summaryrefslogtreecommitdiff
path: root/dom/base/BodyUtil.cpp
blob: c9b447ac97f453d091603f31bf39aac181b816d5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "BodyUtil.h"

#include "nsError.h"
#include "nsString.h"
#include "nsIGlobalObject.h"
#include "nsIUnicodeDecoder.h"

#include "nsCharSeparatedTokenizer.h"
#include "nsDOMString.h"
#include "nsNetUtil.h"
#include "nsReadableUtils.h"
#include "nsStreamUtils.h"
#include "nsStringStream.h"

#include "mozilla/ErrorResult.h"
#include "mozilla/dom/EncodingUtils.h"
#include "mozilla/dom/Exceptions.h"
#include "mozilla/dom/FetchUtil.h"
#include "mozilla/dom/File.h"
#include "mozilla/dom/FormData.h"
#include "mozilla/dom/Headers.h"
#include "mozilla/dom/Promise.h"
#include "mozilla/dom/URLSearchParams.h"

namespace mozilla {
namespace dom {

namespace {

class StreamDecoder final
{
  nsCOMPtr<nsIUnicodeDecoder> mDecoder;
  nsString mDecoded;

public:
  StreamDecoder()
    : mDecoder(EncodingUtils::DecoderForEncoding("UTF-8"))
  {
    MOZ_ASSERT(mDecoder);
  }

  nsresult
  AppendText(const char* aSrcBuffer, uint32_t aSrcBufferLen)
  {
    int32_t destBufferLen;
    nsresult rv =
      mDecoder->GetMaxLength(aSrcBuffer, aSrcBufferLen, &destBufferLen);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }

    if (!mDecoded.SetCapacity(mDecoded.Length() + destBufferLen, fallible)) {
      return NS_ERROR_OUT_OF_MEMORY;
    }

    char16_t* destBuffer = mDecoded.BeginWriting() + mDecoded.Length();
    int32_t totalChars = mDecoded.Length();

    int32_t srcLen = (int32_t) aSrcBufferLen;
    int32_t outLen = destBufferLen;
    rv = mDecoder->Convert(aSrcBuffer, &srcLen, destBuffer, &outLen);
    MOZ_ASSERT(NS_SUCCEEDED(rv));

    totalChars += outLen;
    mDecoded.SetLength(totalChars);

    return NS_OK;
  }

  nsString&
  GetText()
  {
    return mDecoded;
  }
};

// Reads over a CRLF and positions start after it.
static bool
PushOverLine(nsACString::const_iterator& aStart,
	     const nsACString::const_iterator& aEnd)
{
  if (*aStart == nsCRT::CR && (aEnd - aStart > 1) && *(++aStart) == nsCRT::LF) {
    ++aStart; // advance to after CRLF
    return true;
  }

  return false;
}

class MOZ_STACK_CLASS FillFormIterator final
  : public URLSearchParams::ForEachIterator
{
public:
  explicit FillFormIterator(FormData* aFormData)
    : mFormData(aFormData)
  {
    MOZ_ASSERT(aFormData);
  }

  bool URLParamsIterator(const nsString& aName,
                         const nsString& aValue) override
  {
    ErrorResult rv;
    mFormData->Append(aName, aValue, rv);
    MOZ_ASSERT(!rv.Failed());
    return true;
  }

private:
  FormData* mFormData;
};

/**
 * A simple multipart/form-data parser as defined in RFC 2388 and RFC 2046.
 * This does not respect any encoding specified per entry, using UTF-8
 * throughout. This is as the Fetch spec states in the consume body algorithm.
 * Borrows some things from Necko's nsMultiMixedConv, but is simpler since
 * unlike Necko we do not have to deal with receiving incomplete chunks of data.
 *
 * This parser will fail the entire parse on any invalid entry, so it will
 * never return a partially filled FormData.
 * The content-disposition header is used to figure out the name and filename
 * entries. The inclusion of the filename parameter decides if the entry is
 * inserted into the FormData as a string or a File.
 *
 * File blobs are copies of the underlying data string since we cannot adopt
 * char* chunks embedded within the larger body without significant effort.
 */
class MOZ_STACK_CLASS FormDataParser
{
private:
  RefPtr<FormData> mFormData;
  nsCString mMimeType;
  nsCString mData;

