Import LinuxCNC source tree

lib/python/mtc/http_agent.py

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+# Copyright (C) 2026 LinuxCNC contributors
+#
+# This program 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.
+#
+# This program 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 this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+
+# Embedded lightweight MTConnect HTTP agent.
+#
+# Serves the four MTConnect endpoints directly from an AgentState, with no
+# dependency on the official cppagent:
+#   GET /probe    -> MTConnectDevices
+#   GET /current  -> MTConnectStreams (latest value of each DataItem)
+#   GET /sample?from=<seq>&count=<n>  -> MTConnectStreams (sequence range)
+#   GET /assets   -> MTConnectAssets (CuttingTool assets)
+#
+# Runs in a background daemon thread so the agent's poll loop keeps the main
+# thread.
+
+import threading
+from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
+from urllib.parse import urlparse, parse_qs
+from xml.sax.saxutils import escape, quoteattr
+
+from .agent import OutOfRange, now_iso
+
+_XML = "application/xml; charset=utf-8"
+
+
+def _error_document(code, message):
+    # code and message are escaped: message embeds the raw request route, so an
+    # unescaped '<'/'&'/'"' would otherwise break well-formedness or let a
+    # crafted route forge sibling elements.  quoteattr() supplies the attribute
+    # quotes itself.
+    return (
+        '<?xml version="1.0" encoding="UTF-8"?>\n'
+        '<MTConnectError xmlns="urn:mtconnect.org:MTConnectError:1.7">\n'
+        '  <Header creationTime="%s" sender="linuxcnc-mtconnect" '
+        'instanceId="1" version="1.7" bufferSize="131072"/>\n'
+        '  <Errors><Error errorCode=%s>%s</Error></Errors>\n'
+        '</MTConnectError>\n'
+        % (now_iso(), quoteattr(str(code)), escape(str(message)))
+    )
+
+
+def make_handler(agent):
+    class Handler(BaseHTTPRequestHandler):
+        server_version = "linuxcnc-mtconnect/0.1"
+
+        def _send(self, body, status=200, content_type=_XML):
+            data = body.encode("utf-8") if isinstance(body, str) else body
+            self.send_response(status)
+            self.send_header("Content-Type", content_type)
+            self.send_header("Content-Length", str(len(data)))
+            self.end_headers()
+            self.wfile.write(data)
+
+        def do_GET(self):
+            parsed = urlparse(self.path)
+            route = parsed.path.rstrip("/") or "/"
+            try:
+                if route in ("/", "/probe"):
+                    self._send(agent.probe_document())
+                elif route == "/current":
+                    self._send(agent.current_document())
+                elif route == "/sample":
+                    q = parse_qs(parsed.query)
+                    from_seq = _int(q.get("from"), None)
+                    count = _int(q.get("count"), 100)
+                    self._send(agent.sample_document(from_seq, count))
+                elif route == "/assets":
+                    self._send(agent.assets_document())
+                elif route in ("/mtconnect-linuxcnc-1.xsd",
+                               "/schemas/mtconnect-linuxcnc-1.xsd"):
+                    result = agent.extension_schema()
+                    if result is None:
+                        self._send(_error_document("NOT_FOUND",
+                                   "extension schema not bundled"), status=404)
+                    else:
+                        data, content_type = result
+                        self._send(data, content_type=content_type)
+                elif route.startswith("/models/"):
+                    result = agent.model_file(route[len("/models/"):])
+                    if result is None:
+                        self._send(_error_document("NOT_FOUND",
+                                   "no such model: %s" % route), status=404)
+                    else:
+                        data, content_type = result
+                        self._send(data, content_type=content_type)
+                else:
+                    self._send(_error_document("UNSUPPORTED",
+                               "unsupported request: %s" % route), status=404)
+            except OutOfRange as exc:
+                self._send(_error_document("OUT_OF_RANGE", str(exc)), status=406)
+            except Exception as exc:  # keep the server alive on any handler bug
+                self._send(_error_document("INTERNAL_ERROR", str(exc)), status=500)
+
+        def log_message(self, fmt, *args):
+            # Quieter than the default stderr access log.
+            return
+
+    return Handler
+
+
+def _int(values, default):
+    if not values:
+        return default
+    try:
+        return int(values[0])
+    except (ValueError, TypeError):
+        return default
+
+
+class HttpAgent:
+    # Default to loopback; exposing the agent on the LAN is an explicit opt-in
+    # (INI [MTCONNECT]HTTP_BIND) so a machine isn't published by accident.
+    def __init__(self, agent, host="127.0.0.1", port=5000):
+        self.httpd = ThreadingHTTPServer((host, port),
+                                         make_handler(agent))
+        self.thread = threading.Thread(target=self.httpd.serve_forever,
+                                       name="mtconnect-http", daemon=True)
+
+    @property
+    def port(self):
+        return self.httpd.server_address[1]
+
+    def start(self):
+        self.thread.start()
+
+    def stop(self):
+        self.httpd.shutdown()
+        self.httpd.server_close()