Source code for labgrid.driver.shelldriver

# pylint: disable=no-member,missing-kwoa,unused-argument
"""The ShellDriver provides the CommandProtocol, ConsoleProtocol and
 InfoProtocol on top of a SerialPort."""
import io
import logging
import re
import shlex
import ipaddress

import attr
from pexpect import TIMEOUT
import xmodem

from ..factory import target_factory
from ..protocol import CommandProtocol, ConsoleProtocol, FileTransferProtocol
from ..step import step
from ..util import gen_marker, Timeout
from .commandmixin import CommandMixin
from .common import Driver
from .exception import ExecutionError


[docs]@target_factory.reg_driver @attr.s(eq=False) class ShellDriver(CommandMixin, Driver, CommandProtocol, FileTransferProtocol): """ShellDriver - Driver to execute commands on the shell ShellDriver binds on top of a ConsoleProtocol. On activation, the ShellDriver will look for the login prompt on the console, and login to provide shell access. Args: prompt (regex): the shell prompt to detect login_prompt (regex): the login prompt to detect username (str): username to login with password (str): password to login with keyfile (str): keyfile to bind mount over users authorized keys login_timeout (int): optional, timeout for login prompt detection console_ready (regex): optional, pattern used by the kernel to inform the user that a console can be activated by pressing enter. await_login_timeout (int): optional, time in seconds of silence that needs to pass before sending a newline to device. post_login_settle_time (int): optional, seconds of silence after logging in before check for a prompt. Useful when the console is interleaved with boot output which may interrupt prompt detection. """ bindings = {"console": ConsoleProtocol, } prompt = attr.ib(validator=attr.validators.instance_of(str)) login_prompt = attr.ib(validator=attr.validators.instance_of(str)) username = attr.ib(validator=attr.validators.instance_of(str)) password = attr.ib(default="", validator=attr.validators.instance_of(str)) keyfile = attr.ib(default="", validator=attr.validators.instance_of(str)) login_timeout = attr.ib(default=60, validator=attr.validators.instance_of(int)) console_ready = attr.ib(default="", validator=attr.validators.instance_of(str)) await_login_timeout = attr.ib(default=2, validator=attr.validators.instance_of(int)) post_login_settle_time = attr.ib(default=0, validator=attr.validators.instance_of(int))
[docs] def __attrs_post_init__(self): super().__attrs_post_init__() self.re_vt100 = re.compile( r'(\x1b\[|\x9b)[^@-_a-z]*[@-_a-z]|\x1b[@-_a-z]' ) # pylint: disable=attribute-defined-outside-init,anomalous-backslash-in-string self.logger = logging.getLogger(f"{self}:{self.target}") self._status = 0 # pylint: disable=attribute-defined-outside-init self._xmodem_cached_rx_cmd = "" self._xmodem_cached_sx_cmd = ""
[docs] def on_activate(self): if self._status == 0: self._await_login() self._inject_run() if self.keyfile: keyfile_path = self.keyfile if self.target.env: keyfile_path = self.target.env.config.resolve_path(self.keyfile) self._put_ssh_key(keyfile_path)
[docs] def on_deactivate(self): self._status = 0
def _run(self, cmd, *, timeout=30.0, codec="utf-8", decodeerrors="strict"): """ Runs the specified cmd on the shell and returns the output. Arguments: cmd - cmd to run on the shell """ # FIXME: Handle pexpect Timeout self._check_prompt() marker = gen_marker() # hide marker from expect cmp_command = f'''MARKER='{marker[:4]}''{marker[4:]}' run {shlex.quote(cmd)}''' self.console.sendline(cmp_command) _, _, match, _ = self.console.expect( rf'{marker}(.*){marker}\s+(\d+)\s+{self.prompt}', timeout=timeout ) # Remove VT100 Codes, split by newline and remove surrounding newline data = self.re_vt100.sub('', match.group(1).decode(codec, decodeerrors)).split('\r\n') if data and not data[-1]: del data[-1] self.logger.debug("Received Data: %s", data) # Get exit code exitcode = int(match.group(2)) return (data, [], exitcode)
