ungleich-game/server.py

#!/usr/bin/env python3

USERLENGTH = 50

import ipaddress
import random
import sys
import etcd
import json
import datetime

from flask import Flask, abort, request, Response
from flask_restful import reqparse

def get_random_ip(network):
    net = ipaddress.IPv6Network(network)
    addr_offset = random.randrange(2**64)
    addr = net[0] + addr_offset

    return addr

def require_args(*args):
    parser = reqparse.RequestParser()
    for arg in args:
        parser.add_argument(arg, required=True)
    return parser.parse_args()

class etcdWrapper(object):
    """ Generalises some etcd actions """

    def __init__(self, client, base):
        self.client = client
        self.base = base

    def read_key_or_none(self, path, recursive=False):
        try:
            data = self.client.read(path, recursive=recursive)
        except etcd.EtcdKeyNotFound:
            return None
        except Exception:
            abort(Response(status=400, response="Error connecting to etcd"))

        return data

    def get_user_key_or_none(self, user, key):
        path = "{}/user/{}/{}".format(self.base, user, key)
        return self.read_key_or_none(path)

    def set_user_key(self, user, key, value):
        path = "{}/user/{}/{}".format(self.base, user, key)
        self.client.write(path, value)


class Challenge(object):
    """ A sample challenge -- inherit this and overwrite accordingly """

    points = 0
    provides = []
    requires = []
    description = None
    dependencies_provided_by = {}

    def __init__(self, wrapper):
        self.db = wrapper

    def game(self):
        if request.method == 'GET':
            return self.describe()
        if request.method == 'POST':
            return self.solve()

    def describe(self):
        return self.description

    def save_points(self, user):
        """ should be called when the challenge was solved successfully"""

        key = "points/{}".format(user, type(self).__name__)
        self.db.set_user_key(user, key, self.points)

    def solve(self):
        """ Needs to be implemented per challenge """
        pass

class RegisterNet(Challenge):
    points = 10
    provides = [ "network" ]

    description = """
Register a /64 IPv6 network that you fully control.
Many other challenges depend on this. You will need to
be able to configure IPv6 addresses in this networks
and to setup services listening on these IPv6 addresses.

Submit your network with the "network" parameter.
"""
    def solve(self):
        args = require_args("user", "network")
        network = args['network']
        user = args['user']

        try:
            net = ipaddress.IPv6Network(network)
        except Exception as e:
            return Response(status=400, response="Cannot register network {}: {}".format(network, e))

        if not net.prefixlen == 64:
            return Response(status=400, response="{} mask is not /64 - please use a /64 network".format(net))

        # Save network
        self.db.set_user_key(user, "network", network)
        self.save_points(user)

        return "Network {} registered, have fun with the next challenge!".format(network)

class IPv6Address(Challenge):
    points = 20
    requires = [ "network" ]

    description = """
You have setup your network, great!
Now it is time to show that you are really controlling your network!

Setup the IPv6 address

{}

and POST to this address, when it should be reachable by ping6.
"""

    def describe(self):
        args = require_args("user")
        user = args['user']
        key = "network"

        network = self.db.get_user_key_or_none(user, key)
        if not network:
            return Response(status=400, response="""
Register a network before trying to be reachable. Possible challenges that
provide the network are:

{}
""".format("\n".join(self.dependencies_provided_by['network'])))


        key = "address"
        address = self.db.get_user_key_or_none(user, key)
        if not address:
            address = get_random_ip(network.value)
            self.db.set_user_key(user, key, address)
        else:
            address = address.value

        return self.description.format(address)

    def solve(self):
        args = require_args("user")
        user = args['user']

        return Response(status=400, response="""
Not yet implemented""")


class Game(object):
    def __init__(self, name, etcdclient, etcbase="/ungleichgame/v1"):
        self.client = etcdclient
        self.etcbase = etcbase

        self.wrapper = etcdWrapper(etcdclient, self.etcbase)

        self.app = Flask(name)

        self.app.add_url_rule('/', 'index', self.index)
        self.app.add_url_rule('/points', 'points', self.points)
        self.app.add_url_rule('/register', 'register', self.register, methods=['POST'])

        # etcd paths are below here

        self.userbase = "{}/user".format(self.etcbase)

