123 lines
2.7 KiB
Go
123 lines
2.7 KiB
Go
// 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.
|
|
|
|
package controlclient
|
|
|
|
import (
|
|
"bytes"
|
|
"compress/gzip"
|
|
"context"
|
|
"fmt"
|
|
"log"
|
|
"net/http"
|
|
"runtime"
|
|
"strconv"
|
|
"time"
|
|
)
|
|
|
|
func dumpGoroutinesToURL(c *http.Client, targetURL string) {
|
|
ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
|
|
defer cancel()
|
|
|
|
zbuf := new(bytes.Buffer)
|
|
zw := gzip.NewWriter(zbuf)
|
|
zw.Write(scrubbedGoroutineDump())
|
|
zw.Close()
|
|
|
|
req, err := http.NewRequestWithContext(ctx, "PUT", targetURL, zbuf)
|
|
if err != nil {
|
|
log.Printf("dumpGoroutinesToURL: %v", err)
|
|
return
|
|
}
|
|
req.Header.Set("Content-Encoding", "gzip")
|
|
t0 := time.Now()
|
|
_, err = c.Do(req)
|
|
d := time.Since(t0).Round(time.Millisecond)
|
|
if err != nil {
|
|
log.Printf("dumpGoroutinesToURL error: %v to %v (after %v)", err, targetURL, d)
|
|
} else {
|
|
log.Printf("dumpGoroutinesToURL complete to %v (after %v)", targetURL, d)
|
|
}
|
|
}
|
|
|
|
// scrubbedGoroutineDump returns the list of all current goroutines, but with the actual
|
|
// values of arguments scrubbed out, lest it contain some private key material.
|
|
func scrubbedGoroutineDump() []byte {
|
|
var buf []byte
|
|
// Grab stacks multiple times into increasingly larger buffer sizes
|
|
// to minimize the risk that we blow past our iOS memory limit.
|
|
for size := 1 << 10; size <= 1<<20; size += 1 << 10 {
|
|
buf = make([]byte, size)
|
|
buf = buf[:runtime.Stack(buf, true)]
|
|
if len(buf) < size {
|
|
// It fit.
|
|
break
|
|
}
|
|
}
|
|
return scrubHex(buf)
|
|
}
|
|
|
|
func scrubHex(buf []byte) []byte {
|
|
saw := map[string][]byte{} // "0x123" => "v1%3" (unique value 1 and its value mod 8)
|
|
|
|
foreachHexAddress(buf, func(in []byte) {
|
|
if string(in) == "0x0" {
|
|
return
|
|
}
|
|
if v, ok := saw[string(in)]; ok {
|
|
for i := range in {
|
|
in[i] = '_'
|
|
}
|
|
copy(in, v)
|
|
return
|
|
}
|
|
inStr := string(in)
|
|
u64, err := strconv.ParseUint(string(in[2:]), 16, 64)
|
|
for i := range in {
|
|
in[i] = '_'
|
|
}
|
|
if err != nil {
|
|
in[0] = '?'
|
|
return
|
|
}
|
|
v := []byte(fmt.Sprintf("v%d%%%d", len(saw)+1, u64%8))
|
|
saw[inStr] = v
|
|
copy(in, v)
|
|
})
|
|
return buf
|
|
}
|
|
|
|
var ohx = []byte("0x")
|
|
|
|
// foreachHexAddress calls f with each subslice of b that matches
|
|
// regexp `0x[0-9a-f]*`.
|
|
func foreachHexAddress(b []byte, f func([]byte)) {
|
|
for len(b) > 0 {
|
|
i := bytes.Index(b, ohx)
|
|
if i == -1 {
|
|
return
|
|
}
|
|
b = b[i:]
|
|
hx := hexPrefix(b)
|
|
f(hx)
|
|
b = b[len(hx):]
|
|
}
|
|
}
|
|
|
|
func hexPrefix(b []byte) []byte {
|
|
for i, c := range b {
|
|
if i < 2 {
|
|
continue
|
|
}
|
|
if !isHexByte(c) {
|
|
return b[:i]
|
|
}
|
|
}
|
|
return b
|
|
}
|
|
|
|
func isHexByte(b byte) bool {
|
|
return '0' <= b && b <= '9' || 'a' <= b && b <= 'f' || 'A' <= b && b <= 'F'
|
|
}
|