xref: /openbmc/linux/net/sched/cls_bpf.c (revision 46a73e9e)
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 	/* Needed here for accessing maps. */
89 	rcu_read_lock();
90 	list_for_each_entry_rcu(prog, &head->plist, link) {
91 		int filter_res;
92 
93 		qdisc_skb_cb(skb)->tc_classid = prog->res.classid;
94 
95 		if (tc_skip_sw(prog->gen_flags)) {
96 			filter_res = prog->exts_integrated ? TC_ACT_UNSPEC : 0;
97 		} else if (at_ingress) {
98 			/* It is safe to push/pull even if skb_shared() */
99 			__skb_push(skb, skb->mac_len);
100 			bpf_compute_data_pointers(skb);
101 			filter_res = BPF_PROG_RUN(prog->filter, skb);
102 			__skb_pull(skb, skb->mac_len);
103 		} else {
104 			bpf_compute_data_pointers(skb);
105 			filter_res = BPF_PROG_RUN(prog->filter, skb);
106 		}
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 	rcu_read_unlock();
135 
136 	return ret;
137 }
138 
139 static bool cls_bpf_is_ebpf(const struct cls_bpf_prog *prog)
140 {
141 	return !prog->bpf_ops;
142 }
143 
144 static int cls_bpf_offload_cmd(struct tcf_proto *tp, struct cls_bpf_prog *prog,
145 			       struct cls_bpf_prog *oldprog,
146 			       struct netlink_ext_ack *extack)
147 {
148 	struct tcf_block *block = tp->chain->block;
149 	struct tc_cls_bpf_offload cls_bpf = {};
150 	struct cls_bpf_prog *obj;
151 	bool skip_sw;
152 	int err;
153 
154 	skip_sw = prog && tc_skip_sw(prog->gen_flags);
155 	obj = prog ?: oldprog;
156 
157 	tc_cls_common_offload_init(&cls_bpf.common, tp, obj->gen_flags, extack);
158 	cls_bpf.command = TC_CLSBPF_OFFLOAD;
159 	cls_bpf.exts = &obj->exts;
160 	cls_bpf.prog = prog ? prog->filter : NULL;
161 	cls_bpf.oldprog = oldprog ? oldprog->filter : NULL;
162 	cls_bpf.name = obj->bpf_name;
163 	cls_bpf.exts_integrated = obj->exts_integrated;
164 
165 	if (oldprog)
166 		err = tc_setup_cb_replace(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
167 					  skip_sw, &oldprog->gen_flags,
168 					  &oldprog->in_hw_count,
169 					  &prog->gen_flags, &prog->in_hw_count,
170 					  true);
171 	else
172 		err = tc_setup_cb_add(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
173 				      skip_sw, &prog->gen_flags,
174 				      &prog->in_hw_count, true);
175 
176 	if (prog && err) {
177 		cls_bpf_offload_cmd(tp, oldprog, prog, extack);
178 		return err;
179 	}
180 
181 	if (prog && skip_sw && !(prog->gen_flags & TCA_CLS_FLAGS_IN_HW))
182 		return -EINVAL;
183 
184 	return 0;
185 }
186 
187 static u32 cls_bpf_flags(u32 flags)
188 {
189 	return flags & CLS_BPF_SUPPORTED_GEN_FLAGS;
190 }
191 
192 static int cls_bpf_offload(struct tcf_proto *tp, struct cls_bpf_prog *prog,
193 			   struct cls_bpf_prog *oldprog,
194 			   struct netlink_ext_ack *extack)
195 {
196 	if (prog && oldprog &&
197 	    cls_bpf_flags(prog->gen_flags) !=
198 	    cls_bpf_flags(oldprog->gen_flags))
199 		return -EINVAL;
200 
201 	if (prog && tc_skip_hw(prog->gen_flags))
202 		prog = NULL;
203 	if (oldprog && tc_skip_hw(oldprog->gen_flags))
204 		oldprog = NULL;
205 	if (!prog && !oldprog)
206 		return 0;
207 
208 	return cls_bpf_offload_cmd(tp, prog, oldprog, extack);
209 }
210 
211 static void cls_bpf_stop_offload(struct tcf_proto *tp,
212 				 struct cls_bpf_prog *prog,
213 				 struct netlink_ext_ack *extack)
214 {
215 	int err;
216 
217 	err = cls_bpf_offload_cmd(tp, NULL, prog, extack);
218 	if (err)
219 		pr_err("Stopping hardware offload failed: %d\n", err);
220 }
