Files
bee/audit/internal/platform/install_to_ram.go
2026-04-07 20:21:06 +03:00

302 lines
8.2 KiB
Go

package platform
import (
"context"
"encoding/json"
"fmt"
"io"
"os"
"os/exec"
"path/filepath"
"strings"
)
func (s *System) IsLiveMediaInRAM() bool {
fsType := mountFSType("/run/live/medium")
if fsType == "" {
return toramActive()
}
return strings.EqualFold(fsType, "tmpfs")
}
func (s *System) LiveBootSource() LiveBootSource {
fsType := mountFSType("/run/live/medium")
source := mountSource("/run/live/medium")
device := findLiveBootDevice()
status := LiveBootSource{
InRAM: strings.EqualFold(fsType, "tmpfs"),
Source: source,
Device: device,
}
if fsType == "" && source == "" && device == "" {
if toramActive() {
status.InRAM = true
status.Kind = "ram"
status.Source = "tmpfs"
return status
}
status.Kind = "unknown"
return status
}
status.Kind = inferLiveBootKind(fsType, source, blockDeviceType(device), blockDeviceTransport(device))
if status.Kind == "" {
status.Kind = "unknown"
}
if status.InRAM && strings.TrimSpace(status.Source) == "" {
status.Source = "tmpfs"
}
return status
}
func (s *System) RunInstallToRAM(ctx context.Context, logFunc func(string)) error {
log := func(msg string) {
if logFunc != nil {
logFunc(msg)
}
}
if s.IsLiveMediaInRAM() {
log("Already running from RAM — installation media can be safely disconnected.")
return nil
}
squashfsFiles, err := filepath.Glob("/run/live/medium/live/*.squashfs")
if err != nil || len(squashfsFiles) == 0 {
return fmt.Errorf("no squashfs files found in /run/live/medium/live/")
}
free := freeMemBytes()
var needed int64
for _, sf := range squashfsFiles {
fi, err2 := os.Stat(sf)
if err2 != nil {
return fmt.Errorf("stat %s: %v", sf, err2)
}
needed += fi.Size()
}
const headroom = 256 * 1024 * 1024
if free > 0 && needed+headroom > free {
return fmt.Errorf("insufficient RAM: need %s, available %s",
humanBytes(needed+headroom), humanBytes(free))
}
dstDir := "/dev/shm/bee-live"
if err := os.MkdirAll(dstDir, 0755); err != nil {
return fmt.Errorf("create tmpfs dir: %v", err)
}
for _, sf := range squashfsFiles {
if err := ctx.Err(); err != nil {
return err
}
base := filepath.Base(sf)
dst := filepath.Join(dstDir, base)
log(fmt.Sprintf("Copying %s to RAM...", base))
if err := copyFileLarge(ctx, sf, dst, log); err != nil {
return fmt.Errorf("copy %s: %v", base, err)
}
log(fmt.Sprintf("Copied %s.", base))
loopDev, err := findLoopForFile(sf)
if err != nil {
log(fmt.Sprintf("Loop device for %s not found (%v) — skipping re-association.", base, err))
continue
}
if err := reassociateLoopDevice(loopDev, dst); err != nil {
log(fmt.Sprintf("Warning: could not re-associate %s → %s: %v", loopDev, dst, err))
} else {
log(fmt.Sprintf("Loop device %s now backed by RAM copy.", loopDev))
}
}
log("Copying remaining medium files...")
if err := cpDir(ctx, "/run/live/medium", dstDir, log); err != nil {
log(fmt.Sprintf("Warning: partial copy: %v", err))
}
if err := ctx.Err(); err != nil {
return err
}
mediumRebound := false
if err := bindMount(dstDir, "/run/live/medium"); err != nil {
log(fmt.Sprintf("Warning: rebind /run/live/medium → %s failed: %v", dstDir, err))
} else {
mediumRebound = true
}
log("Verifying live medium now served from RAM...")
status := s.LiveBootSource()
if err := verifyInstallToRAMStatus(status, dstDir, mediumRebound, log); err != nil {
return err
}
if status.InRAM {
log(fmt.Sprintf("Verification passed: live medium now served from %s.", describeLiveBootSource(status)))
}
log("Done. Squashfs files are in RAM. Installation media can be safely disconnected.")
return nil
}
func verifyInstallToRAMStatus(status LiveBootSource, dstDir string, mediumRebound bool, log func(string)) error {
if status.InRAM {
return nil
}
// The live medium mount was not redirected to RAM. This is expected when
// booting from an ISO/CD-ROM: the squashfs loop device has a non-zero
// offset and LOOP_CHANGE_FD cannot be used; the bind mount also fails
// because the CD-ROM mount is in use. Check whether files were at least
// copied to the tmpfs directory — that is sufficient for safe disconnection
// once the kernel has paged in all actively-used data.
files, _ := filepath.Glob(filepath.Join(dstDir, "*.squashfs"))
if len(files) > 0 {
if !mediumRebound {
log(fmt.Sprintf("Note: squashfs copied to RAM (%s) but /run/live/medium still shows the original source.", dstDir))
log("This is normal for CD-ROM boots. For a fully transparent RAM boot, add 'toram' to the kernel parameters.")
