xref: /openbmc/linux/net/sched/cls_bpf.c (revision e15a5365)
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 && prog)
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 if (prog)
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 	else
176 		err = tc_setup_cb_destroy(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
177 					  skip_sw, &oldprog->gen_flags,
178 					  &oldprog->in_hw_count, true);
179 
180 	if (prog && err) {
181 		cls_bpf_offload_cmd(tp, oldprog, prog, extack);
182 		return err;
183 	}
184 
185 	if (prog && skip_sw && !(prog->gen_flags & TCA_CLS_FLAGS_IN_HW))
186 		return -EINVAL;
187 
188 	return 0;
189 }
190 
191 static u32 cls_bpf_flags(u32 flags)
192 {
193 	return flags & CLS_BPF_SUPPORTED_GEN_FLAGS;
194 }
195 
196 static int cls_bpf_offload(struct tcf_proto *tp, struct cls_bpf_prog *prog,
197 			   struct cls_bpf_prog *oldprog,
198 			   struct netlink_ext_ack *extack)
199 {
200 	if (prog && oldprog &&
201 	    cls_bpf_flags(prog->gen_flags) !=
202 	    cls_bpf_flags(oldprog->gen_flags))
203 		return -EINVAL;
204 
205 	if (prog && tc_skip_hw(prog->gen_flags))
206 		prog = NULL;
207 	if (oldprog && tc_skip_hw(oldprog->gen_flags))
208 		oldprog = NULL;
209 	if (!prog && !oldprog)
210 		return 0;
211 
212 	return cls_bpf_offload_cmd(tp, prog, oldprog, extack);
213 }
214 
215 static void cls_bpf_stop_offload(struct tcf_proto *tp,
216 				 struct cls_bpf_prog *prog,
217 				 struct netlink_ext_ack *extack)
218 {
219 	int err;
220 
221 	err = cls_bpf_offload_cmd(tp, NULL, prog, extack);
222 	if (err)
223 		pr_err("Stopping hardware offload failed: %d\n", err);
224 }
225 
226 static void cls_bpf_offload_update_stats(struct tcf_proto *tp,
227 					 struct cls_bpf_prog *prog)
228 {
229 	struct tcf_block *block = tp->chain->block;
230 	struct tc_cls_bpf_offload cls_bpf = {};
231 
232 	tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags, NULL);
233 	cls_bpf.command = TC_CLSBPF_STATS;
234 	cls_bpf.exts = &prog->exts;
235 	cls_bpf.prog = prog->filter;
236 	cls_bpf.name = prog->bpf_name;
237 	cls_bpf.exts_integrated = prog->exts_integrated;
238 
239 	tc_setup_cb_call(block, TC_SETUP_CLSBPF, &cls_bpf, false, true);
240 }
241 
242 static int cls_bpf_init(struct tcf_proto *tp)
243 {
244 	struct cls_bpf_head *head;
245 
246 	head = kzalloc(sizeof(*head), GFP_KERNEL);
247 	if (head == NULL)
248 		return -ENOBUFS;
249 
250 	INIT_LIST_HEAD_RCU(&head->plist);
251 	idr_init(&head->handle_idr);
252 	rcu_assign_pointer(tp->root, head);
253 
254 	return 0;
255 }
256 
257 static void cls_bpf_free_parms(struct cls_bpf_prog *prog)
258 {
259 	if (cls_bpf_is_ebpf(prog))
260 		bpf_prog_put(prog->filter);
261 	else
262 		bpf_prog_destroy(prog->filter);
263 
264 	kfree(prog->bpf_name);
265 	kfree(prog->bpf_ops);
266 }
267 
268 static void __cls_bpf_delete_prog(struct cls_bpf_prog *prog)
269 {
270 	tcf_exts_destroy(&prog->exts);
271 	tcf_exts_put_net(&prog->exts);
272 
273 	cls_bpf_free_parms(prog);
274 	kfree(prog);
275 }
276 
277 static void cls_bpf_delete_prog_work(struct work_struct *work)
278 {
