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(m: file, fmt: "%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(msecs: 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(prog: ns->bpf_offloaded, loaded: 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, loaded: 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(dev: ns->netdev, common: &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 /* Note: progs without skip_sw will probably not be dev bound */
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 /* Don't remove if oldprog doesn't match driver's state */
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, prog: 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, prog: bpf->prog, oldprog: 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(info: 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(size: 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 /* Program id is not populated yet when we create the state. */
234 sprintf(buf: name, fmt: "%u", nsim_dev->prog_id_gen++);
235 state->ddir = debugfs_create_dir(name, parent: nsim_dev->ddir_bpf_bound_progs);
236 if (IS_ERR(ptr: state->ddir)) {
237 ret = PTR_ERR(ptr: state->ddir);
238 kfree(objp: state);
239 return ret;
240 }
241
242 debugfs_create_u32(name: "id", mode: 0400, parent: state->ddir, value: &prog->aux->id);
243 debugfs_create_file(name: "state", mode: 0400, parent: state->ddir,
244 data: &state->state, fops: &nsim_bpf_string_fops);
245 debugfs_create_bool(name: "loaded", mode: 0400, parent: state->ddir, value: &state->is_loaded);
246
247 list_add_tail(new: &state->l, head: &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(offdev: 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(dentry: state->ddir);
281 list_del(entry: &state->l);
282 kfree(objp: 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
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(p: key, q: e->key, size: 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(map: &offmap->map, e: &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(size: offmap->map.key_size,
351 GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
352 if (!nmap->entry[idx].key)
353 return -ENOMEM;
354 nmap->entry[idx].value = kmalloc(size: offmap->map.value_size,
355 GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
356 if (!nmap->entry[idx].value) {
357 kfree(objp: 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(lock: &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(lock: &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(lock: &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(objp: nmap->entry[idx].key);
467 kfree(objp: nmap->entry[idx].value);
468 memset(&nmap->entry[idx], 0, sizeof(nmap->entry[idx]));
469 }
470
471 mutex_unlock(lock: &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(size: sizeof(*nmap), GFP_KERNEL_ACCOUNT);
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, idx: i);
511 if (err)
512 goto err_free;
513 key = nmap->entry[i].key;
514 *key = i;
515 memset(nmap->entry[i].value, 0, offmap->map.value_size);
516 }
517 }
518
519 offmap->dev_ops = &nsim_bpf_map_ops;
520 list_add_tail(new: &nmap->l, head: &ns->nsim_dev->bpf_bound_maps);
521
522 return 0;
523
524err_free:
525 while (--i >= 0) {
526 kfree(objp: nmap->entry[i].key);
527 kfree(objp: nmap->entry[i].value);
528 }
529 kfree(objp: nmap);
530 return err;
531}
532
533static void nsim_bpf_map_free(struct bpf_offloaded_map *offmap)
534{
535 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
536 unsigned int i;
537
538 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) {
539 kfree(objp: nmap->entry[i].key);
