xref: /linux/net/sched/cls_bpf.c (revision 1fd02f6605b855b4af2883f29a2abc88bdf17857)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Berkeley Packet Filter based traffic classifier
4  *
5  * Might be used to classify traffic through flexible, user-defined and
6  * possibly JIT-ed BPF filters for traffic control as an alternative to
7  * ematches.
8  *
9  * (C) 2013 Daniel Borkmann <dborkman@redhat.com>
10  */
11 
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/skbuff.h>
15 #include <linux/filter.h>
16 #include <linux/bpf.h>
17 #include <linux/idr.h>
18 
19 #include <net/rtnetlink.h>
20 #include <net/pkt_cls.h>
21 #include <net/sock.h>
22 
23 MODULE_LICENSE("GPL");
24 MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
25 MODULE_DESCRIPTION("TC BPF based classifier");
26 
27 #define CLS_BPF_NAME_LEN	256
28 #define CLS_BPF_SUPPORTED_GEN_FLAGS		\
29 	(TCA_CLS_FLAGS_SKIP_HW | TCA_CLS_FLAGS_SKIP_SW)
30 
31 struct cls_bpf_head {
32 	struct list_head plist;
33 	struct idr handle_idr;
34 	struct rcu_head rcu;
35 };
36 
37 struct cls_bpf_prog {
38 	struct bpf_prog *filter;
39 	struct list_head link;
40 	struct tcf_result res;
41 	bool exts_integrated;
42 	u32 gen_flags;
43 	unsigned int in_hw_count;
44 	struct tcf_exts exts;
45 	u32 handle;
46 	u16 bpf_num_ops;
47 	struct sock_filter *bpf_ops;
48 	const char *bpf_name;
49 	struct tcf_proto *tp;
50 	struct rcu_work rwork;
51 };
52 
53 static const struct nla_policy bpf_policy[TCA_BPF_MAX + 1] = {
54 	[TCA_BPF_CLASSID]	= { .type = NLA_U32 },
55 	[TCA_BPF_FLAGS]		= { .type = NLA_U32 },
56 	[TCA_BPF_FLAGS_GEN]	= { .type = NLA_U32 },
57 	[TCA_BPF_FD]		= { .type = NLA_U32 },
58 	[TCA_BPF_NAME]		= { .type = NLA_NUL_STRING,
59 				    .len = CLS_BPF_NAME_LEN },
60 	[TCA_BPF_OPS_LEN]	= { .type = NLA_U16 },
61 	[TCA_BPF_OPS]		= { .type = NLA_BINARY,
62 				    .len = sizeof(struct sock_filter) * BPF_MAXINSNS },
63 };
64 
65 static int cls_bpf_exec_opcode(int code)
66 {
67 	switch (code) {
68 	case TC_ACT_OK:
69 	case TC_ACT_SHOT:
70 	case TC_ACT_STOLEN:
71 	case TC_ACT_TRAP:
72 	case TC_ACT_REDIRECT:
73 	case TC_ACT_UNSPEC:
74 		return code;
75 	default:
76 		return TC_ACT_UNSPEC;
77 	}
78 }
79 
80 static int cls_bpf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
81 			    struct tcf_result *res)
82 {
83 	struct cls_bpf_head *head = rcu_dereference_bh(tp->root);
84 	bool at_ingress = skb_at_tc_ingress(skb);
85 	struct cls_bpf_prog *prog;
86 	int ret = -1;
87 
88 	list_for_each_entry_rcu(prog, &head->plist, link) {
89 		int filter_res;
90 
91 		qdisc_skb_cb(skb)->tc_classid = prog->res.classid;
92 
93 		if (tc_skip_sw(prog->gen_flags)) {
94 			filter_res = prog->exts_integrated ? TC_ACT_UNSPEC : 0;
95 		} else if (at_ingress) {
96 			/* It is safe to push/pull even if skb_shared() */
97 			__skb_push(skb, skb->mac_len);
98 			bpf_compute_data_pointers(skb);
99 			filter_res = bpf_prog_run(prog->filter, skb);
100 			__skb_pull(skb, skb->mac_len);
101 		} else {
102 			bpf_compute_data_pointers(skb);
103 			filter_res = bpf_prog_run(prog->filter, skb);
104 		}
105 		if (unlikely(!skb->tstamp && skb->mono_delivery_time))
106 			skb->mono_delivery_time = 0;
107 
108 		if (prog->exts_integrated) {
109 			res->class   = 0;
110 			res->classid = TC_H_MAJ(prog->res.classid) |
111 				       qdisc_skb_cb(skb)->tc_classid;
112 
113 			ret = cls_bpf_exec_opcode(filter_res);
