1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * net/sched/cls_fw.c Classifier mapping ipchains' fwmark to traffic class.
4 *
5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
6 *
7 * Changes:
8 * Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_walk off by one
9 * Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_delete killed all the filter (and kernel).
10 * Alex <alex@pilotsoft.com> : 2004xxyy: Added Action extension
11 */
12
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include <linux/types.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/errno.h>
19 #include <linux/skbuff.h>
20 #include <net/netlink.h>
21 #include <net/act_api.h>
22 #include <net/pkt_cls.h>
23 #include <net/sch_generic.h>
24 #include <net/tc_wrapper.h>
25
26 #define HTSIZE 256
27
28 struct fw_head {
29 u32 mask;
30 struct fw_filter __rcu *ht[HTSIZE];
31 struct rcu_head rcu;
32 };
33
34 struct fw_filter {
35 struct fw_filter __rcu *next;
36 u32 id;
37 struct tcf_result res;
38 int ifindex;
39 struct tcf_exts exts;
40 struct tcf_proto *tp;
41 struct rcu_work rwork;
42 };
43
44 static u32 fw_hash(u32 handle)
45 {
46 handle ^= (handle >> 16);
47 handle ^= (handle >> 8);
48 return handle % HTSIZE;
49 }
50
51 TC_INDIRECT_SCOPE int fw_classify(struct sk_buff *skb,
52 const struct tcf_proto *tp,
53 struct tcf_result *res)
54 {
55 struct fw_head *head = rcu_dereference_bh(tp->root);
56 struct fw_filter *f;
57 int r;
58 u32 id = skb->mark;
59
60 if (head != NULL) {
61 id &= head->mask;
62
63 for (f = rcu_dereference_bh(head->ht[fw_hash(id)]); f;
64 f = rcu_dereference_bh(f->next)) {
65 if (f->id == id) {
66 *res = f->res;
67 if (!tcf_match_indev(skb, f->ifindex))
68 continue;
69 r = tcf_exts_exec(skb, &f->exts, res);
70 if (r < 0)
71 continue;
72
73 return r;
74 }
75 }
76 } else {
77 struct Qdisc *q = tcf_block_q(tp->chain->block);
78
79 /* Old method: classify the packet using its skb mark. */
80 if (id && (TC_H_MAJ(id) == 0 ||
81 !(TC_H_MAJ(id ^ q->handle)))) {
82 res->classid = id;
83 res->class = 0;
84 return 0;
85 }
86 }
87
88 return -1;
89 }
90
91 static void *fw_get(struct tcf_proto *tp, u32 handle)
92 {
93 struct fw_head *head = rtnl_dereference(tp->root);
94 struct fw_filter *f;
95
96 if (head == NULL)
97 return NULL;
98
99 f = rtnl_dereference(head->ht[fw_hash(handle)]);
100 for (; f; f = rtnl_dereference(f->next)) {
101 if (f->id == handle)
102 return f;
103 }
104 return NULL;
105 }
106
107 static int fw_init(struct tcf_proto *tp)
108 {
109 /* We don't allocate fw_head here, because in the old method
110 * we don't need it at all.
111 */
112 return 0;
113 }
114
115 static void __fw_delete_filter(struct fw_filter *f)
116 {
117 tcf_exts_destroy(&f->exts);
118 tcf_exts_put_net(&f->exts);
119 kfree(f);
120 }
121
122 static void fw_delete_filter_work(struct work_struct *work)
123 {
124 struct fw_filter *f = container_of(to_rcu_work(work),
125 struct fw_filter,
126 rwork);
127 rtnl_lock();
128 __fw_delete_filter(f);
129 rtnl_unlock();
130 }
131
132 static void fw_destroy(struct tcf_proto *tp, bool rtnl_held,
133 struct netlink_ext_ack *extack)
134 {
135 struct fw_head *head = rtnl_dereference(tp->root);
136 struct fw_filter *f;
137 int h;
138
139 if (head == NULL)
140 return;
141
142 for (h = 0; h < HTSIZE; h++) {
143 while ((f = rtnl_dereference(head->ht[h])) != NULL) {
144 RCU_INIT_POINTER(head->ht[h],
145 rtnl_dereference(f->next));
146 tcf_unbind_filter(tp, &f->res);
147 if (tcf_exts_get_net(&f->exts))
148 tcf_queue_work(&f->rwork, fw_delete_filter_work);
149 else
150 __fw_delete_filter(f);
151 }
152 }
153 kfree_rcu(head, rcu);
154 }
155
