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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * net/sched/cls_flow.c Generic flow classifier
4 *
5 * Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net>
6 */
7
8#include <linux/kernel.h>
9#include <linux/init.h>
10#include <linux/list.h>
11#include <linux/jhash.h>
12#include <linux/random.h>
13#include <linux/pkt_cls.h>
14#include <linux/skbuff.h>
15#include <linux/in.h>
16#include <linux/ip.h>
17#include <linux/ipv6.h>
18#include <linux/if_vlan.h>
19#include <linux/slab.h>
20#include <linux/module.h>
21#include <net/inet_sock.h>
22
23#include <net/pkt_cls.h>
24#include <net/ip.h>
25#include <net/route.h>
26#include <net/flow_dissector.h>
27#include <net/tc_wrapper.h>
28
29#if IS_ENABLED(CONFIG_NF_CONNTRACK)
30#include <net/netfilter/nf_conntrack.h>
31#endif
32
33struct flow_head {
34 struct list_head filters;
35 struct rcu_head rcu;
36};
37
38struct flow_filter {
39 struct list_head list;
40 struct tcf_exts exts;
41 struct tcf_ematch_tree ematches;
42 struct tcf_proto *tp;
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 struct rcu_work rwork;
58};
59
60static inline u32 addr_fold(void *addr)
61{
62 unsigned long a = (unsigned long)addr;
63
64 return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
65}
66
67static u32 flow_get_src(const struct sk_buff *skb, const struct flow_keys *flow)
68{
69 __be32 src = flow_get_u32_src(flow);
70
71 if (src)
72 return ntohl(src);
73
74 return addr_fold(skb->sk);
75}
76
77static u32 flow_get_dst(const struct sk_buff *skb, const struct flow_keys *flow)
78{
79 __be32 dst = flow_get_u32_dst(flow);
80
81 if (dst)
82 return ntohl(dst);
83
84 return addr_fold(skb_dst(skb)) ^ (__force u16)skb_protocol(skb, true);
85}
86
87static u32 flow_get_proto(const struct sk_buff *skb,
88 const struct flow_keys *flow)
89{
90 return flow->basic.ip_proto;
91}
92
93static u32 flow_get_proto_src(const struct sk_buff *skb,
94 const struct flow_keys *flow)
95{
96 if (flow->ports.ports)
97 return ntohs(flow->ports.src);
98
99 return addr_fold(skb->sk);
100}
101
102static u32 flow_get_proto_dst(const struct sk_buff *skb,
103 const struct flow_keys *flow)
104{
105 if (flow->ports.ports)
106 return ntohs(flow->ports.dst);
107
108 return addr_fold(skb_dst(skb)) ^ (__force u16)skb_protocol(skb, true);
109}
110
111static u32 flow_get_iif(const struct sk_buff *skb)
112{
113 return skb->skb_iif;
114}
115
116static u32 flow_get_priority(const struct sk_buff *skb)
117{
118 return skb->priority;
119}
120
121static u32 flow_get_mark(const struct sk_buff *skb)
122{
123 return skb->mark;
124}
125
126static u32 flow_get_nfct(const struct sk_buff *skb)
127{
128#if IS_ENABLED(CONFIG_NF_CONNTRACK)
129 return addr_fold(skb_nfct(skb));
130#else
131 return 0;
132#endif
133}
134
135#if IS_ENABLED(CONFIG_NF_CONNTRACK)
136#define CTTUPLE(skb, member) \
137({ \
138 enum ip_conntrack_info ctinfo; \
139 const struct nf_conn *ct = nf_ct_get(skb, &ctinfo); \
140 if (ct == NULL) \
141 goto fallback; \
142 ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member; \
143})
144#else
145#define CTTUPLE(skb, member) \
146({ \
147 goto fallback; \
148 0; \
149})
150#endif
151
152static u32 flow_get_nfct_src(const struct sk_buff *skb,
153 const struct flow_keys *flow)
154{
155 switch (skb_protocol(skb, true)) {
156 case htons(ETH_P_IP):
157 return ntohl(CTTUPLE(skb, src.u3.ip));
158 case htons(ETH_P_IPV6):
159 return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
160 }
161fallback:
162 return flow_get_src(skb, flow);
163}
164
165static u32 flow_get_nfct_dst(const struct sk_buff *skb,
166 const struct flow_keys *flow)
167{
168 switch (skb_protocol(skb, true)) {
169 case htons(ETH_P_IP):
170 return ntohl(CTTUPLE(skb, dst.u3.ip));
171 case htons(ETH_P_IPV6):
172 return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
173 }
174fallback:
175 return flow_get_dst(skb, flow);
176}
177
178static u32 flow_get_nfct_proto_src(const struct sk_buff *skb,
179 const struct flow_keys *flow)
180{
181 return ntohs(CTTUPLE(skb, src.u.all));
