The libconntrack-cm library implements connection tracking for the RDMA CM protocol.
Initialize the connection tracking data structures by calling ctcm_create
(and cleanup with ctcm_destroy).
Pass packets to the library using
int ctcm_process_packet(
struct ctcm_context *ctcm,
enum ctcm_direction dir,
struct rte_mbuf* packet);
Passing a pre-parsed packet whose metadata points to the packet L3 header as well as the MAD header.
If needed, one may use ctcm_parse_packet to parse the BTH / MAD headers
and filter the CM packets.
You can then query the data structure to find the source QP number of a given
flow by calling ctcm_query_ipv4.
The library provide two helper functions for RoCE v2 Congestion Notification Packet (CNP) generation.
The ctcm_fill_cnp_template function fills a buffer with a template of a CNP
that can be copied and reused for different destinations and flows, and the
ctcm_generate_cnp function fills out destination QP number and calculates
the ICRC. An application using this API should use ctcm_fill_cnp_template,
then fill out the remainder fields (IPv4 source/destination IP), and call
ctcm_generate_cnp to fill out the remaining fields. The code does not fill out
IP checksum, as this can be done using common NIC offloads.
The library is written in C++17. It uses meson to build, and relies on DPDK
and Boost for its implementation. Unit tests are written with gtest.
Use the following commands to build:
meson build
ninja -C build
On BlueField-2, set PKG_CONFIG_PATH to allow meson to find dpdk:
PKG_CONFIG_PATH=/opt/mellanox/dpdk/lib/aarch64-linux-gnu/pkgconfig meson build
ninjc -C build
For system-wide installation:
ninja -C build install
Original code is licensed under BSD-2-Clause, but some header files needed for parsing RoCE packets were taken from the Linux kernel and are licensed GPL-2.0/GPL-2.0-only or Linux-OpenIB.