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# SPDX-License-Identifier: AGPL-3.0-or-later
# kpov_util should be imported by add_assignment.py
instructions = {
'si':"""
<pre>Postavi tri računalnike - SimpleArbiter z diska simpleArbiter, TestClient z diska testClient in NATServer. NATServer naj ima dva omrežna vmesnika - z enim naj bo
povezan na omrežje, od koder bo imel dostop do Interneta, z drugim pa na SimpleArbiter. TestClient naj bo povezan na isto omrežje z dostopom do Interneta kot NATServer.
Poskrbi, da bo NATServer služil kot DHCP strežnik ter privzeti prehod za SimpleArbiter.
Na SimpleArbiter preberi vrednosti NET, PORT_OUTER in PORT_INNER ter vpiši IP_TEST_CLIENT. Poskrbi, da
bo omrežje med SimpleArbiter in NATServer na področju NET. Nato poskrbi, da se
bo TCP promet z omrežja z dostopom do Interneta na vrata PORT_OUTER prepošiljal na SimpleArbiter na vrata PORT_INNER.</pre>"""
}
computers = {
'TestClient': {
'disks': [
{ 'name': 'maliNetworkManager',
},
],
'network_interfaces': [{'network': 'test-net'}],
'flavor': 'm1.tiny',
'config_drive': False
},
'NATServer': {
'disks': [
{ 'name': 'student-NATServer',
},
],
'network_interfaces': [{'network': 'net1'}, {'network': 'test-net'}],
'flavor': 'm1.tiny',
'config_drive': False
},
'SimpleArbiter': {
'disks': [
{ 'name': 'simpleArbiter',
},
],
'network_interfaces': [{'network': 'net1'}],
'flavor': 'm1.tiny',
'config_drive': False
}
}
networks = { 'net1': {'public': False}, 'test-net': {'public': True} }
params_meta = {
'IP_TEST_CLIENT': {'descriptions': {'si': 'Naslov TestClient'}, 'w': True, 'public':True, 'type': 'IP', 'generated': False},
'IP_NAT': {'descriptions': {'si': 'Naslov NATServer, dostopen s TestClient'}, 'w': True, 'public':True, 'type': 'IP', 'generated': False},
'PORT_OUTER': {'descriptions': {'si': 'Zunanja vrata'}, 'w': False, 'public':True, 'type': 'port', 'generated': True},
'PORT_INNER': {'descriptions': {'si': 'Notranja vrata'}, 'w': False, 'public': True, 'type': 'port', 'generated': True},
'NET': {'descriptions': {'si': 'Področje naslovov med SimpleArbiter in TestClient'}, 'w': False, 'public': True, 'type': 'NET', 'generated': True},
}
def task(IP_TEST_CLIENT, IP_NAT, PORT_OUTER, PORT_INNER, NET):
import random
import time
import pexpect
from pexpect import pxssh
results = dict()
tcpdump = pexpect.spawn('sudo /usr/sbin/tcpdump src host {} and dst port {}'.format(IP_TEST_CLIENT, PORT_INNER), encoding='utf-8')
sshconn = pxssh.pxssh(encoding='utf-8')
sshconn.login(IP_TEST_CLIENT, 'student', 'vaje')
r = random.Random()
k = r.randint(10, 15)
results['pre_nc'] = str(k)
results['nc_pre'] = ""
for i in range(k):
sshconn.sendline("nc {} {}".format(IP_NAT, PORT_OUTER))
sshconn.sendline()
sshconn.sendintr()
sshconn.prompt()
results['nc_pre'] += sshconn.before
nc = pexpect.spawn('nc -l -p {}'.format(PORT_INNER), encoding='utf-8')
sshconn.sendline()
sshconn.prompt()
sshconn.sendline("nc {} {}".format(IP_NAT, PORT_OUTER))
results['post_nc'] = "".join([r.choice("abcd\n") for i in range(100)])
sshconn.sendline(results['post_nc'])
time.sleep(1)
sshconn.sendintr()
nc.expect(pexpect.EOF)
results['nc_ret'] = nc.before
results['route'] = pexpect.run('ip route list 0/0', encoding='utf-8')
results['traceroute'] = pexpect.run('traceroute {}'.format(IP_TEST_CLIENT), encoding='utf-8')
# wait for traceroute
time.sleep(10)
tcpdump.sendintr()
tcpdump.expect(pexpect.EOF)
results['tcpdump'] = tcpdump.before
sshconn.prompt()
results['nc_post'] = sshconn.before
sshconn.close()
# nc.expect(pexpect.EOF)
return results
def gen_params(user_id, params_meta):
params = dict()
r = random.Random(user_id)
params['PORT_INNER'] = str(r.randint(6000, 10000))
params['PORT_OUTER'] = str(r.randint(10001, 15000))
params['NET'] = kpov_util.IPv4_subnet_gen(r, "10.36.0.0/14", 24)
return params
def task_check(results, params):
import re
import pickle
score = 0
hints = []
local_net = params['NET'][:params['NET'].rfind('.')]
s = "default via ({}\\.[0-9]+)".format(re.escape(local_net))
res = re.search(s, results['route'])
if res:
ip_nat_internal = res.groups(1)[0]
score += 1
else:
ip_nat_internal = 'abrakadabra'
# print (s, results['route'],)
s = "traceroute to {ip_test} \\({ip_test}\\), 30 hops max, 60 byte packets\
\r\n 1 {ip_nat} \\({ip_nat}\\) [0-9.]+ ms [0-9.]+ ms [0-9.]+ ms\
.*{ip_test} \\({ip_test}\\)".format(
ip_nat = re.escape(ip_nat_internal),
ip_test = re.escape(params['IP_TEST_CLIENT'])
)
if re.search(s, results['traceroute'], re.DOTALL):
score += 1
else:
hints += [s + str(results['traceroute'])]
if len(results['post_nc']) == 100:
score += 1
else:
hints += [str(results['post_nc']) + str(len(results['post_nc']))]
if results['nc_ret'] == (results['post_nc'] + '\n').replace('\n', '\r\n'):
score += 1
else:
hints += ['wrong nc']
s = "Connection refused"
res = re.findall(s, results['nc_pre'])
if len(res) >= 2:
score += 3
else:
hints += [s + str(results['nc_pre'])]
s = "\r\n"
if re.search(s, results['nc_post']):
score += 1
else:
hints += [s + str(results['nc_post'])]
rejected_count = int(results['pre_nc'])
accepted_count = results['nc_ret'].count('\r\n')
s = ".*verbose output suppressed.*listening on.*dropped by kernel.*"
if re.match(s, results['tcpdump'], re.DOTALL):
score += 1
else:
hints += [s + str(results['tcpdump'])]
res = re.findall("length .*\r\n", results['tcpdump'])
total_len = 0
n_empty = 0
for i in res:
k = int(i[len("length "):].strip())
total_len += k
if k == 0:
n_empty += 1
# print total_len, rejected_count, n_empty
if total_len == 101 and rejected_count <= n_empty:
score += 1
else:
hints += [s + str(results['tcpdump'])]
return score, hints
def prepare_disks(templates, task_params, global_params):
write_default_config(templates['simpleArbiter'], global_params)
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