| 1 | package host |
| 2 | |
| 3 | import ( |
| 4 | "encoding/hex" |
| 5 | "strings" |
| 6 | |
| 7 | "github.com/carlosframework/platform/internal/hostbox" |
| 8 | ) |
| 9 | |
| 10 | // Handles identify an inode within its filesystem across boots. Current-boot |
| 11 | // device, mount and inode checks still apply; handles never authorize an open. |
| 12 | type servingParkPersistentDirectory struct { |
| 13 | Filesystem [2]int32 |
| 14 | Type int32 |
| 15 | Handle string |
| 16 | Owner uint32 |
| 17 | Mode uint32 |
| 18 | } |
| 19 | |
| 20 | type servingParkPersistentFile servingParkPersistentDirectory |
| 21 | |
| 22 | func validServingParkHandle(p servingParkPersistentDirectory) bool { |
| 23 | b, err := hex.DecodeString(p.Handle) |
| 24 | return err == nil && len(b) > 0 && len(b) <= 128 && hex.EncodeToString(b) == p.Handle && p.Type > 0 && p.Filesystem != [2]int32{} |
| 25 | } |
| 26 | |
| 27 | func (p servingParkPersistentDirectory) valid() bool { |
| 28 | return validServingParkHandle(p) && p.Mode&0170000 == 0040000 && p.Mode&0022 == 0 |
| 29 | } |
| 30 | |
| 31 | func (p servingParkPersistentFile) valid() bool { |
| 32 | return validServingParkHandle(servingParkPersistentDirectory(p)) && p.Mode&0170000 == 0100000 |
| 33 | } |
| 34 | |
| 35 | // Historical records without handles remain readable. Partial new evidence |
| 36 | // refuses rather than being treated as an old record eligible for recapture. |
| 37 | func validateServingParkPersistentRecord(r servingParkRecord) error { |
| 38 | p := r.Source.Persistent |
| 39 | if p == (servingParkPersistentDirectory{}) { |
| 40 | if r.Source.BootID != "" || r.EventPersistent != (servingParkPersistentDirectory{}) { |
| 41 | return hostbox.ErrChanged |
| 42 | } |
| 43 | for _, f := range r.Source.Files { |
| 44 | if f.Persistent != (servingParkPersistentFile{}) { |
| 45 | return hostbox.ErrChanged |
| 46 | } |
| 47 | } |
| 48 | return nil |
| 49 | } |
| 50 | if !p.valid() || !validServingParkBootID(r.Source.BootID) { |
| 51 | return hostbox.ErrChanged |
| 52 | } |
| 53 | for _, f := range r.Source.Files { |
| 54 | if f.Present { |
| 55 | if !f.Persistent.valid() || f.Persistent.Filesystem != p.Filesystem { |
| 56 | return hostbox.ErrChanged |
| 57 | } |
| 58 | } else if f.Persistent != (servingParkPersistentFile{}) { |
| 59 | return hostbox.ErrChanged |
| 60 | } |
| 61 | } |
| 62 | if r.Prepared { |
| 63 | if !r.EventPersistent.valid() || r.EventPersistent.Filesystem != p.Filesystem || r.EventPersistent.Mode&0077 != 0 { |
| 64 | return hostbox.ErrChanged |
| 65 | } |
| 66 | } else if r.EventPersistent != (servingParkPersistentDirectory{}) { |
| 67 | return hostbox.ErrChanged |
| 68 | } |
| 69 | return nil |
| 70 | } |
| 71 | |
| 72 | func validServingParkBootID(id string) bool { |
| 73 | if len(id) != 36 || id[8] != '-' || id[13] != '-' || id[18] != '-' || id[23] != '-' { |
| 74 | return false |
| 75 | } |
| 76 | raw := strings.ReplaceAll(id, "-", "") |
| 77 | b, err := hex.DecodeString(raw) |
| 78 | return err == nil && len(b) == 16 && hex.EncodeToString(b) == raw && raw != strings.Repeat("0", 32) |
| 79 | } |
| 80 | |
| 81 | // Only the saved source decides whether persistent evidence was captured. New |
| 82 | // observations cannot upgrade an old intent or permanent legacy consumption. |
| 83 | func sameServingParkSource(saved, fresh servingParkSource) bool { |
| 84 | if saved.Persistent == (servingParkPersistentDirectory{}) && saved.BootID == "" { |
| 85 | for _, item := range saved.Files { |
| 86 | if item.Persistent != (servingParkPersistentFile{}) { |
| 87 | return false |
| 88 | } |
| 89 | } |
| 90 | fresh.Persistent = servingParkPersistentDirectory{} |
| 91 | fresh.BootID = "" |
| 92 | for i := range fresh.Files { |
| 93 | fresh.Files[i].Persistent = servingParkPersistentFile{} |
| 94 | } |
| 95 | } |
| 96 | if saved.ParentPersistent == (servingParkPersistentDirectory{}) { |
| 97 | fresh.ParentPersistent = servingParkPersistentDirectory{} |
| 98 | } |
| 99 | if saved.Volume == "" { |
| 100 | fresh.Volume = "" |
| 101 | } |
| 102 | return saved == fresh |
| 103 | } |
| 104 | |
amadan