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16#include <linux/bpf.h>
17#include <linux/bpf_verifier.h>
18#include <linux/debugfs.h>
19#include <linux/kernel.h>
20#include <linux/mutex.h>
21#include <linux/rtnetlink.h>
22#include <net/pkt_cls.h>
23
24#include "netdevsim.h"
25
26#define pr_vlog(env, fmt, ...) \
27 bpf_verifier_log_write(env, "[netdevsim] " fmt, ##__VA_ARGS__)
28
29struct nsim_bpf_bound_prog {
30 struct nsim_dev *nsim_dev;
31 struct bpf_prog *prog;
32 struct dentry *ddir;
33 const char *state;
34 bool is_loaded;
35 struct list_head l;
36};
37
38#define NSIM_BPF_MAX_KEYS 2
39
40struct nsim_bpf_bound_map {
41 struct netdevsim *ns;
42 struct bpf_offloaded_map *map;
43 struct mutex mutex;
44 struct nsim_map_entry {
45 void *key;
46 void *value;
47 } entry[NSIM_BPF_MAX_KEYS];
48 struct list_head l;
49};
50
51static int nsim_bpf_string_show(struct seq_file *file, void *data)
52{
53 const char **str = file->private;
54
55 if (*str)
56 seq_printf(file, "%s\n", *str);
57
58 return 0;
59}
60DEFINE_SHOW_ATTRIBUTE(nsim_bpf_string);
61
62static int
63nsim_bpf_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn)
64{
65 struct nsim_bpf_bound_prog *state;
66 int ret = 0;
67
68 state = env->prog->aux->offload->dev_priv;
69 if (state->nsim_dev->bpf_bind_verifier_delay && !insn_idx)
70 msleep(state->nsim_dev->bpf_bind_verifier_delay);
71
72 if (insn_idx == env->prog->len - 1) {
73 pr_vlog(env, "Hello from netdevsim!\n");
74
75 if (!state->nsim_dev->bpf_bind_verifier_accept)
76 ret = -EOPNOTSUPP;
77 }
78
79 return ret;
80}
81
82static int nsim_bpf_finalize(struct bpf_verifier_env *env)
83{
84 return 0;
85}
86
87static bool nsim_xdp_offload_active(struct netdevsim *ns)
88{
89 return ns->xdp_hw.prog;
90}
91
92static void nsim_prog_set_loaded(struct bpf_prog *prog, bool loaded)
93{
94 struct nsim_bpf_bound_prog *state;
95
96 if (!prog || !prog->aux->offload)
97 return;
98
99 state = prog->aux->offload->dev_priv;
100 state->is_loaded = loaded;
101}
102
103static int
104nsim_bpf_offload(struct netdevsim *ns, struct bpf_prog *prog, bool oldprog)
105{
106 nsim_prog_set_loaded(ns->bpf_offloaded, false);
107
108 WARN(!!ns->bpf_offloaded != oldprog,
109 "bad offload state, expected offload %sto be active",
110 oldprog ? "" : "not ");
111 ns->bpf_offloaded = prog;
112 ns->bpf_offloaded_id = prog ? prog->aux->id : 0;
113 nsim_prog_set_loaded(prog, true);
114
115 return 0;
116}
117
118int nsim_bpf_setup_tc_block_cb(enum tc_setup_type type,
119 void *type_data, void *cb_priv)
120{
121 struct tc_cls_bpf_offload *cls_bpf = type_data;
122 struct bpf_prog *prog = cls_bpf->prog;
123 struct netdevsim *ns = cb_priv;
124 struct bpf_prog *oldprog;
125
126 if (type != TC_SETUP_CLSBPF) {
127 NSIM_EA(cls_bpf->common.extack,
128 "only offload of BPF classifiers supported");
129 return -EOPNOTSUPP;
130 }
131
132 if (!tc_cls_can_offload_and_chain0(ns->netdev, &cls_bpf->common))
133 return -EOPNOTSUPP;
134
135 if (cls_bpf->common.protocol != htons(ETH_P_ALL)) {
136 NSIM_EA(cls_bpf->common.extack,
137 "only ETH_P_ALL supported as filter protocol");
138 return -EOPNOTSUPP;
139 }
140
141 if (!ns->bpf_tc_accept) {
142 NSIM_EA(cls_bpf->common.extack,
143 "netdevsim configured to reject BPF TC offload");
144 return -EOPNOTSUPP;
145 }
146
147 if (prog && !prog->aux->offload && !ns->bpf_tc_non_bound_accept) {
