fmsg: produce all output through fmsg

The behaviour of print functions from package fmt is not thread safe. Functions provided by fmsg wrap around Logger methods. This makes prefix much cleaner and makes it easy to deal with future changes to logging.

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

internal/init/main.go

@@ -4,7 +4,6 @@ import (
 	"encoding/gob"
 	"errors"
 	"flag"
-	"fmt"
 	"os"
 	"os/exec"
 	"os/signal"
@@ -13,7 +12,7 @@ import (
 	"syscall"
 	"time"
 
-	"git.ophivana.moe/security/fortify/internal/verbose"
+	"git.ophivana.moe/security/fortify/internal/fmsg"
 )
 
 const (
@@ -25,49 +24,46 @@ const (
 // 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 {
-			fmt.Println("fortify-init: cannot re-exec self:", err)
+			fmsg.Println("cannot re-exec self:", err)
 			// continue anyway
 		}
 	}
 
-	verbose.Prefix = "fortify-init:"
-
 	var payload Payload
 	p := os.NewFile(fd, "config-stream")
 	if p == nil {
-		fmt.Println("fortify-init: invalid config descriptor")
-		os.Exit(1)
+		fmsg.Fatal("invalid config descriptor")
 	}
 	if err := gob.NewDecoder(p).Decode(&payload); err != nil {
-		fmt.Println("fortify-init: cannot decode init payload:", err)
-		os.Exit(1)
+		fmsg.Fatal("cannot decode init payload:", err)
 	} else {
 		// sharing stdout with parent
 		// USE WITH CAUTION
-		verbose.Set(payload.Verbose)
+		fmsg.SetVerbose(payload.Verbose)
 
 		// child does not need to see this
 		if err = os.Unsetenv(EnvInit); err != nil {
-			fmt.Println("fortify-init: cannot unset", EnvInit+":", err)
+			fmsg.Println("cannot unset", EnvInit+":", err)
 			// not fatal
 		} else {
-			verbose.Println("received configuration")
+			fmsg.VPrintln("received configuration")
 		}
 	}
 
 	// close config fd
 	if err := p.Close(); err != nil {
-		fmt.Println("fortify-init: cannot close config fd:", err)
+		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 {
-		fmt.Println("fortify-init: prctl(PR_SET_PDEATHSIG, SIGKILL):", errno.Error())
-		os.Exit(1)
+		fmsg.Fatal("prctl(PR_SET_PDEATHSIG, SIGKILL):", errno.Error())
 	}
 
 	cmd := exec.Command(payload.Argv0)
@@ -84,8 +80,7 @@ func doInit(fd uintptr) {
 	}
 
 	if err := cmd.Start(); err != nil {
-		fmt.Printf("fortify-init: cannot start %q: %v", payload.Argv0, err)
-		os.Exit(1)
+		fmsg.Fatalf("cannot start %q: %v", payload.Argv0, err)
 	}
 
 	sig := make(chan os.Signal, 2)
@@ -121,7 +116,7 @@ func doInit(fd uintptr) {
 			}
 		}
 		if !errors.Is(err, syscall.ECHILD) {
-			fmt.Println("fortify-init: unexpected wait4 response:", err)
+			fmsg.Println("unexpected wait4 response:", err)
 		}
 
 		close(done)
@@ -133,7 +128,7 @@ func doInit(fd uintptr) {
 	for {
 		select {
 		case s := <-sig:
-			verbose.Println("received", s.String())
+			fmsg.VPrintln("received", s.String())
 			os.Exit(0)
 		case w := <-info:
 			if w.wpid == cmd.Process.Pid {
@@ -154,7 +149,7 @@ func doInit(fd uintptr) {
 		case <-done:
 			os.Exit(r)
 		case <-timeout:
-			fmt.Println("fortify-init: timeout exceeded waiting for lingering processes")
+			fmsg.Println("timeout exceeded waiting for lingering processes")
 			os.Exit(r)
 		}
 	}
@@ -169,8 +164,7 @@ func Try() {
 	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 {
-				fmt.Printf("fortify-init: cannot parse %q: %v", s, err)
-				os.Exit(1)
+				fmsg.Fatalf("cannot parse %q: %v", s, err)
 			} else {
 				doInit(uintptr(fd))
 			}