#!/bin/bash
# 功能：修复Ubuntu Server长时间无网络活动导致网络关闭的问题
# 使用方法：sudo bash fix_network_sleep.sh

# 检查是否以root权限运行
if [ "$(id -u)" -ne 0 ]; then
    echo "错误：请使用root权限运行此脚本（sudo bash $0）" >&2
    exit 1
fi

# 检测网卡名称（获取第一个活动的以太网接口）
get_active_nic() {
    # 排除lo和docker等虚拟接口，获取第一个物理以太网接口
    nic=$(ip -br link show | grep -v 'LOOPBACK' | grep -v 'DOCKER' | grep 'UP' | awk '{print $1}' | head -n 1)
    if [ -z "$nic" ]; then
        # 如果没有找到活动接口，获取第一个以太网接口
        nic=$(ip -br link show | grep -v 'LOOPBACK' | grep -v 'DOCKER' | awk '{print $1}' | head -n 1)
    fi
    echo "$nic"
}

NIC=$(get_active_nic)

if [ -z "$NIC" ]; then
    echo "错误：未检测到网络接口，请检查网络配置"
    exit 1
fi

echo "检测到活动网络接口：$NIC"

# 备份相关配置文件
backup_configs() {
    echo "正在备份配置文件..."
    [ -d /etc/systemd/system/ ] && cp -n /etc/systemd/system/disable-nic-powersave.service /etc/systemd/system/disable-nic-powersave.service.bak 2>/dev/null
}

# 临时禁用网卡节能模式（立即生效）
disable_nic_powersave_temp() {
    echo "正在临时禁用网卡节能模式..."
    if command -v ethtool &> /dev/null; then
        # 禁用EEE节能
        sudo ethtool --change "$NIC" eee off 2>/dev/null
        # 禁用电源管理
        sudo ethtool -s "$NIC" power management off 2>/dev/null
        # 启用WOL功能
        sudo ethtool -s "$NIC" wol g 2>/dev/null
    else
        echo "警告：未安装ethtool，正在安装..."
        sudo apt update >/dev/null
        sudo apt install -y ethtool >/dev/null
        disable_nic_powersave_temp
    fi
}

# 永久禁用网卡节能模式（系统启动时生效）
disable_nic_powersave_permanent() {
    echo "正在配置永久禁用网卡节能模式..."
    
    # 创建systemd服务
    cat << EOF | sudo tee /etc/systemd/system/disable-nic-powersave.service > /dev/null
[Unit]
Description=Disable NIC Power Saving Mode for $NIC
After=network.target

[Service]
Type=oneshot
ExecStart=/usr/sbin/ethtool -s $NIC wol g
ExecStart=/usr/sbin/ethtool --change $NIC eee off
ExecStart=/usr/sbin/ethtool --change $NIC power management off

[Install]
WantedBy=multi-user.target
EOF

    # 启用并启动服务
    sudo systemctl daemon-reload
    sudo systemctl enable disable-nic-powersave.service
    sudo systemctl start disable-nic-powersave.service
}

# 优化SSH保持连接设置
optimize_ssh_settings() {
    echo "正在优化SSH连接设置..."
    SSH_CONFIG="/etc/ssh/sshd_config"
    
    # 备份SSH配置
    [ -f "$SSH_CONFIG" ] && cp -n "$SSH_CONFIG" "$SSH_CONFIG.bak"
    
    # 设置SSH心跳检测
    if ! grep -q "^ClientAliveInterval" "$SSH_CONFIG"; then
        echo "ClientAliveInterval 60" >> "$SSH_CONFIG"
    else
        sed -i 's/^ClientAliveInterval.*/ClientAliveInterval 60/' "$SSH_CONFIG"
    fi
    
    if ! grep -q "^ClientAliveCountMax" "$SSH_CONFIG"; then
        echo "ClientAliveCountMax 3" >> "$SSH_CONFIG"
    else
        sed -i 's/^ClientAliveCountMax.*/ClientAliveCountMax 3/' "$SSH_CONFIG"
    fi
    
    # 重启SSH服务
    sudo systemctl restart sshd
}

# 检查并修复DNS服务问题
fix_dns_service() {
    echo "正在检查DNS服务..."
    if ! systemctl is-active --quiet systemd-resolved; then
        echo "修复DNS服务问题..."
        sudo apt update >/dev/null
        sudo apt install --reinstall -y systemd-resolved >/dev/null
        sudo systemctl enable --now systemd-resolved
    fi
}

# 显示当前网卡电源管理状态
show_status() {
    echo -e "\n当前网络接口状态："
    echo "-------------------------"
    ip link show "$NIC" | grep -A 1 "$NIC"
    echo -e "\n电源管理状态："
    ethtool "$NIC" | grep -iE "power management|energy"
    echo "-------------------------"
    echo "配置已完成，建议重启系统使所有设置生效"
    echo "重启命令：sudo reboot"
}

# 主流程执行
backup_configs
disable_nic_powersave_temp
disable_nic_powersave_permanent
optimize_ssh_settings
fix_dns_service
show_status