182fallback:
183 return flow_get_proto_src(skb, flow);
184}
185
186static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb,
187 const struct flow_keys *flow)
188{
189 return ntohs(CTTUPLE(skb, dst.u.all));
190fallback:
191 return flow_get_proto_dst(skb, flow);
192}
193
194static u32 flow_get_rtclassid(const struct sk_buff *skb)
195{
196#ifdef CONFIG_IP_ROUTE_CLASSID
197 if (skb_dst(skb))
198 return skb_dst(skb)->tclassid;
199#endif
200 return 0;
201}
202
203static u32 flow_get_skuid(const struct sk_buff *skb)
204{
205 struct sock *sk = skb_to_full_sk(skb);
206
207 if (sk && sk->sk_socket && sk->sk_socket->file) {
208 kuid_t skuid = sk->sk_socket->file->f_cred->fsuid;
209
210 return from_kuid(&init_user_ns, skuid);
211 }
212 return 0;
213}
214
215static u32 flow_get_skgid(const struct sk_buff *skb)
216{
217 struct sock *sk = skb_to_full_sk(skb);
218
219 if (sk && sk->sk_socket && sk->sk_socket->file) {
220 kgid_t skgid = sk->sk_socket->file->f_cred->fsgid;
221
222 return from_kgid(&init_user_ns, skgid);
223 }
224 return 0;
225}
226
227static u32 flow_get_vlan_tag(const struct sk_buff *skb)
228{
229 u16 tag;
230
231 if (vlan_get_tag(skb, &tag) < 0)
232 return 0;
233 return tag & VLAN_VID_MASK;
234}
235
236static u32 flow_get_rxhash(struct sk_buff *skb)
237{
238 return skb_get_hash(skb);
239}
240
241static u32 flow_key_get(struct sk_buff *skb, int key, struct flow_keys *flow)
242{
243 switch (key) {
244 case FLOW_KEY_SRC:
245 return flow_get_src(skb, flow);
246 case FLOW_KEY_DST:
247 return flow_get_dst(skb, flow);
248 case FLOW_KEY_PROTO:
249 return flow_get_proto(skb, flow);
250 case FLOW_KEY_PROTO_SRC:
251 return flow_get_proto_src(skb, flow);
252 case FLOW_KEY_PROTO_DST:
253 return flow_get_proto_dst(skb, flow);
254 case FLOW_KEY_IIF:
255 return flow_get_iif(skb);
256 case FLOW_KEY_PRIORITY:
257 return flow_get_priority(skb);
258 case FLOW_KEY_MARK:
259 return flow_get_mark(skb);
260 case FLOW_KEY_NFCT:
261 return flow_get_nfct(skb);
262 case FLOW_KEY_NFCT_SRC:
263 return flow_get_nfct_src(skb, flow);
264 case FLOW_KEY_NFCT_DST:
265 return flow_get_nfct_dst(skb, flow);
266 case FLOW_KEY_NFCT_PROTO_SRC:
267 return flow_get_nfct_proto_src(skb, flow);
268 case FLOW_KEY_NFCT_PROTO_DST:
269 return flow_get_nfct_proto_dst(skb, flow);
270 case FLOW_KEY_RTCLASSID:
271 return flow_get_rtclassid(skb);
272 case FLOW_KEY_SKUID:
273 return flow_get_skuid(skb);
274 case FLOW_KEY_SKGID:
275 return flow_get_skgid(skb);
276 case FLOW_KEY_VLAN_TAG:
277 return flow_get_vlan_tag(skb);
278 case FLOW_KEY_RXHASH:
279 return flow_get_rxhash(skb);
280 default:
281 WARN_ON(1);
282 return 0;
283 }
284}
285
286#define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) | \
287 (1 << FLOW_KEY_DST) | \
288 (1 << FLOW_KEY_PROTO) | \
289 (1 << FLOW_KEY_PROTO_SRC) | \
290 (1 << FLOW_KEY_PROTO_DST) | \
291 (1 << FLOW_KEY_NFCT_SRC) | \
292 (1 << FLOW_KEY_NFCT_DST) | \
293 (1 << FLOW_KEY_NFCT_PROTO_SRC) | \
294 (1 << FLOW_KEY_NFCT_PROTO_DST))
295
296TC_INDIRECT_SCOPE int flow_classify(struct sk_buff *skb,
297 const struct tcf_proto *tp,
298 struct tcf_result *res)
299{
300 struct flow_head *head = rcu_dereference_bh(tp->root);
301 struct flow_filter *f;
302 u32 keymask;
303 u32 classid;
304 unsigned int n, key;
305 int r;
306
307 list_for_each_entry_rcu(f, &head->filters, list) {
308 u32 keys[FLOW_KEY_MAX + 1];
309 struct flow_keys flow_keys;
310
311 if (!tcf_em_tree_match(skb, &f->ematches, NULL))
312 continue;
313
314 keymask = f->keymask;
315 if (keymask & FLOW_KEYS_NEEDED)
316 skb_flow_dissect_flow_keys(skb, &flow_keys, 0);
317
318 for (n = 0; n < f->nkeys; n++) {
319 key = ffs(keymask) - 1;
320 keymask &= ~(1 << key);
321 keys[n] = flow_key_get(skb, key, &flow_keys);
322 }
323
324 if (f->mode == FLOW_MODE_HASH)
325 classid = jhash2(keys, f->nkeys, f->hashrnd);
326 else {
327 classid = keys[0];
328 classid = (classid & f->mask) ^ f->xor;
329 classid = (classid >> f->rshift) + f->addend;
330 }
331
332 if (f->divisor)
333 classid %= f->divisor;
334
335 res->class = 0;
336 res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
