74 lines
1.9 KiB
Go
74 lines
1.9 KiB
Go
// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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package router
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import (
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"sync"
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"tailscale.com/net/dns"
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)
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// CallbackRouter is an implementation of both Router and dns.OSConfigurator.
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// When either network or DNS settings are changed, SetBoth is called with both configs.
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// Mainly used as a shim for OSes that want to set both network and
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// DNS configuration simultaneously (Mac, iOS, Android).
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type CallbackRouter struct {
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SetBoth func(rcfg *Config, dcfg *dns.OSConfig) error
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SplitDNS bool
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// GetBaseConfigFunc optionally specifies a function to return the current DNS
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// config in response to GetBaseConfig.
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//
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// If nil, reading the current config isn't supported and GetBaseConfig()
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// will return ErrGetBaseConfigNotSupported.
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GetBaseConfigFunc func() (dns.OSConfig, error)
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mu sync.Mutex // protects all the following
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rcfg *Config // last applied router config
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dcfg *dns.OSConfig // last applied DNS config
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}
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// Up implements Router.
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func (r *CallbackRouter) Up() error {
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return nil // TODO: check that all callers have no need for initialization
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}
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// Set implements Router.
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func (r *CallbackRouter) Set(rcfg *Config) error {
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r.mu.Lock()
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defer r.mu.Unlock()
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if r.rcfg.Equal(rcfg) {
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return nil
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}
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r.rcfg = rcfg
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return r.SetBoth(r.rcfg, r.dcfg)
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}
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// SetDNS implements dns.OSConfigurator.
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func (r *CallbackRouter) SetDNS(dcfg dns.OSConfig) error {
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r.mu.Lock()
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defer r.mu.Unlock()
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if r.dcfg != nil && r.dcfg.Equal(dcfg) {
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return nil
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}
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r.dcfg = &dcfg
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return r.SetBoth(r.rcfg, r.dcfg)
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}
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// SupportsSplitDNS implements dns.OSConfigurator.
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func (r *CallbackRouter) SupportsSplitDNS() bool {
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return r.SplitDNS
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}
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func (r *CallbackRouter) GetBaseConfig() (dns.OSConfig, error) {
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if r.GetBaseConfigFunc == nil {
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return dns.OSConfig{}, dns.ErrGetBaseConfigNotSupported
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}
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return r.GetBaseConfigFunc()
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}
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func (r *CallbackRouter) Close() error {
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return r.SetBoth(nil, nil) // TODO: check if makes sense
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}
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