Prince Pereira | c1c21d6 | 2021-04-22 08:38:15 +0000 | [diff] [blame] | 1 | // Copyright 2019 The Go Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | package impl |
| 6 | |
| 7 | import ( |
| 8 | "fmt" |
| 9 | "math" |
| 10 | "math/bits" |
| 11 | "reflect" |
| 12 | "unicode/utf8" |
| 13 | |
| 14 | "google.golang.org/protobuf/encoding/protowire" |
| 15 | "google.golang.org/protobuf/internal/encoding/messageset" |
| 16 | "google.golang.org/protobuf/internal/flags" |
| 17 | "google.golang.org/protobuf/internal/strs" |
| 18 | pref "google.golang.org/protobuf/reflect/protoreflect" |
| 19 | preg "google.golang.org/protobuf/reflect/protoregistry" |
| 20 | piface "google.golang.org/protobuf/runtime/protoiface" |
| 21 | ) |
| 22 | |
| 23 | // ValidationStatus is the result of validating the wire-format encoding of a message. |
| 24 | type ValidationStatus int |
| 25 | |
| 26 | const ( |
| 27 | // ValidationUnknown indicates that unmarshaling the message might succeed or fail. |
| 28 | // The validator was unable to render a judgement. |
| 29 | // |
| 30 | // The only causes of this status are an aberrant message type appearing somewhere |
| 31 | // in the message or a failure in the extension resolver. |
| 32 | ValidationUnknown ValidationStatus = iota + 1 |
| 33 | |
| 34 | // ValidationInvalid indicates that unmarshaling the message will fail. |
| 35 | ValidationInvalid |
| 36 | |
| 37 | // ValidationValid indicates that unmarshaling the message will succeed. |
| 38 | ValidationValid |
| 39 | ) |
| 40 | |
| 41 | func (v ValidationStatus) String() string { |
| 42 | switch v { |
| 43 | case ValidationUnknown: |
| 44 | return "ValidationUnknown" |
| 45 | case ValidationInvalid: |
| 46 | return "ValidationInvalid" |
| 47 | case ValidationValid: |
| 48 | return "ValidationValid" |
| 49 | default: |
| 50 | return fmt.Sprintf("ValidationStatus(%d)", int(v)) |
| 51 | } |
| 52 | } |
| 53 | |
| 54 | // Validate determines whether the contents of the buffer are a valid wire encoding |
| 55 | // of the message type. |
| 56 | // |
| 57 | // This function is exposed for testing. |
| 58 | func Validate(mt pref.MessageType, in piface.UnmarshalInput) (out piface.UnmarshalOutput, _ ValidationStatus) { |
| 59 | mi, ok := mt.(*MessageInfo) |
| 60 | if !ok { |
| 61 | return out, ValidationUnknown |
| 62 | } |
| 63 | if in.Resolver == nil { |
| 64 | in.Resolver = preg.GlobalTypes |
| 65 | } |
| 66 | o, st := mi.validate(in.Buf, 0, unmarshalOptions{ |
| 67 | flags: in.Flags, |
| 68 | resolver: in.Resolver, |
| 69 | }) |
| 70 | if o.initialized { |
| 71 | out.Flags |= piface.UnmarshalInitialized |
| 72 | } |
| 73 | return out, st |
| 74 | } |
| 75 | |
| 76 | type validationInfo struct { |
| 77 | mi *MessageInfo |
| 78 | typ validationType |
| 79 | keyType, valType validationType |
| 80 | |
| 81 | // For non-required fields, requiredBit is 0. |
| 82 | // |
| 83 | // For required fields, requiredBit's nth bit is set, where n is a |
| 84 | // unique index in the range [0, MessageInfo.numRequiredFields). |
| 85 | // |
| 86 | // If there are more than 64 required fields, requiredBit is 0. |
| 87 | requiredBit uint64 |
