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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
25#include <net/pkt_cls.h>
26#include <net/ip.h>
27#include <net/route.h>
28#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
29#include <net/netfilter/nf_conntrack.h>
30#endif
31
32struct flow_head {
33 struct list_head filters;
34};
35
36struct flow_filter {
37 struct list_head list;
38 struct tcf_exts exts;
39 struct tcf_ematch_tree ematches;
40 struct timer_list perturb_timer;
41 u32 perturb_period;
42 u32 handle;
43
44 u32 nkeys;
45 u32 keymask;
46 u32 mode;
47 u32 mask;
48 u32 xor;
49 u32 rshift;
50 u32 addend;
51 u32 divisor;
52 u32 baseclass;
53 u32 hashrnd;
54};
55
56static const struct tcf_ext_map flow_ext_map = {
57 .action = TCA_FLOW_ACT,
58 .police = TCA_FLOW_POLICE,
59};
60
61static inline u32 addr_fold(void *addr)
62{
63 unsigned long a = (unsigned long)addr;
64
65 return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
66}
67
68static u32 flow_get_src(struct sk_buff *skb)
69{
70 switch (skb->protocol) {
71 case htons(ETH_P_IP):
72 if (pskb_network_may_pull(skb, sizeof(struct iphdr)))
73 return ntohl(ip_hdr(skb)->saddr);
74 break;
75 case htons(ETH_P_IPV6):
76 if (pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
77 return ntohl(ipv6_hdr(skb)->saddr.s6_addr32[3]);
78 break;
79 }
80
81 return addr_fold(skb->sk);
82}
83
84static u32 flow_get_dst(struct sk_buff *skb)
85{
86 switch (skb->protocol) {
87 case htons(ETH_P_IP):
88 if (pskb_network_may_pull(skb, sizeof(struct iphdr)))
89 return ntohl(ip_hdr(skb)->daddr);
90 break;
91 case htons(ETH_P_IPV6):
92 if (pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
93 return ntohl(ipv6_hdr(skb)->daddr.s6_addr32[3]);
94 break;
95 }
96
97 return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
98}
99
100static u32 flow_get_proto(struct sk_buff *skb)
101{
102 switch (skb->protocol) {
103 case htons(ETH_P_IP):
104 return pskb_network_may_pull(skb, sizeof(struct iphdr)) ?
105 ip_hdr(skb)->protocol : 0;
106 case htons(ETH_P_IPV6):
107 return pskb_network_may_pull(skb, sizeof(struct ipv6hdr)) ?
108 ipv6_hdr(skb)->nexthdr : 0;
109 default:
110 return 0;
111 }
112}
113
114static u32 flow_get_proto_src(struct sk_buff *skb)
115{
116 switch (skb->protocol) {
117 case htons(ETH_P_IP): {
118 struct iphdr *iph;
119 int poff;
120
121 if (!pskb_network_may_pull(skb, sizeof(*iph)))
122 break;
123 iph = ip_hdr(skb);
124 if (ip_is_fragment(iph))
125 break;
126 poff = proto_ports_offset(iph->protocol);
127 if (poff >= 0 &&
128 pskb_network_may_pull(skb, iph->ihl * 4 + 2 + poff)) {
129 iph = ip_hdr(skb);
130 return ntohs(*(__be16 *)((void *)iph + iph->ihl * 4 +
131 poff));
132 }
133 break;
134 }
135 case htons(ETH_P_IPV6): {
136 struct ipv6hdr *iph;
137 int poff;
138
139 if (!pskb_network_may_pull(skb, sizeof(*iph)))
140 break;
141 iph = ipv6_hdr(skb);
142 poff = proto_ports_offset(iph->nexthdr);
143 if (poff >= 0 &&
144 pskb_network_may_pull(skb, sizeof(*iph) + poff + 2)) {
145 iph = ipv6_hdr(skb);
146 return ntohs(*(__be16 *)((void *)iph + sizeof(*iph) +
147 poff));
148 }
149 break;
150 }
151 }
152
153 return addr_fold(skb->sk);
154}
155
156static u32 flow_get_proto_dst(struct sk_buff *skb)
157{
158 switch (skb->protocol) {
159 case htons(ETH_P_IP): {
160 struct iphdr *iph;
161 int poff;
162
163 if (!pskb_network_may_pull(skb, sizeof(*iph)))
164 break;
165 iph = ip_hdr(skb);
166 if (ip_is_fragment(iph))
167 break;
168 poff = proto_ports_offset(iph->protocol);
169 if (poff >= 0 &&
170 pskb_network_may_pull(skb, iph->ihl * 4 + 4 + poff)) {
171 iph = ip_hdr(skb);
172 return ntohs(*(__be16 *)((void *)iph + iph->ihl * 4 +
173 2 + poff));
174 }
175 break;
176 }
177 case htons(ETH_P_IPV6): {
178 struct ipv6hdr *iph;
179 int poff;
180
181 if (!pskb_network_may_pull(skb, sizeof(*iph)))
182 break;
183 iph = ipv6_hdr(skb);
184 poff = proto_ports_offset(iph->nexthdr);
185 if (poff >= 0 &&
186 pskb_network_may_pull(skb, sizeof(*iph) + poff + 4)) {
187 iph = ipv6_hdr(skb);
188 return ntohs(*(__be16 *)((void *)iph + sizeof(*iph) +
189 poff + 2));
190 }
191 break;
192 }
193 }
194
195 return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
196}
197
198static u32 flow_get_iif(const struct sk_buff *skb)
199{
200 return skb->skb_iif;
201}
202
203static u32 flow_get_priority(const struct sk_buff *skb)
204{
205 return skb->priority;
206}
207
208static u32 flow_get_mark(const struct sk_buff *skb)
209{
210 return skb->mark;
211}
212
213static u32 flow_get_nfct(const struct sk_buff *skb)
