[PATCH 3 of 3] QUIC: stream recv shutdown support

[Roman Arutyunyan]

# HG changeset patch
# User Roman Arutyunyan <arut at nginx.com>
# Date 1637695967 -10800
#      Tue Nov 23 22:32:47 2021 +0300
# Branch quic
# Node ID e1de02d829f7f85b1e2e6b289ec4c20318712321
# Parent  3d2354bfa1a2a257b9f73772ad0836585be85a6c
QUIC: stream recv shutdown support.

Recv shutdown sends STOP_SENDING to client.  Both send and recv shutdown
functions are now called from stream cleanup handler.  While here, setting
c->read->pending_eof is moved down to fix recv shutdown in the cleanup handler.

diff --git a/src/event/quic/ngx_event_quic_streams.c b/src/event/quic/ngx_event_quic_streams.c
--- a/src/event/quic/ngx_event_quic_streams.c
+++ b/src/event/quic/ngx_event_quic_streams.c
@@ -13,6 +13,8 @@
 #define NGX_QUIC_STREAM_GONE     (void *) -1
 
 
+static ngx_int_t ngx_quic_shutdown_stream_send(ngx_connection_t *c);
+static ngx_int_t ngx_quic_shutdown_stream_recv(ngx_connection_t *c);
 static ngx_quic_stream_t *ngx_quic_get_stream(ngx_connection_t *c, uint64_t id);
 static ngx_int_t ngx_quic_reject_stream(ngx_connection_t *c, uint64_t id);
 static void ngx_quic_init_stream_handler(ngx_event_t *ev);
@@ -257,16 +259,24 @@ ngx_quic_reset_stream(ngx_connection_t *
 ngx_int_t
 ngx_quic_shutdown_stream(ngx_connection_t *c, int how)
 {
+    if (how == NGX_WRITE_SHUTDOWN) {
+        return ngx_quic_shutdown_stream_send(c);
+
+    } else {
+        return ngx_quic_shutdown_stream_recv(c);
+    }
+}
+
+
+static ngx_int_t
+ngx_quic_shutdown_stream_send(ngx_connection_t *c)
+{
     ngx_event_t            *wev;
     ngx_connection_t       *pc;
     ngx_quic_frame_t       *frame;
     ngx_quic_stream_t      *qs;
     ngx_quic_connection_t  *qc;
 
-    if (how != NGX_WRITE_SHUTDOWN) {
-        return NGX_OK;
-    }
-
     wev = c->write;
 
     if (wev->error) {
@@ -283,7 +293,7 @@ ngx_quic_shutdown_stream(ngx_connection_
     }
 
     ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
-                   "quic stream id:0x%xL shutdown", qs->id);
+                   "quic stream id:0x%xL send shutdown", qs->id);
 
     frame->level = ssl_encryption_application;
     frame->type = NGX_QUIC_FT_STREAM;
@@ -304,6 +314,48 @@ ngx_quic_shutdown_stream(ngx_connection_
 }
 
 
+static ngx_int_t
+ngx_quic_shutdown_stream_recv(ngx_connection_t *c)
+{
+    ngx_event_t            *rev;
+    ngx_connection_t       *pc;
+    ngx_quic_frame_t       *frame;
+    ngx_quic_stream_t      *qs;
+    ngx_quic_connection_t  *qc;
+
+    rev = c->read;
+
+    if (rev->pending_eof || rev->error) {
+        return NGX_OK;
+    }
+
+    qs = c->quic;
+    pc = qs->parent;
+    qc = ngx_quic_get_connection(pc);
+
+    if (qc->conf->stream_close_code == 0) {
+        return NGX_OK;
+    }
+
+    frame = ngx_quic_alloc_frame(pc);
+    if (frame == NULL) {
+        return NGX_ERROR;
+    }
+
+    ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
+                   "quic stream id:0x%xL recv shutdown", qs->id);
+
+    frame->level = ssl_encryption_application;
+    frame->type = NGX_QUIC_FT_STOP_SENDING;
+    frame->u.stop_sending.id = qs->id;
+    frame->u.stop_sending.error_code = qc->conf->stream_close_code;
+
+    ngx_quic_queue_frame(qc, frame);
+
+    return NGX_OK;
+}
+
+
 static ngx_quic_stream_t *
 ngx_quic_get_stream(ngx_connection_t *c, uint64_t id)
 {
@@ -918,30 +970,18 @@ ngx_quic_stream_cleanup_handler(void *da
         goto done;
     }
 
-    c->read->pending_eof = 1;
-
-    (void) ngx_quic_update_flow(c, qs->recv_last);
-
     if ((qs->id & NGX_QUIC_STREAM_SERVER_INITIATED) == 0
         || (qs->id & NGX_QUIC_STREAM_UNIDIRECTIONAL) == 0)
     {
-        if (!c->read->pending_eof && !c->read->error
-            && qc->conf->stream_close_code)
-        {
-            frame = ngx_quic_alloc_frame(pc);
-            if (frame == NULL) {
-                goto done;
-            }
-
-            frame->level = ssl_encryption_application;
-            frame->type = NGX_QUIC_FT_STOP_SENDING;
-            frame->u.stop_sending.id = qs->id;
-            frame->u.stop_sending.error_code = qc->conf->stream_close_code;
-
-            ngx_quic_queue_frame(qc, frame);
+        if (ngx_quic_shutdown_stream_recv(c) != NGX_OK) {
+            goto done;
         }
     }
 
+    c->read->pending_eof = 1;
+
+    (void) ngx_quic_update_flow(c, qs->recv_last);
+
     if ((qs->id & NGX_QUIC_STREAM_SERVER_INITIATED) == 0) {
         frame = ngx_quic_alloc_frame(pc);
         if (frame == NULL) {
@@ -968,29 +1008,7 @@ ngx_quic_stream_cleanup_handler(void *da
         }
     }
 
-    if (c->write->error) {
-        goto done;
-    }
-
-    ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
-                   "quic stream id:0x%xL send fin", qs->id);
-
-    frame = ngx_quic_alloc_frame(pc);
-    if (frame == NULL) {
-        goto done;
-    }
-
-    frame->level = ssl_encryption_application;
-    frame->type = NGX_QUIC_FT_STREAM;
-    frame->u.stream.off = 1;
-    frame->u.stream.len = 1;
-    frame->u.stream.fin = 1;
-
-    frame->u.stream.stream_id = qs->id;
-    frame->u.stream.offset = c->sent;
-    frame->u.stream.length = 0;
-
-    ngx_quic_queue_frame(qc, frame);
+    (void) ngx_quic_shutdown_stream_send(c);
 
 done: