We want to replace iptables TPROXY with a BPF program at TC ingress. To make this work in all cases we need to assign a SO_REUSEPORT socket to an skb, which is currently prohibited. This series adds support for such sockets to bpf_sk_assing. I did some refactoring to cut down on the amount of duplicate code. The key to this is to use INDIRECT_CALL in the reuseport helpers. To show that this approach is not just beneficial to TC sk_assign I removed duplicate code for bpf_sk_lookup as well. Joint work with Daniel Borkmann. Signed-off-by: Lorenz Bauer <lmb@xxxxxxxxxxxxx> --- Changes in v4: - WARN_ON_ONCE if reuseport socket is refcounted (Kuniyuki) - Use inet[6]_ehashfn_t to shorten function declarations (Kuniyuki) - Shuffle documentation patch around (Kuniyuki) - Update commit message to explain why IPv6 needs EXPORT_SYMBOL - Link to v3: https://lore.kernel.org/r/20230613-so-reuseport-v3-0-907b4cbb7b99@xxxxxxxxxxxxx Changes in v3: - Fix warning re udp_ehashfn and udp6_ehashfn (Simon) - Return higher scoring connected UDP reuseport sockets (Kuniyuki) - Fix ipv6 module builds - Link to v2: https://lore.kernel.org/r/20230613-so-reuseport-v2-0-b7c69a342613@xxxxxxxxxxxxx Changes in v2: - Correct commit abbrev length (Kuniyuki) - Reduce duplication (Kuniyuki) - Add checks on sk_state (Martin) - Split exporting inet[6]_lookup_reuseport into separate patch (Eric) --- Daniel Borkmann (1): selftests/bpf: Test that SO_REUSEPORT can be used with sk_assign helper Lorenz Bauer (6): udp: re-score reuseport groups when connected sockets are present net: export inet_lookup_reuseport and inet6_lookup_reuseport net: remove duplicate reuseport_lookup functions net: document inet[6]_lookup_reuseport sk_state requirements net: remove duplicate sk_lookup helpers bpf, net: Support SO_REUSEPORT sockets with bpf_sk_assign include/net/inet6_hashtables.h | 81 ++++++++- include/net/inet_hashtables.h | 74 +++++++- include/net/sock.h | 7 +- include/uapi/linux/bpf.h | 3 - net/core/filter.c | 2 - net/ipv4/inet_hashtables.c | 67 ++++--- net/ipv4/udp.c | 88 ++++----- net/ipv6/inet6_hashtables.c | 70 +++++--- net/ipv6/udp.c | 98 ++++------ tools/include/uapi/linux/bpf.h | 3 - tools/testing/selftests/bpf/network_helpers.c | 3 + .../selftests/bpf/prog_tests/assign_reuse.c | 197 +++++++++++++++++++++ .../selftests/bpf/progs/test_assign_reuse.c | 142 +++++++++++++++ 13 files changed, 656 insertions(+), 179 deletions(-) --- base-commit: 970308a7b544fa1c7ee98a2721faba3765be8dd8 change-id: 20230613-so-reuseport-e92c526173ee Best regards, -- Lorenz Bauer <lmb@xxxxxxxxxxxxx>
