Delete WebMetal implementation in favor of WebGPU
[WebKit-https.git] / Source / WebCore / platform / ReferrerPolicy.cpp
1 /*
2  * Copyright (C) 2018 Apple Inc. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1.  Redistributions of source code must retain the above copyright
8  *     notice, this list of conditions and the following disclaimer.
9  * 2.  Redistributions in binary form must reproduce the above copyright
10  *     notice, this list of conditions and the following disclaimer in the
11  *     documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
16  * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
17  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
18  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
22  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23  */ 
24
25 #include "config.h"
26 #include "ReferrerPolicy.h"
27
28 #include "HTTPParsers.h"
29 #include <wtf/Optional.h>
30
31 namespace WebCore {
32
33 enum class ShouldParseLegacyKeywords { No, Yes };
34
35 static Optional<ReferrerPolicy> parseReferrerPolicyToken(StringView policy, ShouldParseLegacyKeywords shouldParseLegacyKeywords)
36 {
37     // "never" / "default" / "always" are legacy keywords that we support and still defined in the HTML specification:
38     // https://html.spec.whatwg.org/#meta-referrer
39     if (shouldParseLegacyKeywords == ShouldParseLegacyKeywords::Yes) {
40         if (equalLettersIgnoringASCIICase(policy, "never"))
41             return ReferrerPolicy::NoReferrer;
42         if (equalLettersIgnoringASCIICase(policy, "always"))
43             return ReferrerPolicy::UnsafeUrl;
44         if (equalLettersIgnoringASCIICase(policy, "default"))
45             return ReferrerPolicy::NoReferrerWhenDowngrade;
46     }
47
48     if (equalLettersIgnoringASCIICase(policy, "no-referrer"))
49         return ReferrerPolicy::NoReferrer;
50     if (equalLettersIgnoringASCIICase(policy, "unsafe-url"))
51         return ReferrerPolicy::UnsafeUrl;
52     if (equalLettersIgnoringASCIICase(policy, "origin"))
53         return ReferrerPolicy::Origin;
54     if (equalLettersIgnoringASCIICase(policy, "origin-when-cross-origin"))
55         return ReferrerPolicy::OriginWhenCrossOrigin;
56     if (equalLettersIgnoringASCIICase(policy, "same-origin"))
57         return ReferrerPolicy::SameOrigin;
58     if (equalLettersIgnoringASCIICase(policy, "strict-origin"))
59         return ReferrerPolicy::StrictOrigin;
60     if (equalLettersIgnoringASCIICase(policy, "strict-origin-when-cross-origin"))
61         return ReferrerPolicy::StrictOriginWhenCrossOrigin;
62     if (equalLettersIgnoringASCIICase(policy, "no-referrer-when-downgrade"))
63         return ReferrerPolicy::NoReferrerWhenDowngrade;
64     if (!policy.isNull() && policy.isEmpty())
65         return ReferrerPolicy::EmptyString;
66
67     return WTF::nullopt;
68 }
69     
70 Optional<ReferrerPolicy> parseReferrerPolicy(StringView policyString, ReferrerPolicySource source)
71 {
72     switch (source) {
73     case ReferrerPolicySource::HTTPHeader: {
74         // Implementing https://www.w3.org/TR/2017/CR-referrer-policy-20170126/#parse-referrer-policy-from-header.
75         Optional<ReferrerPolicy> result;
76         for (auto tokenView : policyString.split(',')) {
77             auto token = parseReferrerPolicyToken(stripLeadingAndTrailingHTTPSpaces(tokenView), ShouldParseLegacyKeywords::No);
78             if (token && token.value() != ReferrerPolicy::EmptyString)
79                 result = token.value();
80         }
81         return result;
82     }
83     case ReferrerPolicySource::MetaTag:
84         return parseReferrerPolicyToken(policyString, ShouldParseLegacyKeywords::Yes);
85     case ReferrerPolicySource::ReferrerPolicyAttribute:
86         return parseReferrerPolicyToken(policyString, ShouldParseLegacyKeywords::No);
87     }
88     ASSERT_NOT_REACHED();
89     return WTF::nullopt;
90 }
91
92 } // namespace WebCore