| 1 | package host |
| 2 | |
| 3 | import ( |
| 4 | "bytes" |
| 5 | "context" |
| 6 | "crypto/sha256" |
| 7 | "encoding/hex" |
| 8 | "encoding/json" |
| 9 | "errors" |
| 10 | "io" |
| 11 | "os" |
| 12 | |
| 13 | "github.com/carlosframework/platform/internal/rootstate" |
| 14 | ) |
| 15 | |
| 16 | type claimUnitMaterialization struct { |
| 17 | Migration *claimUnitMigration |
| 18 | Prior claimUnitBinding |
| 19 | PriorIdentity rootstate.FileIdentity |
| 20 | Binding claimUnitBinding |
| 21 | Digest string |
| 22 | Identity rootstate.FileIdentity |
| 23 | Retiring, Retired bool |
| 24 | } |
| 25 | |
| 26 | type claimUnitMaterializer struct { |
| 27 | admit func() error |
| 28 | socketCapture func(context.Context, claimUnitShape, claimUnitPredecessor) (claimUnitSocketIdentity, error) |
| 29 | socketPark func(claimUnitBinding, claimUnitSocketIdentity) error |
| 30 | predecessor func(context.Context, claimUnitBinding) (claimUnitPredecessor, error) |
| 31 | stopPredecessor func(context.Context, claimUnitPredecessor) error |
| 32 | idle func(string) error |
| 33 | state rootstate.Store |
| 34 | read func(string) ([]byte, rootstate.FileIdentity, error) |
| 35 | create func(string, []byte) error |
| 36 | replace func(string, rootstate.FileIdentity, []byte) error |
| 37 | } |
| 38 | |
| 39 | func claimUnitDigest(b []byte) string { sum := sha256.Sum256(b); return hex.EncodeToString(sum[:]) } |
| 40 | |
| 41 | func (m claimUnitMaterializer) load(host string) (claimUnitMaterialization, error) { |
| 42 | var r claimUnitMaterialization |
| 43 | raw, err := m.state.Read(host + ".unit.json") |
| 44 | if err != nil { |
| 45 | return r, err |
| 46 | } |
| 47 | dec := json.NewDecoder(bytes.NewReader(raw)) |
| 48 | dec.DisallowUnknownFields() |
| 49 | if dec.Decode(&r) != nil || dec.Decode(new(any)) != io.EOF || !r.Binding.valid() || r.Binding.Owner.Host != host || !claimHexDigest(r.Digest) || (r.Retired && !r.Retiring) { |
| 50 | return r, os.ErrPermission |
| 51 | } |
| 52 | if r.Migration != nil && (!r.Migration.valid(r.Binding) || r.Prior != (claimUnitBinding{})) { |
| 53 | return r, os.ErrPermission |
| 54 | } |
| 55 | if r.Prior != (claimUnitBinding{}) && (!r.Prior.valid() || !r.Prior.Retired || r.Prior.Shape != r.Binding.Shape || r.Prior.Owner == r.Binding.Owner || r.PriorIdentity == (rootstate.FileIdentity{})) { |
| 56 | return r, os.ErrPermission |
| 57 | } |
| 58 | return r, nil |
| 59 | } |
| 60 | func (m claimUnitMaterializer) save(r claimUnitMaterialization) error { |
| 61 | raw, err := json.Marshal(r) |
| 62 | if err != nil { |
| 63 | return err |
| 64 | } |
| 65 | return m.state.Write(r.Binding.Owner.Host+".unit.json", raw) |
| 66 | } |
| 67 | func claimOwnedUnitDefinition(b claimUnitBinding) ([]byte, error) { |
| 68 | raw, err := claimBoundUnitDefinition(b.Shape) |
| 69 | if err != nil { |
| 70 | return nil, err |
| 71 | } |
| 72 | owner, _ := json.Marshal(b.Owner) |
| 73 | return append([]byte("# claim-owner="+claimUnitDigest(owner)+"\n"), raw...), nil |
| 74 | } |
| 75 | func claimRetiredUnitDefinition(b claimUnitBinding) []byte { |
| 76 | owner, _ := json.Marshal(b.Owner) |
| 77 | return []byte("# claim-retired=" + claimUnitDigest(owner) + "\n[Unit]\nRefuseManualStart=yes\n[Service]\nType=oneshot\nExecStart=/usr/bin/false\nRestart=no\n") |
| 78 | } |
| 79 | |
| 80 | func (m claimUnitMaterializer) install(ctx context.Context, b claimUnitBinding) error { |
| 81 | if m.admit != nil { |
| 82 | if err := m.admit(); err != nil { |
| 83 | return err |
| 84 | } |
| 85 | } |
| 86 | if m.state == nil || m.read == nil || m.create == nil || m.idle == nil || !b.valid() || b.Retiring || b.Retired { |
| 87 | return os.ErrPermission |
| 88 | } |
| 89 | unlock, err := m.state.Lock(ctx, "materialize") |
| 90 | if err != nil { |
| 91 | return err |
| 92 | } |
| 93 | defer unlock() |
| 94 | want, err := claimOwnedUnitDefinition(b) |
| 95 | if err != nil { |
| 96 | return err |
| 97 | } |
| 98 | r, err := m.load(b.Owner.Host) |
| 99 | if errors.Is(err, os.ErrNotExist) { |
