mbox series

[v4,bpf-next,0/5] bpf-nex: Add socket destroy capability

Message ID 20230323200633.3175753-1-aditi.ghag@isovalent.com (mailing list archive)
Headers show
Series bpf-nex: Add socket destroy capability | expand

Message

Aditi Ghag March 23, 2023, 8:06 p.m. UTC 
This patch adds the capability to destroy sockets in BPF. We plan to use
the capability in Cilium to force client sockets to reconnect when their
remote load-balancing backends are deleted. The other use case is
on-the-fly policy enforcement where existing socket connections prevented
by policies need to be terminated.

The use cases, and more details around
the selected approach was presented at LPC 2022 -
https://lpc.events/event/16/contributions/1358/.
RFC discussion -
https://lore.kernel.org/netdev/CABG=zsBEh-P4NXk23eBJw7eajB5YJeRS7oPXnTAzs=yob4EMoQ@mail.gmail.com/T/#u.
v2 patch series -
https://lore.kernel.org/bpf/20230223215311.926899-1-aditi.ghag@isovalent.com/T/#t

v4 highlights:
- Updated locking in BPF TCP iterator.
- Adapted *-server selftests similar to the client selftests per the
  discussions.
- Addressed Stan's comment to revert skipping spin locks in tcp_abort.
- Dropped the fix to unhash UDP sockets during abort.
- Moved the iterator resume related changes to the right commit. 

(Below notes are same as last patch series.)
- I hit a snag while writing the kfunc where verifier complained about the
  `sock_common` type passed from TCP iterator. With kfuncs, there don't
  seem to be any options available to pass BTF type hints to the verifier
  (equivalent of `ARG_PTR_TO_BTF_ID_SOCK_COMMON`, as was the case with the
  helper).  As a result, I changed the argument type of the sock_destory
  kfunc to `sock_common`.


Aditi Ghag (4):
  bpf: Implement batching in UDP iterator
  bpf: Add bpf_sock_destroy kfunc
  bpf,tcp: Avoid taking fast sock lock in iterator
  selftests/bpf: Add tests for bpf_sock_destroy

 include/net/udp.h                             |   1 +
 net/core/filter.c                             |  54 ++++
 net/ipv4/tcp.c                                |  10 +-
 net/ipv4/tcp_ipv4.c                           |   5 +-
 net/ipv4/udp.c                                | 261 +++++++++++++++++-
 .../selftests/bpf/prog_tests/sock_destroy.c   | 195 +++++++++++++
 .../selftests/bpf/progs/sock_destroy_prog.c   | 151 ++++++++++
 7 files changed, 660 insertions(+), 17 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/sock_destroy.c
 create mode 100644 tools/testing/selftests/bpf/progs/sock_destroy_prog.c