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
|
// Copyright (c) 2012 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.
// This file defines utility functions for working with html.
#ifndef CHROME_FRAME_HTML_UTILS_H_
#define CHROME_FRAME_HTML_UTILS_H_
#include <string>
#include <vector>
#include "base/basictypes.h"
#include "base/gtest_prod_util.h"
#include "net/http/http_util.h"
// Forward declarations
class HtmlUtilUnittest;
//
// Class designed to take a string of HTML and extract from it named
// attribute values from named tags.
//
// Caveat: this class currently doesn't handle multi-word UTF-16 encoded
// characters. Doesn't handle implies that any data following such a
// character could possibly be misinterpreted.
//
class HTMLScanner {
public:
typedef std::wstring::const_iterator StrPos;
// Structure maintaining const_iterators into html_string_.
class StringRange {
friend class HTMLScanner;
public:
StringRange();
StringRange(StrPos start, StrPos end);
bool LowerCaseEqualsASCII(const char* other) const;
bool Equals(const wchar_t* other) const;
// Copies the data described by StringRange into destination.
std::wstring Copy() const;
// If this StringRange represents a tag, this method extracts the name of
// the tag and sticks it in tag_name.
// Returns true if the tag name was successfully extracted.
// Returns false if this string doesn't look like a valid tag.
bool GetTagName(std::wstring* tag_name) const;
// From a given string range, uses a string tokenizer to extract the value
// of the named attribute if a simple scan finds that the attribute name is
// present.
//
// Returns true if the named attribute can be located and it has a value
// which has been placed in attribute_value.
//
// Note that the attribute value is unquoted here as well, so that
// GetTagAttribute(*<foo bar="baz">*, L"bar", *out_value*) will stick
// 'bar' in out_value and not '"bar"'.
//
// Returns false if the named attribute is not present in the tag or if it
// did not have a value.
//
bool GetTagAttribute(const wchar_t* attribute_name,
StringRange* attribute_value) const;
// Unquotes a StringRange by removing a matching pair of either ' or "
// characters from the beginning and end of the string if present.
// Returns true if string was modified, false otherwise.
bool UnQuote();
private:
StrPos start_;
StrPos end_;
};
typedef std::vector<StringRange> StringRangeList;
// html_string must be a null-terminated string containing the HTML
// to be scanned.
explicit HTMLScanner(const wchar_t* html_string);
// Returns the set of ranges denoting HTML tags that match the given name.
// If stop_tag_name is given, then as soon as a tag with this name is
// encountered this method will return.
void GetTagsByName(const wchar_t* name, StringRangeList* tag_list,
const wchar_t* stop_tag_name);
private:
friend class HtmlUtilUnittest;
FRIEND_TEST_ALL_PREFIXES(HtmlUtilUnittest, BasicTest);
// Given html_string which represents the remaining html range, this method
// returns the next tag in tag and advances html_string to one character after
// the end of tag. This method is intended to be called repeatedly to extract
// all of the tags in sequence.
//
// Returns true if another tag was found and 'tag' was populated with a valid
// range.
// Returns false if we have reached the end of the html data.
bool NextTag(StringRange* html_string, StringRange* tag);
// Returns true if c can be found in quotes_, false otherwise
bool IsQuote(wchar_t c);
// Returns true if pos refers to the last character in an HTML comment in a
// string described by html_string, false otherwise.
// For example with html_string describing <!-- foo> -->, pos must refer to
// the last > for this method to return true.
bool IsHTMLCommentClose(const StringRange* html_string, StrPos pos);
// Returns true if pos refers to the last character in the terminator of the
// opening tag of a downlevel-hidden conditional comment in IE as per
// http://msdn.microsoft.com/en-us/library/ms537512(VS.85).aspx#syntax
// For example with html_string describing <![if booga >wooga]>, pos must
// refer to the last > for this method to return true.
bool IsIEConditionalCommentClose(const StringRange* html_string, StrPos pos);
// We store a (CollapsedWhitespace'd) copy of the html data.
const std::wstring html_string_;
// Store the string of quote characters to avoid repeated construction.
const std::wstring quotes_;
DISALLOW_COPY_AND_ASSIGN(HTMLScanner);
};
namespace http_utils {
// Adds "chromeframe/a.b.c.d" to the User-Agent string (a.b.c.d is the version).
// If the cf tag has already been added to the string, the original string is
// returned.
std::string AddChromeFrameToUserAgentValue(const std::string& value);
// Removes "chromeframe/a.b.c.d" from the User-Agent string (a.b.c.d is the
// version). If the cf tag is not present in the string, the original string is
// returned.
std::string RemoveChromeFrameFromUserAgentValue(const std::string& value);
// Fetches the user agent from urlmon and adds chrome frame to the
// comment section.
// NOTE: The returned string includes the "User-Agent: " header name.
std::string GetDefaultUserAgentHeaderWithCFTag();
// Returns the User-Agent header as would be used by Chrome itself.
const char* GetChromeUserAgent();
// Fetches the default user agent string from urlmon.
// This value does not include the "User-Agent:" header name.
std::string GetDefaultUserAgent();
// Returns the Chrome Frame user agent. E.g. "chromeframe/1.0".
// Note that in unit tests this will be "chromeframe/0.0" due to the version
// table not being present in the unit test executable.
const char* GetChromeFrameUserAgent();
// Returns true if there is a frame busting header (other than the do-nothing
// "X-Frame-Options: ALLOWALL") in the provided header block. Note that there
// may be multiple X-Frame-Options values specified; if there is one anywhere in
// the list with a value other than ALLOWALL, this returns true.
bool HasFrameBustingHeader(const std::string& http_headers);
// Returns the header passed in from the headers list.
std::string GetHttpHeaderFromHeaderList(const std::string& header_name,
const std::string& headers);
} // namespace http_utils
#endif // CHROME_FRAME_HTML_UTILS_H_
|