| 100 | raw, id, e := m.read(b.Shape.Unit) |
| 101 | r = claimUnitMaterialization{Binding: b, Digest: claimUnitDigest(want)} |
| 102 | if e == nil { |
| 103 | r.Migration, err = m.migration(ctx, b, raw, id) |
| 104 | if err != nil { |
| 105 | return err |
| 106 | } |
| 107 | } else if !errors.Is(e, os.ErrNotExist) { |
| 108 | return e |
| 109 | } |
| 110 | |
| 111 | } else if err != nil { |
| 112 | return err |
| 113 | } |
| 114 | if r.Binding != b || r.Digest != claimUnitDigest(want) || r.Retiring || r.Retired { |
| 115 | return os.ErrPermission |
| 116 | } |
| 117 | if r.Identity == (rootstate.FileIdentity{}) && r.Migration == nil { |
| 118 | if err := m.idle(b.Shape.Host); err != nil { |
| 119 | return err |
| 120 | } |
| 121 | } |
| 122 | if err = m.save(r); err != nil { |
| 123 | return err |
| 124 | } |
| 125 | if r.Identity == (rootstate.FileIdentity{}) && r.Migration != nil { |
| 126 | return m.finishMigration(ctx, r, want) |
| 127 | } |
| 128 | raw, id, err := m.read(b.Shape.Unit) |
| 129 | if errors.Is(err, os.ErrNotExist) && r.Identity == (rootstate.FileIdentity{}) { |
| 130 | if err = m.create(b.Shape.Unit, want); err != nil { |
| 131 | return err |
| 132 | } |
| 133 | raw, id, err = m.read(b.Shape.Unit) |
| 134 | } |
| 135 | if err != nil { |
| 136 | return err |
| 137 | } |
| 138 | if !bytes.Equal(raw, want) || id == (rootstate.FileIdentity{}) || (r.Identity != (rootstate.FileIdentity{}) && !r.Identity.Same(id)) { |
| 139 | return os.ErrPermission |
| 140 | } |
| 141 | r.Identity = id |
| 142 | return m.save(r) |
| 143 | } |
| 144 | |
| 145 | func (m claimUnitMaterializer) verify(b claimUnitBinding) error { |
| 146 | r, err := m.load(b.Owner.Host) |
| 147 | if err != nil { |
| 148 | return err |
| 149 | } |
| 150 | if r.Binding != b || r.Retiring || r.Retired || r.Identity == (rootstate.FileIdentity{}) { |
| 151 | return os.ErrPermission |
| 152 | } |
| 153 | raw, id, err := m.read(b.Shape.Unit) |
| 154 | if err != nil { |
| 155 | return err |
| 156 | } |
| 157 | want, err := claimOwnedUnitDefinition(b) |
| 158 | if err != nil { |
| 159 | return err |
| 160 | } |
| 161 | if !id.Same(r.Identity) || !bytes.Equal(raw, want) || claimUnitDigest(raw) != r.Digest { |
| 162 | return os.ErrPermission |
| 163 | } |
| 164 | return nil |
| 165 | } |
| 166 | |
| 167 | func (m claimUnitMaterializer) retire(ctx context.Context, b claimUnitBinding, gone func() error) error { |
| 168 | if m.state == nil || m.read == nil || m.replace == nil || gone == nil || !b.valid() { |
| 169 | return os.ErrPermission |
| 170 | } |
| 171 | unlock, err := m.state.Lock(ctx, "materialize") |
| 172 | if err != nil { |
| 173 | return err |
| 174 | } |
| 175 | defer unlock() |
| 176 | r, err := m.load(b.Owner.Host) |
| 177 | if err != nil { |
| 178 | return err |
| 179 | } |
| 180 | if r.Binding != b || r.Identity == (rootstate.FileIdentity{}) { |
| 181 | return os.ErrPermission |
| 182 | } |
| 183 | raw, id, err := m.read(b.Shape.Unit) |
| 184 | if err != nil { |
| 185 | return err |
| 186 | } |
| 187 | tombstone := claimRetiredUnitDefinition(b) |
| 188 | if r.Retiring && bytes.Equal(raw, tombstone) { |
| 189 | if r.Retired && !r.Identity.Same(id) { |
| 190 | return os.ErrPermission |
| 191 | } |
| 192 | r.Identity = id |
| 193 | r.Retired = true |
| 194 | return m.save(r) |
| 195 | } |
| 196 | if r.Retired || !id.Same(r.Identity) || claimUnitDigest(raw) != r.Digest { |
| 197 | return os.ErrPermission |
| 198 | } |
| 199 | r.Retiring = true |
| 200 | if err = m.save(r); err != nil { |
| 201 | return err |
| 202 | } |
| 203 | if err = gone(); err != nil { |
| 204 | return err |
| 205 | } |
| 206 | if err = m.replace(b.Shape.Unit, r.Identity, tombstone); err != nil { |
| 207 | return err |
| 208 | } |
| 209 | raw, id, err = m.read(b.Shape.Unit) |
| 210 | if err != nil { |
| 211 | return err |
| 212 | } |
| 213 | if !bytes.Equal(raw, tombstone) { |
| 214 | return os.ErrPermission |
| 215 | } |
| 216 | r.Identity = id |
| 217 | r.Retired = true |
| 218 | return m.save(r) |
| 219 | } |
| 220 | |
amadan