cls_api.c 13.3 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
/*
 * net/sched/cls_api.c	Packet classifier API.
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 * Changes:
 *
 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
 *
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/kmod.h>
25
#include <linux/netlink.h>
26
#include <linux/err.h>
27 28
#include <net/net_namespace.h>
#include <net/sock.h>
29
#include <net/netlink.h>
L
Linus Torvalds 已提交
30 31 32 33 34
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>

/* The list of all installed classifier types */

35
static struct tcf_proto_ops *tcf_proto_base __read_mostly;
L
Linus Torvalds 已提交
36 37 38 39 40 41

/* Protects list of registered TC modules. It is pure SMP lock. */
static DEFINE_RWLOCK(cls_mod_lock);

/* Find classifier type by string name */

42
static struct tcf_proto_ops *tcf_proto_lookup_ops(struct nlattr *kind)
L
Linus Torvalds 已提交
43 44 45 46 47 48
{
	struct tcf_proto_ops *t = NULL;

	if (kind) {
		read_lock(&cls_mod_lock);
		for (t = tcf_proto_base; t; t = t->next) {
49
			if (nla_strcmp(kind, t->kind) == 0) {
L
Linus Torvalds 已提交
50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78
				if (!try_module_get(t->owner))
					t = NULL;
				break;
			}
		}
		read_unlock(&cls_mod_lock);
	}
	return t;
}

/* Register(unregister) new classifier type */

int register_tcf_proto_ops(struct tcf_proto_ops *ops)
{
	struct tcf_proto_ops *t, **tp;
	int rc = -EEXIST;

	write_lock(&cls_mod_lock);
	for (tp = &tcf_proto_base; (t = *tp) != NULL; tp = &t->next)
		if (!strcmp(ops->kind, t->kind))
			goto out;

	ops->next = NULL;
	*tp = ops;
	rc = 0;
out:
	write_unlock(&cls_mod_lock);
	return rc;
}
79
EXPORT_SYMBOL(register_tcf_proto_ops);
L
Linus Torvalds 已提交
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98

int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
{
	struct tcf_proto_ops *t, **tp;
	int rc = -ENOENT;

	write_lock(&cls_mod_lock);
	for (tp = &tcf_proto_base; (t=*tp) != NULL; tp = &t->next)
		if (t == ops)
			break;

	if (!t)
		goto out;
	*tp = t->next;
	rc = 0;
out:
	write_unlock(&cls_mod_lock);
	return rc;
}
99
EXPORT_SYMBOL(unregister_tcf_proto_ops);
L
Linus Torvalds 已提交
100 101 102 103 104 105 106

static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n,
			  struct tcf_proto *tp, unsigned long fh, int event);


/* Select new prio value from the range, managed by kernel. */

107
static inline u32 tcf_auto_prio(struct tcf_proto *tp)
L
Linus Torvalds 已提交
108
{
109
	u32 first = TC_H_MAKE(0xC0000000U, 0U);
L
Linus Torvalds 已提交
110 111 112 113 114 115 116 117 118 119 120

	if (tp)
		first = tp->prio-1;

	return first;
}

/* Add/change/delete/get a filter node */

static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
{
121
	struct net *net = sock_net(skb->sk);
122
	struct nlattr *tca[TCA_MAX + 1];
L
Linus Torvalds 已提交
123 124 125 126 127 128 129 130 131 132
	struct tcmsg *t;
	u32 protocol;
	u32 prio;
	u32 nprio;
	u32 parent;
	struct net_device *dev;
	struct Qdisc  *q;
	struct tcf_proto **back, **chain;
	struct tcf_proto *tp;
	struct tcf_proto_ops *tp_ops;
133
	const struct Qdisc_class_ops *cops;
L
Linus Torvalds 已提交
134 135 136 137
	unsigned long cl;
	unsigned long fh;
	int err;

138 139 140
	if (net != &init_net)
		return -EINVAL;