214{
215#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
216 return addr_fold(skb->nfct);
217#else
218 return 0;
219#endif
220}
221
222#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
223#define CTTUPLE(skb, member) \
224({ \
225 enum ip_conntrack_info ctinfo; \
226 struct nf_conn *ct = nf_ct_get(skb, &ctinfo); \
227 if (ct == NULL) \
228 goto fallback; \
229 ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member; \
230})
231#else
232#define CTTUPLE(skb, member) \
233({ \
234 goto fallback; \
235 0; \
236})
237#endif
238
239static u32 flow_get_nfct_src(struct sk_buff *skb)
240{
241 switch (skb->protocol) {
242 case htons(ETH_P_IP):
243 return ntohl(CTTUPLE(skb, src.u3.ip));
244 case htons(ETH_P_IPV6):
245 return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
246 }
247fallback:
248 return flow_get_src(skb);
249}
250
251static u32 flow_get_nfct_dst(struct sk_buff *skb)
252{
253 switch (skb->protocol) {
254 case htons(ETH_P_IP):
255 return ntohl(CTTUPLE(skb, dst.u3.ip));
256 case htons(ETH_P_IPV6):
257 return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
258 }
259fallback:
260 return flow_get_dst(skb);
261}
262
263static u32 flow_get_nfct_proto_src(struct sk_buff *skb)
264{
265 return ntohs(CTTUPLE(skb, src.u.all));
266fallback:
267 return flow_get_proto_src(skb);
268}
269
270static u32 flow_get_nfct_proto_dst(struct sk_buff *skb)
271{
272 return ntohs(CTTUPLE(skb, dst.u.all));
273fallback:
274 return flow_get_proto_dst(skb);
275}
276
277static u32 flow_get_rtclassid(const struct sk_buff *skb)
278{
279#ifdef CONFIG_IP_ROUTE_CLASSID
280 if (skb_dst(skb))
281 return skb_dst(skb)->tclassid;
282#endif
283 return 0;
284}
285
286static u32 flow_get_skuid(const struct sk_buff *skb)
287{
288 if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
289 return skb->sk->sk_socket->file->f_cred->fsuid;
290 return 0;
291}
292
293static u32 flow_get_skgid(const struct sk_buff *skb)
294{
295 if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
296 return skb->sk->sk_socket->file->f_cred->fsgid;
297 return 0;
298}
299
300static u32 flow_get_vlan_tag(const struct sk_buff *skb)
301{
302 u16 uninitialized_var(tag);
303
304 if (vlan_get_tag(skb, &tag) < 0)
305 return 0;
306 return tag & VLAN_VID_MASK;
307}
308
309static u32 flow_get_rxhash(struct sk_buff *skb)
310{
311 return skb_get_rxhash(skb);
312}
313
314static u32 flow_key_get(struct sk_buff *skb, int key)
315{
316 switch (key) {
317 case FLOW_KEY_SRC:
318 return flow_get_src(skb);
319 case FLOW_KEY_DST:
320 return flow_get_dst(skb);
321 case FLOW_KEY_PROTO:
322 return flow_get_proto(skb);
323 case FLOW_KEY_PROTO_SRC:
324 return flow_get_proto_src(skb);
325 case FLOW_KEY_PROTO_DST:
326 return flow_get_proto_dst(skb);
327 case FLOW_KEY_IIF:
328 return flow_get_iif(skb);
329 case FLOW_KEY_PRIORITY:
330 return flow_get_priority(skb);
331 case FLOW_KEY_MARK:
332 return flow_get_mark(skb);
333 case FLOW_KEY_NFCT:
334 return flow_get_nfct(skb);
335 case FLOW_KEY_NFCT_SRC:
336 return flow_get_nfct_src(skb);
337 case FLOW_KEY_NFCT_DST:
338 return flow_get_nfct_dst(skb);
339 case FLOW_KEY_NFCT_PROTO_SRC:
340 return flow_get_nfct_proto_src(skb);
341 case FLOW_KEY_NFCT_PROTO_DST:
342 return flow_get_nfct_proto_dst(skb);
343 case FLOW_KEY_RTCLASSID:
344 return flow_get_rtclassid(skb);
345 case FLOW_KEY_SKUID:
346 return flow_get_skuid(skb);
347 case FLOW_KEY_SKGID:
348 return flow_get_skgid(skb);
349 case FLOW_KEY_VLAN_TAG:
350 return flow_get_vlan_tag(skb);
351 case FLOW_KEY_RXHASH:
352 return flow_get_rxhash(skb);
353 default:
354 WARN_ON(1);
355 return 0;
356 }
357}
358
359static int flow_classify(struct sk_buff *skb, const struct tcf_proto *tp,
360 struct tcf_result *res)
361{
362 struct flow_head *head = tp->root;
363 struct flow_filter *f;
364 u32 keymask;
365 u32 classid;
366 unsigned int n, key;
367 int r;
368
369 list_for_each_entry(f, &head->filters, list) {
370 u32 keys[f->nkeys];
371
372 if (!tcf_em_tree_match(skb, &f->ematches, NULL))
373 continue;
374
375 keymask = f->keymask;
376
377 for (n = 0; n < f->nkeys; n++) {
378 key = ffs(keymask) - 1;
379 keymask &= ~(1 << key);
380 keys[n] = flow_key_get(skb, key);
381 }
382
383 if (f->mode == FLOW_MODE_HASH)
384 classid = jhash2(keys, f->nkeys, f->hashrnd);
385 else {
386 classid = keys[0];
387 classid = (classid & f->mask) ^ f->xor;
388 classid = (classid >> f->rshift) + f->addend;
389 }
390
391 if (f->divisor)
392 classid %= f->divisor;
393
394 res->class = 0;
