Here are some patches for the MPTCP PM, including some refactoring that I thought it would be best to send at the end of a cycle to avoid conflicts between net and net-next that could last a few weeks.
The most interesting changes are in the first and last patch, the rest are patches refactoring the code & tests to validate the modifications.
- Patches 1 & 2: When servers set the C-flag in their MP_CAPABLE to tell clients not to create subflows to the initial address and port -- e.g. a deployment behind a L4 load balancer like a typical CDN deployment -- clients will not use their other endpoints when default settings are used. That's because the in-kernel path-manager uses the 'subflow' endpoints to create subflows only to the initial address and port. The first patch fixes that (for >=v5.14), and the second one validates it.
- Patches 3-14: various patches refactoring the code around the in-kernel PM (mainly): split too long functions, rename variables and functions to avoid confusions, reduce structure size, and compare IDs instead of IP addresses. Note that one patch modifies one internal variable used in one BPF selftest.
- Patch 15: ability to control endpoints that are used in reaction to a new address announced by the other peer. With that, endpoints can be used only once.
Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- Notes: - Patches 1 & 2 are sent to net-next on purpose: to delay a bit the backports, just in case. Plus we are at the end of a cycle, and not to delay the other refactoring patches. - Sorry, I wanted to send this series earlier on, but due to some unrelated issues (and holiday), it got delayed. Most patches are pure refactoring ones.
--- Matthieu Baerts (NGI0) (15): mptcp: pm: in-kernel: usable client side with C-flag selftests: mptcp: join: validate C-flag + def limit mptcp: pm: in-kernel: refactor fill_local_addresses_vec mptcp: pm: in-kernel: refactor fill_remote_addresses_vec mptcp: pm: rename 'subflows' to 'extra_subflows' mptcp: pm: in-kernel: rename 'subflows_max' to 'limit_extra_subflows' mptcp: pm: in-kernel: rename 'add_addr_signal_max' to 'endp_signal_max' mptcp: pm: in-kernel: rename 'add_addr_accept_max' to 'limit_add_addr_accepted' mptcp: pm: in-kernel: rename 'local_addr_max' to 'endp_subflow_max' mptcp: pm: in-kernel: rename 'local_addr_list' to 'endp_list' mptcp: pm: in-kernel: rename 'addrs' to 'endpoints' mptcp: pm: in-kernel: remove stale_loss_cnt mptcp: pm: in-kernel: reduce pernet struct size mptcp: pm: in-kernel: compare IDs instead of addresses mptcp: pm: in-kernel: add laminar endpoints
include/uapi/linux/mptcp.h | 11 +- net/mptcp/pm.c | 32 +- net/mptcp/pm_kernel.c | 569 ++++++++++++++-------- net/mptcp/pm_userspace.c | 2 +- net/mptcp/protocol.h | 21 +- net/mptcp/sockopt.c | 22 +- tools/testing/selftests/bpf/progs/mptcp_subflow.c | 2 +- tools/testing/selftests/net/mptcp/mptcp_join.sh | 11 + 8 files changed, 441 insertions(+), 229 deletions(-) --- base-commit: a1f1f2422e098485b09e55a492de05cf97f9954d change-id: 20250925-net-next-mptcp-c-flag-laminar-f8442e4d4bd9
Best regards,