xref: /linux/tools/testing/selftests/bpf/progs/test_sk_lookup.c (revision 1ac731c529cd4d6adbce134754b51ff7d822b145) 
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_lookup")
check_ifindex(struct bpf_sk_lookup * ctx)88 int check_ifindex(struct bpf_sk_lookup *ctx)
89 {
90 	if (ctx->ingress_ifindex == 1)
91 		return SK_DROP;
92 	return SK_PASS;
93 }
94 
95 SEC("sk_reuseport")
reuseport_pass(struct sk_reuseport_md * ctx)96 int reuseport_pass(struct sk_reuseport_md *ctx)
97 {
98 	return SK_PASS;
99 }
100 
101 SEC("sk_reuseport")
reuseport_drop(struct sk_reuseport_md * ctx)102 int reuseport_drop(struct sk_reuseport_md *ctx)
103 {
104 	return SK_DROP;
105 }
106 
107 /* Redirect packets destined for port DST_PORT to socket at redir_map[0]. */
108 SEC("sk_lookup")
redir_port(struct bpf_sk_lookup * ctx)109 int redir_port(struct bpf_sk_lookup *ctx)
110 {
111 	struct bpf_sock *sk;
112 	int err;
113 
114 	if (ctx->local_port != DST_PORT)
115 		return SK_PASS;
116 
117 	sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
118 	if (!sk)
119 		return SK_PASS;
120 
121 	err = bpf_sk_assign(ctx, sk, 0);
122 	bpf_sk_release(sk);
123 	return err ? SK_DROP : SK_PASS;
124 }
125 
126 /* Redirect packets destined for DST_IP4 address to socket at redir_map[0]. */
127 SEC("sk_lookup")
redir_ip4(struct bpf_sk_lookup * ctx)128 int redir_ip4(struct bpf_sk_lookup *ctx)
129 {
130 	struct bpf_sock *sk;
131 	int err;
132 
133 	if (ctx->family != AF_INET)
134 		return SK_PASS;
135 	if (ctx->local_port != DST_PORT)
136 		return SK_PASS;
137 	if (ctx->local_ip4 != DST_IP4)
138 		return SK_PASS;
139 
140 	sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
141 	if (!sk)
142 		return SK_PASS;
143 
144 	err = bpf_sk_assign(ctx, sk, 0);
145 	bpf_sk_release(sk);
146 	return err ? SK_DROP : SK_PASS;
147 }
148 
149 /* Redirect packets destined for DST_IP6 address to socket at redir_map[0]. */
150 SEC("sk_lookup")
redir_ip6(struct bpf_sk_lookup * ctx)151 int redir_ip6(struct bpf_sk_lookup *ctx)
152 {
153 	struct bpf_sock *sk;
154 	int err;
155 
156 	if (ctx->family != AF_INET6)
157 		return SK_PASS;
158 	if (ctx->local_port != DST_PORT)
159 		return SK_PASS;
160 	if (ctx->local_ip6[0] != DST_IP6[0] ||
161 	    ctx->local_ip6[1] != DST_IP6[1] ||
162 	    ctx->local_ip6[2] != DST_IP6[2] ||
163 	    ctx->local_ip6[3] != DST_IP6[3])
164 		return SK_PASS;
165 
166 	sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
167 	if (!sk)
168 		return SK_PASS;
169 
170 	err = bpf_sk_assign(ctx, sk, 0);
171 	bpf_sk_release(sk);
172 	return err ? SK_DROP : SK_PASS;
173 }
174 
175 SEC("sk_lookup")
select_sock_a(struct bpf_sk_lookup * ctx)176 int select_sock_a(struct bpf_sk_lookup *ctx)
177 {
178 	struct bpf_sock *sk;
179 	int err;
180 
181 	sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
182 	if (!sk)
183 		return SK_PASS;
184 
185 	err = bpf_sk_assign(ctx, sk, 0);
186 	bpf_sk_release(sk);
187 	return err ? SK_DROP : SK_PASS;
188 }
189 
190 SEC("sk_lookup")
select_sock_a_no_reuseport(struct bpf_sk_lookup * ctx)191 int select_sock_a_no_reuseport(struct bpf_sk_lookup *ctx)
192 {
193 	struct bpf_sock *sk;
194 	int err;
195 
196 	sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
197 	if (!sk)
198 		return SK_DROP;
199 
