1/*
  2 * net/sched/cls_matchll.c		Match-all classifier
  3 *
  4 * Copyright (c) 2016 Jiri Pirko <jiri@mellanox.com>
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License as published by
  8 * the Free Software Foundation; either version 2 of the License, or
  9 * (at your option) any later version.
 10 */
 11
 12#include <linux/kernel.h>
 13#include <linux/init.h>
 14#include <linux/module.h>
 15
 16#include <net/sch_generic.h>
 17#include <net/pkt_cls.h>
 18
 19struct cls_mall_head {
 20	struct tcf_exts exts;
 21	struct tcf_result res;
 22	u32 handle;
 23	u32 flags;
 24	union {
 25		struct work_struct work;
 26		struct rcu_head	rcu;
 27	};
 28};
 29
 30static int mall_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 31			 struct tcf_result *res)
 32{
 33	struct cls_mall_head *head = rcu_dereference_bh(tp->root);
 34
 35	if (tc_skip_sw(head->flags))
 36		return -1;
 37
 38	*res = head->res;
 39	return tcf_exts_exec(skb, &head->exts, res);
 40}
 41
 42static int mall_init(struct tcf_proto *tp)
 43{
 44	return 0;
 45}
 46
 47static void __mall_destroy(struct cls_mall_head *head)
 48{
 49	tcf_exts_destroy(&head->exts);
 50	tcf_exts_put_net(&head->exts);
 51	kfree(head);
 52}
 53
 54static void mall_destroy_work(struct work_struct *work)
 55{
 56	struct cls_mall_head *head = container_of(work, struct cls_mall_head,
 57						  work);
 58	rtnl_lock();
 59	__mall_destroy(head);
 60	rtnl_unlock();
 61}
 62
 63static void mall_destroy_rcu(struct rcu_head *rcu)
 64{
 65	struct cls_mall_head *head = container_of(rcu, struct cls_mall_head,
 66						  rcu);
 67
 68	INIT_WORK(&head->work, mall_destroy_work);
 69	tcf_queue_work(&head->work);
 70}
 71
 72static void mall_destroy_hw_filter(struct tcf_proto *tp,
 73				   struct cls_mall_head *head,
 74				   unsigned long cookie,
 75				   struct netlink_ext_ack *extack)
 76{
 77	struct tc_cls_matchall_offload cls_mall = {};
 78	struct tcf_block *block = tp->chain->block;
 79
 80	tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, extack);
 81	cls_mall.command = TC_CLSMATCHALL_DESTROY;
 82	cls_mall.cookie = cookie;
 83
 84	tc_setup_cb_call(block, NULL, TC_SETUP_CLSMATCHALL, &cls_mall, false);
 85	tcf_block_offload_dec(block, &head->flags);
 86}
 87
 88static int mall_replace_hw_filter(struct tcf_proto *tp,
 89				  struct cls_mall_head *head,
 90				  unsigned long cookie,
 91				  struct netlink_ext_ack *extack)
 92{
 93	struct tc_cls_matchall_offload cls_mall = {};
 94	struct tcf_block *block = tp->chain->block;
 95	bool skip_sw = tc_skip_sw(head->flags);
 96	int err;
 97
 98	tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, extack);
 99	cls_mall.command = TC_CLSMATCHALL_REPLACE;
100	cls_mall.exts = &head->exts;
101	cls_mall.cookie = cookie;
102
103	err = tc_setup_cb_call(block, NULL, TC_SETUP_CLSMATCHALL,
104			       &cls_mall, skip_sw);
105	if (err < 0) {
106		mall_destroy_hw_filter(tp, head, cookie, NULL);
107		return err;
108	} else if (err > 0) {
109		tcf_block_offload_inc(block, &head->flags);
110	}
111
112	if (skip_sw && !(head->flags & TCA_CLS_FLAGS_IN_HW))
113		return -EINVAL;
114
115	return 0;
116}
117
118static void mall_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
119{
120	struct cls_mall_head *head = rtnl_dereference(tp->root);
121
122	if (!head)
123		return;
124
125	if (!tc_skip_hw(head->flags))
126		mall_destroy_hw_filter(tp, head, (unsigned long) head, extack);
127
128	if (tcf_exts_get_net(&head->exts))
129		call_rcu(&head->rcu, mall_destroy_rcu);
130	else
131		__mall_destroy(head);
132}
133
134static void *mall_get(struct tcf_proto *tp, u32 handle)
135{
136	return NULL;
137}
138
139static const struct nla_policy mall_policy[TCA_MATCHALL_MAX + 1] = {
140	[TCA_MATCHALL_UNSPEC]		= { .type = NLA_UNSPEC },
141	[TCA_MATCHALL_CLASSID]		= { .type = NLA_U32 },
142};
143
144static int mall_set_parms(struct net *net, struct tcf_proto *tp,
145			  struct cls_mall_head *head,
146			  unsigned long base, struct nlattr **tb,
147			  struct nlattr *est, bool ovr,
148			  struct netlink_ext_ack *extack)
149{
150	int err;
151
152	err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr, extack);
153	if (err < 0)
