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v5.14.15
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * INET		An implementation of the TCP/IP protocol suite for the LINUX
   4 *		operating system.  INET is implemented using the  BSD Socket
   5 *		interface as the means of communication with the user level.
   6 *
   7 *		IPv4 Forwarding Information Base: FIB frontend.
   8 *
   9 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 
 
 
 
 
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/uaccess.h>
 
  14#include <linux/bitops.h>
  15#include <linux/capability.h>
  16#include <linux/types.h>
  17#include <linux/kernel.h>
  18#include <linux/mm.h>
  19#include <linux/string.h>
  20#include <linux/socket.h>
  21#include <linux/sockios.h>
  22#include <linux/errno.h>
  23#include <linux/in.h>
  24#include <linux/inet.h>
  25#include <linux/inetdevice.h>
  26#include <linux/netdevice.h>
  27#include <linux/if_addr.h>
  28#include <linux/if_arp.h>
  29#include <linux/skbuff.h>
  30#include <linux/cache.h>
  31#include <linux/init.h>
  32#include <linux/list.h>
  33#include <linux/slab.h>
  34
  35#include <net/ip.h>
  36#include <net/protocol.h>
  37#include <net/route.h>
  38#include <net/tcp.h>
  39#include <net/sock.h>
  40#include <net/arp.h>
  41#include <net/ip_fib.h>
  42#include <net/nexthop.h>
  43#include <net/rtnetlink.h>
  44#include <net/xfrm.h>
  45#include <net/l3mdev.h>
  46#include <net/lwtunnel.h>
  47#include <trace/events/fib.h>
  48
  49#ifndef CONFIG_IP_MULTIPLE_TABLES
  50
  51static int __net_init fib4_rules_init(struct net *net)
  52{
  53	struct fib_table *local_table, *main_table;
  54
  55	main_table  = fib_trie_table(RT_TABLE_MAIN, NULL);
  56	if (!main_table)
  57		return -ENOMEM;
  58
  59	local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
  60	if (!local_table)
  61		goto fail;
  62
  63	hlist_add_head_rcu(&local_table->tb_hlist,
  64				&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
  65	hlist_add_head_rcu(&main_table->tb_hlist,
  66				&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
  67	return 0;
  68
  69fail:
  70	fib_free_table(main_table);
  71	return -ENOMEM;
  72}
  73#else
  74
  75struct fib_table *fib_new_table(struct net *net, u32 id)
  76{
  77	struct fib_table *tb, *alias = NULL;
  78	unsigned int h;
  79
  80	if (id == 0)
  81		id = RT_TABLE_MAIN;
  82	tb = fib_get_table(net, id);
  83	if (tb)
  84		return tb;
  85
  86	if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules)
  87		alias = fib_new_table(net, RT_TABLE_MAIN);
  88
  89	tb = fib_trie_table(id, alias);
  90	if (!tb)
  91		return NULL;
  92
  93	switch (id) {
  94	case RT_TABLE_MAIN:
  95		rcu_assign_pointer(net->ipv4.fib_main, tb);
  96		break;
  97	case RT_TABLE_DEFAULT:
  98		rcu_assign_pointer(net->ipv4.fib_default, tb);
  99		break;
 100	default:
 101		break;
 102	}
 103
 104	h = id & (FIB_TABLE_HASHSZ - 1);
 105	hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
 106	return tb;
 107}
 108EXPORT_SYMBOL_GPL(fib_new_table);
 109
 110/* caller must hold either rtnl or rcu read lock */
 111struct fib_table *fib_get_table(struct net *net, u32 id)
 112{
 113	struct fib_table *tb;
 
 114	struct hlist_head *head;
 115	unsigned int h;
 116
 117	if (id == 0)
 118		id = RT_TABLE_MAIN;
 119	h = id & (FIB_TABLE_HASHSZ - 1);
 120
 
 121	head = &net->ipv4.fib_table_hash[h];
 122	hlist_for_each_entry_rcu(tb, head, tb_hlist,
 123				 lockdep_rtnl_is_held()) {
 124		if (tb->tb_id == id)
 125			return tb;
 
 126	}
 
 127	return NULL;
 128}
 129#endif /* CONFIG_IP_MULTIPLE_TABLES */
 130
 131static void fib_replace_table(struct net *net, struct fib_table *old,
 132			      struct fib_table *new)
 133{
 134#ifdef CONFIG_IP_MULTIPLE_TABLES
 135	switch (new->tb_id) {
 136	case RT_TABLE_MAIN:
 137		rcu_assign_pointer(net->ipv4.fib_main, new);
 138		break;
 139	case RT_TABLE_DEFAULT:
 140		rcu_assign_pointer(net->ipv4.fib_default, new);
 141		break;
 142	default:
 143		break;
 144	}
 145
 146#endif
 147	/* replace the old table in the hlist */
 148	hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
 149}
 150
 151int fib_unmerge(struct net *net)
 152{
 153	struct fib_table *old, *new, *main_table;
 154
 155	/* attempt to fetch local table if it has been allocated */
 156	old = fib_get_table(net, RT_TABLE_LOCAL);
 157	if (!old)
 158		return 0;
 159
 160	new = fib_trie_unmerge(old);
 161	if (!new)
 162		return -ENOMEM;
 163
 164	/* table is already unmerged */
 165	if (new == old)
 166		return 0;
 167
 168	/* replace merged table with clean table */
 169	fib_replace_table(net, old, new);
 170	fib_free_table(old);
 171
 172	/* attempt to fetch main table if it has been allocated */
 173	main_table = fib_get_table(net, RT_TABLE_MAIN);
 174	if (!main_table)
 175		return 0;
 176
 177	/* flush local entries from main table */
 178	fib_table_flush_external(main_table);
 179
 180	return 0;
 181}
 182
 183void fib_flush(struct net *net)
 184{
 185	int flushed = 0;
 
 
 
 186	unsigned int h;
 187
 188	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
 189		struct hlist_head *head = &net->ipv4.fib_table_hash[h];
 190		struct hlist_node *tmp;
 191		struct fib_table *tb;
 192
 193		hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
 194			flushed += fib_table_flush(net, tb, false);
 195	}
 196
 197	if (flushed)
 198		rt_cache_flush(net);
 199}
 200
 201/*
 202 * Find address type as if only "dev" was present in the system. If
 203 * on_dev is NULL then all interfaces are taken into consideration.
 204 */
 205static inline unsigned int __inet_dev_addr_type(struct net *net,
 206						const struct net_device *dev,
 207						__be32 addr, u32 tb_id)
 208{
 209	struct flowi4		fl4 = { .daddr = addr };
 210	struct fib_result	res;
 211	unsigned int ret = RTN_BROADCAST;
 212	struct fib_table *table;
 213
 214	if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
 215		return RTN_BROADCAST;
 216	if (ipv4_is_multicast(addr))
 217		return RTN_MULTICAST;
 218
 219	rcu_read_lock();
 
