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/net/core/fib_rules.c

http://github.com/mirrors/linux
C | 1275 lines | 1014 code | 235 blank | 26 comment | 290 complexity | 8ba3cf8a5260be48e87ba4d67eb62171 MD5 | raw file
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * net/core/fib_rules.c		Generic Routing Rules
   4 *
   5 * Authors:	Thomas Graf <tgraf@suug.ch>
   6 */
   7
   8#include <linux/types.h>
   9#include <linux/kernel.h>
  10#include <linux/slab.h>
  11#include <linux/list.h>
  12#include <linux/module.h>
  13#include <net/net_namespace.h>
  14#include <net/sock.h>
  15#include <net/fib_rules.h>
  16#include <net/ip_tunnels.h>
  17
  18static const struct fib_kuid_range fib_kuid_range_unset = {
  19	KUIDT_INIT(0),
  20	KUIDT_INIT(~0),
  21};
  22
  23bool fib_rule_matchall(const struct fib_rule *rule)
  24{
  25	if (rule->iifindex || rule->oifindex || rule->mark || rule->tun_id ||
  26	    rule->flags)
  27		return false;
  28	if (rule->suppress_ifgroup != -1 || rule->suppress_prefixlen != -1)
  29		return false;
  30	if (!uid_eq(rule->uid_range.start, fib_kuid_range_unset.start) ||
  31	    !uid_eq(rule->uid_range.end, fib_kuid_range_unset.end))
  32		return false;
  33	if (fib_rule_port_range_set(&rule->sport_range))
  34		return false;
  35	if (fib_rule_port_range_set(&rule->dport_range))
  36		return false;
  37	return true;
  38}
  39EXPORT_SYMBOL_GPL(fib_rule_matchall);
  40
  41int fib_default_rule_add(struct fib_rules_ops *ops,
  42			 u32 pref, u32 table, u32 flags)
  43{
  44	struct fib_rule *r;
  45
  46	r = kzalloc(ops->rule_size, GFP_KERNEL);
  47	if (r == NULL)
  48		return -ENOMEM;
  49
  50	refcount_set(&r->refcnt, 1);
  51	r->action = FR_ACT_TO_TBL;
  52	r->pref = pref;
  53	r->table = table;
  54	r->flags = flags;
  55	r->proto = RTPROT_KERNEL;
  56	r->fr_net = ops->fro_net;
  57	r->uid_range = fib_kuid_range_unset;
  58
  59	r->suppress_prefixlen = -1;
  60	r->suppress_ifgroup = -1;
  61
  62	/* The lock is not required here, the list in unreacheable
  63	 * at the moment this function is called */
  64	list_add_tail(&r->list, &ops->rules_list);
  65	return 0;
  66}
  67EXPORT_SYMBOL(fib_default_rule_add);
  68
  69static u32 fib_default_rule_pref(struct fib_rules_ops *ops)
  70{
  71	struct list_head *pos;
  72	struct fib_rule *rule;
  73
  74	if (!list_empty(&ops->rules_list)) {
  75		pos = ops->rules_list.next;
  76		if (pos->next != &ops->rules_list) {
  77			rule = list_entry(pos->next, struct fib_rule, list);
  78			if (rule->pref)
  79				return rule->pref - 1;
  80		}
  81	}
  82
  83	return 0;
  84}
  85
  86static void notify_rule_change(int event, struct fib_rule *rule,
  87			       struct fib_rules_ops *ops, struct nlmsghdr *nlh,
  88			       u32 pid);
  89
  90static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family)
  91{
  92	struct fib_rules_ops *ops;
  93
  94	rcu_read_lock();
  95	list_for_each_entry_rcu(ops, &net->rules_ops, list) {
  96		if (ops->family == family) {
  97			if (!try_module_get(ops->owner))
  98				ops = NULL;
  99			rcu_read_unlock();
 100			return ops;
 101		}
 102	}
 103	rcu_read_unlock();
 104
 105	return NULL;
 106}
 107
 108static void rules_ops_put(struct fib_rules_ops *ops)
 109{
 110	if (ops)
 111		module_put(ops->owner);
 112}
 113
 114static void flush_route_cache(struct fib_rules_ops *ops)
 115{
 116	if (ops->flush_cache)
 117		ops->flush_cache(ops);
 118}
 119
 120static int __fib_rules_register(struct fib_rules_ops *ops)
 121{
 122	int err = -EEXIST;
 123	struct fib_rules_ops *o;
 124	struct net *net;
 125
 126	net = ops->fro_net;
 127
 128	if (ops->rule_size < sizeof(struct fib_rule))
 129		return -EINVAL;
 130
 131	if (ops->match == NULL || ops->configure == NULL ||
 132	    ops->compare == NULL || ops->fill == NULL ||
 133	    ops->action == NULL)
 134		return -EINVAL;
 135
 136	spin_lock(&net->rules_mod_lock);
 137	list_for_each_entry(o, &net->rules_ops, list)
 138		if (ops->family == o->family)
 139			goto errout;
 140
 141	list_add_tail_rcu(&ops->list, &net->rules_ops);
 142	err = 0;
 143errout:
 144	spin_unlock(&net->rules_mod_lock);
 145
 146	return err;
 147}
 148
 149struct fib_rules_ops *
 150fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
 151{
 152	struct fib_rules_ops *ops;
 153	int err;
 154
 155	ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL);
 156	if (ops == NULL)
 157		return ERR_PTR(-ENOMEM);
 158
 159	INIT_LIST_HEAD(&ops->rules_list);
 160	ops->fro_net = net;
 161
 162	err = __fib_rules_register(ops);
 163	if (err) {
 164		kfree(ops);
 165		ops = ERR_PTR(err);
 166	}
 167
 168	return ops;
 169}
 170EXPORT_SYMBOL_GPL(fib_rules_register);
 171
 172static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
 173{
 174	struct fib_rule *rule, *tmp;
 175
 176	list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
 177		list_del_rcu(&rule->list);
 178		if (ops->delete)
 179			ops->delete(rule);
 180		fib_rule_put(rule);
 181	}
 182}
 183
 184void fib_rules_unregister(struct fib_rules_ops *ops)
 185{
 186	struct net *net = ops->fro_net;
 187
 188	spin_lock(&net->rules_mod_lock);
 189	list_del_rcu(&ops->list);
 190	spin_unlock(&net->rules_mod_lock);
 191
 192	fib_rules_cleanup_ops(ops);
 193	kfree_rcu(ops, rcu);
 194}
 195EXPORT_SYMBOL_GPL(fib_rules_unregister);
 196
 197static int uid_range_set(struct fib_kuid_range *range)
 198{
 199	return uid_valid(range->start) && uid_valid(range->end);
 200}
 201
 202static struct fib_kuid_range nla_get_kuid_range(struct nlattr **tb)
 203{
 204	struct fib_rule_uid_range *in;
 205	struct fib_kuid_range out;
 206
 207	in = (struct fib_rule_uid_range *)nla_data(tb[FRA_UID_RANGE]);
 208
 209	out.start = make_kuid(current_user_ns(), in->start);
 210	out.end = make_kuid(current_user_ns(), in->end);
 211
 212	return out;
 213}
 214
 215static int nla_put_uid_range(struct sk_buff *skb, struct fib_kuid_range *range)
 216{
 217	struct fib_rule_uid_range out = {
 218		from_kuid_munged(current_user_ns(), range->start),
 219		from_kuid_munged(current_user_ns(), range->end)
 220	};
 221
 222	return nla_put(skb, FRA_UID_RANGE, sizeof(out), &out);
 223}
 224
 225static int nla_get_port_range(struct nlattr *pattr,
 226			      struct fib_rule_port_range *port_range)
 227{
 228	const struct fib_rule_port_range *pr = nla_data(pattr);
 229
 230	if (!fib_rule_port_range_valid(pr))
 231		return -EINVAL;
 232
 233	port_range->start = pr->start;
 234	port_range->end = pr->end;
 235
 236	return 0;
 237}
 238
 239static int nla_put_port_range(struct sk_buff *skb, int attrtype,
 240			      struct fib_rule_port_range *range)
 241{
 242	return nla_put(skb, attrtype, sizeof(*range), range);
 243}
 244
 245static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
 246			  struct flowi *fl, int flags,
 247			  struct fib_lookup_arg *arg)
 248{
 249	int ret = 0;
 250
 251	if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
 252		goto out;
 253
 254	if (rule->oifindex && (rule->oifindex != fl->flowi_oif))
 255		goto out;
 256
 257	if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
 258		goto out;
 259
 260	if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id))
 261		goto out;
 262
 263	if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg))
 264		goto out;
 265
 266	if (uid_lt(fl->flowi_uid, rule->uid_range.start) ||
 267	    uid_gt(fl->flowi_uid, rule->uid_range.end))
 268		goto out;
 269
 270	ret = ops->match(rule, fl, flags);
 271out:
 272	return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
 273}
 274
 275int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
 276		     int flags, struct fib_lookup_arg *arg)
 277{
 278	struct fib_rule *rule;
 279	int err;
 280
 281	rcu_read_lock();
 282
 283	list_for_each_entry_rcu(rule, &ops->rules_list, list) {
 284jumped:
 285		if (!fib_rule_match(rule, ops, fl, flags, arg))
 286			continue;
 287
 288		if (rule->action == FR_ACT_GOTO) {
 289			struct fib_rule *target;
 290
 291			target = rcu_dereference(rule->ctarget);
 292			if (target == NULL) {
 293				continue;
 294			} else {
 295				rule = target;
 296				goto jumped;
 297			}
 298		} else if (rule->action == FR_ACT_NOP)
 299			continue;
 300		else
 301			err = ops->action(rule, fl, flags, arg);
 302
 303		if (!err && ops->suppress && ops->suppress(rule, arg))
 304			continue;
 305
 306		if (err != -EAGAIN) {
 307			if ((arg->flags & FIB_LOOKUP_NOREF) ||
 308			    likely(refcount_inc_not_zero(&rule->refcnt))) {
 309				arg->rule = rule;
 310				goto out;
 311			}
 312			break;
 313		}
 314	}
 315
 316	err = -ESRCH;
 317out:
 318	rcu_read_unlock();
 319
 320	return err;
 321}
 322EXPORT_SYMBOL_GPL(fib_rules_lookup);
 323
 324static int call_fib_rule_notifier(struct notifier_block *nb,
 325				  enum fib_event_type event_type,
 326				  struct fib_rule *rule, int family,
 327				  struct netlink_ext_ack *extack)
 328{
 329	struct fib_rule_notifier_info info = {
 330		.info.family = family,
 331		.info.extack = extack,
 332		.rule = rule,
 333	};
 334
 335	return call_fib_notifier(nb, event_type, &info.info);
 336}
 337
 338static int call_fib_rule_notifiers(struct net *net,
 339				   enum fib_event_type event_type,
 340				   struct fib_rule *rule,
 341				   struct fib_rules_ops *ops,
 342				   struct netlink_ext_ack *extack)
 343{
 344	struct fib_rule_notifier_info info = {
 345		.info.family = ops->family,
 346		.info.extack = extack,
 347		.rule = rule,
 348	};
 349
 350	ops->fib_rules_seq++;
 351	return call_fib_notifiers(net, event_type, &info.info);
 352}
 353
 354/* Called with rcu_read_lock() */
 355int fib_rules_dump(struct net *net, struct notifier_block *nb, int family,
 356		   struct netlink_ext_ack *extack)
 357{
 358	struct fib_rules_ops *ops;
 359	struct fib_rule *rule;
 360	int err = 0;
 361
 362	ops = lookup_rules_ops(net, family);
 363	if (!ops)
 364		return -EAFNOSUPPORT;
 365	list_for_each_entry_rcu(rule, &ops->rules_list, list) {
 366		err = call_fib_rule_notifier(nb, FIB_EVENT_RULE_ADD,
 367					     rule, family, extack);
 368		if (err)
 369			break;
 370	}
 371	rules_ops_put(ops);
 372
 373	return err;
 374}
 375EXPORT_SYMBOL_GPL(fib_rules_dump);
 376
 377unsigned int fib_rules_seq_read(struct net *net, int family)
 378{
 379	unsigned int fib_rules_seq;
 380	struct fib_rules_ops *ops;
 381
 382	ASSERT_RTNL();
 383
 384	ops = lookup_rules_ops(net, family);
 385	if (!ops)
 386		return 0;
 387	fib_rules_seq = ops->fib_rules_seq;
 388	rules_ops_put(ops);
 389
 390	return fib_rules_seq;
 391}
 392EXPORT_SYMBOL_GPL(fib_rules_seq_read);
 393
 394static struct fib_rule *rule_find(struct fib_rules_ops *ops,
 395				  struct fib_rule_hdr *frh,
 396				  struct nlattr **tb,
 397				  struct fib_rule *rule,
 398				  bool user_priority)
 399{
 400	struct fib_rule *r;
 401
 402	list_for_each_entry(r, &ops->rules_list, list) {
 403		if (rule->action && r->action != rule->action)
 404			continue;
 405
 406		if (rule->table && r->table != rule->table)
 407			continue;
 408
 409		if (user_priority && r->pref != rule->pref)
 410			continue;
 411
 412		if (rule->iifname[0] &&
 413		    memcmp(r->iifname, rule->iifname, IFNAMSIZ))
 414			continue;
 415
 416		if (rule->oifname[0] &&
 417		    memcmp(r->oifname, rule->oifname, IFNAMSIZ))
 418			continue;
 419
 420		if (rule->mark && r->mark != rule->mark)
 421			continue;
 422
 423		if (rule->suppress_ifgroup != -1 &&
 424		    r->suppress_ifgroup != rule->suppress_ifgroup)
 425			continue;
 426
 427		if (rule->suppress_prefixlen != -1 &&
 428		    r->suppress_prefixlen != rule->suppress_prefixlen)
 429			continue;
 430
 431		if (rule->mark_mask && r->mark_mask != rule->mark_mask)
 432			continue;
 433
 434		if (rule->tun_id && r->tun_id != rule->tun_id)
 435			continue;
 436
 437		if (r->fr_net != rule->fr_net)
 438			continue;
 439
 440		if (rule->l3mdev && r->l3mdev != rule->l3mdev)
 441			continue;
 442
 443		if (uid_range_set(&rule->uid_range) &&
 444		    (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
 445		    !uid_eq(r->uid_range.end, rule->uid_range.end)))
 446			continue;
 447
 448		if (rule->ip_proto && r->ip_proto != rule->ip_proto)
 449			continue;
 450
 451		if (rule->proto && r->proto != rule->proto)
 452			continue;
 453
 454		if (fib_rule_port_range_set(&rule->sport_range) &&
 455		    !fib_rule_port_range_compare(&r->sport_range,
 456						 &rule->sport_range))
 457			continue;
 458
 459		if (fib_rule_port_range_set(&rule->dport_range) &&
 460		    !fib_rule_port_range_compare(&r->dport_range,
 461						 &rule->dport_range))
 462			continue;
 463
 464		if (!ops->compare(r, frh, tb))
 465			continue;
 466		return r;
 467	}
 468
 469	return NULL;
 470}
 471
 472#ifdef CONFIG_NET_L3_MASTER_DEV
 473static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule,
 474			      struct netlink_ext_ack *extack)
 475{
 476	nlrule->l3mdev = nla_get_u8(nla);
 477	if (nlrule->l3mdev != 1) {
 478		NL_SET_ERR_MSG(extack, "Invalid l3mdev attribute");
 479		return -1;
 480	}
 481
 482	return 0;
 483}
 484#else
 485static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule,
 486			      struct netlink_ext_ack *extack)
