1 // SPDX-License-Identifier: GPL-2.0
2 #include <vmlinux.h>
3 #include <bpf/bpf_tracing.h>
4 #include <bpf/bpf_helpers.h>
5 #include <bpf/bpf_core_read.h>
6 #include <bpf/bpf_endian.h>
7 #include "bpf_misc.h"
8 #include "bpf_experimental.h"
9
10 #ifndef ETH_P_IP
11 #define ETH_P_IP 0x0800
12 #endif
13
14 struct {
15 __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
16 __uint(max_entries, 4);
17 __uint(key_size, sizeof(__u32));
18 __uint(value_size, sizeof(__u32));
19 } jmp_table SEC(".maps");
20
21 static __noinline int static_func(u64 i)
22 {
23 bpf_throw(32);
24 return i;
25 }
26
27 __noinline int global2static_simple(u64 i)
28 {
29 static_func(i + 2);
30 return i - 1;
31 }
32
33 __noinline int global2static(u64 i)
34 {
35 if (i == ETH_P_IP)
36 bpf_throw(16);
37 return static_func(i);
38 }
39
40 static __noinline int static2global(u64 i)
41 {
42 return global2static(i) + i;
43 }
44
45 SEC("tc")
46 int exception_throw_always_1(struct __sk_buff *ctx)
47 {
48 bpf_throw(64);
49 return 0;
50 }
51
52 /* In this case, the global func will never be seen executing after call to
53 * static subprog, hence verifier will DCE the remaining instructions. Ensure we
54 * are resilient to that.
55 */
56 SEC("tc")
57 int exception_throw_always_2(struct __sk_buff *ctx)
58 {
59 return global2static_simple(ctx->protocol);
60 }
61
62 SEC("tc")
63 int exception_throw_unwind_1(struct __sk_buff *ctx)
64 {
65 return static2global(bpf_ntohs(ctx->protocol));
66 }
67
68 SEC("tc")
69 int exception_throw_unwind_2(struct __sk_buff *ctx)
70 {
71 return static2global(bpf_ntohs(ctx->protocol) - 1);
72 }
73
74 SEC("tc")
75 int exception_throw_default(struct __sk_buff *ctx)
76 {
77 bpf_throw(0);
78 return 1;
79 }
80
81 SEC("tc")
82 int exception_throw_default_value(struct __sk_buff *ctx)
83 {
84 bpf_throw(5);
85 return 1;
86 }
87
88 SEC("tc")
89 int exception_tail_call_target(struct __sk_buff *ctx)
90 {
91 bpf_throw(16);
92 return 0;
93 }
94
95 static __noinline
96 int exception_tail_call_subprog(struct __sk_buff *ctx)
97 {
98 volatile int ret = 10;
99
100 bpf_tail_call_static(ctx, &jmp_table, 0);
101 return ret;
102 }
103
104 SEC("tc")
105 int exception_tail_call(struct __sk_buff *ctx) {
106 volatile int ret = 0;
107
108 ret = exception_tail_call_subprog(ctx);
109 return ret + 8;
110 }
111
112 __noinline int exception_ext_global(struct __sk_buff *ctx)
113 {
114 volatile int ret = 0;
115
116 return ret;
117 }
118
119 static __noinline int exception_ext_static(struct __sk_buff *ctx)
120 {
121 return exception_ext_global(ctx);
122 }
123
124 SEC("tc")
125 int exception_ext(struct __sk_buff *ctx)
126 {
127 return exception_ext_static(ctx);
128 }
129
130 __noinline int exception_cb_mod_global(u64 cookie)
131 {
132 volatile int ret = 0;
133
134 return ret;
135 }
136
137 /* Example of how the exception callback supplied during verification can still
138 * introduce extensions by calling to dummy global functions, and alter runtime
139 * behavior.
140 *
141 * Right now we don't allow freplace attachment to exception callback itself,
142 * but if the need arises this restriction is technically feasible to relax in
143 * the future.