200 	err = bpf_sk_assign(ctx, sk, BPF_SK_LOOKUP_F_NO_REUSEPORT);
201 	bpf_sk_release(sk);
202 	return err ? SK_DROP : SK_PASS;
203 }
204 
205 SEC("sk_reuseport")
select_sock_b(struct sk_reuseport_md * ctx)206 int select_sock_b(struct sk_reuseport_md *ctx)
207 {
208 	__u32 key = KEY_SERVER_B;
209 	int err;
210 
211 	err = bpf_sk_select_reuseport(ctx, &redir_map, &key, 0);
212 	return err ? SK_DROP : SK_PASS;
213 }
214 
215 /* Check that bpf_sk_assign() returns -EEXIST if socket already selected. */
216 SEC("sk_lookup")
sk_assign_eexist(struct bpf_sk_lookup * ctx)217 int sk_assign_eexist(struct bpf_sk_lookup *ctx)
218 {
219 	struct bpf_sock *sk;
220 	int err, ret;
221 
222 	ret = SK_DROP;
223 	sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_B);
224 	if (!sk)
225 		goto out;
226 	err = bpf_sk_assign(ctx, sk, 0);
227 	if (err)
228 		goto out;
229 	bpf_sk_release(sk);
230 
231 	sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
232 	if (!sk)
233 		goto out;
234 	err = bpf_sk_assign(ctx, sk, 0);
235 	if (err != -EEXIST) {
236 		bpf_printk("sk_assign returned %d, expected %d\n",
237 			   err, -EEXIST);
238 		goto out;
239 	}
240 
241 	ret = SK_PASS; /* Success, redirect to KEY_SERVER_B */
242 out:
243 	if (sk)
244 		bpf_sk_release(sk);
245 	return ret;
246 }
247 
248 /* Check that bpf_sk_assign(BPF_SK_LOOKUP_F_REPLACE) can override selection. */
249 SEC("sk_lookup")
sk_assign_replace_flag(struct bpf_sk_lookup * ctx)250 int sk_assign_replace_flag(struct bpf_sk_lookup *ctx)
251 {
252 	struct bpf_sock *sk;
253 	int err, ret;
254 
255 	ret = SK_DROP;
256 	sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
257 	if (!sk)
258 		goto out;
259 	err = bpf_sk_assign(ctx, sk, 0);
260 	if (err)
261 		goto out;
262 	bpf_sk_release(sk);
263 
264 	sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_B);
265 	if (!sk)
266 		goto out;
267 	err = bpf_sk_assign(ctx, sk, BPF_SK_LOOKUP_F_REPLACE);
268 	if (err) {
269 		bpf_printk("sk_assign returned %d, expected 0\n", err);
270 		goto out;
271 	}
272 
273 	ret = SK_PASS; /* Success, redirect to KEY_SERVER_B */
274 out:
275 	if (sk)
276 		bpf_sk_release(sk);
277 	return ret;
278 }
279 
280 /* Check that bpf_sk_assign(sk=NULL) is accepted. */
281 SEC("sk_lookup")
sk_assign_null(struct bpf_sk_lookup * ctx)282 int sk_assign_null(struct bpf_sk_lookup *ctx)
283 {
284 	struct bpf_sock *sk = NULL;
285 	int err, ret;
286 
287 	ret = SK_DROP;
288 
289 	err = bpf_sk_assign(ctx, NULL, 0);
290 	if (err) {
291 		bpf_printk("sk_assign returned %d, expected 0\n", err);
292 		goto out;
293 	}
294 
295 	sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_B);
296 	if (!sk)
297 		goto out;
298 	err = bpf_sk_assign(ctx, sk, BPF_SK_LOOKUP_F_REPLACE);
299 	if (err) {
300 		bpf_printk("sk_assign returned %d, expected 0\n", err);
301 		goto out;
302 	}
303 
304 	if (ctx->sk != sk)
305 		goto out;
306 	err = bpf_sk_assign(ctx, NULL, 0);
307 	if (err != -EEXIST)
308 		goto out;
309 	err = bpf_sk_assign(ctx, NULL, BPF_SK_LOOKUP_F_REPLACE);
310 	if (err)
311 		goto out;
312 	err = bpf_sk_assign(ctx, sk, BPF_SK_LOOKUP_F_REPLACE);
313 	if (err)
314 		goto out;
315 
316 	ret = SK_PASS; /* Success, redirect to KEY_SERVER_B */
317 out:
318 	if (sk)
319 		bpf_sk_release(sk);
320 	return ret;
321 }
322 
323 /* Check that selected sk is accessible through context. */
324 SEC("sk_lookup")
access_ctx_sk(struct bpf_sk_lookup * ctx)325 int access_ctx_sk(struct bpf_sk_lookup *ctx)
326 {
327 	struct bpf_sock *sk1 = NULL, *sk2 = NULL;
328 	int err, ret;
329 
330 	ret = SK_DROP;
331 
332 	/* Try accessing unassigned (NULL) ctx->sk field */
333 	if (ctx->sk && ctx->sk->family != AF_INET)
334 		goto out;
335 
336 	/* Assign a value to ctx->sk */
337 	sk1 = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
338 	if (!sk1)
339 		goto out;
340 	err = bpf_sk_assign(ctx, sk1, 0);
341 	if (err)
342 		goto out;
343 	if (ctx->sk != sk1)
344 		goto out;
345 
346 	/* Access ctx->sk fields */
347 	if (ctx->sk->family != AF_INET ||
348 	    ctx->sk->type != SOCK_STREAM ||
349 	    ctx->sk->state != BPF_TCP_LISTEN)
350 		goto out;
351 
352 	/* Reset selection */
353 	err = bpf_sk_assign(ctx, NULL, BPF_SK_LOOKUP_F_REPLACE);
354 	if (err)
355 		goto out;
356 	if (ctx->sk)
357 		goto out;
358 
359 	/* Assign another socket */
360 	sk2 = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_B);
361 	if (!sk2)
362 		goto out;
363 	err = bpf_sk_assign(ctx, sk2, BPF_SK_LOOKUP_F_REPLACE);
364 	if (err)
365 		goto out;
366 	if (ctx->sk != sk2)
367 		goto out;
368 
369 	/* Access reassigned ctx->sk fields */
370 	if (ctx->sk->family != AF_INET ||
371 	    ctx->sk->type != SOCK_STREAM ||
372 	    ctx->sk->state != BPF_TCP_LISTEN)
373 		goto out;
374 
375 	ret = SK_PASS; /* Success, redirect to KEY_SERVER_B */
376 out:
377 	if (sk1)
378 		bpf_sk_release(sk1);
379 	if (sk2)
380 		bpf_sk_release(sk2);
381 	return ret;
382 }
383 
384 /* Check narrow loads from ctx fields that support them.
385  *
386  * Narrow loads of size >= target field size from a non-zero offset
387  * are not covered because they give bogus results, that is the
388  * verifier ignores the offset.
389  */
390 SEC("sk_lookup")
ctx_narrow_access(struct bpf_sk_lookup * ctx)391 int ctx_narrow_access(struct bpf_sk_lookup *ctx)
392 {
393 	struct bpf_sock *sk;
394 	__u32 val_u32;
395 	bool v4;
396 
397 	v4 = (ctx->family == AF_INET);
398 
399 	/* Narrow loads from family field */
400 	if (LSB(ctx->family, 0) != (v4 ? AF_INET : AF_INET6) ||
401 	    LSB(ctx->family, 1) != 0 || LSB(ctx->family, 2) != 0 || LSB(ctx->family, 3) != 0)
402 		return SK_DROP;
403 	if (LSW(ctx->family, 0) != (v4 ? AF_INET : AF_INET6))
404 		return SK_DROP;
405 
406 	/* Narrow loads from protocol field */
407 	if (LSB(ctx->protocol, 0) != IPPROTO_TCP ||
408 	    LSB(ctx->protocol, 1) != 0 || LSB(ctx->protocol, 2) != 0 || LSB(ctx->protocol, 3) != 0)
409 		return SK_DROP;
410 	if (LSW(ctx->protocol, 0) != IPPROTO_TCP)
411 		return SK_DROP;
412 
413 	/* Narrow loads from remote_port field. Expect SRC_PORT. */
414 	if (LSB(ctx->remote_port, 0) != ((SRC_PORT >> 0) & 0xff) ||
415 	    LSB(ctx->remote_port, 1) != ((SRC_PORT >> 8) & 0xff))
416 		return SK_DROP;
417 	if (LSW(ctx->remote_port, 0) != SRC_PORT)
418 		return SK_DROP;
419 
420 	/*
421 	 * NOTE: 4-byte load from bpf_sk_lookup at remote_port offset
422 	 * is quirky. It gets rewritten by the access converter to a
423 	 * 2-byte load for backward compatibility. Treating the load
424 	 * result as a be16 value makes the code portable across
425 	 * little- and big-endian platforms.
