(original_str):
@ -86,7 +86,7 @@ def processor(source_code, filename, module):
license_processing(tree, module)
globals_processing(tree, module)
structs_sym_tab = structs_proc(tree, module, bpf_chunks)
map_sym_tab = maps_proc(tree, module, bpf_chunks)
map_sym_tab = maps_proc(tree, module, bpf_chunks, structs_sym_tab)
func_proc(tree, module, bpf_chunks, map_sym_tab, structs_sym_tab)
globals_list_creation(tree, module)
@ -218,13 +218,11 @@ def compile(loglevel=logging.WARNING) -> bool:
def BPF(loglevel=logging.WARNING) -> BpfObject:
caller_frame = inspect.stack()[1]
src = inspect.getsource(caller_frame.frame)
with tempfile.NamedTemporaryFile(
mode="w+", delete=True, suffix=".py"
) as f, tempfile.NamedTemporaryFile(
mode="w+", delete=True, suffix=".ll"
) as inter, tempfile.NamedTemporaryFile(
mode="w+", delete=False, suffix=".o"
) as obj_file:
with (
tempfile.NamedTemporaryFile(mode="w+", delete=True, suffix=".py") as f,
tempfile.NamedTemporaryFile(mode="w+", delete=True, suffix=".ll") as inter,
tempfile.NamedTemporaryFile(mode="w+", delete=False, suffix=".o") as obj_file,
):
f.write(src)
f.flush()
source = f.name

View File

@ -49,6 +49,10 @@ class DebugInfoGenerator:
)
return self._type_cache[key]
def get_uint8_type(self) -> Any:
"""Get debug info for signed 8-bit integer"""
return self.get_basic_type("char", 8, dc.DW_ATE_unsigned)
def get_int32_type(self) -> Any:
"""Get debug info for signed 32-bit integer"""
return self.get_basic_type("int", 32, dc.DW_ATE_signed)

View File

@ -12,8 +12,8 @@ from .type_normalization import (
get_base_type_and_depth,
deref_to_depth,
)
from pythonbpf.vmlinux_parser.assignment_info import Field
from .vmlinux_registry import VmlinuxHandlerRegistry
from ..vmlinux_parser.dependency_node import Field
logger: Logger = logging.getLogger(__name__)
@ -61,6 +61,7 @@ def _handle_constant_expr(module, builder, expr: ast.Constant):
def _handle_attribute_expr(
func,
expr: ast.Attribute,
local_sym_tab: Dict,
structs_sym_tab: Dict,
@ -76,6 +77,89 @@ def _handle_attribute_expr(
logger.info(
f"Variable type: {var_type}, Variable ptr: {var_ptr}, Variable Metadata: {var_metadata}"
)
# Check if this is a pointer to a struct (from map lookup)
if (
isinstance(var_type, ir.PointerType)
and var_metadata
and isinstance(var_metadata, str)
):
if var_metadata in structs_sym_tab:
logger.info(
f"Handling pointer to struct {var_metadata} from map lookup"
)
if func is None:
raise ValueError(
f"func parameter required for null-safe pointer access to {var_name}.{attr_name}"
)
# Load the pointer value (ptr<struct>)
struct_ptr = builder.load(var_ptr)
# Create blocks for null check
null_check_block = builder.block
not_null_block = func.append_basic_block(
name=f"{var_name}_not_null"
)
merge_block = func.append_basic_block(name=f"{var_name}_merge")
# Check if pointer is null
null_ptr = ir.Constant(struct_ptr.type, None)
is_not_null = builder.icmp_signed("!=", struct_ptr, null_ptr)
logger.info(f"Inserted null check for pointer {var_name}")
builder.cbranch(is_not_null, not_null_block, merge_block)
# Not-null block: Access the field
builder.position_at_end(not_null_block)
# Get struct metadata
metadata = structs_sym_tab[var_metadata]
struct_ptr = builder.bitcast(
struct_ptr, metadata.ir_type.as_pointer()
)
if attr_name not in metadata.fields:
raise ValueError(
f"Field '{attr_name}' not found in struct '{var_metadata}'"
)
# GEP to field
field_gep = metadata.gep(builder, struct_ptr, attr_name)
# Load field value
field_val = builder.load(field_gep)
field_type = metadata.field_type(attr_name)
logger.info(
f"Loaded field {attr_name} from struct pointer, type: {field_type}"
)
# Branch to merge
not_null_after_load = builder.block
builder.branch(merge_block)
# Merge block: PHI node for the result
builder.position_at_end(merge_block)
phi = builder.phi(field_type, name=f"{var_name}_{attr_name}")
# If null, return zero/default value
if isinstance(field_type, ir.IntType):
zero_value = ir.Constant(field_type, 0)
elif isinstance(field_type, ir.PointerType):
zero_value = ir.Constant(field_type, None)
elif isinstance(field_type, ir.ArrayType):
# For arrays, we can't easily create a zero constant
# This case is tricky - for now, just use undef
zero_value = ir.Constant(field_type, ir.Undefined)
else:
zero_value = ir.Constant(field_type, ir.Undefined)
phi.add_incoming(zero_value, null_check_block)
phi.add_incoming(field_val, not_null_after_load)
logger.info(f"Created PHI node for {var_name}.{attr_name}")
return phi, field_type
if (
hasattr(var_metadata, "__module__")
and var_metadata.__module__ == "vmlinux"
@ -89,8 +173,16 @@ def _handle_attribute_expr(
return vmlinux_result
else:
raise RuntimeError("Vmlinux struct did not process successfully")
metadata = structs_sym_tab[var_metadata]
if attr_name in metadata.fields:
elif isinstance(var_metadata, Field):
logger.error(
f"Cannot access field '{attr_name}' on already-loaded field value '{var_name}'"
)
return None
# Regular user-defined struct
metadata = structs_sym_tab.get(var_metadata)
if metadata and attr_name in metadata.fields:
gep = metadata.gep(builder, var_ptr, attr_name)
val = builder.load(gep)
field_type = metadata.field_type(attr_name)
@ -525,6 +617,66 @@ def _handle_boolean_op(
return None
# ============================================================================
# VMLinux casting
# ============================================================================
def _handle_vmlinux_cast(
func,
module,
builder,
expr,
local_sym_tab,
map_sym_tab,
structs_sym_tab=None,
):
# handle expressions such as struct_request(ctx.di) where struct_request is a vmlinux
# struct and ctx.di is a pointer to a struct but is actually represented as a c_uint64
# which needs to be cast to a pointer. This is also a field of another vmlinux struct
"""Handle vmlinux struct cast expressions like struct_request(ctx.di)."""
if len(expr.args) != 1:
logger.info("vmlinux struct cast takes exactly one argument")
return None
# Get the struct name
struct_name = expr.func.id
# Evaluate the argument (e.g., ctx.di which is a c_uint64)
arg_result = eval_expr(
func,
module,
builder,
expr.args[0],
local_sym_tab,
map_sym_tab,
structs_sym_tab,
)
if arg_result is None:
logger.info("Failed to evaluate argument to vmlinux struct cast")
return None
arg_val, arg_type = arg_result
# Get the vmlinux struct type
vmlinux_struct_type = VmlinuxHandlerRegistry.get_struct_type(struct_name)
if vmlinux_struct_type is None:
logger.error(f"Failed to get vmlinux struct type for {struct_name}")
return None
# Cast the integer/value to a pointer to the struct
# If arg_val is an integer type, we need to inttoptr it
ptr_type = ir.PointerType()
# TODO: add a integer check here later
if ctypes_to_ir(arg_type.type.__name__):
# Cast integer to pointer
casted_ptr = builder.inttoptr(arg_val, ptr_type)
else:
logger.error(f"Unsupported type for vmlinux cast: {arg_type}")
return None
return casted_ptr, vmlinux_struct_type
# ============================================================================
# Expression Dispatcher
# ============================================================================
@ -545,6 +697,18 @@ def eval_expr(
elif isinstance(expr, ast.Constant):
return _handle_constant_expr(module, builder, expr)
elif isinstance(expr, ast.Call):
if isinstance(expr.func, ast.Name) and VmlinuxHandlerRegistry.is_vmlinux_struct(
expr.func.id
):
return _handle_vmlinux_cast(
func,
module,
builder,
expr,
local_sym_tab,
map_sym_tab,
structs_sym_tab,
)
if isinstance(expr.func, ast.Name) and expr.func.id == "deref":
return _handle_deref_call(expr, local_sym_tab, builder)
@ -568,7 +732,9 @@ def eval_expr(
logger.warning(f"Unknown call: {ast.dump(expr)}")
return None
elif isinstance(expr, ast.Attribute):
return _handle_attribute_expr(expr, local_sym_tab, structs_sym_tab, builder)
return _handle_attribute_expr(
func, expr, local_sym_tab, structs_sym_tab, builder
)
elif isinstance(expr, ast.BinOp):
return _handle_binary_op(
func,

View File

@ -48,3 +48,10 @@ def deref_to_depth(func, builder, val, target_depth):
cur_val = phi
cur_type = pointee_type
return cur_val
def deref_struct_ptr(
func, builder, struct_ptr, struct_metadata, field_name, structs_sym_tab
):
"""Dereference a pointer to a struct type."""
return deref_to_depth(func, builder, struct_ptr, 1)

View File

@ -39,7 +39,7 @@ logger = logging.getLogger(__name__)
def count_temps_in_call(call_node, local_sym_tab):
"""Count the number of temporary variables needed for a function call."""
count = 0
count = {}
is_helper = False
# NOTE: We exclude print calls for now
@ -49,21 +49,28 @@ def count_temps_in_call(call_node, local_sym_tab):
and call_node.func.id != "print"
):
is_helper = True
func_name = call_node.func.id
elif isinstance(call_node.func, ast.Attribute):
if HelperHandlerRegistry.has_handler(call_node.func.attr):
is_helper = True
func_name = call_node.func.attr
if not is_helper:
return 0
return {} # No temps needed
for arg in call_node.args:
for arg_idx in range(len(call_node.args)):
# NOTE: Count all non-name arguments
# For struct fields, if it is being passed as an argument,
# The struct object should already exist in the local_sym_tab
if not isinstance(arg, ast.Name) and not (
arg = call_node.args[arg_idx]
if isinstance(arg, ast.Name) or (
isinstance(arg, ast.Attribute) and arg.value.id in local_sym_tab
):
count += 1
continue
param_type = HelperHandlerRegistry.get_param_type(func_name, arg_idx)
if isinstance(param_type, ir.PointerType):
pointee_type = param_type.pointee
count[pointee_type] = count.get(pointee_type, 0) + 1
return count
@ -99,11 +106,15 @@ def handle_if_allocation(
def allocate_mem(
module, builder, body, func, ret_type, map_sym_tab, local_sym_tab, structs_sym_tab
):
max_temps_needed = 0
max_temps_needed = {}
def merge_type_counts(count_dict):
nonlocal max_temps_needed
for typ, cnt in count_dict.items():
max_temps_needed[typ] = max(max_temps_needed.get(typ, 0), cnt)
def update_max_temps_for_stmt(stmt):
nonlocal max_temps_needed
temps_needed = 0
if isinstance(stmt, ast.If):
for s in stmt.body:
@ -112,10 +123,13 @@ def allocate_mem(
update_max_temps_for_stmt(s)
return
stmt_temps = {}
for node in ast.walk(stmt):
if isinstance(node, ast.Call):
temps_needed += count_temps_in_call(node, local_sym_tab)
max_temps_needed = max(max_temps_needed, temps_needed)
call_temps = count_temps_in_call(node, local_sym_tab)
for typ, cnt in call_temps.items():
stmt_temps[typ] = stmt_temps.get(typ, 0) + cnt
merge_type_counts(stmt_temps)
for stmt in body:
update_max_temps_for_stmt(stmt)
@ -133,7 +147,9 @@ def allocate_mem(
structs_sym_tab,
)
elif isinstance(stmt, ast.Assign):
handle_assign_allocation(builder, stmt, local_sym_tab, structs_sym_tab)
handle_assign_allocation(
builder, stmt, local_sym_tab, map_sym_tab, structs_sym_tab
)
allocate_temp_pool(builder, max_temps_needed, local_sym_tab)

