doc(initial): skeleton with license

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

CHANGELOG.md

+# RELEASE NOTES: #
+
+## vX.X.X -- YYY 2021 ##
+
+* Initial release
+

CONTRIBUTING.md

+# Contributing to OpenAir-CN-5G #
+
+We want to make contributing to this project as easy and transparent as possible.
+
+Please refer to the steps described on our website: [How to contribute to OAI](https://www.openairinterface.org/?page_id=112)
+
+1. Sign and return a Contributor License Agreement to OAI team.
+2. Create an account on [Eurecom GiLab Server](https://gitlab.eurecom.fr/users/sign_in) if you do not have any.
+   - If your email domain (`@domain.com`) is not whitelisted, please contact us (mailto:contact@openairinterface.org).
+   - Eurecom GitLab does NOT accept public email domains.
+3. Provide the `username` of this account to the OAI team (mailto:contact@openairinterface.org) so you have developer rights on this repository.
+4. The policies are described in these wiki pages: [OAI Policies](https://gitlab.eurecom.fr/oai/openairinterface5g/wikis/oai-policies-home)
+   - You can fork onto another hosting system. But we will **NOT** accept a pull request from a forked repository.
+      * This decision was made for the license reasons.
+      * The Continuous Integration will reject your pull request.
+   - All pull requests SHALL have **`develop`** branch as target branch.
+
+## Coding Styles ##
+
+We are using `clang-format` as formatting tool on the C/C++ code.
+
+At the time of writing (March 30th, 2020), we are using `clang-format` version 8.0.0 or above. By default, on a Ubuntu bionic Desktop edition, you would install version 6.0.0.
+
+So it is very likely you will have to install it manually. Again, at the time of writing, the working version we found was 9.0.0.
+
+```bash
+$ wget https://releases.llvm.org/9.0.0/clang+llvm-9.0.0-x86_64-linux-gnu-ubuntu-18.04.tar.xz
+$ mkdir clang_tmp
+$ tar xvfJ  clang+llvm-9.0.0-x86_64-linux-gnu-ubuntu-18.04.tar.xz -C ./clang_tmp
+$ sudo cp clang_tmp/clang+llvm-9.0.0-x86_64-linux-gnu-ubuntu-18.04/bin/clang-format /usr/bin/clang-format
+$ rm -Rf clang*
+$ clang-format --version
+clang-format version 9.0.0 (tags/RELEASE_900/final)
+```
+
+How to format:
+
+```bash
+$ cd myClonedWorkspace/src
+$ clang-format -i theFilesYouWantToFormat
+```
+
+## License ##
+
+By contributing to OpenAirInterface, you agree that your contributions will be licensed under the [LICENSE](LICENSE) file in the root directory of this source tree.
+
+## Continuous Integration process ##
+
+1.  You push your modified code with the new branch onto our [official GitLab repository](https://gitlab.eurecom.fr/oai/cn5g/oai-cn5g-nef).
+    -  Please make the name of the branch explicit and short.
+2.  You create a pull request from the [dedicated web page](https://gitlab.eurecom.fr/oai/cn5g/oai-cn5g-nef/-/merge_requests).
+    -  The `target` (`base` in the web-page) branch **SHALL be `develop`**.
+    -  The `source` (`compare` in the web-page) branch is your branch.
+3.  Our Continuous Integration (CI) process will be triggered automatically on your proposed modified code and check the validity.
+    -  Check build
+    -  Check some formatting rules
+    -  Run a bunch of tests
+4.  If at least one of these steps fails, you will have to push corrections onto your source branch.
+    -  The step 3. will be again automatically triggered on this new commit.
+    -  Please wait that your run is finished before committing and pushing new modifications on your source branch.
+    -  That will allow fairness on the CI usage to other contributors.
+4.  When this automated process passes, one of our CI administrators will review your changes or assign a senior contributor
+  to do a peer-review.
+5.  Once the peer reviewer accepts your modification, one of our CI administrators will accept and merge your pull request
+    -  The CI will run again on the new `develop` branch commit.
+    -  The source branch WILL be deleted by one of our CI administrators.
+

