TheArchive/tailscale
1
0
Fork 0
mirror of https://github.com/tailscale/tailscale.git synced 2025-02-18 02:48:40 +00:00
Code Issues Packages Projects Releases Wiki Activity

cmd/tailscaled, net/dns, wgengine/router: start Windows child processes with DETACHED_PROCESS when I/O is being piped

Browse Source 
When we're starting child processes on Windows that are CLI programs that
don't need to output to a console, we should pass in DETACHED_PROCESS as a
CreationFlag on SysProcAttr. This prevents the OS from even creating a console
for the child (and paying the associated time/space penalty for new conhost
processes). This is more efficient than letting the OS create the console
window and then subsequently trying to hide it, which we were doing at a few
callsites.

Fixes #12270

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
This commit is contained in:
Aaron Klotz 2024-06-05 14:57:08 -06:00
parent 4cdc4ed7db
commit 3511d1f8a2
5 changed files with 25 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
cmd/tailscaled/tailscaled_windows.go
View File

@ -435,6 +435,9 @@ func babysitProc(ctx context.Context, args []string, logf logger.Logf) {
startTime := time.Now()
log.Printf("exec: %#v %v", executable, args)
cmd := exec.Command(executable, args...)
cmd.SysProcAttr = &syscall.SysProcAttr{
CreationFlags: windows.DETACHED_PROCESS,
}
// Create a pipe object to use as the subproc's stdin.
// When the writer goes away, the reader gets EOF.

9
net/dns/flush_windows.go
View File

@ -6,10 +6,17 @@ package dns
import (
"fmt"
"os/exec"
"syscall"
"golang.org/x/sys/windows"
)
func flushCaches() error {
out, err := exec.Command("ipconfig", "/flushdns").CombinedOutput()
cmd := exec.Command("ipconfig", "/flushdns")
cmd.SysProcAttr = &syscall.SysProcAttr{
CreationFlags: windows.DETACHED_PROCESS,
}
out, err := cmd.CombinedOutput()
if err != nil {
return fmt.Errorf("%v (output: %s)", err, out)
}

8
net/dns/manager_windows.go
View File

@ -373,7 +373,9 @@ func (m *windowsManager) SetDNS(cfg OSConfig) error {
t0 := time.Now()
m.logf("running ipconfig /registerdns ...")
cmd := exec.Command("ipconfig", "/registerdns")
cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}
cmd.SysProcAttr = &syscall.SysProcAttr{
CreationFlags: windows.DETACHED_PROCESS,
}
err := cmd.Run()
d := time.Since(t0).Round(time.Millisecond)
if err != nil {
@ -385,7 +387,9 @@ func (m *windowsManager) SetDNS(cfg OSConfig) error {
t0 = time.Now()
m.logf("running ipconfig /flushdns ...")
cmd = exec.Command("ipconfig", "/flushdns")
cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}
cmd.SysProcAttr = &syscall.SysProcAttr{
CreationFlags: windows.DETACHED_PROCESS,
}
err = cmd.Run()
d = time.Since(t0).Round(time.Millisecond)
if err != nil {

4
net/dns/wsl_windows.go
View File

@ -228,8 +228,8 @@ func wslRun(cmd *exec.Cmd) (err error) {
}
cmd.SysProcAttr = &syscall.SysProcAttr{
Token: syscall.Token(token),
HideWindow: true,
CreationFlags: windows.CREATE_NO_WINDOW,
Token: syscall.Token(token),
}
return cmd.Run()
}

7
wgengine/router/router_windows.go
View File

@ -233,7 +233,9 @@ func (ft *firewallTweaker) runFirewall(args ...string) (time.Duration, error) {
t0 := time.Now()
args = append([]string{"advfirewall", "firewall"}, args...)
cmd := exec.Command(ft.getNetshPath(), args...)
cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}
cmd.SysProcAttr = &syscall.SysProcAttr{
CreationFlags: windows.DETACHED_PROCESS,
}
b, err := cmd.CombinedOutput()
if err != nil {
err = fmt.Errorf("%w: %v", err, string(b))
@ -356,6 +358,9 @@ func (ft *firewallTweaker) doSet(local []string, killswitch bool, clear bool, pr
return err
}
proc := exec.Command(exe, "/firewall", ft.tunGUID.String())
proc.SysProcAttr = &syscall.SysProcAttr{
CreationFlags: windows.DETACHED_PROCESS,
}
in, err := proc.StdinPipe()
if err != nil {
return err