]>
Commit | Line | Data |
---|---|---|
2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * net/sched/ematch.c Extended Match API | |
4 | * | |
1da177e4 LT |
5 | * Authors: Thomas Graf <tgraf@suug.ch> |
6 | * | |
7 | * ========================================================================== | |
8 | * | |
9 | * An extended match (ematch) is a small classification tool not worth | |
10 | * writing a full classifier for. Ematches can be interconnected to form | |
11 | * a logic expression and get attached to classifiers to extend their | |
12 | * functionatlity. | |
13 | * | |
14 | * The userspace part transforms the logic expressions into an array | |
15 | * consisting of multiple sequences of interconnected ematches separated | |
16 | * by markers. Precedence is implemented by a special ematch kind | |
17 | * referencing a sequence beyond the marker of the current sequence | |
18 | * causing the current position in the sequence to be pushed onto a stack | |
19 | * to allow the current position to be overwritten by the position referenced | |
20 | * in the special ematch. Matching continues in the new sequence until a | |
21 | * marker is reached causing the position to be restored from the stack. | |
22 | * | |
23 | * Example: | |
24 | * A AND (B1 OR B2) AND C AND D | |
25 | * | |
26 | * ------->-PUSH------- | |
27 | * -->-- / -->-- \ -->-- | |
28 | * / \ / / \ \ / \ | |
29 | * +-------+-------+-------+-------+-------+--------+ | |
30 | * | A AND | B AND | C AND | D END | B1 OR | B2 END | | |
31 | * +-------+-------+-------+-------+-------+--------+ | |
32 | * \ / | |
33 | * --------<-POP--------- | |
34 | * | |
35 | * where B is a virtual ematch referencing to sequence starting with B1. | |
10297b99 | 36 | * |
1da177e4 LT |
37 | * ========================================================================== |
38 | * | |
39 | * How to write an ematch in 60 seconds | |
40 | * ------------------------------------ | |
10297b99 | 41 | * |
1da177e4 LT |
42 | * 1) Provide a matcher function: |
43 | * static int my_match(struct sk_buff *skb, struct tcf_ematch *m, | |
44 | * struct tcf_pkt_info *info) | |
45 | * { | |
46 | * struct mydata *d = (struct mydata *) m->data; | |
47 | * | |
48 | * if (...matching goes here...) | |
49 | * return 1; | |
50 | * else | |
51 | * return 0; | |
52 | * } | |
53 | * | |
54 | * 2) Fill out a struct tcf_ematch_ops: | |
55 | * static struct tcf_ematch_ops my_ops = { | |
56 | * .kind = unique id, | |
57 | * .datalen = sizeof(struct mydata), | |
58 | * .match = my_match, | |
59 | * .owner = THIS_MODULE, | |
60 | * }; | |
61 | * | |
62 | * 3) Register/Unregister your ematch: | |
63 | * static int __init init_my_ematch(void) | |
64 | * { | |
65 | * return tcf_em_register(&my_ops); | |
66 | * } | |
67 | * | |
68 | * static void __exit exit_my_ematch(void) | |
69 | * { | |
4d24b52a | 70 | * tcf_em_unregister(&my_ops); |
1da177e4 LT |
71 | * } |
72 | * | |
73 | * module_init(init_my_ematch); | |
74 | * module_exit(exit_my_ematch); | |
75 | * | |
76 | * 4) By now you should have two more seconds left, barely enough to | |
77 | * open up a beer to watch the compilation going. | |
78 | */ | |
79 | ||
1da177e4 | 80 | #include <linux/module.h> |
5a0e3ad6 | 81 | #include <linux/slab.h> |
1da177e4 LT |
82 | #include <linux/types.h> |
83 | #include <linux/kernel.h> | |
1da177e4 | 84 | #include <linux/errno.h> |
1da177e4 LT |
85 | #include <linux/rtnetlink.h> |
