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