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Merge tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux
[linux-2.6.git] / net / sched / cls_flow.c
blob7881e2fccbc2ea1b7cd0eaf98ac3f0675836e150
1 /*
2 * net/sched/cls_flow.c Generic flow classifier
3 *
4 * Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version 2
9 * of the License, or (at your option) any later version.
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/list.h>
15 #include <linux/jhash.h>
16 #include <linux/random.h>
17 #include <linux/pkt_cls.h>
18 #include <linux/skbuff.h>
19 #include <linux/in.h>
20 #include <linux/ip.h>
21 #include <linux/ipv6.h>
22 #include <linux/if_vlan.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25
26 #include <net/pkt_cls.h>
27 #include <net/ip.h>
28 #include <net/route.h>
29 #include <net/flow_keys.h>
30
31 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
32 #include <net/netfilter/nf_conntrack.h>
33 #endif
34
35 struct flow_head {
36 struct list_head filters;
37 };
38
39 struct flow_filter {
40 struct list_head list;
41 struct tcf_exts exts;
42 struct tcf_ematch_tree ematches;
43 struct timer_list perturb_timer;
44 u32 perturb_period;
45 u32 handle;
46
47 u32 nkeys;
48 u32 keymask;
49 u32 mode;
50 u32 mask;
51 u32 xor;
52 u32 rshift;
53 u32 addend;
54 u32 divisor;
55 u32 baseclass;
56 u32 hashrnd;
57 };
58
59 static const struct tcf_ext_map flow_ext_map = {
60 .action = TCA_FLOW_ACT,
61 .police = TCA_FLOW_POLICE,
62 };
63
64 static inline u32 addr_fold(void *addr)
65 {
66 unsigned long a = (unsigned long)addr;
67
68 return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
69 }
70
71 static u32 flow_get_src(const struct sk_buff *skb, const struct flow_keys *flow)
72 {
73 if (flow->src)
74 return ntohl(flow->src);
75 return addr_fold(skb->sk);
76 }
77
78 static u32 flow_get_dst(const struct sk_buff *skb, const struct flow_keys *flow)
79 {
80 if (flow->dst)
81 return ntohl(flow->dst);
82 return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
83 }
84
85 static u32 flow_get_proto(const struct sk_buff *skb, const struct flow_keys *flow)
86 {
87 return flow->ip_proto;
88 }
89
90 static u32 flow_get_proto_src(const struct sk_buff *skb, const struct flow_keys *flow)
91 {
92 if (flow->ports)
93 return ntohs(flow->port16[0]);
94
95 return addr_fold(skb->sk);
96 }
97
98 static u32 flow_get_proto_dst(const struct sk_buff *skb, const struct flow_keys *flow)
99 {
100 if (flow->ports)
101 return ntohs(flow->port16[1]);
102
103 return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
104 }
105
106 static u32 flow_get_iif(const struct sk_buff *skb)
107 {
108 return skb->skb_iif;
109 }
110
111 static u32 flow_get_priority(const struct sk_buff *skb)
112 {
113 return skb->priority;
114 }
115
116 static u32 flow_get_mark(const struct sk_buff *skb)
117 {
118 return skb->mark;
119 }
120
121 static u32 flow_get_nfct(const struct sk_buff *skb)
122 {
123 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
124 return addr_fold(skb->nfct);
125 #else
126 return 0;
127 #endif
128 }
129
130 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
131 #define CTTUPLE(skb, member) \
132 ({ \
133 enum ip_conntrack_info ctinfo; \
134 const struct nf_conn *ct = nf_ct_get(skb, &ctinfo); \
135 if (ct == NULL) \
136 goto fallback; \
137 ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member; \
138 })
139 #else
140 #define CTTUPLE(skb, member) \
141 ({ \
142 goto fallback; \
143 0; \
144 })
145 #endif
146
