1// Copyright 2017 Google Inc. All Rights Reserved.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package driver
16
17import (
18	"bytes"
19	"fmt"
20	"html/template"
21	"net"
22	"net/http"
23	gourl "net/url"
24	"os"
25	"os/exec"
26	"strconv"
27	"strings"
28	"time"
29
30	"github.com/google/pprof/internal/graph"
31	"github.com/google/pprof/internal/plugin"
32	"github.com/google/pprof/internal/report"
33	"github.com/google/pprof/profile"
34)
35
36// webInterface holds the state needed for serving a browser based interface.
37type webInterface struct {
38	prof         *profile.Profile
39	options      *plugin.Options
40	help         map[string]string
41	templates    *template.Template
42	settingsFile string
43}
44
45func makeWebInterface(p *profile.Profile, opt *plugin.Options) (*webInterface, error) {
46	settingsFile, err := settingsFileName()
47	if err != nil {
48		return nil, err
49	}
50	templates := template.New("templategroup")
51	addTemplates(templates)
52	report.AddSourceTemplates(templates)
53	return &webInterface{
54		prof:         p,
55		options:      opt,
56		help:         make(map[string]string),
57		templates:    templates,
58		settingsFile: settingsFile,
59	}, nil
60}
61
62// maxEntries is the maximum number of entries to print for text interfaces.
63const maxEntries = 50
64
65// errorCatcher is a UI that captures errors for reporting to the browser.
66type errorCatcher struct {
67	plugin.UI
68	errors []string
69}
70
71func (ec *errorCatcher) PrintErr(args ...interface{}) {
72	ec.errors = append(ec.errors, strings.TrimSuffix(fmt.Sprintln(args...), "\n"))
73	ec.UI.PrintErr(args...)
74}
75
76// webArgs contains arguments passed to templates in webhtml.go.
77type webArgs struct {
78	Title       string
79	Errors      []string
80	Total       int64
81	SampleTypes []string
82	Legend      []string
83	Help        map[string]string
84	Nodes       []string
85	HTMLBody    template.HTML
86	TextBody    string
87	Top         []report.TextItem
88	FlameGraph  template.JS
89	Configs     []configMenuEntry
90}
91
92func serveWebInterface(hostport string, p *profile.Profile, o *plugin.Options, disableBrowser bool) error {
93	host, port, err := getHostAndPort(hostport)
94	if err != nil {
95		return err
96	}
97	interactiveMode = true
98	ui, err := makeWebInterface(p, o)
99	if err != nil {
100		return err
101	}
102	for n, c := range pprofCommands {
103		ui.help[n] = c.description
104	}
105	for n, help := range configHelp {
106		ui.help[n] = help
107	}
108	ui.help["details"] = "Show information about the profile and this view"
109	ui.help["graph"] = "Display profile as a directed graph"
110	ui.help["reset"] = "Show the entire profile"
111	ui.help["save_config"] = "Save current settings"
112
113	server := o.HTTPServer
114	if server == nil {
115		server = defaultWebServer
116	}
117	args := &plugin.HTTPServerArgs{
118		Hostport: net.JoinHostPort(host, strconv.Itoa(port)),
119		Host:     host,
120		Port:     port,
121		Handlers: map[string]http.Handler{
122			"/":             http.HandlerFunc(ui.dot),
123			"/top":          http.HandlerFunc(ui.top),
124			"/disasm":       http.HandlerFunc(ui.disasm),
125			"/source":       http.HandlerFunc(ui.source),
126			"/peek":         http.HandlerFunc(ui.peek),
127			"/flamegraph":   http.HandlerFunc(ui.flamegraph),
128			"/saveconfig":   http.HandlerFunc(ui.saveConfig),
129			"/deleteconfig": http.HandlerFunc(ui.deleteConfig),