337
338 r = tcf_exts_exec(skb, &f->exts, res);
339 if (r < 0)
340 continue;
341 return r;
342 }
343 return -1;
344}
345
346static void flow_perturbation(struct timer_list *t)
347{
348 struct flow_filter *f = from_timer(f, t, perturb_timer);
349
350 get_random_bytes(&f->hashrnd, 4);
351 if (f->perturb_period)
352 mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
353}
354
355static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
356 [TCA_FLOW_KEYS] = { .type = NLA_U32 },
357 [TCA_FLOW_MODE] = { .type = NLA_U32 },
358 [TCA_FLOW_BASECLASS] = { .type = NLA_U32 },
359 [TCA_FLOW_RSHIFT] = NLA_POLICY_MAX(NLA_U32,
360 31 /* BITS_PER_U32 - 1 */),
361 [TCA_FLOW_ADDEND] = { .type = NLA_U32 },
362 [TCA_FLOW_MASK] = { .type = NLA_U32 },
363 [TCA_FLOW_XOR] = { .type = NLA_U32 },
364 [TCA_FLOW_DIVISOR] = { .type = NLA_U32 },
365 [TCA_FLOW_ACT] = { .type = NLA_NESTED },
366 [TCA_FLOW_POLICE] = { .type = NLA_NESTED },
367 [TCA_FLOW_EMATCHES] = { .type = NLA_NESTED },
368 [TCA_FLOW_PERTURB] = { .type = NLA_U32 },
369};
370
371static void __flow_destroy_filter(struct flow_filter *f)
372{
373 timer_shutdown_sync(&f->perturb_timer);
374 tcf_exts_destroy(&f->exts);
375 tcf_em_tree_destroy(&f->ematches);
376 tcf_exts_put_net(&f->exts);
377 kfree(f);
378}
379
380static void flow_destroy_filter_work(struct work_struct *work)
381{
382 struct flow_filter *f = container_of(to_rcu_work(work),
383 struct flow_filter,
384 rwork);
385 rtnl_lock();
386 __flow_destroy_filter(f);
387 rtnl_unlock();
388}
389
390static int flow_change(struct net *net, struct sk_buff *in_skb,
391 struct tcf_proto *tp, unsigned long base,
392 u32 handle, struct nlattr **tca,
393 void **arg, u32 flags,
394 struct netlink_ext_ack *extack)
395{
396 struct flow_head *head = rtnl_dereference(tp->root);
397 struct flow_filter *fold, *fnew;
398 struct nlattr *opt = tca[TCA_OPTIONS];
399 struct nlattr *tb[TCA_FLOW_MAX + 1];
400 unsigned int nkeys = 0;
401 unsigned int perturb_period = 0;
402 u32 baseclass = 0;
403 u32 keymask = 0;
404 u32 mode;
405 int err;
406
407 if (opt == NULL)
408 return -EINVAL;
409
410 err = nla_parse_nested_deprecated(tb, TCA_FLOW_MAX, opt, flow_policy,
411 NULL);
412 if (err < 0)
413 return err;
414
415 if (tb[TCA_FLOW_BASECLASS]) {
416 baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
417 if (TC_H_MIN(baseclass) == 0)
418 return -EINVAL;
419 }
420
421 if (tb[TCA_FLOW_KEYS]) {
422 keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
423
424 nkeys = hweight32(keymask);
425 if (nkeys == 0)
426 return -EINVAL;
427
428 if (fls(keymask) - 1 > FLOW_KEY_MAX)
429 return -EOPNOTSUPP;
430
431 if ((keymask & (FLOW_KEY_SKUID|FLOW_KEY_SKGID)) &&
432 sk_user_ns(NETLINK_CB(in_skb).sk) != &init_user_ns)
433 return -EOPNOTSUPP;
434 }
435
436 fnew = kzalloc(sizeof(*fnew), GFP_KERNEL);
437 if (!fnew)
438 return -ENOBUFS;
439
440 err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &fnew->ematches);
441 if (err < 0)
442 goto err1;
443
444 err = tcf_exts_init(&fnew->exts, net, TCA_FLOW_ACT, TCA_FLOW_POLICE);
445 if (err < 0)
446 goto err2;
447
448 err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &fnew->exts, flags,
449 extack);
450 if (err < 0)
451 goto err2;
452
453 fold = *arg;
454 if (fold) {
455 err = -EINVAL;
456 if (fold->handle != handle && handle)
457 goto err2;
458
459 /* Copy fold into fnew */
460 fnew->tp = fold->tp;
461 fnew->handle = fold->handle;
462 fnew->nkeys = fold->nkeys;
463 fnew->keymask = fold->keymask;
464 fnew->mode = fold->mode;
465 fnew->mask = fold->mask;
466 fnew->xor = fold->xor;
467 fnew->rshift = fold->rshift;
468 fnew->addend = fold->addend;
469 fnew->divisor = fold->divisor;
470 fnew->baseclass = fold->baseclass;
471 fnew->hashrnd = fold->hashrnd;
472
473 mode = fold->mode;
474 if (tb[TCA_FLOW_MODE])
475 mode = nla_get_u32(tb[TCA_FLOW_MODE]);
476 if (mode != FLOW_MODE_HASH && nkeys > 1)
477 goto err2;
478
479 if (mode == FLOW_MODE_HASH)
480 perturb_period = fold->perturb_period;
481 if (tb[TCA_FLOW_PERTURB]) {
482 if (mode != FLOW_MODE_HASH)
483 goto err2;
