#!/bin/bash
# 把网络调优做成开机自动应用。
#
# 为什么需要：
#   MSS 规则和 sysctl 都是**运行时的**，重启就没了 ——
#   不持久化的话，设备一重启就回到 48% 可用率。
set -u

RELAY_DIR=/root/lanremote-relay

echo "===== 1. 确保调优脚本在位 ====="
if [ ! -x "$RELAY_DIR/net-tune.sh" ]; then
    echo "  找不到 $RELAY_DIR/net-tune.sh"
    exit 1
fi
echo "  $RELAY_DIR/net-tune.sh 就绪"

echo
echo "===== 2. 装 sysctl 配置（内核参数持久化）====="
cat > /etc/sysctl.d/99-lanremote-mtu.conf <<'EOF'
# LanRemote: 修路径 MTU 问题
# 实测接口 MTU 1500 时大包会被丢（1488/1500 全丢），
# 导致 TLS 握手约 30% 失败。打开探测让内核自己收敛。
net.ipv4.tcp_mtu_probing = 1
EOF
sysctl -p /etc/sysctl.d/99-lanremote-mtu.conf 2>/dev/null | sed 's/^/  /'

echo
echo "===== 3. 装开机服务 ====="
cat > /etc/systemd/system/lanremote-nettune.service <<EOF
[Unit]
Description=LanRemote 网络调优（修 MTU：夹 MSS + 路径探测）
# 网络起来之后再跑 —— 要拿到 wlan0
After=network-online.target
Wants=network-online.target
Before=lanremote-relay.service lanremote-tunnel.service

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=$RELAY_DIR/net-tune.sh

[Install]
WantedBy=multi-user.target
EOF

systemctl daemon-reload
systemctl enable lanremote-nettune.service 2>&1 | sed 's/^/  /'
systemctl start lanremote-nettune.service
sleep 1

echo
echo "===== 4. 确认 ====="
echo "  服务: $(systemctl is-active lanremote-nettune.service) / $(systemctl is-enabled lanremote-nettune.service)"
echo "  tcp_mtu_probing = $(cat /proc/sys/net/ipv4/tcp_mtu_probing)"
echo "  MSS 规则："
iptables -t mangle -L -n 2>/dev/null | grep -i mss | sed 's/^/    /'

echo
echo "===== 5. 重启隧道让它用新参数建连接 ====="
systemctl restart lanremote-tunnel
sleep 35
echo "  隧道: $(systemctl is-active lanremote-tunnel)"
echo "  连接数: $(curl -s --max-time 5 http://127.0.0.1:20241/metrics 2>/dev/null | grep '^cloudflared_tunnel_ha_connections' | awk '{print $2}')"