 487{
 488	NL_SET_ERR_MSG(extack, "l3mdev support is not enabled in kernel");
 489	return -1;
 490}
 491#endif
 492
 493static int fib_nl2rule(struct sk_buff *skb, struct nlmsghdr *nlh,
 494		       struct netlink_ext_ack *extack,
 495		       struct fib_rules_ops *ops,
 496		       struct nlattr *tb[],
 497		       struct fib_rule **rule,
 498		       bool *user_priority)
 499{
 500	struct net *net = sock_net(skb->sk);
 501	struct fib_rule_hdr *frh = nlmsg_data(nlh);
 502	struct fib_rule *nlrule = NULL;
 503	int err = -EINVAL;
 504
 505	if (frh->src_len)
 506		if (!tb[FRA_SRC] ||
 507		    frh->src_len > (ops->addr_size * 8) ||
 508		    nla_len(tb[FRA_SRC]) != ops->addr_size) {
 509			NL_SET_ERR_MSG(extack, "Invalid source address");
 510			goto errout;
 511	}
 512
 513	if (frh->dst_len)
 514		if (!tb[FRA_DST] ||
 515		    frh->dst_len > (ops->addr_size * 8) ||
 516		    nla_len(tb[FRA_DST]) != ops->addr_size) {
 517			NL_SET_ERR_MSG(extack, "Invalid dst address");
 518			goto errout;
 519	}
 520
 521	nlrule = kzalloc(ops->rule_size, GFP_KERNEL);
 522	if (!nlrule) {
 523		err = -ENOMEM;
 524		goto errout;
 525	}
 526	refcount_set(&nlrule->refcnt, 1);
 527	nlrule->fr_net = net;
 528
 529	if (tb[FRA_PRIORITY]) {
 530		nlrule->pref = nla_get_u32(tb[FRA_PRIORITY]);
 531		*user_priority = true;
 532	} else {
 533		nlrule->pref = fib_default_rule_pref(ops);
 534	}
 535
 536	nlrule->proto = tb[FRA_PROTOCOL] ?
 537		nla_get_u8(tb[FRA_PROTOCOL]) : RTPROT_UNSPEC;
 538
 539	if (tb[FRA_IIFNAME]) {
 540		struct net_device *dev;
 541
 542		nlrule->iifindex = -1;
 543		nla_strlcpy(nlrule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
 544		dev = __dev_get_by_name(net, nlrule->iifname);
 545		if (dev)
 546			nlrule->iifindex = dev->ifindex;
 547	}
 548
 549	if (tb[FRA_OIFNAME]) {
 550		struct net_device *dev;
 551
 552		nlrule->oifindex = -1;
 553		nla_strlcpy(nlrule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
 554		dev = __dev_get_by_name(net, nlrule->oifname);
 555		if (dev)
 556			nlrule->oifindex = dev->ifindex;
 557	}
 558
 559	if (tb[FRA_FWMARK]) {
 560		nlrule->mark = nla_get_u32(tb[FRA_FWMARK]);
 561		if (nlrule->mark)
 562			/* compatibility: if the mark value is non-zero all bits
 563			 * are compared unless a mask is explicitly specified.
 564			 */
 565			nlrule->mark_mask = 0xFFFFFFFF;
 566	}
 567
 568	if (tb[FRA_FWMASK])
 569		nlrule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
 570
 571	if (tb[FRA_TUN_ID])
 572		nlrule->tun_id = nla_get_be64(tb[FRA_TUN_ID]);
 573
 574	err = -EINVAL;
 575	if (tb[FRA_L3MDEV] &&
 576	    fib_nl2rule_l3mdev(tb[FRA_L3MDEV], nlrule, extack) < 0)
 577		goto errout_free;
 578
 579	nlrule->action = frh->action;
 580	nlrule->flags = frh->flags;
 581	nlrule->table = frh_get_table(frh, tb);
 582	if (tb[FRA_SUPPRESS_PREFIXLEN])
 583		nlrule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
 584	else
 585		nlrule->suppress_prefixlen = -1;
 586
 587	if (tb[FRA_SUPPRESS_IFGROUP])
 588		nlrule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]);
 589	else
 590		nlrule->suppress_ifgroup = -1;
 591
 592	if (tb[FRA_GOTO]) {
 593		if (nlrule->action != FR_ACT_GOTO) {
 594			NL_SET_ERR_MSG(extack, "Unexpected goto");
 595			goto errout_free;
 596		}
 597
 598		nlrule->target = nla_get_u32(tb[FRA_GOTO]);
 599		/* Backward jumps are prohibited to avoid endless loops */
 600		if (nlrule->target <= nlrule->pref) {
 601			NL_SET_ERR_MSG(extack, "Backward goto not supported");
 602			goto errout_free;
 603		}
 604	} else if (nlrule->action == FR_ACT_GOTO) {
 605		NL_SET_ERR_MSG(extack, "Missing goto target for action goto");
 606		goto errout_free;
 607	}
 608
 609	if (nlrule->l3mdev && nlrule->table) {
 610		NL_SET_ERR_MSG(extack, "l3mdev and table are mutually exclusive");
 611		goto errout_free;
 612	}
 613
 614	if (tb[FRA_UID_RANGE]) {
 615		if (current_user_ns() != net->user_ns) {
 616			err = -EPERM;
 617			NL_SET_ERR_MSG(extack, "No permission to set uid");
 618			goto errout_free;
 619		}
 620
 621		nlrule->uid_range = nla_get_kuid_range(tb);
 622
 623		if (!uid_range_set(&nlrule->uid_range) ||
 624		    !uid_lte(nlrule->uid_range.start, nlrule->uid_range.end)) {
 625			NL_SET_ERR_MSG(extack, "Invalid uid range");
 626			goto errout_free;
 627		}
 628	} else {
 629		nlrule->uid_range = fib_kuid_range_unset;
 630	}
 631
 632	if (tb[FRA_IP_PROTO])
 633		nlrule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]);
 634
 635	if (tb[FRA_SPORT_RANGE]) {
 636		err = nla_get_port_range(tb[FRA_SPORT_RANGE],
 637					 &nlrule->sport_range);
 638		if (err) {
 639			NL_SET_ERR_MSG(extack, "Invalid sport range");
 640			goto errout_free;
 641		}
 642	}
 643
 644	if (tb[FRA_DPORT_RANGE]) {
 645		err = nla_get_port_range(tb[FRA_DPORT_RANGE],
 646					 &nlrule->dport_range);
 647		if (err) {
 648			NL_SET_ERR_MSG(extack, "Invalid dport range");
 649			goto errout_free;
 650		}
 651	}
 652
 653	*rule = nlrule;
 654
 655	return 0;
 656
 657errout_free:
 658	kfree(nlrule);
 659errout:
 660	return err;
 661}
 662
 663static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh,
 664		       struct nlattr **tb, struct fib_rule *rule)
 665{
 666	struct fib_rule *r;
 667
 668	list_for_each_entry(r, &ops->rules_list, list) {
 669		if (r->action != rule->action)
 670			continue;
 671
 672		if (r->table != rule->table)
 673			continue;
 674
 675		if (r->pref != rule->pref)
 676			continue;
 677
 678		if (memcmp(r->iifname, rule->iifname, IFNAMSIZ))
 679			continue;
 680
 681		if (memcmp(r->oifname, rule->oifname, IFNAMSIZ))
 682			continue;
 683
 684		if (r->mark != rule->mark)
 685			continue;
 686
 687		if (r->suppress_ifgroup != rule->suppress_ifgroup)
 688			continue;
 689
 690		if (r->suppress_prefixlen != rule->suppress_prefixlen)
 691			continue;
 692
 693		if (r->mark_mask != rule->mark_mask)
 694			continue;
 695
 696		if (r->tun_id != rule->tun_id)
 697			continue;
 698
 699		if (r->fr_net != rule->fr_net)
 700			continue;
 701
 702		if (r->l3mdev != rule->l3mdev)
 703			continue;
 704
 705		if (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
 706		    !uid_eq(r->uid_range.end, rule->uid_range.end))
 707			continue;
 708
 709		if (r->ip_proto != rule->ip_proto)
 710			continue;
 711
 712		if (r->proto != rule->proto)
 713			continue;
 714
 715		if (!fib_rule_port_range_compare(&r->sport_range,
 716						 &rule->sport_range))
 717			continue;
 718
 719		if (!fib_rule_port_range_compare(&r->dport_range,
 720						 &rule->dport_range))
 721			continue;
 722
 723		if (!ops->compare(r, frh, tb))
 724			continue;
 725		return 1;
 726	}
 727	return 0;
 728}
 729
 730int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
 731		   struct netlink_ext_ack *extack)
 732{
 733	struct net *net = sock_net(skb->sk);
 734	struct fib_rule_hdr *frh = nlmsg_data(nlh);
 735	struct fib_rules_ops *ops = NULL;
 736	struct fib_rule *rule = NULL, *r, *last = NULL;
 737	struct nlattr *tb[FRA_MAX + 1];
 738	int err = -EINVAL, unresolved = 0;
 739	bool user_priority = false;
 740
 741	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
 742		NL_SET_ERR_MSG(extack, "Invalid msg length");
 743		goto errout;
 744	}
 745
 746	ops = lookup_rules_ops(net, frh->family);
 747	if (!ops) {
 748		err = -EAFNOSUPPORT;
 749		NL_SET_ERR_MSG(extack, "Rule family not supported");
 750		goto errout;
 751	}
 752
 753	err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX,
 754				     ops->policy, extack);
 755	if (err < 0) {
 756		NL_SET_ERR_MSG(extack, "Error parsing msg");
 757		goto errout;
 758	}
 759
 760	err = fib_nl2rule(skb, nlh, extack, ops, tb, &rule, &user_priority);
 761	if (err)
 762		goto errout;
 763
 764	if ((nlh->nlmsg_flags & NLM_F_EXCL) &&
 765	    rule_exists(ops, frh, tb, rule)) {
 766		err = -EEXIST;
 767		goto errout_free;
 768	}
 769
 770	err = ops->configure(rule, skb, frh, tb, extack);
 771	if (err < 0)
 772		goto errout_free;
 773
 774	err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops,
 775				      extack);
 776	if (err < 0)
 777		goto errout_free;
 778
 779	list_for_each_entry(r, &ops->rules_list, list) {
 780		if (r->pref == rule->target) {
 781			RCU_INIT_POINTER(rule->ctarget, r);
 782			break;
 783		}
 784	}
 785
 786	if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
 787		unresolved = 1;
 788
 789	list_for_each_entry(r, &ops->rules_list, list) {
 790		if (r->pref > rule->pref)
 791			break;
 792		last = r;
 793	}
 794
 795	if (last)
 796		list_add_rcu(&rule->list, &last->list);
 797	else
 798		list_add_rcu(&rule->list, &ops->rules_list);
 799
 800	if (ops->unresolved_rules) {
 801		/*
 802		 * There are unresolved goto rules in the list, check if
 803		 * any of them are pointing to this new rule.
