avalonsec 22 июл в 15:47

Ч. 2 — Дальнобойный Wi-Fi. Реализация интернет шлюза на базе Debian 12

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29 мин

Обзор

Ч. 1 — Дальнобойный Wi-Fi. Выбор аппаратного обеспечения.

Статья ещё не дописана!!!

В моём сценарии WPA2 отключен, для аутентификации пользователей и выдачи доступа к интернету используется openvpn, но при этом пользователи имеют доступ к локальным ресурсам и могут взаимодействовать внутри локальной сети.

На точке необходимо отключить встроенные функции dhcp и dns.

Настройка сетевых интерфейсов

При нескольких сетевых картах возникает ситуация когда система не понимает к какому интерфейсу обращаться за интернетом. Для того что бы исправить это нам надо указать маршрут и метрику. Чем больше число метрики, тем меньше приоритет интерфейса. В данном случае для WAN он 10, а для LAN 5000.

Узнаём имена интерфейсов с помощью команды

ip a

Команда post-up выполняет действие после подключения интерфейса.

## /etc/network/interfaces

source /etc/network/interfaces.d/*

auto lo
iface lo inet loopback

# WAN
allow-hotplug enp1s0
iface enp1s0 inet dhcp
        post-up sh -c 'ip route del default || true; ip route add default via 192.168.1.1 dev enp1s0 metric 10' 
        post-up sh -c 'echo "nameserver 9.9.9.9" > /etc/resolv.conf'  # Фикс перезаписи resolv долбанным systemd-resolved

# LAN
auto enp3s0
iface enp3s0 inet static
        address 192.168.2.1
        netmask 255.255.255.0
        dns-nameservers 192.168.2.1
        metric 5000

Настройка SSH

Генерация ключей ssh

sudo ssh-keygen -t ed25519 -f /etc/ssh/ssh_host_ed25519_key -N ''
sudo ssh-keygen -t ecdsa -b 521 -f /etc/ssh/ssh_host_ecdsa_key -N ''
sudo ssh-keygen -t rsa -b 4096 -f /etc/ssh/ssh_host_rsa_key -N ''

## /etc/ssh/sshd_config

Port 2222
ListenAddress 0.0.0.0

# Ключи хоста (серверные)
HostKey /etc/ssh/ssh_host_ed25519_key
HostKey /etc/ssh/ssh_host_ecdsa_key
HostKey /etc/ssh/ssh_host_rsa_key  # RSA 4096

# Аутентификация
#PubkeyAuthentication yes        
PubkeyAuthentication no           # Явное отключение аутентификации по ключам

PasswordAuthentication yes        # Разрешаем только парольную аутентификацию

#ChallengeResponseAuthentication yes
ChallengeResponseAuthentication no  # Отключаем интерактивные вызовы

#KbdInteractiveAuthentication yes
KbdInteractiveAuthentication no     # Отключаем интерактивную аутентификацию (kbd-interactive)

PermitRootLogin no                  # Запрет входа под root по SSH

# Шифры (ciphers) — баланс безопасности и совместимости
Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr

# MAC алгоритмы
MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha1-etm@openssh.com

# Алгоритмы обмена ключами (Kex)
KexAlgorithms curve25519-sha256,curve25519-sha256@libssh.org,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1

# Ограничение по времени и объёму для смены ключа сессии (Forward Secrecy)
RekeyLimit 1G 1h

# Логирование
SyslogFacility AUTH
LogLevel VERBOSE

# Отключаем DNS-обратные запросы для ускорения и безопасности
UseDNS no

# Разрешаем форвардинг TCP и порты
AllowTcpForwarding yes
GatewayPorts yes

# Отключаем X11 форвардинг — снижает риск атак
X11Forwarding no

# Подсистема SFTP отключена
#Subsystem sftp /usr/lib/openssh/sftp-server
Subsystem sftp /bin/false

# Сжатие данных отключено (лучше для безопасности)
Compression no

# Удержание живого соединения и таймауты
TCPKeepAlive yes
ClientAliveInterval 300
ClientAliveCountMax 3

# Использовать PAM (при необходимости)
UsePAM yes

Настройка параметров ядра

## /etc/sysctl.conf

# --- Основное (маршрутизация, NAT, производительность) ---
net.ipv4.ip_forward = 1

# --- Надежность TCP и защита ---
net.ipv4.tcp_syncookies = 1                               # Защита от SYN flood
net.ipv4.tcp_rfc1337 = 1                                  # Защита от TIME_WAIT spoofing
net.ipv4.tcp_fin_timeout = 10

# --- Быстрое открытие TCP-соединений (TFO) ---
net.ipv4.tcp_fastopen = 3                                 # Клиент и сервер


# --- Безопасность и фильтрация ---
net.ipv4.conf.all.rp_filter = 2                            # Усиленный антиспуфинг (strict mode)
net.ipv4.conf.default.rp_filter = 2

net.ipv4.conf.all.accept_redirects = 0                     # Отключаем ICMP redirect
net.ipv4.conf.default.accept_redirects = 0

net.ipv4.conf.all.send_redirects = 0                       # Не отправлять ICMP redirect
net.ipv4.conf.default.send_redirects = 0

net.ipv4.conf.all.accept_source_route = 0                  # Отключаем source routing
net.ipv4.conf.default.accept_source_route = 0


# --- Ограничение ICMP (защита от DoS) ---
net.ipv4.icmp_echo_ignore_broadcasts = 1                   # Игнорирование broadcast ping

# --- Оптимизация TCP ---
net.ipv4.tcp_abort_on_overflow = 1                          # Быстро сбрасывать соединения при переполнении очереди
net.ipv4.tcp_mtu_probing = 1                                # Автоматическое определение MTU (помогает проблемам с VPN/NAT)
net.ipv4.tcp_timestamps = 1                                 # Включить TCP timestamps (улучшенная производительность)


# --- Современный congestion control
net.core.default_qdisc = fq                                 
net.ipv4.tcp_congestion_control = bbr

Настройка DHCP (выдача ip-адресов)