395 res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
396
397 r = tcf_exts_exec(skb, &f->exts, res);
398 if (r < 0)
399 continue;
400 return r;
401 }
402 return -1;
403}
404
405static void flow_perturbation(unsigned long arg)
406{
407 struct flow_filter *f = (struct flow_filter *)arg;
408
409 get_random_bytes(&f->hashrnd, 4);
410 if (f->perturb_period)
411 mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
412}
413
414static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
415 [TCA_FLOW_KEYS] = { .type = NLA_U32 },
416 [TCA_FLOW_MODE] = { .type = NLA_U32 },
417 [TCA_FLOW_BASECLASS] = { .type = NLA_U32 },
418 [TCA_FLOW_RSHIFT] = { .type = NLA_U32 },
419 [TCA_FLOW_ADDEND] = { .type = NLA_U32 },
420 [TCA_FLOW_MASK] = { .type = NLA_U32 },
421 [TCA_FLOW_XOR] = { .type = NLA_U32 },
422 [TCA_FLOW_DIVISOR] = { .type = NLA_U32 },
423 [TCA_FLOW_ACT] = { .type = NLA_NESTED },
424 [TCA_FLOW_POLICE] = { .type = NLA_NESTED },
425 [TCA_FLOW_EMATCHES] = { .type = NLA_NESTED },
426 [TCA_FLOW_PERTURB] = { .type = NLA_U32 },
427};
428
429static int flow_change(struct tcf_proto *tp, unsigned long base,
430 u32 handle, struct nlattr **tca,
431 unsigned long *arg)
432{
433 struct flow_head *head = tp->root;
434 struct flow_filter *f;
435 struct nlattr *opt = tca[TCA_OPTIONS];
436 struct nlattr *tb[TCA_FLOW_MAX + 1];
437 struct tcf_exts e;
438 struct tcf_ematch_tree t;
439 unsigned int nkeys = 0;
440 unsigned int perturb_period = 0;
441 u32 baseclass = 0;
442 u32 keymask = 0;
443 u32 mode;
444 int err;
445
446 if (opt == NULL)
447 return -EINVAL;
448
449 err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy);
450 if (err < 0)
451 return err;
452
453 if (tb[TCA_FLOW_BASECLASS]) {
454 baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
455 if (TC_H_MIN(baseclass) == 0)
456 return -EINVAL;
457 }
458
459 if (tb[TCA_FLOW_KEYS]) {
460 keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
461
462 nkeys = hweight32(keymask);
463 if (nkeys == 0)
464 return -EINVAL;
465
466 if (fls(keymask) - 1 > FLOW_KEY_MAX)
467 return -EOPNOTSUPP;
468 }
469
470 err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &flow_ext_map);
471 if (err < 0)
472 return err;
473
474 err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &t);
475 if (err < 0)
476 goto err1;
477
478 f = (struct flow_filter *)*arg;
479 if (f != NULL) {
480 err = -EINVAL;
481 if (f->handle != handle && handle)
482 goto err2;
483
484 mode = f->mode;
485 if (tb[TCA_FLOW_MODE])
486 mode = nla_get_u32(tb[TCA_FLOW_MODE]);
487 if (mode != FLOW_MODE_HASH && nkeys > 1)
488 goto err2;
489
490 if (mode == FLOW_MODE_HASH)
491 perturb_period = f->perturb_period;
492 if (tb[TCA_FLOW_PERTURB]) {
493 if (mode != FLOW_MODE_HASH)
494 goto err2;
495 perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
496 }
497 } else {
498 err = -EINVAL;
499 if (!handle)
500 goto err2;
501 if (!tb[TCA_FLOW_KEYS])
502 goto err2;
503
504 mode = FLOW_MODE_MAP;
505 if (tb[TCA_FLOW_MODE])
506 mode = nla_get_u32(tb[TCA_FLOW_MODE]);
507 if (mode != FLOW_MODE_HASH && nkeys > 1)
508 goto err2;
509
510 if (tb[TCA_FLOW_PERTURB]) {
511 if (mode != FLOW_MODE_HASH)
512 goto err2;
513 perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
514 }
515
516 if (TC_H_MAJ(baseclass) == 0)
517 baseclass = TC_H_MAKE(tp->q->handle, baseclass);
518 if (TC_H_MIN(baseclass) == 0)
519 baseclass = TC_H_MAKE(baseclass, 1);
520
521 err = -ENOBUFS;
522 f = kzalloc(sizeof(*f), GFP_KERNEL);
523 if (f == NULL)
524 goto err2;
525
526 f->handle = handle;
527 f->mask = ~0U;
528
529 get_random_bytes(&f->hashrnd, 4);
530 f->perturb_timer.function = flow_perturbation;
531 f->perturb_timer.data = (unsigned long)f;
532 init_timer_deferrable(&f->perturb_timer);
533 }
534
535 tcf_exts_change(tp, &f->exts, &e);
536 tcf_em_tree_change(tp, &f->ematches, &t);
537
538 tcf_tree_lock(tp);
539
540 if (tb[TCA_FLOW_KEYS]) {
541 f->keymask = keymask;
542 f->nkeys = nkeys;
543 }
544
545 f->mode = mode;
546
547 if (tb[TCA_FLOW_MASK])
548 f->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
549 if (tb[TCA_FLOW_XOR])
550 f->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
551 if (tb[TCA_FLOW_RSHIFT])
552 f->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
553 if (tb[TCA_FLOW_ADDEND])
554 f->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
555
556 if (tb[TCA_FLOW_DIVISOR])
557 f->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
558 if (baseclass)
559 f->baseclass = baseclass;
560
561 f->perturb_period = perturb_period;
