1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * net/sched/cls_basic.c Basic Packet Classifier.
4 *
5 * Authors: Thomas Graf <tgraf@suug.ch>
6 */
7
8 #include <linux/module.h>
9 #include <linux/slab.h>
10 #include <linux/types.h>
11 #include <linux/kernel.h>
12 #include <linux/string.h>
13 #include <linux/errno.h>
14 #include <linux/rtnetlink.h>
15 #include <linux/skbuff.h>
16 #include <linux/idr.h>
17 #include <linux/percpu.h>
18 #include <net/netlink.h>
19 #include <net/act_api.h>
20 #include <net/pkt_cls.h>
21
22 struct basic_head {
23 struct list_head flist;
24 struct idr handle_idr;
25 struct rcu_head rcu;
26 };
27
28 struct basic_filter {
29 u32 handle;
30 struct tcf_exts exts;
31 struct tcf_ematch_tree ematches;
32 struct tcf_result res;
33 struct tcf_proto *tp;
34 struct list_head link;
35 struct tc_basic_pcnt __percpu *pf;
36 struct rcu_work rwork;
37 };
38
basic_classify(struct sk_buff * skb,const struct tcf_proto * tp,struct tcf_result * res)39 static int basic_classify(struct sk_buff *skb, const struct tcf_proto *tp,
40 struct tcf_result *res)
41 {
42 int r;
43 struct basic_head *head = rcu_dereference_bh(tp->root);
44 struct basic_filter *f;
45
46 list_for_each_entry_rcu(f, &head->flist, link) {
47 __this_cpu_inc(f->pf->rcnt);
48 if (!tcf_em_tree_match(skb, &f->ematches, NULL))
49 continue;
50 __this_cpu_inc(f->pf->rhit);
51 *res = f->res;
52 r = tcf_exts_exec(skb, &f->exts, res);
53 if (r < 0)
54 continue;
55 return r;
56 }
57 return -1;
58 }
59
basic_get(struct tcf_proto * tp,u32 handle)60 static void *basic_get(struct tcf_proto *tp, u32 handle)
61 {
62 struct basic_head *head = rtnl_dereference(tp->root);
63 struct basic_filter *f;
64
65 list_for_each_entry(f, &head->flist, link) {
66 if (f->handle == handle) {
67 return f;
68 }
69 }
70
71 return NULL;
72 }
73
basic_init(struct tcf_proto * tp)74 static int basic_init(struct tcf_proto *tp)
75 {
76 struct basic_head *head;
77
78 head = kzalloc(sizeof(*head), GFP_KERNEL);
79 if (head == NULL)
80 return -ENOBUFS;
81 INIT_LIST_HEAD(&head->flist);
82 idr_init(&head->handle_idr);
83 rcu_assign_pointer(tp->root, head);
84 return 0;
85 }
86
__basic_delete_filter(struct basic_filter * f)87 static void __basic_delete_filter(struct basic_filter *f)
88 {
89 tcf_exts_destroy(&f->exts);
90 tcf_em_tree_destroy(&f->ematches);
91 tcf_exts_put_net(&f->exts);
92 free_percpu(f->pf);
93 kfree(f);
94 }
95
basic_delete_filter_work(struct work_struct * work)96 static void basic_delete_filter_work(struct work_struct *work)
97 {
98 struct basic_filter *f = container_of(to_rcu_work(work),
99 struct basic_filter,
100 rwork);
101 rtnl_lock();
102 __basic_delete_filter(f);
103 rtnl_unlock();
104 }
105
basic_destroy(struct tcf_proto * tp,bool rtnl_held,struct netlink_ext_ack * extack)106 static void basic_destroy(struct tcf_proto *tp, bool rtnl_held,
107 struct netlink_ext_ack *extack)
108 {
109 struct basic_head *head = rtnl_dereference(tp->root);
110 struct basic_filter *f, *n;
111
112 list_for_each_entry_safe(f, n, &head->flist, link) {
113 list_del_rcu(&f->link);
114 tcf_unbind_filter(tp, &f->res);
115 idr_remove(&head->handle_idr, f->handle);
116 if (tcf_exts_get_net(&f->exts))
117 tcf_queue_work(&f->rwork, basic_delete_filter_work);
118 else
119 __basic_delete_filter(f);
120 }
