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