144 */
145 __noinline int exception_cb_mod(u64 cookie)
146 {
147 return exception_cb_mod_global(cookie) + cookie + 10;
148 }
149
150 SEC("tc")
151 __exception_cb(exception_cb_mod)
152 int exception_ext_mod_cb_runtime(struct __sk_buff *ctx)
153 {
154 bpf_throw(25);
155 return 0;
156 }
157
158 __noinline static int subprog(struct __sk_buff *ctx)
159 {
160 return bpf_ktime_get_ns();
161 }
162
163 __noinline static int throwing_subprog(struct __sk_buff *ctx)
164 {
165 if (ctx->tstamp)
166 bpf_throw(0);
167 return bpf_ktime_get_ns();
168 }
169
170 __noinline int global_subprog(struct __sk_buff *ctx)
171 {
172 return bpf_ktime_get_ns();
173 }
174
175 __noinline int throwing_global_subprog(struct __sk_buff *ctx)
176 {
177 if (ctx->tstamp)
178 bpf_throw(0);
179 return bpf_ktime_get_ns();
180 }
181
182 SEC("tc")
183 int exception_throw_subprog(struct __sk_buff *ctx)
184 {
185 switch (ctx->protocol) {
186 case 1:
187 return subprog(ctx);
188 case 2:
189 return global_subprog(ctx);
190 case 3:
191 return throwing_subprog(ctx);
192 case 4:
193 return throwing_global_subprog(ctx);
194 default:
195 break;
196 }
197 bpf_throw(1);
198 return 0;
199 }
200
201 __noinline int assert_nz_gfunc(u64 c)
202 {
203 volatile u64 cookie = c;
204
205 bpf_assert(cookie != 0);
206 return 0;
207 }
208
209 __noinline int assert_zero_gfunc(u64 c)
210 {
211 volatile u64 cookie = c;
212
213 bpf_assert(bpf_cmp_unlikely(cookie, ==, 0));
214 return 0;
215 }
216
217 __noinline int assert_neg_gfunc(s64 c)
218 {
219 volatile s64 cookie = c;
220
221 bpf_assert(bpf_cmp_unlikely(cookie, <, 0));
222 return 0;
223 }
224
225 __noinline int assert_pos_gfunc(s64 c)
226 {
227 volatile s64 cookie = c;
228
229 bpf_assert(bpf_cmp_unlikely(cookie, >, 0));
230 return 0;
231 }
232
233 __noinline int assert_negeq_gfunc(s64 c)
234 {
235 volatile s64 cookie = c;
236
237 bpf_assert(bpf_cmp_unlikely(cookie, <=, -1));
238 return 0;
239 }
240
241 __noinline int assert_poseq_gfunc(s64 c)
242 {
243 volatile s64 cookie = c;
244
245 bpf_assert(bpf_cmp_unlikely(cookie, >=, 1));
246 return 0;
247 }
248
249 __noinline int assert_nz_gfunc_with(u64 c)
250 {
251 volatile u64 cookie = c;
252
253 bpf_assert_with(cookie != 0, cookie + 100);
254 return 0;
255 }
256
257 __noinline int assert_zero_gfunc_with(u64 c)
258 {
259 volatile u64 cookie = c;
260
261 bpf_assert_with(bpf_cmp_unlikely(cookie, ==, 0), cookie + 100);
262 return 0;
263 }
264
265 __noinline int assert_neg_gfunc_with(s64 c)
266 {
267 volatile s64 cookie = c;
268
269 bpf_assert_with(bpf_cmp_unlikely(cookie, <, 0), cookie + 100);
270 return 0;
271 }
272
273 __noinline int assert_pos_gfunc_with(s64 c)
274 {
275 volatile s64 cookie = c;
276
277 bpf_assert_with(bpf_cmp_unlikely(cookie, >, 0), cookie + 100);
278 return 0;
279 }
280
281 __noinline int assert_negeq_gfunc_with(s64 c)
282 {
283 volatile s64 cookie = c;
284
285 bpf_assert_with(bpf_cmp_unlikely(cookie, <=, -1), cookie + 100);
286 return 0;
287 }
288
289 __noinline int assert_poseq_gfunc_with(s64 c)
290 {
291 volatile s64 cookie = c;
292
293 bpf_assert_with(bpf_cmp_unlikely(cookie, >=, 1), cookie + 100);
294 return 0;
295 }
296
297 #define check_assert(name, cookie, tag) \
298 SEC("tc") \
299 int exception##tag##name(struct __sk_buff *ctx) \
300 { \
301 return name(cookie) + 1; \
302 }
303
304 check_assert(assert_nz_gfunc, 5, _);
305 check_assert(assert_zero_gfunc, 0, _);
306 check_assert(assert_neg_gfunc, -100, _);
307 check_assert(assert_pos_gfunc, 100, _);
308 check_assert(assert_negeq_gfunc, -1, _);
309 check_assert(assert_poseq_gfunc, 1, _);
310
311 check_assert(assert_nz_gfunc_with, 5, _);
312 check_assert(assert_zero_gfunc_with, 0, _);
313 check_assert(assert_neg_gfunc_with, -100, _);
314 check_assert(assert_pos_gfunc_with, 100, _);
315 check_assert(assert_negeq_gfunc_with, -1, _);
316 check_assert(assert_poseq_gfunc_with, 1, _);
317
318 check_assert(assert_nz_gfunc, 0, _bad_);
319 check_assert(assert_zero_gfunc, 5, _bad_);
320 check_assert(assert_neg_gfunc, 100, _bad_);
321 check_assert(assert_pos_gfunc, -100, _bad_);
322 check_assert(assert_negeq_gfunc, 1, _bad_);
323 check_assert(assert_poseq_gfunc, -1, _bad_);
324
325 check_assert(assert_nz_gfunc_with, 0, _bad_);
326 check_assert(assert_zero_gfunc_with, 5, _bad_);
327 check_assert(assert_neg_gfunc_with, 100, _bad_);
328 check_assert(assert_pos_gfunc_with, -100, _bad_);
329 check_assert(assert_negeq_gfunc_with, 1, _bad_);
330 check_assert(assert_poseq_gfunc_with, -1, _bad_);
331
332 SEC("tc")
333 int exception_assert_range(struct __sk_buff *ctx)
334 {
335 u64 time = bpf_ktime_get_ns();
336
337 bpf_assert_range(time, 0, ~0ULL);
338 return 1;
339 }
340
341 SEC("tc")
342 int exception_assert_range_with(struct __sk_buff *ctx)
343 {
344 u64 time = bpf_ktime_get_ns();
345
346 bpf_assert_range_with(time, 0, ~0ULL, 10);
347 return 1;
348 }
349
350 SEC("tc")
351 int exception_bad_assert_range(struct __sk_buff *ctx)
352 {
353 u64 time = bpf_ktime_get_ns();
354
355 bpf_assert_range(time, -100, 100);
356 return 1;
357 }
358
359 SEC("tc")
360 int exception_bad_assert_range_with(struct __sk_buff *ctx)
361 {
362 u64 time = bpf_ktime_get_ns();
363
364 bpf_assert_range_with(time, -1000, 1000, 10);
365 return 1;
366 }
367
368 char _license[] SEC("license") = "GPL";
369
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