1 /*
2 * Copyright 2015 Google Inc. All rights reserved.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "flatbuffers/reflection.h"
18 #include "flatbuffers/util.h"
19
20 // Helper functionality for reflection.
21
22 namespace flatbuffers {
23
GetAnyValueI(reflection::BaseType type,const uint8_t * data)24 int64_t GetAnyValueI(reflection::BaseType type, const uint8_t *data) {
25 // clang-format off
26 #define FLATBUFFERS_GET(T) static_cast<int64_t>(ReadScalar<T>(data))
27 switch (type) {
28 case reflection::UType:
29 case reflection::Bool:
30 case reflection::UByte: return FLATBUFFERS_GET(uint8_t);
31 case reflection::Byte: return FLATBUFFERS_GET(int8_t);
32 case reflection::Short: return FLATBUFFERS_GET(int16_t);
33 case reflection::UShort: return FLATBUFFERS_GET(uint16_t);
34 case reflection::Int: return FLATBUFFERS_GET(int32_t);
35 case reflection::UInt: return FLATBUFFERS_GET(uint32_t);
36 case reflection::Long: return FLATBUFFERS_GET(int64_t);
37 case reflection::ULong: return FLATBUFFERS_GET(uint64_t);
38 case reflection::Float: return FLATBUFFERS_GET(float);
39 case reflection::Double: return FLATBUFFERS_GET(double);
40 case reflection::String: {
41 auto s = reinterpret_cast<const String *>(ReadScalar<uoffset_t>(data) +
42 data);
43 return s ? StringToInt(s->c_str()) : 0;
44 }
45 default: return 0; // Tables & vectors do not make sense.
46 }
47 #undef FLATBUFFERS_GET
48 // clang-format on
49 }
50
GetAnyValueF(reflection::BaseType type,const uint8_t * data)51 double GetAnyValueF(reflection::BaseType type, const uint8_t *data) {
52 switch (type) {
53 case reflection::Float: return static_cast<double>(ReadScalar<float>(data));
54 case reflection::Double: return ReadScalar<double>(data);
55 case reflection::String: {
56 auto s =
57 reinterpret_cast<const String *>(ReadScalar<uoffset_t>(data) + data);
58 return s ? strtod(s->c_str(), nullptr) : 0.0;
59 }
60 default: return static_cast<double>(GetAnyValueI(type, data));
61 }
62 }
63
GetAnyValueS(reflection::BaseType type,const uint8_t * data,const reflection::Schema * schema,int type_index)64 std::string GetAnyValueS(reflection::BaseType type, const uint8_t *data,
65 const reflection::Schema *schema, int type_index) {
66 switch (type) {
67 case reflection::Float:
68 case reflection::Double: return NumToString(GetAnyValueF(type, data));
69 case reflection::String: {
70 auto s =
71 reinterpret_cast<const String *>(ReadScalar<uoffset_t>(data) + data);
72 return s ? s->c_str() : "";
73 }
74 case reflection::Obj:
75 if (schema) {
76 // Convert the table to a string. This is mostly for debugging purposes,
77 // and does NOT promise to be JSON compliant.
78 // Also prefixes the type.
79 auto &objectdef = *schema->objects()->Get(type_index);
80 auto s = objectdef.name()->str();
81 if (objectdef.is_struct()) {
82 s += "(struct)"; // TODO: implement this as well.
83 } else {
84 auto table_field = reinterpret_cast<const Table *>(
85 ReadScalar<uoffset_t>(data) + data);
86 s += " { ";
87 auto fielddefs = objectdef.fields();
88 for (auto it = fielddefs->begin(); it != fielddefs->end(); ++it) {
89 auto &fielddef = **it;
90 if (!table_field->CheckField(fielddef.offset())) continue;
91 auto val = GetAnyFieldS(*table_field, fielddef, schema);
92 if (fielddef.type()->base_type() == reflection::String) {
93 std::string esc;
94 flatbuffers::EscapeString(val.c_str(), val.length(), &esc, true,
95 false);
96 val = esc;
97 }
98 s += fielddef.name()->str();
99 s += ": ";
100 s += val;
101 s += ", ";
102 }
103 s += "}";
104 }
105 return s;
106 } else {
107 return "(table)";
108 }
109 case reflection::Vector:
110 return "[(elements)]"; // TODO: implement this as well.