 804		 */
 805		list_for_each_entry(r, &ops->rules_list, list) {
 806			if (r->action == FR_ACT_GOTO &&
 807			    r->target == rule->pref &&
 808			    rtnl_dereference(r->ctarget) == NULL) {
 809				rcu_assign_pointer(r->ctarget, rule);
 810				if (--ops->unresolved_rules == 0)
 811					break;
 812			}
 813		}
 814	}
 815
 816	if (rule->action == FR_ACT_GOTO)
 817		ops->nr_goto_rules++;
 818
 819	if (unresolved)
 820		ops->unresolved_rules++;
 821
 822	if (rule->tun_id)
 823		ip_tunnel_need_metadata();
 824
 825	notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
 826	flush_route_cache(ops);
 827	rules_ops_put(ops);
 828	return 0;
 829
 830errout_free:
 831	kfree(rule);
 832errout:
 833	rules_ops_put(ops);
 834	return err;
 835}
 836EXPORT_SYMBOL_GPL(fib_nl_newrule);
 837
 838int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh,
 839		   struct netlink_ext_ack *extack)
 840{
 841	struct net *net = sock_net(skb->sk);
 842	struct fib_rule_hdr *frh = nlmsg_data(nlh);
 843	struct fib_rules_ops *ops = NULL;
 844	struct fib_rule *rule = NULL, *r, *nlrule = NULL;
 845	struct nlattr *tb[FRA_MAX+1];
 846	int err = -EINVAL;
 847	bool user_priority = false;
 848
 849	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
 850		NL_SET_ERR_MSG(extack, "Invalid msg length");
 851		goto errout;
 852	}
 853
 854	ops = lookup_rules_ops(net, frh->family);
 855	if (ops == NULL) {
 856		err = -EAFNOSUPPORT;
 857		NL_SET_ERR_MSG(extack, "Rule family not supported");
 858		goto errout;
 859	}
 860
 861	err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX,
 862				     ops->policy, extack);
 863	if (err < 0) {
 864		NL_SET_ERR_MSG(extack, "Error parsing msg");
 865		goto errout;
 866	}
 867
 868	err = fib_nl2rule(skb, nlh, extack, ops, tb, &nlrule, &user_priority);
 869	if (err)
 870		goto errout;
 871
 872	rule = rule_find(ops, frh, tb, nlrule, user_priority);
 873	if (!rule) {
 874		err = -ENOENT;
 875		goto errout;
 876	}
 877
 878	if (rule->flags & FIB_RULE_PERMANENT) {
 879		err = -EPERM;
 880		goto errout;
 881	}
 882
 883	if (ops->delete) {
 884		err = ops->delete(rule);
 885		if (err)
 886			goto errout;
 887	}
 888
 889	if (rule->tun_id)
 890		ip_tunnel_unneed_metadata();
 891
 892	list_del_rcu(&rule->list);
 893
 894	if (rule->action == FR_ACT_GOTO) {
 895		ops->nr_goto_rules--;
 896		if (rtnl_dereference(rule->ctarget) == NULL)
 897			ops->unresolved_rules--;
 898	}
 899
 900	/*
 901	 * Check if this rule is a target to any of them. If so,
 902	 * adjust to the next one with the same preference or
 903	 * disable them. As this operation is eventually very
 904	 * expensive, it is only performed if goto rules, except
 905	 * current if it is goto rule, have actually been added.
