/src/libwebsockets/lib/roles/h2/http2.c

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/*
 * libwebsockets - small server side websockets and web server implementation
 *
 * Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include "private-lib-core.h"

/*
 * bitmap of control messages that are valid to receive for each http2 state
 */

static const uint16_t http2_rx_validity[] = {
  /* LWS_H2S_IDLE */
    (1 << LWS_H2_FRAME_TYPE_SETTINGS) |
    (1 << LWS_H2_FRAME_TYPE_PRIORITY) |
//    (1 << LWS_H2_FRAME_TYPE_WINDOW_UPDATE)| /* ignore */
    (1 << LWS_H2_FRAME_TYPE_HEADERS) |
    (1 << LWS_H2_FRAME_TYPE_CONTINUATION),
  /* LWS_H2S_RESERVED_LOCAL */
    (1 << LWS_H2_FRAME_TYPE_SETTINGS) |
    (1 << LWS_H2_FRAME_TYPE_RST_STREAM) |
    (1 << LWS_H2_FRAME_TYPE_PRIORITY) |
    (1 << LWS_H2_FRAME_TYPE_WINDOW_UPDATE),
  /* LWS_H2S_RESERVED_REMOTE */
    (1 << LWS_H2_FRAME_TYPE_SETTINGS) |
    (1 << LWS_H2_FRAME_TYPE_HEADERS) |
    (1 << LWS_H2_FRAME_TYPE_CONTINUATION) |
    (1 << LWS_H2_FRAME_TYPE_RST_STREAM) |
    (1 << LWS_H2_FRAME_TYPE_PRIORITY),
  /* LWS_H2S_OPEN */
    (1 << LWS_H2_FRAME_TYPE_DATA) |
    (1 << LWS_H2_FRAME_TYPE_HEADERS) |
    (1 << LWS_H2_FRAME_TYPE_PRIORITY) |
    (1 << LWS_H2_FRAME_TYPE_RST_STREAM) |
    (1 << LWS_H2_FRAME_TYPE_SETTINGS) |
    (1 << LWS_H2_FRAME_TYPE_PUSH_PROMISE) |
    (1 << LWS_H2_FRAME_TYPE_PING) |
    (1 << LWS_H2_FRAME_TYPE_GOAWAY) |
    (1 << LWS_H2_FRAME_TYPE_WINDOW_UPDATE) |
    (1 << LWS_H2_FRAME_TYPE_CONTINUATION),
  /* LWS_H2S_HALF_CLOSED_REMOTE */
    (1 << LWS_H2_FRAME_TYPE_SETTINGS) |
    (1 << LWS_H2_FRAME_TYPE_WINDOW_UPDATE) |
    (1 << LWS_H2_FRAME_TYPE_PRIORITY) |
    (1 << LWS_H2_FRAME_TYPE_RST_STREAM),
  /* LWS_H2S_HALF_CLOSED_LOCAL */
    (1 << LWS_H2_FRAME_TYPE_DATA) |
    (1 << LWS_H2_FRAME_TYPE_HEADERS) |
    (1 << LWS_H2_FRAME_TYPE_PRIORITY) |
    (1 << LWS_H2_FRAME_TYPE_RST_STREAM) |
    (1 << LWS_H2_FRAME_TYPE_SETTINGS) |
    (1 << LWS_H2_FRAME_TYPE_PUSH_PROMISE) |
    (1 << LWS_H2_FRAME_TYPE_PING) |
    (1 << LWS_H2_FRAME_TYPE_GOAWAY) |
    (1 << LWS_H2_FRAME_TYPE_WINDOW_UPDATE) |
    (1 << LWS_H2_FRAME_TYPE_CONTINUATION),
  /* LWS_H2S_CLOSED */
    (1 << LWS_H2_FRAME_TYPE_SETTINGS) |
    (1 << LWS_H2_FRAME_TYPE_PRIORITY) |
    (1 << LWS_H2_FRAME_TYPE_WINDOW_UPDATE) |
    (1 << LWS_H2_FRAME_TYPE_RST_STREAM),
};

static const char *preface = "PRI * HTTP/2.0\x0d\x0a\x0d\x0aSM\x0d\x0a\x0d\x0a";

static const char * const h2_state_names[] = {
  "LWS_H2S_IDLE",
  "LWS_H2S_RESERVED_LOCAL",
  "LWS_H2S_RESERVED_REMOTE",
  "LWS_H2S_OPEN",
  "LWS_H2S_HALF_CLOSED_REMOTE",
  "LWS_H2S_HALF_CLOSED_LOCAL",
  "LWS_H2S_CLOSED",
};

#if 0
static const char * const h2_setting_names[] = {
  "",
  "H2SET_HEADER_TABLE_SIZE",
  "H2SET_ENABLE_PUSH",
  "H2SET_MAX_CONCURRENT_STREAMS",
  "H2SET_INITIAL_WINDOW_SIZE",
  "H2SET_MAX_FRAME_SIZE",
  "H2SET_MAX_HEADER_LIST_SIZE",
  "reserved",
  "H2SET_ENABLE_CONNECT_PROTOCOL"
};

void
lws_h2_dump_settings(struct http2_settings *set)
{
  int n;

  for (n = 1; n < H2SET_COUNT; n++)
    lwsl_notice("   %30s: %10d\n", h2_setting_names[n], set->s[n]);
}
#else
void
lws_h2_dump_settings(struct http2_settings *set)
{
}
#endif

struct lws_h2_protocol_send *
lws_h2_new_pps(enum lws_h2_protocol_send_type type)
{
  struct lws_h2_protocol_send *pps = lws_malloc(sizeof(*pps), "pps");

  if (pps)
    pps->type = type;

  return pps;
}

void lws_h2_init(struct lws *wsi)
{
  wsi->h2.h2n->our_set = wsi->a.vhost->h2.set;
  wsi->h2.h2n->peer_set = lws_h2_defaults;
}

void
lws_h2_state(struct lws *wsi, enum lws_h2_states s)
{
  if (!wsi)
    return;
  lwsl_info("%s: %s: state %s -> %s\n", __func__, lws_wsi_tag(wsi),
      h2_state_names[wsi->h2.h2_state],
      h2_state_names[s]);
    
  (void)h2_state_names;
  wsi->h2.h2_state = (uint8_t)s;
}

int
lws_h2_update_peer_txcredit(struct lws *wsi, unsigned int sid, int bump)
{
  struct lws *nwsi = lws_get_network_wsi(wsi);
  struct lws_h2_protocol_send *pps;

  assert(wsi);

  if (!bump)
    return 0;

  if (sid == (unsigned int)-1)
    sid = wsi->mux.my_sid;

  lwsl_info("%s: sid %d: bump %d -> %d\n", __func__, sid, bump,
      (int)wsi->txc.peer_tx_cr_est + bump);

  pps = lws_h2_new_pps(LWS_H2_PPS_UPDATE_WINDOW);
  if (!pps)
    return 1;

  pps->u.update_window.sid = (unsigned int)sid;
  pps->u.update_window.credit = (unsigned int)bump;
  wsi->txc.peer_tx_cr_est += bump;

  lws_wsi_txc_describe(&wsi->txc, __func__, wsi->mux.my_sid);

  lws_pps_schedule(wsi, pps);

  pps = lws_h2_new_pps(LWS_H2_PPS_UPDATE_WINDOW);
  if (!pps)
    return 1;

  pps->u.update_window.sid = 0;
  pps->u.update_window.credit = (unsigned int)bump;
  nwsi->txc.peer_tx_cr_est += bump;

  lws_wsi_txc_describe(&nwsi->txc, __func__, nwsi->mux.my_sid);

  lws_pps_schedule(nwsi, pps);

  return 0;
}

int
lws_h2_get_peer_txcredit_estimate(struct lws *wsi)
{
  lws_wsi_txc_describe(&wsi->txc, __func__, wsi->mux.my_sid);
  return (int)wsi->txc.peer_tx_cr_est;
}

static int
lws_h2_update_peer_txcredit_thresh(struct lws *wsi, unsigned int sid, int threshold, int bump)
{
  if (wsi->txc.peer_tx_cr_est > threshold)
    return 0;

  return lws_h2_update_peer_txcredit(wsi, sid, bump);
}

/* cx + vh lock */

static struct lws *
__lws_wsi_server_new(struct lws_vhost *vh, struct lws *parent_wsi,
         unsigned int sid)
{
  struct lws *nwsi = lws_get_network_wsi(parent_wsi);
  struct lws_h2_netconn *h2n = nwsi->h2.h2n;
  char tmp[50], tmp1[50];
  unsigned int n, b = 0;
  struct lws *wsi;
  const char *p;

  lws_context_assert_lock_held(vh->context);
  lws_vhost_assert_lock_held(vh);

  /*
   * The identifier of a newly established stream MUST be numerically
     * greater than all streams that the initiating endpoint has opened or
     * reserved.  This governs streams that are opened using a HEADERS frame
     * and streams that are reserved using PUSH_PROMISE.  An endpoint that
     * receives an unexpected stream identifier MUST respond with a
     * connection error (Section 5.4.1) of type PROTOCOL_ERROR.
   */
  if (sid <= h2n->highest_sid_opened) {
    lwsl_info("%s: tried to open lower sid %d (%d)\n", __func__,
        sid, (int)h2n->highest_sid_opened);
    lws_h2_goaway(nwsi, H2_ERR_PROTOCOL_ERROR, "Bad sid");
    return NULL;
  }

  /* no more children allowed by parent */
  if (parent_wsi->mux.child_count + 1 >
      parent_wsi->h2.h2n->our_set.s[H2SET_MAX_CONCURRENT_STREAMS]) {
    lwsl_notice("reached concurrent stream limit\n");
    return NULL;
  }

  n = 0;
  p = &parent_wsi->lc.gutag[1];
  do {
    if (*p == '|') {
      b++;
      if (b == 3)
        continue;
    }
    tmp1[n++] = *p++;
  } while (b < 3 && n < sizeof(tmp1) - 2);
  tmp1[n] = '\0';
  lws_snprintf(tmp, sizeof(tmp), "h2_sid%u_(%s)", sid, tmp1);
  wsi = lws_create_new_server_wsi(vh, parent_wsi->tsi, LWSLCG_WSI_MUX, tmp);
  if (!wsi) {
    lwsl_notice("new server wsi failed (%s)\n", lws_vh_tag(vh));
    return NULL;
  }

#if defined(LWS_WITH_SERVER)
  if (lwsi_role_server(parent_wsi)) {
    lws_metrics_caliper_bind(wsi->cal_conn, wsi->a.context->mth_srv);
  }
#endif

  h2n->highest_sid_opened = sid;

  lws_wsi_mux_insert(wsi, parent_wsi, sid);
  if (sid >= h2n->highest_sid)
    h2n->highest_sid = sid + 2;

  wsi->mux_substream = 1;
  wsi->seen_nonpseudoheader = 0;

  wsi->txc.tx_cr = (int32_t)nwsi->h2.h2n->peer_set.s[H2SET_INITIAL_WINDOW_SIZE];
  wsi->txc.peer_tx_cr_est =
      (int32_t)nwsi->h2.h2n->our_set.s[H2SET_INITIAL_WINDOW_SIZE];

  lwsi_set_state(wsi, LRS_ESTABLISHED);
  lwsi_set_role(wsi, lwsi_role(parent_wsi));

  wsi->a.protocol = &vh->protocols[0];
  if (lws_ensure_user_space(wsi))
    goto bail1;

#if defined(LWS_WITH_SERVER) && defined(LWS_WITH_SECURE_STREAMS)
  if (lws_adopt_ss_server_accept(wsi))
    goto bail1;
#endif

  /* get the ball rolling */
  lws_validity_confirmed(wsi);

  lwsl_info("%s: %s new ch %s, sid %d, usersp=%p\n", __func__,
      lws_wsi_tag(parent_wsi), lws_wsi_tag(wsi), sid, wsi->user_space);

  lws_wsi_txc_describe(&wsi->txc, __func__, wsi->mux.my_sid);
  lws_wsi_txc_describe(&nwsi->txc, __func__, 0);

  return wsi;

bail1:
  /* undo the insert */
  parent_wsi->mux.child_list = wsi->mux.sibling_list;
  parent_wsi->mux.child_count--;

  if (wsi->user_space)
    lws_free_set_NULL(wsi->user_space);
  vh->protocols[0].callback(wsi, LWS_CALLBACK_WSI_DESTROY, NULL, NULL, 0);
  __lws_vhost_unbind_wsi(wsi);
  lws_free(wsi);

  return NULL;
}

struct lws *
lws_wsi_h2_adopt(struct lws *parent_wsi, struct lws *wsi)
{
  struct lws *nwsi = lws_get_network_wsi(parent_wsi);

  /* no more children allowed by parent */
  if (parent_wsi->mux.child_count + 1 >
      parent_wsi->h2.h2n->our_set.s[H2SET_MAX_CONCURRENT_STREAMS]) {
    lwsl_notice("reached concurrent stream limit\n");
    return NULL;
  }

  /* sid is set just before issuing the headers, ensuring monoticity */

  wsi->seen_nonpseudoheader = 0;
#if defined(LWS_WITH_CLIENT)
  wsi->client_mux_substream = 1;
#endif
  wsi->h2.initialized = 1;

