Support direct writes to nf_conn:mark from TC and XDP prog types. This is useful when applications want to store per-connection metadata. This is also particularly useful for applications that run both bpf and iptables/nftables because the latter can trivially access this metadata. One example use case would be if a bpf prog is responsible for advanced packet classification and iptables/nftables is later used for routing due to pre-existing/legacy code. Past discussion: - v1: https://lore.kernel.org/bpf/cover.1660592020.git.dxu@xxxxxxxxx/ Changes since v1: - Add unimplemented stub for when !CONFIG_BPF_SYSCALL Daniel Xu (4): bpf: Remove duplicate PTR_TO_BTF_ID RO check bpf: Add stub for btf_struct_access() bpf: Add support for writing to nf_conn:mark selftests/bpf: Add tests for writing to nf_conn:mark include/linux/bpf.h | 9 ++++ include/net/netfilter/nf_conntrack_bpf.h | 18 +++++++ kernel/bpf/verifier.c | 3 -- net/core/filter.c | 34 +++++++++++++ net/netfilter/nf_conntrack_bpf.c | 50 +++++++++++++++++++ .../testing/selftests/bpf/prog_tests/bpf_nf.c | 1 + .../testing/selftests/bpf/progs/test_bpf_nf.c | 6 ++- .../selftests/bpf/progs/test_bpf_nf_fail.c | 14 ++++++ 8 files changed, 130 insertions(+), 5 deletions(-) -- 2.37.1
