1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 #include <network_helpers.h>
4 
5 struct meta {
6 	int ifindex;
7 	__u32 cb32_0;
8 	__u8 cb8_0;
9 };
10 
11 static union {
12 	__u32 cb32[5];
13 	__u8 cb8[20];
14 } cb = {
15 	.cb32[0] = 0x81828384,
16 };
17 
on_sample(void * ctx,int cpu,void * data,__u32 size)18 static void on_sample(void *ctx, int cpu, void *data, __u32 size)
19 {
20 	struct meta *meta = (struct meta *)data;
21 	struct ipv6_packet *pkt_v6 = data + sizeof(*meta);
22 	int duration = 0;
23 
24 	if (CHECK(size != 72 + sizeof(*meta), "check_size", "size %u != %zu\n",
25 		  size, 72 + sizeof(*meta)))
26 		return;
27 	if (CHECK(meta->ifindex != 1, "check_meta_ifindex",
28 		  "meta->ifindex = %d\n", meta->ifindex))
29 		/* spurious kfree_skb not on loopback device */
30 		return;
31 	if (CHECK(meta->cb8_0 != cb.cb8[0], "check_cb8_0", "cb8_0 %x != %x\n",
32 		  meta->cb8_0, cb.cb8[0]))
33 		return;
34 	if (CHECK(meta->cb32_0 != cb.cb32[0], "check_cb32_0",
35 		  "cb32_0 %x != %x\n",
36 		  meta->cb32_0, cb.cb32[0]))
37 		return;
38 	if (CHECK(pkt_v6->eth.h_proto != 0xdd86, "check_eth",
39 		  "h_proto %x\n", pkt_v6->eth.h_proto))
40 		return;
41 	if (CHECK(pkt_v6->iph.nexthdr != 6, "check_ip",
42 		  "iph.nexthdr %x\n", pkt_v6->iph.nexthdr))
43 		return;
44 	if (CHECK(pkt_v6->tcp.doff != 5, "check_tcp",
45 		  "tcp.doff %x\n", pkt_v6->tcp.doff))
46 		return;
47 
48 	*(bool *)ctx = true;
49 }
50 
51 /* TODO: fix kernel panic caused by this test in parallel mode */
serial_test_kfree_skb(void)52 void serial_test_kfree_skb(void)
53 {
54 	struct __sk_buff skb = {};
55 	struct bpf_prog_test_run_attr tattr = {
56 		.data_in = &pkt_v6,
57 		.data_size_in = sizeof(pkt_v6),
58 		.ctx_in = &skb,
59 		.ctx_size_in = sizeof(skb),
60 	};
61 	struct bpf_prog_load_attr attr = {
62 		.file = "./kfree_skb.o",
63 	};
64 
65 	struct bpf_link *link = NULL, *link_fentry = NULL, *link_fexit = NULL;
66 	struct bpf_map *perf_buf_map, *global_data;
67 	struct bpf_program *prog, *fentry, *fexit;
68 	struct bpf_object *obj, *obj2 = NULL;
69 	struct perf_buffer_opts pb_opts = {};
70 	struct perf_buffer *pb = NULL;
71 	int err, kfree_skb_fd;
72 	bool passed = false;
73 	__u32 duration = 0;
74 	const int zero = 0;
75 	bool test_ok[2];
76 
77 	err = bpf_prog_load("./test_pkt_access.o", BPF_PROG_TYPE_SCHED_CLS,
78 			    &obj, &tattr.prog_fd);
79 	if (CHECK(err, "prog_load sched cls", "err %d errno %d\n", err, errno))
80 		return;
81 
82 	err = bpf_prog_load_xattr(&attr, &obj2, &kfree_skb_fd);
83 	if (CHECK(err, "prog_load raw tp", "err %d errno %d\n", err, errno))
84 		goto close_prog;
85 
86 	prog = bpf_object__find_program_by_title(obj2, "tp_btf/kfree_skb");
87 	if (CHECK(!prog, "find_prog", "prog kfree_skb not found\n"))
88 		goto close_prog;
89 	fentry = bpf_object__find_program_by_title(obj2, "fentry/eth_type_trans");
90 	if (CHECK(!fentry, "find_prog", "prog eth_type_trans not found\n"))
91 		goto close_prog;
92 	fexit = bpf_object__find_program_by_title(obj2, "fexit/eth_type_trans");
93 	if (CHECK(!fexit, "find_prog", "prog eth_type_trans not found\n"))
94 		goto close_prog;
95 
96 	global_data = bpf_object__find_map_by_name(obj2, ".bss");
97 	if (CHECK(!global_data, "find global data", "not found\n"))
98 		goto close_prog;
99 
100 	link = bpf_program__attach_raw_tracepoint(prog, NULL);
101 	if (!ASSERT_OK_PTR(link, "attach_raw_tp"))
102 		goto close_prog;
103 	link_fentry = bpf_program__attach_trace(fentry);
104 	if (!ASSERT_OK_PTR(link_fentry, "attach fentry"))
105 		goto close_prog;
106 	link_fexit = bpf_program__attach_trace(fexit);
107 	if (!ASSERT_OK_PTR(link_fexit, "attach 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 (!ASSERT_OK_PTR(pb, "perf_buf__new"))
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 	ASSERT_TRUE(passed, "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 	bpf_link__destroy(link);
147 	bpf_link__destroy(link_fentry);
148 	bpf_link__destroy(link_fexit);
149 	bpf_object__close(obj);
150 	bpf_object__close(obj2);
151 }
152