279 	struct cls_bpf_prog *prog = container_of(to_rcu_work(work),
280 						 struct cls_bpf_prog,
281 						 rwork);
282 	rtnl_lock();
283 	__cls_bpf_delete_prog(prog);
284 	rtnl_unlock();
285 }
286 
287 static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog,
288 			     struct netlink_ext_ack *extack)
289 {
290 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
291 
292 	idr_remove(&head->handle_idr, prog->handle);
293 	cls_bpf_stop_offload(tp, prog, extack);
294 	list_del_rcu(&prog->link);
295 	tcf_unbind_filter(tp, &prog->res);
296 	if (tcf_exts_get_net(&prog->exts))
297 		tcf_queue_work(&prog->rwork, cls_bpf_delete_prog_work);
298 	else
299 		__cls_bpf_delete_prog(prog);
300 }
301 
302 static int cls_bpf_delete(struct tcf_proto *tp, void *arg, bool *last,
303 			  bool rtnl_held, struct netlink_ext_ack *extack)
304 {
305 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
306 
307 	__cls_bpf_delete(tp, arg, extack);
308 	*last = list_empty(&head->plist);
309 	return 0;
310 }
311 
312 static void cls_bpf_destroy(struct tcf_proto *tp, bool rtnl_held,
313 			    struct netlink_ext_ack *extack)
314 {
315 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
316 	struct cls_bpf_prog *prog, *tmp;
317 
318 	list_for_each_entry_safe(prog, tmp, &head->plist, link)
319 		__cls_bpf_delete(tp, prog, extack);
320 
321 	idr_destroy(&head->handle_idr);
322 	kfree_rcu(head, rcu);
323 }
324 
325 static void *cls_bpf_get(struct tcf_proto *tp, u32 handle)
326 {
327 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
328 	struct cls_bpf_prog *prog;
329 
330 	list_for_each_entry(prog, &head->plist, link) {
331 		if (prog->handle == handle)
332 			return prog;
333 	}
334 
335 	return NULL;
336 }
337 
338 static int cls_bpf_prog_from_ops(struct nlattr **tb, struct cls_bpf_prog *prog)
339 {
340 	struct sock_filter *bpf_ops;
341 	struct sock_fprog_kern fprog_tmp;
342 	struct bpf_prog *fp;
343 	u16 bpf_size, bpf_num_ops;
344 	int ret;
345 
346 	bpf_num_ops = nla_get_u16(tb[TCA_BPF_OPS_LEN]);
347 	if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0)
348 		return -EINVAL;
349 
350 	bpf_size = bpf_num_ops * sizeof(*bpf_ops);
351 	if (bpf_size != nla_len(tb[TCA_BPF_OPS]))
352 		return -EINVAL;
353 
354 	bpf_ops = kmemdup(nla_data(tb[TCA_BPF_OPS]), bpf_size, GFP_KERNEL);
355 	if (bpf_ops == NULL)
356 		return -ENOMEM;
357 
358 	fprog_tmp.len = bpf_num_ops;
359 	fprog_tmp.filter = bpf_ops;
360 
361 	ret = bpf_prog_create(&fp, &fprog_tmp);
362 	if (ret < 0) {
363 		kfree(bpf_ops);
364 		return ret;
365 	}
366 
367 	prog->bpf_ops = bpf_ops;
368 	prog->bpf_num_ops = bpf_num_ops;
369 	prog->bpf_name = NULL;
370 	prog->filter = fp;
371 
372 	return 0;
373 }
374 
375 static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
376 				 u32 gen_flags, const struct tcf_proto *tp)
377 {
378 	struct bpf_prog *fp;
379 	char *name = NULL;
380 	bool skip_sw;
381 	u32 bpf_fd;
382 
383 	bpf_fd = nla_get_u32(tb[TCA_BPF_FD]);
384 	skip_sw = gen_flags & TCA_CLS_FLAGS_SKIP_SW;
385 
386 	fp = bpf_prog_get_type_dev(bpf_fd, BPF_PROG_TYPE_SCHED_CLS, skip_sw);
387 	if (IS_ERR(fp))
