nghttp2 - HTTP/2.0 C Library ============================ This is an experimental implementation of Hypertext Transfer Protocol version 2.0. Development Status ------------------ We started to implement HTTP-draft-09/2.0 (http://tools.ietf.org/html/draft-ietf-httpbis-http2-09) and the header compression (http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-05). The nghttp2 code base was forked from spdylay project. ========================== ================= Features HTTP-draft-09/2.0 ========================== ================= :authority Done HPACK-draft-05 Done SETTINGS_HEADER_TABLE_SIZE Done SETTINGS_ENABLE_PUSH Done FRAME_SIZE_ERROR Done SETTINGS with ACK Done Header Continuation ALPN Done ========================== ================= Public Test Server ------------------ The following endpoints are available to try out nghttp2 implementation. These endpoints supports ``HTTP-draft-09/2.0`` and the earlier draft versions are not supporeted. * https://106.186.112.116 (TLS + NPN) NPN offers ``HTTP-draft-09/2.0``, ``spdy/3.1``, ``spdy/3``, ``spdy/2`` and ``http/1.1``. Note: certificate is self-signed and a browser will show alert * http://106.186.112.116 (Upgrade + Direct) Requirements ------------ The following packages are needed to build the library: * pkg-config >= 0.20 * zlib >= 1.2.3 To build and run the unit test programs, the following packages are required: * cunit >= 2.1 To build the documentation, you need to install: * sphinx (http://sphinx-doc.org/) To build and run the application programs (``nghttp``, ``nghttpd`` and ``nghttpx``) in ``src`` directory, the following packages are required: * OpenSSL >= 1.0.1 * libevent-openssl >= 2.0.8 ALPN support requires unreleased version OpenSSL >= 1.0.2. To enable SPDY protocol in the application program ``nghttpx``, the following packages are required: * spdylay >= 1.2.3 To enable ``-a`` option (getting linked assets from the downloaded resource) in ``nghttp``, the following packages are needed: * libxml2 >= 2.7.7 The HPACK tools require the following package: * jansson >= 2.5 The Python bindings require the following packages: * cython >= 0.19 * python >= 2.7 If you are using Ubuntu 12.04, you need the following packages installed: * autoconf * automake * autotools-dev * libtool * pkg-config * zlib1g-dev * libcunit1-dev * libssl-dev * libxml2-dev * libevent-dev * libjansson-dev spdylay is not packaged in Ubuntu, so you need to build it yourself: http://tatsuhiro-t.github.io/spdylay/ Build from git -------------- Building from git is easy, but please be sure that at least autoconf 2.68 is used:: $ autoreconf -i $ automake $ autoconf $ ./configure $ make Building documentation ---------------------- .. note:: Documentation is still incomplete. To build documentation, run:: $ make html The documents will be generated under ``doc/manual/html/``. The generated documents will not be installed with ``make install``. The online documentation is available at http://tatsuhiro-t.github.io/nghttp2/ Client, Server and Proxy programs --------------------------------- The src directory contains HTTP/2.0 client, server and proxy programs. nghttp - client +++++++++++++++ ``nghttp`` is a HTTP/2.0 client. It can connect to the HTTP/2.0 server with prior knowledge, HTTP Upgrade and NPN/ALPN TLS extension. It has verbose output mode for framing information. Here is sample output from ``nghttp`` client:: $ src/nghttp -vn https://localhost:8443 [ 0.003] NPN select next protocol: the remote server offers: * HTTP-draft-09/2.0 * spdy/3 * spdy/2 * http/1.1 NPN selected the protocol: HTTP-draft-09/2.0 [ 0.005] send SETTINGS frame (niv=2) [SETTINGS_MAX_CONCURRENT_STREAMS(4):100] [SETTINGS_INITIAL_WINDOW_SIZE(7):65535] [ 0.006] send HEADERS frame ; END_STREAM | END_HEADERS ; Open new stream :authority: localhost:8443 :method: GET :path: / :scheme: https accept: */* accept-encoding: gzip, deflate user-agent: nghttp2/0.1.0-DEV [ 0.006] recv SETTINGS frame (niv=2) [SETTINGS_MAX_CONCURRENT_STREAMS(4):100] [SETTINGS_INITIAL_WINDOW_SIZE(7):65535] [ 0.006] send SETTINGS frame ; ACK (niv=0) [ 0.006] recv WINDOW_UPDATE frame (window_size_increment=1000000007) [ 