562 del_timer(&f->perturb_timer);
563 if (perturb_period)
564 mod_timer(&f->perturb_timer, jiffies + perturb_period);
565
566 if (*arg == 0)
567 list_add_tail(&f->list, &head->filters);
568
569 tcf_tree_unlock(tp);
570
571 *arg = (unsigned long)f;
572 return 0;
573
574err2:
575 tcf_em_tree_destroy(tp, &t);
576err1:
577 tcf_exts_destroy(tp, &e);
578 return err;
579}
580
581static void flow_destroy_filter(struct tcf_proto *tp, struct flow_filter *f)
582{
583 del_timer_sync(&f->perturb_timer);
584 tcf_exts_destroy(tp, &f->exts);
585 tcf_em_tree_destroy(tp, &f->ematches);
586 kfree(f);
587}
588
589static int flow_delete(struct tcf_proto *tp, unsigned long arg)
590{
591 struct flow_filter *f = (struct flow_filter *)arg;
592
593 tcf_tree_lock(tp);
594 list_del(&f->list);
595 tcf_tree_unlock(tp);
596 flow_destroy_filter(tp, f);
597 return 0;
598}
599
600static int flow_init(struct tcf_proto *tp)
601{
602 struct flow_head *head;
603
604 head = kzalloc(sizeof(*head), GFP_KERNEL);
605 if (head == NULL)
606 return -ENOBUFS;
607 INIT_LIST_HEAD(&head->filters);
608 tp->root = head;
609 return 0;
610}
611
612static void flow_destroy(struct tcf_proto *tp)
613{
614 struct flow_head *head = tp->root;
615 struct flow_filter *f, *next;
616
617 list_for_each_entry_safe(f, next, &head->filters, list) {
618 list_del(&f->list);
619 flow_destroy_filter(tp, f);
620 }
621 kfree(head);
622}
623
624static unsigned long flow_get(struct tcf_proto *tp, u32 handle)
625{
626 struct flow_head *head = tp->root;
627 struct flow_filter *f;
628
629 list_for_each_entry(f, &head->filters, list)
630 if (f->handle == handle)
631 return (unsigned long)f;
632 return 0;
633}
634
635static void flow_put(struct tcf_proto *tp, unsigned long f)
636{
637}
638
639static int flow_dump(struct tcf_proto *tp, unsigned long fh,
640 struct sk_buff *skb, struct tcmsg *t)
641{
642 struct flow_filter *f = (struct flow_filter *)fh;
643 struct nlattr *nest;
644
645 if (f == NULL)
646 return skb->len;
647
648 t->tcm_handle = f->handle;
649
650 nest = nla_nest_start(skb, TCA_OPTIONS);
651 if (nest == NULL)
652 goto nla_put_failure;
653
654 NLA_PUT_U32(skb, TCA_FLOW_KEYS, f->keymask);
655 NLA_PUT_U32(skb, TCA_FLOW_MODE, f->mode);
656
657 if (f->mask != ~0 || f->xor != 0) {
658 NLA_PUT_U32(skb, TCA_FLOW_MASK, f->mask);
659 NLA_PUT_U32(skb, TCA_FLOW_XOR, f->xor);
660 }
661 if (f->rshift)
662 NLA_PUT_U32(skb, TCA_FLOW_RSHIFT, f->rshift);
663 if (f->addend)
664 NLA_PUT_U32(skb, TCA_FLOW_ADDEND, f->addend);
665
666 if (f->divisor)
667 NLA_PUT_U32(skb, TCA_FLOW_DIVISOR, f->divisor);
668 if (f->baseclass)
669 NLA_PUT_U32(skb, TCA_FLOW_BASECLASS, f->baseclass);
670
671 if (f->perturb_period)
672 NLA_PUT_U32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ);
673
674 if (tcf_exts_dump(skb, &f->exts, &flow_ext_map) < 0)
675 goto nla_put_failure;
676#ifdef CONFIG_NET_EMATCH
677 if (f->ematches.hdr.nmatches &&
678 tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
679 goto nla_put_failure;
680#endif
681 nla_nest_end(skb, nest);
682
683 if (tcf_exts_dump_stats(skb, &f->exts, &flow_ext_map) < 0)
684 goto nla_put_failure;
685
686 return skb->len;
687
688nla_put_failure:
689 nlmsg_trim(skb, nest);
690 return -1;
691}
692
693static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
694{
695 struct flow_head *head = tp->root;
696 struct flow_filter *f;
697
698 list_for_each_entry(f, &head->filters, list) {
699 if (arg->count < arg->skip)
700 goto skip;
701 if (arg->fn(tp, (unsigned long)f, arg) < 0) {
702 arg->stop = 1;
703 break;
704 }
705skip:
706 arg->count++;
707 }
708}
709
710static struct tcf_proto_ops cls_flow_ops __read_mostly = {
711 .kind = "flow",
712 .classify = flow_classify,
713 .init = flow_init,
714 .destroy = flow_destroy,
715 .change = flow_change,
716 .delete = flow_delete,
717 .get = flow_get,
718 .put = flow_put,
719 .dump = flow_dump,
720 .walk = flow_walk,
721 .owner = THIS_MODULE,
722};
723
724static int __init cls_flow_init(void)
725{
726 return register_tcf_proto_ops(&cls_flow_ops);
727}
728
729static void __exit cls_flow_exit(void)
730{
731 unregister_tcf_proto_ops(&cls_flow_ops);
732}
733
734module_init(cls_flow_init);
735module_exit(cls_flow_exit);
736
737MODULE_LICENSE("GPL");
738MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
739MODULE_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#include <net/inet_sock.h>
26
27#include <net/pkt_cls.h>
28#include <net/ip.h>
29#include <net/route.h>
30#include <net/flow_dissector.h>
31
32#if IS_ENABLED(CONFIG_NF_CONNTRACK)
