xref: /linux/tools/testing/selftests/bpf/prog_tests/kfree_skb.c (revision 2c63221cd9e5c0dad0424029aeb1c40faada8330)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 
4 static void on_sample(void *ctx, int cpu, void *data, __u32 size)
5 {
6 	int ifindex = *(int *)data, duration = 0;
7 	struct ipv6_packet *pkt_v6 = data + 4;
8 
9 	if (ifindex != 1)
10 		/* spurious kfree_skb not on loopback device */
11 		return;
12 	if (CHECK(size != 76, "check_size", "size %u != 76\n", size))
13 		return;
14 	if (CHECK(pkt_v6->eth.h_proto != 0xdd86, "check_eth",
15 		  "h_proto %x\n", pkt_v6->eth.h_proto))
16 		return;
17 	if (CHECK(pkt_v6->iph.nexthdr != 6, "check_ip",
18 		  "iph.nexthdr %x\n", pkt_v6->iph.nexthdr))
19 		return;
20 	if (CHECK(pkt_v6->tcp.doff != 5, "check_tcp",
21 		  "tcp.doff %x\n", pkt_v6->tcp.doff))
22 		return;
23 
24 	*(bool *)ctx = true;
25 }
26 
27 void test_kfree_skb(void)
28 {
29 	struct bpf_prog_load_attr attr = {
30 		.file = "./kfree_skb.o",
31 	};
32 
33 	struct bpf_object *obj, *obj2 = NULL;
34 	struct perf_buffer_opts pb_opts = {};
35 	struct perf_buffer *pb = NULL;
36 	struct bpf_link *link = NULL;
37 	struct bpf_map *perf_buf_map;
38 	struct bpf_program *prog;
39 	__u32 duration, retval;
40 	int err, pkt_fd, kfree_skb_fd;
41 	bool passed = false;
42 
43 	err = bpf_prog_load("./test_pkt_access.o", BPF_PROG_TYPE_SCHED_CLS, &obj, &pkt_fd);
44 	if (CHECK(err, "prog_load sched cls", "err %d errno %d\n", err, errno))
45 		return;
46 
47 	err = bpf_prog_load_xattr(&attr, &obj2, &kfree_skb_fd);
48 	if (CHECK(err, "prog_load raw tp", "err %d errno %d\n", err, errno))
49 		goto close_prog;
50 
51 	prog = bpf_object__find_program_by_title(obj2, "tp_btf/kfree_skb");
52 	if (CHECK(!prog, "find_prog", "prog kfree_skb not found\n"))
53 		goto close_prog;
54 	link = bpf_program__attach_raw_tracepoint(prog, NULL);
55 	if (CHECK(IS_ERR(link), "attach_raw_tp", "err %ld\n", PTR_ERR(link)))
56 		goto close_prog;
57 
58 	perf_buf_map = bpf_object__find_map_by_name(obj2, "perf_buf_map");
59 	if (CHECK(!perf_buf_map, "find_perf_buf_map", "not found\n"))
60 		goto close_prog;
61 
62 	/* set up perf buffer */
63 	pb_opts.sample_cb = on_sample;
64 	pb_opts.ctx = &passed;
65 	pb = perf_buffer__new(bpf_map__fd(perf_buf_map), 1, &pb_opts);
66 	if (CHECK(IS_ERR(pb), "perf_buf__new", "err %ld\n", PTR_ERR(pb)))
67 		goto close_prog;
68 
69 	err = bpf_prog_test_run(pkt_fd, 1, &pkt_v6, sizeof(pkt_v6),
70 				NULL, NULL, &retval, &duration);
71 	CHECK(err || retval, "ipv6",
72 	      "err %d errno %d retval %d duration %d\n",
73 	      err, errno, retval, duration);
74 
75 	/* read perf buffer */
76 	err = perf_buffer__poll(pb, 100);
77 	if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err))
78 		goto close_prog;
79 	/* make sure kfree_skb program was triggered
80 	 * and it sent expected skb into ring buffer
81 	 */
82 	CHECK_FAIL(!passed);
83 close_prog:
84 	perf_buffer__free(pb);
85 	if (!IS_ERR_OR_NULL(link))
86 		bpf_link__destroy(link);
87 	bpf_object__close(obj);
88 	bpf_object__close(obj2);
89 }
90