130		},
131	}
132
133	url := "http://" + args.Hostport
134
135	o.UI.Print("Serving web UI on ", url)
136
137	if o.UI.WantBrowser() && !disableBrowser {
138		go openBrowser(url, o)
139	}
140	return server(args)
141}
142
143func getHostAndPort(hostport string) (string, int, error) {
144	host, portStr, err := net.SplitHostPort(hostport)
145	if err != nil {
146		return "", 0, fmt.Errorf("could not split http address: %v", err)
147	}
148	if host == "" {
149		host = "localhost"
150	}
151	var port int
152	if portStr == "" {
153		ln, err := net.Listen("tcp", net.JoinHostPort(host, "0"))
154		if err != nil {
155			return "", 0, fmt.Errorf("could not generate random port: %v", err)
156		}
157		port = ln.Addr().(*net.TCPAddr).Port
158		err = ln.Close()
159		if err != nil {
160			return "", 0, fmt.Errorf("could not generate random port: %v", err)
161		}
162	} else {
163		port, err = strconv.Atoi(portStr)
164		if err != nil {
165			return "", 0, fmt.Errorf("invalid port number: %v", err)
166		}
167	}
168	return host, port, nil
169}
170func defaultWebServer(args *plugin.HTTPServerArgs) error {
171	ln, err := net.Listen("tcp", args.Hostport)
172	if err != nil {
173		return err
174	}
175	isLocal := isLocalhost(args.Host)
176	handler := http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
177		if isLocal {
178			// Only allow local clients
179			host, _, err := net.SplitHostPort(req.RemoteAddr)
180			if err != nil || !isLocalhost(host) {
181				http.Error(w, "permission denied", http.StatusForbidden)
182				return
183			}
184		}
185		h := args.Handlers[req.URL.Path]
186		if h == nil {
187			// Fall back to default behavior
188			h = http.DefaultServeMux
189		}
190		h.ServeHTTP(w, req)
191	})
192
193	// We serve the ui at /ui/ and redirect there from the root. This is done
194	// to surface any problems with serving the ui at a non-root early. See:
195	//
196	// https://github.com/google/pprof/pull/348
197	mux := http.NewServeMux()
198	mux.Handle("/ui/", http.StripPrefix("/ui", handler))
199	mux.Handle("/", redirectWithQuery("/ui"))
200	s := &http.Server{Handler: mux}
201	return s.Serve(ln)
202}
203
204func redirectWithQuery(path string) http.HandlerFunc {
205	return func(w http.ResponseWriter, r *http.Request) {
206		pathWithQuery := &gourl.URL{Path: path, RawQuery: r.URL.RawQuery}
207		http.Redirect(w, r, pathWithQuery.String(), http.StatusTemporaryRedirect)
208	}
209}
210
211func isLocalhost(host string) bool {
212	for _, v := range []string{"localhost", "127.0.0.1", "[::1]", "::1"} {
213		if host == v {
214			return true
215		}
216	}
217	return false
218}
219
220func openBrowser(url string, o *plugin.Options) {
221	// Construct URL.
222	baseURL, _ := gourl.Parse(url)
223	current := currentConfig()
224	u, _ := current.makeURL(*baseURL)
225
226	// Give server a little time to get ready.
227	time.Sleep(time.Millisecond * 500)
228
229	for _, b := range browsers() {
230		args := strings.Split(b, " ")
231		if len(args) == 0 {
232			continue
233		}
234		viewer := exec.Command(args[0], append(args[1:], u.String())...)
235		viewer.Stderr = os.Stderr
236		if err := viewer.Start(); err == nil {
237			return
238		}
239	}
240	// No visualizer succeeded, so just print URL.
241	o.UI.PrintErr(u.String())
242}
243
244// makeReport generates a report for the specified command.
245// If configEditor is not null, it is used to edit the config used for the report.