114 			if (ret == TC_ACT_UNSPEC)
115 				continue;
116 			break;
117 		}
118 
119 		if (filter_res == 0)
120 			continue;
121 		if (filter_res != -1) {
122 			res->class   = 0;
123 			res->classid = filter_res;
124 		} else {
125 			*res = prog->res;
126 		}
127 
128 		ret = tcf_exts_exec(skb, &prog->exts, res);
129 		if (ret < 0)
130 			continue;
131 
132 		break;
133 	}
134 
135 	return ret;
136 }
137 
138 static bool cls_bpf_is_ebpf(const struct cls_bpf_prog *prog)
139 {
140 	return !prog->bpf_ops;
141 }
142 
143 static int cls_bpf_offload_cmd(struct tcf_proto *tp, struct cls_bpf_prog *prog,
144 			       struct cls_bpf_prog *oldprog,
145 			       struct netlink_ext_ack *extack)
146 {
147 	struct tcf_block *block = tp->chain->block;
148 	struct tc_cls_bpf_offload cls_bpf = {};
149 	struct cls_bpf_prog *obj;
150 	bool skip_sw;
151 	int err;
152 
153 	skip_sw = prog && tc_skip_sw(prog->gen_flags);
154 	obj = prog ?: oldprog;
155 
156 	tc_cls_common_offload_init(&cls_bpf.common, tp, obj->gen_flags, extack);
157 	cls_bpf.command = TC_CLSBPF_OFFLOAD;
158 	cls_bpf.exts = &obj->exts;
159 	cls_bpf.prog = prog ? prog->filter : NULL;
160 	cls_bpf.oldprog = oldprog ? oldprog->filter : NULL;
161 	cls_bpf.name = obj->bpf_name;
162 	cls_bpf.exts_integrated = obj->exts_integrated;
163 
164 	if (oldprog && prog)
165 		err = tc_setup_cb_replace(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
166 					  skip_sw, &oldprog->gen_flags,
167 					  &oldprog->in_hw_count,
168 					  &prog->gen_flags, &prog->in_hw_count,
169 					  true);
170 	else if (prog)
171 		err = tc_setup_cb_add(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
172 				      skip_sw, &prog->gen_flags,
173 				      &prog->in_hw_count, true);
174 	else
175 		err = tc_setup_cb_destroy(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
176 					  skip_sw, &oldprog->gen_flags,
177 					  &oldprog->in_hw_count, true);
178 
179 	if (prog && err) {
180 		cls_bpf_offload_cmd(tp, oldprog, prog, extack);
181 		return err;
182 	}
183 
184 	if (prog && skip_sw && !(prog->gen_flags & TCA_CLS_FLAGS_IN_HW))
185 		return -EINVAL;
186 
187 	return 0;
188 }
189 
190 static u32 cls_bpf_flags(u32 flags)
191 {
192 	return flags & CLS_BPF_SUPPORTED_GEN_FLAGS;
193 }
194 
195 static int cls_bpf_offload(struct tcf_proto *tp, struct cls_bpf_prog *prog,
196 			   struct cls_bpf_prog *oldprog,
197 			   struct netlink_ext_ack *extack)
198 {
199 	if (prog && oldprog &&
200 	    cls_bpf_flags(prog->gen_flags) !=
201 	    cls_bpf_flags(oldprog->gen_flags))
202 		return -EINVAL;
203 
204 	if (prog && tc_skip_hw(prog->gen_flags))
205 		prog = NULL;
206 	if (oldprog && tc_skip_hw(oldprog->gen_flags))
207 		oldprog = NULL;
208 	if (!prog && !oldprog)
209 		return 0;
210 
211 	return cls_bpf_offload_cmd(tp, prog, oldprog, extack);
212 }
213 
214 static void cls_bpf_stop_offload(struct tcf_proto *tp,
215 				 struct cls_bpf_prog *prog,
216 				 struct netlink_ext_ack *extack)
217 {
218 	int err;
219 
220 	err = cls_bpf_offload_cmd(tp, NULL, prog, extack);
221 	if (err)
222 		pr_err("Stopping hardware offload failed: %d\n", err);
223 }
224 
225 static void cls_bpf_offload_update_stats(struct tcf_proto *tp,
226 					 struct cls_bpf_prog *prog)
227 {
228 	struct tcf_block *block = tp->chain->block;
229 	struct tc_cls_bpf_offload cls_bpf = {};
230 
231 	tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags, NULL);
