| 1 | package protocol |
| 2 | |
| 3 | import "bytes" |
| 4 | |
| 5 | const ( |
| 6 | CgroupLookupKnown uint16 = 0 |
| 7 | CgroupLookupUnknownRetryLater uint16 = 1 |
| 8 | CgroupLookupUnknownPermanent uint16 = 2 |
| 9 | |
| 10 | CgroupsLookupReqHdr = 16 |
| 11 | CgroupsLookupRespHdr = 16 |
| 12 | CgroupsLookupItemHdr = 28 |
| 13 | |
| 14 | cgroupsLookupUnknownFixedBytes = CgroupsLookupItemHdr + 1 |
| 15 | ) |
| 16 | |
| 17 | type CgroupsLookupRequestView struct { |
| 18 | ItemCount uint32 |
| 19 | payload []byte |
| 20 | } |
| 21 | |
| 22 | type CgroupsLookupResponseView struct { |
| 23 | LayoutVersion uint16 |
| 24 | Flags uint16 |
| 25 | ItemCount uint32 |
| 26 | Generation uint64 |
| 27 | payload []byte |
| 28 | } |
| 29 | |
| 30 | type CgroupsLookupItemView struct { |
| 31 | Status uint16 |
| 32 | Orchestrator uint16 |
| 33 | Path CStringView |
| 34 | Name CStringView |
| 35 | LabelCount uint16 |
| 36 | item []byte |
| 37 | labelTableOffset int |
| 38 | } |
| 39 | |
| 40 | func validateCgroupsLookupSemantics(status, orchestrator uint16, pathLen, nameLen, labelCount int) error { |
| 41 | if status != CgroupLookupKnown && status != CgroupLookupUnknownRetryLater && status != CgroupLookupUnknownPermanent { |
| 42 | return ErrBadLayout |
| 43 | } |
| 44 | if pathLen == 0 { |
| 45 | return ErrBadLayout |
| 46 | } |
| 47 | if status != CgroupLookupKnown && (orchestrator != 0 || nameLen != 0 || labelCount != 0) { |
| 48 | return ErrBadLayout |
| 49 | } |
| 50 | return nil |
| 51 | } |
| 52 | |
| 53 | func EncodeCgroupsLookupRequest(paths [][]byte, buf []byte) (int, error) { |
| 54 | count := len(paths) |
| 55 | if uint64(count) > uint64(^uint32(0)) { |
| 56 | return 0, ErrOverflow |
| 57 | } |
| 58 | dirSize, ok := checkedMulInt(count, LookupDirEntrySize) |
| 59 | if !ok { |
| 60 | return 0, ErrOverflow |
| 61 | } |
| 62 | packedStart, ok := checkedAddInt(CgroupsLookupReqHdr, dirSize) |
| 63 | if !ok { |
| 64 | return 0, ErrOverflow |
| 65 | } |
| 66 | if len(buf) < packedStart { |
| 67 | return 0, ErrOverflow |
| 68 | } |
| 69 | data := packedStart |
| 70 | for i, path := range paths { |
| 71 | if invalidSourceString(path, true) { |
| 72 | return 0, ErrBadLayout |
| 73 | } |
| 74 | aligned, ok := checkedAlign8(data) |
| 75 | if !ok { |
| 76 | return 0, ErrOverflow |
| 77 | } |
| 78 | keyLen, ok := checkedAddInt(len(path), 1) |
| 79 | if !ok { |
| 80 | return 0, ErrOverflow |
| 81 | } |
| 82 | end, ok := checkedAddInt(aligned, keyLen) |
| 83 | if !ok { |
| 84 | return 0, ErrOverflow |
| 85 | } |
| 86 | if end > len(buf) { |
| 87 | return 0, ErrOverflow |
| 88 | } |
| 89 | clear(buf[data:aligned]) |
| 90 | offset32, ok := checkedU32Int(aligned - packedStart) |
| 91 | if !ok { |
| 92 | return 0, ErrOverflow |
| 93 | } |
| 94 | keyLen32, ok := checkedU32Int(keyLen) |
| 95 | if !ok { |
| 96 | return 0, ErrOverflow |
| 97 | } |
