1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2 // Copyright (c) 2020 Cloudflare
3
4 #include <errno.h>
5 #include <stdbool.h>
6 #include <stddef.h>
7 #include <linux/bpf.h>
8 #include <linux/in.h>
9 #include <sys/socket.h>
10
11 #include <bpf/bpf_endian.h>
12 #include <bpf/bpf_helpers.h>
13
14 #define IP4(a, b, c, d) \
15 bpf_htonl((((__u32)(a) & 0xffU) << 24) | \
16 (((__u32)(b) & 0xffU) << 16) | \
17 (((__u32)(c) & 0xffU) << 8) | \
18 (((__u32)(d) & 0xffU) << 0))
19 #define IP6(aaaa, bbbb, cccc, dddd) \
20 { bpf_htonl(aaaa), bpf_htonl(bbbb), bpf_htonl(cccc), bpf_htonl(dddd) }
21
22 /* Macros for least-significant byte and word accesses. */
23 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
24 #define LSE_INDEX(index, size) (index)
25 #else
26 #define LSE_INDEX(index, size) ((size) - (index) - 1)
27 #endif
28 #define LSB(value, index) \
29 (((__u8 *)&(value))[LSE_INDEX((index), sizeof(value))])
30 #define LSW(value, index) \
31 (((__u16 *)&(value))[LSE_INDEX((index), sizeof(value) / 2)])
32
33 #define MAX_SOCKS 32
34
35 struct {
36 __uint(type, BPF_MAP_TYPE_SOCKMAP);
37 __uint(max_entries, MAX_SOCKS);
38 __type(key, __u32);
39 __type(value, __u64);
40 } redir_map SEC(".maps");
41
42 struct {
43 __uint(type, BPF_MAP_TYPE_ARRAY);
44 __uint(max_entries, 2);
45 __type(key, int);
46 __type(value, int);
47 } run_map SEC(".maps");
48
49 enum {
50 PROG1 = 0,
51 PROG2,
52 };
53
54 enum {
55 SERVER_A = 0,
56 SERVER_B,
57 };
58
59 /* Addressable key/value constants for convenience */
60 static const int KEY_PROG1 = PROG1;
61 static const int KEY_PROG2 = PROG2;
62 static const int PROG_DONE = 1;
63
64 static const __u32 KEY_SERVER_A = SERVER_A;
65 static const __u32 KEY_SERVER_B = SERVER_B;
66
67 static const __u16 SRC_PORT = bpf_htons(8008);
68 static const __u32 SRC_IP4 = IP4(127, 0, 0, 2);
69 static const __u32 SRC_IP6[] = IP6(0xfd000000, 0x0, 0x0, 0x00000002);
70
71 static const __u16 DST_PORT = 7007; /* Host byte order */
72 static const __u32 DST_IP4 = IP4(127, 0, 0, 1);
73 static const __u32 DST_IP6[] = IP6(0xfd000000, 0x0, 0x0, 0x00000001);
74
75 SEC("sk_lookup")
lookup_pass(struct bpf_sk_lookup * ctx)76 int lookup_pass(struct bpf_sk_lookup *ctx)
77 {
78 return SK_PASS;
79 }
80
81 SEC("sk_lookup")
lookup_drop(struct bpf_sk_lookup * ctx)82 int lookup_drop(struct bpf_sk_lookup *ctx)
83 {
84 return SK_DROP;
85 }
86
87 SEC("sk_reuseport")
reuseport_pass(struct sk_reuseport_md * ctx)88 int reuseport_pass(struct sk_reuseport_md *ctx)
89 {
90 return SK_PASS;
91 }
92
93 SEC("sk_reuseport")
reuseport_drop(struct sk_reuseport_md * ctx)94 int reuseport_drop(struct sk_reuseport_md *ctx)