LICENSE

+        The OpenAirInterface Software Alliance (OSA)
+          OAI Public License (Version 1.1)
+
+LICENSE TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION OF OPENAIR 5G SOFTWARE.
+
+1.  Definitions.
+
+“License” shall mean the terms and conditions for use, reproduction, and distribution set forth 
+in this document.
+
+“Licensor” shall mean the OpenAirInterface Software Alliance.
+
+“Legal Entity” shall mean the union, at the time an acting entity joins the Alliance, of the 
+acting entity and all other entities that control, are controlled by, or are under common control 
+with that entity. For the purposes of this definition, “control” means (i) the power, direct or 
+indirect, to cause the direction or management of such entity, whether by contract or 
+otherwise, or (ii) ownership of fifty percent (50%) or more of the outstanding shares, or (iii) 
+beneficial ownership of such entity.
+
+“You” (or “Your”) shall mean an individual or Legal Entity exercising permissions granted by 
+this License.
+
+“Source” form shall mean the preferred form for making modifications, including but not 
+limited to software source code, documentation source, and configuration files.
+
+“Object” form shall mean any form resulting from mechanical transformation or translation of 
+a Source form, including but not limited to compiled object code, generated documentation, 
+and conversions to other media types.
+
+“OpenAirInterface Software Alliance” shall mean the endowment fund established at the 
+initiative of Eurecom, an educational and research establishment located at Campus Sophia 
+Tech, 450 Route des Chappes, 06410 Biot, France, which statutes were signed on 18 
+November 2014.
+
+“Work” shall mean the work of authorship, whether in Source or Object form, made available 
+under the License, as indicated by a copyright notice that is included in or attached to the 
+work (an example is provided in the Appendix below).
+
+“Derivative Works” shall mean any work, whether in Source or Object form, that is based on 
+(or derived from) the Work and for which the editorial revisions, annotations, elaborations, or 
+other modifications represent, as a whole, an original work of authorship. For the purposes of 
+this License, Derivative Works shall not include works that remain separable from, or merely 
+link (or bind by name) to the interfaces of, the Work and Derivative Works thereof.
+
+“Contribution” shall mean any work of authorship that is intentionally submitted to Licensor 
+for inclusion in the Work by the copyright owner or by an individual or Legal Entity 
+authorized to submit on behalf of the copyright owner. For the purposes of this definition, 
+“submitted” means any form of electronic, , or written communication sent to the Licensor or 
+its representatives, including but not limited to communication on electronic mailing lists, 
+source code control systems, and issue tracking systems that are managed by, or on behalf of, 
+the Licensor for the purpose of discussing and improving the Work
+
+“Contributor License Agreement” shall mean the agreement signed by any Contributor setting 
+forth the terms and conditions applicable to its Contribution. 
+
+“Contributor” shall mean any individual or Legal Entity on behalf of whom a Contribution 
+has been received by Licensor and subsequently incorporated within the Work.
+
+2.  Grant of Copyright License.
+Subject to the terms and conditions of this License, Licensor and each Contributor hereby 
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable 
+copyright license to reproduce, prepare Derivative Works of, publicly display, publicly 
+perform, and distribute the Work and such Derivative Works in Source or Object form
+
+3.  Grant of Patent License.
+
+3.1 Grant of Patent License for study, testing and research purposes:
+Subject to the terms and conditions of this License, Licensor and each Contributor hereby 
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable 
+(except as stated in this section) patent license to make, have made, use, and otherwise 
+transfer (excluding selling) the Work, solely for study, testing and research purposes, where 
+such license applies only to those patent claims licensable by Licensor or such Contributor 
+that are necessarily infringed respectively by the Work and/or the said Contributor 
+Contribution(s) alone or by combination of their Contribution(s) with the Work  to which 
+such Contribution(s) was submitted (“Essential Patents”).
+
+3.2 Grant of Patent License for purposes other than study and research:
+For purposes other than study, testing and research, and subject to the terms and conditions of 
+this License, You commit to be prepared to negotiate a non-exclusive, non-transferable, non-
+assignable license of Essential Patents with each Contributor and/or the Licensor on Fair, 
+Reasonable and Non-Discriminatory (“FRAND”) terms and conditions for the use of the 
+Work or Contribution(s) incorporated within the Work.
+Licensor and/or each Contributor, by submitting a Contribution, will identify any of its known 
+Essential Patent it owns related to the Work and/or its Contribution.
+
+3.3 Patent Litigation
+If You institute patent litigation against any entity making use of the Work solely for study, 
+testing and research purposes (including a cross-claim or counterclaim in a lawsuit) alleging 
+that the Work or a Contribution incorporated within the Work constitutes direct or 
+contributory patent infringement, then the patent licenses granted to You under section 3.1 of 
+this License for that Work shall terminate as of the date such litigation is filed.
+
+4. Sublicensing
+You may grant sublicenses under the licenses granted under sections 2 and 3.1 provided that 
+the sublicense is subject to and inclusive of all the terms of and rights under this License to 
+which the Work is or was distributed by the OpenAirInterface Software Alliance.
+
+5. Redistribution
+Subject to terms and conditions set forth in sections 2 and 3, You may reproduce and 
