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napalm-amt/napalm_amt/wsman.py
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christianmanivong 0052ba7884 feat: Intel AMT driver over WS-Management (0.1.0)
An `amt` driver (napalm_amt.AmtDriver), a ManagementControllerDriver for the
management controller of Intel vPro machines, with its own lean WS-Management
client (requests + ElementTree, HTTP Digest, ports 16992/16993).

It reads the machine's identity, hardware with the SMBIOS system UUID, firmware
(AMT with build, BIOS), power state and the hardware event log, reports what AMT
listens on (plain HTTP or TLS, KVM incl. port 5900, IDE-R), and switches the
machine's power. AMT cannot be reset over WS-Management, so there is no
reboot_host. Discovery recognises AMT by its ports and its Server header.

Tested against Intel's published AMT 12 recordings (go-wsman-messages,
Apache-2.0, see NOTICE). `python -m napalm_amt.record` records a real AMT
read-only; the first test devices are two Lenovo ThinkCentre M910x.
2026-10-18 14:55:32 +02:00

285 lines
11 KiB
Python

"""A lean WS-Management client for Intel AMT.
AMT speaks WS-Management (DMTF DSP0226) with the CIM binding: SOAP 1.2 envelopes POSTed to
``/wsman``, on port 16992 over plain HTTP or 16993 over TLS, authenticated with HTTP Digest.
This client covers the four operations a driver needs: ``Get`` one instance, ``Enumerate``
plus ``Pull`` all instances of a class, and invoke a method. Instances come back as plain
dicts keyed by local element names; a repeated element becomes a list, an element with
children a nested dict, and every value a string, as on the wire.
The envelopes follow Intel's own go-wsman-messages, which every AMT since version 6 accepts.
"""
from __future__ import annotations
import itertools
import xml.etree.ElementTree as ET
from collections.abc import Callable, Iterable, Mapping
from typing import Any
from xml.sax.saxutils import escape, quoteattr
import requests
from requests.auth import HTTPDigestAuth
SOAP_NS = "http://www.w3.org/2003/05/soap-envelope"
ADDRESSING_NS = "http://schemas.xmlsoap.org/ws/2004/08/addressing"
WSMAN_NS = "http://schemas.dmtf.org/wbem/wsman/1/wsman.xsd"
ENUMERATION_NS = "http://schemas.xmlsoap.org/ws/2004/09/enumeration"
TRANSFER_NS = "http://schemas.xmlsoap.org/ws/2004/09/transfer"
ANONYMOUS = ADDRESSING_NS + "/role/anonymous"
PORT = 16992
TLS_PORT = 16993
#: Class name prefix -> the schema its resource URI lives under.
_SCHEMAS = {
"AMT_": "http://intel.com/wbem/wscim/1/amt-schema/1/",
"IPS_": "http://intel.com/wbem/wscim/1/ips-schema/1/",
"CIM_": "http://schemas.dmtf.org/wbem/wscim/1/cim-schema/2/",
}
#: Pages an enumeration may take. AMT's longest lists are a few dozen instances, and it
#: returns all of them in one page when asked for 999; this only stops a runaway loop.
_MAX_PAGES = 100
_HEADERS = {"Content-Type": "application/soap+xml;charset=UTF-8"}
Instance = dict[str, Any]
class WsmanError(Exception):
"""AMT did not answer, or answered with something other than the expected response."""
class WsmanAuthError(WsmanError):
"""AMT refused the credentials (HTTP 401 after the Digest exchange)."""
class WsmanFault(WsmanError):
"""AMT answered with a SOAP fault."""
def __init__(self, code: str, subcode: str, reason: str, detail: str) -> None:
self.code = code
self.subcode = subcode
self.reason = reason
self.detail = detail
super().__init__(f"{subcode or code}: {reason}" + (f" ({detail})" if detail else ""))
def resource_uri(resource: str) -> str:
"""The resource URI of a class, from its prefix (``AMT_``, ``IPS_``, ``CIM_``)."""