148 NSIM_EA(cls_bpf->common.extack,
149 "netdevsim configured to reject unbound programs");
150 return -EOPNOTSUPP;
151 }
152
153 if (cls_bpf->command != TC_CLSBPF_OFFLOAD)
154 return -EOPNOTSUPP;
155
156 oldprog = cls_bpf->oldprog;
157
158
159 if (ns->bpf_offloaded != oldprog) {
160 oldprog = NULL;
161 if (!cls_bpf->prog)
162 return 0;
163 if (ns->bpf_offloaded) {
164 NSIM_EA(cls_bpf->common.extack,
165 "driver and netdev offload states mismatch");
166 return -EBUSY;
167 }
168 }
169
170 return nsim_bpf_offload(ns, cls_bpf->prog, oldprog);
171}
172
173int nsim_bpf_disable_tc(struct netdevsim *ns)
174{
175 if (ns->bpf_offloaded && !nsim_xdp_offload_active(ns))
176 return -EBUSY;
177 return 0;
178}
179
180static int nsim_xdp_offload_prog(struct netdevsim *ns, struct netdev_bpf *bpf)
181{
182 if (!nsim_xdp_offload_active(ns) && !bpf->prog)
183 return 0;
184 if (!nsim_xdp_offload_active(ns) && bpf->prog && ns->bpf_offloaded) {
185 NSIM_EA(bpf->extack, "TC program is already loaded");
186 return -EBUSY;
187 }
188
189 return nsim_bpf_offload(ns, bpf->prog, nsim_xdp_offload_active(ns));
190}
191
192static int
193nsim_xdp_set_prog(struct netdevsim *ns, struct netdev_bpf *bpf,
194 struct xdp_attachment_info *xdp)
195{
196 int err;
197
198 if (bpf->command == XDP_SETUP_PROG && !ns->bpf_xdpdrv_accept) {
199 NSIM_EA(bpf->extack, "driver XDP disabled in DebugFS");
200 return -EOPNOTSUPP;
201 }
202 if (bpf->command == XDP_SETUP_PROG_HW && !ns->bpf_xdpoffload_accept) {
203 NSIM_EA(bpf->extack, "XDP offload disabled in DebugFS");
204 return -EOPNOTSUPP;
205 }
206
207 if (bpf->command == XDP_SETUP_PROG_HW) {
208 err = nsim_xdp_offload_prog(ns, bpf);
209 if (err)
210 return err;
211 }
212
213 xdp_attachment_setup(xdp, bpf);
214
215 return 0;
216}
217
218static int nsim_bpf_create_prog(struct nsim_dev *nsim_dev,
219 struct bpf_prog *prog)
220{
221 struct nsim_bpf_bound_prog *state;
222 char name[16];
223 int ret;
224
225 state = kzalloc(sizeof(*state), GFP_KERNEL);
226 if (!state)
227 return -ENOMEM;
228
229 state->nsim_dev = nsim_dev;
230 state->prog = prog;
231 state->state = "verify";
232
233
234 sprintf(name, "%u", nsim_dev->prog_id_gen++);
235 state->ddir = debugfs_create_dir(name, nsim_dev->ddir_bpf_bound_progs);
236 if (IS_ERR(state->ddir)) {
237 ret = PTR_ERR(state->ddir);
238 kfree(state);
239 return ret;
240 }
241
242 debugfs_create_u32("id", 0400, state->ddir, &prog->aux->id);
243 debugfs_create_file("state", 0400, state->ddir,
244 &state->state, &nsim_bpf_string_fops);
245 debugfs_create_bool("loaded", 0400, state->ddir, &state->is_loaded);
246
247 list_add_tail(&state->l, &nsim_dev->bpf_bound_progs);
248
249 prog->aux->offload->dev_priv = state;
250
251 return 0;
252}
253
254static int nsim_bpf_verifier_prep(struct bpf_prog *prog)
255{
256 struct nsim_dev *nsim_dev =
257 bpf_offload_dev_priv(prog->aux->offload->offdev);
258
259 if (!nsim_dev->bpf_bind_accept)
260 return -EOPNOTSUPP;
261
262 return nsim_bpf_create_prog(nsim_dev, prog);
263}
264
265static int nsim_bpf_translate(struct bpf_prog *prog)
266{
267 struct nsim_bpf_bound_prog *state = prog->aux->offload->dev_priv;
268
269 state->state = "xlated";
270 return 0;
271}
272
273static void nsim_bpf_destroy_prog(struct bpf_prog *prog)
274{
275 struct nsim_bpf_bound_prog *state;
276
