This series adds support for transmitting packets using XDP in bpf_prog_run(), by enabling the xdp_do_redirect() callback so XDP programs can perform "real" redirects to devices or maps, using an opt-in flag when executing the program. The primary use case for this is testing the redirect map types and the ndo_xdp_xmit driver operation without generating external traffic. But it turns out to also be useful for creating a programmable traffic generator. The last patch adds a sample traffic generator to bpf/samples, which can transmit up to 11.5 Mpps/core on my test machine. To transmit the frames, the new mode instantiates a page_pool structure in bpf_prog_run() and initialises the pages with the data passed in by userspace. These pages can then be redirected using the normal redirection mechanism, and the existing page_pool code takes care of returning and recycling them. The setup is optimised for high performance with a high number of repetitions to support stress testing and the traffic generator use case; see patch 6 for details. The series is structured as follows: Patches 1-2 adds a few features to page_pool that are needed for the usage in bpf_prog_run(). Similarly, patches 3-5 performs a couple of preparatory refactorings of the XDP redirect and memory management code. Patch 6 adds the support to bpf_prog_run() itself, patch 7 adds a selftest, and patch 8 adds the traffic generator example to samples/bpf. v2: - Split up up __xdp_do_redirect to avoid passing two pointers to it (John) - Always reset context pointers before each test run (John) - Use get_mac_addr() from xdp_sample_user.h instead of rolling our own (Kumar) - Fix wrong offset for metadata pointer Toke Høiland-Jørgensen (8): page_pool: Add callback to init pages when they are allocated page_pool: Store the XDP mem id xdp: Allow registering memory model without rxq reference xdp: Move conversion to xdp_frame out of map functions xdp: add xdp_do_redirect_frame() for pre-computed xdp_frames bpf: Add XDP_REDIRECT support to XDP for bpf_prog_run() selftests/bpf: Add selftest for XDP_REDIRECT in bpf_prog_run() samples/bpf: Add xdp_trafficgen sample include/linux/bpf.h | 20 +- include/linux/filter.h | 4 + include/net/page_pool.h | 11 +- include/net/xdp.h | 3 + include/uapi/linux/bpf.h | 2 + kernel/bpf/Kconfig | 1 + kernel/bpf/cpumap.c | 8 +- kernel/bpf/devmap.c | 32 +- net/bpf/test_run.c | 218 ++++++++- net/core/filter.c | 73 ++- net/core/page_pool.c | 6 +- net/core/xdp.c | 94 ++-- samples/bpf/.gitignore | 1 + samples/bpf/Makefile | 4 + samples/bpf/xdp_redirect.bpf.c | 34 ++ samples/bpf/xdp_trafficgen_user.c | 421 ++++++++++++++++++ tools/include/uapi/linux/bpf.h | 2 + .../bpf/prog_tests/xdp_do_redirect.c | 74 +++ .../bpf/progs/test_xdp_do_redirect.c | 34 ++ 19 files changed, 948 insertions(+), 94 deletions(-) create mode 100644 samples/bpf/xdp_trafficgen_user.c create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_do_redirect.c -- 2.34.0
