LaForge's home page (Posts about osmodevcon)

OsmoDevCon 2024: "Introduction to XDP, eBPF and AF_XDP"

Harald Welte — Sat, 04 May 2024 16:00:00 GMT

I've presented a talk Introduction to XDP, eBPF and AF_XDP as part of the OsmoDevCon 2024 conference on Open Source Mobile Communications.

This talk provides a generic introduction to a set of modern Linux kernel technologies:

eBPF (extended Berkeley Packet Filter) is a kind of virtual machine that runs sandboxed programs inside the Linux kernel.
XDP (eXpress Data Path) is a framework for eBPF that enables high-performance programmable packet processing in the Linux kernel
AF_XDP is an address family that is optimized for high-performance packet processing. It allows in-kernel XDP eBPF programs to efficiently pass packets to userspace via memory-mapped ring buffers.

The talk provides a high-level overview. It should provide some basics before the other/later talks on bpftrace and eUPF.

You can find the video recording at https://media.ccc.de/v/osmodevcon2024-204-introduction-to-xdp-ebpf-and-afxdp

OsmoDevCon 2024: "Using bpftrace to analyze osmocom performance"

Harald Welte — Sat, 04 May 2024 16:00:00 GMT

I've presented a talk Using bpftrace to analyze osmocom performance as part of the OsmoDevCon 2024 conference on Open Source Mobile Communications.

bpftrace is a utility that uses the Linux kernel tracing infrastructure (and eBPF) in order to provide tracing capabilities within the kernel, like uprobe, kprobe, tracepoints, etc.

bpftrace can help us to analyze the performance of [unmodified] Osmocom programs and quickly provide information like, for example:

Histogram of time spent in a specific system call
Histogram of any argument or return value of any system call

You can find the video recording at https://media.ccc.de/v/osmodevcon2024-203-using-bpftrace-to-analyze-osmocom-performance

OsmoDevCon 2024: "Anatomy of the eSIM Profile"

Harald Welte — Fri, 03 May 2024 16:00:00 GMT

I've presented a talk Anatomy of the eSIM Profile as part of the OsmoDevCon 2024 conference on Open Source Mobile Communications.

In the eSIM universe, eSIM profiles are the virtualised content of a classic USIM (possibly with ISIM, CSIM, applets, etc.).

Let's have a look what an eSIM profile is:

how is the data structured / organized?
what data can be represented in it?
how to handle features provided by eUICC, how can the eSIM profile mandate some of them?
how does personalization of eSIM profiles work?

There is also hands-on navigation through profiles, based on the pySim.esim.saip module.

You can find the video recording at https://media.ccc.de/v/osmodevcon2024-174-anatomy-of-the-esim-profile

OsmoDevCon 2024: "Detailed workings of OTA for SIM/USIM/eUICC"

Harald Welte — Fri, 03 May 2024 16:00:00 GMT

I've presented a talk Detailed workings of OTA for SIM/USIM/eUICC as part of the OsmoDevCon 2024 conference on Open Source Mobile Communications.

Everyone knows that OTA (over the air) access to SIM cards exists for decades, and that somehow authenticated APDUs can be sent via SMS.

But let's look at the OTA architecture in more detail:

OTA transport (SCP80) over SMS, USSD, CellBroadcast, CAT-TP, BIP
The new SCP81 transport (HTTPS via TLS-PSK)
how to address individal applications on the card via their TAR
common applications like RFM and RAM
custom applications on the card
OTA in the world of eUICCs
talking to the ECASD
talking to the ISD-R
talking to the ISD-P/MNO-SD or applications therein

You can find the video recording at https://media.ccc.de/v/osmodevcon2024-175-detailed-workings-of-ota-for-sim-usim-euicc

OsmoDevCon 2024: "GlobalPlatform in USIM and eUICC"

Harald Welte — Fri, 03 May 2024 16:00:00 GMT

I've presented a talk GlobalPlatform in USIM and eUICC as part of the OsmoDevCon 2024 conference on Open Source Mobile Communications.

The GlobalPlatform Card Specification and its many amendments play a significant role in most real-world USIM/ISIM, and even more so in eUICC.

The talk will try to provide an overview of what GlobalPlatform does in the telecommunications context.

Topics include:

security domains
key loading
card and application life cycle
loading and installation of applications
Secure Channel Protocols SCP02, SCP03

You can find the video recording at https://media.ccc.de/v/osmodevcon2024-173-globalplatform-in-usim-and-euicc

OsmoDevCon 2024: "High-performance I/O using io_uring via osmo_io"

Harald Welte — Thu, 02 May 2024 16:00:00 GMT

I've co-presented a talk (together with Andreas Eversberg High-performance I/O using io_uring via osmo_io as part of the OsmoDevCon 2024 conference on Open Source Mobile Communications.

Traditional socket I/O via read/write/recvfrom/sendto/recvmsg/sendmsg and friends creates a very high system call load. A highly-loaded osmo-bsc spends most of its time in syscall entry and syscall exit.

io_uring is a modern Linux kernel mechanism to avoid this syscall overhead. We have introduced the osmo_io`API to libosmocore as a generic back-end for non-blocking/asynchronous I/O and a back-end for our classic `osmo_fd / poll approach as well as a new backend for io_uring.

The talk will cover

a very basic io_uring introduction
a description of the osmo_io API
the difficulties porting from osmo_fd to osmo_io
status of porting various sub-systems over to osmo_io

You can find the video recording at https://media.ccc.de/v/osmodevcon2024-209-high-performance-i-o-using-iouring-via-osmoio