86 | #include <linux/skbuff.h> | |
87 | #include <net/pkt_cls.h> | |
1da177e4 LT |
88 | |
89 | static LIST_HEAD(ematch_ops); | |
90 | static DEFINE_RWLOCK(ematch_mod_lock); | |
91 | ||
cc7ec456 | 92 | static struct tcf_ematch_ops *tcf_em_lookup(u16 kind) |
1da177e4 LT |
93 | { |
94 | struct tcf_ematch_ops *e = NULL; | |
95 | ||
96 | read_lock(&ematch_mod_lock); | |
97 | list_for_each_entry(e, &ematch_ops, link) { | |
98 | if (kind == e->kind) { | |
99 | if (!try_module_get(e->owner)) | |
100 | e = NULL; | |
101 | read_unlock(&ematch_mod_lock); | |
102 | return e; | |
103 | } | |
104 | } | |
105 | read_unlock(&ematch_mod_lock); | |
106 | ||
107 | return NULL; | |
108 | } | |
109 | ||
110 | /** | |
111 | * tcf_em_register - register an extended match | |
10297b99 | 112 | * |
1da177e4 LT |
113 | * @ops: ematch operations lookup table |
114 | * | |
115 | * This function must be called by ematches to announce their presence. | |
116 | * The given @ops must have kind set to a unique identifier and the | |
117 | * callback match() must be implemented. All other callbacks are optional | |
118 | * and a fallback implementation is used instead. | |
119 | * | |
120 | * Returns -EEXISTS if an ematch of the same kind has already registered. | |
121 | */ | |
122 | int tcf_em_register(struct tcf_ematch_ops *ops) | |
123 | { | |
124 | int err = -EEXIST; | |
125 | struct tcf_ematch_ops *e; | |
126 | ||
127 | if (ops->match == NULL) | |
128 | return -EINVAL; | |
129 | ||
130 | write_lock(&ematch_mod_lock); | |
131 | list_for_each_entry(e, &ematch_ops, link) | |
132 | if (ops->kind == e->kind) | |
133 | goto errout; | |
134 | ||
135 | list_add_tail(&ops->link, &ematch_ops); | |
136 | err = 0; | |
137 | errout: | |
138 | write_unlock(&ematch_mod_lock); | |
139 | return err; | |
140 | } | |
62e3ba1b | 141 | EXPORT_SYMBOL(tcf_em_register); |
1da177e4 LT |
142 | |
143 | /** | |
144 | * tcf_em_unregister - unregster and extended match | |
145 | * | |
146 | * @ops: ematch operations lookup table | |
147 | * | |
148 | * This function must be called by ematches to announce their disappearance | |
149 | * for examples when the module gets unloaded. The @ops parameter must be | |
150 | * the same as the one used for registration. | |
151 | * | |
152 | * Returns -ENOENT if no matching ematch was found. | |
153 | */ | |
4d24b52a | 154 | void tcf_em_unregister(struct tcf_ematch_ops *ops) |
1da177e4 | 155 | { |
1da177e4 | 156 | write_lock(&ematch_mod_lock); |
4d24b52a | 157 | list_del(&ops->link); |
1da177e4 | 158 | write_unlock(&ematch_mod_lock); |
1da177e4 | 159 | } |
62e3ba1b | 160 | EXPORT_SYMBOL(tcf_em_unregister); |
1da177e4 | 161 | |
cc7ec456 ED |
162 | static inline struct tcf_ematch *tcf_em_get_match(struct tcf_ematch_tree *tree, |
163 | int index) | |
1da177e4 LT |
164 | { |
165 | return &tree->matches[index]; | |
166 | } | |
167 | ||
168 | ||
169 | static int tcf_em_validate(struct tcf_proto *tp, | |
170 | struct tcf_ematch_tree_hdr *tree_hdr, | |
add93b61 | 171 | struct tcf_ematch *em, struct nlattr *nla, int idx) |
1da177e4 LT |
172 | { |
173 | int err = -EINVAL; | |
add93b61 PM |
174 | struct tcf_ematch_hdr *em_hdr = nla_data(nla); |
175 | int data_len = nla_len(nla) - sizeof(*em_hdr); | |
1da177e4 | 176 | void *data = (void *) em_hdr + sizeof(*em_hdr); |
c1954561 | 177 | struct net *net = tp->chain->block->net; |
1da177e4 LT |
178 | |
179 | if (!TCF_EM_REL_VALID(em_hdr->flags)) | |
180 | goto errout; | |
181 | ||