  // Entry state, reset in START_PART.
  nsCString mName;
  nsCString mFilename;
  nsCString mContentType;

  enum
  {
    START_PART,
    PARSE_HEADER,
    PARSE_BODY,
  } mState;

  nsIGlobalObject* mParentObject;

  // Reads over a boundary and sets start to the position after the end of the
  // boundary. Returns false if no boundary is found immediately.
  bool
  PushOverBoundary(const nsACString& aBoundaryString,
                   nsACString::const_iterator& aStart,
                   nsACString::const_iterator& aEnd)
  {
    // We copy the end iterator to keep the original pointing to the real end
    // of the string.
    nsACString::const_iterator end(aEnd);
    const char* beginning = aStart.get();
    if (FindInReadable(aBoundaryString, aStart, end)) {
      // We either should find the body immediately, or after 2 chars with the
      // 2 chars being '-', everything else is failure.
      if ((aStart.get() - beginning) == 0) {
        aStart.advance(aBoundaryString.Length());
        return true;
      }

      if ((aStart.get() - beginning) == 2) {
        if (*(--aStart) == '-' && *(--aStart) == '-') {
          aStart.advance(aBoundaryString.Length() + 2);
          return true;
        }
      }
    }

    return false;
  }

  bool
  ParseHeader(nsACString::const_iterator& aStart,
              nsACString::const_iterator& aEnd,
              bool* aWasEmptyHeader)
  {
    nsAutoCString headerName, headerValue;
    if (!FetchUtil::ExtractHeader(aStart, aEnd,
                                  headerName, headerValue,
                                  aWasEmptyHeader)) {
      return false;
    }
    if (*aWasEmptyHeader) {
      return true;
    }

    if (headerName.LowerCaseEqualsLiteral("content-disposition")) {
      nsCCharSeparatedTokenizer tokenizer(headerValue, ';');
      bool seenFormData = false;
      while (tokenizer.hasMoreTokens()) {
        const nsDependentCSubstring& token = tokenizer.nextToken();
        if (token.IsEmpty()) {
          continue;
        }

        if (token.EqualsLiteral("form-data")) {
          seenFormData = true;
          continue;
        }

        if (seenFormData &&
            StringBeginsWith(token, NS_LITERAL_CSTRING("name="))) {
          mName = StringTail(token, token.Length() - 5);
          mName.Trim(" \"");
          continue;
        }

        if (seenFormData &&
            StringBeginsWith(token, NS_LITERAL_CSTRING("filename="))) {
          mFilename = StringTail(token, token.Length() - 9);
          mFilename.Trim(" \"");
          continue;
        }
      }

      if (mName.IsVoid()) {
        // Could not parse a valid entry name.
        return false;
      }
    } else if (headerName.LowerCaseEqualsLiteral("content-type")) {
      mContentType = headerValue;
    }

    return true;
  }

  // The end of a body is marked by a CRLF followed by the boundary. So the
  // CRLF is part of the boundary and not the body, but any prior CRLFs are
  // part of the body. This will position the iterator at the beginning of the
  // boundary (after the CRLF).
  bool
  ParseBody(const nsACString& aBoundaryString,
            nsACString::const_iterator& aStart,
            nsACString::const_iterator& aEnd)
  {
    const char* beginning = aStart.get();

    // Find the boundary marking the end of the body.
    nsACString::const_iterator end(aEnd);
    if (!FindInReadable(aBoundaryString, aStart, end)) {
      return false;
    }

    // We found a boundary, strip the just prior CRLF, and consider
    // everything else the body section.
    if (aStart.get() - beginning < 2) {
      // Only the first entry can have a boundary right at the beginning. Even
      // an empty body will have a CRLF before the boundary. So this is
      // a failure.
      return false;
    }

    // Check that there is a CRLF right before the boundary.
    aStart.advance(-2);

    // Skip optional hyphens.
    if (*aStart == '-' && *(aStart.get()+1) == '-') {
      if (aStart.get() - beginning < 2) {
        return false;
      }

      aStart.advance(-2);
    }

    if (*aStart != nsCRT::CR || *(aStart.get()+1) != nsCRT::LF) {
      return false;
    }

    nsAutoCString body(beginning, aStart.get() - beginning);