#if 0
  /* only assign sid at header send time when we know it */
  if (!wsi->mux.my_sid) {
    wsi->mux.my_sid = nwsi->h2.h2n->highest_sid;
    nwsi->h2.h2n->highest_sid += 2;
  }
#endif

  lwsl_info("%s: binding wsi %s to sid %d (next %d)\n", __func__,
    lws_wsi_tag(wsi), (int)wsi->mux.my_sid, (int)nwsi->h2.h2n->highest_sid);

  lws_wsi_mux_insert(wsi, parent_wsi, wsi->mux.my_sid);

  wsi->txc.tx_cr = (int32_t)nwsi->h2.h2n->peer_set.s[H2SET_INITIAL_WINDOW_SIZE];
  wsi->txc.peer_tx_cr_est = (int32_t)
      nwsi->h2.h2n->our_set.s[H2SET_INITIAL_WINDOW_SIZE];

  lws_wsi_txc_describe(&wsi->txc, __func__, wsi->mux.my_sid);

  if (lws_ensure_user_space(wsi))
    goto bail1;

  lws_role_transition(wsi, LWSIFR_CLIENT, LRS_H2_WAITING_TO_SEND_HEADERS,
          &role_ops_h2);

  lws_callback_on_writable(wsi);

  return wsi;

bail1:
  /* undo the insert */
  parent_wsi->mux.child_list = wsi->mux.sibling_list;
  parent_wsi->mux.child_count--;

  if (wsi->user_space)
    lws_free_set_NULL(wsi->user_space);
  wsi->a.protocol->callback(wsi, LWS_CALLBACK_WSI_DESTROY, NULL, NULL, 0);
  lws_free(wsi);

  return NULL;
}


int
lws_h2_issue_preface(struct lws *wsi)
{
  struct lws_h2_netconn *h2n = wsi->h2.h2n;
  struct lws_h2_protocol_send *pps;

  if (!h2n) {
    lwsl_warn("%s: no valid h2n\n", __func__);
    return 1;
  }

  if (h2n->sent_preface)
    return 1;

  lwsl_debug("%s: %s: fd %d\n", __func__, lws_wsi_tag(wsi), (int)wsi->desc.sockfd);

  if (lws_issue_raw(wsi, (uint8_t *)preface, strlen(preface)) !=
    (int)strlen(preface))
    return 1;

  h2n->sent_preface = 1;

  lws_role_transition(wsi, LWSIFR_CLIENT, LRS_H2_WAITING_TO_SEND_HEADERS,
          &role_ops_h2);

  h2n->count = 0;
  wsi->txc.tx_cr = 65535;

  /*
   * we must send a settings frame
   */
  pps = lws_h2_new_pps(LWS_H2_PPS_MY_SETTINGS);
  if (!pps)
    return 1;
  lws_pps_schedule(wsi, pps);
  lwsl_info("%s: h2 client sending settings\n", __func__);

  return 0;
}

void
lws_pps_schedule(struct lws *wsi, struct lws_h2_protocol_send *pps)
{
  struct lws *nwsi = lws_get_network_wsi(wsi);
  struct lws_h2_netconn *h2n = nwsi->h2.h2n;

  if (!h2n) {
    lwsl_warn("%s: null h2n\n", __func__);
    lws_free(pps);
    return;
  }

  pps->next = h2n->pps;
  h2n->pps = pps;
  lws_rx_flow_control(wsi, LWS_RXFLOW_REASON_APPLIES_DISABLE |
         LWS_RXFLOW_REASON_H2_PPS_PENDING);
  lws_callback_on_writable(wsi);
}

int
lws_h2_goaway(struct lws *wsi, uint32_t err, const char *reason)
{
  struct lws_h2_netconn *h2n = wsi->h2.h2n;
  struct lws_h2_protocol_send *pps;

  if (h2n->type == LWS_H2_FRAME_TYPE_COUNT)
    return 0;

  pps = lws_h2_new_pps(LWS_H2_PPS_GOAWAY);
  if (!pps)
    return 1;

  lwsl_info("%s: %s: ERR 0x%x, '%s'\n", __func__, lws_wsi_tag(wsi), (int)err, reason);

  pps->u.ga.err = err;
  pps->u.ga.highest_sid = h2n->highest_sid;
  lws_strncpy(pps->u.ga.str, reason, sizeof(pps->u.ga.str));
  lws_pps_schedule(wsi, pps);

  h2n->type = LWS_H2_FRAME_TYPE_COUNT; /* ie, IGNORE */

  return 0;
}

int
lws_h2_rst_stream(struct lws *wsi, uint32_t err, const char *reason)
{
  struct lws *nwsi = lws_get_network_wsi(wsi);
  struct lws_h2_netconn *h2n = nwsi->h2.h2n;
  struct lws_h2_protocol_send *pps;

  if (!h2n)
    return 0;

  if (!wsi->h2_stream_carries_ws && h2n->type == LWS_H2_FRAME_TYPE_COUNT)
    return 0;

  pps = lws_h2_new_pps(LWS_H2_PPS_RST_STREAM);
  if (!pps)
    return 1;

  lwsl_info("%s: RST_STREAM 0x%x, sid %d, REASON '%s'\n", __func__,
      (int)err, wsi->mux.my_sid, reason);

  pps->u.rs.sid = wsi->mux.my_sid;
  pps->u.rs.err = err;

  lws_pps_schedule(wsi, pps);

  h2n->type = LWS_H2_FRAME_TYPE_COUNT; /* ie, IGNORE */
  lws_h2_state(wsi, LWS_H2_STATE_CLOSED);

  return 0;
}

int
lws_h2_settings(struct lws *wsi, struct http2_settings *settings,
    unsigned char *buf, int len)
{
  struct lws *nwsi = lws_get_network_wsi(wsi);
  unsigned int a, b;

  if (!len)
    return 0;

  if (len < LWS_H2_SETTINGS_LEN)
    return 1;

  while (len >= LWS_H2_SETTINGS_LEN) {
    a = (unsigned int)((buf[0] << 8) | buf[1]);
    if (!a || a >= H2SET_COUNT)
      goto skip;
    b = (unsigned int)(buf[2] << 24 | buf[3] << 16 | buf[4] << 8 | buf[5]);

    switch (a) {
    case H2SET_HEADER_TABLE_SIZE:
      break;
    case H2SET_ENABLE_PUSH:
      if (b > 1) {
        lws_h2_goaway(nwsi, H2_ERR_PROTOCOL_ERROR,
                "ENABLE_PUSH invalid arg");
        return 1;
      }
      break;
    case H2SET_MAX_CONCURRENT_STREAMS:
      break;
    case H2SET_INITIAL_WINDOW_SIZE:
      if (b > 0x7fffffff) {
        lws_h2_goaway(nwsi, H2_ERR_FLOW_CONTROL_ERROR,
                "Initial Window beyond max");
        return 1;
      }

#if defined(LWS_WITH_CLIENT)
#if defined(LWS_AMAZON_RTOS) || defined(LWS_AMAZON_LINUX)
      if (
#else
      if (wsi->flags & LCCSCF_H2_QUIRK_OVERFLOWS_TXCR &&
#endif
          b == 0x7fffffff) {
        b >>= 4;

        break;
      }
#endif

      /*
       * In addition to changing the flow-control window for
       * streams that are not yet active, a SETTINGS frame
       * can alter the initial flow-control window size for
       * streams with active flow-control windows (that is,
       * streams in the "open" or "half-closed (remote)"
       * state).  When the value of
       * SETTINGS_INITIAL_WINDOW_SIZE changes, a receiver
       * MUST adjust the size of all stream flow-control
       * windows that it maintains by the difference between
       * the new value and the old value.
       */

      lws_start_foreach_ll(struct lws *, w,
               nwsi->mux.child_list) {
        lwsl_info("%s: adi child tc cr %d +%d -> %d",
            __func__, (int)w->txc.tx_cr,
            b - (unsigned int)settings->s[a],
            (int)(w->txc.tx_cr + (int)b -
              (int)settings->s[a]));
        w->txc.tx_cr += (int)b - (int)settings->s[a];
        if (w->txc.tx_cr > 0 &&
            w->txc.tx_cr <=
              (int32_t)(b - settings->s[a]))

          lws_callback_on_writable(w);
      } lws_end_foreach_ll(w, mux.sibling_list);

      break;
    case H2SET_MAX_FRAME_SIZE:
      if (b < wsi->a.vhost->h2.set.s[H2SET_MAX_FRAME_SIZE]) {
        lws_h2_goaway(nwsi, H2_ERR_PROTOCOL_ERROR,
                "Frame size < initial");
        return 1;
      }
      if (b > 0x00ffffff) {
        lws_h2_goaway(nwsi, H2_ERR_PROTOCOL_ERROR,
                "Settings Frame size above max");
        return 1;
      }
      break;
    case H2SET_MAX_HEADER_LIST_SIZE:
      break;
    }
    settings->s[a] = b;
    lwsl_info("http2 settings %d <- 0x%x\n", a, b);
skip:
    len -= LWS_H2_SETTINGS_LEN;
    buf += LWS_H2_SETTINGS_LEN;
  }

  if (len)
    return 1;

  lws_h2_dump_settings(settings);

  return 0;
}

/* RFC7640 Sect 6.9
 *
 * The WINDOW_UPDATE frame can be specific to a stream or to the entire
 * connection.  In the former case, the frame's stream identifier
 * indicates the affected stream; in the latter, the value "0" indicates
 * that the entire connection is the subject of the frame.
 *
 * ...
 *
 * Two flow-control windows are applicable: the stream flow-control
 * window and the connection flow-control window.  The sender MUST NOT
 * send a flow-controlled frame with a length that exceeds the space
 * available in either of the flow-control windows advertised by the
 * receiver.  Frames with zero length with the END_STREAM flag set (that
 * is, an empty DATA frame) MAY be sent if there is no available space
 * in either flow-control window.
 */

int
lws_h2_tx_cr_get(struct lws *wsi)
{
  int c = wsi->txc.tx_cr;
  struct lws *nwsi = lws_get_network_wsi(wsi);

  if (!wsi->mux_substream && !nwsi->upgraded_to_http2)
    return ~0x80000000;

  lwsl_info ("%s: %s: own tx credit %d: nwsi credit %d\n",
         __func__, lws_wsi_tag(wsi), c, (int)nwsi->txc.tx_cr);

  if (nwsi->txc.tx_cr < c)
    c = nwsi->txc.tx_cr;

  if (c < 0)
    return 0;

  return c;
}

void
lws_h2_tx_cr_consume(struct lws *wsi, int consumed)
{
  struct lws *nwsi = lws_get_network_wsi(wsi);

  wsi->txc.tx_cr -= consumed;

  if (nwsi != wsi)
    nwsi->txc.tx_cr -= consumed;
}

int lws_h2_frame_write(struct lws *wsi, int type, int flags,
           unsigned int sid, unsigned int len, unsigned char *buf)
{
  struct lws *nwsi = lws_get_network_wsi(wsi);
  unsigned char *p = &buf[-LWS_H2_FRAME_HEADER_LENGTH];
  int n;

  //if (wsi->h2_stream_carries_ws)
  // lwsl_hexdump_level(LLL_NOTICE, buf, len);

  *p++ = (uint8_t)(len >> 16);
  *p++ = (uint8_t)(len >> 8);
  *p++ = (uint8_t)len;
  *p++ = (uint8_t)type;
  *p++ = (uint8_t)flags;
  *p++ = (uint8_t)(sid >> 24);
  *p++ = (uint8_t)(sid >> 16);
  *p++ = (uint8_t)(sid >> 8);
  *p++ = (uint8_t)sid;

  lwsl_debug("%s: %s (eff %s). typ %d, fl 0x%x, sid=%d, len=%d, "
       "txcr=%d, nwsi->txcr=%d\n", __func__, lws_wsi_tag(wsi),
       lws_wsi_tag(nwsi), type, flags,
       sid, len, (int)wsi->txc.tx_cr, (int)nwsi->txc.tx_cr);

  if (type == LWS_H2_FRAME_TYPE_DATA) {
    if (wsi->txc.tx_cr < (int)len)

      lwsl_info("%s: %s: sending payload len %d"
         " but tx_cr only %d!\n", __func__,
         lws_wsi_tag(wsi), len, (int)wsi->txc.tx_cr);
        lws_h2_tx_cr_consume(wsi, (int)len);
  }

  n = lws_issue_raw(nwsi, &buf[-LWS_H2_FRAME_HEADER_LENGTH],
        len + LWS_H2_FRAME_HEADER_LENGTH);
  if (n < 0)
    return n;

  if (n >= LWS_H2_FRAME_HEADER_LENGTH)
    return n - LWS_H2_FRAME_HEADER_LENGTH;

  return n;
}

static void lws_h2_set_bin(struct lws *wsi, int n, unsigned char *buf)
{
  *buf++ = (uint8_t)(n >> 8);
  *buf++ = (uint8_t)n;
  *buf++ = (uint8_t)(wsi->h2.h2n->our_set.s[n] >> 24);
  *buf++ = (uint8_t)(wsi->h2.h2n->our_set.s[n] >> 16);
  *buf++ = (uint8_t)(wsi->h2.h2n->our_set.s[n] >> 8);
  *buf = (uint8_t)wsi->h2.h2n->our_set.s[n];
}

