cmd: shim and init into separate binaries

This change also fixes a deadlock when shim fails to connect and complete the setup.

Signed-off-by: Ophestra Umiker <cat@ophivana.moe>

1 files changed, 0 insertions, 174 deletions

diff --git a/internal/init/main.go b/internal/init/main.go
deleted file mode 100644
index f2927728..00000000
--- a/internal/init/main.go
+++ /dev/null
@@ -1,174 +0,0 @@
-package init0
-
-import (
-	"encoding/gob"
-	"errors"
-	"flag"
-	"os"
-	"os/exec"
-	"os/signal"
-	"path"
-	"strconv"
-	"syscall"
-	"time"
-
-	"git.ophivana.moe/security/fortify/internal/fmsg"
-)
-
-const (
-	// time to wait for linger processes after death initial process
-	residualProcessTimeout = 5 * time.Second
-)
-
-// everything beyond this point runs within pid namespace
-// proceed with caution!
-
-func doInit(fd uintptr) {
-	fmsg.SetPrefix("init")
-
-	// re-exec
-	if len(os.Args) > 0 && os.Args[0] != "fortify" && path.IsAbs(os.Args[0]) {
-		if err := syscall.Exec(os.Args[0], []string{"fortify", "init"}, os.Environ()); err != nil {
-			fmsg.Println("cannot re-exec self:", err)
-			// continue anyway
-		}
-	}
-
-	var payload Payload
-	p := os.NewFile(fd, "config-stream")
-	if p == nil {
-		fmsg.Fatal("invalid config descriptor")
-	}
-	if err := gob.NewDecoder(p).Decode(&payload); err != nil {
-		fmsg.Fatal("cannot decode init payload:", err)
-	} else {
-		// sharing stdout with parent
-		// USE WITH CAUTION
-		fmsg.SetVerbose(payload.Verbose)
-
-		// child does not need to see this
-		if err = os.Unsetenv(EnvInit); err != nil {
-			fmsg.Println("cannot unset", EnvInit+":", err)
-			// not fatal
-		} else {
-			fmsg.VPrintln("received configuration")
-		}
-	}
-
-	// close config fd
-	if err := p.Close(); err != nil {
-		fmsg.Println("cannot close config fd:", err)
-		// not fatal
-	}
-
-	// die with parent
-	if _, _, errno := syscall.RawSyscall(syscall.SYS_PRCTL, syscall.PR_SET_PDEATHSIG, uintptr(syscall.SIGKILL), 0); errno != 0 {
-		fmsg.Fatal("prctl(PR_SET_PDEATHSIG, SIGKILL):", errno.Error())
-	}
-
-	cmd := exec.Command(payload.Argv0)
-	cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
-	cmd.Args = payload.Argv
-	cmd.Env = os.Environ()
-
-	// pass wayland fd
-	if payload.WL != -1 {
-		if f := os.NewFile(uintptr(payload.WL), "wayland"); f != nil {
-			cmd.Env = append(cmd.Env, "WAYLAND_SOCKET="+strconv.Itoa(3+len(cmd.ExtraFiles)))
-			cmd.ExtraFiles = append(cmd.ExtraFiles, f)
-		}
-	}
-
-	if err := cmd.Start(); err != nil {
-		fmsg.Fatalf("cannot start %q: %v", payload.Argv0, err)
-	}
-
-	sig := make(chan os.Signal, 2)
-	signal.Notify(sig, syscall.SIGINT, syscall.SIGTERM)
-
-	type winfo struct {
-		wpid    int
-		wstatus syscall.WaitStatus
-	}
-	info := make(chan winfo, 1)
-	done := make(chan struct{})
-
-	go func() {
-		var (
-			err     error
-			wpid    = -2
-			wstatus syscall.WaitStatus
-		)
-
-		// keep going until no child process is left
-		for wpid != -1 {
-			if err != nil {
-				break
-			}
-
-			if wpid != -2 {
-				info <- winfo{wpid, wstatus}
-			}
-
-			err = syscall.EINTR
-			for errors.Is(err, syscall.EINTR) {
-				wpid, err = syscall.Wait4(-1, &wstatus, 0, nil)
-			}
-		}
-		if !errors.Is(err, syscall.ECHILD) {
-			fmsg.Println("unexpected wait4 response:", err)
-		}
-
-		close(done)
-	}()
-
-	timeout := make(chan struct{})
-
-	r := 2
-	for {
-		select {
-		case s := <-sig:
-			fmsg.VPrintln("received", s.String())
-			fmsg.Exit(0)
-		case w := <-info:
-			if w.wpid == cmd.Process.Pid {
-				switch {
-				case w.wstatus.Exited():
-					r = w.wstatus.ExitStatus()
-				case w.wstatus.Signaled():
-					r = 128 + int(w.wstatus.Signal())
-				default:
-					r = 255
-				}
-
-				go func() {
-					time.Sleep(residualProcessTimeout)
-					close(timeout)
-				}()
-			}
-		case <-done:
-			fmsg.Exit(r)
-		case <-timeout:
-			fmsg.Println("timeout exceeded waiting for lingering processes")
-			fmsg.Exit(r)
-		}
-	}
-}
-
-// Try runs init and stops execution if FORTIFY_INIT is set.
-func Try() {
-	if os.Getpid() != 1 {
-		return
-	}
-
-	if args := flag.Args(); len(args) == 1 && args[0] == "init" {
-		if s, ok := os.LookupEnv(EnvInit); ok {
-			if fd, err := strconv.Atoi(s); err != nil {
-				fmsg.Fatalf("cannot parse %q: %v", s, err)
-			} else {
-				doInit(uintptr(fd))
-			}
-			panic("unreachable")
-		}
-	}
-}