    // Restore iterator to after the \r\n as we promised.
    // We do not need to handle the extra hyphens case since our boundary
    // parser in PushOverBoundary()
    aStart.advance(2);

    if (!mFormData) {
      mFormData = new FormData();
    }

    NS_ConvertUTF8toUTF16 name(mName);

    if (mFilename.IsVoid()) {
      ErrorResult rv;
      mFormData->Append(name, NS_ConvertUTF8toUTF16(body), rv);
      MOZ_ASSERT(!rv.Failed());
    } else {
      // Unfortunately we've to copy the data first since all our strings are
      // going to free it. We also need fallible alloc, so we can't just use
      // ToNewCString().
      char* copy = static_cast<char*>(moz_xmalloc(body.Length()));
      if (!copy) {
        NS_WARNING("Failed to copy File entry body.");
        return false;
      }
      nsCString::const_iterator bodyIter, bodyEnd;
      body.BeginReading(bodyIter);
      body.EndReading(bodyEnd);
      char *p = copy;
      while (bodyIter != bodyEnd) {
        *p++ = *bodyIter++;
      }
      p = nullptr;

      RefPtr<Blob> file =
        File::CreateMemoryFile(mParentObject,
                               reinterpret_cast<void *>(copy), body.Length(),
                               NS_ConvertUTF8toUTF16(mFilename),
                               NS_ConvertUTF8toUTF16(mContentType), /* aLastModifiedDate */ 0);
      Optional<nsAString> dummy;
      ErrorResult rv;
      mFormData->Append(name, *file, dummy, rv);
      if (NS_WARN_IF(rv.Failed())) {
        rv.SuppressException();
        return false;
      }
    }

    return true;
  }

public:
  FormDataParser(const nsACString& aMimeType, const nsACString& aData, nsIGlobalObject* aParent)
    : mMimeType(aMimeType), mData(aData), mState(START_PART), mParentObject(aParent)
  {
  }

  bool
  Parse()
  {
    // Determine boundary from mimetype.
    const char* boundaryId = nullptr;
    boundaryId = strstr(mMimeType.BeginWriting(), "boundary");
    if (!boundaryId) {
      return false;
    }

    boundaryId = strchr(boundaryId, '=');
    if (!boundaryId) {
      return false;
    }

    // Skip over '='.
    boundaryId++;

    char *attrib = (char *) strchr(boundaryId, ';');
    if (attrib) *attrib = '\0';

    nsAutoCString boundaryString(boundaryId);
    if (attrib) *attrib = ';';

    boundaryString.Trim(" \"");

    if (boundaryString.Length() == 0) {
      return false;
    }

    nsACString::const_iterator start, end;
    mData.BeginReading(start);
    // This should ALWAYS point to the end of data.
    // Helpers make copies.
    mData.EndReading(end);

    while (start != end) {
      switch(mState) {
        case START_PART:
          mName.SetIsVoid(true);
          mFilename.SetIsVoid(true);
          mContentType = NS_LITERAL_CSTRING("text/plain");

          // MUST start with boundary.
          if (!PushOverBoundary(boundaryString, start, end)) {
            return false;
          }

          if (start != end && *start == '-') {
            // End of data.
            if (!mFormData) {
              mFormData = new FormData();
            }
            return true;
          }

          if (!PushOverLine(start, end)) {
            return false;
          }
          mState = PARSE_HEADER;
          break;

        case PARSE_HEADER:
          bool emptyHeader;
          if (!ParseHeader(start, end, &emptyHeader)) {
            return false;
          }

          if (emptyHeader && !PushOverLine(start, end)) {
            return false;
          }

          mState = emptyHeader ? PARSE_BODY : PARSE_HEADER;
          break;

        case PARSE_BODY:
          if (mName.IsVoid()) {
            NS_WARNING("No content-disposition header with a valid name was "
                       "found. Failing at body parse.");
            return false;
          }

          if (!ParseBody(boundaryString, start, end)) {
            return false;
          }

          mState = START_PART;
          break;

        default:
          MOZ_CRASH("Invalid case");
      }
    }

    NS_NOTREACHED("Should never reach here.");
    return false;
  }

  already_AddRefed<FormData> GetFormData()
  {
    return mFormData.forget();
  }
};
}

