1 /*
2 * net/sched/cls_rsvp.h Template file for RSVPv[46] classifiers.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 */
11
12 /*
13 Comparing to general packet classification problem,
14 RSVP needs only sevaral relatively simple rules:
15
16 * (dst, protocol) are always specified,
17 so that we are able to hash them.
18 * src may be exact, or may be wildcard, so that
19 we can keep a hash table plus one wildcard entry.
20 * source port (or flow label) is important only if src is given.
21
22 IMPLEMENTATION.
23
24 We use a two level hash table: The top level is keyed by
25 destination address and protocol ID, every bucket contains a list
26 of "rsvp sessions", identified by destination address, protocol and
27 DPI(="Destination Port ID"): triple (key, mask, offset).
28
29 Every bucket has a smaller hash table keyed by source address
30 (cf. RSVP flowspec) and one wildcard entry for wildcard reservations.
31 Every bucket is again a list of "RSVP flows", selected by
32 source address and SPI(="Source Port ID" here rather than
33 "security parameter index"): triple (key, mask, offset).
34
35
36 NOTE 1. All the packets with IPv6 extension headers (but AH and ESP)
37 and all fragmented packets go to the best-effort traffic class.
38
39
40 NOTE 2. Two "port id"'s seems to be redundant, rfc2207 requires
41 only one "Generalized Port Identifier". So that for classic
42 ah, esp (and udp,tcp) both *pi should coincide or one of them
43 should be wildcard.
44
45 At first sight, this redundancy is just a waste of CPU
46 resources. But DPI and SPI add the possibility to assign different
47 priorities to GPIs. Look also at note 4 about tunnels below.
48
49
50 NOTE 3. One complication is the case of tunneled packets.
51 We implement it as following: if the first lookup
52 matches a special session with "tunnelhdr" value not zero,
53 flowid doesn't contain the true flow ID, but the tunnel ID (1...255).
54 In this case, we pull tunnelhdr bytes and restart lookup
55 with tunnel ID added to the list of keys. Simple and stupid 8)8)
56 It's enough for PIMREG and IPIP.
57
58
59 NOTE 4. Two GPIs make it possible to parse even GRE packets.
60 F.e. DPI can select ETH_P_IP (and necessary flags to make
61 tunnelhdr correct) in GRE protocol field and SPI matches
62 GRE key. Is it not nice? 8)8)
63
64
65 Well, as result, despite its simplicity, we get a pretty
66 powerful classification engine. */
67
68
69 struct rsvp_head {
70 u32 tmap[256/32];
71 u32 hgenerator;
72 u8 tgenerator;
73 struct rsvp_session *ht[256];
74 };
75
76 struct rsvp_session {
77 struct rsvp_session *next;
78 __be32 dst[RSVP_DST_LEN];
79 struct tc_rsvp_gpi dpi;
80 u8 protocol;
81 u8 tunnelid;
82 /* 16 (src,sport) hash slots, and one wildcard source slot */
83 struct rsvp_filter *ht[16 + 1];
84 };
85
86
87 struct rsvp_filter {
88 struct rsvp_filter *next;
