From 3daf8e703ec3dcf73a27a7dcabbac152793eb114 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Tue, 9 Apr 2019 11:49:11 -0700 Subject: [PATCH] selftests: bpf: add selftest for __sk_buff context in BPF_PROG_TEST_RUN Simple test that sets cb to {1,2,3,4,5} and priority to 6, runs bpf program that fails if cb is not what we expect and increments cb[i] and priority. When the test finishes, we check that cb is now {2,3,4,5,6} and priority is 7. We also test the sanity checks: * ctx_in is provided, but ctx_size_in is zero (same for ctx_out/ctx_size_out) * unexpected non-zero fields in __sk_buff return EINVAL Signed-off-by: Stanislav Fomichev Acked-by: Martin KaFai Lau Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/prog_tests/skb_ctx.c | 89 ++++++++++++++++++++++++ tools/testing/selftests/bpf/progs/test_skb_ctx.c | 21 ++++++ 2 files changed, 110 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/skb_ctx.c create mode 100644 tools/testing/selftests/bpf/progs/test_skb_ctx.c diff --git a/tools/testing/selftests/bpf/prog_tests/skb_ctx.c b/tools/testing/selftests/bpf/prog_tests/skb_ctx.c new file mode 100644 index 0000000..e95baa3 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/skb_ctx.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0 +#include + +void test_skb_ctx(void) +{ + struct __sk_buff skb = { + .cb[0] = 1, + .cb[1] = 2, + .cb[2] = 3, + .cb[3] = 4, + .cb[4] = 5, + .priority = 6, + }; + struct bpf_prog_test_run_attr tattr = { + .data_in = &pkt_v4, + .data_size_in = sizeof(pkt_v4), + .ctx_in = &skb, + .ctx_size_in = sizeof(skb), + .ctx_out = &skb, + .ctx_size_out = sizeof(skb), + }; + struct bpf_object *obj; + int err; + int i; + + err = bpf_prog_load("./test_skb_ctx.o", BPF_PROG_TYPE_SCHED_CLS, &obj, + &tattr.prog_fd); + if (CHECK_ATTR(err, "load", "err %d errno %d\n", err, errno)) + return; + + /* ctx_in != NULL, ctx_size_in == 0 */ + + tattr.ctx_size_in = 0; + err = bpf_prog_test_run_xattr(&tattr); + CHECK_ATTR(err == 0, "ctx_size_in", "err %d errno %d\n", err, errno); + tattr.ctx_size_in = sizeof(skb); + + /* ctx_out != NULL, ctx_size_out == 0 */ + + tattr.ctx_size_out = 0; + err = bpf_prog_test_run_xattr(&tattr); + CHECK_ATTR(err == 0, "ctx_size_out", "err %d errno %d\n", err, errno); + tattr.ctx_size_out = sizeof(skb); + + /* non-zero [len, tc_index] fields should be rejected*/ + + skb.len = 1; + err = bpf_prog_test_run_xattr(&tattr); + CHECK_ATTR(err == 0, "len", "err %d errno %d\n", err, errno); + skb.len = 0; + + skb.tc_index = 1; + err = bpf_prog_test_run_xattr(&tattr); + CHECK_ATTR(err == 0, "tc_index", "err %d errno %d\n", err, errno); + skb.tc_index = 0; + + /* non-zero [hash, sk] fields should be rejected */ + + skb.hash = 1; + err = bpf_prog_test_run_xattr(&tattr); + CHECK_ATTR(err == 0, "hash", "err %d errno %d\n", err, errno); + skb.hash = 0; + + skb.sk = (struct bpf_sock *)1; + err = bpf_prog_test_run_xattr(&tattr); + CHECK_ATTR(err == 0, "sk", "err %d errno %d\n", err, errno); + skb.sk = 0; + + err = bpf_prog_test_run_xattr(&tattr); + CHECK_ATTR(err != 0 || tattr.retval, + "run", + "err %d errno %d retval %d\n", + err, errno, tattr.retval); + + CHECK_ATTR(tattr.ctx_size_out != sizeof(skb), + "ctx_size_out", + "incorrect output size, want %lu have %u\n", + sizeof(skb), tattr.ctx_size_out); + + for (i = 0; i < 5; i++) + CHECK_ATTR(skb.cb[i] != i + 2, + "ctx_out_cb", + "skb->cb[i] == %d, expected %d\n", + skb.cb[i], i + 2); + CHECK_ATTR(skb.priority != 7, + "ctx_out_priority", + "skb->priority == %d, expected %d\n", + skb.priority, 7); +} diff --git a/tools/testing/selftests/bpf/progs/test_skb_ctx.c b/tools/testing/selftests/bpf/progs/test_skb_ctx.c new file mode 100644 index 0000000..7a80960 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_skb_ctx.c @@ -0,0 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include "bpf_helpers.h" + +int _version SEC("version") = 1; +char _license[] SEC("license") = "GPL"; + +SEC("skb_ctx") +int process(struct __sk_buff *skb) +{ + #pragma clang loop unroll(full) + for (int i = 0; i < 5; i++) { + if (skb->cb[i] != i + 1) + return 1; + skb->cb[i]++; + } + skb->priority++; + + return 0; +} -- 2.7.4