111 case reflection::Union: return "(union)"; // TODO: implement this as well.
112 default: return NumToString(GetAnyValueI(type, data));
113 }
114 }
115
SetAnyValueI(reflection::BaseType type,uint8_t * data,int64_t val)116 void SetAnyValueI(reflection::BaseType type, uint8_t *data, int64_t val) {
117 // clang-format off
118 #define FLATBUFFERS_SET(T) WriteScalar(data, static_cast<T>(val))
119 switch (type) {
120 case reflection::UType:
121 case reflection::Bool:
122 case reflection::UByte: FLATBUFFERS_SET(uint8_t ); break;
123 case reflection::Byte: FLATBUFFERS_SET(int8_t ); break;
124 case reflection::Short: FLATBUFFERS_SET(int16_t ); break;
125 case reflection::UShort: FLATBUFFERS_SET(uint16_t); break;
126 case reflection::Int: FLATBUFFERS_SET(int32_t ); break;
127 case reflection::UInt: FLATBUFFERS_SET(uint32_t); break;
128 case reflection::Long: FLATBUFFERS_SET(int64_t ); break;
129 case reflection::ULong: FLATBUFFERS_SET(uint64_t); break;
130 case reflection::Float: FLATBUFFERS_SET(float ); break;
131 case reflection::Double: FLATBUFFERS_SET(double ); break;
132 // TODO: support strings
133 default: break;
134 }
135 #undef FLATBUFFERS_SET
136 // clang-format on
137 }
138
SetAnyValueF(reflection::BaseType type,uint8_t * data,double val)139 void SetAnyValueF(reflection::BaseType type, uint8_t *data, double val) {
140 switch (type) {
141 case reflection::Float: WriteScalar(data, static_cast<float>(val)); break;
142 case reflection::Double: WriteScalar(data, val); break;
143 // TODO: support strings.
144 default: SetAnyValueI(type, data, static_cast<int64_t>(val)); break;
145 }
146 }
147
SetAnyValueS(reflection::BaseType type,uint8_t * data,const char * val)148 void SetAnyValueS(reflection::BaseType type, uint8_t *data, const char *val) {
149 switch (type) {
150 case reflection::Float:
151 case reflection::Double:
152 SetAnyValueF(type, data, strtod(val, nullptr));
153 break;
154 // TODO: support strings.
155 default: SetAnyValueI(type, data, StringToInt(val)); break;
156 }
157 }
158
159 // Resize a FlatBuffer in-place by iterating through all offsets in the buffer
160 // and adjusting them by "delta" if they straddle the start offset.
161 // Once that is done, bytes can now be inserted/deleted safely.
162 // "delta" may be negative (shrinking).
163 // Unless "delta" is a multiple of the largest alignment, you'll create a small
164 // amount of garbage space in the buffer (usually 0..7 bytes).
165 // If your FlatBuffer's root table is not the schema's root table, you should
166 // pass in your root_table type as well.
167 class ResizeContext {
168 public:
ResizeContext(const reflection::Schema & schema,uoffset_t start,int delta,std::vector<uint8_t> * flatbuf,const reflection::Object * root_table=nullptr)169 ResizeContext(const reflection::Schema &schema, uoffset_t start, int delta,
170 std::vector<uint8_t> *flatbuf,
171 const reflection::Object *root_table = nullptr)
172 : schema_(schema),
173 startptr_(vector_data(*flatbuf) + start),
174 delta_(delta),
175 buf_(*flatbuf),
176 dag_check_(flatbuf->size() / sizeof(uoffset_t), false) {
177 auto mask = static_cast<int>(sizeof(largest_scalar_t) - 1);
178 delta_ = (delta_ + mask) & ~mask;
179 if (!delta_) return; // We can't shrink by less than largest_scalar_t.
