QUIC: clear SSL_OP_ENABLE_MIDDLEBOX_COMPAT on SSL context switch. The SSL_OP_ENABLE_MIDDLEBOX_COMPAT option is provided by QuicTLS and enabled by default in the newly created SSL contexts. SSL_set_quic_method() is used to clear it, which is required for SSL handshake to work on QUIC connections. Switching context in the ngx_http_ssl_servername() SNI callback overrides SSL options from the new SSL context. This results in the option set again. Fix is to explicitly clear it when switching to another SSL context. Initially reported here (in Russian): http://mailman.nginx.org/pipermail/nginx-ru/2021-November/063989.html

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>


int
ngx_nonblocking(ngx_socket_t s)
{
    unsigned long  nb = 1;

    return ioctlsocket(s, FIONBIO, &nb);
}


int
ngx_blocking(ngx_socket_t s)
{
    unsigned long  nb = 0;

    return ioctlsocket(s, FIONBIO, &nb);
}


int
ngx_socket_nread(ngx_socket_t s, int *n)
{
    unsigned long  nread;

    if (ioctlsocket(s, FIONREAD, &nread) == -1) {
        return -1;
    }

    *n = nread;

    return 0;
}


int
ngx_tcp_push(ngx_socket_t s)
{
    return 0;
}