0.006] recv SETTINGS frame ; ACK (niv=0) [ 0.006] recv HEADERS frame ; END_HEADERS ; First response header :status: 200 accept-ranges: bytes content-encoding: gzip content-length: 146 content-type: text/html date: Sun, 27 Oct 2013 14:23:54 GMT etag: "b1-4e5535a027780-gzip" last-modified: Sun, 01 Sep 2013 14:34:22 GMT server: Apache/2.4.6 (Debian) vary: Accept-Encoding via: 1.1 nghttpx [ 0.006] recv DATA frame [ 0.006] recv DATA frame ; END_STREAM [ 0.007] send GOAWAY frame (last_stream_id=0, error_code=NO_ERROR(0), opaque_data(0)=[]) The HTTP Upgrade is performed like this:: $ src/nghttp -vnu http://localhost:8080 [ 0.000] HTTP Upgrade request GET / HTTP/1.1 Host: localhost:8080 Connection: Upgrade, HTTP2-Settings Upgrade: HTTP-draft-09/2.0 HTTP2-Settings: AAAABAAAAGQAAAAHAAD__w Accept: */* User-Agent: nghttp2/0.1.0-DEV [ 0.000] HTTP Upgrade response HTTP/1.1 101 Switching Protocols Connection: Upgrade Upgrade: HTTP-draft-09/2.0 [ 0.001] HTTP Upgrade success [ 0.001] send SETTINGS frame (niv=2) [SETTINGS_MAX_CONCURRENT_STREAMS(4):100] [SETTINGS_INITIAL_WINDOW_SIZE(7):65535] [ 0.001] recv SETTINGS frame (niv=2) [SETTINGS_MAX_CONCURRENT_STREAMS(4):100] [SETTINGS_INITIAL_WINDOW_SIZE(7):65535] [ 0.001] recv WINDOW_UPDATE frame (window_size_increment=1000000007) [ 0.001] recv HEADERS frame ; END_HEADERS ; First response header :status: 200 accept-ranges: bytes content-length: 177 content-type: text/html date: Sun, 27 Oct 2013 14:26:04 GMT etag: "b1-4e5535a027780" last-modified: Sun, 01 Sep 2013 14:34:22 GMT server: Apache/2.4.6 (Debian) vary: Accept-Encoding via: 1.1 nghttpx [ 0.001] recv DATA frame [ 0.001] recv DATA frame ; END_STREAM [ 0.001] send SETTINGS frame ; ACK (niv=0) [ 0.001] send GOAWAY frame (last_stream_id=0, error_code=NO_ERROR(0), opaque_data(0)=[]) [ 0.001] recv SETTINGS frame ; ACK (niv=0) nghttpd - server ++++++++++++++++ ``nghttpd`` is static web server. It is single threaded and multiplexes connections using non-blocking socket. By default, it uses SSL/TLS connection. Use ``--no-tls`` option to disable it. ``nghttpd`` only accept the HTTP/2.0 connection via NPN/ALPN or direct HTTP/2.0 connection. No HTTP Upgrade is supported. ``-p`` option allows users to configure server push. Just like ``nghttp``, it has verbose output mode for framing information. Here is sample output from ``nghttpd`` server:: $ src/nghttpd --no-tls -v 8080 IPv4: listen on port 8080 IPv6: listen on port 8080 [id=1] [ 1.189] send SETTINGS frame (niv=1) [SETTINGS_MAX_CONCURRENT_STREAMS(4):100] [id=1] [ 1.191] recv SETTINGS frame (niv=2) [SETTINGS_MAX_CONCURRENT_STREAMS(4):100] [SETTINGS_INITIAL_WINDOW_SIZE(7):65535] [id=1] [ 1.191] recv HEADERS frame ; END_STREAM | END_HEADERS ; Open new stream :authority: localhost:8080 :method: GET :path: / :scheme: http accept: */* accept-encoding: gzip, deflate user-agent: nghttp2/0.1.0-DEV [id=1] [ 1.192] send SETTINGS frame ; ACK (niv=0) [id=1] [ 1.192] send HEADERS frame ; END_HEADERS ; First response header :status: 404 content-encoding: gzip content-type: text/html; charset=UTF-8 date: Sun, 27 Oct 2013 14:27:53 GMT server: nghttpd nghttp2/0.1.0-DEV [id=1] [ 1.192] send DATA frame [id=1] [ 1.192] send DATA frame ; END_STREAM [id=1] [ 1.192] stream_id=1 closed [id=1] [ 1.192] recv SETTINGS frame ; ACK (niv=0) [id=1] [ 1.192] recv GOAWAY frame (last_stream_id=0, error_code=NO_ERROR(0), opaque_data(0)=[]) [id=1] [ 1.192] closed nghttpx - proxy +++++++++++++++ The ``nghttpx`` is a multi-threaded reverse proxy for HTTP-draft-09/2.0, SPDY and HTTP/1.1. It has several operation modes: ================== ============================== ============== ============= Mode option Frontend Backend Note ================== ============================== ============== ============= default mode HTTP/2.0, SPDY, HTTP/1.1 (TLS) HTTP/1.1 Reverse proxy ``--http2-proxy`` HTTP/2.0, SPDY, HTTP/1.1 (TLS) HTTP/1.1 SPDY proxy ``--http2-bridge`` HTTP/2.0, SPDY, HTTP/1.1 (TLS) HTTP/2.0 (TLS) ``--client`` HTTP/2.0, HTTP/1.1 HTTP/2.0 (TLS) ``--client-proxy`` HTTP/2.0, HTTP/1.1 HTTP/2.0 (TLS) Forward proxy ================== ============================== ============== ============= The interesting