Adding upstream version 2.4.58.upstream/2.4.58

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1827 insertions, 0 deletions

diff --git a/modules/http2/h2_stream.c b/modules/http2/h2_stream.c
new file mode 100644
index 0000000..f6c9202
--- /dev/null
+++ b/modules/http2/h2_stream.c
@@ -0,0 +1,1827 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <stddef.h>
+
+#include "apr.h"
+#include "apr_strings.h"
+#include "apr_lib.h"
+#include "apr_strmatch.h"
+
+#include <httpd.h>
+#include <http_core.h>
+#include <http_connection.h>
+#include <http_log.h>
+#include <http_protocol.h>
+#include <http_ssl.h>
+
+#include <nghttp2/nghttp2.h>
+
+#include "h2_private.h"
+#include "h2.h"
+#include "h2_bucket_beam.h"
+#include "h2_c1.h"
+#include "h2_config.h"
+#include "h2_protocol.h"
+#include "h2_mplx.h"
+#include "h2_push.h"
+#include "h2_request.h"
+#include "h2_headers.h"
+#include "h2_session.h"
+#include "h2_stream.h"
+#include "h2_c2.h"
+#include "h2_conn_ctx.h"
+#include "h2_c2.h"
+#include "h2_util.h"
+
+
+static const char *h2_ss_str(const h2_stream_state_t state)
+{
+    switch (state) {
+        case H2_SS_IDLE:
+            return "IDLE";
+        case H2_SS_RSVD_L:
+            return "RESERVED_LOCAL";
+        case H2_SS_RSVD_R:
+            return "RESERVED_REMOTE";
+        case H2_SS_OPEN:
+            return "OPEN";
+        case H2_SS_CLOSED_L:
+            return "HALF_CLOSED_LOCAL";
+        case H2_SS_CLOSED_R:
+            return "HALF_CLOSED_REMOTE";
+        case H2_SS_CLOSED:
+            return "CLOSED";
+        case H2_SS_CLEANUP:
+            return "CLEANUP";
+        default:
+            return "UNKNOWN";
+    }
+}
+
+const char *h2_stream_state_str(const h2_stream *stream)
+{
+    return h2_ss_str(stream->state);
+}
+
+/* Abbreviations for stream transit tables */
+#define S_XXX     (-2)                      /* Programming Error */
+#define S_ERR     (-1)                      /* Protocol Error */
+#define S_NOP     (0)                       /* No Change */
+#define S_IDL     (H2_SS_IDL + 1)
+#define S_RS_L    (H2_SS_RSVD_L + 1)
+#define S_RS_R    (H2_SS_RSVD_R + 1)
+#define S_OPEN    (H2_SS_OPEN + 1)
+#define S_CL_L    (H2_SS_CLOSED_L + 1)
+#define S_CL_R    (H2_SS_CLOSED_R + 1)
+#define S_CLS     (H2_SS_CLOSED + 1)
+#define S_CLN     (H2_SS_CLEANUP + 1)
+
+/* state transisitions when certain frame types are sent */
+static int trans_on_send[][H2_SS_MAX] = {
+/*S_IDLE,S_RS_R, S_RS_L, S_OPEN, S_CL_R, S_CL_L, S_CLS,  S_CLN, */        
+{ S_ERR, S_ERR,  S_ERR,  S_NOP,  S_NOP,  S_ERR,  S_NOP,  S_NOP, },/* DATA */ 
+{ S_ERR, S_ERR,  S_CL_R, S_NOP,  S_NOP,  S_ERR,  S_NOP,  S_NOP, },/* HEADERS */ 
+{ S_NOP, S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP, },/* PRIORITY */    
+{ S_CLS, S_CLS,  S_CLS,  S_CLS,  S_CLS,  S_CLS,  S_NOP,  S_NOP, },/* RST_STREAM */ 
+{ S_ERR, S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR, },/* SETTINGS */ 
+{ S_RS_L,S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR, },/* PUSH_PROMISE */  
+{ S_ERR, S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR, },/* PING */ 
+{ S_ERR, S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR, },/* GOAWAY */ 
+{ S_NOP, S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP, },/* WINDOW_UPDATE */ 
+{ S_NOP, S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP, },/* CONT */ 
+};
+/* state transisitions when certain frame types are received */
+static int trans_on_recv[][H2_SS_MAX] = {
+/*S_IDLE,S_RS_R, S_RS_L, S_OPEN, S_CL_R, S_CL_L, S_CLS,  S_CLN, */        
+{ S_ERR, S_ERR,  S_ERR,  S_NOP,  S_ERR,  S_NOP,  S_NOP,  S_NOP, },/* DATA */ 
+{ S_OPEN,S_CL_L, S_ERR,  S_NOP,  S_ERR,  S_NOP,  S_NOP,  S_NOP, },/* HEADERS */ 
+{ S_NOP, S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP, },/* PRIORITY */    
+{ S_ERR, S_CLS,  S_CLS,  S_CLS,  S_CLS,  S_CLS,  S_NOP,  S_NOP, },/* RST_STREAM */ 
+{ S_ERR, S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR, },/* SETTINGS */ 
+{ S_RS_R,S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR, },/* PUSH_PROMISE */  
+{ S_ERR, S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR, },/* PING */ 
+{ S_ERR, S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR,  S_ERR, },/* GOAWAY */ 
+{ S_NOP, S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP, },/* WINDOW_UPDATE */ 
+{ S_NOP, S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP,  S_NOP, },/* CONT */ 
+};
+/* state transisitions when certain events happen */
+static int trans_on_event[][H2_SS_MAX] = {
+/*S_IDLE,S_RS_R, S_RS_L, S_OPEN, S_CL_R, S_CL_L, S_CLS,  S_CLN, */        
+{ S_XXX, S_ERR,  S_ERR,  S_CL_L, S_CLS,  S_XXX,  S_XXX,  S_XXX, },/* EV_CLOSED_L*/
+{ S_ERR, S_ERR,  S_ERR,  S_CL_R, S_ERR,  S_CLS,  S_NOP,  S_NOP, },/* EV_CLOSED_R*/
+{ S_CLS, S_CLS,  S_CLS,  S_CLS,  S_CLS,  S_CLS,  S_NOP,  S_NOP, },/* EV_CANCELLED*/
+{ S_NOP, S_XXX,  S_XXX,  S_XXX,  S_XXX,  S_CLS,  S_CLN,  S_NOP, },/* EV_EOS_SENT*/
+{ S_NOP, S_XXX,  S_CLS,  S_XXX,  S_XXX,  S_CLS,  S_XXX,  S_XXX, },/* EV_IN_ERROR*/
+};
+
+static int on_map(h2_stream_state_t state, int map[H2_SS_MAX])
+{
+    int op = map[state];
+    switch (op) {
+        case S_XXX:
+        case S_ERR:
+            return op;
+        case S_NOP:
+            return state;
+        default:
+            return op-1;
+    }
+}
+
+static int on_frame(h2_stream_state_t state, int frame_type, 
+                    int frame_map[][H2_SS_MAX], apr_size_t maxlen)
+{
+    ap_assert(frame_type >= 0);
+    ap_assert(state >= 0);
+    if ((apr_size_t)frame_type >= maxlen) {
+        return state; /* NOP, ignore unknown frame types */
+    }
+    return on_map(state, frame_map[frame_type]);
+}
+
+static int on_frame_send(h2_stream_state_t state, int frame_type)
+{
+    return on_frame(state, frame_type, trans_on_send, H2_ALEN(trans_on_send));
+}
+
+static int on_frame_recv(h2_stream_state_t state, int frame_type)
+{
+    return on_frame(state, frame_type, trans_on_recv, H2_ALEN(trans_on_recv));
+}
+
+static int on_event(h2_stream* stream, h2_stream_event_t ev)
+{
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    if (stream->monitor && stream->monitor->on_event) {
+        stream->monitor->on_event(stream->monitor->ctx, stream, ev);
+    }
+    if (ev < H2_ALEN(trans_on_event)) {
+        return on_map(stream->state, trans_on_event[ev]);
+    }
+    return stream->state;
+}
+
+static ssize_t stream_data_cb(nghttp2_session *ng2s,
+                              int32_t stream_id,
+                              uint8_t *buf,
+                              size_t length,
+                              uint32_t *data_flags,
+                              nghttp2_data_source *source,
+                              void *puser);
+
+static void H2_STREAM_OUT_LOG(int lvl, h2_stream *s, const char *tag)
+{
+    if (APLOG_C_IS_LEVEL(s->session->c1, lvl)) {
+        conn_rec *c = s->session->c1;
+        char buffer[4 * 1024];
+        apr_size_t len, bmax = sizeof(buffer)/sizeof(buffer[0]);
+        
+        len = h2_util_bb_print(buffer, bmax, tag, "", s->out_buffer);
+        ap_log_cerror(APLOG_MARK, lvl, 0, c, 
+                      H2_STRM_MSG(s, "out-buffer(%s)"), len? buffer : "empty");
+    }
+}
+
+static void stream_setup_input(h2_stream *stream)
+{
+    if (stream->input != NULL) return;
+    ap_assert(!stream->input_closed);
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, stream->session->c1,
+                  H2_STRM_MSG(stream, "setup input beam"));
+    h2_beam_create(&stream->input, stream->session->c1,
+                   stream->pool, stream->id,
+                   "input", 0, stream->session->s->timeout);
+}
+
+apr_status_t h2_stream_prepare_processing(h2_stream *stream)
+{
+    /* Right before processing starts, last chance to decide if
+     * there is need to an input beam. */
+    if (!stream->input_closed) {
+        stream_setup_input(stream);
+    }
+    return APR_SUCCESS;
+}
+
+static int input_buffer_is_empty(h2_stream *stream)
+{
+    return !stream->in_buffer || APR_BRIGADE_EMPTY(stream->in_buffer);
+}
+
+static apr_status_t input_flush(h2_stream *stream)
+{
+    apr_status_t status = APR_SUCCESS;
+    apr_off_t written;
+