232 	cls_bpf.command = TC_CLSBPF_STATS;
233 	cls_bpf.exts = &prog->exts;
234 	cls_bpf.prog = prog->filter;
235 	cls_bpf.name = prog->bpf_name;
236 	cls_bpf.exts_integrated = prog->exts_integrated;
237 
238 	tc_setup_cb_call(block, TC_SETUP_CLSBPF, &cls_bpf, false, true);
239 }
240 
241 static int cls_bpf_init(struct tcf_proto *tp)
242 {
243 	struct cls_bpf_head *head;
244 
245 	head = kzalloc(sizeof(*head), GFP_KERNEL);
246 	if (head == NULL)
247 		return -ENOBUFS;
248 
249 	INIT_LIST_HEAD_RCU(&head->plist);
250 	idr_init(&head->handle_idr);
251 	rcu_assign_pointer(tp->root, head);
252 
253 	return 0;
254 }
255 
256 static void cls_bpf_free_parms(struct cls_bpf_prog *prog)
257 {
258 	if (cls_bpf_is_ebpf(prog))
259 		bpf_prog_put(prog->filter);
260 	else
261 		bpf_prog_destroy(prog->filter);
262 
263 	kfree(prog->bpf_name);
264 	kfree(prog->bpf_ops);
265 }
266 
267 static void __cls_bpf_delete_prog(struct cls_bpf_prog *prog)
268 {
269 	tcf_exts_destroy(&prog->exts);
270 	tcf_exts_put_net(&prog->exts);
271 
272 	cls_bpf_free_parms(prog);
273 	kfree(prog);
274 }
275 
276 static void cls_bpf_delete_prog_work(struct work_struct *work)
277 {
278 	struct cls_bpf_prog *prog = container_of(to_rcu_work(work),
279 						 struct cls_bpf_prog,
280 						 rwork);
281 	rtnl_lock();
282 	__cls_bpf_delete_prog(prog);
283 	rtnl_unlock();
284 }
285 
286 static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog,
287 			     struct netlink_ext_ack *extack)
288 {
289 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
290 
291 	idr_remove(&head->handle_idr, prog->handle);
292 	cls_bpf_stop_offload(tp, prog, extack);
293 	list_del_rcu(&prog->link);
294 	tcf_unbind_filter(tp, &prog->res);
295 	if (tcf_exts_get_net(&prog->exts))
296 		tcf_queue_work(&prog->rwork, cls_bpf_delete_prog_work);
297 	else
298 		__cls_bpf_delete_prog(prog);
299 }
300 
301 static int cls_bpf_delete(struct tcf_proto *tp, void *arg, bool *last,
302 			  bool rtnl_held, struct netlink_ext_ack *extack)
303 {
304 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
305 
306 	__cls_bpf_delete(tp, arg, extack);
307 	*last = list_empty(&head->plist);
308 	return 0;
309 }
310 
311 static void cls_bpf_destroy(struct tcf_proto *tp, bool rtnl_held,
312 			    struct netlink_ext_ack *extack)
313 {
314 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
315 	struct cls_bpf_prog *prog, *tmp;
316 
317 	list_for_each_entry_safe(prog, tmp, &head->plist, link)
318 		__cls_bpf_delete(tp, prog, extack);
319 
320 	idr_destroy(&head->handle_idr);
321 	kfree_rcu(head, rcu);
322 }
323 
324 static void *cls_bpf_get(struct tcf_proto *tp, u32 handle)
325 {
326 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
327 	struct cls_bpf_prog *prog;
328 
329 	list_for_each_entry(prog, &head->plist, link) {
330 		if (prog->handle == handle)
331 			return prog;
332 	}
333 
334 	return NULL;
335 }
336 
337 static int cls_bpf_prog_from_ops(struct nlattr **tb, struct cls_bpf_prog *prog)
338 {
339 	struct sock_filter *bpf_ops;
340 	struct sock_fprog_kern fprog_tmp;
341 	struct bpf_prog *fp;
342 	u16 bpf_size, bpf_num_ops;
343 	int ret;
344 
345 	bpf_num_ops = nla_get_u16(tb[TCA_BPF_OPS_LEN]);
346 	if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0)
347 		return -EINVAL;
348 
349 	bpf_size = bpf_num_ops * sizeof(*bpf_ops);
350 	if (bpf_size != nla_len(tb[TCA_BPF_OPS]))
