1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2022 Facebook */
3 
4 #include <test_progs.h>
5 #include "test_custom_sec_handlers.skel.h"
6 
7 #define COOKIE_ABC1 1
8 #define COOKIE_ABC2 2
9 #define COOKIE_CUSTOM 3
10 #define COOKIE_FALLBACK 4
11 #define COOKIE_KPROBE 5
12 
13 static int custom_setup_prog(struct bpf_program *prog, long cookie)
14 {
15 	if (cookie == COOKIE_ABC1)
16 		bpf_program__set_autoload(prog, false);
17 
18 	return 0;
19 }
20 
21 static int custom_prepare_load_prog(struct bpf_program *prog,
22 				    struct bpf_prog_load_opts *opts, long cookie)
23 {
24 	if (cookie == COOKIE_FALLBACK)
25 		opts->prog_flags |= BPF_F_SLEEPABLE;
26 	else if (cookie == COOKIE_ABC1)
27 		ASSERT_FALSE(true, "unexpected preload for abc");
28 
29 	return 0;
30 }
31 
32 static int custom_attach_prog(const struct bpf_program *prog, long cookie,
33 			      struct bpf_link **link)
34 {
35 	switch (cookie) {
36 	case COOKIE_ABC2:
37 		*link = bpf_program__attach_raw_tracepoint(prog, "sys_enter");
38 		return libbpf_get_error(*link);
39 	case COOKIE_CUSTOM:
40 		*link = bpf_program__attach_tracepoint(prog, "syscalls", "sys_enter_nanosleep");
41 		return libbpf_get_error(*link);
42 	case COOKIE_KPROBE:
43 	case COOKIE_FALLBACK:
44 		/* no auto-attach for SEC("xyz") and SEC("kprobe") */
45 		*link = NULL;
46 		return 0;
47 	default:
48 		ASSERT_FALSE(true, "unexpected cookie");
49 		return -EINVAL;
50 	}
51 }
52 
53 static int abc1_id;
54 static int abc2_id;
55 static int custom_id;
56 static int fallback_id;
57 static int kprobe_id;
58 
59 __attribute__((constructor))
60 static void register_sec_handlers(void)
61 {
62 	LIBBPF_OPTS(libbpf_prog_handler_opts, abc1_opts,
63 		.cookie = COOKIE_ABC1,
64 		.prog_setup_fn = custom_setup_prog,
65 		.prog_prepare_load_fn = custom_prepare_load_prog,
66 		.prog_attach_fn = NULL,
67 	);
68 	LIBBPF_OPTS(libbpf_prog_handler_opts, abc2_opts,
69 		.cookie = COOKIE_ABC2,
70 		.prog_setup_fn = custom_setup_prog,
71 		.prog_prepare_load_fn = custom_prepare_load_prog,
72 		.prog_attach_fn = custom_attach_prog,
73 	);
74 	LIBBPF_OPTS(libbpf_prog_handler_opts, custom_opts,
75 		.cookie = COOKIE_CUSTOM,
76 		.prog_setup_fn = NULL,
77 		.prog_prepare_load_fn = NULL,
78 		.prog_attach_fn = custom_attach_prog,
79 	);
80 
81 	abc1_id = libbpf_register_prog_handler("abc", BPF_PROG_TYPE_RAW_TRACEPOINT, 0, &abc1_opts);
82 	abc2_id = libbpf_register_prog_handler("abc/", BPF_PROG_TYPE_RAW_TRACEPOINT, 0, &abc2_opts);
83 	custom_id = libbpf_register_prog_handler("custom+", BPF_PROG_TYPE_TRACEPOINT, 0, &custom_opts);
84 }
85 
86 __attribute__((destructor))
87 static void unregister_sec_handlers(void)
88 {
89 	libbpf_unregister_prog_handler(abc1_id);
90 	libbpf_unregister_prog_handler(abc2_id);
91 	libbpf_unregister_prog_handler(custom_id);
92 }
93 
94 void test_custom_sec_handlers(void)
95 {
96 	LIBBPF_OPTS(libbpf_prog_handler_opts, opts,
97 		.prog_setup_fn = custom_setup_prog,
98 		.prog_prepare_load_fn = custom_prepare_load_prog,
99 		.prog_attach_fn = custom_attach_prog,
100 	);
101 	struct test_custom_sec_handlers* skel;
102 	int err;
103 
104 	ASSERT_GT(abc1_id, 0, "abc1_id");
105 	ASSERT_GT(abc2_id, 0, "abc2_id");
106 	ASSERT_GT(custom_id, 0, "custom_id");
107 
108 	/* override libbpf's handle of SEC("kprobe/...") but also allow pure
109 	 * SEC("kprobe") due to "kprobe+" specifier. Register it as
110 	 * TRACEPOINT, just for fun.
