| ## Description: add some description |
| ## Origin/Author: add some origin or author |
| ## Bug: bug URL |
| From 9ddb300d874a30db35e3ad58f188944bef0bf31b Mon Sep 17 00:00:00 2001 |
| From: Peter Thorson <git@zaphoyd.com> |
| Date: Sun, 11 Jun 2017 15:24:43 -0500 |
| Subject: [PATCH] Update permessage-deflate support to reflect that zlib |
| doesn't support a 256 bit window. Improve extension negotiation error |
| checking and documentation. fixes #596 fixes #653 |
| |
| --- |
| changelog.md | 8 ++ |
| test/extension/permessage_deflate.cpp | 153 +++++++++++++++++---- |
| .../extensions/permessage_deflate/enabled.hpp | 94 ++++++++++--- |
| websocketpp/impl/connection_impl.hpp | 10 +- |
| websocketpp/processors/hybi13.hpp | 28 +++- |
| 5 files changed, 247 insertions(+), 46 deletions(-) |
| |
| diff --git a/changelog.md b/changelog.md |
| index bba753cb..de98edd2 100644 |
| #--- a/changelog.md |
| #+++ b/changelog.md |
| #@@ -17,6 +17,14 @@ HEAD |
| # - Compatibility: Update `telemetry_client` to use a slightly more cross platform |
| # method of sleeping. Should work on windows now. Thank you Meir Yanovich for |
| # reporting. |
| #+- Compatibility: Updated permessage-deflate support to reflect that the zlib |
| #+ library does not actually support a sliding window size of 256 bits. |
| #+ WebSocket++ will no longer negotiate 256 bit deflate windows. If the user |
| #+ of the library tries to request a 256 bit window a 512 bit window will be |
| #+ specified instead (This was the previous behavior). #596 #653 Thank you |
| #+ Vinnie Falco and Gianfranco Costamagna for reporting. |
| #+- Compatibility: Better error handling and logging in cases where extension |
| #+ requests parse correctly but negotiation fails. |
| # - Bug: Store loggers in shared pointers to avoid crashes related to connections |
| # trying to write logs entries after their respective endpoint has been |
| # deallocated. Thank you Thalhammer for reporting and Jupp Müller for the |
| diff --git a/test/extension/permessage_deflate.cpp b/test/extension/permessage_deflate.cpp |
| index 4cd3e7b6..805afcc3 100644 |
| --- a/test/extension/permessage_deflate.cpp |
| +++ b/test/extension/permessage_deflate.cpp |
| @@ -186,15 +186,22 @@ BOOST_AUTO_TEST_CASE( negotiate_server_max_window_bits_invalid ) { |
| |
| BOOST_AUTO_TEST_CASE( negotiate_server_max_window_bits_valid ) { |
| ext_vars v; |
| + |
| + // confirm that a request for a value of 8 is interpreted as 9 |
| v.attr["server_max_window_bits"] = "8"; |
| + v.esp = v.exts.negotiate(v.attr); |
| + BOOST_CHECK( v.exts.is_enabled() ); |
| + BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; server_max_window_bits=9"); |
| |
| + v.attr["server_max_window_bits"] = "9"; |
| v.esp = v.exts.negotiate(v.attr); |
| BOOST_CHECK( v.exts.is_enabled() ); |
| BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| - BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; server_max_window_bits=8"); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; server_max_window_bits=9"); |
| |
| - v.attr["server_max_window_bits"] = "15"; |
| |
| + v.attr["server_max_window_bits"] = "15"; |
| v.esp = v.exts.negotiate(v.attr); |
| BOOST_CHECK( v.exts.is_enabled() ); |
| BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| @@ -213,7 +220,7 @@ BOOST_AUTO_TEST_CASE( invalid_set_server_max_window_bits ) { |
| |
| BOOST_AUTO_TEST_CASE( negotiate_server_max_window_bits_decline ) { |
| ext_vars v; |
| - v.attr["server_max_window_bits"] = "8"; |
| + v.attr["server_max_window_bits"] = "9"; |
| |
| v.ec = v.exts.set_server_max_window_bits(15,pmd_mode::decline); |
| v.esp = v.exts.negotiate(v.attr); |
| @@ -223,7 +230,7 @@ BOOST_AUTO_TEST_CASE( negotiate_server_max_window_bits_decline ) { |
| BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate"); |
| } |
| |
| -BOOST_AUTO_TEST_CASE( negotiate_server_max_window_bits_accept ) { |
| +BOOST_AUTO_TEST_CASE( negotiate_server_max_window_bits_accept_8 ) { |
| ext_vars v; |
| v.attr["server_max_window_bits"] = "8"; |
| |
| @@ -232,10 +239,22 @@ BOOST_AUTO_TEST_CASE( negotiate_server_max_window_bits_accept ) { |
| BOOST_CHECK( v.exts.is_enabled() ); |
| BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| - BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; server_max_window_bits=8"); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; server_max_window_bits=9"); |