121 idr_destroy(&head->handle_idr);
122 kfree_rcu(head, rcu);
123 }
124
basic_delete(struct tcf_proto * tp,void * arg,bool * last,bool rtnl_held,struct netlink_ext_ack * extack)125 static int basic_delete(struct tcf_proto *tp, void *arg, bool *last,
126 bool rtnl_held, struct netlink_ext_ack *extack)
127 {
128 struct basic_head *head = rtnl_dereference(tp->root);
129 struct basic_filter *f = arg;
130
131 list_del_rcu(&f->link);
132 tcf_unbind_filter(tp, &f->res);
133 idr_remove(&head->handle_idr, f->handle);
134 tcf_exts_get_net(&f->exts);
135 tcf_queue_work(&f->rwork, basic_delete_filter_work);
136 *last = list_empty(&head->flist);
137 return 0;
138 }
139
140 static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = {
141 [TCA_BASIC_CLASSID] = { .type = NLA_U32 },
142 [TCA_BASIC_EMATCHES] = { .type = NLA_NESTED },
143 };
144
basic_set_parms(struct net * net,struct tcf_proto * tp,struct basic_filter * f,unsigned long base,struct nlattr ** tb,struct nlattr * est,bool ovr,struct netlink_ext_ack * extack)145 static int basic_set_parms(struct net *net, struct tcf_proto *tp,
146 struct basic_filter *f, unsigned long base,
147 struct nlattr **tb,
148 struct nlattr *est, bool ovr,
149 struct netlink_ext_ack *extack)
150 {
151 int err;
152
153 err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr, true, extack);
154 if (err < 0)
155 return err;
156
157 err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &f->ematches);
158 if (err < 0)
159 return err;
160
161 if (tb[TCA_BASIC_CLASSID]) {
162 f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]);
163 tcf_bind_filter(tp, &f->res, base);
164 }
165
166 f->tp = tp;
167 return 0;
168 }
169
basic_change(struct net * net,struct sk_buff * in_skb,struct tcf_proto * tp,unsigned long base,u32 handle,struct nlattr ** tca,void ** arg,bool ovr,bool rtnl_held,struct netlink_ext_ack * extack)170 static int basic_change(struct net *net, struct sk_buff *in_skb,
171 struct tcf_proto *tp, unsigned long base, u32 handle,
172 struct nlattr **tca, void **arg, bool ovr,
173 bool rtnl_held, struct netlink_ext_ack *extack)
174 {
175 int err;
176 struct basic_head *head = rtnl_dereference(tp->root);
177 struct nlattr *tb[TCA_BASIC_MAX + 1];
178 struct basic_filter *fold = (struct basic_filter *) *arg;
179 struct basic_filter *fnew;
180
181 if (tca[TCA_OPTIONS] == NULL)
182 return -EINVAL;
183
184 err = nla_parse_nested_deprecated(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS],
185 basic_policy, NULL);
186 if (err < 0)
187 return err;
188
189 if (fold != NULL) {
190 if (handle && fold->handle != handle)
191 return -EINVAL;
192 }
193
194 fnew = kzalloc(sizeof(*fnew), GFP_KERNEL);
195 if (!fnew)
196 return -ENOBUFS;
197
198 err = tcf_exts_init(&fnew->exts, net, TCA_BASIC_ACT, TCA_BASIC_POLICE);
199 if (err < 0)
200 goto errout;
201
202 if (!handle) {
203 handle = 1;
204 err = idr_alloc_u32(&head->handle_idr, fnew, &handle,
205 INT_MAX, GFP_KERNEL);
206 } else if (!fold) {
207 err = idr_alloc_u32(&head->handle_idr, fnew, &handle,
208 handle, GFP_KERNEL);
209 }
210 if (err)
211 goto errout;
212 fnew->handle = handle;
213 fnew->pf = alloc_percpu(struct tc_basic_pcnt);
214 if (!fnew->pf) {
215 err = -ENOMEM;
216 goto errout;
217 }
218
219 err = basic_set_parms(net, tp, fnew, base, tb, tca[TCA_RATE], ovr,
220 extack);
