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#!/usr/bin/env python3
# Copyright (c) Clevernet
# Licensed under the Apache License, Version 2.0 (the "License")
# test program for the 'disassemble_func' and 'decode_table' methods
from bcc import BPF
from bcc import disassembler
import ctypes as ct
import random
from unittest import main, TestCase
class BPFInstr(ct.Structure):
_pack_ = 1
_fields_ = [('opcode', ct.c_uint8),
('dst', ct.c_uint8, 4),
('src', ct.c_uint8, 4),
('offset', ct.c_int16),
('imm', ct.c_int32)]
class TestDisassembler(TestCase):
opcodes = [(0x04, "%dst += %imm"),
(0x05, "goto %off <%jmp>"),
(0x07, "%dst += %imm"),
(0x0c, "%dst += %src"),
(0x0f, "%dst += %src"),
(0x14, "%dst -= %imm"),
(0x15, "if %dst == %imm goto pc%off <%jmp>"),
(0x17, "%dst -= %imm"),
#(0x18, "lddw"),
(0x1c, "%dst -= %src"),
(0x1d, "if %dst == %src goto pc%off <%jmp>"),
(0x1f, "%dst -= %src"),
(0x20, "r0 = *(u32*)skb[%imm]"),
(0x24, "%dst *= %imm"),
(0x25, "if %dst > %imm goto pc%off <%jmp>"),
(0x27, "%dst *= %imm"),
(0x28, "r0 = *(u16*)skb[%imm]"),
(0x2c, "%dst *= %src"),
(0x2d, "if %dst > %src goto pc%off <%jmp>"),
(0x2f, "%dst *= %src"),
(0x30, "r0 = *(u8*)skb[%imm]"),
(0x34, "%dst /= %imm"),
(0x35, "if %dst >= %imm goto pc%off <%jmp>"),
(0x37, "%dst /= %imm"),
(0x38, "r0 = *(u64*)skb[%imm]"),
(0x3c, "%dst /= %src"),
(0x3d, "if %dst >= %src goto pc%off <%jmp>"),
(0x3f, "%dst /= %src"),
(0x40, "r0 = *(u32*)skb[%src %sim]"),
(0x44, "%dst |= %ibw"),
(0x45, "if %dst & %imm goto pc%off <%jmp>"),
(0x47, "%dst |= %ibw"),
(0x48, "r0 = *(u16*)skb[%src %sim]"),
(0x4c, "%dst |= %src"),
(0x4d, "if %dst & %src goto pc%off <%jmp>"),
(0x4f, "%dst |= %src"),
(0x50, "r0 = *(u8*)skb[%src %sim]"),
(0x54, "%dst &= %ibw"),
(0x55, "if %dst != %imm goto pc%off <%jmp>"),
(0x57, "%dst &= %ibw"),
(0x58, "r0 = *(u64*)skb[%src %sim]"),
(0x5c, "%dst &= %src"),
(0x5d, "if %dst != %src goto pc%off <%jmp>"),
(0x5f, "%dst &= %src"),
(0x61, "%dst = *(u32*)(%src %off)"),
(0x62, "*(u32*)(%dst %off) = %imm"),
(0x63, "*(u32*)(%dst %off) = %src"),
(0x64, "%dst <<= %imm"),
(0x65, "if %dst s> %imm goto pc%off <%jmp>"),
(0x67, "%dst <<= %imm"),
(0x69, "%dst = *(u16*)(%src %off)"),
(0x6a, "*(u16*)(%dst %off) = %imm"),
(0x6b, "*(u16*)(%dst %off) = %src"),
(0x6c, "%dst <<= %src"),
(0x6d, "if %dst s> %src goto pc%off <%jmp>"),
(0x6f, "%dst <<= %src"),
(0x71, "%dst = *(u8*)(%src %off)"),
(0x72, "*(u8*)(%dst %off) = %imm"),
(0x73, "*(u8*)(%dst %off) = %src"),
(0x74, "%dst >>= %imm"),
(0x75, "if %dst s>= %imm goto pc%off <%jmp>"),
(0x77, "%dst >>= %imm"),
(0x79, "%dst = *(u64*)(%src %off)"),
(0x7a, "*(u64*)(%dst %off) = %imm"),
(0x7b, "*(u64*)(%dst %off) = %src"),
(0x7c, "%dst >>= %src"),
(0x7d, "if %dst s>= %src goto pc%off <%jmp>"),
(0x7f, "%dst >>= %src"),
(0x84, "%dst = ~ (u32)%dst"),
#(0x85, "call"),
(0x87, "%dst = ~ (u64)%dst"),
(0x94, "%dst %= %imm"),
(0x95, "exit"),
