2 * net/sched/em_meta.c Metadata ematch
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.
9 * Authors: Thomas Graf <tgraf@suug.ch>
11 * ==========================================================================
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.
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.
28 * +-----------+ +-----------+
29 * | type: INT | | type: INT |
30 * def | id: INDEV | | id: VALUE |
31 * | data: | | data: 3 |
32 * +-----------+ +-----------+
34 * ---> meta_ops[INT][INDEV](...) |
38 * +-----------+ +-----------+
39 * | type: INT | | type: INT |
40 * obj | id: INDEV | | id: VALUE |
41 * | data: 2 |<--data got filled out | data: 3 |
42 * +-----------+ +-----------+
44 * --------------> 2 equals 3 <--------------
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.
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
57 * NOTE: Certain meta values depend on other subsystems and are
58 * only available if that subsytem is enabled in the kernel.
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>
71 #include <net/route.h>
72 #include <net/pkt_cls.h>
82 struct tcf_meta_val hdr;
89 struct meta_value lvalue;
90 struct meta_value rvalue;
93 static inline int meta_id(struct meta_value *v)
95 return TCF_META_ID(v->hdr.kind);
98 static inline int meta_type(struct meta_value *v)
100 return TCF_META_TYPE(v->hdr.kind);
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)
107 /**************************************************************************
108 * System status & misc
109 **************************************************************************/
111 META_COLLECTOR(int_random)
113 get_random_bytes(&dst->value, sizeof(dst->value));
116 static inline unsigned long fixed_loadavg(int load)
118 int rnd_load = load + (FIXED_1/200);
119 int rnd_frac = ((rnd_load & (FIXED_1-1)) * 100) >> FSHIFT;
121 return ((rnd_load >> FSHIFT) * 100) + rnd_frac;
124 META_COLLECTOR(int_loadavg_0)
126 dst->value = fixed_loadavg(avenrun[0]);
129 META_COLLECTOR(int_loadavg_1)
131 dst->value = fixed_loadavg(avenrun[1]);
134 META_COLLECTOR(int_loadavg_2)
136 dst->value = fixed_loadavg(avenrun[2]);
139 /**************************************************************************
140 * Device names & indices
141 **************************************************************************/
143 static inline int int_dev(struct net_device *dev, struct meta_obj *dst)
145 if (unlikely(dev == NULL))
148 dst->value = dev->ifindex;
152 static inline int var_dev(struct net_device *dev, struct meta_obj *dst)
154 if (unlikely(dev == NULL))
157 dst->value = (unsigned long) dev->name;
158 dst->len = strlen(dev->name);
162 META_COLLECTOR(int_dev)
164 *err = int_dev(skb->dev, dst);
167 META_COLLECTOR(var_dev)
169 *err = var_dev(skb->dev, dst);
172 META_COLLECTOR(int_indev)
174 *err = int_dev(skb->input_dev, dst);
177 META_COLLECTOR(var_indev)
179 *err = var_dev(skb->input_dev, dst);
182 META_COLLECTOR(int_realdev)
184 *err = int_dev(skb->real_dev, dst);
187 META_COLLECTOR(var_realdev)
189 *err = var_dev(skb->real_dev, dst);
192 /**************************************************************************
194 **************************************************************************/
196 META_COLLECTOR(int_priority)
198 dst->value = skb->priority;
201 META_COLLECTOR(int_protocol)
203 /* Let userspace take care of the byte ordering */
204 dst->value = skb->protocol;
207 META_COLLECTOR(int_security)
209 dst->value = skb->security;
212 META_COLLECTOR(int_pkttype)
214 dst->value = skb->pkt_type;
217 META_COLLECTOR(int_pktlen)
219 dst->value = skb->len;
222 META_COLLECTOR(int_datalen)
224 dst->value = skb->data_len;
227 META_COLLECTOR(int_maclen)
229 dst->value = skb->mac_len;
232 /**************************************************************************
234 **************************************************************************/
236 #ifdef CONFIG_NETFILTER
237 META_COLLECTOR(int_nfmark)
239 dst->value = skb->nfmark;
243 /**************************************************************************
245 **************************************************************************/
247 META_COLLECTOR(int_tcindex)
249 dst->value = skb->tc_index;
252 #ifdef CONFIG_NET_CLS_ACT
253 META_COLLECTOR(int_tcverd)
255 dst->value = skb->tc_verd;
258 META_COLLECTOR(int_tcclassid)
260 dst->value = skb->tc_classid;
264 /**************************************************************************
266 **************************************************************************/
268 #ifdef CONFIG_NET_CLS_ROUTE
269 META_COLLECTOR(int_rtclassid)
271 if (unlikely(skb->dst == NULL))
274 dst->value = skb->dst->tclassid;
278 META_COLLECTOR(int_rtiif)
280 if (unlikely(skb->dst == NULL))
283 dst->value = ((struct rtable*) skb->dst)->fl.iif;
286 /**************************************************************************
287 * Meta value collectors assignment table
288 **************************************************************************/
292 void (*get)(struct sk_buff *, struct tcf_pkt_info *,
293 struct meta_value *, struct meta_obj *, int *);
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 }
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 },
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 },
327 #ifdef CONFIG_NET_CLS_ROUTE
328 [TCF_META_ID_RTCLASSID] = { .get = meta_int_rtclassid },
330 [TCF_META_ID_RTIIF] = { .get = meta_int_rtiif }
334 static inline struct meta_ops * meta_ops(struct meta_value *val)
336 return &__meta_ops[meta_type(val)][meta_id(val)];