484 perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
485 }
486 } else {
487 err = -EINVAL;
488 if (!handle)
489 goto err2;
490 if (!tb[TCA_FLOW_KEYS])
491 goto err2;
492
493 mode = FLOW_MODE_MAP;
494 if (tb[TCA_FLOW_MODE])
495 mode = nla_get_u32(tb[TCA_FLOW_MODE]);
496 if (mode != FLOW_MODE_HASH && nkeys > 1)
497 goto err2;
498
499 if (tb[TCA_FLOW_PERTURB]) {
500 if (mode != FLOW_MODE_HASH)
501 goto err2;
502 perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
503 }
504
505 if (TC_H_MAJ(baseclass) == 0) {
506 struct Qdisc *q = tcf_block_q(tp->chain->block);
507
508 baseclass = TC_H_MAKE(q->handle, baseclass);
509 }
510 if (TC_H_MIN(baseclass) == 0)
511 baseclass = TC_H_MAKE(baseclass, 1);
512
513 fnew->handle = handle;
514 fnew->mask = ~0U;
515 fnew->tp = tp;
516 get_random_bytes(&fnew->hashrnd, 4);
517 }
518
519 timer_setup(&fnew->perturb_timer, flow_perturbation, TIMER_DEFERRABLE);
520
521 tcf_block_netif_keep_dst(tp->chain->block);
522
523 if (tb[TCA_FLOW_KEYS]) {
524 fnew->keymask = keymask;
525 fnew->nkeys = nkeys;
526 }
527
528 fnew->mode = mode;
529
530 if (tb[TCA_FLOW_MASK])
531 fnew->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
532 if (tb[TCA_FLOW_XOR])
533 fnew->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
534 if (tb[TCA_FLOW_RSHIFT])
535 fnew->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
536 if (tb[TCA_FLOW_ADDEND])
537 fnew->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
538
539 if (tb[TCA_FLOW_DIVISOR])
540 fnew->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
541 if (baseclass)
542 fnew->baseclass = baseclass;
543
544 fnew->perturb_period = perturb_period;
545 if (perturb_period)
546 mod_timer(&fnew->perturb_timer, jiffies + perturb_period);
547
548 if (!*arg)
549 list_add_tail_rcu(&fnew->list, &head->filters);
550 else
551 list_replace_rcu(&fold->list, &fnew->list);
552
553 *arg = fnew;
554
555 if (fold) {
556 tcf_exts_get_net(&fold->exts);
557 tcf_queue_work(&fold->rwork, flow_destroy_filter_work);
558 }
559 return 0;
560
561err2:
562 tcf_exts_destroy(&fnew->exts);
563 tcf_em_tree_destroy(&fnew->ematches);
564err1:
565 kfree(fnew);
566 return err;
567}
568
569static int flow_delete(struct tcf_proto *tp, void *arg, bool *last,
570 bool rtnl_held, struct netlink_ext_ack *extack)
571{
572 struct flow_head *head = rtnl_dereference(tp->root);
573 struct flow_filter *f = arg;
574
575 list_del_rcu(&f->list);
576 tcf_exts_get_net(&f->exts);
577 tcf_queue_work(&f->rwork, flow_destroy_filter_work);
578 *last = list_empty(&head->filters);
579 return 0;
580}
581
582static int flow_init(struct tcf_proto *tp)
583{
584 struct flow_head *head;
585
586 head = kzalloc(sizeof(*head), GFP_KERNEL);
587 if (head == NULL)
588 return -ENOBUFS;
589 INIT_LIST_HEAD(&head->filters);
590 rcu_assign_pointer(tp->root, head);
591 return 0;
592}
593
594static void flow_destroy(struct tcf_proto *tp, bool rtnl_held,
595 struct netlink_ext_ack *extack)
596{
597 struct flow_head *head = rtnl_dereference(tp->root);
598 struct flow_filter *f, *next;
599
600 list_for_each_entry_safe(f, next, &head->filters, list) {
601 list_del_rcu(&f->list);
602 if (tcf_exts_get_net(&f->exts))
603 tcf_queue_work(&f->rwork, flow_destroy_filter_work);
604 else
605 __flow_destroy_filter(f);
606 }
607 kfree_rcu(head, rcu);
608}
609
610static void *flow_get(struct tcf_proto *tp, u32 handle)
611{
612 struct flow_head *head = rtnl_dereference(tp->root);
613 struct flow_filter *f;
614
615 list_for_each_entry(f, &head->filters, list)
616 if (f->handle == handle)
617 return f;
618 return NULL;
619}
620
621static int flow_dump(struct net *net, struct tcf_proto *tp, void *fh,
622 struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
623{
624 struct flow_filter *f = fh;
625 struct nlattr *nest;
626
627 if (f == NULL)
628 return skb->len;
629
630 t->tcm_handle = f->handle;
631
632 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
633 if (nest == NULL)
634 goto nla_put_failure;
635
636 if (nla_put_u32(skb, TCA_FLOW_KEYS, f->keymask) ||
637 nla_put_u32(skb, TCA_FLOW_MODE, f->mode))