426 	 */
427 	val_u32 = *(__u32 *)&ctx->remote_port;
428 	if (val_u32 != SRC_PORT)
429 		return SK_DROP;
430 
431 	/* Narrow loads from local_port field. Expect DST_PORT. */
432 	if (LSB(ctx->local_port, 0) != ((DST_PORT >> 0) & 0xff) ||
433 	    LSB(ctx->local_port, 1) != ((DST_PORT >> 8) & 0xff) ||
434 	    LSB(ctx->local_port, 2) != 0 || LSB(ctx->local_port, 3) != 0)
435 		return SK_DROP;
436 	if (LSW(ctx->local_port, 0) != DST_PORT)
437 		return SK_DROP;
438 
439 	/* Narrow loads from IPv4 fields */
440 	if (v4) {
441 		/* Expect SRC_IP4 in remote_ip4 */
442 		if (LSB(ctx->remote_ip4, 0) != ((SRC_IP4 >> 0) & 0xff) ||
443 		    LSB(ctx->remote_ip4, 1) != ((SRC_IP4 >> 8) & 0xff) ||
444 		    LSB(ctx->remote_ip4, 2) != ((SRC_IP4 >> 16) & 0xff) ||
445 		    LSB(ctx->remote_ip4, 3) != ((SRC_IP4 >> 24) & 0xff))
446 			return SK_DROP;
447 		if (LSW(ctx->remote_ip4, 0) != ((SRC_IP4 >> 0) & 0xffff) ||
448 		    LSW(ctx->remote_ip4, 1) != ((SRC_IP4 >> 16) & 0xffff))
449 			return SK_DROP;
450 
451 		/* Expect DST_IP4 in local_ip4 */
452 		if (LSB(ctx->local_ip4, 0) != ((DST_IP4 >> 0) & 0xff) ||
453 		    LSB(ctx->local_ip4, 1) != ((DST_IP4 >> 8) & 0xff) ||
454 		    LSB(ctx->local_ip4, 2) != ((DST_IP4 >> 16) & 0xff) ||
455 		    LSB(ctx->local_ip4, 3) != ((DST_IP4 >> 24) & 0xff))
456 			return SK_DROP;
457 		if (LSW(ctx->local_ip4, 0) != ((DST_IP4 >> 0) & 0xffff) ||
458 		    LSW(ctx->local_ip4, 1) != ((DST_IP4 >> 16) & 0xffff))
459 			return SK_DROP;
460 	} else {
461 		/* Expect 0.0.0.0 IPs when family != AF_INET */
462 		if (LSB(ctx->remote_ip4, 0) != 0 || LSB(ctx->remote_ip4, 1) != 0 ||
463 		    LSB(ctx->remote_ip4, 2) != 0 || LSB(ctx->remote_ip4, 3) != 0)
464 			return SK_DROP;
465 		if (LSW(ctx->remote_ip4, 0) != 0 || LSW(ctx->remote_ip4, 1) != 0)
466 			return SK_DROP;
467 
468 		if (LSB(ctx->local_ip4, 0) != 0 || LSB(ctx->local_ip4, 1) != 0 ||
469 		    LSB(ctx->local_ip4, 2) != 0 || LSB(ctx->local_ip4, 3) != 0)
470 			return SK_DROP;
471 		if (LSW(ctx->local_ip4, 0) != 0 || LSW(ctx->local_ip4, 1) != 0)
472 			return SK_DROP;
473 	}
474 
475 	/* Narrow loads from IPv6 fields */
476 	if (!v4) {
477 		/* Expect SRC_IP6 in remote_ip6 */
478 		if (LSB(ctx->remote_ip6[0], 0) != ((SRC_IP6[0] >> 0) & 0xff) ||
479 		    LSB(ctx->remote_ip6[0], 1) != ((SRC_IP6[0] >> 8) & 0xff) ||
480 		    LSB(ctx->remote_ip6[0], 2) != ((SRC_IP6[0] >> 16) & 0xff) ||
481 		    LSB(ctx->remote_ip6[0], 3) != ((SRC_IP6[0] >> 24) & 0xff) ||
482 		    LSB(ctx->remote_ip6[1], 0) != ((SRC_IP6[1] >> 0) & 0xff) ||
483 		    LSB(ctx->remote_ip6[1], 1) != ((SRC_IP6[1] >> 8) & 0xff) ||
484 		    LSB(ctx->remote_ip6[1], 2) != ((SRC_IP6[1] >> 16) & 0xff) ||