180 // Now change all the offsets by delta_.
181 auto root = GetAnyRoot(vector_data(buf_));
182 Straddle<uoffset_t, 1>(vector_data(buf_), root, vector_data(buf_));
183 ResizeTable(root_table ? *root_table : *schema.root_table(), root);
184 // We can now add or remove bytes at start.
185 if (delta_ > 0)
186 buf_.insert(buf_.begin() + start, delta_, 0);
187 else
188 buf_.erase(buf_.begin() + start, buf_.begin() + start - delta_);
189 }
190
191 // Check if the range between first (lower address) and second straddles
192 // the insertion point. If it does, change the offset at offsetloc (of
193 // type T, with direction D).
194 template<typename T, int D>
Straddle(const void * first,const void * second,void * offsetloc)195 void Straddle(const void *first, const void *second, void *offsetloc) {
196 if (first <= startptr_ && second >= startptr_) {
197 WriteScalar<T>(offsetloc, ReadScalar<T>(offsetloc) + delta_ * D);
198 DagCheck(offsetloc) = true;
199 }
200 }
201
202 // This returns a boolean that records if the corresponding offset location
203 // has been modified already. If so, we can't even read the corresponding
204 // offset, since it is pointing to a location that is illegal until the
205 // resize actually happens.
206 // This must be checked for every offset, since we can't know which offsets
207 // will straddle and which won't.
DagCheck(const void * offsetloc)208 uint8_t &DagCheck(const void *offsetloc) {
209 auto dag_idx = reinterpret_cast<const uoffset_t *>(offsetloc) -
210 reinterpret_cast<const uoffset_t *>(vector_data(buf_));
211 return dag_check_[dag_idx];
212 }
213
ResizeTable(const reflection::Object & objectdef,Table * table)214 void ResizeTable(const reflection::Object &objectdef, Table *table) {
215 if (DagCheck(table)) return; // Table already visited.
216 auto vtable = table->GetVTable();
217 // Early out: since all fields inside the table must point forwards in
218 // memory, if the insertion point is before the table we can stop here.
219 auto tableloc = reinterpret_cast<uint8_t *>(table);
220 if (startptr_ <= tableloc) {
221 // Check if insertion point is between the table and a vtable that
222 // precedes it. This can't happen in current construction code, but check
223 // just in case we ever change the way flatbuffers are built.
224 Straddle<soffset_t, -1>(vtable, table, table);
225 } else {
226 // Check each field.
227 auto fielddefs = objectdef.fields();
228 for (auto it = fielddefs->begin(); it != fielddefs->end(); ++it) {
229 auto &fielddef = **it;
230 auto base_type = fielddef.type()->base_type();
231 // Ignore scalars.
232 if (base_type <= reflection::Double) continue;
233 // Ignore fields that are not stored.
234 auto offset = table->GetOptionalFieldOffset(fielddef.offset());
235 if (!offset) continue;
236 // Ignore structs.
237 auto subobjectdef =
238 base_type == reflection::Obj
239 ? schema_.objects()->Get(fielddef.type()->index())
240 : nullptr;
241 if (subobjectdef && subobjectdef->is_struct()) continue;
242 // Get this fields' offset, and read it if safe.
243 auto offsetloc = tableloc + offset;
244 if (DagCheck(offsetloc)) continue; // This offset already visited.
245 auto ref = offsetloc + ReadScalar<uoffset_t>(offsetloc);
246 Straddle<uoffset_t, 1>(offsetloc, ref, offsetloc);
247 // Recurse.
