mirror of
https://github.com/oneclickvirt/basics.git
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325 lines
9.5 KiB
Go
325 lines
9.5 KiB
Go
package ipv6
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import (
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"context"
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"fmt"
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"net"
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"os"
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"os/exec"
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"regexp"
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"sort"
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"strings"
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"syscall"
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"time"
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)
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// 获取第一个以 eth 或 en 开头的网络接口
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func getInterface() (string, error) {
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cmd := exec.Command("sh", "-c", "ls /sys/class/net/ | grep -E '^(eth|en)' | head -n 1")
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output, err := cmd.Output()
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if err != nil {
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return "", err
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}
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return strings.TrimSpace(string(output)), nil
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}
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// 获取当前的公网 IPv6 地址
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func getCurrentIPv6() (string, error) {
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cmd := exec.Command("curl", "-s", "-6", "-m", "5", "ipv6.ip.sb")
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output, err := cmd.Output()
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if err != nil {
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return "", err
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}
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return strings.TrimSpace(string(output)), nil
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}
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// Router Advertisement前缀选项类型
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const (
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ICMPv6RouterAdvertisement = 134
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ICMPv6OptionPrefix = 3
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)
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// ICMPv6报文头部结构
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type ICMPv6Header struct {
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Type uint8
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Code uint8
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Checksum uint16
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}
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// Router Advertisement报文结构
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type RouterAdvertisement struct {
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CurHopLimit uint8
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Flags uint8
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RouterLifetime uint16
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ReachableTime uint32
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RetransTimer uint32
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Options []byte
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}
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// 前缀信息选项结构
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type PrefixInfoOption struct {
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Type uint8
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Length uint8
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PrefixLength uint8
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Flags uint8
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ValidLifetime uint32
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PreferredLifetime uint32
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Reserved uint32
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Prefix [16]byte
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}
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// 从RA报文中提取前缀长度信息
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func extractPrefixFromRAOption(data []byte) []string {
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var prefixLengths []string
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// 跳过ICMPv6头部(4字节)和Router Advertisement基本信息(12字节)
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optionStart := 16
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// 遍历所有选项
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for optionStart < len(data) {
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// 确保有足够的数据可读
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if optionStart+2 > len(data) {
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break
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}
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optionType := data[optionStart]
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optionLen := data[optionStart+1] * 8 // 长度以8字节为单位
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// 确保选项长度有效
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if optionLen == 0 || optionStart+int(optionLen) > len(data) {
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break
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}
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// 解析前缀信息选项
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if optionType == ICMPv6OptionPrefix && optionLen >= 32 {
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// 前缀长度在选项开始后2字节处
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prefixLen := data[optionStart+2]
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// 前缀值从选项开始后16字节处
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prefixStart := optionStart + 16
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if prefixStart+16 <= len(data) {
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var prefix [16]byte
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copy(prefix[:], data[prefixStart:prefixStart+16])
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// 排除非全局单播地址
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if !isNonGlobalPrefix(prefix) {
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prefixLengths = append(prefixLengths, fmt.Sprintf("%d", prefixLen))
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}
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}
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}
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optionStart += int(optionLen)
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}
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return prefixLengths
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}
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// 判断是否为非全局单播地址前缀
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func isNonGlobalPrefix(prefix [16]byte) bool {
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// 链路本地地址 fe80::/10
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if prefix[0] == 0xfe && (prefix[1]&0xc0) == 0x80 {
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return true
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}
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// 唯一本地地址 fc00::/7
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if (prefix[0] & 0xfe) == 0xfc {
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return true
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}
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// 回环地址 ::1
