From f32babdc9b1244c5fda72847112300cc0c1d8af0 Mon Sep 17 00:00:00 2001 From: Tushar Vyavahare Date: Fri, 21 Mar 2025 00:54:18 +0000 Subject: [PATCH 1/2] selftests/xsk: Add packet stream replacement function Add pkt_stream_replace_ifobject function to replace the packet stream for a given ifobject. Enable separate TX and RX packet replacement, allowing RX side packet length adjustments using bpf_xdp_adjust_tail() in the upcoming patch. Currently, pkt_stream_replace() works on both TX and RX packet streams, and this new function provides the ability to modify one of them. Signed-off-by: Tushar Vyavahare Reviewed-by: Maciej Fijalkowski --- tools/testing/selftests/bpf/xskxceiver.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/bpf/xskxceiver.c b/tools/testing/selftests/bpf/xskxceiver.c index 11f047b8af752..d60ee6a31c09e 100644 --- a/tools/testing/selftests/bpf/xskxceiver.c +++ b/tools/testing/selftests/bpf/xskxceiver.c @@ -757,14 +757,15 @@ static struct pkt_stream *pkt_stream_clone(struct pkt_stream *pkt_stream) return pkt_stream_generate(pkt_stream->nb_pkts, pkt_stream->pkts[0].len); } -static void pkt_stream_replace(struct test_spec *test, u32 nb_pkts, u32 pkt_len) +static void pkt_stream_replace_ifobject(struct ifobject *ifobj, u32 nb_pkts, u32 pkt_len) { - struct pkt_stream *pkt_stream; + ifobj->xsk->pkt_stream = pkt_stream_generate(nb_pkts, pkt_len); +} - pkt_stream = pkt_stream_generate(nb_pkts, pkt_len); - test->ifobj_tx->xsk->pkt_stream = pkt_stream; - pkt_stream = pkt_stream_generate(nb_pkts, pkt_len); - test->ifobj_rx->xsk->pkt_stream = pkt_stream; +static void pkt_stream_replace(struct test_spec *test, u32 nb_pkts, u32 pkt_len) +{ + pkt_stream_replace_ifobject(test->ifobj_tx, nb_pkts, pkt_len); + pkt_stream_replace_ifobject(test->ifobj_rx, nb_pkts, pkt_len); } static void __pkt_stream_replace_half(struct ifobject *ifobj, u32 pkt_len, From cb54c0671c1370b880c02d82ab2ba1c48ceb74c7 Mon Sep 17 00:00:00 2001 From: Tushar Vyavahare Date: Fri, 21 Mar 2025 00:54:19 +0000 Subject: [PATCH 2/2] selftests/xsk: Add tail adjustment tests and support check Introduce tail adjustment functionality in xskxceiver using bpf_xdp_adjust_tail(). Add `xsk_xdp_adjust_tail` to modify packet sizes and drop unmodified packets. Implement `is_adjust_tail_supported` to check helper availability. Develop packet resizing tests, including shrinking and growing scenarios, with functions for both single-buffer and multi-buffer cases. Update the test framework to handle various scenarios and adjust MTU settings. These changes enhance the testing of packet tail adjustments, improving AF_XDP framework reliability. Signed-off-by: Tushar Vyavahare Reviewed-by: Maciej Fijalkowski --- .../selftests/bpf/progs/xsk_xdp_progs.c | 50 +++++++++ tools/testing/selftests/bpf/xsk_xdp_common.h | 1 + tools/testing/selftests/bpf/xskxceiver.c | 105 +++++++++++++++++- tools/testing/selftests/bpf/xskxceiver.h | 2 + 4 files changed, 156 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/progs/xsk_xdp_progs.c b/tools/testing/selftests/bpf/progs/xsk_xdp_progs.c index ccde6a4c63196..683306db8594e 100644 --- a/tools/testing/selftests/bpf/progs/xsk_xdp_progs.c +++ b/tools/testing/selftests/bpf/progs/xsk_xdp_progs.c @@ -4,6 +4,8 @@ #include #include #include +#include +#include #include "xsk_xdp_common.h" struct { @@ -14,6 +16,7 @@ struct { } xsk SEC(".maps"); static unsigned int idx; +int adjust_value = 0; int count = 0; SEC("xdp.frags") int xsk_def_prog(struct xdp_md *xdp) @@ -70,4 +73,51 @@ SEC("xdp") int xsk_xdp_shared_umem(struct xdp_md *xdp) return bpf_redirect_map(&xsk, idx, XDP_DROP); } +SEC("xdp.frags") int xsk_xdp_adjust_tail(struct xdp_md *xdp) +{ + __u32 buff_len, curr_buff_len; + int ret; + + buff_len = bpf_xdp_get_buff_len(xdp); + if (buff_len == 0) + return XDP_DROP; + + ret = bpf_xdp_adjust_tail(xdp, adjust_value); + if (ret < 0) { + /* Handle unsupported cases */ + if (ret == -EOPNOTSUPP) { + /* Set adjust_value to -EOPNOTSUPP to indicate to userspace that this case + * is unsupported + */ + adjust_value = -EOPNOTSUPP; + return bpf_redirect_map(&xsk, 0, XDP_DROP); + } + + return XDP_DROP; + } + + curr_buff_len = bpf_xdp_get_buff_len(xdp); + if (curr_buff_len != buff_len + adjust_value) + return XDP_DROP; + + if (curr_buff_len > buff_len) { + __u32 *pkt_data = (void *)(long)xdp->data; + __u32 len, words_to_end, seq_num; + + len = curr_buff_len - PKT_HDR_ALIGN; + words_to_end = len / sizeof(*pkt_data) - 1; + seq_num = words_to_end; + + /* Convert sequence number to network byte order. Store this in the last 4 bytes of + * the packet. Use 'adjust_value' to determine the position at the end of the + * packet for storing the sequence number. + */ + seq_num = __constant_htonl(words_to_end); + bpf_xdp_store_bytes(xdp, curr_buff_len - sizeof(seq_num), &seq_num, + sizeof(seq_num)); + } + + return bpf_redirect_map(&xsk, 0, XDP_DROP); +} + char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/xsk_xdp_common.h b/tools/testing/selftests/bpf/xsk_xdp_common.h index 5a6f36f07383c..45810ff552dae 100644 --- a/tools/testing/selftests/bpf/xsk_xdp_common.h +++ b/tools/testing/selftests/bpf/xsk_xdp_common.h @@ -4,6 +4,7 @@ #define XSK_XDP_COMMON_H_ #define MAX_SOCKETS 2 +#define PKT_HDR_ALIGN (sizeof(struct ethhdr) + 2) /* Just to align the data in the packet */ struct xdp_info { __u64 count; diff --git a/tools/testing/selftests/bpf/xskxceiver.c b/tools/testing/selftests/bpf/xskxceiver.c index d60ee6a31c09e..0ced4026ee443 100644 --- a/tools/testing/selftests/bpf/xskxceiver.c +++ b/tools/testing/selftests/bpf/xskxceiver.c @@ -524,6 +524,8 @@ static void __test_spec_init(struct test_spec *test, struct ifobject *ifobj_tx, test->nb_sockets = 1; test->fail = false; test->set_ring = false; + test->adjust_tail = false; + test->adjust_tail_support = false; test->mtu = MAX_ETH_PKT_SIZE; test->xdp_prog_rx = ifobj_rx->xdp_progs->progs.xsk_def_prog; test->xskmap_rx = ifobj_rx->xdp_progs->maps.xsk; @@ -992,6 +994,31 @@ static bool is_metadata_correct(struct pkt *pkt, void *buffer, u64 addr) return true; } +static bool is_adjust_tail_supported(struct xsk_xdp_progs *skel_rx) +{ + struct bpf_map *data_map; + int adjust_value = 0; + int key = 0; + int ret; + + data_map = bpf_object__find_map_by_name(skel_rx->obj, "xsk_xdp_.bss"); + if (!data_map || !bpf_map__is_internal(data_map)) { + ksft_print_msg("Error: could not find bss section of XDP program\n"); + exit_with_error(errno); + } + + ret = bpf_map_lookup_elem(bpf_map__fd(data_map), &key, &adjust_value); + if (ret) { + ksft_print_msg("Error: bpf_map_lookup_elem failed with error %d\n", ret); + exit_with_error(errno); + } + + /* Set the 'adjust_value' variable to -EOPNOTSUPP in the XDP program if the adjust_tail + * helper is not supported. Skip the adjust_tail test case in this scenario. + */ + return adjust_value != -EOPNOTSUPP; +} + static bool is_frag_valid(struct xsk_umem_info *umem, u64 addr, u32 len, u32 expected_pkt_nb, u32 bytes_processed) { @@ -1768,8 +1795,13 @@ static void *worker_testapp_validate_rx(void *arg) if (!err && ifobject->validation_func) err = ifobject->validation_func(ifobject); - if (err) - report_failure(test); + + if (err) { + if (test->adjust_tail && !is_adjust_tail_supported(ifobject->xdp_progs)) + test->adjust_tail_support = false; + else + report_failure(test); + } pthread_exit(NULL); } @@ -2516,6 +2548,71 @@ static int testapp_hw_sw_max_ring_size(struct test_spec *test) return testapp_validate_traffic(test); } +static int testapp_xdp_adjust_tail(struct test_spec *test, int adjust_value) +{ + struct xsk_xdp_progs *skel_rx = test->ifobj_rx->xdp_progs; + struct xsk_xdp_progs *skel_tx = test->ifobj_tx->xdp_progs; + + test_spec_set_xdp_prog(test, skel_rx->progs.xsk_xdp_adjust_tail, + skel_tx->progs.xsk_xdp_adjust_tail, + skel_rx->maps.xsk, skel_tx->maps.xsk); + + skel_rx->bss->adjust_value = adjust_value; + + return testapp_validate_traffic(test); +} + +static int testapp_adjust_tail(struct test_spec *test, u32 value, u32 pkt_len) +{ + int ret; + + test->adjust_tail_support = true; + test->adjust_tail = true; + test->total_steps = 1; + + pkt_stream_replace_ifobject(test->ifobj_tx, DEFAULT_BATCH_SIZE, pkt_len); + pkt_stream_replace_ifobject(test->ifobj_rx, DEFAULT_BATCH_SIZE, pkt_len + value); + + ret = testapp_xdp_adjust_tail(test, value); + if (ret) + return ret; + + if (!test->adjust_tail_support) { + ksft_test_result_skip("%s %sResize pkt with bpf_xdp_adjust_tail() not supported\n", + mode_string(test), busy_poll_string(test)); + return TEST_SKIP; + } + + return 0; +} + +static int testapp_adjust_tail_shrink(struct test_spec *test) +{ + /* Shrink by 4 bytes for testing purpose */ + return testapp_adjust_tail(test, -4, MIN_PKT_SIZE * 2); +} + +static int testapp_adjust_tail_shrink_mb(struct test_spec *test) +{ + test->mtu = MAX_ETH_JUMBO_SIZE; + /* Shrink by the frag size */ + return testapp_adjust_tail(test, -XSK_UMEM__MAX_FRAME_SIZE, XSK_UMEM__LARGE_FRAME_SIZE * 2); +} + +static int testapp_adjust_tail_grow(struct test_spec *test) +{ + /* Grow by 4 bytes for testing purpose */ + return testapp_adjust_tail(test, 4, MIN_PKT_SIZE * 2); +} + +static int testapp_adjust_tail_grow_mb(struct test_spec *test) +{ + test->mtu = MAX_ETH_JUMBO_SIZE; + /* Grow by (frag_size - last_frag_Size) - 1 to stay inside the last fragment */ + return testapp_adjust_tail(test, (XSK_UMEM__MAX_FRAME_SIZE / 2) - 1, + XSK_UMEM__LARGE_FRAME_SIZE * 2); +} + static void run_pkt_test(struct test_spec *test) { int ret; @@ -2622,6 +2719,10 @@ static const struct test_spec tests[] = { {.name = "TOO_MANY_FRAGS", .test_func = testapp_too_many_frags}, {.name = "HW_SW_MIN_RING_SIZE", .test_func = testapp_hw_sw_min_ring_size}, {.name = "HW_SW_MAX_RING_SIZE", .test_func = testapp_hw_sw_max_ring_size}, + {.name = "XDP_ADJUST_TAIL_SHRINK", .test_func = testapp_adjust_tail_shrink}, + {.name = "XDP_ADJUST_TAIL_SHRINK_MULTI_BUFF", .test_func = testapp_adjust_tail_shrink_mb}, + {.name = "XDP_ADJUST_TAIL_GROW", .test_func = testapp_adjust_tail_grow}, + {.name = "XDP_ADJUST_TAIL_GROW_MULTI_BUFF", .test_func = testapp_adjust_tail_grow_mb}, }; static void print_tests(void) diff --git a/tools/testing/selftests/bpf/xskxceiver.h b/tools/testing/selftests/bpf/xskxceiver.h index e46e823f6a1aa..67fc44b2813b2 100644 --- a/tools/testing/selftests/bpf/xskxceiver.h +++ b/tools/testing/selftests/bpf/xskxceiver.h @@ -173,6 +173,8 @@ struct test_spec { u16 nb_sockets; bool fail; bool set_ring; + bool adjust_tail; + bool adjust_tail_support; enum test_mode mode; char name[MAX_TEST_NAME_SIZE]; };