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
25 #define HTSIZE 256
26
27 struct fw_head {
28 u32 mask;
29 struct fw_filter __rcu *ht[HTSIZE];
30 struct rcu_head rcu;
31 };
32
33 struct fw_filter {
34 struct fw_filter __rcu *next;
35 u32 id;
36 struct tcf_result res;
37 int ifindex;
38 struct tcf_exts exts;
39 struct tcf_proto *tp;
40 struct rcu_work rwork;
41 };
42
fw_hash(u32 handle)43 static u32 fw_hash(u32 handle)
44 {
45 handle ^= (handle >> 16);
46 handle ^= (handle >> 8);
47 return handle % HTSIZE;
48 }
49
fw_classify(struct sk_buff * skb,const struct tcf_proto * tp,struct tcf_result * res)50 static int fw_classify(struct sk_buff *skb, const struct tcf_proto *tp,
51 struct tcf_result *res)
52 {
53 struct fw_head *head = rcu_dereference_bh(tp->root);
54 struct fw_filter *f;
55 int r;
56 u32 id = skb->mark;
57
58 if (head != NULL) {
59 id &= head->mask;
60
61 for (f = rcu_dereference_bh(head->ht[fw_hash(id)]); f;
62 f = rcu_dereference_bh(f->next)) {
63 if (f->id == id) {
64 *res = f->res;
65 if (!tcf_match_indev(skb, f->ifindex))
66 continue;
67 r = tcf_exts_exec(skb, &f->exts, res);
68 if (r < 0)
69 continue;
70
71 return r;
72 }
73 }
74 } else {
75 struct Qdisc *q = tcf_block_q(tp->chain->block);
76
77 /* Old method: classify the packet using its skb mark. */
78 if (id && (TC_H_MAJ(id) == 0 ||
79 !(TC_H_MAJ(id ^ q->handle)))) {
80 res->classid = id;
81 res->class = 0;
82 return 0;
83 }
84 }
85
86 return -1;
87 }
88
fw_get(struct tcf_proto * tp,u32 handle)89 static void *fw_get(struct tcf_proto *tp, u32 handle)
90 {
91 struct fw_head *head = rtnl_dereference(tp->root);
92 struct fw_filter *f;
93
94 if (head == NULL)
95 return NULL;
96
97 f = rtnl_dereference(head->ht[fw_hash(handle)]);
98 for (; f; f = rtnl_dereference(f->next)) {
99 if (f->id == handle)
100 return f;
101 }
102 return NULL;
103 }
104
fw_init(struct tcf_proto * tp)105 static int fw_init(struct tcf_proto *tp)
106 {
107 /* We don't allocate fw_head here, because in the old method
108 * we don't need it at all.
109 */
110 return 0;
111 }
112
__fw_delete_filter(struct fw_filter * f)113 static void __fw_delete_filter(struct fw_filter *f)
114 {
115 tcf_exts_destroy(&f->exts);
116 tcf_exts_put_net(&f->exts);
117 kfree(f);
118 }
119
fw_delete_filter_work(struct work_struct * work)120 static void fw_delete_filter_work(struct work_struct *work)
121 {
122 struct fw_filter *f = container_of(to_rcu_work(work),
123 struct fw_filter,
124 rwork);
125 rtnl_lock();
126 __fw_delete_filter(f);
127 rtnl_unlock();
128 }
129
fw_destroy(struct tcf_proto * tp,bool rtnl_held,struct netlink_ext_ack * extack)130 static void fw_destroy(struct tcf_proto *tp, bool rtnl_held,
131 struct netlink_ext_ack *extack)
132 {
133 struct fw_head *head = rtnl_dereference(tp->root);
134 struct fw_filter *f;
135 int h;
136
137 if (head == NULL)
138 return;
139
140 for (h = 0; h < HTSIZE; h++) {
141 while ((f = rtnl_dereference(head->ht[h])) != NULL) {
142 RCU_INIT_POINTER(head->ht[h],
143 rtnl_dereference(f->next));
144 tcf_unbind_filter(tp, &f->res);
145 if (tcf_exts_get_net(&f->exts))
146 tcf_queue_work(&f->rwork, fw_delete_filter_work);
147 else
148 __fw_delete_filter(f);
149 }
150 }
151 kfree_rcu(head, rcu);
152 }
153
fw_delete(struct tcf_proto * tp,void * arg,bool * last,bool rtnl_held,struct netlink_ext_ack * extack)154 static int fw_delete(struct tcf_proto *tp, void *arg, bool *last,
155 bool rtnl_held, struct netlink_ext_ack *extack)
156 {
157 struct fw_head *head = rtnl_dereference(tp->root);
158 struct fw_filter *f = arg;
159 struct fw_filter __rcu **fp;
160 struct fw_filter *pfp;
161 int ret = -EINVAL;
162 int h;
163
164 if (head == NULL || f == NULL)
165 goto out;
166
167 fp = &head->ht[fw_hash(f->id)];
168
