Date:   Sun, 24 May 2020 09:50:12 -0700
From:   John Fastabend <john.fastabend@...il.com>
To:     yhs@...com, andrii.nakryiko@...il.com, ast@...nel.org,
        daniel@...earbox.net
Cc:     netdev@...r.kernel.org, bpf@...r.kernel.org,
        john.fastabend@...il.com
Subject: [bpf-next PATCH v5 0/5] bpf: Add sk_msg and networking helpers

This series adds helpers for sk_msg program type and based on feedback
from v1 adds *_task_* helpers and probe_* helpers to all networking
programs with perfmon_capable() capabilities.

The list of helpers breaks down as follows,

Networking with perfmon_capable() guard (patch2):

 BPF_FUNC_get_current_task
 BPF_FUNC_probe_read_user
 BPF_FUNC_probe_read_kernel
 BPF_FUNC_probe_read_user_str
 BPF_FUNC_probe_read_kernel_str

Added to sk_msg program types (patch1,3):

 BPF_FUNC_perf_event_output
 BPF_FUNC_get_current_uid_gid
 BPF_FUNC_get_current_pid_tgid
 BPF_FUNC_get_current_cgroup_id
 BPF_FUNC_get_current_ancestor_cgroup_id
 BPF_FUNC_get_cgroup_classid

 BPF_FUNC_sk_storage_get
 BPF_FUNC_sk_storage_delete

For testing we create two tests. One specifically for the sk_msg
program types which encodes a common pattern we use to test verifier
logic now and as the verifier evolves.

Next we have skb classifier test. This uses the test run infra to
run a test which uses the get_current_task, current_task_under_cgroup,
probe_read_kernel, and probe_reak_kernel_str.

Note we dropped the old probe_read variants probe_read() and
probe_read_str() in v2.

v4->v5:
 Remove BPF_FUNC_current_task_under_cgroup because it requires a
 valid current and at least at the moment seems less usable in all
 contexts. It also probably doesn't need to be guarded by perfoman_cap.
 We can add it on a per type basis when its needed or decide later
 after some more experience that its universally useful.

v3->v4:
 patch4, remove macros and put code inline, add test cleanup, remove
 version in bpf program.
 patch5, use ctask returned from task_under_cgroup so that we avoid
 any potential compiler warnings, add test cleanup, use BTF style
 maps.

v2->v3:
 Pulled header update of tools sk_msg_md{} structure into patch3 for
 easier review. ACKs from Yonghong pushed into v3

v1->v2:
 Pulled generic helpers *current_task* and probe_* into the
 base func helper so they can be used more widely in networking scope.
 BPF capabilities patch is now in bpf-next so use perfmon_capable() check
 instead of CAP_SYS_ADMIN.

 Drop old probe helpers, probe_read() and probe_read_str()

 Added tests.

 Thanks to Daniel, Yonghong, and Andrii for review and feedback.

---

John Fastabend (5):
      bpf, sk_msg: add some generic helpers that may be useful from sk_msg
      bpf: extend bpf_base_func_proto helpers with probe_* and *current_task*
      bpf, sk_msg: add get socket storage helpers
      bpf, selftests: add sk_msg helpers load and attach test
      bpf, selftests: test probe_* helpers from SCHED_CLS


 include/uapi/linux/bpf.h                           |    2 +
 kernel/bpf/helpers.c                               |   24 ++++++++++
 kernel/trace/bpf_trace.c                           |   10 ++--
 net/core/filter.c                                  |   31 +++++++++++++
 tools/include/uapi/linux/bpf.h                     |    2 +
 .../testing/selftests/bpf/prog_tests/skb_helpers.c |   30 +++++++++++++
 .../selftests/bpf/prog_tests/sockmap_basic.c       |   35 +++++++++++++++
 .../testing/selftests/bpf/progs/test_skb_helpers.c |   28 ++++++++++++
 .../selftests/bpf/progs/test_skmsg_load_helpers.c  |   47 ++++++++++++++++++++
 9 files changed, 204 insertions(+), 5 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/skb_helpers.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_skb_helpers.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_skmsg_load_helpers.c

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