540 kfree(objp: nmap->entry[i].value);
541 }
542 list_del_init(entry: &nmap->l);
543 mutex_destroy(lock: &nmap->mutex);
544 kfree(objp: nmap);
545}
546
547int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf)
548{
549 struct netdevsim *ns = netdev_priv(dev);
550 int err;
551
552 ASSERT_RTNL();
553
554 switch (bpf->command) {
555 case XDP_SETUP_PROG:
556 err = nsim_setup_prog_checks(ns, bpf);
557 if (err)
558 return err;
559
560 return nsim_xdp_set_prog(ns, bpf, xdp: &ns->xdp);
561 case XDP_SETUP_PROG_HW:
562 err = nsim_setup_prog_hw_checks(ns, bpf);
563 if (err)
564 return err;
565
566 return nsim_xdp_set_prog(ns, bpf, xdp: &ns->xdp_hw);
567 case BPF_OFFLOAD_MAP_ALLOC:
568 if (!ns->bpf_map_accept)
569 return -EOPNOTSUPP;
570
571 return nsim_bpf_map_alloc(ns, offmap: bpf->offmap);
572 case BPF_OFFLOAD_MAP_FREE:
573 nsim_bpf_map_free(offmap: bpf->offmap);
574 return 0;
575 default:
576 return -EINVAL;
577 }
578}
579
580int nsim_bpf_dev_init(struct nsim_dev *nsim_dev)
581{
582 int err;
583
584 INIT_LIST_HEAD(list: &nsim_dev->bpf_bound_progs);
585 INIT_LIST_HEAD(list: &nsim_dev->bpf_bound_maps);
586
587 nsim_dev->ddir_bpf_bound_progs = debugfs_create_dir(name: "bpf_bound_progs",
588 parent: nsim_dev->ddir);
589 if (IS_ERR(ptr: nsim_dev->ddir_bpf_bound_progs))
590 return PTR_ERR(ptr: nsim_dev->ddir_bpf_bound_progs);
591
592 nsim_dev->bpf_dev = bpf_offload_dev_create(ops: &nsim_bpf_dev_ops, priv: nsim_dev);
593 err = PTR_ERR_OR_ZERO(ptr: nsim_dev->bpf_dev);
594 if (err)
595 return err;
596
597 nsim_dev->bpf_bind_accept = true;
598 debugfs_create_bool(name: "bpf_bind_accept", mode: 0600, parent: nsim_dev->ddir,
599 value: &nsim_dev->bpf_bind_accept);
600 debugfs_create_u32(name: "bpf_bind_verifier_delay", mode: 0600, parent: nsim_dev->ddir,
601 value: &nsim_dev->bpf_bind_verifier_delay);
602 nsim_dev->bpf_bind_verifier_accept = true;
603 debugfs_create_bool(name: "bpf_bind_verifier_accept", mode: 0600, parent: nsim_dev->ddir,
604 value: &nsim_dev->bpf_bind_verifier_accept);
605 return 0;
606}
607
608void nsim_bpf_dev_exit(struct nsim_dev *nsim_dev)
609{
610 WARN_ON(!list_empty(&nsim_dev->bpf_bound_progs));
611 WARN_ON(!list_empty(&nsim_dev->bpf_bound_maps));
612 bpf_offload_dev_destroy(offdev: nsim_dev->bpf_dev);
613}
614
615int nsim_bpf_init(struct netdevsim *ns)
616{
617 struct dentry *ddir = ns->nsim_dev_port->ddir;
618 int err;
619
620 err = bpf_offload_dev_netdev_register(offdev: ns->nsim_dev->bpf_dev,
621 netdev: ns->netdev);
622 if (err)
623 return err;
624
625 debugfs_create_u32(name: "bpf_offloaded_id", mode: 0400, parent: ddir,
626 value: &ns->bpf_offloaded_id);
627
628 ns->bpf_tc_accept = true;
629 debugfs_create_bool(name: "bpf_tc_accept", mode: 0600, parent: ddir,
630 value: &ns->bpf_tc_accept);
631 debugfs_create_bool(name: "bpf_tc_non_bound_accept", mode: 0600, parent: ddir,
632 value: &ns->bpf_tc_non_bound_accept);
633 ns->bpf_xdpdrv_accept = true;
634 debugfs_create_bool(name: "bpf_xdpdrv_accept", mode: 0600, parent: ddir,
635 value: &ns->bpf_xdpdrv_accept);
636 ns->bpf_xdpoffload_accept = true;
637 debugfs_create_bool(name: "bpf_xdpoffload_accept", mode: 0600, parent: ddir,
638 value: &ns->bpf_xdpoffload_accept);
639
640 ns->bpf_map_accept = true;
641 debugfs_create_bool(name: "bpf_map_accept", mode: 0600, parent: ddir,
642 value: &ns->bpf_map_accept);
643
644 return 0;
645}
646
647void nsim_bpf_uninit(struct netdevsim *ns)
648{
649 WARN_ON(ns->xdp.prog);
650 WARN_ON(ns->xdp_hw.prog);
651 WARN_ON(ns->bpf_offloaded);
652 bpf_offload_dev_netdev_unregister(offdev: ns->nsim_dev->bpf_dev, netdev: ns->netdev);
653}
654

source code of linux/drivers/net/netdevsim/bpf.c