 906	 */
 907	if (ops->nr_goto_rules > 0) {
 908		struct fib_rule *n;
 909
 910		n = list_next_entry(rule, list);
 911		if (&n->list == &ops->rules_list || n->pref != rule->pref)
 912			n = NULL;
 913		list_for_each_entry(r, &ops->rules_list, list) {
 914			if (rtnl_dereference(r->ctarget) != rule)
 915				continue;
 916			rcu_assign_pointer(r->ctarget, n);
 917			if (!n)
 918				ops->unresolved_rules++;
 919		}
 920	}
 921
 922	call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops,
 923				NULL);
 924	notify_rule_change(RTM_DELRULE, rule, ops, nlh,
 925			   NETLINK_CB(skb).portid);
 926	fib_rule_put(rule);
 927	flush_route_cache(ops);
 928	rules_ops_put(ops);
 929	kfree(nlrule);
 930	return 0;
 931
 932errout:
 933	kfree(nlrule);
 934	rules_ops_put(ops);
 935	return err;
 936}
 937EXPORT_SYMBOL_GPL(fib_nl_delrule);
 938
 939static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
 940					 struct fib_rule *rule)
 941{
 942	size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
 943			 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
 944			 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
 945			 + nla_total_size(4) /* FRA_PRIORITY */
 946			 + nla_total_size(4) /* FRA_TABLE */
 947			 + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */
 948			 + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */
 949			 + nla_total_size(4) /* FRA_FWMARK */
 950			 + nla_total_size(4) /* FRA_FWMASK */
 951			 + nla_total_size_64bit(8) /* FRA_TUN_ID */
 952			 + nla_total_size(sizeof(struct fib_kuid_range))
 953			 + nla_total_size(1) /* FRA_PROTOCOL */
 954			 + nla_total_size(1) /* FRA_IP_PROTO */
 955			 + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */
 956			 + nla_total_size(sizeof(struct fib_rule_port_range)); /* FRA_DPORT_RANGE */
 957
 958	if (ops->nlmsg_payload)
 959		payload += ops->nlmsg_payload(rule);
 960
 961	return payload;
 962}
 963
 964static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
 965			    u32 pid, u32 seq, int type, int flags,
 966			    struct fib_rules_ops *ops)
 967{
 968	struct nlmsghdr *nlh;
 969	struct fib_rule_hdr *frh;
 970
 971	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
 972	if (nlh == NULL)
 973		return -EMSGSIZE;
 974
 975	frh = nlmsg_data(nlh);
 976	frh->family = ops->family;
 977	frh->table = rule->table < 256 ? rule->table : RT_TABLE_COMPAT;
 978	if (nla_put_u32(skb, FRA_TABLE, rule->table))
 979		goto nla_put_failure;
 980	if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen))
 981		goto nla_put_failure;
 982	frh->res1 = 0;
 983	frh->res2 = 0;
 984	frh->action = rule->action;
 985	frh->flags = rule->flags;
 986
 987	if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto))
 988		goto nla_put_failure;
 989
 990	if (rule->action == FR_ACT_GOTO &&
 991	    rcu_access_pointer(rule->ctarget) == NULL)
 992		frh->flags |= FIB_RULE_UNRESOLVED;
 993
 994	if (rule->iifname[0]) {
 995		if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
 996			goto nla_put_failure;
 997		if (rule->iifindex == -1)
 998			frh->flags |= FIB_RULE_IIF_DETACHED;
 999	}
1000
1001	if (rule->oifname[0]) {
1002		if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
1003			goto nla_put_failure;
1004		if (rule->oifindex == -1)
1005			frh->flags |= FIB_RULE_OIF_DETACHED;
1006	}
1007
1008	if ((rule->pref &&
1009	     nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
1010	    (rule->mark &&
1011	     nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
1012	    ((rule->mark_mask || rule->mark) &&
1013	     nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
1014	    (rule->target &&
1015	     nla_put_u32(skb, FRA_GOTO, rule->target)) ||
1016	    (rule->tun_id &&
1017	     nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) ||
1018	    (rule->l3mdev &&
1019	     nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) ||
1020	    (uid_range_set(&rule->uid_range) &&
1021	     nla_put_uid_range(skb, &rule->uid_range)) ||
1022	    (fib_rule_port_range_set(&rule->sport_range) &&
1023	     nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) ||
1024	    (fib_rule_port_range_set(&rule->dport_range) &&
1025	     nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) ||
1026	    (rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto)))
1027		goto nla_put_failure;
1028
1029	if (rule->suppress_ifgroup != -1) {
1030		if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup))
1031			goto nla_put_failure;
1032	}
1033
1034	if (ops->fill(rule, skb, frh) < 0)
1035		goto nla_put_failure;
1036
1037	nlmsg_end(skb, nlh);
1038	return 0;
1039
1040nla_put_failure:
1041	nlmsg_cancel(skb, nlh);
1042	return -EMSGSIZE;
1043}
1044
1045static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
1046		      struct fib_rules_ops *ops)
1047{
1048	int idx = 0;
1049	struct fib_rule *rule;
1050	int err = 0;
1051
1052	rcu_read_lock();
1053	list_for_each_entry_rcu(rule, &ops->rules_list, list) {
1054		if (idx < cb->args[1])
1055			goto skip;
1056
1057		err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
1058				       cb->nlh->nlmsg_seq, RTM_NEWRULE,
1059				       NLM_F_MULTI, ops);
1060		if (err)
1061			break;
1062skip:
1063		idx++;
1064	}
1065	rcu_read_unlock();
1066	cb->args[1] = idx;
1067	rules_ops_put(ops);
1068
1069	return err;
1070}
1071
1072static int fib_valid_dumprule_req(const struct nlmsghdr *nlh,
1073				   struct netlink_ext_ack *extack)