View File

@ -1,7 +1,25 @@
from .helper_registry import HelperHandlerRegistry
from .helper_utils import reset_scratch_pool
from .bpf_helper_handler import handle_helper_call, emit_probe_read_kernel_str_call
from .helpers import ktime, pid, deref, comm, probe_read_str, XDP_DROP, XDP_PASS
from .bpf_helper_handler import (
handle_helper_call,
emit_probe_read_kernel_str_call,
emit_probe_read_kernel_call,
)
from .helpers import (
ktime,
pid,
deref,
comm,
probe_read_str,
random,
probe_read,
smp_processor_id,
uid,
skb_store_bytes,
get_stack,
XDP_DROP,
XDP_PASS,
)
# Register the helper handler with expr module
@ -60,11 +78,18 @@ __all__ = [
"reset_scratch_pool",
"handle_helper_call",
"emit_probe_read_kernel_str_call",
"emit_probe_read_kernel_call",
"ktime",
"pid",
"deref",
"comm",
"probe_read_str",
"random",
"probe_read",
"smp_processor_id",
"uid",
"skb_store_bytes",
"get_stack",
"XDP_DROP",
"XDP_PASS",
]

View File

@ -8,30 +8,44 @@ from .helper_utils import (
get_flags_val,
get_data_ptr_and_size,
get_buffer_ptr_and_size,
get_char_array_ptr_and_size,
get_ptr_from_arg,
get_int_value_from_arg,
)
from .printk_formatter import simple_string_print, handle_fstring_print
from logging import Logger
from pythonbpf.maps import BPFMapType
import logging
logger: Logger = logging.getLogger(__name__)
logger = logging.getLogger(__name__)
class BPFHelperID(Enum):
BPF_MAP_LOOKUP_ELEM = 1
BPF_MAP_UPDATE_ELEM = 2
BPF_MAP_DELETE_ELEM = 3
BPF_PROBE_READ = 4
BPF_KTIME_GET_NS = 5
BPF_PRINTK = 6
BPF_GET_PRANDOM_U32 = 7
BPF_GET_SMP_PROCESSOR_ID = 8
BPF_SKB_STORE_BYTES = 9
BPF_GET_CURRENT_PID_TGID = 14
BPF_GET_CURRENT_UID_GID = 15
BPF_GET_CURRENT_COMM = 16
BPF_PERF_EVENT_OUTPUT = 25
BPF_GET_STACK = 67
BPF_PROBE_READ_KERNEL_STR = 115
BPF_PROBE_READ_KERNEL = 113
BPF_RINGBUF_OUTPUT = 130
BPF_RINGBUF_RESERVE = 131
BPF_RINGBUF_SUBMIT = 132
BPF_RINGBUF_DISCARD = 133
@HelperHandlerRegistry.register("ktime")
@HelperHandlerRegistry.register(
"ktime",
param_types=[],
return_type=ir.IntType(64),
)
def bpf_ktime_get_ns_emitter(
call,
map_ptr,
@ -54,7 +68,11 @@ def bpf_ktime_get_ns_emitter(
return result, ir.IntType(64)
@HelperHandlerRegistry.register("lookup")
@HelperHandlerRegistry.register(
"lookup",
param_types=[ir.PointerType(ir.IntType(64))],
return_type=ir.PointerType(ir.IntType(64)),
)
def bpf_map_lookup_elem_emitter(
call,
map_ptr,
@ -96,6 +114,7 @@ def bpf_map_lookup_elem_emitter(
return result, ir.PointerType()
# NOTE: This has special handling so we won't reflect the signature here.
@HelperHandlerRegistry.register("print")
def bpf_printk_emitter(
call,
@ -144,7 +163,15 @@ def bpf_printk_emitter(
return True
@HelperHandlerRegistry.register("update")
@HelperHandlerRegistry.register(
"update",
param_types=[
ir.PointerType(ir.IntType(64)),
ir.PointerType(ir.IntType(64)),
ir.IntType(64),
],
return_type=ir.PointerType(ir.IntType(64)),
)
def bpf_map_update_elem_emitter(
call,
map_ptr,
@ -199,7 +226,11 @@ def bpf_map_update_elem_emitter(
return result, None
@HelperHandlerRegistry.register("delete")
@HelperHandlerRegistry.register(
"delete",
param_types=[ir.PointerType(ir.IntType(64))],
return_type=ir.PointerType(ir.IntType(64)),
)
def bpf_map_delete_elem_emitter(
call,
map_ptr,
@ -239,7 +270,11 @@ def bpf_map_delete_elem_emitter(
return result, None
@HelperHandlerRegistry.register("comm")
@HelperHandlerRegistry.register(
"comm",
param_types=[ir.PointerType(ir.IntType(8))],
return_type=ir.IntType(64),
)
def bpf_get_current_comm_emitter(
call,
map_ptr,
@ -296,7 +331,11 @@ def bpf_get_current_comm_emitter(
return result, None
@HelperHandlerRegistry.register("pid")
@HelperHandlerRegistry.register(
"pid",
param_types=[],
return_type=ir.IntType(64),
)
def bpf_get_current_pid_tgid_emitter(
call,
map_ptr,
@ -318,12 +357,12 @@ def bpf_get_current_pid_tgid_emitter(
result = builder.call(fn_ptr, [], tail=False)
# Extract the lower 32 bits (PID) using bitwise AND with 0xFFFFFFFF
# TODO: return both PID and TGID if we end up needing TGID somewhere
mask = ir.Constant(ir.IntType(64), 0xFFFFFFFF)
pid = builder.and_(result, mask)
return pid, ir.IntType(64)
@HelperHandlerRegistry.register("output")
def bpf_perf_event_output_handler(
call,
map_ptr,
@ -334,6 +373,10 @@ def bpf_perf_event_output_handler(
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Emit LLVM IR for bpf_perf_event_output helper function call.
"""
if len(call.args) != 1:
raise ValueError(
f"Perf event output expects exactly one argument, got {len(call.args)}"
@ -371,6 +414,98 @@ def bpf_perf_event_output_handler(
return result, None
def bpf_ringbuf_output_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Emit LLVM IR for bpf_ringbuf_output helper function call.
"""
if len(call.args) != 1:
raise ValueError(
f"Ringbuf output expects exactly one argument, got {len(call.args)}"
)
data_arg = call.args[0]
data_ptr, size_val = get_data_ptr_and_size(data_arg, local_sym_tab, struct_sym_tab)
flags_val = ir.Constant(ir.IntType(64), 0)
map_void_ptr = builder.bitcast(map_ptr, ir.PointerType())
data_void_ptr = builder.bitcast(data_ptr, ir.PointerType())
fn_type = ir.FunctionType(
ir.IntType(64),
[
ir.PointerType(),
ir.PointerType(),
ir.IntType(64),
ir.IntType(64),
],
var_arg=False,
)
fn_ptr_type = ir.PointerType(fn_type)
# helper id
fn_addr = ir.Constant(ir.IntType(64), BPFHelperID.BPF_RINGBUF_OUTPUT.value)
fn_ptr = builder.inttoptr(fn_addr, fn_ptr_type)
result = builder.call(
fn_ptr, [map_void_ptr, data_void_ptr, size_val, flags_val], tail=False
)
return result, None
@HelperHandlerRegistry.register(
"output",
param_types=[ir.PointerType(ir.IntType(8))],
return_type=ir.IntType(64),
)
def handle_output_helper(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Route output helper to the appropriate emitter based on map type.
"""
match map_sym_tab[map_ptr.name].type:
case BPFMapType.PERF_EVENT_ARRAY:
return bpf_perf_event_output_handler(
call,
map_ptr,
module,
builder,
func,
local_sym_tab,
struct_sym_tab,
map_sym_tab,
)
case BPFMapType.RINGBUF:
return bpf_ringbuf_output_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab,
struct_sym_tab,
map_sym_tab,
)
case _:
logger.error("Unsupported map type for output helper.")
raise NotImplementedError("Output helper for this map type is not implemented.")
def emit_probe_read_kernel_str_call(builder, dst_ptr, dst_size, src_ptr):
"""Emit LLVM IR call to bpf_probe_read_kernel_str"""
@ -398,7 +533,14 @@ def emit_probe_read_kernel_str_call(builder, dst_ptr, dst_size, src_ptr):
return result
@HelperHandlerRegistry.register("probe_read_str")
@HelperHandlerRegistry.register(
"probe_read_str",
param_types=[
ir.PointerType(ir.IntType(8)),
ir.PointerType(ir.IntType(8)),
],
return_type=ir.IntType(64),
)
def bpf_probe_read_kernel_str_emitter(
call,
map_ptr,
@ -417,8 +559,8 @@ def bpf_probe_read_kernel_str_emitter(
)
# Get destination buffer (char array -> i8*)
dst_ptr, dst_size = get_char_array_ptr_and_size(
call.args[0], builder, local_sym_tab, struct_sym_tab
dst_ptr, dst_size = get_or_create_ptr_from_arg(
func, module, call.args[0], builder, local_sym_tab, map_sym_tab, struct_sym_tab
)
# Get source pointer (evaluate expression)
@ -433,6 +575,499 @@ def bpf_probe_read_kernel_str_emitter(
return result, ir.IntType(64)
def emit_probe_read_kernel_call(builder, dst_ptr, dst_size, src_ptr):
"""Emit LLVM IR call to bpf_probe_read_kernel"""
fn_type = ir.FunctionType(
ir.IntType(64),
[ir.PointerType(), ir.IntType(32), ir.PointerType()],
var_arg=False,
)
fn_ptr = builder.inttoptr(
ir.Constant(ir.IntType(64), BPFHelperID.BPF_PROBE_READ_KERNEL.value),
ir.PointerType(fn_type),
)
result = builder.call(
fn_ptr,
[
builder.bitcast(dst_ptr, ir.PointerType()),
ir.Constant(ir.IntType(32), dst_size),
builder.bitcast(src_ptr, ir.PointerType()),
],
tail=False,
)
logger.info(f"Emitted bpf_probe_read_kernel (size={dst_size})")
return result
@HelperHandlerRegistry.register(
"probe_read_kernel",
param_types=[
ir.PointerType(ir.IntType(8)),
ir.PointerType(ir.IntType(8)),
],
return_type=ir.IntType(64),
)
def bpf_probe_read_kernel_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""Emit LLVM IR for bpf_probe_read_kernel helper."""
if len(call.args) != 2:
raise ValueError(
f"probe_read_kernel expects 2 args (dst, src), got {len(call.args)}"
)
# Get destination buffer (char array -> i8*)
dst_ptr, dst_size = get_or_create_ptr_from_arg(
func, module, call.args[0], builder, local_sym_tab, map_sym_tab, struct_sym_tab
)
# Get source pointer (evaluate expression)
src_ptr, src_type = get_ptr_from_arg(
call.args[1], func, module, builder, local_sym_tab, map_sym_tab, struct_sym_tab
)
# Emit the helper call
result = emit_probe_read_kernel_call(builder, dst_ptr, dst_size, src_ptr)
logger.info(f"Emitted bpf_probe_read_kernel (size={dst_size})")
return result, ir.IntType(64)
@HelperHandlerRegistry.register(
"random",
param_types=[],
