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, ifindex: f->ifindex)) |
68 | continue; |
69 | r = tcf_exts_exec(skb, exts: &f->exts, res); |
70 | if (r < 0) |
71 | continue; |
72 | |
73 | return r; |
74 | } |
75 | } |
76 | } else { |
77 | struct Qdisc *q = tcf_block_q(block: 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(exts: &f->exts); |
118 | tcf_exts_put_net(exts: &f->exts); |
119 | kfree(objp: 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, r: &f->res); |
147 | if (tcf_exts_get_net(exts: &f->exts)) |
148 | tcf_queue_work(rwork: &f->rwork, func: 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(handle: 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, r: &f->res); |
176 | tcf_exts_get_net(exts: &f->exts); |
177 | tcf_queue_work(rwork: &f->rwork, func: 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, rate_tlv: tca[TCA_RATE], exts: &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, indev_tlv: 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(nla: 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(nla: tb[TCA_FW_CLASSID]); |
233 | tcf_bind_filter(tp, r: &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, nla: opt, policy: 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(size: 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(exts: &fnew->exts, net, action: TCA_FW_ACT, |
274 | police: TCA_FW_POLICE); |
275 | if (err < 0) { |
276 | kfree(objp: fnew); |
277 | return err; |
278 | } |
279 | |
280 | err = fw_set_parms(net, tp, f: fnew, tb, tca, base, flags, extack); |
281 | if (err < 0) { |
282 | tcf_exts_destroy(exts: &fnew->exts); |
283 | kfree(objp: fnew); |
284 | return err; |
285 | } |
286 | |
287 | fp = &head->ht[fw_hash(handle: 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, r: &f->res); |
296 | tcf_exts_get_net(exts: &f->exts); |
297 | tcf_queue_work(rwork: &f->rwork, func: 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(nla: tb[TCA_FW_MASK]); |
310 | |
311 | head = kzalloc(size: 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(size: sizeof(struct fw_filter), GFP_KERNEL); |
320 | if (f == NULL) |
321 | return -ENOBUFS; |
322 | |
323 | err = tcf_exts_init(exts: &f->exts, net, action: TCA_FW_ACT, police: 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(exts: &f->exts); |
341 | kfree(objp: 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, filter: 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(exts: &f->exts)) |
381 | return skb->len; |
382 | |
383 | nest = nla_nest_start_noflag(skb, attrtype: TCA_OPTIONS); |
384 | if (nest == NULL) |
385 | goto nla_put_failure; |
386 | |
387 | if (f->res.classid && |
388 | nla_put_u32(skb, attrtype: TCA_FW_CLASSID, value: f->res.classid)) |
389 | goto nla_put_failure; |
390 | if (f->ifindex) { |
391 | struct net_device *dev; |
392 | dev = __dev_get_by_index(net, ifindex: f->ifindex); |
393 | if (dev && nla_put_string(skb, attrtype: TCA_FW_INDEV, str: dev->name)) |
394 | goto nla_put_failure; |
395 | } |
396 | if (head->mask != 0xFFFFFFFF && |
397 | nla_put_u32(skb, attrtype: TCA_FW_MASK, value: head->mask)) |
398 | goto nla_put_failure; |
399 | |
400 | if (tcf_exts_dump(skb, exts: &f->exts) < 0) |
401 | goto nla_put_failure; |
402 | |
403 | nla_nest_end(skb, start: nest); |
404 | |
405 | if (tcf_exts_dump_stats(skb, exts: &f->exts) < 0) |
406 | goto nla_put_failure; |
407 | |
408 | return skb->len; |
409 | |
410 | nla_put_failure: |
411 | nla_nest_cancel(skb, start: 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, res: &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 | |
437 | static int __init init_fw(void) |
438 | { |
439 | return register_tcf_proto_ops(ops: &cls_fw_ops); |
440 | } |
441 | |
442 | static void __exit exit_fw(void) |
443 | { |
444 | unregister_tcf_proto_ops(ops: &cls_fw_ops); |
445 | } |
446 | |
447 | module_init(init_fw) |
448 | module_exit(exit_fw) |
449 | MODULE_LICENSE("GPL" ); |
450 | |