import sys
import os
import tempfile
import struct
import re
import elftools.elf.structs
from subprocess import Popen, PIPE
from nose.plugins.skip import Skip, SkipTest
from elftools.construct import Container
from elftools.elf.constants import SH_FLAGS
import testdata
import ubpf.assembler
VM = os.path.join(os.path.dirname(os.path.realpath(__file__)), "..", "vm", "test")
def template():
parts = {}
parts['order'] = []
def add(name, value):
parts[name] = value
parts['order'].append(name)
add('ehdr', Container(
e_ident=Container(
EI_MAG=[0x7f, ord('E'), ord('L'), ord('F')],
EI_CLASS='ELFCLASS64',
EI_DATA='ELFDATA2LSB',
EI_VERSION='EV_CURRENT',
EI_OSABI='ELFOSABI_SYSV',
EI_ABIVERSION=0),
e_type='ET_REL',
e_machine='EM_NONE',
e_version=0,
e_entry=0,
e_phoff=0,
e_shoff=64,
e_flags=0,
e_ehsize=64,
e_phentsize=0,
e_phnum=0,
e_shentsize=64,
e_shnum=5,
e_shstrndx=2))
add('first_shdr', Container(
sh_name=0,
sh_type='SHT_NULL',
sh_flags=0,
sh_addr=0,
sh_offset=0,
sh_size=0,
sh_link=0,
sh_info=0,
sh_addralign=0,
sh_entsize=0))
add('text_shdr', Container(
sh_name=1,
sh_type='SHT_PROGBITS',
sh_flags=SH_FLAGS.SHF_ALLOC|SH_FLAGS.SHF_EXECINSTR,
sh_addr=0,
sh_offset=384,
sh_size=24,
sh_link=0,
sh_info=0,
sh_addralign=8,
sh_entsize=0))
add('strtab_shdr', Container(
sh_name=7,
sh_type='SHT_STRTAB',
sh_flags=0,
sh_addr=0,
sh_offset=408,
sh_size=34,
sh_link=0,
sh_info=0,
sh_addralign=1,
sh_entsize=0))
add('symtab_shdr', Container(
sh_name=15,
sh_type='SHT_SYMTAB',
sh_flags=0,
sh_addr=0,
sh_offset=442,
sh_size=48,
sh_link=2,
sh_info=0,
sh_addralign=8,
sh_entsize=24))
add('rel_shdr', Container(
sh_name=23,
sh_type='SHT_REL',
sh_flags=0,
sh_addr=0,
sh_offset=490,
sh_size=16,
sh_link=3,
sh_info=1,
sh_addralign=8,
sh_entsize=16))
asm = """
mov %r1, 1764
call 0xffffffff
exit
"""
text = ubpf.assembler.assemble(asm)
add("text", text)
add("strtab", b"\0.text\0.strtab\0.symtab\0.rel\0sqrti\0")
add("first_sym", Container(
st_name=0,
st_value=0,
st_size=0,
st_info=Container(bind='STB_WEAK', type='STT_FUNC'),
st_other=Container(local=0, visibility='STV_DEFAULT'),
st_shndx=0))
add("sqrti_sym", Container(
st_name=28,
st_value=0,
st_size=0,
st_info=Container(bind='STB_WEAK', type='STT_FUNC'),
st_other=Container(local=0, visibility='STV_DEFAULT'),
st_shndx=0))
add("sqrti_rel", Container(
r_info=(1 << 32) | 2,
r_info_sym=0,
r_info_type=0,
r_offset=8))
return parts
def serialize(parts):
s = elftools.elf.structs.ELFStructs(elfclass=64)
s.create_basic_structs()
ehdr = parts['ehdr']
s.create_advanced_structs(ehdr['e_type'], ehdr['e_machine'], ehdr['e_ident']['EI_OSABI'])
tmp = []
offset = 0
for name in parts['order']:
part = parts[name]
serializer = lambda x: x
if name == 'ehdr':
serializer = s.Elf_Ehdr.build
elif name.endswith('shdr'):
serializer = s.Elf_Shdr.build
elif name.endswith('rel'):
serializer = s.Elf_Rel.build
elif name.endswith('sym'):
serializer = s.Elf_Sym.build
data = serializer(part)
tmp.append(data)
offset += len(data)
return b''.join(tmp)
def generate_elf(pyelf):
parts = template()
exec(pyelf, parts)
return serialize(parts)
def check_datafile(filename):
data = testdata.read(filename)
if 'pyelf' not in data:
raise SkipTest("no pyelf section in datafile")
if 'result' not in data and 'error' not in data and 'error pattern' not in data:
raise SkipTest("no result or error section in datafile")
if not os.path.exists(VM):
raise SkipTest("VM not found")
elf = generate_elf(data['pyelf'])
cmd = [VM]
cmd.append('-')
vm = Popen(cmd, stdin=PIPE, stdout=PIPE, stderr=PIPE)
stdout, stderr = vm.communicate(elf)
stdout = stdout.decode("utf-8")
stderr = stderr.decode("utf-8")
stderr = stderr.strip()
if 'error' in data:
if data['error'] != stderr:
raise AssertionError("Expected error %r, got %r" % (data['error'], stderr))
elif 'error pattern' in data:
if not re.search(data['error pattern'], stderr):
raise AssertionError("Expected error matching %r, got %r" % (data['error pattern'], stderr))
else:
if stderr:
raise AssertionError("Unexpected error %r" % stderr)
if 'result' in data:
if vm.returncode != 0:
raise AssertionError("VM exited with status %d, stderr=%r" % (vm.returncode, stderr))
expected = int(data['result'], 0)
result = int(stdout, 0)
if expected != result:
raise AssertionError("Expected result 0x%x, got 0x%x, stderr=%r" % (expected, result, stderr))
else:
if vm.returncode == 0:
raise AssertionError("Expected VM to exit with an error code")
def test_datafiles():
for filename in testdata.list_files():
yield check_datafile, filename