246func (ui *webInterface) makeReport(w http.ResponseWriter, req *http.Request,
247	cmd []string, configEditor func(*config)) (*report.Report, []string) {
248	cfg := currentConfig()
249	if err := cfg.applyURL(req.URL.Query()); err != nil {
250		http.Error(w, err.Error(), http.StatusBadRequest)
251		ui.options.UI.PrintErr(err)
252		return nil, nil
253	}
254	if configEditor != nil {
255		configEditor(&cfg)
256	}
257	catcher := &errorCatcher{UI: ui.options.UI}
258	options := *ui.options
259	options.UI = catcher
260	_, rpt, err := generateRawReport(ui.prof, cmd, cfg, &options)
261	if err != nil {
262		http.Error(w, err.Error(), http.StatusBadRequest)
263		ui.options.UI.PrintErr(err)
264		return nil, nil
265	}
266	return rpt, catcher.errors
267}
268
269// render generates html using the named template based on the contents of data.
270func (ui *webInterface) render(w http.ResponseWriter, req *http.Request, tmpl string,
271	rpt *report.Report, errList, legend []string, data webArgs) {
272	file := getFromLegend(legend, "File: ", "unknown")
273	profile := getFromLegend(legend, "Type: ", "unknown")
274	data.Title = file + " " + profile
275	data.Errors = errList
276	data.Total = rpt.Total()
277	data.SampleTypes = sampleTypes(ui.prof)
278	data.Legend = legend
279	data.Help = ui.help
280	data.Configs = configMenu(ui.settingsFile, *req.URL)
281
282	html := &bytes.Buffer{}
283	if err := ui.templates.ExecuteTemplate(html, tmpl, data); err != nil {
284		http.Error(w, "internal template error", http.StatusInternalServerError)
285		ui.options.UI.PrintErr(err)
286		return
287	}
288	w.Header().Set("Content-Type", "text/html")
289	w.Write(html.Bytes())
290}
291
292// dot generates a web page containing an svg diagram.
293func (ui *webInterface) dot(w http.ResponseWriter, req *http.Request) {
294	rpt, errList := ui.makeReport(w, req, []string{"svg"}, nil)
295	if rpt == nil {
296		return // error already reported
297	}
298
299	// Generate dot graph.
300	g, config := report.GetDOT(rpt)
301	legend := config.Labels
302	config.Labels = nil
303	dot := &bytes.Buffer{}
304	graph.ComposeDot(dot, g, &graph.DotAttributes{}, config)
305
306	// Convert to svg.
307	svg, err := dotToSvg(dot.Bytes())
308	if err != nil {
309		http.Error(w, "Could not execute dot; may need to install graphviz.",
310			http.StatusNotImplemented)
311		ui.options.UI.PrintErr("Failed to execute dot. Is Graphviz installed?\n", err)
312		return
313	}
314
315	// Get all node names into an array.
316	nodes := []string{""} // dot starts with node numbered 1
317	for _, n := range g.Nodes {
318		nodes = append(nodes, n.Info.Name)
319	}
320
321	ui.render(w, req, "graph", rpt, errList, legend, webArgs{
322		HTMLBody: template.HTML(string(svg)),
323		Nodes:    nodes,
324	})
325}
326
327func dotToSvg(dot []byte) ([]byte, error) {
328	cmd := exec.Command("dot", "-Tsvg")
329	out := &bytes.Buffer{}
330	cmd.Stdin, cmd.Stdout, cmd.Stderr = bytes.NewBuffer(dot), out, os.Stderr
331	if err := cmd.Run(); err != nil {
332		return nil, err
333	}
334
335	// Fix dot bug related to unquoted ampersands.
336	svg := bytes.Replace(out.Bytes(), []byte("&;"), []byte("&;"), -1)
337
338	// Cleanup for embedding by dropping stuff before the <svg> start.
339	if pos := bytes.Index(svg, []byte("<svg")); pos >= 0 {
340		svg = svg[pos:]
341	}
342	return svg, nil
343}
344
345func (ui *webInterface) top(w http.ResponseWriter, req *http.Request) {
346	rpt, errList := ui.makeReport(w, req, []string{"top"}, func(cfg *config) {
347		cfg.NodeCount = 500
348	})
349	if rpt == nil {
350		return // error already reported
351	}
352	top, legend := report.TextItems(rpt)
353	var nodes []string
354	for _, item := range top {
355		nodes = append(nodes, item.Name)
356	}
357
358	ui.render(w, req, "top", rpt, errList, legend, webArgs{
359		Top:   top,
360		Nodes: nodes,
361	})
362}
363
364// disasm generates a web page containing disassembly.
