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Input: add ps2_drain() to libps2 to allow reading and discarding
[linux-2.6/linux-2.6-openrd.git] / net / sched / em_meta.c
blobf1eeaf65cee5f833aabb493c53442ef80e983eef
1 /*
2 * net/sched/em_meta.c Metadata ematch
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: Thomas Graf <tgraf@suug.ch>
10 *
11 * ==========================================================================
12 *
13 * The metadata ematch compares two meta objects where each object
14 * represents either a meta value stored in the kernel or a static
15 * value provided by userspace. The objects are not provided by
16 * userspace itself but rather a definition providing the information
17 * to build them. Every object is of a certain type which must be
18 * equal to the object it is being compared to.
19 *
20 * The definition of a objects conists of the type (meta type), a
21 * identifier (meta id) and additional type specific information.
22 * The meta id is either TCF_META_TYPE_VALUE for values provided by
23 * userspace or a index to the meta operations table consisting of
24 * function pointers to type specific meta data collectors returning
25 * the value of the requested meta value.
26 *
27 * lvalue rvalue
28 * +-----------+ +-----------+
29 * | type: INT | | type: INT |
30 * def | id: INDEV | | id: VALUE |
31 * | data: | | data: 3 |
32 * +-----------+ +-----------+
33 * | |
34 * ---> meta_ops[INT][INDEV](...) |
35 * | |
36 * ----------- |
37 * V V
38 * +-----------+ +-----------+
39 * | type: INT | | type: INT |
40 * obj | id: INDEV | | id: VALUE |
41 * | data: 2 |<--data got filled out | data: 3 |
42 * +-----------+ +-----------+
43 * | |
44 * --------------> 2 equals 3 <--------------
45 *
46 * This is a simplified schema, the complexity varies depending
47 * on the meta type. Obviously, the length of the data must also
48 * be provided for non-numeric types.
49 *
50 * Additionaly, type dependant modifiers such as shift operators
51 * or mask may be applied to extend the functionaliy. As of now,
52 * the variable length type supports shifting the byte string to
53 * the right, eating up any number of octets and thus supporting
54 * wildcard interface name comparisons such as "ppp%" matching
55 * ppp0..9.
56 *
57 * NOTE: Certain meta values depend on other subsystems and are
58 * only available if that subsytem is enabled in the kernel.
59 */
60
61 #include <linux/config.h>
62 #include <linux/module.h>
63 #include <linux/types.h>
64 #include <linux/kernel.h>
65 #include <linux/sched.h>
66 #include <linux/string.h>
67 #include <linux/skbuff.h>
68 #include <linux/random.h>
69 #include <linux/tc_ematch/tc_em_meta.h>
70 #include <net/dst.h>
71 #include <net/route.h>
72 #include <net/pkt_cls.h>
73
74 struct meta_obj
75 {
76 unsigned long value;
77 unsigned int len;
78 };
79
80 struct meta_value
81 {
82 struct tcf_meta_val hdr;
83 unsigned long val;
84 unsigned int len;
85 };
86
87 struct meta_match
88 {
89 struct meta_value lvalue;
90 struct meta_value rvalue;
91 };
92
93 static inline int meta_id(struct meta_value *v)
94 {
95 return TCF_META_ID(v->hdr.kind);
96 }
97
98 static inline int meta_type(struct meta_value *v)
99 {
100 return TCF_META_TYPE(v->hdr.kind);
101 }
102
103 #define META_COLLECTOR(FUNC) static void meta_##FUNC(struct sk_buff *skb, \
104 struct tcf_pkt_info *info, struct meta_value *v, \
105 struct meta_obj *dst, int *err)
106
107 /**************************************************************************
108 * System status & misc
109 **************************************************************************/
110
111 META_COLLECTOR(int_random)
112 {
