Current File : //lib/python3/dist-packages/duplicity/backends/xorrisobackend.py
# -*- Mode:Python; indent-tabs-mode:nil; tab-width:4; encoding:utf-8 -*-
#
# Copyright 2002 Ben Escotoben@emerose.org>
# Copyright 2007 Kenneth Loafman <kenneth@loafman.com>
# Copyright 2022 Thomas Kramer <code@tkramer.ch>
#
# This file is part of duplicity.
#
# Duplicity is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2 of the License, or (at your
# option) any later version.
#
# Duplicity is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with duplicity; if not, write to the Free Software Foundation,
# Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
import os
import fcntl
import re
import shlex
import subprocess
import time
from duplicity import util
import duplicity.backend
from duplicity import (
path,
progress,
)
from duplicity.errors import (
FatalBackendException,
BackendException,
InvalidBackendURL,
)
class Xorriso:
"""
Wrapper around a xorriso subprocess.
"""
def __init__(self, device, xorriso_path="xorriso", xorriso_args=None):
self.device = device
# Xorriso process
self.proc = None
# Default arguments for xorriso.
self.xorriso_args = [
"-abort_on",
"FAILURE",
"-return_with",
"SORRY",
"0",
"-osirrox",
"on", # Enable copying from ISO to disk.
"-calm_drive",
"off", # Don't immediately turn off device. Increases access speed for next action.abs
"-joliet",
"on",
]
if xorriso_args is not None:
self.xorriso_args.extend(xorriso_args)
self.__start_subprocess(
[xorriso_path]
+ self.xorriso_args
+ [
"-dev",
self.device,
"-dialog",
"on", # Enable interactive mode
]
)
stdout, stderr = self.__recv_stdout_stderr()
self.__handle_xorriso_error(stderr)
stdout, stderr = self.__send_cmd("-version") # Test connectivity to subprocess.
def __start_subprocess(self, commandline):
def setNonBlocking(fd):
flags = fcntl.fcntl(fd, fcntl.F_GETFL)
flags = flags | os.O_NONBLOCK
fcntl.fcntl(fd, fcntl.F_SETFL, flags)
try:
p = subprocess.Popen(
commandline,
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
)
self.proc = p
except FileNotFoundError as err:
raise FatalBackendException(f"Xorriso binary not found: {self.xorriso_cmd}")
setNonBlocking(self.proc.stdout)
setNonBlocking(self.proc.stderr)
def __send_cmd(self, *args):
# Drain stdout and stderr
while self.proc.stdout.readline():
pass
while self.proc.stderr.readline():
pass
try:
for arg in args:
self.proc.stdin.write(shlex.quote(arg).encode("utf-8"))
self.proc.stdin.write(b" ")
self.proc.stdin.write(b"\n")
self.proc.stdin.flush()
except BrokenPipeError as e:
raise FatalBackendException("BrokenPipe: lost connection to xorriso subprocess")
stdout, stderr = self.__recv_stdout_stderr()
self.__handle_xorriso_error(stderr)
return stdout, stderr
def __recv_stdout_stderr(self):
stdout = []
stderr = []
while True:
if self.proc.poll() is not None:
# Process terminated
break
no_input = True
while True:
line = self.proc.stdout.readline().decode("utf-8").strip()
if line:
stdout.append(line)
else:
no_input = False
break
while True:
line = self.proc.stderr.readline().decode("utf-8").strip()
if line:
stderr.append(line)
else:
no_input = False
break
if stderr and stderr[-1] == "enter option and arguments :":
break
if no_input:
time.sleep(0.1)
return stdout, stderr
def __handle_xorriso_error(self, stderr):
"""
Detect errors from stderr of xorriso.
Convert the errors into exceptions.
"""
lines = stderr
stderr = "\n".join(lines)
is_fatal = "FATAL" in stderr
is_failure = "FAILURE" in stderr
if is_fatal:
msg = "\n".join(l for l in lines if ": FATAL" in l)
raise BackendException(msg)
elif is_failure:
msg = "\n".join(l for l in lines if ": FAILURE" in l)
raise BackendException(stderr)
def ls(self, pattern="."):
"""
List files on optical disc.
"""
files = [f for f, _ in self.lsl(pattern)]
return files
def lsl(self, pattern="."):
"""
List files on optical disc.
"""
stdout, stderr = self.__send_cmd("-lsl", pattern)
# Parse output of `xorriso -lsl`
lines = stdout
files = []
for line in lines:
line = line.strip()
if not line: # Skip empty lines
continue
parts = re.split("\\s+", line, maxsplit=8)
if len(parts) != 9:
continue
mode, _, _uid, _gid, size, _month, _day, _time, filename = parts
if not filename.startswith("'") or not filename.endswith("'"):
raise BackendException("Got unexpected format from xorriso -lsl.")
# Parse size into an integer.
try:
size = int(size)
except Exception as e:
raise BackendException("Could not parse file size.")
filename = filename[1:-1] # strip leading and trailing `'`s
files.append((filename, {"size": size}))
return files
def commit(self):
"""
Commit changes and write them to the image.
