From 0cfb14a18be3510de6a519310fd162ae5b7761a6 Mon Sep 17 00:00:00 2001
From: johnthecoderpro <149151524+johnthecoderpro@users.noreply.github.com>
Date: Mon, 30 Oct 2023 21:12:35 +0330
Subject: [PATCH] Fix geoip download bug

This is how sing-box tries to handle downloading geoip.db file

Senari 1
if the geoip.db file path exists then it tries to open the file and parse it. if file is empty or has invalid content it return error invalid MaxMind DB otherwise it parse the file successfully

Senari 2
if the geoip.db file path does not exist first it creates the geoip.db file but with empty content and then it tries to download the geoip.db file.if file downloaded successfully it copy the response to the to the geoip.db file but if download gets an error it return error and the geoip.db file remains with empty content and zero size so in the next run we have Senari 1 because the file path exists but we get an error because the file is empty.

Solution
so i change the order of create file to fix that problem
the file created only after the file  successfully downloaded.

Signed-off-by: johnthecoderpro <149151524+johnthecoderpro@users.noreply.github.com>
---
 route/router_geo_resources.go | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/route/router_geo_resources.go b/route/router_geo_resources.go
index 7abc5db5..b35515d1 100644
--- a/route/router_geo_resources.go
+++ b/route/router_geo_resources.go
@@ -157,12 +157,6 @@ func (r *Router) downloadGeoIPDatabase(savePath string) error {
 		filemanager.MkdirAll(r.ctx, parentDir, 0o755)
 	}
 
-	saveFile, err := filemanager.Create(r.ctx, savePath)
-	if err != nil {
-		return E.Cause(err, "open output file: ", downloadURL)
-	}
-	defer saveFile.Close()
-
 	httpClient := &http.Client{
 		Transport: &http.Transport{
 			ForceAttemptHTTP2:   true,
@@ -182,6 +176,13 @@ func (r *Router) downloadGeoIPDatabase(savePath string) error {
 		return err
 	}
 	defer response.Body.Close()
+
+	saveFile, err := filemanager.Create(r.ctx, savePath)
+	if err != nil {
+		return E.Cause(err, "open output file: ", downloadURL)
+	}
+	defer saveFile.Close()
+	
 	_, err = io.Copy(saveFile, response.Body)
 	return err
 }
@@ -209,12 +210,6 @@ func (r *Router) downloadGeositeDatabase(savePath string) error {
 		filemanager.MkdirAll(r.ctx, parentDir, 0o755)
 	}
 
-	saveFile, err := filemanager.Create(r.ctx, savePath)
-	if err != nil {
-		return E.Cause(err, "open output file: ", downloadURL)
-	}
-	defer saveFile.Close()
-
 	httpClient := &http.Client{
 		Transport: &http.Transport{
 			ForceAttemptHTTP2:   true,
@@ -234,6 +229,13 @@ func (r *Router) downloadGeositeDatabase(savePath string) error {
 		return err
 	}
 	defer response.Body.Close()
+
+	saveFile, err := filemanager.Create(r.ctx, savePath)
+	if err != nil {
+		return E.Cause(err, "open output file: ", downloadURL)
+	}
+	defer saveFile.Close()
+	
 	_, err = io.Copy(saveFile, response.Body)
 	return err
 }