bee/audit/internal/platform/export.go

package platform

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"sort"
	"strings"
)

var exportExecCommand = exec.Command

func formatMountTargetError(target RemovableTarget, raw string, err error) error {
	msg := strings.TrimSpace(raw)
	fstype := strings.ToLower(strings.TrimSpace(target.FSType))
	if fstype == "exfat" && strings.Contains(strings.ToLower(msg), "unknown filesystem type 'exfat'") {
		return fmt.Errorf("mount %s: exFAT support is missing in this ISO build: %w", target.Device, err)
	}
	if msg == "" {
		return err
	}
	return fmt.Errorf("%s: %w", msg, err)
}

func removableTargetReadOnly(fields map[string]string) bool {
	if fields["RO"] == "1" {
		return true
	}
	switch strings.ToLower(strings.TrimSpace(fields["FSTYPE"])) {
	case "iso9660", "squashfs":
		return true
	default:
		return false
	}
}

func ensureWritableMountpoint(mountpoint string) error {
	probe, err := os.CreateTemp(mountpoint, ".bee-write-test-*")
	if err != nil {
		return fmt.Errorf("target filesystem is not writable: %w", err)
	}
	name := probe.Name()
	if closeErr := probe.Close(); closeErr != nil {
		_ = os.Remove(name)
		return closeErr
	}
	if err := os.Remove(name); err != nil {
		return err
	}
	return nil
}

func (s *System) ListRemovableTargets() ([]RemovableTarget, error) {
	raw, err := exportExecCommand("lsblk", "-P", "-o", "NAME,TYPE,PKNAME,RM,RO,FSTYPE,MOUNTPOINT,SIZE,LABEL,MODEL").Output()
	if err != nil {
		return nil, err
	}

	var out []RemovableTarget
	for _, line := range strings.Split(strings.TrimSpace(string(raw)), "\n") {
		if strings.TrimSpace(line) == "" {
			continue
		}
		fields := parseLSBLKPairs(line)
		deviceType := fields["TYPE"]
		if deviceType == "rom" || deviceType == "loop" {
			continue
		}

		removable := fields["RM"] == "1"
		if !removable {
			if parent := fields["PKNAME"]; parent != "" {
				if data, err := os.ReadFile(filepath.Join("/sys/class/block", parent, "removable")); err == nil {
					removable = strings.TrimSpace(string(data)) == "1"
				}
			}
		}
		if !removable || fields["FSTYPE"] == "" || removableTargetReadOnly(fields) {
			continue
		}

		out = append(out, RemovableTarget{
			Device:     "/dev/" + fields["NAME"],
			FSType:     fields["FSTYPE"],
			Size:       fields["SIZE"],
			Label:      fields["LABEL"],
			Model:      fields["MODEL"],
			Mountpoint: fields["MOUNTPOINT"],
		})
	}

	sort.Slice(out, func(i, j int) bool { return out[i].Device < out[j].Device })
	return out, nil
}

func (s *System) ExportFileToTarget(src string, target RemovableTarget) (dst string, retErr error) {
	if src == "" || target.Device == "" {
		return "", fmt.Errorf("source and target are required")
	}
	if _, err := os.Stat(src); err != nil {
		return "", err
	}

	mountpoint := strings.TrimSpace(target.Mountpoint)
	mountedHere := false
	mounted := mountpoint != ""
	if mountpoint == "" {
		mountpoint = filepath.Join("/tmp", "bee-export-"+filepath.Base(target.Device))
		if err := os.MkdirAll(mountpoint, 0755); err != nil {
			return "", err
		}
		if raw, err := exportExecCommand("mount", target.Device, mountpoint).CombinedOutput(); err != nil {
			_ = os.Remove(mountpoint)
			return "", formatMountTargetError(target, string(raw), err)
		}
		mountedHere = true
		mounted = true
	}
	defer func() {
		if !mounted {
			return
		}
		_ = exportExecCommand("sync").Run()
		if raw, err := exportExecCommand("umount", mountpoint).CombinedOutput(); err != nil && retErr == nil {
			msg := strings.TrimSpace(string(raw))
			if msg == "" {
				retErr = err
			} else {
				retErr = fmt.Errorf("%s: %w", msg, err)
			}
		}
		if mountedHere {
			_ = os.Remove(mountpoint)
		}
	}()

	if err := ensureWritableMountpoint(mountpoint); err != nil {
		return "", err
	}

	filename := filepath.Base(src)
	dst = filepath.Join(mountpoint, filename)
	data, err := os.ReadFile(src)
	if err != nil {
		return "", err
	}
	if err := os.WriteFile(dst, data, 0644); err != nil {
		return "", err
	}

	return dst, nil
}

// mountRemovableTargetReadOnly mounts target for reading if it isn't
// already mounted (reusing its existing mountpoint otherwise), returning
// whether this call did the mounting so the caller knows whether to
// unmount afterward.
func mountRemovableTargetReadOnly(target RemovableTarget) (mountpoint string, mountedHere bool, err error) {
	if mp := strings.TrimSpace(target.Mountpoint); mp != "" {
		return mp, false, nil
	}
	mountpoint = filepath.Join("/tmp", "bee-scenario-"+filepath.Base(target.Device))
	if err := os.MkdirAll(mountpoint, 0755); err != nil {
		return "", false, err
	}
	if raw, err := exportExecCommand("mount", target.Device, mountpoint).CombinedOutput(); err != nil {
		_ = os.Remove(mountpoint)
		return "", false, formatMountTargetError(target, string(raw), err)
	}
	return mountpoint, true, nil
}

