Add IP blacklist support

gophersrv.py

@@ -34,8 +34,9 @@ import subprocess
 import threading
 
 # Config
-port       = 7070
-gopherroot = os.environ['HOME']+'/gopher'
+port          = 7070
+gopherroot    = os.environ['HOME']+'/gopher'
+blacklistfile = os.environ['HOME']+'/gopher_blacklist'
 
 # Set up socket
 sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
@@ -269,6 +270,44 @@ class Serve(threading.Thread):
 		except socket.error:
 			self.conn.close()
 
+def toint(addr):
+	a1, a2, a3, a4 = [int(i) for i in addr.split('.')]
+	return a1<<24 | a2<<16 | a3<<8 | a4
+
+try:
+	f = open(blacklistfile, 'r')
+except IOError:
+	blacklist = []
+else:
+	blacklist = []
+	for line in f:
+		if len(line) > 0 and line[-1] == '\n':
+			line = line[:-1]
+
+		line = line.split('/')
+		if len(line) == 1:
+			addr = toint(line[0])
+			upto = 32
+		elif len(line) == 2:
+			addr = toint(line[0])
+			upto = int(line[1])
+		else:
+			assert(not 'Invalid line format')
+
+		blacklist.append((addr, upto))
+
+	f.close()
+
+def matchaddr(addr, blacklist_entry):
+	blacklist_addr, upto = blacklist_entry
+	shift = 32 - upto
+	return addr >> shift == blacklist_addr >> shift
+
 while True:
 	conn, addr = sock.accept()
-	Serve(conn).start()
+	ip, port = addr
+	if not any(map(lambda x: matchaddr(toint(ip), x), blacklist)):
+		print ip, blacklist#debg
+		Serve(conn).start()
+	else:
+		conn.close()