221 
222 static void cls_bpf_offload_update_stats(struct tcf_proto *tp,
223 					 struct cls_bpf_prog *prog)
224 {
225 	struct tcf_block *block = tp->chain->block;
226 	struct tc_cls_bpf_offload cls_bpf = {};
227 
228 	tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags, NULL);
229 	cls_bpf.command = TC_CLSBPF_STATS;
230 	cls_bpf.exts = &prog->exts;
231 	cls_bpf.prog = prog->filter;
232 	cls_bpf.name = prog->bpf_name;
233 	cls_bpf.exts_integrated = prog->exts_integrated;
234 
235 	tc_setup_cb_call(block, TC_SETUP_CLSBPF, &cls_bpf, false, true);
236 }
237 
238 static int cls_bpf_init(struct tcf_proto *tp)
239 {
240 	struct cls_bpf_head *head;
241 
242 	head = kzalloc(sizeof(*head), GFP_KERNEL);
243 	if (head == NULL)
244 		return -ENOBUFS;
245 
246 	INIT_LIST_HEAD_RCU(&head->plist);
247 	idr_init(&head->handle_idr);
248 	rcu_assign_pointer(tp->root, head);
249 
250 	return 0;
251 }
252 
253 static void cls_bpf_free_parms(struct cls_bpf_prog *prog)
254 {
255 	if (cls_bpf_is_ebpf(prog))
256 		bpf_prog_put(prog->filter);
257 	else
258 		bpf_prog_destroy(prog->filter);
259 
260 	kfree(prog->bpf_name);
261 	kfree(prog->bpf_ops);
262 }
263 
264 static void __cls_bpf_delete_prog(struct cls_bpf_prog *prog)
265 {
266 	tcf_exts_destroy(&prog->exts);
267 	tcf_exts_put_net(&prog->exts);
268 
269 	cls_bpf_free_parms(prog);
270 	kfree(prog);
271 }
272 
273 static void cls_bpf_delete_prog_work(struct work_struct *work)
274 {
275 	struct cls_bpf_prog *prog = container_of(to_rcu_work(work),
276 						 struct cls_bpf_prog,
277 						 rwork);
278 	rtnl_lock();
279 	__cls_bpf_delete_prog(prog);
280 	rtnl_unlock();
281 }
282 
283 static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog,
284 			     struct netlink_ext_ack *extack)
285 {
286 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
287 
288 	idr_remove(&head->handle_idr, prog->handle);
289 	cls_bpf_stop_offload(tp, prog, extack);
290 	list_del_rcu(&prog->link);
291 	tcf_unbind_filter(tp, &prog->res);
292 	if (tcf_exts_get_net(&prog->exts))
293 		tcf_queue_work(&prog->rwork, cls_bpf_delete_prog_work);
294 	else
295 		__cls_bpf_delete_prog(prog);
296 }
297 
298 static int cls_bpf_delete(struct tcf_proto *tp, void *arg, bool *last,
299 			  bool rtnl_held, struct netlink_ext_ack *extack)
300 {
301 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
302 
303 	__cls_bpf_delete(tp, arg, extack);
304 	*last = list_empty(&head->plist);
305 	return 0;
306 }
307 
308 static void cls_bpf_destroy(struct tcf_proto *tp, bool rtnl_held,
309 			    struct netlink_ext_ack *extack)
310 {
311 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
312 	struct cls_bpf_prog *prog, *tmp;
313 
314 	list_for_each_entry_safe(prog, tmp, &head->plist, link)
315 		__cls_bpf_delete(tp, prog, extack);
316 
317 	idr_destroy(&head->handle_idr);
318 	kfree_rcu(head, rcu);
319 }
320 
321 static void *cls_bpf_get(struct tcf_proto *tp, u32 handle)
322 {
323 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
324 	struct cls_bpf_prog *prog;
325 
326 	list_for_each_entry(prog, &head->plist, link) {
327 		if (prog->handle == handle)
328 			return prog;
329 	}
330 
331 	return NULL;
332 }
333 
334 static int cls_bpf_prog_from_ops(struct nlattr **tb, struct cls_bpf_prog *prog)
335 {
336 	struct sock_filter *bpf_ops;
337 	struct sock_fprog_kern fprog_tmp;
338 	struct bpf_prog *fp;
339 	u16 bpf_size, bpf_num_ops;
340 	int ret;
341 
