// // Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com) // // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) // // Official repository: https://github.com/boostorg/beast // #ifndef BOOST_BEAST_HTTP_IMPL_FIELD_IPP #define BOOST_BEAST_HTTP_IMPL_FIELD_IPP #include #include #include #include #include #include namespace boost { namespace beast { namespace http { namespace detail { struct field_table { static std::uint32_t get_chars( unsigned char const* p) noexcept { // VFALCO memcpy is endian-dependent //std::memcpy(&v, p, 4); // Compiler should be smart enough to // optimize this down to one instruction. return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24); } using array_type = std::array; // Strings are converted to lowercase static std::uint32_t digest(string_view s) { std::uint32_t r = 0; std::size_t n = s.size(); auto p = reinterpret_cast< unsigned char const*>(s.data()); // consume N characters at a time // VFALCO Can we do 8 on 64-bit systems? while(n >= 4) { auto const v = get_chars(p); r = (r * 5 + ( v | 0x20202020 )); // convert to lower p += 4; n -= 4; } // handle remaining characters while( n > 0 ) { r = r * 5 + ( *p | 0x20 ); ++p; --n; } return r; } // This comparison is case-insensitive, and the // strings must contain only valid http field characters. static bool equals(string_view lhs, string_view rhs) { using Int = std::uint32_t; // VFALCO std::size_t? auto n = lhs.size(); if(n != rhs.size()) return false; auto p1 = reinterpret_cast< unsigned char const*>(lhs.data()); auto p2 = reinterpret_cast< unsigned char const*>(rhs.data()); auto constexpr S = sizeof(Int); auto constexpr Mask = static_cast( 0xDFDFDFDFDFDFDFDF & ~Int{0}); for(; n >= S; p1 += S, p2 += S, n -= S) { Int const v1 = get_chars(p1); Int const v2 = get_chars(p2); if((v1 ^ v2) & Mask) return false; } for(; n; ++p1, ++p2, --n) if(( *p1 ^ *p2) & 0xDF) return false; return true; } array_type by_name_; enum { N = 1367 }; unsigned char map_[ N ] = {}; /* From: https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers https://www.iana.org/assignments/http-fields/http-fields.xhtml */ field_table() : by_name_({{ "", "Accept", "Accept-CH", "Accept-Charset", "Accept-Encoding", "Accept-Language", "Accept-Patch", "Accept-Post", "Accept-Ranges", "Accept-Signature", "Access-Control-Allow-Credentials", "Access-Control-Allow-Headers", "Access-Control-Allow-Methods", "Access-Control-Allow-Origin", "Access-Control-Expose-Headers", "Access-Control-Max-Age", "Access-Control-Request-Headers", "Access-Control-Request-Method", "Age", "Allow", "Alt-Svc", "Alt-Used", "Authorization", "Cache-Control", "Clear-Site-Data", "Connection", "Content-Digest", "Content-Disposition", "Content-DPR", "Content-Encoding", "Content-Language", "Content-Length", "Content-Location", "Content-Range", "Content-Security-Policy", "Content-Security-Policy-Report-Only", "Content-Type", "Cookie", "Cross-Origin-Embedder-Policy", "Cross-Origin-Opener-Policy", "Cross-Origin-Resource-Policy", "Date", "Deprecation", "Device-Memory", "Digest", "DNT", "DPR", "ETag", "Expect", "Expect-CT", "Expires", "Forwarded", "From", "Host", "HTTP2-Settings", "If-Match", "If-Modified-Since", "If-None-Match", "If-Range", "If-Unmodified-Since", "Keep-Alive", "Last-Modified", "Link", "Location", "Max-Forwards", "Origin", "Origin-Agent-Cluster", "Pragma", "Prefer", "Preference-Applied", "Priority", "Proxy-Authenticate", "Proxy-Authorization", "Proxy-Connection", "Range", "Referer", "Referrer-Policy", "Refresh", "Report-To", "Reporting-Endpoints", "Repr-Digest", "Retry-After", "Sec-CH-UA-Full-Version", "Sec-Fetch-Dest", "Sec-Fetch-Mode", "Sec-Fetch-Site", "Sec-Fetch-User", "Sec-Purpose", "Sec-WebSocket-Accept", "Sec-WebSocket-Extensions", "Sec-WebSocket-Key", "Sec-WebSocket-Protocol", "Sec-WebSocket-Version", "Server", "Server-Timing", "Service-Worker", "Service-Worker-Allowed", "Service-Worker-Navigation-Preload", "Set-Cookie", "Set-Login", "Signature", "Signature-Input", "SourceMap", "Strict-Transport-Security", "TE", "Timing-Allow-Origin", "Tk", "Trailer", "Transfer-Encoding", "Upgrade", "Upgrade-Insecure-Requests", "User-Agent", "Vary", "Via", "Viewport-Width", "Want-Content-Digest", "Want-Repr-Digest", "Warning", "Width", "WWW-Authenticate", "X-Content-Type-Options", "X-DNS-Prefetch-Control", "X-Forwarded-For", "X-Forwarded-Host", "X-Forwarded-Proto", "X-Frame-Options", "X-Permitted-Cross-Domain-Policies", "X-Powered-By", "X-Robots-Tag", "X-XSS-Protection" }}) { for(std::size_t i = 1; i < by_name_.size(); ++i) { auto sv = by_name_[ i ]; auto h = digest(sv); auto j = h % N; BOOST_ASSERT(map_[j] == 0); map_[j] = static_cast(i); } } field string_to_field(string_view s) const { auto h = digest(s); auto j = h % N; int i = map_[j]; if(i != 0 && equals(s, by_name_[i])) return static_cast(i); return field::unknown; } // // Deprecated // using const_iterator = array_type::const_iterator; std::size_t size() const { return by_name_.size(); } const_iterator begin() const { return by_name_.begin(); } const_iterator end() const { return by_name_.end(); } }; BOOST_BEAST_DECL field_table const& get_field_table() { static field_table const tab; return tab; } BOOST_BEAST_DECL string_view to_string(field f) { auto const& v = get_field_table(); BOOST_ASSERT(static_cast(f) < v.size()); return v.begin()[static_cast(f)]; } } // detail string_view to_string(field f) { return detail::to_string(f); } field string_to_field(string_view s) { return detail::get_field_table().string_to_field(s); } std::ostream& operator<<(std::ostream& os, field f) { return os << to_string(f); } } // http } // beast } // boost #endif