return_type=ir.IntType(32),
)
def bpf_get_prandom_u32_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Emit LLVM IR for bpf_get_prandom_u32 helper function call.
"""
helper_id = ir.Constant(ir.IntType(64), BPFHelperID.BPF_GET_PRANDOM_U32.value)
fn_type = ir.FunctionType(ir.IntType(32), [], var_arg=False)
fn_ptr_type = ir.PointerType(fn_type)
fn_ptr = builder.inttoptr(helper_id, fn_ptr_type)
result = builder.call(fn_ptr, [], tail=False)
return result, ir.IntType(32)
@HelperHandlerRegistry.register(
"probe_read",
param_types=[
ir.PointerType(ir.IntType(8)),
ir.IntType(32),
ir.PointerType(ir.IntType(8)),
],
return_type=ir.IntType(64),
)
def bpf_probe_read_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Emit LLVM IR for bpf_probe_read helper function
"""
if len(call.args) != 3:
logger.warn("Expected 3 args for probe_read helper")
return
dst_ptr = get_or_create_ptr_from_arg(
func,
module,
call.args[0],
builder,
local_sym_tab,
map_sym_tab,
struct_sym_tab,
ir.IntType(8),
)
size_val = get_int_value_from_arg(
call.args[1],
func,
module,
builder,
local_sym_tab,
map_sym_tab,
struct_sym_tab,
)
src_ptr = get_or_create_ptr_from_arg(
func,
module,
call.args[2],
builder,
local_sym_tab,
map_sym_tab,
struct_sym_tab,
ir.IntType(8),
)
fn_type = ir.FunctionType(
ir.IntType(64),
[ir.PointerType(), ir.IntType(32), ir.PointerType()],
var_arg=False,
)
fn_ptr = builder.inttoptr(
ir.Constant(ir.IntType(64), BPFHelperID.BPF_PROBE_READ.value),
ir.PointerType(fn_type),
)
result = builder.call(
fn_ptr,
[
builder.bitcast(dst_ptr, ir.PointerType()),
builder.trunc(size_val, ir.IntType(32)),
builder.bitcast(src_ptr, ir.PointerType()),
],
tail=False,
)
logger.info(f"Emitted bpf_probe_read (size={size_val})")
return result, ir.IntType(64)
@HelperHandlerRegistry.register(
"smp_processor_id",
param_types=[],
return_type=ir.IntType(32),
)
def bpf_get_smp_processor_id_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Emit LLVM IR for bpf_get_smp_processor_id helper function call.
"""
helper_id = ir.Constant(ir.IntType(64), BPFHelperID.BPF_GET_SMP_PROCESSOR_ID.value)
fn_type = ir.FunctionType(ir.IntType(32), [], var_arg=False)
fn_ptr_type = ir.PointerType(fn_type)
fn_ptr = builder.inttoptr(helper_id, fn_ptr_type)
result = builder.call(fn_ptr, [], tail=False)
logger.info("Emitted bpf_get_smp_processor_id call")
return result, ir.IntType(32)
@HelperHandlerRegistry.register(
"uid",
param_types=[],
return_type=ir.IntType(64),
)
def bpf_get_current_uid_gid_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Emit LLVM IR for bpf_get_current_uid_gid helper function call.
"""
helper_id = ir.Constant(ir.IntType(64), BPFHelperID.BPF_GET_CURRENT_UID_GID.value)
fn_type = ir.FunctionType(ir.IntType(64), [], var_arg=False)
fn_ptr_type = ir.PointerType(fn_type)
fn_ptr = builder.inttoptr(helper_id, fn_ptr_type)
result = builder.call(fn_ptr, [], tail=False)
# Extract the lower 32 bits (UID) using bitwise AND with 0xFFFFFFFF
# TODO: return both UID and GID if we end up needing GID somewhere
mask = ir.Constant(ir.IntType(64), 0xFFFFFFFF)
pid = builder.and_(result, mask)
return pid, ir.IntType(64)
@HelperHandlerRegistry.register(
"skb_store_bytes",
param_types=[
ir.IntType(32),
ir.PointerType(ir.IntType(8)),
ir.IntType(32),
ir.IntType(64),
],
return_type=ir.IntType(64),
)
def bpf_skb_store_bytes_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Emit LLVM IR for bpf_skb_store_bytes helper function call.
Expected call signature: skb_store_bytes(skb, offset, from, len, flags)
"""
args_signature = [
ir.PointerType(), # skb pointer
ir.IntType(32), # offset
ir.PointerType(), # from
ir.IntType(32), # len
ir.IntType(64), # flags
]
if len(call.args) not in (3, 4):
raise ValueError(
f"skb_store_bytes expects 3 or 4 args (offset, from, len, flags), got {len(call.args)}"
)
skb_ptr = func.args[0] # First argument to the function is skb
offset_val = get_int_value_from_arg(
call.args[0],
func,
module,
builder,
local_sym_tab,
map_sym_tab,
struct_sym_tab,
)
from_ptr = get_or_create_ptr_from_arg(
func,
module,
call.args[1],
builder,
local_sym_tab,
map_sym_tab,
struct_sym_tab,
args_signature[2],
)
len_val = get_int_value_from_arg(
call.args[2],
func,
module,
builder,
local_sym_tab,
map_sym_tab,
struct_sym_tab,
)
if len(call.args) == 4:
flags_val = get_flags_val(call.args[3], builder, local_sym_tab)
else:
flags_val = 0
if isinstance(flags_val, int):
flags = ir.Constant(ir.IntType(64), flags_val)
else:
flags = flags_val
fn_type = ir.FunctionType(
ir.IntType(64),
args_signature,
var_arg=False,
)
fn_ptr = builder.inttoptr(
ir.Constant(ir.IntType(64), BPFHelperID.BPF_SKB_STORE_BYTES.value),
ir.PointerType(fn_type),
)
result = builder.call(
fn_ptr,
[
builder.bitcast(skb_ptr, ir.PointerType()),
builder.trunc(offset_val, ir.IntType(32)),
builder.bitcast(from_ptr, ir.PointerType()),
builder.trunc(len_val, ir.IntType(32)),
flags,
],
tail=False,
)
logger.info("Emitted bpf_skb_store_bytes call")
return result, ir.IntType(64)
@HelperHandlerRegistry.register(
"reserve",
param_types=[ir.IntType(64)],
return_type=ir.PointerType(ir.IntType(8)),
)
def bpf_ringbuf_reserve_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Emit LLVM IR for bpf_ringbuf_reserve helper function call.
Expected call signature: ringbuf.reserve(size)
"""
if len(call.args) != 1:
raise ValueError(
f"ringbuf.reserve expects exactly one argument (size), got {len(call.args)}"
)
size_val = get_int_value_from_arg(
call.args[0],
func,
module,
builder,
local_sym_tab,
map_sym_tab,
struct_sym_tab,
)
map_void_ptr = builder.bitcast(map_ptr, ir.PointerType())
fn_type = ir.FunctionType(
ir.PointerType(ir.IntType(8)),
[ir.PointerType(), ir.IntType(64)],
var_arg=False,
)
fn_ptr_type = ir.PointerType(fn_type)
fn_addr = ir.Constant(ir.IntType(64), BPFHelperID.BPF_RINGBUF_RESERVE.value)
fn_ptr = builder.inttoptr(fn_addr, fn_ptr_type)
result = builder.call(fn_ptr, [map_void_ptr, size_val], tail=False)
return result, ir.PointerType(ir.IntType(8))
@HelperHandlerRegistry.register(
"submit",
param_types=[ir.PointerType(ir.IntType(8)), ir.IntType(64)],
return_type=ir.VoidType(),
)
def bpf_ringbuf_submit_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Emit LLVM IR for bpf_ringbuf_submit helper function call.
Expected call signature: ringbuf.submit(data, flags=0)
"""
if len(call.args) not in (1, 2):
raise ValueError(
f"ringbuf.submit expects 1 or 2 args (data, flags), got {len(call.args)}"
)
data_arg = call.args[0]
flags_arg = call.args[1] if len(call.args) == 2 else None
data_ptr = get_or_create_ptr_from_arg(
func,
module,
data_arg,
builder,
local_sym_tab,
map_sym_tab,
struct_sym_tab,
ir.PointerType(ir.IntType(8)),
)
flags_const = get_flags_val(flags_arg, builder, local_sym_tab)
if isinstance(flags_const, int):
flags_const = ir.Constant(ir.IntType(64), flags_const)
map_void_ptr = builder.bitcast(map_ptr, ir.PointerType())
fn_type = ir.FunctionType(
ir.VoidType(),
[ir.PointerType(), ir.PointerType(), ir.IntType(64)],
var_arg=False,
)
fn_ptr_type = ir.PointerType(fn_type)
fn_addr = ir.Constant(ir.IntType(64), BPFHelperID.BPF_RINGBUF_SUBMIT.value)
fn_ptr = builder.inttoptr(fn_addr, fn_ptr_type)
result = builder.call(fn_ptr, [map_void_ptr, data_ptr, flags_const], tail=False)
return result, None
@HelperHandlerRegistry.register(
"get_stack",
param_types=[ir.PointerType(ir.IntType(8)), ir.IntType(64)],
return_type=ir.IntType(64),
)
def bpf_get_stack_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Emit LLVM IR for bpf_get_stack helper function call.
"""
if len(call.args) not in (1, 2):
raise ValueError(
f"get_stack expects atmost two arguments (buf, flags), got {len(call.args)}"
)
ctx_ptr = func.args[0] # First argument to the function is ctx
buf_arg = call.args[0]
flags_arg = call.args[1] if len(call.args) == 2 else None
buf_ptr, buf_size = get_buffer_ptr_and_size(
buf_arg, builder, local_sym_tab, struct_sym_tab
)
flags_val = get_flags_val(flags_arg, builder, local_sym_tab)
if isinstance(flags_val, int):
flags_val = ir.Constant(ir.IntType(64), flags_val)
buf_void_ptr = builder.bitcast(buf_ptr, ir.PointerType())
fn_type = ir.FunctionType(
ir.IntType(64),
[
ir.PointerType(ir.IntType(8)),
ir.PointerType(),
ir.IntType(64),
ir.IntType(64),
],
var_arg=False,
)
fn_ptr_type = ir.PointerType(fn_type)
fn_addr = ir.Constant(ir.IntType(64), BPFHelperID.BPF_GET_STACK.value)
fn_ptr = builder.inttoptr(fn_addr, fn_ptr_type)
result = builder.call(
fn_ptr,
[ctx_ptr, buf_void_ptr, ir.Constant(ir.IntType(64), buf_size), flags_val],
tail=False,
)
return result, ir.IntType(64)
def handle_helper_call(
call,
module,
@ -487,6 +1122,6 @@ def handle_helper_call(
if not map_sym_tab or map_name not in map_sym_tab:
raise ValueError(f"Map '{map_name}' not found in symbol table")
return invoke_helper(method_name, map_sym_tab[map_name])
return invoke_helper(method_name, map_sym_tab[map_name].sym)
return None