}
return nil
}
return fmt.Errorf("install to RAM verification failed: live medium still mounted from %s and no squashfs found in %s", describeLiveBootSource(status), dstDir)
}
func describeLiveBootSource(status LiveBootSource) string {
source := strings.TrimSpace(status.Device)
if source == "" {
source = strings.TrimSpace(status.Source)
}
if source == "" {
source = "unknown source"
}
switch strings.TrimSpace(status.Kind) {
case "ram":
return "RAM"
case "usb":
return "USB (" + source + ")"
case "cdrom":
return "CD-ROM (" + source + ")"
case "disk":
return "disk (" + source + ")"
default:
return source
}
}
func copyFileLarge(ctx context.Context, src, dst string, logFunc func(string)) error {
in, err := os.Open(src)
if err != nil {
return err
}
defer in.Close()
fi, err := in.Stat()
if err != nil {
return err
}
out, err := os.Create(dst)
if err != nil {
return err
}
defer out.Close()
total := fi.Size()
var copied int64
buf := make([]byte, 4*1024*1024)
for {
if err := ctx.Err(); err != nil {
return err
}
n, err := in.Read(buf)
if n > 0 {
if _, werr := out.Write(buf[:n]); werr != nil {
return werr
}
copied += int64(n)
if logFunc != nil && total > 0 {
pct := int(float64(copied) / float64(total) * 100)
logFunc(fmt.Sprintf(" %s / %s (%d%%)", humanBytes(copied), humanBytes(total), pct))
}
}
if err == io.EOF {
break
}
if err != nil {
return err
}
}
return out.Sync()
}
func cpDir(ctx context.Context, src, dst string, logFunc func(string)) error {
return filepath.Walk(src, func(path string, fi os.FileInfo, err error) error {
if ctx.Err() != nil {
return ctx.Err()
}
if err != nil {
return nil
}
rel, _ := filepath.Rel(src, path)
target := filepath.Join(dst, rel)
if fi.IsDir() {
return os.MkdirAll(target, fi.Mode())
}
if strings.HasSuffix(path, ".squashfs") {
return nil
}
if _, err := os.Stat(target); err == nil {
return nil
}
return copyFileLarge(ctx, path, target, nil)
})
}
func findLoopForFile(backingFile string) (string, error) {
out, err := exec.Command("losetup", "--list", "--json").Output()
if err != nil {
return "", err
}
var result struct {
Loopdevices []struct {
Name string `json:"name"`
BackFile string `json:"back-file"`
} `json:"loopdevices"`
}
if err := json.Unmarshal(out, &result); err != nil {
return "", err
}
for _, dev := range result.Loopdevices {
if dev.BackFile == backingFile {
return dev.Name, nil
}
}
return "", fmt.Errorf("no loop device found for %s", backingFile)
}
// loopDeviceOffset returns the byte offset configured for the loop device,
// or -1 if it cannot be determined.
func loopDeviceOffset(loopDev string) int64 {
out, err := exec.Command("losetup", "--json", loopDev).Output()
if err != nil {
return -1
}
var result struct {
Loopdevices []struct {
Offset int64 `json:"offset"`
} `json:"loopdevices"`
}
if err := json.Unmarshal(out, &result); err != nil || len(result.Loopdevices) == 0 {
return -1
}
return result.Loopdevices[0].Offset
}
func reassociateLoopDevice(loopDev, newFile string) error {
// LOOP_CHANGE_FD requires lo_offset == 0. ISO/CD-ROM loop devices are
// typically set up with a non-zero offset (squashfs lives inside the ISO),
// so the ioctl returns EINVAL. Detect this early for a clear error message.
if off := loopDeviceOffset(loopDev); off > 0 {
return fmt.Errorf("loop device has non-zero offset (%d bytes, typical for ISO/CD-ROM) — LOOP_CHANGE_FD not supported; use 'toram' kernel parameter for RAM boot", off)
}
if err := exec.Command("losetup", "--replace", loopDev, newFile).Run(); err == nil {
return nil
}
return loopChangeFD(loopDev, newFile)
}