/* we get called on the network connection */

int lws_h2_do_pps_send(struct lws *wsi)
{
  struct lws_h2_netconn *h2n = wsi->h2.h2n;
  struct lws_h2_protocol_send *pps = NULL;
  struct lws *cwsi;
  uint8_t set[LWS_PRE + 64], *p = &set[LWS_PRE], *q;
  int n, m = 0, flags = 0;

  if (!h2n)
    return 1;

  /* get the oldest pps */

  lws_start_foreach_llp(struct lws_h2_protocol_send **, pps1, h2n->pps) {
    if ((*pps1)->next == NULL) { /* we are the oldest in the list */
      pps = *pps1; /* remove us from the list */
      *pps1 = NULL;
      continue;
    }
  } lws_end_foreach_llp(pps1, next);

  if (!pps)
    return 1;

  lwsl_info("%s: %s: %d\n", __func__, lws_wsi_tag(wsi), pps->type);

  switch (pps->type) {

  case LWS_H2_PPS_MY_SETTINGS:

    /*
     * if any of our settings varies from h2 "default defaults"
     * then we must inform the peer
     */
    for (n = 1; n < H2SET_COUNT; n++)
      if (h2n->our_set.s[n] != lws_h2_defaults.s[n]) {
        lwsl_debug("sending SETTING %d 0x%x\n", n,
             (unsigned int)
               wsi->h2.h2n->our_set.s[n]);

        lws_h2_set_bin(wsi, n, &set[LWS_PRE + m]);
        m += (int)sizeof(h2n->one_setting);
      }
    n = lws_h2_frame_write(wsi, LWS_H2_FRAME_TYPE_SETTINGS,
               flags, LWS_H2_STREAM_ID_MASTER, (unsigned int)m,
                   &set[LWS_PRE]);
    if (n != m) {
      lwsl_info("send %d %d\n", n, m);
      goto bail;
    }
    break;

  case LWS_H2_PPS_SETTINGS_INITIAL_UPDATE_WINDOW:
    q = &set[LWS_PRE];
    *q++ = (uint8_t)(H2SET_INITIAL_WINDOW_SIZE >> 8);
    *q++ = (uint8_t)(H2SET_INITIAL_WINDOW_SIZE);
    *q++ = (uint8_t)(pps->u.update_window.credit >> 24);
    *q++ = (uint8_t)(pps->u.update_window.credit >> 16);
    *q++ = (uint8_t)(pps->u.update_window.credit >> 8);
    *q = (uint8_t)(pps->u.update_window.credit);

    lwsl_debug("%s: resetting initial window to %d\n", __func__,
        (int)pps->u.update_window.credit);

    n = lws_h2_frame_write(wsi, LWS_H2_FRAME_TYPE_SETTINGS,
               flags, LWS_H2_STREAM_ID_MASTER, 6,
                   &set[LWS_PRE]);
    if (n != 6) {
      lwsl_info("send %d %d\n", n, m);
      goto bail;
    }
    break;

  case LWS_H2_PPS_ACK_SETTINGS:
    /* send ack ... always empty */
    n = lws_h2_frame_write(wsi, LWS_H2_FRAME_TYPE_SETTINGS, 1,
               LWS_H2_STREAM_ID_MASTER, 0,
               &set[LWS_PRE]);
    if (n) {
      lwsl_err("%s: writing settings ack frame failed %d\n", __func__, n);
      goto bail;
    }
    wsi->h2_acked_settings = 0;
    /* this is the end of the preface dance then? */
    if (lwsi_state(wsi) == LRS_H2_AWAIT_SETTINGS) {
      lwsi_set_state(wsi, LRS_ESTABLISHED);
#if defined(LWS_WITH_FILE_OPS)
      wsi->http.fop_fd = NULL;
#endif
      if (lws_is_ssl(lws_get_network_wsi(wsi)))
        break;

      if (wsi->a.vhost->options &
        LWS_SERVER_OPTION_H2_PRIOR_KNOWLEDGE)
        break;

      /*
       * we need to treat the headers from the upgrade as the
       * first job.  So these need to get shifted to sid 1.
       */

      lws_context_lock(wsi->a.context, "h2 mig");
      lws_vhost_lock(wsi->a.vhost);

      h2n->swsi = __lws_wsi_server_new(wsi->a.vhost, wsi, 1);

      lws_vhost_unlock(wsi->a.vhost);
      lws_context_unlock(wsi->a.context);

      if (!h2n->swsi)
        goto bail;

      /* pass on the initial headers to SID 1 */
      h2n->swsi->http.ah = wsi->http.ah;
      wsi->http.ah = NULL;

      lwsl_info("%s: inherited headers %p\n", __func__,
          h2n->swsi->http.ah);
      h2n->swsi->txc.tx_cr = (int32_t)
        h2n->our_set.s[H2SET_INITIAL_WINDOW_SIZE];
      lwsl_info("initial tx credit on %s: %d\n",
          lws_wsi_tag(h2n->swsi),
          (int)h2n->swsi->txc.tx_cr);
      h2n->swsi->h2.initialized = 1;
      /* demanded by HTTP2 */
      h2n->swsi->h2.END_STREAM = 1;
      lwsl_info("servicing initial http request\n");

#if defined(LWS_WITH_SERVER)
      if (lws_http_action(h2n->swsi))
        goto bail;
#endif
      break;
    }
    break;

  /*
   * h2 only has PING... ACK = 0 = ping, ACK = 1 = pong
   */

  case LWS_H2_PPS_PING:
  case LWS_H2_PPS_PONG:
    if (pps->type == LWS_H2_PPS_PING)
      lwsl_info("sending PING\n");
    else {
      lwsl_info("sending PONG\n");
      flags = LWS_H2_FLAG_SETTINGS_ACK;
    }

    memcpy(&set[LWS_PRE], pps->u.ping.ping_payload, 8);
    n = lws_h2_frame_write(wsi, LWS_H2_FRAME_TYPE_PING, flags,
               LWS_H2_STREAM_ID_MASTER, 8,
               &set[LWS_PRE]);
    if (n != 8)
      goto bail;

    break;

  case LWS_H2_PPS_GOAWAY:
    lwsl_info("LWS_H2_PPS_GOAWAY\n");
    *p++ = (uint8_t)(pps->u.ga.highest_sid >> 24);
    *p++ = (uint8_t)(pps->u.ga.highest_sid >> 16);
    *p++ = (uint8_t)(pps->u.ga.highest_sid >> 8);
    *p++ = (uint8_t)(pps->u.ga.highest_sid);
    *p++ = (uint8_t)(pps->u.ga.err >> 24);
    *p++ = (uint8_t)(pps->u.ga.err >> 16);
    *p++ = (uint8_t)(pps->u.ga.err >> 8);
    *p++ = (uint8_t)(pps->u.ga.err);
    q = (unsigned char *)pps->u.ga.str;
    n = 0;
    while (*q && n++ < (int)sizeof(pps->u.ga.str))
      *p++ = *q++;
    h2n->we_told_goaway = 1;
    n = lws_h2_frame_write(wsi, LWS_H2_FRAME_TYPE_GOAWAY, 0,
               LWS_H2_STREAM_ID_MASTER,
               (unsigned int)lws_ptr_diff(p, &set[LWS_PRE]),
               &set[LWS_PRE]);
    if (n != 4) {
      lwsl_info("send %d %d\n", n, m);
      goto bail;
    }
    goto bail;

  case LWS_H2_PPS_RST_STREAM:
    lwsl_info("LWS_H2_PPS_RST_STREAM\n");
    *p++ = (uint8_t)(pps->u.rs.err >> 24);
    *p++ = (uint8_t)(pps->u.rs.err >> 16);
    *p++ = (uint8_t)(pps->u.rs.err >> 8);
    *p++ = (uint8_t)(pps->u.rs.err);
    n = lws_h2_frame_write(wsi, LWS_H2_FRAME_TYPE_RST_STREAM,
               0, pps->u.rs.sid, 4, &set[LWS_PRE]);
    if (n != 4) {
      lwsl_info("send %d %d\n", n, m);
      goto bail;
    }
    cwsi = lws_wsi_mux_from_id(wsi, pps->u.rs.sid);
    if (cwsi) {
      lwsl_debug("%s: closing cwsi %s %s %s (wsi %s)\n",
           __func__, lws_wsi_tag(cwsi),
           cwsi->role_ops->name,
           cwsi->a.protocol->name, lws_wsi_tag(wsi));
      lws_close_free_wsi(cwsi, 0, "reset stream");
    }
    break;

  case LWS_H2_PPS_UPDATE_WINDOW:
    lwsl_info("Issuing LWS_H2_PPS_UPDATE_WINDOW: sid %d: add %d\n",
          (int)pps->u.update_window.sid,
          (int)pps->u.update_window.credit);
    *p++ = (uint8_t)((pps->u.update_window.credit >> 24) & 0x7f); /* 31b */
    *p++ = (uint8_t)(pps->u.update_window.credit >> 16);
    *p++ = (uint8_t)(pps->u.update_window.credit >> 8);
    *p++ = (uint8_t)(pps->u.update_window.credit);
    n = lws_h2_frame_write(wsi, LWS_H2_FRAME_TYPE_WINDOW_UPDATE,
               0, pps->u.update_window.sid, 4,
               &set[LWS_PRE]);
    if (n != 4) {
      lwsl_info("send %d %d\n", n, m);
      goto bail;
    }
    break;

  default:
    break;
  }

  lws_free(pps);

  return 0;

bail:
  lws_free(pps);

  return 1;
}

static int
lws_h2_parse_end_of_frame(struct lws *wsi);

/*
 * The frame header part has just completely arrived.
 * Perform actions for header completion.
 */
static int
lws_h2_parse_frame_header(struct lws *wsi)
{
  struct lws_h2_netconn *h2n = wsi->h2.h2n;
  struct lws_h2_protocol_send *pps;
  int n;

  /*
   * We just got the frame header
   */
  h2n->count = 0;
  h2n->swsi = wsi;
  /* b31 is a reserved bit */
  h2n->sid = h2n->sid & 0x7fffffff;

  if (h2n->sid && !(h2n->sid & 1)) {
    char pes[32];
    lws_snprintf(pes, sizeof(pes), "Even Stream ID 0x%x", (unsigned int)h2n->sid);
    lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR, pes);

    return 0;
  }

  /* let the network wsi live a bit longer if subs are active */

  if (!wsi->immortal_substream_count) {
    int ds = lws_wsi_keepalive_timeout_eff(wsi);

    /*
     * A short (5s) timeout here affects the reverse proxy if
     * the onward box takes a long time to respond, eg to a POST.
     * The mount can override the keepalive timeout, eg, to give
     * the right behaviour depending on reverse proxy for a particular
     * server.
     */
    lws_set_timeout(wsi, PENDING_TIMEOUT_HTTP_KEEPALIVE_IDLE, ds);
  }
  if (h2n->sid)
    h2n->swsi = lws_wsi_mux_from_id(wsi, h2n->sid);

  lwsl_debug("%s (%s): fr hdr: typ 0x%x, fla 0x%x, sid 0x%x, len 0x%x\n",
      lws_wsi_tag(wsi), lws_wsi_tag(h2n->swsi), h2n->type,
      h2n->flags, (unsigned int)h2n->sid, (unsigned int)h2n->length);

  if (h2n->we_told_goaway && h2n->sid > h2n->highest_sid)
    h2n->type = LWS_H2_FRAME_TYPE_COUNT; /* ie, IGNORE */

  if (h2n->type >= LWS_H2_FRAME_TYPE_COUNT) {
    lwsl_info("%s: ignoring unknown frame type %d (len %d)\n", __func__, h2n->type, (unsigned int)h2n->length);
    /* we MUST ignore frames we don't understand */
    h2n->type = LWS_H2_FRAME_TYPE_COUNT;
  }

  /*
   * Even if we have decided to logically ignore this frame, we must
   * consume the correct "frame length" amount of data to retain sync
   */

  if (h2n->length > h2n->our_set.s[H2SET_MAX_FRAME_SIZE]) {
    /*
     * peer sent us something bigger than we told
     * it we would allow
     */
    lwsl_info("%s: received oversize frame %d\n", __func__,
        (unsigned int)h2n->length);
    lws_h2_goaway(wsi, H2_ERR_FRAME_SIZE_ERROR,
            "Peer ignored our frame size setting");
    return 1;
  }

  if (h2n->swsi)
    lwsl_info("%s: %s, State: %s, received cmd %d\n",
      __func__, lws_wsi_tag(h2n->swsi),
      h2_state_names[h2n->swsi->h2.h2_state], h2n->type);
  else {
    /* if it's data, either way no swsi means CLOSED state */
    if (h2n->type == LWS_H2_FRAME_TYPE_DATA) {
      if (h2n->sid <= h2n->highest_sid_opened
#if defined(LWS_WITH_CLIENT)
          && wsi->client_h2_alpn
#endif
      ) {
        if (h2n->flags & LWS_H2_FLAG_END_STREAM)
          lwsl_notice("%s: stragging EOS\n", __func__);
        else {
          lwsl_wsi_notice(wsi, "ignoring straggling "
            "DATA (flags 0x%x, length %d)",
              h2n->flags, (int)h2n->length);
          /* ie, IGNORE */
          h2n->type = LWS_H2_FRAME_TYPE_COUNT;
        }
      } else {
        lwsl_info("%s: received %d bytes data for unknown sid %d, highest known %d\n",
            __func__, (int)h2n->length, (int)h2n->sid, (int)h2n->highest_sid_opened);