L
Linus Torvalds 已提交
141 142 143 144 145 146 147 148 149 150 151 152
replay:
	t = NLMSG_DATA(n);
	protocol = TC_H_MIN(t->tcm_info);
	prio = TC_H_MAJ(t->tcm_info);
	nprio = prio;
	parent = t->tcm_parent;
	cl = 0;

	if (prio == 0) {
		/* If no priority is given, user wants we allocated it. */
		if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE))
			return -ENOENT;
153
		prio = TC_H_MAKE(0x80000000U, 0U);
L
Linus Torvalds 已提交
154 155 156 157 158
	}

	/* Find head of filter chain. */

	/* Find link */
159 160
	dev = __dev_get_by_index(&init_net, t->tcm_ifindex);
	if (dev == NULL)
L
Linus Torvalds 已提交
161 162
		return -ENODEV;

163 164 165 166
	err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL);
	if (err < 0)
		return err;

L
Linus Torvalds 已提交
167 168 169 170
	/* Find qdisc */
	if (!parent) {
		q = dev->qdisc_sleeping;
		parent = q->handle;
171 172 173 174 175
	} else {
		q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
		if (q == NULL)
			return -EINVAL;
	}
L
Linus Torvalds 已提交
176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208

	/* Is it classful? */
	if ((cops = q->ops->cl_ops) == NULL)
		return -EINVAL;

	/* Do we search for filter, attached to class? */
	if (TC_H_MIN(parent)) {
		cl = cops->get(q, parent);
		if (cl == 0)
			return -ENOENT;
	}

	/* And the last stroke */
	chain = cops->tcf_chain(q, cl);
	err = -EINVAL;
	if (chain == NULL)
		goto errout;

	/* Check the chain for existence of proto-tcf with this priority */
	for (back = chain; (tp=*back) != NULL; back = &tp->next) {
		if (tp->prio >= prio) {
			if (tp->prio == prio) {
				if (!nprio || (tp->protocol != protocol && protocol))
					goto errout;
			} else
				tp = NULL;
			break;
		}
	}

	if (tp == NULL) {
		/* Proto-tcf does not exist, create new one */

209
		if (tca[TCA_KIND] == NULL || !protocol)
L
Linus Torvalds 已提交
210 211 212 213 214 215 216 217 218 219
			goto errout;

		err = -ENOENT;
		if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE))
			goto errout;


		/* Create new proto tcf */

		err = -ENOBUFS;
220 221
		tp = kzalloc(sizeof(*tp), GFP_KERNEL);
		if (tp == NULL)
L
Linus Torvalds 已提交
222 223
			goto errout;
		err = -EINVAL;
224
		tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND]);
L
Linus Torvalds 已提交
225 226
		if (tp_ops == NULL) {
#ifdef CONFIG_KMOD
227
			struct nlattr *kind = tca[TCA_KIND];
L
Linus Torvalds 已提交
228 229 230
			char name[IFNAMSIZ];

			if (kind != NULL &&
231
			    nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
L
Linus Torvalds 已提交
232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256
				rtnl_unlock();
				request_module("cls_%s", name);
				rtnl_lock();
				tp_ops = tcf_proto_lookup_ops(kind);
				/* We dropped the RTNL semaphore in order to
				 * perform the module load.  So, even if we
				 * succeeded in loading the module we have to
				 * replay the request.  We indicate this using
				 * -EAGAIN.
				 */
				if (tp_ops != NULL) {
					module_put(tp_ops->owner);
					err = -EAGAIN;
				}
			}
#endif
			kfree(tp);
			goto errout;
		}
		tp->ops = tp_ops;
		tp->protocol = protocol;
		tp->prio = nprio ? : tcf_auto_prio(*back);
		tp->q = q;
		tp->classify = tp_ops->classify;
		tp->classid = parent;
257 258 259

		err = tp_ops->init(tp);
		if (err != 0) {
L
Linus Torvalds 已提交
260 261 262 263 264 265 266 267 268 269
			module_put(tp_ops->owner);
			kfree(tp);
			goto errout;
		}

		qdisc_lock_tree(dev);
		tp->next = *back;
		*back = tp;
		qdisc_unlock_tree(dev);