95 {
96 return SK_DROP;
97 }
98
99 /* Redirect packets destined for port DST_PORT to socket at redir_map[0]. */
100 SEC("sk_lookup")
redir_port(struct bpf_sk_lookup * ctx)101 int redir_port(struct bpf_sk_lookup *ctx)
102 {
103 struct bpf_sock *sk;
104 int err;
105
106 if (ctx->local_port != DST_PORT)
107 return SK_PASS;
108
109 sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
110 if (!sk)
111 return SK_PASS;
112
113 err = bpf_sk_assign(ctx, sk, 0);
114 bpf_sk_release(sk);
115 return err ? SK_DROP : SK_PASS;
116 }
117
118 /* Redirect packets destined for DST_IP4 address to socket at redir_map[0]. */
119 SEC("sk_lookup")
redir_ip4(struct bpf_sk_lookup * ctx)120 int redir_ip4(struct bpf_sk_lookup *ctx)
121 {
122 struct bpf_sock *sk;
123 int err;
124
125 if (ctx->family != AF_INET)
126 return SK_PASS;
127 if (ctx->local_port != DST_PORT)
128 return SK_PASS;
129 if (ctx->local_ip4 != DST_IP4)
130 return SK_PASS;
131
132 sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
133 if (!sk)
134 return SK_PASS;
135
136 err = bpf_sk_assign(ctx, sk, 0);
137 bpf_sk_release(sk);
138 return err ? SK_DROP : SK_PASS;
139 }
140
141 /* Redirect packets destined for DST_IP6 address to socket at redir_map[0]. */
142 SEC("sk_lookup")
redir_ip6(struct bpf_sk_lookup * ctx)143 int redir_ip6(struct bpf_sk_lookup *ctx)
144 {
145 struct bpf_sock *sk;
146 int err;
147
148 if (ctx->family != AF_INET6)
149 return SK_PASS;
150 if (ctx->local_port != DST_PORT)
151 return SK_PASS;
152 if (ctx->local_ip6[0] != DST_IP6[0] ||
153 ctx->local_ip6[1] != DST_IP6[1] ||
154 ctx->local_ip6[2] != DST_IP6[2] ||
155 ctx->local_ip6[3] != DST_IP6[3])
156 return SK_PASS;
157
158 sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
159 if (!sk)
160 return SK_PASS;
161
162 err = bpf_sk_assign(ctx, sk, 0);
163 bpf_sk_release(sk);
164 return err ? SK_DROP : SK_PASS;
165 }
166
167 SEC("sk_lookup")
select_sock_a(struct bpf_sk_lookup * ctx)168 int select_sock_a(struct bpf_sk_lookup *ctx)
169 {
170 struct bpf_sock *sk;
171 int err;
172
173 sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
174 if (!sk)
175 return SK_PASS;
176
177 err = bpf_sk_assign(ctx, sk, 0);
178 bpf_sk_release(sk);
179 return err ? SK_DROP : SK_PASS;
180 }
181
182 SEC("sk_lookup")
select_sock_a_no_reuseport(struct bpf_sk_lookup * ctx)183 int select_sock_a_no_reuseport(struct bpf_sk_lookup *ctx)
184 {
185 struct bpf_sock *sk;
186 int err;
187
188 sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
189 if (!sk)
190 return SK_DROP;
191
192 err = bpf_sk_assign(ctx, sk, BPF_SK_LOOKUP_F_NO_REUSEPORT);
193 bpf_sk_release(sk);
194 return err ? SK_DROP : SK_PASS;