//        if (h2n->sid > h2n->highest_sid_opened) {
        lws_h2_goaway(wsi, H2_ERR_STREAM_CLOSED,
              "Data for nonexistent sid");
        return 0;
//        }
      }
    }
    /* if the sid is credible, treat as wsi for it closed */
    if (h2n->sid > h2n->highest_sid_opened &&
        h2n->type != LWS_H2_FRAME_TYPE_HEADERS &&
        h2n->type != LWS_H2_FRAME_TYPE_PRIORITY) {
      /* if not credible, reject it */
      lwsl_info("%s: %s, No child for sid %d, rxcmd %d\n",
        __func__, lws_wsi_tag(h2n->swsi), (unsigned int)h2n->sid, h2n->type);
      lws_h2_goaway(wsi, H2_ERR_STREAM_CLOSED,
             "Data for nonexistent sid");
      return 0;
    }
  }

  if (h2n->swsi && h2n->sid && h2n->type != LWS_H2_FRAME_TYPE_COUNT &&
      !(http2_rx_validity[h2n->swsi->h2.h2_state] & (1 << h2n->type))) {
    lwsl_info("%s: %s, State: %s, ILLEGAL cmdrx %d (OK 0x%x)\n",
        __func__, lws_wsi_tag(h2n->swsi),
        h2_state_names[h2n->swsi->h2.h2_state], h2n->type,
        http2_rx_validity[h2n->swsi->h2.h2_state]);

    if (h2n->swsi->h2.h2_state == LWS_H2_STATE_CLOSED ||
        h2n->swsi->h2.h2_state == LWS_H2_STATE_HALF_CLOSED_REMOTE)
      n = H2_ERR_STREAM_CLOSED;
    else
      n = H2_ERR_PROTOCOL_ERROR;
    lws_h2_goaway(wsi, (unsigned int)n, "invalid rx for state");

    return 0;
  }

  if (h2n->cont_exp && h2n->type != LWS_H2_FRAME_TYPE_COUNT &&
      (h2n->cont_exp_sid != h2n->sid ||
            h2n->type != LWS_H2_FRAME_TYPE_CONTINUATION)) {
    lwsl_info("%s: expected cont on sid %u (got %d on sid %u)\n",
        __func__, (unsigned int)h2n->cont_exp_sid, h2n->type,
        (unsigned int)h2n->sid);
    h2n->cont_exp = 0;
    if (h2n->cont_exp_headers)
      n = H2_ERR_COMPRESSION_ERROR;
    else
      n = H2_ERR_PROTOCOL_ERROR;
    lws_h2_goaway(wsi, (unsigned int)n, "Continuation hdrs State");

    return 0;
  }

  switch (h2n->type) {
  case LWS_H2_FRAME_TYPE_DATA:
    lwsl_info("seen incoming LWS_H2_FRAME_TYPE_DATA start\n");
    if (!h2n->sid) {
      lwsl_info("DATA: 0 sid\n");
      lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR, "DATA 0 sid");
      break;
    }
    lwsl_info("Frame header DATA: sid %u, flags 0x%x, len %u\n",
        (unsigned int)h2n->sid, h2n->flags,
        (unsigned int)h2n->length);

    if (!h2n->swsi) {
      lwsl_notice("DATA: NULL swsi\n");
      break;
    }

    lwsl_info("DATA rx on state %d\n", h2n->swsi->h2.h2_state);

    if (
        h2n->swsi->h2.h2_state == LWS_H2_STATE_HALF_CLOSED_REMOTE ||
        h2n->swsi->h2.h2_state == LWS_H2_STATE_CLOSED) {
      lws_h2_goaway(wsi, H2_ERR_STREAM_CLOSED, "conn closed");
      break;
    }

    if (h2n->length == 0)
      lws_h2_parse_end_of_frame(wsi);

    break;

  case LWS_H2_FRAME_TYPE_PRIORITY:
    lwsl_info("LWS_H2_FRAME_TYPE_PRIORITY complete frame\n");
    if (!h2n->sid) {
      lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR,
              "Priority has 0 sid");
      break;
    }
    if (h2n->length != 5) {
      lws_h2_goaway(wsi, H2_ERR_FRAME_SIZE_ERROR,
              "Priority has length other than 5");
      break;
    }
    break;
  case LWS_H2_FRAME_TYPE_PUSH_PROMISE:
    lwsl_info("LWS_H2_FRAME_TYPE_PUSH_PROMISE complete frame\n");
    lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR, "Server only");
    break;

  case LWS_H2_FRAME_TYPE_GOAWAY:
    lwsl_debug("LWS_H2_FRAME_TYPE_GOAWAY received\n");
    break;

  case LWS_H2_FRAME_TYPE_RST_STREAM:
    if (!h2n->sid)
      return 1;
    if (!h2n->swsi) {
      if (h2n->sid <= h2n->highest_sid_opened)
        break;
      lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR,
              "crazy sid on RST_STREAM");
      return 1;
    }
    if (h2n->length != 4) {
      lws_h2_goaway(wsi, H2_ERR_FRAME_SIZE_ERROR,
              "RST_STREAM can only be length 4");
      break;
    }
    lws_h2_state(h2n->swsi, LWS_H2_STATE_CLOSED);
    break;

  case LWS_H2_FRAME_TYPE_SETTINGS:
    lwsl_info("LWS_H2_FRAME_TYPE_SETTINGS complete frame\n");
    /* nonzero sid on settings is illegal */
    if (h2n->sid) {
      lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR,
           "Settings has nonzero sid");
      break;
    }

    if (!(h2n->flags & LWS_H2_FLAG_SETTINGS_ACK)) {
      if (h2n->length % 6) {
        lws_h2_goaway(wsi, H2_ERR_FRAME_SIZE_ERROR,
             "Settings length error");
        break;
      }

      if (h2n->type == LWS_H2_FRAME_TYPE_COUNT)
        return 0;

      if (wsi->upgraded_to_http2 &&
#if defined(LWS_WITH_CLIENT)
          (!(wsi->flags & LCCSCF_H2_QUIRK_NGHTTP2_END_STREAM) ||
#else
          (
#endif
              !wsi->h2_acked_settings)) {

        pps = lws_h2_new_pps(LWS_H2_PPS_ACK_SETTINGS);
        if (!pps)
          return 1;
        lws_pps_schedule(wsi, pps);
        wsi->h2_acked_settings = 1;
      }
      break;
    }
    /* came to us with ACK set... not allowed to have payload */

    if (h2n->length) {
      lws_h2_goaway(wsi, H2_ERR_FRAME_SIZE_ERROR,
              "Settings with ACK not allowed payload");
      break;
    }
    break;
  case LWS_H2_FRAME_TYPE_PING:
    if (h2n->sid) {
      lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR,
              "Ping has nonzero sid");
      break;
    }
    if (h2n->length != 8) {
      lws_h2_goaway(wsi, H2_ERR_FRAME_SIZE_ERROR,
              "Ping payload can only be 8");
      break;
    }
    break;
  case LWS_H2_FRAME_TYPE_CONTINUATION:
    lwsl_info("LWS_H2_FRAME_TYPE_CONTINUATION: sid = %u %d %d\n",
        (unsigned int)h2n->sid, (int)h2n->cont_exp,
        (int)h2n->cont_exp_sid);

    if (!h2n->cont_exp ||
         h2n->cont_exp_sid != h2n->sid ||
         !h2n->sid ||
         !h2n->swsi) {
      lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR,
              "unexpected CONTINUATION");
      break;
    }

    if (h2n->swsi->h2.END_HEADERS) {
      lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR,
              "END_HEADERS already seen");
      break;
    }
    /* END_STREAM is in HEADERS, skip resetting it */
    goto update_end_headers;

  case LWS_H2_FRAME_TYPE_HEADERS:
    lwsl_info("HEADERS: frame header: sid = %u\n",
        (unsigned int)h2n->sid);
    if (!h2n->sid) {
      lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR, "sid 0");
      return 1;
    }

    if (h2n->swsi && !h2n->swsi->h2.END_STREAM &&
        h2n->swsi->h2.END_HEADERS &&
        !(h2n->flags & LWS_H2_FLAG_END_STREAM)) {
      lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR,
              "extra HEADERS together");
      return 1;
    }

#if defined(LWS_WITH_CLIENT)
    if (wsi->client_h2_alpn) {
      if (h2n->sid) {
        h2n->swsi = lws_wsi_mux_from_id(wsi, h2n->sid);
        lwsl_info("HEADERS: nwsi %s: sid %u mapped "
            "to wsi %s\n", lws_wsi_tag(wsi),
            (unsigned int)h2n->sid,
            lws_wsi_tag(h2n->swsi));
        if (!h2n->swsi)
          break;
      }
      goto update_end_headers;
    }
#endif

    if (!h2n->swsi) {
      /* no more children allowed by parent */
      if (wsi->mux.child_count + 1 >
          wsi->h2.h2n->our_set.s[H2SET_MAX_CONCURRENT_STREAMS]) {
        lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR,
        "Another stream not allowed");

        return 1;
      }

      /*
       * The peer has sent us a HEADERS implying the creation
       * of a new stream
       */

      lws_context_lock(wsi->a.context, "h2 new str");
      lws_vhost_lock(wsi->a.vhost);

      h2n->swsi = __lws_wsi_server_new(wsi->a.vhost, wsi,
                     h2n->sid);

      lws_vhost_unlock(wsi->a.vhost);
      lws_context_unlock(wsi->a.context);

      if (!h2n->swsi) {
        lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR,
                "OOM");

        return 1;
      }

      if (h2n->sid >= h2n->highest_sid)
        h2n->highest_sid = h2n->sid + 2;

      h2n->swsi->h2.initialized = 1;

      if (lws_h2_update_peer_txcredit(h2n->swsi,
          h2n->swsi->mux.my_sid, 4 * 65536))
        goto cleanup_wsi;
    }

    /*
     * ah needs attaching to child wsi, even though
     * we only fill it from network wsi
     */
    if (!h2n->swsi->http.ah)
      if (lws_header_table_attach(h2n->swsi, 0)) {
        lwsl_err("%s: Failed to get ah\n", __func__);
        return 1;
      }

    /*
     * The first use of a new stream identifier implicitly closes
     * all streams in the "idle" state that might have been
     * initiated by that peer with a lower-valued stream identifier.
     *
     * For example, if a client sends a HEADERS frame on stream 7
     * without ever sending a frame on stream 5, then stream 5
     * transitions to the "closed" state when the first frame for
     * stream 7 is sent or received.
     */
    lws_start_foreach_ll(struct lws *, w, wsi->mux.child_list) {
      if (w->mux.my_sid < h2n->sid &&
          w->h2.h2_state == LWS_H2_STATE_IDLE)
        lws_close_free_wsi(w, 0, "h2 sid close");
      assert(w->mux.sibling_list != w);
    } lws_end_foreach_ll(w, mux.sibling_list);

    h2n->cont_exp = !(h2n->flags & LWS_H2_FLAG_END_HEADERS);
    h2n->cont_exp_sid = h2n->sid;
    h2n->cont_exp_headers = 1;
  //  lws_header_table_reset(h2n->swsi, 0);

update_end_headers:
    if (lws_check_opt(h2n->swsi->a.vhost->options,
             LWS_SERVER_OPTION_VH_H2_HALF_CLOSED_LONG_POLL)) {

      /*
       * We don't directly timeout streams that enter the
       * half-closed remote state, allowing immortal long
       * poll
       */
      lws_mux_mark_immortal(h2n->swsi);
      lwsl_info("%s: %s: h2 stream entering long poll\n",
          __func__, lws_wsi_tag(h2n->swsi));

    } else {
      h2n->swsi->h2.END_STREAM =
          !!(h2n->flags & LWS_H2_FLAG_END_STREAM);
      lwsl_debug("%s: hdr END_STREAM = %d\n",__func__,
        h2n->swsi->h2.END_STREAM);
    }