[docs] @Driver.check_active @step(args=['cmd'], result=True) def run(self, cmd, timeout=30.0, codec="utf-8", decodeerrors="strict"): return self._run(cmd, timeout=timeout, codec=codec, decodeerrors=decodeerrors)
@step() def _await_login(self): """Awaits the login prompt and logs the user in""" timeout = Timeout(float(self.login_timeout)) expectations = [self.prompt, self.login_prompt, "Password: ", TIMEOUT] if self.console_ready != "": expectations.append(self.console_ready) # We call console.expect with a short timeout here to detect if the # console is idle, which results in a timeout without any changes to # the before property. So we store the last before value we've seen. # Because pexpect keeps any read data in it's buffer when a timeout # occours, we can't lose any data this way. last_before = b'' did_login = False did_silence_kernel = False while True: index, before, _, _ = self.console.expect( expectations, timeout=self.await_login_timeout ) if index == 0: if did_login and not did_silence_kernel: # Silence the kernel and wait for another prompt self.console.sendline("dmesg -n 1") did_silence_kernel = True else: # we got a prompt. no need for any further action to # activate this driver. self.status = 1 break elif index == 1: # we need to login self.console.sendline(self.username) did_login = True elif index == 2: if self.password: self.console.sendline(self.password) else: raise Exception("Password entry needed but no password set") elif index == 3: # expect hit a timeout while waiting for a match if before == last_before: # we did not receive anything during # self.await_login_timeout. # let's assume the target is idle and we can safely issue a # newline to check the state self.console.sendline("") elif index == 4: # we have just activated a console here # lets start over again and see if login or prompt will appear # now. self.console.sendline("") last_before = before if timeout.expired: raise TIMEOUT(f"Timeout of {self.login_timeout} seconds exceeded during waiting for login") # pylint: disable=line-too-long if did_login: if self.post_login_settle_time > 0: self.console.settle(self.post_login_settle_time, timeout=timeout.remaining) self._check_prompt()
[docs] @step() def get_status(self): """Returns the status of the shell-driver. 0 means not connected/found, 1 means shell """ return self._status
def _check_prompt(self): """ Internal function to check if we have a valid prompt """ marker = gen_marker() # hide marker from expect self.console.sendline(f"echo '{marker[:4]}''{marker[4:]}'") try: self.console.expect( rf"{marker}\s+{self.prompt}", timeout=5 ) self._status = 1 except TIMEOUT: self._status = 0 raise def _inject_run(self): self.console.sendline( '''run() { echo -n "$MARKER"; sh -c "$@"; echo "$MARKER $?"; }''' ) self.console.expect(self.prompt) @step(args=['keyfile_path']) def _put_ssh_key(self, keyfile_path): """Upload an SSH Key to a target""" regex = re.compile( r"""ssh-rsa # Only match RSA Keys \s+(?P<key>[a-zA-Z0-9/+=]+) # Match Keystring \s+(?P<comment>.*) # Match comment""", re.X ) with open(keyfile_path) as keyfile: keyline = keyfile.readline() self.logger.debug("Read Keyline: %s", keyline) match = regex.match(keyline) if match: new_key = match.groupdict() else: raise IOError( f"Could not parse SSH-Key from file: {keyfile}" ) self.logger.debug("Read Key: %s", new_key) auth_keys, _, read_keys = self._run("cat ~/.ssh/authorized_keys") self.logger.debug("Exitcode trying to read keys: %s, keys: %s", read_keys, auth_keys) result = [] _, _, test_write = self._run("touch ~/.test") if read_keys == 0: for line in auth_keys: match = regex.match(line) if match: match = match.groupdict() self.logger.debug("Match dict: %s", match) result.append(match) self.logger.debug("Complete result: %s", result) for key in result: self.logger.debug( "Key, newkey: %s,%s", key['key'], new_key['key'] ) if key['key'] == new_key['key']: self.logger.debug("Key already