169 for (pfp = rtnl_dereference(*fp); pfp;
170 fp = &pfp->next, pfp = rtnl_dereference(*fp)) {
171 if (pfp == f) {
172 RCU_INIT_POINTER(*fp, rtnl_dereference(f->next));
173 tcf_unbind_filter(tp, &f->res);
174 tcf_exts_get_net(&f->exts);
175 tcf_queue_work(&f->rwork, fw_delete_filter_work);
176 ret = 0;
177 break;
178 }
179 }
180
181 *last = true;
182 for (h = 0; h < HTSIZE; h++) {
183 if (rcu_access_pointer(head->ht[h])) {
184 *last = false;
185 break;
186 }
187 }
188
189 out:
190 return ret;
191 }
192
193 static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
194 [TCA_FW_CLASSID] = { .type = NLA_U32 },
195 [TCA_FW_INDEV] = { .type = NLA_STRING, .len = IFNAMSIZ },
196 [TCA_FW_MASK] = { .type = NLA_U32 },
197 };
198
fw_set_parms(struct net * net,struct tcf_proto * tp,struct fw_filter * f,struct nlattr ** tb,struct nlattr ** tca,unsigned long base,u32 flags,struct netlink_ext_ack * extack)199 static int fw_set_parms(struct net *net, struct tcf_proto *tp,
200 struct fw_filter *f, struct nlattr **tb,
201 struct nlattr **tca, unsigned long base, u32 flags,
202 struct netlink_ext_ack *extack)
203 {
204 struct fw_head *head = rtnl_dereference(tp->root);
205 u32 mask;
206 int err;
207
208 err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &f->exts, flags,
209 extack);
210 if (err < 0)
211 return err;
212
213 if (tb[TCA_FW_INDEV]) {
214 int ret;
215 ret = tcf_change_indev(net, tb[TCA_FW_INDEV], extack);
216 if (ret < 0)
217 return ret;
218 f->ifindex = ret;
219 }
220
221 err = -EINVAL;
222 if (tb[TCA_FW_MASK]) {
223 mask = nla_get_u32(tb[TCA_FW_MASK]);
224 if (mask != head->mask)
225 return err;
226 } else if (head->mask != 0xFFFFFFFF)
227 return err;
228
229 if (tb[TCA_FW_CLASSID]) {
230 f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
231 tcf_bind_filter(tp, &f->res, base);
232 }
233
234 return 0;
235 }
236
fw_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)237 static int fw_change(struct net *net, struct sk_buff *in_skb,
238 struct tcf_proto *tp, unsigned long base,
239 u32 handle, struct nlattr **tca, void **arg,
240 u32 flags, struct netlink_ext_ack *extack)
241 {
242 struct fw_head *head = rtnl_dereference(tp->root);
243 struct fw_filter *f = *arg;
244 struct nlattr *opt = tca[TCA_OPTIONS];
245 struct nlattr *tb[TCA_FW_MAX + 1];
246 int err;
247
248 if (!opt)
249 return handle ? -EINVAL : 0; /* Succeed if it is old method. */
250
251 err = nla_parse_nested_deprecated(tb, TCA_FW_MAX, opt, fw_policy,
252 NULL);
253 if (err < 0)
254 return err;
255
256 if (f) {
257 struct fw_filter *pfp, *fnew;
258 struct fw_filter __rcu **fp;
259
260 if (f->id != handle && handle)
261 return -EINVAL;
262
263 fnew = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
264 if (!fnew)
265 return -ENOBUFS;
266
267 fnew->id = f->id;
268 fnew->ifindex = f->ifindex;
269 fnew->tp = f->tp;
270
271 err = tcf_exts_init(&fnew->exts, net, TCA_FW_ACT,
272 TCA_FW_POLICE);
273 if (err < 0) {
274 kfree(fnew);
275 return err;
276 }
277
278 err = fw_set_parms(net, tp, fnew, tb, tca, base, flags, extack);
279 if (err < 0) {
280 tcf_exts_destroy(&fnew->exts);
281 kfree(fnew);
282 return err;
283 }
284
285 fp = &head->ht[fw_hash(fnew->id)];
286 for (pfp = rtnl_dereference(*fp); pfp;
287 fp = &pfp->next, pfp = rtnl_dereference(*fp))
288 if (pfp == f)
289 break;
290
291 RCU_INIT_POINTER(fnew->next, rtnl_dereference(pfp->next));
292 rcu_assign_pointer(*fp, fnew);
293 tcf_unbind_filter(tp, &f->res);
294 tcf_exts_get_net(&f->exts);
295 tcf_queue_work(&f->rwork, fw_delete_filter_work);
296
297 *arg = fnew;
298 return err;
299 }
300
301 if (!handle)
302 return -EINVAL;
303
304 if (!head) {
305 u32 mask = 0xFFFFFFFF;
306 if (tb[TCA_FW_MASK])
307 mask = nla_get_u32(tb[TCA_FW_MASK]);
308
