=encoding utf-8

=head1 NAME

ngx_http_v3_module - Module ngx_http_v3_module




=head1



The C<ngx_http_v3_module> module (1.25.0) provides
experimental support for
L<HTTPE<sol>3|https://datatracker.ietf.org/doc/html/rfc9114>.





This module is not built by default, it should be enabled with the
L<C<--with-http_v3_module>|configure>
configuration parameter.

B<NOTE>

An SSL library that provides QUIC support
such as
L<BoringSSL|https://boringssl.googlesource.com/boringssl>,
L<LibreSSL|https://www.libressl.org>, or
L<QuicTLS|https://github.com/quictls/openssl>
is recommended to build and run this module.
Otherwise,
when using the L<OpenSSL|https://openssl.org> library,
OpenSSL compatibility layer will be used that does not support
L<early data|ngx_http_ssl_module>.





=head1 Known Issues



The module is experimental, caveat emptor applies.




=head1 Example Configuration




    
    http {
        log_format quic '$remote_addr - $remote_user [$time_local] '
                        '"$request" $status $body_bytes_sent '
                        '"$http_referer" "$http_user_agent" "$http3"';
    
        access_log logs/access.log quic;
    
        server {
            # for better compatibility it's recommended
            # to use the same port for http/3 and https
            listen 8443 quic reuseport;
            listen 8443 ssl;
    
            ssl_certificate     certs/example.com.crt;
            ssl_certificate_key certs/example.com.key;
    
            location / {
                # used to advertise the availability of HTTP/3
                add_header Alt-Svc 'h3=":8443"; ma=86400';
            }
        }
    }


Note that accepting HTTPE<sol>3 connections over TLS requires
the TLSv1.3 protocol support, which is available since
L<OpenSSL|http://www.openssl.org> version 1.1.1.




=head1 Directives

=head2 http3


B<syntax:> http3 I<C<on> E<verbar> C<off>>


B<default:> I<on>


B<context:> I<http>


B<context:> I<server>





Enables
L<HTTPE<sol>3|https://datatracker.ietf.org/doc/html/rfc9114>
protocol negotiation.







 =head2 http3_hq


B<syntax:> http3_hq I<C<on> E<verbar> C<off>>


B<default:> I<off>


B<context:> I<http>


B<context:> I<server>





Enables HTTPE<sol>0.9 protocol negotiation
used in
L<QUIC
interoperability tests|https://github.com/marten-seemann/quic-interop-runner>.







=head2 http3_max_concurrent_streams


B<syntax:> http3_max_concurrent_streams I<I<C<number>>>


B<default:> I<128>


B<context:> I<http>


B<context:> I<server>





Sets the maximum number of concurrent HTTPE<sol>3 request streams
in a connection.







=head2 http3_stream_buffer_size


B<syntax:> http3_stream_buffer_size I<I<C<size>>>


B<default:> I<64k>


B<context:> I<http>


B<context:> I<server>





Sets the size of the buffer used for reading and writing of the
QUIC streams.







=head2 quic_active_connection_id_limit


B<syntax:> quic_active_connection_id_limit I<I<C<number>>>


B<default:> I<2>


B<context:> I<http>


B<context:> I<server>





Sets the
QUIC C<active_connection_id_limit> transport parameter value.
This is the maximum number of client connection IDs
which can be stored on the server.







=head2 quic_bpf


B<syntax:> quic_bpf I<C<on> E<verbar> C<off>>


B<default:> I<off>


B<context:> I<main>





Enables routing of QUIC packets using
L<eBPF|https://ebpf.io/>.
When enabled, this allows supporting QUIC connection migration.






B<NOTE>

The directive is only supported on Linux 5.7+.








=head2 quic_gso


B<syntax:> quic_gso I<C<on> E<verbar> C<off>>


B<default:> I<off>


B<context:> I<http>


B<context:> I<server>





Enables sending in optimized batch mode
using segmentation offloading.






B<NOTE>

Optimized sending is supported only on Linux
featuring C<UDP_SEGMENT>.








=head2 quic_host_key


B<syntax:> quic_host_key I<I<C<file>>>



B<context:> I<http>


B<context:> I<server>





Sets a I<C<file>> with the secret key used to encrypt
stateless reset and address validation tokens.
By default, a random key is generated on each reload.
Tokens generated with old keys are not accepted.







=head2 quic_retry


B<syntax:> quic_retry I<C<on> E<verbar> C<off>>


B<default:> I<off>


B<context:> I<http>


B<context:> I<server>





Enables the
L<QUIC
Address Validation|https://datatracker.ietf.org/doc/html/rfc9000#name-address-validation> feature.
This includes sending a new token in a C<Retry> packet
or a C<NEW_TOKEN> frame
and
validating a token received in the C<Initial> packet.







=head1 Embedded Variables



The C<ngx_http_v3_module> module
supports the following embedded variables:

=over



=item C<$http3>




negotiated protocol identifier:
“C<h3>” for HTTPE<sol>3 connections,
“C<hq>” for hq connections,
or an empty string otherwise.




=back