        # Automate this
        challenges = [ RegisterNet, IPv6Address ]
        challenge_instances = []

        self.app.add_url_rule('/challenge', 'list_of_challenges', self.list_of_challenges)
        self.app.add_url_rule('/challenge/', 'list_of_challenges', self.list_of_challenges)

        self.providers = {}
        self.challenge_names = []
        for challenge in challenges:
            c = challenge(self.wrapper)
            challenge_instances.append(c)

            name = type(c).__name__
            self.challenge_names.append(name)
            path = "/challenge/{}".format(name)

            self.app.add_url_rule(path, name, c.game, methods=['GET', 'POST'])

            for provider in challenge.provides:
                if not provider in self.providers:
                    self.providers[provider] = []

                self.providers[provider].append(name)

        # Update challenges with provider information
        for challenge in challenge_instances:
            for requirement in challenge.requires:
                if not requirement in self.providers:
                    raise Exception("Unplayable server/game: {}".format(type(challenge).__name__))

                challenge.dependencies_provided_by[requirement] = self.providers[requirement]



    def list_of_challenges(self):
        base = request.base_url
        challenges = [ "{} ({})".format(name, "{}/{}".format(base, name)) for name in self.challenge_names ]

        return """The following challenges are available on this server:

{}

""".format("\n".join(challenges))



    def get_points(self):
        """ Returns a dict['username'] = points """

        user_points = {}

        path = "{}/".format(self.userbase)
        users = self.wrapper.read_key_or_none(path)

        if users:
            for user in users.children:
                username = user.key.replace(path,"")
                user_points[username] = 0

                point_path = "{}/points".format(user.key)
                points = self.wrapper.read_key_or_none(point_path, recursive=True)

                if not points:
                    continue

                for challenge in points.children:
                    user_points[username] += int(challenge.value)

        return user_points

    def index(self):
        points = self.points()

        return """Welcome to the game server!

Current point list is:

{}

For more information visit

https://code.ungleich.ch/nico/ungleich-game
""".format(points)

    def points(self):
        point_list = self.get_points()
        res = []
        if not point_list:
            return Response("No winners yet!")

        for k, v in point_list.items():
            res.append("{} has {} points".format(k, v))

        return """
Point list (aka high score)
---------------------------
{}
""".format("\n".join(res))

    def register(self):
        args = require_args("user")
        path = "{}/{}/registered_at".format(self.userbase, args['user'])
        value = str(datetime.datetime.now())

        cur = self.read_etcd(path)

        if cur:
            value = cur.value
        else:
            self.client.write(path, value)

        return "Registered at: {}\n".format(value)

#     def get_ip_address():
#         args = self.require_args("network", "user")

#         # Needs to be fixed with ungleich-otp
#         username=args['user']

#         if request.method == 'GET':
#             return Response("""
# This is an easy level - just register any /64 network
# that you fully control. After submission the game server will generate
# a random IPv6 address in this network.
# """)

#     client = etcd.Client(port=2379)
#     try:
#         data = client.read("/ungleichgame/v1/{}/network".format(username))
#     # FIXME: differentiate keynotfound and other errors
#     except Exception as e:
#         return Response(status=400, response="Cannot read your network, try registering first (error: {})".format(e))

#     return Response("data={}".format(data.value))
#     address = get_random_ip(data.value)
#     # FIXME: catch errors
#     client.write("/ungleichgame/v1/{}/address".format(username), address)

#     return Response("Your IPv6 address for this game is {}. Make it pingable and post to /level/1/result".format(address))

# @app.route("/level/2", methods=['GET', 'POST']) # post for username
# def pingme():
#     parser = reqparse.RequestParser()
#     parser.add_argument('user', required=True)
#     args = parser.parse_args()

#     # Needs to be fixed with ungleich-otp
#     username=args['user']

#     if request.method == 'GET':
#         return Response("""
# Proof that you can really control the network that you submitted:

# - Setup the IPv6 address to be ping6 able globally
# - POST to this address when it is configured
# """)

#     if request.method == 'POST':
#         try:
#             data = client.read("/ungleichgame/v1/{}/address".format(username), address)
#         except Exception as e:
#             return Response(status=400,
#                             response="""
# You need to register a network before trying to be reachable.
# Please go back to Level 1 for registering your network.
# """)
#         return Response("something good")


if __name__ == '__main__':
    g = Game(__name__, etcd.Client(port=2379))
    g.app.run(host="::", port='5002')