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https://github.com/varun-r-mallya/Python-BPF.git
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65 lines
2.2 KiB
Python
65 lines
2.2 KiB
Python
import ast
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from llvmlite import ir
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def bpf_ktime_get_ns_emitter(call, module, builder, func):
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pass
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def bpf_map_lookup_elem_emitter(map_ptr, key_ptr, module, builder):
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"""
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Emit LLVM IR for bpf_map_lookup_elem helper function call.
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"""
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# Cast pointers to void*
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map_void_ptr = builder.bitcast(map_ptr, ir.PointerType())
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# Define function type for bpf_map_lookup_elem
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# The function takes two void* arguments and returns void*
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fn_type = ir.FunctionType(
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ir.PointerType(), # Return type: void*
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[ir.PointerType(), ir.PointerType()], # Args: (void*, void*)
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var_arg=False
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)
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fn_ptr_type = ir.PointerType(fn_type)
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# Helper ID 1 is bpf_map_lookup_elem
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fn_addr = ir.Constant(ir.IntType(64), 1)
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fn_ptr = builder.inttoptr(fn_addr, fn_ptr_type)
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# Call the helper function
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result = builder.call(fn_ptr, [map_void_ptr, key_ptr], tail=False)
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return result
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def bpf_printk_emitter(call, module, builder, func):
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if not hasattr(func, "_fmt_counter"):
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func._fmt_counter = 0
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for arg in call.args:
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if isinstance(arg, ast.Constant) and isinstance(arg.value, str):
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fmt_str = arg.value + "\n" + "\0"
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fmt_name = f"{func.name}____fmt{func._fmt_counter}"
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func._fmt_counter += 1
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fmt_gvar = ir.GlobalVariable(
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module, ir.ArrayType(ir.IntType(8), len(fmt_str)), name=fmt_name)
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fmt_gvar.global_constant = True
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fmt_gvar.initializer = ir.Constant( # type: ignore
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ir.ArrayType(ir.IntType(8), len(fmt_str)),
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bytearray(fmt_str.encode("utf8"))
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)
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fmt_gvar.linkage = "internal"
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fmt_gvar.align = 1 # type: ignore
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fmt_ptr = builder.bitcast(fmt_gvar, ir.PointerType())
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fn_type = ir.FunctionType(ir.IntType(
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64), [ir.PointerType(), ir.IntType(32)], var_arg=True)
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fn_ptr_type = ir.PointerType(fn_type)
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fn_addr = ir.Constant(ir.IntType(64), 6)
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fn_ptr = builder.inttoptr(fn_addr, fn_ptr_type)
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builder.call(fn_ptr, [fmt_ptr, ir.Constant(
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ir.IntType(32), len(fmt_str))], tail=True)
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