/*

 * libwebsockets - small server side websockets and web server implementation

 *

 * Copyright (C) 2019 - 2020 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>

extern int

secstream_h1(struct lws *wsi, enum lws_callback_reasons reason, void *user,

       void *in, size_t len);

static int

secstream_h2(struct lws *wsi, enum lws_callback_reasons reason, void *user,

       void *in, size_t len)

{

  lws_ss_handle_t *h = (lws_ss_handle_t *)lws_get_opaque_user_data(wsi);

  lws_ss_state_return_t r;

  int n;

  switch (reason) {

  case LWS_CALLBACK_ESTABLISHED_CLIENT_HTTP:

    if (!h)

      return -1;

#if defined(LWS_WITH_SECURE_STREAMS_PROXY_API)

    if (h->being_serialized) {

      /*

       * We are the proxy-side SS for a remote client... we

       * need to inform the client about the initial tx credit

       * to write to it that the remote h2 server set up

       */

      lwsl_info("%s: reporting initial tx cr from server %d\n",

          __func__, wsi->txc.tx_cr);

      ss_proxy_onward_txcr((void *)(h + 1), wsi->txc.tx_cr);

    }

#endif

    n = secstream_h1(wsi, reason, user, in, len);

    if (!n && (h->policy->flags & LWSSSPOLF_LONG_POLL)) {

      lwsl_notice("%s: h2 client %s entering LONG_POLL\n",

          __func__, lws_wsi_tag(wsi));

      lws_h2_client_stream_long_poll_rxonly(wsi);

    }

    return n;

  case LWS_CALLBACK_CLOSED_CLIENT_HTTP:

    /*

     * Only allow the wsi that the handle believes is representing

     * him to report closure up to h1

     */

    if (!h || h->wsi != wsi)

      return 0;

    break;

  case LWS_CALLBACK_COMPLETED_CLIENT_HTTP:

    if (!h)

      return -1;

    // lwsl_err("%s: h2 COMPLETED_CLIENT_HTTP\n", __func__);

    r = 0;

    if (h->hanging_som)

      r = h->info.rx(ss_to_userobj(h), NULL, 0, LWSSS_FLAG_EOM);

    h->txn_ok = 1;

    lws_cancel_service(lws_get_context(wsi)); /* abort poll wait */

    if (h->hanging_som && r == LWSSSSRET_DESTROY_ME)

      return _lws_ss_handle_state_ret_CAN_DESTROY_HANDLE(r, wsi, &h);

    h->hanging_som = 0;

    break;

  case LWS_CALLBACK_WSI_TX_CREDIT_GET:

    if (!h)

      return -1;

    /*

     * The peer has sent us additional tx credit...

     */

    lwsl_info("%s: LWS_CALLBACK_WSI_TX_CREDIT_GET: %d\n",

          __func__, (int)len);

#if defined(LWS_WITH_SECURE_STREAMS_PROXY_API)

    if (h->being_serialized)

      /* we are the proxy-side SS for a remote client */

      ss_proxy_onward_txcr((void *)(h + 1), (int)len);

#endif

    break;

  default:

    break;

  }

  return secstream_h1(wsi, reason, user, in, len);

}

const struct lws_protocols protocol_secstream_h2 = {

  "lws-secstream-h2",

  secstream_h2,

  0, 0, 0, NULL, 0

};

/*

 * Munge connect info according to protocol-specific considerations... this

 * usually means interpreting aux in a protocol-specific way and using the

 * pieces at connection setup time, eg, http url pieces.

 *

 * len bytes of buf can be used for things with scope until after the actual

 * connect.

 */

int

secstream_connect_munge_h2(lws_ss_handle_t *h, char *buf, size_t len,

         struct lws_client_connect_info *i,

         union lws_ss_contemp *ct)

{

  const char *pbasis = h->policy->u.http.url;

  size_t used_in, used_out;

  lws_strexp_t exp;

  /* i.path on entry is used to override the policy urlpath if not "" */

  if (i->path[0])

    pbasis = i->path;

  if (h->policy->flags & LWSSSPOLF_QUIRK_NGHTTP2_END_STREAM)

    i->ssl_connection |= LCCSCF_H2_QUIRK_NGHTTP2_END_STREAM;

  if (h->policy->flags & LWSSSPOLF_H2_QUIRK_OVERFLOWS_TXCR)

    i->ssl_connection |= LCCSCF_H2_QUIRK_OVERFLOWS_TXCR;

  if (h->policy->flags & LWSSSPOLF_HTTP_MULTIPART)

    i->ssl_connection |= LCCSCF_HTTP_MULTIPART_MIME;

  if (h->policy->flags & LWSSSPOLF_HTTP_X_WWW_FORM_URLENCODED)

    i->ssl_connection |= LCCSCF_HTTP_X_WWW_FORM_URLENCODED;

  if (h->policy->flags & LWSSSPOLF_HTTP_CACHE_COOKIES)

    i->ssl_connection |= LCCSCF_CACHE_COOKIES;

  i->ssl_connection |= LCCSCF_PIPELINE;

  i->alpn = "h2";

  /* initial peer tx credit */

  if (h->info.manual_initial_tx_credit) {

    i->ssl_connection |= LCCSCF_H2_MANUAL_RXFLOW;

    i->manual_initial_tx_credit = h->info.manual_initial_tx_credit;

    lwsl_info("%s: initial txcr %d\n", __func__,

        i->manual_initial_tx_credit);

  }

  if (!pbasis)

    return 0;

  /* protocol aux is the path part */

  i->path = buf;

  buf[0] = '/';

  lws_strexp_init(&exp, (void *)h, lws_ss_exp_cb_metadata, buf + 1, len - 1);

  if (lws_strexp_expand(&exp, pbasis, strlen(pbasis),

            &used_in, &used_out) != LSTRX_DONE)

    return 1;

  __lws_lc_tag_append(&h->lc, buf);

  return 0;

}

static int

secstream_tx_credit_add_h2(lws_ss_handle_t *h, int add)

{

  lwsl_info("%s: %s: add %d\n", __func__, lws_ss_tag(h), add);

  if (h->wsi)

    return lws_wsi_tx_credit(h->wsi, LWSTXCR_PEER_TO_US, add);

  return 0;

}

static int

secstream_tx_credit_est_h2(lws_ss_handle_t *h)

{

  if (h->wsi) {

    lwsl_info("%s: %s: est %d\n", __func__, lws_ss_tag(h),

        lws_h2_get_peer_txcredit_estimate(h->wsi));

    return lws_h2_get_peer_txcredit_estimate(h->wsi);

  }

  lwsl_info("%s: %s: Unknown (0)\n", __func__, lws_ss_tag(h));

  return 0;

}

const struct ss_pcols ss_pcol_h2 = {

  "h2",

  "h2",

  &protocol_secstream_h2,

  secstream_connect_munge_h2,

  secstream_tx_credit_add_h2,

  secstream_tx_credit_est_h2

};