This patch set is a follow up on a suggestion from LPC '19 discussions to make SOCKMAP (or a new map type derived from it) a generic type for storing established as well as listening sockets. We found ourselves in need of a map type that keeps references to listening sockets when working on making the socket lookup programmable, aka BPF inet_lookup [1]. Initially we repurposed REUSEPORT_SOCKARRAY but found it problematic to extend due to being tightly coupled with reuseport logic (see slides [2]). So we've turned our attention to SOCKMAP instead. As it turns out the changes needed to make SOCKMAP suitable for storing listening sockets are self-contained and have use outside of programming the socket lookup. Hence this patch set. With these patches SOCKMAP can be used in SK_REUSEPORT BPF programs as a drop-in replacement for REUSEPORT_SOCKARRAY for TCP. This can hopefully lead to code consolidation between the two map types in the future. Having said that, the main intention here is to lay groundwork for using SOCKMAP in the next iteration of programmable socket lookup patches. I'm looking for feedback if there's anything fundamentally wrong with extending SOCKMAP map type like this that I might have missed. Thanks, Jakub [1] https://lore.kernel.org/bpf/20190828072250.29828-1-jakub@xxxxxxxxxxxxxx/ [2] https://linuxplumbersconf.org/event/4/contributions/487/attachments/238/417/Programmable_socket_lookup_LPC_19.pdf Jakub Sitnicki (5): bpf, sockmap: Let BPF helpers use lookup operation on SOCKMAP bpf, sockmap: Allow inserting listening TCP sockets into SOCKMAP bpf, sockmap: Don't let child socket inherit psock or its ops on copy bpf: Allow selecting reuseport socket from a SOCKMAP selftests/bpf: Extend SK_REUSEPORT tests to cover SOCKMAP kernel/bpf/verifier.c | 6 +- net/core/sock_map.c | 11 +- net/ipv4/tcp_bpf.c | 30 ++++ tools/testing/selftests/bpf/Makefile | 7 +- .../selftests/bpf/test_select_reuseport.c | 141 ++++++++++++++---- .../selftests/bpf/test_select_reuseport.sh | 14 ++ 6 files changed, 173 insertions(+), 36 deletions(-) create mode 100755 tools/testing/selftests/bpf/test_select_reuseport.sh -- 2.20.1