on target") return if test_write == 0 and read_keys == 0: self.logger.debug("Key not on target and writeable, concatenating...") self._run_check(f'echo "{keyline}" >> ~/.ssh/authorized_keys') self._run_check("rm ~/.test") return if test_write == 0: self.logger.debug("Key not on target, testing for .ssh directory") _, _, ssh_dir = self._run("[ -d ~/.ssh/ ]") if ssh_dir != 0: self.logger.debug("~/.ssh did not exist, creating") self._run("mkdir ~/.ssh/") self._run_check("chmod 700 ~/.ssh/") self.logger.debug("Creating ~/.ssh/authorized_keys") self._run_check(f'echo "{keyline}" > ~/.ssh/authorized_keys') self._run_check("rm ~/.test") return self.logger.debug("Key not on target and not writeable, using bind mount...") self._run_check('mkdir -m 700 /tmp/labgrid-ssh/') self._run("cp -a ~/.ssh/* /tmp/labgrid-ssh/") self._run_check(f'echo "{keyline}" >> /tmp/labgrid-ssh/authorized_keys') self._run_check('chmod 600 /tmp/labgrid-ssh/authorized_keys') out, err, exitcode = self._run('mount --bind /tmp/labgrid-ssh/ ~/.ssh/') if exitcode != 0: self.logger.warning("Could not bind mount ~/.ssh directory: %s %s", out, err)
[docs] @Driver.check_active def put_ssh_key(self, keyfile_path): self._put_ssh_key(keyfile_path)
def _xmodem_getc(self, size, timeout=10): """ called by the xmodem.XMODEM instance to read protocol data from the console """ try: # use the underlying expect mechanism, which may have already accidentally read # something of the XMODEM protocol data into its internal buffers: xpct = self.console.expect(r'.{%d}' % size, timeout=timeout) s = xpct[2].group() self.logger.debug('XMODEM GETC(%d): read %r', size, s) return s except TIMEOUT: self.logger.debug('XMODEM GETC(%s): TIMEOUT after %d seconds', size, timeout) return None def _xmodem_putc(self, data, timeout=1): """ called by the xmodem.XMODEM instance to write protocol data to the console """ # Note: we ignore the timeout because we cannot pass it through. self.logger.debug('XMODEM PUTC: %r', data) self.console.write(data) return len(data) def _start_xmodem_transfer(self, cmd): """ Start transfer command and synchronize until start of XMODEM stream. We don't use _run() here because it expects a prompt, but we want to read from the console directly into our XMODEM instance instead. """ marker = gen_marker() marked_cmd = f"echo '{marker[:4]}''{marker[4:]}'; {cmd}" self.console.sendline(marked_cmd) self.console.expect(marker, timeout=30) def _get_xmodem_rx_cmd(self, filename): """ Detect which XMODEM receive command can be used on the target, and cache the result. """ if not self._xmodem_cached_rx_cmd: if self._run('which lrz')[2] == 0: # redirect stderr to prevent lrz from printing "ready to receive # $file", which will confuse the XMODEM instance self._xmodem_cached_rx_cmd = "lrz -X -y -c -b '{filename}' 2>/dev/null" elif self._run('which rz')[2] == 0: # renamed binaries packaged by some distros self._xmodem_cached_rx_cmd = "rz -X -y -c -b '{filename}' 2>/dev/null" elif self._run('which rx')[2] == 0: # busybox rx # lrz may provide rx so redirect stderr for the same reason as above self._xmodem_cached_rx_cmd = "rx '{filename}' 2>/dev/null" else: raise ExecutionError('No XMODEM receiver (lrz, rz, rx) available on target') # use the cached string template to make the full command with parameters return self._xmodem_cached_rx_cmd.format(filename=filename) def _get_xmodem_sx_cmd(self, filename): """ Detect which XMODEM send command can be used on the target, and cache the result. """ if not self._xmodem_cached_sx_cmd: if self._run('which lsz')[2] == 0: # redirect stderr to prevent lsz from printing "Give XMODEM receive # cmd now", which will confuse the XMODEM instance self._xmodem_cached_sx_cmd = "lsz -b -X -m 1200 -M 10 '{filename}' 2>/dev/null" elif self._run('which sz')[2] == 0: # renamed binaries packaged by some distros self._xmodem_cached_sx_cmd = "sz -b -X -m 1200 -M 10 '{filename}' 2>/dev/null" else: raise ExecutionError('No