for prefix, base in _SCHEMAS.items():
if resource.startswith(prefix):
return base + resource
raise ValueError(f"{resource!r} is not an AMT, IPS or CIM class")
def _local(tag: str) -> str:
return tag.rsplit("}", 1)[-1]
def _value(element: ET.Element) -> str | Instance:
"""An element as a string (no children) or a dict of its children."""
children = list(element)
if not children:
return (element.text or "").strip()
result: Instance = {}
for child in children:
key, value = _local(child.tag), _value(child)
if key not in result:
result[key] = value
elif isinstance(result[key], list):
result[key].append(value)
else:
result[key] = [result[key], value]
return result
def to_instance(element: ET.Element | None) -> Instance:
"""An instance element as a dict; an empty or missing one as an empty dict."""
if element is None:
return {}
value = _value(element)
return value if isinstance(value, dict) else {}
def _fault(element: ET.Element) -> WsmanFault:
def text(path: str) -> str:
found = element.find(path)
return "".join(found.itertext()).strip() if found is not None else ""
def unprefixed(qname: str) -> str:
return qname.split(":", 1)[-1]
s = f"{{{SOAP_NS}}}"
return WsmanFault(
code=unprefixed(text(f"{s}Code/{s}Value")),
subcode=unprefixed(text(f"{s}Code/{s}Subcode/{s}Value")),
reason=text(f"{s}Reason/{s}Text"),
detail=text(f"{s}Detail"),
)
class WsmanTransport:
"""WS-Management over HTTP(S) with Digest auth, to one AMT.
``tls`` defaults to on for port 16993 and off otherwise. ``verify`` is passed to
``requests``: ``True`` checks the certificate against its CA bundle, a path against
that CA file, ``False`` not at all. ``retries`` counts extra attempts after a
connection error; a response, even an error, is never retried. ``recorder``, when set,
is called with the class, the operation and the raw body of every answer (to record
fixtures).
"""
def __init__(
self,
host: str,
username: str,
password: str,
port: int | None = None,
tls: bool | None = None,
verify: bool | str = True,
timeout: float = 60,
retries: int = 1,
) -> None:
self.port = int(port or PORT)
self.tls = self.port == TLS_PORT if tls is None else bool(tls)
self.url = f"{'https' if self.tls else 'http'}://{host}:{self.port}/wsman"
self.timeout = timeout
self.retries = max(0, int(retries))
self.session = requests.Session()
self.session.auth = HTTPDigestAuth(username, password)
self.session.verify = verify
self._message_ids = itertools.count(1)
self.recorder: Callable[[str, str, bytes], None] | None = None
def close(self) -> None:
self.session.close()
# --- operations ----------------------------------------------------------------------
def get(self, resource: str, selectors: Mapping[str, str] | None = None) -> Instance:
"""The one instance of ``resource`` (or the one ``selectors`` pick)."""
body = self._post(resource, f"{TRANSFER_NS}/Get", "", selectors)
return to_instance(next(iter(body), None))
def enumerate(self, resource: str) -> list[Instance]:
"""Every instance of ``resource``: ``Enumerate``, then ``Pull`` to the end."""
e = f"{{{ENUMERATION_NS}}}"
body = self._post(
resource, f"{ENUMERATION_NS}/Enumerate", f'<Enumerate xmlns="{ENUMERATION_NS}"/>'
)
context = body.findtext(f"{e}EnumerateResponse/{e}EnumerationContext")
instances: list[Instance] = []
for _ in range(_MAX_PAGES):
if not context:
return instances
body = self._post(
resource,
f"{ENUMERATION_NS}/Pull",
f'<Pull xmlns="{ENUMERATION_NS}"><EnumerationContext>{escape(context)}'
f"</EnumerationContext><MaxElements>999</MaxElements>"
f"<MaxCharacters>99999</MaxCharacters></Pull>",
)
page = body.find(f"{e}PullResponse")
if page is None:
raise WsmanError(f"{resource}: Pull answered without a PullResponse")
instances.extend(to_instance(item) for item in page.findall(f"{e}Items/*"))
if page.find(f"{e}EndOfSequence") is not None:
return instances
context = page.findtext(f"{e}EnumerationContext")
raise WsmanError(f"{resource}: no end of the enumeration after {_MAX_PAGES} pages")
def invoke(
self,
resource: str,
method: str,
params: Iterable[tuple[str, Any]] = (),
raw: str = "",
selectors: Mapping[str, str] | None = None,
check: bool = True,
) -> Instance:
"""Call ``method`` of ``resource`` and return its output parameters.