// static
void
BodyUtil::ConsumeArrayBuffer(JSContext* aCx,
                              JS::MutableHandle<JSObject*> aValue,
                              uint32_t aInputLength, uint8_t* aInput,
                              ErrorResult& aRv)
{
  JS::Rooted<JSObject*> arrayBuffer(aCx);
  arrayBuffer = JS_NewArrayBufferWithContents(aCx, aInputLength,
    reinterpret_cast<void *>(aInput));
  if (!arrayBuffer) {
    JS_ClearPendingException(aCx);
    aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
    return;
  }
  aValue.set(arrayBuffer);
}

// static
already_AddRefed<Blob>
BodyUtil::ConsumeBlob(nsISupports* aParent, const nsString& aMimeType,
                       uint32_t aInputLength, uint8_t* aInput,
                       ErrorResult& aRv)
{
  RefPtr<Blob> blob =
    Blob::CreateMemoryBlob(aParent,
                           reinterpret_cast<void *>(aInput), aInputLength,
                           aMimeType);

  if (!blob) {
    aRv.Throw(NS_ERROR_DOM_UNKNOWN_ERR);
    return nullptr;
  }
  return blob.forget();
}

// static
already_AddRefed<FormData>
BodyUtil::ConsumeFormData(nsIGlobalObject* aParent, const nsCString& aMimeType,
                           const nsCString& aStr, ErrorResult& aRv)
{
  NS_NAMED_LITERAL_CSTRING(formDataMimeType, "multipart/form-data");

  // Allow semicolon separated boundary/encoding suffix like multipart/form-data; boundary=
  // but disallow multipart/form-datafoobar.
  bool isValidFormDataMimeType = StringBeginsWith(aMimeType, formDataMimeType);

  if (isValidFormDataMimeType && aMimeType.Length() > formDataMimeType.Length()) {
    isValidFormDataMimeType = aMimeType[formDataMimeType.Length()] == ';';
  }

  if (isValidFormDataMimeType) {
    FormDataParser parser(aMimeType, aStr, aParent);
    if (!parser.Parse()) {
      aRv.ThrowTypeError<MSG_BAD_FORMDATA>();
      return nullptr;
    }

    RefPtr<FormData> fd = parser.GetFormData();
    MOZ_ASSERT(fd);
    return fd.forget();
  }

  NS_NAMED_LITERAL_CSTRING(urlDataMimeType, "application/x-www-form-urlencoded");
  bool isValidUrlEncodedMimeType = StringBeginsWith(aMimeType, urlDataMimeType);

  if (isValidUrlEncodedMimeType && aMimeType.Length() > urlDataMimeType.Length()) {
    isValidUrlEncodedMimeType = aMimeType[urlDataMimeType.Length()] == ';';
  }

  if (isValidUrlEncodedMimeType) {
    URLParams params;
    params.ParseInput(aStr);

    RefPtr<FormData> fd = new FormData(aParent);
    FillFormIterator iterator(fd);
    DebugOnly<bool> status = params.ForEach(iterator);
    MOZ_ASSERT(status);

    return fd.forget();
  }

  aRv.ThrowTypeError<MSG_BAD_FORMDATA>();
  return nullptr;
}

// static
nsresult
BodyUtil::ConsumeText(uint32_t aInputLength, uint8_t* aInput,
                       nsString& aText)
{
  StreamDecoder decoder;
  nsresult rv = decoder.AppendText(reinterpret_cast<char*>(aInput),
                                   aInputLength);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }
  aText = decoder.GetText();
  return NS_OK;
}

// static
void
BodyUtil::ConsumeJson(JSContext* aCx, JS::MutableHandle<JS::Value> aValue,
                       const nsString& aStr, ErrorResult& aRv)
{
  aRv.MightThrowJSException();

  JS::Rooted<JS::Value> json(aCx);
  if (!JS_ParseJSON(aCx, aStr.get(), aStr.Length(), &json)) {
    if (!JS_IsExceptionPending(aCx)) {
      aRv.Throw(NS_ERROR_DOM_UNKNOWN_ERR);
      return;
    }

    JS::Rooted<JS::Value> exn(aCx);
    DebugOnly<bool> gotException = JS_GetPendingException(aCx, &exn);
    MOZ_ASSERT(gotException);

    JS_ClearPendingException(aCx);
    aRv.ThrowJSException(aCx, exn);
    return;
  }

  aValue.set(json);
}

} // namespace dom
} // namespace mozilla