Function handle_close_hook

plugins/experimental/block_errors/block_errors.cc:227–270

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//-------------------------------------------------------------------------
static int
handle_close_hook(TSCont * /* contp ATS_UNUSED */, TSEvent /* event ATS_UNUSED */, void *edata)
{
  Dbg(dbg_ctl, "handle_close_hook");
  auto txnp = static_cast<TSHttpTxn>(edata);

  if (enabled == false) {
    Dbg(dbg_ctl, "plugin disabled");
    TSHttpTxnReenable(txnp, TS_EVENT_HTTP_CONTINUE);
    return 0;
  }

  // get the errors from the state machine
  Errors transaction;
  Errors session;
  TSHttpTxnClientReceivedErrorGet(txnp, &transaction.cls, &transaction.code);
  TSHttpTxnClientSentErrorGet(txnp, &session.cls, &session.code);

  // debug if we have an error
  if (transaction.cls != 0 || session.cls != 0 || transaction.code != 0 || session.code != 0) {
    Dbg(dbg_ctl, "transaction error class=%d code=%" PRIu64 " session error class=%d code=%" PRIu64, transaction.cls,
        transaction.code, session.cls, session.code);
  }

  // count the error if there is a transaction error CANCEL or a session error ENHANCE_YOUR_CALM
  // https://www.rfc-editor.org/rfc/rfc9113.html#name-error-codes
  if ((transaction.cls == 2 && transaction.code == 8) || (session.cls == 1 && session.code == 11)) {
    TSHttpSsn       ssn   = TSHttpTxnSsnGet(txnp);
    TSVConn         vconn = TSHttpSsnClientVConnGet(ssn);
    const sockaddr *addr  = TSNetVConnRemoteAddrGet(vconn);
    swoc::IPAddr    ipaddr(addr);
    uint32_t        count = ip_table.increment(ipaddr);
    if (count > RESET_LIMIT) {
      std::string address;
      Dbg(dbg_ctl, "ip=%s count=%d is over the limit, shutdown connection on close", ipaddr_to_string(ipaddr, address).c_str(),
          count);
      int fd = TSVConnFdGet(vconn);
      shutdown(fd, SHUT_RDWR);
    }
  }

  TSHttpTxnReenable(txnp, TS_EVENT_HTTP_CONTINUE);
  return 0;
}

//-------------------------------------------------------------------------
static int