| 1 | package host |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "crypto/rand" |
| 6 | "crypto/sha256" |
| 7 | "encoding/hex" |
| 8 | "encoding/json" |
| 9 | "errors" |
| 10 | "os" |
| 11 | "strings" |
| 12 | "time" |
| 13 | |
| 14 | "github.com/carlosframework/platform/internal/hostwrite" |
| 15 | "github.com/carlosframework/platform/internal/release" |
| 16 | "github.com/carlosframework/platform/internal/rootstate" |
| 17 | ) |
| 18 | |
| 19 | const rollbackMargin = 30 * time.Second |
| 20 | const rootRestartState = "/var/lib/carlos-release/private/restarts" |
| 21 | |
| 22 | type rollbackAttempt struct { |
| 23 | ID string |
| 24 | Host string |
| 25 | Created time.Time |
| 26 | Deadline time.Time |
| 27 | Failed bool |
| 28 | Recovering bool |
| 29 | Settled bool |
| 30 | Verified bool `json:",omitempty"` |
| 31 | Independent bool `json:",omitempty"` |
| 32 | Target string |
| 33 | Previous string `json:",omitempty"` |
| 34 | PreviousDigest string `json:",omitempty"` |
| 35 | Identity hostwrite.Identity |
| 36 | History *release.HistoryAttempt `json:",omitempty"` |
| 37 | HistoryBinding release.HistoryBinding `json:",omitempty"` |
| 38 | TargetDigest string |
| 39 | } |
| 40 | |
| 41 | type rollbackCapability struct { |
| 42 | Attempt rollbackAttempt |
| 43 | Binding proofBinding |
| 44 | } |
| 45 | |
| 46 | func rollbackHostKey(host string) string { |
| 47 | h := sha256.Sum256([]byte(host)) |
| 48 | return hex.EncodeToString(h[:]) |
| 49 | } |
| 50 | func rollbackJournalKey(host string) string { return rollbackHostKey(host) + ".attempt" } |
| 51 | func rollbackCapabilityKey(host, id string) string { return rollbackHostKey(host) + "." + id + ".cap" } |
| 52 | |
| 53 | func writeRollbackState(s rootstate.Store, key string, v any) error { |
| 54 | b, err := json.Marshal(v) |
| 55 | if err != nil { |
| 56 | return err |
| 57 | } |
| 58 | return s.Write(key, b) |
| 59 | } |
| 60 | |
| 61 | func readRollbackAttempt(s rootstate.Store, host string) (rollbackAttempt, error) { |
| 62 | var a rollbackAttempt |
| 63 | b, err := s.Read(rollbackJournalKey(host)) |
| 64 | if err != nil { |
| 65 | return a, err |
| 66 | } |
| 67 | if json.Unmarshal(b, &a) != nil || a.Host != host || len(a.ID) != 32 { |
| 68 | return a, os.ErrPermission |
| 69 | } |
| 70 | if _, err := hex.DecodeString(a.ID); err != nil { |
| 71 | return a, os.ErrPermission |
| 72 | } |
| 73 | return a, nil |
| 74 | } |
| 75 | |
| 76 | func settleRollbackAttempt(s rootstate.Store, a rollbackAttempt) error { |
| 77 | if !a.Settled { |
| 78 | a.Settled = true |
| 79 | if a.Independent { |
| 80 | if err := writeRollbackState(s, recoveryResultKey(a), a); err != nil { |
| 81 | return err |
| 82 | } |
| 83 | } |
| 84 | if err := writeRollbackState(s, rollbackJournalKey(a.Host), a); err != nil { |
| 85 | return err |
| 86 | } |
| 87 | } |
| 88 | return removeRollbackCapabilities(s, a.Host) |
| 89 | } |
| 90 | |
| 91 | func captureRollback(s rootstate.Store, b proofBinding, now time.Time, timeout time.Duration, target string, identity hostwrite.Identity, link ...historyRollbackLink) (rollbackAttempt, error) { |
| 92 | if b.Source == "" || b.Version == "" || b.Digest == "" { |
| 93 | return rollbackAttempt{}, os.ErrPermission |
| 94 | } |
| 95 | if prior, err := readRollbackAttempt(s, b.Route.Host); err == nil { |
| 96 | if !prior.Settled && !now.After(prior.Deadline.Add(rollbackMargin)) { |
| 97 | return rollbackAttempt{}, os.ErrPermission |
| 98 | } |
| 99 | if err := settleRollbackAttempt(s, prior); err != nil { |
| 100 | return rollbackAttempt{}, err |
| 101 | } |
| 102 | } else if !errors.Is(err, os.ErrNotExist) { |
| 103 | return rollbackAttempt{}, err |
| 104 | } |
| 105 | id := make([]byte, 16) |
| 106 | if _, err := rand.Read(id); err != nil { |
| 107 | return rollbackAttempt{}, err |
| 108 | } |
| 109 | a := rollbackAttempt{ID: hex.EncodeToString(id), Host: b.Route.Host, Created: now, Deadline: now.Add(2 * timeout), Target: target, Identity: identity, Previous: b.Version, PreviousDigest: b.Digest} |
| 110 | if len(link) > 1 { |