485 		    LSB(ctx->remote_ip6[1], 3) != ((SRC_IP6[1] >> 24) & 0xff) ||
486 		    LSB(ctx->remote_ip6[2], 0) != ((SRC_IP6[2] >> 0) & 0xff) ||
487 		    LSB(ctx->remote_ip6[2], 1) != ((SRC_IP6[2] >> 8) & 0xff) ||
488 		    LSB(ctx->remote_ip6[2], 2) != ((SRC_IP6[2] >> 16) & 0xff) ||
489 		    LSB(ctx->remote_ip6[2], 3) != ((SRC_IP6[2] >> 24) & 0xff) ||
490 		    LSB(ctx->remote_ip6[3], 0) != ((SRC_IP6[3] >> 0) & 0xff) ||
491 		    LSB(ctx->remote_ip6[3], 1) != ((SRC_IP6[3] >> 8) & 0xff) ||
492 		    LSB(ctx->remote_ip6[3], 2) != ((SRC_IP6[3] >> 16) & 0xff) ||
493 		    LSB(ctx->remote_ip6[3], 3) != ((SRC_IP6[3] >> 24) & 0xff))
494 			return SK_DROP;
495 		if (LSW(ctx->remote_ip6[0], 0) != ((SRC_IP6[0] >> 0) & 0xffff) ||
496 		    LSW(ctx->remote_ip6[0], 1) != ((SRC_IP6[0] >> 16) & 0xffff) ||
497 		    LSW(ctx->remote_ip6[1], 0) != ((SRC_IP6[1] >> 0) & 0xffff) ||
498 		    LSW(ctx->remote_ip6[1], 1) != ((SRC_IP6[1] >> 16) & 0xffff) ||
499 		    LSW(ctx->remote_ip6[2], 0) != ((SRC_IP6[2] >> 0) & 0xffff) ||
500 		    LSW(ctx->remote_ip6[2], 1) != ((SRC_IP6[2] >> 16) & 0xffff) ||
501 		    LSW(ctx->remote_ip6[3], 0) != ((SRC_IP6[3] >> 0) & 0xffff) ||
502 		    LSW(ctx->remote_ip6[3], 1) != ((SRC_IP6[3] >> 16) & 0xffff))
503 			return SK_DROP;
504 		/* Expect DST_IP6 in local_ip6 */
505 		if (LSB(ctx->local_ip6[0], 0) != ((DST_IP6[0] >> 0) & 0xff) ||
506 		    LSB(ctx->local_ip6[0], 1) != ((DST_IP6[0] >> 8) & 0xff) ||
507 		    LSB(ctx->local_ip6[0], 2) != ((DST_IP6[0] >> 16) & 0xff) ||
508 		    LSB(ctx->local_ip6[0], 3) != ((DST_IP6[0] >> 24) & 0xff) ||
509 		    LSB(ctx->local_ip6[1], 0) != ((DST_IP6[1] >> 0) & 0xff) ||
510 		    LSB(ctx->local_ip6[1], 1) != ((DST_IP6[1] >> 8) & 0xff) ||
511 		    LSB(ctx->local_ip6[1], 2) != ((DST_IP6[1] >> 16) & 0xff) ||
512 		    LSB(ctx->local_ip6[1], 3) != ((DST_IP6[1] >> 24) & 0xff) ||
513 		    LSB(ctx->local_ip6[2], 0) != ((DST_IP6[2] >> 0) & 0xff) ||
514 		    LSB(ctx->local_ip6[2], 1) != ((DST_IP6[2] >> 8) & 0xff) ||
515 		    LSB(ctx->local_ip6[2], 2) != ((DST_IP6[2] >> 16) & 0xff) ||
516 		    LSB(ctx->local_ip6[2], 3) != ((DST_IP6[2] >> 24) & 0xff) ||
517 		    LSB(ctx->local_ip6[3], 0) != ((DST_IP6[3] >> 0) & 0xff) ||
518 		    LSB(ctx->local_ip6[3], 1) != ((DST_IP6[3] >> 8) & 0xff) ||
519 		    LSB(ctx->local_ip6[3], 2) != ((DST_IP6[3] >> 16) & 0xff) ||
520 		    LSB(ctx->local_ip6[3], 3) != ((DST_IP6[3] >> 24) & 0xff))
521 			return SK_DROP;
522 		if (LSW(ctx->local_ip6[0], 0) != ((DST_IP6[0] >> 0) & 0xffff) ||
523 		    LSW(ctx->local_ip6[0], 1) != ((DST_IP6[0] >> 16) & 0xffff) ||
524 		    LSW(ctx->local_ip6[1], 0) != ((DST_IP6[1] >> 0) & 0xffff) ||