277 state = prog->aux->offload->dev_priv;
278 WARN(state->is_loaded,
279 "offload state destroyed while program still bound");
280 debugfs_remove_recursive(state->ddir);
281 list_del(&state->l);
282 kfree(state);
283}
284
285static const struct bpf_prog_offload_ops nsim_bpf_dev_ops = {
286 .insn_hook = nsim_bpf_verify_insn,
287 .finalize = nsim_bpf_finalize,
288 .prepare = nsim_bpf_verifier_prep,
289 .translate = nsim_bpf_translate,
290 .destroy = nsim_bpf_destroy_prog,
291};
292
293static int nsim_setup_prog_checks(struct netdevsim *ns, struct netdev_bpf *bpf)
294{
295 if (bpf->prog && bpf->prog->aux->offload) {
296 NSIM_EA(bpf->extack, "attempt to load offloaded prog to drv");
297 return -EINVAL;
298 }
299 if (ns->netdev->mtu > NSIM_XDP_MAX_MTU) {
300 NSIM_EA(bpf->extack, "MTU too large w/ XDP enabled");
301 return -EINVAL;
302 }
303 return 0;
304}
305
306static int
307nsim_setup_prog_hw_checks(struct netdevsim *ns, struct netdev_bpf *bpf)
308{
309 struct nsim_bpf_bound_prog *state;
310
311 if (!bpf->prog)
312 return 0;
313
314 if (!bpf->prog->aux->offload) {
315 NSIM_EA(bpf->extack, "xdpoffload of non-bound program");
316 return -EINVAL;
317 }
318 if (!bpf_offload_dev_match(bpf->prog, ns->netdev)) {
319 NSIM_EA(bpf->extack, "program bound to different dev");
320 return -EINVAL;
321 }
322
323 state = bpf->prog->aux->offload->dev_priv;
324 if (WARN_ON(strcmp(state->state, "xlated"))) {
325 NSIM_EA(bpf->extack, "offloading program in bad state");
326 return -EINVAL;
327 }
328 return 0;
329}
330
331static bool
332nsim_map_key_match(struct bpf_map *map, struct nsim_map_entry *e, void *key)
333{
334 return e->key && !memcmp(key, e->key, map->key_size);
335}
336
337static int nsim_map_key_find(struct bpf_offloaded_map *offmap, void *key)
338{
339 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
340 unsigned int i;
341
342 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++)
343 if (nsim_map_key_match(&offmap->map, &nmap->entry[i], key))
344 return i;
345
346 return -ENOENT;
347}
348
349static int
350nsim_map_alloc_elem(struct bpf_offloaded_map *offmap, unsigned int idx)
351{
352 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
353
354 nmap->entry[idx].key = kmalloc(offmap->map.key_size, GFP_USER);
355 if (!nmap->entry[idx].key)
356 return -ENOMEM;
357 nmap->entry[idx].value = kmalloc(offmap->map.value_size, GFP_USER);
358 if (!nmap->entry[idx].value) {
359 kfree(nmap->entry[idx].key);
360 nmap->entry[idx].key = NULL;
361 return -ENOMEM;
362 }
363
364 return 0;
365}
366
367static int
368nsim_map_get_next_key(struct bpf_offloaded_map *offmap,
369 void *key, void *next_key)
370{
371 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
372 int idx = -ENOENT;
373
374 mutex_lock(&nmap->mutex);
375
376 if (key)
377 idx = nsim_map_key_find(offmap, key);
378 if (idx == -ENOENT)
379 idx = 0;
380 else
381 idx++;
382
383 for (; idx < ARRAY_SIZE(nmap->entry); idx++) {
384 if (nmap->entry[idx].key) {
385 memcpy(next_key, nmap->entry[idx].key,
386 offmap->map.key_size);
387 break;
388 }
389 }
390
391 mutex_unlock(&nmap->mutex);
392
393 if (idx == ARRAY_SIZE(nmap->entry))
394 return -ENOENT;
395 return 0;
396}
397
398static int
399nsim_map_lookup_elem(struct bpf_offloaded_map *offmap, void *key, void *value)
400{
401 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
