parse CIDR notation using the "netip" package

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mikuru996 2022-10-05 18:45:54 +08:00
parent 6902044592
commit f2cd8ac7da
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1 changed files with 52 additions and 123 deletions

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@ -5,149 +5,78 @@ import (
"log"
"math/rand"
"net"
"net/netip"
"os"
"strconv"
"strings"
"regexp"
)
const defaultInputFile = "ip.txt"
var (
// IPv6 IP version is 6
// Use ipv6 in the test
IPv6 = false
// TestAll test all ip
// If true, test all the addresses
TestAll = false
// IPFile is the filename of IP Rangs
IPFile = defaultInputFile
// The filename of ip range data
IPFile string
)
func randIPEndWith(num byte) byte {
if num == 0 { // 对于 /32 这种单独的 IP
return byte(0)
}
return byte(rand.Intn(int(num)))
}
type IPRanges struct {
ips []*net.IPAddr
mask string
firstIP net.IP
ipNet *net.IPNet
}
func newIPRanges() *IPRanges {
return &IPRanges{
ips: make([]*net.IPAddr, 0),
}
}
func (r *IPRanges) fixIP(ip string) string {
// 如果不含有 '/' 则代表不是 IP 段,而是一个单独的 IP因此需要加上 /32 /128 子网掩码
if i := strings.IndexByte(ip, '/'); i < 0 {
r.mask = "/32"
if IPv6 {
r.mask = "/128"
}
ip += r.mask
} else {
r.mask = ip[i:]
}
return ip
}
func (r *IPRanges) parseCIDR(ip string) {
var err error
if r.firstIP, r.ipNet, err = net.ParseCIDR(r.fixIP(ip)); err != nil {
log.Fatalln("ParseCIDR err", err)
}
}
func (r *IPRanges) appendIPv4(d byte) {
r.appendIP(net.IPv4(r.firstIP[12], r.firstIP[13], r.firstIP[14], d))
}
func (r *IPRanges) appendIP(ip net.IP) {
r.ips = append(r.ips, &net.IPAddr{IP: ip})
}
// 返回第四段 ip 的最小值及可用数目
func (r *IPRanges) getIPRange() (minIP, hosts byte) {
minIP = r.firstIP[15] & r.ipNet.Mask[3] // IP 第四段最小值
// 根据子网掩码获取主机数量
m := net.IPv4Mask(255, 255, 255, 255)
for i, v := range r.ipNet.Mask {
m[i] ^= v
}
total, _ := strconv.ParseInt(m.String(), 16, 32) // 总可用 IP 数
if total > 255 { // 矫正 第四段 可用 IP 数
hosts = 255
return
}
hosts = byte(total)
return
}
func (r *IPRanges) chooseIPv4() {
minIP, hosts := r.getIPRange()
for r.ipNet.Contains(r.firstIP) {
if TestAll { // 如果是测速全部 IP
for i := 0; i <= int(hosts); i++ { // 遍历 IP 最后一段最小值到最大值
r.appendIPv4(byte(i) + minIP)
}
} else { // 随机 IP 的最后一段 0.0.0.X
r.appendIPv4(minIP + randIPEndWith(hosts))
}
r.firstIP[14]++ // 0.0.(X+1).X
if r.firstIP[14] == 0 {
r.firstIP[13]++ // 0.(X+1).X.X
if r.firstIP[13] == 0 {
r.firstIP[12]++ // (X+1).X.X.X
}
}
}
}
func (r *IPRanges) chooseIPv6() {
var tempIP uint8
for r.ipNet.Contains(r.firstIP) {
//fmt.Println(firstIP)
//fmt.Println(firstIP[0], firstIP[1], firstIP[2], firstIP[3], firstIP[4], firstIP[5], firstIP[6], firstIP[7], firstIP[8], firstIP[9], firstIP[10], firstIP[11], firstIP[12], firstIP[13], firstIP[14], firstIP[15])
if r.mask != "/128" {
r.firstIP[15] = randIPEndWith(255) // 随机 IP 的最后一段
r.firstIP[14] = randIPEndWith(255) // 随机 IP 的最后一段
}
targetIP := make([]byte, len(r.firstIP))
copy(targetIP, r.firstIP)
r.appendIP(targetIP)
for i := 13; i >= 0; i-- {
tempIP = r.firstIP[i]
r.firstIP[i] += randIPEndWith(255)
if r.firstIP[i] >= tempIP {
break
}
func rangeNormalize(s string) string {
noMask := !regexp.MustCompile(`.*\/[0-9]+`).MatchString(s)
if noMask {
addr := netip.MustParseAddr(s)
switch {
case addr.Is4():
return s + "/32"
case addr.Is6():
return s + "/128"
}
}
return s
}
func loadIPRanges() []*net.IPAddr {
if IPFile == "" {
IPFile = defaultInputFile
}
var ips []*net.IPAddr
// try to open data file
file, err := os.Open(IPFile)
if err != nil {
log.Fatal(err)
}
defer file.Close()
ranges := newIPRanges()
// load in file line by line
scanner := bufio.NewScanner(file)
for scanner.Scan() {
ranges.parseCIDR(scanner.Text())
if IPv6 {
ranges.chooseIPv6()
continue
// normalize the expression
line := rangeNormalize(scanner.Text())
// parse the network part
prefix := netip.MustParsePrefix(line)
// ensure we are using the standard form
prefix = prefix.Masked()
// get all possible address
var addrs []netip.Addr
if prefix.IsSingleIP() {
for addr := prefix.Addr(); prefix.Contains(addr); addr = addr.Next() {
addrs = append(addrs, addr)
}
addrs = addrs[1 : len(addrs)-1]
} else {
addrs = append(addrs, prefix.Addr())
}
// choose one addr if we don't need all
if !TestAll {
addrs = []netip.Addr{addrs[rand.Intn(len(addrs))]}
}
// add them to the original "ips" array
for _, v := range addrs {
ips = append(ips, &net.IPAddr{IP: net.IP(v.AsSlice())})
}
ranges.chooseIPv4()
}
return ranges.ips
return ips
}