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- // Copyright (c) 2011 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.
- #ifndef NET_BASE_MIME_SNIFFER_H__
- #define NET_BASE_MIME_SNIFFER_H__
- #include <stddef.h>
- #include <string>
- #include "base/strings/string_piece.h"
- #include "net/base/net_export.h"
- class GURL;
- namespace net {
- // The maximum number of bytes used by any internal mime sniffing routine. May
- // be useful for callers to determine an efficient buffer size to pass to
- // |SniffMimeType|.
- // This must be updated if any internal sniffing routine needs more bytes.
- const int kMaxBytesToSniff = 1024;
- // Whether to force the MIME sniffer to sniff the contents of file URLs for
- // HTML. kDisabled is recommended.
- enum class ForceSniffFileUrlsForHtml {
- kDisabled,
- kEnabled,
- };
- // Examine the URL and the mime_type and decide whether to sniff a replacement
- // mime type from the content.
- //
- // |url| is the URL from which the content was obtained.
- // |mime_type| is the current mime type, e.g. from the Content-Type header.
- // Returns true if the mime type should be sniffed.
- NET_EXPORT bool ShouldSniffMimeType(const GURL& url,
- base::StringPiece mime_type);
- // Guess a mime type from the first few bytes of content an its URL. Always
- // assigns |result| with its best guess of a mime type.
- //
- // |content| contains the bytes to sniff.
- // |url| is the URL from which the content was obtained.
- // |type_hint| is the current mime type, e.g. from the Content-Type header.
- // |result| is the address at which to place the sniffed mime type.
- // If |force_sniff_file_url_for_html| is enabled, the contents of |file| URLs
- // will be sniffed to see if they contain HTML. It is recommended this be
- // disabled.
- //
- // Returns true if |content| had enough data to guess the mime type. Otherwise,
- // |result| will be populated with a putative MIME type, but the method should
- // be called again with more of the content.
- NET_EXPORT bool SniffMimeType(
- base::StringPiece content,
- const GURL& url,
- const std::string& type_hint,
- ForceSniffFileUrlsForHtml force_sniff_file_url_for_html,
- std::string* result);
- // Attempt to identify a MIME type from the first few bytes of content only.
- // Uses a bigger set of media file searches than |SniffMimeType()|.
- // If finds a match, fills in |result| and returns true,
- // otherwise returns false.
- //
- // The caller should understand the security ramifications of trusting
- // uncontrolled data before accepting the results of this function.
- //
- // |content| contains the bytes to sniff.
- // |result| is address at which to place the sniffed mime type.
- // Returns true if a MIME type match was found.
- NET_EXPORT bool SniffMimeTypeFromLocalData(base::StringPiece content,
- std::string* result);
- // Returns true if |content| contains bytes that are control codes that do
- // not usually appear in plain text.
- NET_EXPORT_PRIVATE bool LooksLikeBinary(base::StringPiece content);
- } // namespace net
- #endif // NET_BASE_MIME_SNIFFER_H__
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