1 files changed, 3 insertions, 84 deletions
diff --git a/control/controlclient/debug.go b/control/controlclient/debug.go
index b14643f7a..bc58b4fd5 100644
--- a/control/controlclient/debug.go
+++ b/control/controlclient/debug.go
@@ -8,12 +8,11 @@ import (
 	"bytes"
 	"compress/gzip"
 	"context"
-	"fmt"
 	"log"
 	"net/http"
-	"runtime"
-	"strconv"
 	"time"
+
+	"tailscale.com/util/goroutines"
 )
 
 func dumpGoroutinesToURL(c *http.Client, targetURL string) {
@@ -22,7 +21,7 @@ func dumpGoroutinesToURL(c *http.Client, targetURL string) {
 
 	zbuf := new(bytes.Buffer)
 	zw := gzip.NewWriter(zbuf)
-	zw.Write(scrubbedGoroutineDump())
+	zw.Write(goroutines.ScrubbedGoroutineDump())
 	zw.Close()
 
 	req, err := http.NewRequestWithContext(ctx, "PUT", targetURL, zbuf)
@@ -40,83 +39,3 @@ func dumpGoroutinesToURL(c *http.Client, targetURL string) {
 		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'
-}