195 }
196
197 SEC("sk_reuseport")
select_sock_b(struct sk_reuseport_md * ctx)198 int select_sock_b(struct sk_reuseport_md *ctx)
199 {
200 __u32 key = KEY_SERVER_B;
201 int err;
202
203 err = bpf_sk_select_reuseport(ctx, &redir_map, &key, 0);
204 return err ? SK_DROP : SK_PASS;
205 }
206
207 /* Check that bpf_sk_assign() returns -EEXIST if socket already selected. */
208 SEC("sk_lookup")
sk_assign_eexist(struct bpf_sk_lookup * ctx)209 int sk_assign_eexist(struct bpf_sk_lookup *ctx)
210 {
211 struct bpf_sock *sk;
212 int err, ret;
213
214 ret = SK_DROP;
215 sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_B);
216 if (!sk)
217 goto out;
218 err = bpf_sk_assign(ctx, sk, 0);
219 if (err)
220 goto out;
221 bpf_sk_release(sk);
222
223 sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
224 if (!sk)
225 goto out;
226 err = bpf_sk_assign(ctx, sk, 0);
227 if (err != -EEXIST) {
228 bpf_printk("sk_assign returned %d, expected %d\n",
229 err, -EEXIST);
230 goto out;
231 }
232
233 ret = SK_PASS; /* Success, redirect to KEY_SERVER_B */
234 out:
235 if (sk)
236 bpf_sk_release(sk);
237 return ret;
238 }
239
240 /* Check that bpf_sk_assign(BPF_SK_LOOKUP_F_REPLACE) can override selection. */
241 SEC("sk_lookup")
sk_assign_replace_flag(struct bpf_sk_lookup * ctx)242 int sk_assign_replace_flag(struct bpf_sk_lookup *ctx)
243 {
244 struct bpf_sock *sk;
245 int err, ret;
246
247 ret = SK_DROP;
248 sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
249 if (!sk)
250 goto out;
251 err = bpf_sk_assign(ctx, sk, 0);
252 if (err)
253 goto out;
254 bpf_sk_release(sk);
255
256 sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_B);
257 if (!sk)
258 goto out;
259 err = bpf_sk_assign(ctx, sk, BPF_SK_LOOKUP_F_REPLACE);
260 if (err) {
261 bpf_printk("sk_assign returned %d, expected 0\n", err);
262 goto out;
263 }
264
265 ret = SK_PASS; /* Success, redirect to KEY_SERVER_B */
266 out:
267 if (sk)
268 bpf_sk_release(sk);
269 return ret;
270 }
271
272 /* Check that bpf_sk_assign(sk=NULL) is accepted. */
273 SEC("sk_lookup")
sk_assign_null(struct bpf_sk_lookup * ctx)274 int sk_assign_null(struct bpf_sk_lookup *ctx)
275 {
276 struct bpf_sock *sk = NULL;
277 int err, ret;
278
279 ret = SK_DROP;
280
281 err = bpf_sk_assign(ctx, NULL, 0);
282 if (err) {
283 bpf_printk("sk_assign returned %d, expected 0\n", err);
284 goto out;
285 }
286
287 sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_B);
288 if (!sk)
289 goto out;
290 err = bpf_sk_assign(ctx, sk, BPF_SK_LOOKUP_F_REPLACE);
291 if (err) {
292 bpf_printk("sk_assign returned %d, expected 0\n", err);
293 goto out;
294 }
295
296 if (ctx->sk != sk)
297 goto out;