248 switch (base_type) {
249 case reflection::Obj: {
250 ResizeTable(*subobjectdef, reinterpret_cast<Table *>(ref));
251 break;
252 }
253 case reflection::Vector: {
254 auto elem_type = fielddef.type()->element();
255 if (elem_type != reflection::Obj && elem_type != reflection::String)
256 break;
257 auto vec = reinterpret_cast<Vector<uoffset_t> *>(ref);
258 auto elemobjectdef =
259 elem_type == reflection::Obj
260 ? schema_.objects()->Get(fielddef.type()->index())
261 : nullptr;
262 if (elemobjectdef && elemobjectdef->is_struct()) break;
263 for (uoffset_t i = 0; i < vec->size(); i++) {
264 auto loc = vec->Data() + i * sizeof(uoffset_t);
265 if (DagCheck(loc)) continue; // This offset already visited.
266 auto dest = loc + vec->Get(i);
267 Straddle<uoffset_t, 1>(loc, dest, loc);
268 if (elemobjectdef)
269 ResizeTable(*elemobjectdef, reinterpret_cast<Table *>(dest));
270 }
271 break;
272 }
273 case reflection::Union: {
274 ResizeTable(GetUnionType(schema_, objectdef, fielddef, *table),
275 reinterpret_cast<Table *>(ref));
276 break;
277 }
278 case reflection::String: break;
279 default: FLATBUFFERS_ASSERT(false);
280 }
281 }
282 // Check if the vtable offset points beyond the insertion point.
283 // Must do this last, since GetOptionalFieldOffset above still reads
284 // this value.
285 Straddle<soffset_t, -1>(table, vtable, table);
286 }
287 }
288
289 void operator=(const ResizeContext &rc);
290
291 private:
292 const reflection::Schema &schema_;
293 uint8_t *startptr_;
294 int delta_;
295 std::vector<uint8_t> &buf_;
296 std::vector<uint8_t> dag_check_;
297 };
298
SetString(const reflection::Schema & schema,const std::string & val,const String * str,std::vector<uint8_t> * flatbuf,const reflection::Object * root_table)299 void SetString(const reflection::Schema &schema, const std::string &val,
300 const String *str, std::vector<uint8_t> *flatbuf,
301 const reflection::Object *root_table) {
302 auto delta = static_cast<int>(val.size()) - static_cast<int>(str->size());
303 auto str_start = static_cast<uoffset_t>(
304 reinterpret_cast<const uint8_t *>(str) - vector_data(*flatbuf));
305 auto start = str_start + static_cast<uoffset_t>(sizeof(uoffset_t));
306 if (delta) {
307 // Clear the old string, since we don't want parts of it remaining.
308 memset(vector_data(*flatbuf) + start, 0, str->size());
309 // Different size, we must expand (or contract).
310 ResizeContext(schema, start, delta, flatbuf, root_table);
311 // Set the new length.
312 WriteScalar(vector_data(*flatbuf) + str_start,
313 static_cast<uoffset_t>(val.size()));
314 }
315 // Copy new data. Safe because we created the right amount of space.
316 memcpy(vector_data(*flatbuf) + start, val.c_str(), val.size() + 1);
317 }
318
ResizeAnyVector(const reflection::Schema & schema,uoffset_t newsize,const VectorOfAny * vec,uoffset_t num_elems,uoffset_t elem_size,std::vector<uint8_t> * flatbuf,const reflection::Object * root_table)319 uint8_t *ResizeAnyVector(const reflection::Schema &schema, uoffset_t newsize,
320 const VectorOfAny *vec, uoffset_t num_elems,
321 uoffset_t elem_size, std::vector<uint8_t> *flatbuf,
322 const reflection::Object *root_table) {
323 auto delta_elem = static_cast<int>(newsize) - static_cast<int>(num_elems);
324 auto delta_bytes = delta_elem * static_cast<int>(elem_size);
325 auto vec_start =
326 reinterpret_cast<const uint8_t *>(vec) - vector_data(*flatbuf);
327 auto start = static_cast<uoffset_t>(vec_start + sizeof(uoffset_t) +
328 elem_size * num_elems);
329 if (delta_bytes) {
330 if (delta_elem < 0) {
331 // Clear elements we're throwing away, since some might remain in the
332 // buffer.
