portlist: reduce log spam/scariness for portlist in mac sandbox
Fixes tailscale/corp#235
"log"
"os"
"strings"
+ "sync/atomic"
"time"
exec "tailscale.com/tempfork/osexec"
@@ -25,6 +26,8 @@ func listPorts() (List, error) {
return listPortsNetstat("-na")
}
+var lsofFailed int64 // atomic bool
+
// In theory, lsof could replace the function of both listPorts() and
// addProcesses(), since it provides a superset of the netstat output.
// However, "netstat -na" runs ~100x faster than lsof on my machine, so
@@ -33,19 +36,24 @@ func listPorts() (List, error) {
// TODO(apenwarr): this fails in a macOS sandbox (ie. our usual case).
// We might as well just delete this code if we can't find a solution.
func addProcesses(pl []Port) ([]Port, error) {
+ if atomic.LoadInt64(&lsofFailed) != 0 {
+ // This previously failed in the macOS sandbox, so don't try again.
+ return pl, nil
+ }
exe, err := exec.LookPath("lsof")
if err != nil {
return nil, fmt.Errorf("lsof: lookup: %v", err)
}
output, err := exec.Command(exe, "-F", "-n", "-P", "-O", "-S2", "-T", "-i4", "-i6").Output()
if err != nil {
- xe, ok := err.(*exec.ExitError)
- stderr := ""
- if ok {
- stderr = strings.TrimSpace(string(xe.Stderr))
+ var stderr []byte
+ if xe, ok := err.(*exec.ExitError); ok {
+ stderr = xe.Stderr
}
// fails when run in a macOS sandbox, so make this non-fatal.
- log.Printf("portlist: lsof: %v (%q)\n", err, stderr)
+ if atomic.CompareAndSwapInt64(&lsofFailed, 0, 1) {
+ log.Printf("portlist: can't run lsof in Mac sandbox; omitting process names from service list. Error details: %v, %s", err, bytes.TrimSpace(stderr))
+ }
return pl, nil
}