 
 220
 221	table = fib_get_table(net, tb_id);
 222	if (table) {
 223		ret = RTN_UNICAST;
 224		if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
 225			struct fib_nh_common *nhc = fib_info_nhc(res.fi, 0);
 226
 227			if (!dev || dev == nhc->nhc_dev)
 228				ret = res.type;
 229		}
 
 230	}
 231
 232	rcu_read_unlock();
 233	return ret;
 234}
 235
 236unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
 237{
 238	return __inet_dev_addr_type(net, NULL, addr, tb_id);
 239}
 240EXPORT_SYMBOL(inet_addr_type_table);
 241
 242unsigned int inet_addr_type(struct net *net, __be32 addr)
 243{
 244	return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
 245}
 246EXPORT_SYMBOL(inet_addr_type);
 247
 248unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
 249				__be32 addr)
 250{
 251	u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
 252
 253	return __inet_dev_addr_type(net, dev, addr, rt_table);
 254}
 255EXPORT_SYMBOL(inet_dev_addr_type);
 256
 257/* inet_addr_type with dev == NULL but using the table from a dev
 258 * if one is associated
 259 */
 260unsigned int inet_addr_type_dev_table(struct net *net,
 261				      const struct net_device *dev,
 262				      __be32 addr)
 263{
 264	u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
 265
 266	return __inet_dev_addr_type(net, NULL, addr, rt_table);
 267}
 268EXPORT_SYMBOL(inet_addr_type_dev_table);
 269
 270__be32 fib_compute_spec_dst(struct sk_buff *skb)
 271{
 272	struct net_device *dev = skb->dev;
 273	struct in_device *in_dev;
 274	struct fib_result res;
 275	struct rtable *rt;
 276	struct net *net;
 277	int scope;
 278
 279	rt = skb_rtable(skb);
 280	if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
 281	    RTCF_LOCAL)
 282		return ip_hdr(skb)->daddr;
 283
 284	in_dev = __in_dev_get_rcu(dev);
 285
 286	net = dev_net(dev);
 287
 288	scope = RT_SCOPE_UNIVERSE;
 289	if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
 290		bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev);
 291		struct flowi4 fl4 = {
 292			.flowi4_iif = LOOPBACK_IFINDEX,
 293			.flowi4_oif = l3mdev_master_ifindex_rcu(dev),
 294			.daddr = ip_hdr(skb)->saddr,
 295			.flowi4_tos = ip_hdr(skb)->tos & IPTOS_RT_MASK,
 296			.flowi4_scope = scope,
 297			.flowi4_mark = vmark ? skb->mark : 0,
 298		};
 299		if (!fib_lookup(net, &fl4, &res, 0))
 300			return fib_result_prefsrc(net, &res);
 301	} else {
 302		scope = RT_SCOPE_LINK;
 303	}
 304
 305	return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
 306}
 307
 308bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev)
 309{
 310	bool dev_match = false;
 311#ifdef CONFIG_IP_ROUTE_MULTIPATH
 312	if (unlikely(fi->nh)) {
 313		dev_match = nexthop_uses_dev(fi->nh, dev);
 314	} else {
 315		int ret;
 316
 317		for (ret = 0; ret < fib_info_num_path(fi); ret++) {
 318			const struct fib_nh_common *nhc = fib_info_nhc(fi, ret);
 319
 320			if (nhc_l3mdev_matches_dev(nhc, dev)) {
 321				dev_match = true;
 322				break;
 323			}
 324		}
 325	}
 326#else
 327	if (fib_info_nhc(fi, 0)->nhc_dev == dev)
 328		dev_match = true;
 329#endif
 330
 331	return dev_match;
 332}
 333EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev);
 334
 335/* Given (packet source, input interface) and optional (dst, oif, tos):
 336 * - (main) check, that source is valid i.e. not broadcast or our local
 337 *   address.
 338 * - figure out what "logical" interface this packet arrived
 339 *   and calculate "specific destination" address.
 340 * - check, that packet arrived from expected physical interface.
 341 * called with rcu_read_lock()
 342 */
 343static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 344				 u8 tos, int oif, struct net_device *dev,
 345				 int rpf, struct in_device *idev, u32 *itag)
 346{
 347	struct net *net = dev_net(dev);
 348	struct flow_keys flkeys;
 349	int ret, no_addr;
 350	struct fib_result res;
 351	struct flowi4 fl4;
 
 
 352	bool dev_match;
 
 
 353
 354	fl4.flowi4_oif = 0;
 355	fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
 356	if (!fl4.flowi4_iif)
 357		fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
 358	fl4.daddr = src;
 359	fl4.saddr = dst;
 360	fl4.flowi4_tos = tos;
 361	fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
 362	fl4.flowi4_tun_key.tun_id = 0;
 363	fl4.flowi4_flags = 0;
 364	fl4.flowi4_uid = sock_net_uid(net, NULL);
 365	fl4.flowi4_multipath_hash = 0;
 366
 367	no_addr = idev->ifa_list == NULL;
 368
 369	fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
 370	if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) {
 371		fl4.flowi4_proto = 0;
 372		fl4.fl4_sport = 0;
 373		fl4.fl4_dport = 0;
 374	} else {
 375		swap(fl4.fl4_sport, fl4.fl4_dport);
 376	}
 377
 378	if (fib_lookup(net, &fl4, &res, 0))
 379		goto last_resort;
 380	if (res.type != RTN_UNICAST &&
 381	    (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
 382		goto e_inval;
 
 
 
 
 
 
 
 
 
 383	fib_combine_itag(itag, &res);
 
 384
 385	dev_match = fib_info_nh_uses_dev(res.fi, dev);
 386	/* This is not common, loopback packets retain skb_dst so normally they
 387	 * would not even hit this slow path.
 388	 */
 389	dev_match = dev_match || (res.type == RTN_LOCAL &&
 390				  dev == net->loopback_dev);
 
 
 
 
 
 
 
 391	if (dev_match) {
 392		ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
 393		return ret;
 394	}
 395	if (no_addr)
 396		goto last_resort;
 397	if (rpf == 1)
 398		goto e_rpf;
 399	fl4.flowi4_oif = dev->ifindex;
 400
 401	ret = 0;
 402	if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
 403		if (res.type == RTN_UNICAST)
 404			ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
 
 
 405	}
 406	return ret;
 407
 408last_resort:
 409	if (rpf)
 410		goto e_rpf;
 