333 auto size_clear = -delta_elem * elem_size;
334 memset(vector_data(*flatbuf) + start - size_clear, 0, size_clear);
335 }
336 ResizeContext(schema, start, delta_bytes, flatbuf, root_table);
337 WriteScalar(vector_data(*flatbuf) + vec_start, newsize); // Length field.
338 // Set new elements to 0.. this can be overwritten by the caller.
339 if (delta_elem > 0) {
340 memset(vector_data(*flatbuf) + start, 0, delta_elem * elem_size);
341 }
342 }
343 return vector_data(*flatbuf) + start;
344 }
345
AddFlatBuffer(std::vector<uint8_t> & flatbuf,const uint8_t * newbuf,size_t newlen)346 const uint8_t *AddFlatBuffer(std::vector<uint8_t> &flatbuf,
347 const uint8_t *newbuf, size_t newlen) {
348 // Align to sizeof(uoffset_t) past sizeof(largest_scalar_t) since we're
349 // going to chop off the root offset.
350 while ((flatbuf.size() & (sizeof(uoffset_t) - 1)) ||
351 !(flatbuf.size() & (sizeof(largest_scalar_t) - 1))) {
352 flatbuf.push_back(0);
353 }
354 auto insertion_point = static_cast<uoffset_t>(flatbuf.size());
355 // Insert the entire FlatBuffer minus the root pointer.
356 flatbuf.insert(flatbuf.end(), newbuf + sizeof(uoffset_t), newbuf + newlen);
357 auto root_offset = ReadScalar<uoffset_t>(newbuf) - sizeof(uoffset_t);
358 return vector_data(flatbuf) + insertion_point + root_offset;
359 }
360
CopyInline(FlatBufferBuilder & fbb,const reflection::Field & fielddef,const Table & table,size_t align,size_t size)361 void CopyInline(FlatBufferBuilder &fbb, const reflection::Field &fielddef,
362 const Table &table, size_t align, size_t size) {
363 fbb.Align(align);
364 fbb.PushBytes(table.GetStruct<const uint8_t *>(fielddef.offset()), size);
365 fbb.TrackField(fielddef.offset(), fbb.GetSize());
366 }
367
CopyTable(FlatBufferBuilder & fbb,const reflection::Schema & schema,const reflection::Object & objectdef,const Table & table,bool use_string_pooling)368 Offset<const Table *> CopyTable(FlatBufferBuilder &fbb,
369 const reflection::Schema &schema,
370 const reflection::Object &objectdef,
371 const Table &table, bool use_string_pooling) {
372 // Before we can construct the table, we have to first generate any
373 // subobjects, and collect their offsets.
374 std::vector<uoffset_t> offsets;
375 auto fielddefs = objectdef.fields();
376 for (auto it = fielddefs->begin(); it != fielddefs->end(); ++it) {
377 auto &fielddef = **it;
378 // Skip if field is not present in the source.
