[PATCH 2 of 2] QUIC: handle DATA_BLOCKED frame from client

Vladimir Homutov vl at nginx.com
Mon Nov 22 12:00:20 UTC 2021


On Mon, Nov 22, 2021 at 02:54:20PM +0300, Roman Arutyunyan wrote:
> On Mon, Nov 22, 2021 at 11:26:10AM +0300, Vladimir Homutov wrote:
> > On Wed, Nov 17, 2021 at 10:31:02AM +0300, Roman Arutyunyan wrote:
> > > # HG changeset patch
> > > # User Roman Arutyunyan <arut at nginx.com>
> > > # Date 1637086755 -10800
> > > #      Tue Nov 16 21:19:15 2021 +0300
> > > # Branch quic
> > > # Node ID 0fb2613594f6bd8dd8f07a30c69900866b573158
> > > # Parent  4e3a7fc0533192f51a01042a1e9dd2b595881420
> > > QUIC: handle DATA_BLOCKED frame from client.
> > >
> > > Previously the frame was not handled and connection was closed with an error.
> > > Now, after receiving this frame, global flow control is updated and new
> > > flow control credit is sent to client.
> > >
> > > diff --git a/src/event/quic/ngx_event_quic.c b/src/event/quic/ngx_event_quic.c
> > > --- a/src/event/quic/ngx_event_quic.c
> > > +++ b/src/event/quic/ngx_event_quic.c
> > > @@ -1252,6 +1252,17 @@ ngx_quic_handle_frames(ngx_connection_t
> > >
> > >              break;
> > >
> > > +        case NGX_QUIC_FT_DATA_BLOCKED:
> > > +
> > > +            if (ngx_quic_handle_data_blocked_frame(c, pkt,
> > > +                                                   &frame.u.data_blocked)
> > > +                != NGX_OK)
> > > +            {
> > > +                return NGX_ERROR;
> > > +            }
> > > +
> > > +            break;
> > > +
> > >          case NGX_QUIC_FT_STREAM_DATA_BLOCKED:
> > >
> > >              if (ngx_quic_handle_stream_data_blocked_frame(c, pkt,
> > > 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
> > > @@ -32,6 +32,7 @@ static void ngx_quic_stream_cleanup_hand
> > >  static ngx_int_t ngx_quic_control_flow(ngx_connection_t *c, uint64_t last);
> > >  static ngx_int_t ngx_quic_update_flow(ngx_connection_t *c, uint64_t last);
> > >  static ngx_int_t ngx_quic_update_max_stream_data(ngx_connection_t *c);
> > > +static ngx_int_t ngx_quic_update_max_data(ngx_connection_t *c);
> > >
> > >
> > >  ngx_connection_t *
> > > @@ -1188,6 +1189,14 @@ ngx_quic_handle_streams_blocked_frame(ng
> > >
> > >
> > >  ngx_int_t
> > > +ngx_quic_handle_data_blocked_frame(ngx_connection_t *c,
> > > +    ngx_quic_header_t *pkt, ngx_quic_data_blocked_frame_t *f)
> > > +{
> > > +    return ngx_quic_update_max_data(c);
> > > +}
> > > +
> > > +
> > > +ngx_int_t
> > >  ngx_quic_handle_stream_data_blocked_frame(ngx_connection_t *c,
> > >      ngx_quic_header_t *pkt, ngx_quic_stream_data_blocked_frame_t *f)
> > >  {
> > > @@ -1544,7 +1553,6 @@ ngx_quic_update_flow(ngx_connection_t *c
> > >      uint64_t                len;
> > >      ngx_event_t            *rev;
> > >      ngx_connection_t       *pc;
> > > -    ngx_quic_frame_t       *frame;
> > >      ngx_quic_stream_t      *qs;
> > >      ngx_quic_connection_t  *qc;
> > >
> > > @@ -1577,22 +1585,9 @@ ngx_quic_update_flow(ngx_connection_t *c
> > >      if (qc->streams.recv_max_data
> > >          <= qc->streams.recv_offset + qc->streams.recv_window / 2)
> > >      {
> > > -        qc->streams.recv_max_data = qc->streams.recv_offset
> > > -                                    + qc->streams.recv_window;
> > > -
> > > -        ngx_log_debug1(NGX_LOG_DEBUG_EVENT, pc->log, 0,
> > > -                       "quic flow update md:%uL", qc->streams.recv_max_data);
> > > -
> > > -        frame = ngx_quic_alloc_frame(pc);
> > > -        if (frame == NULL) {
> > > +        if (ngx_quic_update_max_data(pc) != NGX_OK) {
> > >              return NGX_ERROR;
> > >          }
> > > -
> > > -        frame->level = ssl_encryption_application;
> > > -        frame->type = NGX_QUIC_FT_MAX_DATA;
> > > -        frame->u.max_data.max_data = qc->streams.recv_max_data;
> > > -
> > > -        ngx_quic_queue_frame(qc, frame);
> > >      }
> > >
> > >      return NGX_OK;
> > > @@ -1637,6 +1632,41 @@ ngx_quic_update_max_stream_data(ngx_conn
> > >  }
> > >
> > >
> > > +static ngx_int_t
> > > +ngx_quic_update_max_data(ngx_connection_t *c)
> > > +{
> > > +    uint64_t                recv_max_data;
> > > +    ngx_quic_frame_t       *frame;
> > > +    ngx_quic_connection_t  *qc;
> > > +
> > > +    qc = ngx_quic_get_connection(c);
> > > +
> > > +    recv_max_data = qc->streams.recv_offset + qc->streams.recv_window;
> > > +
> > > +    if (qc->streams.recv_max_data == recv_max_data) {
> > > +        return NGX_OK;
> > > +    }
> >
> > same question as in previous patch; logic is the same;
>
> Same answer.

