65 lines
1.7 KiB
Go
65 lines
1.7 KiB
Go
// Copyright 2018-present the CoreDHCP Authors. All rights reserved
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// This source code is licensed under the MIT license found in the
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// LICENSE file in the root directory of this source tree.
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package ipv6only
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// This plugin implements RFC8925: if the client has requested the
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// IPv6-Only Preferred option, then add the option response and then
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// terminate processing immediately.
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//
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// This module should be invoked *before* any IP address
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// allocation has been done, so that the yiaddr is 0.0.0.0 and
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// no pool addresses are consumed for compatible clients.
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//
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// The optional argument is the V6ONLY_WAIT configuration variable,
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// described in RFC8925 section 3.2.
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import (
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"errors"
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"time"
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"github.com/coredhcp/coredhcp/handler"
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"github.com/coredhcp/coredhcp/logger"
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"github.com/coredhcp/coredhcp/plugins"
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"github.com/insomniacslk/dhcp/dhcpv4"
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"github.com/sirupsen/logrus"
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)
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var log = logger.GetLogger("plugins/ipv6only")
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var v6only_wait time.Duration
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var Plugin = plugins.Plugin{
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Name: "ipv6only",
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Setup4: setup4,
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}
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func setup4(args ...string) (handler.Handler4, error) {
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if len(args) > 0 {
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dur, err := time.ParseDuration(args[0])
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if err != nil {
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log.Errorf("invalid duration: %v", args[0])
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return nil, errors.New("ipv6only failed to initialize")
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}
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v6only_wait = dur
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}
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if len(args) > 1 {
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return nil, errors.New("too many arguments")
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}
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return Handler4, nil
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}
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func Handler4(req, resp *dhcpv4.DHCPv4) (*dhcpv4.DHCPv4, bool) {
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v6pref := req.IsOptionRequested(dhcpv4.OptionIPv6OnlyPreferred)
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log.WithFields(logrus.Fields{
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"mac": req.ClientHWAddr.String(),
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"ipv6only": v6pref,
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}).Debug("ipv6only status")
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if v6pref {
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resp.UpdateOption(dhcpv4.OptIPv6OnlyPreferred(v6only_wait))
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return resp, true
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}
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return resp, false
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}
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