View File

@ -1,17 +1,31 @@
from dataclasses import dataclass
from llvmlite import ir
from typing import Callable
@dataclass
class HelperSignature:
"""Signature of a BPF helper function"""
arg_types: list[ir.Type]
return_type: ir.Type
func: Callable
class HelperHandlerRegistry:
"""Registry for BPF helpers"""
_handlers: dict[str, Callable] = {}
_handlers: dict[str, HelperSignature] = {}
@classmethod
def register(cls, helper_name):
def register(cls, helper_name, param_types=None, return_type=None):
"""Decorator to register a handler function for a helper"""
def decorator(func):
cls._handlers[helper_name] = func
helper_sig = HelperSignature(
arg_types=param_types, return_type=return_type, func=func
)
cls._handlers[helper_name] = helper_sig
return func
return decorator
@ -19,9 +33,29 @@ class HelperHandlerRegistry:
@classmethod
def get_handler(cls, helper_name):
"""Get the handler function for a helper"""
return cls._handlers.get(helper_name)
handler = cls._handlers.get(helper_name)
return handler.func if handler else None
@classmethod
def has_handler(cls, helper_name):
"""Check if a handler function is registered for a helper"""
return helper_name in cls._handlers
@classmethod
def get_signature(cls, helper_name):
"""Get the signature of a helper function"""
return cls._handlers.get(helper_name)
@classmethod
def get_param_type(cls, helper_name, index):
"""Get the type of a parameter of a helper function by the index"""
signature = cls.get_signature(helper_name)
if signature and signature.arg_types and 0 <= index < len(signature.arg_types):
return signature.arg_types[index]
return None
@classmethod
def get_return_type(cls, helper_name):
"""Get the return type of a helper function"""
signature = cls.get_signature(helper_name)
return signature.return_type if signature else None

View File

@ -14,26 +14,43 @@ class ScratchPoolManager:
"""Manage the temporary helper variables in local_sym_tab"""
def __init__(self):
self._counter = 0
self._counters = {}
@property
def counter(self):
return self._counter
return sum(self._counters.values())
def reset(self):
self._counter = 0
self._counters.clear()
logger.debug("Scratch pool counter reset to 0")
def get_next_temp(self, local_sym_tab):
temp_name = f"__helper_temp_{self._counter}"
self._counter += 1
def _get_type_name(self, ir_type):
if isinstance(ir_type, ir.PointerType):
return "ptr"
elif isinstance(ir_type, ir.IntType):
return f"i{ir_type.width}"
elif isinstance(ir_type, ir.ArrayType):
return f"[{ir_type.count}x{self._get_type_name(ir_type.element)}]"
else:
return str(ir_type).replace(" ", "")
def get_next_temp(self, local_sym_tab, expected_type=None):
# Default to i64 if no expected type provided
type_name = self._get_type_name(expected_type) if expected_type else "i64"
if type_name not in self._counters:
self._counters[type_name] = 0
counter = self._counters[type_name]
temp_name = f"__helper_temp_{type_name}_{counter}"
self._counters[type_name] += 1
if temp_name not in local_sym_tab:
raise ValueError(
f"Scratch pool exhausted or inadequate: {temp_name}. "
f"Current counter: {self._counter}"
f"Type: {type_name} Counter: {counter}"
)
logger.debug(f"Using {temp_name} for type {type_name}")
return local_sym_tab[temp_name].var, temp_name
@ -60,24 +77,73 @@ def get_var_ptr_from_name(var_name, local_sym_tab):
def create_int_constant_ptr(value, builder, local_sym_tab, int_width=64):
"""Create a pointer to an integer constant."""
# Default to 64-bit integer
ptr, temp_name = _temp_pool_manager.get_next_temp(local_sym_tab)
int_type = ir.IntType(int_width)
ptr, temp_name = _temp_pool_manager.get_next_temp(local_sym_tab, int_type)
logger.info(f"Using temp variable '{temp_name}' for int constant {value}")
const_val = ir.Constant(ir.IntType(int_width), value)
const_val = ir.Constant(int_type, value)
builder.store(const_val, ptr)
return ptr
def get_or_create_ptr_from_arg(
func, module, arg, builder, local_sym_tab, map_sym_tab, struct_sym_tab=None
func,
module,
arg,
builder,
local_sym_tab,
map_sym_tab,
struct_sym_tab=None,
expected_type=None,
):
"""Extract or create pointer from the call arguments."""
logger.info(f"Getting pointer from arg: {ast.dump(arg)}")
sz = None
if isinstance(arg, ast.Name):
# Stack space is already allocated
ptr = get_var_ptr_from_name(arg.id, local_sym_tab)
elif isinstance(arg, ast.Constant) and isinstance(arg.value, int):
ptr = create_int_constant_ptr(arg.value, builder, local_sym_tab)
int_width = 64 # Default to i64
if expected_type and isinstance(expected_type, ir.IntType):
int_width = expected_type.width
ptr = create_int_constant_ptr(arg.value, builder, local_sym_tab, int_width)
elif isinstance(arg, ast.Attribute):
# A struct field
struct_name = arg.value.id
field_name = arg.attr
if not local_sym_tab or struct_name not in local_sym_tab:
raise ValueError(f"Struct '{struct_name}' not found")
struct_type = local_sym_tab[struct_name].metadata
if not struct_sym_tab or struct_type not in struct_sym_tab:
raise ValueError(f"Struct type '{struct_type}' not found")
struct_info = struct_sym_tab[struct_type]
if field_name not in struct_info.fields:
raise ValueError(
f"Field '{field_name}' not found in struct '{struct_name}'"
)
field_type = struct_info.field_type(field_name)
struct_ptr = local_sym_tab[struct_name].var
# Special handling for char arrays
if (
isinstance(field_type, ir.ArrayType)
and isinstance(field_type.element, ir.IntType)
and field_type.element.width == 8
):
ptr, sz = get_char_array_ptr_and_size(
arg, builder, local_sym_tab, struct_sym_tab
)
if not ptr:
raise ValueError("Failed to get char array pointer from struct field")
else:
ptr = struct_info.gep(builder, struct_ptr, field_name)
else:
# NOTE: For any integer expression reaching this branch, it is probably a struct field or a binop
# Evaluate the expression and store the result in a temp variable
val = get_operand_value(
func, module, arg, builder, local_sym_tab, map_sym_tab, struct_sym_tab
@ -85,13 +151,20 @@ def get_or_create_ptr_from_arg(
if val is None:
raise ValueError("Failed to evaluate expression for helper arg.")
# NOTE: We assume the result is an int64 for now
# if isinstance(arg, ast.Attribute):
# return val
ptr, temp_name = _temp_pool_manager.get_next_temp(local_sym_tab)
ptr, temp_name = _temp_pool_manager.get_next_temp(local_sym_tab, expected_type)
logger.info(f"Using temp variable '{temp_name}' for expression result")
if (
isinstance(val.type, ir.IntType)
and expected_type
and val.type.width > expected_type.width
):
val = builder.trunc(val, expected_type)
builder.store(val, ptr)
# NOTE: For char arrays, also return size
if sz:
return ptr, sz
return ptr
@ -214,7 +287,10 @@ def get_char_array_ptr_and_size(buf_arg, builder, local_sym_tab, struct_sym_tab)
field_type = struct_info.field_type(field_name)
if not _is_char_array(field_type):
raise ValueError("Expected char array field")
logger.info(
"Field is not a char array, falling back to int or ptr detection"
)
return None, 0
struct_ptr = local_sym_tab[var_name].var
field_ptr = struct_info.gep(builder, struct_ptr, field_name)
@ -274,3 +350,23 @@ def get_ptr_from_arg(
raise ValueError(f"Expected pointer type, got {val_type}")
return val, val_type
def get_int_value_from_arg(
arg, func, module, builder, local_sym_tab, map_sym_tab, struct_sym_tab
):
"""Evaluate argument and return integer value"""
result = eval_expr(
func, module, builder, arg, local_sym_tab, map_sym_tab, struct_sym_tab
)
if not result:
raise ValueError("Failed to evaluate argument")
val, val_type = result
if not isinstance(val_type, ir.IntType):
raise ValueError(f"Expected integer type, got {val_type}")
return val

View File

@ -27,6 +27,36 @@ def probe_read_str(dst, src):
return ctypes.c_int64(0)
def random():
"""get a pseudorandom u32 number"""
return ctypes.c_int32(0)
def probe_read(dst, size, src):
"""Safely read data from kernel memory"""
return ctypes.c_int64(0)
def smp_processor_id():
"""get the current CPU id"""
return ctypes.c_int32(0)
def uid():
"""get current user id"""
return ctypes.c_int32(0)
def skb_store_bytes(offset, from_buf, size, flags=0):
"""store bytes into a socket buffer"""
return ctypes.c_int64(0)
def get_stack(buf, flags=0):
"""get the current stack trace"""
return ctypes.c_int64(0)
XDP_ABORTED = ctypes.c_int64(0)
XDP_DROP = ctypes.c_int64(1)
XDP_PASS = ctypes.c_int64(2)