| 98 | base := CgroupsLookupReqHdr + i*LookupDirEntrySize |
| 99 | ne.PutUint32(buf[base:base+4], offset32) |
| 100 | ne.PutUint32(buf[base+4:base+8], keyLen32) |
| 101 | copy(buf[aligned:], path) |
| 102 | buf[aligned+len(path)] = 0 |
| 103 | data = end |
| 104 | } |
| 105 | ne.PutUint16(buf[0:2], 1) |
| 106 | ne.PutUint16(buf[2:4], 0) |
| 107 | ne.PutUint32(buf[4:8], uint32(count)) |
| 108 | ne.PutUint32(buf[8:12], 0) |
| 109 | ne.PutUint32(buf[12:16], 0) |
| 110 | return data, nil |
| 111 | } |
| 112 | |
| 113 | func DecodeCgroupsLookupRequest(buf []byte) (*CgroupsLookupRequestView, error) { |
| 114 | if len(buf) < CgroupsLookupReqHdr { |
| 115 | return nil, ErrTruncated |
| 116 | } |
| 117 | if ne.Uint16(buf[0:2]) != 1 || ne.Uint16(buf[2:4]) != 0 || |
| 118 | ne.Uint32(buf[8:12]) != 0 || ne.Uint32(buf[12:16]) != 0 { |
| 119 | return nil, ErrBadLayout |
| 120 | } |
| 121 | itemCount := ne.Uint32(buf[4:8]) |
| 122 | dirSize64 := uint64(itemCount) * uint64(LookupDirEntrySize) |
| 123 | dirEnd, ok := checkedInt(uint64(CgroupsLookupReqHdr) + dirSize64) |
| 124 | if !ok { |
| 125 | return nil, ErrBadItemCount |
| 126 | } |
| 127 | if dirEnd > len(buf) { |
| 128 | return nil, ErrTruncated |
| 129 | } |
| 130 | if err := validateLookupDir(buf, CgroupsLookupReqHdr, itemCount, len(buf)-dirEnd, 2, -1); err != nil { |
| 131 | return nil, err |
| 132 | } |
| 133 | for i := range itemCount { |
| 134 | base := CgroupsLookupReqHdr + int(i)*LookupDirEntrySize |
| 135 | off, length, err := lookupDirEntry(buf, base) |
| 136 | if err != nil { |
| 137 | return nil, err |
| 138 | } |
| 139 | key, err := lookupPayloadSlice(buf, dirEnd, off, length) |
| 140 | if err != nil { |
| 141 | return nil, err |
| 142 | } |
| 143 | if key[length-1] != 0 { |
| 144 | return nil, ErrMissingNul |
| 145 | } |
| 146 | if bytes.Contains(key[:length-1], []byte{0}) { |
| 147 | return nil, ErrBadLayout |
| 148 | } |
| 149 | } |
| 150 | return &CgroupsLookupRequestView{ItemCount: itemCount, payload: buf}, nil |
| 151 | } |
| 152 | |
| 153 | func (v *CgroupsLookupRequestView) Item(index uint32) (CStringView, error) { |
| 154 | if index >= v.ItemCount { |
| 155 | return CStringView{}, ErrOutOfBounds |
| 156 | } |
| 157 | dirEnd, ok := lookupBuilderDataOffset(CgroupsLookupReqHdr, v.ItemCount) |
| 158 | if !ok { |
| 159 | return CStringView{}, ErrOverflow |
| 160 | } |
| 161 | base, ok := lookupDirOffset(CgroupsLookupReqHdr, index) |
| 162 | if !ok { |
| 163 | return CStringView{}, ErrOverflow |
| 164 | } |
| 165 | off, length, err := lookupDirEntry(v.payload, base) |
| 166 | if err != nil { |
| 167 | return CStringView{}, err |
| 168 | } |
| 169 | item, err := lookupPayloadSlice(v.payload, dirEnd, off, length) |
| 170 | if err != nil { |
| 171 | return CStringView{}, err |
| 172 | } |
| 173 | stringLen, ok := checkedU32Int(length - 1) |
| 174 | if !ok { |
| 175 | return CStringView{}, ErrOutOfBounds |