33#include <net/netfilter/nf_conntrack.h>
34#endif
35
36struct flow_head {
37 struct list_head filters;
38 struct rcu_head rcu;
39};
40
41struct flow_filter {
42 struct list_head list;
43 struct tcf_exts exts;
44 struct tcf_ematch_tree ematches;
45 struct tcf_proto *tp;
46 struct timer_list perturb_timer;
47 u32 perturb_period;
48 u32 handle;
49
50 u32 nkeys;
51 u32 keymask;
52 u32 mode;
53 u32 mask;
54 u32 xor;
55 u32 rshift;
56 u32 addend;
57 u32 divisor;
58 u32 baseclass;
59 u32 hashrnd;
60 union {
61 struct work_struct work;
62 struct rcu_head rcu;
63 };
64};
65
66static inline u32 addr_fold(void *addr)
67{
68 unsigned long a = (unsigned long)addr;
69
70 return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
71}
72
73static u32 flow_get_src(const struct sk_buff *skb, const struct flow_keys *flow)
74{
75 __be32 src = flow_get_u32_src(flow);
76
77 if (src)
78 return ntohl(src);
79
80 return addr_fold(skb->sk);
81}
82
83static u32 flow_get_dst(const struct sk_buff *skb, const struct flow_keys *flow)
84{
85 __be32 dst = flow_get_u32_dst(flow);
86
87 if (dst)
88 return ntohl(dst);
89
90 return addr_fold(skb_dst(skb)) ^ (__force u16) tc_skb_protocol(skb);
91}
92
93static u32 flow_get_proto(const struct sk_buff *skb,
94 const struct flow_keys *flow)
95{
96 return flow->basic.ip_proto;
97}
98
99static u32 flow_get_proto_src(const struct sk_buff *skb,
100 const struct flow_keys *flow)
101{
102 if (flow->ports.ports)
103 return ntohs(flow->ports.src);
104
105 return addr_fold(skb->sk);
106}
107
108static u32 flow_get_proto_dst(const struct sk_buff *skb,
109 const struct flow_keys *flow)
110{
111 if (flow->ports.ports)
112 return ntohs(flow->ports.dst);
113
114 return addr_fold(skb_dst(skb)) ^ (__force u16) tc_skb_protocol(skb);
115}
116
117static u32 flow_get_iif(const struct sk_buff *skb)
118{
119 return skb->skb_iif;
120}
121
122static u32 flow_get_priority(const struct sk_buff *skb)
123{
124 return skb->priority;
125}
126
127static u32 flow_get_mark(const struct sk_buff *skb)
128{
129 return skb->mark;
130}
131
132static u32 flow_get_nfct(const struct sk_buff *skb)
133{
134#if IS_ENABLED(CONFIG_NF_CONNTRACK)
135 return addr_fold(skb_nfct(skb));
136#else
137 return 0;
138#endif
139}
140
141#if IS_ENABLED(CONFIG_NF_CONNTRACK)
142#define CTTUPLE(skb, member) \
143({ \
144 enum ip_conntrack_info ctinfo; \
145 const struct nf_conn *ct = nf_ct_get(skb, &ctinfo); \
146 if (ct == NULL) \
147 goto fallback; \
148 ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member; \
149})
150#else
151#define CTTUPLE(skb, member) \
152({ \
153 goto fallback; \
154 0; \
155})
156#endif
157
158static u32 flow_get_nfct_src(const struct sk_buff *skb,
159 const struct flow_keys *flow)
160{
161 switch (tc_skb_protocol(skb)) {
162 case htons(ETH_P_IP):
163 return ntohl(CTTUPLE(skb, src.u3.ip));
164 case htons(ETH_P_IPV6):
165 return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
166 }
167fallback:
168 return flow_get_src(skb, flow);
169}
170
171static u32 flow_get_nfct_dst(const struct sk_buff *skb,
172 const struct flow_keys *flow)
173{
174 switch (tc_skb_protocol(skb)) {
175 case htons(ETH_P_IP):
176 return ntohl(CTTUPLE(skb, dst.u3.ip));
177 case htons(ETH_P_IPV6):
178 return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
179 }
180fallback:
181 return flow_get_dst(skb, flow);
182}
183
184static u32 flow_get_nfct_proto_src(const struct sk_buff *skb,
185 const struct flow_keys *flow)
186{
187 return ntohs(CTTUPLE(skb, src.u.all));
188fallback:
189 return flow_get_proto_src(skb, flow);
190}
191
192static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb,
193 const struct flow_keys *flow)
194{
195 return ntohs(CTTUPLE(skb, dst.u.all));
196fallback:
197 return flow_get_proto_dst(skb, flow);
198}
199
200static u32 flow_get_rtclassid(const struct sk_buff *skb)
201{
202#ifdef CONFIG_IP_ROUTE_CLASSID
203 if (skb_dst(skb))
204 return skb_dst(skb)->tclassid;
205#endif
206 return 0;
207}
208
209static u32 flow_get_skuid(const struct sk_buff *skb)
210{
211 struct sock *sk = skb_to_full_sk(skb);
212
213 if (sk && sk->sk_socket && sk->sk_socket->file) {
214 kuid_t skuid = sk->sk_socket->file->f_cred->fsuid;
215
216 return from_kuid(&init_user_ns, skuid);
217 }
218 return 0;
219}
220
221static u32 flow_get_skgid(const struct sk_buff *skb)
222{
223 struct sock *sk = skb_to_full_sk(skb);
224
225 if (sk && sk->sk_socket && sk->sk_socket->file) {
226 kgid_t skgid = sk->sk_socket->file->f_cred->fsgid;
227