// ReadScenarioFromRemovableMedia mounts each removable target in turn
// (unmounting again afterward if it mounted it itself), looking for
// scenarios/<name>.json, and returns the contents of the first one found.
// Lets an air-gapped engineer author a scenario JSON file on another
// machine, drop it under scenarios/ on the same flash drive already
// plugged in for blackbox, and run it on the host with no network path
// required — see RunScenario/ParseScenarioJSON.
func (s *System) ReadScenarioFromRemovableMedia(name string) ([]byte, error) {
	name = strings.TrimSpace(name)
	if name == "" {
		return nil, fmt.Errorf("scenario name is required")
	}
	targets, err := s.ListRemovableTargets()
	if err != nil {
		return nil, err
	}
	for _, target := range targets {
		mountpoint, mountedHere, mountErr := mountRemovableTargetReadOnly(target)
		if mountErr != nil {
			continue
		}
		data, readErr := os.ReadFile(filepath.Join(mountpoint, "scenarios", name+".json"))
		if mountedHere {
			_, _ = exportExecCommand("umount", mountpoint).CombinedOutput()
			_ = os.Remove(mountpoint)
		}
		if readErr == nil {
			return data, nil
		}
	}
	return nil, fmt.Errorf("scenarios/%s.json not found on any removable media", name)
}

// ScenarioFileOnRemovableMedia is one scenarios/*.json file found on a
// mounted removable target, as returned by ListScenarioFilesOnRemovableMedia.
type ScenarioFileOnRemovableMedia struct {
	Name   string // filename without ".json" — what ReadScenarioFromRemovableMedia/bee run expects
	Device string // which removable target it was found on
}

// ListScenarioFilesOnRemovableMedia mounts each removable target in turn
// (unmounting again afterward if it mounted it itself) and collects every
// *.json file under a top-level scenarios/ directory. Used by the webui's
// Scenario page to show what's available to run without requiring the
// operator to already know a file's exact name.
func (s *System) ListScenarioFilesOnRemovableMedia() ([]ScenarioFileOnRemovableMedia, error) {
	targets, err := s.ListRemovableTargets()
	if err != nil {
		return nil, err
	}
	var out []ScenarioFileOnRemovableMedia
	for _, target := range targets {
		mountpoint, mountedHere, mountErr := mountRemovableTargetReadOnly(target)
		if mountErr != nil {
			continue
		}
		entries, readErr := os.ReadDir(filepath.Join(mountpoint, "scenarios"))
		if readErr == nil {
			for _, e := range entries {
				if e.IsDir() || !strings.HasSuffix(e.Name(), ".json") {
					continue
				}
				out = append(out, ScenarioFileOnRemovableMedia{
					Name:   strings.TrimSuffix(e.Name(), ".json"),
					Device: target.Device,
				})
			}
		}
		if mountedHere {
			_, _ = exportExecCommand("umount", mountpoint).CombinedOutput()
			_ = os.Remove(mountpoint)
		}
	}
	sort.Slice(out, func(i, j int) bool { return out[i].Name < out[j].Name })
	return out, nil
}

// LocalScenariosDir is where scenario JSON files shipped with the ISO
// itself live (rsync'd from this repo's scenarios/ into the overlay at
// build time — see iso/builder/build.sh's "preparing staged overlay" step
// and iso/overlay/usr/share/bee/scenarios/). Part of the read-only
// squashfs, so a scenario here is always available with no USB stick
// needed. A package var (not a const) so tests can point it at a temp dir.
var LocalScenariosDir = "/usr/share/bee/scenarios"

// ReadScenarioLocal reads scenarios/<name>.json from LocalScenariosDir.
func (s *System) ReadScenarioLocal(name string) ([]byte, error) {
	name = strings.TrimSpace(name)
	if name == "" {
		return nil, fmt.Errorf("scenario name is required")
	}
	return os.ReadFile(filepath.Join(LocalScenariosDir, name+".json"))
}

// ListLocalScenarioFiles lists the *.json files under LocalScenariosDir.
func (s *System) ListLocalScenarioFiles() ([]ScenarioFileOnRemovableMedia, error) {
	entries, err := os.ReadDir(LocalScenariosDir)
	if err != nil {
		if os.IsNotExist(err) {
			return nil, nil
		}
		return nil, err
	}
	var out []ScenarioFileOnRemovableMedia
	for _, e := range entries {
		if e.IsDir() || !strings.HasSuffix(e.Name(), ".json") {
			continue
		}
		out = append(out, ScenarioFileOnRemovableMedia{
			Name:   strings.TrimSuffix(e.Name(), ".json"),
			Device: "local (shipped with image)",
		})
	}
	sort.Slice(out, func(i, j int) bool { return out[i].Name < out[j].Name })
	return out, nil
}

// ReadScenario resolves scenarios/<name>.json, checking LocalScenariosDir
// first (always available, no removable media required) and falling back
// to ReadScenarioFromRemovableMedia. Prefer this over calling either one
// directly unless you specifically need to restrict the lookup to one
// source (as the tests for each do).
func (s *System) ReadScenario(name string) ([]byte, error) {
	if data, err := s.ReadScenarioLocal(name); err == nil {
		return data, nil
	}
	return s.ReadScenarioFromRemovableMedia(name)
}

// ListAvailableScenarios merges ListLocalScenarioFiles (first) with
// ListScenarioFilesOnRemovableMedia, for UIs that want to show everything
// runnable via ReadScenario in one list.
func (s *System) ListAvailableScenarios() ([]ScenarioFileOnRemovableMedia, error) {
	local, err := s.ListLocalScenarioFiles()
	if err != nil {
		return nil, err
	}
	removable, err := s.ListScenarioFilesOnRemovableMedia()
	if err != nil {
		// A removable-media scan failure (e.g. no lsblk) shouldn't hide the
		// scenarios that are always available regardless of media.
		return local, nil
	}
	return append(local, removable...), nil
}