| } |
| |
| -BOOST_AUTO_TEST_CASE( negotiate_server_max_window_bits_largest ) { |
| +BOOST_AUTO_TEST_CASE( negotiate_server_max_window_bits_accept ) { |
| + ext_vars v; |
| + v.attr["server_max_window_bits"] = "9"; |
| + |
| + v.ec = v.exts.set_server_max_window_bits(15,pmd_mode::accept); |
| + v.esp = v.exts.negotiate(v.attr); |
| + BOOST_CHECK( v.exts.is_enabled() ); |
| + BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| + BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; server_max_window_bits=9"); |
| +} |
| + |
| +BOOST_AUTO_TEST_CASE( negotiate_server_max_window_bits_largest_8 ) { |
| ext_vars v; |
| v.attr["server_max_window_bits"] = "8"; |
| |
| @@ -244,10 +263,22 @@ BOOST_AUTO_TEST_CASE( negotiate_server_max_window_bits_largest ) { |
| BOOST_CHECK( v.exts.is_enabled() ); |
| BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| - BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; server_max_window_bits=8"); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; server_max_window_bits=9"); |
| } |
| |
| -BOOST_AUTO_TEST_CASE( negotiate_server_max_window_bits_smallest ) { |
| +BOOST_AUTO_TEST_CASE( negotiate_server_max_window_bits_largest ) { |
| + ext_vars v; |
| + v.attr["server_max_window_bits"] = "9"; |
| + |
| + v.ec = v.exts.set_server_max_window_bits(15,pmd_mode::largest); |
| + v.esp = v.exts.negotiate(v.attr); |
| + BOOST_CHECK( v.exts.is_enabled() ); |
| + BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| + BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; server_max_window_bits=9"); |
| +} |
| + |
| +BOOST_AUTO_TEST_CASE( negotiate_server_max_window_bits_smallest_8 ) { |
| ext_vars v; |
| v.attr["server_max_window_bits"] = "8"; |
| |
| @@ -256,7 +287,19 @@ BOOST_AUTO_TEST_CASE( negotiate_server_max_window_bits_smallest ) { |
| BOOST_CHECK( v.exts.is_enabled() ); |
| BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| - BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; server_max_window_bits=8"); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; server_max_window_bits=9"); |
| +} |
| + |
| +BOOST_AUTO_TEST_CASE( negotiate_server_max_window_bits_smallest ) { |
| + ext_vars v; |
| + v.attr["server_max_window_bits"] = "9"; |
| + |
| + v.ec = v.exts.set_server_max_window_bits(15,pmd_mode::smallest); |
| + v.esp = v.exts.negotiate(v.attr); |
| + BOOST_CHECK( v.exts.is_enabled() ); |
| + BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| + BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; server_max_window_bits=9"); |
| } |
| |
| // Negotiate server_max_window_bits |
| @@ -292,7 +335,13 @@ BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_valid ) { |
| v.esp = v.exts.negotiate(v.attr); |
| BOOST_CHECK( v.exts.is_enabled() ); |
| BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| - BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; client_max_window_bits=8"); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; client_max_window_bits=9"); |
| + |
| + v.attr["client_max_window_bits"] = "9"; |
| + v.esp = v.exts.negotiate(v.attr); |
| + BOOST_CHECK( v.exts.is_enabled() ); |
| + BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; client_max_window_bits=9"); |
| |
| v.attr["client_max_window_bits"] = "15"; |
| v.esp = v.exts.negotiate(v.attr); |
| @@ -311,7 +360,7 @@ BOOST_AUTO_TEST_CASE( invalid_set_client_max_window_bits ) { |
| BOOST_CHECK_EQUAL(v.ec,pmde::make_error_code(pmde::invalid_max_window_bits)); |
| } |
| |
| -BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_decline ) { |
| +BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_decline_8 ) { |
| ext_vars v; |
| v.attr["client_max_window_bits"] = "8"; |
| |
| @@ -323,7 +372,19 @@ BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_decline ) { |
| BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate"); |
| } |
| |
| -BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_accept ) { |
| +BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_decline ) { |
| + ext_vars v; |
| + v.attr["client_max_window_bits"] = "9"; |
| + |
| + v.ec = v.exts.set_client_max_window_bits(9,pmd_mode::decline); |
| + v.esp = v.exts.negotiate(v.attr); |
| + BOOST_CHECK( v.exts.is_enabled() ); |
| + BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| + BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate"); |
| +} |
| + |
