44 lines
1.5 KiB
Python
44 lines
1.5 KiB
Python
from django.db import transaction
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from django.db.models import Count, F
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from .models import *
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def get_suitable_pools(subnetwork_mask):
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"""
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Find suitable pools for a certain network size.
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First, filter for all pools that offer the requested subnetwork_size.
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Then find those pools that are not fully exhausted:
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The number of available networks in a pool is 2^(subnetwork_size-network_size.
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The number of available networks in a pool is given by the number of VPNNetworkreservations.
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"""
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return WireGuardVPNPool.objects.annotate(
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num_reservations=Count('wireguardvpn'),
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max_reservations=2**(F('subnetwork_mask')-F('network_mask'))).filter(
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num_reservations__lt=F('max_reservations'),
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subnetwork_mask=subnetwork_mask)
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def allowed_vpn_network_reservation_size():
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"""
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Find all possible sizes of subnetworks that are available.
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Select all pools with free networks.
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Get their subnetwork sizes, reduce to a set
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"""
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pools = WireGuardVPNPool.objects.annotate(num_reservations=Count('wireguardvpn'),
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max_reservations=2**(F('subnetwork_mask')-F('network_mask'))).filter(
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num_reservations__lt=F('max_reservations'))
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# Need to return set of tuples, see
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# https://docs.djangoproject.com/en/3.1/ref/models/fields/#field-choices
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# return set([ (pool.subnetwork_mask, pool.subnetwork_mask) for pool in pools ])
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return set([pool.subnetwork_mask for pool in pools ])
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