mirror of
https://github.com/tailscale/tailscale.git
synced 2024-11-26 11:35:35 +00:00
82 lines
2.1 KiB
Go
82 lines
2.1 KiB
Go
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// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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package vnet
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import (
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"fmt"
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"net/netip"
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)
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var vips = map[string]virtualIP{} // DNS name => details
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var (
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fakeDNS = newVIP("dns", "4.11.4.11", "2000:4:11::4:11")
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fakeProxyControlplane = newVIP("controlplane.tailscale.com", 1)
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fakeTestAgent = newVIP("test-driver.tailscale", 2)
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fakeControl = newVIP("control.tailscale", 3)
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fakeDERP1 = newVIP("derp1.tailscale", "33.4.0.1") // 3340=DERP; 1=derp 1
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fakeDERP2 = newVIP("derp2.tailscale", "33.4.0.2") // 3340=DERP; 2=derp 2
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fakeLogCatcher = newVIP("log.tailscale.io", 4)
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fakeSyslog = newVIP("syslog.tailscale", 9)
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)
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type virtualIP struct {
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name string // for DNS
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v4 netip.Addr
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v6 netip.Addr
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}
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func (v virtualIP) Match(a netip.Addr) bool {
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return v.v4 == a.Unmap() || v.v6 == a
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}
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// newVIP returns a new virtual IP.
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//
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// opts may be an IPv4 an IPv6 (in string form) or an int (bounded by uint8) to
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// use IPv4 of 52.52.0.x.
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//
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// If the IPv6 is omitted, one is derived from the IPv4.
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//
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// If an opt is invalid or the DNS name is already used, it panics.
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func newVIP(name string, opts ...any) (v virtualIP) {
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if _, ok := vips[name]; ok {
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panic(fmt.Sprintf("duplicate VIP %q", name))
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}
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v.name = name
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for _, o := range opts {
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switch o := o.(type) {
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case string:
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if ip, err := netip.ParseAddr(o); err == nil {
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if ip.Is4() {
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v.v4 = ip
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} else if ip.Is6() {
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v.v6 = ip
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}
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} else {
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panic(fmt.Sprintf("unsupported string option %q", o))
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}
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case int:
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if o <= 0 || o > 255 {
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panic(fmt.Sprintf("bad octet %d", o))
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}
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v.v4 = netip.AddrFrom4([4]byte{52, 52, 0, byte(o)})
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default:
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panic(fmt.Sprintf("unknown option type %T", o))
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}
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}
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if !v.v6.IsValid() && v.v4.IsValid() {
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// Map 1.2.3.4 to 2052::0102:0304
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a := [16]byte{0: 2, 2: 5, 3: 2} // 2052::
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copy(a[12:], v.v4.AsSlice())
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v.v6 = netip.AddrFrom16(a)
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}
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for _, b := range vips {
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if b.Match(v.v4) || b.Match(v.v6) {
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panic(fmt.Sprintf("VIP %q collides with %q", name, v.name))
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}
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}
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vips[name] = v
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return v
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}
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