| +BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_accept_8 ) { |
| ext_vars v; |
| v.attr["client_max_window_bits"] = "8"; |
| |
| @@ -332,10 +393,22 @@ BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_accept ) { |
| BOOST_CHECK( v.exts.is_enabled() ); |
| BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| - BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; client_max_window_bits=8"); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; client_max_window_bits=9"); |
| } |
| |
| -BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_largest ) { |
| +BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_accept ) { |
| + ext_vars v; |
| + v.attr["client_max_window_bits"] = "9"; |
| + |
| + v.ec = v.exts.set_client_max_window_bits(15,pmd_mode::accept); |
| + v.esp = v.exts.negotiate(v.attr); |
| + BOOST_CHECK( v.exts.is_enabled() ); |
| + BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| + BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; client_max_window_bits=9"); |
| +} |
| + |
| +BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_largest_8 ) { |
| ext_vars v; |
| v.attr["client_max_window_bits"] = "8"; |
| |
| @@ -344,10 +417,22 @@ BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_largest ) { |
| BOOST_CHECK( v.exts.is_enabled() ); |
| BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| - BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; client_max_window_bits=8"); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; client_max_window_bits=9"); |
| } |
| |
| -BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_smallest ) { |
| +BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_largest ) { |
| + ext_vars v; |
| + v.attr["client_max_window_bits"] = "9"; |
| + |
| + v.ec = v.exts.set_client_max_window_bits(15,pmd_mode::largest); |
| + v.esp = v.exts.negotiate(v.attr); |
| + BOOST_CHECK( v.exts.is_enabled() ); |
| + BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| + BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; client_max_window_bits=9"); |
| +} |
| + |
| +BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_smallest_8 ) { |
| ext_vars v; |
| v.attr["client_max_window_bits"] = "8"; |
| |
| @@ -356,7 +441,19 @@ BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_smallest ) { |
| BOOST_CHECK( v.exts.is_enabled() ); |
| BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| - BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; client_max_window_bits=8"); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; client_max_window_bits=9"); |
| +} |
| + |
| +BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_smallest ) { |
| + ext_vars v; |
| + v.attr["client_max_window_bits"] = "9"; |
| + |
| + v.ec = v.exts.set_client_max_window_bits(15,pmd_mode::smallest); |
| + v.esp = v.exts.negotiate(v.attr); |
| + BOOST_CHECK( v.exts.is_enabled() ); |
| + BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| + BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() ); |
| + BOOST_CHECK_EQUAL( v.esp.second, "permessage-deflate; client_max_window_bits=9"); |
| } |
| |
| |
| @@ -507,7 +604,8 @@ BOOST_AUTO_TEST_CASE( compress_data ) { |
| std::string compress_out; |
| std::string decompress_out; |
| |
| - v.exts.init(true); |
| + v.ec = v.exts.init(true); |
| + BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| |
| v.ec = v.exts.compress(compress_in,compress_out); |
| BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| @@ -520,7 +618,8 @@ BOOST_AUTO_TEST_CASE( compress_data ) { |
| BOOST_AUTO_TEST_CASE( compress_data_multiple ) { |
| ext_vars v; |
| |
| - v.exts.init(true); |
| + v.ec = v.exts.init(true); |
| + BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| |
| for (int i = 0; i < 2; i++) { |
| std::string compress_in = "Hello"; |
| @@ -545,11 +644,12 @@ BOOST_AUTO_TEST_CASE( compress_data_large ) { |
| |
| websocketpp::http::attribute_list alist; |
| |
| - alist["server_max_window_bits"] = "8"; |
| - v.exts.set_server_max_window_bits(8,websocketpp::extensions::permessage_deflate::mode::smallest); |
| + alist["server_max_window_bits"] = "9"; |
| + v.exts.set_server_max_window_bits(9,websocketpp::extensions::permessage_deflate::mode::smallest); |
| |
| v.exts.negotiate(alist); |
| - v.exts.init(true); |
| + v.ec = v.exts.init(true); |
| + BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| |