113 get_random_bytes(&dst->value, sizeof(dst->value));
114 }
115
116 static inline unsigned long fixed_loadavg(int load)
117 {
118 int rnd_load = load + (FIXED_1/200);
119 int rnd_frac = ((rnd_load & (FIXED_1-1)) * 100) >> FSHIFT;
120
121 return ((rnd_load >> FSHIFT) * 100) + rnd_frac;
122 }
123
124 META_COLLECTOR(int_loadavg_0)
125 {
126 dst->value = fixed_loadavg(avenrun[0]);
127 }
128
129 META_COLLECTOR(int_loadavg_1)
130 {
131 dst->value = fixed_loadavg(avenrun[1]);
132 }
133
134 META_COLLECTOR(int_loadavg_2)
135 {
136 dst->value = fixed_loadavg(avenrun[2]);
137 }
138
139 /**************************************************************************
140 * Device names & indices
141 **************************************************************************/
142
143 static inline int int_dev(struct net_device *dev, struct meta_obj *dst)
144 {
145 if (unlikely(dev == NULL))
146 return -1;
147
148 dst->value = dev->ifindex;
149 return 0;
150 }
151
152 static inline int var_dev(struct net_device *dev, struct meta_obj *dst)
153 {
154 if (unlikely(dev == NULL))
155 return -1;
156
157 dst->value = (unsigned long) dev->name;
158 dst->len = strlen(dev->name);
159 return 0;
160 }
161
162 META_COLLECTOR(int_dev)
163 {
164 *err = int_dev(skb->dev, dst);
165 }
166
167 META_COLLECTOR(var_dev)
168 {
169 *err = var_dev(skb->dev, dst);
170 }
171
172 META_COLLECTOR(int_indev)
173 {
174 *err = int_dev(skb->input_dev, dst);
175 }
176
177 META_COLLECTOR(var_indev)
178 {
179 *err = var_dev(skb->input_dev, dst);
180 }
181
182 META_COLLECTOR(int_realdev)
183 {
184 *err = int_dev(skb->real_dev, dst);
185 }
186
187 META_COLLECTOR(var_realdev)
188 {
189 *err = var_dev(skb->real_dev, dst);
190 }
191
192 /**************************************************************************
193 * skb attributes
194 **************************************************************************/
195
196 META_COLLECTOR(int_priority)
197 {
198 dst->value = skb->priority;
199 }
200
201 META_COLLECTOR(int_protocol)
202 {
203 /* Let userspace take care of the byte ordering */
204 dst->value = skb->protocol;
205 }
206
207 META_COLLECTOR(int_security)
208 {
209 dst->value = skb->security;
210 }
211
212 META_COLLECTOR(int_pkttype)
213 {
214 dst->value = skb->pkt_type;
215 }
216
217 META_COLLECTOR(int_pktlen)
218 {
219 dst->value = skb->len;
220 }
221
222 META_COLLECTOR(int_datalen)
223 {
224 dst->value = skb->data_len;
225 }
226
227 META_COLLECTOR(int_maclen)
228 {
229 dst->value = skb->mac_len;
230 }
231
232 /**************************************************************************
233 * Netfilter
234 **************************************************************************/
235
236 #ifdef CONFIG_NETFILTER
237 META_COLLECTOR(int_nfmark)
238 {
239 dst->value = skb->nfmark;
240 }
241 #endif
242
243 /**************************************************************************
244 * Traffic Control
245 **************************************************************************/
246
247 META_COLLECTOR(int_tcindex)
248 {
249 dst->value = skb->tc_index;
250 }
251
252 #ifdef CONFIG_NET_CLS_ACT
253 META_COLLECTOR(int_tcverd)
254 {
255 dst->value = skb->tc_verd;
256 }
257
258 META_COLLECTOR(int_tcclassid)
259 {
260 dst->value = skb->tc_classid;
261 }
262 #endif
263
264 /**************************************************************************
265 * Routing
266 **************************************************************************/
267
268 #ifdef CONFIG_NET_CLS_ROUTE
269 META_COLLECTOR(int_rtclassid)
270 {
271 if (unlikely(skb->dst == NULL))
272 *err = -1;
273 else
274 dst->value = skb->dst->tclassid;
275 }
276 #endif
277
278 META_COLLECTOR(int_rtiif)
279 {
280 if (unlikely(skb->dst == NULL))