 411	*itag = 0;
 412	return 0;
 413
 414e_inval:
 415	return -EINVAL;
 416e_rpf:
 417	return -EXDEV;
 418}
 419
 420/* Ignore rp_filter for packets protected by IPsec. */
 421int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 422			u8 tos, int oif, struct net_device *dev,
 423			struct in_device *idev, u32 *itag)
 424{
 425	int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
 426	struct net *net = dev_net(dev);
 427
 428	if (!r && !fib_num_tclassid_users(net) &&
 429	    (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
 430		if (IN_DEV_ACCEPT_LOCAL(idev))
 431			goto ok;
 432		/* with custom local routes in place, checking local addresses
 433		 * only will be too optimistic, with custom rules, checking
 434		 * local addresses only can be too strict, e.g. due to vrf
 435		 */
 436		if (net->ipv4.fib_has_custom_local_routes ||
 437		    fib4_has_custom_rules(net))
 438			goto full_check;
 439		if (inet_lookup_ifaddr_rcu(net, src))
 440			return -EINVAL;
 441
 442ok:
 443		*itag = 0;
 444		return 0;
 445	}
 446
 447full_check:
 448	return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
 449}
 450
 451static inline __be32 sk_extract_addr(struct sockaddr *addr)
 452{
 453	return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
 454}
 455
 456static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
 457{
 458	struct nlattr *nla;
 459
 460	nla = (struct nlattr *) ((char *) mx + len);
 461	nla->nla_type = type;
 462	nla->nla_len = nla_attr_size(4);
 463	*(u32 *) nla_data(nla) = value;
 464
 465	return len + nla_total_size(4);
 466}
 467
 468static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
 469				 struct fib_config *cfg)
 470{
 471	__be32 addr;
 472	int plen;
 473
 474	memset(cfg, 0, sizeof(*cfg));
 475	cfg->fc_nlinfo.nl_net = net;
 476
 477	if (rt->rt_dst.sa_family != AF_INET)
 478		return -EAFNOSUPPORT;
 479
 480	/*
 481	 * Check mask for validity:
 482	 * a) it must be contiguous.
 483	 * b) destination must have all host bits clear.
 484	 * c) if application forgot to set correct family (AF_INET),
 485	 *    reject request unless it is absolutely clear i.e.
 486	 *    both family and mask are zero.
 487	 */
 488	plen = 32;
 489	addr = sk_extract_addr(&rt->rt_dst);
 490	if (!(rt->rt_flags & RTF_HOST)) {
 491		__be32 mask = sk_extract_addr(&rt->rt_genmask);
 492
 493		if (rt->rt_genmask.sa_family != AF_INET) {
 494			if (mask || rt->rt_genmask.sa_family)
 495				return -EAFNOSUPPORT;
 496		}
 497
 498		if (bad_mask(mask, addr))
 499			return -EINVAL;
 500
 501		plen = inet_mask_len(mask);
 502	}
 503
 504	cfg->fc_dst_len = plen;
 505	cfg->fc_dst = addr;
 506
 507	if (cmd != SIOCDELRT) {
 508		cfg->fc_nlflags = NLM_F_CREATE;
 509		cfg->fc_protocol = RTPROT_BOOT;
 510	}
 511
 512	if (rt->rt_metric)
 513		cfg->fc_priority = rt->rt_metric - 1;
 514
 515	if (rt->rt_flags & RTF_REJECT) {
 516		cfg->fc_scope = RT_SCOPE_HOST;
 517		cfg->fc_type = RTN_UNREACHABLE;
 518		return 0;
 519	}
 520
 521	cfg->fc_scope = RT_SCOPE_NOWHERE;
 522	cfg->fc_type = RTN_UNICAST;
 523
 524	if (rt->rt_dev) {
 525		char *colon;
 526		struct net_device *dev;
 527		char devname[IFNAMSIZ];
 528
 529		if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
 530			return -EFAULT;
 531
 532		devname[IFNAMSIZ-1] = 0;
 533		colon = strchr(devname, ':');
 534		if (colon)
 535			*colon = 0;
 536		dev = __dev_get_by_name(net, devname);
 537		if (!dev)
 538			return -ENODEV;
 539		cfg->fc_oif = dev->ifindex;
 540		cfg->fc_table = l3mdev_fib_table(dev);
 541		if (colon) {
 542			const struct in_ifaddr *ifa;
 543			struct in_device *in_dev;
 544
 545			in_dev = __in_dev_get_rtnl(dev);
 546			if (!in_dev)
 547				return -ENODEV;
 548
 549			*colon = ':';
 550
 551			rcu_read_lock();
 552			in_dev_for_each_ifa_rcu(ifa, in_dev) {
 553				if (strcmp(ifa->ifa_label, devname) == 0)
 554					break;
 555			}
 556			rcu_read_unlock();
 557
 558			if (!ifa)
 559				return -ENODEV;
 560			cfg->fc_prefsrc = ifa->ifa_local;
 561		}
 562	}
 563
 564	addr = sk_extract_addr(&rt->rt_gateway);
 565	if (rt->rt_gateway.sa_family == AF_INET && addr) {
 566		unsigned int addr_type;
 567
 568		cfg->fc_gw4 = addr;
 569		cfg->fc_gw_family = AF_INET;
 570		addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
 571		if (rt->rt_flags & RTF_GATEWAY &&
 572		    addr_type == RTN_UNICAST)
 573			cfg->fc_scope = RT_SCOPE_UNIVERSE;
 574	}
 575
 576	if (cmd == SIOCDELRT)
 577		return 0;
 578
 579	if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family)
 580		return -EINVAL;
 581
 582	if (cfg->fc_scope == RT_SCOPE_NOWHERE)
 583		cfg->fc_scope = RT_SCOPE_LINK;
 584
 585	if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
 586		struct nlattr *mx;
 587		int len = 0;
 588
 589		mx = kcalloc(3, nla_total_size(4), GFP_KERNEL);
 590		if (!mx)
 591			return -ENOMEM;
 592
 593		if (rt->rt_flags & RTF_MTU)
 594			len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
 595
 596		if (rt->rt_flags & RTF_WINDOW)
 597			len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
 598
 599		if (rt->rt_flags & RTF_IRTT)
 600			len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
 601
 602		cfg->fc_mx = mx;
 603		cfg->fc_mx_len = len;
 604	}
 605
 606	return 0;
 607}
 608
 609/*
 610 * Handle IP routing ioctl calls.
 611 * These are used to manipulate the routing tables
 612 */
 613int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
 614{
 615	struct fib_config cfg;
 
 616	int err;
 617
 618	switch (cmd) {
 619	case SIOCADDRT:		/* Add a route */
 620	case SIOCDELRT:		/* Delete a route */
 621		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 622			return -EPERM;
 623
 
 
 