| v.ec = v.exts.compress(compress_in,compress_out); |
| BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| @@ -573,7 +673,8 @@ BOOST_AUTO_TEST_CASE( compress_data_no_context_takeover ) { |
| v.exts.enable_server_no_context_takeover(); |
| |
| v.exts.negotiate(alist); |
| - v.exts.init(true); |
| + v.ec = v.exts.init(true); |
| + BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| |
| v.ec = v.exts.compress(compress_in,compress_out1); |
| BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| @@ -609,7 +710,8 @@ BOOST_AUTO_TEST_CASE( compress_empty ) { |
| std::string compress_out; |
| std::string decompress_out; |
| |
| - v.exts.init(true); |
| + v.ec = v.exts.init(true); |
| + BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| |
| v.ec = v.exts.compress(compress_in,compress_out); |
| BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| @@ -640,7 +742,8 @@ BOOST_AUTO_TEST_CASE( decompress_data ) { |
| std::string out; |
| std::string reference = "Hello"; |
| |
| - v.exts.init(true); |
| + v.ec = v.exts.init(true); |
| + BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() ); |
| |
| v.ec = v.exts.decompress(in,11,out); |
| |
| diff --git a/websocketpp/extensions/permessage_deflate/enabled.hpp b/websocketpp/extensions/permessage_deflate/enabled.hpp |
| index 1581f14c..f20a1b1d 100644 |
| --- a/websocketpp/extensions/permessage_deflate/enabled.hpp |
| +++ b/websocketpp/extensions/permessage_deflate/enabled.hpp |
| @@ -46,7 +46,7 @@ |
| namespace websocketpp { |
| namespace extensions { |
| |
| -/// Implementation of the draft permessage-deflate WebSocket extension |
| +/// Implementation of RFC 7692, the permessage-deflate WebSocket extension |
| /** |
| * ### permessage-deflate interface |
| * |
| @@ -174,18 +174,30 @@ namespace websocketpp { |
| namespace extensions { |
| namespace permessage_deflate { |
| |
| -/// Default value for server_max_window_bits as defined by draft 17 |
| +/// Default value for server_max_window_bits as defined by RFC 7692 |
| static uint8_t const default_server_max_window_bits = 15; |
| -/// Minimum value for server_max_window_bits as defined by draft 17 |
| +/// Minimum value for server_max_window_bits as defined by RFC 7692 |
| +/** |
| + * NOTE: A value of 8 is not actually supported by zlib, the deflate |
| + * library that WebSocket++ uses. To preserve backwards compatibility |
| + * with RFC 7692 and previous versions of the library a value of 8 |
| + * is accepted by the library but will always be negotiated as 9. |
| + */ |
| static uint8_t const min_server_max_window_bits = 8; |
| -/// Maximum value for server_max_window_bits as defined by draft 17 |
| +/// Maximum value for server_max_window_bits as defined by RFC 7692 |
| static uint8_t const max_server_max_window_bits = 15; |
| |
| -/// Default value for client_max_window_bits as defined by draft 17 |
| +/// Default value for client_max_window_bits as defined by RFC 7692 |
| static uint8_t const default_client_max_window_bits = 15; |
| -/// Minimum value for client_max_window_bits as defined by draft 17 |
| +/// Minimum value for client_max_window_bits as defined by RFC 7692 |
| +/** |
| + * NOTE: A value of 8 is not actually supported by zlib, the deflate |
| + * library that WebSocket++ uses. To preserve backwards compatibility |
| + * with RFC 7692 and previous versions of the library a value of 8 |
| + * is accepted by the library but will always be negotiated as 9. |
| + */ |
| static uint8_t const min_client_max_window_bits = 8; |
| -/// Maximum value for client_max_window_bits as defined by draft 17 |
| +/// Maximum value for client_max_window_bits as defined by RFC 7692 |
| static uint8_t const max_client_max_window_bits = 15; |
| |
| namespace mode { |
| @@ -372,7 +384,7 @@ class enabled { |
| /** |
| * The bits setting is the base 2 logarithm of the maximum window size that |
| * the server must use to compress outgoing messages. The permitted range |
| - * is 8 to 15 inclusive. 8 represents a 256 byte window and 15 a 32KiB |
| + * is 9 to 15 inclusive. 9 represents a 512 byte window and 15 a 32KiB |
| * window. The default setting is 15. |
| * |
| * Mode Options: |
| @@ -386,6 +398,14 @@ class enabled { |
| * adjusted by the server. A server may unilaterally set this value without |
| * client support. |
| * |
| + * NOTE: The permessage-deflate spec specifies that a value of 8 is allowed. |
