mpm: discovery can now be bound to subnet

2 files changed, 48 insertions, 25 deletions

diff --git a/mpm/python/usrp_hwd.py b/mpm/python/usrp_hwd.py
index 8abc89923..c44f3a109 100755
--- a/mpm/python/usrp_hwd.py
+++ b/mpm/python/usrp_hwd.py
@@ -51,6 +51,12 @@ def setup_arg_parser():
         default=None
     )
     parser.add_argument(
+        '--discovery-addr',
+        help="Bind discovery socket to this address only. Defaults to all " \
+             "addresses.",
+        default="0.0.0.0",
+    )
+    parser.add_argument(
         '--default-args',
         help="Provide a comma-separated list of key=value pairs that are" \
              "used as defaults for device initialization.",
@@ -122,7 +128,8 @@ def main():
         return True
     log.info("Spawning discovery process...")
     _PROCESSES.append(
-        mpm.spawn_discovery_process(discovery_info, shared))
+        mpm.spawn_discovery_process(discovery_info, shared, args.discovery_addr)
+    )
     log.info("Spawning RPC process...")
     _PROCESSES.append(
         mpm.spawn_rpc_process(mpm.mpmtypes.MPM_RPC_PORT, shared, mgr))
diff --git a/mpm/python/usrp_mpm/discovery.py b/mpm/python/usrp_mpm/discovery.py
index 5f025283d..47088c7e7 100644
--- a/mpm/python/usrp_mpm/discovery.py
+++ b/mpm/python/usrp_mpm/discovery.py
@@ -30,21 +30,26 @@ RESPONSE_PREAMBLE = "USRP-MPM"
 RESPONSE_SEP = ";"
 RESPONSE_CLAIMED_KEY = "claimed"
 
-def spawn_discovery_process(device_info, shared_state):
+def spawn_discovery_process(device_info, shared_state, discovery_addr):
     """
     Returns a process that contains the device discovery.
 
     Arguments:
     device_info -- A dictionary of type string -> string. All of these items
                    will be included in the response string.
+    shared_state -- Shared state of device (is it claimed, etc.). Is a
+                    SharedState() object.
+    discovery_addr -- Discovery will listen on this address(es)
     """
-    # claim_status = Value(ctypes.c_bool, False)
-    proc = Process(target=_discovery_process, args=(device_info, shared_state))
+    proc = Process(
+        target=_discovery_process,
+        args=(device_info, shared_state, discovery_addr)
+    )
     proc.start()
     return proc
 
 
-def _discovery_process(device_info, state):
+def _discovery_process(device_info, state, discovery_addr):
     """
     The actual process for device discovery. Is spawned by
     spawn_discovery_process().
@@ -59,27 +64,38 @@ def _discovery_process(device_info, state):
     log = get_main_logger().getChild('discovery')
 
     sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    # FIXME really, we should only bind to the subnet but I haven't gotten that
+    # working yet
     sock.bind((("0.0.0.0", MPM_DISCOVERY_PORT)))
-
     send_sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
 
-    # try:
-    while True:
-        data, sender = sock.recvfrom(8000)
-        log.info("Got poked by: %s", sender[0])
-        if data.strip(b"\0") == b"MPM-DISC":
-            log.info("Sending discovery response to %s port: %d",
-                     sender[0], sender[1])
-            send_data = bytes(create_response_string(), 'ascii')
-            log.info(send_data)
-            send_sock.sendto(send_data, sender)
-        elif data.strip(b"\0").startswith(b"MPM-ECHO"):
-            log.info("Received echo request from {sender}".format(sender=sender[0]))
-            send_data = data
-            send_sock.sendto(send_data, sender)
+    # TODO yeah I know that's not how you do this
+    discovery_addr_prefix  = discovery_addr.replace('.255', '')
+    if discovery_addr == '0.0.0.0':
+        discovery_addr_prefix = ''
 
-    # except Exception as err:
-    #     log.info("Error: %s", err)
-    #     log.info("Error type: %s", type(err))
-    #     sock.close()
-    #     send_sock.close()
+    try:
+        while True:
+            data, sender = sock.recvfrom(8000)
+            log.info("Got poked by: %s", sender[0])
+            # TODO this is still part of the awful subnet identification
+            if not sender[0].startswith(discovery_addr_prefix):
+                continue
+            if data.strip(b"\0") == b"MPM-DISC":
+                log.info("Sending discovery response to %s port: %d",
+                         sender[0], sender[1])
+                send_data = bytes(create_response_string(), 'ascii')
+                log.info(send_data)
+                send_sock.sendto(send_data, sender)
+            elif data.strip(b"\0").startswith(b"MPM-ECHO"):
+                log.info("Received echo request from {sender}".format(
+                    sender=sender[0])
+                )
+                send_data = data
+                send_sock.sendto(send_data, sender)
+    except Exception as err:
+        log.error("Error: %s", err)
+        log.error("Error type: %s", type(err))
+        sock.close()
+        send_sock.close()
+        exit(1)