gtp5g - 5G compatible GTP kernel module

gtp5g is a customized Linux kernel module gtp5g to handle packet by PFCP IEs such as PDR and FAR. For detailed information, please reference to 3GPP specification TS 29.281 and TS 29.244.

Notice

Due to the evolution of Linux kernel, this module would not work with every kernel version. Please run this module with kernel version 5.0.0-23-generic, upper than 5.4 (Ubuntu 20.04) or RHEL8.

Usage

Clone

The latest version

git clone https://github.com/free5gc/gtp5g.git

The specific version

# git clone -b {version} https://github.com/free5gc/gtp5g.git
git clone -b v0.8.10 https://github.com/free5gc/gtp5g.git

Install Required Packages

sudo apt -y update
sudo apt -y install gcc g++ cmake autoconf libtool pkg-config libmnl-dev libyaml-dev

Compile

cd gtp5g
make clean && make

Install kernel module

Install the module to the system and load automatically at boot

sudo make install

Remove kernel module

Remove the kernel module from the system

sudo make uninstall

DKMS support

When updating the kernel gtp5g needs to get rebuilt against the current kernel source. This can be automated using DKMS.

To use the DKMS support the following steps are required:

1. Copy the repository to /usr/src/gtp5g-<VERSION> (e.g., /usr/src/gtp5g-0.9.5/).
2. Run the following command to add the DKMS module to the module tree:

   # sudo dkms add -m gtp5g -v <VERSION>
   sudo dkms add -m gtp5g -v 0.9.5
   

3. Run this command to install the DKMS module:

   # sudo dkms install -m gtp5g -v <VERSION>
   sudo dkms install -m gtp5g -v 0.9.5
   

After a reboot of the system everything should be set up. Whether the kernel module is loaded can be checked by running:

lsmod | grep gtp

Which should result in a similar output to:

gtp5g                 200704  0
udp_tunnel             28672  2 gtp5g,sctp

Check Rules

Get PDR/FAR/QER information by "/proc"

# if UPF used legacy netlink struct without SEID, need use #SEID=0 to query related info as below:
echo #interfaceName #SEID #PDRID > /proc/gtp5g/pdr
echo #interfaceName #SEID #FARID > /proc/gtp5g/far
echo #interfaceName #SEID #QERID > /proc/gtp5g/qer

cat /proc/gtp5g/pdr
cat /proc/gtp5g/far
cat /proc/gtp5g/qer

Enable/Disable QoS (Default is disabled)

Support Session AMBR and MFBR.

1. Check whether QoS is enabled or disabled. (1 means enabled, 0 means disabled)

   cat /proc/gtp5g/qos
   

2. Enable or disable QoS
   • enable

     echo 1 >  /proc/gtp5g/qos
     

   • disable

     echo 0 >  /proc/gtp5g/qos
     

Enable/Disable GTP-U Sequence Number (Default is enabled)

Support GTP-U Sequence Number.

1. Check whether GTP-U Sequence Number is enabled or disabled. (1 means enabled, 0 means disabled)

   cat /proc/gtp5g/seq
   

2. Enable or disable GTP-U Sequence Number
   • enable

     echo 1 >  /proc/gtp5g/seq
     

   • disable

     echo 0 >  /proc/gtp5g/seq
     

Log Related

1. check log

   dmesg
   

2. update log level

   # [number] is 0~4 
   # e.g. echo 4 > /proc/gtp5g/dbg
   echo [number] > /proc/gtp5g/dbg
   

Tools

• go-gtp5gnl