351 		return -EINVAL;
352 
353 	bpf_ops = kmemdup(nla_data(tb[TCA_BPF_OPS]), bpf_size, GFP_KERNEL);
354 	if (bpf_ops == NULL)
355 		return -ENOMEM;
356 
357 	fprog_tmp.len = bpf_num_ops;
358 	fprog_tmp.filter = bpf_ops;
359 
360 	ret = bpf_prog_create(&fp, &fprog_tmp);
361 	if (ret < 0) {
362 		kfree(bpf_ops);
363 		return ret;
364 	}
365 
366 	prog->bpf_ops = bpf_ops;
367 	prog->bpf_num_ops = bpf_num_ops;
368 	prog->bpf_name = NULL;
369 	prog->filter = fp;
370 
371 	return 0;
372 }
373 
374 static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
375 				 u32 gen_flags, const struct tcf_proto *tp)
376 {
377 	struct bpf_prog *fp;
378 	char *name = NULL;
379 	bool skip_sw;
380 	u32 bpf_fd;
381 
382 	bpf_fd = nla_get_u32(tb[TCA_BPF_FD]);
383 	skip_sw = gen_flags & TCA_CLS_FLAGS_SKIP_SW;
384 
385 	fp = bpf_prog_get_type_dev(bpf_fd, BPF_PROG_TYPE_SCHED_CLS, skip_sw);
386 	if (IS_ERR(fp))
387 		return PTR_ERR(fp);
388 
389 	if (tb[TCA_BPF_NAME]) {
390 		name = nla_memdup(tb[TCA_BPF_NAME], GFP_KERNEL);
391 		if (!name) {
392 			bpf_prog_put(fp);
393 			return -ENOMEM;
394 		}
395 	}
396 
397 	prog->bpf_ops = NULL;
398 	prog->bpf_name = name;
399 	prog->filter = fp;
400 
401 	if (fp->dst_needed)
402 		tcf_block_netif_keep_dst(tp->chain->block);
403 
404 	return 0;
405 }
406 
407 static int cls_bpf_set_parms(struct net *net, struct tcf_proto *tp,
408 			     struct cls_bpf_prog *prog, unsigned long base,
409 			     struct nlattr **tb, struct nlattr *est, u32 flags,
410 			     struct netlink_ext_ack *extack)
411 {
412 	bool is_bpf, is_ebpf, have_exts = false;
413 	u32 gen_flags = 0;
414 	int ret;
415 
416 	is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
417 	is_ebpf = tb[TCA_BPF_FD];
418 	if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf))
419 		return -EINVAL;
420 
421 	ret = tcf_exts_validate(net, tp, tb, est, &prog->exts, flags,
422 				extack);
423 	if (ret < 0)
424 		return ret;
425 
426 	if (tb[TCA_BPF_FLAGS]) {
427 		u32 bpf_flags = nla_get_u32(tb[TCA_BPF_FLAGS]);
428 
429 		if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT)
430 			return -EINVAL;
431 
432 		have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT;
433 	}
434 	if (tb[TCA_BPF_FLAGS_GEN]) {
435 		gen_flags = nla_get_u32(tb[TCA_BPF_FLAGS_GEN]);
436 		if (gen_flags & ~CLS_BPF_SUPPORTED_GEN_FLAGS ||
437 		    !tc_flags_valid(gen_flags))
438 			return -EINVAL;
439 	}
440 
441 	prog->exts_integrated = have_exts;
442 	prog->gen_flags = gen_flags;
443 
444 	ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
445 		       cls_bpf_prog_from_efd(tb, prog, gen_flags, tp);
446 	if (ret < 0)
447 		return ret;
448 
449 	if (tb[TCA_BPF_CLASSID]) {
450 		prog->res.classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
451 		tcf_bind_filter(tp, &prog->res, base);
452 	}
453 
454 	return 0;
455 }
456 
457 static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
458 			  struct tcf_proto *tp, unsigned long base,
459 			  u32 handle, struct nlattr **tca,
460 			  void **arg, u32 flags,
461 			  struct netlink_ext_ack *extack)
462 {
463 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
464 	struct cls_bpf_prog *oldprog = *arg;
465 	struct nlattr *tb[TCA_BPF_MAX + 1];
466 	struct cls_bpf_prog *prog;
467 	int ret;
468 
469 	if (tca[TCA_OPTIONS] == NULL)
470 		return -EINVAL;
471 
472 	ret = nla_parse_nested_deprecated(tb, TCA_BPF_MAX, tca[TCA_OPTIONS],