147 static u32 flow_get_nfct_src(const struct sk_buff *skb, const struct flow_keys *flow)
148 {
149 switch (skb->protocol) {
150 case htons(ETH_P_IP):
151 return ntohl(CTTUPLE(skb, src.u3.ip));
152 case htons(ETH_P_IPV6):
153 return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
154 }
155 fallback:
156 return flow_get_src(skb, flow);
157 }
158
159 static u32 flow_get_nfct_dst(const struct sk_buff *skb, const struct flow_keys *flow)
160 {
161 switch (skb->protocol) {
162 case htons(ETH_P_IP):
163 return ntohl(CTTUPLE(skb, dst.u3.ip));
164 case htons(ETH_P_IPV6):
165 return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
166 }
167 fallback:
168 return flow_get_dst(skb, flow);
169 }
170
171 static u32 flow_get_nfct_proto_src(const struct sk_buff *skb, const struct flow_keys *flow)
172 {
173 return ntohs(CTTUPLE(skb, src.u.all));
174 fallback:
175 return flow_get_proto_src(skb, flow);
176 }
177
178 static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb, const struct flow_keys *flow)
179 {
180 return ntohs(CTTUPLE(skb, dst.u.all));
181 fallback:
182 return flow_get_proto_dst(skb, flow);
183 }
184
185 static u32 flow_get_rtclassid(const struct sk_buff *skb)
186 {
187 #ifdef CONFIG_IP_ROUTE_CLASSID
188 if (skb_dst(skb))
189 return skb_dst(skb)->tclassid;
190 #endif
191 return 0;
192 }
193
194 static u32 flow_get_skuid(const struct sk_buff *skb)
195 {
196 if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file) {
197 kuid_t skuid = skb->sk->sk_socket->file->f_cred->fsuid;
198 return from_kuid(&init_user_ns, skuid);
199 }
200 return 0;
201 }
202
203 static u32 flow_get_skgid(const struct sk_buff *skb)
204 {
205 if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file) {
206 kgid_t skgid = skb->sk->sk_socket->file->f_cred->fsgid;
207 return from_kgid(&init_user_ns, skgid);
208 }
209 return 0;
210 }
211
212 static u32 flow_get_vlan_tag(const struct sk_buff *skb)
213 {
214 u16 uninitialized_var(tag);
215
216 if (vlan_get_tag(skb, &tag) < 0)
217 return 0;
218 return tag & VLAN_VID_MASK;
219 }
220
221 static u32 flow_get_rxhash(struct sk_buff *skb)
222 {
223 return skb_get_rxhash(skb);
224 }
225
226 static u32 flow_key_get(struct sk_buff *skb, int key, struct flow_keys *flow)
227 {
228 switch (key) {
229 case FLOW_KEY_SRC:
230 return flow_get_src(skb, flow);
231 case FLOW_KEY_DST:
232 return flow_get_dst(skb, flow);
233 case FLOW_KEY_PROTO:
234 return flow_get_proto(skb, flow);
235 case FLOW_KEY_PROTO_SRC:
236 return flow_get_proto_src(skb, flow);
237 case FLOW_KEY_PROTO_DST:
238 return flow_get_proto_dst(skb, flow);
239 case FLOW_KEY_IIF:
240 return flow_get_iif(skb);
241 case FLOW_KEY_PRIORITY:
242 return flow_get_priority(skb);
243 case FLOW_KEY_MARK:
244 return flow_get_mark(skb);
245 case FLOW_KEY_NFCT:
246 return flow_get_nfct(skb);
247 case FLOW_KEY_NFCT_SRC:
248 return flow_get_nfct_src(skb, flow);
249 case FLOW_KEY_NFCT_DST:
250 return flow_get_nfct_dst(skb, flow);
251 case FLOW_KEY_NFCT_PROTO_SRC:
252 return flow_get_nfct_proto_src(skb, flow);
253 case FLOW_KEY_NFCT_PROTO_DST:
254 return flow_get_nfct_proto_dst(skb, flow);
255 case FLOW_KEY_RTCLASSID:
256 return flow_get_rtclassid(skb);
257 case FLOW_KEY_SKUID:
258 return flow_get_skuid(skb);
259 case FLOW_KEY_SKGID:
260 return flow_get_skgid(skb);
261 case FLOW_KEY_VLAN_TAG:
262 return flow_get_vlan_tag(skb);
263 case FLOW_KEY_RXHASH:
264 return flow_get_rxhash(skb);
265 default:
266 WARN_ON(1);
267 return 0;
268 }
269 }
270
271 #define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) | \
