怎么用脚本检测端口转发

本文目录导读：

1. 使用 netcat (nc) 检测基本连通性
2. 更完善的 Python 检测脚本
3. 使用 curl 检测 HTTP 端口转发
4. 完整的检测脚本（包含多种检测方式）
5. PowerShell 版本（Windows）
6. 使用示例

使用 netcat (nc) 检测基本连通性

#!/bin/bash
# port_forward_check.sh
HOST="example.com"
PORT=8080
# 使用 timeout 防止长时间阻塞
timeout 5 bash -c "echo > /dev/tcp/$HOST/$PORT" 2>/dev/null && \
    echo "端口 $PORT 转发正常" || \
    echo "端口 $PORT 转发异常"

更完善的 Python 检测脚本

#!/usr/bin/env python3
# port_forward_detect.py
import socket
import sys
import argparse
from concurrent.futures import ThreadPoolExecutor, as_completed
def check_port_forward(target_host, target_port, local_host='127.0.0.1', 
                      local_port=None, timeout=5):
    """
    检测端口转发
    """
    try:
        # 创建 socket 连接
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.settimeout(timeout)
        # 如果是本地端口转发检测
        if local_port:
            result = sock.connect_ex((local_host, local_port))
            if result == 0:
                print(f"✓ 本地 {local_host}:{local_port} 已监听")
        else:
            result = sock.connect_ex((target_host, target_port))
            if result == 0:
                print(f"✓ 端口 {target_host}:{target_port} 转发正常")
            else:
                print(f"✗ 端口 {target_host}:{target_port} 转发异常")
        sock.close()
        return result == 0
    except socket.timeout:
        print(f"✗ 连接超时 - {target_host}:{target_port}")
        return False
    except socket.error as e:
        print(f"✗ 连接错误: {e}")
        return False
def detect_forward_type(target_host, target_port, timeout=3):
    """
    检测端口转发类型
    """
    try:
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.settimeout(timeout)
        sock.connect((target_host, target_port))
        # 获取远程地址
        remote_addr = sock.getpeername()
        local_addr = sock.getsockname()
        print(f"本地地址: {local_addr[0]}:{local_addr[1]}")
        print(f"远程地址: {remote_addr[0]}:{remote_addr[1]}")
        # 尝试判断转发类型
        if local_addr[0] != '127.0.0.1':
            print("⚠ 检测到非本地地址，可能是远程端口转发")
        else:
            print("ℹ 本地端口转发")
        sock.close()
    except Exception as e:
        print(f"无法检测转发类型: {e}")
def scan_ports(target_host, start_port=1, end_port=1024, threads=50):
    """
    扫描端口范围检查转发
    """
    open_ports = []
    def scan_port(port):
        try:
            sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            sock.settimeout(1)
            result = sock.connect_ex((target_host, port))
            sock.close()
            if result == 0:
                return port
        except:
            pass
        return None
    with ThreadPoolExecutor(max_workers=threads) as executor:
        futures = {executor.submit(scan_port, port): port 
                   for port in range(start_port, end_port + 1)}
        for future in as_completed(futures):
            result = future.result()
            if result:
                open_ports.append(result)
                print(f"发现开放端口: {result}")
    return open_ports
def main():
    parser = argparse.ArgumentParser(description='端口转发检测工具')
    parser.add_argument('host', help='目标主机')
    parser.add_argument('port', type=int, help='目标端口')
    parser.add_argument('--local-port', type=int, help='本地端口（可选）')
    parser.add_argument('--scan', action='store_true', help='扫描端口范围')
    parser.add_argument('--start', type=int, default=1, help='起始端口')
    parser.add_argument('--end', type=int, default=1024, help='结束端口')
    args = parser.parse_args()
    if args.scan:
        print(f"扫描 {args.host} 端口范围 {args.start}-{args.end}")
        open_ports = scan_ports(args.host, args.start, args.end)
        print(f"发现 {len(open_ports)} 个开放端口")
    else:
        # 检查单个端口
        print(f"检测 {args.host}:{args.port}")
        result = check_port_forward(args.host, args.port, 
                                   local_port=args.local_port)
        if result:
            detect_forward_type(args.host, args.port)
if __name__ == "__main__":
    main()

使用 curl 检测 HTTP 端口转发

#!/bin/bash
# http_port_forward_check.sh
URL="http://example.com"
CHECK_KEY="expected_text"
# 检查 HTTP 端口转发
check_http_forward() {
    local response=$(curl -s -o /dev/null -w "%{http_code}" --connect-timeout 5 "$1")
    case $response in
        200)
            echo "HTTP 转发正常 (状态码: $response)"
            ;;
        301|302|307|308)
            redirect_url=$(curl -sI --connect-timeout 5 "$1" | grep -i "location:" | cut -d' ' -f2)
            echo "HTTP 转发到: $redirect_url"
            ;;
        *)
            echo "HTTP 转发异常 (状态码: $response)"
            ;;
    esac
}
# 检查特定响应内容
check_response_content() {
    local content=$(curl -s --connect-timeout 5 "$1")
    if echo "$content" | grep -q "$2"; then
        echo "响应内容包含期望的关键字"
    else
        echo "响应内容异常"
    fi
}
check_http_forward "$URL"
check_response_content "$URL" "$CHECK_KEY"