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if prefix[0] == 0 && prefix[1] == 0 && prefix[15] == 1 {
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return true
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}
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// 组播地址 ff00::/8
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if prefix[0] == 0xff {
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return true
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}
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return false
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}
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// 方法1：尝试原生实现从Router Advertisement获取前缀长度
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func getPrefixFromRA(interfaceName string) (string, error) {
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// 尝试先用radvdump，如果存在的话
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radvdumpPath, err := exec.LookPath("radvdump")
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if err == nil && radvdumpPath != "" {
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cmd := exec.Command("radvdump", "-i", interfaceName)
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output, err := cmd.Output()
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if err == nil {
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re := regexp.MustCompile(`(?i)prefix\s+([a-fA-F0-9:]+)/(\d+)`)
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matches := re.FindAllStringSubmatch(string(output), -1)
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for _, match := range matches {
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prefix := match[1]
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prefixLen := match[2]
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// 排除非公网地址前缀
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if !strings.HasPrefix(prefix, "fe80") &&
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!strings.HasPrefix(prefix, "::1") &&
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!strings.HasPrefix(prefix, "fc") &&
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!strings.HasPrefix(prefix, "fd") &&
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!strings.HasPrefix(prefix, "ff") {
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return prefixLen, nil
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}
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}
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}
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}
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// 如果radvdump不可用或未找到有效前缀，使用原生实现
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intf, err := net.InterfaceByName(interfaceName)
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if err != nil {
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return "", fmt.Errorf("获取网络接口失败: %v", err)
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}
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// 创建原始套接字接收ICMPv6消息
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fd, err := syscall.Socket(syscall.AF_INET6, syscall.SOCK_RAW, syscall.IPPROTO_ICMPV6)
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if err != nil {
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return "", fmt.Errorf("创建原始套接字失败: %v", err)
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}
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defer syscall.Close(fd)
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// 绑定到指定接口
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if err := syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_BINDTODEVICE, intf.Index); err != nil {
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return "", fmt.Errorf("绑定套接字到接口失败: %v", err)
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}
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// 设置过滤器，只接收Router Advertisement消息
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if err := syscall.SetsockoptInt(fd, syscall.IPPROTO_IPV6, syscall.IPV6_RECVPKTINFO, 1); err != nil {
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return "", fmt.Errorf("设置套接字选项失败: %v", err)
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}
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// 设置接收超时
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tv := syscall.Timeval{
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Sec: 5, // 5秒超时
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Usec: 0,
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}
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if err := syscall.SetsockoptTimeval(fd, syscall.SOL_SOCKET, syscall.SO_RCVTIMEO, &tv); err != nil {
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return "", fmt.Errorf("设置接收超时失败: %v", err)
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}
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// 创建上下文，用于发送Router Solicitation并等待Router Advertisement
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ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
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defer cancel()
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// 发送Router Solicitation
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go func() {
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// 实际应用中可能需要构造并发送Router Solicitation消息
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// 这里为简化代码，仅依赖网络上周期性的Router Advertisement
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}()
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// 接收Router Advertisement
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buffer := make([]byte, 1500)
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for {
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select {
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case <-ctx.Done():
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return "", fmt.Errorf("等待Router Advertisement超时")
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default:
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n, _, err := syscall.Recvfrom(fd, buffer, 0)
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if err != nil {
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if err == syscall.EAGAIN || err == syscall.EWOULDBLOCK {
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continue
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}
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return "", fmt.Errorf("接收数据失败: %v", err)
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}
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// 确保收到的是ICMPv6消息
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if n < 4 {
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continue
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}
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// 检查是否为Router Advertisement
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if buffer[0] == ICMPv6RouterAdvertisement {
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// 解析数据包提取前缀长度
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prefixLengths := extractPrefixFromRAOption(buffer[:n])
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if len(prefixLengths) > 0 {
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// 返回第一个有效前缀长度
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return prefixLengths[0], nil
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}
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}
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}
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}
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}
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// 方法2：从ip命令获取前缀长度
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func getPrefixFromIPCommand(interfaceName string) (string, error) {
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cmd := exec.Command("ip", "-o", "-6", "addr", "show", interfaceName)