+    if (input_buffer_is_empty(stream)) goto cleanup;
+
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, stream->session->c1,
+                  H2_STRM_MSG(stream, "flush input"));
+    status = h2_beam_send(stream->input, stream->session->c1,
+                          stream->in_buffer, APR_BLOCK_READ, &written);
+    stream->in_last_write = apr_time_now();
+    if (APR_SUCCESS != status && h2_stream_is_at(stream, H2_SS_CLOSED_L)) {
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE2, status, stream->session->c1,
+                      H2_STRM_MSG(stream, "send input error"));
+        h2_stream_dispatch(stream, H2_SEV_IN_ERROR);
+    }
+cleanup:
+    return status;
+}
+
+static void input_append_bucket(h2_stream *stream, apr_bucket *b)
+{
+    if (!stream->in_buffer) {
+        stream_setup_input(stream);
+        stream->in_buffer = apr_brigade_create(
+            stream->pool, stream->session->c1->bucket_alloc);
+    }
+    APR_BRIGADE_INSERT_TAIL(stream->in_buffer, b);
+}
+
+static void input_append_data(h2_stream *stream, const char *data, apr_size_t len)
+{
+    if (!stream->in_buffer) {
+        stream_setup_input(stream);
+        stream->in_buffer = apr_brigade_create(
+            stream->pool, stream->session->c1->bucket_alloc);
+    }
+    apr_brigade_write(stream->in_buffer, NULL, NULL, data, len);
+}
+
+
+static apr_status_t close_input(h2_stream *stream)
+{
+    conn_rec *c = stream->session->c1;
+    apr_status_t rv = APR_SUCCESS;
+    apr_bucket *b;
+
+    if (stream->input_closed) goto cleanup;
+
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, stream->session->c1,
+                  H2_STRM_MSG(stream, "closing input"));
+    if (!stream->rst_error
+        && stream->trailers_in
+        && !apr_is_empty_table(stream->trailers_in)) {
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, stream->session->c1,
+                      H2_STRM_MSG(stream, "adding trailers"));
+#if AP_HAS_RESPONSE_BUCKETS
+        b = ap_bucket_headers_create(stream->trailers_in,
+                                     stream->pool, c->bucket_alloc);
+#else
+        b = h2_bucket_headers_create(c->bucket_alloc,
+            h2_headers_create(HTTP_OK, stream->trailers_in, NULL,
+                              stream->in_trailer_octets, stream->pool));
+#endif
+        input_append_bucket(stream, b);
+        stream->trailers_in = NULL;
+    }
+
+    stream->input_closed = 1;
+    if (stream->input) {
+        b = apr_bucket_eos_create(c->bucket_alloc);
+        input_append_bucket(stream, b);
+        input_flush(stream);
+        h2_stream_dispatch(stream, H2_SEV_IN_DATA_PENDING);
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, stream->session->c1,
+                      H2_STRM_MSG(stream, "input flush + EOS"));
+    }
+
+cleanup:
+    return rv;
+}
+
+static void on_state_enter(h2_stream *stream)
+{
+    if (stream->monitor && stream->monitor->on_state_enter) {
+        stream->monitor->on_state_enter(stream->monitor->ctx, stream);
+    }
+}
+
+static void on_state_event(h2_stream *stream, h2_stream_event_t ev) 
+{
+    if (stream->monitor && stream->monitor->on_state_event) {
+        stream->monitor->on_state_event(stream->monitor->ctx, stream, ev);
+    }
+}
+
+static void on_state_invalid(h2_stream *stream) 
+{
+    if (stream->monitor && stream->monitor->on_state_invalid) {
+        stream->monitor->on_state_invalid(stream->monitor->ctx, stream);
+    }
+    /* stream got an event/frame invalid in its state */
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, stream->session->c1,
+                  H2_STRM_MSG(stream, "invalid state event")); 
+    switch (stream->state) {
+        case H2_SS_OPEN:
+        case H2_SS_RSVD_L:
+        case H2_SS_RSVD_R:
+        case H2_SS_CLOSED_L:
+        case H2_SS_CLOSED_R:
+            h2_stream_rst(stream, H2_ERR_INTERNAL_ERROR);
+            break;
+        default:
+            break;
+    }
+}
+
+static apr_status_t transit(h2_stream *stream, int new_state)
+{
+    if ((h2_stream_state_t)new_state == stream->state) {
+        return APR_SUCCESS;
+    }
+    else if (new_state < 0) {
+        ap_log_cerror(APLOG_MARK, APLOG_WARNING, 0, stream->session->c1,
+                      H2_STRM_LOG(APLOGNO(03081), stream, "invalid transition"));
+        on_state_invalid(stream);
+        return APR_EINVAL;
+    }
+    
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, stream->session->c1,
+                  H2_STRM_MSG(stream, "transit to [%s]"), h2_ss_str(new_state));
+    stream->state = new_state;
+    switch (new_state) {
+        case H2_SS_IDLE:
+            break;
+        case H2_SS_RSVD_L:
+            close_input(stream);
+            break;
+        case H2_SS_RSVD_R:
+            break;
+        case H2_SS_OPEN:
+            break;
+        case H2_SS_CLOSED_L:
+            break;
+        case H2_SS_CLOSED_R:
+            close_input(stream);
+            break;
+        case H2_SS_CLOSED:
+            close_input(stream);
+            if (stream->out_buffer) {
+                apr_brigade_cleanup(stream->out_buffer);
+            }
+            break;
+        case H2_SS_CLEANUP:
+            break;
+    }
+    on_state_enter(stream);
+    return APR_SUCCESS;
+}
+
+void h2_stream_set_monitor(h2_stream *stream, h2_stream_monitor *monitor)
+{
+    stream->monitor = monitor;
+}
+
+void h2_stream_dispatch(h2_stream *stream, h2_stream_event_t ev)
+{
+    int new_state;
+    
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, stream->session->c1,
+                  H2_STRM_MSG(stream, "dispatch event %d"), ev);
+    new_state = on_event(stream, ev);
+    if (new_state < 0) {
+        ap_log_cerror(APLOG_MARK, APLOG_WARNING, 0, stream->session->c1,
+                      H2_STRM_LOG(APLOGNO(10002), stream, "invalid event %d"), ev);
+        on_state_invalid(stream);
+        AP_DEBUG_ASSERT(new_state > S_XXX);
+        return;
+    }
+    else if ((h2_stream_state_t)new_state == stream->state) {
+        /* nop */
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, stream->session->c1,
+                      H2_STRM_MSG(stream, "non-state event %d"), ev);
+        return;
+    }
+    else {
+        on_state_event(stream, ev);
+        transit(stream, new_state);
+    }
+}
+
+static void set_policy_for(h2_stream *stream, h2_request *r) 
+{
+    int enabled = h2_session_push_enabled(stream->session);
+    stream->push_policy = h2_push_policy_determine(r->headers, stream->pool, enabled);
+}
+
+apr_status_t h2_stream_send_frame(h2_stream *stream, int ftype, int flags, size_t frame_len)
+{
+    apr_status_t status = APR_SUCCESS;
+    int new_state, eos = 0;
+
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    new_state = on_frame_send(stream->state, ftype);
+    if (new_state < 0) {
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, stream->session->c1,
+                      H2_STRM_MSG(stream, "invalid frame %d send"), ftype);
+        AP_DEBUG_ASSERT(new_state > S_XXX);
+        return transit(stream, new_state);
+    }
+
+    ++stream->out_frames;
+    stream->out_frame_octets += frame_len;
+    if(stream->c2) {
+      h2_conn_ctx_t *conn_ctx = h2_conn_ctx_get(stream->c2);
+      if(conn_ctx)
+        conn_ctx->bytes_sent = stream->out_frame_octets;
+    }
+
+    switch (ftype) {
+        case NGHTTP2_DATA:
+            eos = (flags & NGHTTP2_FLAG_END_STREAM);
+            break;
+            
+        case NGHTTP2_HEADERS:
+            eos = (flags & NGHTTP2_FLAG_END_STREAM);
+            break;
+            
+        case NGHTTP2_PUSH_PROMISE:
+                /* start pushed stream */
+                ap_assert(stream->request == NULL);
+                ap_assert(stream->rtmp != NULL);
+                status = h2_stream_end_headers(stream, 1, 0);
+                if (status != APR_SUCCESS) goto leave;
+            break;
+            
+        default:
+            break;
+    }
+    status = transit(stream, new_state);
+    if (status == APR_SUCCESS && eos) {
+        status = transit(stream, on_event(stream, H2_SEV_CLOSED_L));
+    }
+leave:
+    return status;
+}
+
+apr_status_t h2_stream_recv_frame(h2_stream *stream, int ftype, int flags, size_t frame_len)