    /* no END_HEADERS means CONTINUATION must come */
    h2n->swsi->h2.END_HEADERS =
        !!(h2n->flags & LWS_H2_FLAG_END_HEADERS);
    lwsl_info("%s: %s: END_HEADERS %d\n", __func__, lws_wsi_tag(h2n->swsi),
        h2n->swsi->h2.END_HEADERS);
    if (h2n->swsi->h2.END_HEADERS)
      h2n->cont_exp = 0;
    lwsl_debug("END_HEADERS %d\n", h2n->swsi->h2.END_HEADERS);
    break;

cleanup_wsi:

    return 1;

  case LWS_H2_FRAME_TYPE_WINDOW_UPDATE:
    if (h2n->length != 4) {
      lws_h2_goaway(wsi, H2_ERR_FRAME_SIZE_ERROR,
              "window update frame not 4");
      break;
    }
    lwsl_info("LWS_H2_FRAME_TYPE_WINDOW_UPDATE\n");
    break;
  case LWS_H2_FRAME_TYPE_COUNT:
    if (h2n->length == 0)
      lws_h2_parse_end_of_frame(wsi);
    else
      lwsl_debug("%s: going on to deal with unknown frame remaining len %d\n", __func__, (unsigned int)h2n->length);
    break;
  default:
    lwsl_info("%s: ILLEGAL FRAME TYPE %d\n", __func__, h2n->type);
    h2n->type = LWS_H2_FRAME_TYPE_COUNT; /* ie, IGNORE */
    break;
  }
  if (h2n->length == 0)
    h2n->frame_state = 0;

  return 0;
}

static const char * const method_names[] = {
  "GET", "POST",
#if defined(LWS_WITH_HTTP_UNCOMMON_HEADERS)
  "OPTIONS", "PUT", "PATCH", "DELETE",
#endif
  "CONNECT", "HEAD"
};
static unsigned char method_index[] = {
  WSI_TOKEN_GET_URI,
  WSI_TOKEN_POST_URI,
#if defined(LWS_WITH_HTTP_UNCOMMON_HEADERS)
  WSI_TOKEN_OPTIONS_URI,
  WSI_TOKEN_PUT_URI,
  WSI_TOKEN_PATCH_URI,
  WSI_TOKEN_DELETE_URI,
#endif
  WSI_TOKEN_CONNECT,
  WSI_TOKEN_HEAD_URI,
};

/*
 * The last byte of the whole frame has been handled.
 * Perform actions for frame completion.
 *
 * This is the crunch time for parsing that may have occured on a network
 * wsi with a pending partial send... we may call lws_http_action() to send
 * a response, conflicting with the partial.
 *
 * So in that case we change the wsi state and do the lws_http_action() in the
 * WRITABLE handler as a priority.
 */
static int
lws_h2_parse_end_of_frame(struct lws *wsi)
{
  struct lws_h2_netconn *h2n = wsi->h2.h2n;
  struct lws *eff_wsi = wsi;
  const char *p;
  int n;

  h2n->frame_state = 0;
  h2n->count = 0;

  if (h2n->sid)
    h2n->swsi = lws_wsi_mux_from_id(wsi, h2n->sid);

  if (h2n->sid > h2n->highest_sid)
    h2n->highest_sid = h2n->sid;

  if (h2n->collected_priority && (h2n->dep & ~(1u << 31)) == h2n->sid) {
    lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR, "depends on own sid");
    return 0;
  }

  switch (h2n->type) {

  case LWS_H2_FRAME_TYPE_SETTINGS:

#if defined(LWS_WITH_CLIENT)
    if (wsi->client_h2_alpn && !wsi->client_mux_migrated &&
        !(h2n->flags & LWS_H2_FLAG_SETTINGS_ACK)) {
      struct lws_h2_protocol_send *pps;

      /* migrate original client ask on to substream 1 */
#if defined(LWS_WITH_FILE_OPS)
      wsi->http.fop_fd = NULL;
#endif
      lwsl_info("%s: migrating\n", __func__);
      wsi->client_mux_migrated = 1;
      /*
       * we need to treat the headers from the upgrade as the
       * first job.  So these need to get shifted to sid 1.
       */
      lws_context_lock(wsi->a.context, "h2 mig");
      lws_vhost_lock(wsi->a.vhost);

      h2n->swsi = __lws_wsi_server_new(wsi->a.vhost, wsi, 1);

      lws_vhost_unlock(wsi->a.vhost);
      lws_context_unlock(wsi->a.context);

      if (!h2n->swsi)
        return 1;
      h2n->sid = 1;

      assert(lws_wsi_mux_from_id(wsi, 1) == h2n->swsi);

    //  lws_role_transition(wsi, LWSIFR_CLIENT,
    //          LRS_H2_WAITING_TO_SEND_HEADERS,
    //          &role_ops_h2);

      lws_role_transition(h2n->swsi, LWSIFR_CLIENT,
              LRS_H2_WAITING_TO_SEND_HEADERS,
              &role_ops_h2);

      /* pass on the initial headers to SID 1 */
      h2n->swsi->http.ah = wsi->http.ah;
#if defined(LWS_WITH_SYS_FAULT_INJECTION)
      lws_fi_import(&h2n->swsi->fic, &wsi->fic);
#endif
      h2n->swsi->client_mux_substream = 1;
      h2n->swsi->client_h2_alpn = 1;
#if defined(LWS_WITH_CLIENT)
      h2n->swsi->flags = wsi->flags;
#if defined(LWS_WITH_CONMON)
      /* sid1 needs to represent the connection experience
       * ... we take over responsibility for the DNS list
       * copy as well
       */
      h2n->swsi->conmon = wsi->conmon;
      h2n->swsi->conmon_datum = wsi->conmon_datum;
      h2n->swsi->sa46_peer = wsi->sa46_peer;
      wsi->conmon.dns_results_copy = NULL;
#endif
#endif /* CLIENT */

#if defined(LWS_WITH_SECURE_STREAMS)
      if (wsi->for_ss) {
        lws_ss_handle_t *h = (lws_ss_handle_t *)lws_get_opaque_user_data(wsi);

        if (!h)
          return 1;
        h2n->swsi->for_ss = 1;
        wsi->for_ss = 0;

        if (h->wsi == wsi)
          h->wsi = h2n->swsi;
      }
#endif

      h2n->swsi->a.protocol = wsi->a.protocol;
      if (h2n->swsi->user_space &&
          !h2n->swsi->user_space_externally_allocated)
        lws_free(h2n->swsi->user_space);
      h2n->swsi->user_space = wsi->user_space;
      h2n->swsi->user_space_externally_allocated =
          wsi->user_space_externally_allocated;
      h2n->swsi->a.opaque_user_data = wsi->a.opaque_user_data;
      wsi->a.opaque_user_data = NULL;
      h2n->swsi->txc.manual_initial_tx_credit =
          wsi->txc.manual_initial_tx_credit;

#if defined(LWS_WITH_TLS)
      lws_strncpy(h2n->swsi->alpn, wsi->alpn,
          sizeof(wsi->alpn));
#endif

      wsi->user_space = NULL;

      if (h2n->swsi->http.ah)
        h2n->swsi->http.ah->wsi = h2n->swsi;
      wsi->http.ah = NULL;

      lwsl_info("%s: MIGRATING nwsi %s -> swsi %s\n", __func__,
          lws_wsi_tag(wsi), lws_wsi_tag(h2n->swsi));
      h2n->swsi->txc.tx_cr = (int32_t)
        h2n->peer_set.s[H2SET_INITIAL_WINDOW_SIZE];
      lwsl_info("%s: initial tx credit on %s: %d\n",
          __func__, lws_wsi_tag(h2n->swsi),
          (int)h2n->swsi->txc.tx_cr);
      h2n->swsi->h2.initialized = 1;

      /* set our initial window size */
      if (!wsi->h2.initialized) {
        wsi->txc.tx_cr = (int32_t)
             h2n->peer_set.s[H2SET_INITIAL_WINDOW_SIZE];

        lwsl_info("%s: initial tx credit for us to "
            "write on nwsi %s: %d\n", __func__,
            lws_wsi_tag(wsi), (int)wsi->txc.tx_cr);
        wsi->h2.initialized = 1;
      }

      lws_callback_on_writable(h2n->swsi);

      if (!wsi->h2_acked_settings ||
          !(wsi->flags & LCCSCF_H2_QUIRK_NGHTTP2_END_STREAM)
      ) {
        pps = lws_h2_new_pps(LWS_H2_PPS_ACK_SETTINGS);
        if (!pps)
          return 1;
        lws_pps_schedule(wsi, pps);
        lwsl_info("%s: SETTINGS ack PPS\n", __func__);
        wsi->h2_acked_settings = 1;
      }

      /* also attach any queued guys */

      lws_wsi_mux_apply_queue(wsi);
    }
#endif
    break;

  case LWS_H2_FRAME_TYPE_CONTINUATION:
  case LWS_H2_FRAME_TYPE_HEADERS:

    if (!h2n->swsi)
      break;

    /* service the http request itself */

    if (h2n->last_action_dyntable_resize) {
      lws_h2_goaway(wsi, H2_ERR_COMPRESSION_ERROR,
        "dyntable resize last in headers");
      break;
    }

    if (!h2n->swsi->h2.END_HEADERS) {
      /* we are not finished yet */
      lwsl_info("withholding http action for continuation\n");
      h2n->cont_exp_sid = h2n->sid;
      h2n->cont_exp = 1;
      break;
    }

    /* confirm the hpack stream state is reasonable for finishing */

    if (h2n->hpack != HPKS_TYPE) {
      /* hpack incomplete */
      lwsl_info("hpack incomplete %d (type %d, len %u)\n",
          h2n->hpack, h2n->type,
          (unsigned int)h2n->hpack_len);
      lws_h2_goaway(wsi, H2_ERR_COMPRESSION_ERROR,
              "hpack incomplete");
      break;
    }

    /* this is the last part of HEADERS */
    switch (h2n->swsi->h2.h2_state) {
    case LWS_H2_STATE_IDLE:
      lws_h2_state(h2n->swsi, LWS_H2_STATE_OPEN);
      break;
    case LWS_H2_STATE_RESERVED_REMOTE:
      lws_h2_state(h2n->swsi, LWS_H2_STATE_HALF_CLOSED_LOCAL);
      break;
    }

    lwsl_info("http req, %s, h2n->swsi=%s\n", lws_wsi_tag(wsi),
        lws_wsi_tag(h2n->swsi));
    h2n->swsi->hdr_parsing_completed = 1;

#if defined(LWS_WITH_CLIENT)
    if (h2n->swsi->client_mux_substream &&
        lws_client_interpret_server_handshake(h2n->swsi)) {
      /*
       * This is more complicated than it looks, one exit from
       * interpret_server_handshake() is to do a close that
       * turns into a redirect.
       *
       * In that case, the wsi survives having being reset
       * and detached from any h2 identity.  We need to get
       * our parents out from touching it any more
       */
      lwsl_info("%s: cli int serv hs closed, or redir\n", __func__);
      return 2;
    }
#endif

    if (lws_hdr_extant(h2n->swsi, WSI_TOKEN_HTTP_CONTENT_LENGTH)) {
      const char *simp = lws_hdr_simple_ptr(h2n->swsi,
                WSI_TOKEN_HTTP_CONTENT_LENGTH);

      if (!simp) /* coverity */
        return 1;
      h2n->swsi->http.rx_content_length = (unsigned long long)atoll(simp);
      h2n->swsi->http.rx_content_remain =
          h2n->swsi->http.rx_content_length;
      h2n->swsi->http.content_length_given = 1;
      lwsl_info("setting rx_content_length %lld\n",
          (long long)h2n->swsi->http.rx_content_length);
    }

    {
      int n = 0, len;
      char buf[256];
      const unsigned char *c;

      do {
        c = lws_token_to_string((enum lws_token_indexes)n);
        if (!c) {
          n++;
          continue;
        }

        len = lws_hdr_total_length(h2n->swsi, (enum lws_token_indexes)n);
        if (!len || len > (int)sizeof(buf) - 1) {
          n++;
          continue;
        }

        if (lws_hdr_copy(h2n->swsi, buf, sizeof buf,
            (enum lws_token_indexes)n) < 0) {
          lwsl_info("    %s !oversize!\n",
              (char *)c);
        } else {
          buf[sizeof(buf) - 1] = '\0';

          lwsl_info("    %s = %s\n",
              (char *)c, buf);
        }
        n++;
      } while (c);
    }

    if (h2n->swsi->h2.h2_state == LWS_H2_STATE_HALF_CLOSED_REMOTE ||
        h2n->swsi->h2.h2_state == LWS_H2_STATE_CLOSED) {
      lws_h2_goaway(wsi, H2_ERR_STREAM_CLOSED,
              "Banning service on CLOSED_REMOTE");
      break;
    }

    switch (h2n->swsi->h2.h2_state) {
    case LWS_H2_STATE_IDLE:
      lws_h2_state(h2n->swsi, LWS_H2_STATE_OPEN);
      break;
    case LWS_H2_STATE_OPEN:
      if (h2n->swsi->h2.END_STREAM)
        lws_h2_state(h2n->swsi,
               LWS_H2_STATE_HALF_CLOSED_REMOTE);
      break;
    case LWS_H2_STATE_HALF_CLOSED_LOCAL:
      if (h2n->swsi->h2.END_STREAM)
        /*
         * action the END_STREAM
         */
        lws_h2_state(h2n->swsi, LWS_H2_STATE_CLOSED);
      break;
    }

#if defined(LWS_WITH_CLIENT)