281 *err = -1;
282 else
283 dst->value = ((struct rtable*) skb->dst)->fl.iif;
284 }
285
286 /**************************************************************************
287 * Meta value collectors assignment table
288 **************************************************************************/
289
290 struct meta_ops
291 {
292 void (*get)(struct sk_buff *, struct tcf_pkt_info *,
293 struct meta_value *, struct meta_obj *, int *);
294 };
295
296 /* Meta value operations table listing all meta value collectors and
297 * assigns them to a type and meta id. */
298 static struct meta_ops __meta_ops[TCF_META_TYPE_MAX+1][TCF_META_ID_MAX+1] = {
299 [TCF_META_TYPE_VAR] = {
300 [TCF_META_ID_DEV] = { .get = meta_var_dev },
301 [TCF_META_ID_INDEV] = { .get = meta_var_indev },
302 [TCF_META_ID_REALDEV] = { .get = meta_var_realdev }
303 },
304 [TCF_META_TYPE_INT] = {
305 [TCF_META_ID_RANDOM] = { .get = meta_int_random },
306 [TCF_META_ID_LOADAVG_0] = { .get = meta_int_loadavg_0 },
307 [TCF_META_ID_LOADAVG_1] = { .get = meta_int_loadavg_1 },
308 [TCF_META_ID_LOADAVG_2] = { .get = meta_int_loadavg_2 },
309 [TCF_META_ID_DEV] = { .get = meta_int_dev },
310 [TCF_META_ID_INDEV] = { .get = meta_int_indev },
311 [TCF_META_ID_REALDEV] = { .get = meta_int_realdev },
312 [TCF_META_ID_PRIORITY] = { .get = meta_int_priority },
313 [TCF_META_ID_PROTOCOL] = { .get = meta_int_protocol },
314 [TCF_META_ID_SECURITY] = { .get = meta_int_security },
315 [TCF_META_ID_PKTTYPE] = { .get = meta_int_pkttype },
316 [TCF_META_ID_PKTLEN] = { .get = meta_int_pktlen },
317 [TCF_META_ID_DATALEN] = { .get = meta_int_datalen },
318 [TCF_META_ID_MACLEN] = { .get = meta_int_maclen },
319 #ifdef CONFIG_NETFILTER
320 [TCF_META_ID_NFMARK] = { .get = meta_int_nfmark },
321 #endif
322 [TCF_META_ID_TCINDEX] = { .get = meta_int_tcindex },
323 #ifdef CONFIG_NET_CLS_ACT
324 [TCF_META_ID_TCVERDICT] = { .get = meta_int_tcverd },
325 [TCF_META_ID_TCCLASSID] = { .get = meta_int_tcclassid },
326 #endif
327 #ifdef CONFIG_NET_CLS_ROUTE
328 [TCF_META_ID_RTCLASSID] = { .get = meta_int_rtclassid },
329 #endif
330 [TCF_META_ID_RTIIF] = { .get = meta_int_rtiif }
331 }
332 };
333
334 static inline struct meta_ops * meta_ops(struct meta_value *val)
335 {
336 return &__meta_ops[meta_type(val)][meta_id(val)];
337 }
338
339 /**************************************************************************
340 * Type specific operations for TCF_META_TYPE_VAR
341 **************************************************************************/
342
343 static int meta_var_compare(struct meta_obj *a, struct meta_obj *b)
344 {
345 int r = a->len - b->len;
346
347 if (r == 0)
348 r = memcmp((void *) a->value, (void *) b->value, a->len);
349
350 return r;
351 }
352
353 static int meta_var_change(struct meta_value *dst, struct rtattr *rta)
354 {
355 int len = RTA_PAYLOAD(rta);
356
357 dst->val = (unsigned long) kmalloc(len, GFP_KERNEL);
358 if (dst->val == 0UL)
359 return -ENOMEM;
360 memcpy((void *) dst->val, RTA_DATA(rta), len);
361 dst->len = len;
362 return 0;
363 }
364
365 static void meta_var_destroy(struct meta_value *v)
366 {
367 if (v->val)
368 kfree((void *) v->val);
369 }
370
371 static void meta_var_apply_extras(struct meta_value *v,
372 struct meta_obj *dst)
373 {
374 int shift = v->hdr.shift;
375
376 if (shift && shift < dst->len)
377 dst->len -= shift;
378 }
379
380 static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
381 {
382 if (v->val && v->len)
383 RTA_PUT(skb, tlv, v->len, (void *) v->val);
384 return 0;
385
386 rtattr_failure:
387 return -1;
388 }
389
390 /**************************************************************************