298 err = bpf_sk_assign(ctx, NULL, 0);
299 if (err != -EEXIST)
300 goto out;
301 err = bpf_sk_assign(ctx, NULL, BPF_SK_LOOKUP_F_REPLACE);
302 if (err)
303 goto out;
304 err = bpf_sk_assign(ctx, sk, BPF_SK_LOOKUP_F_REPLACE);
305 if (err)
306 goto out;
307
308 ret = SK_PASS; /* Success, redirect to KEY_SERVER_B */
309 out:
310 if (sk)
311 bpf_sk_release(sk);
312 return ret;
313 }
314
315 /* Check that selected sk is accessible through context. */
316 SEC("sk_lookup")
access_ctx_sk(struct bpf_sk_lookup * ctx)317 int access_ctx_sk(struct bpf_sk_lookup *ctx)
318 {
319 struct bpf_sock *sk1 = NULL, *sk2 = NULL;
320 int err, ret;
321
322 ret = SK_DROP;
323
324 /* Try accessing unassigned (NULL) ctx->sk field */
325 if (ctx->sk && ctx->sk->family != AF_INET)
326 goto out;
327
328 /* Assign a value to ctx->sk */
329 sk1 = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
330 if (!sk1)
331 goto out;
332 err = bpf_sk_assign(ctx, sk1, 0);
333 if (err)
334 goto out;
335 if (ctx->sk != sk1)
336 goto out;
337
338 /* Access ctx->sk fields */
339 if (ctx->sk->family != AF_INET ||
340 ctx->sk->type != SOCK_STREAM ||
341 ctx->sk->state != BPF_TCP_LISTEN)
342 goto out;
343
344 /* Reset selection */
345 err = bpf_sk_assign(ctx, NULL, BPF_SK_LOOKUP_F_REPLACE);
346 if (err)
347 goto out;
348 if (ctx->sk)
349 goto out;
350
351 /* Assign another socket */
352 sk2 = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_B);
353 if (!sk2)
354 goto out;
355 err = bpf_sk_assign(ctx, sk2, BPF_SK_LOOKUP_F_REPLACE);
356 if (err)
357 goto out;
358 if (ctx->sk != sk2)
359 goto out;
360
361 /* Access reassigned ctx->sk fields */
362 if (ctx->sk->family != AF_INET ||
363 ctx->sk->type != SOCK_STREAM ||
364 ctx->sk->state != BPF_TCP_LISTEN)
365 goto out;
366
367 ret = SK_PASS; /* Success, redirect to KEY_SERVER_B */
368 out:
369 if (sk1)
370 bpf_sk_release(sk1);
371 if (sk2)
372 bpf_sk_release(sk2);
373 return ret;
374 }
375
376 /* Check narrow loads from ctx fields that support them.
377 *
378 * Narrow loads of size >= target field size from a non-zero offset
379 * are not covered because they give bogus results, that is the
380 * verifier ignores the offset.
381 */
382 SEC("sk_lookup")
ctx_narrow_access(struct bpf_sk_lookup * ctx)383 int ctx_narrow_access(struct bpf_sk_lookup *ctx)
384 {
385 struct bpf_sock *sk;
386 int err, family;
387 bool v4;
388
389 v4 = (ctx->family == AF_INET);
390
391 /* Narrow loads from family field */
392 if (LSB(ctx->family, 0) != (v4 ? AF_INET : AF_INET6) ||
393 LSB(ctx->family, 1) != 0 || LSB(ctx->family, 2) != 0 || LSB(ctx->family, 3) != 0)
394 return SK_DROP;