Установка

apt install isc-dhcp-server

Конфигурация

## /etc/dhcp/dhcpd.conf

option captive-portal code 160 = text;
option captive-portal "http://freedom.local";

default-lease-time 600;
max-lease-time 7200;

ddns-update-style none;
authoritative;

subnet 192.168.2.0 netmask 255.255.255.0 {
  range 192.168.2.1 192.168.2.254;
  option domain-name-servers 192.168.2.1;
  option domain-name "freedom.local";
  option routers 192.168.2.1;
  option broadcast-address 192.168.2.255;
  default-lease-time 600;
  max-lease-time 7200;
}

Выбор интерфейса раздачи адресов

## /etc/default/isc-dhcp-server

INTERFACESv4="enp3s0"
INTERFACESv6=""

Настройка простого DNS сервера с апстримом dnscrypt (DoH)

Установка

apt install dnsmasq

Актуальный билд dnscrypt можно взять тут

Возьмите за привычку пользовательские программы которые были установлены вручную размещать либо в /usr/local, либо в /opt

Конфигурация dnsmasq

## /etc/dnsmasq.conf

port=53

# Не пересылать запросы без доменного имени (например, просто "localhost")
domain-needed

# Привязывать dnsmasq только к указанным интерфейсам, чтобы не слушать на всех
bind-interfaces

# Не использовать системный файл /etc/resolv.conf для поиска upstream DNS-серверов
no-resolv

# Защита от DNS rebind-атак — блокирует ответы с подозрительными IP-адресами
stop-dns-rebind

# Жёстко назначить домен freedom.net на IP-адрес 192.168.2.1
address=/freedom.net/192.168.2.1

# Жёстко назначить домен freedom.local на IP-адрес 192.168.2.1
address=/freedom.local/192.168.2.1

# Заменяем yandex на duckduckgo. Что бы узнать адреса используйте dig +short +nodnssec duckduckgo.com
# Для моего региона это:

address=/yandex.ru/20.204.244.192
address=/ya.ru/20.204.244.192
# ----
address=/yandex.ru/40.114.177.156
address=/ya.ru/40.114.177.156


# Использовать локальный DNSCrypt сервер на 127.0.0.1:5353 как upstream DNS
server=127.0.0.1#5353

# Вариант: использовать публичный DNS-сервер Quad9
# server=9.9.9.9

# Слушать DNS-запросы на сетевом интерфейсе enp3s0
interface=enp3s0

# dnsmasq работает только как DNS
no-dhcp-interface=*

Конфигурация DNSCrypt

## dnscrypt-proxy.toml

###############################################################################
#                             Global settings                                  #
###############################################################################

## List of servers to use
##
## Servers from the "public-resolvers" source (see down below) can
## be viewed here: https://dnscrypt.info/public-servers
##
## The proxy will automatically pick working servers from this list.
## Note that the require_* filters do NOT apply when using this setting.
##
## By default, this list is empty and all registered servers matching the
## require_* filters will be used instead.
##
## Remove the leading # first to enable this; lines starting with # are ignored.

# server_names = ['scaleway-fr', 'google', 'yandex', 'cloudflare']


## List of local addresses and ports to listen to. Can be IPv4 and/or IPv6.
## Example with both IPv4 and IPv6:
## listen_addresses = ['127.0.0.1:53', '[::1]:53']
##
## To listen to all IPv4 addresses, use `listen_addresses = ['0.0.0.0:53']`
## To listen to all IPv4+IPv6 addresses, use `listen_addresses = ['[::]:53']`

listen_addresses = ['127.0.0.1:5353']


## Maximum number of simultaneous client connections to accept

max_clients = 250


## Switch to a different system user after listening sockets have been created.
## Note (1): this feature is currently unsupported on Windows.
## Note (2): this feature is not compatible with systemd socket activation.
## Note (3): when using -pidfile, the PID file directory must be writable by the new user

# user_name = 'nobody'


###############################################################################
#                            Server Selection                                  #
###############################################################################

## Require servers (from remote sources) to satisfy specific properties

# Use servers reachable over IPv4
ipv4_servers = true

# Use servers reachable over IPv6 -- Do not enable if you don't have IPv6 connectivity
ipv6_servers = false

# Use servers implementing the DNSCrypt protocol
dnscrypt_servers = true

# Use servers implementing the DNS-over-HTTPS protocol
doh_servers = false

# Use servers implementing the Oblivious DoH protocol
odoh_servers = true


## Require servers defined by remote sources to satisfy specific properties

# Server must support DNS security extensions (DNSSEC)
require_dnssec = false

# Server must not log user queries (declarative)
require_nolog = true

# Server must not enforce its own blocklist (for parental control, ads blocking...)
require_nofilter = true

# Server names to avoid even if they match all criteria
disabled_server_names = []


###############################################################################
#                           Connection Settings                                #
###############################################################################

## Always use TCP to connect to upstream servers.
## This can be useful if you need to route everything through Tor.
## Otherwise, leave this to `false`, as it doesn't improve security
## (dnscrypt-proxy will always encrypt everything even using UDP), and can
## only increase latency.

force_tcp = false


## Enable *experimental* support for HTTP/3 (HTTP over QUIC)
## Note that, like DNSCrypt but unlike other HTTP versions, this uses
## UDP and (usually) port 443 instead of TCP.

http3 = false

## When http3 is true, always try HTTP/3 first for DoH servers.
## If the HTTP/3 connection fails, fallback to HTTP/2 and don't try
## HTTP/3 again for that server. By default, HTTP/3 is only used for
## servers that advertise support via the Alt-Svc header.
##
## WARNING: This setting is disabled by default because it will make
## connections significantly slower for servers that don't support HTTP/3.
## This is primarily a workaround for server operators who haven't
## configured their servers to send proper Alt-Svc headers. The better
## solution is to reach out to these operators and encourage them to
## fix their servers to correctly advertise HTTP/3 support.

http3_probe = false

## How long a DNS query will wait for a response, in milliseconds.
## If you have a network with *a lot* of latency, you may need to
## increase this. Startup may be slower if you do so.
## Don't increase it too much. 10000 is the highest reasonable value.
## A timeout below 5000 is not recommended.

timeout = 5000


## Keepalive for HTTP (HTTPS, HTTP/2, HTTP/3) queries, in seconds

keepalive = 30

## Use the system logger (syslog on Unix, Event Log on Windows)

# use_syslog = true


## Automatic log files rotation

# Maximum log files size in MB - Set to 0 for unlimited.
log_files_max_size = 10

# How long to keep backup files, in days
log_files_max_age = 7

# Maximum log files backups to keep (or 0 to keep all backups)
log_files_max_backups = 1


###############################################################################
#                           Certificate Management                             #
###############################################################################

## The maximum concurrency to reload certificates from the resolvers.
## Default is 10.

# cert_refresh_concurrency = 10


## Delay, in minutes, after which certificates are reloaded

cert_refresh_delay = 240


## Initially don't check DNSCrypt server certificates for expiration, and
## only start checking them after a first successful connection to a resolver.
## This can be useful on routers with no battery-backed clock.