182 | if (em_hdr->kind == TCF_EM_CONTAINER) { | |
183 | /* Special ematch called "container", carries an index | |
cc7ec456 ED |
184 | * referencing an external ematch sequence. |
185 | */ | |
1da177e4 LT |
186 | u32 ref; |
187 | ||
188 | if (data_len < sizeof(ref)) | |
189 | goto errout; | |
190 | ref = *(u32 *) data; | |
191 | ||
192 | if (ref >= tree_hdr->nmatches) | |
193 | goto errout; | |
194 | ||
195 | /* We do not allow backward jumps to avoid loops and jumps | |
cc7ec456 ED |
196 | * to our own position are of course illegal. |
197 | */ | |
1da177e4 LT |
198 | if (ref <= idx) |
199 | goto errout; | |
200 | ||
10297b99 | 201 | |
1da177e4 LT |
202 | em->data = ref; |
203 | } else { | |
204 | /* Note: This lookup will increase the module refcnt | |
205 | * of the ematch module referenced. In case of a failure, | |
206 | * a destroy function is called by the underlying layer | |
207 | * which automatically releases the reference again, therefore | |
208 | * the module MUST not be given back under any circumstances | |
209 | * here. Be aware, the destroy function assumes that the | |
cc7ec456 ED |
210 | * module is held if the ops field is non zero. |
211 | */ | |
1da177e4 LT |
212 | em->ops = tcf_em_lookup(em_hdr->kind); |
213 | ||
214 | if (em->ops == NULL) { | |
215 | err = -ENOENT; | |
95a5afca | 216 | #ifdef CONFIG_MODULES |
db3d99c0 PM |
217 | __rtnl_unlock(); |
218 | request_module("ematch-kind-%u", em_hdr->kind); | |
219 | rtnl_lock(); | |
220 | em->ops = tcf_em_lookup(em_hdr->kind); | |
221 | if (em->ops) { | |
222 | /* We dropped the RTNL mutex in order to | |
223 | * perform the module load. Tell the caller | |
cc7ec456 ED |
224 | * to replay the request. |
225 | */ | |
db3d99c0 | 226 | module_put(em->ops->owner); |
34eea79e | 227 | em->ops = NULL; |
db3d99c0 PM |
228 | err = -EAGAIN; |
229 | } | |
230 | #endif | |
1da177e4 LT |
231 | goto errout; |
232 | } | |
233 | ||
234 | /* ematch module provides expected length of data, so we | |
cc7ec456 ED |
235 | * can do a basic sanity check. |
236 | */ | |
1da177e4 LT |
237 | if (em->ops->datalen && data_len < em->ops->datalen) |
238 | goto errout; | |
239 | ||
240 | if (em->ops->change) { | |
82a470f1 | 241 | err = em->ops->change(net, data, data_len, em); |
1da177e4 LT |
242 | if (err < 0) |
243 | goto errout; | |
244 | } else if (data_len > 0) { | |
245 | /* ematch module doesn't provide an own change | |
246 | * procedure and expects us to allocate and copy | |
247 | * the ematch data. | |
248 | * | |
249 | * TCF_EM_SIMPLE may be specified stating that the | |
250 | * data only consists of a u32 integer and the module | |
251 | * does not expected a memory reference but rather | |
cc7ec456 ED |
252 | * the value carried. |
253 | */ | |
1da177e4 LT |
254 | if (em_hdr->flags & TCF_EM_SIMPLE) { |
255 | if (data_len < sizeof(u32)) | |
256 | goto errout; | |
257 | em->data = *(u32 *) data; | |
258 | } else { | |
c7b1b249 | 259 | void *v = kmemdup(data, data_len, GFP_KERNEL); |
1da177e4 LT |
260 | if (v == NULL) { |
261 | err = -ENOBUFS; | |
262 | goto errout; | |
263 | } | |
1da177e4 LT |
264 | em->data = (unsigned long) v; |
265 | } | |
266 | } | |
267 | } | |
268 | ||
269 | em->matchid = em_hdr->matchid; | |
270 | em->flags = em_hdr->flags; | |
271 | em->datalen = data_len; | |
82a470f1 | 272 | em->net = net; |
1da177e4 LT |
273 | |
274 | err = 0; | |
275 | errout: | |
276 | return err; | |
277 | } | |
278 | ||
7a9c1bd4 PM |