525 		    LSW(ctx->local_ip6[1], 1) != ((DST_IP6[1] >> 16) & 0xffff) ||
526 		    LSW(ctx->local_ip6[2], 0) != ((DST_IP6[2] >> 0) & 0xffff) ||
527 		    LSW(ctx->local_ip6[2], 1) != ((DST_IP6[2] >> 16) & 0xffff) ||
528 		    LSW(ctx->local_ip6[3], 0) != ((DST_IP6[3] >> 0) & 0xffff) ||
529 		    LSW(ctx->local_ip6[3], 1) != ((DST_IP6[3] >> 16) & 0xffff))
530 			return SK_DROP;
531 	} else {
532 		/* Expect :: IPs when family != AF_INET6 */
533 		if (LSB(ctx->remote_ip6[0], 0) != 0 || LSB(ctx->remote_ip6[0], 1) != 0 ||
534 		    LSB(ctx->remote_ip6[0], 2) != 0 || LSB(ctx->remote_ip6[0], 3) != 0 ||
535 		    LSB(ctx->remote_ip6[1], 0) != 0 || LSB(ctx->remote_ip6[1], 1) != 0 ||
536 		    LSB(ctx->remote_ip6[1], 2) != 0 || LSB(ctx->remote_ip6[1], 3) != 0 ||
537 		    LSB(ctx->remote_ip6[2], 0) != 0 || LSB(ctx->remote_ip6[2], 1) != 0 ||
538 		    LSB(ctx->remote_ip6[2], 2) != 0 || LSB(ctx->remote_ip6[2], 3) != 0 ||
539 		    LSB(ctx->remote_ip6[3], 0) != 0 || LSB(ctx->remote_ip6[3], 1) != 0 ||
540 		    LSB(ctx->remote_ip6[3], 2) != 0 || LSB(ctx->remote_ip6[3], 3) != 0)
541 			return SK_DROP;
542 		if (LSW(ctx->remote_ip6[0], 0) != 0 || LSW(ctx->remote_ip6[0], 1) != 0 ||
543 		    LSW(ctx->remote_ip6[1], 0) != 0 || LSW(ctx->remote_ip6[1], 1) != 0 ||
544 		    LSW(ctx->remote_ip6[2], 0) != 0 || LSW(ctx->remote_ip6[2], 1) != 0 ||
545 		    LSW(ctx->remote_ip6[3], 0) != 0 || LSW(ctx->remote_ip6[3], 1) != 0)
546 			return SK_DROP;
547 
548 		if (LSB(ctx->local_ip6[0], 0) != 0 || LSB(ctx->local_ip6[0], 1) != 0 ||
549 		    LSB(ctx->local_ip6[0], 2) != 0 || LSB(ctx->local_ip6[0], 3) != 0 ||
550 		    LSB(ctx->local_ip6[1], 0) != 0 || LSB(ctx->local_ip6[1], 1) != 0 ||
551 		    LSB(ctx->local_ip6[1], 2) != 0 || LSB(ctx->local_ip6[1], 3) != 0 ||
552 		    LSB(ctx->local_ip6[2], 0) != 0 || LSB(ctx->local_ip6[2], 1) != 0 ||
553 		    LSB(ctx->local_ip6[2], 2) != 0 || LSB(ctx->local_ip6[2], 3) != 0 ||
554 		    LSB(ctx->local_ip6[3], 0) != 0 || LSB(ctx->local_ip6[3], 1) != 0 ||
555 		    LSB(ctx->local_ip6[3], 2) != 0 || LSB(ctx->local_ip6[3], 3) != 0)
556 			return SK_DROP;
557 		if (LSW(ctx->remote_ip6[0], 0) != 0 || LSW(ctx->remote_ip6[0], 1) != 0 ||
558 		    LSW(ctx->remote_ip6[1], 0) != 0 || LSW(ctx->remote_ip6[1], 1) != 0 ||
559 		    LSW(ctx->remote_ip6[2], 0) != 0 || LSW(ctx->remote_ip6[2], 1) != 0 ||
560 		    LSW(ctx->remote_ip6[3], 0) != 0 || LSW(ctx->remote_ip6[3], 1) != 0)
561 			return SK_DROP;
562 	}
563 
564 	/* Success, redirect to KEY_SERVER_B */
565 	sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_B);
566 	if (sk) {
567 		bpf_sk_assign(ctx, sk, 0);