+{
+    apr_status_t status = APR_SUCCESS;
+    int new_state, eos = 0;
+
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    new_state = on_frame_recv(stream->state, ftype);
+    if (new_state < 0) {
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, stream->session->c1,
+                      H2_STRM_MSG(stream, "invalid frame %d recv"), ftype);
+        AP_DEBUG_ASSERT(new_state > S_XXX);
+        return transit(stream, new_state);
+    }
+    
+    switch (ftype) {
+        case NGHTTP2_DATA:
+            eos = (flags & NGHTTP2_FLAG_END_STREAM);
+            break;
+            
+        case NGHTTP2_HEADERS:
+            eos = (flags & NGHTTP2_FLAG_END_STREAM);
+            if (h2_stream_is_at_or_past(stream, H2_SS_OPEN)) {
+                /* trailer HEADER */
+                if (!eos) {
+                    h2_stream_rst(stream, H2_ERR_PROTOCOL_ERROR);
+                }
+                stream->in_trailer_octets += frame_len;
+            }
+            else {
+                /* request HEADER */
+                ap_assert(stream->request == NULL);
+                if (stream->rtmp == NULL) {
+                    /* This can only happen, if the stream has received no header
+                     * name/value pairs at all. The latest nghttp2 version have become
+                     * pretty good at detecting this early. In any case, we have
+                     * to abort the connection here, since this is clearly a protocol error */
+                    return APR_EINVAL;
+                }
+                status = h2_stream_end_headers(stream, eos, frame_len);
+                if (status != APR_SUCCESS) goto leave;
+            }
+            break;
+            
+        default:
+            break;
+    }
+    status = transit(stream, new_state);
+    if (status == APR_SUCCESS && eos) {
+        status = transit(stream, on_event(stream, H2_SEV_CLOSED_R));
+    }
+leave:
+    return status;
+}
+
+apr_status_t h2_stream_recv_DATA(h2_stream *stream, uint8_t flags,
+                                    const uint8_t *data, size_t len)
+{
+    h2_session *session = stream->session;
+    apr_status_t status = APR_SUCCESS;
+    
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    stream->in_data_frames++;
+    if (len > 0) {
+        if (APLOGctrace3(session->c1)) {
+            const char *load = apr_pstrndup(stream->pool, (const char *)data, len);
+            ap_log_cerror(APLOG_MARK, APLOG_TRACE3, 0, session->c1,
+                          H2_STRM_MSG(stream, "recv DATA, len=%d: -->%s<--"), 
+                          (int)len, load);
+        }
+        else {
+            ap_log_cerror(APLOG_MARK, APLOG_TRACE2, status, session->c1,
+                          H2_STRM_MSG(stream, "recv DATA, len=%d"), (int)len);
+        }
+        stream->in_data_octets += len;
+        input_append_data(stream, (const char*)data, len);
+        input_flush(stream);
+        h2_stream_dispatch(stream, H2_SEV_IN_DATA_PENDING);
+    }
+    return status;
+}
+
+#ifdef AP_DEBUG
+static apr_status_t stream_pool_destroy(void *data)
+{
+    h2_stream *stream = data;
+    switch (stream->magic) {
+    case H2_STRM_MAGIC_OK:
+        ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, stream->session->c1,
+                      H2_STRM_MSG(stream, "was not destroyed explicitly"));
+        AP_DEBUG_ASSERT(0);
+        break;
+    case H2_STRM_MAGIC_SDEL:
+        /* stream has been explicitly destroyed, as it should */
+        H2_STRM_ASSIGN_MAGIC(stream, H2_STRM_MAGIC_PDEL);
+        break;
+    case H2_STRM_MAGIC_PDEL:
+        ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, stream->session->c1,
+                      H2_STRM_MSG(stream, "already pool destroyed"));
+        AP_DEBUG_ASSERT(0);
+        break;
+    default:
+        AP_DEBUG_ASSERT(0);
+    }
+    return APR_SUCCESS;
+}
+#endif
+
+h2_stream *h2_stream_create(int id, apr_pool_t *pool, h2_session *session,
+                            h2_stream_monitor *monitor, int initiated_on)
+{
+    h2_stream *stream = apr_pcalloc(pool, sizeof(h2_stream));
+
+    H2_STRM_ASSIGN_MAGIC(stream, H2_STRM_MAGIC_OK);
+    stream->id           = id;
+    stream->initiated_on = initiated_on;
+    stream->created      = apr_time_now();
+    stream->state        = H2_SS_IDLE;
+    stream->pool         = pool;
+    stream->session      = session;
+    stream->monitor      = monitor;
+#ifdef AP_DEBUG
+    if (id) { /* stream 0 has special lifetime */
+        apr_pool_cleanup_register(pool, stream, stream_pool_destroy,
+                                  apr_pool_cleanup_null);
+    }
+#endif
+
+#ifdef H2_NG2_LOCAL_WIN_SIZE
+    if (id) {
+        stream->in_window_size =
+            nghttp2_session_get_stream_local_window_size(
+                stream->session->ngh2, stream->id);
+    }
+#endif
+    ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, session->c1,
+                  H2_STRM_LOG(APLOGNO(03082), stream, "created"));
+    on_state_enter(stream);
+    return stream;
+}
+
+void h2_stream_cleanup(h2_stream *stream)
+{
+    /* Stream is done on c1. There might still be processing on a c2
+     * going on. The input/output beams get aborted and the stream's
+     * end of the in/out notifications get closed.
+     */
+    ap_assert(stream);
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    if (stream->out_buffer) {
+        apr_brigade_cleanup(stream->out_buffer);
+    }
+}
+
+void h2_stream_destroy(h2_stream *stream)
+{
+    ap_assert(stream);
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE3, 0, stream->session->c1,
+                  H2_STRM_MSG(stream, "destroy"));
+    H2_STRM_ASSIGN_MAGIC(stream, H2_STRM_MAGIC_SDEL);
+    apr_pool_destroy(stream->pool);
+}
+
+void h2_stream_rst(h2_stream *stream, int error_code)
+{
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    stream->rst_error = error_code;
+    if (stream->c2) {
+        h2_c2_abort(stream->c2, stream->session->c1);
+    }
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, stream->session->c1,
+                  H2_STRM_MSG(stream, "reset, error=%d"), error_code);
+    h2_stream_dispatch(stream, H2_SEV_CANCELLED);
+}
+
+apr_status_t h2_stream_set_request_rec(h2_stream *stream, 
+                                       request_rec *r, int eos)
+{
+    h2_request *req;
+    apr_status_t status;
+
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    ap_assert(stream->request == NULL);
+    ap_assert(stream->rtmp == NULL);
+    if (stream->rst_error) {
+        return APR_ECONNRESET;
+    }
+    status = h2_request_rcreate(&req, stream->pool, r);
+    if (status == APR_SUCCESS) {
+        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, status, r, 
+                      H2_STRM_LOG(APLOGNO(03058), stream, 
+                      "set_request_rec %s host=%s://%s%s"),
+                      req->method, req->scheme, req->authority, req->path);
+        stream->rtmp = req;
+        /* simulate the frames that led to this */
+        return h2_stream_recv_frame(stream, NGHTTP2_HEADERS, 
+                                    NGHTTP2_FLAG_END_STREAM, 0);
+    }
+    return status;
+}
+
+void h2_stream_set_request(h2_stream *stream, const h2_request *r)
+{
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    ap_assert(stream->request == NULL);
+    ap_assert(stream->rtmp == NULL);
+    stream->rtmp = h2_request_clone(stream->pool, r);
+}
+
+static void set_error_response(h2_stream *stream, int http_status)
+{
+    if (!h2_stream_is_ready(stream) && stream->rtmp) {
+        stream->rtmp->http_status = http_status;
+    }
+}
+
+static apr_status_t add_trailer(h2_stream *stream,
+                                const char *name, size_t nlen,
+                                const char *value, size_t vlen,
+                                size_t max_field_len, int *pwas_added)
+{
+    conn_rec *c = stream->session->c1;
+    char *hname, *hvalue;
+    const char *existing;
+
+    *pwas_added = 0;
+    if (nlen == 0 || name[0] == ':') {
+        ap_log_cerror(APLOG_MARK, APLOG_DEBUG, APR_EINVAL, c, 
+                      H2_STRM_LOG(APLOGNO(03060), stream, 