View File

@ -4,6 +4,7 @@ import logging
from llvmlite import ir
from pythonbpf.expr import eval_expr, get_base_type_and_depth, deref_to_depth
from pythonbpf.expr.vmlinux_registry import VmlinuxHandlerRegistry
from pythonbpf.helper.helper_utils import get_char_array_ptr_and_size
logger = logging.getLogger(__name__)
@ -219,11 +220,12 @@ def _prepare_expr_args(expr, func, module, builder, local_sym_tab, struct_sym_ta
"""Evaluate and prepare an expression to use as an arg for bpf_printk."""
# Special case: struct field char array needs pointer to first element
char_array_ptr = _get_struct_char_array_ptr(
expr, builder, local_sym_tab, struct_sym_tab
)
if char_array_ptr:
return char_array_ptr
if isinstance(expr, ast.Attribute):
char_array_ptr, _ = get_char_array_ptr_and_size(
expr, builder, local_sym_tab, struct_sym_tab
)
if char_array_ptr:
return char_array_ptr
# Regular expression evaluation
val, _ = eval_expr(func, module, builder, expr, local_sym_tab, None, struct_sym_tab)
@ -242,52 +244,6 @@ def _prepare_expr_args(expr, func, module, builder, local_sym_tab, struct_sym_ta
return ir.Constant(ir.IntType(64), 0)
def _get_struct_char_array_ptr(expr, builder, local_sym_tab, struct_sym_tab):
"""Get pointer to first element of char array in struct field, or None."""
if not (isinstance(expr, ast.Attribute) and isinstance(expr.value, ast.Name)):
return None
var_name = expr.value.id
field_name = expr.attr
# Check if it's a valid struct field
if not (
local_sym_tab
and var_name in local_sym_tab
and struct_sym_tab
and local_sym_tab[var_name].metadata in struct_sym_tab
):
return None
struct_type = local_sym_tab[var_name].metadata
struct_info = struct_sym_tab[struct_type]
if field_name not in struct_info.fields:
return None
field_type = struct_info.field_type(field_name)
# Check if it's a char array
is_char_array = (
isinstance(field_type, ir.ArrayType)
and isinstance(field_type.element, ir.IntType)
and field_type.element.width == 8
)
if not is_char_array:
return None
# Get field pointer and GEP to first element: [N x i8]* -> i8*
struct_ptr = local_sym_tab[var_name].var
field_ptr = struct_info.gep(builder, struct_ptr, field_name)
return builder.gep(
field_ptr,
[ir.Constant(ir.IntType(32), 0), ir.Constant(ir.IntType(32), 0)],
inbounds=True,
)
def _handle_pointer_arg(val, func, builder):
"""Convert pointer type for bpf_printk."""
target, depth = get_base_type_and_depth(val.type)

View File

@ -1,4 +1,5 @@
from .maps import HashMap, PerfEventArray, RingBuf
from .maps import HashMap, PerfEventArray, RingBuffer
from .maps_pass import maps_proc
from .map_types import BPFMapType
__all__ = ["HashMap", "PerfEventArray", "maps_proc", "RingBuf"]
__all__ = ["HashMap", "PerfEventArray", "maps_proc", "RingBuffer", "BPFMapType"]

View File

@ -1,22 +1,31 @@
import logging
from llvmlite import ir
from pythonbpf.debuginfo import DebugInfoGenerator
from .map_types import BPFMapType
logger: logging.Logger = logging.getLogger(__name__)
def create_map_debug_info(module, map_global, map_name, map_params):
def create_map_debug_info(module, map_global, map_name, map_params, structs_sym_tab):
"""Generate debug info metadata for BPF maps HASH and PERF_EVENT_ARRAY"""
generator = DebugInfoGenerator(module)
logger.info(f"Creating debug info for map {map_name} with params {map_params}")
uint_type = generator.get_uint32_type()
ulong_type = generator.get_uint64_type()
array_type = generator.create_array_type(
uint_type, map_params.get("type", BPFMapType.UNSPEC).value
)
type_ptr = generator.create_pointer_type(array_type, 64)
key_ptr = generator.create_pointer_type(
array_type if "key_size" in map_params else ulong_type, 64
array_type
if "key_size" in map_params
else _get_key_val_dbg_type(map_params.get("key"), generator, structs_sym_tab),
64,
)
value_ptr = generator.create_pointer_type(
array_type if "value_size" in map_params else ulong_type, 64
array_type
if "value_size" in map_params
else _get_key_val_dbg_type(map_params.get("value"), generator, structs_sym_tab),
64,
)
elements_arr = []
@ -64,7 +73,13 @@ def create_map_debug_info(module, map_global, map_name, map_params):
return global_var
def create_ringbuf_debug_info(module, map_global, map_name, map_params):
# TODO: This should not be exposed outside of the module.
# Ideally we should expose a single create_map_debug_info function that handles all map types.
# We can probably use a registry pattern to register different map types and their debug info generators.
# map_params["type"] will be used to determine which generator to use.
def create_ringbuf_debug_info(
module, map_global, map_name, map_params, structs_sym_tab
):
"""Generate debug information metadata for BPF RINGBUF map"""
generator = DebugInfoGenerator(module)
@ -91,3 +106,66 @@ def create_ringbuf_debug_info(module, map_global, map_name, map_params):
)
map_global.set_metadata("dbg", global_var)
return global_var
def _get_key_val_dbg_type(name, generator, structs_sym_tab):
"""Get the debug type for key/value based on type object"""
if not name:
logger.warn("No name provided for key/value type, defaulting to uint64")
return generator.get_uint64_type()
type_obj = structs_sym_tab.get(name)
if type_obj:
logger.info(f"Found struct named {name}, generating debug type")
return _get_struct_debug_type(type_obj, generator, structs_sym_tab)
# Fallback to basic types
logger.info(f"No struct named {name}, falling back to basic type")
# NOTE: Only handling int and long for now
if name in ["c_int32", "c_uint32"]:
return generator.get_uint32_type()
# Default fallback for now
return generator.get_uint64_type()
def _get_struct_debug_type(struct_obj, generator, structs_sym_tab):
"""Recursively create debug type for struct"""
elements_arr = []
for fld in struct_obj.fields.keys():
fld_type = struct_obj.field_type(fld)
if isinstance(fld_type, ir.IntType):
if fld_type.width == 32:
fld_dbg_type = generator.get_uint32_type()
else:
# NOTE: Assuming 64-bit for all other int types
fld_dbg_type = generator.get_uint64_type()
elif isinstance(fld_type, ir.ArrayType):
# NOTE: Array types have u8 elements only for now
# Debug info generation should fail for other types
elem_type = fld_type.element
if isinstance(elem_type, ir.IntType) and elem_type.width == 8:
char_type = generator.get_uint8_type()
fld_dbg_type = generator.create_array_type(char_type, fld_type.count)
else:
logger.warning(
f"Array element type {str(elem_type)} not supported for debug info, skipping"
)
continue
else:
# NOTE: Only handling int and char arrays for now
logger.warning(
f"Field type {str(fld_type)} not supported for debug info, skipping"
)
continue
member = generator.create_struct_member(
fld, fld_dbg_type, struct_obj.field_size(fld)
)
elements_arr.append(member)
struct_type = generator.create_struct_type(
elements_arr, struct_obj.size * 8, is_distinct=True
)
return struct_type

View File

@ -36,11 +36,14 @@ class PerfEventArray:
pass # Placeholder for output method
class RingBuf:
class RingBuffer:
def __init__(self, max_entries):
self.max_entries = max_entries
def reserve(self, size: int, flags=0):
def output(self, data, flags=0):
pass
def reserve(self, size: int):
if size > self.max_entries:
raise ValueError("size cannot be greater than set maximum entries")
return 0
@ -48,4 +51,7 @@ class RingBuf:
def submit(self, data, flags=0):
pass
def discard(self, data, flags=0):
pass
# add discard, output and also give names to flags and stuff

View File

@ -3,7 +3,7 @@ import logging
from logging import Logger
from llvmlite import ir
from .maps_utils import MapProcessorRegistry
from .maps_utils import MapProcessorRegistry, MapSymbol
from .map_types import BPFMapType
from .map_debug_info import create_map_debug_info, create_ringbuf_debug_info
from pythonbpf.expr.vmlinux_registry import VmlinuxHandlerRegistry
@ -12,13 +12,15 @@ from pythonbpf.expr.vmlinux_registry import VmlinuxHandlerRegistry
logger: Logger = logging.getLogger(__name__)
def maps_proc(tree, module, chunks):
def maps_proc(tree, module, chunks, structs_sym_tab):
"""Process all functions decorated with @map to find BPF maps"""
map_sym_tab = {}
for func_node in chunks:
if is_map(func_node):
logger.info(f"Found BPF map: {func_node.name}")
map_sym_tab[func_node.name] = process_bpf_map(func_node, module)
map_sym_tab[func_node.name] = process_bpf_map(
func_node, module, structs_sym_tab
)
return map_sym_tab
@ -46,7 +48,7 @@ def create_bpf_map(module, map_name, map_params):
map_global.align = 8
logger.info(f"Created BPF map: {map_name} with params {map_params}")
return map_global
return MapSymbol(type=map_params["type"], sym=map_global, params=map_params)
def _parse_map_params(rval, expected_args=None):
@ -60,7 +62,8 @@ def _parse_map_params(rval, expected_args=None):
if i < len(rval.args):
arg = rval.args[i]
if isinstance(arg, ast.Name):
params[arg_name] = arg.id
result = _get_vmlinux_enum(handler, arg.id)
params[arg_name] = result if result is not None else arg.id
elif isinstance(arg, ast.Constant):
params[arg_name] = arg.value
@ -68,33 +71,48 @@ def _parse_map_params(rval, expected_args=None):
for keyword in rval.keywords:
if isinstance(keyword.value, ast.Name):
name = keyword.value.id
if handler and handler.is_vmlinux_enum(name):
result = handler.get_vmlinux_enum_value(name)
params[keyword.arg] = result if result is not None else name
else:
params[keyword.arg] = name
result = _get_vmlinux_enum(handler, name)
params[keyword.arg] = result if result is not None else name
elif isinstance(keyword.value, ast.Constant):
params[keyword.arg] = keyword.value.value
return params
@MapProcessorRegistry.register("RingBuf")
def process_ringbuf_map(map_name, rval, module):
def _get_vmlinux_enum(handler, name):
if handler and handler.is_vmlinux_enum(name):
return handler.get_vmlinux_enum_value(name)
@MapProcessorRegistry.register("RingBuffer")
def process_ringbuf_map(map_name, rval, module, structs_sym_tab):
"""Process a BPF_RINGBUF map declaration"""
logger.info(f"Processing Ringbuf: {map_name}")
map_params = _parse_map_params(rval, expected_args=["max_entries"])
map_params["type"] = BPFMapType.RINGBUF
# NOTE: constraints borrowed from https://docs.ebpf.io/linux/map-type/BPF_MAP_TYPE_RINGBUF/
max_entries = map_params.get("max_entries")
if (
not isinstance(max_entries, int)
or max_entries < 4096
or (max_entries & (max_entries - 1)) != 0
):
raise ValueError(
"Ringbuf max_entries must be a power of two greater than or equal to the page size (4096)"
)
logger.info(f"Ringbuf map parameters: {map_params}")
map_global = create_bpf_map(module, map_name, map_params)
create_ringbuf_debug_info(module, map_global, map_name, map_params)
create_ringbuf_debug_info(
module, map_global.sym, map_name, map_params, structs_sym_tab
)
return map_global
@MapProcessorRegistry.register("HashMap")
def process_hash_map(map_name, rval, module):
def process_hash_map(map_name, rval, module, structs_sym_tab):
"""Process a BPF_HASH map declaration"""
logger.info(f"Processing HashMap: {map_name}")
map_params = _parse_map_params(rval, expected_args=["key", "value", "max_entries"])
@ -103,12 +121,12 @@ def process_hash_map(map_name, rval, module):
logger.info(f"Map parameters: {map_params}")
map_global = create_bpf_map(module, map_name, map_params)
# Generate debug info for BTF
create_map_debug_info(module, map_global, map_name, map_params)
create_map_debug_info(module, map_global.sym, map_name, map_params, structs_sym_tab)
return map_global
@MapProcessorRegistry.register("PerfEventArray")
def process_perf_event_map(map_name, rval, module):
def process_perf_event_map(map_name, rval, module, structs_sym_tab):
"""Process a BPF_PERF_EVENT_ARRAY map declaration"""
logger.info(f"Processing PerfEventArray: {map_name}")
map_params = _parse_map_params(rval, expected_args=["key_size", "value_size"])
@ -117,11 +135,11 @@ def process_perf_event_map(map_name, rval, module):
logger.info(f"Map parameters: {map_params}")
map_global = create_bpf_map(module, map_name, map_params)
# Generate debug info for BTF
create_map_debug_info(module, map_global, map_name, map_params)
create_map_debug_info(module, map_global.sym, map_name, map_params)
return map_global
def process_bpf_map(func_node, module):
def process_bpf_map(func_node, module, structs_sym_tab):
"""Process a BPF map (a function decorated with @map)"""
map_name = func_node.name
logger.info(f"Processing BPF map: {map_name}")
@ -140,7 +158,7 @@ def process_bpf_map(func_node, module):
if isinstance(rval, ast.Call) and isinstance(rval.func, ast.Name):
handler = MapProcessorRegistry.get_processor(rval.func.id)
if handler:
return handler(map_name, rval, module)
return handler(map_name, rval, module, structs_sym_tab)
else:
logger.warning(f"Unknown map type {rval.func.id}, defaulting to HashMap")
return process_hash_map(map_name, rval, module)

