[v3,bpf-next,0/3] cgroup/connect{4,6} programs for unprivileged ICMP ping

Message

YiFei Zhu Sept. 8, 2022, 11:16 p.m. UTC

Usually when a TCP/UDP connection is initiated, we can bind the socket
to a specific IP attached to an interface in a cgroup/connect hook.
But for pings, this is impossible, as the hook is not being called.

This series adds the invocation for cgroup/connect{4,6} programs to
unprivileged ICMP ping (i.e. ping sockets created with SOCK_DGRAM
IPPROTO_ICMP(V6) as opposed to SOCK_RAW). This also adds a test to
verify that the hooks are being called and invoking bpf_bind() from
within the hook actually binds the socket.

Patch 1 adds the invocation of the hook.
Patch 2 deduplicates write_sysctl in BPF test_progs.
Patch 3 adds the tests for this hook.

v1 -> v2:
* Added static to bindaddr_v6 in prog_tests/connect_ping.c
* Deduplicated much of the test logic in prog_tests/connect_ping.c
* Deduplicated write_sysctl() to test_progs.c

v2 -> v3:
* Renamed variable "obj" to "skel" for the BPF skeleton object in
  prog_tests/connect_ping.c

YiFei Zhu (3):
  bpf: Invoke cgroup/connect{4,6} programs for unprivileged ICMP ping
  selftests/bpf: Deduplicate write_sysctl() to test_progs.c
  selftests/bpf: Ensure cgroup/connect{4,6} programs can bind unpriv
    ICMP ping

 net/ipv4/ping.c                               |  15 ++
 net/ipv6/ping.c                               |  16 ++
 .../bpf/prog_tests/btf_skc_cls_ingress.c      |  20 --
 .../selftests/bpf/prog_tests/connect_ping.c   | 177 ++++++++++++++++++
 .../bpf/prog_tests/tcp_hdr_options.c          |  20 --
 .../selftests/bpf/progs/connect_ping.c        |  53 ++++++
 tools/testing/selftests/bpf/test_progs.c      |  17 ++
 tools/testing/selftests/bpf/test_progs.h      |   1 +
 8 files changed, 279 insertions(+), 40 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/connect_ping.c
 create mode 100644 tools/testing/selftests/bpf/progs/connect_ping.c