mirror of
https://github.com/oneclickvirt/basics.git
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257 lines
7.3 KiB
Go
257 lines
7.3 KiB
Go
//go:build linux
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// +build linux
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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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"strconv"
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"strings"
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"syscall"
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"time"
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)
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const (
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ICMPv6RouterAdvertisement = 134
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ICMPv6RouterSolicitation = 133
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ICMPv6OptionPrefix = 3
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)
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func extractPrefixFromRAOption(data []byte) []string {
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var prefixLengths []string
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optionStart := 16
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for optionStart < len(data) {
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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
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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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if optionType == ICMPv6OptionPrefix && optionLen >= 32 {
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prefixLen := data[optionStart+2]
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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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if !isNonGlobalPrefix(prefix) && isPrefixLengthValid(int(prefixLen)) {
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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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func isPrefixLengthValid(prefixLen int) bool {
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return prefixLen >= 1 && prefixLen <= 128
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}
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func sendRouterSolicitation(fd int, interfaceName string) error {
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intf, err := net.InterfaceByName(interfaceName)
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if err != nil {
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return fmt.Errorf("获取接口信息失败: %v", err)
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}
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msg := make([]byte, 8)
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msg[0] = ICMPv6RouterSolicitation
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msg[1] = 0
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if len(intf.HardwareAddr) == 6 {
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msg = append(msg, 1)
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msg = append(msg, 1)
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msg = append(msg, intf.HardwareAddr...)
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msg = append(msg, 0, 0)
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}
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var allRoutersAddr [16]byte
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copy(allRoutersAddr[:], net.ParseIP("ff02::2").To16())
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var addr syscall.SockaddrInet6
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addr.ZoneId = uint32(intf.Index)
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copy(addr.Addr[:], allRoutersAddr[:])
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if err := syscall.Sendto(fd, msg, 0, &addr); err != nil {
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return fmt.Errorf("发送Router Solicitation失败: %v", err)
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}
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return nil
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}
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func getPrefixFromRA(interfaceName string) (string, error) {
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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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prefixLenInt, err := strconv.Atoi(prefixLen)
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if err != nil || !isPrefixLengthValid(prefixLenInt) {
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continue
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}
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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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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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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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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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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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tv := syscall.Timeval{
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Sec: 5,
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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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ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
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defer cancel()
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err = sendRouterSolicitation(fd, interfaceName)
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if err != nil {
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return "", fmt.Errorf("发送Router Solicitation失败: %v", err)
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}
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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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if n < 4 {
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continue
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}
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if buffer[0] == ICMPv6RouterAdvertisement {
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prefixLengths := extractPrefixFromRAOption(buffer[:n])
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if len(prefixLengths) > 0 {
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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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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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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 []int
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for _, match := range matches {
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ipv6Addr := match[1]
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if strings.HasPrefix(ipv6Addr, "fe80") ||
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strings.HasPrefix(ipv6Addr, "::1") ||
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strings.HasPrefix(ipv6Addr, "fc") ||
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strings.HasPrefix(ipv6Addr, "fd") ||
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strings.HasPrefix(ipv6Addr, "ff") {
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continue
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}
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if len(match) > 2 {
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prefixLen, err := strconv.Atoi(match[2])
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if err != nil || !isPrefixLengthValid(prefixLen) {
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continue
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}
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prefixLens = append(prefixLens, prefixLen)
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}
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}
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if len(prefixLens) >= 1 {
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sort.Ints(prefixLens)
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return strconv.Itoa(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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func getPrefixFromConfigFiles() (string, error) {
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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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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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prefixLen, err := strconv.Atoi(matches[2])
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if err != nil || !isPrefixLengthValid(prefixLen) {
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continue
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}
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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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func GetIPv6Mask(publicIPv6, language string) (string, error) {
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if publicIPv6 == "" {
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return "", fmt.Errorf("无公网IPV6地址")
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}
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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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var prefixLen string
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// 优先级1：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 len, err := strconv.Atoi(prefixLen); err == nil && isPrefixLengthValid(len) {
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return formatIPv6Mask(prefixLen, language), nil
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}
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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 len, err := strconv.Atoi(prefixLen); err == nil && isPrefixLengthValid(len) {
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return formatIPv6Mask(prefixLen, language), nil
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}
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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 len, err := strconv.Atoi(prefixLen); err == nil && isPrefixLengthValid(len) {
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return formatIPv6Mask(prefixLen, language), nil
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}
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}
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return formatIPv6Mask("128", language), nil
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}
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