XMODEM sender (lsz, sz) available on target') # use the cached string template to make the full command with parameters return self._xmodem_cached_sx_cmd.format(filename=filename) @step(title='put_bytes', args=['remotefile']) def _put_bytes(self, buf: bytes, remotefile: str): # OK, a little explanation on what we're doing here: # XMODEM is a fairly simple, but also a fairly historic protocol. For example, all packets # carry exactly 128 bytes of payload, and if the file being sent is not a multiple of 128 # bytes, the last packet will be padded by CPM's EOF, which is 0x1a. There is no file size # or anything in the protocol itself, so we'll have to take care of that and truncate the # file ourselves. def _target_cleanup(tmpfile): self._run(f"rm -f '{tmpfile}'") stream = io.BytesIO(buf) # We first write to a temp file, which we'll `dd` onto the destination file later tmpfile = self._run_check('mktemp') if not tmpfile: raise ExecutionError('Could not make temporary file on target') tmpfile = tmpfile[0] try: rx_cmd = self._get_xmodem_rx_cmd(tmpfile) self.logger.debug('XMODEM receive command on target: %s', rx_cmd) except ExecutionError: _target_cleanup(tmpfile) raise self._start_xmodem_transfer(rx_cmd) modem = xmodem.XMODEM(self._xmodem_getc, self._xmodem_putc) ret = modem.send(stream) self.logger.debug('xmodem.send() returned %r', ret) self.console.expect(self.prompt, timeout=30) # truncate the file to get rid of CPMEOF padding dd_cmd = f"dd if='{tmpfile}' of='{remotefile}' bs=1 count={len(buf)}" self.logger.debug('dd command: %s', dd_cmd) out, _, ret = self._run(dd_cmd) _target_cleanup(tmpfile) if ret != 0: raise ExecutionError(f'Could not truncate destination file: dd returned {ret}: {out}')
[docs] @Driver.check_active def put_bytes(self, buf: bytes, remotefile: str): """ Upload a file to the target. Will silently overwrite the remote file if it already exists. Args: buf (bytes): file contents remotefile (str): destination filename on the target Raises: ExecutionError: if something went wrong """ return self._put_bytes(buf, remotefile)
@step(title='put', args=['localfile', 'remotefile']) def _put(self, localfile: str, remotefile: str): with open(localfile, 'rb') as fh: buf = fh.read(None) self._put_bytes(buf, remotefile)
[docs] @Driver.check_active def put(self, localfile: str, remotefile: str): """ Upload a file to the target. Will silently overwrite the remote file if it already exists. Args: localfile (str): source filename on the local machine remotefile (str): destination filename on the target Raises: IOError: if the provided localfile could not be found ExecutionError: if something else went wrong """ self._put(localfile, remotefile)
@step(title='get_bytes', args=['remotefile']) def _get_bytes(self, remotefile: str): buf = io.BytesIO() cmd = self._get_xmodem_sx_cmd(remotefile) self.logger.info('XMODEM send command on target: %s', cmd) # get file size to remove XMODEM's CPMEOF padding at the end of the last packet out, _, ret = self._run(f"stat '{remotefile}'") match = re.search(r'Size:\s+(?P<size>\d+)', '\n'.join(out)) if ret != 0 or not match or not match.group("size"): raise ExecutionError(f"Could not stat '{remotefile}' on target") file_size = int(match.group('size')) self.logger.debug('file size on target is %d', file_size) self._start_xmodem_transfer(cmd) modem = xmodem.XMODEM(self._xmodem_getc, self._xmodem_putc) recvd_size = modem.recv(buf) self.logger.debug('xmodem.recv() returned %r', recvd_size) # remove CPMEOF (0x1a) padding if recvd_size < file_size: raise ExecutionError(f'Only received {recvd_size} bytes of {file_size} expected') self.logger.debug('received %d bytes of payload', file_size) buf.truncate(file_size) self.console.expect(self.prompt, timeout=30) # return everything as bytes buf.seek(0) return buf.read()
[docs] @Driver.check_active def get_bytes(self, remotefile: str): """ Download a file from the target. Args: remotefile (str): source filename on the target Returns: (bytes) file contents Raises: ExecutionError: if something went wrong """ return self._get_bytes(remotefile)