    /*
     * If we already had the END_STREAM along with the END_HEADERS,
     * we have already transitioned to STATE_CLOSED and we are not
     * going to be doing anything further on this stream.
     *
     * In that case handle the transaction completion and
     * finalize the stream for the peer
     */

    if (h2n->swsi->h2.h2_state == LWS_H2_STATE_CLOSED &&
      h2n->swsi->client_mux_substream) {

      lws_h2_rst_stream(h2n->swsi, H2_ERR_NO_ERROR,
        "client done");

      if (lws_http_transaction_completed_client(h2n->swsi))
        lwsl_debug("tx completed returned close\n");
      break;
    }

    if (h2n->swsi->client_mux_substream) {
      lwsl_info("%s: %s: headers: client path (h2 state %s)\n",
          __func__, lws_wsi_tag(wsi),
          h2_state_names[h2n->swsi->h2.h2_state]);
      break;
    }
#endif

    if (!lws_hdr_total_length(h2n->swsi, WSI_TOKEN_HTTP_COLON_PATH) ||
        !lws_hdr_total_length(h2n->swsi, WSI_TOKEN_HTTP_COLON_METHOD) ||
        !lws_hdr_total_length(h2n->swsi, WSI_TOKEN_HTTP_COLON_SCHEME) ||
         lws_hdr_total_length(h2n->swsi, WSI_TOKEN_HTTP_COLON_STATUS) ||
         lws_hdr_extant(h2n->swsi, WSI_TOKEN_CONNECTION)) {
      lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR,
              "Pseudoheader checks");
      break;
    }

    if (lws_hdr_extant(h2n->swsi, WSI_TOKEN_TE)) {
      n = lws_hdr_total_length(h2n->swsi, WSI_TOKEN_TE);

      if (n != 8 ||
          !lws_hdr_simple_ptr(h2n->swsi, WSI_TOKEN_TE) ||
          strncmp(lws_hdr_simple_ptr(h2n->swsi, WSI_TOKEN_TE),
          "trailers", (unsigned int)n)) {
        lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR,
                "Illegal transfer-encoding");
        break;
      }
    }

#if defined(LWS_WITH_HTTP_STREAM_COMPRESSION)
    lws_http_compression_validate(h2n->swsi);
#endif

    p = lws_hdr_simple_ptr(h2n->swsi, WSI_TOKEN_HTTP_COLON_METHOD);
    /*
     * duplicate :path into the individual method uri header
     * index, so that it looks the same as h1 in the ah
     */
    for (n = 0; n < (int)LWS_ARRAY_SIZE(method_names); n++)
      if (p && !strcasecmp(p, method_names[n])) {
        h2n->swsi->http.ah->frag_index[method_index[n]] =
            h2n->swsi->http.ah->frag_index[
                             WSI_TOKEN_HTTP_COLON_PATH];
        break;
      }

    {
      lwsl_debug("%s: setting DEF_ACT from 0x%x\n", __func__,
           (unsigned int)h2n->swsi->wsistate);
      lwsi_set_state(h2n->swsi, LRS_DEFERRING_ACTION);
      lws_callback_on_writable(h2n->swsi);
    }
    break;

  case LWS_H2_FRAME_TYPE_DATA:
    lwsl_info("%s: DATA flags 0x%x\n", __func__, h2n->flags);
    if (!h2n->swsi)
      break;

    if (lws_hdr_total_length(h2n->swsi,
           WSI_TOKEN_HTTP_CONTENT_LENGTH) &&
        h2n->swsi->h2.END_STREAM &&
        h2n->swsi->http.rx_content_length &&
        h2n->swsi->http.rx_content_remain) {
      lws_h2_rst_stream(h2n->swsi, H2_ERR_PROTOCOL_ERROR,
            "Not enough rx content");
      break;
    }

    if (h2n->swsi->h2.END_STREAM &&
        h2n->swsi->h2.h2_state == LWS_H2_STATE_OPEN)
      lws_h2_state(h2n->swsi,
             LWS_H2_STATE_HALF_CLOSED_REMOTE);

    if (h2n->swsi->h2.END_STREAM &&
        h2n->swsi->h2.h2_state == LWS_H2_STATE_HALF_CLOSED_LOCAL)
      lws_h2_state(h2n->swsi, LWS_H2_STATE_CLOSED);

#if defined(LWS_WITH_CLIENT)
    /*
     * client... remote END_STREAM implies we weren't going to
     * send anything else anyway.
     */

    if (h2n->swsi->client_mux_substream &&
        (h2n->flags & LWS_H2_FLAG_END_STREAM)) {
      lwsl_info("%s: %s: DATA: end stream\n",
          __func__, lws_wsi_tag(h2n->swsi));

      if (h2n->swsi->h2.h2_state == LWS_H2_STATE_OPEN) {
        lws_h2_state(h2n->swsi,
               LWS_H2_STATE_HALF_CLOSED_REMOTE);
    //    lws_h2_rst_stream(h2n->swsi, H2_ERR_NO_ERROR,
    //          "client done");

    //    if (lws_http_transaction_completed_client(h2n->swsi))
    //      lwsl_debug("tx completed returned close\n");
      }

      //if (h2n->swsi->h2.h2_state == LWS_H2_STATE_HALF_CLOSED_LOCAL)
      {
        lws_h2_state(h2n->swsi, LWS_H2_STATE_CLOSED);

        lws_h2_rst_stream(h2n->swsi, H2_ERR_NO_ERROR,
              "client done");

        if (lws_http_transaction_completed_client(h2n->swsi))
          lwsl_debug("tx completed returned close\n");
      }
    }
#endif
    break;

  case LWS_H2_FRAME_TYPE_PING:
    if (h2n->flags & LWS_H2_FLAG_SETTINGS_ACK)
      lws_validity_confirmed(wsi);
    else {
      /* they're sending us a ping request */
      struct lws_h2_protocol_send *pps =
          lws_h2_new_pps(LWS_H2_PPS_PONG);
      if (!pps)
        return 1;

      lwsl_info("rx ping, preparing pong\n");

      memcpy(pps->u.ping.ping_payload, h2n->ping_payload, 8);
      lws_pps_schedule(wsi, pps);
    }

    break;

  case LWS_H2_FRAME_TYPE_WINDOW_UPDATE:
    /*
     * We only have an unsigned 31-bit (positive) increment possible
     */
    h2n->hpack_e_dep &= ~(1u << 31);
    lwsl_info("WINDOW_UPDATE: sid %u %u (0x%x)\n",
        (unsigned int)h2n->sid,
        (unsigned int)h2n->hpack_e_dep,
        (unsigned int)h2n->hpack_e_dep);

    if (h2n->sid)
      eff_wsi = h2n->swsi;

    if (!eff_wsi) {
      if (h2n->sid > h2n->highest_sid_opened)
        lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR,
                "alien sid");
      break; /* ignore */
    }

    if (eff_wsi->a.vhost->options &
            LWS_SERVER_OPTION_H2_JUST_FIX_WINDOW_UPDATE_OVERFLOW &&
        (uint64_t)eff_wsi->txc.tx_cr + (uint64_t)h2n->hpack_e_dep >
        (uint64_t)0x7fffffff)
      h2n->hpack_e_dep = (uint32_t)(0x7fffffff - eff_wsi->txc.tx_cr);

    if ((uint64_t)eff_wsi->txc.tx_cr + (uint64_t)h2n->hpack_e_dep >
        (uint64_t)0x7fffffff) {
      lwsl_warn("%s: WINDOW_UPDATE 0x%llx + 0x%llx = 0x%llx, too high\n",
          __func__, (unsigned long long)eff_wsi->txc.tx_cr,
          (unsigned long long)h2n->hpack_e_dep,
          (unsigned long long)eff_wsi->txc.tx_cr + (unsigned long long)h2n->hpack_e_dep);
      if (h2n->sid)
        lws_h2_rst_stream(h2n->swsi,
              H2_ERR_FLOW_CONTROL_ERROR,
              "Flow control exceeded max");
      else
        lws_h2_goaway(wsi, H2_ERR_FLOW_CONTROL_ERROR,
                "Flow control exceeded max");
      break;
    }

    if (!h2n->hpack_e_dep) {
      lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR,
              "Zero length window update");
      break;
    }
    n = eff_wsi->txc.tx_cr;
    eff_wsi->txc.tx_cr += (int32_t)h2n->hpack_e_dep;

    lws_wsi_txc_report_manual_txcr_in(eff_wsi,
              (int32_t)h2n->hpack_e_dep);

    lws_wsi_txc_describe(&eff_wsi->txc, "WINDOW_UPDATE in",
             eff_wsi->mux.my_sid);

    if (n <= 0 && eff_wsi->txc.tx_cr <= 0)
      /* it helps, but won't change sendability for anyone */
      break;

    /*
     * It may have changed sendability (depends on SID 0 tx credit
     * too)... for us and any children waiting on us... reassess
     * blockage for all children first
     */
    lws_start_foreach_ll(struct lws *, w, wsi->mux.child_list) {
      lws_callback_on_writable(w);
    } lws_end_foreach_ll(w, mux.sibling_list);

    if (eff_wsi->txc.skint &&
        !lws_wsi_txc_check_skint(&eff_wsi->txc,
               lws_h2_tx_cr_get(eff_wsi)))
      /*
       * This one became un-skint, schedule a writeable
       * callback
       */
      lws_callback_on_writable(eff_wsi);

    break;

  case LWS_H2_FRAME_TYPE_GOAWAY:
    lwsl_notice("GOAWAY: last sid %u, error 0x%08X, string '%s'\n",
        (unsigned int)h2n->goaway_last_sid,
        (unsigned int)h2n->goaway_err, h2n->goaway_str);

    return 1;

  case LWS_H2_FRAME_TYPE_RST_STREAM:
    lwsl_info("LWS_H2_FRAME_TYPE_RST_STREAM: sid %u: reason 0x%x\n",
        (unsigned int)h2n->sid,
        (unsigned int)h2n->hpack_e_dep);
    break;

  case LWS_H2_FRAME_TYPE_COUNT: /* IGNORING FRAME */
    break;
  }

  return 0;
}

/*
 * This may want to send something on the network wsi, which may be in the
 * middle of a partial send.  PPS sends are OK because they are queued to
 * go through the WRITABLE handler already.
 *
 * The read parser for the network wsi has no choice but to parse its stream
 * anyway, because otherwise it will not be able to get tx credit window
 * messages.
 *
 * Therefore if we will send non-PPS, ie, lws_http_action() for a stream
 * wsi, we must change its state and handle it as a priority in the
 * POLLOUT handler instead of writing it here.
 *
 * About closing... for the main network wsi, it should return nonzero to
 * close it all.  If it needs to close an swsi, it can do it here.
 */
int
lws_h2_parser(struct lws *wsi, unsigned char *in, lws_filepos_t _inlen,
        lws_filepos_t *inused)
{
  struct lws_h2_netconn *h2n = wsi->h2.h2n;
  struct lws_h2_protocol_send *pps;
  unsigned char c, *oldin = in, *iend = in + (size_t)_inlen;
  int n, m;

  if (!h2n)
    goto fail;

  while (in < iend) {

    c = *in++;

    switch (lwsi_state(wsi)) {
    case LRS_H2_AWAIT_PREFACE:
      if (preface[h2n->count++] != c)
        goto fail;

      if (preface[h2n->count])
        break;

      lwsl_info("http2: %s: established\n", lws_wsi_tag(wsi));
      lwsi_set_state(wsi, LRS_H2_AWAIT_SETTINGS);
      lws_validity_confirmed(wsi);
      h2n->count = 0;
      wsi->txc.tx_cr = 65535;

      /*
       * we must send a settings frame -- empty one is OK...
       * that must be the first thing sent by server
       * and the peer must send a SETTINGS with ACK flag...
       */
      pps = lws_h2_new_pps(LWS_H2_PPS_MY_SETTINGS);
      if (!pps)
        goto fail;
      lws_pps_schedule(wsi, pps);
      break;

    case LRS_H2_WAITING_TO_SEND_HEADERS:
    case LRS_ESTABLISHED:
    case LRS_H2_AWAIT_SETTINGS:

      if (h2n->frame_state != LWS_H2_FRAME_HEADER_LENGTH)
        goto try_frame_start;

      /*
       * post-header, preamble / payload / padding part
       */
      h2n->count++;

      if (h2n->type == LWS_H2_FRAME_TYPE_COUNT) { /* IGNORING FRAME */
        //lwsl_debug("%s: consuming for ignored %u %u\n", __func__, (unsigned int)h2n->count, (unsigned int)h2n->length);
        goto frame_end;
      }


      if (h2n->flags & LWS_H2_FLAG_PADDED &&
          !h2n->pad_length) {
        /*
         * Get the padding count... actual padding is
         * at the end of the frame.
         */
        h2n->padding = c;
        h2n->pad_length = 1;
        h2n->preamble++;

        if (h2n->padding > h2n->length - 1)
          lws_h2_goaway(wsi,
                  H2_ERR_PROTOCOL_ERROR,
                  "execssive padding");
        break; /* we consumed this */
      }

      if (h2n->flags & LWS_H2_FLAG_PRIORITY &&
          !h2n->collected_priority) {
        /* going to be 5 preamble bytes */

        lwsl_debug("PRIORITY FLAG:  0x%x\n", c);

        if (h2n->preamble++ - h2n->pad_length < 4) {
          h2n->dep = ((h2n->dep) << 8) | c;
          break; /* we consumed this */
        }
        h2n->weight_temp = c;
        h2n->collected_priority = 1;
        lwsl_debug("PRI FL: dep 0x%x, weight 0x%02X\n",
             (unsigned int)h2n->dep,
             h2n->weight_temp);
        break; /* we consumed this */
      }
      if (h2n->padding && h2n->count >
          (h2n->length - h2n->padding)) {
        if (c) {
          lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR,
                  "nonzero padding");
          break;
        }
        goto frame_end;
      }

