sim: Clarify Naming of Streams

ChdrSniffer is renamed to ChdrEndpoint to clarify its function as the
actual destination of chdr packets, rather than just an observer.
TxWorker has been renamed to OutputStream and RxWorker has been renamed
to InputStream to avoid ambiguities regarding Tx and Rx terminology.

Signed-off-by: Samuel O'Brien <sam.obrien@ni.com>

1 files changed, 99 insertions, 0 deletions

diff --git a/mpm/python/usrp_mpm/simulator/chdr_endpoint.py b/mpm/python/usrp_mpm/simulator/chdr_endpoint.py
new file mode 100644
index 000000000..616cd0ce9
--- /dev/null
+++ b/mpm/python/usrp_mpm/simulator/chdr_endpoint.py
@@ -0,0 +1,99 @@
+#
+# Copyright 2020 Ettus Research, a National Instruments Brand
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+"""This module houses the ChdrEndpoint class, which handles networking,
+packet dispatch, and acts as an interface between these and the RFNoC
+Graph.
+"""
+
+from threading import Thread
+import socket
+from uhd.chdr import ChdrPacket, ChdrWidth, PacketType
+from .rfnoc_graph import XbarNode, XportNode, StreamEndpointNode, RFNoCGraph, NodeType
+
+CHDR_W = ChdrWidth.W64
+
+class ChdrEndpoint:
+    """This class is created by the sim periph_manager
+    It is responsible for opening sockets, dispatching all chdr packet
+    traffic to the appropriate destination, and responding to said
+    traffic.
+
+    The extra_args parameter is passed in from the periph_manager, and
+    coresponds to the --default_args flag of usrp_hwd.py on the
+    command line
+    """
+    def __init__(self, log, extra_args):
+        self.log = log.getChild("ChdrEndpoint")
+        self.thread = Thread(target=self.socket_worker, daemon=True)
+        self.thread.start()
+        self.graph = RFNoCGraph(self.get_default_nodes(), self.log, 1, self.begin_tx,
+                                self.end_tx, self.send_strc, self.begin_rx)
+        self.xport_map = {}
+
+    def set_sample_rate(self, rate):
+        """Set the sample_rate of the next tx_stream.
+
+        This method is called by the daughterboard. It coresponds to
+        sim_dboard.py:sim_db#set_catalina_clock_rate()
+        """
+        self.graph.get_stream_spec().sample_rate = rate
+
+    def get_default_nodes(self):
+        """Get a sensible NoC Core setup. This is the simplest
+        functional layout. It has one of each required component.
+        """
+        nodes = [
+            XportNode(0),
+            XbarNode(0, [2], [0]),
+            StreamEndpointNode(0)
+        ]
+        return nodes
+
+    def send_strc(self, stream_ep, addr):
+        pass # TODO: currently not implemented
+
+    def begin_tx(self, src_epid, stream_spec):
+        pass # TODO: currently not implemented
+
+    def end_tx(self, src_epid):
+        pass # TODO: currently not implemented
+
+    def begin_rx(self, dst_epid):
+        pass # TODO: currently not implemented
+
+    def socket_worker(self):
+        """This is the method that runs in a background thread. It
+        blocks on the CHDR socket and processes packets as they come
+        in.
+        """
+        self.log.info("Starting ChdrEndpoint Thread")
+        main_sock = socket.socket(socket.AF_INET,
+                                  socket.SOCK_DGRAM)
+        main_sock.bind(("0.0.0.0", 49153))
+
+        while True:
+            # This allows us to block on multiple sockets at the same time
+            buffer = bytearray(8000) # Max MTU
+            # received Data over socket
+            n_bytes, sender = main_sock.recvfrom_into(buffer)
+            self.log.trace("received {} bytes of data from {}"
+                           .format(n_bytes, sender))
+            try:
+                packet = ChdrPacket.deserialize(CHDR_W, buffer[:n_bytes])
+                self.log.trace("Decoded Packet: {}".format(packet.to_string_with_payload()))
+                entry_xport = (1, NodeType.XPORT, 0)
+                pkt_type = packet.get_header().pkt_type
+                response = self.graph.handle_packet(packet, entry_xport, sender)
+
+                if response is not None:
+                    data = response.serialize()
+                    self.log.trace("Returning Packet: {}"
+                                   .format(packet.to_string_with_payload()))
+                    main_sock.sendto(bytes(data), sender)
+            except BaseException as ex:
+                self.log.warning("Unable to decode packet: {}"
+                                 .format(ex))
+                raise ex