568 		bpf_sk_release(sk);
569 	}
570 	return SK_PASS;
571 }
572 
573 /* Check that sk_assign rejects SERVER_A socket with -ESOCKNOSUPPORT */
574 SEC("sk_lookup")
sk_assign_esocknosupport(struct bpf_sk_lookup * ctx)575 int sk_assign_esocknosupport(struct bpf_sk_lookup *ctx)
576 {
577 	struct bpf_sock *sk;
578 	int err, ret;
579 
580 	ret = SK_DROP;
581 	sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
582 	if (!sk)
583 		goto out;
584 
585 	err = bpf_sk_assign(ctx, sk, 0);
586 	if (err != -ESOCKTNOSUPPORT) {
587 		bpf_printk("sk_assign returned %d, expected %d\n",
588 			   err, -ESOCKTNOSUPPORT);
589 		goto out;
590 	}
591 
592 	ret = SK_PASS; /* Success, pass to regular lookup */
593 out:
594 	if (sk)
595 		bpf_sk_release(sk);
596 	return ret;
597 }
598 
599 SEC("sk_lookup")
multi_prog_pass1(struct bpf_sk_lookup * ctx)600 int multi_prog_pass1(struct bpf_sk_lookup *ctx)
601 {
602 	bpf_map_update_elem(&run_map, &KEY_PROG1, &PROG_DONE, BPF_ANY);
603 	return SK_PASS;
604 }
605 
606 SEC("sk_lookup")
multi_prog_pass2(struct bpf_sk_lookup * ctx)607 int multi_prog_pass2(struct bpf_sk_lookup *ctx)
608 {
609 	bpf_map_update_elem(&run_map, &KEY_PROG2, &PROG_DONE, BPF_ANY);
610 	return SK_PASS;
611 }
612 
613 SEC("sk_lookup")
multi_prog_drop1(struct bpf_sk_lookup * ctx)614 int multi_prog_drop1(struct bpf_sk_lookup *ctx)
615 {
616 	bpf_map_update_elem(&run_map, &KEY_PROG1, &PROG_DONE, BPF_ANY);
617 	return SK_DROP;
618 }
619 
620 SEC("sk_lookup")
multi_prog_drop2(struct bpf_sk_lookup * ctx)621 int multi_prog_drop2(struct bpf_sk_lookup *ctx)
622 {
623 	bpf_map_update_elem(&run_map, &KEY_PROG2, &PROG_DONE, BPF_ANY);
624 	return SK_DROP;
625 }
626 
select_server_a(struct bpf_sk_lookup * ctx)627 static __always_inline int select_server_a(struct bpf_sk_lookup *ctx)
628 {
629 	struct bpf_sock *sk;
630 	int err;
631 
632 	sk = bpf_map_lookup_elem(&redir_map, &KEY_SERVER_A);
633 	if (!sk)
634 		return SK_DROP;
635 
636 	err = bpf_sk_assign(ctx, sk, 0);
637 	bpf_sk_release(sk);
638 	if (err)
639 		return SK_DROP;
640 
641 	return SK_PASS;
642 }
643 
644 SEC("sk_lookup")
multi_prog_redir1(struct bpf_sk_lookup * ctx)645 int multi_prog_redir1(struct bpf_sk_lookup *ctx)
646 {
647 	(void)select_server_a(ctx);
648 	bpf_map_update_elem(&run_map, &KEY_PROG1, &PROG_DONE, BPF_ANY);
649 	return SK_PASS;
650 }
651 
652 SEC("sk_lookup")
multi_prog_redir2(struct bpf_sk_lookup * ctx)653 int multi_prog_redir2(struct bpf_sk_lookup *ctx)
654 {
655 	(void)select_server_a(ctx);
656 	bpf_map_update_elem(&run_map, &KEY_PROG2, &PROG_DONE, BPF_ANY);
657 	return SK_PASS;
658 }
659 
660 char _license[] SEC("license") = "Dual BSD/GPL";
661