379 if (!table.CheckField(fielddef.offset())) continue;
380 uoffset_t offset = 0;
381 switch (fielddef.type()->base_type()) {
382 case reflection::String: {
383 offset = use_string_pooling
384 ? fbb.CreateSharedString(GetFieldS(table, fielddef)).o
385 : fbb.CreateString(GetFieldS(table, fielddef)).o;
386 break;
387 }
388 case reflection::Obj: {
389 auto &subobjectdef = *schema.objects()->Get(fielddef.type()->index());
390 if (!subobjectdef.is_struct()) {
391 offset =
392 CopyTable(fbb, schema, subobjectdef, *GetFieldT(table, fielddef))
393 .o;
394 }
395 break;
396 }
397 case reflection::Union: {
398 auto &subobjectdef = GetUnionType(schema, objectdef, fielddef, table);
399 offset =
400 CopyTable(fbb, schema, subobjectdef, *GetFieldT(table, fielddef)).o;
401 break;
402 }
403 case reflection::Vector: {
404 auto vec =
405 table.GetPointer<const Vector<Offset<Table>> *>(fielddef.offset());
406 auto element_base_type = fielddef.type()->element();
407 auto elemobjectdef =
408 element_base_type == reflection::Obj
409 ? schema.objects()->Get(fielddef.type()->index())
410 : nullptr;
411 switch (element_base_type) {
412 case reflection::String: {
413 std::vector<Offset<const String *>> elements(vec->size());
414 auto vec_s = reinterpret_cast<const Vector<Offset<String>> *>(vec);
415 for (uoffset_t i = 0; i < vec_s->size(); i++) {
416 elements[i] = use_string_pooling
417 ? fbb.CreateSharedString(vec_s->Get(i)).o
418 : fbb.CreateString(vec_s->Get(i)).o;
419 }
420 offset = fbb.CreateVector(elements).o;
421 break;
422 }
423 case reflection::Obj: {
424 if (!elemobjectdef->is_struct()) {
425 std::vector<Offset<const Table *>> elements(vec->size());
426 for (uoffset_t i = 0; i < vec->size(); i++) {
427 elements[i] =
428 CopyTable(fbb, schema, *elemobjectdef, *vec->Get(i));
429 }
430 offset = fbb.CreateVector(elements).o;
431 break;
432 }
433 }
434 FLATBUFFERS_FALLTHROUGH(); // fall thru
435 default: { // Scalars and structs.
436 auto element_size = GetTypeSize(element_base_type);
437 if (elemobjectdef && elemobjectdef->is_struct())
438 element_size = elemobjectdef->bytesize();
439 fbb.StartVector(vec->size(), element_size);
440 fbb.PushBytes(vec->Data(), element_size * vec->size());
441 offset = fbb.EndVector(vec->size());
442 break;
443 }
444 }
445 break;
446 }
447 default: // Scalars.
448 break;
449 }
450 if (offset) { offsets.push_back(offset); }
451 }
452 // Now we can build the actual table from either offsets or scalar data.
453 auto start = objectdef.is_struct() ? fbb.StartStruct(objectdef.minalign())
454 : fbb.StartTable();
455 size_t offset_idx = 0;
456 for (auto it = fielddefs->begin(); it != fielddefs->end(); ++it) {
457 auto &fielddef = **it;
458 if (!table.CheckField(fielddef.offset())) continue;
459 auto base_type = fielddef.type()->base_type();
460 switch (base_type) {
461 case reflection::Obj: {
462 auto &subobjectdef = *schema.objects()->Get(fielddef.type()->index());
463 if (subobjectdef.is_struct()) {
464 CopyInline(fbb, fielddef, table, subobjectdef.minalign(),
465 subobjectdef.bytesize());
466 break;
467 }
468 }
469 FLATBUFFERS_FALLTHROUGH(); // fall thru
470 case reflection::Union:
471 case reflection::String:
472 case reflection::Vector:
473 fbb.AddOffset(fielddef.offset(), Offset<void>(offsets[offset_idx++]));
474 break;
475 default: { // Scalars.