ok, got it now.

>
> > > +    qc->streams.recv_max_data = recv_max_data;
> > > +
> > > +    ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
> > > +                   "quic flow update md:%uL", qc->streams.recv_max_data);
> > > +
> > > +    frame = ngx_quic_alloc_frame(c);
> >
> > looks like the same issue as in the previous patch - should be pc here
>
> No.  Here we already have the parent connection, not a stream connection.
> Maybe we need to rename 'c' to 'pc' everywhere for parent connection to make it
> clear.

I don't think it's worth it, since we get 'c' as argument and no other
connection is supposed.

Both patches look good for me.

>
> > > +    if (frame == NULL) {
> > > +        return NGX_ERROR;
> > > +    }
> > > +
> > > +    frame->level = ssl_encryption_application;
> > > +    frame->type = NGX_QUIC_FT_MAX_DATA;
> > > +    frame->u.max_data.max_data = qc->streams.recv_max_data;
> > > +
> > > +    ngx_quic_queue_frame(qc, frame);
> > > +
> > > +    return NGX_OK;
> > > +}
> > > +
> > > +
> > >  ngx_int_t
> > >  ngx_quic_handle_read_event(ngx_event_t *rev, ngx_uint_t flags)
> > >  {
> > > diff --git a/src/event/quic/ngx_event_quic_streams.h b/src/event/quic/ngx_event_quic_streams.h
> > > --- a/src/event/quic/ngx_event_quic_streams.h
> > > +++ b/src/event/quic/ngx_event_quic_streams.h
> > > @@ -20,6 +20,8 @@ ngx_int_t ngx_quic_handle_max_data_frame
> > >      ngx_quic_max_data_frame_t *f);
> > >  ngx_int_t ngx_quic_handle_streams_blocked_frame(ngx_connection_t *c,
> > >      ngx_quic_header_t *pkt, ngx_quic_streams_blocked_frame_t *f);
> > > +ngx_int_t ngx_quic_handle_data_blocked_frame(ngx_connection_t *c,
> > > +    ngx_quic_header_t *pkt, ngx_quic_data_blocked_frame_t *f);
> > >  ngx_int_t ngx_quic_handle_stream_data_blocked_frame(ngx_connection_t *c,
> > >      ngx_quic_header_t *pkt, ngx_quic_stream_data_blocked_frame_t *f);
> > >  ngx_int_t ngx_quic_handle_max_stream_data_frame(ngx_connection_t *c,
> >
> >
> > _______________________________________________
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> > nginx-devel at nginx.org
> > http://mailman.nginx.org/mailman/listinfo/nginx-devel
>
> --
> Roman Arutyunyan
> _______________________________________________
> nginx-devel mailing list
> nginx-devel at nginx.org
> http://mailman.nginx.org/mailman/listinfo/nginx-devel


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