changed it so that the response from the polls is not turned

into a string until it returns to the poller loop. This allows
poll functions to manipulate the raw responses from the socket
reads. Also added an ACK to tftdp poller so that the tftpd
daemon stops whining about the socket closing without an ACK.

pollster/pollster.py

@@ -70,20 +70,17 @@ def socket_poll(ip, port, msg, prot, max_recv=1):
 	sock.send(msg)
 
 	# get a response
-	resp = ''
+	resp = []
 	try:
-		# first read
-		data = sock.recv(1024)
-		resp += data.decode('utf-8')
-		max_recv -= 1
-
-		# remaining reads as necessary until timeout or socket closes
-		while(len(data) > 0 and max_recv > 0):
+		# read from the socket until <max_recv> responses or read,
+		# a timeout occurs, the socket closes, or some other exception 
+		# is raised
+		for i in range(max_recv):
 			data = sock.recv(1024)
-			resp += data.decode('utf-8')
-			max_recv -= 1
-		sock.close()
-
+			if len(data) == 0:
+				break
+			resp.append(data)
+	
 	except socket.timeout as e:
 		print('pollster: timed out waiting for a response from %s:%d (%s)' % (ip, port, e))
 		traceback.print_exc()
@@ -91,10 +88,12 @@ def socket_poll(ip, port, msg, prot, max_recv=1):
 		print('pollster: receive from %s:%d failed (%s)' % (ip, port, e))
 		traceback.print_exc()
 	
+	sock.close()
+
 	if len(resp) == 0:
 		return None
 
-	return resp
+	return b''.join(resp)
 
 # PUT POLLS FUNCTIONS HERE
 #  Each function should take an IP address and return a team name or None
@@ -105,14 +104,14 @@ def poll_fingerd(ip):
 	resp = socket_poll(ip, 79, b'flag\n', socket.SOCK_STREAM)
 	if resp is None:
 		return None
-	return resp.strip('\r\n')
+	return resp.strip(b'\r\n')
 
 def poll_noted(ip):
 	''' Poll the noted service. Returns None or a team name. '''
 	resp = socket_poll(ip, 4000, b'rflag\n', socket.SOCK_STREAM)
 	if resp is None:
 		return None
-	return resp.strip('\r\n')
+	return resp.strip(b'\r\n')
 
 def poll_catcgi(ip):
 	''' Poll the cat.cgi web service. Returns None or a team name. '''
@@ -121,11 +120,11 @@ def poll_catcgi(ip):
 	if resp is None:
 		return None
 
-	content = resp.split('\r\n\r\n')
+	content = resp.split(b'\r\n\r\n')
 	if len(content) < 3:
 		return None
 
-	content = content[1].split('\r\n')
+	content = content[1].split(b'\r\n')
 
 	try:
 		content_len = int(content[0])
@@ -134,7 +133,7 @@ def poll_catcgi(ip):
 	
 	if content_len <= 0:
 		return None
-	return content[1].strip('\r\n')
+	return content[1].strip(b'\r\n')
 
 def poll_tftpd(ip):
 	''' Poll the tftp service. Returns None or a team name. '''
@@ -145,8 +144,12 @@ def poll_tftpd(ip):
 	if len(resp) <= 5:
 		return None
 	
-	resp = resp.split('\n')[0]
-	return resp[4:].strip('\r\n')
+	resp = resp.split(b'\n')[0]
+
+	# ack
+	resp = socket_poll(ip, 69, b'\x00\x04' + resp[2:4], socket.SOCK_DGRAM, 0)
+
+	return resp[4:].strip(b'\r\n')
 	
 # PUT POLL FUNCTIONS IN HERE OR THEY WONT BE POLLED
 POLLS = {
@@ -217,7 +220,7 @@ while True:
 
 		# perform polls
 		for service,func in POLLS.items():
-			team = func(ip)
+			team = str(func(ip))
 			if team is None:
 				team = 'dirtbags'