[nginx] QUIC: allowed ngx_quic_frame_sendto() to return NGX_AGAIN.

[Roman Arutyunyan]

details:   https://hg.nginx.org/nginx/rev/f3412ec3b6d1
branches:  
changeset: 9146:f3412ec3b6d1
user:      Roman Arutyunyan <arut at nginx.com>
date:      Tue Aug 08 10:43:17 2023 +0400
description:
QUIC: allowed ngx_quic_frame_sendto() to return NGX_AGAIN.

Previously, NGX_AGAIN returned by ngx_quic_send() was treated by
ngx_quic_frame_sendto() as error, which triggered errors in its callers.
However, a blocked socket is not an error.  Now NGX_AGAIN is passed as is to
the ngx_quic_frame_sendto() callers, which can safely ignore it.

diffstat:

 src/event/quic/ngx_event_quic_migration.c |  6 +++---
 src/event/quic/ngx_event_quic_output.c    |  2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diffs (40 lines):

diff -r 93aee926d27f -r f3412ec3b6d1 src/event/quic/ngx_event_quic_migration.c
--- a/src/event/quic/ngx_event_quic_migration.c	Thu Jul 06 11:30:47 2023 +0400
+++ b/src/event/quic/ngx_event_quic_migration.c	Tue Aug 08 10:43:17 2023 +0400
@@ -46,7 +46,7 @@ ngx_quic_handle_path_challenge_frame(ngx
      * An endpoint MUST expand datagrams that contain a PATH_RESPONSE frame
      * to at least the smallest allowed maximum datagram size of 1200 bytes.
      */
-    if (ngx_quic_frame_sendto(c, &frame, 1200, pkt->path) != NGX_OK) {
+    if (ngx_quic_frame_sendto(c, &frame, 1200, pkt->path) == NGX_ERROR) {
         return NGX_ERROR;
     }
 
@@ -544,13 +544,13 @@ ngx_quic_send_path_challenge(ngx_connect
      */
 
      /* same applies to PATH_RESPONSE frames */
-    if (ngx_quic_frame_sendto(c, &frame, 1200, path) != NGX_OK) {
+    if (ngx_quic_frame_sendto(c, &frame, 1200, path) == NGX_ERROR) {
         return NGX_ERROR;
     }
 
     ngx_memcpy(frame.u.path_challenge.data, path->challenge2, 8);
 
-    if (ngx_quic_frame_sendto(c, &frame, 1200, path) != NGX_OK) {
+    if (ngx_quic_frame_sendto(c, &frame, 1200, path) == NGX_ERROR) {
         return NGX_ERROR;
     }
 
diff -r 93aee926d27f -r f3412ec3b6d1 src/event/quic/ngx_event_quic_output.c
--- a/src/event/quic/ngx_event_quic_output.c	Thu Jul 06 11:30:47 2023 +0400
+++ b/src/event/quic/ngx_event_quic_output.c	Tue Aug 08 10:43:17 2023 +0400
@@ -1233,7 +1233,7 @@ ngx_quic_frame_sendto(ngx_connection_t *
 
     sent = ngx_quic_send(c, res.data, res.len, path->sockaddr, path->socklen);
     if (sent < 0) {
-        return NGX_ERROR;
+        return sent;
     }
 
     path->sent += sent;