def getLoopbackNet_per_net(sessionid, netid, ipversion):
Loopback.cfg_sanitation_checks(ipversion=ipversion)
loopback_net = 'ipv%d_loopback_net' % ipversion
loopback_net_per_netid = 'ipv%d_loopback_net_per_netid' % ipversion
if ipversion == 4:
ipprefix_cls = IPv4Prefix
elif ipversion == 6:
ipprefix_cls = IPv6Prefix
else:
raise ValueError('IP version is neither 4 nor 6: %s' % str(ipversion))
# local means per netid (e.g., AS)
try:
local_prefixlen = int(CONFIGS['ipaddrs'][loopback_net_per_netid])
except ValueError:
raise ValueError('Could not parse %s from ipaddrs.conf' % loopback_net_per_netid)
global_loopback_prefix = Loopback.getLoopbackNet(ipversion)
global_prefixbase, global_prefixlen = str(global_loopback_prefix).split('/')
subnet_id = NetIDSubnetMap.register_netid(sessionid, netid, ipversion)
baseprefix = ipprefix_cls('%s/%d' % (global_prefixbase, local_prefixlen))
target_network_baseaddr = baseprefix.minaddr() + ((subnet_id) * (baseprefix.numaddr() + 2))
target_network_prefix = ipprefix_cls('%s/%d' % (target_network_baseaddr, local_prefixlen))
return target_network_prefix
def clear_session(cls, session):
NetIDSubnetMap.clear_map(session.sessionid)
