1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 #include <network_helpers.h>
4 #include "kfree_skb.skel.h"
5 
6 struct meta {
7 	int ifindex;
8 	__u32 cb32_0;
9 	__u8 cb8_0;
10 };
11 
12 static union {
13 	__u32 cb32[5];
14 	__u8 cb8[20];
15 } cb = {
16 	.cb32[0] = 0x81828384,
17 };
18 
on_sample(void * ctx,int cpu,void * data,__u32 size)19 static void on_sample(void *ctx, int cpu, void *data, __u32 size)
20 {
21 	struct meta *meta = (struct meta *)data;
22 	struct ipv6_packet *pkt_v6 = data + sizeof(*meta);
23 	int duration = 0;
24 
25 	if (CHECK(size != 72 + sizeof(*meta), "check_size", "size %u != %zu\n",
26 		  size, 72 + sizeof(*meta)))
27 		return;
28 	if (CHECK(meta->ifindex != 1, "check_meta_ifindex",
29 		  "meta->ifindex = %d\n", meta->ifindex))
30 		/* spurious kfree_skb not on loopback device */
31 		return;
32 	if (CHECK(meta->cb8_0 != cb.cb8[0], "check_cb8_0", "cb8_0 %x != %x\n",
33 		  meta->cb8_0, cb.cb8[0]))
34 		return;
35 	if (CHECK(meta->cb32_0 != cb.cb32[0], "check_cb32_0",
36 		  "cb32_0 %x != %x\n",
37 		  meta->cb32_0, cb.cb32[0]))
38 		return;
39 	if (CHECK(pkt_v6->eth.h_proto != htons(ETH_P_IPV6), "check_eth",
40 		  "h_proto %x\n", pkt_v6->eth.h_proto))
41 		return;
42 	if (CHECK(pkt_v6->iph.nexthdr != 6, "check_ip",
43 		  "iph.nexthdr %x\n", pkt_v6->iph.nexthdr))
44 		return;
45 	if (CHECK(pkt_v6->tcp.doff != 5, "check_tcp",
46 		  "tcp.doff %x\n", pkt_v6->tcp.doff))
47 		return;
48 
49 	*(bool *)ctx = true;
50 }
51 
52 /* TODO: fix kernel panic caused by this test in parallel mode */
serial_test_kfree_skb(void)53 void serial_test_kfree_skb(void)
54 {
55 	struct __sk_buff skb = {};
56 	LIBBPF_OPTS(bpf_test_run_opts, topts,
57 		.data_in = &pkt_v6,
58 		.data_size_in = sizeof(pkt_v6),
59 		.ctx_in = &skb,
60 		.ctx_size_in = sizeof(skb),
61 	);
62 	struct kfree_skb *skel = NULL;
63 	struct bpf_link *link;
64 	struct bpf_object *obj;
65 	struct perf_buffer *pb = NULL;
66 	int err, prog_fd;
67 	bool passed = false;
68 	__u32 duration = 0;
69 	const int zero = 0;
70 	bool test_ok[2];
71 
72 	err = bpf_prog_test_load("./test_pkt_access.bpf.o", BPF_PROG_TYPE_SCHED_CLS,
73 				 &obj, &prog_fd);
74 	if (CHECK(err, "prog_load sched cls", "err %d errno %d\n", err, errno))
75 		return;
76 
77 	skel = kfree_skb__open_and_load();
78 	if (!ASSERT_OK_PTR(skel, "kfree_skb_skel"))
79 		goto close_prog;
80 
81 	link = bpf_program__attach_raw_tracepoint(skel->progs.trace_kfree_skb, NULL);
82 	if (!ASSERT_OK_PTR(link, "attach_raw_tp"))
83 		goto close_prog;
84 	skel->links.trace_kfree_skb = link;
85 
86 	link = bpf_program__attach_trace(skel->progs.fentry_eth_type_trans);
87 	if (!ASSERT_OK_PTR(link, "attach fentry"))
88 		goto close_prog;
89 	skel->links.fentry_eth_type_trans = link;
90 
91 	link = bpf_program__attach_trace(skel->progs.fexit_eth_type_trans);
92 	if (!ASSERT_OK_PTR(link, "attach fexit"))
93 		goto close_prog;
94 	skel->links.fexit_eth_type_trans = link;
95 
96 	/* set up perf buffer */
97 	pb = perf_buffer__new(bpf_map__fd(skel->maps.perf_buf_map), 1,
98 			      on_sample, NULL, &passed, NULL);
99 	if (!ASSERT_OK_PTR(pb, "perf_buf__new"))
100 		goto close_prog;
101 
102 	memcpy(skb.cb, &cb, sizeof(cb));
103 	err = bpf_prog_test_run_opts(prog_fd, &topts);
104 	ASSERT_OK(err, "ipv6 test_run");
105 	ASSERT_OK(topts.retval, "ipv6 test_run retval");
106 
107 	/* read perf buffer */
108 	err = perf_buffer__poll(pb, 100);
109 	if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err))
110 		goto close_prog;
111 
112 	/* make sure kfree_skb program was triggered
113 	 * and it sent expected skb into ring buffer
114 	 */
115 	ASSERT_TRUE(passed, "passed");
116 
117 	err = bpf_map_lookup_elem(bpf_map__fd(skel->maps.bss), &zero, test_ok);
118 	if (CHECK(err, "get_result",
119 		  "failed to get output data: %d\n", err))
120 		goto close_prog;
121 
122 	CHECK_FAIL(!test_ok[0] || !test_ok[1]);
123 close_prog:
124 	perf_buffer__free(pb);
125 	bpf_object__close(obj);
126 	kfree_skb__destroy(skel);
127 }
128