mode at the moment is the default mode. It works like a reverse proxy and listens HTTP-draft-09/2.0, SPDY and HTTP/1.1 and can be deployed SSL/TLS terminator for existing web server. The default mode, ``--http2-proxy`` and ``--http2-bridge`` modes use SSL/TLS in the frontend connection by default. To disable SSL/TLS, use ``--frontend-no-tls`` option. If that option is used, SPDY is disabled in the frontend and incoming HTTP/1.1 connection can be upgraded to HTTP/2.0 through HTTP Upgrade. The ``--http2-bridge``, ``--client`` and ``--client-proxy`` modes use SSL/TLS in the backend connection by deafult. To disable SSL/TLS, use ``--backend-no-tls`` option. The ``nghttpx`` supports configuration file. See ``--conf`` option and sample configuration file ``nghttpx.conf.sample``. The ``nghttpx`` does not support server push. In the default mode, (without any of ``--http2-proxy``, ``--http2-bridge``, ``--client-proxy`` and ``--client`` options), ``nghttpx`` works as reverse proxy to the backend server:: Client <-- (HTTP/2.0, SPDY, HTTP/1.1) --> nghttpx <-- (HTTP/1.1) --> Web Server [reverse proxy] With ``--http2-proxy`` option, it works as so called secure proxy (aka SPDY proxy):: Client <-- (HTTP/2.0, SPDY, HTTP/1.1) --> nghttpx <-- (HTTP/1.1) --> Proxy [secure proxy] (e.g., Squid) The ``Client`` in the above is needs to be configured to use ``nghttpx`` as secure proxy. At the time of this writing, Chrome is the only browser which supports secure proxy. The one way to configure Chrome to use secure proxy is create proxy.pac script like this:: function FindProxyForURL(url, host) { return "HTTPS SERVERADDR:PORT"; } ``SERVERADDR`` and ``PORT`` is the hostname/address and port of the machine nghttpx is running. Please note that Chrome requires valid certificate for secure proxy. Then run chrome with the following arguments:: $ google-chrome --proxy-pac-url=file:///path/to/proxy.pac --use-npn With ``--http2-bridge``, it accepts HTTP/2.0, SPDY and HTTP/1.1 connections and communicates with backend in HTTP/2.0:: Client <-- (HTTP/2.0, SPDY, HTTP/1.1) --> nghttpx <-- (HTTP/2.0) --> Web or HTTP/2.0 Proxy etc (e.g., nghttpx -s) With ``--client-proxy`` option, it works as forward proxy and expects that the backend is HTTP/2.0 proxy:: Client <-- (HTTP/2.0, HTTP/1.1) --> nghttpx <-- (HTTP/2.0) --> HTTP/2.0 Proxy [forward proxy] (e.g., nghttpx -s) The ``Client`` is needs to be configured to use nghttpx as forward proxy. The frontend HTTP/1.1 connection can be upgraded to HTTP/2.0 through HTTP Upgrade. With the above configuration, one can use HTTP/1.1 client to access and test their HTTP/2.0 servers. With ``--client`` option, it works as reverse proxy and expects that the backend is HTTP/2.0 Web server:: Client <-- (HTTP/2.0, HTTP/1.1) --> nghttpx <-- (HTTP/2.0) --> Web Server [reverse proxy] The frontend HTTP/1.1 connection can be upgraded to HTTP/2.0 through HTTP Upgrade. For the operation modes which talk to the backend in HTTP/2.0 over SSL/TLS, the backend connections can be tunneled though HTTP proxy. The proxy is specified using ``--backend-http-proxy-uri`` option. The following figure illustrates the example of ``--http2-bridge`` and ``--backend-http-proxy-uri`` option to talk to the outside HTTP/2.0 proxy through HTTP proxy:: Client <-- (HTTP/2.0, SPDY, HTTP/1.1) --> nghttpx <-- (HTTP/2.0) -- --===================---> HTTP/2.0 Proxy (HTTP proxy tunnel) (e.g., nghttpx -s) HPACK tools ----------- The ``src`` directory contains HPACK tools. The ``deflatehd`` is command-line header compression tool. The ``inflatehd`` is command-line header decompression tool. Both tools read input from stdin and write output to stdout. The errors are written to stderr. They take JSON as input and output. We use the same JSON data format used in https://github.com/Jxck/hpack-test-case deflatehd - header compressor +++++++++++++++++++++++++++++ The ``deflatehd`` reads JSON data or HTTP/1-style header fields from stdin and outputs compressed header block in JSON. For the JSON input, the root JSON object must contain ``context`` key, which indicates which compression context is used. If it is ``request``, request compression