View File

@ -1,5 +1,17 @@
from collections.abc import Callable
from dataclasses import dataclass
from llvmlite import ir
from typing import Any
from .map_types import BPFMapType
@dataclass
class MapSymbol:
"""Class representing a symbol on the map"""
type: BPFMapType
sym: ir.GlobalVariable
params: dict[str, Any] | None = None
class MapProcessorRegistry:

View File

@ -16,6 +16,33 @@ def get_module_symbols(module_name: str):
return [name for name in dir(imported_module)], imported_module
def unwrap_pointer_type(type_obj: Any) -> Any:
"""
Recursively unwrap all pointer layers to get the base type.
This handles multiply nested pointers like LP_LP_struct_attribute_group
and returns the base type (struct_attribute_group).
Stops unwrapping when reaching a non-pointer type (one without _type_ attribute).
Args:
type_obj: The type object to unwrap
Returns:
The base type after unwrapping all pointer layers
"""
current_type = type_obj
# Keep unwrapping while it's a pointer/array type (has _type_)
# But stop if _type_ is just a string or basic type marker
while hasattr(current_type, "_type_"):
next_type = current_type._type_
# Stop if _type_ is a string (like 'c' for c_char)
if isinstance(next_type, str):
break
current_type = next_type
return current_type
def process_vmlinux_class(
node,
llvm_module,
@ -158,13 +185,90 @@ def process_vmlinux_post_ast(
if hasattr(elem_type, "_length_") and is_complex_type:
type_length = elem_type._length_
if containing_type.__module__ == "vmlinux":
new_dep_node.add_dependent(
elem_type._type_.__name__
if hasattr(elem_type._type_, "__name__")
else str(elem_type._type_)
# Unwrap all pointer layers to get the base type for dependency tracking
base_type = unwrap_pointer_type(elem_type)
base_type_module = getattr(base_type, "__module__", None)
if base_type_module == "vmlinux":
base_type_name = (
base_type.__name__
if hasattr(base_type, "__name__")
else str(base_type)
)
# ONLY add vmlinux types as dependencies
new_dep_node.add_dependent(base_type_name)
logger.debug(
f"{containing_type} containing type of parent {elem_name} with {elem_type} and ctype {ctype_complex_type} and length {type_length}"
)
new_dep_node.set_field_containing_type(
elem_name, containing_type
)
new_dep_node.set_field_type_size(elem_name, type_length)
new_dep_node.set_field_ctype_complex_type(
elem_name, ctype_complex_type
)
new_dep_node.set_field_type(elem_name, elem_type)
# Check the containing_type module to decide whether to recurse
containing_type_module = getattr(
containing_type, "__module__", None
)
if containing_type_module == "vmlinux":
# Also unwrap containing_type to get base type name
base_containing_type = unwrap_pointer_type(
containing_type
)
containing_type_name = (
base_containing_type.__name__
if hasattr(base_containing_type, "__name__")
else str(base_containing_type)
)
# Check for self-reference or already processed
if containing_type_name == current_symbol_name:
# Self-referential pointer
logger.debug(
f"Self-referential pointer in {current_symbol_name}.{elem_name}"
)
new_dep_node.set_field_ready(elem_name, True)
elif handler.has_node(containing_type_name):
# Already processed
logger.debug(
f"Reusing already processed {containing_type_name}"
)
new_dep_node.set_field_ready(elem_name, True)
else:
# Process recursively - use base containing type, not the pointer wrapper
new_dep_node.add_dependent(containing_type_name)
process_vmlinux_post_ast(
base_containing_type,
llvm_handler,
handler,
processing_stack,
)
new_dep_node.set_field_ready(elem_name, True)
elif (
containing_type_module == ctypes.__name__
or containing_type_module is None
):
logger.debug(
f"Processing ctype internal{containing_type}"
)
new_dep_node.set_field_ready(elem_name, True)
else:
raise TypeError(
f"Module not supported in recursive resolution: {containing_type_module}"
)
elif (
base_type_module == ctypes.__name__
or base_type_module is None
):
# Handle ctypes or types with no module (like some internal ctypes types)
# DO NOT add ctypes as dependencies - just set field metadata and mark ready
logger.debug(
f"Base type {base_type} is ctypes - NOT adding as dependency, just processing field"
)
elif containing_type.__module__ == ctypes.__name__:
if isinstance(elem_type, type):
if issubclass(elem_type, ctypes.Array):
ctype_complex_type = ctypes.Array
@ -176,57 +280,20 @@ def process_vmlinux_post_ast(
)
else:
raise TypeError("Unsupported ctypes subclass")
else:
raise ImportError(
f"Unsupported module of {containing_type}"
)
logger.debug(
f"{containing_type} containing type of parent {elem_name} with {elem_type} and ctype {ctype_complex_type} and length {type_length}"
)
new_dep_node.set_field_containing_type(
elem_name, containing_type
)
new_dep_node.set_field_type_size(elem_name, type_length)
new_dep_node.set_field_ctype_complex_type(
elem_name, ctype_complex_type
)
new_dep_node.set_field_type(elem_name, elem_type)
if containing_type.__module__ == "vmlinux":
containing_type_name = (
containing_type.__name__
if hasattr(containing_type, "__name__")
else str(containing_type)
)
# Check for self-reference or already processed
if containing_type_name == current_symbol_name:
# Self-referential pointer
logger.debug(
f"Self-referential pointer in {current_symbol_name}.{elem_name}"
)
new_dep_node.set_field_ready(elem_name, True)
elif handler.has_node(containing_type_name):
# Already processed
logger.debug(
f"Reusing already processed {containing_type_name}"
)
new_dep_node.set_field_ready(elem_name, True)
else:
# Process recursively - THIS WAS MISSING
new_dep_node.add_dependent(containing_type_name)
process_vmlinux_post_ast(
containing_type,
llvm_handler,
handler,
processing_stack,
)
new_dep_node.set_field_ready(elem_name, True)
elif containing_type.__module__ == ctypes.__name__:
logger.debug(f"Processing ctype internal{containing_type}")
# Set field metadata but DO NOT add dependency or recurse
new_dep_node.set_field_containing_type(
elem_name, containing_type
)
new_dep_node.set_field_type_size(elem_name, type_length)
new_dep_node.set_field_ctype_complex_type(
elem_name, ctype_complex_type
)
new_dep_node.set_field_type(elem_name, elem_type)
new_dep_node.set_field_ready(elem_name, True)
else:
raise TypeError(
"Module not supported in recursive resolution"
raise ImportError(
f"Unsupported module of {base_type}: {base_type_module}"
)
else:
new_dep_node.add_dependent(
@ -245,9 +312,12 @@ def process_vmlinux_post_ast(
raise ValueError(
f"{elem_name} with type {elem_type} from module {module_name} not supported in recursive resolver"
)
elif module_name == ctypes.__name__ or module_name is None:
# Handle ctypes types - these don't need processing, just return
logger.debug(f"Skipping ctypes type {current_symbol_name}")
return True
else:
raise ImportError("UNSUPPORTED Module")
raise ImportError(f"UNSUPPORTED Module {module_name}")
logger.info(
f"{current_symbol_name} processed and handler readiness {handler.is_ready}"

View File

@ -11,7 +11,9 @@ from .class_handler import process_vmlinux_class
logger = logging.getLogger(__name__)
def detect_import_statement(tree: ast.AST) -> list[tuple[str, ast.ImportFrom]]:
def detect_import_statement(
tree: ast.AST,
) -> list[tuple[str, ast.ImportFrom, str, str]]:
"""
Parse AST and detect import statements from vmlinux.
@ -25,7 +27,7 @@ def detect_import_statement(tree: ast.AST) -> list[tuple[str, ast.ImportFrom]]:
List of tuples containing (module_name, imported_item) for each vmlinux import
Raises:
SyntaxError: If multiple imports from vmlinux are attempted or import * is used
SyntaxError: If import * is used
"""
vmlinux_imports = []
@ -40,28 +42,19 @@ def detect_import_statement(tree: ast.AST) -> list[tuple[str, ast.ImportFrom]]:
"Please import specific types explicitly."
)
# Check for multiple imports: from vmlinux import A, B, C
if len(node.names) > 1:
imported_names = [alias.name for alias in node.names]
raise SyntaxError(
f"Multiple imports from vmlinux are not supported. "
f"Found: {', '.join(imported_names)}. "
f"Please use separate import statements for each type."
)
# Check if no specific import is specified (should not happen with valid Python)
if len(node.names) == 0:
raise SyntaxError(
"Import from vmlinux must specify at least one type."
)
# Valid single import
# Support multiple imports: from vmlinux import A, B, C
for alias in node.names:
import_name = alias.name
# Use alias if provided, otherwise use the original name (commented)
# as_name = alias.asname if alias.asname else alias.name
vmlinux_imports.append(("vmlinux", node))
logger.info(f"Found vmlinux import: {import_name}")
# Use alias if provided, otherwise use the original name
as_name = alias.asname if alias.asname else alias.name
vmlinux_imports.append(("vmlinux", node, import_name, as_name))
logger.info(f"Found vmlinux import: {import_name} as {as_name}")
# Handle "import vmlinux" statements (not typical but should be rejected)
elif isinstance(node, ast.Import):
@ -103,40 +96,37 @@ def vmlinux_proc(tree: ast.AST, module):
with open(source_file, "r") as f:
mod_ast = ast.parse(f.read(), filename=source_file)
for import_mod, import_node in import_statements:
for alias in import_node.names:
imported_name = alias.name
found = False
for mod_node in mod_ast.body:
if (
isinstance(mod_node, ast.ClassDef)
and mod_node.name == imported_name
):
process_vmlinux_class(mod_node, module, handler)
found = True
break
if isinstance(mod_node, ast.Assign):
for target in mod_node.targets:
if isinstance(target, ast.Name) and target.id == imported_name:
process_vmlinux_assign(mod_node, module, assignments)
found = True
break
if found:
break
if not found:
logger.info(
f"{imported_name} not found as ClassDef or Assign in vmlinux"
)
for import_mod, import_node, imported_name, as_name in import_statements:
found = False
for mod_node in mod_ast.body:
if isinstance(mod_node, ast.ClassDef) and mod_node.name == imported_name:
process_vmlinux_class(mod_node, module, handler)
found = True
break
if isinstance(mod_node, ast.Assign):
for target in mod_node.targets:
if isinstance(target, ast.Name) and target.id == imported_name:
process_vmlinux_assign(mod_node, module, assignments, as_name)
found = True
break
if found:
break
if not found:
logger.info(f"{imported_name} not found as ClassDef or Assign in vmlinux")
IRGenerator(module, handler, assignments)
return assignments
def process_vmlinux_assign(node, module, assignments: dict[str, AssignmentInfo]):
def process_vmlinux_assign(
node, module, assignments: dict[str, AssignmentInfo], target_name=None
):
"""Process assignments from vmlinux module."""
# Only handle single-target assignments
if len(node.targets) == 1 and isinstance(node.targets[0], ast.Name):
target_name = node.targets[0].id
# Use provided target_name (for aliased imports) or fall back to original name
if target_name is None:
target_name = node.targets[0].id
# Handle constant value assignments
if isinstance(node.value, ast.Constant):