# cert_ignore_timestamp = false


## DNSCrypt: Create a new, unique key for every single DNS query
## This may improve privacy but can also have a significant impact on CPU usage
## Only enable if you don't have a lot of network load

# dnscrypt_ephemeral_keys = false


## DoH: Disable TLS session tickets - increases privacy but also latency

# tls_disable_session_tickets = false


## DoH: Use TLS 1.2 and specific cipher suite instead of the server preference
## 49199 = TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
## 49195 = TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
## 52392 = TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305
## 52393 = TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305
##
## On non-Intel CPUs such as MIPS routers and ARM systems (Android, Raspberry Pi...),
## uncommenting the following line may improve performance.
## This may also help on Intel CPUs running 32-bit operating systems.
## However, this can cause issues fetching sources or connecting to some HTTP servers,
## and should not be set on regular CPUs.
##
## Keep tls_cipher_suite undefined to let the app automatically choose secure parameters.

tls_cipher_suite = [52393, 49199]


## Log TLS key material to a file, for debugging purposes only.
## This file will contain the TLS master key, which can be used to decrypt
## all TLS traffic to/from DoH servers.
## Never ever enable except for debugging purposes with a tool such as mitmproxy.

# tls_key_log_file = '/tmp/keylog.txt'


###############################################################################
#                            Startup & Network                                 #
###############################################################################

## Bootstrap resolvers
##
## These are normal, non-encrypted DNS resolvers, that will be only used
## for one-shot queries when retrieving the initial resolvers list and if
## the system DNS configuration doesn't work.
##
## No user queries will ever be leaked through these resolvers, and they will
## not be used after IP addresses of DoH resolvers have been found (if you are
## using DoH).
##
## They will never be used if lists have already been cached, and if the stamps
## of the configured servers already include IP addresses (which is the case for
## most of DoH servers, and for all DNSCrypt servers and relays).
##
## They will not be used if the configured system DNS works, or after the
## proxy already has at least one usable secure resolver.
##
## Resolvers supporting DNSSEC are recommended, and, if you are using
## DoH, bootstrap resolvers should ideally be operated by a different entity
## than the DoH servers you will be using, especially if you have IPv6 enabled.
##
## People in China may want to use 114.114.114.114:53 here.
## Other popular options include 8.8.8.8, 9.9.9.9 and 1.1.1.1.
##
## If more than one resolver is specified, they will be tried in sequence.
##
## TL;DR: put valid standard resolver addresses here. Your actual queries will
## not be sent there. If you're using DNSCrypt or Anonymized DNS and your
## lists are up to date, these resolvers will not even be used.

bootstrap_resolvers = ['9.9.9.9:53', '8.8.8.8:53']


## When internal DNS resolution is required, for example to retrieve
## the resolvers list:
##
## - queries will be sent to dnscrypt-proxy itself, if it is already
##   running with active servers (*)
## - or else, queries will be sent to fallback servers
## - finally, if `ignore_system_dns` is `false`, queries will be sent
##   to the system DNS
##
## (*) this is incompatible with systemd sockets.
## `listen_addresses` must not be empty.

ignore_system_dns = true


## Maximum time (in seconds) to wait for network connectivity before
## initializing the proxy.
## Useful if the proxy is automatically started at boot, and network
## connectivity is not guaranteed to be immediately available.
## Use 0 to not test for connectivity at all (not recommended),
## and -1 to wait as much as possible.

netprobe_timeout = 60

## Address and port to try initializing a connection to, just to check
## if the network is up. It can be any address and any port, even if
## there is nothing answering these on the other side. Just don't use
## a local address, as the goal is to check for Internet connectivity.
## On Windows, a datagram with a single, nul byte will be sent, only
## when the system starts.
## On other operating systems, the connection will be initialized
## but nothing will be sent at all.

netprobe_address = '9.9.9.9:53'


## Offline mode - Do not use any remote encrypted servers.
## The proxy will remain fully functional to respond to queries that
## plugins can handle directly (forwarding, cloaking, ...)

# offline_mode = false


## Additional data to attach to outgoing queries.
## These strings will be added as TXT records to queries.
## Do not use, except on servers explicitly asking for extra data
## to be present.
## encrypted-dns-server can be configured to use this for access control
## in the [access_control] section

# query_meta = ['key1:value1', 'key2:value2', 'token:MySecretToken']


###############################################################################
#                                 Filters                                      #
###############################################################################

## Note: if you are using dnsmasq, disable the `dnssec` option in dnsmasq if you
## configure dnscrypt-proxy to do any kind of filtering (including the filters
## below and blocklists).
## You can still choose resolvers that do DNSSEC validation.


## Immediately respond to IPv6-related queries with an empty response
## This makes things faster when there is no IPv6 connectivity, but can
## also cause reliability issues with some stub resolvers.

block_ipv6 = false


## Immediately respond to A and AAAA queries for host names without a domain name
## This also prevents "dotless domain names" from being resolved upstream.

block_unqualified = true


## Immediately respond to queries for local zones instead of leaking them to
## upstream resolvers (always causing errors or timeouts).

block_undelegated = true


## TTL for synthetic responses sent when a request has been blocked (due to
## IPv6 or blocklists).

reject_ttl = 10


###############################################################################
#                              Forwarding                                      #
###############################################################################

## Route queries for specific domains to a dedicated set of servers

## See the `example-forwarding-rules.txt` file for an example

# forwarding_rules = 'forwarding-rules.txt'


###############################################################################
#                              Cloaking                                        #
###############################################################################

## Cloaking returns a predefined address for a specific name.
## In addition to acting as a HOSTS file, it can also return the IP address
## of a different name. It will also do CNAME flattening.
## If 'cloak_ptr' is set, then PTR (reverse lookups) are enabled
## for cloaking rules that do not contain wild cards.
##
## See the `example-cloaking-rules.txt` file for an example

# cloaking_rules = 'cloaking-rules.txt'

## TTL used when serving entries in cloaking-rules.txt

# cloak_ttl = 600
# cloak_ptr = false


###############################################################################
#                                DNS Cache                                     #
###############################################################################

## Enable a DNS cache to reduce latency and outgoing traffic

cache = true


## Cache size

cache_size = 4096


## Minimum TTL for cached entries

cache_min_ttl = 2400


## Maximum TTL for cached entries

cache_max_ttl = 86400


## Minimum TTL for negatively cached entries

cache_neg_min_ttl = 60


## Maximum TTL for negatively cached entries

cache_neg_max_ttl = 600


###############################################################################
#                           Captive portal handling                            #
###############################################################################

[captive_portals]

## A file that contains a set of names used by operating systems to
## check for connectivity and captive portals, along with hard-coded
## IP addresses to return.