 624		rtnl_lock();
 625		err = rtentry_to_fib_config(net, cmd, rt, &cfg);
 626		if (err == 0) {
 627			struct fib_table *tb;
 628
 629			if (cmd == SIOCDELRT) {
 630				tb = fib_get_table(net, cfg.fc_table);
 631				if (tb)
 632					err = fib_table_delete(net, tb, &cfg,
 633							       NULL);
 634				else
 635					err = -ESRCH;
 636			} else {
 637				tb = fib_new_table(net, cfg.fc_table);
 638				if (tb)
 639					err = fib_table_insert(net, tb,
 640							       &cfg, NULL);
 641				else
 642					err = -ENOBUFS;
 643			}
 644
 645			/* allocated by rtentry_to_fib_config() */
 646			kfree(cfg.fc_mx);
 647		}
 648		rtnl_unlock();
 649		return err;
 650	}
 651	return -EINVAL;
 652}
 653
 654const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
 655	[RTA_UNSPEC]		= { .strict_start_type = RTA_DPORT + 1 },
 656	[RTA_DST]		= { .type = NLA_U32 },
 657	[RTA_SRC]		= { .type = NLA_U32 },
 658	[RTA_IIF]		= { .type = NLA_U32 },
 659	[RTA_OIF]		= { .type = NLA_U32 },
 660	[RTA_GATEWAY]		= { .type = NLA_U32 },
 661	[RTA_PRIORITY]		= { .type = NLA_U32 },
 662	[RTA_PREFSRC]		= { .type = NLA_U32 },
 663	[RTA_METRICS]		= { .type = NLA_NESTED },
 664	[RTA_MULTIPATH]		= { .len = sizeof(struct rtnexthop) },
 665	[RTA_FLOW]		= { .type = NLA_U32 },
 666	[RTA_ENCAP_TYPE]	= { .type = NLA_U16 },
 667	[RTA_ENCAP]		= { .type = NLA_NESTED },
 668	[RTA_UID]		= { .type = NLA_U32 },
 669	[RTA_MARK]		= { .type = NLA_U32 },
 670	[RTA_TABLE]		= { .type = NLA_U32 },
 671	[RTA_IP_PROTO]		= { .type = NLA_U8 },
 672	[RTA_SPORT]		= { .type = NLA_U16 },
 673	[RTA_DPORT]		= { .type = NLA_U16 },
 674	[RTA_NH_ID]		= { .type = NLA_U32 },
 675};
 676
 677int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
 678		    struct netlink_ext_ack *extack)
 679{
 680	struct rtvia *via;
 681	int alen;
 682
 683	if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
 684		NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA");
 685		return -EINVAL;
 686	}
 687
 688	via = nla_data(nla);
 689	alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr);
 690
 691	switch (via->rtvia_family) {
 692	case AF_INET:
 693		if (alen != sizeof(__be32)) {
 694			NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA");
 695			return -EINVAL;
 696		}
 697		cfg->fc_gw_family = AF_INET;
 698		cfg->fc_gw4 = *((__be32 *)via->rtvia_addr);
 699		break;
 700	case AF_INET6:
 701#if IS_ENABLED(CONFIG_IPV6)
 702		if (alen != sizeof(struct in6_addr)) {
 703			NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA");
 704			return -EINVAL;
 705		}
 706		cfg->fc_gw_family = AF_INET6;
 707		cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr);
 708#else
 709		NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
 710		return -EINVAL;
 711#endif
 712		break;
 713	default:
 714		NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA");
 715		return -EINVAL;
 716	}
 717
 718	return 0;
 719}
 720
 721static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
 722			     struct nlmsghdr *nlh, struct fib_config *cfg,
 723			     struct netlink_ext_ack *extack)
 724{
 725	bool has_gw = false, has_via = false;
 726	struct nlattr *attr;
 727	int err, remaining;
 728	struct rtmsg *rtm;
 729
 730	err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
 731					rtm_ipv4_policy, extack);
 732	if (err < 0)
 733		goto errout;
 734
 735	memset(cfg, 0, sizeof(*cfg));
 736
 737	rtm = nlmsg_data(nlh);
 738	cfg->fc_dst_len = rtm->rtm_dst_len;
 739	cfg->fc_tos = rtm->rtm_tos;
 740	cfg->fc_table = rtm->rtm_table;
 741	cfg->fc_protocol = rtm->rtm_protocol;
 742	cfg->fc_scope = rtm->rtm_scope;
 743	cfg->fc_type = rtm->rtm_type;
 744	cfg->fc_flags = rtm->rtm_flags;
 745	cfg->fc_nlflags = nlh->nlmsg_flags;
 746
 747	cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
 748	cfg->fc_nlinfo.nlh = nlh;
 749	cfg->fc_nlinfo.nl_net = net;
 750
 751	if (cfg->fc_type > RTN_MAX) {
 752		NL_SET_ERR_MSG(extack, "Invalid route type");
 753		err = -EINVAL;
 754		goto errout;
 755	}
 756
 757	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
 758		switch (nla_type(attr)) {
 759		case RTA_DST:
 760			cfg->fc_dst = nla_get_be32(attr);
 761			break;
 762		case RTA_OIF:
 763			cfg->fc_oif = nla_get_u32(attr);
 764			break;
 765		case RTA_GATEWAY:
 766			has_gw = true;
 767			cfg->fc_gw4 = nla_get_be32(attr);
 768			if (cfg->fc_gw4)
 769				cfg->fc_gw_family = AF_INET;
 770			break;
 771		case RTA_VIA:
 772			has_via = true;
 773			err = fib_gw_from_via(cfg, attr, extack);
 774			if (err)
 775				goto errout;
 776			break;
 777		case RTA_PRIORITY:
 778			cfg->fc_priority = nla_get_u32(attr);
 779			break;
 780		case RTA_PREFSRC:
 781			cfg->fc_prefsrc = nla_get_be32(attr);
 782			break;
 783		case RTA_METRICS:
 784			cfg->fc_mx = nla_data(attr);
 785			cfg->fc_mx_len = nla_len(attr);
 786			break;
 787		case RTA_MULTIPATH:
 788			err = lwtunnel_valid_encap_type_attr(nla_data(attr),
 789							     nla_len(attr),
 790							     extack);
 791			if (err < 0)
 792				goto errout;
 793			cfg->fc_mp = nla_data(attr);
 794			cfg->fc_mp_len = nla_len(attr);
 795			break;
 796		case RTA_FLOW:
 797			cfg->fc_flow = nla_get_u32(attr);
 798			break;
 799		case RTA_TABLE:
 800			cfg->fc_table = nla_get_u32(attr);
 801			break;
 802		case RTA_ENCAP:
 803			cfg->fc_encap = attr;
 804			break;
 805		case RTA_ENCAP_TYPE:
 806			cfg->fc_encap_type = nla_get_u16(attr);
 807			err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
 808							extack);
 809			if (err < 0)
 810				goto errout;
 811			break;
 812		case RTA_NH_ID:
 813			cfg->fc_nh_id = nla_get_u32(attr);
 814			break;
 815		}
 816	}
 817
 818	if (cfg->fc_nh_id) {
 819		if (cfg->fc_oif || cfg->fc_gw_family ||
 820		    cfg->fc_encap || cfg->fc_mp) {
 821			NL_SET_ERR_MSG(extack,
 822				       "Nexthop specification and nexthop id are mutually exclusive");
 823			return -EINVAL;
 824		}
 825	}
 826
 827	if (has_gw && has_via) {
 828		NL_SET_ERR_MSG(extack,
 829			       "Nexthop configuration can not contain both GATEWAY and VIA");
 830		return -EINVAL;
 831	}
 832
 833	return 0;
 834errout:
 835	return err;
 836}
 837
 838static int inet_rtm_delroute(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_config cfg;
 843	struct fib_table *tb;
 844	int err;
 845
 846	err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
 847	if (err < 0)
 848		goto errout;
 849
 850	if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) {
 851		NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
 852		err = -EINVAL;
 853		goto errout;
 854	}
 855
 856	tb = fib_get_table(net, cfg.fc_table);
 857	if (!tb) {
 858		NL_SET_ERR_MSG(extack, "FIB table does not exist");
 859		err = -ESRCH;
 860		goto errout;
 861	}
 862
 863	err = fib_table_delete(net, tb, &cfg, extack);
 864errout:
 865	return err;
 866}
 867
 868static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
 869			     struct netlink_ext_ack *extack)
 870{
 871	struct net *net = sock_net(skb->sk);
 872	struct fib_config cfg;
 873	struct fib_table *tb;
 874	int err;
 875
 876	err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
 877	if (err < 0)
 878		goto errout;
 879
 880	tb = fib_new_table(net, cfg.fc_table);
 881	if (!tb) {
 882		err = -ENOBUFS;
 883		goto errout;
 884	}
 885
 886	err = fib_table_insert(net, tb, &cfg, extack);
 887	if (!err && cfg.fc_type == RTN_LOCAL)
 888		net->ipv4.fib_has_custom_local_routes = true;
 889errout:
 890	return err;
 891}
 892
 893int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
 894			  struct fib_dump_filter *filter,
 895			  struct netlink_callback *cb)
 896{
 897	struct netlink_ext_ack *extack = cb->extack;
 898	struct nlattr *tb[RTA_MAX + 1];
 899	struct rtmsg *rtm;
 900	int err, i;
 901
 902	ASSERT_RTNL();
 903
 904	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
 905		NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request");
 906		return -EINVAL;
 907	}
 908
 909	rtm = nlmsg_data(nlh);
 910	if (rtm->rtm_dst_len || rtm->rtm_src_len  || rtm->rtm_tos   ||
 911	    rtm->rtm_scope) {
 912		NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request");
 913		return -EINVAL;
 914	}
 915
 916	if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) {
 917		NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request");
 918		return -EINVAL;
 919	}
 920	if (rtm->rtm_flags & RTM_F_CLONED)
 921		filter->dump_routes = false;
 922	else
 923		filter->dump_exceptions = false;
 924
 925	filter->flags    = rtm->rtm_flags;
 926	filter->protocol = rtm->rtm_protocol;
 927	filter->rt_type  = rtm->rtm_type;
 928	filter->table_id = rtm->rtm_table;
 929
 930	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
 931					    rtm_ipv4_policy, extack);
 932	if (err < 0)
 933		return err;
 934
 935	for (i = 0; i <= RTA_MAX; ++i) {
 936		int ifindex;
 937
 938		if (!tb[i])
 939			continue;
 940
 941		switch (i) {
 942		case RTA_TABLE:
 943			filter->table_id = nla_get_u32(tb[i]);
 944			break;
 945		case RTA_OIF:
 946			ifindex = nla_get_u32(tb[i]);
 947			filter->dev = __dev_get_by_index(net, ifindex);
 948			if (!filter->dev)
 949				return -ENODEV;
 950			break;
 951		default:
 952			NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
 953			return -EINVAL;
 954		}
 955	}
 956
 957	if (filter->flags || filter->protocol || filter->rt_type ||
 958	    filter->table_id || filter->dev) {
 959		filter->filter_set = 1;
 960		cb->answer_flags = NLM_F_DUMP_FILTERED;
 961	}
 962
 963	return 0;
 964}
 965EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req);
 966
 967static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 968{
 969	struct fib_dump_filter filter = { .dump_routes = true,
 970					  .dump_exceptions = true };
 971	const struct nlmsghdr *nlh = cb->nlh;
 972	struct net *net = sock_net(skb->sk);
 973	unsigned int h, s_h;
 974	unsigned int e = 0, s_e;
 975	struct fib_table *tb;
 