View File

@ -21,7 +21,7 @@ def debug_info_generation(
generated_debug_info: List of tuples (struct, debug_info) to track generated debug info
Returns:
The generated global variable debug info
The generated global variable debug info, or None for unsupported types
"""
# Set up debug info generator
generator = DebugInfoGenerator(llvm_module)
@ -31,23 +31,42 @@ def debug_info_generation(
if existing_struct.name == struct.name:
return debug_info
# Check if this is a union (not supported yet)
if not struct.name.startswith("struct_"):
logger.warning(f"Skipping debug info generation for union: {struct.name}")
# Create a minimal forward declaration for unions
union_type = generator.create_struct_type(
[], struct.__sizeof__() * 8, is_distinct=True
)
return union_type
# Process all fields and create members for the struct
members = []
for field_name, field in struct.fields.items():
# Get appropriate debug type for this field
field_type = _get_field_debug_type(
field_name, field, generator, struct, generated_debug_info
)
# Create struct member with proper offset
member = generator.create_struct_member_vmlinux(
field_name, field_type, field.offset * 8
)
members.append(member)
if struct.name.startswith("struct_"):
struct_name = struct.name.removeprefix("struct_")
else:
raise ValueError("Unions are not supported in the current version")
sorted_fields = sorted(struct.fields.items(), key=lambda item: item[1].offset)
for field_name, field in sorted_fields:
try:
# Get appropriate debug type for this field
field_type = _get_field_debug_type(
field_name, field, generator, struct, generated_debug_info
)
# Ensure field_type is a tuple
if not isinstance(field_type, tuple) or len(field_type) != 2:
logger.error(f"Invalid field_type for {field_name}: {field_type}")
continue
# Create struct member with proper offset
member = generator.create_struct_member_vmlinux(
field_name, field_type, field.offset * 8
)
members.append(member)
except Exception as e:
logger.error(f"Failed to process field {field_name} in {struct.name}: {e}")
continue
struct_name = struct.name.removeprefix("struct_")
# Create struct type with all members
struct_type = generator.create_struct_type_with_name(
struct_name, members, struct.__sizeof__() * 8, is_distinct=True
@ -74,11 +93,19 @@ def _get_field_debug_type(
generated_debug_info: List of already generated debug info
Returns:
The debug info type for this field
A tuple of (debug_type, size_in_bits)
"""
# Handle complex types (arrays, pointers)
# Handle complex types (arrays, pointers, function pointers)
if field.ctype_complex_type is not None:
if issubclass(field.ctype_complex_type, ctypes.Array):
# Handle function pointer types (CFUNCTYPE)
if callable(field.ctype_complex_type):
# Function pointers are represented as void pointers
logger.warning(
f"Field {field_name} is a function pointer, using void pointer"
)
void_ptr = generator.create_pointer_type(None, 64)
return void_ptr, 64
elif issubclass(field.ctype_complex_type, ctypes.Array):
# Handle array types
element_type, base_type_size = _get_basic_debug_type(
field.containing_type, generator
@ -100,11 +127,13 @@ def _get_field_debug_type(
for existing_struct, debug_info in generated_debug_info:
if existing_struct.name == struct_name:
# Use existing debug info
return debug_info, existing_struct.__sizeof__()
return debug_info, existing_struct.__sizeof__() * 8
# If not found, create a forward declaration
# This will be completed when the actual struct is processed
logger.warning("Forward declaration in struct created")
logger.info(
f"Forward declaration created for {struct_name} in {parent_struct.name}"
)
forward_type = generator.create_struct_type([], 0, is_distinct=True)
return forward_type, 0

View File

@ -11,6 +11,10 @@ logger = logging.getLogger(__name__)
class IRGenerator:
# This field keeps track of the non_struct names to avoid duplicate name errors.
type_number = 0
unprocessed_store: list[str] = []
# get the assignments dict and add this stuff to it.
def __init__(self, llvm_module, handler: DependencyHandler, assignments):
self.llvm_module = llvm_module
@ -129,7 +133,19 @@ class IRGenerator:
for field_name, field in struct.fields.items():
# does not take arrays and similar types into consideration yet.
if field.ctype_complex_type is not None and issubclass(
if callable(field.ctype_complex_type):
# Function pointer case - generate a simple field accessor
field_co_re_name, returned = self._struct_name_generator(
struct, field, field_index
)
field_index += 1
globvar = ir.GlobalVariable(
self.llvm_module, ir.IntType(64), name=field_co_re_name
)
globvar.linkage = "external"
globvar.set_metadata("llvm.preserve.access.index", debug_info)
self.generated_field_names[struct.name][field_name] = globvar
elif field.ctype_complex_type is not None and issubclass(
field.ctype_complex_type, ctypes.Array
):
array_size = field.type_size
@ -137,7 +153,7 @@ class IRGenerator:
if containing_type.__module__ == ctypes.__name__:
containing_type_size = ctypes.sizeof(containing_type)
if array_size == 0:
field_co_re_name = self._struct_name_generator(
field_co_re_name, returned = self._struct_name_generator(
struct, field, field_index, True, 0, containing_type_size
)
globvar = ir.GlobalVariable(
@ -149,7 +165,7 @@ class IRGenerator:
field_index += 1
continue
for i in range(0, array_size):
field_co_re_name = self._struct_name_generator(
field_co_re_name, returned = self._struct_name_generator(
struct, field, field_index, True, i, containing_type_size
)
globvar = ir.GlobalVariable(
@ -163,12 +179,28 @@ class IRGenerator:
array_size = field.type_size
containing_type = field.containing_type
if containing_type.__module__ == "vmlinux":
containing_type_size = self.handler[
containing_type.__name__
].current_offset
for i in range(0, array_size):
field_co_re_name = self._struct_name_generator(
struct, field, field_index, True, i, containing_type_size
# Unwrap all pointer layers to get the base struct type
base_containing_type = containing_type
while hasattr(base_containing_type, "_type_"):
next_type = base_containing_type._type_
# Stop if _type_ is a string (like 'c' for c_char)
# TODO: stacked pointers not handl;ing ctypes check here as well
if isinstance(next_type, str):
break
base_containing_type = next_type
# Get the base struct name
base_struct_name = (
base_containing_type.__name__
if hasattr(base_containing_type, "__name__")
else str(base_containing_type)
)
# Look up the size using the base struct name
containing_type_size = self.handler[base_struct_name].current_offset
if array_size == 0:
field_co_re_name, returned = self._struct_name_generator(
struct, field, field_index, True, 0, containing_type_size
)
globvar = ir.GlobalVariable(
self.llvm_module, ir.IntType(64), name=field_co_re_name
@ -176,9 +208,30 @@ class IRGenerator:
globvar.linkage = "external"
globvar.set_metadata("llvm.preserve.access.index", debug_info)
self.generated_field_names[struct.name][field_name] = globvar
field_index += 1
field_index += 1
else:
for i in range(0, array_size):
field_co_re_name, returned = self._struct_name_generator(
struct,
field,
field_index,
True,
i,
containing_type_size,
)
globvar = ir.GlobalVariable(
self.llvm_module, ir.IntType(64), name=field_co_re_name
)
globvar.linkage = "external"
globvar.set_metadata(
"llvm.preserve.access.index", debug_info
)
self.generated_field_names[struct.name][field_name] = (
globvar
)
field_index += 1
else:
field_co_re_name = self._struct_name_generator(
field_co_re_name, returned = self._struct_name_generator(
struct, field, field_index
)
field_index += 1
@ -198,7 +251,7 @@ class IRGenerator:
is_indexed: bool = False,
index: int = 0,
containing_type_size: int = 0,
) -> str:
) -> tuple[str, bool]:
# TODO: Does not support Unions as well as recursive pointer and array type naming
if is_indexed:
name = (
@ -208,7 +261,7 @@ class IRGenerator:
+ "$"
+ f"0:{field_index}:{index}"
)
return name
return name, True
elif struct.name.startswith("struct_"):
name = (
"llvm."
@ -217,9 +270,18 @@ class IRGenerator:
+ "$"
+ f"0:{field_index}"
)
return name
return name, True
else:
print(self.handler[struct.name])
raise TypeError(
"Name generation cannot occur due to type name not starting with struct"
logger.warning(
"Blindly handling non-struct type to avoid type errors in vmlinux IR generation. Possibly a union."
)
self.type_number += 1
unprocessed_type = "unprocessed_type_" + str(self.handler[struct.name].name)
if self.unprocessed_store.__contains__(unprocessed_type):
return unprocessed_type + "_" + str(self.type_number), False
else:
self.unprocessed_store.append(unprocessed_type)
return unprocessed_type, False
# raise TypeError(
# "Name generation cannot occur due to type name not starting with struct"
# )

