Previously it was not possible to make a distinction between plain TCP sockets and MPTCP subflow sockets on the BPF_PROG_TYPE_SOCK_OPS hook. This patch series now enables a fine control of subflow sockets. In its current state, it allows to put different sockopt on each subflow from a same MPTCP connection (socket mark, TCP congestion algorithm, ...) using BPF programs. It should also be the basis of exposing MPTCP-specific fields through BPF. Nicolas Rybowski (3): bpf: expose is_mptcp flag to bpf_tcp_sock mptcp: attach subflow socket to parent cgroup bpf: add 'bpf_mptcp_sock' structure and helper include/linux/bpf.h | 33 ++++++++++++++++ include/uapi/linux/bpf.h | 14 +++++++ kernel/bpf/verifier.c | 30 ++++++++++++++ net/core/filter.c | 13 +++++- net/mptcp/Makefile | 2 + net/mptcp/bpf.c | 72 ++++++++++++++++++++++++++++++++++ net/mptcp/subflow.c | 27 +++++++++++++ scripts/bpf_helpers_doc.py | 2 + tools/include/uapi/linux/bpf.h | 14 +++++++ 9 files changed, 206 insertions(+), 1 deletion(-) create mode 100644 net/mptcp/bpf.c -- 2.28.0