| 88 | } |
| 89 | |
| 90 | type validationType uint8 |
| 91 | |
| 92 | const ( |
| 93 | validationTypeOther validationType = iota |
| 94 | validationTypeMessage |
| 95 | validationTypeGroup |
| 96 | validationTypeMap |
| 97 | validationTypeRepeatedVarint |
| 98 | validationTypeRepeatedFixed32 |
| 99 | validationTypeRepeatedFixed64 |
| 100 | validationTypeVarint |
| 101 | validationTypeFixed32 |
| 102 | validationTypeFixed64 |
| 103 | validationTypeBytes |
| 104 | validationTypeUTF8String |
| 105 | validationTypeMessageSetItem |
| 106 | ) |
| 107 | |
| 108 | func newFieldValidationInfo(mi *MessageInfo, si structInfo, fd pref.FieldDescriptor, ft reflect.Type) validationInfo { |
| 109 | var vi validationInfo |
| 110 | switch { |
| 111 | case fd.ContainingOneof() != nil && !fd.ContainingOneof().IsSynthetic(): |
| 112 | switch fd.Kind() { |
| 113 | case pref.MessageKind: |
| 114 | vi.typ = validationTypeMessage |
| 115 | if ot, ok := si.oneofWrappersByNumber[fd.Number()]; ok { |
| 116 | vi.mi = getMessageInfo(ot.Field(0).Type) |
| 117 | } |
| 118 | case pref.GroupKind: |
| 119 | vi.typ = validationTypeGroup |
| 120 | if ot, ok := si.oneofWrappersByNumber[fd.Number()]; ok { |
| 121 | vi.mi = getMessageInfo(ot.Field(0).Type) |
| 122 | } |
| 123 | case pref.StringKind: |
| 124 | if strs.EnforceUTF8(fd) { |
| 125 | vi.typ = validationTypeUTF8String |
| 126 | } |
| 127 | } |
| 128 | default: |
| 129 | vi = newValidationInfo(fd, ft) |
| 130 | } |
| 131 | if fd.Cardinality() == pref.Required { |
| 132 | // Avoid overflow. The required field check is done with a 64-bit mask, with |
| 133 | // any message containing more than 64 required fields always reported as |
| 134 | // potentially uninitialized, so it is not important to get a precise count |
| 135 | // of the required fields past 64. |
| 136 | if mi.numRequiredFields < math.MaxUint8 { |
| 137 | mi.numRequiredFields++ |
| 138 | vi.requiredBit = 1 << (mi.numRequiredFields - 1) |
| 139 | } |
| 140 | } |
| 141 | return vi |
| 142 | } |
| 143 | |
| 144 | func newValidationInfo(fd pref.FieldDescriptor, ft reflect.Type) validationInfo { |
| 145 | var vi validationInfo |
| 146 | switch { |
| 147 | case fd.IsList(): |
| 148 | switch fd.Kind() { |
| 149 | case pref.MessageKind: |
| 150 | vi.typ = validationTypeMessage |
| 151 | if ft.Kind() == reflect.Slice { |
| 152 | vi.mi = getMessageInfo(ft.Elem()) |
| 153 | } |
| 154 | case pref.GroupKind: |
| 155 | vi.typ = validationTypeGroup |
| 156 | if ft.Kind() == reflect.Slice { |
| 157 | vi.mi = getMessageInfo(ft.Elem()) |
| 158 | } |
| 159 | case pref.StringKind: |
| 160 | vi.typ = validationTypeBytes |
| 161 | if strs.EnforceUTF8(fd) { |
| 162 | vi.typ = validationTypeUTF8String |
| 163 | } |
| 164 | default: |
| 165 | switch wireTypes[fd.Kind()] { |
| 166 | case protowire.VarintType: |
| 167 | vi.typ = validationTypeRepeatedVarint |
| 168 | case protowire.Fixed32Type: |
| 169 | vi.typ = validationTypeRepeatedFixed32 |
| 170 | case protowire.Fixed64Type: |
| 171 | vi.typ = validationTypeRepeatedFixed64 |
| 172 | } |
| 173 | } |
| 174 | case fd.IsMap(): |
| 175 | vi.typ = validationTypeMap |