391 * Type specific operations for TCF_META_TYPE_INT
392 **************************************************************************/
393
394 static int meta_int_compare(struct meta_obj *a, struct meta_obj *b)
395 {
396 /* Let gcc optimize it, the unlikely is not really based on
397 * some numbers but jump free code for mismatches seems
398 * more logical. */
399 if (unlikely(a == b))
400 return 0;
401 else if (a < b)
402 return -1;
403 else
404 return 1;
405 }
406
407 static int meta_int_change(struct meta_value *dst, struct rtattr *rta)
408 {
409 if (RTA_PAYLOAD(rta) >= sizeof(unsigned long)) {
410 dst->val = *(unsigned long *) RTA_DATA(rta);
411 dst->len = sizeof(unsigned long);
412 } else if (RTA_PAYLOAD(rta) == sizeof(u32)) {
413 dst->val = *(u32 *) RTA_DATA(rta);
414 dst->len = sizeof(u32);
415 } else
416 return -EINVAL;
417
418 return 0;
419 }
420
421 static void meta_int_apply_extras(struct meta_value *v,
422 struct meta_obj *dst)
423 {
424 if (v->hdr.shift)
425 dst->value >>= v->hdr.shift;
426
427 if (v->val)
428 dst->value &= v->val;
429 }
430
431 static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
432 {
433 if (v->len == sizeof(unsigned long))
434 RTA_PUT(skb, tlv, sizeof(unsigned long), &v->val);
435 else if (v->len == sizeof(u32)) {
436 u32 d = v->val;
437 RTA_PUT(skb, tlv, sizeof(d), &d);
438 }
439
440 return 0;
441
442 rtattr_failure:
443 return -1;
444 }
445
446 /**************************************************************************
447 * Type specific operations table
448 **************************************************************************/
449
450 struct meta_type_ops
451 {
452 void (*destroy)(struct meta_value *);
453 int (*compare)(struct meta_obj *, struct meta_obj *);
454 int (*change)(struct meta_value *, struct rtattr *);
455 void (*apply_extras)(struct meta_value *, struct meta_obj *);
456 int (*dump)(struct sk_buff *, struct meta_value *, int);
457 };
458
459 static struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX+1] = {
460 [TCF_META_TYPE_VAR] = {
461 .destroy = meta_var_destroy,
462 .compare = meta_var_compare,
463 .change = meta_var_change,
464 .apply_extras = meta_var_apply_extras,
465 .dump = meta_var_dump
466 },
467 [TCF_META_TYPE_INT] = {
468 .compare = meta_int_compare,
469 .change = meta_int_change,
470 .apply_extras = meta_int_apply_extras,
471 .dump = meta_int_dump
472 }
473 };
474
475 static inline struct meta_type_ops * meta_type_ops(struct meta_value *v)
476 {
477 return &__meta_type_ops[meta_type(v)];
478 }
479
480 /**************************************************************************
481 * Core
482 **************************************************************************/
483
484 static inline int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info,
485 struct meta_value *v, struct meta_obj *dst)
486 {
487 int err = 0;
488
489 if (meta_id(v) == TCF_META_ID_VALUE) {
490 dst->value = v->val;
491 dst->len = v->len;
492 return 0;
493 }
494
495 meta_ops(v)->get(skb, info, v, dst, &err);
496 if (err < 0)
497 return err;
498
499 if (meta_type_ops(v)->apply_extras)
500 meta_type_ops(v)->apply_extras(v, dst);
501
502 return 0;
503 }
504
505 static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m,
506 struct tcf_pkt_info *info)
507 {
508 int r;
509 struct meta_match *meta = (struct meta_match *) m->data;
510 struct meta_obj l_value, r_value;
511
512 if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 ||
513 meta_get(skb, info, &meta->rvalue, &r_value) < 0)
514 return 0;
515
516 r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value);
517
518 switch (meta->lvalue.hdr.op) {
519 case TCF_EM_OPND_EQ:
520 return !r;
521 case TCF_EM_OPND_LT:
522 return r < 0;