395 if (LSW(ctx->family, 0) != (v4 ? AF_INET : AF_INET6))
396 return SK_DROP;
397
398 /* Narrow loads from protocol field */
399 if (LSB(ctx->protocol, 0) != IPPROTO_TCP ||
400 LSB(ctx->protocol, 1) != 0 || LSB(ctx->protocol, 2) != 0 || LSB(ctx->protocol, 3) != 0)
401 return SK_DROP;
402 if (LSW(ctx->protocol, 0) != IPPROTO_TCP)
403 return SK_DROP;
404
405 /* Narrow loads from remote_port field. Expect SRC_PORT. */
406 if (LSB(ctx->remote_port, 0) != ((SRC_PORT >> 0) & 0xff) ||
407 LSB(ctx->remote_port, 1) != ((SRC_PORT >> 8) & 0xff) ||
408 LSB(ctx->remote_port, 2) != 0 || LSB(ctx->remote_port, 3) != 0)
409 return SK_DROP;
410 if (LSW(ctx->remote_port, 0) != SRC_PORT)
411 return SK_DROP;
412
413 /* Narrow loads from local_port field. Expect DST_PORT. */
414 if (LSB(ctx->local_port, 0) != ((DST_PORT >> 0) & 0xff) ||
415 LSB(ctx->local_port, 1) != ((DST_PORT >> 8) & 0xff) ||
416 LSB(ctx->local_port, 2) != 0 || LSB(ctx->local_port, 3) != 0)
417 return SK_DROP;
418 if (LSW(ctx->local_port, 0) != DST_PORT)
419 return SK_DROP;
420
421 /* Narrow loads from IPv4 fields */
422 if (v4) {
423 /* Expect SRC_IP4 in remote_ip4 */
424 if (LSB(ctx->remote_ip4, 0) != ((SRC_IP4 >> 0) & 0xff) ||
425 LSB(ctx->remote_ip4, 1) != ((SRC_IP4 >> 8) & 0xff) ||
426 LSB(ctx->remote_ip4, 2) != ((SRC_IP4 >> 16) & 0xff) ||
427 LSB(ctx->remote_ip4, 3) != ((SRC_IP4 >> 24) & 0xff))
428 return SK_DROP;
429 if (LSW(ctx->remote_ip4, 0) != ((SRC_IP4 >> 0) & 0xffff) ||
430 LSW(ctx->remote_ip4, 1) != ((SRC_IP4 >> 16) & 0xffff))
431 return SK_DROP;
432
433 /* Expect DST_IP4 in local_ip4 */
434 if (LSB(ctx->local_ip4, 0) != ((DST_IP4 >> 0) & 0xff) ||
435 LSB(ctx->local_ip4, 1) != ((DST_IP4 >> 8) & 0xff) ||
436 LSB(ctx->local_ip4, 2) != ((DST_IP4 >> 16) & 0xff) ||
437 LSB(ctx->local_ip4, 3) != ((DST_IP4 >> 24) & 0xff))
438 return SK_DROP;
439 if (LSW(ctx->local_ip4, 0) != ((DST_IP4 >> 0) & 0xffff) ||
440 LSW(ctx->local_ip4, 1) != ((DST_IP4 >> 16) & 0xffff))
441 return SK_DROP;
442 } else {
443 /* Expect 0.0.0.0 IPs when family != AF_INET */
444 if (LSB(ctx->remote_ip4, 0) != 0 || LSB(ctx->remote_ip4, 1) != 0 ||
445 LSB(ctx->remote_ip4, 2) != 0 || LSB(ctx->remote_ip4, 3) != 0)
446 return SK_DROP;
447 if (LSW(ctx->remote_ip4, 0) != 0 || LSW(ctx->remote_ip4, 1) != 0)
448 return SK_DROP;
449
450 if (LSB(ctx->local_ip4, 0) != 0 || LSB(ctx->local_ip4, 1) != 0 ||
451 LSB(ctx->local_ip4, 2) != 0 || LSB(ctx->local_ip4, 3) != 0)
452 return SK_DROP;
453 if (LSW(ctx->local_ip4, 0) != 0 || LSW(ctx->local_ip4, 1) != 0)
454 return SK_DROP;
455 }
456
457 /* Narrow loads from IPv6 fields */
458 if (!v4) {
459 /* Expect SRC_IP6 in remote_ip6 */