228 return from_kgid(&init_user_ns, skgid);
229 }
230 return 0;
231}
232
233static u32 flow_get_vlan_tag(const struct sk_buff *skb)
234{
235 u16 uninitialized_var(tag);
236
237 if (vlan_get_tag(skb, &tag) < 0)
238 return 0;
239 return tag & VLAN_VID_MASK;
240}
241
242static u32 flow_get_rxhash(struct sk_buff *skb)
243{
244 return skb_get_hash(skb);
245}
246
247static u32 flow_key_get(struct sk_buff *skb, int key, struct flow_keys *flow)
248{
249 switch (key) {
250 case FLOW_KEY_SRC:
251 return flow_get_src(skb, flow);
252 case FLOW_KEY_DST:
253 return flow_get_dst(skb, flow);
254 case FLOW_KEY_PROTO:
255 return flow_get_proto(skb, flow);
256 case FLOW_KEY_PROTO_SRC:
257 return flow_get_proto_src(skb, flow);
258 case FLOW_KEY_PROTO_DST:
259 return flow_get_proto_dst(skb, flow);
260 case FLOW_KEY_IIF:
261 return flow_get_iif(skb);
262 case FLOW_KEY_PRIORITY:
263 return flow_get_priority(skb);
264 case FLOW_KEY_MARK:
265 return flow_get_mark(skb);
266 case FLOW_KEY_NFCT:
267 return flow_get_nfct(skb);
268 case FLOW_KEY_NFCT_SRC:
269 return flow_get_nfct_src(skb, flow);
270 case FLOW_KEY_NFCT_DST:
271 return flow_get_nfct_dst(skb, flow);
272 case FLOW_KEY_NFCT_PROTO_SRC:
273 return flow_get_nfct_proto_src(skb, flow);
274 case FLOW_KEY_NFCT_PROTO_DST:
275 return flow_get_nfct_proto_dst(skb, flow);
276 case FLOW_KEY_RTCLASSID:
277 return flow_get_rtclassid(skb);
278 case FLOW_KEY_SKUID:
279 return flow_get_skuid(skb);
280 case FLOW_KEY_SKGID:
281 return flow_get_skgid(skb);
282 case FLOW_KEY_VLAN_TAG:
283 return flow_get_vlan_tag(skb);
284 case FLOW_KEY_RXHASH:
285 return flow_get_rxhash(skb);
286 default:
287 WARN_ON(1);
288 return 0;
289 }
290}
291
292#define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) | \
293 (1 << FLOW_KEY_DST) | \
294 (1 << FLOW_KEY_PROTO) | \
295 (1 << FLOW_KEY_PROTO_SRC) | \
296 (1 << FLOW_KEY_PROTO_DST) | \
297 (1 << FLOW_KEY_NFCT_SRC) | \
298 (1 << FLOW_KEY_NFCT_DST) | \
299 (1 << FLOW_KEY_NFCT_PROTO_SRC) | \
300 (1 << FLOW_KEY_NFCT_PROTO_DST))
301
302static int flow_classify(struct sk_buff *skb, const struct tcf_proto *tp,
303 struct tcf_result *res)
304{
305 struct flow_head *head = rcu_dereference_bh(tp->root);
306 struct flow_filter *f;
307 u32 keymask;
308 u32 classid;
309 unsigned int n, key;
310 int r;
311
312 list_for_each_entry_rcu(f, &head->filters, list) {
313 u32 keys[FLOW_KEY_MAX + 1];
314 struct flow_keys flow_keys;
315
316 if (!tcf_em_tree_match(skb, &f->ematches, NULL))
317 continue;
318
319 keymask = f->keymask;
320 if (keymask & FLOW_KEYS_NEEDED)
321 skb_flow_dissect_flow_keys(skb, &flow_keys, 0);
322
323 for (n = 0; n < f->nkeys; n++) {
324 key = ffs(keymask) - 1;
325 keymask &= ~(1 << key);
326 keys[n] = flow_key_get(skb, key, &flow_keys);
327 }
328
329 if (f->mode == FLOW_MODE_HASH)
330 classid = jhash2(keys, f->nkeys, f->hashrnd);
331 else {
332 classid = keys[0];
333 classid = (classid & f->mask) ^ f->xor;
334 classid = (classid >> f->rshift) + f->addend;
335 }
336
337 if (f->divisor)
338 classid %= f->divisor;
339
340 res->class = 0;
341 res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
342
343 r = tcf_exts_exec(skb, &f->exts, res);
344 if (r < 0)
345 continue;
346 return r;
347 }
348 return -1;
349}
350
351static void flow_perturbation(struct timer_list *t)
352{
353 struct flow_filter *f = from_timer(f, t, perturb_timer);
354
355 get_random_bytes(&f->hashrnd, 4);
356 if (f->perturb_period)
357 mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
358}
359
360static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
361 [TCA_FLOW_KEYS] = { .type = NLA_U32 },
362 [TCA_FLOW_MODE] = { .type = NLA_U32 },
363 [TCA_FLOW_BASECLASS] = { .type = NLA_U32 },
364 [TCA_FLOW_RSHIFT] = { .type = NLA_U32 },
365 [TCA_FLOW_ADDEND] = { .type = NLA_U32 },
366 [TCA_FLOW_MASK] = { .type = NLA_U32 },
367 [TCA_FLOW_XOR] = { .type = NLA_U32 },
368 [TCA_FLOW_DIVISOR] = { .type = NLA_U32 },
369 [TCA_FLOW_ACT] = { .type = NLA_NESTED },
370 [TCA_FLOW_POLICE] = { .type = NLA_NESTED },
371 [TCA_FLOW_EMATCHES] = { .type = NLA_NESTED },
372 [TCA_FLOW_PERTURB] = { .type = NLA_U32 },
373};
374
375static void __flow_destroy_filter(struct flow_filter *f)
376{
377 del_timer_sync(&f->perturb_timer);
378 tcf_exts_destroy(&f->exts);
379 tcf_em_tree_destroy(&f->ematches);
380 tcf_exts_put_net(&f->exts);
381 kfree(f);
382}
383
384static void flow_destroy_filter_work(struct work_struct *work)
385{
386 struct flow_filter *f = container_of(work, struct flow_filter, work);
387
388 rtnl_lock();
389 __flow_destroy_filter(f);
