chore: refactor

util/config.go

@@ -0,0 +1,112 @@
+package util
+
+import (
+	"flag"
+	"fmt"
+	"regexp"
+	"strings"
+
+	"github.com/pterm/pterm"
+	log "github.com/sirupsen/logrus"
+)
+
+type Config struct {
+	Addr           *string
+	Port           *int
+	Dns            *string
+	Debug          *bool
+	Banner         *bool
+	AllowedPattern *regexp.Regexp
+	AllowedUrls    *regexp.Regexp
+}
+
+type ArrayFlags []string
+
+func (i *ArrayFlags) String() string {
+	return "my string representation"
+}
+
+func (i *ArrayFlags) Set(value string) error {
+	*i = append(*i, value)
+	return nil
+}
+
+var config *Config
+var allowedHosts ArrayFlags
+var allowedPattern *string
+
+func GetConfig() *Config {
+	return config
+}
+
+func (c *Config) PatternExists() bool {
+	return c.AllowedPattern != nil || c.AllowedUrls != nil
+}
+
+func (c *Config) PatternMatches(bytes []byte) bool {
+	return (c.AllowedPattern != nil && c.AllowedPattern.Match(bytes)) ||
+		(c.AllowedUrls != nil && c.AllowedUrls.Match(bytes))
+}
+
+func ParseArgs() {
+	config = &Config{}
+	config.Addr = flag.String("addr", "127.0.0.1", "Listen addr")
+	config.Port = flag.Int("port", 8080, "port")
+	config.Dns = flag.String("dns", "8.8.8.8", "DNS server")
+	config.Debug = flag.Bool("debug", false, "true | false")
+	config.Banner = flag.Bool("banner", true, "true | false")
+
+	flag.Var(&allowedHosts, "url", "Bypass DPI only on this url, can be passed multiple times")
+	allowedPattern = flag.String(
+		"pattern",
+		"",
+		"Bypass DPI only on packets matching this regex pattern",
+	)
+
+	flag.Parse()
+
+	if len(allowedHosts) > 0 {
+		var escapedUrls []string
+		for _, host := range allowedHosts {
+			escapedUrls = append(escapedUrls, regexp.QuoteMeta(host))
+		}
+
+		allowedHostsRegex := strings.Join(escapedUrls, "|")
+		config.AllowedUrls = regexp.MustCompile(allowedHostsRegex)
+	}
+
+    log.Info(*allowedPattern)
+	if *allowedPattern != "" {
+		config.AllowedPattern = regexp.MustCompile(*allowedPattern)
+	}
+}
+
+func PrintColoredBanner() {
+	cyan := pterm.NewLettersFromStringWithStyle("Spoof", pterm.NewStyle(pterm.FgCyan))
+	purple := pterm.NewLettersFromStringWithStyle("DPI", pterm.NewStyle(pterm.FgLightMagenta))
+	pterm.DefaultBigText.WithLetters(cyan, purple).Render()
+
+	pterm.DefaultBulletList.WithItems([]pterm.BulletListItem{
+		{Level: 0, Text: "ADDR    : " + *config.Addr},
+		{Level: 0, Text: "PORT    : " + fmt.Sprint(*config.Port)},
+		{Level: 0, Text: "DNS     : " + *config.Dns},
+		{Level: 0, Text: "DEBUG   : " + fmt.Sprint(*config.Debug)},
+	}).Render()
+
+    if allowedHosts != nil && len(allowedHosts) > 0 {
+        log.Info("White listed urls: ", allowedHosts)
+    }
+
+    if *allowedPattern != "" {
+        log.Info("Regex Pattern: ", *allowedPattern)
+    }
+}
+
+func PrintSimpleInfo() {
+	fmt.Println("")
+	fmt.Println("- ADDR  : ", *config.Addr)
+	fmt.Println("- PORT  : ", *config.Port)
+	fmt.Println("- DNS   : ", *config.Dns)
+	fmt.Println("- DEBUG : ", *config.Debug)
+	fmt.Println("")
+}