+distribute copies of the Work or Derivative Works thereof in any medium, with or without 
+modifications, and in Source or Object form, provided that You meet the following 
+conditions:  
+
+1. You must give any other recipients of the Work or Derivative Works a copy of this 
+License; and
+
+2. You must cause any modified files by You to carry prominent notices stating that You 
+changed the files; and
+
+3. You must retain, in the Source form of any Derivative Works that You distribute, all 
+copyright, patent, trademark, and attribution notices from the Source form of the Work, 
+excluding those notices that do not pertain to any part of the Derivative Works; and
+
+4. If the Work includes a “NOTICE” text file as part of its distribution, then any Derivative 
+Works that You distribute must include a readable copy of the attribution notices contained 
+within such NOTICE file, excluding those notices that do not pertain to any part of the 
+Derivative Works, in at least one of the following places: within a NOTICE text file 
+distributed as part of the Derivative Works; within the Source form or documentation, if 
+provided along with the Derivative Works; or, within a display generated by the Derivative 
+Works, if and wherever such third-party notices normally appear. The contents of the 
+NOTICE file are for informational purposes only and do not modify the License. You may 
+add Your own attribution notices within Derivative Works that You distribute, alongside or as 
+an addendum to the NOTICE text from the Work, provided that such additional attribution 
+notices cannot be construed as modifying the License. 
+You may add Your own copyright statement to Your modifications and may provide 
+additional or different license terms and conditions for use, reproduction, or distribution of 
+Your modifications, or for any such Derivative Works as a whole, provided Your use, 
+reproduction, and distribution of the Work otherwise complies with the conditions stated in 
+this License.
+
+6. Submission of Contributions. 
+Contribution intentionally submitted for inclusion in the Work by You to the Licensor shall be 
+under the terms and conditions of this License, without any additional terms or conditions. 
+Notwithstanding the above, nothing herein shall supersede or modify the terms of any 
+separate license agreement such as the Contributor License Agreement You may have 
+executed with Licensor regarding such Contributions.
+
+7. Trademarks. 
+This License does not grant permission to use the trade names, trademarks, service marks, or 
+product names of the Licensor, except as required for reasonable and customary use in 
+describing the origin of the Work and reproducing the content of the NOTICE file.
+
+8. Disclaimer of Warranty. 
+Unless required by applicable law or agreed to in writing, Licensor provides the Work (and 
+each Contributor provides its Contributions) on an “AS IS” BASIS, WITHOUT 
+WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied, including, 
+without limitation, any warranties or conditions of TITLE, NON-INFRINGEMENT, 
+MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are solely 
+responsible for determining the appropriateness of using or redistributing the Work and 
+assume any risks associated with your exercise of permissions under this License.
+
+9. Limitation of Liability. 
+In no event and under no legal theory, whether in tort (including negligence), contract, or 
+otherwise, unless required by applicable law (such as deliberate and grossly negligent acts) or 
+agreed to in writing, shall Licensor and any Contributor, as such, be liable to You for 
+damages, including any direct, indirect, special, incidental, or consequential damages of any 
+character arising as a result of this License or out of Your use or inability to use the Work 
+(including but not limited to damages for loss of goodwill, work stoppage, computer failure or 
+malfunction, or any and all other commercial damages or losses), even if such Contributor has 
+been advised of the possibility of such damages.
+
+10. Accepting Warranty or Additional Liability. 
+While redistributing the Work or Derivative Works thereof, You may choose to offer, and 
+charge a fee for, acceptance of support, warranty, indemnity, or other liability obligations 
+and/or rights consistent with this License. However, in accepting such obligations, You may 
+act only on Your own behalf and on Your sole responsibility, not on behalf of any other 
+Contributor and/or the Licensor, and only if You agree to indemnify, defend, and hold each 
+Contributor and/or the Licensor harmless for any liability incurred by, or claims asserted 
+against, such Contributor and/or Licensor by reason of Your accepting any such warranty or 
+additional liability.
+
+11. Applicable law. 
+The present license shall be governed by the laws of France.
+
+END OF TERMS AND CONDITIONS
+
+1.  APPENDIX: How to apply the PRESENT OPENAIR 5G License to your work
+To apply the present License to your work, attach the following boilerplate notice, with the 
+fields enclosed by brackets “[]” replaced with your own identifying information. (Don’t 
+include the brackets!) The text should be enclosed in the appropriate comment syntax for the 
+file format. We also recommend that a file or class name and description of purpose be 
+included on the same “printed page” as the copyright notice for easier identification within 
+third-party archives.
+
+Copyright [yyyy] [name of copyright owner]
+
+Licensed under the License terms and conditions for use, reproduction, and distribution of 
+OPENAIR 5G software (the “License”);
+
+you may not use this file except in compliance with the License. You may obtain a copy of 
+the License at
+
+Unless required by applicable law or agreed to in writing, software distributed under the 
+License is distributed on an “AS IS” BASIS,
+
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+
+See the License for the specific language governing permissions and limitations under the 
+License.
+