| 176 | switch fd.MapKey().Kind() { |
| 177 | case pref.StringKind: |
| 178 | if strs.EnforceUTF8(fd) { |
| 179 | vi.keyType = validationTypeUTF8String |
| 180 | } |
| 181 | } |
| 182 | switch fd.MapValue().Kind() { |
| 183 | case pref.MessageKind: |
| 184 | vi.valType = validationTypeMessage |
| 185 | if ft.Kind() == reflect.Map { |
| 186 | vi.mi = getMessageInfo(ft.Elem()) |
| 187 | } |
| 188 | case pref.StringKind: |
| 189 | if strs.EnforceUTF8(fd) { |
| 190 | vi.valType = validationTypeUTF8String |
| 191 | } |
| 192 | } |
| 193 | default: |
| 194 | switch fd.Kind() { |
| 195 | case pref.MessageKind: |
| 196 | vi.typ = validationTypeMessage |
| 197 | if !fd.IsWeak() { |
| 198 | vi.mi = getMessageInfo(ft) |
| 199 | } |
| 200 | case pref.GroupKind: |
| 201 | vi.typ = validationTypeGroup |
| 202 | vi.mi = getMessageInfo(ft) |
| 203 | case pref.StringKind: |
| 204 | vi.typ = validationTypeBytes |
| 205 | if strs.EnforceUTF8(fd) { |
| 206 | vi.typ = validationTypeUTF8String |
| 207 | } |
| 208 | default: |
| 209 | switch wireTypes[fd.Kind()] { |
| 210 | case protowire.VarintType: |
| 211 | vi.typ = validationTypeVarint |
| 212 | case protowire.Fixed32Type: |
| 213 | vi.typ = validationTypeFixed32 |
| 214 | case protowire.Fixed64Type: |
| 215 | vi.typ = validationTypeFixed64 |
| 216 | case protowire.BytesType: |
| 217 | vi.typ = validationTypeBytes |
| 218 | } |
| 219 | } |
| 220 | } |
| 221 | return vi |
| 222 | } |
| 223 | |
| 224 | func (mi *MessageInfo) validate(b []byte, groupTag protowire.Number, opts unmarshalOptions) (out unmarshalOutput, result ValidationStatus) { |
| 225 | mi.init() |
| 226 | type validationState struct { |
| 227 | typ validationType |
| 228 | keyType, valType validationType |
| 229 | endGroup protowire.Number |
| 230 | mi *MessageInfo |
| 231 | tail []byte |
| 232 | requiredMask uint64 |
| 233 | } |
| 234 | |
| 235 | // Pre-allocate some slots to avoid repeated slice reallocation. |
| 236 | states := make([]validationState, 0, 16) |
| 237 | states = append(states, validationState{ |
| 238 | typ: validationTypeMessage, |
| 239 | mi: mi, |
| 240 | }) |
| 241 | if groupTag > 0 { |
| 242 | states[0].typ = validationTypeGroup |
| 243 | states[0].endGroup = groupTag |
| 244 | } |
| 245 | initialized := true |
| 246 | start := len(b) |
| 247 | State: |
| 248 | for len(states) > 0 { |
| 249 | st := &states[len(states)-1] |
| 250 | for len(b) > 0 { |
| 251 | // Parse the tag (field number and wire type). |
| 252 | var tag uint64 |
| 253 | if b[0] < 0x80 { |
| 254 | tag = uint64(b[0]) |
| 255 | b = b[1:] |
| 256 | } else if len(b) >= 2 && b[1] < 128 { |
| 257 | tag = uint64(b[0]&0x7f) + uint64(b[1])<<7 |
| 258 | b = b[2:] |
| 259 | } else { |
| 260 | var n int |
| 261 | tag, n = protowire.ConsumeVarint(b) |
| 262 | if n < 0 { |
| 263 | return out, ValidationInvalid |
| 264 | } |
| 265 | b = b[n:] |
| 266 | } |
| 267 | var num protowire.Number |
| 268 | if n := tag >> 3; n < uint64(protowire.MinValidNumber) || n > uint64(protowire.MaxValidNumber) { |
| 269 | return out, ValidationInvalid |
| 270 | } else { |
| 271 | num = protowire.Number(n) |
| 272 | } |
