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1/*
2 * Copyright (C) 2017 Netronome Systems, Inc.
3 *
4 * This software is licensed under the GNU General License Version 2,
5 * June 1991 as shown in the file COPYING in the top-level directory of this
6 * source tree.
7 *
8 * THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS"
9 * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
10 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
11 * FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
12 * OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
13 * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
14 */
15
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 || !bpf_prog_is_offloaded(prog->aux))
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 (!tc_cls_can_offload_and_chain0(ns->netdev, &cls_bpf->common))
127 return -EOPNOTSUPP;
128
129 if (cls_bpf->common.protocol != htons(ETH_P_ALL)) {
130 NSIM_EA(cls_bpf->common.extack,
131 "only ETH_P_ALL supported as filter protocol");
132 return -EOPNOTSUPP;
133 }
134
135 if (!ns->bpf_tc_accept) {
136 NSIM_EA(cls_bpf->common.extack,
137 "netdevsim configured to reject BPF TC offload");
138 return -EOPNOTSUPP;
139 }
140 /* Note: progs without skip_sw will probably not be dev bound */
141 if (prog && !prog->aux->offload && !ns->bpf_tc_non_bound_accept) {
142 NSIM_EA(cls_bpf->common.extack,
143 "netdevsim configured to reject unbound programs");
144 return -EOPNOTSUPP;
145 }
146
147 if (cls_bpf->command != TC_CLSBPF_OFFLOAD)
148 return -EOPNOTSUPP;
149
150 oldprog = cls_bpf->oldprog;
151
152 /* Don't remove if oldprog doesn't match driver's state */
153 if (ns->bpf_offloaded != oldprog) {
154 oldprog = NULL;
155 if (!cls_bpf->prog)
156 return 0;
157 if (ns->bpf_offloaded) {
158 NSIM_EA(cls_bpf->common.extack,
159 "driver and netdev offload states mismatch");
160 return -EBUSY;
161 }
162 }
163
164 return nsim_bpf_offload(ns, cls_bpf->prog, oldprog);
165}
166
167int nsim_bpf_disable_tc(struct netdevsim *ns)
168{
169 if (ns->bpf_offloaded && !nsim_xdp_offload_active(ns))
170 return -EBUSY;
171 return 0;
172}
173
174static int nsim_xdp_offload_prog(struct netdevsim *ns, struct netdev_bpf *bpf)
175{
176 if (!nsim_xdp_offload_active(ns) && !bpf->prog)
177 return 0;
178 if (!nsim_xdp_offload_active(ns) && bpf->prog && ns->bpf_offloaded) {
179 NSIM_EA(bpf->extack, "TC program is already loaded");
180 return -EBUSY;
181 }
182
183 return nsim_bpf_offload(ns, bpf->prog, nsim_xdp_offload_active(ns));
184}
185
186static int
187nsim_xdp_set_prog(struct netdevsim *ns, struct netdev_bpf *bpf,
188 struct xdp_attachment_info *xdp)
189{
190 int err;
191
192 if (bpf->command == XDP_SETUP_PROG && !ns->bpf_xdpdrv_accept) {
193 NSIM_EA(bpf->extack, "driver XDP disabled in DebugFS");
194 return -EOPNOTSUPP;
195 }
196 if (bpf->command == XDP_SETUP_PROG_HW && !ns->bpf_xdpoffload_accept) {
197 NSIM_EA(bpf->extack, "XDP offload disabled in DebugFS");
198 return -EOPNOTSUPP;
199 }
200
201 if (bpf->command == XDP_SETUP_PROG_HW) {
202 err = nsim_xdp_offload_prog(ns, bpf);
203 if (err)
204 return err;
205 }
206
207 xdp_attachment_setup(xdp, bpf);
208
209 return 0;
210}
211
212static int nsim_bpf_create_prog(struct nsim_dev *nsim_dev,
213 struct bpf_prog *prog)
214{
215 struct nsim_bpf_bound_prog *state;
216 char name[16];
217 int ret;
218
219 state = kzalloc_obj(*state);
220 if (!state)
221 return -ENOMEM;
222
