[bpf-next,00/10] New BPF helpers to accelerate synproxy

Message

Maxim Mikityanskiy Oct. 19, 2021, 2:46 p.m. UTC

This series starts with some cleanup and bugfixing in the existing BPF
helpers for SYN cookies. The second half adds new functionality that
allows XDP to accelerate iptables synproxy.

struct nf_conn is exposed to BPF, new helpers are added to query
conntrack info by 5-tuple. The only field exposed for now is status, but
it can be extended easily in the future.

New helpers are added to issue SYN and timestamp cookies and to check
SYN cookies without binding to a socket, which is useful in the synproxy
scenario.

Finally, a sample XDP and userspace program is added that show how all
components work together. The XDP program uses socketless SYN cookie
helpers and queries conntrack status instead of socket status. A demo
script shows how to deploy the synproxy+XDP solution.

The draft of the new functionality was presented on Netdev 0x15:

https://netdevconf.info/0x15/session.html?Accelerating-synproxy-with-XDP

Maxim Mikityanskiy (10):
  bpf: Use ipv6_only_sock in bpf_tcp_gen_syncookie
  bpf: Support dual-stack sockets in bpf_tcp_check_syncookie
  bpf: Use EOPNOTSUPP in bpf_tcp_check_syncookie
  bpf: Make errors of bpf_tcp_check_syncookie distinguishable
  bpf: Fix documentation of th_len in bpf_tcp_{gen,check}_syncookie
  bpf: Expose struct nf_conn to BPF
  bpf: Add helpers to query conntrack info
  bpf: Add helpers to issue and check SYN cookies in XDP
  bpf: Add a helper to issue timestamp cookies in XDP
  bpf: Add sample for raw syncookie helpers

 include/linux/bpf.h            |  46 +++
 include/net/tcp.h              |   2 +
 include/uapi/linux/bpf.h       | 193 ++++++++++-
 kernel/bpf/verifier.c          | 104 +++++-
 net/core/filter.c              | 433 +++++++++++++++++++++++-
 net/ipv4/syncookies.c          |  60 ++++
 net/ipv4/tcp_input.c           |   3 +-
 samples/bpf/.gitignore         |   1 +
 samples/bpf/Makefile           |   3 +
 samples/bpf/syncookie_kern.c   | 591 +++++++++++++++++++++++++++++++++
 samples/bpf/syncookie_test.sh  |  55 +++
 samples/bpf/syncookie_user.c   | 388 ++++++++++++++++++++++
 scripts/bpf_doc.py             |   1 +
 tools/include/uapi/linux/bpf.h | 193 ++++++++++-
 14 files changed, 2047 insertions(+), 26 deletions(-)
 create mode 100644 samples/bpf/syncookie_kern.c
 create mode 100755 samples/bpf/syncookie_test.sh
 create mode 100644 samples/bpf/syncookie_user.c