dwarf-assembly/shared_python.py

116 lines
3.5 KiB
Python

""" Shared snippets between the various python scripts of this project """
import subprocess
import re
import os
from collections import namedtuple
def is_newer(file1, file2):
''' Returns True iff file1 is newer than file2 '''
try:
f1_mtime = os.path.getmtime(file1)
f2_mtime = os.path.getmtime(file2)
if f1_mtime > f2_mtime:
return True
except OSError:
pass
return False
def elf_so_deps(path):
''' Get the list of shared objects dependencies of the given ELF object.
This is obtained by running `ldd`. '''
deps_list = []
try:
ldd_output = subprocess.check_output(['/usr/bin/ldd', path]) \
.decode('utf-8')
ldd_re = re.compile(r'^.* => (.*) \(0x[0-9a-fA-F]*\)$')
ldd_lines = ldd_output.strip().split('\n')
for line in ldd_lines:
line = line.strip()
match = ldd_re.match(line)
if match is None:
continue # Just ignore that line — it might be eg. linux-vdso
deps_list.append(match.group(1))
return deps_list
except subprocess.CalledProcessError as exn:
raise Exception(
("Cannot get dependencies for {}: ldd terminated with exit code "
"{}.").format(path, exn.returncode))
def do_remote(remote, command, send_files=None, retr_files=None):
''' Execute remotely (via ssh) a given command
The command is executed on the machine described by `remote` (see ssh(1)).
send_files is a list of file paths that must be first copied at the root of
a temporary directory on `remote` before running the command. Consider
yourself jailed in that directory.
retr_files is a list of files that will be copied to the local machine
after the command is executed. Each list item can either be a string, which
is both the path on the remote and the local machine; or a pair
`(file_name, local_path)`. In the latter case, `file_name` is copied as
`local_path/file_name` if `local_path` is a directory, or as `local_path`
otherwise, on the local machine.
'''
def ssh_do(cmd_args, working_directory=None):
try:
cmd = ['ssh', remote]
if working_directory:
cmd += ['cd', working_directory, '&&']
cmd += cmd_args
return subprocess.check_output(cmd).decode('utf-8').strip()
except subprocess.CalledProcessError as e:
return None
def ssh_copy(what, where, is_upload):
if is_upload:
where = '{}:{}'.format(remote, where)
else:
what = '{}:{}'.format(remote, what)
subprocess.check_output(['scp', what, where])
TransferredFile = namedtuple('TransferredFile', 'local remote')
def interpret_transferred_file(descr):
if isinstance(descr, type('')):
return TransferredFile(descr, descr)
if os.path.isdir(descr[1]):
to = os.path.join(descr[1], descr[0])
else:
to = descr[1]
return TransferredFile(descr[0], to)
# Create temp dir
tmp_dir = ssh_do(['mktemp', '-d'])
# Upload `send_files`
for f in send_files:
dest = tmp_dir+'/'
ssh_copy(f, dest, is_upload=True)
# Do whatever must be done
output = ssh_do(command, working_directory=tmp_dir)
# Download `retr_files`
for f in map(interpret_transferred_file, retr_files):
src = os.path.join(tmp_dir, f.local)
ssh_copy(src, f.remote, is_upload=False)
# Remove temp dir
ssh_do(['rm', '-rf', tmp_dir])
return output