# map_file = 'example-captive-portals.txt'


###############################################################################
#                            Local DoH server                                  #
###############################################################################

[local_doh]

## dnscrypt-proxy can act as a local DoH server. By doing so, web browsers
## requiring a direct connection to a DoH server in order to enable some
## features will enable these, without bypassing your DNS proxy.

## Addresses that the local DoH server should listen to

# listen_addresses = ['127.0.0.1:3000']


## Path of the DoH URL. This is not a file, but the part after the hostname
## in the URL. By convention, `/dns-query` is frequently chosen.
## For each `listen_address` the complete URL to access the server will be:
## `https://<listen_address><path>` (ex: `https://127.0.0.1/dns-query`)

# path = '/dns-query'


## Certificate file and key - Note that the certificate has to be trusted.
## Can be generated using the following command:
## openssl req -x509 -nodes -newkey rsa:2048 -days 5000 -sha256 -keyout localhost.pem -out localhost.pem
## See the documentation (wiki) for more information.

# cert_file = 'localhost.pem'
# cert_key_file = 'localhost.pem'


###############################################################################
#                              Query logging                                   #
###############################################################################

[query_log]

## Path to the query log file (absolute, or relative to the same directory as the config file)
## Can be set to /dev/stdout in order to log to the standard output.

# file = 'query.log'


## Query log format (currently supported: tsv and ltsv)

format = 'tsv'


## Do not log these query types, to reduce verbosity. Keep empty to log everything.

# ignored_qtypes = ['DNSKEY', 'NS']


###############################################################################
#                        Suspicious queries logging                            #
###############################################################################

[nx_log]

## Log queries for nonexistent zones
## These queries can reveal the presence of malware, broken/obsolete applications,
## and devices signaling their presence to 3rd parties.

## Path to the query log file (absolute, or relative to the same directory as the config file)

# file = 'nx.log'


## Query log format (currently supported: tsv and ltsv)

format = 'tsv'


###############################################################################
#                    Pattern-based blocking (blocklists)                       #
###############################################################################

## Blocklists are made of one pattern per line. Example of valid patterns:
##
##   example.com
##   =example.com
##   *sex*
##   ads.*
##   ads*.example.*
##   ads*.example[0-9]*.com
##
## Example blocklist files can be found at https://download.dnscrypt.info/blocklists/
## A script to build blocklists from public feeds can be found in the
## `utils/generate-domains-blocklists` directory of the dnscrypt-proxy source code.

[blocked_names]

## Path to the file of blocking rules (absolute, or relative to the same directory as the config file)

# blocked_names_file = 'blocked-names.txt'


## Optional path to a file logging blocked queries

# log_file = 'blocked-names.log'


## Optional log format: tsv or ltsv (default: tsv)

# log_format = 'tsv'


###############################################################################
#                  Pattern-based IP blocking (IP blocklists)                   #
###############################################################################

## IP blocklists are made of one pattern per line. Example of valid patterns:
##
##   127.*
##   fe80:abcd:*
##   192.168.1.4

[blocked_ips]

## Path to the file of blocking rules (absolute, or relative to the same directory as the config file)

# blocked_ips_file = 'blocked-ips.txt'


## Optional path to a file logging blocked queries

# log_file = 'blocked-ips.log'


## Optional log format: tsv or ltsv (default: tsv)

# log_format = 'tsv'


###############################################################################
#                 Pattern-based allow lists (blocklists bypass)                #
###############################################################################

## Allowlists support the same patterns as blocklists
## If a name matches an allowlist entry, the corresponding session
## will bypass names and IP filters.
##
## Time-based rules are also supported to make some websites only accessible at specific times of the day.

[allowed_names]

## Path to the file of allow list rules (absolute, or relative to the same directory as the config file)

# allowed_names_file = 'allowed-names.txt'


## Optional path to a file logging allowed queries

# log_file = 'allowed-names.log'


## Optional log format: tsv or ltsv (default: tsv)

# log_format = 'tsv'


###############################################################################
#           Pattern-based allowed IPs lists (blocklists bypass)                #
###############################################################################

## Allowed IP lists support the same patterns as IP blocklists
## If an IP response matches an allowed entry, the corresponding session
## will bypass IP filters.
##
## Time-based rules are also supported to make some websites only accessible at specific times of the day.

[allowed_ips]

## Path to the file of allowed ip rules (absolute, or relative to the same directory as the config file)

# allowed_ips_file = 'allowed-ips.txt'


## Optional path to a file logging allowed queries

# log_file = 'allowed-ips.log'

## Optional log format: tsv or ltsv (default: tsv)

# log_format = 'tsv'


###############################################################################
#                        Time access restrictions                              #
###############################################################################

## One or more weekly schedules can be defined here.
## Patterns in the name-based blocked_names file can optionally be followed with @schedule_name
## to apply the pattern 'schedule_name' only when it matches a time range of that schedule.
##
## For example, the following rule in a blocklist file:
## *.youtube.* @time-to-sleep
## would block access to YouTube during the times defined by the 'time-to-sleep' schedule.
##
## {after='21:00', before= '7:00'} matches 0:00-7:00 and 21:00-0:00
## {after= '9:00', before='18:00'} matches 9:00-18:00

[schedules]