| + * Prior to version 0.8.0 a value of 8 was also allowed by this library. |
| + * zlib, the deflate compression library that WebSocket++ uses has always |
| + * silently adjusted a value of 8 to 9. In recent versions of zlib (1.2.9 |
| + * and greater) a value of 8 is now explicitly rejected. WebSocket++ 0.8.0 |
| + * continues to perform the 8->9 conversion for backwards compatibility |
| + * purposes but this should be considered deprecated functionality. |
| + * |
| * @param bits The size to request for the outgoing window size |
| * @param mode The mode to use for negotiating this parameter |
| * @return A status code |
| @@ -394,6 +414,12 @@ class enabled { |
| if (bits < min_server_max_window_bits || bits > max_server_max_window_bits) { |
| return error::make_error_code(error::invalid_max_window_bits); |
| } |
| + |
| + // See note in doc comment above about what is happening here |
| + if (bits == 8) { |
| + bits = 9; |
| + } |
| + |
| m_server_max_window_bits = bits; |
| m_server_max_window_bits_mode = mode; |
| |
| @@ -403,8 +429,8 @@ class enabled { |
| /// Limit client LZ77 sliding window size |
| /** |
| * The bits setting is the base 2 logarithm of the window size that the |
| - * client must use to compress outgoing messages. The permitted range is 8 |
| - * to 15 inclusive. 8 represents a 256 byte window and 15 a 32KiB window. |
| + * client must use to compress outgoing messages. The permitted range is 9 |
| + * to 15 inclusive. 9 represents a 512 byte window and 15 a 32KiB window. |
| * The default setting is 15. |
| * |
| * Mode Options: |
| @@ -417,6 +443,14 @@ class enabled { |
| * outgoing window size unilaterally. A server may only limit the client's |
| * window size if the remote client supports that feature. |
| * |
| + * NOTE: The permessage-deflate spec specifies that a value of 8 is allowed. |
| + * Prior to version 0.8.0 a value of 8 was also allowed by this library. |
| + * zlib, the deflate compression library that WebSocket++ uses has always |
| + * silently adjusted a value of 8 to 9. In recent versions of zlib (1.2.9 |
| + * and greater) a value of 8 is now explicitly rejected. WebSocket++ 0.8.0 |
| + * continues to perform the 8->9 conversion for backwards compatibility |
| + * purposes but this should be considered deprecated functionality. |
| + * |
| * @param bits The size to request for the outgoing window size |
| * @param mode The mode to use for negotiating this parameter |
| * @return A status code |
| @@ -425,6 +459,12 @@ class enabled { |
| if (bits < min_client_max_window_bits || bits > max_client_max_window_bits) { |
| return error::make_error_code(error::invalid_max_window_bits); |
| } |
| + |
| + // See note in doc comment above about what is happening here |
| + if (bits == 8) { |
| + bits = 9; |
| + } |
| + |
| m_client_max_window_bits = bits; |
| m_client_max_window_bits_mode = mode; |
| |
| @@ -642,11 +682,17 @@ class enabled { |
| * client requested that we use. |
| * |
| * options: |
| - * - decline (refuse to use the attribute) |
| - * - accept (use whatever the client says) |
| - * - largest (use largest possible value) |
| + * - decline (ignore value, offer our default instead) |
| + * - accept (use the value requested by the client) |
| + * - largest (use largest value acceptable to both) |
| * - smallest (use smallest possible value) |
| * |
| + * NOTE: As a value of 8 is no longer explicitly supported by zlib but might |
| + * be requested for negotiation by an older client/server, if the result of |
| + * the negotiation would be to send a value of 8, a value of 9 is offered |
| + * instead. This ensures that WebSocket++ will only ever negotiate connections |
| + * with compression settings explicitly supported by zlib. |
| + * |
| * @param [in] value The value of the attribute from the offer |
| * @param [out] ec A reference to the error code to return errors via |
| */ |
| @@ -678,6 +724,11 @@ class enabled { |
| ec = make_error_code(error::invalid_mode); |
| m_server_max_window_bits = default_server_max_window_bits; |
| } |
| + |
| + // See note in doc comment |
| + if (m_server_max_window_bits == 8) { |
| + m_server_max_window_bits = 9; |
| + } |
| } |
| |
| /// Negotiate client_max_window_bits attribute |
| @@ -687,11 +738,17 @@ class enabled { |
| * negotiation mode. |
| * |
| * options: |
| - * - decline (refuse to use the attribute) |