523 case TCF_EM_OPND_GT:
524 return r > 0;
525 }
526
527 return 0;
528 }
529
530 static inline void meta_delete(struct meta_match *meta)
531 {
532 struct meta_type_ops *ops = meta_type_ops(&meta->lvalue);
533
534 if (ops && ops->destroy) {
535 ops->destroy(&meta->lvalue);
536 ops->destroy(&meta->rvalue);
537 }
538
539 kfree(meta);
540 }
541
542 static inline int meta_change_data(struct meta_value *dst, struct rtattr *rta)
543 {
544 if (rta) {
545 if (RTA_PAYLOAD(rta) == 0)
546 return -EINVAL;
547
548 return meta_type_ops(dst)->change(dst, rta);
549 }
550
551 return 0;
552 }
553
554 static inline int meta_is_supported(struct meta_value *val)
555 {
556 return (!meta_id(val) || meta_ops(val)->get);
557 }
558
559 static int em_meta_change(struct tcf_proto *tp, void *data, int len,
560 struct tcf_ematch *m)
561 {
562 int err = -EINVAL;
563 struct rtattr *tb[TCA_EM_META_MAX];
564 struct tcf_meta_hdr *hdr;
565 struct meta_match *meta = NULL;
566
567 if (rtattr_parse(tb, TCA_EM_META_MAX, data, len) < 0)
568 goto errout;
569
570 if (tb[TCA_EM_META_HDR-1] == NULL ||
571 RTA_PAYLOAD(tb[TCA_EM_META_HDR-1]) < sizeof(*hdr))
572 goto errout;
573 hdr = RTA_DATA(tb[TCA_EM_META_HDR-1]);
574
575 if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) ||
576 TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX ||
577 TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX ||
578 TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX)
579 goto errout;
580
581 meta = kmalloc(sizeof(*meta), GFP_KERNEL);
582 if (meta == NULL)
583 goto errout;
584 memset(meta, 0, sizeof(*meta));
585
586 memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left));
587 memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right));
588
589 if (!meta_is_supported(&meta->lvalue) ||
590 !meta_is_supported(&meta->rvalue)) {
591 err = -EOPNOTSUPP;
592 goto errout;
593 }
594
595 if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE-1]) < 0 ||
596 meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE-1]) < 0)
597 goto errout;
598
599 m->datalen = sizeof(*meta);
600 m->data = (unsigned long) meta;
601
602 err = 0;
603 errout:
604 if (err && meta)
605 meta_delete(meta);
606 return err;
607 }
608
609 static void em_meta_destroy(struct tcf_proto *tp, struct tcf_ematch *m)
610 {
611 if (m)
612 meta_delete((struct meta_match *) m->data);
613 }
614
615 static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em)
616 {
617 struct meta_match *meta = (struct meta_match *) em->data;
618 struct tcf_meta_hdr hdr;
619 struct meta_type_ops *ops;
620
621 memset(&hdr, 0, sizeof(hdr));
622 memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left));
623 memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right));
624
625 RTA_PUT(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr);
626
627 ops = meta_type_ops(&meta->lvalue);
628 if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 ||
629 ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0)
630 goto rtattr_failure;
631
632 return 0;
633
634 rtattr_failure:
635 return -1;
636 }
637
638 static struct tcf_ematch_ops em_meta_ops = {
639 .kind = TCF_EM_META,
640 .change = em_meta_change,
641 .match = em_meta_match,
642 .destroy = em_meta_destroy,
643 .dump = em_meta_dump,
644 .owner = THIS_MODULE,
645 .link = LIST_HEAD_INIT(em_meta_ops.link)
646 };
647
648 static int __init init_em_meta(void)
649 {
650 return tcf_em_register(&em_meta_ops);
651 }
652
653 static void __exit exit_em_meta(void)
654 {
655 tcf_em_unregister(&em_meta_ops);
656 }
657
658 MODULE_LICENSE("GPL");
659
660 module_init(init_em_meta);
661 module_exit(exit_em_meta);
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