# [schedules.time-to-sleep]
#   mon = [{after='21:00', before='7:00'}]
#   tue = [{after='21:00', before='7:00'}]
#   wed = [{after='21:00', before='7:00'}]
#   thu = [{after='21:00', before='7:00'}]
#   fri = [{after='23:00', before='7:00'}]
#   sat = [{after='23:00', before='7:00'}]
#   sun = [{after='21:00', before='7:00'}]

# [schedules.work]
#   mon = [{after='9:00', before='18:00'}]
#   tue = [{after='9:00', before='18:00'}]
#   wed = [{after='9:00', before='18:00'}]
#   thu = [{after='9:00', before='18:00'}]
#   fri = [{after='9:00', before='17:00'}]


###############################################################################
#                                Servers                                       #
###############################################################################

## Remote lists of available servers
## Multiple sources can be used simultaneously, but every source
## requires a dedicated cache file.
##
## Refer to the documentation for URLs of public sources.
##
## A prefix can be prepended to server names in order to
## avoid collisions if different sources share the same for
## different servers. In that case, names listed in `server_names`
## must include the prefixes.
##
## If the `urls` property is missing, cache files and valid signatures
## must already be present. This doesn't prevent these cache files from
## expiring after `refresh_delay` hours.
## `refreshed_delay` must be in the [24..168] interval.
## The minimum delay of 24 hours (1 day) avoids unnecessary requests to servers.
## The maximum delay of 168 hours (1 week) ensures cache freshness.

[sources]

### An example of a remote source from https://github.com/DNSCrypt/dnscrypt-resolvers

[sources.public-resolvers]
urls = [
  'https://raw.githubusercontent.com/DNSCrypt/dnscrypt-resolvers/master/v3/public-resolvers.md',
  'https://download.dnscrypt.info/resolvers-list/v3/public-resolvers.md',
]
cache_file = 'public-resolvers.md'
minisign_key = 'RWQf6LRCGA9i53mlYecO4IzT51TGPpvWucNSCh1CBM0QTaLn73Y7GFO3'
refresh_delay = 73
prefix = ''

### Anonymized DNS relays

[sources.relays]
urls = [
  'https://raw.githubusercontent.com/DNSCrypt/dnscrypt-resolvers/master/v3/relays.md',
  'https://download.dnscrypt.info/resolvers-list/v3/relays.md',
]
cache_file = 'relays.md'
minisign_key = 'RWQf6LRCGA9i53mlYecO4IzT51TGPpvWucNSCh1CBM0QTaLn73Y7GFO3'
refresh_delay = 73
prefix = ''

### ODoH (Oblivious DoH) servers and relays

 [sources.odoh-servers]
   urls = ['https://raw.githubusercontent.com/DNSCrypt/dnscrypt-resolvers/master/v3/odoh-servers.md', 'https://download.dnscrypt.info/resolvers-list/v3/odoh-servers.md']
   cache_file = 'odoh-servers.md'
   minisign_key = 'RWQf6LRCGA9i53mlYecO4IzT51TGPpvWucNSCh1CBM0QTaLn73Y7GFO3'
   refresh_delay = 73
   prefix = ''
 [sources.odoh-relays]
   urls = ['https://raw.githubusercontent.com/DNSCrypt/dnscrypt-resolvers/master/v3/odoh-relays.md', 'https://download.dnscrypt.info/resolvers-list/v3/odoh-relays.md']
   cache_file = 'odoh-relays.md'
   minisign_key = 'RWQf6LRCGA9i53mlYecO4IzT51TGPpvWucNSCh1CBM0QTaLn73Y7GFO3'
   refresh_delay = 73
   prefix = ''

### Quad9

# [sources.quad9-resolvers]
#   urls = ['https://quad9.net/dnscrypt/quad9-resolvers.md', 'https://raw.githubusercontent.com/Quad9DNS/dnscrypt-settings/main/dnscrypt/quad9-resolvers.md']
#   minisign_key = 'RWQBphd2+f6eiAqBsvDZEBXBGHQBJfeG6G+wJPPKxCZMoEQYpmoysKUN'
#   cache_file = 'quad9-resolvers.md'
#   prefix = 'quad9-'

### Another example source, with resolvers censoring some websites not appropriate for children
### This is a subset of the `public-resolvers` list, so enabling both is useless.

# [sources.parental-control]
#   urls = ['https://raw.githubusercontent.com/DNSCrypt/dnscrypt-resolvers/master/v3/parental-control.md', 'https://download.dnscrypt.info/resolvers-list/v3/parental-control.md']
#   cache_file = 'parental-control.md'
#   minisign_key = 'RWQf6LRCGA9i53mlYecO4IzT51TGPpvWucNSCh1CBM0QTaLn73Y7GFO3'

### dnscry.pt servers - See https://www.dnscry.pt

#  [sources.dnscry-pt-resolvers]
#    urls = ["https://www.dnscry.pt/resolvers.md"]
#    minisign_key = "RWQM31Nwkqh01x88SvrBL8djp1NH56Rb4mKLHz16K7qsXgEomnDv6ziQ"
#    cache_file = "dnscry.pt-resolvers.md"
#    refresh_delay = 73
#    prefix = "dnscry.pt-"


###############################################################################
#                        Servers with known bugs                               #
###############################################################################

[broken_implementations]

## Cisco servers currently cannot handle queries larger than 1472 bytes, and don't
## truncate responses larger than questions as expected by the DNSCrypt protocol.
## This prevents large responses from being received over UDP and over relays.
##
## Older versions of the `dnsdist` server software had a bug with queries larger
## than 1500 bytes. This is fixed since `dnsdist` version 1.5.0, but
## some server may still run an outdated version.
##
## The list below enables workarounds to make non-relayed usage more reliable
## until the servers are fixed.

fragments_blocked = [
  'cisco',
  'cisco-ipv6',
  'cisco-familyshield',
  'cisco-familyshield-ipv6',
  'cisco-sandbox',
  'cleanbrowsing-adult',
  'cleanbrowsing-adult-ipv6',
  'cleanbrowsing-family',
  'cleanbrowsing-family-ipv6',
  'cleanbrowsing-security',
  'cleanbrowsing-security-ipv6',
]


###############################################################################
#                Certificate-based client authentication for DoH               #
###############################################################################

[doh_client_x509_auth]

## Use an X509 certificate to authenticate yourself when connecting to DoH servers.
## This is only useful if you are operating your own, private DoH server(s).
## 'creds' maps servers to certificates, and supports multiple entries.
## If you are not using the standard root CA, an optional "root_ca"
## property set to the path to a root CRT file can be added to a server entry.

