save

uds_async/client.py

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+from __future__ import annotations
+
+from dataclasses import dataclass
+from typing import Optional
+
+from isotp_async.transport import IsoTpChannel
+from .exceptions import UdsError, UdsNegativeResponse
+
+
+@dataclass
+class UdsClient:
+
+    isotp: IsoTpChannel
+    p2_timeout: float = 1.0
+
+    async def _request(self, payload: bytes) -> bytes:
+        await self.isotp.send_pdu(payload)
+        resp = await self.isotp.recv_pdu(timeout=self.p2_timeout)
+        if resp is None:
+            raise TimeoutError("UDS response timeout")
+
+        if resp[0] == 0x7F:
+            if len(resp) < 3:
+                raise UdsError("Malformed UDS negative response")
+            sid = resp[1]
+            nrc = resp[2]
+            raise UdsNegativeResponse(req_sid=sid, nrc=nrc)
+
+        return resp
+
+    async def diagnostic_session_control(self, session: int) -> bytes:
+        req = bytes([0x10, session & 0xFF])
+        resp = await self._request(req)
+        if resp[0] != 0x50:
+            raise UdsError(f"Unexpected SID 0x{resp[0]:02X} for DSC")
+        return resp
+
+    async def tester_present(self, suppress_response: bool = False) -> Optional[bytes]:
+
+        sub = 0x80 if suppress_response else 0x00
+        req = bytes([0x3E, sub])
+
+        if suppress_response:
+            try:
+                resp = await self._request(req)
+            except TimeoutError:
+                return None
+            return resp
+
+        resp = await self._request(req)
+        if resp[0] != 0x7E:
+            raise UdsError(f"Unexpected SID 0x{resp[0]:02X} for TesterPresent")
+        return resp
+
+    async def read_data_by_identifier(self, did: int) -> bytes:
+
+        req = bytes([0x22, (did >> 8) & 0xFF, did & 0xFF])
+        resp = await self._request(req)
+        if resp[0] != 0x62:
+            raise UdsError(f"Unexpected SID 0x{resp[0]:02X} for RDBI")
+        if len(resp) < 3:
+            raise UdsError("Malformed RDBI response")
+        return resp[3:]