[bpf-next,v7,0/4] bpf: support input xdp_md context in BPF_PROG_TEST_RUN

Message

Zvi Effron June 24, 2021, 9:13 p.m. UTC

This patchset adds support for passing an xdp_md via ctx_in/ctx_out in
bpf_attr for BPF_PROG_TEST_RUN of XDP programs.

Patch 1 adds a function to validate XDP meta data lengths.

Patch 2 adds initial support for passing XDP meta data in addition to
packet data.

Patch 3 adds support for also specifying the ingress interface and
rx queue.

Patch 4 adds selftests to ensure functionality is correct.

Changelog:
----------
v6->v7
v6: https://lore.kernel.org/bpf/[e-mail]/

 * Add Yonghong Song's Acked-by to commit message in patch 1
 * Add Yonghong Song's Acked-by to commit message in patch 2
 * Extracted the post-update of the xdp_md context into a function (again)
 * Validate that the rx queue was registered with XDP info
 * Decrement the reference count on a found netdevice on failure to find
  a valid rx queue
 * Decrement the reference count on a found netdevice after the XDP
  program is run
 * Drop Yonghong Song's Acked-By for patch 3 because of patch changes
 * Improve a comment in the selftests
 * Drop Yonghong Song's Acked-By for patch 4 because of patch changes

v5->v6
v5: https://lore.kernel.org/bpf/[e-mail]/

 * Correct commit messages in patches 1 and 3
 * Add Acked-by to commit message in patch 4
 * Use gotos instead of returns to correctly free resources in
  bpf_prog_test_run_xdp
 * Rename xdp_metalen_valid to xdp_metalen_invalid
 * Improve the function signature for xdp_metalen_invalid
 * Merged declaration of ingress_ifindex and rx_queue_index into one line

v4->v5
v4: https://lore.kernel.org/bpf/[e-mail]/

 * Add new patch to introduce xdp_metalen_valid inline function to avoid
  duplicated code from net/core/filter.c
 * Correct size of bad_ctx in selftests
 * Make all declarations reverse Christmas tree
 * Move data check from xdp_convert_md_to_buff to bpf_prog_test_run_xdp
 * Merge xdp_convert_buff_to_md into bpf_prog_test_run_xdp
 * Fix line too long
 * Extracted common checks in selftests to a helper function
 * Removed redundant assignment in selftests
 * Reordered test cases in selftests
 * Check data against 0 instead of data_meta in selftests
 * Made selftests use EINVAL instead of hardcoded 22
 * Dropped "_" from XDP function name
 * Changed casts in XDP program from unsigned long to long
 * Added a comment explaining the use of the loopback interface in selftests
 * Change parameter order in xdp_convert_md_to_buff to be input first
 * Assigned xdp->ingress_ifindex and xdp->rx_queue_index to local variables in
  xdp_convert_md_to_buff
 * Made use of "meta data" versus "metadata" consistent in comments and commit
  messages

v3->v4
v3: https://lore.kernel.org/bpf/[e-mail]/

 * Clean up nits
 * Validate xdp_md->data_end in bpf_prog_test_run_xdp
 * Remove intermediate metalen variables

v2 -> v3
v2: https://lore.kernel.org/bpf/[e-mail]/

 * Check errno first in selftests
 * Use DECLARE_LIBBPF_OPTS
 * Rename tattr to opts in selftests
 * Remove extra new line
 * Rename convert_xdpmd_to_xdpb to xdp_convert_md_to_buff
 * Rename convert_xdpb_to_xdpmd to xdp_convert_buff_to_md
 * Move declaration of device and rxqueue in xdp_convert_md_to_buff to
  patch 2
 * Reorder the kfree calls in bpf_prog_test_run_xdp

v1 -> v2
v1: https://lore.kernel.org/bpf/[e-mail]

 * Fix null pointer dereference with no context
 * Use the BPF skeleton and replace CHECK with ASSERT macros

Zvi Effron (4):
  bpf: add function for XDP meta data length check
  bpf: support input xdp_md context in BPF_PROG_TEST_RUN
  bpf: support specifying ingress via xdp_md context in
    BPF_PROG_TEST_RUN
  selftests/bpf: Add test for xdp_md context in BPF_PROG_TEST_RUN

 include/net/xdp.h                             |   5 +
 include/uapi/linux/bpf.h                      |   3 -
 net/bpf/test_run.c                            | 107 ++++++++++++++++--
 net/core/filter.c                             |   4 +-
 .../bpf/prog_tests/xdp_context_test_run.c     | 105 +++++++++++++++++
 .../bpf/progs/test_xdp_context_test_run.c     |  20 ++++
 6 files changed, 231 insertions(+), 13 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_context_test_run.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_context_test_run.c


base-commit: ee62a5c6bb100b6fb07f3da3818c10a24d440e10