270
	} else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind))
L
Linus Torvalds 已提交
271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287
		goto errout;

	fh = tp->ops->get(tp, t->tcm_handle);

	if (fh == 0) {
		if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
			qdisc_lock_tree(dev);
			*back = tp->next;
			qdisc_unlock_tree(dev);

			tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER);
			tcf_destroy(tp);
			err = 0;
			goto errout;
		}

		err = -ENOENT;
288 289
		if (n->nlmsg_type != RTM_NEWTFILTER ||
		    !(n->nlmsg_flags & NLM_F_CREATE))
L
Linus Torvalds 已提交
290 291 292
			goto errout;
	} else {
		switch (n->nlmsg_type) {
293
		case RTM_NEWTFILTER:
L
Linus Torvalds 已提交
294
			err = -EEXIST;
295
			if (n->nlmsg_flags & NLM_F_EXCL)
L
Linus Torvalds 已提交
296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324
				goto errout;
			break;
		case RTM_DELTFILTER:
			err = tp->ops->delete(tp, fh);
			if (err == 0)
				tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER);
			goto errout;
		case RTM_GETTFILTER:
			err = tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER);
			goto errout;
		default:
			err = -EINVAL;
			goto errout;
		}
	}

	err = tp->ops->change(tp, cl, t->tcm_handle, tca, &fh);
	if (err == 0)
		tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER);

errout:
	if (cl)
		cops->put(q, cl);
	if (err == -EAGAIN)
		/* Replay the request. */
		goto replay;
	return err;
}

325 326
static int tcf_fill_node(struct sk_buff *skb, struct tcf_proto *tp,
			 unsigned long fh, u32 pid, u32 seq, u16 flags, int event)
L
Linus Torvalds 已提交
327 328 329
{
	struct tcmsg *tcm;
	struct nlmsghdr  *nlh;
330
	unsigned char *b = skb_tail_pointer(skb);
L
Linus Torvalds 已提交
331

J
Jamal Hadi Salim 已提交
332
	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
L
Linus Torvalds 已提交
333 334
	tcm = NLMSG_DATA(nlh);
	tcm->tcm_family = AF_UNSPEC;
335 336
	tcm->tcm__pad1 = 0;
	tcm->tcm__pad1 = 0;
L
Linus Torvalds 已提交
337 338 339
	tcm->tcm_ifindex = tp->q->dev->ifindex;
	tcm->tcm_parent = tp->classid;
	tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
340
	NLA_PUT_STRING(skb, TCA_KIND, tp->ops->kind);
L
Linus Torvalds 已提交
341 342 343 344
	tcm->tcm_handle = fh;
	if (RTM_DELTFILTER != event) {
		tcm->tcm_handle = 0;
		if (tp->ops->dump && tp->ops->dump(tp, fh, skb, tcm) < 0)
345
			goto nla_put_failure;
L
Linus Torvalds 已提交
346
	}
347
	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
L
Linus Torvalds 已提交
348 349 350
	return skb->len;

nlmsg_failure:
351
nla_put_failure:
352
	nlmsg_trim(skb, b);
L
Linus Torvalds 已提交
353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370
	return -1;
}

static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n,
			  struct tcf_proto *tp, unsigned long fh, int event)
{
	struct sk_buff *skb;
	u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;

	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
	if (!skb)
		return -ENOBUFS;

	if (tcf_fill_node(skb, tp, fh, pid, n->nlmsg_seq, 0, event) <= 0) {
		kfree_skb(skb);
		return -EINVAL;
	}

371 372
	return rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC,
			      n->nlmsg_flags & NLM_F_ECHO);
L
Linus Torvalds 已提交
373 374
}

375
struct tcf_dump_args {
L
Linus Torvalds 已提交
376 377 378 379 380
	struct tcf_walker w;
	struct sk_buff *skb;
	struct netlink_callback *cb;
};

