awg-dash/tests/netns/topology.sh

#!/usr/bin/env bash
# topology.sh — netns-топология тестового стенда awg-dash (задача #21).
#
#   topology.sh up              создать netns, veth-пары, адреса, маршруты, правила меток
#   topology.sh down            удалить netns и veth-пары (идемпотентно)
#   topology.sh status          показать состояние топологии (exit 0 — стенд поднят)
#   topology.sh killswitch on   включить fail-closed правило в шлюзе
#   topology.sh killswitch off  выключить fail-closed правило в шлюзе
#   topology.sh fw-kind         напечатать backend netfilter (nft|iptables)
#
# Требует root и CAP_NET_ADMIN (в контейнере — --privileged либо NET_ADMIN+SYS_ADMIN).
set -euo pipefail

HERE="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
# shellcheck source=tests/netns/lib.sh
source "$HERE/lib.sh"

topology_present() {
  ns_exists "$AWG_NS_CLIENT" && ns_exists "$AWG_NS_GW" && ns_exists "$AWG_NS_UPLINK"
}

topology_down() {
  local quiet="${1:-}"
  [ "$quiet" = quiet ] || log "удаляю топологию"
  # netns удаляем первыми: вместе с ними уходят veth-концы и процессы внутри.
  for ns in "$AWG_NS_CLIENT" "$AWG_NS_GW" "$AWG_NS_UPLINK"; do
    if ns_exists "$ns"; then ip netns del "$ns" 2>/dev/null || true; fi
  done
  # страховка на случай, если veth остался в корневом netns
  for ifc in "$AWG_VETH_CLIENT" "$AWG_VETH_GW_LAN" "$AWG_VETH_GW_WAN" "$AWG_VETH_UPLINK"; do
    if ip link show "$ifc" >/dev/null 2>&1; then ip link del "$ifc" 2>/dev/null || true; fi
  done
  [ "$quiet" = quiet ] || ok "топология удалена"
}

topology_up() {
  require_root
  require_cmd ip
  require_cmd python3
  require_netns_capability

  log "создаю netns: client=$AWG_NS_CLIENT gw=$AWG_NS_GW uplink=$AWG_NS_UPLINK"
  topology_down quiet

  local ns
  for ns in "$AWG_NS_CLIENT" "$AWG_NS_GW" "$AWG_NS_UPLINK"; do
    ip netns add "$ns"
    ip -n "$ns" link set lo up
  done

  # --- client <-> gw (LAN) --------------------------------------------------
  ip link add "$AWG_VETH_CLIENT" type veth peer name "$AWG_VETH_GW_LAN"
  ip link set "$AWG_VETH_CLIENT" netns "$AWG_NS_CLIENT"
  ip link set "$AWG_VETH_GW_LAN" netns "$AWG_NS_GW"
  ip -n "$AWG_NS_CLIENT" addr add "${AWG_CLIENT_IP}/24" dev "$AWG_VETH_CLIENT"
  ip -n "$AWG_NS_CLIENT" link set "$AWG_VETH_CLIENT" up
  ip -n "$AWG_NS_GW" addr add "${AWG_GW_LAN_IP}/24" dev "$AWG_VETH_GW_LAN"
  ip -n "$AWG_NS_GW" link set "$AWG_VETH_GW_LAN" up

  # --- gw <-> uplink (WAN) --------------------------------------------------
  ip link add "$AWG_VETH_GW_WAN" type veth peer name "$AWG_VETH_UPLINK"
  ip link set "$AWG_VETH_GW_WAN" netns "$AWG_NS_GW"
  ip link set "$AWG_VETH_UPLINK" netns "$AWG_NS_UPLINK"
  ip -n "$AWG_NS_GW" addr add "${AWG_GW_WAN_IP}/24" dev "$AWG_VETH_GW_WAN"
  ip -n "$AWG_NS_GW" link set "$AWG_VETH_GW_WAN" up
  ip -n "$AWG_NS_UPLINK" addr add "${AWG_UPLINK_IP}/24" dev "$AWG_VETH_UPLINK"
  ip -n "$AWG_NS_UPLINK" link set "$AWG_VETH_UPLINK" up