完整的检测脚本（包含多种检测方式）

#!/bin/bash
# comprehensive_port_check.sh
TIMEOUT=5
HOSTS=("192.168.1.1" "localhost" "0.0.0.0")
PORTS=(22 80 443 8080 3306)
# 颜色输出
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color
log_info() {
    echo -e "${GREEN}[INFO]${NC} $1"
}
log_warn() {
    echo -e "${YELLOW}[WARN]${NC} $1"
}
log_error() {
    echo -e "${RED}[ERROR]${NC} $1"
}
# 检测端口是否可达
check_port_forward() {
    local host=$1
    local port=$2
    if timeout $TIMEOUT bash -c "echo >/dev/tcp/$host/$port" 2>/dev/null; then
        return 0
    else
        return 1
    fi
}
# 检测 iptables 端口转发规则
check_iptables_rules() {
    log_info "检查 iptables 端口转发规则..."
    if command -v iptables &> /dev/null; then
        # 检查 NAT 表
        if iptables -t nat -L -n | grep -q "DNAT\|REDIRECT"; then
            log_warn "发现端口转发规则:"
            iptables -t nat -L -n --line-numbers | grep -E "DNAT|REDIRECT"
        else
            log_info "未发现端口转发规则"
        fi
    fi
}
# 检测 SSH 端口转发
check_ssh_forward() {
    log_info "检查 SSH 端口转发..."
    # 检查 SSH 进程
    if ps aux | grep -q "[s]sh.*-L\|[s]sh.*-R\|[s]sh.*-D"; then
        log_warn "发现 SSH 转发连接:"
        ps aux | grep "[s]sh.*-L\|[s]sh.*-R\|[s]sh.*-D"
    else
        log_info "未发现 SSH 转发"
    fi
}
# 检测 socat 转发
check_socat_forward() {
    log_info "检查 socat 转发..."
    if ps aux | grep -q "[s]ocat"; then
        log_warn "发现 socat 进程:"
        ps aux | grep "[s]ocat"
    fi
}
# 主检测循环
main() {
    log_info "开始端口转发检测..."
    echo "----------------------------------------"
    # 检测本地端口
    for host in "${HOSTS[@]}"; do
        for port in "${PORTS[@]}"; do
            if check_port_forward "$host" "$port"; then
                log_info "端口 $host:$port 可达"
            fi
        done
    done
    echo "----------------------------------------"
    # 系统级检测
    check_iptables_rules
    echo "----------------------------------------"
    check_ssh_forward
    echo "----------------------------------------"
    check_socat_forward
    echo "----------------------------------------"
    log_info "检测完成"
}
main

PowerShell 版本（Windows）

# port_forward_check.ps1
param(
    [string]$Host = "localhost",
    [int]$Port = 80,
    [switch]$Scan,
    [int]$StartPort = 1,
    [int]$EndPort = 1024
)
function Test-PortForward {
    param(
        [string]$TargetHost,
        [int]$TargetPort
    )
    try {
        $tcpClient = New-Object System.Net.Sockets.TcpClient
        $result = $tcpClient.BeginConnect($TargetHost, $TargetPort, $null, $null)
        $timeout = [System.TimeSpan]::FromSeconds(5)
        if ($result.AsyncWaitHandle.WaitOne($timeout)) {
            $tcpClient.EndConnect($result) | Out-Null
            Write-Host "✓ 端口 $TargetHost`:$TargetPort 转发正常" -ForegroundColor Green
            return $true
        } else {
            Write-Host "✗ 端口 $TargetHost`:$TargetPort 连接超时" -ForegroundColor Red
            return $false
        }
        $tcpClient.Close()
    } catch {
        Write-Host "✗ 端口 $TargetHost`:$TargetPort 转发异常: $_" -ForegroundColor Red
        return $false
    }
}
# 主逻辑
if ($Scan) {
    Write-Host "扫描 $Host 端口范围 $StartPort-$EndPort" -ForegroundColor Yellow
    for ($port = $StartPort; $port -le $EndPort; $port++) {
        Test-PortForward -TargetHost $Host -TargetPort $port
    }
} else {
    Test-PortForward -TargetHost $Host -TargetPort $Port
}

使用示例

# 检查单个端口
python3 port_forward_detect.py example.com 8080
# 扫描端口范围
python3 port_forward_detect.py example.com --scan --start 1 --end 1000
# 使用bash脚本
./port_forward_check.sh
# 完整的检测
./comprehensive_port_check.sh

这些脚本可以检测：

• 基本的 TCP 端口连通性
• HTTP/HTTPS 端口转发
• iptables 端口转发规则
• SSH 隧道转发
• socat 转发
• 本地和远程端口转发

根据实际需求选择合适的脚本即可。