context is used. Otherwise, response compression context is used. The value of ``cases`` key contains the sequence of input header set. They share the same compression context and are processed in the order they appear. Each item in the sequence is a JSON object and it must have at least ``headers`` key. Its value is an array of a JSON object containing exactly one name/value pair. Example:: { "context": "request", "cases": [ { "headers": [ { ":method": "GET" }, { ":path": "/" } ] }, { "headers": [ { ":method": "POST" }, { ":path": "/" } ] } ] } With ``-t`` option, the program can accept more familiar HTTP/1 style header field block. Each header set is delimited by empty line: Example:: :method: GET :scheme: https :path: / :method: POST user-agent: nghttp2 The output is JSON object. It contains ``context`` key and its value is ``request`` if the compression context is request, otherwise ``response``. The root JSON object also contains ``cases`` key and its value is an array of JSON object, which has at least following keys: seq The index of header set in the input. input_length The sum of length of name/value pair in the input. output_length The length of compressed header block. percentage_of_original_size ``input_length`` / ``output_length`` * 100 wire The compressed header block in hex string. headers The input header set. header_table_size The header table size adjsuted before deflating header set. Examples:: { "context": "request", "cases": [ { "seq": 0, "input_length": 66, "output_length": 20, "percentage_of_original_size": 30.303030303030305, "wire": "01881f3468e5891afcbf83868a3d856659c62e3f", "headers": [ { ":authority": "example.org" }, { ":method": "GET" }, { ":path": "/" }, { ":scheme": "https" }, { "user-agent": "nghttp2" } ], "header_table_size": 4096 } , { "seq": 1, "input_length": 74, "output_length": 10, "percentage_of_original_size": 13.513513513513514, "wire": "88448504252dd5918485", "headers": [ { ":authority": "example.org" }, { ":method": "POST" }, { ":path": "/account" }, { ":scheme": "https" }, { "user-agent": "nghttp2" } ], "header_table_size": 4096 } ] } The output can be used as the input for ``inflatehd`` and ``deflatehd``. With ``-d`` option, the extra ``header_table`` key is added and its associated value contains the state of dyanmic header table after the corresponding header set was processed. The value contains following keys: entries The entry in the header table. If ``referenced`` is ``true``, it is in the reference set. The ``size`` includes the overhead (32 bytes). The ``index`` corresponds to the index of header table. The ``name`` is the header field name and the ``value`` is the header field value. They may be displayed as ``**DEALLOCATED**``, which means that the memory for that string is freed and not available. This will happen when the specifying smaller value in ``-S`` than ``-s``. size The sum of the spaces entries occupied, this includes the entry overhead. max_size The maximum header table size. deflate_size The sum of the spaces entries occupied within ``max_deflate_size``. max_deflate_size The maximum header table size encoder uses. This can be smaller than ``max_size``. In this case, encoder only uses up to first ``max_deflate_size`` buffer. Since the header table size is still ``max_size``, the encoder has to keep track of entries ouside the ``max_deflate_size`` but inside the ``max_size`` and make sure that they are no longer referenced. Example:: { "context": "request", "cases": [ { "seq": 0, "input_length": 66, "output_length": 20, "percentage_of_original_size": 30.303030303030305, "wire": "01881f3468e5891afcbf83868a3d856659c62e3f", "headers": [ { ":authority": "example.org" }, { ":method": "GET" }, { ":path": "/" }, { ":scheme": "https" }, { "user-agent": "nghttp2" } ], "header_table_size": 4096, "header_table": { "entries": [ { "index": 1, "name": "user-agent", "value": "nghttp2", "referenced": true, "size": 49 }, { "index": 2, "name": ":scheme", "value": "https", "referenced": true, "size": 44 }, { "index": 3, "name": ":path", "value": "/", "referenced": true, "size": 38 }, { "index": 4, "name": ":method", "value": "GET", "referenced": true, "size": 