 976	struct hlist_head *head;
 977	int dumped = 0, err;
 978
 979	if (cb->strict_check) {
 980		err = ip_valid_fib_dump_req(net, nlh, &filter, cb);
 981		if (err < 0)
 982			return err;
 983	} else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
 984		struct rtmsg *rtm = nlmsg_data(nlh);
 985
 986		filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED);
 987	}
 988
 989	/* ipv4 does not use prefix flag */
 990	if (filter.flags & RTM_F_PREFIX)
 991		return skb->len;
 992
 993	if (filter.table_id) {
 994		tb = fib_get_table(net, filter.table_id);
 995		if (!tb) {
 996			if (rtnl_msg_family(cb->nlh) != PF_INET)
 997				return skb->len;
 998
 999			NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist");
1000			return -ENOENT;
1001		}
1002
1003		rcu_read_lock();
1004		err = fib_table_dump(tb, skb, cb, &filter);
1005		rcu_read_unlock();
1006		return skb->len ? : err;
1007	}
1008
1009	s_h = cb->args[0];
1010	s_e = cb->args[1];
1011
1012	rcu_read_lock();
1013
1014	for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
1015		e = 0;
1016		head = &net->ipv4.fib_table_hash[h];
1017		hlist_for_each_entry_rcu(tb, head, tb_hlist) {
1018			if (e < s_e)
1019				goto next;
1020			if (dumped)
1021				memset(&cb->args[2], 0, sizeof(cb->args) -
1022						 2 * sizeof(cb->args[0]));
1023			err = fib_table_dump(tb, skb, cb, &filter);
1024			if (err < 0) {
1025				if (likely(skb->len))
1026					goto out;
1027
1028				goto out_err;
1029			}
1030			dumped = 1;
1031next:
1032			e++;
1033		}
1034	}
1035out:
1036	err = skb->len;
1037out_err:
1038	rcu_read_unlock();
1039
1040	cb->args[1] = e;
1041	cb->args[0] = h;
1042
1043	return err;
1044}
1045
1046/* Prepare and feed intra-kernel routing request.
1047 * Really, it should be netlink message, but :-( netlink
1048 * can be not configured, so that we feed it directly
1049 * to fib engine. It is legal, because all events occur
1050 * only when netlink is already locked.
1051 */
1052static void fib_magic(int cmd, int type, __be32 dst, int dst_len,
1053		      struct in_ifaddr *ifa, u32 rt_priority)
1054{
1055	struct net *net = dev_net(ifa->ifa_dev->dev);
1056	u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
1057	struct fib_table *tb;
1058	struct fib_config cfg = {
1059		.fc_protocol = RTPROT_KERNEL,
1060		.fc_type = type,
1061		.fc_dst = dst,
1062		.fc_dst_len = dst_len,
1063		.fc_priority = rt_priority,
1064		.fc_prefsrc = ifa->ifa_local,
1065		.fc_oif = ifa->ifa_dev->dev->ifindex,
1066		.fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
1067		.fc_nlinfo = {
1068			.nl_net = net,
1069		},
1070	};
1071
1072	if (!tb_id)
1073		tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
 