89 __be32 src[RSVP_DST_LEN];
90 struct tc_rsvp_gpi spi;
91 u8 tunnelhdr;
92
93 struct tcf_result res;
94 struct tcf_exts exts;
95
96 u32 handle;
97 struct rsvp_session *sess;
98 };
99
hash_dst(__be32 * dst,u8 protocol,u8 tunnelid)100 static inline unsigned int hash_dst(__be32 *dst, u8 protocol, u8 tunnelid)
101 {
102 unsigned int h = (__force __u32)dst[RSVP_DST_LEN - 1];
103
104 h ^= h>>16;
105 h ^= h>>8;
106 return (h ^ protocol ^ tunnelid) & 0xFF;
107 }
108
hash_src(__be32 * src)109 static inline unsigned int hash_src(__be32 *src)
110 {
111 unsigned int h = (__force __u32)src[RSVP_DST_LEN-1];
112
113 h ^= h>>16;
114 h ^= h>>8;
115 h ^= h>>4;
116 return h & 0xF;
117 }
118
119 static struct tcf_ext_map rsvp_ext_map = {
120 .police = TCA_RSVP_POLICE,
121 .action = TCA_RSVP_ACT
122 };
123
124 #define RSVP_APPLY_RESULT() \
125 { \
126 int r = tcf_exts_exec(skb, &f->exts, res); \
127 if (r < 0) \
128 continue; \
129 else if (r > 0) \
130 return r; \
131 }
132
rsvp_classify(struct sk_buff * skb,const struct tcf_proto * tp,struct tcf_result * res)133 static int rsvp_classify(struct sk_buff *skb, const struct tcf_proto *tp,
134 struct tcf_result *res)
135 {
136 struct rsvp_session **sht = ((struct rsvp_head *)tp->root)->ht;
137 struct rsvp_session *s;
138 struct rsvp_filter *f;
139 unsigned int h1, h2;
140 __be32 *dst, *src;
141 u8 protocol;
142 u8 tunnelid = 0;
143 u8 *xprt;
144 #if RSVP_DST_LEN == 4
145 struct ipv6hdr *nhptr;
146
147 if (!pskb_network_may_pull(skb, sizeof(*nhptr)))
148 return -1;
149 nhptr = ipv6_hdr(skb);
150 #else
151 struct iphdr *nhptr;
152
153 if (!pskb_network_may_pull(skb, sizeof(*nhptr)))
154 return -1;
155 nhptr = ip_hdr(skb);
156 #endif
157
158 restart:
159
160 #if RSVP_DST_LEN == 4
161 src = &nhptr->saddr.s6_addr32[0];
162 dst = &nhptr->daddr.s6_addr32[0];
163 protocol = nhptr->nexthdr;
164 xprt = ((u8 *)nhptr) + sizeof(struct ipv6hdr);
165 #else
166 src = &nhptr->saddr;
167 dst = &nhptr->daddr;
168 protocol = nhptr->protocol;
169 xprt = ((u8 *)nhptr) + (nhptr->ihl<<2);
170 if (ip_is_fragment(nhptr))
171 return -1;
172 #endif
173
174 h1 = hash_dst(dst, protocol, tunnelid);
175 h2 = hash_src(src);
176
177 for (s = sht[h1]; s; s = s->next) {
178 if (dst[RSVP_DST_LEN-1] == s->dst[RSVP_DST_LEN - 1] &&
179 protocol == s->protocol &&
180 !(s->dpi.mask &
181 (*(u32 *)(xprt + s->dpi.offset) ^ s->dpi.key)) &&
182 #if RSVP_DST_LEN == 4
183 dst[0] == s->dst[0] &&
184 dst[1] == s->dst[1] &&
185 dst[2] == s->dst[2] &&
186 #endif
187 tunnelid == s->tunnelid) {
188
189 for (f = s->ht[h2]; f; f = f->next) {
190 if (src[RSVP_DST_LEN-1] == f->src[RSVP_DST_LEN - 1] &&
191 !(f->spi.mask & (*(u32 *)(xprt + f->spi.offset) ^ f->spi.key))
192 #if RSVP_DST_LEN == 4
193 &&
194 src[0] == f->src[0] &&
195 src[1] == f->src[1] &&
196 src[2] == f->src[2]
197 #endif
198 ) {
199 *res = f->res;
200 RSVP_APPLY_RESULT();
201
202 matched:
203 if (f->tunnelhdr == 0)
204 return 0;
205
206 tunnelid = f->res.classid;
207 nhptr = (void *)(xprt + f->tunnelhdr - sizeof(*nhptr));
208 goto restart;
209 }
210 }
211
212 /* And wildcard bucket... */
213 for (f = s->ht[16]; f; f = f->next) {
214 *res = f->res;
215 RSVP_APPLY_RESULT();
216 goto matched;
217 }
218 return -1;
219 }
220 }
221 return -1;
222 }
223
rsvp_get(struct tcf_proto * tp,u32 handle)224 static unsigned long rsvp_get(struct tcf_proto *tp, u32 handle)
225 {
226 struct rsvp_session **sht = ((struct rsvp_head *)tp->root)->ht;
227 struct rsvp_session *s;
228 struct rsvp_filter *f;
229 unsigned int h1 = handle & 0xFF;
230 unsigned int h2 = (handle >> 8) & 0xFF;
231
232 if (h2 > 16)
233 return 0;
234
235 for (s = sht[h1]; s; s = s->next) {
236 for (f = s->ht[h2]; f; f = f->next) {
237 if (f->handle == handle)
238 return (unsigned long)f;
239 }
240 }
241 return 0;
242 }
243
rsvp_put(struct tcf_proto * tp,unsigned long f)244 static void rsvp_put(struct tcf_proto *tp, unsigned long f)
245 {
246 }
247
rsvp_init(struct tcf_proto * tp)248 static int rsvp_init(struct tcf_proto *tp)
249 {
250 struct rsvp_head *data;
251
252 data = kzalloc(sizeof(struct rsvp_head), GFP_KERNEL);
253 if (data) {
254 tp->root = data;
255 return 0;
256 }
257 return -ENOBUFS;
258 }
259
260 static void
rsvp_delete_filter(struct tcf_proto * tp,struct rsvp_filter * f)261 rsvp_delete_filter(struct tcf_proto *tp, struct rsvp_filter *f)
262 {
263 tcf_unbind_filter(tp, &f->res);
264 tcf_exts_destroy(tp, &f->exts);
265 kfree(f);
266 }
267
rsvp_destroy(struct tcf_proto * tp)268 static void rsvp_destroy(struct tcf_proto *tp)
269 {
270 struct rsvp_head *data = xchg(&tp->root, NULL);
271 struct rsvp_session **sht;
272 int h1, h2;
273
274 if (data == NULL)
275 return;
276
277 sht = data->ht;
278
279 for (h1 = 0; h1 < 256; h1++) {
280 struct rsvp_session *s;
281
282 while ((s = sht[h1]) != NULL) {
283 sht[h1] = s->next;
284
285 for (h2 = 0; h2 <= 16; h2++) {
286 struct rsvp_filter *f;
287
288 while ((f = s->ht[h2]) != NULL) {
289 s->ht[h2] = f->next;
290 rsvp_delete_filter(tp, f);
291 }
292 }
293 kfree(s);
294 }
295 }
296 kfree(data);
297 }
298
rsvp_delete(struct tcf_proto * tp,unsigned long arg)299 static int rsvp_delete(struct tcf_proto *tp, unsigned long arg)
300 {
301 struct rsvp_filter **fp, *f = (struct rsvp_filter *)arg;
302 unsigned int h = f->handle;
303 struct rsvp_session **sp;
304 struct rsvp_session *s = f->sess;
305 int i;
306
307 for (fp = &s->ht[(h >> 8) & 0xFF]; *fp; fp = &(*fp)->next) {
308 if (*fp == f) {
309 tcf_tree_lock(tp);
310 *fp = f->next;
311 tcf_tree_unlock(tp);
312 rsvp_delete_filter(tp, f);
313
314 /* Strip tree */
315
316 for (i = 0; i <= 16; i++)
317 if (s->ht[i])
318 return 0;
319
320 /* OK, session has no flows */
321 for (sp = &((struct rsvp_head *)tp->root)->ht[h & 0xFF];