473 					  bpf_policy, NULL);
474 	if (ret < 0)
475 		return ret;
476 
477 	prog = kzalloc(sizeof(*prog), GFP_KERNEL);
478 	if (!prog)
479 		return -ENOBUFS;
480 
481 	ret = tcf_exts_init(&prog->exts, net, TCA_BPF_ACT, TCA_BPF_POLICE);
482 	if (ret < 0)
483 		goto errout;
484 
485 	if (oldprog) {
486 		if (handle && oldprog->handle != handle) {
487 			ret = -EINVAL;
488 			goto errout;
489 		}
490 	}
491 
492 	if (handle == 0) {
493 		handle = 1;
494 		ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
495 				    INT_MAX, GFP_KERNEL);
496 	} else if (!oldprog) {
497 		ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
498 				    handle, GFP_KERNEL);
499 	}
500 
501 	if (ret)
502 		goto errout;
503 	prog->handle = handle;
504 
505 	ret = cls_bpf_set_parms(net, tp, prog, base, tb, tca[TCA_RATE], flags,
506 				extack);
507 	if (ret < 0)
508 		goto errout_idr;
509 
510 	ret = cls_bpf_offload(tp, prog, oldprog, extack);
511 	if (ret)
512 		goto errout_parms;
513 
514 	if (!tc_in_hw(prog->gen_flags))
515 		prog->gen_flags |= TCA_CLS_FLAGS_NOT_IN_HW;
516 
517 	if (oldprog) {
518 		idr_replace(&head->handle_idr, prog, handle);
519 		list_replace_rcu(&oldprog->link, &prog->link);
520 		tcf_unbind_filter(tp, &oldprog->res);
521 		tcf_exts_get_net(&oldprog->exts);
522 		tcf_queue_work(&oldprog->rwork, cls_bpf_delete_prog_work);
523 	} else {
524 		list_add_rcu(&prog->link, &head->plist);
525 	}
526 
527 	*arg = prog;
528 	return 0;
529 
530 errout_parms:
531 	cls_bpf_free_parms(prog);
532 errout_idr:
533 	if (!oldprog)
534 		idr_remove(&head->handle_idr, prog->handle);
535 errout:
536 	tcf_exts_destroy(&prog->exts);
537 	kfree(prog);
538 	return ret;
539 }
540 
541 static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog,
542 				 struct sk_buff *skb)
543 {
544 	struct nlattr *nla;
545 
546 	if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_num_ops))
547 		return -EMSGSIZE;
548 
549 	nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_num_ops *
550 			  sizeof(struct sock_filter));
551 	if (nla == NULL)
552 		return -EMSGSIZE;
553 
554 	memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
555 
556 	return 0;
557 }
558 
559 static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
560 				  struct sk_buff *skb)
561 {
562 	struct nlattr *nla;
563 
564 	if (prog->bpf_name &&
565 	    nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
566 		return -EMSGSIZE;
567 
568 	if (nla_put_u32(skb, TCA_BPF_ID, prog->filter->aux->id))
569 		return -EMSGSIZE;
570 
571 	nla = nla_reserve(skb, TCA_BPF_TAG, sizeof(prog->filter->tag));
572 	if (nla == NULL)
573 		return -EMSGSIZE;
574 
575 	memcpy(nla_data(nla), prog->filter->tag, nla_len(nla));
576 
577 	return 0;
578 }
579 
580 static int cls_bpf_dump(struct net *net, struct tcf_proto *tp, void *fh,
581 			struct sk_buff *skb, struct tcmsg *tm, bool rtnl_held)
582 {
583 	struct cls_bpf_prog *prog = fh;
584 	struct nlattr *nest;
585 	u32 bpf_flags = 0;
586 	int ret;
587 
588 	if (prog == NULL)
589 		return skb->len;
590 
591 	tm->tcm_handle = prog->handle;
592 
593 	cls_bpf_offload_update_stats(tp, prog);
594 
595 	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
596 	if (nest == NULL)
597 		goto nla_put_failure;
598 
599 	if (prog->res.classid &&
600 	    nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
601 		goto nla_put_failure;
602 