272 (1 << FLOW_KEY_DST) | \
273 (1 << FLOW_KEY_PROTO) | \
274 (1 << FLOW_KEY_PROTO_SRC) | \
275 (1 << FLOW_KEY_PROTO_DST) | \
276 (1 << FLOW_KEY_NFCT_SRC) | \
277 (1 << FLOW_KEY_NFCT_DST) | \
278 (1 << FLOW_KEY_NFCT_PROTO_SRC) | \
279 (1 << FLOW_KEY_NFCT_PROTO_DST))
280
281 static int flow_classify(struct sk_buff *skb, const struct tcf_proto *tp,
282 struct tcf_result *res)
283 {
284 struct flow_head *head = tp->root;
285 struct flow_filter *f;
286 u32 keymask;
287 u32 classid;
288 unsigned int n, key;
289 int r;
290
291 list_for_each_entry(f, &head->filters, list) {
292 u32 keys[FLOW_KEY_MAX + 1];
293 struct flow_keys flow_keys;
294
295 if (!tcf_em_tree_match(skb, &f->ematches, NULL))
296 continue;
297
298 keymask = f->keymask;
299 if (keymask & FLOW_KEYS_NEEDED)
300 skb_flow_dissect(skb, &flow_keys);
301
302 for (n = 0; n < f->nkeys; n++) {
303 key = ffs(keymask) - 1;
304 keymask &= ~(1 << key);
305 keys[n] = flow_key_get(skb, key, &flow_keys);
306 }
307
308 if (f->mode == FLOW_MODE_HASH)
309 classid = jhash2(keys, f->nkeys, f->hashrnd);
310 else {
311 classid = keys[0];
312 classid = (classid & f->mask) ^ f->xor;
313 classid = (classid >> f->rshift) + f->addend;
314 }
315
316 if (f->divisor)
317 classid %= f->divisor;
318
319 res->class = 0;
320 res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
321
322 r = tcf_exts_exec(skb, &f->exts, res);
323 if (r < 0)
324 continue;
325 return r;
326 }
327 return -1;
328 }
329
330 static void flow_perturbation(unsigned long arg)
331 {
332 struct flow_filter *f = (struct flow_filter *)arg;
333
334 get_random_bytes(&f->hashrnd, 4);
335 if (f->perturb_period)
336 mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
337 }
338
339 static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
340 [TCA_FLOW_KEYS] = { .type = NLA_U32 },
341 [TCA_FLOW_MODE] = { .type = NLA_U32 },
342 [TCA_FLOW_BASECLASS] = { .type = NLA_U32 },
343 [TCA_FLOW_RSHIFT] = { .type = NLA_U32 },
344 [TCA_FLOW_ADDEND] = { .type = NLA_U32 },
345 [TCA_FLOW_MASK] = { .type = NLA_U32 },
346 [TCA_FLOW_XOR] = { .type = NLA_U32 },
347 [TCA_FLOW_DIVISOR] = { .type = NLA_U32 },
348 [TCA_FLOW_ACT] = { .type = NLA_NESTED },
349 [TCA_FLOW_POLICE] = { .type = NLA_NESTED },
350 [TCA_FLOW_EMATCHES] = { .type = NLA_NESTED },
351 [TCA_FLOW_PERTURB] = { .type = NLA_U32 },
352 };
353
354 static int flow_change(struct net *net, struct sk_buff *in_skb,
355 struct tcf_proto *tp, unsigned long base,
356 u32 handle, struct nlattr **tca,
357 unsigned long *arg)
358 {
359 struct flow_head *head = tp->root;
360 struct flow_filter *f;
361 struct nlattr *opt = tca[TCA_OPTIONS];
362 struct nlattr *tb[TCA_FLOW_MAX + 1];
363 struct tcf_exts e;
364 struct tcf_ematch_tree t;
365 unsigned int nkeys = 0;
366 unsigned int perturb_period = 0;
367 u32 baseclass = 0;
368 u32 keymask = 0;
369 u32 mode;
370 int err;
371
372 if (opt == NULL)
373 return -EINVAL;
374
375 err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy);
376 if (err < 0)
377 return err;
378
379 if (tb[TCA_FLOW_BASECLASS]) {
380 baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
381 if (TC_H_MIN(baseclass) == 0)
382 return -EINVAL;
383 }
384
385 if (tb[TCA_FLOW_KEYS]) {
386 keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
387
388 nkeys = hweight32(keymask);
389 if (nkeys == 0)
390 return -EINVAL;
391
392 if (fls(keymask) - 1 > FLOW_KEY_MAX)
393 return -EOPNOTSUPP;
394
395 if ((keymask & (FLOW_KEY_SKUID|FLOW_KEY_SKGID)) &&
396 sk_user_ns(NETLINK_CB(in_skb).sk) != &init_user_ns)
397 return -EOPNOTSUPP;
