mirror of
https://github.com/varun-r-mallya/Python-BPF.git
synced 2025-12-31 21:06:25 +00:00
270 lines
8.9 KiB
Python
270 lines
8.9 KiB
Python
import ast
|
|
from llvmlite import ir
|
|
from .type_deducer import ctypes_to_ir
|
|
from . import dwarf_constants as dc
|
|
from enum import Enum
|
|
|
|
map_sym_tab = {}
|
|
|
|
|
|
def maps_proc(tree, module, chunks):
|
|
for func_node in chunks:
|
|
if is_map(func_node):
|
|
print(f"Found BPF map: {func_node.name}")
|
|
process_bpf_map(func_node, module)
|
|
continue
|
|
return map_sym_tab
|
|
|
|
|
|
def is_map(func_node):
|
|
return any(
|
|
isinstance(decorator, ast.Name) and decorator.id == "map"
|
|
for decorator in func_node.decorator_list
|
|
)
|
|
|
|
|
|
class BPFMapType(Enum):
|
|
HASH = 1
|
|
PERF_EVENT_ARRAY = 4
|
|
|
|
|
|
BPF_MAP_MAPPINGS = {
|
|
"HASH": 1, # BPF_MAP_TYPE_HASH
|
|
"PERF_EVENT_ARRAY": 4, # BPF_MAP_TYPE_PERF_EVENT_ARRAY
|
|
}
|
|
|
|
|
|
def create_bpf_map(module, map_name, map_params):
|
|
"""Create a BPF map in the module with the given parameters and debug info"""
|
|
|
|
map_type_str = map_params.get("type", "HASH")
|
|
map_type = BPF_MAP_MAPPINGS.get(map_type_str)
|
|
|
|
# Create the anonymous struct type for BPF map
|
|
map_struct_type = ir.LiteralStructType(
|
|
[ir.PointerType() for _ in range(len(map_params))])
|
|
|
|
# Create the global variable
|
|
map_global = ir.GlobalVariable(module, map_struct_type, name=map_name)
|
|
map_global.linkage = 'dso_local'
|
|
map_global.global_constant = False
|
|
map_global.initializer = ir.Constant(
|
|
map_struct_type, None) # type: ignore
|
|
map_global.section = ".maps"
|
|
map_global.align = 8 # type: ignore
|
|
|
|
# Generate debug info for BTF
|
|
create_map_debug_info(module, map_global, map_name, map_params)
|
|
|
|
print(f"Created BPF map: {map_name}")
|
|
map_sym_tab[map_name] = map_global
|
|
return map_global
|
|
|
|
|
|
def create_map_debug_info(module, map_global, map_name, map_params):
|
|
"""Generate debug information metadata for BPF map"""
|
|
file_metadata = module._file_metadata
|
|
compile_unit = module._debug_compile_unit
|
|
|
|
# Create basic type for unsigned int (32-bit)
|
|
uint_type = module.add_debug_info("DIBasicType", {
|
|
"name": "unsigned int",
|
|
"size": 32,
|
|
"encoding": dc.DW_ATE_unsigned
|
|
})
|
|
|
|
# Create basic type for unsigned long long (64-bit)
|
|
ulong_type = module.add_debug_info("DIBasicType", {
|
|
"name": "unsigned long long",
|
|
"size": 64,
|
|
"encoding": dc.DW_ATE_unsigned
|
|
})
|
|
|
|
# Create array type for map type field (array of 1 unsigned int)
|
|
array_subrange = module.add_debug_info(
|
|
"DISubrange", {"count": BPF_MAP_MAPPINGS[map_params.get("type", "HASH")]})
|
|
array_type = module.add_debug_info("DICompositeType", {
|
|
"tag": dc.DW_TAG_array_type,
|
|
"baseType": uint_type,
|
|
"size": 32,
|
|
"elements": [array_subrange]
|
|
})
|
|
|
|
# Create pointer types
|
|