381 382
static int tcf_node_dump(struct tcf_proto *tp, unsigned long n,
			 struct tcf_walker *arg)
L
Linus Torvalds 已提交
383
{
384
	struct tcf_dump_args *a = (void *)arg;
L
Linus Torvalds 已提交
385 386 387 388 389 390 391

	return tcf_fill_node(a->skb, tp, n, NETLINK_CB(a->cb->skb).pid,
			     a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER);
}

static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
{
392
	struct net *net = sock_net(skb->sk);
L
Linus Torvalds 已提交
393 394 395 396 397
	int t;
	int s_t;
	struct net_device *dev;
	struct Qdisc *q;
	struct tcf_proto *tp, **chain;
398
	struct tcmsg *tcm = (struct tcmsg *)NLMSG_DATA(cb->nlh);
L
Linus Torvalds 已提交
399
	unsigned long cl = 0;
400
	const struct Qdisc_class_ops *cops;
L
Linus Torvalds 已提交
401 402
	struct tcf_dump_args arg;

403 404 405
	if (net != &init_net)
		return 0;

L
Linus Torvalds 已提交
406 407
	if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
		return skb->len;
408
	if ((dev = dev_get_by_index(&init_net, tcm->tcm_ifindex)) == NULL)
L
Linus Torvalds 已提交
409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441
		return skb->len;

	if (!tcm->tcm_parent)
		q = dev->qdisc_sleeping;
	else
		q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
	if (!q)
		goto out;
	if ((cops = q->ops->cl_ops) == NULL)
		goto errout;
	if (TC_H_MIN(tcm->tcm_parent)) {
		cl = cops->get(q, tcm->tcm_parent);
		if (cl == 0)
			goto errout;
	}
	chain = cops->tcf_chain(q, cl);
	if (chain == NULL)
		goto errout;

	s_t = cb->args[0];

	for (tp=*chain, t=0; tp; tp = tp->next, t++) {
		if (t < s_t) continue;
		if (TC_H_MAJ(tcm->tcm_info) &&
		    TC_H_MAJ(tcm->tcm_info) != tp->prio)
			continue;
		if (TC_H_MIN(tcm->tcm_info) &&
		    TC_H_MIN(tcm->tcm_info) != tp->protocol)
			continue;
		if (t > s_t)
			memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
		if (cb->args[1] == 0) {
			if (tcf_fill_node(skb, tp, 0, NETLINK_CB(cb->skb).pid,
442 443
					  cb->nlh->nlmsg_seq, NLM_F_MULTI,
					  RTM_NEWTFILTER) <= 0)
L
Linus Torvalds 已提交
444
				break;
445

L
Linus Torvalds 已提交
446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471
			cb->args[1] = 1;
		}
		if (tp->ops->walk == NULL)
			continue;
		arg.w.fn = tcf_node_dump;
		arg.skb = skb;
		arg.cb = cb;
		arg.w.stop = 0;
		arg.w.skip = cb->args[1]-1;
		arg.w.count = 0;
		tp->ops->walk(tp, &arg.w);
		cb->args[1] = arg.w.count+1;
		if (arg.w.stop)
			break;
	}

	cb->args[0] = t;

errout:
	if (cl)
		cops->put(q, cl);
out:
	dev_put(dev);
	return skb->len;
}

472
void tcf_exts_destroy(struct tcf_proto *tp, struct tcf_exts *exts)
L
Linus Torvalds 已提交
473 474 475 476 477 478 479 480
{
#ifdef CONFIG_NET_CLS_ACT
	if (exts->action) {
		tcf_action_destroy(exts->action, TCA_ACT_UNBIND);
		exts->action = NULL;
	}
#endif
}
481
EXPORT_SYMBOL(tcf_exts_destroy);
L
Linus Torvalds 已提交
482

483 484
int tcf_exts_validate(struct tcf_proto *tp, struct nlattr **tb,
		  struct nlattr *rate_tlv, struct tcf_exts *exts,
485
		  const struct tcf_ext_map *map)
L
Linus Torvalds 已提交
486 487
{
	memset(exts, 0, sizeof(*exts));
488

L
Linus Torvalds 已提交
489 490 491 492
#ifdef CONFIG_NET_CLS_ACT
	{
		struct tc_action *act;