638 goto nla_put_failure;
639
640 if (f->mask != ~0 || f->xor != 0) {
641 if (nla_put_u32(skb, TCA_FLOW_MASK, f->mask) ||
642 nla_put_u32(skb, TCA_FLOW_XOR, f->xor))
643 goto nla_put_failure;
644 }
645 if (f->rshift &&
646 nla_put_u32(skb, TCA_FLOW_RSHIFT, f->rshift))
647 goto nla_put_failure;
648 if (f->addend &&
649 nla_put_u32(skb, TCA_FLOW_ADDEND, f->addend))
650 goto nla_put_failure;
651
652 if (f->divisor &&
653 nla_put_u32(skb, TCA_FLOW_DIVISOR, f->divisor))
654 goto nla_put_failure;
655 if (f->baseclass &&
656 nla_put_u32(skb, TCA_FLOW_BASECLASS, f->baseclass))
657 goto nla_put_failure;
658
659 if (f->perturb_period &&
660 nla_put_u32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ))
661 goto nla_put_failure;
662
663 if (tcf_exts_dump(skb, &f->exts) < 0)
664 goto nla_put_failure;
665#ifdef CONFIG_NET_EMATCH
666 if (f->ematches.hdr.nmatches &&
667 tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
668 goto nla_put_failure;
669#endif
670 nla_nest_end(skb, nest);
671
672 if (tcf_exts_dump_stats(skb, &f->exts) < 0)
673 goto nla_put_failure;
674
675 return skb->len;
676
677nla_put_failure:
678 nla_nest_cancel(skb, nest);
679 return -1;
680}
681
682static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg,
683 bool rtnl_held)
684{
685 struct flow_head *head = rtnl_dereference(tp->root);
686 struct flow_filter *f;
687
688 list_for_each_entry(f, &head->filters, list) {
689 if (!tc_cls_stats_dump(tp, arg, f))
690 break;
691 }
692}
693
694static struct tcf_proto_ops cls_flow_ops __read_mostly = {
695 .kind = "flow",
696 .classify = flow_classify,
697 .init = flow_init,
698 .destroy = flow_destroy,
699 .change = flow_change,
700 .delete = flow_delete,
701 .get = flow_get,
702 .dump = flow_dump,
703 .walk = flow_walk,
704 .owner = THIS_MODULE,
705};
706MODULE_ALIAS_NET_CLS("flow");
707
708static int __init cls_flow_init(void)
709{
710 return register_tcf_proto_ops(&cls_flow_ops);
711}
712
713static void __exit cls_flow_exit(void)
714{
715 unregister_tcf_proto_ops(&cls_flow_ops);
716}
717
718module_init(cls_flow_init);
719module_exit(cls_flow_exit);
720
721MODULE_LICENSE("GPL");
722MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
723MODULE_DESCRIPTION("TC flow classifier");
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
35struct flow_head {
36 struct list_head filters;
37};
38
39struct 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
59static const struct tcf_ext_map flow_ext_map = {
60 .action = TCA_FLOW_ACT,
61 .police = TCA_FLOW_POLICE,
62};
63
64static 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
71static 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
78static 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
85static u32 flow_get_proto(const struct sk_buff *skb, const struct flow_keys *flow)
86{
87 return flow->ip_proto;
88}
89
90static 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
98static 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
106static u32 flow_get_iif(const struct sk_buff *skb)
107{
108 return skb->skb_iif;
109}
110
111static u32 flow_get_priority(const struct sk_buff *skb)
112{
113 return skb->priority;
114}
115
116static u32 flow_get_mark(const struct sk_buff *skb)
117{
118 return skb->mark;
119}
120
121static 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
147static 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 }
155fallback:
156 return flow_get_src(skb, flow);
157}
158
159static 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 }
167fallback:
168 return flow_get_dst(skb, flow);
169}
170
171static 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));
174fallback:
175 return flow_get_proto_src(skb, flow);
176}
177
178static 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));
181fallback:
182 return flow_get_proto_dst(skb, flow);
183}
184
185static 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
194static u32 flow_get_skuid(const struct sk_buff *skb)
195{
196 if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
197 return skb->sk->sk_socket->file->f_cred->fsuid;
