Move fetch-related predicates to core/fetch.

Source/core/fetch/FetchUtils.cpp

Index: Source/core/fetch/FetchUtils.cpp
diff --git a/Source/core/fetch/FetchUtils.cpp b/Source/core/fetch/FetchUtils.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..86ad9bb0fa73bca0e8fa7fc4663c90195ead4fd8
--- /dev/null
+++ b/Source/core/fetch/FetchUtils.cpp
@@ -0,0 +1,169 @@
+// Copyright 2014 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 "config.h"
+#include "core/fetch/FetchUtils.h"
+
+#include "platform/network/HTTPHeaderMap.h"
+#include "platform/network/HTTPParsers.h"
+#include "wtf/HashSet.h"
+#include "wtf/Threading.h"
+#include "wtf/text/AtomicString.h"
+#include "wtf/text/WTFString.h"
+
+namespace blink {
+
+namespace {
+
+class ForbiddenHeaderNames {
+    WTF_MAKE_NONCOPYABLE(ForbiddenHeaderNames); WTF_MAKE_FAST_ALLOCATED;
+public:
+    bool has(const String& name) const
+    {
+        return m_fixedNames.contains(name)
+            || name.startsWith(m_proxyHeaderPrefix, false)
+            || name.startsWith(m_secHeaderPrefix, false);
+    }
+
+    static const ForbiddenHeaderNames* get();
+
+private:
+    ForbiddenHeaderNames();
+
+    String m_proxyHeaderPrefix;
+    String m_secHeaderPrefix;
+    HashSet<String, CaseFoldingHash> m_fixedNames;
+};
+
+ForbiddenHeaderNames::ForbiddenHeaderNames()
+    : m_proxyHeaderPrefix("proxy-")
+    , m_secHeaderPrefix("sec-")
+{
+    m_fixedNames.add("accept-charset");
+    m_fixedNames.add("accept-encoding");
+    m_fixedNames.add("access-control-request-headers");
+    m_fixedNames.add("access-control-request-method");
+    m_fixedNames.add("connection");
+    m_fixedNames.add("content-length");
+    m_fixedNames.add("cookie");
+    m_fixedNames.add("cookie2");
+    m_fixedNames.add("date");
+    m_fixedNames.add("dnt");
+    m_fixedNames.add("expect");
+    m_fixedNames.add("host");
+    m_fixedNames.add("keep-alive");
+    m_fixedNames.add("origin");
+    m_fixedNames.add("referer");
+    m_fixedNames.add("te");
+    m_fixedNames.add("trailer");
+    m_fixedNames.add("transfer-encoding");
+    m_fixedNames.add("upgrade");
+    m_fixedNames.add("user-agent");
+    m_fixedNames.add("via");
+}
+
+const ForbiddenHeaderNames* ForbiddenHeaderNames::get()
+{
+    AtomicallyInitializedStatic(const ForbiddenHeaderNames*, instance = new ForbiddenHeaderNames);
+    return instance;
+}
+
+} // namespace
+
+bool FetchUtils::isSimpleMethod(const String& method)
+{
+    // http://fetch.spec.whatwg.org/#simple-method
+    // "A simple method is a method that is `GET`, `HEAD`, or `POST`."
+    return method == "GET" || method == "HEAD" || method == "POST";
+}
+
+bool FetchUtils::isSimpleHeader(const AtomicString& name, const AtomicString& value)
+{
+    // http://fetch.spec.whatwg.org/#simple-header
+    // "A simple header is a header whose name is either one of `Accept`,
+    // `Accept-Language`, and `Content-Language`, or whose name is
+    // `Content-Type` and value, once parsed, is one of
+    // `application/x-www-form-urlencoded`, `multipart/form-data`, and
+    // `text/plain`."
+
+    if (equalIgnoringCase(name, "accept")
+        || equalIgnoringCase(name, "accept-language")
+        || equalIgnoringCase(name, "content-language"))
+        return true;
+
+    if (equalIgnoringCase(name, "content-type")) {
+        AtomicString mimeType = extractMIMETypeFromMediaType(value);
+        return equalIgnoringCase(mimeType, "application/x-www-form-urlencoded")
+            || equalIgnoringCase(mimeType, "multipart/form-data")
+            || equalIgnoringCase(mimeType, "text/plain");
+    }
+
+    return false;
+}
+
+bool FetchUtils::isSimpleRequest(const String& method, const HTTPHeaderMap& headerMap)
+{
+    if (!isSimpleMethod(method))
+        return false;
+
+    HTTPHeaderMap::const_iterator end = headerMap.end();
+    for (HTTPHeaderMap::const_iterator it = headerMap.begin(); it != end; ++it) {
+        // Preflight is required for MIME types that can not be sent via form
+        // submission.
+        if (!isSimpleHeader(it->key, it->value))
+            return false;
+    }
+
+    return true;
+}
+
+bool FetchUtils::isForbiddenMethod(const String& method)
+{
+    // http://fetch.spec.whatwg.org/#forbidden-method
+    // "A forbidden method is a method that is a byte case-insensitive match"
+    //  for one of `CONNECT`, `TRACE`, and `TRACK`."
+    return equalIgnoringCase(method, "TRACE")
+        || equalIgnoringCase(method, "TRACK")
+        || equalIgnoringCase(method, "CONNECT");
+}
+
+bool FetchUtils::isForbiddenHeaderName(const String& name)
+{
+    // http://fetch.spec.whatwg.org/#forbidden-header-name
+    // "A forbidden header name is a header names that is one of:
+    //   `Accept-Charset`, `Accept-Encoding`, `Access-Control-Request-Headers`,
+    //   `Access-Control-Request-Method`, `Connection`,
+    //   `Content-Length, Cookie`, `Cookie2`, `Date`, `DNT`, `Expect`, `Host`,
+    //   `Keep-Alive`, `Origin`, `Referer`, `TE`, `Trailer`,
+    //   `Transfer-Encoding`, `Upgrade`, `User-Agent`, `Via`
+    // or starts with `Proxy-` or `Sec-` (including when it is just `Proxy-` or
+    // `Sec-`)."
+
+    return ForbiddenHeaderNames::get()->has(name);
+}
+
+bool FetchUtils::isForbiddenResponseHeaderName(const String& name)
+{
+    // http://fetch.spec.whatwg.org/#forbidden-response-header-name
+    // "A forbidden response header name is a header name that is one of:
+    // `Set-Cookie`, `Set-Cookie2`"
+
+    return equalIgnoringCase(name, "set-cookie") || equalIgnoringCase(name, "set-cookie2");
+}
+
+bool FetchUtils::isSimpleOrForbiddenRequest(const String& method, const HTTPHeaderMap& headerMap)
+{
+    if (!isSimpleMethod(method))
+        return false;
+
+    HTTPHeaderMap::const_iterator end = headerMap.end();
+    for (HTTPHeaderMap::const_iterator it = headerMap.begin(); it != end; ++it) {
+        if (!isSimpleHeader(it->key, it->value) && !isForbiddenHeaderName(it->key))
+            return false;
+    }
+
+    return true;
+}
+
+} // namespace blink