"""
stdout, stderr = self.__send_cmd("-commit")
if "exceeds free space on media" in "\n".join(stderr):
raise BackendException("Not enough free space on media.")
def end(self):
"""
Terminate the xorriso subprocess
"""
stdout, stderr = self.__send_cmd("-end")
def cp(self, files, dest):
"""
Copy file to the ISO image. Does not commit the changes yet.
"""
assert isinstance(files, list)
stdout, stderr = self.__send_cmd(
"-cpr",
*files,
dest,
"--",
)
if "exceeds free space on media" in "\n".join(stderr):
raise BackendException("Not enough free space on media.")
def rm(self, files):
"""
Remove a list of files from the image. Does not commit the changes yet.
"""
assert isinstance(files, list)
if not files:
return
stdout, stderr = self.__send_cmd(
"-rm",
*files,
# Don't commit yet.
)
def extract(self, files, dest):
"""
Extract files from the ISO image.
"""
assert isinstance(files, list)
assert not os.path.exists(dest) or os.path.isfile(dest)
if len(files) == 0:
return
stdout, stderr = self.__send_cmd("-cpx", *files, dest)
class XorrisoBackend(duplicity.backend.Backend):
"""Backend for writing to optical discs or ISO images using xorriso.
Simple URLs look like `xorriso:///dev/sr0` if the backup location is at the root of the filesystem.
or if `xorriso://dev/sr0:/path/to/a/directory/on/iso` if the backup location is in a directory.
Especially for testing also an ISO file can be used: xorriso://path/to/image.iso
The path to the `xorriso` executable can be specified with teh `XORRISO_PATH` environment variable.
Environment variables:
* XORRISO_PATH: Alternative path to the `xorriso` executable
* XORRISO_WRITE_SPEED: Specify the speed for writing to the optical disc. One of ["min", "max"].
* XORRISO_ASSERT_VOLID: Abort when the volume ID of the ISO image does not match the given value.
* XORRISO_ARGS: Arbitrary arguments to xorriso, inserted before the filesystem operations. For experts only.
"""
def __init__(self, parsed_url):
duplicity.backend.Backend.__init__(self, parsed_url)
# Path to xorriso executable.
xorriso_cmd = os.environ.get("XORRISO_PATH", default="xorriso")
# Check if xorriso is installed.
if xorriso_cmd == "xorriso":
if not util.which("xorriso"):
raise FatalBackendException("xorriso not installed")
# Default arguments for xorriso.
self.xorriso_args = []
args_pre = os.environ.get("XORRISO_ARGS")
if args_pre is not None:
arg_list = shlex.split(args_pre)
self.xorriso_args.extend(arg_list)
assert_volid = os.environ.get("XORRISO_ASSERT_VOLID")
if assert_volid is not None:
self.xorriso_args += ["-assert_volid", assert_volid, "FAILURE"]
speed = os.environ.get("XORRISO_WRITE_SPEED", default="min")
if speed in ["min", "max"]:
self.xorriso_args += ["-speed", speed]
else:
self.xorriso_args += ["-speed", "min"]
# The URL form "file:MyFile" is not a valid duplicity target.
if not parsed_url.path.startswith("//"):
raise InvalidBackendURl("Bad xorriso:// path syntax.")
path = parsed_url.path[2:] # Strip '//'
parts = path.split(":", maxsplit=1)
if len(parts) == 2:
self.device = parts[0]
self.iso_path = parts[1]
else:
self.device = parts[0]
self.iso_path = "/"
if not self.iso_path.endswith("/"):
self.iso_path += "/"
if not os.path.exists(self.device):
raise InvalidBackendURL(f"Optical disc device does not exist: {self.device}")
# Start xorriso subprocess.
self.xorriso = Xorriso(device=self.device, xorriso_path=xorriso_cmd, xorriso_args=self.xorriso_args)
def _put(self, source_path, remote_filename):
assert not os.path.isdir(source_path.name.decode("utf8"))
source_path.setdata()
source_size = source_path.getsize()
progress.report_transfer(0, source_size)
self.xorriso.cp(
[source_path.name.decode("utf8")],
self.iso_path + remote_filename.decode("utf8"),
)
self.xorriso.commit()
progress.report_transfer(source_size, source_size)
def _get(self, filename, local_path):
self.xorriso.extract([self.iso_path + filename.decode("utf8")], local_path.name.decode("utf8"))
def _list(self):
files = self.xorriso.ls(pattern=self.iso_path)
return [f.encode() for f in files]
def _delete(self, filename):
self.xorriso.rm([self.iso_path + filename.decode("utf8")])
def _delete_list(self, filenames):
filenames = [self.iso_path + f.decode("utf8") for f in filenames]
self.xorriso.rm(filenames)
def _query(self, filename):
filename = self.iso_path + filename.decode("utf8")
files = self.xorriso.lsl(filename)
if len(files) == 0 or files[0][0] != filename:
size = -1
else:
size = files[0][1]["size"]
return {"size": size}
def _close(self):
self.xorriso.commit()
self.xorriso.end()
duplicity.backend.register_backend("xorriso", XorrisoBackend)
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