From 90be9a8ab95a06d7e622852bf312116c7e199d48 Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Fri, 30 Sep 2022 12:20:07 +0200
Subject: [PATCH] downstream: stop sending HTTP OPTIONS request on WEBPUSH
 REGISTER

We were sending a test notification later anyways. Let's just do
that to check that the endpoint accepts our messages.
---
 downstream.go | 66 ++++++++++++---------------------------------------
 1 file changed, 15 insertions(+), 51 deletions(-)

diff --git a/downstream.go b/downstream.go
index 12dcaff..6302a5c 100644
--- a/downstream.go
+++ b/downstream.go
@@ -9,7 +9,6 @@ import (
 	"fmt"
 	"io"
 	"net"
-	"net/http"
 	"strconv"
 	"strings"
 	"time"
@@ -3060,14 +3059,6 @@ func (dc *downstreamConn) handleMessageRegistered(ctx context.Context, msg *irc.
 				return err
 			}
 
-			if err := checkWebPushEndpoint(ctx, endpoint); err != nil {
-				dc.logger.Printf("failed to check Web push endpoint %q: %v", endpoint, err)
-				return ircError{&irc.Message{
-					Command: "FAIL",
-					Params:  []string{"WEBPUSH", "INVALID_PARAMS", subcommand, "Invalid endpoint"},
-				}}
-			}
-
 			rawKeys := irc.ParseTags(keysStr)
 			authKey, hasAuthKey := rawKeys["auth"]
 			p256dhKey, hasP256dh := rawKeys["p256dh"]
@@ -3112,16 +3103,7 @@ func (dc *downstreamConn) handleMessageRegistered(ctx context.Context, msg *irc.
 				networkID = dc.network.ID
 			}
 
-			// TODO: limit max number of subscriptions, prune old ones
-
-			if err := dc.user.srv.db.StoreWebPushSubscription(ctx, dc.user.ID, networkID, &newSub); err != nil {
-				dc.logger.Printf("failed to store Web push subscription: %v", err)
-				return ircError{&irc.Message{
-					Command: "FAIL",
-					Params:  []string{"WEBPUSH", "INTERNAL_ERROR", subcommand, "Internal error"},
-				}}
-			}
-
+			// Send a test Web Push message, to make sure the endpoint is valid
 			err = dc.srv.sendWebPush(ctx, &webpush.Subscription{
 				Endpoint: newSub.Endpoint,
 				Keys: webpush.Keys{
@@ -3134,6 +3116,20 @@ func (dc *downstreamConn) handleMessageRegistered(ctx context.Context, msg *irc.
 			})
 			if err != nil {
 				dc.logger.Printf("failed to send Web push notification to endpoint %q: %v", newSub.Endpoint, err)
+				return ircError{&irc.Message{
+					Command: "FAIL",
+					Params:  []string{"WEBPUSH", "INVALID_PARAMS", subcommand, "Invalid endpoint"},
+				}}
+			}
+
+			// TODO: limit max number of subscriptions, prune old ones
+
+			if err := dc.user.srv.db.StoreWebPushSubscription(ctx, dc.user.ID, networkID, &newSub); err != nil {
+				dc.logger.Printf("failed to store Web push subscription: %v", err)
+				return ircError{&irc.Message{
+					Command: "FAIL",
+					Params:  []string{"WEBPUSH", "INTERNAL_ERROR", subcommand, "Internal error"},
+				}}
 			}
 
 			dc.SendMessage(&irc.Message{
@@ -3336,35 +3332,3 @@ func sendNames(dc *downstreamConn, ch *upstreamChannel) {
 		dc.SendMessage(msg)
 	}
 }
-
-func checkWebPushEndpoint(ctx context.Context, endpoint string) error {
-	req, err := http.NewRequestWithContext(ctx, http.MethodOptions, endpoint, nil)
-	if err != nil {
-		return fmt.Errorf("failed to create HTTP request: %v", err)
-	}
-
-	resp, err := http.DefaultClient.Do(req)
-	if err != nil {
-		return fmt.Errorf("HTTP request failed: %v", err)
-	}
-	resp.Body.Close()
-
-	if resp.StatusCode/100 != 2 {
-		return fmt.Errorf("HTTP request failed: %v", resp.Status)
-	}
-
-	allow := strings.Split(resp.Header.Get("Allow"), ",")
-	found := false
-	for _, method := range allow {
-		if strings.EqualFold(strings.TrimSpace(method), http.MethodPost) {
-			found = true
-			break
-		}
-	}
-
-	if !found {
-		return fmt.Errorf("POST missing from Allow header in OPTIONS response")
-	}
-
-	return nil
-}