156 static int fw_delete(struct tcf_proto *tp, void *arg, bool *last,
157 bool rtnl_held, struct netlink_ext_ack *extack)
158 {
159 struct fw_head *head = rtnl_dereference(tp->root);
160 struct fw_filter *f = arg;
161 struct fw_filter __rcu **fp;
162 struct fw_filter *pfp;
163 int ret = -EINVAL;
164 int h;
165
166 if (head == NULL || f == NULL)
167 goto out;
168
169 fp = &head->ht[fw_hash(f->id)];
170
171 for (pfp = rtnl_dereference(*fp); pfp;
172 fp = &pfp->next, pfp = rtnl_dereference(*fp)) {
173 if (pfp == f) {
174 RCU_INIT_POINTER(*fp, rtnl_dereference(f->next));
175 tcf_unbind_filter(tp, &f->res);
176 tcf_exts_get_net(&f->exts);
177 tcf_queue_work(&f->rwork, fw_delete_filter_work);
178 ret = 0;
179 break;
180 }
181 }
182
183 *last = true;
184 for (h = 0; h < HTSIZE; h++) {
185 if (rcu_access_pointer(head->ht[h])) {
186 *last = false;
187 break;
188 }
189 }
190
191 out:
192 return ret;
193 }
194
195 static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
196 [TCA_FW_CLASSID] = { .type = NLA_U32 },
197 [TCA_FW_INDEV] = { .type = NLA_STRING, .len = IFNAMSIZ },
198 [TCA_FW_MASK] = { .type = NLA_U32 },
199 };
200
201 static int fw_set_parms(struct net *net, struct tcf_proto *tp,
202 struct fw_filter *f, struct nlattr **tb,
203 struct nlattr **tca, unsigned long base, u32 flags,
204 struct netlink_ext_ack *extack)
205 {
206 struct fw_head *head = rtnl_dereference(tp->root);
207 u32 mask;
208 int err;
209
210 err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &f->exts, flags,
211 extack);
212 if (err < 0)
213 return err;
214
215 if (tb[TCA_FW_INDEV]) {
216 int ret;
217 ret = tcf_change_indev(net, tb[TCA_FW_INDEV], extack);
218 if (ret < 0)
219 return ret;
220 f->ifindex = ret;
221 }
222
223 err = -EINVAL;
224 if (tb[TCA_FW_MASK]) {
225 mask = nla_get_u32(tb[TCA_FW_MASK]);
226 if (mask != head->mask)
227 return err;
228 } else if (head->mask != 0xFFFFFFFF)
229 return err;
230
231 if (tb[TCA_FW_CLASSID]) {
232 f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
233 tcf_bind_filter(tp, &f->res, base);
234 }
235
236 return 0;
237 }
238
239 static int fw_change(struct net *net, struct sk_buff *in_skb,
240 struct tcf_proto *tp, unsigned long base,
241 u32 handle, struct nlattr **tca, void **arg,
242 u32 flags, struct netlink_ext_ack *extack)
243 {
244 struct fw_head *head = rtnl_dereference(tp->root);
245 struct fw_filter *f = *arg;
246 struct nlattr *opt = tca[TCA_OPTIONS];
247 struct nlattr *tb[TCA_FW_MAX + 1];
248 int err;
249
250 if (!opt)
251 return handle ? -EINVAL : 0; /* Succeed if it is old method. */
252
253 err = nla_parse_nested_deprecated(tb, TCA_FW_MAX, opt, fw_policy,
254 NULL);
255 if (err < 0)
256 return err;
257
258 if (f) {
259 struct fw_filter *pfp, *fnew;
260 struct fw_filter __rcu **fp;
261
262 if (f->id != handle && handle)
263 return -EINVAL;
264
265 fnew = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
266 if (!fnew)
267 return -ENOBUFS;
268
269 fnew->id = f->id;
270 fnew->ifindex = f->ifindex;
271 fnew->tp = f->tp;
272
273 err = tcf_exts_init(&fnew->exts, net, TCA_FW_ACT,
274 TCA_FW_POLICE);
275 if (err < 0) {
276 kfree(fnew);
277 return err;
278 }
279
280 err = fw_set_parms(net, tp, fnew, tb, tca, base, flags, extack);
281 if (err < 0) {
282 tcf_exts_destroy(&fnew->exts);
283 kfree(fnew);
284 return err;
285 }
286
287 fp = &head->ht[fw_hash(fnew->id)];
288 for (pfp = rtnl_dereference(*fp); pfp;
289 fp = &pfp->next, pfp = rtnl_dereference(*fp))
290 if (pfp == f)
291 break;
292
293 RCU_INIT_POINTER(fnew->next, rtnl_dereference(pfp->next));
294 rcu_assign_pointer(*fp, fnew);
295 tcf_unbind_filter(tp, &f->res);
296 tcf_exts_get_net(&f->exts);