| 176 | } |
| 177 | return NewCStringView(item, stringLen), nil |
| 178 | } |
| 179 | |
| 180 | func DecodeCgroupsLookupResponse(buf []byte) (*CgroupsLookupResponseView, error) { |
| 181 | if len(buf) < CgroupsLookupRespHdr { |
| 182 | return nil, ErrTruncated |
| 183 | } |
| 184 | if ne.Uint16(buf[0:2]) != 1 || ne.Uint16(buf[2:4]) != 0 { |
| 185 | return nil, ErrBadLayout |
| 186 | } |
| 187 | itemCount := ne.Uint32(buf[4:8]) |
| 188 | dirEnd, ok := checkedInt(uint64(CgroupsLookupRespHdr) + uint64(itemCount)*uint64(LookupDirEntrySize)) |
| 189 | if !ok { |
| 190 | return nil, ErrBadItemCount |
| 191 | } |
| 192 | if dirEnd > len(buf) { |
| 193 | return nil, ErrTruncated |
| 194 | } |
| 195 | if err := validateLookupDir(buf, CgroupsLookupRespHdr, itemCount, len(buf)-dirEnd, CgroupsLookupItemHdr, -1); err != nil { |
| 196 | return nil, err |
| 197 | } |
| 198 | for i := range itemCount { |
| 199 | base := CgroupsLookupRespHdr + int(i)*LookupDirEntrySize |
| 200 | off, length, err := lookupDirEntry(buf, base) |
| 201 | if err != nil { |
| 202 | return nil, err |
| 203 | } |
| 204 | item, err := lookupPayloadSlice(buf, dirEnd, off, length) |
| 205 | if err != nil { |
| 206 | return nil, err |
| 207 | } |
| 208 | if _, err := decodeCgroupsLookupItem(item); err != nil { |
| 209 | return nil, err |
| 210 | } |
| 211 | } |
| 212 | return &CgroupsLookupResponseView{ |
| 213 | LayoutVersion: 1, |
| 214 | Flags: 0, |
| 215 | ItemCount: itemCount, |
| 216 | Generation: ne.Uint64(buf[8:16]), |
| 217 | payload: buf, |
| 218 | }, nil |
| 219 | } |
| 220 | |
| 221 | func (v *CgroupsLookupResponseView) Item(index uint32) (*CgroupsLookupItemView, error) { |
| 222 | if index >= v.ItemCount { |
| 223 | return nil, ErrOutOfBounds |
| 224 | } |
| 225 | dirEnd, ok := lookupBuilderDataOffset(CgroupsLookupRespHdr, v.ItemCount) |
| 226 | if !ok { |
| 227 | return nil, ErrOverflow |
| 228 | } |
| 229 | base, ok := lookupDirOffset(CgroupsLookupRespHdr, index) |
| 230 | if !ok { |
| 231 | return nil, ErrOverflow |
| 232 | } |
| 233 | off, length, err := lookupDirEntry(v.payload, base) |
| 234 | if err != nil { |
| 235 | return nil, err |
| 236 | } |
| 237 | item, err := lookupPayloadSlice(v.payload, dirEnd, off, length) |
| 238 | if err != nil { |
| 239 | return nil, err |
| 240 | } |
| 241 | return decodeCgroupsLookupItem(item) |
| 242 | } |
| 243 | |
| 244 | func decodeCgroupsLookupItem(item []byte) (*CgroupsLookupItemView, error) { |
| 245 | if len(item) < CgroupsLookupItemHdr { |
| 246 | return nil, ErrTruncated |
| 247 | } |
| 248 | status := ne.Uint16(item[2:4]) |
| 249 | orchestrator := ne.Uint16(item[4:6]) |
| 250 | pathOff, err := checkedWireU32Int(item, 8) |
| 251 | if err != nil { |
| 252 | return nil, err |
| 253 | } |
| 254 | pathLen, err := checkedWireU32Int(item, 12) |
| 255 | if err != nil { |
| 256 | return nil, err |
| 257 | } |
