remove rttime-rlimit as root during loading

main.go

@@ -1,11 +1,13 @@
 package main
 
 import (
+	"flag"
 	"image"
 	"io"
 	"io/ioutil"
 	"log"
 	"os"
+	"syscall"
 
 	"github.com/aarzilli/nucular/font"
 
@@ -28,6 +30,19 @@ type input struct {
 
 func main() {
 
+	var pulsepid int
+	flag.IntVar(&pulsepid, "removerlimit", -1, "for internal use only")
+	flag.Parse()
+	if pulsepid > 0 {
+		const MaxUint = ^uint64(0)
+		new := syscall.Rlimit{Cur: MaxUint, Max: MaxUint}
+		err := setRlimit(pulsepid, &new)
+		if err != nil {
+			os.Exit(1)
+		}
+		os.Exit(0)
+	}
+
 	f, err := os.OpenFile("/tmp/noisetorch.log", os.O_RDWR|os.O_CREATE|os.O_APPEND, 0644)
 	if err != nil {
 		log.Fatalf("error opening file: %v\n", err)

module.go

@@ -59,6 +59,29 @@ func supressorState(c *pulseaudio.Client) int {
 }
 
 func loadSupressor(c *pulseaudio.Client, inp input, ui *uistate) error {
+
+	log.Printf("Querying pulse rlimit\n")
+
+	pid, err := getPulsePid()
+	if err != nil {
+		return err
+	}
+
+	lim, err := getRlimit(pid)
+	if err != nil {
+		return err
+	}
+	log.Printf("Rlimit: %+v. Trying to remove.\n", lim)
+	removeRlimitAsRoot(pid)
+	defer setRlimit(pid, &lim) // lowering RLIMIT doesn't require root
+
+	newLim, err := getRlimit(pid)
+	if err != nil {
+		return err
+	}
+	log.Printf("Rlimit: %+v\n", newLim)
+
+	time.Sleep(time.Millisecond * 1000) // pulseaudio gets SIGKILL'd because of RLIMITS if we send these too fast
 	log.Printf("Loading supressor\n")
 	idx, err := c.LoadModule("module-null-sink", "sink_name=nui_mic_denoised_out")
 	if err != nil {
@@ -108,6 +131,7 @@ func unloadSupressor(c *pulseaudio.Client) error {
 		log.Printf("Found null-sink at id [%d], sending unload command\n", m.Index)
 		c.UnloadModule(m.Index)
 	}
+	time.Sleep(time.Millisecond * 500) // pulseaudio gets SIGKILL'd because of RLIMITS if we send these too fast
 	log.Printf("Searching for ladspa-sink\n")
 	m, found, err = findModule(c, "module-ladspa-sink", "sink_name=nui_mic_raw_in sink_master=nui_mic_denoised_out")
 	if err != nil {
@@ -117,6 +141,7 @@ func unloadSupressor(c *pulseaudio.Client) error {
 		log.Printf("Found ladspa-sink at id [%d], sending unload command\n", m.Index)
 		c.UnloadModule(m.Index)
 	}
+	time.Sleep(time.Millisecond * 500) // pulseaudio gets SIGKILL'd because of RLIMITS if we send these too fast
 	log.Printf("Searching for loopback\n")
 	m, found, err = findModule(c, "module-loopback", "sink=nui_mic_raw_in")
 	if err != nil {
@@ -126,7 +151,7 @@ func unloadSupressor(c *pulseaudio.Client) error {
 		log.Printf("Found loopback at id [%d], sending unload command\n", m.Index)
 		c.UnloadModule(m.Index)
 	}
-
+	time.Sleep(time.Millisecond * 500) // pulseaudio gets SIGKILL'd because of RLIMITS if we send these too fast
 	log.Printf("Searching for remap-source\n")
 	m, found, err = findModule(c, "module-remap-source", "master=nui_mic_denoised_out.monitor source_name=nui_mic_remap")
 	if err != nil {

rlimit.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"io/ioutil"
+	"log"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"syscall"
+	"unsafe"
+)
+
+const rlimitRTTime = 15
+
+func getPulsePid() (int, error) {
+	runtimeDir := os.Getenv("XDG_RUNTIME_DIR")
+	pulsepidfile := filepath.Join(runtimeDir, "pulse/pid")
+	pidbuf, err := ioutil.ReadFile(pulsepidfile)
+	if err != nil {
+		return 0, err
+	}
+	pid, err := strconv.Atoi(strings.TrimSpace(string(pidbuf)))
+	if err != nil {
+		return 0, err
+	}
+	return pid, nil
+}
+
+func getRlimit(pid int) (syscall.Rlimit, error) {
+	var res syscall.Rlimit
+	err := pRlimit(pid, rlimitRTTime, nil, &res)
+	return res, err
+}
+
+func setRlimit(pid int, new *syscall.Rlimit) error {
+	var junk syscall.Rlimit
+	err := pRlimit(pid, rlimitRTTime, new, &junk)
+	return err
+}
+
+func removeRlimitAsRoot(pid int) {
+	self, err := os.Executable()
+	if err != nil {
+		log.Printf("Couldn't find path to own binary, trying PATH\n")
+		self = "noisetorch" //try PATH and hope for the best
+	}
+
+	cmd := exec.Command("pkexec", self, "-removerlimit", strconv.Itoa(pid))
+	log.Printf("Calling: %s\n", cmd.String())
+	err = cmd.Run()
+	if err != nil {
+		log.Printf("Couldn't remove rlimit as root: %v\n", err)
+	}
+}
+
+func pRlimit(pid int, limit uintptr, new *syscall.Rlimit, old *syscall.Rlimit) error {
+	_, _, errno := syscall.RawSyscall6(syscall.SYS_PRLIMIT64,
+		uintptr(pid),
+		limit,
+		uintptr(unsafe.Pointer(new)),
+		uintptr(unsafe.Pointer(old)), 0, 0)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}