| - * - accept (use whatever the client says) |
| - * - largest (use largest possible value) |
| + * - decline (ignore value, offer our default instead) |
| + * - accept (use the value requested by the client) |
| + * - largest (use largest value acceptable to both) |
| * - smallest (use smallest possible value) |
| * |
| + * NOTE: As a value of 8 is no longer explicitly supported by zlib but might |
| + * be requested for negotiation by an older client/server, if the result of |
| + * the negotiation would be to send a value of 8, a value of 9 is offered |
| + * instead. This ensures that WebSocket++ will only ever negotiate connections |
| + * with compression settings explicitly supported by zlib. |
| + * |
| * @param [in] value The value of the attribute from the offer |
| * @param [out] ec A reference to the error code to return errors via |
| */ |
| @@ -727,6 +784,11 @@ class enabled { |
| ec = make_error_code(error::invalid_mode); |
| m_client_max_window_bits = default_client_max_window_bits; |
| } |
| + |
| + // See note in doc comment |
| + if (m_client_max_window_bits == 8) { |
| + m_client_max_window_bits = 9; |
| + } |
| } |
| |
| bool m_enabled; |
| diff --git a/websocketpp/impl/connection_impl.hpp b/websocketpp/impl/connection_impl.hpp |
| index 105911db..ae55c338 100644 |
| --- a/websocketpp/impl/connection_impl.hpp |
| +++ b/websocketpp/impl/connection_impl.hpp |
| @@ -1222,12 +1222,18 @@ lib::error_code connection<config>::process_handshake_request() { |
| std::pair<lib::error_code,std::string> neg_results; |
| neg_results = m_processor->negotiate_extensions(m_request); |
| |
| - if (neg_results.first) { |
| + if (neg_results.first == error::make_error_code(error::extension_parse_error)) { |
| // There was a fatal error in extension parsing that should result in |
| // a failed connection attempt. |
| - m_alog.write(log::alevel::devel, "Bad request: " + neg_results.first.message()); |
| + m_alog.write(log::alevel::info, "Bad request: " + neg_results.first.message()); |
| m_response.set_status(http::status_code::bad_request); |
| return neg_results.first; |
| + } else if (neg_results.first) { |
| + // There was a fatal error in extension processing that is probably our |
| + // fault. Consider extension negotiation to have failed and continue as |
| + // if extensions were not supported |
| + m_alog.write(log::alevel::info, |
| + "Extension negotiation failed: " + neg_results.first.message()); |
| } else { |
| // extension negotiation succeeded, set response header accordingly |
| // we don't send an empty extensions header because it breaks many |
| diff --git a/websocketpp/processors/hybi13.hpp b/websocketpp/processors/hybi13.hpp |
| index 79486654..a95bc649 100644 |
| --- a/websocketpp/processors/hybi13.hpp |
| +++ b/websocketpp/processors/hybi13.hpp |
| @@ -97,6 +97,11 @@ class hybi13 : public processor<config> { |
| /** |
| * This exists mostly because the code for requests and responses is |
| * identical and I can't have virtual template methods. |
| + * |
| + * NOTE: this method makes assumptions that the permessage-deflate |
| + * extension is the only one supported. If additional extensions are |
| + * ever supported it should be reviewed carefully. Most cases where |
| + * that assumption is made are explicitly noted. |
| */ |
| template <typename header_type> |
| err_str_pair negotiate_extensions_helper(header_type const & header) { |
| @@ -149,9 +154,26 @@ class hybi13 : public processor<config> { |
| } else { |
| // Note: this list will need commas if WebSocket++ ever |
| // supports more than one extension |
| - ret.second += neg_ret.second; |
| - m_permessage_deflate.init(base::m_server); |
| - continue; |
| + |
| + // Actually try to initialize the extension before we |
| + // deem negotiation complete |
| + ret.first = m_permessage_deflate.init(base::m_server); |
| + if (!ret.first) { |
| + |
| + // TODO: support multiple extensions. |
| + // right now, because there is only one extension |
| + // supported, it failing to negotiate means we are |
| + // done with all negotiating. In the future if more |
| + // extensions are supported a better solution will |
| + // be needed here. |
| + break; |
| + } else { |
| + ret.second += neg_ret.second; |
| + |
| + // continue looking for more extensions |
| + continue; |
| + } |
| + |
| } |
| } |
| } |