221 if (err < 0) {
222 if (!fold)
223 idr_remove(&head->handle_idr, fnew->handle);
224 goto errout;
225 }
226
227 *arg = fnew;
228
229 if (fold) {
230 idr_replace(&head->handle_idr, fnew, fnew->handle);
231 list_replace_rcu(&fold->link, &fnew->link);
232 tcf_unbind_filter(tp, &fold->res);
233 tcf_exts_get_net(&fold->exts);
234 tcf_queue_work(&fold->rwork, basic_delete_filter_work);
235 } else {
236 list_add_rcu(&fnew->link, &head->flist);
237 }
238
239 return 0;
240 errout:
241 free_percpu(fnew->pf);
242 tcf_exts_destroy(&fnew->exts);
243 kfree(fnew);
244 return err;
245 }
246
basic_walk(struct tcf_proto * tp,struct tcf_walker * arg,bool rtnl_held)247 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg,
248 bool rtnl_held)
249 {
250 struct basic_head *head = rtnl_dereference(tp->root);
251 struct basic_filter *f;
252
253 list_for_each_entry(f, &head->flist, link) {
254 if (arg->count < arg->skip)
255 goto skip;
256
257 if (arg->fn(tp, f, arg) < 0) {
258 arg->stop = 1;
259 break;
260 }
261 skip:
262 arg->count++;
263 }
264 }
265
basic_bind_class(void * fh,u32 classid,unsigned long cl)266 static void basic_bind_class(void *fh, u32 classid, unsigned long cl)
267 {
268 struct basic_filter *f = fh;
269
270 if (f && f->res.classid == classid)
271 f->res.class = cl;
272 }
273
basic_dump(struct net * net,struct tcf_proto * tp,void * fh,struct sk_buff * skb,struct tcmsg * t,bool rtnl_held)274 static int basic_dump(struct net *net, struct tcf_proto *tp, void *fh,
275 struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
276 {
277 struct tc_basic_pcnt gpf = {};
278 struct basic_filter *f = fh;
279 struct nlattr *nest;
280 int cpu;
281
282 if (f == NULL)
283 return skb->len;
284
285 t->tcm_handle = f->handle;
286
287 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
288 if (nest == NULL)
289 goto nla_put_failure;
290
291 if (f->res.classid &&
292 nla_put_u32(skb, TCA_BASIC_CLASSID, f->res.classid))
293 goto nla_put_failure;
294
295 for_each_possible_cpu(cpu) {
296 struct tc_basic_pcnt *pf = per_cpu_ptr(f->pf, cpu);
297
298 gpf.rcnt += pf->rcnt;
299 gpf.rhit += pf->rhit;
300 }
301
302 if (nla_put_64bit(skb, TCA_BASIC_PCNT,
303 sizeof(struct tc_basic_pcnt),
304 &gpf, TCA_BASIC_PAD))
305 goto nla_put_failure;
306
307 if (tcf_exts_dump(skb, &f->exts) < 0 ||
308 tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0)
309 goto nla_put_failure;
310
311 nla_nest_end(skb, nest);
312
313 if (tcf_exts_dump_stats(skb, &f->exts) < 0)
314 goto nla_put_failure;
315
316 return skb->len;
317
318 nla_put_failure:
319 nla_nest_cancel(skb, nest);
320 return -1;
321 }
322
323 static struct tcf_proto_ops cls_basic_ops __read_mostly = {
324 .kind = "basic",
325 .classify = basic_classify,
326 .init = basic_init,
327 .destroy = basic_destroy,
328 .get = basic_get,
329 .change = basic_change,
330 .delete = basic_delete,
331 .walk = basic_walk,
332 .dump = basic_dump,
333 .bind_class = basic_bind_class,
334 .owner = THIS_MODULE,
335 };
336
init_basic(void)337 static int __init init_basic(void)
338 {
339 return register_tcf_proto_ops(&cls_basic_ops);
340 }
341
exit_basic(void)342 static void __exit exit_basic(void)
343 {
344 unregister_tcf_proto_ops(&cls_basic_ops);
345 }
346
347 module_init(init_basic)
348 module_exit(exit_basic)
349 MODULE_LICENSE("GPL");
350