| 273 | wtyp := protowire.Type(tag & 7) |
| 274 | |
| 275 | if wtyp == protowire.EndGroupType { |
| 276 | if st.endGroup == num { |
| 277 | goto PopState |
| 278 | } |
| 279 | return out, ValidationInvalid |
| 280 | } |
| 281 | var vi validationInfo |
| 282 | switch { |
| 283 | case st.typ == validationTypeMap: |
| 284 | switch num { |
| 285 | case 1: |
| 286 | vi.typ = st.keyType |
| 287 | case 2: |
| 288 | vi.typ = st.valType |
| 289 | vi.mi = st.mi |
| 290 | vi.requiredBit = 1 |
| 291 | } |
| 292 | case flags.ProtoLegacy && st.mi.isMessageSet: |
| 293 | switch num { |
| 294 | case messageset.FieldItem: |
| 295 | vi.typ = validationTypeMessageSetItem |
| 296 | } |
| 297 | default: |
| 298 | var f *coderFieldInfo |
| 299 | if int(num) < len(st.mi.denseCoderFields) { |
| 300 | f = st.mi.denseCoderFields[num] |
| 301 | } else { |
| 302 | f = st.mi.coderFields[num] |
| 303 | } |
| 304 | if f != nil { |
| 305 | vi = f.validation |
| 306 | if vi.typ == validationTypeMessage && vi.mi == nil { |
| 307 | // Probable weak field. |
| 308 | // |
| 309 | // TODO: Consider storing the results of this lookup somewhere |
| 310 | // rather than recomputing it on every validation. |
| 311 | fd := st.mi.Desc.Fields().ByNumber(num) |
| 312 | if fd == nil || !fd.IsWeak() { |
| 313 | break |
| 314 | } |
| 315 | messageName := fd.Message().FullName() |
| 316 | messageType, err := preg.GlobalTypes.FindMessageByName(messageName) |
| 317 | switch err { |
| 318 | case nil: |
| 319 | vi.mi, _ = messageType.(*MessageInfo) |
| 320 | case preg.NotFound: |
| 321 | vi.typ = validationTypeBytes |
| 322 | default: |
| 323 | return out, ValidationUnknown |
| 324 | } |
| 325 | } |
| 326 | break |
| 327 | } |
| 328 | // Possible extension field. |
| 329 | // |
| 330 | // TODO: We should return ValidationUnknown when: |
| 331 | // 1. The resolver is not frozen. (More extensions may be added to it.) |
| 332 | // 2. The resolver returns preg.NotFound. |
| 333 | // In this case, a type added to the resolver in the future could cause |
| 334 | // unmarshaling to begin failing. Supporting this requires some way to |
| 335 | // determine if the resolver is frozen. |
| 336 | xt, err := opts.resolver.FindExtensionByNumber(st.mi.Desc.FullName(), num) |
| 337 | if err != nil && err != preg.NotFound { |
| 338 | return out, ValidationUnknown |
| 339 | } |
| 340 | if err == nil { |
| 341 | vi = getExtensionFieldInfo(xt).validation |
| 342 | } |
| 343 | } |
| 344 | if vi.requiredBit != 0 { |
| 345 | // Check that the field has a compatible wire type. |
| 346 | // We only need to consider non-repeated field types, |
| 347 | // since repeated fields (and maps) can never be required. |
| 348 | ok := false |
| 349 | switch vi.typ { |
| 350 | case validationTypeVarint: |
| 351 | ok = wtyp == protowire.VarintType |
| 352 | case validationTypeFixed32: |
| 353 | ok = wtyp == protowire.Fixed32Type |
| 354 | case validationTypeFixed64: |
| 355 | ok = wtyp == protowire.Fixed64Type |
| 356 | case validationTypeBytes, validationTypeUTF8String, validationTypeMessage: |
| 357 | ok = wtyp == protowire.BytesType |
| 358 | case validationTypeGroup: |
