[PATCH bpf-next v2 0/4] Support direct writes to nf_conn:mark

Daniel Xu
2022-08-17T18:43:44Z

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@dxuuu.xyz/

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