279 | static const struct nla_policy em_policy[TCA_EMATCH_TREE_MAX + 1] = { |
280 | [TCA_EMATCH_TREE_HDR] = { .len = sizeof(struct tcf_ematch_tree_hdr) }, | |
281 | [TCA_EMATCH_TREE_LIST] = { .type = NLA_NESTED }, | |
282 | }; | |
283 | ||
1da177e4 LT |
284 | /** |
285 | * tcf_em_tree_validate - validate ematch config TLV and build ematch tree | |
286 | * | |
287 | * @tp: classifier kind handle | |
add93b61 | 288 | * @nla: ematch tree configuration TLV |
1da177e4 LT |
289 | * @tree: destination ematch tree variable to store the resulting |
290 | * ematch tree. | |
291 | * | |
add93b61 | 292 | * This function validates the given configuration TLV @nla and builds an |
1da177e4 LT |
293 | * ematch tree in @tree. The resulting tree must later be copied into |
294 | * the private classifier data using tcf_em_tree_change(). You MUST NOT | |
295 | * provide the ematch tree variable of the private classifier data directly, | |
296 | * the changes would not be locked properly. | |
297 | * | |
298 | * Returns a negative error code if the configuration TLV contains errors. | |
299 | */ | |
add93b61 | 300 | int tcf_em_tree_validate(struct tcf_proto *tp, struct nlattr *nla, |
1da177e4 LT |
301 | struct tcf_ematch_tree *tree) |
302 | { | |
cee63723 | 303 | int idx, list_len, matches_len, err; |
add93b61 PM |
304 | struct nlattr *tb[TCA_EMATCH_TREE_MAX + 1]; |
305 | struct nlattr *rt_match, *rt_hdr, *rt_list; | |
1da177e4 LT |
306 | struct tcf_ematch_tree_hdr *tree_hdr; |
307 | struct tcf_ematch *em; | |
308 | ||
268bcca1 SH |
309 | memset(tree, 0, sizeof(*tree)); |
310 | if (!nla) | |
b541ca2c | 311 | return 0; |
b541ca2c | 312 | |
8cb08174 JB |
313 | err = nla_parse_nested_deprecated(tb, TCA_EMATCH_TREE_MAX, nla, |
314 | em_policy, NULL); | |
cee63723 | 315 | if (err < 0) |
1da177e4 LT |
316 | goto errout; |
317 | ||
cee63723 | 318 | err = -EINVAL; |
add93b61 PM |
319 | rt_hdr = tb[TCA_EMATCH_TREE_HDR]; |
320 | rt_list = tb[TCA_EMATCH_TREE_LIST]; | |
1da177e4 LT |
321 | |
322 | if (rt_hdr == NULL || rt_list == NULL) | |
323 | goto errout; | |
324 | ||
add93b61 | 325 | tree_hdr = nla_data(rt_hdr); |
1da177e4 LT |
326 | memcpy(&tree->hdr, tree_hdr, sizeof(*tree_hdr)); |
327 | ||
add93b61 PM |
328 | rt_match = nla_data(rt_list); |
329 | list_len = nla_len(rt_list); | |
1da177e4 LT |
330 | matches_len = tree_hdr->nmatches * sizeof(*em); |
331 | ||
0da974f4 | 332 | tree->matches = kzalloc(matches_len, GFP_KERNEL); |
1da177e4 LT |
333 | if (tree->matches == NULL) |
334 | goto errout; | |
1da177e4 | 335 | |
add93b61 | 336 | /* We do not use nla_parse_nested here because the maximum |
1da177e4 LT |
337 | * number of attributes is unknown. This saves us the allocation |
338 | * for a tb buffer which would serve no purpose at all. | |
10297b99 | 339 | * |
1da177e4 LT |
340 | * The array of rt attributes is parsed in the order as they are |
341 | * provided, their type must be incremental from 1 to n. Even | |
342 | * if it does not serve any real purpose, a failure of sticking | |
cc7ec456 ED |
343 | * to this policy will result in parsing failure. |
344 | */ | |
add93b61 | 345 | for (idx = 0; nla_ok(rt_match, list_len); idx++) { |
1da177e4 LT |
346 | err = -EINVAL; |
347 | ||
add93b61 | 348 | if (rt_match->nla_type != (idx + 1)) |
1da177e4 LT |
349 | goto errout_abort; |
350 | ||
351 | if (idx >= tree_hdr->nmatches) | |
352 | goto errout_abort; | |
353 | ||
add93b61 | 354 | if (nla_len(rt_match) < sizeof(struct tcf_ematch_hdr)) |