+                      "pseudo header in trailer"));
+        return APR_EINVAL;
+    }
+    if (h2_ignore_req_trailer(name, nlen)) {
+        return APR_SUCCESS;
+    }
+    if (!stream->trailers_in) {
+        stream->trailers_in = apr_table_make(stream->pool, 5);
+    }
+    hname = apr_pstrndup(stream->pool, name, nlen);
+    h2_util_camel_case_header(hname, nlen);
+    existing = apr_table_get(stream->trailers_in, hname);
+    if (max_field_len 
+        && ((existing? strlen(existing)+2 : 0) + vlen + nlen + 2 > max_field_len)) {
+        /* "key: (oldval, )?nval" is too long */
+        return APR_EINVAL;
+    }
+    if (!existing) *pwas_added = 1;
+    hvalue = apr_pstrndup(stream->pool, value, vlen);
+    apr_table_mergen(stream->trailers_in, hname, hvalue);
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, c, 
+                  H2_STRM_MSG(stream, "added trailer '%s: %s'"), hname, hvalue);
+    
+    return APR_SUCCESS;
+}
+
+apr_status_t h2_stream_add_header(h2_stream *stream,
+                                  const char *name, size_t nlen,
+                                  const char *value, size_t vlen)
+{
+    h2_session *session = stream->session;
+    int error = 0, was_added = 0;
+    apr_status_t status = APR_SUCCESS;
+    
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    if (stream->response) {
+        return APR_EINVAL;    
+    }
+
+    if (name[0] == ':') {
+        if (vlen > APR_INT32_MAX || (int)vlen > session->s->limit_req_line) {
+            /* pseudo header: approximation of request line size check */
+            if (!h2_stream_is_ready(stream)) {
+                ap_log_cerror(APLOG_MARK, APLOG_INFO, 0, session->c1,
+                              H2_STRM_LOG(APLOGNO(10178), stream,
+                                          "Request pseudo header exceeds "
+                                          "LimitRequestFieldSize: %s"), name);
+            }
+            error = HTTP_REQUEST_URI_TOO_LARGE;
+            goto cleanup;
+        }
+    }
+    
+    if (session->s->limit_req_fields > 0 
+        && stream->request_headers_added > session->s->limit_req_fields) {
+        /* already over limit, count this attempt, but do not take it in */
+        ++stream->request_headers_added;
+    }
+    else if (H2_SS_IDLE == stream->state) {
+        if (!stream->rtmp) {
+            stream->rtmp = h2_request_create(stream->id, stream->pool,
+                                             NULL, NULL, NULL, NULL, NULL);
+        }
+        status = h2_request_add_header(stream->rtmp, stream->pool,
+                                       name, nlen, value, vlen,
+                                       session->s->limit_req_fieldsize, &was_added);
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE2, status, session->c1,
+                      H2_STRM_MSG(stream, "add_header: '%.*s: %.*s"),
+                      (int)nlen, name, (int)vlen, value);
+        if (was_added) ++stream->request_headers_added;
+    }
+    else if (H2_SS_OPEN == stream->state) {
+        status = add_trailer(stream, name, nlen, value, vlen,
+                             session->s->limit_req_fieldsize, &was_added);
+        if (was_added) ++stream->request_headers_added;
+    }
+    else {
+        status = APR_EINVAL;
+        goto cleanup;
+    }
+    
+    if (APR_EINVAL == status) {
+        /* header too long */
+        if (!h2_stream_is_ready(stream)) {
+            ap_log_cerror(APLOG_MARK, APLOG_INFO, 0, session->c1,
+                          H2_STRM_LOG(APLOGNO(10180), stream,"Request header exceeds "
+                                      "LimitRequestFieldSize: %.*s"),
+                          (int)H2MIN(nlen, 80), name);
+        }
+        error = HTTP_REQUEST_HEADER_FIELDS_TOO_LARGE;
+        goto cleanup;
+    }
+    
+    if (session->s->limit_req_fields > 0 
+        && stream->request_headers_added > session->s->limit_req_fields) {
+        /* too many header lines */
+        if (stream->request_headers_added > session->s->limit_req_fields + 100) {
+            /* yeah, right, this request is way over the limit, say goodbye */
+            h2_stream_rst(stream, H2_ERR_ENHANCE_YOUR_CALM);
+            return APR_ECONNRESET;
+        }
+        if (!h2_stream_is_ready(stream)) {
+            ap_log_cerror(APLOG_MARK, APLOG_INFO, 0, session->c1,
+                          H2_STRM_LOG(APLOGNO(10181), stream, "Number of request headers "
+                                      "exceeds LimitRequestFields"));
+        }
+        error = HTTP_REQUEST_HEADER_FIELDS_TOO_LARGE;
+        goto cleanup;
+    }
+    
+cleanup:
+    if (error) {
+        set_error_response(stream, error);
+        return APR_EINVAL; 
+    }
+    else if (status != APR_SUCCESS) {
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, session->c1,
+                      H2_STRM_MSG(stream, "header %s not accepted"), name);
+        h2_stream_dispatch(stream, H2_SEV_CANCELLED);
+    }
+    return status;
+}
+
+typedef struct {
+    apr_size_t maxlen;
+    const char *failed_key;
+} val_len_check_ctx;
+
+static int table_check_val_len(void *baton, const char *key, const char *value)
+{
+    val_len_check_ctx *ctx = baton;
+
+    if (strlen(value) <= ctx->maxlen) return 1;
+    ctx->failed_key = key;
+    return 0;
+}
+
+apr_status_t h2_stream_end_headers(h2_stream *stream, int eos, size_t raw_bytes)
+{
+    apr_status_t status;
+    val_len_check_ctx ctx;
+    int is_http_or_https;
+    h2_request *req = stream->rtmp;
+
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    status = h2_request_end_headers(req, stream->pool, raw_bytes);
+    if (APR_SUCCESS != status || req->http_status != H2_HTTP_STATUS_UNSET) {
+        goto cleanup;
+    }
+
+    /* keep on returning APR_SUCCESS for error responses, so that we
+     * send it and do not RST the stream.
+     */
+    set_policy_for(stream, req);
+
+    ctx.maxlen = stream->session->s->limit_req_fieldsize;
+    ctx.failed_key = NULL;
+    apr_table_do(table_check_val_len, &ctx, req->headers, NULL);
+    if (ctx.failed_key) {
+        if (!h2_stream_is_ready(stream)) {
+            ap_log_cerror(APLOG_MARK, APLOG_INFO, 0, stream->session->c1,
+                          H2_STRM_LOG(APLOGNO(10230), stream,"Request header exceeds "
+                                      "LimitRequestFieldSize: %.*s"),
+                          (int)H2MIN(strlen(ctx.failed_key), 80), ctx.failed_key);
+        }
+        set_error_response(stream, HTTP_REQUEST_HEADER_FIELDS_TOO_LARGE);
+        goto cleanup;
+    }
+
+    /* http(s) scheme. rfc7540, ch. 8.1.2.3:
+     * This [:path] pseudo-header field MUST NOT be empty for "http" or "https"
+     * URIs; "http" or "https" URIs that do not contain a path component
+     * MUST include a value of '/'.  The exception to this rule is an
+     * OPTIONS request for an "http" or "https" URI that does not include
+     * a path component; these MUST include a ":path" pseudo-header field
+     * with a value of '*'
+     *
+     * All HTTP/2 requests MUST include exactly one valid value for the
+     * ":method", ":scheme", and ":path" pseudo-header fields, unless it is
+     * a CONNECT request.
+     */
+    is_http_or_https = (!req->scheme
+            || !(ap_cstr_casecmpn(req->scheme, "http", 4) != 0
+                 || (req->scheme[4] != '\0'
+                     && (apr_tolower(req->scheme[4]) != 's'
+                         || req->scheme[5] != '\0'))));
+
+    /* CONNECT. rfc7540, ch. 8.3:
+     * In HTTP/2, the CONNECT method is used to establish a tunnel over a
+     * single HTTP/2 stream to a remote host for similar purposes.  The HTTP
+     * header field mapping works as defined in Section 8.1.2.3 ("Request
+     * Pseudo-Header Fields"), with a few differences.  Specifically:
+     *   o  The ":method" pseudo-header field is set to "CONNECT".
+     *   o  The ":scheme" and ":path" pseudo-header fields MUST be omitted.
+     *   o  The ":authority" pseudo-header field contains the host and port to
+     *      connect to (equivalent to the authority-form of the request-target
+     *      of CONNECT requests (see [RFC7230], Section 5.3)).
