diff options
author | Jakub Sitnicki <jakub@cloudflare.com> | 2019-10-11 10:29:46 +0200 |
---|---|---|
committer | Daniel Borkmann <daniel@iogearbox.net> | 2019-10-11 22:26:22 +0200 |
commit | f97eea1756f383fefc147f4c76c54942944a3d95 (patch) | |
tree | b8d6bb6b3df7a6623482e5ac13e5456085de4ded /tools/testing | |
parent | 719b78a5674f15fef2e4a56484614657fd759978 (diff) | |
download | linux-f97eea1756f383fefc147f4c76c54942944a3d95.tar.bz2 |
selftests/bpf: Check that flow dissector can be re-attached
Make sure a new flow dissector program can be attached to replace the old
one with a single syscall. Also check that attaching the same program twice
is prohibited.
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191011082946.22695-3-jakub@cloudflare.com
Diffstat (limited to 'tools/testing')
-rw-r--r-- | tools/testing/selftests/bpf/prog_tests/flow_dissector_reattach.c | 127 |
1 files changed, 127 insertions, 0 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 new file mode 100644 index 000000000000..777faffc4639 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/flow_dissector_reattach.c @@ -0,0 +1,127 @@ +// 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. + */ + +#define _GNU_SOURCE +#include <errno.h> +#include <fcntl.h> +#include <sched.h> +#include <stdbool.h> +#include <unistd.h> + +#include <linux/bpf.h> +#include <bpf/bpf.h> + +#include "test_progs.h" + +static bool is_attached(int netns) +{ + __u32 cnt; + int err; + + err = bpf_prog_query(netns, BPF_FLOW_DISSECTOR, 0, NULL, NULL, &cnt); + if (CHECK_FAIL(err)) { + perror("bpf_prog_query"); + return true; /* fail-safe */ + } + + return cnt > 0; +} + +static int load_prog(void) +{ + struct bpf_insn prog[] = { + BPF_MOV64_IMM(BPF_REG_0, BPF_OK), + BPF_EXIT_INSN(), + }; + int fd; + + fd = bpf_load_program(BPF_PROG_TYPE_FLOW_DISSECTOR, prog, + ARRAY_SIZE(prog), "GPL", 0, NULL, 0); + if (CHECK_FAIL(fd < 0)) + perror("bpf_load_program"); + + return fd; +} + +static void do_flow_dissector_reattach(void) +{ + int prog_fd[2] = { -1, -1 }; + int err; + + prog_fd[0] = load_prog(); + if (prog_fd[0] < 0) + return; + + prog_fd[1] = load_prog(); + if (prog_fd[1] < 0) + goto out_close; + + err = bpf_prog_attach(prog_fd[0], 0, BPF_FLOW_DISSECTOR, 0); + if (CHECK_FAIL(err)) { + perror("bpf_prog_attach-0"); + goto out_close; + } + + /* Expect success when attaching a different program */ + err = bpf_prog_attach(prog_fd[1], 0, BPF_FLOW_DISSECTOR, 0); + if (CHECK_FAIL(err)) { + perror("bpf_prog_attach-1"); + goto out_detach; + } + + /* Expect failure when attaching the same program twice */ + err = bpf_prog_attach(prog_fd[1], 0, BPF_FLOW_DISSECTOR, 0); + if (CHECK_FAIL(!err || errno != EINVAL)) + perror("bpf_prog_attach-2"); + +out_detach: + err = bpf_prog_detach(0, BPF_FLOW_DISSECTOR); + if (CHECK_FAIL(err)) + perror("bpf_prog_detach"); + +out_close: + close(prog_fd[1]); + close(prog_fd[0]); +} + +void test_flow_dissector_reattach(void) +{ + int init_net, err; + + init_net = open("/proc/1/ns/net", O_RDONLY); + if (CHECK_FAIL(init_net < 0)) { + perror("open(/proc/1/ns/net)"); + return; + } + + err = setns(init_net, CLONE_NEWNET); + if (CHECK_FAIL(err)) { + perror("setns(/proc/1/ns/net)"); + goto out_close; + } + + if (is_attached(init_net)) { + test__skip(); + printf("Can't test with flow dissector attached to init_net\n"); + return; + } + + /* First run tests in root network namespace */ + do_flow_dissector_reattach(); + + /* Then repeat tests in a non-root namespace */ + err = unshare(CLONE_NEWNET); + if (CHECK_FAIL(err)) { + perror("unshare(CLONE_NEWNET)"); + goto out_close; + } + do_flow_dissector_reattach(); + +out_close: + close(init_net); +} |