styx/filters/main.go

package filters

import (
	"bufio"
	"io/ioutil"
	"net"
	"os"
	"path/filepath"
	"regexp"
	"runtime"

	"github.com/sirupsen/logrus"
)

var (
	_, b, _, _ = runtime.Caller(0)
	basepath   = filepath.Dir(b)
)

// RunIPFilters runs the battery of filters for an IP.
func RunIPFilters(inputIP string) bool {
	ip := net.ParseIP(inputIP)
	if ip == nil {
		return false
	}
	if ip.To4() != nil {
		path := basepath + "/data/ipv4/"
		sliceIPv4, err := ioutil.ReadDir(path)
		if err != nil {
			logrus.Warn("filters#ReadDir#ipv4", err)
		}

		for _, file := range sliceIPv4 {
			f, err := os.OpenFile(path+file.Name(), 1, 0644)
			if err != nil {
				logrus.Warn("filters#OpenFile#", err)
			}
			defer f.Close()

			scanner := bufio.NewScanner(f)
			for scanner.Scan() {
				_, ipNet, err := net.ParseCIDR(scanner.Text())
				if err != nil {
					continue
				}
				if ipNet.Contains(ip) {
					return true
				}
			}
		}
	} else if ip.To16() != nil {
		// run ipv6 filter battery
	} else {
		logrus.Error("filters#invalid IP format for", inputIP)
		return false
	}

	return false
}

// RunDomainFilters run filters on a targeted domain.
func RunDomainFilters(domain string) bool {
	path := basepath + "/data/domain/"
	sliceDomain, err := ioutil.ReadDir(path)
	if err != nil {
		logrus.Warn("filters#ReadDir#domains", err)
	}

	for _, file := range sliceDomain {
		f, err := os.OpenFile(path+file.Name(), 1, 0644)
		if err != nil {
			logrus.Warn("filters#OpenFile#", err)
		}
		defer f.Close()
		scanner := bufio.NewScanner(f)

		for scanner.Scan() {
			r, err := regexp.Compile(scanner.Text())
			if err != nil {
				logrus.Warn("filters#Compile#", err)
			}
			if r.MatchString(domain) {
				return false
			}
		}
	}
	return true
}