+     */
+    if (!ap_cstr_casecmp(req->method, "CONNECT")) {
+        if (req->protocol) {
+            if (!strcmp("websocket", req->protocol)) {
+                if (!req->scheme || !req->path) {
+                    ap_log_cerror(APLOG_MARK, APLOG_INFO, 0, stream->session->c1,
+                                  H2_STRM_LOG(APLOGNO(10457), stream, "Request to websocket CONNECT "
+                                  "without :scheme or :path, sending 400 answer"));
+                    set_error_response(stream, HTTP_BAD_REQUEST);
+                    goto cleanup;
+                }
+            }
+            else {
+                /* do not know that protocol */
+                ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, stream->session->c1, APLOGNO(10460)
+                              "':protocol: %s' header present in %s request",
+                              req->protocol, req->method);
+                set_error_response(stream, HTTP_NOT_IMPLEMENTED);
+                goto cleanup;
+            }
+        }
+        else if (req->scheme || req->path) {
+            ap_log_cerror(APLOG_MARK, APLOG_INFO, 0, stream->session->c1,
+                          H2_STRM_LOG(APLOGNO(10384), stream, "Request to CONNECT "
+                          "with :scheme or :path specified, sending 400 answer"));
+            set_error_response(stream, HTTP_BAD_REQUEST);
+            goto cleanup;
+        }
+    }
+    else if (is_http_or_https) {
+        if (!req->path) {
+            ap_log_cerror(APLOG_MARK, APLOG_INFO, 0, stream->session->c1,
+                          H2_STRM_LOG(APLOGNO(10385), stream, "Request for http(s) "
+                          "resource without :path, sending 400 answer"));
+            set_error_response(stream, HTTP_BAD_REQUEST);
+            goto cleanup;
+        }
+        if (!req->scheme) {
+            req->scheme = ap_ssl_conn_is_ssl(stream->session->c1)? "https" : "http";
+        }
+    }
+
+    if (req->scheme && (req->path && req->path[0] != '/')) {
+        /* We still have a scheme, which means we need to pass an absolute URI into
+         * our HTTP protocol handling and the missing '/' at the start will prevent
+         * us from doing so (as it then confuses path and authority). */
+        ap_log_cerror(APLOG_MARK, APLOG_INFO, 0, stream->session->c1,
+                      H2_STRM_LOG(APLOGNO(10379), stream, "Request :scheme '%s' and "
+                      "path '%s' do not allow creating an absolute URL. Failing "
+                      "request with 400."), req->scheme, req->path);
+        set_error_response(stream, HTTP_BAD_REQUEST);
+        goto cleanup;
+    }
+
+cleanup:
+    if (APR_SUCCESS == status) {
+        stream->request = req;
+        stream->rtmp = NULL;
+
+        if (APLOGctrace4(stream->session->c1)) {
+            int i;
+            const apr_array_header_t *t_h = apr_table_elts(req->headers);
+            const apr_table_entry_t *t_elt = (apr_table_entry_t *)t_h->elts;
+            ap_log_cerror(APLOG_MARK, APLOG_TRACE4, 0, stream->session->c1,
+                          H2_STRM_MSG(stream,"headers received from client:"));
+            for (i = 0; i < t_h->nelts; i++, t_elt++) {
+                ap_log_cerror(APLOG_MARK, APLOG_TRACE4, 0, stream->session->c1,
+                              H2_STRM_MSG(stream, "  %s: %s"),
+                              ap_escape_logitem(stream->pool, t_elt->key),
+                              ap_escape_logitem(stream->pool, t_elt->val));
+            }
+        }
+    }
+    return status;
+}
+
+static apr_bucket *get_first_response_bucket(apr_bucket_brigade *bb)
+{
+    if (bb) {
+        apr_bucket *b = APR_BRIGADE_FIRST(bb);
+        while (b != APR_BRIGADE_SENTINEL(bb)) {
+#if AP_HAS_RESPONSE_BUCKETS
+            if (AP_BUCKET_IS_RESPONSE(b)) {
+                return b;
+            }
+#else
+            if (H2_BUCKET_IS_HEADERS(b)) {
+                return b;
+            }
+#endif
+            b = APR_BUCKET_NEXT(b);
+        }
+    }
+    return NULL;
+}
+
+static void stream_do_error_bucket(h2_stream *stream, apr_bucket *b)
+{
+    int err = ((ap_bucket_error *)(b->data))->status;
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, stream->session->c1,
+                  H2_STRM_MSG(stream, "error bucket received, err=%d"), err);
+    if (err >= 500) {
+        err = NGHTTP2_INTERNAL_ERROR;
+    }
+    else if (err >= 400) {
+        err = NGHTTP2_STREAM_CLOSED;
+    }
+    else {
+        err = NGHTTP2_PROTOCOL_ERROR;
+    }
+    h2_stream_rst(stream, err);
+}
+
+static apr_status_t buffer_output_receive(h2_stream *stream)
+{
+    apr_status_t rv = APR_EAGAIN;
+    apr_off_t buf_len;
+    conn_rec *c1 = stream->session->c1;
+    apr_bucket *b, *e;
+
+    if (!stream->output) {
+        goto cleanup;
+    }
+    if (stream->rst_error) {
+        rv = APR_ECONNRESET;
+        goto cleanup;
+    }
+
+    if (!stream->out_buffer) {
+        stream->out_buffer = apr_brigade_create(stream->pool, c1->bucket_alloc);
+        buf_len = 0;
+    }
+    else {
+        /* if the brigade contains a file bucket, its normal report length
+         * might be megabytes, but the memory used is tiny. For buffering,
+         * we are only interested in the memory footprint. */
+        buf_len = h2_brigade_mem_size(stream->out_buffer);
+    }
+
+    if (buf_len > APR_INT32_MAX
+        || (apr_size_t)buf_len >= stream->session->max_stream_mem) {
+        /* we have buffered enough. No need to read more.
+         * However, we have now output pending for which we may not
+         * receive another poll event. We need to make sure that this
+         * stream is not suspended so we keep on processing output.
+         */
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE1, rv, c1,
+                      H2_STRM_MSG(stream, "out_buffer, already has %ld length"),
+                      (long)buf_len);
+        rv = APR_SUCCESS;
+        goto cleanup;
+    }
+
+    if (stream->output_eos) {
+        rv = APR_BRIGADE_EMPTY(stream->out_buffer)? APR_EOF : APR_SUCCESS;
+    }
+    else {
+        H2_STREAM_OUT_LOG(APLOG_TRACE2, stream, "pre");
+        rv = h2_beam_receive(stream->output, stream->session->c1, stream->out_buffer,
+                             APR_NONBLOCK_READ, stream->session->max_stream_mem - buf_len);
+        if (APR_SUCCESS != rv) {
+            if (APR_EAGAIN != rv) {
+                ap_log_cerror(APLOG_MARK, APLOG_TRACE1, rv, c1,
+                              H2_STRM_MSG(stream, "out_buffer, receive unsuccessful"));
+            }
+        }
+    }
+
+    /* get rid of buckets we have no need for */
+    if (!APR_BRIGADE_EMPTY(stream->out_buffer)) {
+        b = APR_BRIGADE_FIRST(stream->out_buffer);
+        while (b != APR_BRIGADE_SENTINEL(stream->out_buffer)) {
+            e = APR_BUCKET_NEXT(b);
+            if (APR_BUCKET_IS_METADATA(b)) {
+                if (APR_BUCKET_IS_FLUSH(b)) {  /* we flush any c1 data already */
+                    APR_BUCKET_REMOVE(b);
+                    apr_bucket_destroy(b);
+                }
+                else if (APR_BUCKET_IS_EOS(b)) {
+                    stream->output_eos = 1;
+                }
+                else if (AP_BUCKET_IS_ERROR(b)) {
+                    stream_do_error_bucket(stream, b);
+                    break;
+                }
+            }
+            else if (b->length == 0) {  /* zero length data */
+                APR_BUCKET_REMOVE(b);
+                apr_bucket_destroy(b);
+            }
+            b = e;
+        }
+    }
+    H2_STREAM_OUT_LOG(APLOG_TRACE2, stream, "out_buffer, after receive");
+
+cleanup:
+    return rv;
+}
+
+static int bucket_pass_to_c1(apr_bucket *b)
+{
+#if AP_HAS_RESPONSE_BUCKETS
+    return !AP_BUCKET_IS_RESPONSE(b)
+           && !AP_BUCKET_IS_HEADERS(b)
+           && !APR_BUCKET_IS_EOS(b);
+#else
+    return !H2_BUCKET_IS_HEADERS(b) && !APR_BUCKET_IS_EOS(b);
+#endif
+}
+
+apr_status_t h2_stream_read_to(h2_stream *stream, apr_bucket_brigade *bb, 
+                               apr_off_t *plen, int *peos)
+{
+    apr_status_t rv = APR_SUCCESS;
+
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    if (stream->rst_error) {
+        return APR_ECONNRESET;
+    }
+    rv = h2_append_brigade(bb, stream->out_buffer, plen, peos, bucket_pass_to_c1);
+    if (APR_SUCCESS  == rv && !*peos && !*plen) {
+        rv = APR_EAGAIN;
+    }
+    return rv;
+}
+
+static apr_status_t stream_do_trailers(h2_stream *stream)
+{
+    conn_rec *c1 = stream->session->c1;
+    int ngrv;
+    h2_ngheader *nh = NULL;
+    apr_bucket *b, *e;
+#if AP_HAS_RESPONSE_BUCKETS
+    ap_bucket_headers *headers = NULL;
+#else
+    h2_headers *headers = NULL;
+#endif
+    apr_status_t rv;
+
+    ap_assert(stream->response);
+    ap_assert(stream->out_buffer);
+
+    b = APR_BRIGADE_FIRST(stream->out_buffer);
+    while (b != APR_BRIGADE_SENTINEL(stream->out_buffer)) {
+        e = APR_BUCKET_NEXT(b);
+        if (APR_BUCKET_IS_METADATA(b)) {
+#if AP_HAS_RESPONSE_BUCKETS
+            if (AP_BUCKET_IS_HEADERS(b)) {
+                headers = b->data;
+#else /* AP_HAS_RESPONSE_BUCKETS */
+            if (H2_BUCKET_IS_HEADERS(b)) {
+                headers = h2_bucket_headers_get(b);
+#endif /* else AP_HAS_RESPONSE_BUCKETS */