(0x97, "%dst %= %imm"),
(0x9c, "%dst %= %src"),
(0x9f, "%dst %= %src"),
(0xa4, "%dst ^= %ibw"),
(0xa5, "if %dst < %imm goto pc%off <%jmp>"),
(0xa7, "%dst ^= %ibw"),
(0xac, "%dst ^= %src"),
(0xad, "if %dst < %src goto pc%off <%jmp>"),
(0xaf, "%dst ^= %src"),
(0xb4, "%dst = %imm"),
(0xb5, "if %dst <= %imm goto pc%off <%jmp>"),
(0xb7, "%dst = %imm"),
(0xbc, "%dst = %src"),
(0xbd, "if %dst <= %src goto pc%off <%jmp>"),
(0xbf, "%dst = %src"),
(0xc4, "%dst s>>= %imm"),
(0xc5, "if %dst s< %imm goto pc%off <%jmp>"),
(0xc7, "%dst s>>= %imm"),
(0xcc, "%dst s>>= %src"),
(0xcd, "if %dst s< %src goto pc%off <%jmp>"),
(0xcf, "%dst s>>= %src"),
(0xd5, "if %dst s<= %imm goto pc%off <%jmp>"),
(0xdc, "%dst endian %src"),
(0xdd, "if %dst s<= %imm goto pc%off <%jmp>"),]
@classmethod
def build_instr(cls, op):
dst = random.randint(0, 0xf)
src = random.randint(0, 0xf)
offset = random.randint(0, 0xffff)
imm = random.randint(0, 0xffffffff)
return BPFInstr(op, dst, src, offset, imm)
@classmethod
def format_instr(cls, instr, fmt):
uimm = ct.c_uint32(instr.imm).value
return (fmt.replace("%dst", "r%d" % (instr.dst))
.replace("%src", "r%d" % (instr.src))
.replace("%imm", "%d" % (instr.imm))
.replace("%ibw", "0x%x" % (uimm))
.replace("%sim", "%+d" % (instr.imm))
.replace("%off", "%+d" % (instr.offset))
.replace("%jmp", "%d" % (instr.offset + 1)))
def test_func(self):
b = BPF(text=b"""
struct key_t {int a; short b; struct {int c:4; int d:8;} e;} __attribute__((__packed__));
BPF_HASH(test_map, struct key_t);
int test_func(void)
{
return 1;
}""")
self.assertEqual(
"""Disassemble of BPF program b'test_func':
0: (b7) r0 = 1
1: (95) exit""",
b.disassemble_func(b"test_func"))
def _assert_equal_ignore_fd_id(s1, s2):
# In first line of string like
# Layout of BPF map test_map (type HASH, FD 3, ID 0):
# Ignore everything from FD to end-of-line
# Compare rest of string normally
s1_lines = s1.split('\n')
s2_lines = s2.split('\n')
s1_first_cut = s1_lines[0]
s1_first_cut = s1_first_cut[0:s1_first_cut.index("FD")]
s2_first_cut = s2_lines[0]
s2_first_cut = s2_first_cut[0:s2_first_cut.index("FD")]
self.assertEqual(s1_first_cut, s2_first_cut)
s1_rest = '\n'.join(s1_lines[1:])
s2_rest = '\n'.join(s2_lines[1:])
self.assertEqual(s1_rest, s2_rest)
_assert_equal_ignore_fd_id(
"""Layout of BPF map b'test_map' (type HASH, FD 3, ID 0):
struct {
int a;
short b;
struct {
int c:4;
int d:8;
} e;
} key;
unsigned long long value;""",
b.decode_table(b"test_map"))
def test_bpf_isa(self):
for op, instr_fmt in self.opcodes:
instr_fmt
if instr_fmt is None:
continue
instr = self.build_instr(op)
instr_str = ct.string_at(ct.addressof(instr), ct.sizeof(instr))
target_text = self.format_instr(instr, instr_fmt)
self.assertEqual(disassembler.disassemble_str(instr_str)[0],
"%4d: (%02x) %s" % (0, op, target_text))
if __name__ == "__main__":
main()
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