| 359 | ok = wtyp == protowire.StartGroupType |
| 360 | } |
| 361 | if ok { |
| 362 | st.requiredMask |= vi.requiredBit |
| 363 | } |
| 364 | } |
| 365 | |
| 366 | switch wtyp { |
| 367 | case protowire.VarintType: |
| 368 | if len(b) >= 10 { |
| 369 | switch { |
| 370 | case b[0] < 0x80: |
| 371 | b = b[1:] |
| 372 | case b[1] < 0x80: |
| 373 | b = b[2:] |
| 374 | case b[2] < 0x80: |
| 375 | b = b[3:] |
| 376 | case b[3] < 0x80: |
| 377 | b = b[4:] |
| 378 | case b[4] < 0x80: |
| 379 | b = b[5:] |
| 380 | case b[5] < 0x80: |
| 381 | b = b[6:] |
| 382 | case b[6] < 0x80: |
| 383 | b = b[7:] |
| 384 | case b[7] < 0x80: |
| 385 | b = b[8:] |
| 386 | case b[8] < 0x80: |
| 387 | b = b[9:] |
| 388 | case b[9] < 0x80 && b[9] < 2: |
| 389 | b = b[10:] |
| 390 | default: |
| 391 | return out, ValidationInvalid |
| 392 | } |
| 393 | } else { |
| 394 | switch { |
| 395 | case len(b) > 0 && b[0] < 0x80: |
| 396 | b = b[1:] |
| 397 | case len(b) > 1 && b[1] < 0x80: |
| 398 | b = b[2:] |
| 399 | case len(b) > 2 && b[2] < 0x80: |
| 400 | b = b[3:] |
| 401 | case len(b) > 3 && b[3] < 0x80: |
| 402 | b = b[4:] |
| 403 | case len(b) > 4 && b[4] < 0x80: |
| 404 | b = b[5:] |
| 405 | case len(b) > 5 && b[5] < 0x80: |
| 406 | b = b[6:] |
| 407 | case len(b) > 6 && b[6] < 0x80: |
| 408 | b = b[7:] |
| 409 | case len(b) > 7 && b[7] < 0x80: |
| 410 | b = b[8:] |
| 411 | case len(b) > 8 && b[8] < 0x80: |
| 412 | b = b[9:] |
| 413 | case len(b) > 9 && b[9] < 2: |
| 414 | b = b[10:] |
| 415 | default: |
| 416 | return out, ValidationInvalid |
| 417 | } |
| 418 | } |
| 419 | continue State |
| 420 | case protowire.BytesType: |
| 421 | var size uint64 |
| 422 | if len(b) >= 1 && b[0] < 0x80 { |
| 423 | size = uint64(b[0]) |
| 424 | b = b[1:] |
| 425 | } else if len(b) >= 2 && b[1] < 128 { |
| 426 | size = uint64(b[0]&0x7f) + uint64(b[1])<<7 |
| 427 | b = b[2:] |
| 428 | } else { |
| 429 | var n int |
| 430 | size, n = protowire.ConsumeVarint(b) |
| 431 | if n < 0 { |
| 432 | return out, ValidationInvalid |
| 433 | } |
| 434 | b = b[n:] |
| 435 | } |
| 436 | if size > uint64(len(b)) { |
| 437 | return out, ValidationInvalid |
| 438 | } |
| 439 | v := b[:size] |
| 440 | b = b[size:] |
| 441 | switch vi.typ { |
| 442 | case validationTypeMessage: |
| 443 | if vi.mi == nil { |
| 444 | return out, ValidationUnknown |
| 445 | } |
| 446 | vi.mi.init() |
| 447 | fallthrough |
| 448 | case validationTypeMap: |
| 449 | if vi.mi != nil { |
| 450 | vi.mi.init() |
| 451 | } |
| 452 | states = append(states, validationState{ |
| 453 | typ: vi.typ, |
| 454 | keyType: vi.keyType, |
| 455 | valType: vi.valType, |
| 456 | mi: vi.mi, |
| 457 | tail: b, |
| 458 | }) |
| 459 | b = v |
| 460 | continue State |
| 461 | case validationTypeRepeatedVarint: |
| 462 | // Packed field. |
| 463 | for len(v) > 0 { |
| 464 | _, n := protowire.ConsumeVarint(v) |
| 465 | if n < 0 { |
| 466 | return out, ValidationInvalid |
| 467 | } |
| 468 | v = v[n:] |
| 469 | } |
| 470 | case validationTypeRepeatedFixed32: |
| 471 | // Packed field. |
| 472 | if len(v)%4 != 0 { |
| 473 | return out, ValidationInvalid |
| 474 | } |
| 475 | case validationTypeRepeatedFixed64: |
