1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 
4 struct meta {
5 	int ifindex;
6 	__u32 cb32_0;
7 	__u8 cb8_0;
8 };
9 
10 static union {
11 	__u32 cb32[5];
12 	__u8 cb8[20];
13 } cb = {
14 	.cb32[0] = 0x81828384,
15 };
16 
17 static void on_sample(void *ctx, int cpu, void *data, __u32 size)
18 {
19 	struct meta *meta = (struct meta *)data;
20 	struct ipv6_packet *pkt_v6 = data + sizeof(*meta);
21 	int duration = 0;
22 
23 	if (CHECK(size != 72 + sizeof(*meta), "check_size", "size %u != %zu\n",
24 		  size, 72 + sizeof(*meta)))
25 		return;
26 	if (CHECK(meta->ifindex != 1, "check_meta_ifindex",
27 		  "meta->ifindex = %d\n", meta->ifindex))
28 		/* spurious kfree_skb not on loopback device */
29 		return;
30 	if (CHECK(meta->cb8_0 != cb.cb8[0], "check_cb8_0", "cb8_0 %x != %x\n",
31 		  meta->cb8_0, cb.cb8[0]))
32 		return;
33 	if (CHECK(meta->cb32_0 != cb.cb32[0], "check_cb32_0",
34 		  "cb32_0 %x != %x\n",
35 		  meta->cb32_0, cb.cb32[0]))
36 		return;
37 	if (CHECK(pkt_v6->eth.h_proto != 0xdd86, "check_eth",
38 		  "h_proto %x\n", pkt_v6->eth.h_proto))
39 		return;
40 	if (CHECK(pkt_v6->iph.nexthdr != 6, "check_ip",
41 		  "iph.nexthdr %x\n", pkt_v6->iph.nexthdr))
42 		return;
43 	if (CHECK(pkt_v6->tcp.doff != 5, "check_tcp",
44 		  "tcp.doff %x\n", pkt_v6->tcp.doff))
45 		return;
46 
47 	*(bool *)ctx = true;
48 }
49 
50 void test_kfree_skb(void)
51 {
52 	struct __sk_buff skb = {};
53 	struct bpf_prog_test_run_attr tattr = {
54 		.data_in = &pkt_v6,
55 		.data_size_in = sizeof(pkt_v6),
56 		.ctx_in = &skb,
57 		.ctx_size_in = sizeof(skb),
58 	};
59 	struct bpf_prog_load_attr attr = {
60 		.file = "./kfree_skb.o",
61 	};
62 
63 	struct bpf_link *link = NULL, *link_fentry = NULL, *link_fexit = NULL;
64 	struct bpf_map *perf_buf_map, *global_data;
65 	struct bpf_program *prog, *fentry, *fexit;
66 	struct bpf_object *obj, *obj2 = NULL;
67 	struct perf_buffer_opts pb_opts = {};
68 	struct perf_buffer *pb = NULL;
69 	int err, kfree_skb_fd;
70 	bool passed = false;
71 	__u32 duration = 0;
72 	const int zero = 0;
73 	bool test_ok[2];
74 
75 	err = bpf_prog_load("./test_pkt_access.o", BPF_PROG_TYPE_SCHED_CLS,
76 			    &obj, &tattr.prog_fd);
77 	if (CHECK(err, "prog_load sched cls", "err %d errno %d\n", err, errno))
78 		return;
79 
80 	err = bpf_prog_load_xattr(&attr, &obj2, &kfree_skb_fd);
81 	if (CHECK(err, "prog_load raw tp", "err %d errno %d\n", err, errno))
82 		goto close_prog;
83 
84 	prog = bpf_object__find_program_by_title(obj2, "tp_btf/kfree_skb");
85 	if (CHECK(!prog, "find_prog", "prog kfree_skb not found\n"))
86 		goto close_prog;
87 	fentry = bpf_object__find_program_by_title(obj2, "fentry/eth_type_trans");
88 	if (CHECK(!fentry, "find_prog", "prog eth_type_trans not found\n"))
89 		goto close_prog;
90 	fexit = bpf_object__find_program_by_title(obj2, "fexit/eth_type_trans");
91 	if (CHECK(!fexit, "find_prog", "prog eth_type_trans not found\n"))
92 		goto close_prog;
93 
94 	global_data = bpf_object__find_map_by_name(obj2, "kfree_sk.bss");
95 	if (CHECK(!global_data, "find global data", "not found\n"))
96 		goto close_prog;
97 
98 	link = bpf_program__attach_raw_tracepoint(prog, NULL);
99 	if (CHECK(IS_ERR(link), "attach_raw_tp", "err %ld\n", PTR_ERR(link)))
100 		goto close_prog;
101 	link_fentry = bpf_program__attach_trace(fentry);
102 	if (CHECK(IS_ERR(link_fentry), "attach fentry", "err %ld\n",
103 		  PTR_ERR(link_fentry)))
104 		goto close_prog;
105 	link_fexit = bpf_program__attach_trace(fexit);
106 	if (CHECK(IS_ERR(link_fexit), "attach fexit", "err %ld\n",
107 		  PTR_ERR(link_fexit)))
108 		goto close_prog;
109 
110 	perf_buf_map = bpf_object__find_map_by_name(obj2, "perf_buf_map");
111 	if (CHECK(!perf_buf_map, "find_perf_buf_map", "not found\n"))
112 		goto close_prog;
113 
114 	/* set up perf buffer */
115 	pb_opts.sample_cb = on_sample;
116 	pb_opts.ctx = &passed;
117 	pb = perf_buffer__new(bpf_map__fd(perf_buf_map), 1, &pb_opts);
118 	if (CHECK(IS_ERR(pb), "perf_buf__new", "err %ld\n", PTR_ERR(pb)))
119 		goto close_prog;
120 
121 	memcpy(skb.cb, &cb, sizeof(cb));
122 	err = bpf_prog_test_run_xattr(&tattr);
123 	duration = tattr.duration;
124 	CHECK(err || tattr.retval, "ipv6",
125 	      "err %d errno %d retval %d duration %d\n",
126 	      err, errno, tattr.retval, duration);
127 
128 	/* read perf buffer */
129 	err = perf_buffer__poll(pb, 100);
130 	if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err))
131 		goto close_prog;
132 
133 	/* make sure kfree_skb program was triggered
134 	 * and it sent expected skb into ring buffer
135 	 */
136 	CHECK_FAIL(!passed);
137 
138 	err = bpf_map_lookup_elem(bpf_map__fd(global_data), &zero, test_ok);
139 	if (CHECK(err, "get_result",
140 		  "failed to get output data: %d\n", err))
141 		goto close_prog;
142 
143 	CHECK_FAIL(!test_ok[0] || !test_ok[1]);
144 close_prog:
145 	perf_buffer__free(pb);
146 	if (!IS_ERR_OR_NULL(link))
147 		bpf_link__destroy(link);
148 	if (!IS_ERR_OR_NULL(link_fentry))
149 		bpf_link__destroy(link_fentry);
150 	if (!IS_ERR_OR_NULL(link_fexit))
151 		bpf_link__destroy(link_fexit);
152 	bpf_object__close(obj);
153 	bpf_object__close(obj2);
154 }
155