``params`` are sent in order as ``<h:Name>value</h:Name>``; ``raw`` is appended
unescaped after them, for parameters that are references (``h:`` is the class's
namespace). With ``check``, a ``ReturnValue`` other than 0 raises.
"""
uri = resource_uri(resource)
inner = "".join(f"<h:{name}>{escape(str(value))}</h:{name}>" for name, value in params)
body = self._post(
resource,
f"{uri}/{method}",
f'<h:{method}_INPUT xmlns:h="{uri}">{inner}{raw}</h:{method}_INPUT>',
selectors,
)
output = to_instance(body.find(f"{{{uri}}}{method}_OUTPUT"))
code = output.get("ReturnValue")
if check and code not in (None, "0"):
raise WsmanError(f"{resource}.{method} failed: ReturnValue {code}")
return output
# --- plumbing ------------------------------------------------------------------------
def _envelope(
self, uri: str, action: str, body: str, selectors: Mapping[str, str] | None
) -> str:
selector_set = ""
if selectors:
selector_set = (
"<w:SelectorSet>"
+ "".join(
f"<w:Selector Name={quoteattr(name)}>{escape(value)}</w:Selector>"
for name, value in selectors.items()
)
+ "</w:SelectorSet>"
)
return (
f'<?xml version="1.0" encoding="utf-8"?>'
f'<Envelope xmlns="{SOAP_NS}" xmlns:a="{ADDRESSING_NS}" xmlns:w="{WSMAN_NS}">'
f"<Header><a:Action>{action}</a:Action><a:To>/wsman</a:To>"
f"<w:ResourceURI>{uri}</w:ResourceURI>"
f"<a:MessageID>{next(self._message_ids)}</a:MessageID>"
f"<a:ReplyTo><a:Address>{ANONYMOUS}</a:Address></a:ReplyTo>"
f"<w:OperationTimeout>PT60S</w:OperationTimeout>{selector_set}</Header>"
f"<Body>{body}</Body></Envelope>"
)
def _post(
self, resource: str, action: str, body: str, selectors: Mapping[str, str] | None = None
) -> ET.Element:
envelope = self._envelope(resource_uri(resource), action, body, selectors)
response = self._send(envelope.encode())
if self.recorder is not None:
self.recorder(resource, action.rsplit("/", 1)[-1], response.content)
return self._body(response)
def _send(self, data: bytes) -> requests.Response:
error: requests.RequestException | None = None
for _ in range(self.retries + 1):
try:
return self.session.post(
self.url, data=data, headers=_HEADERS, timeout=self.timeout
)
except requests.RequestException as exc:
error = exc
raise WsmanError(f"{self.url}: {error}") from error
def _body(self, response: requests.Response) -> ET.Element:
"""The SOAP body of a response; a fault, a refusal or anything else raises."""
if response.status_code == 401:
raise WsmanAuthError(f"{self.url}: credentials refused (HTTP 401)")
body = None
# A DTD has no business in a WS-Management response; refusing one keeps entity
# expansion out of the parser.
if b"<!DOCTYPE" not in response.content:
try:
body = ET.fromstring(response.content).find(f"{{{SOAP_NS}}}Body")
except ET.ParseError:
body = None
if body is not None:
fault = body.find(f"{{{SOAP_NS}}}Fault")
if fault is not None:
raise _fault(fault)
if body is None or response.status_code >= 400:
raise WsmanError(f"{self.url}: HTTP {response.status_code}, no WS-Management answer")
return body