365func (ui *webInterface) disasm(w http.ResponseWriter, req *http.Request) {
366	args := []string{"disasm", req.URL.Query().Get("f")}
367	rpt, errList := ui.makeReport(w, req, args, nil)
368	if rpt == nil {
369		return // error already reported
370	}
371
372	out := &bytes.Buffer{}
373	if err := report.PrintAssembly(out, rpt, ui.options.Obj, maxEntries); err != nil {
374		http.Error(w, err.Error(), http.StatusBadRequest)
375		ui.options.UI.PrintErr(err)
376		return
377	}
378
379	legend := report.ProfileLabels(rpt)
380	ui.render(w, req, "plaintext", rpt, errList, legend, webArgs{
381		TextBody: out.String(),
382	})
383
384}
385
386// source generates a web page containing source code annotated with profile
387// data.
388func (ui *webInterface) source(w http.ResponseWriter, req *http.Request) {
389	args := []string{"weblist", req.URL.Query().Get("f")}
390	rpt, errList := ui.makeReport(w, req, args, nil)
391	if rpt == nil {
392		return // error already reported
393	}
394
395	// Generate source listing.
396	var body bytes.Buffer
397	if err := report.PrintWebList(&body, rpt, ui.options.Obj, maxEntries); err != nil {
398		http.Error(w, err.Error(), http.StatusBadRequest)
399		ui.options.UI.PrintErr(err)
400		return
401	}
402
403	legend := report.ProfileLabels(rpt)
404	ui.render(w, req, "sourcelisting", rpt, errList, legend, webArgs{
405		HTMLBody: template.HTML(body.String()),
406	})
407}
408
409// peek generates a web page listing callers/callers.
410func (ui *webInterface) peek(w http.ResponseWriter, req *http.Request) {
411	args := []string{"peek", req.URL.Query().Get("f")}
412	rpt, errList := ui.makeReport(w, req, args, func(cfg *config) {
413		cfg.Granularity = "lines"
414	})
415	if rpt == nil {
416		return // error already reported
417	}
418
419	out := &bytes.Buffer{}
420	if err := report.Generate(out, rpt, ui.options.Obj); err != nil {
421		http.Error(w, err.Error(), http.StatusBadRequest)
422		ui.options.UI.PrintErr(err)
423		return
424	}
425
426	legend := report.ProfileLabels(rpt)
427	ui.render(w, req, "plaintext", rpt, errList, legend, webArgs{
428		TextBody: out.String(),
429	})
430}
431
432// saveConfig saves URL configuration.
433func (ui *webInterface) saveConfig(w http.ResponseWriter, req *http.Request) {
434	if err := setConfig(ui.settingsFile, *req.URL); err != nil {
435		http.Error(w, err.Error(), http.StatusBadRequest)
436		ui.options.UI.PrintErr(err)
437		return
438	}
439}
440
441// deleteConfig deletes a configuration.
442func (ui *webInterface) deleteConfig(w http.ResponseWriter, req *http.Request) {
443	name := req.URL.Query().Get("config")
444	if err := removeConfig(ui.settingsFile, name); err != nil {
445		http.Error(w, err.Error(), http.StatusBadRequest)
446		ui.options.UI.PrintErr(err)
447		return
448	}
449}
450
451// getFromLegend returns the suffix of an entry in legend that starts
452// with param.  It returns def if no such entry is found.
453func getFromLegend(legend []string, param, def string) string {
454	for _, s := range legend {
455		if strings.HasPrefix(s, param) {
456			return s[len(param):]
457		}
458	}
459	return def
460}
461