223 state->nsim_dev = nsim_dev;
224 state->prog = prog;
225 state->state = "verify";
226
227 /* Program id is not populated yet when we create the state. */
228 sprintf(name, "%u", nsim_dev->prog_id_gen++);
229 state->ddir = debugfs_create_dir(name, nsim_dev->ddir_bpf_bound_progs);
230 if (IS_ERR(state->ddir)) {
231 ret = PTR_ERR(state->ddir);
232 kfree(state);
233 return ret;
234 }
235
236 debugfs_create_u32("id", 0400, state->ddir, &prog->aux->id);
237 debugfs_create_file("state", 0400, state->ddir,
238 &state->state, &nsim_bpf_string_fops);
239 debugfs_create_bool("loaded", 0400, state->ddir, &state->is_loaded);
240
241 mutex_lock(&nsim_dev->progs_list_lock);
242 list_add_tail(&state->l, &nsim_dev->bpf_bound_progs);
243 mutex_unlock(&nsim_dev->progs_list_lock);
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 struct nsim_dev *nsim_dev;
273
274 state = prog->aux->offload->dev_priv;
275 nsim_dev = state->nsim_dev;
276 WARN(state->is_loaded,
277 "offload state destroyed while program still bound");
278 debugfs_remove_recursive(state->ddir);
279 mutex_lock(&nsim_dev->progs_list_lock);
280 list_del(&state->l);
281 mutex_unlock(&nsim_dev->progs_list_lock);
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 (bpf->prog && !bpf->prog->aux->xdp_has_frags &&
300 ns->netdev->mtu > NSIM_XDP_MAX_MTU) {
301 NSIM_EA(bpf->extack, "MTU too large w/ XDP enabled");
302 return -EINVAL;
303 }
304 return 0;
305}
306
307static int
308nsim_setup_prog_hw_checks(struct netdevsim *ns, struct netdev_bpf *bpf)
309{
310 struct nsim_bpf_bound_prog *state;
311
312 if (!bpf->prog)
313 return 0;
314
315 if (!bpf_prog_is_offloaded(bpf->prog->aux)) {
316 NSIM_EA(bpf->extack, "xdpoffload of non-bound program");
317 return -EINVAL;
318 }
319
320 state = bpf->prog->aux->offload->dev_priv;
321 if (WARN_ON(strcmp(state->state, "xlated"))) {
322 NSIM_EA(bpf->extack, "offloading program in bad state");
323 return -EINVAL;
324 }
325 return 0;
326}
327
328static bool
329nsim_map_key_match(struct bpf_map *map, struct nsim_map_entry *e, void *key)
330{
331 return e->key && !memcmp(key, e->key, map->key_size);
332}
333
334static int nsim_map_key_find(struct bpf_offloaded_map *offmap, void *key)
335{
336 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
337 unsigned int i;
338
339 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++)
340 if (nsim_map_key_match(&offmap->map, &nmap->entry[i], key))
341 return i;
342
343 return -ENOENT;
344}
345
346static int
347nsim_map_alloc_elem(struct bpf_offloaded_map *offmap, unsigned int idx)
348{
349 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
350
351 nmap->entry[idx].key = kmalloc(offmap->map.key_size,
352 GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
353 if (!nmap->entry[idx].key)
354 return -ENOMEM;
355 nmap->entry[idx].value = kmalloc(offmap->map.value_size,
356 GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
357 if (!nmap->entry[idx].value) {
358 kfree(nmap->entry[idx].key);
359 nmap->entry[idx].key = NULL;
360 return -ENOMEM;
361 }
362
363 return 0;
364}
365
366static int
367nsim_map_get_next_key(struct bpf_offloaded_map *offmap,
368 void *key, void *next_key)
369{
370 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
371 int idx = -ENOENT;
372
373 mutex_lock(&nmap->mutex);
374
375 if (key)
376 idx = nsim_map_key_find(offmap, key);
377 if (idx == -ENOENT)
378 idx = 0;
379 else
380 idx++;
381
382 for (; idx < ARRAY_SIZE(nmap->entry); idx++) {