402 int idx;
403
404 mutex_lock(&nmap->mutex);
405
406 idx = nsim_map_key_find(offmap, key);
407 if (idx >= 0)
408 memcpy(value, nmap->entry[idx].value, offmap->map.value_size);
409
410 mutex_unlock(&nmap->mutex);
411
412 return idx < 0 ? idx : 0;
413}
414
415static int
416nsim_map_update_elem(struct bpf_offloaded_map *offmap,
417 void *key, void *value, u64 flags)
418{
419 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
420 int idx, err = 0;
421
422 mutex_lock(&nmap->mutex);
423
424 idx = nsim_map_key_find(offmap, key);
425 if (idx < 0 && flags == BPF_EXIST) {
426 err = idx;
427 goto exit_unlock;
428 }
429 if (idx >= 0 && flags == BPF_NOEXIST) {
430 err = -EEXIST;
431 goto exit_unlock;
432 }
433
434 if (idx < 0) {
435 for (idx = 0; idx < ARRAY_SIZE(nmap->entry); idx++)
436 if (!nmap->entry[idx].key)
437 break;
438 if (idx == ARRAY_SIZE(nmap->entry)) {
439 err = -E2BIG;
440 goto exit_unlock;
441 }
442
443 err = nsim_map_alloc_elem(offmap, idx);
444 if (err)
445 goto exit_unlock;
446 }
447
448 memcpy(nmap->entry[idx].key, key, offmap->map.key_size);
449 memcpy(nmap->entry[idx].value, value, offmap->map.value_size);
450exit_unlock:
451 mutex_unlock(&nmap->mutex);
452
453 return err;
454}
455
456static int nsim_map_delete_elem(struct bpf_offloaded_map *offmap, void *key)
457{
458 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
459 int idx;
460
461 if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY)
462 return -EINVAL;
463
464 mutex_lock(&nmap->mutex);
465
466 idx = nsim_map_key_find(offmap, key);
467 if (idx >= 0) {
468 kfree(nmap->entry[idx].key);
469 kfree(nmap->entry[idx].value);
470 memset(&nmap->entry[idx], 0, sizeof(nmap->entry[idx]));
471 }
472
473 mutex_unlock(&nmap->mutex);
474
475 return idx < 0 ? idx : 0;
476}
477
478static const struct bpf_map_dev_ops nsim_bpf_map_ops = {
479 .map_get_next_key = nsim_map_get_next_key,
480 .map_lookup_elem = nsim_map_lookup_elem,
481 .map_update_elem = nsim_map_update_elem,
482 .map_delete_elem = nsim_map_delete_elem,
483};
484
485static int
486nsim_bpf_map_alloc(struct netdevsim *ns, struct bpf_offloaded_map *offmap)
487{
488 struct nsim_bpf_bound_map *nmap;
489 int i, err;
490
491 if (WARN_ON(offmap->map.map_type != BPF_MAP_TYPE_ARRAY &&
492 offmap->map.map_type != BPF_MAP_TYPE_HASH))
493 return -EINVAL;
494 if (offmap->map.max_entries > NSIM_BPF_MAX_KEYS)
495 return -ENOMEM;
496 if (offmap->map.map_flags)
497 return -EINVAL;
498
499 nmap = kzalloc(sizeof(*nmap), GFP_USER);
500 if (!nmap)
501 return -ENOMEM;
502
503 offmap->dev_priv = nmap;
504 nmap->ns = ns;
505 nmap->map = offmap;
506 mutex_init(&nmap->mutex);
507
508 if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY) {
509 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) {
510 u32 *key;
511
512 err = nsim_map_alloc_elem(offmap, i);
513 if (err)
514 goto err_free;
515 key = nmap->entry[i].key;
516 *key = i;
517 }
518 }
519
520 offmap->dev_ops = &nsim_bpf_map_ops;
521 list_add_tail(&nmap->l, &ns->nsim_dev->bpf_bound_maps);
522
523 return 0;
524
525err_free:
526 while (--i >= 0) {
527 kfree(nmap->entry[i].key);
528 kfree(nmap->entry[i].value);
529 }
530 kfree(nmap);
531 return err;
532}
533
534static void nsim_bpf_map_free(struct bpf_offloaded_map *offmap)
535{
536 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