View File

@ -94,17 +94,140 @@ class VmlinuxHandler:
f"Attempting to access field {field_name} of possible vmlinux struct {struct_var_name}"
)
python_type: type = var_info.metadata
struct_name = python_type.__name__
globvar_ir, field_data = self.get_field_type(struct_name, field_name)
builder.function.args[0].type = ir.PointerType(ir.IntType(8))
field_ptr = self.load_ctx_field(
builder, builder.function.args[0], globvar_ir, field_data, struct_name
)
# Return pointer to field and field type
return field_ptr, field_data
# Check if this is a context field (ctx) or a cast struct
is_context_field = var_info.var is None
if is_context_field:
# Handle context field access (original behavior)
struct_name = python_type.__name__
globvar_ir, field_data = self.get_field_type(struct_name, field_name)
builder.function.args[0].type = ir.PointerType(ir.IntType(8))
field_ptr = self.load_ctx_field(
builder,
builder.function.args[0],
globvar_ir,
field_data,
struct_name,
)
return field_ptr, field_data
else:
# Handle cast struct field access
struct_name = python_type.__name__
globvar_ir, field_data = self.get_field_type(struct_name, field_name)
# Handle cast struct field access (use bpf_probe_read_kernel)
# Load the struct pointer from the local variable
struct_ptr = builder.load(var_info.var)
# Use bpf_probe_read_kernel for non-context struct field access
field_value = self.load_struct_field(
builder, struct_ptr, globvar_ir, field_data, struct_name
)
# Return field value and field type
return field_value, field_data
else:
raise RuntimeError("Variable accessed not found in symbol table")
@staticmethod
def load_struct_field(
builder, struct_ptr_int, offset_global, field_data, struct_name=None
):
"""
Generate LLVM IR to load a field from a regular (non-context) struct using bpf_probe_read_kernel.
Args:
builder: llvmlite IRBuilder instance
struct_ptr_int: The struct pointer as an i64 value (already loaded from alloca)
offset_global: Global variable containing the field offset (i64)
field_data: contains data about the field
struct_name: Name of the struct being accessed (optional)
Returns:
The loaded value
"""
# Load the offset value
offset = builder.load(offset_global)
# Convert i64 to pointer type (BPF stores pointers as i64)
i8_ptr_type = ir.PointerType(ir.IntType(8))
struct_ptr = builder.inttoptr(struct_ptr_int, i8_ptr_type)
# GEP with offset to get field pointer
field_ptr = builder.gep(
struct_ptr,
[offset],
inbounds=False,
)
# Determine the appropriate field size based on field information
field_size_bytes = 8 # Default to 8 bytes (64-bit)
int_width = 64 # Default to 64-bit
needs_zext = False
if field_data is not None:
# Try to determine the size from field metadata
if field_data.type.__module__ == ctypes.__name__:
try:
field_size_bytes = ctypes.sizeof(field_data.type)
field_size_bits = field_size_bytes * 8
if field_size_bits in [8, 16, 32, 64]:
int_width = field_size_bits
logger.info(
f"Determined field size: {int_width} bits ({field_size_bytes} bytes)"
)
# Special handling for struct_xdp_md i32 fields
if struct_name == "struct_xdp_md" and int_width == 32:
needs_zext = True
logger.info(
"struct_xdp_md i32 field detected, will zero-extend to i64"
)
else:
logger.warning(
f"Unusual field size {field_size_bits} bits, using default 64"
)
except Exception as e:
logger.warning(
f"Could not determine field size: {e}, using default 64"
)
elif field_data.type.__module__ == "vmlinux":
# For pointers to structs or complex vmlinux types
if field_data.ctype_complex_type is not None and issubclass(
field_data.ctype_complex_type, ctypes._Pointer
):
int_width = 64 # Pointers are always 64-bit
field_size_bytes = 8
logger.info("Field is a pointer type, using 64 bits")
else:
logger.warning("Complex vmlinux field type, using default 64 bits")
# Allocate local storage for the field value
local_storage = builder.alloca(ir.IntType(int_width))
local_storage_i8_ptr = builder.bitcast(local_storage, i8_ptr_type)
# Use bpf_probe_read_kernel to safely read the field
# This generates:
# %gep = getelementptr i8, ptr %struct_ptr, i64 %offset (already done above as field_ptr)
# %passed = tail call ptr @llvm.bpf.passthrough.p0.p0(i32 2, ptr %gep)
# %result = call i64 inttoptr (i64 113 to ptr)(ptr %local_storage, i32 %size, ptr %passed)
from pythonbpf.helper import emit_probe_read_kernel_call
emit_probe_read_kernel_call(
builder, local_storage_i8_ptr, field_size_bytes, field_ptr
)
# Load the value from local storage
value = builder.load(local_storage)
# Zero-extend i32 to i64 if needed
if needs_zext:
value = builder.zext(value, ir.IntType(64))
logger.info("Zero-extended i32 value to i64")
return value
@staticmethod
def load_ctx_field(builder, ctx_arg, offset_global, field_data, struct_name=None):
"""

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@ -3,21 +3,20 @@ CFLAGS := -emit-llvm -target bpf -c
SRC := $(wildcard *.bpf.c)
LL := $(SRC:.bpf.c=.bpf.ll)
LL2 := $(SRC:.bpf.c=.bpf.o2.ll)
OBJ := $(SRC:.bpf.c=.bpf.o)
LL0 := $(SRC:.bpf.c=.bpf.o0.ll)
.PHONY: all clean
all: $(LL) $(OBJ) $(LL2)
all: $(LL) $(OBJ) $(LL0)
%.bpf.o: %.bpf.c
$(BPF_CLANG) -O2 -g -target bpf -c $< -o $@
%.bpf.ll: %.bpf.c
$(BPF_CLANG) -O0 $(CFLAGS) -g -S $< -o $@
$(BPF_CLANG) $(CFLAGS) -O2 -g -S $< -o $@
%.bpf.o2.ll: %.bpf.c
$(BPF_CLANG) -O2 $(CFLAGS) -g -S $< -o $@
%.bpf.o0.ll: %.bpf.c
$(BPF_CLANG) $(CFLAGS) -O0 -g -S $< -o $@
clean:
rm -f $(LL) $(OBJ) $(LL2)
rm -f $(LL) $(OBJ) $(LL0)

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@ -0,0 +1,18 @@
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_core_read.h>
char LICENSE[] SEC("license") = "GPL";
SEC("kprobe/blk_mq_start_request")
int example(struct pt_regs *ctx)
{
u64 a = ctx->r15;
struct request *req = (struct request *)(ctx->di);
unsigned int something_ns = BPF_CORE_READ(req, timeout);
unsigned int data_len = BPF_CORE_READ(req, __data_len);
bpf_printk("data length %lld %ld %ld\n", data_len, something_ns, a);
return 0;
}

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@ -0,0 +1,18 @@
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_core_read.h>
char LICENSE[] SEC("license") = "GPL";
SEC("kprobe/blk_mq_start_request")
int example(struct pt_regs *ctx)
{
u64 a = ctx->r15;
struct request *req = (struct request *)(ctx->di);
unsigned int something_ns = req->timeout;
unsigned int data_len = req->__data_len;
bpf_printk("data length %lld %ld %ld\n", data_len, something_ns, a);
return 0;
}

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@ -0,0 +1,22 @@
from vmlinux import XDP_PASS
from pythonbpf import bpf, section, bpfglobal, compile_to_ir
import logging
from ctypes import c_int64, c_void_p
@bpf
@section("kprobe/blk_mq_start_request")
def example(ctx: c_void_p) -> c_int64:
d = XDP_PASS # This gives an error, but
e = XDP_PASS + 0 # this does not
print(f"test1 {e} test2 {d}")
return c_int64(0)
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile_to_ir("assignment_handling.py", "assignment_handling.ll", loglevel=logging.INFO)

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@ -0,0 +1,42 @@
from pythonbpf import bpf, section, struct, bpfglobal, compile, map
from pythonbpf.maps import HashMap
from pythonbpf.helper import pid
from ctypes import c_void_p, c_int64
@bpf
@struct
class val_type:
counter: c_int64
shizzle: c_int64
@bpf
@map
def last() -> HashMap:
return HashMap(key=val_type, value=c_int64, max_entries=16)
@bpf
@section("tracepoint/syscalls/sys_enter_clone")
def hello_world(ctx: c_void_p) -> c_int64:
obj = val_type()
obj.counter, obj.shizzle = 42, 96
t = last.lookup(obj)
if t:
print(f"Found existing entry: counter={obj.counter}, pid={t}")
last.delete(obj)
return 0 # type: ignore [return-value]
val = pid()
last.update(obj, val)
print(f"Map updated!, {obj.counter}, {obj.shizzle}, {val}")
return 0 # type: ignore [return-value]
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile()

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@ -0,0 +1,29 @@
from pythonbpf import bpf, section, bpfglobal, compile, struct
from ctypes import c_void_p, c_int64, c_uint64, c_uint32
from pythonbpf.helper import probe_read
@bpf
@struct
class data_t:
pid: c_uint32
value: c_uint64
@bpf
@section("tracepoint/syscalls/sys_enter_execve")
def test_probe_read(ctx: c_void_p) -> c_int64:
"""Test bpf_probe_read helper function"""
data = data_t()
probe_read(data.value, 8, ctx)
probe_read(data.pid, 4, ctx)
return 0
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile()

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@ -0,0 +1,25 @@
from pythonbpf import bpf, bpfglobal, section, BPF, trace_pipe
from ctypes import c_void_p, c_int64
from pythonbpf.helper import random
@bpf
@section("tracepoint/syscalls/sys_enter_clone")
def hello_world(ctx: c_void_p) -> c_int64:
r = random()
print(f"Hello, World!, {r}")
return 0 # type: ignore [return-value]
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
# Compile and load
b = BPF()
b.load()
b.attach_all()
trace_pipe()

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@ -0,0 +1,40 @@
from pythonbpf import bpf, section, bpfglobal, compile, struct
from ctypes import c_void_p, c_int64, c_uint32, c_uint64
from pythonbpf.helper import smp_processor_id, ktime
@bpf
@struct
class cpu_event_t:
cpu_id: c_uint32
timestamp: c_uint64
@bpf
@section("tracepoint/syscalls/sys_enter_execve")
def trace_with_cpu(ctx: c_void_p) -> c_int64:
"""Test bpf_get_smp_processor_id helper function"""
# Get the current CPU ID
cpu = smp_processor_id()
# Print it
print(f"Running on CPU {cpu}")
# Use it in a struct
event = cpu_event_t()
event.cpu_id = smp_processor_id()
event.timestamp = ktime()
print(f"Event on CPU {event.cpu_id} at time {event.timestamp}")
return 0
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile()

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@ -0,0 +1,31 @@
from pythonbpf import bpf, section, bpfglobal, compile
from ctypes import c_void_p, c_int64
from pythonbpf.helper import uid, pid
@bpf
@section("tracepoint/syscalls/sys_enter_execve")
def filter_by_user(ctx: c_void_p) -> c_int64:
"""Filter events by specific user ID"""
current_uid = uid()
# Only trace root user (UID 0)
if current_uid == 0:
process_id = pid()
print(f"Root process {process_id} executed")
# Or trace specific user (e.g., UID 1000)
if current_uid == 1002:
print("User 1002 executed something")
return 0
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile()

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@ -0,0 +1,27 @@
from vmlinux import struct_request, struct_pt_regs
from pythonbpf import bpf, section, bpfglobal, compile_to_ir, compile
import logging
from ctypes import c_int64
@bpf
@section("kprobe/blk_mq_start_request")
def example(ctx: struct_pt_regs) -> c_int64:
a = ctx.r15
req = struct_request(ctx.di)
d = req.__data_len
b = ctx.r12
c = req.timeout
print(f"data length {d} and {c} and {a}")
print(f"ctx arg {b}")
return c_int64(0)
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile_to_ir("requests.py", "requests.ll", loglevel=logging.INFO)
compile()

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@ -0,0 +1,21 @@
from vmlinux import struct_pt_regs
from pythonbpf import bpf, section, bpfglobal, compile_to_ir
import logging
from ctypes import c_int64
@bpf
@section("kprobe/blk_mq_start_request")
def example(ctx: struct_pt_regs) -> c_int64:
req = ctx.di
print(f"data length {req}")
return c_int64(0)
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile_to_ir("requests2.py", "requests2.ll", loglevel=logging.INFO)