1 files changed, 107 insertions, 0 deletions
diff --git a/mpm/python/usrp_mpm/simulator/chdr_sniffer.py b/mpm/python/usrp_mpm/simulator/chdr_sniffer.py
new file mode 100644
index 000000000..8ff467cf2
--- /dev/null
+++ b/mpm/python/usrp_mpm/simulator/chdr_sniffer.py
@@ -0,0 +1,107 @@
+#
+# Copyright 2020 Ettus Research, a National Instruments Brand
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+"""This module houses the ChdrSniffer class, which handles networking,
+packet dispatch, and the nitty gritty of spinning up rx and tx workers.
+
+Note: Rx and Tx are reversed when compared to their definitions in the
+UHD radio_control_impl.cpp file. Rx is when samples are coming to the
+simulator. Tx is when samples are being sent by the simulator.
+
+TODO: This class is run based on threads for development simplicity. If
+more throughput is desired, it should be rewritten to use processes
+instead. This allows the socket workers to truly work in parallel.
+Python threads are limited by holding the GIL while they are executing.
+"""
+
+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 ChdrSniffer:
+    """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("ChdrSniffer")
+        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 ChdrSniffer 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(8192) # 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