1074{
1075	struct fib_rule_hdr *frh;
1076
1077	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
1078		NL_SET_ERR_MSG(extack, "Invalid header for fib rule dump request");
1079		return -EINVAL;
1080	}
1081
1082	frh = nlmsg_data(nlh);
1083	if (frh->dst_len || frh->src_len || frh->tos || frh->table ||
1084	    frh->res1 || frh->res2 || frh->action || frh->flags) {
1085		NL_SET_ERR_MSG(extack,
1086			       "Invalid values in header for fib rule dump request");
1087		return -EINVAL;
1088	}
1089
1090	if (nlmsg_attrlen(nlh, sizeof(*frh))) {
1091		NL_SET_ERR_MSG(extack, "Invalid data after header in fib rule dump request");
1092		return -EINVAL;
1093	}
1094
1095	return 0;
1096}
1097
1098static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
1099{
1100	const struct nlmsghdr *nlh = cb->nlh;
1101	struct net *net = sock_net(skb->sk);
1102	struct fib_rules_ops *ops;
1103	int idx = 0, family;
1104
1105	if (cb->strict_check) {
1106		int err = fib_valid_dumprule_req(nlh, cb->extack);
1107
1108		if (err < 0)
1109			return err;
1110	}
1111
1112	family = rtnl_msg_family(nlh);
1113	if (family != AF_UNSPEC) {
1114		/* Protocol specific dump request */
1115		ops = lookup_rules_ops(net, family);
1116		if (ops == NULL)
1117			return -EAFNOSUPPORT;
1118
1119		dump_rules(skb, cb, ops);
1120
1121		return skb->len;
1122	}
1123
1124	rcu_read_lock();
1125	list_for_each_entry_rcu(ops, &net->rules_ops, list) {
1126		if (idx < cb->args[0] || !try_module_get(ops->owner))
1127			goto skip;
1128
1129		if (dump_rules(skb, cb, ops) < 0)
1130			break;
1131
1132		cb->args[1] = 0;
1133skip:
1134		idx++;
1135	}
1136	rcu_read_unlock();
1137	cb->args[0] = idx;
1138
1139	return skb->len;
1140}
1141
1142static void notify_rule_change(int event, struct fib_rule *rule,
1143			       struct fib_rules_ops *ops, struct nlmsghdr *nlh,
1144			       u32 pid)
1145{
1146	struct net *net;
1147	struct sk_buff *skb;
1148	int err = -ENOBUFS;
1149
1150	net = ops->fro_net;
1151	skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
1152	if (skb == NULL)
1153		goto errout;
1154
1155	err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
1156	if (err < 0) {
1157		/* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
1158		WARN_ON(err == -EMSGSIZE);
1159		kfree_skb(skb);
1160		goto errout;
1161	}
1162
1163	rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
1164	return;
1165errout:
1166	if (err < 0)
1167		rtnl_set_sk_err(net, ops->nlgroup, err);
1168}
1169
1170static void attach_rules(struct list_head *rules, struct net_device *dev)
1171{
1172	struct fib_rule *rule;
1173
1174	list_for_each_entry(rule, rules, list) {
1175		if (rule->iifindex == -1 &&
1176		    strcmp(dev->name, rule->iifname) == 0)
1177			rule->iifindex = dev->ifindex;
1178		if (rule->oifindex == -1 &&
1179		    strcmp(dev->name, rule->oifname) == 0)
1180			rule->oifindex = dev->ifindex;
1181	}
1182}
1183
1184static void detach_rules(struct list_head *rules, struct net_device *dev)
1185{
1186	struct fib_rule *rule;
1187
1188	list_for_each_entry(rule, rules, list) {
1189		if (rule->iifindex == dev->ifindex)
1190			rule->iifindex = -1;
1191		if (rule->oifindex == dev->ifindex)
1192			rule->oifindex = -1;
1193	}
1194}
1195
1196
1197static int fib_rules_event(struct notifier_block *this, unsigned long event,
1198			   void *ptr)
1199{
1200	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1201	struct net *net = dev_net(dev);
1202	struct fib_rules_ops *ops;
1203
1204	ASSERT_RTNL();
1205
1206	switch (event) {
1207	case NETDEV_REGISTER:
1208		list_for_each_entry(ops, &net->rules_ops, list)
1209			attach_rules(&ops->rules_list, dev);
1210		break;
1211
1212	case NETDEV_CHANGENAME:
1213		list_for_each_entry(ops, &net->rules_ops, list) {
1214			detach_rules(&ops->rules_list, dev);
1215			attach_rules(&ops->rules_list, dev);
1216		}
1217		break;
1218
1219	case NETDEV_UNREGISTER:
1220		list_for_each_entry(ops, &net->rules_ops, list)
1221			detach_rules(&ops->rules_list, dev);
1222		break;
1223	}
1224
1225	return NOTIFY_DONE;
1226}
1227
1228static struct notifier_block fib_rules_notifier = {
1229	.notifier_call = fib_rules_event,
1230};
1231
1232static int __net_init fib_rules_net_init(struct net *net)
1233{
1234	INIT_LIST_HEAD(&net->rules_ops);
1235	spin_lock_init(&net->rules_mod_lock);
1236	return 0;
1237}
1238
1239static void __net_exit fib_rules_net_exit(struct net *net)
1240{
1241	WARN_ON_ONCE(!list_empty(&net->rules_ops));
1242}
1243
1244static struct pernet_operations fib_rules_net_ops = {
1245	.init = fib_rules_net_init,
1246	.exit = fib_rules_net_exit,
1247};
1248
1249static int __init fib_rules_init(void)
1250{
1251	int err;
1252	rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, 0);
1253	rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, 0);
1254	rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, 0);
1255
1256	err = register_pernet_subsys(&fib_rules_net_ops);
1257	if (err < 0)
1258		goto fail;
1259
1260	err = register_netdevice_notifier(&fib_rules_notifier);
1261	if (err < 0)
1262		goto fail_unregister;
1263
1264	return 0;
1265
1266fail_unregister:
1267	unregister_pernet_subsys(&fib_rules_net_ops);
1268fail:
1269	rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
1270	rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
1271	rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
1272	return err;
1273}
1274
1275subsys_initcall(fib_rules_init);