1da177e4 LT |
355 | goto errout_abort; |
356 | ||
357 | em = tcf_em_get_match(tree, idx); | |
358 | ||
359 | err = tcf_em_validate(tp, tree_hdr, em, rt_match, idx); | |
360 | if (err < 0) | |
361 | goto errout_abort; | |
362 | ||
add93b61 | 363 | rt_match = nla_next(rt_match, &list_len); |
1da177e4 LT |
364 | } |
365 | ||
366 | /* Check if the number of matches provided by userspace actually | |
367 | * complies with the array of matches. The number was used for | |
368 | * the validation of references and a mismatch could lead to | |
cc7ec456 ED |
369 | * undefined references during the matching process. |
370 | */ | |
1da177e4 LT |
371 | if (idx != tree_hdr->nmatches) { |
372 | err = -EINVAL; | |
373 | goto errout_abort; | |
374 | } | |
375 | ||
376 | err = 0; | |
377 | errout: | |
378 | return err; | |
379 | ||
380 | errout_abort: | |
82a470f1 | 381 | tcf_em_tree_destroy(tree); |
1da177e4 LT |
382 | return err; |
383 | } | |
62e3ba1b | 384 | EXPORT_SYMBOL(tcf_em_tree_validate); |
1da177e4 LT |
385 | |
386 | /** | |
387 | * tcf_em_tree_destroy - destroy an ematch tree | |
388 | * | |
389 | * @tp: classifier kind handle | |
390 | * @tree: ematch tree to be deleted | |
391 | * | |
392 | * This functions destroys an ematch tree previously created by | |
393 | * tcf_em_tree_validate()/tcf_em_tree_change(). You must ensure that | |
394 | * the ematch tree is not in use before calling this function. | |
395 | */ | |
82a470f1 | 396 | void tcf_em_tree_destroy(struct tcf_ematch_tree *tree) |
1da177e4 LT |
397 | { |
398 | int i; | |
399 | ||
400 | if (tree->matches == NULL) | |
401 | return; | |
402 | ||
403 | for (i = 0; i < tree->hdr.nmatches; i++) { | |
404 | struct tcf_ematch *em = tcf_em_get_match(tree, i); | |
405 | ||
406 | if (em->ops) { | |
407 | if (em->ops->destroy) | |
82a470f1 | 408 | em->ops->destroy(em); |
954415e3 | 409 | else if (!tcf_em_is_simple(em)) |
30ddb159 | 410 | kfree((void *) em->data); |
1da177e4 LT |
411 | module_put(em->ops->owner); |
412 | } | |
413 | } | |
10297b99 | 414 | |
1da177e4 LT |
415 | tree->hdr.nmatches = 0; |
416 | kfree(tree->matches); | |
954415e3 | 417 | tree->matches = NULL; |
1da177e4 | 418 | } |
62e3ba1b | 419 | EXPORT_SYMBOL(tcf_em_tree_destroy); |
1da177e4 LT |
420 | |
421 | /** | |
422 | * tcf_em_tree_dump - dump ematch tree into a rtnl message | |
423 | * | |
424 | * @skb: skb holding the rtnl message | |
425 | * @t: ematch tree to be dumped | |
426 | * @tlv: TLV type to be used to encapsulate the tree | |
427 | * | |
428 | * This function dumps a ematch tree into a rtnl message. It is valid to | |
429 | * call this function while the ematch tree is in use. | |
430 | * | |
431 | * Returns -1 if the skb tailroom is insufficient. | |
432 | */ | |
433 | int tcf_em_tree_dump(struct sk_buff *skb, struct tcf_ematch_tree *tree, int tlv) | |
434 | { | |
435 | int i; | |
27a884dc | 436 | u8 *tail; |
4b3550ef | 437 | struct nlattr *top_start; |
add93b61 | 438 | struct nlattr *list_start; |
1da177e4 | 439 | |
ae0be8de | 440 | top_start = nla_nest_start_noflag(skb, tlv); |
4b3550ef PM |
441 | if (top_start == NULL) |
442 | goto nla_put_failure; | |
443 | ||
1b34ec43 DM |
444 | if (nla_put(skb, TCA_EMATCH_TREE_HDR, sizeof(tree->hdr), &tree->hdr)) |
445 | goto nla_put_failure; | |
1da177e4 | 446 | |
ae0be8de | 447 | list_start = nla_nest_start_noflag(skb, TCA_EMATCH_TREE_LIST); |
4b3550ef PM |
448 | if (list_start == NULL) |
