canbus_query: Add tool to query CANBUS uuid

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 53 insertions, 0 deletions

diff --git a/scripts/canbus_query.py b/scripts/canbus_query.py
new file mode 100644
index 00000000..7312a0c6
--- /dev/null
+++ b/scripts/canbus_query.py
@@ -0,0 +1,53 @@
+#!/usr/bin/env python2
+# Tool to query CAN bus uuids
+#
+# Copyright (C) 2021  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+import sys, os, optparse, time
+import can
+
+CANBUS_ID_ADMIN = 0x3f0
+CMD_QUERY_UNASSIGNED = 0x00
+RESP_NEED_NODEID = 0x20
+
+def query_unassigned(canbus_iface):
+    # Open CAN socket
+    filters = [{"can_id": CANBUS_ID_ADMIN + 1, "can_mask": 0x7ff,
+                "extended": False}]
+    bus = can.interface.Bus(channel=canbus_iface, can_filters=filters,
+                            bustype='socketcan')
+    # Send query
+    msg = can.Message(arbitration_id=CANBUS_ID_ADMIN,
+                      data=[CMD_QUERY_UNASSIGNED], is_extended_id=False)
+    bus.send(msg)
+    # Read responses
+    found_ids = {}
+    start_time = curtime = time.time()
+    while 1:
+        tdiff = start_time + 2. - curtime
+        if tdiff <= 0.:
+            break
+        msg = bus.recv(tdiff)
+        curtime = time.time()
+        if (msg is None or msg.arbitration_id != CANBUS_ID_ADMIN + 1
+            or msg.dlc < 7 or msg.data[0] != RESP_NEED_NODEID):
+            continue
+        uuid = sum([v << ((5-i)*8) for i, v in enumerate(msg.data[1:7])])
+        if uuid in found_ids:
+            continue
+        found_ids[uuid] = 1
+        sys.stdout.write("Found canbus_uuid=%012x\n" % (uuid,))
+    sys.stdout.write("Total %d uuids found\n" % (len(found_ids,)))
+
+def main():
+    usage = "%prog [options] <can interface>"
+    opts = optparse.OptionParser(usage)
+    options, args = opts.parse_args()
+    if len(args) != 1:
+        opts.error("Incorrect number of arguments")
+    canbus_iface = args[0]
+    query_unassigned(canbus_iface)
+
+if __name__ == '__main__':
+    main()