111 	 */
112 	opts.cookie = COOKIE_KPROBE;
113 	kprobe_id = libbpf_register_prog_handler("kprobe+", BPF_PROG_TYPE_TRACEPOINT, 0, &opts);
114 	/* fallback treats everything as BPF_PROG_TYPE_SYSCALL program to test
115 	 * setting custom BPF_F_SLEEPABLE bit in preload handler
116 	 */
117 	opts.cookie = COOKIE_FALLBACK;
118 	fallback_id = libbpf_register_prog_handler(NULL, BPF_PROG_TYPE_SYSCALL, 0, &opts);
119 
120 	if (!ASSERT_GT(fallback_id, 0, "fallback_id") /* || !ASSERT_GT(kprobe_id, 0, "kprobe_id")*/) {
121 		if (fallback_id > 0)
122 			libbpf_unregister_prog_handler(fallback_id);
123 		if (kprobe_id > 0)
124 			libbpf_unregister_prog_handler(kprobe_id);
125 		return;
126 	}
127 
128 	/* open skeleton and validate assumptions */
129 	skel = test_custom_sec_handlers__open();
130 	if (!ASSERT_OK_PTR(skel, "skel_open"))
131 		goto cleanup;
132 
133 	ASSERT_EQ(bpf_program__type(skel->progs.abc1), BPF_PROG_TYPE_RAW_TRACEPOINT, "abc1_type");
134 	ASSERT_FALSE(bpf_program__autoload(skel->progs.abc1), "abc1_autoload");
135 
136 	ASSERT_EQ(bpf_program__type(skel->progs.abc2), BPF_PROG_TYPE_RAW_TRACEPOINT, "abc2_type");
137 	ASSERT_EQ(bpf_program__type(skel->progs.custom1), BPF_PROG_TYPE_TRACEPOINT, "custom1_type");
138 	ASSERT_EQ(bpf_program__type(skel->progs.custom2), BPF_PROG_TYPE_TRACEPOINT, "custom2_type");
139 	ASSERT_EQ(bpf_program__type(skel->progs.kprobe1), BPF_PROG_TYPE_TRACEPOINT, "kprobe1_type");
140 	ASSERT_EQ(bpf_program__type(skel->progs.xyz), BPF_PROG_TYPE_SYSCALL, "xyz_type");
141 
142 	skel->rodata->my_pid = getpid();
143 
144 	/* now attempt to load everything */
145 	err = test_custom_sec_handlers__load(skel);
146 	if (!ASSERT_OK(err, "skel_load"))
147 		goto cleanup;
148 
149 	/* now try to auto-attach everything */
150 	err = test_custom_sec_handlers__attach(skel);
151 	if (!ASSERT_OK(err, "skel_attach"))
152 		goto cleanup;
153 
154 	skel->links.xyz = bpf_program__attach(skel->progs.kprobe1);
155 	ASSERT_EQ(errno, EOPNOTSUPP, "xyz_attach_err");
156 	ASSERT_ERR_PTR(skel->links.xyz, "xyz_attach");
157 
158 	/* trigger programs */
159 	usleep(1);
160 
161 	/* SEC("abc") is set to not auto-loaded */
162 	ASSERT_FALSE(skel->bss->abc1_called, "abc1_called");
163 	ASSERT_TRUE(skel->bss->abc2_called, "abc2_called");
164 	ASSERT_TRUE(skel->bss->custom1_called, "custom1_called");
165 	ASSERT_TRUE(skel->bss->custom2_called, "custom2_called");
166 	/* SEC("kprobe") shouldn't be auto-attached */
167 	ASSERT_FALSE(skel->bss->kprobe1_called, "kprobe1_called");
168 	/* SEC("xyz") shouldn't be auto-attached */
169 	ASSERT_FALSE(skel->bss->xyz_called, "xyz_called");
170 
171 cleanup:
172 	test_custom_sec_handlers__destroy(skel);
173 
174 	ASSERT_OK(libbpf_unregister_prog_handler(fallback_id), "unregister_fallback");
175 	ASSERT_OK(libbpf_unregister_prog_handler(kprobe_id), "unregister_kprobe");
176 }
177