339 /**************************************************************************
340 * Type specific operations for TCF_META_TYPE_VAR
341 **************************************************************************/
343 static int meta_var_compare(struct meta_obj *a, struct meta_obj *b)
345 int r = a->len - b->len;
348 r = memcmp((void *) a->value, (void *) b->value, a->len);
353 static int meta_var_change(struct meta_value *dst, struct rtattr *rta)
355 int len = RTA_PAYLOAD(rta);
357 dst->val = (unsigned long) kmalloc(len, GFP_KERNEL);
360 memcpy((void *) dst->val, RTA_DATA(rta), len);
365 static void meta_var_destroy(struct meta_value *v)
368 kfree((void *) v->val);
371 static void meta_var_apply_extras(struct meta_value *v,
372 struct meta_obj *dst)
374 int shift = v->hdr.shift;
376 if (shift && shift < dst->len)
380 static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
382 if (v->val && v->len)
383 RTA_PUT(skb, tlv, v->len, (void *) v->val);
390 /**************************************************************************
391 * Type specific operations for TCF_META_TYPE_INT
392 **************************************************************************/
394 static int meta_int_compare(struct meta_obj *a, struct meta_obj *b)
396 /* Let gcc optimize it, the unlikely is not really based on
397 * some numbers but jump free code for mismatches seems
399 if (unlikely(a == b))
407 static int meta_int_change(struct meta_value *dst, struct rtattr *rta)
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);
421 static void meta_int_apply_extras(struct meta_value *v,
422 struct meta_obj *dst)
425 dst->value >>= v->hdr.shift;
428 dst->value &= v->val;
431 static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
433 if (v->len == sizeof(unsigned long))
434 RTA_PUT(skb, tlv, sizeof(unsigned long), &v->val);
435 else if (v->len == sizeof(u32)) {
437 RTA_PUT(skb, tlv, sizeof(d), &d);
446 /**************************************************************************
447 * Type specific operations table
448 **************************************************************************/
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);
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
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
475 static inline struct meta_type_ops * meta_type_ops(struct meta_value *v)
477 return &__meta_type_ops[meta_type(v)];
480 /**************************************************************************
482 **************************************************************************/
484 static inline int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info,
485 struct meta_value *v, struct meta_obj *dst)
489 if (meta_id(v) == TCF_META_ID_VALUE) {
495 meta_ops(v)->get(skb, info, v, dst, &err);
499 if (meta_type_ops(v)->apply_extras)
500 meta_type_ops(v)->apply_extras(v, dst);
505 static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m,
506 struct tcf_pkt_info *info)
509 struct meta_match *meta = (struct meta_match *) m->data;
510 struct meta_obj l_value, r_value;
512 if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 ||
513 meta_get(skb, info, &meta->rvalue, &r_value) < 0)
516 r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value);
518 switch (meta->lvalue.hdr.op) {
530 static inline void meta_delete(struct meta_match *meta)
532 struct meta_type_ops *ops = meta_type_ops(&meta->lvalue);
534 if (ops && ops->destroy) {
535 ops->destroy(&meta->lvalue);
536 ops->destroy(&meta->rvalue);
542 static inline int meta_change_data(struct meta_value *dst, struct rtattr *rta)
545 if (RTA_PAYLOAD(rta) == 0)
548 return meta_type_ops(dst)->change(dst, rta);
554 static inline int meta_is_supported(struct meta_value *val)
556 return (!meta_id(val) || meta_ops(val)->get);
559 static int em_meta_change(struct tcf_proto *tp, void *data, int len,
560 struct tcf_ematch *m)
563 struct rtattr *tb[TCA_EM_META_MAX];
564 struct tcf_meta_hdr *hdr;
565 struct meta_match *meta = NULL;
567 if (rtattr_parse(tb, TCA_EM_META_MAX, data, len) < 0)
570 if (tb[TCA_EM_META_HDR-1] == NULL ||
571 RTA_PAYLOAD(tb[TCA_EM_META_HDR-1]) < sizeof(*hdr))
573 hdr = RTA_DATA(tb[TCA_EM_META_HDR-1]);
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)
581 meta = kmalloc(sizeof(*meta), GFP_KERNEL);
584 memset(meta, 0, sizeof(*meta));
586 memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left));
587 memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right));
589 if (!meta_is_supported(&meta->lvalue) ||
590 !meta_is_supported(&meta->rvalue)) {
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)
599 m->datalen = sizeof(*meta);
600 m->data = (unsigned long) meta;
609 static void em_meta_destroy(struct tcf_proto *tp, struct tcf_ematch *m)
612 meta_delete((struct meta_match *) m->data);
615 static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em)
617 struct meta_match *meta = (struct meta_match *) em->data;
618 struct tcf_meta_hdr hdr;
619 struct meta_type_ops *ops;
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));
625 RTA_PUT(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr);
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)
638 static struct tcf_ematch_ops em_meta_ops = {
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)
648 static int __init init_em_meta(void)
650 return tcf_em_register(&em_meta_ops);
653 static void __exit exit_em_meta(void)
655 tcf_em_unregister(&em_meta_ops);
658 MODULE_LICENSE("GPL");
660 module_init(init_em_meta);
661 module_exit(exit_em_meta);