| 258 | nameOff, err := checkedWireU32Int(item, 16) |
| 259 | if err != nil { |
| 260 | return nil, err |
| 261 | } |
| 262 | nameLen, err := checkedWireU32Int(item, 20) |
| 263 | if err != nil { |
| 264 | return nil, err |
| 265 | } |
| 266 | labelCount := ne.Uint16(item[24:26]) |
| 267 | if ne.Uint16(item[0:2]) != 1 || ne.Uint16(item[6:8]) != 0 || ne.Uint16(item[26:28]) != 0 { |
| 268 | return nil, ErrBadLayout |
| 269 | } |
| 270 | if err := validateCgroupsLookupSemantics(status, orchestrator, pathLen, nameLen, int(labelCount)); err != nil { |
| 271 | return nil, err |
| 272 | } |
| 273 | if status != CgroupLookupKnown { |
| 274 | return decodeCgroupsLookupUnknownItem(item, status, pathOff, pathLen, nameOff) |
| 275 | } |
| 276 | path, pathEnd, err := lookupString(item, CgroupsLookupItemHdr, pathOff, pathLen) |
| 277 | if err != nil { |
| 278 | return nil, err |
| 279 | } |
| 280 | name, nameEnd, err := lookupString(item, CgroupsLookupItemHdr, nameOff, nameLen) |
| 281 | if err != nil { |
| 282 | return nil, err |
| 283 | } |
| 284 | if overlap(pathOff, pathEnd, nameOff, nameEnd) { |
| 285 | return nil, ErrBadLayout |
| 286 | } |
| 287 | table, err := validateLabels(item, CgroupsLookupItemHdr, labelCount, max(pathEnd, nameEnd)) |
| 288 | if err != nil { |
| 289 | return nil, err |
| 290 | } |
| 291 | return &CgroupsLookupItemView{ |
| 292 | Status: status, |
| 293 | Orchestrator: orchestrator, |
| 294 | Path: path, |
| 295 | Name: name, |
| 296 | LabelCount: labelCount, |
| 297 | item: item, |
| 298 | labelTableOffset: table, |
| 299 | }, nil |
| 300 | } |
| 301 | |
| 302 | func decodeCgroupsLookupUnknownItem(item []byte, status uint16, pathOff, pathLen, nameOff int) (*CgroupsLookupItemView, error) { |
| 303 | path, pathEnd, err := lookupString(item, CgroupsLookupItemHdr, pathOff, pathLen) |
| 304 | if err != nil { |
| 305 | return nil, err |
| 306 | } |
| 307 | name, nameEnd, err := lookupEmptyString(item, CgroupsLookupItemHdr, nameOff) |
| 308 | if err != nil { |
| 309 | return nil, err |
| 310 | } |
| 311 | if overlap(pathOff, pathEnd, nameOff, nameEnd) { |
| 312 | return nil, ErrBadLayout |
| 313 | } |
| 314 | labelTableOffset := max(pathEnd, nameEnd) |
| 315 | if labelTableOffset != len(item) { |
| 316 | return nil, ErrBadLayout |
| 317 | } |
| 318 | return &CgroupsLookupItemView{ |
| 319 | Status: status, |
| 320 | Path: path, |
| 321 | Name: name, |
| 322 | item: item, |
| 323 | labelTableOffset: labelTableOffset, |
| 324 | }, nil |
| 325 | } |
| 326 | |
| 327 | func (v *CgroupsLookupItemView) Label(index uint32) (LookupLabelView, error) { |
| 328 | return lookupLabelAt(v.item, CgroupsLookupItemHdr, v.LabelCount, v.labelTableOffset, index) |
| 329 | } |
| 330 | |
| 331 | type CgroupsLookupBuilder struct { |
| 332 | buf []byte |
| 333 | generation uint64 |
| 334 | itemCount uint32 |
| 335 | maxItems uint32 |
| 336 | dataOffset int |
