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
|
// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "core/fetch/MultipartImageResourceParser.h"
#include "public/platform/Platform.h"
#include "public/platform/WebURLResponse.h"
#include "wtf/NotFound.h"
#include "wtf/text/WTFString.h"
#include <algorithm>
namespace blink {
MultipartImageResourceParser::MultipartImageResourceParser(const ResourceResponse& response, const Vector<char>& boundary, Client* client)
: m_originalResponse(response)
, m_boundary(boundary)
, m_client(client)
{
// Some servers report a boundary prefixed with "--". See https://crbug.com/5786.
if (m_boundary.size() < 2 || m_boundary[0] != '-' || m_boundary[1] != '-')
m_boundary.prepend("--", 2);
}
void MultipartImageResourceParser::appendData(const char* bytes, size_t size)
{
ASSERT(!isCancelled());
// m_sawLastBoundary means that we've already received the final boundary
// token. The server should stop sending us data at this point, but if it
// does, we just throw it away.
if (m_sawLastBoundary)
return;
m_data.append(bytes, size);
if (m_isParsingTop) {
// Eat leading \r\n
size_t pos = skippableLength(m_data, 0);
// +2 for "--"
if (m_data.size() < m_boundary.size() + 2 + pos) {
// We don't have enough data yet to make a boundary token. Just
// wait until the next chunk of data arrives.
return;
}
if (pos)
m_data.remove(0, pos);
// Some servers don't send a boundary token before the first chunk of
// data. We handle this case anyway (Gecko does too).
if (0 != memcmp(m_data.data(), m_boundary.data(), m_boundary.size())) {
m_data.prepend("\n", 1);
m_data.prependVector(m_boundary);
}
m_isParsingTop = false;
}
// Headers
if (m_isParsingHeaders) {
if (!parseHeaders()) {
// Get more data before trying again.
return;
}
// Successfully parsed headers.
m_isParsingHeaders = false;
if (isCancelled())
return;
}
size_t boundaryPosition;
while ((boundaryPosition = findBoundary(m_data, &m_boundary)) != kNotFound) {
// Strip out trailing \r\n characters in the buffer preceding the
// boundary on the same lines as does Firefox.
size_t dataSize = boundaryPosition;
if (boundaryPosition > 0 && m_data[boundaryPosition - 1] == '\n') {
dataSize--;
if (boundaryPosition > 1 && m_data[boundaryPosition - 2] == '\r') {
dataSize--;
}
}
if (dataSize) {
m_client->multipartDataReceived(m_data.data(), dataSize);
if (isCancelled())
return;
}
size_t boundaryEndPosition = boundaryPosition + m_boundary.size();
if (boundaryEndPosition < m_data.size() && '-' == m_data[boundaryEndPosition]) {
// This was the last boundary so we can stop processing.
m_sawLastBoundary = true;
m_data.clear();
return;
}
// We can now throw out data up through the boundary
m_data.remove(0, boundaryEndPosition);
// Ok, back to parsing headers
if (!parseHeaders()) {
m_isParsingHeaders = true;
break;
}
if (isCancelled())
return;
}
// At this point, we should send over any data we have, but keep enough
// data buffered to handle a boundary that may have been truncated.
// "+2" for CRLF, as we may ignore the last CRLF.
if (!m_isParsingHeaders && m_data.size() > m_boundary.size() + 2) {
size_t sendLength = m_data.size() - m_boundary.size() - 2;
m_client->multipartDataReceived(m_data.data(), sendLength);
m_data.remove(0, sendLength);
}
}
void MultipartImageResourceParser::finish()
{
ASSERT(!isCancelled());
if (m_sawLastBoundary)
return;
// If we have any pending data and we're not in a header, go ahead and send
// it to the client.
if (!m_isParsingHeaders && !m_data.isEmpty())
m_client->multipartDataReceived(m_data.data(), m_data.size());
m_data.clear();
m_sawLastBoundary = true;
}
size_t MultipartImageResourceParser::skippableLength(const Vector<char>& data, size_t pos)
{
if (data.size() >= pos + 2 && data[pos] == '\r' && data[pos + 1] == '\n')
return 2;
if (data.size() >= pos + 1 && data[pos] == '\n')
return 1;
return 0;
}
bool MultipartImageResourceParser::parseHeaders()
{
// Eat leading \r\n
size_t pos = skippableLength(m_data, 0);
// Create a WebURLResponse based on the original set of headers + the
// replacement headers. We only replace the same few headers that gecko
// does. See netwerk/streamconv/converters/nsMultiMixedConv.cpp.
WebURLResponse response(m_originalResponse.url());
for (const auto& header : m_originalResponse.httpHeaderFields())
response.addHTTPHeaderField(header.key, header.value);
size_t end = 0;
if (!Platform::current()->parseMultipartHeadersFromBody(m_data.data() + pos, m_data.size() - pos, &response, &end))
return false;
m_data.remove(0, end + pos);
// Send the response!
m_client->onePartInMultipartReceived(response.toResourceResponse());
return true;
}
// Boundaries are supposed to be preceeded with --, but it looks like gecko
// doesn't require the dashes to exist. See nsMultiMixedConv::FindToken.
size_t MultipartImageResourceParser::findBoundary(const Vector<char>& data, Vector<char>* boundary)
{
auto it = std::search(data.data(), data.data() + data.size(), boundary->data(), boundary->data() + boundary->size());
if (it == data.data() + data.size())
return kNotFound;
size_t boundaryPosition = it - data.data();
// Back up over -- for backwards compat
// TODO(tc): Don't we only want to do this once? Gecko code doesn't
// seem to care.
if (boundaryPosition >= 2) {
if (data[boundaryPosition - 1] == '-' && data[boundaryPosition - 2] == '-') {
boundaryPosition -= 2;
Vector<char> v(2, '-');
v.appendVector(*boundary);
*boundary = v;
}
}
return boundaryPosition;
}
DEFINE_TRACE(MultipartImageResourceParser)
{
visitor->trace(m_client);
}
} // namespace blink
|