154		return err;
155
156	if (tb[TCA_MATCHALL_CLASSID]) {
157		head->res.classid = nla_get_u32(tb[TCA_MATCHALL_CLASSID]);
158		tcf_bind_filter(tp, &head->res, base);
159	}
160	return 0;
161}
162
163static int mall_change(struct net *net, struct sk_buff *in_skb,
164		       struct tcf_proto *tp, unsigned long base,
165		       u32 handle, struct nlattr **tca,
166		       void **arg, bool ovr, struct netlink_ext_ack *extack)
167{
168	struct cls_mall_head *head = rtnl_dereference(tp->root);
169	struct nlattr *tb[TCA_MATCHALL_MAX + 1];
170	struct cls_mall_head *new;
171	u32 flags = 0;
172	int err;
173
174	if (!tca[TCA_OPTIONS])
175		return -EINVAL;
176
177	if (head)
178		return -EEXIST;
179
180	err = nla_parse_nested(tb, TCA_MATCHALL_MAX, tca[TCA_OPTIONS],
181			       mall_policy, NULL);
182	if (err < 0)
183		return err;
184
185	if (tb[TCA_MATCHALL_FLAGS]) {
186		flags = nla_get_u32(tb[TCA_MATCHALL_FLAGS]);
187		if (!tc_flags_valid(flags))
188			return -EINVAL;
189	}
190
191	new = kzalloc(sizeof(*new), GFP_KERNEL);
192	if (!new)
193		return -ENOBUFS;
194
195	err = tcf_exts_init(&new->exts, TCA_MATCHALL_ACT, 0);
196	if (err)
197		goto err_exts_init;
198
199	if (!handle)
200		handle = 1;
201	new->handle = handle;
202	new->flags = flags;
203
204	err = mall_set_parms(net, tp, new, base, tb, tca[TCA_RATE], ovr,
205			     extack);
206	if (err)
207		goto err_set_parms;
208
209	if (!tc_skip_hw(new->flags)) {
210		err = mall_replace_hw_filter(tp, new, (unsigned long)new,
211					     extack);
212		if (err)
213			goto err_replace_hw_filter;
214	}
215
216	if (!tc_in_hw(new->flags))
217		new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
218
219	*arg = head;
220	rcu_assign_pointer(tp->root, new);
221	return 0;
222
223err_replace_hw_filter:
224err_set_parms:
225	tcf_exts_destroy(&new->exts);
226err_exts_init:
227	kfree(new);
228	return err;
229}
230
231static int mall_delete(struct tcf_proto *tp, void *arg, bool *last,
232		       struct netlink_ext_ack *extack)
233{
234	return -EOPNOTSUPP;
235}
236
237static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg)
238{
239	struct cls_mall_head *head = rtnl_dereference(tp->root);
240
241	if (arg->count < arg->skip)
242		goto skip;
243	if (arg->fn(tp, head, arg) < 0)
244		arg->stop = 1;
245skip:
246	arg->count++;
247}
248
249static int mall_dump(struct net *net, struct tcf_proto *tp, void *fh,
250		     struct sk_buff *skb, struct tcmsg *t)
251{
252	struct cls_mall_head *head = fh;
253	struct nlattr *nest;
254
255	if (!head)
256		return skb->len;
257
258	t->tcm_handle = head->handle;
259
260	nest = nla_nest_start(skb, TCA_OPTIONS);
261	if (!nest)
262		goto nla_put_failure;
263
264	if (head->res.classid &&
265	    nla_put_u32(skb, TCA_MATCHALL_CLASSID, head->res.classid))
266		goto nla_put_failure;
267
268	if (head->flags && nla_put_u32(skb, TCA_MATCHALL_FLAGS, head->flags))
269		goto nla_put_failure;
270
271	if (tcf_exts_dump(skb, &head->exts))
272		goto nla_put_failure;
273
274	nla_nest_end(skb, nest);
275
276	if (tcf_exts_dump_stats(skb, &head->exts) < 0)
277		goto nla_put_failure;
278
279	return skb->len;
280
281nla_put_failure:
282	nla_nest_cancel(skb, nest);
283	return -1;
284}
285
286static void mall_bind_class(void *fh, u32 classid, unsigned long cl)
287{
288	struct cls_mall_head *head = fh;
289
290	if (head && head->res.classid == classid)
291		head->res.class = cl;
292}
293
294static struct tcf_proto_ops cls_mall_ops __read_mostly = {
295	.kind		= "matchall",
296	.classify	= mall_classify,
297	.init		= mall_init,
298	.destroy	= mall_destroy,
299	.get		= mall_get,
300	.change		= mall_change,
301	.delete		= mall_delete,
302	.walk		= mall_walk,
303	.dump		= mall_dump,
304	.bind_class	= mall_bind_class,
305	.owner		= THIS_MODULE,
306};
307
308static int __init cls_mall_init(void)
309{
310	return register_tcf_proto_ops(&cls_mall_ops);
311}
312
313static void __exit cls_mall_exit(void)
314{
315	unregister_tcf_proto_ops(&cls_mall_ops);
316}
317
318module_init(cls_mall_init);
319module_exit(cls_mall_exit);
320
321MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
322MODULE_DESCRIPTION("Match-all classifier");
323MODULE_LICENSE("GPL v2");