Loading...
Note: File does not exist in v3.15.
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
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 /* Note: progs without skip_sw will probably not be dev bound */
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 /* Don't remove if oldprog doesn't match driver's state */
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 int ret;
222
223 state = kzalloc(sizeof(*state), GFP_KERNEL);
224 if (!state)
225 return -ENOMEM;
226
227 state->nsim_dev = nsim_dev;
228 state->prog = prog;
229 state->state = "verify";
230
231 /* Program id is not populated yet when we create the state. */
232 sprintf(name, "%u", nsim_dev->prog_id_gen++);
233 state->ddir = debugfs_create_dir(name, nsim_dev->ddir_bpf_bound_progs);
234 if (IS_ERR(state->ddir)) {
235 ret = PTR_ERR(state->ddir);
236 kfree(state);
237 return ret;
238 }
239
240 debugfs_create_u32("id", 0400, state->ddir, &prog->aux->id);
241 debugfs_create_file("state", 0400, state->ddir,
242 &state->state, &nsim_bpf_string_fops);
243 debugfs_create_bool("loaded", 0400, state->ddir, &state->is_loaded);
244
245 list_add_tail(&state->l, &nsim_dev->bpf_bound_progs);
246
247 prog->aux->offload->dev_priv = state;
248
249 return 0;
250}
251
252static int nsim_bpf_verifier_prep(struct bpf_prog *prog)
253{
254 struct nsim_dev *nsim_dev =
255 bpf_offload_dev_priv(prog->aux->offload->offdev);
256
257 if (!nsim_dev->bpf_bind_accept)
258 return -EOPNOTSUPP;
259
260 return nsim_bpf_create_prog(nsim_dev, prog);
261}
262
263static int nsim_bpf_translate(struct bpf_prog *prog)
264{
265 struct nsim_bpf_bound_prog *state = prog->aux->offload->dev_priv;
266
267 state->state = "xlated";
268 return 0;
269}
270
271static void nsim_bpf_destroy_prog(struct bpf_prog *prog)
272{
273 struct nsim_bpf_bound_prog *state;
274
275 state = prog->aux->offload->dev_priv;
276 WARN(state->is_loaded,
277 "offload state destroyed while program still bound");
278 debugfs_remove_recursive(state->ddir);
279 list_del(&state->l);
280 kfree(state);
281}
282
283static const struct bpf_prog_offload_ops nsim_bpf_dev_ops = {
284 .insn_hook = nsim_bpf_verify_insn,
285 .finalize = nsim_bpf_finalize,
286 .prepare = nsim_bpf_verifier_prep,
287 .translate = nsim_bpf_translate,
288 .destroy = nsim_bpf_destroy_prog,
289};
290
291static int nsim_setup_prog_checks(struct netdevsim *ns, struct netdev_bpf *bpf)
292{
293 if (bpf->prog && bpf->prog->aux->offload) {
294 NSIM_EA(bpf->extack, "attempt to load offloaded prog to drv");
295 return -EINVAL;
296 }
297 if (ns->netdev->mtu > NSIM_XDP_MAX_MTU) {
298 NSIM_EA(bpf->extack, "MTU too large w/ XDP enabled");
299 return -EINVAL;
300 }
301 return 0;
302}
303
304static int
305nsim_setup_prog_hw_checks(struct netdevsim *ns, struct netdev_bpf *bpf)
306{
307 struct nsim_bpf_bound_prog *state;
308
309 if (!bpf->prog)
310 return 0;
311
312 if (!bpf->prog->aux->offload) {
313 NSIM_EA(bpf->extack, "xdpoffload of non-bound program");
314 return -EINVAL;
315 }
316 if (!bpf_offload_dev_match(bpf->prog, ns->netdev)) {
317 NSIM_EA(bpf->extack, "program bound to different dev");
318 return -EINVAL;
319 }
320
321 state = bpf->prog->aux->offload->dev_priv;
322 if (WARN_ON(strcmp(state->state, "xlated"))) {
323 NSIM_EA(bpf->extack, "offloading program in bad state");
324 return -EINVAL;
325 }
326 return 0;
327}
328
329static bool
330nsim_map_key_match(struct bpf_map *map, struct nsim_map_entry *e, void *key)
331{
332 return e->key && !memcmp(key, e->key, map->key_size);
333}
334
335static int nsim_map_key_find(struct bpf_offloaded_map *offmap, void *key)
336{
337 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
338 unsigned int i;
339
340 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++)
341 if (nsim_map_key_match(&offmap->map, &nmap->entry[i], key))
342 return i;
343
344 return -ENOENT;
345}
346
347static int
348nsim_map_alloc_elem(struct bpf_offloaded_map *offmap, unsigned int idx)
349{
350 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
351
352 nmap->entry[idx].key = kmalloc(offmap->map.key_size, GFP_USER);
353 if (!nmap->entry[idx].key)
354 return -ENOMEM;
355 nmap->entry[idx].value = kmalloc(offmap->map.value_size, GFP_USER);
356 if (!nmap->entry[idx].value) {
357 kfree(nmap->entry[idx].key);
358 nmap->entry[idx].key = NULL;
359 return -ENOMEM;
360 }
361
362 return 0;
363}
364
365static int
366nsim_map_get_next_key(struct bpf_offloaded_map *offmap,
367 void *key, void *next_key)
368{
369 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
370 int idx = -ENOENT;
371
372 mutex_lock(&nmap->mutex);
373
374 if (key)
375 idx = nsim_map_key_find(offmap, key);
376 if (idx == -ENOENT)
377 idx = 0;
378 else
379 idx++;
380
381 for (; idx < ARRAY_SIZE(nmap->entry); idx++) {
382 if (nmap->entry[idx].key) {
383 memcpy(next_key, nmap->entry[idx].key,
384 offmap->map.key_size);
385 break;
386 }
387 }
388
389 mutex_unlock(&nmap->mutex);
390
391 if (idx == ARRAY_SIZE(nmap->entry))
392 return -ENOENT;
393 return 0;
394}
395
396static int
397nsim_map_lookup_elem(struct bpf_offloaded_map *offmap, void *key, void *value)
398{
399 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
400 int idx;
401
402 mutex_lock(&nmap->mutex);
403
404 idx = nsim_map_key_find(offmap, key);
405 if (idx >= 0)
406 memcpy(value, nmap->entry[idx].value, offmap->map.value_size);
407
408 mutex_unlock(&nmap->mutex);
409
410 return idx < 0 ? idx : 0;
411}
412
413static int
414nsim_map_update_elem(struct bpf_offloaded_map *offmap,
415 void *key, void *value, u64 flags)
416{
417 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
418 int idx, err = 0;
419
420 mutex_lock(&nmap->mutex);
421
422 idx = nsim_map_key_find(offmap, key);
423 if (idx < 0 && flags == BPF_EXIST) {
424 err = idx;
425 goto exit_unlock;
426 }
427 if (idx >= 0 && flags == BPF_NOEXIST) {
428 err = -EEXIST;
429 goto exit_unlock;
430 }
431
432 if (idx < 0) {
433 for (idx = 0; idx < ARRAY_SIZE(nmap->entry); idx++)
434 if (!nmap->entry[idx].key)
435 break;
436 if (idx == ARRAY_SIZE(nmap->entry)) {
437 err = -E2BIG;
438 goto exit_unlock;
439 }
440
441 err = nsim_map_alloc_elem(offmap, idx);
442 if (err)
443 goto exit_unlock;
444 }
445
446 memcpy(nmap->entry[idx].key, key, offmap->map.key_size);
447 memcpy(nmap->entry[idx].value, value, offmap->map.value_size);
448exit_unlock:
449 mutex_unlock(&nmap->mutex);
450
451 return err;
452}
453
454static int nsim_map_delete_elem(struct bpf_offloaded_map *offmap, void *key)
455{
456 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
457 int idx;
458
459 if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY)
460 return -EINVAL;
461
462 mutex_lock(&nmap->mutex);
463
464 idx = nsim_map_key_find(offmap, key);
465 if (idx >= 0) {
466 kfree(nmap->entry[idx].key);
467 kfree(nmap->entry[idx].value);
468 memset(&nmap->entry[idx], 0, sizeof(nmap->entry[idx]));
469 }
470
471 mutex_unlock(&nmap->mutex);
472
473 return idx < 0 ? idx : 0;
474}
475
476static const struct bpf_map_dev_ops nsim_bpf_map_ops = {
477 .map_get_next_key = nsim_map_get_next_key,
478 .map_lookup_elem = nsim_map_lookup_elem,
479 .map_update_elem = nsim_map_update_elem,
480 .map_delete_elem = nsim_map_delete_elem,
481};
482
483static int
484nsim_bpf_map_alloc(struct netdevsim *ns, struct bpf_offloaded_map *offmap)
485{
486 struct nsim_bpf_bound_map *nmap;
487 int i, err;
488
489 if (WARN_ON(offmap->map.map_type != BPF_MAP_TYPE_ARRAY &&
490 offmap->map.map_type != BPF_MAP_TYPE_HASH))
491 return -EINVAL;
492 if (offmap->map.max_entries > NSIM_BPF_MAX_KEYS)
493 return -ENOMEM;
494 if (offmap->map.map_flags)
495 return -EINVAL;
496
497 nmap = kzalloc(sizeof(*nmap), GFP_USER);
498 if (!nmap)
499 return -ENOMEM;
500
501 offmap->dev_priv = nmap;
502 nmap->ns = ns;
503 nmap->map = offmap;