198 return 0;
199}
200
201static u32 flow_get_skgid(const struct sk_buff *skb)
202{
203 if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
204 return skb->sk->sk_socket->file->f_cred->fsgid;
205 return 0;
206}
207
208static u32 flow_get_vlan_tag(const struct sk_buff *skb)
209{
210 u16 uninitialized_var(tag);
211
212 if (vlan_get_tag(skb, &tag) < 0)
213 return 0;
214 return tag & VLAN_VID_MASK;
215}
216
217static u32 flow_get_rxhash(struct sk_buff *skb)
218{
219 return skb_get_rxhash(skb);
220}
221
222static u32 flow_key_get(struct sk_buff *skb, int key, struct flow_keys *flow)
223{
224 switch (key) {
225 case FLOW_KEY_SRC:
226 return flow_get_src(skb, flow);
227 case FLOW_KEY_DST:
228 return flow_get_dst(skb, flow);
229 case FLOW_KEY_PROTO:
230 return flow_get_proto(skb, flow);
231 case FLOW_KEY_PROTO_SRC:
232 return flow_get_proto_src(skb, flow);
233 case FLOW_KEY_PROTO_DST:
234 return flow_get_proto_dst(skb, flow);
235 case FLOW_KEY_IIF:
236 return flow_get_iif(skb);
237 case FLOW_KEY_PRIORITY:
238 return flow_get_priority(skb);
239 case FLOW_KEY_MARK:
240 return flow_get_mark(skb);
241 case FLOW_KEY_NFCT:
242 return flow_get_nfct(skb);
243 case FLOW_KEY_NFCT_SRC:
244 return flow_get_nfct_src(skb, flow);
245 case FLOW_KEY_NFCT_DST:
246 return flow_get_nfct_dst(skb, flow);
247 case FLOW_KEY_NFCT_PROTO_SRC:
248 return flow_get_nfct_proto_src(skb, flow);
249 case FLOW_KEY_NFCT_PROTO_DST:
250 return flow_get_nfct_proto_dst(skb, flow);
251 case FLOW_KEY_RTCLASSID:
252 return flow_get_rtclassid(skb);
253 case FLOW_KEY_SKUID:
254 return flow_get_skuid(skb);
255 case FLOW_KEY_SKGID:
256 return flow_get_skgid(skb);
257 case FLOW_KEY_VLAN_TAG:
258 return flow_get_vlan_tag(skb);
259 case FLOW_KEY_RXHASH:
260 return flow_get_rxhash(skb);
261 default:
262 WARN_ON(1);
263 return 0;
264 }
265}
266
267#define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) | \
268 (1 << FLOW_KEY_DST) | \
269 (1 << FLOW_KEY_PROTO) | \
270 (1 << FLOW_KEY_PROTO_SRC) | \
271 (1 << FLOW_KEY_PROTO_DST) | \
272 (1 << FLOW_KEY_NFCT_SRC) | \
273 (1 << FLOW_KEY_NFCT_DST) | \
274 (1 << FLOW_KEY_NFCT_PROTO_SRC) | \
275 (1 << FLOW_KEY_NFCT_PROTO_DST))
276
277static int flow_classify(struct sk_buff *skb, const struct tcf_proto *tp,
278 struct tcf_result *res)
279{
280 struct flow_head *head = tp->root;
281 struct flow_filter *f;
282 u32 keymask;
283 u32 classid;
284 unsigned int n, key;
285 int r;
286
287 list_for_each_entry(f, &head->filters, list) {
288 u32 keys[FLOW_KEY_MAX + 1];
289 struct flow_keys flow_keys;
290
291 if (!tcf_em_tree_match(skb, &f->ematches, NULL))
292 continue;
293
294 keymask = f->keymask;
295 if (keymask & FLOW_KEYS_NEEDED)
296 skb_flow_dissect(skb, &flow_keys);
297
298 for (n = 0; n < f->nkeys; n++) {
299 key = ffs(keymask) - 1;
300 keymask &= ~(1 << key);
301 keys[n] = flow_key_get(skb, key, &flow_keys);
302 }
303
304 if (f->mode == FLOW_MODE_HASH)
305 classid = jhash2(keys, f->nkeys, f->hashrnd);
306 else {
307 classid = keys[0];
308 classid = (classid & f->mask) ^ f->xor;
309 classid = (classid >> f->rshift) + f->addend;
310 }
311
312 if (f->divisor)
313 classid %= f->divisor;
314
315 res->class = 0;
316 res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
317
318 r = tcf_exts_exec(skb, &f->exts, res);
319 if (r < 0)
320 continue;
321 return r;
322 }
323 return -1;
324}
325
326static void flow_perturbation(unsigned long arg)
327{
328 struct flow_filter *f = (struct flow_filter *)arg;
329
330 get_random_bytes(&f->hashrnd, 4);
331 if (f->perturb_period)
332 mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
333}
334
335static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
336 [TCA_FLOW_KEYS] = { .type = NLA_U32 },
337 [TCA_FLOW_MODE] = { .type = NLA_U32 },
338 [TCA_FLOW_BASECLASS] = { .type = NLA_U32 },
339 [TCA_FLOW_RSHIFT] = { .type = NLA_U32 },
340 [TCA_FLOW_ADDEND] = { .type = NLA_U32 },
341 [TCA_FLOW_MASK] = { .type = NLA_U32 },
342 [TCA_FLOW_XOR] = { .type = NLA_U32 },
343 [TCA_FLOW_DIVISOR] = { .type = NLA_U32 },
344 [TCA_FLOW_ACT] = { .type = NLA_NESTED },