460 if (LSB(ctx->remote_ip6[0], 0) != ((SRC_IP6[0] >> 0) & 0xff) ||
461 LSB(ctx->remote_ip6[0], 1) != ((SRC_IP6[0] >> 8) & 0xff) ||
462 LSB(ctx->remote_ip6[0], 2) != ((SRC_IP6[0] >> 16) & 0xff) ||
463 LSB(ctx->remote_ip6[0], 3) != ((SRC_IP6[0] >> 24) & 0xff) ||
464 LSB(ctx->remote_ip6[1], 0) != ((SRC_IP6[1] >> 0) & 0xff) ||
465 LSB(ctx->remote_ip6[1], 1) != ((SRC_IP6[1] >> 8) & 0xff) ||
466 LSB(ctx->remote_ip6[1], 2) != ((SRC_IP6[1] >> 16) & 0xff) ||
467 LSB(ctx->remote_ip6[1], 3) != ((SRC_IP6[1] >> 24) & 0xff) ||
468 LSB(ctx->remote_ip6[2], 0) != ((SRC_IP6[2] >> 0) & 0xff) ||
469 LSB(ctx->remote_ip6[2], 1) != ((SRC_IP6[2] >> 8) & 0xff) ||
470 LSB(ctx->remote_ip6[2], 2) != ((SRC_IP6[2] >> 16) & 0xff) ||
471 LSB(ctx->remote_ip6[2], 3) != ((SRC_IP6[2] >> 24) & 0xff) ||
472 LSB(ctx->remote_ip6[3], 0) != ((SRC_IP6[3] >> 0) & 0xff) ||
473 LSB(ctx->remote_ip6[3], 1) != ((SRC_IP6[3] >> 8) & 0xff) ||
474 LSB(ctx->remote_ip6[3], 2) != ((SRC_IP6[3] >> 16) & 0xff) ||
475 LSB(ctx->remote_ip6[3], 3) != ((SRC_IP6[3] >> 24) & 0xff))
476 return SK_DROP;
477 if (LSW(ctx->remote_ip6[0], 0) != ((SRC_IP6[0] >> 0) & 0xffff) ||
478 LSW(ctx->remote_ip6[0], 1) != ((SRC_IP6[0] >> 16) & 0xffff) ||
479 LSW(ctx->remote_ip6[1], 0) != ((SRC_IP6[1] >> 0) & 0xffff) ||
480 LSW(ctx->remote_ip6[1], 1) != ((SRC_IP6[1] >> 16) & 0xffff) ||
481 LSW(ctx->remote_ip6[2], 0) != ((SRC_IP6[2] >> 0) & 0xffff) ||
482 LSW(ctx->remote_ip6[2], 1) != ((SRC_IP6[2] >> 16) & 0xffff) ||
483 LSW(ctx->remote_ip6[3], 0) != ((SRC_IP6[3] >> 0) & 0xffff) ||
484 LSW(ctx->remote_ip6[3], 1) != ((SRC_IP6[3] >> 16) & 0xffff))
485 return SK_DROP;
486 /* Expect DST_IP6 in local_ip6 */
487 if (LSB(ctx->local_ip6[0], 0) != ((DST_IP6[0] >> 0) & 0xff) ||
488 LSB(ctx->local_ip6[0], 1) != ((DST_IP6[0] >> 8) & 0xff) ||
489 LSB(ctx->local_ip6[0], 2) != ((DST_IP6[0] >> 16) & 0xff) ||
490 LSB(ctx->local_ip6[0], 3) != ((DST_IP6[0] >> 24) & 0xff) ||
491 LSB(ctx->local_ip6[1], 0) != ((DST_IP6[1] >> 0) & 0xff) ||
492 LSB(ctx->local_ip6[1], 1) != ((DST_IP6[1] >> 8) & 0xff) ||
493 LSB(ctx->local_ip6[1], 2) != ((DST_IP6[1] >> 16) & 0xff) ||
494 LSB(ctx->local_ip6[1], 3) != ((DST_IP6[1] >> 24) & 0xff) ||
495 LSB(ctx->local_ip6[2], 0) != ((DST_IP6[2] >> 0) & 0xff) ||
496 LSB(ctx->local_ip6[2], 1) != ((DST_IP6[2] >> 8) & 0xff) ||
497 LSB(ctx->local_ip6[2], 2) != ((DST_IP6[2] >> 16) & 0xff) ||
498 LSB(ctx->local_ip6[2], 3) != ((DST_IP6[2] >> 24) & 0xff) ||
499 LSB(ctx->local_ip6[3], 0) != ((DST_IP6[3] >> 0) & 0xff) ||
500 LSB(ctx->local_ip6[3], 1) != ((DST_IP6[3] >> 8) & 0xff) ||
501 LSB(ctx->local_ip6[3], 2) != ((DST_IP6[3] >> 16) & 0xff) ||
502 LSB(ctx->local_ip6[3], 3) != ((DST_IP6[3] >> 24) & 0xff))