 
1074
1075	tb = fib_new_table(net, tb_id);
1076	if (!tb)
1077		return;
1078
1079	cfg.fc_table = tb->tb_id;
1080
1081	if (type != RTN_LOCAL)
1082		cfg.fc_scope = RT_SCOPE_LINK;
1083	else
1084		cfg.fc_scope = RT_SCOPE_HOST;
1085
1086	if (cmd == RTM_NEWROUTE)
1087		fib_table_insert(net, tb, &cfg, NULL);
1088	else
1089		fib_table_delete(net, tb, &cfg, NULL);
1090}
1091
1092void fib_add_ifaddr(struct in_ifaddr *ifa)
1093{
1094	struct in_device *in_dev = ifa->ifa_dev;
1095	struct net_device *dev = in_dev->dev;
1096	struct in_ifaddr *prim = ifa;
1097	__be32 mask = ifa->ifa_mask;
1098	__be32 addr = ifa->ifa_local;
1099	__be32 prefix = ifa->ifa_address & mask;
1100
1101	if (ifa->ifa_flags & IFA_F_SECONDARY) {
1102		prim = inet_ifa_byprefix(in_dev, prefix, mask);
1103		if (!prim) {
1104			pr_warn("%s: bug: prim == NULL\n", __func__);
1105			return;
1106		}
1107	}
1108
1109	fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0);
1110
1111	if (!(dev->flags & IFF_UP))
1112		return;
1113
1114	/* Add broadcast address, if it is explicitly assigned. */
1115	if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
1116		fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1117			  prim, 0);
1118
1119	if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
1120	    (prefix != addr || ifa->ifa_prefixlen < 32)) {
1121		if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1122			fib_magic(RTM_NEWROUTE,
1123				  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1124				  prefix, ifa->ifa_prefixlen, prim,
1125				  ifa->ifa_rt_priority);
1126
1127		/* Add the network broadcast address, when it makes sense */
1128		if (ifa->ifa_prefixlen < 31) {
 
1129			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
1130				  32, prim, 0);
1131		}
1132	}
1133}
1134
1135void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric)
1136{
1137	__be32 prefix = ifa->ifa_address & ifa->ifa_mask;
1138	struct in_device *in_dev = ifa->ifa_dev;
1139	struct net_device *dev = in_dev->dev;
1140
1141	if (!(dev->flags & IFF_UP) ||
1142	    ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) ||
1143	    ipv4_is_zeronet(prefix) ||
1144	    (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32))
1145		return;
1146
1147	/* add the new */
1148	fib_magic(RTM_NEWROUTE,
1149		  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1150		  prefix, ifa->ifa_prefixlen, ifa, new_metric);
1151
1152	/* delete the old */
1153	fib_magic(RTM_DELROUTE,
1154		  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1155		  prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority);
1156}
1157
1158/* Delete primary or secondary address.
1159 * Optionally, on secondary address promotion consider the addresses
1160 * from subnet iprim as deleted, even if they are in device list.
1161 * In this case the secondary ifa can be in device list.
1162 */
1163void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
1164{
1165	struct in_device *in_dev = ifa->ifa_dev;
1166	struct net_device *dev = in_dev->dev;
1167	struct in_ifaddr *ifa1;
1168	struct in_ifaddr *prim = ifa, *prim1 = NULL;
1169	__be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
1170	__be32 any = ifa->ifa_address & ifa->ifa_mask;
1171#define LOCAL_OK	1
1172#define BRD_OK		2
1173#define BRD0_OK		4
1174#define BRD1_OK		8
1175	unsigned int ok = 0;
1176	int subnet = 0;		/* Primary network */
1177	int gone = 1;		/* Address is missing */
1178	int same_prefsrc = 0;	/* Another primary with same IP */
1179
1180	if (ifa->ifa_flags & IFA_F_SECONDARY) {
1181		prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
1182		if (!prim) {
1183			/* if the device has been deleted, we don't perform
1184			 * address promotion
1185			 */
1186			if (!in_dev->dead)
1187				pr_warn("%s: bug: prim == NULL\n", __func__);
1188			return;
1189		}
1190		if (iprim && iprim != prim) {
1191			pr_warn("%s: bug: iprim != prim\n", __func__);
1192			return;
1193		}
1194	} else if (!ipv4_is_zeronet(any) &&
1195		   (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
1196		if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1197			fib_magic(RTM_DELROUTE,
1198				  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1199				  any, ifa->ifa_prefixlen, prim, 0);
1200		subnet = 1;
1201	}
1202
1203	if (in_dev->dead)
1204		goto no_promotions;
1205
1206	/* Deletion is more complicated than add.
1207	 * We should take care of not to delete too much :-)
1208	 *
1209	 * Scan address list to be sure that addresses are really gone.
1210	 */
1211	rcu_read_lock();
1212	in_dev_for_each_ifa_rcu(ifa1, in_dev) {
1213		if (ifa1 == ifa) {
1214			/* promotion, keep the IP */
1215			gone = 0;
1216			continue;
1217		}
1218		/* Ignore IFAs from our subnet */
1219		if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
1220		    inet_ifa_match(ifa1->ifa_address, iprim))
1221			continue;
1222
1223		/* Ignore ifa1 if it uses different primary IP (prefsrc) */
1224		if (ifa1->ifa_flags & IFA_F_SECONDARY) {
1225			/* Another address from our subnet? */
1226			if (ifa1->ifa_mask == prim->ifa_mask &&
1227			    inet_ifa_match(ifa1->ifa_address, prim))
1228				prim1 = prim;
1229			else {
1230				/* We reached the secondaries, so
1231				 * same_prefsrc should be determined.
1232				 */
1233				if (!same_prefsrc)
1234					continue;
1235				/* Search new prim1 if ifa1 is not
1236				 * using the current prim1
1237				 */
1238				if (!prim1 ||
1239				    ifa1->ifa_mask != prim1->ifa_mask ||
1240				    !inet_ifa_match(ifa1->ifa_address, prim1))
1241					prim1 = inet_ifa_byprefix(in_dev,
1242							ifa1->ifa_address,
1243							ifa1->ifa_mask);
1244				if (!prim1)
1245					continue;
1246				if (prim1->ifa_local != prim->ifa_local)
1247					continue;
1248			}
1249		} else {
1250			if (prim->ifa_local != ifa1->ifa_local)
1251				continue;
1252			prim1 = ifa1;
1253			if (prim != prim1)
1254				same_prefsrc = 1;
1255		}
1256		if (ifa->ifa_local == ifa1->ifa_local)
1257			ok |= LOCAL_OK;
1258		if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1259			ok |= BRD_OK;
1260		if (brd == ifa1->ifa_broadcast)
1261			ok |= BRD1_OK;
1262		if (any == ifa1->ifa_broadcast)
1263			ok |= BRD0_OK;
1264		/* primary has network specific broadcasts */
1265		if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1266			__be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1267			__be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1268
1269			if (!ipv4_is_zeronet(any1)) {
1270				if (ifa->ifa_broadcast == brd1 ||
1271				    ifa->ifa_broadcast == any1)
1272					ok |= BRD_OK;
1273				if (brd == brd1 || brd == any1)
1274					ok |= BRD1_OK;
1275				if (any == brd1 || any == any1)
1276					ok |= BRD0_OK;
1277			}
1278		}
1279	}
1280	rcu_read_unlock();
1281
1282no_promotions:
1283	if (!(ok & BRD_OK))
1284		fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1285			  prim, 0);
1286	if (subnet && ifa->ifa_prefixlen < 31) {
1287		if (!(ok & BRD1_OK))
1288			fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32,
1289				  prim, 0);
1290		if (!(ok & BRD0_OK))
1291			fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32,
1292				  prim, 0);
1293	}
1294	if (!(ok & LOCAL_OK)) {
1295		unsigned int addr_type;
1296
1297		fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0);
1298
1299		/* Check, that this local address finally disappeared. */
1300		addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1301						     ifa->ifa_local);
1302		if (gone && addr_type != RTN_LOCAL) {
1303			/* And the last, but not the least thing.
1304			 * We must flush stray FIB entries.
1305			 *
1306			 * First of all, we scan fib_info list searching
1307			 * for stray nexthop entries, then ignite fib_flush.
1308			 */
1309			if (fib_sync_down_addr(dev, ifa->ifa_local))
1310				fib_flush(dev_net(dev));
1311		}
1312	}
1313#undef LOCAL_OK
1314#undef BRD_OK
1315#undef BRD0_OK
1316#undef BRD1_OK
1317}
1318
1319static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1320{
1321
1322	struct fib_result       res;
1323	struct flowi4           fl4 = {
1324		.flowi4_mark = frn->fl_mark,
1325		.daddr = frn->fl_addr,
1326		.flowi4_tos = frn->fl_tos,
1327		.flowi4_scope = frn->fl_scope,
1328	};
1329	struct fib_table *tb;
1330
1331	rcu_read_lock();
1332
1333	tb = fib_get_table(net, frn->tb_id_in);
1334
1335	frn->err = -ENOENT;
1336	if (tb) {
1337		local_bh_disable();
1338
1339		frn->tb_id = tb->tb_id;
 
