store changes

vendortools/prologic_sim.py

@@ -70,6 +70,87 @@ MAX_ATTEMPTS                    = 10
 MAX_TIMEOUT                     = 0.5
 
 
+class nf_header():
+    """
+    Wrapper for netfind header packets
+    """
+    def __init__(self, hdr=None):
+        if hdr is None:
+            # create a default header
+            hdr = bytes([NF_MAGIC, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+                         0, 0])
+        if type(hdr) != bytes:
+            raise TypeError("hdr must by bytes object")
+        if len(hdr) != bytes:
+            raise ValueError("hdr must be 12 bytes long")
+        if hdr[0] != NF_MAGIC:
+            raise ValueError("First byte of hdr must be NF_MAGIC byte")
+        if hdr[10] != 0 and hdr[11] != 0:
+            raise ValueError("Last two bytes of hdr should be NULL")
+        self.__header = bytearray(hdr)
+
+    @property
+    def id(self):
+        return self.__header[0]
+
+    @property
+    def command(self):
+        return self.__header[1]
+
+    @command.setter
+    def command(self, cmd):
+        if type(cmd) not in (bytes, int):
+            raise TypeError("cmd must be <int> or <bytes>")
+        if type(cmd) == bytes:
+            if len(cmd) != 1:
+                raise ValueError("cmd must be between 0 and 16")
+            cmd = ord(cmd) # convert bytes to int
+        if type(cmd) == int:
+            if cmd < 0 or cmd > 16:
+                raise ValueError("cmd must be > 0 and < 16")
+            self.__header[1] = cmd
+
+    @property
+    def seq(self):
+        return int.from_bytes(self.__header[2:4], "big")
+
+    @seq.setter
+    def seq(self, seq):
+        if type(seq) not in (bytes, int):
+            raise TypeError("Seq must be int or bytes object")
+        if type(seq) == bytes:
+            if len(seq) != 2:
+                raise ValueError("Seq of type <bytes> must be 2 bytes")
+            seq = int.from_bytes(seq, "big")
+        if type(seq) == int and (seq < 1 or seq > 65535):
+            raise ValueError("Seq must be greater than 0 and less than 65536")
+        # by this point seq should be a valid int between 1 and 65535
+        self.__header[2:4] = seq.to_bytes(length=2,
+                                          byteorder="big"
+                                          signed=False)
+
+    @property
+    def target(self):
+        return self.__header[4:10]
+
+    @target.setter
+    def target(self, addr):
+        if type(addr) != bytes:
+            raise TypeError("addr must be bytes object")
+        if len(addr) != 6:
+            raise ValueError("addr must be 6 bytes")
+        self.__header[4:10] = addr
+
+    @property
+    def pad(self):
+        return self.__header[10:]
+
+    @property
+    def bytes(self):
+        return bytes(self.__header)
+
+
+
 class gpib_eth():
     """
     Prologix GPIB Ethernet Simulator Version 1.0
@@ -118,7 +199,11 @@ class gpib_eth():
         Send data (msg)
         """
 
-    def receive(self):
+    def monitor_broadcast(self):
+        broadcast_msg = self.receive('<broadcast>', NETFINDER_SERVER_PORT)
+        return broadcast_msg
+
+    def receive(self, addr, port, buffer=1024):
         """
         Receive data (msg)
         """
@@ -129,8 +214,12 @@ class gpib_eth():
         # 6 byte - Eth addr ((b'\xFF' * 6) for broadcast)
         # 2 byte - Null byte x2 (pad bytes) [EOM ?]
         rcv_sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
-        rcv_sock.bind(('<broadcast>', NETFINDER_SERVER_PORT))
-        msg = rcv_sock.recvfrom(1024)
+        rcv_sock.bind((addr, port))
+        netpack = rcv_sock.recvfrom(buffer)
+        if len(netpack) => 12 and netpack[0] == NF_MAGIC:
+            packet = {}
+            header = nf_header(netpack[0:12])
+            # Header format: 2 char (bytes) - NF_MAGIC + Command
         return msg