42 }, { "index": 5, "name": ":authority", "value": "example.org", "referenced": true, "size": 53 } ], "size": 226, "max_size": 4096, "deflate_size": 226, "max_deflate_size": 4096 } } , { "seq": 1, "input_length": 74, "output_length": 10, "percentage_of_original_size": 13.513513513513514, "wire": "88448504252dd5918485", "headers": [ { ":authority": "example.org" }, { ":method": "POST" }, { ":path": "/account" }, { ":scheme": "https" }, { "user-agent": "nghttp2" } ], "header_table_size": 4096, "header_table": { "entries": [ { "index": 1, "name": ":method", "value": "POST", "referenced": true, "size": 43 }, { "index": 2, "name": "user-agent", "value": "nghttp2", "referenced": true, "size": 49 }, { "index": 3, "name": ":scheme", "value": "https", "referenced": true, "size": 44 }, { "index": 4, "name": ":path", "value": "/", "referenced": false, "size": 38 }, { "index": 5, "name": ":method", "value": "GET", "referenced": false, "size": 42 }, { "index": 6, "name": ":authority", "value": "example.org", "referenced": true, "size": 53 } ], "size": 269, "max_size": 4096, "deflate_size": 269, "max_deflate_size": 4096 } } ] } inflatehd - header decompressor +++++++++++++++++++++++++++++++ The ``inflatehd`` reads JSON data from stdin and outputs decompressed name/value pairs in JSON. The root JSON object must contain ``context`` key, which indicates which compression context is used. If it is ``request``, request compression context is used. Otherwise, response compression context is used. The value of ``cases`` key contains the sequence of compressed header block. They share the same compression context and are processed in the order they appear. Each item in the sequence is a JSON object and it must have at least ``wire`` key. Its value is a string containing compressed header block in hex string. Example:: { "context": "request", "cases": [ { "wire": "8285" }, { "wire": "8583" } ] } The output is JSON object. It contains ``context`` key and its value is ``request`` if the compression context is request, otherwise ``response``. The root JSON object also contains ``cases`` key and its value is an array of JSON object, which has at least following keys: seq The index of header set in the input. headers The JSON array contains decompressed name/value pairs. wire The compressed header block in hex string. header_table_size The header table size adjsuted before inflating compressed header block. Example:: { "context": "request", "cases": [ { "seq": 0, "wire": "01881f3468e5891afcbf83868a3d856659c62e3f", "headers": [ { ":authority": "example.org" }, { ":method": "GET" }, { ":path": "/" }, { ":scheme": "https" }, { "user-agent": "nghttp2" } ], "header_table_size": 4096 } , { "seq": 1, "wire": "88448504252dd5918485", "headers": [ { ":method": "POST" }, { ":path": "/account" }, { "user-agent": "nghttp2" }, { ":scheme": "https" }, { ":authority": "example.org" } ], "header_table_size": 4096 } ] } The output can be used as the input for ``deflatehd`` and ``inflatehd``. With ``-d`` option, the extra ``header_table`` key is added and its associated value contains the state of dyanmic header table after the corresponding header set was processed. The format is the same as ``deflatehd``. Python bindings --------------- This ``python`` directory contains nghttp2 Python bindings. The bindings currently only provide HPACK compressor and decompressor classes. The extension module is called ``nghttp2``. ``make`` will build the bindings and target Python version is determined by configure script. If the detected Python version is not what you expect, specify a path to Python executable in ``PYTHON`` variable as an argument to configure script (e.g., ``./configure PYTHON=/usr/bin/python3.3``). Example +++++++ The following example code illustrates basic usage of HPACK compressor and decompressor in Python: .. code-block:: python import binascii import nghttp2 deflater = nghttp2.HDDeflater(nghttp2.HD_SIDE_REQUEST) inflater = nghttp2.HDInflater(nghttp2.HD_SIDE_REQUEST) data = deflater.deflate([(b'foo', b'bar'), (b'baz', b'buz')]) print(binascii.b2a_hex(data)) hdrs = inflater.inflate(data) print(hdrs)