503 return SK_DROP;
504 if (LSW(ctx->local_ip6[0], 0) != ((DST_IP6[0] >> 0) & 0xffff) ||
505 LSW(ctx->local_ip6[0], 1) != ((DST_IP6[0] >> 16) & 0xffff) ||
506 LSW(ctx->local_ip6[1], 0) != ((DST_IP6[1] >> 0) & 0xffff) ||
507 LSW(ctx->local_ip6[1], 1) != ((DST_IP6[1] >> 16) & 0xffff) ||
508 LSW(ctx->local_ip6[2], 0) != ((DST_IP6[2] >> 0) & 0xffff) ||
509 LSW(ctx->local_ip6[2], 1) != ((DST_IP6[2] >> 16) & 0xffff) ||
510 LSW(ctx->local_ip6[3], 0) != ((DST_IP6[3] >> 0) & 0xffff) ||
511 LSW(ctx->local_ip6[3], 1) != ((DST_IP6[3] >> 16) & 0xffff))
512 return SK_DROP;
513 } else {
514 /* Expect :: IPs when family != AF_INET6 */
515 if (LSB(ctx->remote_ip6[0], 0) != 0 || LSB(ctx->remote_ip6[0], 1) != 0 ||
516 LSB(ctx->remote_ip6[0], 2) != 0 || LSB(ctx->remote_ip6[0], 3) != 0 ||
517 LSB(ctx->remote_ip6[1], 0) != 0 || LSB(ctx->remote_ip6[1], 1) != 0 ||
518 LSB(ctx->remote_ip6[1], 2) != 0 || LSB(ctx->remote_ip6[1], 3) != 0 ||
519 LSB(ctx->remote_ip6[2], 0) != 0 || LSB(ctx->remote_ip6[2], 1) != 0 ||
520 LSB(ctx->remote_ip6[2], 2) != 0 || LSB(ctx->remote_ip6[2], 3) != 0 ||
521 LSB(ctx->remote_ip6[3], 0) != 0 || LSB(ctx->remote_ip6[3], 1) != 0 ||
522 LSB(ctx->remote_ip6[3], 2) != 0 || LSB(ctx->remote_ip6[3], 3) != 0)
523 return SK_DROP;
524 if (LSW(ctx->remote_ip6[0], 0) != 0 || LSW(ctx->remote_ip6[0], 1) != 0 ||
525 LSW(ctx->remote_ip6[1], 0) != 0 || LSW(ctx->remote_ip6[1], 1) != 0 ||
526 LSW(ctx->remote_ip6[2], 0) != 0 || LSW(ctx->remote_ip6[2], 1) != 0 ||
527 LSW(ctx->remote_ip6[3], 0) != 0 || LSW(ctx->remote_ip6[3], 1) != 0)
528 return SK_DROP;
529
530 if (LSB(ctx->local_ip6[0], 0) != 0 || LSB(ctx->local_ip6[0], 1) != 0 ||
531 LSB(ctx->local_ip6[0], 2) != 0 || LSB(ctx->local_ip6[0], 3) != 0 ||
532 LSB(ctx->local_ip6[1], 0) != 0 || LSB(ctx->local_ip6[1], 1) != 0 ||
533 LSB(ctx->local_ip6[1], 2) != 0 || LSB(ctx->local_ip6[1], 3) != 0 ||
534 LSB(ctx->local_ip6[2], 0) != 0 || LSB(ctx->local_ip6[2], 1) != 0 ||
535 LSB(ctx->local_ip6[2], 2) != 0 || LSB(ctx->local_ip6[2], 3) != 0 ||
536 LSB(ctx->local_ip6[3], 0) != 0 || LSB(ctx->local_ip6[3], 1) != 0 ||
537 LSB(ctx->local_ip6[3], 2) != 0 || LSB(ctx->local_ip6[3], 3) != 0)
538 return SK_DROP;
539 if (LSW(ctx->remote_ip6[0], 0) != 0 || LSW(ctx->remote_ip6[0], 1) != 0 ||
540 LSW(ctx->remote_ip6[1], 0) != 0 || LSW(ctx->remote_ip6[1], 1) != 0 ||
541 LSW(ctx->remote_ip6[2], 0) != 0 || LSW(ctx->remote_ip6[2], 1) != 0 ||
542 LSW(ctx->remote_ip6[3], 0) != 0 || LSW(ctx->remote_ip6[3], 1) != 0)
543 return SK_DROP;
544 }
545
546 /* Success, redirect to KEY_SERVER_B */
547 sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_B);
548 if (sk) {