345 [TCA_FLOW_POLICE] = { .type = NLA_NESTED },
346 [TCA_FLOW_EMATCHES] = { .type = NLA_NESTED },
347 [TCA_FLOW_PERTURB] = { .type = NLA_U32 },
348};
349
350static int flow_change(struct tcf_proto *tp, unsigned long base,
351 u32 handle, struct nlattr **tca,
352 unsigned long *arg)
353{
354 struct flow_head *head = tp->root;
355 struct flow_filter *f;
356 struct nlattr *opt = tca[TCA_OPTIONS];
357 struct nlattr *tb[TCA_FLOW_MAX + 1];
358 struct tcf_exts e;
359 struct tcf_ematch_tree t;
360 unsigned int nkeys = 0;
361 unsigned int perturb_period = 0;
362 u32 baseclass = 0;
363 u32 keymask = 0;
364 u32 mode;
365 int err;
366
367 if (opt == NULL)
368 return -EINVAL;
369
370 err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy);
371 if (err < 0)
372 return err;
373
374 if (tb[TCA_FLOW_BASECLASS]) {
375 baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
376 if (TC_H_MIN(baseclass) == 0)
377 return -EINVAL;
378 }
379
380 if (tb[TCA_FLOW_KEYS]) {
381 keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
382
383 nkeys = hweight32(keymask);
384 if (nkeys == 0)
385 return -EINVAL;
386
387 if (fls(keymask) - 1 > FLOW_KEY_MAX)
388 return -EOPNOTSUPP;
389 }
390
391 err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &flow_ext_map);
392 if (err < 0)
393 return err;
394
395 err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &t);
396 if (err < 0)
397 goto err1;
398
399 f = (struct flow_filter *)*arg;
400 if (f != NULL) {
401 err = -EINVAL;
402 if (f->handle != handle && handle)
403 goto err2;
404
405 mode = f->mode;
406 if (tb[TCA_FLOW_MODE])
407 mode = nla_get_u32(tb[TCA_FLOW_MODE]);
408 if (mode != FLOW_MODE_HASH && nkeys > 1)
409 goto err2;
410
411 if (mode == FLOW_MODE_HASH)
412 perturb_period = f->perturb_period;
413 if (tb[TCA_FLOW_PERTURB]) {
414 if (mode != FLOW_MODE_HASH)
415 goto err2;
416 perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
417 }
418 } else {
419 err = -EINVAL;
420 if (!handle)
421 goto err2;
422 if (!tb[TCA_FLOW_KEYS])
423 goto err2;
424
425 mode = FLOW_MODE_MAP;
426 if (tb[TCA_FLOW_MODE])
427 mode = nla_get_u32(tb[TCA_FLOW_MODE]);
428 if (mode != FLOW_MODE_HASH && nkeys > 1)
429 goto err2;
430
431 if (tb[TCA_FLOW_PERTURB]) {
432 if (mode != FLOW_MODE_HASH)
433 goto err2;
434 perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
435 }
436
437 if (TC_H_MAJ(baseclass) == 0)
438 baseclass = TC_H_MAKE(tp->q->handle, baseclass);
439 if (TC_H_MIN(baseclass) == 0)
440 baseclass = TC_H_MAKE(baseclass, 1);
441
442 err = -ENOBUFS;
443 f = kzalloc(sizeof(*f), GFP_KERNEL);
444 if (f == NULL)
445 goto err2;
446
447 f->handle = handle;
448 f->mask = ~0U;
449
450 get_random_bytes(&f->hashrnd, 4);
451 f->perturb_timer.function = flow_perturbation;
452 f->perturb_timer.data = (unsigned long)f;
453 init_timer_deferrable(&f->perturb_timer);
454 }
455
456 tcf_exts_change(tp, &f->exts, &e);
457 tcf_em_tree_change(tp, &f->ematches, &t);
458
459 tcf_tree_lock(tp);
460
461 if (tb[TCA_FLOW_KEYS]) {
462 f->keymask = keymask;
463 f->nkeys = nkeys;
464 }
465
466 f->mode = mode;
467
468 if (tb[TCA_FLOW_MASK])
469 f->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
470 if (tb[TCA_FLOW_XOR])
471 f->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
472 if (tb[TCA_FLOW_RSHIFT])
473 f->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
474 if (tb[TCA_FLOW_ADDEND])
475 f->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
476
477 if (tb[TCA_FLOW_DIVISOR])
478 f->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
479 if (baseclass)
480 f->baseclass = baseclass;
481
482 f->perturb_period = perturb_period;
483 del_timer(&f->perturb_timer);
484 if (perturb_period)
485 mod_timer(&f->perturb_timer, jiffies + perturb_period);
486
487 if (*arg == 0)
488 list_add_tail(&f->list, &head->filters);
489
490 tcf_tree_unlock(tp);
491
492 *arg = (unsigned long)f;
493 return 0;
494
495err2:
496 tcf_em_tree_destroy(tp, &t);
497err1:
498 tcf_exts_destroy(tp, &e);
499 return err;
500}
501
502static void flow_destroy_filter(struct tcf_proto *tp, struct flow_filter *f)
503{
