add osmo-pfcp-tool

A tool for quick testing of PFCP interaction with a UPF, based on VTY
scripts / interaction.

The main motivation to create this tool was to test both the CPF and UPF
sides of the new PFCP protocol encoding and decoding, and then to test
interaction of osmo-upf with the kernel modules. It may also come in
handy as a fast way to verify basic operation in a production
environment.

Related: SYS#5599
Change-Id: I34a80d43a14c7b68952c7d337d8042d6f28ceae7
---
M configure.ac
A contrib/osmo-pfcp-tool-scripts/assoc_setup.vty
A contrib/osmo-pfcp-tool-scripts/assoc_setup_retrans.vty
A contrib/osmo-pfcp-tool-scripts/encaps_plus_tunmap.vty
A contrib/osmo-pfcp-tool-scripts/endecaps_session_est.vty
A contrib/osmo-pfcp-tool-scripts/heartbeat.vty
A contrib/osmo-pfcp-tool-scripts/osmo-pfcp-tool.cfg
A contrib/osmo-pfcp-tool-scripts/osmo-upf-11.cfg
A contrib/osmo-pfcp-tool-scripts/osmo-upf-12.cfg
A contrib/osmo-pfcp-tool-scripts/session_est_without_assoc.vty
A contrib/osmo-pfcp-tool-scripts/session_mod.vty
A contrib/osmo-pfcp-tool-scripts/tunmap_session_est.vty
M src/Makefile.am
A src/osmo-pfcp-tool/Makefile.am
A src/osmo-pfcp-tool/osmo_pfcp_tool_main.c
A src/osmo-pfcp-tool/pfcp_tool.c
A src/osmo-pfcp-tool/pfcp_tool.h
A src/osmo-pfcp-tool/pfcp_tool_vty.c
18 files changed, 1,624 insertions(+), 0 deletions(-)