398 }
399
400 err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, &flow_ext_map);
401 if (err < 0)
402 return err;
403
404 err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &t);
405 if (err < 0)
406 goto err1;
407
408 f = (struct flow_filter *)*arg;
409 if (f != NULL) {
410 err = -EINVAL;
411 if (f->handle != handle && handle)
412 goto err2;
413
414 mode = f->mode;
415 if (tb[TCA_FLOW_MODE])
416 mode = nla_get_u32(tb[TCA_FLOW_MODE]);
417 if (mode != FLOW_MODE_HASH && nkeys > 1)
418 goto err2;
419
420 if (mode == FLOW_MODE_HASH)
421 perturb_period = f->perturb_period;
422 if (tb[TCA_FLOW_PERTURB]) {
423 if (mode != FLOW_MODE_HASH)
424 goto err2;
425 perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
426 }
427 } else {
428 err = -EINVAL;
429 if (!handle)
430 goto err2;
431 if (!tb[TCA_FLOW_KEYS])
432 goto err2;
433
434 mode = FLOW_MODE_MAP;
435 if (tb[TCA_FLOW_MODE])
436 mode = nla_get_u32(tb[TCA_FLOW_MODE]);
437 if (mode != FLOW_MODE_HASH && nkeys > 1)
438 goto err2;
439
440 if (tb[TCA_FLOW_PERTURB]) {
441 if (mode != FLOW_MODE_HASH)
442 goto err2;
443 perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
444 }
445
446 if (TC_H_MAJ(baseclass) == 0)
447 baseclass = TC_H_MAKE(tp->q->handle, baseclass);
448 if (TC_H_MIN(baseclass) == 0)
449 baseclass = TC_H_MAKE(baseclass, 1);
450
451 err = -ENOBUFS;
452 f = kzalloc(sizeof(*f), GFP_KERNEL);
453 if (f == NULL)
454 goto err2;
455
456 f->handle = handle;
457 f->mask = ~0U;
458
459 get_random_bytes(&f->hashrnd, 4);
460 f->perturb_timer.function = flow_perturbation;
461 f->perturb_timer.data = (unsigned long)f;
462 init_timer_deferrable(&f->perturb_timer);
463 }
464
465 tcf_exts_change(tp, &f->exts, &e);
466 tcf_em_tree_change(tp, &f->ematches, &t);
467
468 tcf_tree_lock(tp);
469
470 if (tb[TCA_FLOW_KEYS]) {
471 f->keymask = keymask;
472 f->nkeys = nkeys;
473 }
474
475 f->mode = mode;
476
477 if (tb[TCA_FLOW_MASK])
478 f->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
479 if (tb[TCA_FLOW_XOR])
480 f->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
481 if (tb[TCA_FLOW_RSHIFT])
482 f->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
483 if (tb[TCA_FLOW_ADDEND])
484 f->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
485
486 if (tb[TCA_FLOW_DIVISOR])
487 f->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
488 if (baseclass)
489 f->baseclass = baseclass;
490
491 f->perturb_period = perturb_period;
492 del_timer(&f->perturb_timer);
493 if (perturb_period)
494 mod_timer(&f->perturb_timer, jiffies + perturb_period);
495
496 if (*arg == 0)
497 list_add_tail(&f->list, &head->filters);
498
499 tcf_tree_unlock(tp);
500
501 *arg = (unsigned long)f;
502 return 0;
503
504 err2:
505 tcf_em_tree_destroy(tp, &t);
506 err1:
507 tcf_exts_destroy(tp, &e);
508 return err;
509 }
510
511 static void flow_destroy_filter(struct tcf_proto *tp, struct flow_filter *f)
512 {
513 del_timer_sync(&f->perturb_timer);
514 tcf_exts_destroy(tp, &f->exts);
515 tcf_em_tree_destroy(tp, &f->ematches);
516 kfree(f);
517 }
518
519 static int flow_delete(struct tcf_proto *tp, unsigned long arg)
520 {
521 struct flow_filter *f = (struct flow_filter *)arg;
522
523 tcf_tree_lock(tp);
524 list_del(&f->list);
525 tcf_tree_unlock(tp);
526 flow_destroy_filter(tp, f);
527 return 0;
528 }
529
530 static int flow_init(struct tcf_proto *tp)
531 {
532 struct flow_head *head;
533
534 head = kzalloc(sizeof(*head), GFP_KERNEL);
535 if (head == NULL)
536 return -ENOBUFS;
537 INIT_LIST_HEAD(&head->filters);