342 	bpf_num_ops = nla_get_u16(tb[TCA_BPF_OPS_LEN]);
343 	if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0)
344 		return -EINVAL;
345 
346 	bpf_size = bpf_num_ops * sizeof(*bpf_ops);
347 	if (bpf_size != nla_len(tb[TCA_BPF_OPS]))
348 		return -EINVAL;
349 
350 	bpf_ops = kmemdup(nla_data(tb[TCA_BPF_OPS]), bpf_size, GFP_KERNEL);
351 	if (bpf_ops == NULL)
352 		return -ENOMEM;
353 
354 	fprog_tmp.len = bpf_num_ops;
355 	fprog_tmp.filter = bpf_ops;
356 
357 	ret = bpf_prog_create(&fp, &fprog_tmp);
358 	if (ret < 0) {
359 		kfree(bpf_ops);
360 		return ret;
361 	}
362 
363 	prog->bpf_ops = bpf_ops;
364 	prog->bpf_num_ops = bpf_num_ops;
365 	prog->bpf_name = NULL;
366 	prog->filter = fp;
367 
368 	return 0;
369 }
370 
371 static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
372 				 u32 gen_flags, const struct tcf_proto *tp)
373 {
374 	struct bpf_prog *fp;
375 	char *name = NULL;
376 	bool skip_sw;
377 	u32 bpf_fd;
378 
379 	bpf_fd = nla_get_u32(tb[TCA_BPF_FD]);
380 	skip_sw = gen_flags & TCA_CLS_FLAGS_SKIP_SW;
381 
382 	fp = bpf_prog_get_type_dev(bpf_fd, BPF_PROG_TYPE_SCHED_CLS, skip_sw);
383 	if (IS_ERR(fp))
384 		return PTR_ERR(fp);
385 
386 	if (tb[TCA_BPF_NAME]) {
387 		name = nla_memdup(tb[TCA_BPF_NAME], GFP_KERNEL);
388 		if (!name) {
389 			bpf_prog_put(fp);
390 			return -ENOMEM;
391 		}
392 	}
393 
394 	prog->bpf_ops = NULL;
395 	prog->bpf_name = name;
396 	prog->filter = fp;
397 
398 	if (fp->dst_needed)
399 		tcf_block_netif_keep_dst(tp->chain->block);
400 
401 	return 0;
402 }
403 
404 static int cls_bpf_set_parms(struct net *net, struct tcf_proto *tp,
405 			     struct cls_bpf_prog *prog, unsigned long base,
406 			     struct nlattr **tb, struct nlattr *est, bool ovr,
407 			     struct netlink_ext_ack *extack)
408 {
409 	bool is_bpf, is_ebpf, have_exts = false;
410 	u32 gen_flags = 0;
411 	int ret;
412 
413 	is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
414 	is_ebpf = tb[TCA_BPF_FD];
415 	if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf))
416 		return -EINVAL;
417 
418 	ret = tcf_exts_validate(net, tp, tb, est, &prog->exts, ovr, true,
419 				extack);
420 	if (ret < 0)
421 		return ret;
422 
423 	if (tb[TCA_BPF_FLAGS]) {
424 		u32 bpf_flags = nla_get_u32(tb[TCA_BPF_FLAGS]);
425 
426 		if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT)
427 			return -EINVAL;
428 
429 		have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT;
430 	}
431 	if (tb[TCA_BPF_FLAGS_GEN]) {
432 		gen_flags = nla_get_u32(tb[TCA_BPF_FLAGS_GEN]);
433 		if (gen_flags & ~CLS_BPF_SUPPORTED_GEN_FLAGS ||
434 		    !tc_flags_valid(gen_flags))
435 			return -EINVAL;
436 	}
437 
438 	prog->exts_integrated = have_exts;
439 	prog->gen_flags = gen_flags;
440 
441 	ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
442 		       cls_bpf_prog_from_efd(tb, prog, gen_flags, tp);
443 	if (ret < 0)
444 		return ret;
445 
446 	if (tb[TCA_BPF_CLASSID]) {
447 		prog->res.classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
448 		tcf_bind_filter(tp, &prog->res, base);
449 	}
450 
451 	return 0;
452 }
453 
454 static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
455 			  struct tcf_proto *tp, unsigned long base,
456 			  u32 handle, struct nlattr **tca,
457 			  void **arg, bool ovr, bool rtnl_held,
458 			  struct netlink_ext_ack *extack)
459 {
460 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
461 	struct cls_bpf_prog *oldprog = *arg;