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output, err := cmd.Output()
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if err != nil {
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return "", err
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}
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// 匹配 inet6 地址和前缀长度
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re := regexp.MustCompile(`\s*inet6\s+([a-fA-F0-9:]+)/(\d+)\s+scope\s+global`)
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matches := re.FindAllStringSubmatch(string(output), -1)
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if len(matches) == 0 {
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return "", fmt.Errorf("未找到全局IPv6地址")
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}
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var prefixLens []string
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for _, match := range matches {
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ipv6Addr := match[1]
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// 排除非公网地址前缀
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if strings.HasPrefix(ipv6Addr, "fe80") || // 链路本地地址
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strings.HasPrefix(ipv6Addr, "::1") || // 回环地址
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strings.HasPrefix(ipv6Addr, "fc") || // 本地唯一地址
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strings.HasPrefix(ipv6Addr, "fd") || // 本地唯一地址
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strings.HasPrefix(ipv6Addr, "ff") { // 组播地址
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continue
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}
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// 提取 prefixlen
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if len(match) > 2 {
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prefixLens = append(prefixLens, match[2])
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}
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}
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if len(prefixLens) >= 1 {
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sort.Strings(prefixLens)
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return prefixLens[0], nil
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}
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return "", fmt.Errorf("未找到有效的IPv6前缀长度")
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}
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// 方法3：从配置文件获取前缀长度
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func getPrefixFromConfigFiles() (string, error) {
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// 尝试从常见的网络配置文件中读取
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configFiles := []string{
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"/etc/network/interfaces",
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"/etc/netplan/01-netcfg.yaml",
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"/etc/netplan/50-cloud-init.yaml",
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"/etc/sysconfig/network-scripts/ifcfg-eth0",
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}
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for _, file := range configFiles {
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if _, err := os.Stat(file); err == nil {
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content, err := os.ReadFile(file)
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if err != nil {
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continue
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}
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// 在配置文件中查找IPv6前缀长度
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re := regexp.MustCompile(`(?i)(prefix-length|prefixlen|netmask)[\s:=]+(\d+)`)
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matches := re.FindStringSubmatch(string(content))
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if len(matches) >= 3 {
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return matches[2], nil
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}
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}
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}
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return "", fmt.Errorf("在配置文件中未找到IPv6前缀长度信息")
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}
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// 获取 IPv6 子网掩码
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// 获取 IPv6 子网掩码
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func GetIPv6Mask(language string) (string, error) {
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// 首先检查是否有公网IPv6地址
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publicIPv6, err := getCurrentIPv6()
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if err != nil || publicIPv6 == "" {
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// 没有公网IPv6，返回空字符串
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return "", nil
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}
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// 获取网络接口
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interfaceName, err := getInterface()
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if err != nil || interfaceName == "" {
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return "", fmt.Errorf("获取网络接口失败: %v", err)
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}
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// 优先级1：尝试从RA报文获取前缀长度
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prefixLen, err := getPrefixFromRA(interfaceName)
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if err == nil && prefixLen != "" {
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if language == "en" {
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return fmt.Sprintf(" IPv6 Mask : /%s", prefixLen), nil
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}
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return fmt.Sprintf(" IPv6 子网掩码 : /%s", prefixLen), nil
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}
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// 优先级2：从ip命令获取前缀长度
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prefixLen, err = getPrefixFromIPCommand(interfaceName)
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if err == nil && prefixLen != "" {
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if language == "en" {
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return fmt.Sprintf(" IPv6 Mask : /%s", prefixLen), nil
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}
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return fmt.Sprintf(" IPv6 子网掩码 : /%s", prefixLen), nil
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}
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// 优先级3：从配置文件获取前缀长度
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prefixLen, err = getPrefixFromConfigFiles()
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if err == nil && prefixLen != "" {
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if language == "en" {
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return fmt.Sprintf(" IPv6 Mask : /%s", prefixLen), nil
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}
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return fmt.Sprintf(" IPv6 子网掩码 : /%s", prefixLen), nil
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}
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// 如果以上方法都失败但确实有公网IPv6，使用/128作为默认子网掩码
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if language == "en" {
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return " IPv6 Mask : /128", nil
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}
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return " IPv6 子网掩码 : /128", nil
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}
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