1 files changed, 126 insertions, 0 deletions
diff --git a/test/sharefs/main.go b/test/sharefs/main.go
new file mode 100644
index 00000000..536a61b3
--- /dev/null
+++ b/test/sharefs/main.go
@@ -0,0 +1,126 @@
+//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"
+	"slices"
+	"strings"
+
+	"hakurei.app/test/internal/testsuite"
+)
+
+// checkBadOpts invokes cmd/sharefs with the specified options and compares
+// the resulting error message.
+func checkBadOpts(username, opts, want string) {
+	var buf strings.Builder
+	buf.Grow(len(want))
+
+	sudo := []string{"sudo", "-u", username, "-i", "--"}
+	if username == "root" {
+		sudo = nil
+	}
+
+	a := slices.Concat(sudo, []string{
+		"sharefs",
+		"-f",
+		"-o", "source=/etc," + opts,
+		"/mnt",
+	})
+	cmd := exec.Command(a[0], a[1:]...)
+	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()
+
+	if err := os.Mkdir("result", 0755); err != nil {
+		log.Fatal(err)
+	}
+
+	if len(os.Args) != 2 {
+		log.Fatal("expecting 1 argument")
+	}
+	username := os.Args[1]
+
+	done := make(chan struct{})
+	go func() {
+		defer close(done)
+
+		testsuite.MustRun(
+			"fs_mark",
+			"-v",
+			"-d", "/sdcard/fs_mark",
+			"-l", "result/fs_mark.log",
+		)
+	}()
+
+	log.Println("checking malformed setuid/setgid representation")
+	checkBadOpts(username, "setuid=ff", "sharefs: invalid value for option setuid\n")
+	checkBadOpts(username, "setgid=ff", "sharefs: invalid value for option setgid\n")
+
+	log.Println("checking bounds check for setuid/setgid")
+	checkBadOpts(username, "setuid=0", "sharefs: invalid value for option setuid\n")
+	checkBadOpts(username, "setgid=0", "sharefs: invalid value for option setgid\n")
+	checkBadOpts(username, "setuid=-1", "sharefs: invalid value for option setuid\n")
+	checkBadOpts(username, "setgid=-1", "sharefs: invalid value for option setgid\n")
+
+	log.Println("checking non-root setuid/setgid")
+	checkBadOpts(username, "setuid=1023", "sharefs: setuid and setgid has no effect when not starting as root\n")
+	checkBadOpts(username, "setgid=1023", "sharefs: setuid and setgid has no effect when not starting as root\n")
+	checkBadOpts(username, "setuid=1023,setgid=1023", "sharefs: setuid and setgid has no effect when not starting as root\n")
+	checkBadOpts(username, "mkdir", "sharefs: mkdir has no effect when not starting as root\n")
+
+	log.Println("checking root without setuid/setgid")
+	checkBadOpts("root", "allow_other", "sharefs: setuid and setgid must not be 0\n")
+	checkBadOpts("root", "setuid=1023", "sharefs: setuid and setgid must not be 0\n")
+	checkBadOpts("root", "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.MustRunAs(username, "-i", "mkdir", "/tmp/sdcard", "/tmp/persistent")
+	testsuite.MustRunAs(username, "-i", "sharefs", "-o", "source=/tmp/persistent", "/tmp/sdcard")
+	testsuite.MustRunAs(username, "-i", "touch", "/tmp/sdcard/check")
+	testsuite.MustRunAs(username, "-i", "umount", "/tmp/sdcard")
+	testsuite.MustRunAs(username, "-i", "rm", "/tmp/persistent/check")
+	testsuite.MustRunAs(username, "-i", "rmdir", "/tmp/sdcard", "/tmp/persistent")
+
+	log.Println("waiting for fs_mark to complete")
+	<-done
+
+	const (
+		backingDir  = "/var/lib/sdcard"
+		sharefsUser = "media_rw"
+	)
+	log.Println("checking permissions")
+	testsuite.MustRunAs(sharefsUser, "touch", backingDir+"/fs_mark/.check")
+	testsuite.MustRunAs(sharefsUser, "rm", backingDir+"/fs_mark/.check")
+	testsuite.MustRunAs(username, "-i", "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)
+	}
+}