type_ptr = module.add_debug_info("DIDerivedType", {
|
|
"tag": dc.DW_TAG_pointer_type,
|
|
"baseType": array_type,
|
|
"size": 64
|
|
})
|
|
|
|
key_ptr = module.add_debug_info("DIDerivedType", {
|
|
"tag": dc.DW_TAG_pointer_type,
|
|
# Adjust based on actual key type
|
|
"baseType": array_type if "key_size" in map_params else uint_type,
|
|
"size": 64
|
|
})
|
|
|
|
value_ptr = module.add_debug_info("DIDerivedType", {
|
|
"tag": dc.DW_TAG_pointer_type,
|
|
# Adjust based on actual value type
|
|
"baseType": array_type if "value_size" in map_params else ulong_type,
|
|
"size": 64
|
|
})
|
|
|
|
elements_arr = []
|
|
|
|
# Create struct members
|
|
# scope field does not appear for some reason
|
|
cnt = 0
|
|
for elem in map_params:
|
|
if elem == "max_entries":
|
|
continue
|
|
if elem == "type":
|
|
ptr = type_ptr
|
|
elif "key" in elem:
|
|
ptr = key_ptr
|
|
else:
|
|
ptr = value_ptr
|
|
member = module.add_debug_info("DIDerivedType", {
|
|
"tag": dc.DW_TAG_member,
|
|
"name": elem,
|
|
"file": file_metadata,
|
|
"baseType": ptr,
|
|
"size": 64,
|
|
"offset": cnt * 64
|
|
})
|
|
elements_arr.append(member)
|
|
cnt += 1
|
|
|
|
if "max_entries" in map_params:
|
|
array_subrange_max_entries = module.add_debug_info(
|
|
"DISubrange", {"count": map_params["max_entries"]})
|
|
array_type_max_entries = module.add_debug_info("DICompositeType", {
|
|
"tag": dc.DW_TAG_array_type,
|
|
"baseType": uint_type,
|
|
"size": 32,
|
|
"elements": [array_subrange_max_entries]
|
|
})
|
|
max_entries_ptr = module.add_debug_info("DIDerivedType", {
|
|
"tag": dc.DW_TAG_pointer_type,
|
|
"baseType": array_type_max_entries,
|
|
"size": 64
|
|
})
|
|
max_entries_member = module.add_debug_info("DIDerivedType", {
|
|
"tag": dc.DW_TAG_member,
|
|
"name": "max_entries",
|
|
"file": file_metadata,
|
|
"baseType": max_entries_ptr,
|
|
"size": 64,
|
|
"offset": cnt * 64
|
|
})
|
|
elements_arr.append(max_entries_member)
|
|
|
|
# Create the struct type
|
|
struct_type = module.add_debug_info("DICompositeType", {
|
|
"tag": dc.DW_TAG_structure_type,
|
|
"file": file_metadata,
|
|
"size": 64 * len(elements_arr), # 4 * 64-bit pointers
|
|
"elements": elements_arr,
|
|
}, is_distinct=True)
|
|
|
|
# Create global variable debug info
|
|
global_var = module.add_debug_info("DIGlobalVariable", {
|
|
"name": map_name,
|
|
"scope": compile_unit,
|
|
"file": file_metadata,
|
|
"type": struct_type,
|
|
"isLocal": False,
|
|
"isDefinition": True
|
|
}, is_distinct=True)
|
|
|
|
# Create global variable expression
|
|
global_var_expr = module.add_debug_info("DIGlobalVariableExpression", {
|
|
"var": global_var,
|
|
"expr": module.add_debug_info("DIExpression", {})
|
|
})
|
|
|
|
# Attach debug info to the global variable
|
|
map_global.set_metadata("dbg", global_var_expr)
|
|
|
|
return global_var_expr
|
|
|
|
|
|
def process_hash_map(map_name, rval, module):
|
|
print(f"Creating HashMap map: {map_name}")
|
|
