crowdsec/pkg/exprhelpers/exprlib.go
Thibault "bui" Koechlin a3d00fe130
skip empty lines to avoid issue of #630 (#631)
* skip empty lines to avoid issue of #630

* add tests on empty lines and comms
2021-02-25 09:57:24 +01:00

136 lines
3.1 KiB
Go

package exprhelpers
import (
"bufio"
"fmt"
"net"
"os"
"path"
"regexp"
"strconv"
"strings"
"github.com/davecgh/go-spew/spew"
log "github.com/sirupsen/logrus"
)
var dataFile map[string][]string
var dataFileRegex map[string][]*regexp.Regexp
func Atof(x string) float64 {
log.Debugf("debug atof %s", x)
ret, err := strconv.ParseFloat(x, 64)
if err != nil {
log.Warningf("Atof : can't convert float '%s' : %v", x, err)
}
return ret
}
func Upper(s string) string {
return strings.ToUpper(s)
}
func GetExprEnv(ctx map[string]interface{}) map[string]interface{} {
var ExprLib = map[string]interface{}{
"Atof": Atof,
"JsonExtract": JsonExtract,
"JsonExtractLib": JsonExtractLib,
"File": File,
"RegexpInFile": RegexpInFile,
"Upper": Upper,
"IpInRange": IpInRange,
}
for k, v := range ctx {
ExprLib[k] = v
}
return ExprLib
}
func Init() error {
dataFile = make(map[string][]string)
dataFileRegex = make(map[string][]*regexp.Regexp)
return nil
}
func FileInit(fileFolder string, filename string, fileType string) error {
log.Debugf("init (folder:%s) (file:%s) (type:%s)", fileFolder, filename, fileType)
filepath := path.Join(fileFolder, filename)
file, err := os.Open(filepath)
if err != nil {
return err
}
defer file.Close()
if fileType == "" {
log.Debugf("ignored file %s%s because no type specified", fileFolder, filename)
return nil
}
if _, ok := dataFile[filename]; !ok {
dataFile[filename] = []string{}
}
scanner := bufio.NewScanner(file)
for scanner.Scan() {
if strings.HasPrefix(scanner.Text(), "#") { // allow comments
continue
}
if len(scanner.Text()) == 0 { //skip empty lines
continue
}
switch fileType {
case "regex", "regexp":
dataFileRegex[filename] = append(dataFileRegex[filename], regexp.MustCompile(scanner.Text()))
case "string":
dataFile[filename] = append(dataFile[filename], scanner.Text())
default:
return fmt.Errorf("unknown data type '%s' for : '%s'", fileType, filename)
}
}
if err := scanner.Err(); err != nil {
return err
}
return nil
}
func File(filename string) []string {
if _, ok := dataFile[filename]; ok {
return dataFile[filename]
}
log.Errorf("file '%s' (type:string) not found in expr library", filename)
log.Errorf("expr library : %s", spew.Sdump(dataFile))
return []string{}
}
func RegexpInFile(data string, filename string) bool {
if _, ok := dataFileRegex[filename]; ok {
for _, re := range dataFileRegex[filename] {
if re.Match([]byte(data)) {
return true
}
}
} else {
log.Errorf("file '%s' (type:regexp) not found in expr library", filename)
log.Errorf("expr library : %s", spew.Sdump(dataFileRegex))
}
return false
}
func IpInRange(ip string, ipRange string) bool {
var err error
var ipParsed net.IP
var ipRangeParsed *net.IPNet
ipParsed = net.ParseIP(ip)
if ipParsed == nil {
log.Debugf("'%s' is not a valid IP", ip)
return false
}
if _, ipRangeParsed, err = net.ParseCIDR(ipRange); err != nil {
log.Debugf("'%s' is not a valid IP Range", ipRange)
return false
}
if ipRangeParsed.Contains(ipParsed) {
return true
}
return false
}