+                APR_BUCKET_REMOVE(b);
+                apr_bucket_destroy(b);
+                ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c1,
+                              H2_STRM_MSG(stream, "process trailers"));
+                break;
+            }
+            else if (APR_BUCKET_IS_EOS(b)) {
+                break;
+            }
+        }
+        else {
+            break;
+        }
+        b = e;
+    }
+
+    if (!headers) {
+        rv = APR_EAGAIN;
+        goto cleanup;
+    }
+
+    rv = h2_res_create_ngtrailer(&nh, stream->pool, headers);
+    ap_log_cerror(APLOG_MARK, APLOG_DEBUG, rv, c1,
+                  H2_STRM_LOG(APLOGNO(03072), stream, "submit %d trailers"),
+                  (int)nh->nvlen);
+    if (APR_SUCCESS != rv) {
+        ap_log_cerror(APLOG_MARK, APLOG_DEBUG, rv, c1,
+                      H2_STRM_LOG(APLOGNO(10024), stream, "invalid trailers"));
+        h2_stream_rst(stream, NGHTTP2_PROTOCOL_ERROR);
+        goto cleanup;
+    }
+
+    ngrv = nghttp2_submit_trailer(stream->session->ngh2, stream->id, nh->nv, nh->nvlen);
+    if (nghttp2_is_fatal(ngrv)) {
+        rv = APR_EGENERAL;
+        h2_session_dispatch_event(stream->session,
+                                 H2_SESSION_EV_PROTO_ERROR, ngrv, nghttp2_strerror(rv));
+        ap_log_cerror(APLOG_MARK, APLOG_ERR, rv, c1,
+                      APLOGNO(02940) "submit_response: %s",
+                      nghttp2_strerror(rv));
+    }
+    stream->sent_trailers = 1;
+
+cleanup:
+    return rv;
+}
+
+#if AP_HAS_RESPONSE_BUCKETS
+apr_status_t h2_stream_submit_pushes(h2_stream *stream, ap_bucket_response *response)
+#else
+apr_status_t h2_stream_submit_pushes(h2_stream *stream, h2_headers *response)
+#endif
+{
+    apr_status_t status = APR_SUCCESS;
+    apr_array_header_t *pushes;
+    int i;
+    
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    pushes = h2_push_collect_update(stream, stream->request, response);
+    if (pushes && !apr_is_empty_array(pushes)) {
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, stream->session->c1,
+                      H2_STRM_MSG(stream, "found %d push candidates"),
+                      pushes->nelts);
+        for (i = 0; i < pushes->nelts; ++i) {
+            h2_push *push = APR_ARRAY_IDX(pushes, i, h2_push*);
+            h2_stream *s = h2_session_push(stream->session, stream, push);
+            if (!s) {
+                status = APR_ECONNRESET;
+                break;
+            }
+        }
+    }
+    return status;
+}
+
+apr_table_t *h2_stream_get_trailers(h2_stream *stream)
+{
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    return NULL;
+}
+
+#if AP_HAS_RESPONSE_BUCKETS
+const h2_priority *h2_stream_get_priority(h2_stream *stream,
+                                          ap_bucket_response *response)
+#else
+const h2_priority *h2_stream_get_priority(h2_stream *stream,
+                                          h2_headers *response)
+#endif
+{
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    if (response && stream->initiated_on) {
+        const char *ctype = apr_table_get(response->headers, "content-type");
+        if (ctype) {
+            /* FIXME: Not good enough, config needs to come from request->server */
+            return h2_cconfig_get_priority(stream->session->c1, ctype);
+        }
+    }
+    return NULL;
+}
+
+int h2_stream_is_ready(h2_stream *stream)
+{
+    /* Have we sent a response or do we have the response in our buffer? */
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    if (stream->response) {
+        return 1;
+    }
+    else if (stream->out_buffer && get_first_response_bucket(stream->out_buffer)) {
+        return 1;
+    }
+    return 0;
+}
+
+int h2_stream_wants_send_data(h2_stream *stream)
+{
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    return h2_stream_is_ready(stream) &&
+           ((stream->out_buffer && !APR_BRIGADE_EMPTY(stream->out_buffer)) ||
+            (stream->output && !h2_beam_empty(stream->output)));
+}
+
+int h2_stream_is_at(const h2_stream *stream, h2_stream_state_t state)
+{
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    return stream->state == state;
+}
+
+int h2_stream_is_at_or_past(const h2_stream *stream, h2_stream_state_t state)
+{
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    switch (state) {
+        case H2_SS_IDLE:
+            return 1; /* by definition */
+        case H2_SS_RSVD_R: /*fall through*/
+        case H2_SS_RSVD_L: /*fall through*/
+        case H2_SS_OPEN:
+            return stream->state == state || stream->state >= H2_SS_OPEN;
+        case H2_SS_CLOSED_R: /*fall through*/
+        case H2_SS_CLOSED_L: /*fall through*/
+        case H2_SS_CLOSED:
+            return stream->state == state || stream->state >= H2_SS_CLOSED;
+        case H2_SS_CLEANUP:
+            return stream->state == state;
+        default:
+            return 0;
+    }
+}
+
+apr_status_t h2_stream_in_consumed(h2_stream *stream, apr_off_t amount)
+{
+    h2_session *session = stream->session;
+    
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    if (amount > 0) {
+        apr_off_t consumed = amount;
+        
+        while (consumed > 0) {
+            int len = (consumed > INT_MAX)? INT_MAX : (int)consumed;
+            nghttp2_session_consume(session->ngh2, stream->id, len);
+            consumed -= len;
+        }
+
+#ifdef H2_NG2_LOCAL_WIN_SIZE
+        if (1) {
+            int cur_size = nghttp2_session_get_stream_local_window_size(
+                session->ngh2, stream->id);
+            int win = stream->in_window_size;
+            int thigh = win * 8/10;
+            int tlow = win * 2/10;
+            const int win_max = 2*1024*1024;
+            const int win_min = 32*1024;
+            
+            /* Work in progress, probably should add directives for these
+             * values once this stabilizes somewhat. The general idea is
+             * to adapt stream window sizes if the input window changes
+             * a) very quickly (< good RTT) from full to empty
+             * b) only a little bit (> bad RTT)
+             * where in a) it grows and in b) it shrinks again.
+             */
+            if (cur_size > thigh && amount > thigh && win < win_max) {
+                /* almost empty again with one reported consumption, how
+                 * long did this take? */
+                long ms = apr_time_msec(apr_time_now() - stream->in_last_write);
+                if (ms < 40) {
+                    win = H2MIN(win_max, win + (64*1024));
+                }
+            }
+            else if (cur_size < tlow && amount < tlow && win > win_min) {
+                /* staying full, for how long already? */
+                long ms = apr_time_msec(apr_time_now() - stream->in_last_write);
+                if (ms > 700) {
+                    win = H2MAX(win_min, win - (32*1024));
+                }
+            }
+            
+            if (win != stream->in_window_size) {
+                stream->in_window_size = win;
+                nghttp2_session_set_local_window_size(session->ngh2, 
+                        NGHTTP2_FLAG_NONE, stream->id, win);
+            } 
+            ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, session->c1,
+                          H2_STRM_MSG(stream, "consumed %ld bytes, window now %d/%d"),
+                          (long)amount, cur_size, stream->in_window_size);
+        }
+#endif /* #ifdef H2_NG2_LOCAL_WIN_SIZE */
+    }
+    return APR_SUCCESS;   
+}
+
+static apr_off_t output_data_buffered(h2_stream *stream, int *peos, int *pheader_blocked)
+{
+    /* How much data do we have in our buffers that we can write? */
+    apr_off_t buf_len = 0;
+    apr_bucket *b;
+
+    *peos = *pheader_blocked = 0;
+    if (stream->out_buffer) {
+        b = APR_BRIGADE_FIRST(stream->out_buffer);
+        while (b != APR_BRIGADE_SENTINEL(stream->out_buffer)) {
+            if (APR_BUCKET_IS_METADATA(b)) {
+                if (APR_BUCKET_IS_EOS(b)) {
+                    *peos = 1;
+                    break;
+                }
+#if AP_HAS_RESPONSE_BUCKETS
+                else if (AP_BUCKET_IS_RESPONSE(b)) {
+                    break;
+                }
+                else if (AP_BUCKET_IS_HEADERS(b)) {
+                    *pheader_blocked = 1;
+                    break;
+                }
+#else
+                else if (H2_BUCKET_IS_HEADERS(b)) {
+                    *pheader_blocked = 1;
+                    break;
+                }
+#endif
+            }
+            else {
+                buf_len += b->length;
+            }
+            b = APR_BUCKET_NEXT(b);
+        }
+    }
+    return buf_len;
+}
+
+static ssize_t stream_data_cb(nghttp2_session *ng2s,
+                              int32_t stream_id,
+                              uint8_t *buf,
+                              size_t length,
+                              uint32_t *data_flags,
+                              nghttp2_data_source *source,
+                              void *puser)
+{
+    h2_session *session = (h2_session *)puser;
+    conn_rec *c1 = session->c1;
+    apr_off_t buf_len;
+    int eos, header_blocked;
+    apr_status_t rv;
+    h2_stream *stream;
+
+    /* nghttp2 wants to send more DATA for the stream.