493
		if (map->police && tb[map->police]) {
494
			act = tcf_action_init_1(tb[map->police], rate_tlv,
495
						"police", TCA_ACT_NOREPLACE,
496 497 498
						TCA_ACT_BIND);
			if (IS_ERR(act))
				return PTR_ERR(act);
L
Linus Torvalds 已提交
499 500 501

			act->type = TCA_OLD_COMPAT;
			exts->action = act;
502
		} else if (map->action && tb[map->action]) {
503
			act = tcf_action_init(tb[map->action], rate_tlv, NULL,
504 505 506
					      TCA_ACT_NOREPLACE, TCA_ACT_BIND);
			if (IS_ERR(act))
				return PTR_ERR(act);
L
Linus Torvalds 已提交
507 508 509 510 511

			exts->action = act;
		}
	}
#else
512 513
	if ((map->action && tb[map->action]) ||
	    (map->police && tb[map->police]))
L
Linus Torvalds 已提交
514 515 516 517 518
		return -EOPNOTSUPP;
#endif

	return 0;
}
519
EXPORT_SYMBOL(tcf_exts_validate);
L
Linus Torvalds 已提交
520

521 522
void tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst,
		     struct tcf_exts *src)
L
Linus Torvalds 已提交
523 524 525 526 527 528 529 530 531 532 533 534
{
#ifdef CONFIG_NET_CLS_ACT
	if (src->action) {
		struct tc_action *act;
		tcf_tree_lock(tp);
		act = xchg(&dst->action, src->action);
		tcf_tree_unlock(tp);
		if (act)
			tcf_action_destroy(act, TCA_ACT_UNBIND);
	}
#endif
}
535
EXPORT_SYMBOL(tcf_exts_change);
L
Linus Torvalds 已提交
536

537
int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts,
538
		  const struct tcf_ext_map *map)
L
Linus Torvalds 已提交
539 540 541 542 543 544 545 546
{
#ifdef CONFIG_NET_CLS_ACT
	if (map->action && exts->action) {
		/*
		 * again for backward compatible mode - we want
		 * to work with both old and new modes of entering
		 * tc data even if iproute2  was newer - jhs
		 */
547
		struct nlattr *nest;
L
Linus Torvalds 已提交
548 549

		if (exts->action->type != TCA_OLD_COMPAT) {
550 551 552
			nest = nla_nest_start(skb, map->action);
			if (nest == NULL)
				goto nla_put_failure;
L
Linus Torvalds 已提交
553
			if (tcf_action_dump(skb, exts->action, 0, 0) < 0)
554
				goto nla_put_failure;
555
			nla_nest_end(skb, nest);
L
Linus Torvalds 已提交
556
		} else if (map->police) {
557 558 559
			nest = nla_nest_start(skb, map->police);
			if (nest == NULL)
				goto nla_put_failure;
L
Linus Torvalds 已提交
560
			if (tcf_action_dump_old(skb, exts->action, 0, 0) < 0)
561
				goto nla_put_failure;
562
			nla_nest_end(skb, nest);
L
Linus Torvalds 已提交
563 564 565 566
		}
	}
#endif
	return 0;
567
nla_put_failure: __attribute__ ((unused))
L
Linus Torvalds 已提交
568 569
	return -1;
}
570
EXPORT_SYMBOL(tcf_exts_dump);
L
Linus Torvalds 已提交
571

572 573

int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts,
574
			const struct tcf_ext_map *map)
L
Linus Torvalds 已提交
575 576 577 578
{
#ifdef CONFIG_NET_CLS_ACT
	if (exts->action)
		if (tcf_action_copy_stats(skb, exts->action, 1) < 0)
579
			goto nla_put_failure;
L
Linus Torvalds 已提交
580 581
#endif
	return 0;
582
nla_put_failure: __attribute__ ((unused))
L
Linus Torvalds 已提交
583 584
	return -1;
}
585
EXPORT_SYMBOL(tcf_exts_dump_stats);
L
Linus Torvalds 已提交
586 587 588

static int __init tc_filter_init(void)
{
589 590 591 592
	rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL);
	rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL);
	rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
						 tc_dump_tfilter);
L
Linus Torvalds 已提交
593 594 595 596 597

	return 0;
}

subsys_initcall(tc_filter_init);