537 unsigned int i;
538
539 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) {
540 kfree(nmap->entry[i].key);
541 kfree(nmap->entry[i].value);
542 }
543 list_del_init(&nmap->l);
544 mutex_destroy(&nmap->mutex);
545 kfree(nmap);
546}
547
548int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf)
549{
550 struct netdevsim *ns = netdev_priv(dev);
551 int err;
552
553 ASSERT_RTNL();
554
555 switch (bpf->command) {
556 case XDP_SETUP_PROG:
557 err = nsim_setup_prog_checks(ns, bpf);
558 if (err)
559 return err;
560
561 return nsim_xdp_set_prog(ns, bpf, &ns->xdp);
562 case XDP_SETUP_PROG_HW:
563 err = nsim_setup_prog_hw_checks(ns, bpf);
564 if (err)
565 return err;
566
567 return nsim_xdp_set_prog(ns, bpf, &ns->xdp_hw);
568 case BPF_OFFLOAD_MAP_ALLOC:
569 if (!ns->bpf_map_accept)
570 return -EOPNOTSUPP;
571
572 return nsim_bpf_map_alloc(ns, bpf->offmap);
573 case BPF_OFFLOAD_MAP_FREE:
574 nsim_bpf_map_free(bpf->offmap);
575 return 0;
576 default:
577 return -EINVAL;
578 }
579}
580
581int nsim_bpf_dev_init(struct nsim_dev *nsim_dev)
582{
583 int err;
584
585 INIT_LIST_HEAD(&nsim_dev->bpf_bound_progs);
586 INIT_LIST_HEAD(&nsim_dev->bpf_bound_maps);
587
588 nsim_dev->ddir_bpf_bound_progs = debugfs_create_dir("bpf_bound_progs",
589 nsim_dev->ddir);
590 if (IS_ERR(nsim_dev->ddir_bpf_bound_progs))
591 return PTR_ERR(nsim_dev->ddir_bpf_bound_progs);
592
593 nsim_dev->bpf_dev = bpf_offload_dev_create(&nsim_bpf_dev_ops, nsim_dev);
594 err = PTR_ERR_OR_ZERO(nsim_dev->bpf_dev);
595 if (err)
596 return err;
597
598 nsim_dev->bpf_bind_accept = true;
599 debugfs_create_bool("bpf_bind_accept", 0600, nsim_dev->ddir,
600 &nsim_dev->bpf_bind_accept);
601 debugfs_create_u32("bpf_bind_verifier_delay", 0600, nsim_dev->ddir,
602 &nsim_dev->bpf_bind_verifier_delay);
603 nsim_dev->bpf_bind_verifier_accept = true;
604 debugfs_create_bool("bpf_bind_verifier_accept", 0600, nsim_dev->ddir,
605 &nsim_dev->bpf_bind_verifier_accept);
606 return 0;
607}
608
609void nsim_bpf_dev_exit(struct nsim_dev *nsim_dev)
610{
611 WARN_ON(!list_empty(&nsim_dev->bpf_bound_progs));
612 WARN_ON(!list_empty(&nsim_dev->bpf_bound_maps));
613 bpf_offload_dev_destroy(nsim_dev->bpf_dev);
614}
615
616int nsim_bpf_init(struct netdevsim *ns)
617{
618 struct dentry *ddir = ns->nsim_dev_port->ddir;
619 int err;
620
621 err = bpf_offload_dev_netdev_register(ns->nsim_dev->bpf_dev,
622 ns->netdev);
623 if (err)
624 return err;
625
626 debugfs_create_u32("bpf_offloaded_id", 0400, ddir,
627 &ns->bpf_offloaded_id);
628
629 ns->bpf_tc_accept = true;
630 debugfs_create_bool("bpf_tc_accept", 0600, ddir,
631 &ns->bpf_tc_accept);
632 debugfs_create_bool("bpf_tc_non_bound_accept", 0600, ddir,
633 &ns->bpf_tc_non_bound_accept);
634 ns->bpf_xdpdrv_accept = true;
635 debugfs_create_bool("bpf_xdpdrv_accept", 0600, ddir,
636 &ns->bpf_xdpdrv_accept);
637 ns->bpf_xdpoffload_accept = true;
638 debugfs_create_bool("bpf_xdpoffload_accept", 0600, ddir,
639 &ns->bpf_xdpoffload_accept);
640
641 ns->bpf_map_accept = true;
642 debugfs_create_bool("bpf_map_accept", 0600, ddir,
643 &ns->bpf_map_accept);
644
645 return 0;
646}
647
648void nsim_bpf_uninit(struct netdevsim *ns)
649{
650 WARN_ON(ns->xdp.prog);
651 WARN_ON(ns->xdp_hw.prog);
652 WARN_ON(ns->bpf_offloaded);
653 bpf_offload_dev_netdev_unregister(ns->nsim_dev->bpf_dev, ns->netdev);
654}
655
