From: Philipp Spitzer <philipp@spitzer.priv.at>
Date: Wed, 5 Mar 2014 22:34:39 +0000 (+0100)
Subject: Now exceptions are derived from a common base class and return codes correspond to... 
X-Git-Tag: 0.0.2~28
X-Git-Url: https://git.toastfreeware.priv.at/toast/tdyndns.git/commitdiff_plain/9202c6675f89f9232f53e9b7622077a6df3d4f31

Now exceptions are derived from a common base class and return codes correspond to dyn.com.
---

diff --git a/cgi-bin/dyndns.py b/cgi-bin/dyndns.py
index a3f436b..8291ac2 100755
--- a/cgi-bin/dyndns.py
+++ b/cgi-bin/dyndns.py
@@ -38,19 +38,65 @@ system   = fields.getvalue('system')
 url      = fields.getvalue('url')
 
 
+# Base class for our exceptions
+class DynDnsError(Exception):
+	pass
+
+class AuthError(DynDnsError):
+	returncode = 'badauth'
+
+class UsernameMissing(AuthError):
+	pass
+
+class UsernameInvalid(AuthError):
+	pass
+
+class PasswordMissing(AuthError):
+	pass
+
+class PasswordWrong(AuthError):
+	pass
+
+class HostnameError(DynDnsError):
+	returncode = 'notfqdn'
+
+class HostnameMissing(HostnameError):
+	pass
+
+class PasswordWrong(HostnameError):
+	pass
+
+class IpError(DynDnsError):
+	returncode = 'badip' # not documented at dyn.com
+
+class IpMissing(IpError):
+	pass
+
+class IpInvalid(IpError):
+	pass
+
 try:
 	# check username
-	user_info = pwd.getpwnam(username) # returns a key error if the user does not exist
+	if username is None:
+		raise UsernameMissing()
+	try:
+		user_info = pwd.getpwnam(username)
+	except KeyError:
+		raise UsernameInvalid()
 	if user_info.pw_uid < 1000:
-		raise RuntimeError('Invalid user name')
+		raise UsernameInvalid()
 
 	# check password
+	if password is None:
+		raise PasswordMissing()
 	if password != PASSWORD:
-		raise RuntimeError('Invalid password')
+		raise PasswordWrong()
 
 	# check hostname
+	if hostname is None:
+		raise HostnameMissing()
 	if re.match(r'[-0-9a-z]+(\.[-0-9a-z]+)*$', hostname) is None:
-		raise RuntimeError('Invalid host name')
+		raise HostnameInvalid()
 
 	# strip zone
 	hostname = hostname.strip()
@@ -58,25 +104,30 @@ try:
 		hostname = hostname[:-len(ZONE)]
 
 	# check IP address
-	ip = ipaddr.IPAddress(myip) # throws axception if the IP address is not valid
+	if myip is None:
+		raise IpMissing()
+	try:
+		ip = ipaddr.IPAddress(myip) # throws an exception if the IP address is not valid
+	except ValueError:
+		raise IpInvalid()
 	if isinstance(ip, ipaddr.IPv4Address):
-		type = 'A'
+		iptype = 'A'
 	elif isinstance(ip, ipaddr.IPv6Address):
-		type = 'AAAA'
+		iptype = 'AAAA'
 	else:
-		raise RuntimeError('Unknown IP address type')
+		raise IpInvalid() # should never happen
 
 	# access granted
 	print "Content-Type: text/html"
 	print
-	call(['sudo', '/usr/local/bin/nsupdate_dyndns', hostname, myip, type])
-	print "OK"
+	call(['sudo', '/usr/local/bin/nsupdate_dyndns', hostname, myip, iptype])
+	print "good"
+	# Note: we should return 'nochg' in case the IP has not changed, however we don't know yet.
 
 
-except:
-	# access denied
+except DynDnsError as error:
 	print "Content-Type: text/html"
-	print "Status: 403 Forbidden"
+	print "Status: 200"
 	print
-	print "Denied"
+	print error.returncode