From d39aec79e5923bf984df991ffe51d4a2b7a9e746 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Fri, 29 May 2020 16:07:16 -0600 Subject: selftest: Add tests for XDP programs in devmap entries MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add tests to verify ability to add an XDP program to a entry in a DEVMAP. Add negative tests to show DEVMAP programs can not be attached to devices as a normal XDP program, and accesses to egress_ifindex require BPF_XDP_DEVMAP attach type. Signed-off-by: David Ahern Signed-off-by: Alexei Starovoitov Acked-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/bpf/20200529220716.75383-6-dsahern@kernel.org Signed-off-by: Alexei Starovoitov --- .../selftests/bpf/prog_tests/xdp_devmap_attach.c | 97 ++++++++++++++++++++++ .../selftests/bpf/progs/test_xdp_devmap_helpers.c | 22 +++++ .../bpf/progs/test_xdp_with_devmap_helpers.c | 44 ++++++++++ 3 files changed, 163 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_with_devmap_helpers.c (limited to 'tools') diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c b/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c new file mode 100644 index 000000000000..d19dbd668f6a --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c @@ -0,0 +1,97 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include + +#include "test_xdp_devmap_helpers.skel.h" +#include "test_xdp_with_devmap_helpers.skel.h" + +#define IFINDEX_LO 1 + +struct bpf_devmap_val { + u32 ifindex; /* device index */ + union { + int fd; /* prog fd on map write */ + u32 id; /* prog id on map read */ + } bpf_prog; +}; + +void test_xdp_with_devmap_helpers(void) +{ + struct test_xdp_with_devmap_helpers *skel; + struct bpf_prog_info info = {}; + struct bpf_devmap_val val = { + .ifindex = IFINDEX_LO, + }; + __u32 len = sizeof(info); + __u32 duration = 0, idx = 0; + int err, dm_fd, map_fd; + + + skel = test_xdp_with_devmap_helpers__open_and_load(); + if (CHECK_FAIL(!skel)) { + perror("test_xdp_with_devmap_helpers__open_and_load"); + return; + } + + /* can not attach program with DEVMAPs that allow programs + * as xdp generic + */ + dm_fd = bpf_program__fd(skel->progs.xdp_redir_prog); + err = bpf_set_link_xdp_fd(IFINDEX_LO, dm_fd, XDP_FLAGS_SKB_MODE); + CHECK(err == 0, "Generic attach of program with 8-byte devmap", + "should have failed\n"); + + dm_fd = bpf_program__fd(skel->progs.xdp_dummy_dm); + map_fd = bpf_map__fd(skel->maps.dm_ports); + err = bpf_obj_get_info_by_fd(dm_fd, &info, &len); + if (CHECK_FAIL(err)) + goto out_close; + + val.bpf_prog.fd = dm_fd; + err = bpf_map_update_elem(map_fd, &idx, &val, 0); + CHECK(err, "Add program to devmap entry", + "err %d errno %d\n", err, errno); + + err = bpf_map_lookup_elem(map_fd, &idx, &val); + CHECK(err, "Read devmap entry", "err %d errno %d\n", err, errno); + CHECK(info.id != val.bpf_prog.id, "Expected program id in devmap entry", + "expected %u read %u\n", info.id, val.bpf_prog.id); + + /* can not attach BPF_XDP_DEVMAP program to a device */ + err = bpf_set_link_xdp_fd(IFINDEX_LO, dm_fd, XDP_FLAGS_SKB_MODE); + CHECK(err == 0, "Attach of BPF_XDP_DEVMAP program", + "should have failed\n"); + + val.ifindex = 1; + val.bpf_prog.fd = bpf_program__fd(skel->progs.xdp_dummy_prog); + err = bpf_map_update_elem(map_fd, &idx, &val, 0); + CHECK(err == 0, "Add non-BPF_XDP_DEVMAP program to devmap entry", + "should have failed\n"); + +out_close: + test_xdp_with_devmap_helpers__destroy(skel); +} + +void test_neg_xdp_devmap_helpers(void) +{ + struct test_xdp_devmap_helpers *skel; + __u32 duration = 0; + + skel = test_xdp_devmap_helpers__open_and_load(); + if (CHECK(skel, + "Load of XDP program accessing egress ifindex without attach type", + "should have failed\n")) { + test_xdp_devmap_helpers__destroy(skel); + } +} + + +void test_xdp_devmap_attach(void) +{ + if (test__start_subtest("DEVMAP with programs in entries")) + test_xdp_with_devmap_helpers(); + + if (test__start_subtest("Verifier check of DEVMAP programs")) + test_neg_xdp_devmap_helpers(); +} diff --git a/tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c b/tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c new file mode 100644 index 000000000000..e5c0f131c8a7 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c @@ -0,0 +1,22 @@ +// SPDX-License-Identifier: GPL-2.0 +/* fails to load without expected_attach_type = BPF_XDP_DEVMAP + * because of access to egress_ifindex + */ +#include "vmlinux.h" +#include + +SEC("xdp_dm_log") +int xdpdm_devlog(struct xdp_md *ctx) +{ + char fmt[] = "devmap redirect: dev %u -> dev %u len %u\n"; + void *data_end = (void *)(long)ctx->data_end; + void *data = (void *)(long)ctx->data; + unsigned int len = data_end - data; + + bpf_trace_printk(fmt, sizeof(fmt), + ctx->ingress_ifindex, ctx->egress_ifindex, len); + + return XDP_PASS; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_helpers.c b/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_helpers.c new file mode 100644 index 000000000000..deef0e050863 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_helpers.c @@ -0,0 +1,44 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "vmlinux.h" +#include + +struct { + __uint(type, BPF_MAP_TYPE_DEVMAP); + __uint(key_size, sizeof(__u32)); + __uint(value_size, sizeof(struct bpf_devmap_val)); + __uint(max_entries, 4); +} dm_ports SEC(".maps"); + +SEC("xdp_redir") +int xdp_redir_prog(struct xdp_md *ctx) +{ + return bpf_redirect_map(&dm_ports, 1, 0); +} + +/* invalid program on DEVMAP entry; + * SEC name means expected attach type not set + */ +SEC("xdp_dummy") +int xdp_dummy_prog(struct xdp_md *ctx) +{ + return XDP_PASS; +} + +/* valid program on DEVMAP entry via SEC name; + * has access to egress and ingress ifindex + */ +SEC("xdp_devmap") +int xdp_dummy_dm(struct xdp_md *ctx) +{ + char fmt[] = "devmap redirect: dev %u -> dev %u len %u\n"; + void *data_end = (void *)(long)ctx->data_end; + void *data = (void *)(long)ctx->data; + unsigned int len = data_end - data; + + bpf_trace_printk(fmt, sizeof(fmt), + ctx->ingress_ifindex, ctx->egress_ifindex, len); + + return XDP_PASS; +} +char _license[] SEC("license") = "GPL"; -- cgit v1.2.3