# creds = [
#    { server_name='*', client_cert='client.crt', client_key='client.key' }
# ]


###############################################################################
#                          Anonymized DNS                                      #
###############################################################################

[anonymized_dns]

## Routes are indirect ways to reach DNSCrypt servers.
##
## A route maps a server name ("server_name") to one or more relays that will be
## used to connect to that server.
##
## A relay can be specified as a DNS Stamp (either a relay stamp, or a
## DNSCrypt stamp) or a server name.
##
## The following example routes "example-server-1" via `anon-example-1` or `anon-example-2`,
## and "example-server-2" via the relay whose relay DNS stamp is
## "sdns://gRIxMzcuNzQuMjIzLjIzNDo0NDM".
##
## !!! THESE ARE JUST EXAMPLES !!!
##
## Review the list of available relays from the "relays.md" file, and, for each
## server you want to use, define the relays you want connections to go through.
##
## Carefully choose relays and servers so that they are run by different entities.
##
## "server_name" can also be set to "*" to define a default route, for all servers:
## { server_name='*', via=['anon-example-1', 'anon-example-2'] }
##
## If a route is ["*"], the proxy automatically picks a relay on a distinct network.
## { server_name='*', via=['*'] } is also an option, but is likely to be suboptimal.
##
## Manual selection is always recommended over automatic selection, so that you can
## select (relay,server) pairs that work well and fit your own criteria (close by or
## in different countries, operated by different entities, on distinct ISPs...)

# routes = [
#    { server_name='example-server-1', via=['anon-example-1', 'anon-example-2'] },
#    { server_name='example-server-2', via=['sdns://gRIxMzcuNzQuMjIzLjIzNDo0NDM'] }
# ]


## Skip resolvers incompatible with anonymization instead of using them directly

skip_incompatible = false


## If public server certificates for a non-conformant server cannot be
## retrieved via a relay, try getting them directly. Actual queries
## will then always go through relays.

# direct_cert_fallback = false


###############################################################################
#                                 DNS64                                        #
###############################################################################

[dns64]

## DNS64 is a mechanism for synthesizing AAAA records from A records.
## It is used with an IPv6/IPv4 translator to enable client-server
## communication between an IPv6-only client and an IPv4-only server,
## without requiring any changes to either the IPv6 or the IPv4 node,
## for the class of applications that work through NATs.
##
## There are two options to synthesize such records:
## Option 1: Using a set of static IPv6 prefixes;
## Option 2: By discovering the IPv6 prefix from DNS64-enabled resolver.
##
## If both options are configured - only static prefixes are used.
## (Ref. RFC6147, RFC6052, RFC7050)
##
## Do not enable unless you know what DNS64 is and why you need it, or else
## you won't be able to connect to anything at all.

## Static prefix(es) as Pref64::/n CIDRs

# prefix = ['64:ff9b::/96']

## DNS64-enabled resolver(s) to discover Pref64::/n CIDRs
## These resolvers are used to query for Well-Known IPv4-only Name (WKN) "ipv4only.arpa." to discover only.
## Set with your ISP's resolvers in case of custom prefixes (other than Well-Known Prefix 64:ff9b::/96).
## IMPORTANT: Default resolvers listed below support Well-Known Prefix 64:ff9b::/96 only.

# resolver = ['[2606:4700:4700::64]:53', '[2001:4860:4860::64]:53']


###############################################################################
#                           IP Encryption                                      #
###############################################################################

[ip_encryption]

## Encrypt client IP addresses in plugin logs using IPCrypt
## This provides privacy for client IP addresses while maintaining
## the ability to distinguish between different clients in logs

## Encryption algorithm (default: "none")
## - "none": No encryption (default)
## - "ipcrypt-deterministic": Deterministic encryption (same IP always encrypts to same value) - requires 16-byte key
## - "ipcrypt-nd": Non-deterministic encryption with 8-byte tweak - requires 16-byte key
## - "ipcrypt-ndx": Non-deterministic encryption with 16-byte tweak (extended) - requires 32-byte key

algorithm = "none"

## Encryption key in hexadecimal format (required if algorithm is not "none")
## Key size depends on algorithm:
## - ipcrypt-deterministic: 32 hex chars (16 bytes) - Generate with: openssl rand -hex 16
## - ipcrypt-nd: 32 hex chars (16 bytes) - Generate with: openssl rand -hex 16
## - ipcrypt-ndx: 64 hex chars (32 bytes) - Generate with: openssl rand -hex 32
## Example for deterministic/nd: key = "1234567890abcdef1234567890abcdef"
## Example for ndx: key = "1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef"
## IMPORTANT: Keep this key secret

key = ""


###############################################################################
#                            Monitoring UI                                     #
###############################################################################

[monitoring_ui]

## Enable the monitoring UI
enabled = false

## Listen address for the monitoring UI
listen_address = "127.0.0.1:8080"

## Optional username and password for basic authentication
## To disable authentication, set username to an empty string: username = ""
## If both username and password are empty, no authentication is required
username = "admin"
password = "changeme"

## Optional TLS certificate and key for HTTPS
## If both are empty, HTTP will be used
tls_certificate = ""
tls_key = ""

## Enable query logging in the monitoring UI
## This will show recent queries in the UI
enable_query_log = true

## Privacy level for the monitoring UI
## 0: show all details including client IPs
## 1: anonymize client IPs (default)
## 2: aggregate data only (no individual queries or domains shown)
privacy_level = 1

## Maximum number of recent query log entries to keep in memory
## Helps control memory usage on high-traffic servers
## Default: 100
# max_query_log_entries = 100

## Maximum memory usage in MB for recent query logs
## Automatic cleanup when limit is exceeded
## Default: 1
# max_memory_mb = 1

## Enable Prometheus metrics endpoint
## Default: false
# prometheus_enabled = false

## Path for Prometheus metrics endpoint
## Default: /metrics
# prometheus_path = "/metrics"


###############################################################################
#                            Static entries                                    #
###############################################################################

[static]

## Optional, local, static list of additional servers
## Mostly useful for testing your own servers.

# [static.myserver]
#   stamp = 'sdns://AQcAAAAAAAAAAAAQMi5kbnNjcnlwdC1jZXJ0Lg'

Вопрос знающим: С чем связано падение сервиса dnscrypt 2.1.12 при подключении опции использования ODoH? Раньше такого не наблюдалось.