  # --- forwarding и rp_filter в шлюзе ---------------------------------------
  ip netns exec "$AWG_NS_GW" sysctl -q -w net.ipv4.ip_forward=1
  # loose rp_filter: маркированная политика даёт асимметрию reverse-пути
  ip netns exec "$AWG_NS_GW" sysctl -q -w net.ipv4.conf.all.rp_filter=2
  ip netns exec "$AWG_NS_GW" sysctl -q -w "net.ipv4.conf.${AWG_VETH_GW_LAN}.rp_filter=2"
  ip netns exec "$AWG_NS_GW" sysctl -q -w "net.ipv4.conf.${AWG_VETH_GW_WAN}.rp_filter=2"

  # --- маршруты -------------------------------------------------------------
  ip -n "$AWG_NS_CLIENT" route add default via "$AWG_GW_LAN_IP" dev "$AWG_VETH_CLIENT"
  ip -n "$AWG_NS_GW" route add default via "$AWG_UPLINK_IP" dev "$AWG_VETH_GW_WAN" metric 100
  ip -n "$AWG_NS_UPLINK" route add "$AWG_NET_CLIENT" via "$AWG_GW_WAN_IP" dev "$AWG_VETH_UPLINK"
  # «публичный» адрес-приманка для детектора утечки (RFC 5737 TEST-NET-2)
  ip -n "$AWG_NS_UPLINK" addr add "${AWG_LEAK_IP}/32" dev lo

  # --- policy routing: fwmark 51820 -> table 51820 -> аплинк ----------------
  ip -n "$AWG_NS_GW" route add default via "$AWG_UPLINK_IP" dev "$AWG_VETH_GW_WAN" table "$AWG_ROUTE_TABLE"
  ip -n "$AWG_NS_GW" rule add fwmark "$AWG_FWMARK" table "$AWG_ROUTE_TABLE"

  # --- netfilter: метки + kill-switch ---------------------------------------
  fw_setup

  ok "стенд поднят: ${AWG_NS_CLIENT}(${AWG_CLIENT_IP}) -> ${AWG_NS_GW}(${AWG_GW_LAN_IP}/${AWG_GW_WAN_IP}) -> ${AWG_NS_UPLINK}(${AWG_UPLINK_IP})"
  ok "policy routing: fwmark ${AWG_FWMARK} -> table ${AWG_ROUTE_TABLE} (default via ${AWG_UPLINK_IP})"
  ok "mock endpoint: udp/${AWG_MOCK_PORT} в ${AWG_NS_UPLINK}; детектор утечки: ${AWG_LEAK_IP}:${AWG_LEAK_PORT}/udp"
}

topology_status() {
  local rc=0
  if ! topology_present; then
    printf 'topology: down\n'
    return 1
  fi
  printf 'topology: up\n'
  local ns
  for ns in "$AWG_NS_CLIENT" "$AWG_NS_GW" "$AWG_NS_UPLINK"; do
    printf '\n[%s] links:\n' "$ns"
    ip -n "$ns" -br addr show || rc=1
  done
  printf '\n[%s] ip rule:\n' "$AWG_NS_GW"
  ip -n "$AWG_NS_GW" rule show
  printf '\n[%s] table %s:\n' "$AWG_NS_GW" "$AWG_ROUTE_TABLE"
  ip -n "$AWG_NS_GW" route show table "$AWG_ROUTE_TABLE"
  printf '\n[%s] netfilter:\n' "$AWG_NS_GW"
  if [ "$(fw_kind)" = nft ]; then
    ip netns exec "$AWG_NS_GW" nft list table inet "$NFT_TABLE" 2>/dev/null || rc=1
  else
    ip netns exec "$AWG_NS_GW" iptables -t mangle -S 2>/dev/null || rc=1
    ip netns exec "$AWG_NS_GW" iptables -t filter -S FORWARD 2>/dev/null || rc=1
  fi
  return $rc
}

case "${1:-status}" in
  up)
    topology_up
    ;;
  down)
    require_root
    topology_down
    ;;
  status)
    topology_status
    ;;
  killswitch)
    require_root
    fw_set_killswitch "${2:?usage: topology.sh killswitch on|off}"
    ok "kill-switch: ${2}"
    ;;
  fw-kind)
    require_root
    fw_kind
    ;;
  *)
    fail "usage: topology.sh {up|down|status|killswitch on|off|fw-kind}"
    ;;
esac