| 337 | err error |
| 338 | } |
| 339 | |
| 340 | func NewCgroupsLookupBuilder(buf []byte, maxItems uint32, generation uint64) *CgroupsLookupBuilder { |
| 341 | minRequired, ok := lookupBuilderDataOffset(CgroupsLookupRespHdr, maxItems) |
| 342 | if !ok { |
| 343 | panic("CgroupsLookupBuilder buffer too small") |
| 344 | } |
| 345 | if len(buf) < minRequired { |
| 346 | panic("CgroupsLookupBuilder buffer too small") |
| 347 | } |
| 348 | return &CgroupsLookupBuilder{buf: buf, generation: generation, maxItems: maxItems, dataOffset: minRequired} |
| 349 | } |
| 350 | |
| 351 | func (b *CgroupsLookupBuilder) SetGeneration(generation uint64) { |
| 352 | b.generation = generation |
| 353 | } |
| 354 | |
| 355 | func (b *CgroupsLookupBuilder) Add(status, orchestrator uint16, path, name []byte, labels []struct{ Key, Value []byte }) error { |
| 356 | if b.itemCount >= b.maxItems { |
| 357 | b.err = ErrOverflow |
| 358 | return ErrOverflow |
| 359 | } |
| 360 | if err := validateCgroupsLookupSemantics(status, orchestrator, len(path), len(name), len(labels)); err != nil { |
| 361 | b.err = err |
| 362 | return err |
| 363 | } |
| 364 | if invalidSourceString(path, true) || invalidSourceString(name, false) { |
| 365 | b.err = ErrBadLayout |
| 366 | return ErrBadLayout |
| 367 | } |
| 368 | if status != CgroupLookupKnown { |
| 369 | return b.addUnknown(status, path) |
| 370 | } |
| 371 | labelCount, ok := checkedU16Int(len(labels)) |
| 372 | if !ok { |
| 373 | b.err = ErrOverflow |
| 374 | return ErrOverflow |
| 375 | } |
| 376 | itemStart, ok := checkedAlign8(b.dataOffset) |
| 377 | if !ok { |
| 378 | b.err = ErrOverflow |
| 379 | return ErrOverflow |
| 380 | } |
| 381 | pathOff := CgroupsLookupItemHdr |
| 382 | nameOff, ok := checkedAddInt(pathOff, len(path)) |
| 383 | if ok { |
| 384 | nameOff, ok = checkedAddInt(nameOff, 1) |
| 385 | } |
| 386 | if !ok { |
| 387 | b.err = ErrOverflow |
| 388 | return ErrOverflow |
| 389 | } |
| 390 | fixedEnd, ok := checkedAddInt(nameOff, len(name)) |
| 391 | if ok { |
| 392 | fixedEnd, ok = checkedAddInt(fixedEnd, 1) |
| 393 | } |
| 394 | if !ok { |
| 395 | b.err = ErrOverflow |
| 396 | return ErrOverflow |
| 397 | } |
| 398 | tableStart, tableBytes, itemSize, err := labelLayoutGo(fixedEnd, labels) |
| 399 | if err != nil { |
| 400 | b.err = err |
| 401 | return err |
| 402 | } |
| 403 | itemEnd, ok := checkedAddInt(itemStart, itemSize) |
| 404 | if !ok { |
| 405 | b.err = ErrOverflow |
| 406 | return ErrOverflow |
| 407 | } |
| 408 | if itemEnd > len(b.buf) { |
| 409 | b.err = ErrOverflow |
| 410 | return ErrOverflow |
| 411 | } |
| 412 | pathOff32, ok := checkedU32Int(pathOff) |
| 413 | if !ok { |
| 414 | b.err = ErrOverflow |
| 415 | return ErrOverflow |
| 416 | } |
| 417 | pathLen32, ok := checkedU32Int(len(path)) |
| 418 | if !ok { |
| 419 | b.err = ErrOverflow |
| 420 | return ErrOverflow |
| 421 | } |