322 *sp; sp = &(*sp)->next) {
323 if (*sp == s) {
324 tcf_tree_lock(tp);
325 *sp = s->next;
326 tcf_tree_unlock(tp);
327
328 kfree(s);
329 return 0;
330 }
331 }
332
333 return 0;
334 }
335 }
336 return 0;
337 }
338
gen_handle(struct tcf_proto * tp,unsigned salt)339 static unsigned int gen_handle(struct tcf_proto *tp, unsigned salt)
340 {
341 struct rsvp_head *data = tp->root;
342 int i = 0xFFFF;
343
344 while (i-- > 0) {
345 u32 h;
346
347 if ((data->hgenerator += 0x10000) == 0)
348 data->hgenerator = 0x10000;
349 h = data->hgenerator|salt;
350 if (rsvp_get(tp, h) == 0)
351 return h;
352 }
353 return 0;
354 }
355
tunnel_bts(struct rsvp_head * data)356 static int tunnel_bts(struct rsvp_head *data)
357 {
358 int n = data->tgenerator >> 5;
359 u32 b = 1 << (data->tgenerator & 0x1F);
360
361 if (data->tmap[n] & b)
362 return 0;
363 data->tmap[n] |= b;
364 return 1;
365 }
366
tunnel_recycle(struct rsvp_head * data)367 static void tunnel_recycle(struct rsvp_head *data)
368 {
369 struct rsvp_session **sht = data->ht;
370 u32 tmap[256/32];
371 int h1, h2;
372
373 memset(tmap, 0, sizeof(tmap));
374
375 for (h1 = 0; h1 < 256; h1++) {
376 struct rsvp_session *s;
377 for (s = sht[h1]; s; s = s->next) {
378 for (h2 = 0; h2 <= 16; h2++) {
379 struct rsvp_filter *f;
380
381 for (f = s->ht[h2]; f; f = f->next) {
382 if (f->tunnelhdr == 0)
383 continue;
384 data->tgenerator = f->res.classid;
385 tunnel_bts(data);
386 }
387 }
388 }
389 }
390
391 memcpy(data->tmap, tmap, sizeof(tmap));
392 }
393
gen_tunnel(struct rsvp_head * data)394 static u32 gen_tunnel(struct rsvp_head *data)
395 {
396 int i, k;
397
398 for (k = 0; k < 2; k++) {
399 for (i = 255; i > 0; i--) {
400 if (++data->tgenerator == 0)
401 data->tgenerator = 1;
402 if (tunnel_bts(data))
403 return data->tgenerator;
404 }
405 tunnel_recycle(data);
406 }
407 return 0;
408 }
409
410 static const struct nla_policy rsvp_policy[TCA_RSVP_MAX + 1] = {
411 [TCA_RSVP_CLASSID] = { .type = NLA_U32 },
412 [TCA_RSVP_DST] = { .type = NLA_BINARY,
413 .len = RSVP_DST_LEN * sizeof(u32) },
414 [TCA_RSVP_SRC] = { .type = NLA_BINARY,
415 .len = RSVP_DST_LEN * sizeof(u32) },
416 [TCA_RSVP_PINFO] = { .len = sizeof(struct tc_rsvp_pinfo) },
417 };
418
rsvp_change(struct tcf_proto * tp,unsigned long base,u32 handle,struct nlattr ** tca,unsigned long * arg)419 static int rsvp_change(struct tcf_proto *tp, unsigned long base,
420 u32 handle,
421 struct nlattr **tca,
422 unsigned long *arg)
423 {
424 struct rsvp_head *data = tp->root;
425 struct rsvp_filter *f, **fp;
426 struct rsvp_session *s, **sp;
427 struct tc_rsvp_pinfo *pinfo = NULL;
428 struct nlattr *opt = tca[TCA_OPTIONS];
429 struct nlattr *tb[TCA_RSVP_MAX + 1];
430 struct tcf_exts e;
431 unsigned int h1, h2;
432 __be32 *dst;
433 int err;
434
435 if (opt == NULL)
436 return handle ? -EINVAL : 0;
437