297 tcf_queue_work(&f->rwork, fw_delete_filter_work);
298
299 *arg = fnew;
300 return err;
301 }
302
303 if (!handle)
304 return -EINVAL;
305
306 if (!head) {
307 u32 mask = 0xFFFFFFFF;
308 if (tb[TCA_FW_MASK])
309 mask = nla_get_u32(tb[TCA_FW_MASK]);
310
311 head = kzalloc(sizeof(*head), GFP_KERNEL);
312 if (!head)
313 return -ENOBUFS;
314 head->mask = mask;
315
316 rcu_assign_pointer(tp->root, head);
317 }
318
319 f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
320 if (f == NULL)
321 return -ENOBUFS;
322
323 err = tcf_exts_init(&f->exts, net, TCA_FW_ACT, TCA_FW_POLICE);
324 if (err < 0)
325 goto errout;
326 f->id = handle;
327 f->tp = tp;
328
329 err = fw_set_parms(net, tp, f, tb, tca, base, flags, extack);
330 if (err < 0)
331 goto errout;
332
333 RCU_INIT_POINTER(f->next, head->ht[fw_hash(handle)]);
334 rcu_assign_pointer(head->ht[fw_hash(handle)], f);
335
336 *arg = f;
337 return 0;
338
339 errout:
340 tcf_exts_destroy(&f->exts);
341 kfree(f);
342 return err;
343 }
344
345 static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg,
346 bool rtnl_held)
347 {
348 struct fw_head *head = rtnl_dereference(tp->root);
349 int h;
350
351 if (head == NULL)
352 arg->stop = 1;
353
354 if (arg->stop)
355 return;
356
357 for (h = 0; h < HTSIZE; h++) {
358 struct fw_filter *f;
359
360 for (f = rtnl_dereference(head->ht[h]); f;
361 f = rtnl_dereference(f->next)) {
362 if (!tc_cls_stats_dump(tp, arg, f))
363 return;
364 }
365 }
366 }
367
368 static int fw_dump(struct net *net, struct tcf_proto *tp, void *fh,
369 struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
370 {
371 struct fw_head *head = rtnl_dereference(tp->root);
372 struct fw_filter *f = fh;
373 struct nlattr *nest;
374
375 if (f == NULL)
376 return skb->len;
377
378 t->tcm_handle = f->id;
379
380 if (!f->res.classid && !tcf_exts_has_actions(&f->exts))
381 return skb->len;
382
383 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
384 if (nest == NULL)
385 goto nla_put_failure;
386
387 if (f->res.classid &&
388 nla_put_u32(skb, TCA_FW_CLASSID, f->res.classid))
389 goto nla_put_failure;
390 if (f->ifindex) {
391 struct net_device *dev;
392 dev = __dev_get_by_index(net, f->ifindex);
393 if (dev && nla_put_string(skb, TCA_FW_INDEV, dev->name))
394 goto nla_put_failure;
395 }
396 if (head->mask != 0xFFFFFFFF &&
397 nla_put_u32(skb, TCA_FW_MASK, head->mask))
398 goto nla_put_failure;
399
400 if (tcf_exts_dump(skb, &f->exts) < 0)
401 goto nla_put_failure;
402
403 nla_nest_end(skb, nest);
404
405 if (tcf_exts_dump_stats(skb, &f->exts) < 0)
406 goto nla_put_failure;
407
408 return skb->len;
409
410 nla_put_failure:
411 nla_nest_cancel(skb, nest);
412 return -1;
413 }
414
415 static void fw_bind_class(void *fh, u32 classid, unsigned long cl, void *q,
416 unsigned long base)
417 {
418 struct fw_filter *f = fh;
419
420 tc_cls_bind_class(classid, cl, q, &f->res, base);
421 }
422
423 static struct tcf_proto_ops cls_fw_ops __read_mostly = {
424 .kind = "fw",
425 .classify = fw_classify,
426 .init = fw_init,
427 .destroy = fw_destroy,
428 .get = fw_get,
429 .change = fw_change,
430 .delete = fw_delete,
431 .walk = fw_walk,
432 .dump = fw_dump,
433 .bind_class = fw_bind_class,
434 .owner = THIS_MODULE,
435 };
436 MODULE_ALIAS_NET_CLS("fw");
437
438 static int __init init_fw(void)
439 {
440 return register_tcf_proto_ops(&cls_fw_ops);
441 }
442
443 static void __exit exit_fw(void)
444 {
445 unregister_tcf_proto_ops(&cls_fw_ops);
446 }
447
448 module_init(init_fw)
449 module_exit(exit_fw)
450 MODULE_DESCRIPTION("SKB mark based TC classifier");
451 MODULE_LICENSE("GPL");
452
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