sushen339
146 lines
5.1 KiB
Bash
146 lines
5.1 KiB
Bash
#!/bin/bash
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# 错误时立即退出
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set -euo pipefail
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# 颜色定义
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GREEN='\033[0;32m'
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RED='\033[0;31m'
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YELLOW='\033[1;33m'
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NC='\033[0m' # No Color
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# 1. 检查 Root 权限
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if [ "$EUID" -ne 0 ]; then
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echo -e "${RED}[错误] 请使用 root 权限运行此脚本 (sudo ./nft.sh)${NC}"
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exit 1
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fi
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echo -e "${YELLOW}[信息] 正在检查系统环境...${NC}"
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# 2. 检测并安装 nftables
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if ! command -v nft &> /dev/null; then
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echo -e "${YELLOW}[提示] 未检测到 nftables，尝试自动安装...${NC}"
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if [ -f /etc/debian_version ]; then
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apt-get update && apt-get install -y nftables
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elif [ -f /etc/redhat-release ]; then
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yum install -y nftables
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else
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echo -e "${RED}[错误] 无法识别的操作系统，请手动安装 nftables。${NC}"
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exit 1
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fi
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# 验证安装是否成功
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if ! command -v nft &> /dev/null; then
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echo -e "${RED}[错误] nftables 安装失败，请手动安装后重试。${NC}"
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exit 1
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fi
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echo -e "${GREEN}[成功] nftables 安装完成。${NC}"
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fi
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# 3. 验证内核支持
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# 尝试加载内核模块 (部分VPS可能需要，如果已经加载则忽略)
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modprobe nf_tables 2>/dev/null
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if ! nft list ruleset &> /dev/null; then
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echo -e "${RED}[错误] 你的系统内核似乎不支持 nftables，或者权限不足。${NC}"
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echo -e " 请确认这是一台 KVM/Xen 架构的 VPS (OpenVZ 可能不支持)。"
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exit 1
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fi
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# 4. 确定配置文件路径
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# Debian/Ubuntu 通常在 /etc/nftables.conf
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# CentOS/RHEL 通常在 /etc/sysconfig/nftables.conf
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if [ -f /etc/debian_version ]; then
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CONF_PATH="/etc/nftables.conf"
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elif [ -f /etc/redhat-release ]; then
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CONF_PATH="/etc/sysconfig/nftables.conf"
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else
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# 默认回退路径
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CONF_PATH="/etc/nftables.conf"
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fi
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echo -e "${GREEN}[成功] 检测到 nftables 支持。配置文件路径: ${CONF_PATH}${NC}"
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# 5. 检测 SSH 端口
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SSH_PORT=$(grep "^Port" /etc/ssh/sshd_config 2>/dev/null | awk '{print $2}' || echo "22")
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SSH_PORT=${SSH_PORT:-22}
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echo -e "${YELLOW}[检测] 当前 SSH 端口: ${SSH_PORT}${NC}"
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# 6. 备份原有配置
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if [ -f "$CONF_PATH" ]; then
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cp "$CONF_PATH" "${CONF_PATH}.bak.$(date +%Y%m%d%H%M%S)"
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echo -e "${YELLOW}[提示] 已备份原有配置为 ${CONF_PATH}.bak...${NC}"
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fi
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# 7. 写入配置
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cat > "$CONF_PATH" <<EOF
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#!/usr/sbin/nft -f
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flush ruleset
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table inet security_firewall {
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# 动态黑名单 (封禁 60 分钟)
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set blackhole_v4 { type ipv4_addr; flags dynamic, timeout; timeout 60m; }
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set blackhole_v6 { type ipv6_addr; flags dynamic, timeout; timeout 60m; }
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chain input {
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# 默认策略: 允许所有 (白名单模式请改为 drop)
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type filter hook input priority 0; policy accept;
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# 1. 快速放行 (回环 + 已连接)
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iif "lo" accept
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ct state established,related accept
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# 2. 垃圾清理 (无效包 + 黑名单)
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ct state invalid drop
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ip saddr @blackhole_v4 drop
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ip6 saddr @blackhole_v6 drop
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# 3. SYN flood 防护 (阈值 2000/s, 突发 2000)
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# 保护系统内存，防止大规模 SYN 攻击导致死机
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tcp flags syn limit rate over 2000/second burst 2000 packets drop
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# 4. ICMP/Ping 限速 (阈值 2000/s, 突发 2000)
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ip protocol icmp limit rate over 2000/second burst 2000 packets drop
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meta l4proto icmpv6 limit rate over 2000/second burst 2000 packets drop
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# 5. SSH 防爆破 (5次/分, 允许瞬间突发5次)
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# 超过限制 -> 加入黑名单 -> 丢弃
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# SSH 端口: $SSH_PORT (自动检测)
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tcp dport $SSH_PORT ct state new meter flood_v4 { ip saddr timeout 60s limit rate over 5/minute burst 5 packets } \\
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add @blackhole_v4 { ip saddr } drop
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tcp dport $SSH_PORT ct state new meter flood_v6 { ip6 saddr timeout 60s limit rate over 5/minute burst 5 packets } \\
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add @blackhole_v6 { ip6 saddr } drop
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}
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}
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EOF
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# 8. 应用并启用服务
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echo -e "${YELLOW}[信息] 正在应用规则...${NC}"
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if nft -f "$CONF_PATH"; then
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echo -e "${GREEN}[成功] 规则语法正确并已加载！${NC}"
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# 设置开机自启
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systemctl enable nftables &> /dev/null
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systemctl restart nftables
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echo -e "${GREEN}[完成] nftables 服务已重启并设置开机自启。${NC}"
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echo -e "${GREEN}---------------------------------------------${NC}"
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echo -e "当前 SSH 防护状态："
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echo -e " - SSH 端口: ${GREEN}${SSH_PORT}${NC}"
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echo -e " - IPv4/IPv6 双栈支持: ${GREEN}YES${NC}"
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echo -e " - SSH 爆破阈值: ${GREEN}5次/分 (突发5次)${NC}"
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echo -e " - 封禁时长: ${GREEN}60分钟${NC}"
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echo -e " - SYN/ICMP 防护: ${GREEN}已开启${NC}"
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echo -e "${GREEN}---------------------------------------------${NC}"
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else
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echo -e "${RED}[错误] 规则加载失败！请检查配置文件。已还原自动备份。${NC}"
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# 尝试还原
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LATEST_BACKUP=$(ls -t ${CONF_PATH}.bak.* 2>/dev/null | head -n1)
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if [ -n "$LATEST_BACKUP" ]; then
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cp "$LATEST_BACKUP" "$CONF_PATH"
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echo -e "${YELLOW}[信息] 已还原配置文件。${NC}"
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fi
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exit 1
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fi |