390 rtnl_unlock();
391}
392
393static void flow_destroy_filter(struct rcu_head *head)
394{
395 struct flow_filter *f = container_of(head, struct flow_filter, rcu);
396
397 INIT_WORK(&f->work, flow_destroy_filter_work);
398 tcf_queue_work(&f->work);
399}
400
401static int flow_change(struct net *net, struct sk_buff *in_skb,
402 struct tcf_proto *tp, unsigned long base,
403 u32 handle, struct nlattr **tca,
404 void **arg, bool ovr, struct netlink_ext_ack *extack)
405{
406 struct flow_head *head = rtnl_dereference(tp->root);
407 struct flow_filter *fold, *fnew;
408 struct nlattr *opt = tca[TCA_OPTIONS];
409 struct nlattr *tb[TCA_FLOW_MAX + 1];
410 unsigned int nkeys = 0;
411 unsigned int perturb_period = 0;
412 u32 baseclass = 0;
413 u32 keymask = 0;
414 u32 mode;
415 int err;
416
417 if (opt == NULL)
418 return -EINVAL;
419
420 err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy, NULL);
421 if (err < 0)
422 return err;
423
424 if (tb[TCA_FLOW_BASECLASS]) {
425 baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
426 if (TC_H_MIN(baseclass) == 0)
427 return -EINVAL;
428 }
429
430 if (tb[TCA_FLOW_KEYS]) {
431 keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
432
433 nkeys = hweight32(keymask);
434 if (nkeys == 0)
435 return -EINVAL;
436
437 if (fls(keymask) - 1 > FLOW_KEY_MAX)
438 return -EOPNOTSUPP;
439
440 if ((keymask & (FLOW_KEY_SKUID|FLOW_KEY_SKGID)) &&
441 sk_user_ns(NETLINK_CB(in_skb).sk) != &init_user_ns)
442 return -EOPNOTSUPP;
443 }
444
445 fnew = kzalloc(sizeof(*fnew), GFP_KERNEL);
446 if (!fnew)
447 return -ENOBUFS;
448
449 err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &fnew->ematches);
450 if (err < 0)
451 goto err1;
452
453 err = tcf_exts_init(&fnew->exts, TCA_FLOW_ACT, TCA_FLOW_POLICE);
454 if (err < 0)
455 goto err2;
456
457 err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &fnew->exts, ovr,
458 extack);
459 if (err < 0)
460 goto err2;
461
462 fold = *arg;
463 if (fold) {
464 err = -EINVAL;
465 if (fold->handle != handle && handle)
466 goto err2;
467
468 /* Copy fold into fnew */
469 fnew->tp = fold->tp;
470 fnew->handle = fold->handle;
471 fnew->nkeys = fold->nkeys;
472 fnew->keymask = fold->keymask;
473 fnew->mode = fold->mode;
474 fnew->mask = fold->mask;
475 fnew->xor = fold->xor;
476 fnew->rshift = fold->rshift;
477 fnew->addend = fold->addend;
478 fnew->divisor = fold->divisor;
479 fnew->baseclass = fold->baseclass;
480 fnew->hashrnd = fold->hashrnd;
481
482 mode = fold->mode;
483 if (tb[TCA_FLOW_MODE])
484 mode = nla_get_u32(tb[TCA_FLOW_MODE]);
485 if (mode != FLOW_MODE_HASH && nkeys > 1)
486 goto err2;
487
488 if (mode == FLOW_MODE_HASH)
489 perturb_period = fold->perturb_period;
490 if (tb[TCA_FLOW_PERTURB]) {
491 if (mode != FLOW_MODE_HASH)
492 goto err2;
493 perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
494 }
495 } else {
496 err = -EINVAL;
497 if (!handle)
498 goto err2;
499 if (!tb[TCA_FLOW_KEYS])
500 goto err2;
501
502 mode = FLOW_MODE_MAP;
503 if (tb[TCA_FLOW_MODE])
504 mode = nla_get_u32(tb[TCA_FLOW_MODE]);
505 if (mode != FLOW_MODE_HASH && nkeys > 1)
506 goto err2;
507
508 if (tb[TCA_FLOW_PERTURB]) {
509 if (mode != FLOW_MODE_HASH)
510 goto err2;
511 perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
512 }
513
514 if (TC_H_MAJ(baseclass) == 0) {
515 struct Qdisc *q = tcf_block_q(tp->chain->block);
516
517 baseclass = TC_H_MAKE(q->handle, baseclass);
518 }
519 if (TC_H_MIN(baseclass) == 0)
520 baseclass = TC_H_MAKE(baseclass, 1);
521
522 fnew->handle = handle;
523 fnew->mask = ~0U;
524 fnew->tp = tp;
525 get_random_bytes(&fnew->hashrnd, 4);
526 }
527
528 timer_setup(&fnew->perturb_timer, flow_perturbation, TIMER_DEFERRABLE);
529
530 tcf_block_netif_keep_dst(tp->chain->block);
531
532 if (tb[TCA_FLOW_KEYS]) {
533 fnew->keymask = keymask;
534 fnew->nkeys = nkeys;
535 }
536
537 fnew->mode = mode;
538
539 if (tb[TCA_FLOW_MASK])
540 fnew->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
541 if (tb[TCA_FLOW_XOR])
542 fnew->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
543 if (tb[TCA_FLOW_RSHIFT])
544 fnew->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
545 if (tb[TCA_FLOW_ADDEND])
546 fnew->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
547
548 if (tb[TCA_FLOW_DIVISOR])
549 fnew->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
550 if (baseclass)
551 fnew->baseclass = baseclass;
552
553 fnew->perturb_period = perturb_period;
554 if (perturb_period)
555 mod_timer(&fnew->perturb_timer, jiffies + perturb_period);