476 auto size = GetTypeSize(base_type);
477 CopyInline(fbb, fielddef, table, size, size);
478 break;
479 }
480 }
481 }
482 FLATBUFFERS_ASSERT(offset_idx == offsets.size());
483 if (objectdef.is_struct()) {
484 fbb.ClearOffsets();
485 return fbb.EndStruct();
486 } else {
487 return fbb.EndTable(start);
488 }
489 }
490
VerifyStruct(flatbuffers::Verifier & v,const flatbuffers::Table & parent_table,voffset_t field_offset,const reflection::Object & obj,bool required)491 bool VerifyStruct(flatbuffers::Verifier &v,
492 const flatbuffers::Table &parent_table,
493 voffset_t field_offset, const reflection::Object &obj,
494 bool required) {
495 auto offset = parent_table.GetOptionalFieldOffset(field_offset);
496 if (required && !offset) { return false; }
497
498 return !offset ||
499 v.Verify(reinterpret_cast<const uint8_t *>(&parent_table), offset,
500 obj.bytesize());
501 }
502
VerifyVectorOfStructs(flatbuffers::Verifier & v,const flatbuffers::Table & parent_table,voffset_t field_offset,const reflection::Object & obj,bool required)503 bool VerifyVectorOfStructs(flatbuffers::Verifier &v,
504 const flatbuffers::Table &parent_table,
505 voffset_t field_offset,
506 const reflection::Object &obj, bool required) {
507 auto p = parent_table.GetPointer<const uint8_t *>(field_offset);
508 if (required && !p) { return false; }
509
510 return !p || v.VerifyVectorOrString(p, obj.bytesize());
511 }
512
513 // forward declare to resolve cyclic deps between VerifyObject and VerifyVector
514 bool VerifyObject(flatbuffers::Verifier &v, const reflection::Schema &schema,
515 const reflection::Object &obj,
516 const flatbuffers::Table *table, bool required);
517
VerifyVector(flatbuffers::Verifier & v,const reflection::Schema & schema,const flatbuffers::Table & table,const reflection::Field & vec_field)518 bool VerifyVector(flatbuffers::Verifier &v, const reflection::Schema &schema,
519 const flatbuffers::Table &table,
520 const reflection::Field &vec_field) {
521 FLATBUFFERS_ASSERT(vec_field.type()->base_type() == reflection::Vector);
522 if (!table.VerifyField<uoffset_t>(v, vec_field.offset())) return false;
523
524 switch (vec_field.type()->element()) {
525 case reflection::None: FLATBUFFERS_ASSERT(false); break;
526 case reflection::UType:
527 return v.VerifyVector(flatbuffers::GetFieldV<uint8_t>(table, vec_field));
528 case reflection::Bool:
529 case reflection::Byte:
530 case reflection::UByte:
531 return v.VerifyVector(flatbuffers::GetFieldV<int8_t>(table, vec_field));
532 case reflection::Short:
533 case reflection::UShort:
534 return v.VerifyVector(flatbuffers::GetFieldV<int16_t>(table, vec_field));
535 case reflection::Int:
536 case reflection::UInt:
537 return v.VerifyVector(flatbuffers::GetFieldV<int32_t>(table, vec_field));
538 case reflection::Long:
539 case reflection::ULong:
540 return v.VerifyVector(flatbuffers::GetFieldV<int64_t>(table, vec_field));
541 case reflection::Float:
542 return v.VerifyVector(flatbuffers::GetFieldV<float>(table, vec_field));
543 case reflection::Double:
544 return v.VerifyVector(flatbuffers::GetFieldV<double>(table, vec_field));
545 case reflection::String: {
546 auto vec_string =
547 flatbuffers::GetFieldV<flatbuffers::Offset<flatbuffers::String>>(
548 table, vec_field);
549 if (v.VerifyVector(vec_string) && v.VerifyVectorOfStrings(vec_string)) {
550 return true;
551 } else {
552 return false;
553 }
554 }
555 case reflection::Vector: FLATBUFFERS_ASSERT(false); break;
556 case reflection::Obj: {
557 auto obj = schema.objects()->Get(vec_field.type()->index());
558 if (obj->is_struct()) {
559 if (!VerifyVectorOfStructs(v, table, vec_field.offset(), *obj,
560 vec_field.required())) {
561 return false;
562 }
563 } else {
564 auto vec =
565 flatbuffers::GetFieldV<flatbuffers::Offset<flatbuffers::Table>>(
566 table, vec_field);
