[PATCH bpf-next v3 4/4] selftests/bpf: Test updating flow_dissector link with same program
From: Jakub Sitnicki <jakub@cloudflare.com>
Date: 2020-06-25 14:14:15
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [selftests] (test runners & infrastructure), kernel selftest framework, the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, Shuah Khan, Linus Torvalds
This case, while not particularly useful, is worth covering because we expect the operation to succeed as opposed when re-attaching the same program directly with PROG_ATTACH. While at it, update the tests summary that fell out of sync when tests extended to cover links. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> --- .../bpf/prog_tests/flow_dissector_reattach.c | 32 ++++++++++++++++--- 1 file changed, 28 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/flow_dissector_reattach.c b/tools/testing/selftests/bpf/prog_tests/flow_dissector_reattach.c
index 15cb554a66d8..a2db3b0f84db 100644
--- a/tools/testing/selftests/bpf/prog_tests/flow_dissector_reattach.c
+++ b/tools/testing/selftests/bpf/prog_tests/flow_dissector_reattach.c@@ -1,9 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 /* - * Test that the flow_dissector program can be updated with a single - * syscall by attaching a new program that replaces the existing one. - * - * Corner case - the same program cannot be attached twice. + * Tests for attaching, detaching, and replacing flow_dissector BPF program. */ #define _GNU_SOURCE
@@ -308,6 +305,31 @@ static void test_link_update_replace_old_prog(int netns, int prog1, int prog2) CHECK_FAIL(prog_is_attached(netns)); } +static void test_link_update_same_prog(int netns, int prog1, int prog2) +{ + DECLARE_LIBBPF_OPTS(bpf_link_create_opts, create_opts); + DECLARE_LIBBPF_OPTS(bpf_link_update_opts, update_opts); + int err, link; + + link = bpf_link_create(prog1, netns, BPF_FLOW_DISSECTOR, &create_opts); + if (CHECK_FAIL(link < 0)) { + perror("bpf_link_create(prog1)"); + return; + } + CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1)); + + /* Expect success updating the prog with the same one */ + update_opts.flags = 0; + update_opts.old_prog_fd = 0; + err = bpf_link_update(link, prog1, &update_opts); + if (CHECK_FAIL(err)) + perror("bpf_link_update"); + CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1)); + + close(link); + CHECK_FAIL(prog_is_attached(netns)); +} + static void test_link_update_invalid_opts(int netns, int prog1, int prog2) { DECLARE_LIBBPF_OPTS(bpf_link_create_opts, create_opts);
@@ -571,6 +593,8 @@ static void run_tests(int netns) test_link_update_no_old_prog }, { "link update with replace old prog", test_link_update_replace_old_prog }, + { "link update with same prog", + test_link_update_same_prog }, { "link update invalid opts", test_link_update_invalid_opts }, { "link update invalid prog",
--
2.25.4