Настройка OpenVPN для аутентификации

apt install openvpn

Свежий билд EasyRSA качаем тут

Переименовываем vars.example в vars

Изменяем параметр set_var EASYRSA_KEY_SIZE на 4096

Даём права EasyRSA на исполнение:

chmod +x easyrsa

./easy-rsa init-pki
./easy-rsa build-ca
./easy-rsa gen-req server nopass
./easy-rsa sign-req server server
./easy-rsa gen-dh
openvpn --genkey secret /etc/openvpn/server/pki/ta.key

## /etc/openvpn/server серверная часть

port 1192
proto tcp

# Виртуальный сетевой интерфейс TUN (уровень IP)
dev tun

# Сертификат центра сертификации (CA)
ca /etc/openvpn/server/pki/ca.crt

# Сертификат сервера
cert /etc/openvpn/server/pki/issued/server.crt

# Закрытый ключ сервера
key /etc/openvpn/server/pki/private/server.key

# Параметры Диффи-Хеллмана для ключевого обмена
dh /etc/openvpn/server/pki/dh.pem

# Подсеть VPN и маска подсети (выдача IP клиентам)
server 10.8.0.0 255.255.255.0

# Использовать топологию подсети (одинаковый пул IP для всех клиентов)
topology subnet

# Перенаправлять весь трафик клиента через VPN (default route через VPN-сервер)
push "redirect-gateway def1"

# Настроить DNS клиента
push "dhcp-option DNS 192.168.2.1"

# Минимальная версия TLS для обеспечения безопасности
tls-version-min 1.2

# TLS-crypt ключ для защиты
tls-crypt /etc/openvpn/server/pki/ta.key

# Специфический набор TLS-шифров для безопасности
tls-cipher TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384

# Качественные современные шифры для данных
data-ciphers AES-256-GCM:CHACHA20-POLY1305

# Алгоритм хэширования (аутентификация сообщений)
auth SHA256

# Сохранять ключи между перезапусками туннеля
persist-key

# Сохранять туннельное устройство между рестартами
persist-tun

# Использовать имя пользователя как common name клиента
username-as-common-name

# Не проверять сертификаты клиента (аутентификация через username/password)
verify-client-cert none

# Скрипт для проверки логина и пароля пользователя
auth-user-pass-verify "/usr/bin/php /etc/openvpn/server/verify.php" via-file

# Позволяет выполнять скрипты с максимальным уровнем безопасности
script-security 3

# Без логов
verb

Даём права на исполнение скрипту

chmod +x verify.php

// тут должно быть про MariaDB и SQL

Установка и настройка СУБД MariaDB

apt install apt-transport-https curl
mkdir -p /etc/apt/keyrings

curl -o /etc/apt/keyrings/mariadb-keyring.pgp 'https://mariadb.org/mariadb_release_signing_key.pgp'
echo "deb [signed-by=/etc/apt/keyrings/mariadb-keyring.pgp] https://mirror.mariadb.org/repo/11.8/debian bookworm main" > /etc/apt/sources.list.d/mariadb118.list

apt install mariadb-server mariadb-client

Базовая настройка безопасности. При настройке не забудьте отключить unix auth иначе скрипт не сможет присоединиться.

mysql_secure_installation

Подготовка таблицы

-- Хост: localhost
-- Время создания: Июл 26 2025 г., 08:25
-- Версия сервера: 11.8.2-MariaDB-deb12
-- Версия PHP: 8.2.28

SET SQL_MODE = "NO_AUTO_VALUE_ON_ZERO";
START TRANSACTION;
SET time_zone = "+00:00";


/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8mb4 */;

--
-- База данных: `openvpn`
--

-- --------------------------------------------------------

--
-- Структура таблицы `users`
--

CREATE TABLE `users` (
  `id` bigint(255) NOT NULL,
  `username` varchar(120) NOT NULL,
  `password_hash` varchar(255) NOT NULL,
  `start_date` date NOT NULL,
  `next_date` date NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

--
-- Индексы сохранённых таблиц
--

--
-- Индексы таблицы `users`
--
ALTER TABLE `users`
  ADD PRIMARY KEY (`id`),
  ADD UNIQUE KEY `username` (`username`);

--
-- AUTO_INCREMENT для сохранённых таблиц
--

--
-- AUTO_INCREMENT для таблицы `users`
--
ALTER TABLE `users`
  MODIFY `id` bigint(255) NOT NULL AUTO_INCREMENT;
COMMIT;

/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;

#!/usr/bin/php
<?php
declare(strict_types=1);

class Database {
    private $pdo;

    /**
     * Конструктор класса Database.
     * 
     * @param array $config Массив конфигурации подключения к БД.
     * @throws PDOException Если подключение к БД не удалось.
     */
    public function __construct(array $config) {
        if (!isset($config['host'], $config['dbname'], $config['user'], $config['password'])) {
            throw new InvalidArgumentException("Недостаточно данных для подключения к БД");
        }

        try {
            $options = [
                PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf8mb4',
                PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
                PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
                PDO::ATTR_EMULATE_PREPARES => false,
            ];
            $this->pdo = new PDO(
                "mysql:host={$config['host']};dbname={$config['dbname']};charset=utf8mb4",
                $config['user'],
                $config['password'],
                $options
            );
        } catch (PDOException $e) {
            throw new PDOException("Database connection failed: " . $e->getMessage());
        }
    }

    /**
     * Подготавливает и выполняет SQL-запрос.
     * 
     * @param string $sql SQL-запрос.
     * @param array $params Параметры запроса.
     * @return PDOStatement Подготовленный и выполненный запрос.
     */
    public function query(string $sql, array $params = []): PDOStatement {
        $stmt = $this->pdo->prepare($sql);
        $stmt->execute($params);
        return $stmt;
    }

    /**
     * Выполняет SQL-запрос и возвращает все результаты.
     * 
     * @param string $sql SQL-запрос.
     * @param array $params Параметры запроса.
     * @return array Массив результатов.
     */
    public function getAll(string $sql, array $params = []): array {
        $stmt = $this->query($sql, $params);
        return $stmt->fetchAll(PDO::FETCH_ASSOC);
    }
}