| 111 | return rollbackAttempt{}, os.ErrPermission |
| 112 | } |
| 113 | if len(link) == 1 { |
| 114 | l := link[0] |
| 115 | a.TargetDigest = l.TargetDigest |
| 116 | if l.Attempt.ID != "" { |
| 117 | if l.Binding.Host != b.Route.Host || l.Binding.Account != b.Route.Account || l.Binding.App != b.Route.App || l.Attempt.Source != b.Source { |
| 118 | return rollbackAttempt{}, os.ErrPermission |
| 119 | } |
| 120 | if l.Independent { |
| 121 | l.Attempt.ID = a.ID |
| 122 | } |
| 123 | a.History, a.HistoryBinding = &l.Attempt, l.Binding |
| 124 | a.Independent = l.Independent |
| 125 | a.TargetDigest = l.Attempt.SHA256 |
| 126 | } |
| 127 | } |
| 128 | if err := writeRollbackState(s, rollbackCapabilityKey(a.Host, a.ID), rollbackCapability{Attempt: a, Binding: b}); err != nil { |
| 129 | return rollbackAttempt{}, err |
| 130 | } |
| 131 | if err := writeRollbackState(s, rollbackJournalKey(a.Host), a); err != nil { |
| 132 | return rollbackAttempt{}, errors.Join(err, s.Remove(rollbackCapabilityKey(a.Host, a.ID))) |
| 133 | } |
| 134 | return a, nil |
| 135 | } |
| 136 | |
| 137 | func loadRollback(s rootstate.Store, host string, now time.Time) (rollbackAttempt, proofBinding, error) { |
| 138 | a, err := readRollbackAttempt(s, host) |
| 139 | if err != nil { |
| 140 | return rollbackAttempt{}, proofBinding{}, errors.Join(err, removeRollbackCapabilities(s, host)) |
| 141 | } |
| 142 | if a.Settled || now.Before(a.Created) || now.After(a.Deadline.Add(rollbackMargin)) { |
| 143 | return a, proofBinding{}, errors.Join(os.ErrPermission, settleRollbackAttempt(s, a)) |
| 144 | } |
| 145 | b, err := s.Read(rollbackCapabilityKey(host, a.ID)) |
| 146 | if err != nil { |
| 147 | return a, proofBinding{}, err |
| 148 | } |
| 149 | var cap rollbackCapability |
| 150 | if json.Unmarshal(b, &cap) != nil || cap.Attempt.ID != a.ID || cap.Attempt.TargetDigest != a.TargetDigest || cap.Attempt.Independent != a.Independent || cap.Attempt.HistoryBinding != a.HistoryBinding || !sameHistoryAttempt(cap.Attempt.History, a.History) || cap.Attempt.Previous != a.Previous || cap.Attempt.PreviousDigest != a.PreviousDigest || cap.Attempt.Host != host || cap.Attempt.Target != a.Target || cap.Attempt.Identity != a.Identity || !cap.Attempt.Deadline.Equal(a.Deadline) || !cap.Attempt.Created.Equal(a.Created) || cap.Binding.Route.Host != host { |
| 151 | return a, proofBinding{}, os.ErrPermission |
| 152 | } |
| 153 | return a, cap.Binding, nil |
| 154 | } |
| 155 | |
| 156 | func (c rootRestartChecks) finish(host string) error { |
| 157 | if c.attempts == nil || c.started == nil { |
| 158 | return os.ErrPermission |
| 159 | } |
| 160 | expected, ok := c.started.Load(host) |
| 161 | if !ok { |
| 162 | return nil |
| 163 | } |
| 164 | defer c.started.Delete(host) |
| 165 | s, err := c.attempts() |
| 166 | if err != nil { |
| 167 | return err |
| 168 | } |
| 169 | defer s.Close() |
| 170 | unlock, err := s.Lock(context.Background(), rollbackHostKey(host)+".lock") |
| 171 | if err != nil { |
| 172 | return err |
| 173 | } |
| 174 | defer unlock() |
| 175 | a, err := readRollbackAttempt(s, host) |
| 176 | if errors.Is(err, os.ErrNotExist) { |
| 177 | return nil |
| 178 | } |
| 179 | if err != nil { |
| 180 | return err |
| 181 | } |
| 182 | if a.ID != expected { |
| 183 | return os.ErrPermission |
| 184 | } |
| 185 | return settleRollbackAttempt(s, a) |
| 186 | } |
| 187 | |
| 188 | func removeRollbackCapabilities(s rootstate.Store, host string) error { |
| 189 | names, err := s.Names() |
| 190 | if err != nil { |
| 191 | return err |
| 192 | } |
| 193 | for _, name := range names { |
| 194 | if !strings.HasPrefix(name, rollbackHostKey(host)+".") || !strings.HasSuffix(name, ".cap") { |
| 195 | continue |
| 196 | } |
| 197 | if err := s.Remove(name); err != nil { |
| 198 | return err |
| 199 | } |
| 200 | } |
| 201 | return nil |
| 202 | } |
| 203 | |
| 204 | func sameHistoryAttempt(a, b *release.HistoryAttempt) bool { |
| 205 | if a == nil || b == nil { |
| 206 | return a == nil && b == nil |
| 207 | } |
| 208 | return *a == *b |
| 209 | } |
| 210 | |
amadan