77 lines
2.0 KiB
Go
77 lines
2.0 KiB
Go
// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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package main
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import (
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"context"
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"errors"
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"fmt"
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"log"
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"net"
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"net/netip"
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"strings"
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"time"
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"tailscale.com/derp"
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"tailscale.com/derp/derphttp"
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"tailscale.com/types/key"
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"tailscale.com/types/logger"
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)
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func startMesh(s *derp.Server) error {
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if *meshWith == "" {
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return nil
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}
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if !s.HasMeshKey() {
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return errors.New("--mesh-with requires --mesh-psk-file")
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}
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for _, host := range strings.Split(*meshWith, ",") {
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if err := startMeshWithHost(s, host); err != nil {
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return err
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}
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}
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return nil
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}
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func startMeshWithHost(s *derp.Server, host string) error {
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logf := logger.WithPrefix(log.Printf, fmt.Sprintf("mesh(%q): ", host))
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c, err := derphttp.NewClient(s.PrivateKey(), "https://"+host+"/derp", logf)
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if err != nil {
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return err
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}
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c.MeshKey = s.MeshKey()
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c.WatchConnectionChanges = true
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// For meshed peers within a region, connect via VPC addresses.
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c.SetURLDialer(func(ctx context.Context, network, addr string) (net.Conn, error) {
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host, port, err := net.SplitHostPort(addr)
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if err != nil {
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return nil, err
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}
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var d net.Dialer
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var r net.Resolver
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if base, ok := strings.CutSuffix(host, ".tailscale.com"); ok && port == "443" {
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subCtx, cancel := context.WithTimeout(ctx, 2*time.Second)
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defer cancel()
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vpcHost := base + "-vpc.tailscale.com"
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ips, _ := r.LookupIP(subCtx, "ip", vpcHost)
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if len(ips) > 0 {
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vpcAddr := net.JoinHostPort(ips[0].String(), port)
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c, err := d.DialContext(subCtx, network, vpcAddr)
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if err == nil {
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log.Printf("connected to %v (%v) instead of %v", vpcHost, ips[0], base)
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return c, nil
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}
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log.Printf("failed to connect to %v (%v): %v; trying non-VPC route", vpcHost, ips[0], err)
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}
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}
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return d.DialContext(ctx, network, addr)
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})
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add := func(k key.NodePublic, _ netip.AddrPort) { s.AddPacketForwarder(k, c) }
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remove := func(k key.NodePublic) { s.RemovePacketForwarder(k, c) }
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go c.RunWatchConnectionLoop(context.Background(), s.PublicKey(), logf, add, remove)
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return nil
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}
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