check recv size

adafruit_wiznet5k/adafruit_wiznet5k.py

@@ -175,6 +175,17 @@ def __init__(
         self.mac_address = mac
         self._src_port = 0
         self._dns = 0
+
+        # First wait link status is on
+        # to avoid the code during DHCP - assert self.link_status, "Ethernet cable disconnected!"
+        start_time = time.monotonic()
+        while True:
+            if self.link_status or ((time.monotonic() - start_time) > 5) :
+                break
+            time.sleep(1)
+            if self._debug:
+                print("My Link is:", self.link_status)
+
         # Set DHCP
         if is_dhcp:
             ret = self.set_dhcp(hostname, dhcp_timeout)

adafruit_wiznet5k/adafruit_wiznet5k_dhcp.py

@@ -127,6 +127,10 @@ def send_dhcp_message(self, state, time_elapsed):
         :param float time_elapsed: Number of seconds elapsed since renewal.
 
         """
+        # before making send packet, shoule init _BUFF. if not, DHCP sometimes fails, wrong padding, garbage bytes, ...
+        for i in range(len(_BUFF)):
+            _BUFF[i] = 0
+
         # OP
         _BUFF[0] = DHCP_BOOT_REQUEST
         # HTYPE
@@ -361,9 +365,9 @@ def request_dhcp_lease(
                     print("* DHCP: Parsing OFFER")
                 msg_type, xid = self.parse_dhcp_response(self._response_timeout)
                 if msg_type == DHCP_OFFER:
-                    # use the _transaction_id the offer returned,
-                    # rather than the current one
-                    self._transaction_id = self._transaction_id.from_bytes(xid, "l")
+                    # # use the _transaction_id the offer returned,
+                    # # rather than the current one
+                    # self._transaction_id = self._transaction_id.from_bytes(xid, "l")
                     if self._debug:
                         print("* DHCP: Request")
                     self.send_dhcp_message(
@@ -372,7 +376,7 @@ def request_dhcp_lease(
                     self._dhcp_state = STATE_DHCP_REQUEST
                 else:
                     print("* Received DHCP Message is not OFFER")
-            elif STATE_DHCP_REQUEST:
+            elif self._dhcp_state == STATE_DHCP_REQUEST:
                 if self._debug:
                     print("* DHCP: Parsing ACK")
                 msg_type, xid = self.parse_dhcp_response(self._response_timeout)

examples/wiznet5k_simpleserver.py

@@ -31,6 +31,8 @@
 while True:
     conn, addr = server.accept()  # Wait for a connection from a client.
     with conn:
-        data = conn.recv()
-        print(data)
-        conn.send(data)  # Echo message back to client
+        while True:
+            data = conn.recv() 
+            if data: # Wait for receiving data
+                print(data)
+                conn.send(data)  # Echo message back to client