438 err = nla_parse_nested(tb, TCA_RSVP_MAX, opt, rsvp_policy);
439 if (err < 0)
440 return err;
441
442 err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &rsvp_ext_map);
443 if (err < 0)
444 return err;
445
446 f = (struct rsvp_filter *)*arg;
447 if (f) {
448 /* Node exists: adjust only classid */
449
450 if (f->handle != handle && handle)
451 goto errout2;
452 if (tb[TCA_RSVP_CLASSID]) {
453 f->res.classid = nla_get_u32(tb[TCA_RSVP_CLASSID]);
454 tcf_bind_filter(tp, &f->res, base);
455 }
456
457 tcf_exts_change(tp, &f->exts, &e);
458 return 0;
459 }
460
461 /* Now more serious part... */
462 err = -EINVAL;
463 if (handle)
464 goto errout2;
465 if (tb[TCA_RSVP_DST] == NULL)
466 goto errout2;
467
468 err = -ENOBUFS;
469 f = kzalloc(sizeof(struct rsvp_filter), GFP_KERNEL);
470 if (f == NULL)
471 goto errout2;
472
473 h2 = 16;
474 if (tb[TCA_RSVP_SRC]) {
475 memcpy(f->src, nla_data(tb[TCA_RSVP_SRC]), sizeof(f->src));
476 h2 = hash_src(f->src);
477 }
478 if (tb[TCA_RSVP_PINFO]) {
479 pinfo = nla_data(tb[TCA_RSVP_PINFO]);
480 f->spi = pinfo->spi;
481 f->tunnelhdr = pinfo->tunnelhdr;
482 }
483 if (tb[TCA_RSVP_CLASSID])
484 f->res.classid = nla_get_u32(tb[TCA_RSVP_CLASSID]);
485
486 dst = nla_data(tb[TCA_RSVP_DST]);
487 h1 = hash_dst(dst, pinfo ? pinfo->protocol : 0, pinfo ? pinfo->tunnelid : 0);
488
489 err = -ENOMEM;
490 if ((f->handle = gen_handle(tp, h1 | (h2<<8))) == 0)
491 goto errout;
492
493 if (f->tunnelhdr) {
494 err = -EINVAL;
495 if (f->res.classid > 255)
496 goto errout;
497
498 err = -ENOMEM;
499 if (f->res.classid == 0 &&
500 (f->res.classid = gen_tunnel(data)) == 0)
501 goto errout;
502 }
503
504 for (sp = &data->ht[h1]; (s = *sp) != NULL; sp = &s->next) {
505 if (dst[RSVP_DST_LEN-1] == s->dst[RSVP_DST_LEN-1] &&
506 pinfo && pinfo->protocol == s->protocol &&
507 memcmp(&pinfo->dpi, &s->dpi, sizeof(s->dpi)) == 0 &&
508 #if RSVP_DST_LEN == 4
509 dst[0] == s->dst[0] &&
510 dst[1] == s->dst[1] &&
511 dst[2] == s->dst[2] &&
512 #endif
513 pinfo->tunnelid == s->tunnelid) {
514
515 insert:
516 /* OK, we found appropriate session */
517
518 fp = &s->ht[h2];
519
520 f->sess = s;
521 if (f->tunnelhdr == 0)
522 tcf_bind_filter(tp, &f->res, base);
523
524 tcf_exts_change(tp, &f->exts, &e);
525
526 for (fp = &s->ht[h2]; *fp; fp = &(*fp)->next)
527 if (((*fp)->spi.mask & f->spi.mask) != f->spi.mask)
528 break;
529 f->next = *fp;
530 wmb();
531 *fp = f;
532
533 *arg = (unsigned long)f;
534 return 0;
535 }
536 }
537
538 /* No session found. Create new one. */
539
540 err = -ENOBUFS;
541 s = kzalloc(sizeof(struct rsvp_session), GFP_KERNEL);
542 if (s == NULL)
543 goto errout;
544 memcpy(s->dst, dst, sizeof(s->dst));
545
546 if (pinfo) {
547 s->dpi = pinfo->dpi;
548 s->protocol = pinfo->protocol;
549 s->tunnelid = pinfo->tunnelid;
550 }
551 for (sp = &data->ht[h1]; *sp; sp = &(*sp)->next) {