// Рекомендуется хранить конфиг подключения в отдельном файле с ограниченным доступом
$dbConfig = [
    'host'     => 'localhost',
    'dbname'   => 'openvpn_auth',
    'user'     => 'openvpn_user',
    'password' => 'strongpassword',
];

// Проверка, что передан ровно один аргумент (путь к файлу с учётными данными)
if ($argc !== 2) {
    error_log("OpenVPN auth error: expected exactly 1 argument, got " . ($argc - 1));
    exit(1);
}

$credentialsFile = $argv[1];

// Проверка существования и читаемости файла с учетными данными
if (!is_file($credentialsFile) || !is_readable($credentialsFile)) {
    error_log("OpenVPN auth error: credentials file '$credentialsFile' not found or unreadable");
    exit(1);
}

// Чтение строк: первая — username, вторая — пароль
$lines = file($credentialsFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
if (count($lines) < 2) {
    error_log("OpenVPN auth error: invalid credentials file format");
    exit(1);
}

$username = trim($lines[0]);
$password = trim($lines[1]);

try {
    $db = new Database($dbConfig);

    // Получаем хеш пароля по username
    $stmt = $db->query('SELECT password_hash FROM users WHERE username = :username LIMIT 1', ['username' => $username]);
    $user = $stmt->fetch();

    if (!$user || !password_verify($password, $user['password_hash'])) {
        error_log("OpenVPN auth failed for user '{$username}'");
        exit(1);
    }

    // Успешная аутентификация
    exit(0);

} catch (Throwable $e) {
    error_log("OpenVPN auth error: " . $e->getMessage());
    exit(1);
}

# openvpn клиентская часть

client
dev tun
proto tcp
remote 192.168.2.1 1192

resolv-retry infinite
nobind

# Встроенный сертификат CA
<ca>
-----BEGIN CERTIFICATE-----
(текст вашего ca.crt)
-----END CERTIFICATE-----
</ca>

remote-cert-tls server

persist-key
persist-tun

auth-user-pass

tls-version-min 1.2

# Встроенный TLS-crypt ключ
<tls-crypt>
-----BEGIN OpenVPN Static key V1-----
(текст вашего ta.key)
-----END OpenVPN Static key V1-----
</tls-crypt>

tls-cipher TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384
data-ciphers AES-256-GCM:CHACHA20-POLY1305
auth SHA256

verb 0

Обход шизоидной блокировки РосКомПозора

Свежие билды ByeDPI для linux тут

Создаём файл byedpi.service по пути /etc/systemd/system/

[Unit]
Description=byedpi daemon service
After=network.target

[Service]
# Type=simple для приложений исполняющихся в основном (родительском) процессе.

# Если исполняется в дочернем процессе
Type=forking
ExecStart=/usr/local/bin/ciadpi -D --transparent --tfo -s1 -q1 -Y -Ar -s5 -o1+s -At -f-1 -r1+s -As --tlsrec 3+s -b+300 --fake-sni "www.vk.com" --ttl 65

Restart=on-failure
RestartSec=5s

# При необходимости использовать неполные права (запуск не от root):
# User=someuser
# Group=somegroup

# Автоматический рестарт при сбоях
Restart=on-failure
RestartSec=5s

# Логирование в журнал systemd
StandardOutput=journal
StandardError=journal

[Install]
WantedBy=multi-user.target

Перечитываем список сервисов и запускаем

systemctl daemon-reload
systemctl enable byedpi
systemctl start byedpi
systemctl status byedpi

Вопрос знающим: Как указать список сайтов к чему применять обход? Если глобально, то некоторые сервисы с IPS/IDS начинают откидывать "аномальные" пакеты.

Настройка правил nftables

#!/usr/sbin/nft -f

flush ruleset

define VPN = "tun0"
define WAN = "enp1s0"
define LAN = "enp3s0"

table inet filter {
    chain input {
        type filter hook input priority filter; policy drop;

        # Разрешаем весь трафик с loopback интерфейса
        iifname "lo" accept;

        # Разрешаем установленные и связанные соединения
        ct state {established, related} accept;

        # ICMP echo-request (ping) с LAN с rate limit
        iifname $LAN icmp type echo-request limit rate 5/second burst 10 packets accept;

        # # OpenVPN TCP 1194
        iifname $LAN tcp dport 1194 accept;

        # # SSH TCP 2222 с WAN с rate limiting и только новые соединения
        iifname $WAN tcp dport 2222 ct state new limit rate 20/second burst 30 packets accept;

        # # HTTP и HTTPS TCP (80, 443)
        tcp dport {80, 443} ct state new limit rate 30/second burst 40 packets accept;

        # # UDP 443 (QUIC)
        udp dport 443 ct state new limit rate 40/second burst 50 packets accept;

        # # DNS UDP 53 на LAN и VPN с ограничением
        iifname { $VPN, $LAN } udp dport 53 limit rate 30/second burst 40 packets accept;
		
        # # DNSCrypt-proxy UDP 5353 с lo и LAN
        iifname { "lo", $LAN } udp dport 5353 accept;

        # # ByeDPI - SOCKS5. В режиме transparent не нужен, трафик идёт напрямую.
        # iifname $VPN tcp dport 1080 accept;
    }
	
    chain output {
        type filter hook output priority filter; policy accept;
    }
	
    chain forward {
        type filter hook forward priority filter; policy drop;

        # Разрешаем установленные и связанные соединения
        ct state {established, related} accept;

        # Трафик VPN -> WAN (интернет)
        iifname $VPN oifname $WAN accept;

        # Трафик WAN -> VPN
        iifname $WAN oifname $VPN accept;
    }


}

table ip nat {
    chain prerouting {
        type nat hook prerouting priority -100; policy accept;
        # captive portal - перенаправление неавторизованных пользователей, на домашний сайт
        ip saddr 192.168.2.0/24 tcp dport 80 redirect to 80;
    }

    chain postrouting {
        type nat hook postrouting priority 100; policy accept;
        # Доступ в интернет авторизированным
        iifname $VPN oifname $WAN masquerade;
    }
}

Если требуется смотрим какие порты используют приложения

ss -tulnp или ss -tulnp | grep :PORT если требуется конкретный порт

Хабы:

Linux