README.md

-# oai-cn5g-nef
+------------------------------------------------------------------------------
 
-**Repository: OpenAir CN 5G for NEF**
+                             OPENAIR-CN-5G
+ An implementation of the 5G Core network by the OpenAirInterface community.
 
-Currently still private
\ No newline at end of file
+------------------------------------------------------------------------------
+
+OPENAIR-CN-5G is an implementation of the 3GPP specifications for the 5G Core Network.
+At the moment, it contains the following network elements:
+
+* Access and Mobility Management Function (**AMF**)
+* Authentication Server Management Function (**AUSF**)
+* Network Repository Function (**NRF**)
+* Session Management Function (**SMF**)
+* Unified Data Management (**UDM**)
+* Unified Data Repository (**UDR**)
+* User Plane Function (**UPF**)
+* Network Slicing Selection Function (**NSSF**)
+* Network Data Analytics Function (**NWDAF**)
+* Network Exposure Function (**NEF**)
+
+Each has its own repository: this repository (`oai-cn5g-nef`) is meant for NEF.
+
+# Licence info
+
+It is distributed under `OAI Public License V1.1`.
+See [OAI Website for more details](https://www.openairinterface.org/?page_id=698).
+
+The text for `OAI Public License V1.1` is also available under [LICENSE](LICENSE)
+file at the root of this repository.
+
+# Where to start
+
+The Openair-CN-5G NEF code is written, executed, and tested on UBUNTU server bionic version.
+Other Linux distributions support will be added later on.
+
+More details on the supported feature set is available on this [page](docs/FEATURE_SET.md).
+
+# Collaborative work
+
+This source code is managed through a GITLAB server, a collaborative development platform:
+
+*  URL: [https://gitlab.eurecom.fr/oai/cn5g/oai-cn5g-nef](https://gitlab.eurecom.fr/oai/cn5g/oai-cn5g-nef).
+
+Process is explained in [CONTRIBUTING](CONTRIBUTING.md) file.
+
+# Contribution requests
+
+In a general way, anybody who is willing can contribute on any part of the
+code in any network component.
+
+Contributions can be simple bugfixes, advices and remarks on the design,
+architecture, coding/implementation.
+
+# Release Notes
+
+They are available on the [CHANGELOG](CHANGELOG.md) file.
+
+# Repository Structure:
+
+The OpenAirInterface CN NEF software is composed of the following parts: 
+
+<pre>
+openair-cn5g-nef
+├── ci-scripts:    Directory containing the script files for CI framework.
+└── src:           Source files of NEF.
+    ├── common:    Common header files
+</pre>