      /* applies to wsi->h2.swsi which may be wsi */
      switch(h2n->type) {

      case LWS_H2_FRAME_TYPE_SETTINGS:
        n = (int)(h2n->count - 1u - h2n->preamble) %
             LWS_H2_SETTINGS_LEN;
        h2n->one_setting[n] = c;
        if (n != LWS_H2_SETTINGS_LEN - 1)
          break;
        lws_h2_settings(wsi, &h2n->peer_set,
            h2n->one_setting,
            LWS_H2_SETTINGS_LEN);
        break;

      case LWS_H2_FRAME_TYPE_CONTINUATION:
      case LWS_H2_FRAME_TYPE_HEADERS:
        if (!h2n->swsi)
          break;
        if (lws_hpack_interpret(h2n->swsi, c)) {
          lwsl_info("%s: hpack failed\n",
              __func__);
          goto fail;
        }
        break;

      case LWS_H2_FRAME_TYPE_GOAWAY:
        switch (h2n->inside++) {
        case 0:
        case 1:
        case 2:
        case 3:
          h2n->goaway_last_sid <<= 8;
          h2n->goaway_last_sid |= c;
          h2n->goaway_str[0] = '\0';
          break;

        case 4:
        case 5:
        case 6:
        case 7:
          h2n->goaway_err <<= 8;
          h2n->goaway_err |= c;
          break;

        default:
          if (h2n->inside - 9 <
              sizeof(h2n->goaway_str) - 1)
            h2n->goaway_str[
                       h2n->inside - 9] = (char)c;
          h2n->goaway_str[
              sizeof(h2n->goaway_str) - 1] = '\0';
          break;
        }
        break;

      case LWS_H2_FRAME_TYPE_DATA:

      //  lwsl_info("%s: LWS_H2_FRAME_TYPE_DATA: fl 0x%x\n",
      //      __func__, h2n->flags);

        /*
         * let the network wsi live a bit longer if
         * subs are active... our frame may take a long
         * time to chew through
         */
        if (!wsi->immortal_substream_count)
          lws_set_timeout(wsi,
            PENDING_TIMEOUT_HTTP_KEEPALIVE_IDLE,
            lws_wsi_keepalive_timeout_eff(wsi));

        if (!h2n->swsi)
          break;

        if (lws_buflist_next_segment_len(
            &h2n->swsi->buflist, NULL))
          lwsl_info("%s: substream has pending\n",
              __func__);

        if (lwsi_role_http(h2n->swsi) &&
            lwsi_state(h2n->swsi) == LRS_ESTABLISHED) {
          lwsi_set_state(h2n->swsi, LRS_BODY);
          lwsl_info("%s: %s to LRS_BODY\n",
              __func__, lws_wsi_tag(h2n->swsi));
        }

        /*
         * in + length may cover multiple frames, we
         * can only consider the length of the DATA
         * in front of us
         */

        if (lws_hdr_total_length(h2n->swsi,
               WSI_TOKEN_HTTP_CONTENT_LENGTH) &&
            h2n->swsi->http.rx_content_length &&
            h2n->swsi->http.rx_content_remain <
                 h2n->length - h2n->inside && /* last */
            h2n->inside < h2n->length) {

          lwsl_warn("%s: rx.cl: %lu, rx.content_remain: %lu, buf left: %lu, "
              "h2->inside: %lu, h2->length: %lu\n", __func__,
              (unsigned long)h2n->swsi->http.rx_content_length,
              (unsigned long)h2n->swsi->http.rx_content_remain,
              (unsigned long)(lws_ptr_diff_size_t(iend, in) + 1),
              (unsigned long)h2n->inside, (unsigned long)h2n->length);

          /* unread data in frame */
          lws_h2_goaway(wsi,
                  H2_ERR_PROTOCOL_ERROR,
              "More rx than content_length told");
          break;
        }

        /*
         * We operate on a frame.  The RX we have at
         * hand may exceed the current frame.
         */

        n = (int)lws_ptr_diff_size_t(iend, in)  + 1;
        if (n > (int)(h2n->length - h2n->count + 1)) {
          if (h2n->count > h2n->length)
            goto close_swsi_and_return;
          n = (int)(h2n->length - h2n->count) + 1;
          lwsl_debug("---- restricting len to %d "
               "\n", n);
        }
#if defined(LWS_WITH_CLIENT)
        if (h2n->swsi->client_mux_substream) {
          if (!h2n->swsi->a.protocol) {
            lwsl_err("%s: %p doesn't have protocol\n",
               __func__, lws_wsi_tag(h2n->swsi));
            m = 1;
          } else {
            h2n->swsi->txc.peer_tx_cr_est -= n;
            wsi->txc.peer_tx_cr_est -= n;
            lws_wsi_txc_describe(&h2n->swsi->txc,
              __func__,
              h2n->swsi->mux.my_sid);
          m = user_callback_handle_rxflow(
            h2n->swsi->a.protocol->callback,
            h2n->swsi,
            LWS_CALLBACK_RECEIVE_CLIENT_HTTP_READ,
            h2n->swsi->user_space,
            in - 1, (unsigned int)n);
          }

          in += n - 1;
          h2n->inside += (unsigned int)n;
          h2n->count += (unsigned int)n - 1;

          if (m) {
            lwsl_info("RECEIVE_CLIENT_HTTP "
                "closed it\n");
            goto close_swsi_and_return;
          }

          goto do_windows;
        }
#endif
        if (lwsi_state(h2n->swsi) == LRS_DEFERRING_ACTION) {
          m = lws_buflist_append_segment(
            &h2n->swsi->buflist, in - 1, (unsigned int)n);
          if (m < 0)
            return -1;

          /*
           * Since we're in an open-ended
           * DEFERRING_ACTION, don't add this swsi
           * to the pt list of wsi holding buflist
           * content yet, we are not in a position
           * to consume it until we get out of
           * DEFERRING_ACTION.
           */

          in += n - 1;
          h2n->inside += (unsigned int)n;
          h2n->count += (unsigned int)n - 1;

          lwsl_debug("%s: deferred %d\n", __func__, n);
          goto do_windows;
        }

        h2n->swsi->outer_will_close = 1;
        /*
         * choose the length for this go so that we end at
         * the frame boundary, in the case there is already
         * more waiting leave it for next time around
         */

        n = lws_read_h1(h2n->swsi, in - 1, (unsigned int)n);
        // lwsl_notice("%s: lws_read_h1 %d\n", __func__, n);
        h2n->swsi->outer_will_close = 0;
        /*
         * can return 0 in POST body with
         * content len exhausted somehow.
         */
        if (n < 0 ||
            (!n && h2n->swsi->http.content_length_given && !lws_buflist_next_segment_len(
                &wsi->buflist, NULL))) {
          lwsl_info("%s: lws_read_h1 told %d %u / %u\n",
            __func__, n,
            (unsigned int)h2n->count,
            (unsigned int)h2n->length);
          in += h2n->length - h2n->count;
          h2n->inside = h2n->length;
          h2n->count = h2n->length - 1;

          //if (n < 0)
          //  goto already_closed_swsi;
          goto close_swsi_and_return;
        }

        lwsl_info("%s: lws_read_h1 telling %d %u / %u\n",
            __func__, n,
            (unsigned int)h2n->count,
            (unsigned int)h2n->length);

        if (n) {
          in += (unsigned int)n - 1;
          h2n->inside += (unsigned int)n;
          h2n->count += (unsigned int)n - 1;

          h2n->swsi->txc.peer_tx_cr_est -= n;
          wsi->txc.peer_tx_cr_est -= n;
        }

do_windows:

#if defined(LWS_WITH_CLIENT)
        if (!(h2n->swsi->flags & LCCSCF_H2_MANUAL_RXFLOW))
#endif
        {
          /*
           * The default behaviour is we just keep
           * cranking the other side's tx credit
           * back up, for simple bulk transfer as
           * fast as we can take it
           */

          m = n  + 65536;

          /* update both the stream and nwsi */

          lws_h2_update_peer_txcredit_thresh(h2n->swsi,
                    h2n->sid, m, m);
        }
#if defined(LWS_WITH_CLIENT)
        else {
          /*
           * If he's handling it himself, only
           * repair the nwsi credit but allow the
           * stream credit to run down until the
           * user code deals with it
           */
          lws_h2_update_peer_txcredit(wsi, (unsigned int)0, n);
          h2n->swsi->txc.manual = 1;
        }
#endif
        break;

      case LWS_H2_FRAME_TYPE_PRIORITY:
        if (h2n->count <= 4) {
          h2n->dep <<= 8;
          h2n->dep |= c;
          break;
        }
        h2n->weight_temp = c;
        lwsl_info("PRIORITY: dep 0x%x, weight 0x%02X\n",
            (unsigned int)h2n->dep, h2n->weight_temp);

        if ((h2n->dep & ~(1u << 31)) == h2n->sid) {
          lws_h2_goaway(wsi, H2_ERR_PROTOCOL_ERROR,
                  "cant depend on own sid");
          break;
        }
        break;

      case LWS_H2_FRAME_TYPE_RST_STREAM:
        h2n->hpack_e_dep <<= 8;
        h2n->hpack_e_dep |= c;
        break;

      case LWS_H2_FRAME_TYPE_PUSH_PROMISE:
        break;

      case LWS_H2_FRAME_TYPE_PING:
        if (h2n->flags & LWS_H2_FLAG_SETTINGS_ACK) { // ack
        } else { /* they're sending us a ping request */
          if (h2n->count > 8)
            return 1;
          h2n->ping_payload[h2n->count - 1] = c;
        }
        break;

      case LWS_H2_FRAME_TYPE_WINDOW_UPDATE:
        h2n->hpack_e_dep <<= 8;
        h2n->hpack_e_dep |= c;
        break;

      case LWS_H2_FRAME_TYPE_COUNT: /* IGNORING FRAME */
        //lwsl_debug("%s: consuming for ignored %u %u\n", __func__, (unsigned int)h2n->count, (unsigned int)h2n->length);
        h2n->count++;
        break;

      default:
        lwsl_notice("%s: unhandled frame type %d\n",
              __func__, h2n->type);

        goto fail;
      }

frame_end:
      if (h2n->count > h2n->length) {
        lwsl_notice("%s: count > length %u %u (type %d)\n",
              __func__, (unsigned int)h2n->count,
              (unsigned int)h2n->length, h2n->type);

      } else
        if (h2n->count != h2n->length)
          break;

      /*
       * end of frame just happened
       */
      n = lws_h2_parse_end_of_frame(wsi);
      if (n == 2) {
        *inused = (lws_filepos_t)lws_ptr_diff_size_t(in, oldin);

        return 2;
      }
      if (n)
        goto fail;

      break;

try_frame_start:
      if (h2n->frame_state <= 8) {

        switch (h2n->frame_state++) {
        case 0:
          h2n->pad_length = 0;
          h2n->collected_priority = 0;
          h2n->padding = 0;
          h2n->preamble = 0;
          h2n->length = c;
          h2n->inside = 0;
          break;
        case 1:
        case 2:
          h2n->length <<= 8;
          h2n->length |= c;
          break;
        case 3:
          h2n->type = c;
          break;
        case 4:
          h2n->flags = c;
          break;

        case 5:
        case 6:
        case 7:
        case 8:
          h2n->sid <<= 8;
          h2n->sid |= c;
          break;
        }
      }

      if (h2n->frame_state == LWS_H2_FRAME_HEADER_LENGTH &&
          lws_h2_parse_frame_header(wsi))
        goto fail;
      break;

    default:
      if (h2n->type == LWS_H2_FRAME_TYPE_COUNT) { /* IGNORING FRAME */
        //lwsl_debug("%s: consuming for ignored %u %u\n", __func__, (unsigned int)h2n->count, (unsigned int)h2n->length);
        h2n->count++;
      }
      break;
    }
  }

  *inused = (lws_filepos_t)lws_ptr_diff_size_t(in, oldin);

  return 0;

close_swsi_and_return:

  lws_close_free_wsi(h2n->swsi, 0, "close_swsi_and_return");
  h2n->swsi = NULL;
  h2n->frame_state = 0;
  h2n->count = 0;

// already_closed_swsi:
  *inused = (lws_filepos_t)lws_ptr_diff_size_t(in, oldin);

  return 2;

fail:
  *inused = (lws_filepos_t)lws_ptr_diff_size_t(in, oldin);

  return 1;
}

#if defined(LWS_WITH_CLIENT)
int
lws_h2_client_handshake(struct lws *wsi)
{
  struct lws_context_per_thread *pt = &wsi->a.context->pt[(int)wsi->tsi];
  uint8_t *buf, *start, *p, *p1, *end;
  char *meth = lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_METHOD),
       *uri = lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_URI), *simp;
  struct lws *nwsi = lws_get_network_wsi(wsi);
  const char *path = "/";
  int n, m;
  /*
   * The identifier of a newly established stream MUST be numerically
   * greater than all streams that the initiating endpoint has opened or
   * reserved.  This governs streams that are opened using a HEADERS frame
   * and streams that are reserved using PUSH_PROMISE.  An endpoint that
   * receives an unexpected stream identifier MUST respond with a
   * connection error (Section 5.4.1) of type PROTOCOL_ERROR.
   */
  unsigned int sid = nwsi->h2.h2n->highest_sid_opened + 2;

  lwsl_debug("%s\n", __func__);

