1 files changed, 119 insertions, 0 deletions
diff --git a/cmd/sharefs/testsuite/main.go b/cmd/sharefs/testsuite/main.go
new file mode 100644
index 00000000..167875a1
--- /dev/null
+++ b/cmd/sharefs/testsuite/main.go
@@ -0,0 +1,119 @@
+//go:build testsuite
+
+// The sharefs test program checks cli behaviour and exercises the filesystem
+// implemented by cmd/sharefs using fs_mark.
+package main
+
+import (
+	"errors"
+	"log"
+	"os"
+	"os/exec"
+	"strings"
+	"syscall"
+
+	"hakurei.app/internal/testsuite"
+)
+
+// checkBadOpts invokes cmd/sharefs with the specified options and compares
+// the resulting error message.
+func checkBadOpts(cred *syscall.Credential, opts, want string) {
+	var buf strings.Builder
+	buf.Grow(len(want))
+
+	cmd := exec.Command(
+		"sharefs",
+		"-f",
+		"-o", "source=/etc,"+opts,
+		"/mnt",
+	)
+	cmd.SysProcAttr = &syscall.SysProcAttr{
+		Pdeathsig:  syscall.SIGKILL,
+		Credential: cred,
+	}
+	cmd.Stderr = &buf
+	err := cmd.Run()
+	if err == nil {
+		log.Fatalf("opts=%q, unexpected success", opts)
+	}
+	if e, ok := errors.AsType[*exec.ExitError](err); !ok {
+		log.Fatal(err)
+	} else if !e.Exited() {
+		log.Fatal(e)
+	}
+
+	if got := buf.String(); got != want {
+		log.Fatalf("opts=%q\n\t got:%q\n\twant:%q", opts, got, want)
+	}
+}
+
+func main() {
+	go testsuite.ReceiveSignals()
+
+	cred := syscall.Credential{Uid: 1000, Gid: 100}
+	if err := os.Mkdir("result", 0755); err != nil {
+		log.Fatal(err)
+	}
+
+	done := make(chan struct{})
+	go func() {
+		defer close(done)
+
+		testsuite.MustRun(
+			nil, nil,
+			"fs_mark",
+			"-v",
+			"-d", "/sdcard/fs_mark",
+			"-l", "result/fs_mark.log",
+		)
+	}()
+
+	log.Println("checking malformed setuid/setgid representation")
+	checkBadOpts(&cred, "setuid=ff", "sharefs: invalid value for option setuid\n")
+	checkBadOpts(&cred, "setgid=ff", "sharefs: invalid value for option setgid\n")
+
+	log.Println("checking bounds check for setuid/setgid")
+	checkBadOpts(&cred, "setuid=0", "sharefs: invalid value for option setuid\n")
+	checkBadOpts(&cred, "setgid=0", "sharefs: invalid value for option setgid\n")
+	checkBadOpts(&cred, "setuid=-1", "sharefs: invalid value for option setuid\n")
+	checkBadOpts(&cred, "setgid=-1", "sharefs: invalid value for option setgid\n")
+
+	log.Println("checking non-root setuid/setgid")
+	checkBadOpts(&cred, "setuid=1023", "sharefs: setuid and setgid has no effect when not starting as root\n")
+	checkBadOpts(&cred, "setgid=1023", "sharefs: setuid and setgid has no effect when not starting as root\n")
+	checkBadOpts(&cred, "setuid=1023,setgid=1023", "sharefs: setuid and setgid has no effect when not starting as root\n")
+	checkBadOpts(&cred, "mkdir", "sharefs: mkdir has no effect when not starting as root\n")
+
+	log.Println("checking root without setuid/setgid")
+	checkBadOpts(nil, "allow_other", "sharefs: setuid and setgid must not be 0\n")
+	checkBadOpts(nil, "setuid=1023", "sharefs: setuid and setgid must not be 0\n")
+	checkBadOpts(nil, "setgid=1023", "sharefs: setuid and setgid must not be 0\n")
+
+	log.Println("verifying mount point")
+	if err := os.Remove("/mnt"); err != nil {
+		log.Fatal(err)
+	}
+
+	log.Println("checking unprivileged mount/unmount")
+	testsuite.MustRun(&cred, nil, "mkdir", "/tmp/sdcard", "/tmp/persistent")
+	testsuite.MustRun(&cred, nil, "sharefs", "-o", "source=/tmp/persistent", "/tmp/sdcard")
+	testsuite.MustRun(&cred, nil, "touch", "/tmp/sdcard/check")
+	testsuite.MustRun(&cred, nil, "umount", "/tmp/sdcard")
+	testsuite.MustRun(&cred, nil, "rm", "/tmp/persistent/check")
+	testsuite.MustRun(&cred, nil, "rmdir", "/tmp/sdcard", "/tmp/persistent")
+
+	log.Println("waiting for fs_mark to complete")
+	<-done
+
+	const backingDir = "/var/lib/sdcard"
+	sharefsCred := syscall.Credential{Uid: 1023, Gid: 1023}
+	log.Println("checking permissions")
+	testsuite.MustRun(&sharefsCred, nil, "touch", backingDir+"/fs_mark/.check")
+	testsuite.MustRun(&sharefsCred, nil, "rm", backingDir+"/fs_mark/.check")
+	testsuite.MustRun(&cred, nil, "rm", "-rf", "/sdcard/fs_mark")
+	if _, err := os.ReadDir(backingDir + "/fs_mark"); err == nil {
+		log.Fatal("fs_mark directory was not removed")
+	} else if !errors.Is(err, os.ErrNotExist) {
+		log.Fatal(err)
+	}
+}