first commit

cfg.go

@@ -0,0 +1,185 @@
+package main
+
+import (
+	"encoding/binary"
+	"io/ioutil"
+	"log"
+	"net"
+	"strconv"
+	"strings"
+)
+
+func GetfileAll(filePath string) ([]byte, error) {
+	result, err := ioutil.ReadFile(filePath)
+	if err != nil {
+		log.Println("read file ", filePath, err)
+		return result, err
+	}
+	return result, nil
+}
+
+func Getfile(filePath string) ([]string, error) {
+	result := []string{}
+	b, err := ioutil.ReadFile(filePath)
+	if err != nil {
+		log.Println("read file ", filePath, err)
+		return result, err
+	}
+	s := string(b)
+	for _, lineStr := range strings.Split(s, "\n") {
+		lineStr = strings.TrimSpace(lineStr)
+		if lineStr == "" {
+			continue
+		}
+		result = append(result, lineStr)
+	}
+	return result, nil
+}
+
+func GetIpList(filePath string) ([]string, error) {
+	res, err := Getfile(filePath)
+	if err != nil {
+		return nil, nil
+	}
+	var allIp []string
+	if len(res) > 0 {
+		for _, sip := range res {
+			aip := ParseIp(sip)
+			for _, ip := range aip {
+				allIp = append(allIp, ip)
+			}
+		}
+	}
+	return allIp, nil
+}
+
+func ParseIp(ip string) []string {
+	var availableIPs []string
+	// if ip is "1.1.1.1/",trim /
+	ip = strings.TrimRight(ip, "/")
+	if strings.Contains(ip, "/") == true {
+		if strings.Contains(ip, "/32") == true {
+			aip := strings.Replace(ip, "/32", "", -1)
+			availableIPs = append(availableIPs, aip)
+		} else {
+			availableIPs = GetAvailableIP(ip)
+		}
+	} else if strings.Contains(ip, "-") == true {
+		ipRange := strings.SplitN(ip, "-", 2)
+		availableIPs = GetAvailableIPRange(ipRange[0], ipRange[1])
+	} else {
+		availableIPs = append(availableIPs, ip)
+	}
+	return availableIPs
+}
+
+func GetAvailableIPRange(ipStart, ipEnd string) []string {
+	var availableIPs []string
+
+	firstIP := net.ParseIP(ipStart)
+	endIP := net.ParseIP(ipEnd)
+	if firstIP.To4() == nil || endIP.To4() == nil {
+		return availableIPs
+	}
+	firstIPNum := ipToInt(firstIP.To4())
+	EndIPNum := ipToInt(endIP.To4())
+	pos := int32(1)
+
+	newNum := firstIPNum
+
+	for newNum <= EndIPNum {
+		availableIPs = append(availableIPs, intToIP(newNum).String())
+		newNum = newNum + pos
+	}
+	return availableIPs
+}
+
+func GetAvailableIP(ipAndMask string) []string {
+	var availableIPs []string
+
+	ipAndMask = strings.TrimSpace(ipAndMask)
+	ipAndMask = IPAddressToCIDR(ipAndMask)
+	_, ipnet, _ := net.ParseCIDR(ipAndMask)
+
+	firstIP, _ := networkRange(ipnet)
+	ipNum := ipToInt(firstIP)
+	size := networkSize(ipnet.Mask)
+	pos := int32(1)
+	max := size - 2 // -1 for the broadcast address, -1 for the gateway address
+
+	var newNum int32
+	for attempt := int32(0); attempt < max; attempt++ {
+		newNum = ipNum + pos
+		pos = pos%max + 1
+		availableIPs = append(availableIPs, intToIP(newNum).String())
+	}
+	return availableIPs
+}
+
+func IPAddressToCIDR(ipAdress string) string {
+	if strings.Contains(ipAdress, "/") == true {
+		ipAndMask := strings.Split(ipAdress, "/")
+		ip := ipAndMask[0]
+		mask := ipAndMask[1]
+		if strings.Contains(mask, ".") == true {
+			mask = IPMaskStringToCIDR(mask)
+		}
+		return ip + "/" + mask
+	} else {
+		return ipAdress
+	}
+}
+
+func IPMaskStringToCIDR(netmask string) string {
+	netmaskList := strings.Split(netmask, ".")
+	var mint []int
+	for _, v := range netmaskList {
+		strv, _ := strconv.Atoi(v)
+		mint = append(mint, strv)
+	}
+	myIPMask := net.IPv4Mask(byte(mint[0]), byte(mint[1]), byte(mint[2]), byte(mint[3]))
+	ones, _ := myIPMask.Size()
+	return strconv.Itoa(ones)
+}
+
+func IPMaskCIDRToString(one string) string {
+	oneInt, _ := strconv.Atoi(one)
+	mIPmask := net.CIDRMask(oneInt, 32)
+	var maskstring []string
+	for _, v := range mIPmask {
+		maskstring = append(maskstring, strconv.Itoa(int(v)))
+	}
+	return strings.Join(maskstring, ".")
+}
+
+// Calculates the first and last IP addresses in an IPNet
+func networkRange(network *net.IPNet) (net.IP, net.IP) {
+	netIP := network.IP.To4()
+	firstIP := netIP.Mask(network.Mask)
+	lastIP := net.IPv4(0, 0, 0, 0).To4()
+	for i := 0; i < len(lastIP); i++ {
+		lastIP[i] = netIP[i] | ^network.Mask[i]
+	}
+	return firstIP, lastIP
+}
+
+// Given a netmask, calculates the number of available hosts
+func networkSize(mask net.IPMask) int32 {
+	m := net.IPv4Mask(0, 0, 0, 0)
+	for i := 0; i < net.IPv4len; i++ {
+		m[i] = ^mask[i]
+	}
+	return int32(binary.BigEndian.Uint32(m)) + 1
+}
+
+// Converts a 4 bytes IP into a 32 bit integer
+func ipToInt(ip net.IP) int32 {
+	return int32(binary.BigEndian.Uint32(ip.To4()))
+}
+
+// Converts 32 bit integer into a 4 bytes IP address
+func intToIP(n int32) net.IP {
+	b := make([]byte, 4)
+	binary.BigEndian.PutUint32(b, uint32(n))
+	return net.IP(b)
+}