504 mutex_init(&nmap->mutex);
505
506 if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY) {
507 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) {
508 u32 *key;
509
510 err = nsim_map_alloc_elem(offmap, i);
511 if (err)
512 goto err_free;
513 key = nmap->entry[i].key;
514 *key = i;
515 }
516 }
517
518 offmap->dev_ops = &nsim_bpf_map_ops;
519 list_add_tail(&nmap->l, &ns->nsim_dev->bpf_bound_maps);
520
521 return 0;
522
523err_free:
524 while (--i >= 0) {
525 kfree(nmap->entry[i].key);
526 kfree(nmap->entry[i].value);
527 }
528 kfree(nmap);
529 return err;
530}
531
532static void nsim_bpf_map_free(struct bpf_offloaded_map *offmap)
533{
534 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
535 unsigned int i;
536
537 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) {
538 kfree(nmap->entry[i].key);
539 kfree(nmap->entry[i].value);
540 }
541 list_del_init(&nmap->l);
542 mutex_destroy(&nmap->mutex);
543 kfree(nmap);
544}
545
546int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf)
547{
548 struct netdevsim *ns = netdev_priv(dev);
549 int err;
550
551 ASSERT_RTNL();
552
553 switch (bpf->command) {
554 case XDP_SETUP_PROG:
555 err = nsim_setup_prog_checks(ns, bpf);
556 if (err)
557 return err;
558
559 return nsim_xdp_set_prog(ns, bpf, &ns->xdp);
560 case XDP_SETUP_PROG_HW:
561 err = nsim_setup_prog_hw_checks(ns, bpf);
562 if (err)
563 return err;
564
565 return nsim_xdp_set_prog(ns, bpf, &ns->xdp_hw);
566 case BPF_OFFLOAD_MAP_ALLOC:
567 if (!ns->bpf_map_accept)
568 return -EOPNOTSUPP;
569
570 return nsim_bpf_map_alloc(ns, bpf->offmap);
571 case BPF_OFFLOAD_MAP_FREE:
572 nsim_bpf_map_free(bpf->offmap);
573 return 0;
574 default:
575 return -EINVAL;
576 }
577}
578
579int nsim_bpf_dev_init(struct nsim_dev *nsim_dev)
580{
581 int err;
582
583 INIT_LIST_HEAD(&nsim_dev->bpf_bound_progs);
584 INIT_LIST_HEAD(&nsim_dev->bpf_bound_maps);
585
586 nsim_dev->ddir_bpf_bound_progs = debugfs_create_dir("bpf_bound_progs",
587 nsim_dev->ddir);
588 if (IS_ERR(nsim_dev->ddir_bpf_bound_progs))
589 return PTR_ERR(nsim_dev->ddir_bpf_bound_progs);
590
591 nsim_dev->bpf_dev = bpf_offload_dev_create(&nsim_bpf_dev_ops, nsim_dev);
592 err = PTR_ERR_OR_ZERO(nsim_dev->bpf_dev);
593 if (err)
594 return err;
595
596 nsim_dev->bpf_bind_accept = true;
597 debugfs_create_bool("bpf_bind_accept", 0600, nsim_dev->ddir,
598 &nsim_dev->bpf_bind_accept);
599 debugfs_create_u32("bpf_bind_verifier_delay", 0600, nsim_dev->ddir,
600 &nsim_dev->bpf_bind_verifier_delay);
601 return 0;
602}
603
604void nsim_bpf_dev_exit(struct nsim_dev *nsim_dev)
605{
606 WARN_ON(!list_empty(&nsim_dev->bpf_bound_progs));
607 WARN_ON(!list_empty(&nsim_dev->bpf_bound_maps));
608 bpf_offload_dev_destroy(nsim_dev->bpf_dev);
609}
610
611int nsim_bpf_init(struct netdevsim *ns)
612{
613 struct dentry *ddir = ns->nsim_dev_port->ddir;
614 int err;
615
616 err = bpf_offload_dev_netdev_register(ns->nsim_dev->bpf_dev,
617 ns->netdev);
618 if (err)
619 return err;
620
621 debugfs_create_u32("bpf_offloaded_id", 0400, ddir,
622 &ns->bpf_offloaded_id);
623
624 ns->bpf_tc_accept = true;
625 debugfs_create_bool("bpf_tc_accept", 0600, ddir,
626 &ns->bpf_tc_accept);
627 debugfs_create_bool("bpf_tc_non_bound_accept", 0600, ddir,
628 &ns->bpf_tc_non_bound_accept);
629 ns->bpf_xdpdrv_accept = true;
630 debugfs_create_bool("bpf_xdpdrv_accept", 0600, ddir,
631 &ns->bpf_xdpdrv_accept);
632 ns->bpf_xdpoffload_accept = true;
633 debugfs_create_bool("bpf_xdpoffload_accept", 0600, ddir,
634 &ns->bpf_xdpoffload_accept);
635
636 ns->bpf_map_accept = true;
637 debugfs_create_bool("bpf_map_accept", 0600, ddir,
638 &ns->bpf_map_accept);
639
640 return 0;
641}
642
643void nsim_bpf_uninit(struct netdevsim *ns)
644{
645 WARN_ON(ns->xdp.prog);
646 WARN_ON(ns->xdp_hw.prog);
647 WARN_ON(ns->bpf_offloaded);
648 bpf_offload_dev_netdev_unregister(ns->nsim_dev->bpf_dev, ns->netdev);
649}