| 422 | nameOff32, ok := checkedU32Int(nameOff) |
| 423 | if !ok { |
| 424 | b.err = ErrOverflow |
| 425 | return ErrOverflow |
| 426 | } |
| 427 | nameLen32, ok := checkedU32Int(len(name)) |
| 428 | if !ok { |
| 429 | b.err = ErrOverflow |
| 430 | return ErrOverflow |
| 431 | } |
| 432 | itemStart32, ok := checkedU32Int(itemStart) |
| 433 | if !ok { |
| 434 | b.err = ErrOverflow |
| 435 | return ErrOverflow |
| 436 | } |
| 437 | itemSize32, ok := checkedU32Int(itemSize) |
| 438 | if !ok { |
| 439 | b.err = ErrOverflow |
| 440 | return ErrOverflow |
| 441 | } |
| 442 | clear(b.buf[b.dataOffset:itemStart]) |
| 443 | item := b.buf[itemStart:itemEnd] |
| 444 | ne.PutUint16(item[0:2], 1) |
| 445 | ne.PutUint16(item[2:4], status) |
| 446 | ne.PutUint16(item[4:6], orchestrator) |
| 447 | ne.PutUint16(item[6:8], 0) |
| 448 | ne.PutUint32(item[8:12], pathOff32) |
| 449 | ne.PutUint32(item[12:16], pathLen32) |
| 450 | ne.PutUint32(item[16:20], nameOff32) |
| 451 | ne.PutUint32(item[20:24], nameLen32) |
| 452 | ne.PutUint16(item[24:26], labelCount) |
| 453 | ne.PutUint16(item[26:28], 0) |
| 454 | copy(item[pathOff:], path) |
| 455 | item[pathOff+len(path)] = 0 |
| 456 | copy(item[nameOff:], name) |
| 457 | item[nameOff+len(name)] = 0 |
| 458 | if len(labels) > 0 { |
| 459 | clear(item[fixedEnd:tableStart]) |
| 460 | next, err := writeLookupLabels(item, tableStart, tableBytes, labels) |
| 461 | if err != nil { |
| 462 | b.err = err |
| 463 | return err |
| 464 | } |
| 465 | itemSize = next |
| 466 | } |
| 467 | dir, ok := lookupDirOffset(CgroupsLookupRespHdr, b.itemCount) |
| 468 | if !ok { |
| 469 | b.err = ErrOverflow |
| 470 | return ErrOverflow |
| 471 | } |
| 472 | ne.PutUint32(b.buf[dir:dir+4], itemStart32) |
| 473 | ne.PutUint32(b.buf[dir+4:dir+8], itemSize32) |
| 474 | b.dataOffset = itemStart + itemSize |
| 475 | b.itemCount++ |
| 476 | return nil |
| 477 | } |
| 478 | |
| 479 | func (b *CgroupsLookupBuilder) addUnknown(status uint16, path []byte) error { |
| 480 | itemStart, ok := checkedAlign8(b.dataOffset) |
| 481 | if !ok { |
| 482 | b.err = ErrOverflow |
| 483 | return ErrOverflow |
| 484 | } |
| 485 | nameOff, ok := checkedAddInt(CgroupsLookupItemHdr, len(path)) |
| 486 | if ok { |
| 487 | nameOff, ok = checkedAddInt(nameOff, 1) |
| 488 | } |
| 489 | if !ok { |
| 490 | b.err = ErrOverflow |
| 491 | return ErrOverflow |
| 492 | } |
| 493 | itemSize, ok := checkedAddInt(nameOff, 1) |
| 494 | if !ok { |
| 495 | b.err = ErrOverflow |
| 496 | return ErrOverflow |
| 497 | } |
| 498 | itemEnd, ok := checkedAddInt(itemStart, itemSize) |
| 499 | if !ok { |
| 500 | b.err = ErrOverflow |
| 501 | return ErrOverflow |
| 502 | } |
| 503 | if itemEnd > len(b.buf) { |
| 504 | b.err = ErrOverflow |
| 505 | return ErrOverflow |
| 506 | } |
| 507 | pathLen32, ok := checkedU32Int(len(path)) |
| 508 | if !ok { |
| 509 | b.err = ErrOverflow |
| 510 | return ErrOverflow |
