ngx_stream_ssl_preread_module conflicts with ngx_stream_socks_module

[muravjov]

If nginx is built with both ngx_stream_ssl_preread_module and ngx_stream_socks_module, one gets an error for the basic config:

...
stream {
    resolver 8.8.8.8 ipv6=off;
    log_format socks 'socks: $socks_connect_addr $socks_name $socks_passwd $socks_protocol';
    server {         
        listen     0.0.0.0:22345;
        socks;
        socks_user_passwd test1 test2;
        access_log socks_access.log socks;
    }
}

The error is:

sudo debian/build-nginx/objs/nginx -t -c /etc/nginx/nginx.conf
nginx: [emerg] the duplicate "ssl_preread_protocol" variable in /etc/nginx/nginx.conf:13
nginx: [error] add var:ssl_preread_protocol error!
nginx: configuration file /etc/nginx/nginx.conf test failed

So I had to remove the ngx_stream_ssl_preread_module to be able to use ngx_stream_socks_module.

How to reproduce:

• ubuntu 22.04.1
• the config:

$ sudo nginx -V
nginx version: nginx/1.23.3
built by gcc 11.3.0 (Ubuntu 11.3.0-1ubuntu1~22.04)
built with OpenSSL 3.0.2 15 Mar 2022
TLS SNI support enabled
configure arguments: --prefix=/etc/nginx --sbin-path=/usr/sbin/nginx --modules-path=/usr/lib/nginx/modules --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --pid-path=/var/run/nginx.pid --lock-path=/var/run/nginx.lock --http-client-body-temp-path=/var/cache/nginx/client_temp --http-proxy-temp-path=/var/cache/nginx/proxy_temp --http-fastcgi-temp-path=/var/cache/nginx/fastcgi_temp --http-uwsgi-temp-path=/var/cache/nginx/uwsgi_temp --http-scgi-temp-path=/var/cache/nginx/scgi_temp --user=nginx --group=nginx --with-compat --with-file-aio --with-threads --with-http_addition_module --with-http_auth_request_module --with-http_dav_module --with-http_flv_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_mp4_module --with-http_random_index_module --with-http_realip_module --with-http_secure_link_module --with-http_slice_module --with-http_ssl_module --with-http_stub_status_module --with-http_sub_module --with-http_v2_module --with-mail --with-mail_ssl_module --with-stream --with-stream_ssl_preread_module --add-module=/home/sa/nginx_build/ngx_stream_socks_module --with-stream_realip_module --with-stream_ssl_module --with-cc-opt='-g -O2 -ffile-prefix-map=/home/sa/nginx_build/nginx-1.23.3=. -flto=auto -ffat-lto-objects -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fPIC' --with-ld-opt='-Wl,-Bsymbolic-functions -flto=auto -ffat-lto-objects -flto=auto -Wl,-z,relro -Wl,-z,now -Wl,--as-needed -pie'

The nginx is built from the ubuntu repo here https://nginx.org/en/linux_packages.html with

# get sources
$ apt-get source nginx

# add github.com/attenuation/ngx_stream_socks_module to configure
$ sed -i 's+--with-stream +--with-stream --add-module=/home/sa/nginx_build/ngx_stream_socks_module +g' debian/rules

# build it
$ debian/rules build

The ngx_stream_socks_module commit is used:

$ git log -1
commit acf31be0a046edf42518958b7a322e5367734761 (HEAD -> main, tag: 0.1.0, tag: 0.1, origin/main, origin/HEAD)
Author: Jun Ouyang <[email protected]>
Date:   Mon Jan 9 22:43:41 2023 +0800

    update readme