388 		return PTR_ERR(fp);
389 
390 	if (tb[TCA_BPF_NAME]) {
391 		name = nla_memdup(tb[TCA_BPF_NAME], GFP_KERNEL);
392 		if (!name) {
393 			bpf_prog_put(fp);
394 			return -ENOMEM;
395 		}
396 	}
397 
398 	prog->bpf_ops = NULL;
399 	prog->bpf_name = name;
400 	prog->filter = fp;
401 
402 	if (fp->dst_needed)
403 		tcf_block_netif_keep_dst(tp->chain->block);
404 
405 	return 0;
406 }
407 
408 static int cls_bpf_set_parms(struct net *net, struct tcf_proto *tp,
409 			     struct cls_bpf_prog *prog, unsigned long base,
410 			     struct nlattr **tb, struct nlattr *est, bool ovr,
411 			     struct netlink_ext_ack *extack)
412 {
413 	bool is_bpf, is_ebpf, have_exts = false;
414 	u32 gen_flags = 0;
415 	int ret;
416 
417 	is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
418 	is_ebpf = tb[TCA_BPF_FD];
419 	if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf))
420 		return -EINVAL;
421 
422 	ret = tcf_exts_validate(net, tp, tb, est, &prog->exts, ovr, true,
423 				extack);
424 	if (ret < 0)
425 		return ret;
426 
427 	if (tb[TCA_BPF_FLAGS]) {
428 		u32 bpf_flags = nla_get_u32(tb[TCA_BPF_FLAGS]);
429 
430 		if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT)
431 			return -EINVAL;
432 
433 		have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT;
434 	}
435 	if (tb[TCA_BPF_FLAGS_GEN]) {
436 		gen_flags = nla_get_u32(tb[TCA_BPF_FLAGS_GEN]);
437 		if (gen_flags & ~CLS_BPF_SUPPORTED_GEN_FLAGS ||
438 		    !tc_flags_valid(gen_flags))
439 			return -EINVAL;
440 	}
441 
442 	prog->exts_integrated = have_exts;
443 	prog->gen_flags = gen_flags;
444 
445 	ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
446 		       cls_bpf_prog_from_efd(tb, prog, gen_flags, tp);
447 	if (ret < 0)
448 		return ret;
449 
450 	if (tb[TCA_BPF_CLASSID]) {
451 		prog->res.classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
452 		tcf_bind_filter(tp, &prog->res, base);
453 	}
454 
455 	return 0;
456 }
457 
458 static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
459 			  struct tcf_proto *tp, unsigned long base,
460 			  u32 handle, struct nlattr **tca,
461 			  void **arg, bool ovr, bool rtnl_held,
462 			  struct netlink_ext_ack *extack)
463 {
464 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
465 	struct cls_bpf_prog *oldprog = *arg;
466 	struct nlattr *tb[TCA_BPF_MAX + 1];
467 	struct cls_bpf_prog *prog;
468 	int ret;
469 
470 	if (tca[TCA_OPTIONS] == NULL)
471 		return -EINVAL;
472 
473 	ret = nla_parse_nested_deprecated(tb, TCA_BPF_MAX, tca[TCA_OPTIONS],
474 					  bpf_policy, NULL);
475 	if (ret < 0)
476 		return ret;
477 
478 	prog = kzalloc(sizeof(*prog), GFP_KERNEL);
479 	if (!prog)
480 		return -ENOBUFS;
481 
482 	ret = tcf_exts_init(&prog->exts, net, TCA_BPF_ACT, TCA_BPF_POLICE);
483 	if (ret < 0)
484 		goto errout;
485 
486 	if (oldprog) {
487 		if (handle && oldprog->handle != handle) {
488 			ret = -EINVAL;
489 			goto errout;
490 		}
491 	}
492 
493 	if (handle == 0) {
494 		handle = 1;
495 		ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
496 				    INT_MAX, GFP_KERNEL);
497 	} else if (!oldprog) {