567 if (!v.VerifyVector(vec)) return false;
568 if (vec) {
569 for (uoffset_t j = 0; j < vec->size(); j++) {
570 if (!VerifyObject(v, schema, *obj, vec->Get(j), true)) {
571 return false;
572 }
573 }
574 }
575 }
576 return true;
577 }
578 case reflection::Union: FLATBUFFERS_ASSERT(false); break;
579 default: FLATBUFFERS_ASSERT(false); break;
580 }
581
582 return false;
583 }
584
VerifyObject(flatbuffers::Verifier & v,const reflection::Schema & schema,const reflection::Object & obj,const flatbuffers::Table * table,bool required)585 bool VerifyObject(flatbuffers::Verifier &v, const reflection::Schema &schema,
586 const reflection::Object &obj,
587 const flatbuffers::Table *table, bool required) {
588 if (!table) {
589 if (!required)
590 return true;
591 else
592 return false;
593 }
594
595 if (!table->VerifyTableStart(v)) return false;
596
597 for (uoffset_t i = 0; i < obj.fields()->size(); i++) {
598 auto field_def = obj.fields()->Get(i);
599 switch (field_def->type()->base_type()) {
600 case reflection::None: FLATBUFFERS_ASSERT(false); break;
601 case reflection::UType:
602 if (!table->VerifyField<uint8_t>(v, field_def->offset())) return false;
603 break;
604 case reflection::Bool:
605 case reflection::Byte:
606 case reflection::UByte:
607 if (!table->VerifyField<int8_t>(v, field_def->offset())) return false;
608 break;
609 case reflection::Short:
610 case reflection::UShort:
611 if (!table->VerifyField<int16_t>(v, field_def->offset())) return false;
612 break;
613 case reflection::Int:
614 case reflection::UInt:
615 if (!table->VerifyField<int32_t>(v, field_def->offset())) return false;
616 break;
617 case reflection::Long:
618 case reflection::ULong:
619 if (!table->VerifyField<int64_t>(v, field_def->offset())) return false;
620 break;
621 case reflection::Float:
622 if (!table->VerifyField<float>(v, field_def->offset())) return false;
623 break;
624 case reflection::Double:
625 if (!table->VerifyField<double>(v, field_def->offset())) return false;
626 break;
627 case reflection::String:
628 if (!table->VerifyField<uoffset_t>(v, field_def->offset()) ||
629 !v.VerifyString(flatbuffers::GetFieldS(*table, *field_def))) {
630 return false;
631 }
632 break;
633 case reflection::Vector:
634 if (!VerifyVector(v, schema, *table, *field_def)) return false;
635 break;
636 case reflection::Obj: {
637 auto child_obj = schema.objects()->Get(field_def->type()->index());
638 if (child_obj->is_struct()) {
639 if (!VerifyStruct(v, *table, field_def->offset(), *child_obj,
640 field_def->required())) {
641 return false;
642 }
643 } else {
644 if (!VerifyObject(v, schema, *child_obj,
645 flatbuffers::GetFieldT(*table, *field_def),
646 field_def->required())) {
647 return false;
648 }
649 }
650 break;
651 }
652 case reflection::Union: {
653 // get union type from the prev field
654 voffset_t utype_offset = field_def->offset() - sizeof(voffset_t);
655 auto utype = table->GetField<uint8_t>(utype_offset, 0);
656 if (utype != 0) {
657 // Means we have this union field present
658 auto fb_enum = schema.enums()->Get(field_def->type()->index());
659 auto child_obj = fb_enum->values()->Get(utype)->object();
660 if (!VerifyObject(v, schema, *child_obj,
661 flatbuffers::GetFieldT(*table, *field_def),
662 field_def->required())) {
663 return false;
664 }
665 }
666 break;
667 }
668 default: FLATBUFFERS_ASSERT(false); break;
669 }
670 }
671
672 if (!v.EndTable()) return false;
673
674 return true;
675 }
676
Verify(const reflection::Schema & schema,const reflection::Object & root,const uint8_t * buf,size_t length)677 bool Verify(const reflection::Schema &schema, const reflection::Object &root,
678 const uint8_t *buf, size_t length) {
679 Verifier v(buf, length);
680 return VerifyObject(v, schema, root, flatbuffers::GetAnyRoot(buf), true);
681 }
682
683 } // namespace flatbuffers
684