462 	struct nlattr *tb[TCA_BPF_MAX + 1];
463 	struct cls_bpf_prog *prog;
464 	int ret;
465 
466 	if (tca[TCA_OPTIONS] == NULL)
467 		return -EINVAL;
468 
469 	ret = nla_parse_nested_deprecated(tb, TCA_BPF_MAX, tca[TCA_OPTIONS],
470 					  bpf_policy, NULL);
471 	if (ret < 0)
472 		return ret;
473 
474 	prog = kzalloc(sizeof(*prog), GFP_KERNEL);
475 	if (!prog)
476 		return -ENOBUFS;
477 
478 	ret = tcf_exts_init(&prog->exts, net, TCA_BPF_ACT, TCA_BPF_POLICE);
479 	if (ret < 0)
480 		goto errout;
481 
482 	if (oldprog) {
483 		if (handle && oldprog->handle != handle) {
484 			ret = -EINVAL;
485 			goto errout;
486 		}
487 	}
488 
489 	if (handle == 0) {
490 		handle = 1;
491 		ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
492 				    INT_MAX, GFP_KERNEL);
493 	} else if (!oldprog) {
494 		ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
495 				    handle, GFP_KERNEL);
496 	}
497 
498 	if (ret)
499 		goto errout;
500 	prog->handle = handle;
501 
502 	ret = cls_bpf_set_parms(net, tp, prog, base, tb, tca[TCA_RATE], ovr,
503 				extack);
504 	if (ret < 0)
505 		goto errout_idr;
506 
507 	ret = cls_bpf_offload(tp, prog, oldprog, extack);
508 	if (ret)
509 		goto errout_parms;
510 
511 	if (!tc_in_hw(prog->gen_flags))
512 		prog->gen_flags |= TCA_CLS_FLAGS_NOT_IN_HW;
513 
514 	if (oldprog) {
515 		idr_replace(&head->handle_idr, prog, handle);
516 		list_replace_rcu(&oldprog->link, &prog->link);
517 		tcf_unbind_filter(tp, &oldprog->res);
518 		tcf_exts_get_net(&oldprog->exts);
519 		tcf_queue_work(&oldprog->rwork, cls_bpf_delete_prog_work);
520 	} else {
521 		list_add_rcu(&prog->link, &head->plist);
522 	}
523 
524 	*arg = prog;
525 	return 0;
526 
527 errout_parms:
528 	cls_bpf_free_parms(prog);
529 errout_idr:
530 	if (!oldprog)
531 		idr_remove(&head->handle_idr, prog->handle);
532 errout:
533 	tcf_exts_destroy(&prog->exts);
534 	kfree(prog);
535 	return ret;
536 }
537 
538 static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog,
539 				 struct sk_buff *skb)
540 {
541 	struct nlattr *nla;
542 
543 	if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_num_ops))
544 		return -EMSGSIZE;
545 
546 	nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_num_ops *
547 			  sizeof(struct sock_filter));
548 	if (nla == NULL)
549 		return -EMSGSIZE;
550 
551 	memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
552 
553 	return 0;
554 }
555 
556 static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
557 				  struct sk_buff *skb)
558 {
559 	struct nlattr *nla;
560 
561 	if (prog->bpf_name &&
562 	    nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
563 		return -EMSGSIZE;
564 
565 	if (nla_put_u32(skb, TCA_BPF_ID, prog->filter->aux->id))
566 		return -EMSGSIZE;
567 
568 	nla = nla_reserve(skb, TCA_BPF_TAG, sizeof(prog->filter->tag));
569 	if (nla == NULL)
570 		return -EMSGSIZE;
571 
572 	memcpy(nla_data(nla), prog->filter->tag, nla_len(nla));
573 
574 	return 0;
575 }
576 
577 static int cls_bpf_dump(struct net *net, struct tcf_proto *tp, void *fh,
578 			struct sk_buff *skb, struct tcmsg *tm, bool rtnl_held)
579 {
580 	struct cls_bpf_prog *prog = fh;
581 	struct nlattr *nest;
582 	u32 bpf_flags = 0;
583 	int ret;
584 
585 	if (prog == NULL)
586 		return skb->len;
587 
588 	tm->tcm_handle = prog->handle;
589 
590 	cls_bpf_offload_update_stats(tp, prog);
591 
592 	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
