arozos/mod/auth/blacklist/blacklist.go

package blacklist

import (
	"errors"
	"net"
	"strconv"
	"strings"

	db "imuslab.com/arozos/mod/database"
)

/*

	ArozOS Blacklist Module
	Author: tobychui

	This module record the IP blacklist of users trying to enter the
	system without permission

*/

type BlackList struct {
	Enabled  bool
	database *db.Database
}

func NewBlacklistManager(sysdb *db.Database) *BlackList {
	sysdb.NewTable("ipblacklist")

	return &BlackList{
		Enabled:  true,
		database: sysdb,
	}
}

func (bl *BlackList) IsBanned(ip string) bool {
	if bl.database.KeyExists("ipblacklist", ip) {
		return true
	}
	return false
}

func (bl *BlackList) SetBan(ipRange string) error {
	//Check if the IP range is correct
	err := validateIpRange(ipRange)
	if err != nil {
		return err
	}

	return nil
}

func ipInRange(ip string, ipRange string) bool {
	ip = strings.TrimSpace(ip)
	ipRange = strings.TrimSpace(ipRange)
	if ip == ipRange {
		//For fields that the ipRange is the ip itself
		return true
	}

	//Try matching range
	if strings.Contains(ipRange, "-") {
		//For range, in A.B.C.D, the A.B.C part must be the same, so do prefix matching
		ips := strings.Split(ipRange, "-")
		startSubnet := ips[0][:strings.LastIndex(ips[0], ".")]
		targetIpSubnet := ip[:strings.LastIndex(ip, ".")]
		if startSubnet == targetIpSubnet {
			//Check the last value in range
			StartDval, _ := strconv.Atoi(ips[0][strings.LastIndex(ips[0], ".")+1:])
			EndDval, _ := strconv.Atoi(ips[1][strings.LastIndex(ips[1], ".")+1:])
			thisDVal, _ := strconv.Atoi(ip[strings.LastIndex(ip, ".")+1:])

			if thisDVal > StartDval && thisDVal < EndDval {
				//In range
				return true
			} else {
				//Not in range
				return false
			}
		} else {
			//Subnet different. Must be not in this range
			return false
		}

	}
	return false
}

//Check if the given IP Range string is actually an IP range
func validateIpRange(ipRange string) error {
	ipRange = strings.TrimSpace(ipRange)
	ipRange = strings.ReplaceAll(ipRange, " ", "")
	if strings.Contains(ipRange, "-") {
		//This is a range
		if strings.Count(ipRange, "-") != 1 {
			//Invalid range defination
			return errors.New("Invalid ip range defination")
		}
		ips := strings.Split(ipRange, "-")
		//Check if the starting IP and ending IP are both valid
		if net.ParseIP(ips[0]) == nil {
			return errors.New("Starting ip is invalid")
		}

		if net.ParseIP(ips[1]) == nil {
			return errors.New("Ending ip is invalid")
		}

		//Check if the ending IP is larger than the starting IP
		startingIpInt, _ := strconv.Atoi(strings.ReplaceAll(ips[0], ".", ""))
		endingIpInt, _ := strconv.Atoi(strings.ReplaceAll(ips[1], ".", ""))

		if startingIpInt >= endingIpInt {
			return errors.New("Invalid ip range: Starting IP is larger or equal to ending ip")
		}

		//Check if they are in the same subnet
		startSubnet := ips[0][:strings.LastIndex(ips[0], ".")]
		endSubnet := ips[1][:strings.LastIndex(ips[1], ".")]

		if startSubnet != endSubnet {
			//They are not in the same subnet
			return errors.New("IP range subnet mismatch")
		}

	} else {
		//This is a single IP instead of range. Check if it is a valid IP addr
		if net.ParseIP(ipRange) != nil {
			//Ok
			return nil
		} else {
			return errors.New("Invalid ip given")
		}
	}

	return nil
}