498 		ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
499 				    handle, GFP_KERNEL);
500 	}
501 
502 	if (ret)
503 		goto errout;
504 	prog->handle = handle;
505 
506 	ret = cls_bpf_set_parms(net, tp, prog, base, tb, tca[TCA_RATE], ovr,
507 				extack);
508 	if (ret < 0)
509 		goto errout_idr;
510 
511 	ret = cls_bpf_offload(tp, prog, oldprog, extack);
512 	if (ret)
513 		goto errout_parms;
514 
515 	if (!tc_in_hw(prog->gen_flags))
516 		prog->gen_flags |= TCA_CLS_FLAGS_NOT_IN_HW;
517 
518 	if (oldprog) {
519 		idr_replace(&head->handle_idr, prog, handle);
520 		list_replace_rcu(&oldprog->link, &prog->link);
521 		tcf_unbind_filter(tp, &oldprog->res);
522 		tcf_exts_get_net(&oldprog->exts);
523 		tcf_queue_work(&oldprog->rwork, cls_bpf_delete_prog_work);
524 	} else {
525 		list_add_rcu(&prog->link, &head->plist);
526 	}
527 
528 	*arg = prog;
529 	return 0;
530 
531 errout_parms:
532 	cls_bpf_free_parms(prog);
533 errout_idr:
534 	if (!oldprog)
535 		idr_remove(&head->handle_idr, prog->handle);
536 errout:
537 	tcf_exts_destroy(&prog->exts);
538 	kfree(prog);
539 	return ret;
540 }
541 
542 static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog,
543 				 struct sk_buff *skb)
544 {
545 	struct nlattr *nla;
546 
547 	if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_num_ops))
548 		return -EMSGSIZE;
549 
550 	nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_num_ops *
551 			  sizeof(struct sock_filter));
552 	if (nla == NULL)
553 		return -EMSGSIZE;
554 
555 	memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
556 
557 	return 0;
558 }
559 
560 static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
561 				  struct sk_buff *skb)
562 {
563 	struct nlattr *nla;
564 
565 	if (prog->bpf_name &&
566 	    nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
567 		return -EMSGSIZE;
568 
569 	if (nla_put_u32(skb, TCA_BPF_ID, prog->filter->aux->id))
570 		return -EMSGSIZE;
571 
572 	nla = nla_reserve(skb, TCA_BPF_TAG, sizeof(prog->filter->tag));
573 	if (nla == NULL)
574 		return -EMSGSIZE;
575 
576 	memcpy(nla_data(nla), prog->filter->tag, nla_len(nla));
577 
578 	return 0;
579 }
580 
581 static int cls_bpf_dump(struct net *net, struct tcf_proto *tp, void *fh,
582 			struct sk_buff *skb, struct tcmsg *tm, bool rtnl_held)
583 {
584 	struct cls_bpf_prog *prog = fh;
585 	struct nlattr *nest;
586 	u32 bpf_flags = 0;
587 	int ret;
588 
589 	if (prog == NULL)
590 		return skb->len;
591 
592 	tm->tcm_handle = prog->handle;
593 
594 	cls_bpf_offload_update_stats(tp, prog);
595 
596 	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
597 	if (nest == NULL)
598 		goto nla_put_failure;
599 
600 	if (prog->res.classid &&
601 	    nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
602 		goto nla_put_failure;
603 
604 	if (cls_bpf_is_ebpf(prog))
605 		ret = cls_bpf_dump_ebpf_info(prog, skb);
606 	else
607 		ret = cls_bpf_dump_bpf_info(prog, skb);
608 	if (ret)
609 		goto nla_put_failure;
610 
611 	if (tcf_exts_dump(skb, &prog->exts) < 0)
612 		goto nla_put_failure;
613 
614 	if (prog->exts_integrated)