449 | goto nla_put_failure; | |
1da177e4 | 450 | |
27a884dc | 451 | tail = skb_tail_pointer(skb); |
1da177e4 | 452 | for (i = 0; i < tree->hdr.nmatches; i++) { |
add93b61 | 453 | struct nlattr *match_start = (struct nlattr *)tail; |
1da177e4 LT |
454 | struct tcf_ematch *em = tcf_em_get_match(tree, i); |
455 | struct tcf_ematch_hdr em_hdr = { | |
456 | .kind = em->ops ? em->ops->kind : TCF_EM_CONTAINER, | |
457 | .matchid = em->matchid, | |
458 | .flags = em->flags | |
459 | }; | |
460 | ||
1b34ec43 DM |
461 | if (nla_put(skb, i + 1, sizeof(em_hdr), &em_hdr)) |
462 | goto nla_put_failure; | |
1da177e4 LT |
463 | |
464 | if (em->ops && em->ops->dump) { | |
465 | if (em->ops->dump(skb, em) < 0) | |
add93b61 | 466 | goto nla_put_failure; |
1da177e4 LT |
467 | } else if (tcf_em_is_container(em) || tcf_em_is_simple(em)) { |
468 | u32 u = em->data; | |
add93b61 | 469 | nla_put_nohdr(skb, sizeof(u), &u); |
1da177e4 | 470 | } else if (em->datalen > 0) |
add93b61 | 471 | nla_put_nohdr(skb, em->datalen, (void *) em->data); |
1da177e4 | 472 | |
27a884dc | 473 | tail = skb_tail_pointer(skb); |
add93b61 | 474 | match_start->nla_len = tail - (u8 *)match_start; |
1da177e4 LT |
475 | } |
476 | ||
4b3550ef PM |
477 | nla_nest_end(skb, list_start); |
478 | nla_nest_end(skb, top_start); | |
1da177e4 LT |
479 | |
480 | return 0; | |
481 | ||
add93b61 | 482 | nla_put_failure: |
1da177e4 LT |
483 | return -1; |
484 | } | |
62e3ba1b | 485 | EXPORT_SYMBOL(tcf_em_tree_dump); |
1da177e4 LT |
486 | |
487 | static inline int tcf_em_match(struct sk_buff *skb, struct tcf_ematch *em, | |
488 | struct tcf_pkt_info *info) | |
489 | { | |
490 | int r = em->ops->match(skb, em, info); | |
cc7ec456 | 491 | |
1da177e4 LT |
492 | return tcf_em_is_inverted(em) ? !r : r; |
493 | } | |
494 | ||
495 | /* Do not use this function directly, use tcf_em_tree_match instead */ | |
496 | int __tcf_em_tree_match(struct sk_buff *skb, struct tcf_ematch_tree *tree, | |
497 | struct tcf_pkt_info *info) | |
498 | { | |
499 | int stackp = 0, match_idx = 0, res = 0; | |
500 | struct tcf_ematch *cur_match; | |
501 | int stack[CONFIG_NET_EMATCH_STACK]; | |
502 | ||
503 | proceed: | |
504 | while (match_idx < tree->hdr.nmatches) { | |
505 | cur_match = tcf_em_get_match(tree, match_idx); | |
506 | ||
507 | if (tcf_em_is_container(cur_match)) { | |
508 | if (unlikely(stackp >= CONFIG_NET_EMATCH_STACK)) | |
509 | goto stack_overflow; | |
510 | ||
511 | stack[stackp++] = match_idx; | |
512 | match_idx = cur_match->data; | |
513 | goto proceed; | |
514 | } | |
515 | ||
516 | res = tcf_em_match(skb, cur_match, info); | |
517 | ||
518 | if (tcf_em_early_end(cur_match, res)) | |
519 | break; | |
520 | ||
521 | match_idx++; | |
522 | } | |
523 | ||
524 | pop_stack: | |
525 | if (stackp > 0) { | |
526 | match_idx = stack[--stackp]; | |
527 | cur_match = tcf_em_get_match(tree, match_idx); | |
528 | ||
34a419d4 IG |
529 | if (tcf_em_is_inverted(cur_match)) |
530 | res = !res; | |
531 | ||
17c9c823 | 532 | if (tcf_em_early_end(cur_match, res)) { |
1da177e4 | 533 | goto pop_stack; |
17c9c823 | 534 | } else { |
1da177e4 LT |
535 | match_idx++; |
536 | goto proceed; | |
537 | } | |
538 | } | |
539 | ||
540 | return res; | |
541 | ||
542 | stack_overflow: | |
e87cc472 | 543 | net_warn_ratelimited("tc ematch: local stack overflow, increase NET_EMATCH_STACK\n"); |
1da177e4 LT |
544 | return -1; |
545 | } | |
1da177e4 | 546 | EXPORT_SYMBOL(__tcf_em_tree_match); |