1340		frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1341
1342		if (!frn->err) {
1343			frn->prefixlen = res.prefixlen;
1344			frn->nh_sel = res.nh_sel;
1345			frn->type = res.type;
1346			frn->scope = res.scope;
1347		}
 
1348		local_bh_enable();
1349	}
1350
1351	rcu_read_unlock();
1352}
1353
1354static void nl_fib_input(struct sk_buff *skb)
1355{
1356	struct net *net;
1357	struct fib_result_nl *frn;
1358	struct nlmsghdr *nlh;
1359	u32 portid;
 
1360
1361	net = sock_net(skb->sk);
1362	nlh = nlmsg_hdr(skb);
1363	if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1364	    skb->len < nlh->nlmsg_len ||
1365	    nlmsg_len(nlh) < sizeof(*frn))
1366		return;
1367
1368	skb = netlink_skb_clone(skb, GFP_KERNEL);
1369	if (!skb)
1370		return;
1371	nlh = nlmsg_hdr(skb);
1372
1373	frn = (struct fib_result_nl *) nlmsg_data(nlh);
1374	nl_fib_lookup(net, frn);
1375
1376	portid = NETLINK_CB(skb).portid;      /* netlink portid */
1377	NETLINK_CB(skb).portid = 0;        /* from kernel */
 