549 bpf_sk_assign(ctx, sk, 0);
550 bpf_sk_release(sk);
551 }
552 return SK_PASS;
553 }
554
555 /* Check that sk_assign rejects SERVER_A socket with -ESOCKNOSUPPORT */
556 SEC("sk_lookup")
sk_assign_esocknosupport(struct bpf_sk_lookup * ctx)557 int sk_assign_esocknosupport(struct bpf_sk_lookup *ctx)
558 {
559 struct bpf_sock *sk;
560 int err, ret;
561
562 ret = SK_DROP;
563 sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
564 if (!sk)
565 goto out;
566
567 err = bpf_sk_assign(ctx, sk, 0);
568 if (err != -ESOCKTNOSUPPORT) {
569 bpf_printk("sk_assign returned %d, expected %d\n",
570 err, -ESOCKTNOSUPPORT);
571 goto out;
572 }
573
574 ret = SK_PASS; /* Success, pass to regular lookup */
575 out:
576 if (sk)
577 bpf_sk_release(sk);
578 return ret;
579 }
580
581 SEC("sk_lookup")
multi_prog_pass1(struct bpf_sk_lookup * ctx)582 int multi_prog_pass1(struct bpf_sk_lookup *ctx)
583 {
584 bpf_map_update_elem(&run_map, &KEY_PROG1, &PROG_DONE, BPF_ANY);
585 return SK_PASS;
586 }
587
588 SEC("sk_lookup")
multi_prog_pass2(struct bpf_sk_lookup * ctx)589 int multi_prog_pass2(struct bpf_sk_lookup *ctx)
590 {
591 bpf_map_update_elem(&run_map, &KEY_PROG2, &PROG_DONE, BPF_ANY);
592 return SK_PASS;
593 }
594
595 SEC("sk_lookup")
multi_prog_drop1(struct bpf_sk_lookup * ctx)596 int multi_prog_drop1(struct bpf_sk_lookup *ctx)
597 {
598 bpf_map_update_elem(&run_map, &KEY_PROG1, &PROG_DONE, BPF_ANY);
599 return SK_DROP;
600 }
601
602 SEC("sk_lookup")
multi_prog_drop2(struct bpf_sk_lookup * ctx)603 int multi_prog_drop2(struct bpf_sk_lookup *ctx)
604 {
605 bpf_map_update_elem(&run_map, &KEY_PROG2, &PROG_DONE, BPF_ANY);
606 return SK_DROP;
607 }
608
select_server_a(struct bpf_sk_lookup * ctx)609 static __always_inline int select_server_a(struct bpf_sk_lookup *ctx)
610 {
611 struct bpf_sock *sk;
612 int err;
613
614 sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
615 if (!sk)
616 return SK_DROP;
617
618 err = bpf_sk_assign(ctx, sk, 0);
619 bpf_sk_release(sk);
620 if (err)
621 return SK_DROP;
622
623 return SK_PASS;
624 }
625
626 SEC("sk_lookup")
multi_prog_redir1(struct bpf_sk_lookup * ctx)627 int multi_prog_redir1(struct bpf_sk_lookup *ctx)
628 {
629 int ret;
630
631 ret = select_server_a(ctx);
632 bpf_map_update_elem(&run_map, &KEY_PROG1, &PROG_DONE, BPF_ANY);
633 return SK_PASS;
634 }
635
636 SEC("sk_lookup")
multi_prog_redir2(struct bpf_sk_lookup * ctx)637 int multi_prog_redir2(struct bpf_sk_lookup *ctx)
638 {
639 int ret;
640
641 ret = select_server_a(ctx);
642 bpf_map_update_elem(&run_map, &KEY_PROG2, &PROG_DONE, BPF_ANY);
643 return SK_PASS;
644 }
645
646 char _license[] SEC("license") = "Dual BSD/GPL";
647