// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. // The hello binary runs hello.ipn.dev. package main // import "tailscale.com/cmd/hello" import ( "context" "encoding/json" "flag" "fmt" "html/template" "io/ioutil" "log" "net" "net/http" "net/url" "strings" "tailscale.com/safesocket" "tailscale.com/tailcfg" ) var ( httpAddr = flag.String("http", ":80", "address to run an HTTP server on, or empty for none") httpsAddr = flag.String("https", ":443", "address to run an HTTPS server on, or empty for none") ) func main() { flag.Parse() if !devMode() { tmpl = template.Must(template.New("home").Parse(slurpHTML())) } http.HandleFunc("/", root) log.Printf("Starting hello server.") errc := make(chan error, 1) if *httpAddr != "" { log.Printf("running HTTP server on %s", *httpAddr) go func() { errc <- http.ListenAndServe(*httpAddr, nil) }() } if *httpsAddr != "" { log.Printf("running HTTPS server on %s", *httpsAddr) go func() { errc <- http.ListenAndServeTLS(*httpsAddr, "/etc/hello/hello.ipn.dev.crt", "/etc/hello/hello.ipn.dev.key", nil, ) }() } log.Fatal(<-errc) } func slurpHTML() string { slurp, err := ioutil.ReadFile("hello.tmpl.html") if err != nil { log.Fatal(err) } return string(slurp) } func devMode() bool { return *httpsAddr == "" && *httpAddr != "" } func getTmpl() (*template.Template, error) { if devMode() { return template.New("home").Parse(slurpHTML()) } return tmpl, nil } var tmpl *template.Template // not used in dev mode, initialized by main after flag parse type tmplData struct { DisplayName string // "Foo Barberson" LoginName string // "foo@bar.com" ProfilePicURL string // "https://..." MachineName string // "imac5k" MachineOS string // "Linux" IP string // "100.2.3.4" } func root(w http.ResponseWriter, r *http.Request) { if r.TLS == nil && *httpsAddr != "" { host := r.Host if strings.Contains(r.Host, "100.101.102.103") { host = "hello.ipn.dev" } http.Redirect(w, r, "https://"+host, http.StatusFound) return } if r.RequestURI != "/" { http.Redirect(w, r, "/", http.StatusFound) return } ip, _, err := net.SplitHostPort(r.RemoteAddr) if err != nil { http.Error(w, "no remote addr", 500) return } tmpl, err := getTmpl() if err != nil { w.Header().Set("Content-Type", "text/plain") http.Error(w, "template error: "+err.Error(), 500) return } who, err := whoIs(ip) var data tmplData if err != nil { if devMode() { data = tmplData{ DisplayName: "Taily Scalerson", LoginName: "taily@scaler.son", ProfilePicURL: "https://placekitten.com/200/200", MachineName: "scaled", MachineOS: "Linux", IP: "100.1.2.3", } } else { log.Printf("whois(%q) error: %v", ip, err) http.Error(w, "Your Tailscale works, but we failed to look you up.", 500) return } } else { data = tmplData{ DisplayName: who.UserProfile.DisplayName, LoginName: who.UserProfile.LoginName, ProfilePicURL: who.UserProfile.ProfilePicURL, MachineName: who.Node.ComputedName, MachineOS: who.Node.Hostinfo.OS, IP: ip, } } w.Header().Set("Content-Type", "text/html; charset=utf-8") tmpl.Execute(w, data) } // tsSockClient does HTTP requests to the local Tailscale daemon. // The hostname in the HTTP request is ignored. var tsSockClient = &http.Client{ Transport: &http.Transport{ DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) { return safesocket.ConnectDefault() }, }, } func whoIs(ip string) (*tailcfg.WhoIsResponse, error) { res, err := tsSockClient.Get("http://local-tailscaled.sock/localapi/v0/whois?ip=" + url.QueryEscape(ip)) if err != nil { return nil, err } defer res.Body.Close() slurp, _ := ioutil.ReadAll(res.Body) if res.StatusCode != 200 { return nil, fmt.Errorf("HTTP %s: %s", res.Status, slurp) } r := new(tailcfg.WhoIsResponse) if err := json.Unmarshal(slurp, r); err != nil { if max := 200; len(slurp) > max { slurp = slurp[:max] } return nil, fmt.Errorf("failed to parse JSON WhoIsResponse from %q", slurp) } return r, nil }