552 if (((*sp)->dpi.mask&s->dpi.mask) != s->dpi.mask)
553 break;
554 }
555 s->next = *sp;
556 wmb();
557 *sp = s;
558
559 goto insert;
560
561 errout:
562 kfree(f);
563 errout2:
564 tcf_exts_destroy(tp, &e);
565 return err;
566 }
567
rsvp_walk(struct tcf_proto * tp,struct tcf_walker * arg)568 static void rsvp_walk(struct tcf_proto *tp, struct tcf_walker *arg)
569 {
570 struct rsvp_head *head = tp->root;
571 unsigned int h, h1;
572
573 if (arg->stop)
574 return;
575
576 for (h = 0; h < 256; h++) {
577 struct rsvp_session *s;
578
579 for (s = head->ht[h]; s; s = s->next) {
580 for (h1 = 0; h1 <= 16; h1++) {
581 struct rsvp_filter *f;
582
583 for (f = s->ht[h1]; f; f = f->next) {
584 if (arg->count < arg->skip) {
585 arg->count++;
586 continue;
587 }
588 if (arg->fn(tp, (unsigned long)f, arg) < 0) {
589 arg->stop = 1;
590 return;
591 }
592 arg->count++;
593 }
594 }
595 }
596 }
597 }
598
rsvp_dump(struct tcf_proto * tp,unsigned long fh,struct sk_buff * skb,struct tcmsg * t)599 static int rsvp_dump(struct tcf_proto *tp, unsigned long fh,
600 struct sk_buff *skb, struct tcmsg *t)
601 {
602 struct rsvp_filter *f = (struct rsvp_filter *)fh;
603 struct rsvp_session *s;
604 unsigned char *b = skb_tail_pointer(skb);
605 struct nlattr *nest;
606 struct tc_rsvp_pinfo pinfo;
607
608 if (f == NULL)
609 return skb->len;
610 s = f->sess;
611
612 t->tcm_handle = f->handle;
613
614 nest = nla_nest_start(skb, TCA_OPTIONS);
615 if (nest == NULL)
616 goto nla_put_failure;
617
618 NLA_PUT(skb, TCA_RSVP_DST, sizeof(s->dst), &s->dst);
619 pinfo.dpi = s->dpi;
620 pinfo.spi = f->spi;
621 pinfo.protocol = s->protocol;
622 pinfo.tunnelid = s->tunnelid;
623 pinfo.tunnelhdr = f->tunnelhdr;
624 pinfo.pad = 0;
625 NLA_PUT(skb, TCA_RSVP_PINFO, sizeof(pinfo), &pinfo);
626 if (f->res.classid)
627 NLA_PUT_U32(skb, TCA_RSVP_CLASSID, f->res.classid);
628 if (((f->handle >> 8) & 0xFF) != 16)
629 NLA_PUT(skb, TCA_RSVP_SRC, sizeof(f->src), f->src);
630
631 if (tcf_exts_dump(skb, &f->exts, &rsvp_ext_map) < 0)
632 goto nla_put_failure;
633
634 nla_nest_end(skb, nest);
635
636 if (tcf_exts_dump_stats(skb, &f->exts, &rsvp_ext_map) < 0)
637 goto nla_put_failure;
638 return skb->len;
639
640 nla_put_failure:
641 nlmsg_trim(skb, b);
642 return -1;
643 }
644
645 static struct tcf_proto_ops RSVP_OPS __read_mostly = {
646 .kind = RSVP_ID,
647 .classify = rsvp_classify,
648 .init = rsvp_init,
649 .destroy = rsvp_destroy,
650 .get = rsvp_get,
651 .put = rsvp_put,
652 .change = rsvp_change,
653 .delete = rsvp_delete,
654 .walk = rsvp_walk,
655 .dump = rsvp_dump,
656 .owner = THIS_MODULE,
657 };
658
init_rsvp(void)659 static int __init init_rsvp(void)
660 {
661 return register_tcf_proto_ops(&RSVP_OPS);
662 }
663
exit_rsvp(void)664 static void __exit exit_rsvp(void)
665 {
666 unregister_tcf_proto_ops(&RSVP_OPS);
667 }
668
669 module_init(init_rsvp)
670 module_exit(exit_rsvp)
671