504 del_timer_sync(&f->perturb_timer);
505 tcf_exts_destroy(tp, &f->exts);
506 tcf_em_tree_destroy(tp, &f->ematches);
507 kfree(f);
508}
509
510static int flow_delete(struct tcf_proto *tp, unsigned long arg)
511{
512 struct flow_filter *f = (struct flow_filter *)arg;
513
514 tcf_tree_lock(tp);
515 list_del(&f->list);
516 tcf_tree_unlock(tp);
517 flow_destroy_filter(tp, f);
518 return 0;
519}
520
521static int flow_init(struct tcf_proto *tp)
522{
523 struct flow_head *head;
524
525 head = kzalloc(sizeof(*head), GFP_KERNEL);
526 if (head == NULL)
527 return -ENOBUFS;
528 INIT_LIST_HEAD(&head->filters);
529 tp->root = head;
530 return 0;
531}
532
533static void flow_destroy(struct tcf_proto *tp)
534{
535 struct flow_head *head = tp->root;
536 struct flow_filter *f, *next;
537
538 list_for_each_entry_safe(f, next, &head->filters, list) {
539 list_del(&f->list);
540 flow_destroy_filter(tp, f);
541 }
542 kfree(head);
543}
544
545static unsigned long flow_get(struct tcf_proto *tp, u32 handle)
546{
547 struct flow_head *head = tp->root;
548 struct flow_filter *f;
549
550 list_for_each_entry(f, &head->filters, list)
551 if (f->handle == handle)
552 return (unsigned long)f;
553 return 0;
554}
555
556static void flow_put(struct tcf_proto *tp, unsigned long f)
557{
558}
559
560static int flow_dump(struct tcf_proto *tp, unsigned long fh,
561 struct sk_buff *skb, struct tcmsg *t)
562{
563 struct flow_filter *f = (struct flow_filter *)fh;
564 struct nlattr *nest;
565
566 if (f == NULL)
567 return skb->len;
568
569 t->tcm_handle = f->handle;
570
571 nest = nla_nest_start(skb, TCA_OPTIONS);
572 if (nest == NULL)
573 goto nla_put_failure;
574
575 if (nla_put_u32(skb, TCA_FLOW_KEYS, f->keymask) ||
576 nla_put_u32(skb, TCA_FLOW_MODE, f->mode))
577 goto nla_put_failure;
578
579 if (f->mask != ~0 || f->xor != 0) {
580 if (nla_put_u32(skb, TCA_FLOW_MASK, f->mask) ||
581 nla_put_u32(skb, TCA_FLOW_XOR, f->xor))
582 goto nla_put_failure;
583 }
584 if (f->rshift &&
585 nla_put_u32(skb, TCA_FLOW_RSHIFT, f->rshift))
586 goto nla_put_failure;
587 if (f->addend &&
588 nla_put_u32(skb, TCA_FLOW_ADDEND, f->addend))
589 goto nla_put_failure;
590
591 if (f->divisor &&
592 nla_put_u32(skb, TCA_FLOW_DIVISOR, f->divisor))
593 goto nla_put_failure;
594 if (f->baseclass &&
595 nla_put_u32(skb, TCA_FLOW_BASECLASS, f->baseclass))
596 goto nla_put_failure;
597
598 if (f->perturb_period &&
599 nla_put_u32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ))
600 goto nla_put_failure;
601
602 if (tcf_exts_dump(skb, &f->exts, &flow_ext_map) < 0)
603 goto nla_put_failure;
604#ifdef CONFIG_NET_EMATCH
605 if (f->ematches.hdr.nmatches &&
606 tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
607 goto nla_put_failure;
608#endif
609 nla_nest_end(skb, nest);
610
611 if (tcf_exts_dump_stats(skb, &f->exts, &flow_ext_map) < 0)
612 goto nla_put_failure;
613
614 return skb->len;
615
616nla_put_failure:
617 nlmsg_trim(skb, nest);
618 return -1;
619}
620
621static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
622{
623 struct flow_head *head = tp->root;
624 struct flow_filter *f;
625
626 list_for_each_entry(f, &head->filters, list) {
627 if (arg->count < arg->skip)
628 goto skip;
629 if (arg->fn(tp, (unsigned long)f, arg) < 0) {
630 arg->stop = 1;
631 break;
632 }
633skip:
634 arg->count++;
635 }
636}
637
638static struct tcf_proto_ops cls_flow_ops __read_mostly = {
639 .kind = "flow",
640 .classify = flow_classify,
641 .init = flow_init,
642 .destroy = flow_destroy,
643 .change = flow_change,
644 .delete = flow_delete,
645 .get = flow_get,
646 .put = flow_put,
647 .dump = flow_dump,
648 .walk = flow_walk,
649 .owner = THIS_MODULE,
650};
651
652static int __init cls_flow_init(void)
653{
654 return register_tcf_proto_ops(&cls_flow_ops);
655}
656
657static void __exit cls_flow_exit(void)
658{
659 unregister_tcf_proto_ops(&cls_flow_ops);
660}
661
662module_init(cls_flow_init);
663module_exit(cls_flow_exit);
664
665MODULE_LICENSE("GPL");
666MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
667MODULE_DESCRIPTION("TC flow classifier");