License is GPL-2.0-only, is the same as of Linux kernel:

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.


Sign-off rule is that of the Linux kernel:

  Developer's Certificate of Origin 1.1

  By making a contribution to this project, I certify that:

  (a) The contribution was created in whole or in part by me and I
      have the right to submit it under the open source license
      indicated in the file; or

  (b) The contribution is based upon previous work that, to the best
      of my knowledge, is covered under an appropriate open source
      license and I have the right under that license to submit that
      work with modifications, whether created in whole or in part
      by me, under the same open source license (unless I am
      permitted to submit under a different license), as indicated
      in the file; or

  (c) The contribution was provided directly to me by some other
      person who certified (a), (b) or (c) and I have not modified
      it.

  (d) I understand and agree that this project and the contribution
      are public and that a record of the contribution (including all
      personal information I submit with it, including my sign-off) is
      maintained indefinitely and may be redistributed consistent with
      this project or the open source license(s) involved.


Principal author and project maintainer:

   ABC <abc@openwall.com> [2015-2020]


xt_hashlimit and xt_recent implementation from Linux Kernel is used for
   reference, also, compatibility layer is using code from Linux Kernel and
   should be attributed to respective Linux developers.


Code and patch contributors:

   Igor Diakonov [2015]
   Alexander Kiselev [2017]


Project supporters and sponsors:

   Igor Diakonov @ Xtrim.ru [2015]