593 	if (nest == NULL)
594 		goto nla_put_failure;
595 
596 	if (prog->res.classid &&
597 	    nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
598 		goto nla_put_failure;
599 
600 	if (cls_bpf_is_ebpf(prog))
601 		ret = cls_bpf_dump_ebpf_info(prog, skb);
602 	else
603 		ret = cls_bpf_dump_bpf_info(prog, skb);
604 	if (ret)
605 		goto nla_put_failure;
606 
607 	if (tcf_exts_dump(skb, &prog->exts) < 0)
608 		goto nla_put_failure;
609 
610 	if (prog->exts_integrated)
611 		bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT;
612 	if (bpf_flags && nla_put_u32(skb, TCA_BPF_FLAGS, bpf_flags))
613 		goto nla_put_failure;
614 	if (prog->gen_flags &&
615 	    nla_put_u32(skb, TCA_BPF_FLAGS_GEN, prog->gen_flags))
616 		goto nla_put_failure;
617 
618 	nla_nest_end(skb, nest);
619 
620 	if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
621 		goto nla_put_failure;
622 
623 	return skb->len;
624 
625 nla_put_failure:
626 	nla_nest_cancel(skb, nest);
627 	return -1;
628 }
629 
630 static void cls_bpf_bind_class(void *fh, u32 classid, unsigned long cl)
631 {
632 	struct cls_bpf_prog *prog = fh;
633 
634 	if (prog && prog->res.classid == classid)
635 		prog->res.class = cl;
636 }
637 
638 static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg,
639 			 bool rtnl_held)
640 {
641 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
642 	struct cls_bpf_prog *prog;
643 
644 	list_for_each_entry(prog, &head->plist, link) {
645 		if (arg->count < arg->skip)
646 			goto skip;
647 		if (arg->fn(tp, prog, arg) < 0) {
648 			arg->stop = 1;
649 			break;
650 		}
651 skip:
652 		arg->count++;
653 	}
654 }
655 
656 static int cls_bpf_reoffload(struct tcf_proto *tp, bool add, flow_setup_cb_t *cb,
657 			     void *cb_priv, struct netlink_ext_ack *extack)
658 {
659 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
660 	struct tcf_block *block = tp->chain->block;
661 	struct tc_cls_bpf_offload cls_bpf = {};
662 	struct cls_bpf_prog *prog;
663 	int err;
664 
665 	list_for_each_entry(prog, &head->plist, link) {
666 		if (tc_skip_hw(prog->gen_flags))
667 			continue;
668 
669 		tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags,
670 					   extack);
671 		cls_bpf.command = TC_CLSBPF_OFFLOAD;
672 		cls_bpf.exts = &prog->exts;
673 		cls_bpf.prog = add ? prog->filter : NULL;
674 		cls_bpf.oldprog = add ? NULL : prog->filter;
675 		cls_bpf.name = prog->bpf_name;
676 		cls_bpf.exts_integrated = prog->exts_integrated;
677 
678 		err = tc_setup_cb_reoffload(block, tp, add, cb, TC_SETUP_CLSBPF,
679 					    &cls_bpf, cb_priv, &prog->gen_flags,
680 					    &prog->in_hw_count);
681 		if (err)
682 			return err;
683 	}
684 
685 	return 0;
686 }
687 
688 static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
689 	.kind		=	"bpf",
690 	.owner		=	THIS_MODULE,
691 	.classify	=	cls_bpf_classify,
692 	.init		=	cls_bpf_init,
693 	.destroy	=	cls_bpf_destroy,
694 	.get		=	cls_bpf_get,
695 	.change		=	cls_bpf_change,
696 	.delete		=	cls_bpf_delete,
697 	.walk		=	cls_bpf_walk,
698 	.reoffload	=	cls_bpf_reoffload,
699 	.dump		=	cls_bpf_dump,
700 	.bind_class	=	cls_bpf_bind_class,
701 };
702 
703 static int __init cls_bpf_init_mod(void)
704 {
705 	return register_tcf_proto_ops(&cls_bpf_ops);
706 }
707 
708 static void __exit cls_bpf_exit_mod(void)
709 {
710 	unregister_tcf_proto_ops(&cls_bpf_ops);
711 }
712 
713 module_init(cls_bpf_init_mod);
714 module_exit(cls_bpf_exit_mod);
715