615 		bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT;
616 	if (bpf_flags && nla_put_u32(skb, TCA_BPF_FLAGS, bpf_flags))
617 		goto nla_put_failure;
618 	if (prog->gen_flags &&
619 	    nla_put_u32(skb, TCA_BPF_FLAGS_GEN, prog->gen_flags))
620 		goto nla_put_failure;
621 
622 	nla_nest_end(skb, nest);
623 
624 	if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
625 		goto nla_put_failure;
626 
627 	return skb->len;
628 
629 nla_put_failure:
630 	nla_nest_cancel(skb, nest);
631 	return -1;
632 }
633 
634 static void cls_bpf_bind_class(void *fh, u32 classid, unsigned long cl,
635 			       void *q, unsigned long base)
636 {
637 	struct cls_bpf_prog *prog = fh;
638 
639 	if (prog && prog->res.classid == classid) {
640 		if (cl)
641 			__tcf_bind_filter(q, &prog->res, base);
642 		else
643 			__tcf_unbind_filter(q, &prog->res);
644 	}
645 }
646 
647 static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg,
648 			 bool rtnl_held)
649 {
650 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
651 	struct cls_bpf_prog *prog;
652 
653 	list_for_each_entry(prog, &head->plist, link) {
654 		if (arg->count < arg->skip)
655 			goto skip;
656 		if (arg->fn(tp, prog, arg) < 0) {
657 			arg->stop = 1;
658 			break;
659 		}
660 skip:
661 		arg->count++;
662 	}
663 }
664 
665 static int cls_bpf_reoffload(struct tcf_proto *tp, bool add, flow_setup_cb_t *cb,
666 			     void *cb_priv, struct netlink_ext_ack *extack)
667 {
668 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
669 	struct tcf_block *block = tp->chain->block;
670 	struct tc_cls_bpf_offload cls_bpf = {};
671 	struct cls_bpf_prog *prog;
672 	int err;
673 
674 	list_for_each_entry(prog, &head->plist, link) {
675 		if (tc_skip_hw(prog->gen_flags))
676 			continue;
677 
678 		tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags,
679 					   extack);
680 		cls_bpf.command = TC_CLSBPF_OFFLOAD;
681 		cls_bpf.exts = &prog->exts;
682 		cls_bpf.prog = add ? prog->filter : NULL;
683 		cls_bpf.oldprog = add ? NULL : prog->filter;
684 		cls_bpf.name = prog->bpf_name;
685 		cls_bpf.exts_integrated = prog->exts_integrated;
686 
687 		err = tc_setup_cb_reoffload(block, tp, add, cb, TC_SETUP_CLSBPF,
688 					    &cls_bpf, cb_priv, &prog->gen_flags,
689 					    &prog->in_hw_count);
690 		if (err)
691 			return err;
692 	}
693 
694 	return 0;
695 }
696 
697 static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
698 	.kind		=	"bpf",
699 	.owner		=	THIS_MODULE,
700 	.classify	=	cls_bpf_classify,
701 	.init		=	cls_bpf_init,
702 	.destroy	=	cls_bpf_destroy,
703 	.get		=	cls_bpf_get,
704 	.change		=	cls_bpf_change,
705 	.delete		=	cls_bpf_delete,
706 	.walk		=	cls_bpf_walk,
707 	.reoffload	=	cls_bpf_reoffload,
708 	.dump		=	cls_bpf_dump,
709 	.bind_class	=	cls_bpf_bind_class,
710 };
711 
712 static int __init cls_bpf_init_mod(void)
713 {
714 	return register_tcf_proto_ops(&cls_bpf_ops);
715 }
716 
717 static void __exit cls_bpf_exit_mod(void)
718 {
719 	unregister_tcf_proto_ops(&cls_bpf_ops);
720 }
721 
722 module_init(cls_bpf_init_mod);
723 module_exit(cls_bpf_exit_mod);
724