| 511 | } |
| 512 | nameOff32, ok := checkedU32Int(nameOff) |
| 513 | if !ok { |
| 514 | b.err = ErrOverflow |
| 515 | return ErrOverflow |
| 516 | } |
| 517 | itemStart32, ok := checkedU32Int(itemStart) |
| 518 | if !ok { |
| 519 | b.err = ErrOverflow |
| 520 | return ErrOverflow |
| 521 | } |
| 522 | itemSize32, ok := checkedU32Int(itemSize) |
| 523 | if !ok { |
| 524 | b.err = ErrOverflow |
| 525 | return ErrOverflow |
| 526 | } |
| 527 | clear(b.buf[b.dataOffset:itemStart]) |
| 528 | item := b.buf[itemStart:itemEnd] |
| 529 | ne.PutUint16(item[0:2], 1) |
| 530 | ne.PutUint16(item[2:4], status) |
| 531 | ne.PutUint16(item[4:6], 0) |
| 532 | ne.PutUint16(item[6:8], 0) |
| 533 | ne.PutUint32(item[8:12], CgroupsLookupItemHdr) |
| 534 | ne.PutUint32(item[12:16], pathLen32) |
| 535 | ne.PutUint32(item[16:20], nameOff32) |
| 536 | ne.PutUint32(item[20:24], 0) |
| 537 | ne.PutUint16(item[24:26], 0) |
| 538 | ne.PutUint16(item[26:28], 0) |
| 539 | copy(item[CgroupsLookupItemHdr:], path) |
| 540 | item[CgroupsLookupItemHdr+len(path)] = 0 |
| 541 | item[nameOff] = 0 |
| 542 | dir, ok := lookupDirOffset(CgroupsLookupRespHdr, b.itemCount) |
| 543 | if !ok { |
| 544 | b.err = ErrOverflow |
| 545 | return ErrOverflow |
| 546 | } |
| 547 | ne.PutUint32(b.buf[dir:dir+4], itemStart32) |
| 548 | ne.PutUint32(b.buf[dir+4:dir+8], itemSize32) |
| 549 | b.dataOffset = itemStart + itemSize |
| 550 | b.itemCount++ |
| 551 | return nil |
| 552 | } |
| 553 | |
| 554 | func (b *CgroupsLookupBuilder) Finish() int { |
| 555 | return finishLookupResponse(b.buf, CgroupsLookupRespHdr, b.itemCount, b.dataOffset, b.generation) |
| 556 | } |
| 557 | |
| 558 | func (b *CgroupsLookupBuilder) Error() error { |
| 559 | return b.err |
| 560 | } |
| 561 | |
| 562 | func (b *CgroupsLookupBuilder) ItemCount() uint32 { |
| 563 | return b.itemCount |
| 564 | } |
| 565 | |
| 566 | func DispatchCgroupsLookup(req []byte, resp []byte, handler func(*CgroupsLookupRequestView, *CgroupsLookupBuilder) bool) (int, error) { |
| 567 | request, err := DecodeCgroupsLookupRequest(req) |
| 568 | if err != nil { |
| 569 | return 0, err |
| 570 | } |
| 571 | minRequired, ok := lookupBuilderDataOffset(CgroupsLookupRespHdr, request.ItemCount) |
| 572 | if !ok || len(resp) < minRequired { |
| 573 | return 0, ErrOverflow |
| 574 | } |
| 575 | builder := NewCgroupsLookupBuilder(resp, request.ItemCount, 0) |
| 576 | if !handler(request, builder) { |
| 577 | if builder.Error() != nil { |
| 578 | return 0, builder.Error() |
| 579 | } |
| 580 | return 0, ErrBadLayout |
| 581 | } |
| 582 | if builder.Error() != nil { |
| 583 | return 0, builder.Error() |
| 584 | } |
| 585 | if builder.itemCount != request.ItemCount { |
| 586 | return 0, ErrBadItemCount |
| 587 | } |
| 588 | n := builder.Finish() |
| 589 | if n == 0 { |
| 590 | return 0, ErrOverflow |
| 591 | } |
| 592 | return n, nil |
| 593 | } |