556
557 if (!*arg)
558 list_add_tail_rcu(&fnew->list, &head->filters);
559 else
560 list_replace_rcu(&fold->list, &fnew->list);
561
562 *arg = fnew;
563
564 if (fold) {
565 tcf_exts_get_net(&fold->exts);
566 call_rcu(&fold->rcu, flow_destroy_filter);
567 }
568 return 0;
569
570err2:
571 tcf_exts_destroy(&fnew->exts);
572 tcf_em_tree_destroy(&fnew->ematches);
573err1:
574 kfree(fnew);
575 return err;
576}
577
578static int flow_delete(struct tcf_proto *tp, void *arg, bool *last,
579 struct netlink_ext_ack *extack)
580{
581 struct flow_head *head = rtnl_dereference(tp->root);
582 struct flow_filter *f = arg;
583
584 list_del_rcu(&f->list);
585 tcf_exts_get_net(&f->exts);
586 call_rcu(&f->rcu, flow_destroy_filter);
587 *last = list_empty(&head->filters);
588 return 0;
589}
590
591static int flow_init(struct tcf_proto *tp)
592{
593 struct flow_head *head;
594
595 head = kzalloc(sizeof(*head), GFP_KERNEL);
596 if (head == NULL)
597 return -ENOBUFS;
598 INIT_LIST_HEAD(&head->filters);
599 rcu_assign_pointer(tp->root, head);
600 return 0;
601}
602
603static void flow_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
604{
605 struct flow_head *head = rtnl_dereference(tp->root);
606 struct flow_filter *f, *next;
607
608 list_for_each_entry_safe(f, next, &head->filters, list) {
609 list_del_rcu(&f->list);
610 if (tcf_exts_get_net(&f->exts))
611 call_rcu(&f->rcu, flow_destroy_filter);
612 else
613 __flow_destroy_filter(f);
614 }
615 kfree_rcu(head, rcu);
616}
617
618static void *flow_get(struct tcf_proto *tp, u32 handle)
619{
620 struct flow_head *head = rtnl_dereference(tp->root);
621 struct flow_filter *f;
622
623 list_for_each_entry(f, &head->filters, list)
624 if (f->handle == handle)
625 return f;
626 return NULL;
627}
628
629static int flow_dump(struct net *net, struct tcf_proto *tp, void *fh,
630 struct sk_buff *skb, struct tcmsg *t)
631{
632 struct flow_filter *f = fh;
633 struct nlattr *nest;
634
635 if (f == NULL)
636 return skb->len;
637
638 t->tcm_handle = f->handle;
639
640 nest = nla_nest_start(skb, TCA_OPTIONS);
641 if (nest == NULL)
642 goto nla_put_failure;
643
644 if (nla_put_u32(skb, TCA_FLOW_KEYS, f->keymask) ||
645 nla_put_u32(skb, TCA_FLOW_MODE, f->mode))
646 goto nla_put_failure;
647
648 if (f->mask != ~0 || f->xor != 0) {
649 if (nla_put_u32(skb, TCA_FLOW_MASK, f->mask) ||
650 nla_put_u32(skb, TCA_FLOW_XOR, f->xor))
651 goto nla_put_failure;
652 }
653 if (f->rshift &&
654 nla_put_u32(skb, TCA_FLOW_RSHIFT, f->rshift))
655 goto nla_put_failure;
656 if (f->addend &&
657 nla_put_u32(skb, TCA_FLOW_ADDEND, f->addend))
658 goto nla_put_failure;
659
660 if (f->divisor &&
661 nla_put_u32(skb, TCA_FLOW_DIVISOR, f->divisor))
662 goto nla_put_failure;
663 if (f->baseclass &&
664 nla_put_u32(skb, TCA_FLOW_BASECLASS, f->baseclass))
665 goto nla_put_failure;
666
667 if (f->perturb_period &&
668 nla_put_u32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ))
669 goto nla_put_failure;
670
671 if (tcf_exts_dump(skb, &f->exts) < 0)
672 goto nla_put_failure;
673#ifdef CONFIG_NET_EMATCH
674 if (f->ematches.hdr.nmatches &&
675 tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
676 goto nla_put_failure;
677#endif
678 nla_nest_end(skb, nest);
679
680 if (tcf_exts_dump_stats(skb, &f->exts) < 0)
681 goto nla_put_failure;
682
683 return skb->len;
684
685nla_put_failure:
686 nla_nest_cancel(skb, nest);
687 return -1;
688}
689
690static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
691{
692 struct flow_head *head = rtnl_dereference(tp->root);
693 struct flow_filter *f;
694
695 list_for_each_entry(f, &head->filters, list) {
696 if (arg->count < arg->skip)
697 goto skip;
698 if (arg->fn(tp, f, arg) < 0) {
699 arg->stop = 1;
700 break;
701 }
702skip:
703 arg->count++;
704 }
705}
706
707static struct tcf_proto_ops cls_flow_ops __read_mostly = {
708 .kind = "flow",
709 .classify = flow_classify,
710 .init = flow_init,
711 .destroy = flow_destroy,
712 .change = flow_change,
713 .delete = flow_delete,
714 .get = flow_get,
715 .dump = flow_dump,
716 .walk = flow_walk,
717 .owner = THIS_MODULE,
718};
719
720static int __init cls_flow_init(void)
721{
722 return register_tcf_proto_ops(&cls_flow_ops);
723}
724
725static void __exit cls_flow_exit(void)
726{
727 unregister_tcf_proto_ops(&cls_flow_ops);
728}
729
730module_init(cls_flow_init);
731module_exit(cls_flow_exit);
732
733MODULE_LICENSE("GPL");
734MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
735MODULE_DESCRIPTION("TC flow classifier");