commit 0a1c6238cc95f37a1b26369247d5d9876ba2b804 Author: Sathyanarayanan Gunasekaran gsathya.ceg@gmail.com Date: Thu May 17 22:19:10 2012 +0530
Add ExitPolicy.get_summary()
This provides a summary description of the policy chain similar to the consensus. --- stem/exit_policy.py | 84 ++++++++++++++++++++++++++++++++++++++++++++++++-- 1 files changed, 80 insertions(+), 4 deletions(-)
diff --git a/stem/exit_policy.py b/stem/exit_policy.py index 0a51f5f..dcee159 100644 --- a/stem/exit_policy.py +++ b/stem/exit_policy.py @@ -3,9 +3,13 @@ Tor Exit Policy information and requirements for its features. These can be easily parsed and compared, for instance...
exit_policies = stem.exit_policy.ExitPolicy()
+>>> exit_policies.add("accept *:80") +>>> exit_policies.add("accept *:443")
exit_policies.add("reject *:*") print exit_policies
-reject *:* +accept *:80 , accept *:443, reject *:* +>>> print exit_policies.get_summary() +accept 80, 443
ExitPolicyLine - Single rule from the exit policy |- __str__ - string representation @@ -16,7 +20,9 @@ ExitPolicy - List of ExitPolicyLine objects |- __iter__ - ExitPolicyLine entries for the exit policy |- check - check if exiting to this ip is allowed |- add - add new rule to the exit policy - +- isExitingAllowed - check if exit node + |- get_summary - provides a summary description of the policy chain + +- is_exiting_allowed - check if exit node + """
# ip address ranges substituted by the 'private' keyword @@ -140,6 +146,7 @@ class ExitPolicy: ExitPolicy constructor """ self._policies = [] + self.summary = ""
def add(self, rule_entry): """ @@ -156,7 +163,76 @@ class ExitPolicy: self._policies.append(ExitPolicyLine(new_entry)) else: self._policies.append(ExitPolicyLine(rule_entry)) - + + def get_summary(self): + """ + Provides a summary description of the policy chain similar to the + consensus. This excludes entries that don't cover all ips, and is either + a whitelist or blacklist policy based on the final entry. + """ + + if not self.summary: + # determines if we're a whitelist or blacklist + is_whitelist = False # default in case we don't have a catch-all policy at the end + + for policy in self._policies: + if policy.is_ip_wildcard and policy.is_port_wildcard: + is_whitelist = not policy.is_accept + break + + # Iterates over the policys and adds the the ports we'll return (ie, allows + # if a whitelist and rejects if a blacklist). Reguardless of a port's + # allow/reject policy, all further entries with that port are ignored since + # policies respect the first matching policy. + + display_ports, skip_ports = [], [] + + for policy in self._policies: + if not policy.is_ip_wildcard: continue + + if policy.min_port == policy.max_port: + port_range = [policy.min_port] + else: + port_range = range(policy.min_port, policy.max_port + 1) + + for port in port_range: + if port in skip_ports: continue + + # if accept + whitelist or reject + blacklist then add + if policy.is_accept == is_whitelist: + display_ports.append(port) + + # all further entries with this port are to be ignored + skip_ports.append(port) + + # gets a list of the port ranges + if display_ports: + display_ranges, temp_range = [], [] + display_ports.sort() + display_ports.append(None) # ending item to include last range in loop + + for port in display_ports: + if not temp_range or temp_range[-1] + 1 == port: + temp_range.append(port) + else: + if len(temp_range) > 1: + display_ranges.append("%i-%i" % (temp_range[0], temp_range[-1])) + else: + display_ranges.append(str(temp_range[0])) + + temp_range = [port] + else: + # everything for the inverse + is_whitelist = not is_whitelist + display_ranges = ["1-65535"] + + # constructs the summary string + label_prefix = "accept " if is_whitelist else "reject " + + self.summary = (label_prefix + ", ".join(display_ranges)).strip() + + return self.summary + def is_exiting_allowed(self): """ Provides true if the policy allows exiting whatsoever, false otherwise. @@ -188,4 +264,4 @@ class ExitPolicy: Provides the string used to construct the Exit Policy """ return ' , '.join([str(policy) for policy in self._policies]) - +