+     * we should have submitted the final response at this time
+     * after receiving output via stream_do_responses() */
+    ap_assert(session);
+    (void)ng2s;
+    (void)buf;
+    (void)source;
+    stream = nghttp2_session_get_stream_user_data(session->ngh2, stream_id);
+
+    if (!stream) {
+        ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c1,
+                      APLOGNO(02937)
+                      H2_SSSN_STRM_MSG(session, stream_id, "data_cb, stream not found"));
+        return NGHTTP2_ERR_CALLBACK_FAILURE;
+    }
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    if (!stream->output || !stream->response || !stream->out_buffer) {
+        return NGHTTP2_ERR_DEFERRED;
+    }
+    if (stream->rst_error) {
+        return NGHTTP2_ERR_DEFERRED;
+    }
+    if (h2_c1_io_needs_flush(&session->io)) {
+        rv = h2_c1_io_pass(&session->io);
+        if (APR_STATUS_IS_EAGAIN(rv)) {
+            ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c1,
+                          H2_SSSN_STRM_MSG(session, stream_id, "suspending on c1 out needs flush"));
+            h2_stream_dispatch(stream, H2_SEV_OUT_C1_BLOCK);
+            return NGHTTP2_ERR_DEFERRED;
+        }
+        else if (rv) {
+            h2_session_dispatch_event(session, H2_SESSION_EV_CONN_ERROR, rv, NULL);
+            return NGHTTP2_ERR_CALLBACK_FAILURE;
+        }
+    }
+
+    /* determine how much we'd like to send. We cannot send more than
+     * is requested. But we can reduce the size in case the master
+     * connection operates in smaller chunks. (TSL warmup) */
+    if (stream->session->io.write_size > 0) {
+        apr_size_t chunk_len = stream->session->io.write_size - H2_FRAME_HDR_LEN;
+        if (length > chunk_len) {
+            length = chunk_len;
+        }
+    }
+    /* We allow configurable max DATA frame length. */
+    if (stream->session->max_data_frame_len > 0
+        && length > stream->session->max_data_frame_len) {
+      length = stream->session->max_data_frame_len;
+    }
+
+    /* How much data do we have in our buffers that we can write?
+     * if not enough, receive more. */
+    buf_len = output_data_buffered(stream, &eos, &header_blocked);
+    if (buf_len < (apr_off_t)length && !eos
+           && !header_blocked && !stream->rst_error) {
+        /* read more? */
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, c1,
+                      H2_SSSN_STRM_MSG(session, stream_id,
+                      "need more (read len=%ld, %ld in buffer)"),
+                      (long)length, (long)buf_len);
+        rv = buffer_output_receive(stream);
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE1, rv, c1,
+                      H2_SSSN_STRM_MSG(session, stream_id,
+                      "buffer_output_received"));
+        if (APR_STATUS_IS_EAGAIN(rv)) {
+            /* currently, no more is available */
+        }
+        else if (APR_SUCCESS == rv) {
+            /* got some, re-assess */
+            buf_len = output_data_buffered(stream, &eos, &header_blocked);
+        }
+        else if (APR_EOF == rv) {
+            if (!stream->output_eos) {
+                /* Seeing APR_EOF without an EOS bucket received before indicates
+                 * that stream output is incomplete. Commonly, we expect to see
+                 * an ERROR bucket to have been generated. But faulty handlers
+                 * may not have generated one.
+                 * We need to RST the stream bc otherwise the client thinks
+                 * it is all fine. */
+                 ap_log_cerror(APLOG_MARK, APLOG_TRACE1, rv, c1,
+                               H2_SSSN_STRM_MSG(session, stream_id, "rst stream"));
+                 h2_stream_rst(stream, H2_ERR_STREAM_CLOSED);
+                 return NGHTTP2_ERR_DEFERRED;
+            }
+            ap_log_cerror(APLOG_MARK, APLOG_TRACE1, rv, c1,
+                          H2_SSSN_STRM_MSG(session, stream_id,
+                          "eof on receive (read len=%ld, %ld in buffer)"),
+                          (long)length, (long)buf_len);
+            eos = 1;
+            rv = APR_SUCCESS;
+        }
+        else if (APR_ECONNRESET == rv || APR_ECONNABORTED == rv) {
+            ap_log_cerror(APLOG_MARK, APLOG_DEBUG, rv, c1,
+                          H2_STRM_LOG(APLOGNO(10471), stream, "data_cb, reading data"));
+            h2_stream_rst(stream, H2_ERR_STREAM_CLOSED);
+            return NGHTTP2_ERR_DEFERRED;
+        }
+        else {
+            ap_log_cerror(APLOG_MARK, APLOG_ERR, rv, c1,
+                          H2_STRM_LOG(APLOGNO(02938), stream, "data_cb, reading data"));
+            h2_stream_rst(stream, H2_ERR_INTERNAL_ERROR);
+            return NGHTTP2_ERR_DEFERRED;
+        }
+    }
+
+    if (stream->rst_error) {
+        return NGHTTP2_ERR_DEFERRED;
+    }
+
+    if (buf_len == 0 && header_blocked) {
+        rv = stream_do_trailers(stream);
+        if (APR_SUCCESS != rv && !APR_STATUS_IS_EAGAIN(rv)) {
+            ap_log_cerror(APLOG_MARK, APLOG_ERR, rv, c1,
+                          H2_STRM_LOG(APLOGNO(10300), stream,
+                          "data_cb, error processing trailers"));
+            return NGHTTP2_ERR_CALLBACK_FAILURE;
+        }
+        length = 0;
+        eos = 0;
+    }
+    else if (buf_len > (apr_off_t)length) {
+        eos = 0;  /* Any EOS we have in the buffer does not apply yet */
+    }
+    else {
+        length = (size_t)buf_len;
+    }
+
+    if (length) {
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, c1,
+                      H2_STRM_MSG(stream, "data_cb, sending len=%ld, eos=%d"),
+                      (long)length, eos);
+        *data_flags |=  NGHTTP2_DATA_FLAG_NO_COPY;
+    }
+    else if (!eos && !stream->sent_trailers) {
+        /* We have not reached the end of DATA yet, DEFER sending */
+        ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c1,
+                      H2_STRM_LOG(APLOGNO(03071), stream, "data_cb, suspending"));
+        return NGHTTP2_ERR_DEFERRED;
+    }
+
+    if (eos) {
+        *data_flags |= NGHTTP2_DATA_FLAG_EOF;
+    }
+    return length;
+}
+
+static apr_status_t stream_do_response(h2_stream *stream)
+{
+    conn_rec *c1 = stream->session->c1;
+    apr_status_t rv = APR_EAGAIN;
+    int ngrv, is_empty = 0;
+    h2_ngheader *nh = NULL;
+    apr_bucket *b, *e;
+#if AP_HAS_RESPONSE_BUCKETS
+    ap_bucket_response *resp = NULL;
+#else
+    h2_headers *resp = NULL;
+#endif
+    nghttp2_data_provider provider, *pprovider = NULL;
+
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    ap_assert(!stream->response);
+    ap_assert(stream->out_buffer);
+
+    b = APR_BRIGADE_FIRST(stream->out_buffer);
+    while (b != APR_BRIGADE_SENTINEL(stream->out_buffer)) {
+        e = APR_BUCKET_NEXT(b);
+        if (APR_BUCKET_IS_METADATA(b)) {
+#if AP_HAS_RESPONSE_BUCKETS
+            if (AP_BUCKET_IS_RESPONSE(b)) {
+                resp = b->data;
+#else /* AP_HAS_RESPONSE_BUCKETS */
+            if (H2_BUCKET_IS_HEADERS(b)) {
+                resp = h2_bucket_headers_get(b);
+#endif /* else AP_HAS_RESPONSE_BUCKETS */
+                APR_BUCKET_REMOVE(b);
+                apr_bucket_destroy(b);
+                ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c1,
+                              H2_STRM_MSG(stream, "process response %d"),
+                              resp->status);
+                is_empty = (e != APR_BRIGADE_SENTINEL(stream->out_buffer)
+                            && APR_BUCKET_IS_EOS(e));
+                break;
+            }
+            else if (APR_BUCKET_IS_EOS(b)) {
+                h2_stream_rst(stream, H2_ERR_INTERNAL_ERROR);
+                rv = APR_EINVAL;
+                goto cleanup;
+            }
+            else if (AP_BUCKET_IS_ERROR(b)) {
+                stream_do_error_bucket(stream, b);
+                rv = APR_EINVAL;
+                goto cleanup;
+            }
+        }
+        else {
+            /* data buckets before response headers, an error */
+            h2_stream_rst(stream, H2_ERR_INTERNAL_ERROR);
+            rv = APR_EINVAL;
+            goto cleanup;
+        }
+        b = e;
+    }
+
+    if (!resp) {
+        rv = APR_EAGAIN;
+        goto cleanup;
+    }
+
+    if (resp->status < 100) {
+        h2_stream_rst(stream, resp->status);
+        goto cleanup;
+    }
+
+    if (resp->status == HTTP_FORBIDDEN && resp->notes) {
+        const char *cause = apr_table_get(resp->notes, "ssl-renegotiate-forbidden");
+        if (cause) {
+            /* This request triggered a TLS renegotiation that is not allowed
+             * in HTTP/2. Tell the client that it should use HTTP/1.1 for this.