  /*
   * We MUST allocate our sid here at the point we're about to send the
   * stream open.  It's because we don't know the order in which multiple
   * open streams will send their headers... in h2, sending the headers
   * is the point the stream is opened.  The peer requires that we only
   * open streams in ascending sid order
   */

  wsi->mux.my_sid = nwsi->h2.h2n->highest_sid_opened = sid;
  lwsl_info("%s: %s: assigning SID %d at header send\n", __func__,
      lws_wsi_tag(wsi), sid);


  lwsl_info("%s: CLIENT_WAITING_TO_SEND_HEADERS: pollout (sid %d)\n",
      __func__, wsi->mux.my_sid);

  p = start = buf = pt->serv_buf + LWS_PRE;
  end = start + (wsi->a.context->pt_serv_buf_size / 2) - LWS_PRE - 1;

  /* it's time for us to send our client stream headers */

  if (!meth)
    meth = "GET";

  /* h2 pseudoheaders must be in a bunch at the start */

  if (lws_add_http_header_by_token(wsi,
        WSI_TOKEN_HTTP_COLON_METHOD,
        (unsigned char *)meth,
        (int)strlen(meth), &p, end))
    goto fail_length;

  if (lws_add_http_header_by_token(wsi,
        WSI_TOKEN_HTTP_COLON_SCHEME,
        (unsigned char *)"https", 5,
        &p, end))
    goto fail_length;


  n = lws_hdr_total_length(wsi, _WSI_TOKEN_CLIENT_URI);
  if (n)
    path = uri;
  else
    if (wsi->stash && wsi->stash->cis[CIS_PATH]) {
      path = wsi->stash->cis[CIS_PATH];
      n = (int)strlen(path);
    } else
      n = 1;

  if (n > 1 && path[0] == '/' && path[1] == '/') {
    path++;
    n--;
  }

  // lwsl_hexdump_notice(path, (size_t)n);

  if (n && lws_add_http_header_by_token(wsi,
        WSI_TOKEN_HTTP_COLON_PATH,
        (unsigned char *)path, n, &p, end))
    goto fail_length;

  n = lws_hdr_total_length(wsi, _WSI_TOKEN_CLIENT_HOST);
  simp = lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_HOST);
  if (!n && wsi->stash && wsi->stash->cis[CIS_ADDRESS]) {
    n = (int)strlen(wsi->stash->cis[CIS_ADDRESS]);
    simp = wsi->stash->cis[CIS_ADDRESS];
  }

//  n = lws_hdr_total_length(wsi, _WSI_TOKEN_CLIENT_ORIGIN);
//  simp = lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_ORIGIN);
#if 0
  if (n && simp && lws_add_http_header_by_token(wsi,
        WSI_TOKEN_HTTP_COLON_AUTHORITY,
        (unsigned char *)simp, n, &p, end))
    goto fail_length;
#endif


  if (/*!wsi->client_h2_alpn && */n && simp &&
      lws_add_http_header_by_token(wsi, WSI_TOKEN_HOST,
        (unsigned char *)simp, n, &p, end))
    goto fail_length;


  if (wsi->flags & LCCSCF_HTTP_MULTIPART_MIME) {
    p1 = lws_http_multipart_headers(wsi, p);
    if (!p1)
      goto fail_length;
    p = p1;
  }

  if (wsi->flags & LCCSCF_HTTP_X_WWW_FORM_URLENCODED) {
    if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE,
         (unsigned char *)"application/x-www-form-urlencoded",
         33, &p, end))
      goto fail_length;
    lws_client_http_body_pending(wsi, 1);
  }

  /* give userland a chance to append, eg, cookies */

#if defined(LWS_WITH_CACHE_NSCOOKIEJAR) && defined(LWS_WITH_CLIENT)
  if (wsi->flags & LCCSCF_CACHE_COOKIES)
    lws_cookie_send_cookies(wsi, (char **)&p, (char *)end);
#endif

  if (wsi->a.protocol->callback(wsi,
        LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
        wsi->user_space, &p, lws_ptr_diff_size_t(end, p) - 12))
    goto fail_length;

  if (lws_finalize_http_header(wsi, &p, end))
    goto fail_length;

  m = LWS_WRITE_HTTP_HEADERS;
#if defined(LWS_WITH_CLIENT)
  /* below is not needed in spec, indeed it destroys the long poll
   * feature, but required by nghttp2 */
  if ((wsi->flags & LCCSCF_H2_QUIRK_NGHTTP2_END_STREAM) &&
      !(wsi->client_http_body_pending  || lws_has_buffered_out(wsi)))
    m |= LWS_WRITE_H2_STREAM_END;
#endif

  // lwsl_hexdump_notice(start, p - start);

  n = lws_write(wsi, start, lws_ptr_diff_size_t(p, start), (enum lws_write_protocol)m);

  if (n != lws_ptr_diff(p, start)) {
    lwsl_err("_write returned %d from %ld\n", n,
       (long)(p - start));
    return -1;
  }

  /*
   * Normally let's charge up the peer tx credit a bit.  But if
   * MANUAL_REFLOW is set, just set it to the initial credit given in
   * the client create info
   */

  n = 4 * 65536;
  if (wsi->flags & LCCSCF_H2_MANUAL_RXFLOW) {
    n = wsi->txc.manual_initial_tx_credit;
    wsi->txc.manual = 1;
  }

  if (lws_h2_update_peer_txcredit(wsi, wsi->mux.my_sid, n))
    return 1;

  lws_h2_state(wsi, LWS_H2_STATE_OPEN);
  lwsi_set_state(wsi, LRS_ESTABLISHED);

  if (wsi->flags & LCCSCF_HTTP_MULTIPART_MIME)
    lws_callback_on_writable(wsi);

  return 0;

fail_length:
  lwsl_err("Client hdrs too long: incr context info.pt_serv_buf_size\n");

  return -1;
}
#endif

#if defined(LWS_ROLE_WS) && defined(LWS_WITH_SERVER)
int
lws_h2_ws_handshake(struct lws *wsi)
{
  uint8_t buf[LWS_PRE + 2048], *p = buf + LWS_PRE, *start = p,
    *end = &buf[sizeof(buf) - 1];
  const struct lws_http_mount *hit;
  const char * uri_ptr;
  size_t m;
  int n;

  if (lws_add_http_header_status(wsi, HTTP_STATUS_OK, &p, end))
    return -1;

  if (lws_hdr_total_length(wsi, WSI_TOKEN_PROTOCOL) > 64)
    return -1;

  if (wsi->proxied_ws_parent && wsi->child_list) {
    if (lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL)) {
      if (lws_add_http_header_by_token(wsi, WSI_TOKEN_PROTOCOL,
        (uint8_t *)lws_hdr_simple_ptr(wsi,
                 WSI_TOKEN_PROTOCOL),
        (int)strlen(lws_hdr_simple_ptr(wsi,
                 WSI_TOKEN_PROTOCOL)),
             &p, end))
      return -1;
    }
  } else {

    /* we can only return the protocol header if:
     *  - one came in, and ... */
    if (lws_hdr_total_length(wsi, WSI_TOKEN_PROTOCOL) &&
        /*  - it is not an empty string */
        wsi->a.protocol->name && wsi->a.protocol->name[0]) {

#if defined(LWS_WITH_SECURE_STREAMS) && defined(LWS_WITH_SERVER)

    /*
     * This is the h2 version of server-ws.c understanding that it
     * did the ws upgrade on a ss server object, therefore it needs
     * to pass back to the peer the policy ws-protocol name, not
     * the generic ss-ws.c protocol name
     */

    if (wsi->a.vhost && wsi->a.vhost->ss_handle &&
        wsi->a.vhost->ss_handle->policy->u.http.u.ws.subprotocol) {
      lws_ss_handle_t *h =
        (lws_ss_handle_t *)wsi->a.opaque_user_data;

      lwsl_notice("%s: Server SS %s .wsi %s switching to ws protocol\n",
          __func__, lws_ss_tag(h), lws_wsi_tag(h->wsi));

      wsi->a.protocol = &protocol_secstream_ws;

      /*
       * inform the SS user code that this has done a one-way
       * upgrade to some other protocol... it will likely
       * want to treat subsequent payloads differently
       */

      lws_ss_event_helper(h, LWSSSCS_SERVER_UPGRADE);

      lws_mux_mark_immortal(wsi);

      if (lws_add_http_header_by_token(wsi, WSI_TOKEN_PROTOCOL,
        (unsigned char *)wsi->a.vhost->ss_handle->policy->
            u.http.u.ws.subprotocol,
        (int)strlen(wsi->a.vhost->ss_handle->policy->
            u.http.u.ws.subprotocol), &p, end))
          return -1;
    } else
#endif

      if (lws_add_http_header_by_token(wsi, WSI_TOKEN_PROTOCOL,
        (unsigned char *)wsi->a.protocol->name,
        (int)strlen(wsi->a.protocol->name), &p, end))
          return -1;
    }
  }

#if !defined(LWS_WITHOUT_EXTENSIONS)
        /*
         * Figure out which extensions the client has that we want to
         * enable on this connection, and give him back the list.
         *
         * Give him a limited write bugdet
         */
        if (lws_extension_server_handshake(wsi, (char **)&p, 192))
               return -1;
#endif

  if (lws_finalize_http_header(wsi, &p, end))
    return -1;

  m = lws_ptr_diff_size_t(p, start);
  // lwsl_hexdump_notice(start, m);
  n = lws_write(wsi, start, m, LWS_WRITE_HTTP_HEADERS);
  if (n != (int)m) {
    lwsl_err("_write returned %d from %d\n", n, (int)m);

    return -1;
  }

  /*
   * alright clean up, set our state to generic ws established, the
   * mode / state of the nwsi will get the h2 processing done.
   */

  lwsi_set_state(wsi, LRS_ESTABLISHED);
  wsi->lws_rx_parse_state = 0; // ==LWS_RXPS_NEW;

  uri_ptr = lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP_COLON_PATH);
  n = lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_COLON_PATH);
  hit = lws_find_mount(wsi, uri_ptr, n);

  if (hit && hit->cgienv &&
      wsi->a.protocol->callback(wsi, LWS_CALLBACK_HTTP_PMO, wsi->user_space,
            (void *)hit->cgienv, 0))
    return 1;

  lws_validity_confirmed(wsi);

  return 0;
}
#endif

int
lws_read_h2(struct lws *wsi, unsigned char *buf, lws_filepos_t len)
{
  unsigned char *oldbuf = buf;

  // lwsl_notice("%s: h2 path: wsistate 0x%x len %d\n", __func__,
  //    wsi->wsistate, (int)len);

  /*
   * wsi here is always the network connection wsi, not a stream
   * wsi.  Once we unpicked the framing we will find the right
   * swsi and make it the target of the frame.
   *
   * If it's ws over h2, the nwsi will get us here to do the h2
   * processing, and that will call us back with the swsi +
   * ESTABLISHED state for the inner payload, handled in a later
   * case.
   */
  while (len) {
    lws_filepos_t body_chunk_len = 0;
    int m;

    /*
     * we were accepting input but now we stopped doing so
     */
    if (lws_is_flowcontrolled(wsi)) {
      lws_rxflow_cache(wsi, buf, 0, (size_t)len);
      buf += len;
      break;
    }

    /*
     * lws_h2_parser() may send something; when it gets the
     * whole frame, it will want to perform some action
     * involving a reply.  But we may be in a partial send
     * situation on the network wsi...
     *
     * Even though we may be in a partial send and unable to
     * send anything new, we still have to parse the network
     * wsi in order to gain tx credit to send, which is
     * potentially necessary to clear the old partial send.
     *
     * ALL network wsi-specific frames are sent by PPS
     * already, these are sent as a priority on the writable
     * handler, and so respect partial sends.  The only
     * problem is when a stream wsi wants to send an, eg,
     * reply headers frame in response to the parsing
     * we will do now... the *stream wsi* must stall in a
     * different state until it is able to do so from a
     * priority on the WRITABLE callback, same way that
     * file transfers operate.
     */

    m = lws_h2_parser(wsi, buf, len, &body_chunk_len);

               body_chunk_len &= 0xffffffff; /* attempt workaround for finding len=7167 --> len = 0xffffffff00001bff on lws.org */

    if (m && m != 2) {
      lwsl_debug("%s: http2_parser bail: %d\n", __func__, m);
      lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS,
             "lws_read_h2 bail");

      return -1;
    }
    if (m == 2) {
      /* swsi has been closed */
      buf += body_chunk_len;
      break;
    }

    buf += body_chunk_len;
    len -= body_chunk_len;
  }

  return lws_ptr_diff(buf, oldbuf);
}

int
lws_h2_client_stream_long_poll_rxonly(struct lws *wsi)
{

  if (!wsi->mux_substream)
    return 1;

  /*
   * Elect to send an empty DATA with END_STREAM, to force the stream
   * into HALF_CLOSED LOCAL
   */
  wsi->h2.long_poll = 1;
  wsi->h2.send_END_STREAM = 1;

  // lws_header_table_detach(wsi, 0);

  lws_callback_on_writable(wsi);

  return 0;
}

Coverage Report

Created: 2025-08-11 06:52