Method handle_upgrade_request

src/proxy/http/HttpTransact.cc:1249–1341

}

bool
HttpTransact::handle_upgrade_request(State *s)
{
  HTTPHdr &request = s->hdr_info.client_request;
  s->method        = request.method_get_wksidx();

  // Quickest way to determine that this is defintely not an upgrade.
  /* RFC 6455 The method of the request MUST be GET, and the HTTP version MUST
        be at least 1.1. */
  if (!s->hdr_info.client_request.presence(MIME_PRESENCE_UPGRADE) ||
      !s->hdr_info.client_request.presence(MIME_PRESENCE_CONNECTION) || s->method != HTTP_WKSIDX_GET ||
      s->hdr_info.client_request.version_get() < HTTP_1_1) {
    return false;
  }

  MIMEField *upgrade_hdr    = s->hdr_info.client_request.field_find(MIME_FIELD_UPGRADE, MIME_LEN_UPGRADE);
  MIMEField *connection_hdr = s->hdr_info.client_request.field_find(MIME_FIELD_CONNECTION, MIME_LEN_CONNECTION);

  StrList          connection_hdr_vals;
  std::string_view upgrade_hdr_val;

  if (!upgrade_hdr || !connection_hdr || connection_hdr->value_get_comma_list(&connection_hdr_vals) == 0 ||
      (upgrade_hdr_val = upgrade_hdr->value_get()).data() == nullptr) {
    TxnDbg(dbg_ctl_http_trans_upgrade, "Transaction wasn't a valid upgrade request, proceeding as a normal HTTP request.");
    return false;
  }

  /*
   * In order for this request to be treated as a normal upgrade request we must have a Connection: Upgrade header
   * and a Upgrade: header, with a non-empty value, otherwise we just assume it's not an Upgrade Request, after
   * we've verified that, we will try to match this upgrade to a known upgrade type such as Websockets.
   */
  bool connection_contains_upgrade = false;
  // Next, let's validate that the Connection header contains an Upgrade key
  for (int i = 0; i < connection_hdr_vals.count; ++i) {
    Str *val = connection_hdr_vals.get_idx(i);
    if (ptr_len_casecmp(val->str, val->len, MIME_FIELD_UPGRADE, MIME_LEN_UPGRADE) == 0) {
      connection_contains_upgrade = true;
      break;
    }
  }

  if (!connection_contains_upgrade) {
    TxnDbg(dbg_ctl_http_trans_upgrade,
           "Transaction wasn't a valid upgrade request, proceeding as a normal HTTP request, missing Connection upgrade header.");
    return false;
  }

  // Mark this request as an upgrade request.
  s->is_upgrade_request = true;

  /*
     RFC 6455
     The request MUST contain an |Upgrade| header field whose value
        MUST include the "websocket" keyword.
     The request MUST contain a |Connection| header field whose value
        MUST include the "Upgrade" token. // Checked Above
     The request MUST include a header field with the name