603 	if (cls_bpf_is_ebpf(prog))
604 		ret = cls_bpf_dump_ebpf_info(prog, skb);
605 	else
606 		ret = cls_bpf_dump_bpf_info(prog, skb);
607 	if (ret)
608 		goto nla_put_failure;
609 
610 	if (tcf_exts_dump(skb, &prog->exts) < 0)
611 		goto nla_put_failure;
612 
613 	if (prog->exts_integrated)
614 		bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT;
615 	if (bpf_flags && nla_put_u32(skb, TCA_BPF_FLAGS, bpf_flags))
616 		goto nla_put_failure;
617 	if (prog->gen_flags &&
618 	    nla_put_u32(skb, TCA_BPF_FLAGS_GEN, prog->gen_flags))
619 		goto nla_put_failure;
620 
621 	nla_nest_end(skb, nest);
622 
623 	if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
624 		goto nla_put_failure;
625 
626 	return skb->len;
627 
628 nla_put_failure:
629 	nla_nest_cancel(skb, nest);
630 	return -1;
631 }
632 
633 static void cls_bpf_bind_class(void *fh, u32 classid, unsigned long cl,
634 			       void *q, unsigned long base)
635 {
636 	struct cls_bpf_prog *prog = fh;
637 
638 	if (prog && prog->res.classid == classid) {
639 		if (cl)
640 			__tcf_bind_filter(q, &prog->res, base);
641 		else
642 			__tcf_unbind_filter(q, &prog->res);
643 	}
644 }
645 
646 static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg,
647 			 bool rtnl_held)
648 {
649 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
650 	struct cls_bpf_prog *prog;
651 
652 	list_for_each_entry(prog, &head->plist, link) {
653 		if (arg->count < arg->skip)
654 			goto skip;
655 		if (arg->fn(tp, prog, arg) < 0) {
656 			arg->stop = 1;
657 			break;
658 		}
659 skip:
660 		arg->count++;
661 	}
662 }
663 
664 static int cls_bpf_reoffload(struct tcf_proto *tp, bool add, flow_setup_cb_t *cb,
665 			     void *cb_priv, struct netlink_ext_ack *extack)
666 {
667 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
668 	struct tcf_block *block = tp->chain->block;
669 	struct tc_cls_bpf_offload cls_bpf = {};
670 	struct cls_bpf_prog *prog;
671 	int err;
672 
673 	list_for_each_entry(prog, &head->plist, link) {
674 		if (tc_skip_hw(prog->gen_flags))
675 			continue;
676 
677 		tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags,
678 					   extack);
679 		cls_bpf.command = TC_CLSBPF_OFFLOAD;
680 		cls_bpf.exts = &prog->exts;
681 		cls_bpf.prog = add ? prog->filter : NULL;
682 		cls_bpf.oldprog = add ? NULL : prog->filter;
683 		cls_bpf.name = prog->bpf_name;
684 		cls_bpf.exts_integrated = prog->exts_integrated;
685 
686 		err = tc_setup_cb_reoffload(block, tp, add, cb, TC_SETUP_CLSBPF,
687 					    &cls_bpf, cb_priv, &prog->gen_flags,
688 					    &prog->in_hw_count);
689 		if (err)
690 			return err;
691 	}
692 
693 	return 0;
694 }
695 
696 static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
697 	.kind		=	"bpf",
698 	.owner		=	THIS_MODULE,
699 	.classify	=	cls_bpf_classify,
700 	.init		=	cls_bpf_init,
701 	.destroy	=	cls_bpf_destroy,
702 	.get		=	cls_bpf_get,
703 	.change		=	cls_bpf_change,
704 	.delete		=	cls_bpf_delete,
705 	.walk		=	cls_bpf_walk,
706 	.reoffload	=	cls_bpf_reoffload,
707 	.dump		=	cls_bpf_dump,
708 	.bind_class	=	cls_bpf_bind_class,
709 };
710 
711 static int __init cls_bpf_init_mod(void)
712 {
713 	return register_tcf_proto_ops(&cls_bpf_ops);
714 }
715 
716 static void __exit cls_bpf_exit_mod(void)
717 {
718 	unregister_tcf_proto_ops(&cls_bpf_ops);
719 }
720 
721 module_init(cls_bpf_init_mod);
722 module_exit(cls_bpf_exit_mod);
723