diff options
| author | Ophestra <cat@gensokyo.uk> | 2025-01-18 11:47:01 +0900 |
|---|---|---|
| committer | Ophestra <cat@gensokyo.uk> | 2025-01-18 11:47:01 +0900 |
| commit | 27d2914286495bf83b163172d5084a91222e7ed7 (patch) | |
| tree | cd1f66cb3808fb65364b13a7865401ff5bb070ec /cmd | |
| parent | ea8f228af36b2c9ae9918f7760c3af4f1e21cfa2 (diff) | |
proc/priv/init: merge init into main program
Signed-off-by: Ophestra <cat@gensokyo.uk>
Diffstat (limited to 'cmd')
| -rw-r--r-- | cmd/finit/ipc/payload.go | 13 | ||||
| -rw-r--r-- | cmd/finit/main.go | 174 |
2 files changed, 0 insertions, 187 deletions
diff --git a/cmd/finit/ipc/payload.go b/cmd/finit/ipc/payload.go deleted file mode 100644 index d1dc9ec3..00000000 --- a/cmd/finit/ipc/payload.go +++ /dev/null @@ -1,13 +0,0 @@ -package init0 - -const Env = "FORTIFY_INIT" - -type Payload struct { - // target full exec path - Argv0 string - // child full argv - Argv []string - - // verbosity pass through - Verbose bool -} diff --git a/cmd/finit/main.go b/cmd/finit/main.go deleted file mode 100644 index 14283f2b..00000000 --- a/cmd/finit/main.go +++ /dev/null @@ -1,174 +0,0 @@ -package main - -import ( - "errors" - "os" - "os/exec" - "os/signal" - "path" - "syscall" - "time" - - init0 "git.gensokyo.uk/security/fortify/cmd/finit/ipc" - "git.gensokyo.uk/security/fortify/internal" - "git.gensokyo.uk/security/fortify/internal/fmsg" - "git.gensokyo.uk/security/fortify/internal/proc" -) - -const ( - // time to wait for linger processes after death of initial process - residualProcessTimeout = 5 * time.Second -) - -// everything beyond this point runs within pid namespace -// proceed with caution! - -func main() { - // sharing stdout with shim - // USE WITH CAUTION - fmsg.SetPrefix("init") - - // setting this prevents ptrace - if err := internal.PR_SET_DUMPABLE__SUID_DUMP_DISABLE(); err != nil { - fmsg.Fatalf("cannot set SUID_DUMP_DISABLE: %s", err) - panic("unreachable") - } - - if os.Getpid() != 1 { - fmsg.Fatal("this process must run as pid 1") - panic("unreachable") - } - - // re-exec - if len(os.Args) > 0 && (os.Args[0] != "finit" || len(os.Args) != 1) && path.IsAbs(os.Args[0]) { - if err := syscall.Exec(os.Args[0], []string{"finit"}, os.Environ()); err != nil { - fmsg.Println("cannot re-exec self:", err) - // continue anyway - } - } - - // receive setup payload - var ( - payload init0.Payload - closeSetup func() error - ) - if f, err := proc.Receive(init0.Env, &payload); err != nil { - if errors.Is(err, proc.ErrInvalid) { - fmsg.Fatal("invalid config descriptor") - } - if errors.Is(err, proc.ErrNotSet) { - fmsg.Fatal("FORTIFY_INIT not set") - } - - fmsg.Fatalf("cannot decode init setup payload: %v", err) - panic("unreachable") - } else { - fmsg.SetVerbose(payload.Verbose) - closeSetup = f - - // child does not need to see this - if err = os.Unsetenv(init0.Env); err != nil { - fmsg.Printf("cannot unset %s: %v", init0.Env, err) - // not fatal - } else { - fmsg.VPrintln("received configuration") - } - } - - // die with parent - if err := internal.PR_SET_PDEATHSIG__SIGKILL(); err != nil { - fmsg.Fatalf("prctl(PR_SET_PDEATHSIG, SIGKILL): %v", err) - } - - 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() - - if err := cmd.Start(); err != nil { - fmsg.Fatalf("cannot start %q: %v", payload.Argv0, err) - } - fmsg.Suspend() - - // close setup pipe as setup is now complete - if err := closeSetup(); err != nil { - fmsg.Println("cannot close setup pipe:", err) - // not fatal - } - - 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) - }() - - // closed after residualProcessTimeout has elapsed after initial process death - timeout := make(chan struct{}) - - r := 2 - for { - select { - case s := <-sig: - fmsg.VPrintln("received", s.String()) - fmsg.Resume() // output could still be withheld at this point, so resume is called - fmsg.Exit(0) - case w := <-info: - if w.wpid == cmd.Process.Pid { - // initial process exited, output is most likely available again - fmsg.Resume() - - 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) - } - } -} |