383 if (nmap->entry[idx].key) {
384 memcpy(next_key, nmap->entry[idx].key,
385 offmap->map.key_size);
386 break;
387 }
388 }
389
390 mutex_unlock(&nmap->mutex);
391
392 if (idx == ARRAY_SIZE(nmap->entry))
393 return -ENOENT;
394 return 0;
395}
396
397static int
398nsim_map_lookup_elem(struct bpf_offloaded_map *offmap, void *key, void *value)
399{
400 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
401 int idx;
402
403 mutex_lock(&nmap->mutex);
404
405 idx = nsim_map_key_find(offmap, key);
406 if (idx >= 0)
407 memcpy(value, nmap->entry[idx].value, offmap->map.value_size);
408
409 mutex_unlock(&nmap->mutex);
410
411 return idx < 0 ? idx : 0;
412}
413
414static int
415nsim_map_update_elem(struct bpf_offloaded_map *offmap,
416 void *key, void *value, u64 flags)
417{
418 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
419 int idx, err = 0;
420
421 mutex_lock(&nmap->mutex);
422
423 idx = nsim_map_key_find(offmap, key);
424 if (idx < 0 && flags == BPF_EXIST) {
425 err = idx;
426 goto exit_unlock;
427 }
428 if (idx >= 0 && flags == BPF_NOEXIST) {
429 err = -EEXIST;
430 goto exit_unlock;
431 }
432
433 if (idx < 0) {
434 for (idx = 0; idx < ARRAY_SIZE(nmap->entry); idx++)
435 if (!nmap->entry[idx].key)
436 break;
437 if (idx == ARRAY_SIZE(nmap->entry)) {
438 err = -E2BIG;
439 goto exit_unlock;
440 }
441
442 err = nsim_map_alloc_elem(offmap, idx);
443 if (err)
444 goto exit_unlock;
445 }
446
447 memcpy(nmap->entry[idx].key, key, offmap->map.key_size);
448 memcpy(nmap->entry[idx].value, value, offmap->map.value_size);
449exit_unlock:
450 mutex_unlock(&nmap->mutex);
451
452 return err;
453}
454
455static int nsim_map_delete_elem(struct bpf_offloaded_map *offmap, void *key)
456{
457 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
458 int idx;
459
460 if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY)
461 return -EINVAL;
462
463 mutex_lock(&nmap->mutex);
464
465 idx = nsim_map_key_find(offmap, key);
466 if (idx >= 0) {
467 kfree(nmap->entry[idx].key);
468 kfree(nmap->entry[idx].value);
469 memset(&nmap->entry[idx], 0, sizeof(nmap->entry[idx]));
470 }
471
472 mutex_unlock(&nmap->mutex);
473
474 return idx < 0 ? idx : 0;
475}
476
477static const struct bpf_map_dev_ops nsim_bpf_map_ops = {
478 .map_get_next_key = nsim_map_get_next_key,
479 .map_lookup_elem = nsim_map_lookup_elem,
480 .map_update_elem = nsim_map_update_elem,
481 .map_delete_elem = nsim_map_delete_elem,
482};
483
484static int
485nsim_bpf_map_alloc(struct netdevsim *ns, struct bpf_offloaded_map *offmap)
486{
487 struct nsim_bpf_bound_map *nmap;
488 int i, err;
489
490 if (WARN_ON(offmap->map.map_type != BPF_MAP_TYPE_ARRAY &&
491 offmap->map.map_type != BPF_MAP_TYPE_HASH))
492 return -EINVAL;
493 if (offmap->map.max_entries > NSIM_BPF_MAX_KEYS)
494 return -ENOMEM;
495 if (offmap->map.map_flags)
496 return -EINVAL;
497
498 nmap = kzalloc_obj(*nmap, GFP_KERNEL_ACCOUNT);
499 if (!nmap)
500 return -ENOMEM;
501
502 offmap->dev_priv = nmap;
503 nmap->ns = ns;
504 nmap->map = offmap;
505 mutex_init(&nmap->mutex);
506
507 if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY) {
508 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) {
509 u32 *key;
510
511 err = nsim_map_alloc_elem(offmap, i);
512 if (err)
513 goto err_free;
514 key = nmap->entry[i].key;
515 *key = i;
516 memset(nmap->entry[i].value, 0, offmap->map.value_size);
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}