| 476 | // Packed field. |
| 477 | if len(v)%8 != 0 { |
| 478 | return out, ValidationInvalid |
| 479 | } |
| 480 | case validationTypeUTF8String: |
| 481 | if !utf8.Valid(v) { |
| 482 | return out, ValidationInvalid |
| 483 | } |
| 484 | } |
| 485 | case protowire.Fixed32Type: |
| 486 | if len(b) < 4 { |
| 487 | return out, ValidationInvalid |
| 488 | } |
| 489 | b = b[4:] |
| 490 | case protowire.Fixed64Type: |
| 491 | if len(b) < 8 { |
| 492 | return out, ValidationInvalid |
| 493 | } |
| 494 | b = b[8:] |
| 495 | case protowire.StartGroupType: |
| 496 | switch { |
| 497 | case vi.typ == validationTypeGroup: |
| 498 | if vi.mi == nil { |
| 499 | return out, ValidationUnknown |
| 500 | } |
| 501 | vi.mi.init() |
| 502 | states = append(states, validationState{ |
| 503 | typ: validationTypeGroup, |
| 504 | mi: vi.mi, |
| 505 | endGroup: num, |
| 506 | }) |
| 507 | continue State |
| 508 | case flags.ProtoLegacy && vi.typ == validationTypeMessageSetItem: |
| 509 | typeid, v, n, err := messageset.ConsumeFieldValue(b, false) |
| 510 | if err != nil { |
| 511 | return out, ValidationInvalid |
| 512 | } |
| 513 | xt, err := opts.resolver.FindExtensionByNumber(st.mi.Desc.FullName(), typeid) |
| 514 | switch { |
| 515 | case err == preg.NotFound: |
| 516 | b = b[n:] |
| 517 | case err != nil: |
| 518 | return out, ValidationUnknown |
| 519 | default: |
| 520 | xvi := getExtensionFieldInfo(xt).validation |
| 521 | if xvi.mi != nil { |
| 522 | xvi.mi.init() |
| 523 | } |
| 524 | states = append(states, validationState{ |
| 525 | typ: xvi.typ, |
| 526 | mi: xvi.mi, |
| 527 | tail: b[n:], |
| 528 | }) |
| 529 | b = v |
| 530 | continue State |
| 531 | } |
| 532 | default: |
| 533 | n := protowire.ConsumeFieldValue(num, wtyp, b) |
| 534 | if n < 0 { |
| 535 | return out, ValidationInvalid |
| 536 | } |
| 537 | b = b[n:] |
| 538 | } |
| 539 | default: |
| 540 | return out, ValidationInvalid |
| 541 | } |
| 542 | } |
| 543 | if st.endGroup != 0 { |
| 544 | return out, ValidationInvalid |
| 545 | } |
| 546 | if len(b) != 0 { |
| 547 | return out, ValidationInvalid |
| 548 | } |
| 549 | b = st.tail |
| 550 | PopState: |
| 551 | numRequiredFields := 0 |
| 552 | switch st.typ { |
| 553 | case validationTypeMessage, validationTypeGroup: |
| 554 | numRequiredFields = int(st.mi.numRequiredFields) |
| 555 | case validationTypeMap: |
| 556 | // If this is a map field with a message value that contains |
| 557 | // required fields, require that the value be present. |
| 558 | if st.mi != nil && st.mi.numRequiredFields > 0 { |
| 559 | numRequiredFields = 1 |
| 560 | } |
| 561 | } |
| 562 | // If there are more than 64 required fields, this check will |
| 563 | // always fail and we will report that the message is potentially |
| 564 | // uninitialized. |
| 565 | if numRequiredFields > 0 && bits.OnesCount64(st.requiredMask) != numRequiredFields { |
| 566 | initialized = false |
| 567 | } |
| 568 | states = states[:len(states)-1] |
| 569 | } |
| 570 | out.n = start - len(b) |
| 571 | if initialized { |
| 572 | out.initialized = true |
| 573 | } |
| 574 | return out, ValidationValid |
| 575 | } |