@step(title='get', args=['remotefile', 'localfile']) def _get(self, remotefile: str, localfile: str): with open(localfile, 'wb') as fh: buf = self._get_bytes(remotefile) fh.write(buf)
[docs] @Driver.check_active def get(self, remotefile: str, localfile: str): """ Download a file from the target. Will silently overwrite the local file if it already exists. Args: remotefile (str): source filename on the target localfile (str): destination filename on the local machine (can be relative) Raises: IOError: if localfile could not be written ExecutionError: if something went wrong """ self._get(remotefile, localfile)
@step(title='run_script', args=['data', 'timeout']) def _run_script(self, data: bytes, timeout: int = 60): hardcoded_remote_file = '/tmp/labgrid-run-script' self._put_bytes(data, hardcoded_remote_file) self._run_check(f"chmod +x '{hardcoded_remote_file}'") return self._run(hardcoded_remote_file, timeout=timeout)
[docs] @Driver.check_active def run_script(self, data: bytes, timeout: int = 60): """ Upload a script to the target and run it. Args: data (bytes): script data timeout (int): timeout for the script to finish execution Returns: Tuple of (stdout: str, stderr: str, return_value: int) Raises: ExecutionError: if something went wrong """ return self._run_script(data, timeout)
@step(title='run_script_file', args=['scriptfile', 'timeout', 'args']) def _run_script_file(self, scriptfile: str, *args, timeout: int = 60): hardcoded_remote_file = '/tmp/labgrid-run-script' self._put(scriptfile, hardcoded_remote_file) self._run_check(f"chmod +x '{hardcoded_remote_file}'") shargs = [shlex.quote(a) for a in args] cmd = f"{hardcoded_remote_file} {' '.join(shargs)}" return self._run(cmd, timeout=timeout)
[docs] @Driver.check_active def run_script_file(self, scriptfile: str, *args, timeout: int = 60): """ Upload a script file to the target and run it. Args: scriptfile (str): source file on the local file system to upload to the target *args: (list of str): any arguments for the script as positional arguments timeout (int): timeout for the script to finish execution Returns: Tuple of (stdout: str, stderr: str, return_value: int) Raises: ExecutionError: if something went wrong IOError: if the provided localfile could not be found """ return self._run_script_file(scriptfile, *args, timeout=timeout)
[docs] @Driver.check_active def get_default_interface_device_name(self, version=4): """ Retrieve the default route's interface device name. Args: version (int): IP version Returns: Name of the device of the default route Raises: ExecutionError: if no or multiple routes are set up """ assert version in (4, 6) regex = r"""default\s+via # leading strings \s+\S+ # IP address \s+dev\s+(\w+) # interface""" default_route = self._run_check(f"ip -{version} route list default") matches = re.findall(regex, "\n".join(default_route), re.X) if not matches: raise ExecutionError(f"No IPv{version} default route found") if len(matches) > 1: raise ExecutionError(f"Multiple IPv{version} default routes found") return matches[0]
[docs] @Driver.check_active def get_ip_addresses(self, device=None): """ Retrieves IP addresses for given interface name. Note that although the return type is named IPv4Interface/IPv6Interface, it contains an IP address with the corresponding network prefix. Args: device (str): Name of the interface to query, defaults to default route's device name. Returns: List of IPv4Interface or IPv6Interface objects """ if device is None: device = self.get_default_interface_device_name() regex = r"""\d+: # leading number \s+\w+ # interface name \s+inet6?\s+(\S+) # IP address, prefix .*global # global scope, not host scope""" ip_show = self._run_check(f"ip -o addr show dev {device}") matches = re.findall(regex, "\n".join(ip_show), re.X) return list(map(ipaddress.ip_interface, matches))