ipv4: tcp: set unicast_sock uc_ttl to -1
[linux-3.10.git] / net / sched / cls_flow.c
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                 return skb->sk->sk_socket->file->f_cred->fsuid;
198         return 0;
199 }
200
201 static 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
208 static 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
217 static u32 flow_get_rxhash(struct sk_buff *skb)
218 {
219         return skb_get_rxhash(skb);
220 }
221
222 static 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
277 static 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
326 static 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
335 static 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
350 static 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
495 err2:
496         tcf_em_tree_destroy(tp, &t);
497 err1:
498         tcf_exts_destroy(tp, &e);
499         return err;
500 }
501
502 static 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
510 static 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
521 static 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
533 static 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
545 static 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
556 static void flow_put(struct tcf_proto *tp, unsigned long f)
557 {
558 }
559
560 static 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
616 nla_put_failure:
617         nlmsg_trim(skb, nest);
618         return -1;
619 }
620
621 static 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                 }
633 skip:
634                 arg->count++;
635         }
636 }
637
638 static 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
652 static int __init cls_flow_init(void)
653 {
654         return register_tcf_proto_ops(&cls_flow_ops);
655 }
656
657 static void __exit cls_flow_exit(void)
658 {
659         unregister_tcf_proto_ops(&cls_flow_ops);
660 }
661
662 module_init(cls_flow_init);
663 module_exit(cls_flow_exit);
664
665 MODULE_LICENSE("GPL");
666 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
667 MODULE_DESCRIPTION("TC flow classifier");