309 head = kzalloc(sizeof(*head), GFP_KERNEL);
310 if (!head)
311 return -ENOBUFS;
312 head->mask = mask;
313
314 rcu_assign_pointer(tp->root, head);
315 }
316
317 f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
318 if (f == NULL)
319 return -ENOBUFS;
320
321 err = tcf_exts_init(&f->exts, net, TCA_FW_ACT, TCA_FW_POLICE);
322 if (err < 0)
323 goto errout;
324 f->id = handle;
325 f->tp = tp;
326
327 err = fw_set_parms(net, tp, f, tb, tca, base, flags, extack);
328 if (err < 0)
329 goto errout;
330
331 RCU_INIT_POINTER(f->next, head->ht[fw_hash(handle)]);
332 rcu_assign_pointer(head->ht[fw_hash(handle)], f);
333
334 *arg = f;
335 return 0;
336
337 errout:
338 tcf_exts_destroy(&f->exts);
339 kfree(f);
340 return err;
341 }
342
fw_walk(struct tcf_proto * tp,struct tcf_walker * arg,bool rtnl_held)343 static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg,
344 bool rtnl_held)
345 {
346 struct fw_head *head = rtnl_dereference(tp->root);
347 int h;
348
349 if (head == NULL)
350 arg->stop = 1;
351
352 if (arg->stop)
353 return;
354
355 for (h = 0; h < HTSIZE; h++) {
356 struct fw_filter *f;
357
358 for (f = rtnl_dereference(head->ht[h]); f;
359 f = rtnl_dereference(f->next)) {
360 if (arg->count < arg->skip) {
361 arg->count++;
362 continue;
363 }
364 if (arg->fn(tp, f, arg) < 0) {
365 arg->stop = 1;
366 return;
367 }
368 arg->count++;
369 }
370 }
371 }
372
fw_dump(struct net * net,struct tcf_proto * tp,void * fh,struct sk_buff * skb,struct tcmsg * t,bool rtnl_held)373 static int fw_dump(struct net *net, struct tcf_proto *tp, void *fh,
374 struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
375 {
376 struct fw_head *head = rtnl_dereference(tp->root);
377 struct fw_filter *f = fh;
378 struct nlattr *nest;
379
380 if (f == NULL)
381 return skb->len;
382
383 t->tcm_handle = f->id;
384
385 if (!f->res.classid && !tcf_exts_has_actions(&f->exts))
386 return skb->len;
387
388 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
389 if (nest == NULL)
390 goto nla_put_failure;
391
392 if (f->res.classid &&
393 nla_put_u32(skb, TCA_FW_CLASSID, f->res.classid))
394 goto nla_put_failure;
395 if (f->ifindex) {
396 struct net_device *dev;
397 dev = __dev_get_by_index(net, f->ifindex);
398 if (dev && nla_put_string(skb, TCA_FW_INDEV, dev->name))
399 goto nla_put_failure;
400 }
401 if (head->mask != 0xFFFFFFFF &&
402 nla_put_u32(skb, TCA_FW_MASK, head->mask))
403 goto nla_put_failure;
404
405 if (tcf_exts_dump(skb, &f->exts) < 0)
406 goto nla_put_failure;
407
408 nla_nest_end(skb, nest);
409
410 if (tcf_exts_dump_stats(skb, &f->exts) < 0)
411 goto nla_put_failure;
412
413 return skb->len;
414
415 nla_put_failure:
416 nla_nest_cancel(skb, nest);
417 return -1;
418 }
419
fw_bind_class(void * fh,u32 classid,unsigned long cl,void * q,unsigned long base)420 static void fw_bind_class(void *fh, u32 classid, unsigned long cl, void *q,
421 unsigned long base)
422 {
423 struct fw_filter *f = fh;
424
425 if (f && f->res.classid == classid) {
426 if (cl)
427 __tcf_bind_filter(q, &f->res, base);
428 else
429 __tcf_unbind_filter(q, &f->res);
430 }
431 }
432
433 static struct tcf_proto_ops cls_fw_ops __read_mostly = {
434 .kind = "fw",
435 .classify = fw_classify,
436 .init = fw_init,
437 .destroy = fw_destroy,
438 .get = fw_get,
439 .change = fw_change,
440 .delete = fw_delete,
441 .walk = fw_walk,
442 .dump = fw_dump,
443 .bind_class = fw_bind_class,
444 .owner = THIS_MODULE,
445 };
446
init_fw(void)447 static int __init init_fw(void)
448 {
449 return register_tcf_proto_ops(&cls_fw_ops);
450 }
451
exit_fw(void)452 static void __exit exit_fw(void)
453 {
454 unregister_tcf_proto_ops(&cls_fw_ops);
455 }
456
457 module_init(init_fw)
458 module_exit(exit_fw)
459 MODULE_LICENSE("GPL");
460