+             */
+            ap_log_cerror(APLOG_MARK, APLOG_DEBUG, resp->status, c1,
+                          H2_STRM_LOG(APLOGNO(03061), stream,
+                          "renegotiate forbidden, cause: %s"), cause);
+            h2_stream_rst(stream, H2_ERR_HTTP_1_1_REQUIRED);
+            goto cleanup;
+        }
+    }
+
+    ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c1,
+                  H2_STRM_LOG(APLOGNO(03073), stream,
+                  "submit response %d"), resp->status);
+
+    /* If this stream is not a pushed one itself,
+     * and HTTP/2 server push is enabled here,
+     * and the response HTTP status is not sth >= 400,
+     * and the remote side has pushing enabled,
+     * -> find and perform any pushes on this stream
+     *    *before* we submit the stream response itself.
+     *    This helps clients avoid opening new streams on Link
+     *    resp that get pushed right afterwards.
+     *
+     * *) the response code is relevant, as we do not want to
+     *    make pushes on 401 or 403 codes and friends.
+     *    And if we see a 304, we do not push either
+     *    as the client, having this resource in its cache, might
+     *    also have the pushed ones as well.
+     */
+    if (!stream->initiated_on
+        && !stream->response
+        && stream->request && stream->request->method
+        && !strcmp("GET", stream->request->method)
+        && (resp->status < 400)
+        && (resp->status != 304)
+        && h2_session_push_enabled(stream->session)) {
+        /* PUSH is possible and enabled on server, unless the request
+         * denies it, submit resources to push */
+        const char *s = apr_table_get(resp->notes, H2_PUSH_MODE_NOTE);
+        if (!s || strcmp(s, "0")) {
+            ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c1,
+                          H2_STRM_MSG(stream, "submit pushes, note=%s"), s);
+            h2_stream_submit_pushes(stream, resp);
+        }
+    }
+
+    if (!stream->pref_priority) {
+        stream->pref_priority = h2_stream_get_priority(stream, resp);
+    }
+    h2_session_set_prio(stream->session, stream, stream->pref_priority);
+
+    if (resp->status == 103
+        && !h2_config_sgeti(stream->session->s, H2_CONF_EARLY_HINTS)) {
+        /* suppress sending this to the client, it might have triggered
+         * pushes and served its purpose nevertheless */
+        rv = APR_SUCCESS;
+        goto cleanup;
+    }
+    if (resp->status >= 200) {
+        stream->response = resp;
+    }
+
+    if (!is_empty) {
+        memset(&provider, 0, sizeof(provider));
+        provider.source.fd = stream->id;
+        provider.read_callback = stream_data_cb;
+        pprovider = &provider;
+    }
+
+    rv = h2_res_create_ngheader(&nh, stream->pool, resp);
+    if (APR_SUCCESS != rv) {
+        ap_log_cerror(APLOG_MARK, APLOG_DEBUG, rv, c1,
+                      H2_STRM_LOG(APLOGNO(10025), stream, "invalid response"));
+        h2_stream_rst(stream, NGHTTP2_PROTOCOL_ERROR);
+        goto cleanup;
+    }
+
+    ngrv = nghttp2_submit_response(stream->session->ngh2, stream->id,
+                                   nh->nv, nh->nvlen, pprovider);
+    if (nghttp2_is_fatal(ngrv)) {
+        rv = APR_EGENERAL;
+        h2_session_dispatch_event(stream->session,
+                                 H2_SESSION_EV_PROTO_ERROR, ngrv, nghttp2_strerror(rv));
+        ap_log_cerror(APLOG_MARK, APLOG_ERR, rv, c1,
+                      APLOGNO(10402) "submit_response: %s",
+                      nghttp2_strerror(rv));
+        goto cleanup;
+    }
+
+    if (stream->initiated_on) {
+        ++stream->session->pushes_submitted;
+    }
+    else {
+        ++stream->session->responses_submitted;
+    }
+
+cleanup:
+    return rv;
+}
+
+static void stream_do_responses(h2_stream *stream)
+{
+    h2_session *session = stream->session;
+    conn_rec *c1 = session->c1;
+    apr_status_t rv;
+
+    ap_assert(!stream->response);
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, c1,
+                  H2_STRM_MSG(stream, "do_response"));
+    rv = buffer_output_receive(stream);
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE1, rv, c1,
+                  H2_SSSN_STRM_MSG(session, stream->id,
+                  "buffer_output_received2"));
+    if (APR_SUCCESS != rv && APR_EAGAIN != rv) {
+        h2_stream_rst(stream, NGHTTP2_PROTOCOL_ERROR);
+    }
+    else {
+        /* process all headers sitting at the buffer head. */
+        do {
+            rv = stream_do_response(stream);
+        } while (APR_SUCCESS == rv
+                 && !stream->rst_error
+                 && !stream->response);
+    }
+}
+
+void h2_stream_on_output_change(h2_stream *stream)
+{
+    conn_rec *c1 = stream->session->c1;
+    apr_status_t rv = APR_EAGAIN;
+
+    /* stream->pout_recv_write signalled a change. Check what has happend, read
+     * from it and act on seeing a response/data. */
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    if (!stream->output) {
+        /* c2 has not assigned the output beam to the stream (yet). */
+        ap_log_cerror(APLOG_MARK, APLOG_WARNING, 0, c1,
+                      H2_STRM_MSG(stream, "read_output, no output beam registered"));
+    }
+    else if (h2_stream_is_at_or_past(stream, H2_SS_CLOSED)) {
+        ap_log_cerror(APLOG_MARK, APLOG_DEBUG, rv, c1,
+                      H2_STRM_LOG(APLOGNO(10301), stream, "already closed"));
+    }
+    else if (h2_stream_is_at(stream, H2_SS_CLOSED_L)) {
+        /* We have delivered a response to a stream that was not closed
+         * by the client. This could be a POST with body that we negate
+         * and we need to RST_STREAM to end if. */
+        ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c1,
+                      H2_STRM_LOG(APLOGNO(10313), stream, "remote close missing"));
+        h2_stream_rst(stream, H2_ERR_NO_ERROR);
+    }
+    else {
+        /* stream is not closed, a change in output happened. There are
+         * two modes of operation here:
+         * 1) the final response has been submitted. nghttp2 is invoking
+         *    stream_data_cb() to progress the stream. This handles DATA,
+         *    trailers, EOS and ERRORs.
+         *    When stream_data_cb() runs out of things to send, it returns
+         *    NGHTTP2_ERR_DEFERRED and nghttp2 *suspends* further processing
+         *    until we tell it to resume.
+         * 2) We have not seen the *final* response yet. The stream can not
+         *    send any response DATA. The nghttp2 stream_data_cb() is not
+         *    invoked. We need to receive output, expecting not DATA but
+         *    RESPONSEs (intermediate may arrive) and submit those. On
+         *    the final response, nghttp2 will start calling stream_data_cb().
+         */
+        if (stream->response) {
+            nghttp2_session_resume_data(stream->session->ngh2, stream->id);
+            ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, c1,
+                          H2_STRM_MSG(stream, "resumed"));
+        }
+        else {
+            stream_do_responses(stream);
+            if (!stream->rst_error) {
+                nghttp2_session_resume_data(stream->session->ngh2, stream->id);
+            }
+        }
+    }
+}
+
+void h2_stream_on_input_change(h2_stream *stream)
+{
+    H2_STRM_ASSERT_MAGIC(stream, H2_STRM_MAGIC_OK);
+    ap_assert(stream->input);
+    h2_beam_report_consumption(stream->input);
+    if (h2_stream_is_at(stream, H2_SS_CLOSED_L)
+        && !h2_mplx_c1_stream_is_running(stream->session->mplx, stream)) {
+        ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, stream->session->c1,
+                      H2_STRM_LOG(APLOGNO(10026), stream, "remote close missing"));
+        h2_stream_rst(stream, H2_ERR_NO_ERROR);
+    }
+}