map_params: = {"type": BPFMapType.HASH}
|
|
|
|
# Assuming order: key_type, value_type, max_entries
|
|
if len(rval.args) >= 1 and isinstance(rval.args[0], ast.Name):
|
|
map_params["key"] = rval.args[0].id
|
|
if len(rval.args) >= 2 and isinstance(rval.args[1], ast.Name):
|
|
map_params["value"] = rval.args[1].id
|
|
if len(rval.args) >= 3 and isinstance(rval.args[2], ast.Constant):
|
|
const_val = rval.args[2].value
|
|
if isinstance(const_val, (int, str)): # safe check
|
|
map_params["max_entries"] = const_val
|
|
|
|
for keyword in rval.keywords:
|
|
if keyword.arg == "key" and isinstance(keyword.value, ast.Name):
|
|
map_params["key"] = keyword.value.id
|
|
elif keyword.arg == "value" and isinstance(keyword.value, ast.Name):
|
|
map_params["value"] = keyword.value.id
|
|
elif keyword.arg == "max_entries" and isinstance(keyword.value, ast.Constant):
|
|
const_val = keyword.value.value
|
|
if isinstance(const_val, (int, str)):
|
|
map_params["max_entries"] = const_val
|
|
|
|
print(f"Map parameters: {map_params}")
|
|
return create_bpf_map(module, map_name, map_params)
|
|
|
|
|
|
def process_perf_event_map(map_name, rval, module):
|
|
print(f"Creating PerfEventArray map: {map_name}")
|
|
map_params = {"type": BPFMapType.PERF_EVENT_ARRAY}
|
|
|
|
if len(rval.args) >= 1 and isinstance(rval.args[0], ast.Name):
|
|
map_params["key_size"] = rval.args[0].id
|
|
if len(rval.args) >= 2 and isinstance(rval.args[1], ast.Name):
|
|
map_params["value_size"] = rval.args[1].id
|
|
|
|
for keyword in rval.keywords:
|
|
if keyword.arg == "key_size" and isinstance(keyword.value, ast.Name):
|
|
map_params["key_size"] = keyword.value.id
|
|
elif keyword.arg == "value_size" and isinstance(keyword.value, ast.Name):
|
|
map_params["value_size"] = keyword.value.id
|
|
|
|
print(f"Map parameters: {map_params}")
|
|
return create_bpf_map(module, map_name, map_params)
|
|
|
|
|
|
def process_bpf_map(func_node, module):
|
|
"""Process a BPF map (a function decorated with @map)"""
|
|
map_name = func_node.name
|
|
print(f"Processing BPF map: {map_name}")
|
|
|
|
BPF_MAP_TYPES = {"HashMap": process_hash_map, # BPF_MAP_TYPE_HASH
|
|
"PerfEventArray": process_perf_event_map, # BPF_MAP_TYPE_PERF_EVENT_ARRAY
|
|
}
|
|
|
|
# For now, assume single return statement
|
|
return_stmt = None
|
|
for stmt in func_node.body:
|
|
if isinstance(stmt, ast.Return):
|
|
return_stmt = stmt
|
|
break
|
|
if return_stmt is None:
|
|
raise ValueError("BPF map must have a return statement")
|
|
|
|
rval = return_stmt.value
|
|
|
|
# Handle only HashMap maps
|
|
if isinstance(rval, ast.Call) and isinstance(rval.func, ast.Name):
|
|
if rval.func.id in BPF_MAP_TYPES:
|
|
handler = BPF_MAP_TYPES[rval.func.id]
|
|
handler(map_name, rval, module)
|
|
else:
|
|
print(f"Unknown map type {rval.func.id}, defaulting to HashMap")
|
|
process_hash_map(map_name, rval, module)
|
|
else:
|
|
raise ValueError("Function under @map must return a map")
|