538 tp->root = head;
539 return 0;
540 }
541
542 static void flow_destroy(struct tcf_proto *tp)
543 {
544 struct flow_head *head = tp->root;
545 struct flow_filter *f, *next;
546
547 list_for_each_entry_safe(f, next, &head->filters, list) {
548 list_del(&f->list);
549 flow_destroy_filter(tp, f);
550 }
551 kfree(head);
552 }
553
554 static unsigned long flow_get(struct tcf_proto *tp, u32 handle)
555 {
556 struct flow_head *head = tp->root;
557 struct flow_filter *f;
558
559 list_for_each_entry(f, &head->filters, list)
560 if (f->handle == handle)
561 return (unsigned long)f;
562 return 0;
563 }
564
565 static void flow_put(struct tcf_proto *tp, unsigned long f)
566 {
567 }
568
569 static int flow_dump(struct tcf_proto *tp, unsigned long fh,
570 struct sk_buff *skb, struct tcmsg *t)
571 {
572 struct flow_filter *f = (struct flow_filter *)fh;
573 struct nlattr *nest;
574
575 if (f == NULL)
576 return skb->len;
577
578 t->tcm_handle = f->handle;
579
580 nest = nla_nest_start(skb, TCA_OPTIONS);
581 if (nest == NULL)
582 goto nla_put_failure;
583
584 if (nla_put_u32(skb, TCA_FLOW_KEYS, f->keymask) ||
585 nla_put_u32(skb, TCA_FLOW_MODE, f->mode))
586 goto nla_put_failure;
587
588 if (f->mask != ~0 || f->xor != 0) {
589 if (nla_put_u32(skb, TCA_FLOW_MASK, f->mask) ||
590 nla_put_u32(skb, TCA_FLOW_XOR, f->xor))
591 goto nla_put_failure;
592 }
593 if (f->rshift &&
594 nla_put_u32(skb, TCA_FLOW_RSHIFT, f->rshift))
595 goto nla_put_failure;
596 if (f->addend &&
597 nla_put_u32(skb, TCA_FLOW_ADDEND, f->addend))
598 goto nla_put_failure;
599
600 if (f->divisor &&
601 nla_put_u32(skb, TCA_FLOW_DIVISOR, f->divisor))
602 goto nla_put_failure;
603 if (f->baseclass &&
604 nla_put_u32(skb, TCA_FLOW_BASECLASS, f->baseclass))
605 goto nla_put_failure;
606
607 if (f->perturb_period &&
608 nla_put_u32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ))
609 goto nla_put_failure;
610
611 if (tcf_exts_dump(skb, &f->exts, &flow_ext_map) < 0)
612 goto nla_put_failure;
613 #ifdef CONFIG_NET_EMATCH
614 if (f->ematches.hdr.nmatches &&
615 tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
616 goto nla_put_failure;
617 #endif
618 nla_nest_end(skb, nest);
619
620 if (tcf_exts_dump_stats(skb, &f->exts, &flow_ext_map) < 0)
621 goto nla_put_failure;
622
623 return skb->len;
624
625 nla_put_failure:
626 nlmsg_trim(skb, nest);
627 return -1;
628 }
629
630 static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
631 {
632 struct flow_head *head = tp->root;
633 struct flow_filter *f;
634
635 list_for_each_entry(f, &head->filters, list) {
636 if (arg->count < arg->skip)
637 goto skip;
638 if (arg->fn(tp, (unsigned long)f, arg) < 0) {
639 arg->stop = 1;
640 break;
641 }
642 skip:
643 arg->count++;
644 }
645 }
646
647 static struct tcf_proto_ops cls_flow_ops __read_mostly = {
648 .kind = "flow",
649 .classify = flow_classify,
650 .init = flow_init,
651 .destroy = flow_destroy,
652 .change = flow_change,
653 .delete = flow_delete,
654 .get = flow_get,
655 .put = flow_put,
656 .dump = flow_dump,
657 .walk = flow_walk,
658 .owner = THIS_MODULE,
659 };
660
661 static int __init cls_flow_init(void)
662 {
663 return register_tcf_proto_ops(&cls_flow_ops);
664 }
665
666 static void __exit cls_flow_exit(void)
667 {
668 unregister_tcf_proto_ops(&cls_flow_ops);
669 }
670
671 module_init(cls_flow_init);
672 module_exit(cls_flow_exit);
673
674 MODULE_LICENSE("GPL");
675 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
676 MODULE_DESCRIPTION("TC flow classifier");
Linus' kernel tree