From fe48230cf2ae27c9e3b96d29908e22e2926fd1ab Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Tue, 21 Jul 2020 23:46:01 -0700 Subject: [PATCH] selftests/bpf: Add BPF XDP link selftests Add selftest validating all the attachment logic around BPF XDP link. Test also link updates and get_obj_info() APIs. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200722064603.3350758-9-andriin@fb.com --- tools/testing/selftests/bpf/prog_tests/xdp_link.c | 137 ++++++++++++++++++++++ tools/testing/selftests/bpf/progs/test_xdp_link.c | 12 ++ 2 files changed, 149 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_link.c create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_link.c diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_link.c b/tools/testing/selftests/bpf/prog_tests/xdp_link.c new file mode 100644 index 0000000..52cba67 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/xdp_link.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ +#include +#include +#include "test_xdp_link.skel.h" + +#define IFINDEX_LO 1 + +void test_xdp_link(void) +{ + __u32 duration = 0, id1, id2, id0 = 0, prog_fd1, prog_fd2, err; + DECLARE_LIBBPF_OPTS(bpf_xdp_set_link_opts, opts, .old_fd = -1); + struct test_xdp_link *skel1 = NULL, *skel2 = NULL; + struct bpf_link_info link_info; + struct bpf_prog_info prog_info; + struct bpf_link *link; + __u32 link_info_len = sizeof(link_info); + __u32 prog_info_len = sizeof(prog_info); + + skel1 = test_xdp_link__open_and_load(); + if (CHECK(!skel1, "skel_load", "skeleton open and load failed\n")) + goto cleanup; + prog_fd1 = bpf_program__fd(skel1->progs.xdp_handler); + + skel2 = test_xdp_link__open_and_load(); + if (CHECK(!skel2, "skel_load", "skeleton open and load failed\n")) + goto cleanup; + prog_fd2 = bpf_program__fd(skel2->progs.xdp_handler); + + memset(&prog_info, 0, sizeof(prog_info)); + err = bpf_obj_get_info_by_fd(prog_fd1, &prog_info, &prog_info_len); + if (CHECK(err, "fd_info1", "failed %d\n", -errno)) + goto cleanup; + id1 = prog_info.id; + + memset(&prog_info, 0, sizeof(prog_info)); + err = bpf_obj_get_info_by_fd(prog_fd2, &prog_info, &prog_info_len); + if (CHECK(err, "fd_info2", "failed %d\n", -errno)) + goto cleanup; + id2 = prog_info.id; + + /* set initial prog attachment */ + err = bpf_set_link_xdp_fd_opts(IFINDEX_LO, prog_fd1, XDP_FLAGS_REPLACE, &opts); + if (CHECK(err, "fd_attach", "initial prog attach failed: %d\n", err)) + goto cleanup; + + /* validate prog ID */ + err = bpf_get_link_xdp_id(IFINDEX_LO, &id0, 0); + CHECK(err || id0 != id1, "id1_check", + "loaded prog id %u != id1 %u, err %d", id0, id1, err); + + /* BPF link is not allowed to replace prog attachment */ + link = bpf_program__attach_xdp(skel1->progs.xdp_handler, IFINDEX_LO); + if (CHECK(!IS_ERR(link), "link_attach_fail", "unexpected success\n")) { + bpf_link__destroy(link); + /* best-effort detach prog */ + opts.old_fd = prog_fd1; + bpf_set_link_xdp_fd_opts(IFINDEX_LO, -1, XDP_FLAGS_REPLACE, &opts); + goto cleanup; + } + + /* detach BPF program */ + opts.old_fd = prog_fd1; + err = bpf_set_link_xdp_fd_opts(IFINDEX_LO, -1, XDP_FLAGS_REPLACE, &opts); + if (CHECK(err, "prog_detach", "failed %d\n", err)) + goto cleanup; + + /* now BPF link should attach successfully */ + link = bpf_program__attach_xdp(skel1->progs.xdp_handler, IFINDEX_LO); + if (CHECK(IS_ERR(link), "link_attach", "failed: %ld\n", PTR_ERR(link))) + goto cleanup; + skel1->links.xdp_handler = link; + + /* validate prog ID */ + err = bpf_get_link_xdp_id(IFINDEX_LO, &id0, 0); + if (CHECK(err || id0 != id1, "id1_check", + "loaded prog id %u != id1 %u, err %d", id0, id1, err)) + goto cleanup; + + /* BPF prog attach is not allowed to replace BPF link */ + opts.old_fd = prog_fd1; + err = bpf_set_link_xdp_fd_opts(IFINDEX_LO, prog_fd2, XDP_FLAGS_REPLACE, &opts); + if (CHECK(!err, "prog_attach_fail", "unexpected success\n")) + goto cleanup; + + /* Can't force-update when BPF link is active */ + err = bpf_set_link_xdp_fd(IFINDEX_LO, prog_fd2, 0); + if (CHECK(!err, "prog_update_fail", "unexpected success\n")) + goto cleanup; + + /* Can't force-detach when BPF link is active */ + err = bpf_set_link_xdp_fd(IFINDEX_LO, -1, 0); + if (CHECK(!err, "prog_detach_fail", "unexpected success\n")) + goto cleanup; + + /* BPF link is not allowed to replace another BPF link */ + link = bpf_program__attach_xdp(skel2->progs.xdp_handler, IFINDEX_LO); + if (CHECK(!IS_ERR(link), "link_attach_fail", "unexpected success\n")) { + bpf_link__destroy(link); + goto cleanup; + } + + bpf_link__destroy(skel1->links.xdp_handler); + skel1->links.xdp_handler = NULL; + + /* new link attach should succeed */ + link = bpf_program__attach_xdp(skel2->progs.xdp_handler, IFINDEX_LO); + if (CHECK(IS_ERR(link), "link_attach", "failed: %ld\n", PTR_ERR(link))) + goto cleanup; + skel2->links.xdp_handler = link; + + err = bpf_get_link_xdp_id(IFINDEX_LO, &id0, 0); + if (CHECK(err || id0 != id2, "id2_check", + "loaded prog id %u != id2 %u, err %d", id0, id1, err)) + goto cleanup; + + /* updating program under active BPF link works as expected */ + err = bpf_link__update_program(link, skel1->progs.xdp_handler); + if (CHECK(err, "link_upd", "failed: %d\n", err)) + goto cleanup; + + memset(&link_info, 0, sizeof(link_info)); + err = bpf_obj_get_info_by_fd(bpf_link__fd(link), &link_info, &link_info_len); + if (CHECK(err, "link_info", "failed: %d\n", err)) + goto cleanup; + + CHECK(link_info.type != BPF_LINK_TYPE_XDP, "link_type", + "got %u != exp %u\n", link_info.type, BPF_LINK_TYPE_XDP); + CHECK(link_info.prog_id != id1, "link_prog_id", + "got %u != exp %u\n", link_info.prog_id, id1); + CHECK(link_info.xdp.ifindex != IFINDEX_LO, "link_ifindex", + "got %u != exp %u\n", link_info.xdp.ifindex, IFINDEX_LO); + +cleanup: + test_xdp_link__destroy(skel1); + test_xdp_link__destroy(skel2); +} diff --git a/tools/testing/selftests/bpf/progs/test_xdp_link.c b/tools/testing/selftests/bpf/progs/test_xdp_link.c new file mode 100644 index 0000000..eb93ea9 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_xdp_link.c @@ -0,0 +1,12 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ +#include +#include + +char LICENSE[] SEC("license") = "GPL"; + +SEC("xdp/handler") +int xdp_handler(struct xdp_md *xdp) +{ + return 0; +} -- 2.7.4