First shot at using regex for referrer check to improve situation on gochan.org

src/server.go

@@ -10,6 +10,7 @@ import (
 	"net/url"
 	"os"
 	"path"
+	"regexp"
 	"strconv"
 	"strings"
 )
@@ -22,6 +23,7 @@ var (
 	request       http.Request
 	exit_error    bool
 	server        *GochanServer
+	referrerRegex *regexp.Regexp
 )
 
 type GochanServer struct {
@@ -179,7 +181,17 @@ func getRealIP(r *http.Request) (ip string) {
 }
 
 func validReferrer(request http.Request) (valid bool) {
-	valid = !(request.Referer() == "" || len(request.Referer()) < len(config.SiteDomain) || request.Referer()[7:len(config.SiteDomain)+7] != config.SiteDomain)
+	if referrerRegex == nil {
+		referrerRegex, err := regexp.Compile(config.DomainRegex)
+		if err != nil || referrerRegex == nil {
+			valid = false
+			return
+		}
+	}
+
+	valid = referrerRegex.MatchString(request.Referer())
+	// Old Referrer check.
+	// valid = !(request.Referer() == "" || len(request.Referer()) < len(config.SiteDomain) || request.Referer()[7:len(config.SiteDomain)+7] != config.SiteDomain)
 	return
 }
 

src/types.go

@@ -293,6 +293,7 @@ type GochanConfig struct {
 	SiteHeaderURL string
 	SiteWebfolder string
 	SiteDomain    string
+	DomainRegex   string
 
 	Styles_img       []string
 	DefaultStyle_img string
@@ -481,6 +482,10 @@ func initConfig() {
 		os.Exit(2)
 	}
 
+	if config.DomainRegex == "" {
+		config.DomainRegex = "/(https|http):\\/\\/(" + config.SiteDomain + ")\\/(.*)/"
+	}
+
 	if config.Styles_img == nil {
 		println(0, "Styles_img not set in gochan.json, halting.")
 		os.Exit(2)