 
1378	NETLINK_CB(skb).dst_group = 0;  /* unicast */
1379	nlmsg_unicast(net->ipv4.fibnl, skb, portid);
1380}
1381
1382static int __net_init nl_fib_lookup_init(struct net *net)
1383{
1384	struct sock *sk;
1385	struct netlink_kernel_cfg cfg = {
1386		.input	= nl_fib_input,
1387	};
1388
1389	sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1390	if (!sk)
1391		return -EAFNOSUPPORT;
1392	net->ipv4.fibnl = sk;
1393	return 0;
1394}
1395
1396static void nl_fib_lookup_exit(struct net *net)
1397{
1398	netlink_kernel_release(net->ipv4.fibnl);
1399	net->ipv4.fibnl = NULL;
1400}
1401
1402static void fib_disable_ip(struct net_device *dev, unsigned long event,
1403			   bool force)
1404{
1405	if (fib_sync_down_dev(dev, event, force))
1406		fib_flush(dev_net(dev));
1407	else
1408		rt_cache_flush(dev_net(dev));
1409	arp_ifdown(dev);
1410}
1411
1412static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1413{
1414	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1415	struct net_device *dev = ifa->ifa_dev->dev;
1416	struct net *net = dev_net(dev);
1417
1418	switch (event) {
1419	case NETDEV_UP:
1420		fib_add_ifaddr(ifa);
1421#ifdef CONFIG_IP_ROUTE_MULTIPATH
1422		fib_sync_up(dev, RTNH_F_DEAD);
1423#endif
1424		atomic_inc(&net->ipv4.dev_addr_genid);
1425		rt_cache_flush(dev_net(dev));
1426		break;
1427	case NETDEV_DOWN:
1428		fib_del_ifaddr(ifa, NULL);
1429		atomic_inc(&net->ipv4.dev_addr_genid);
1430		if (!ifa->ifa_dev->ifa_list) {
1431			/* Last address was deleted from this interface.
1432			 * Disable IP.
1433			 */
1434			fib_disable_ip(dev, event, true);
1435		} else {
1436			rt_cache_flush(dev_net(dev));
1437		}
1438		break;
1439	}
1440	return NOTIFY_DONE;
1441}
1442
1443static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1444{
1445	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1446	struct netdev_notifier_changeupper_info *upper_info = ptr;
1447	struct netdev_notifier_info_ext *info_ext = ptr;
1448	struct in_device *in_dev;
1449	struct net *net = dev_net(dev);
1450	struct in_ifaddr *ifa;
1451	unsigned int flags;
1452
1453	if (event == NETDEV_UNREGISTER) {
1454		fib_disable_ip(dev, event, true);
1455		rt_flush_dev(dev);
1456		return NOTIFY_DONE;
1457	}
1458
1459	in_dev = __in_dev_get_rtnl(dev);
1460	if (!in_dev)
1461		return NOTIFY_DONE;
1462
1463	switch (event) {
1464	case NETDEV_UP:
1465		in_dev_for_each_ifa_rtnl(ifa, in_dev) {
1466			fib_add_ifaddr(ifa);
1467		}
1468#ifdef CONFIG_IP_ROUTE_MULTIPATH
1469		fib_sync_up(dev, RTNH_F_DEAD);
1470#endif
1471		atomic_inc(&net->ipv4.dev_addr_genid);
1472		rt_cache_flush(net);
1473		break;
1474	case NETDEV_DOWN:
1475		fib_disable_ip(dev, event, false);
1476		break;
1477	case NETDEV_CHANGE:
1478		flags = dev_get_flags(dev);
1479		if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1480			fib_sync_up(dev, RTNH_F_LINKDOWN);
1481		else
1482			fib_sync_down_dev(dev, event, false);
1483		rt_cache_flush(net);
1484		break;
1485	case NETDEV_CHANGEMTU:
1486		fib_sync_mtu(dev, info_ext->ext.mtu);
1487		rt_cache_flush(net);
1488		break;
1489	case NETDEV_CHANGEUPPER:
1490		upper_info = ptr;
1491		/* flush all routes if dev is linked to or unlinked from
1492		 * an L3 master device (e.g., VRF)
1493		 */
1494		if (upper_info->upper_dev &&
1495		    netif_is_l3_master(upper_info->upper_dev))
1496			fib_disable_ip(dev, NETDEV_DOWN, true);
1497		break;
1498	}
1499	return NOTIFY_DONE;
1500}
1501
1502static struct notifier_block fib_inetaddr_notifier = {
1503	.notifier_call = fib_inetaddr_event,
1504};
1505
1506static struct notifier_block fib_netdev_notifier = {
1507	.notifier_call = fib_netdev_event,
1508};
1509
1510static int __net_init ip_fib_net_init(struct net *net)
1511{
1512	int err;
1513	size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1514
1515	err = fib4_notifier_init(net);
1516	if (err)
1517		return err;
1518
1519#ifdef CONFIG_IP_ROUTE_MULTIPATH
1520	/* Default to 3-tuple */
1521	net->ipv4.sysctl_fib_multipath_hash_fields =
1522		FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK;
1523#endif
1524
1525	/* Avoid false sharing : Use at least a full cache line */
1526	size = max_t(size_t, size, L1_CACHE_BYTES);
1527
1528	net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1529	if (!net->ipv4.fib_table_hash) {
1530		err = -ENOMEM;
1531		goto err_table_hash_alloc;
1532	}
1533
1534	err = fib4_rules_init(net);
1535	if (err < 0)
1536		goto err_rules_init;
1537	return 0;
1538
1539err_rules_init:
1540	kfree(net->ipv4.fib_table_hash);
1541err_table_hash_alloc:
1542	fib4_notifier_exit(net);
1543	return err;
1544}
1545
1546static void ip_fib_net_exit(struct net *net)
1547{
1548	int i;
1549
1550	rtnl_lock();
1551#ifdef CONFIG_IP_MULTIPLE_TABLES
1552	RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1553	RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1554#endif
1555	/* Destroy the tables in reverse order to guarantee that the
1556	 * local table, ID 255, is destroyed before the main table, ID
1557	 * 254. This is necessary as the local table may contain
1558	 * references to data contained in the main table.
1559	 */
1560	for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1561		struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1562		struct hlist_node *tmp;
1563		struct fib_table *tb;
 
 
1564
1565		hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1566			hlist_del(&tb->tb_hlist);
1567			fib_table_flush(net, tb, true);
 
1568			fib_free_table(tb);
1569		}
1570	}
1571
1572#ifdef CONFIG_IP_MULTIPLE_TABLES
1573	fib4_rules_exit(net);
1574#endif
1575	rtnl_unlock();
1576	kfree(net->ipv4.fib_table_hash);
1577	fib4_notifier_exit(net);
1578}
1579
1580static int __net_init fib_net_init(struct net *net)
1581{
1582	int error;
1583
1584#ifdef CONFIG_IP_ROUTE_CLASSID
1585	net->ipv4.fib_num_tclassid_users = 0;
1586#endif
1587	error = ip_fib_net_init(net);
1588	if (error < 0)
1589		goto out;
1590	error = nl_fib_lookup_init(net);
1591	if (error < 0)
1592		goto out_nlfl;
1593	error = fib_proc_init(net);
1594	if (error < 0)
1595		goto out_proc;
1596out:
1597	return error;
1598
1599out_proc:
1600	nl_fib_lookup_exit(net);
1601out_nlfl:
1602	ip_fib_net_exit(net);
1603	goto out;
1604}
1605
1606static void __net_exit fib_net_exit(struct net *net)
1607{
1608	fib_proc_exit(net);
1609	nl_fib_lookup_exit(net);
1610	ip_fib_net_exit(net);
1611}
1612
1613static struct pernet_operations fib_net_ops = {
1614	.init = fib_net_init,
1615	.exit = fib_net_exit,
1616};
1617
1618void __init ip_fib_init(void)
1619{
1620	fib_trie_init();
 
 
1621
1622	register_pernet_subsys(&fib_net_ops);
1623
1624	register_netdevice_notifier(&fib_netdev_notifier);
1625	register_inetaddr_notifier(&fib_inetaddr_notifier);
1626
1627	rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0);
1628	rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0);
1629	rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0);
1630}
v3.1
 
   1/*
   2 * INET		An implementation of the TCP/IP protocol suite for the LINUX
   3 *		operating system.  INET is implemented using the  BSD Socket
   4 *		interface as the means of communication with the user level.
   5 *
   6 *		IPv4 Forwarding Information Base: FIB frontend.
   7 *
   8 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   9 *
  10 *		This program is free software; you can redistribute it and/or
  11 *		modify it under the terms of the GNU General Public License
  12 *		as published by the Free Software Foundation; either version
  13 *		2 of the License, or (at your option) any later version.
  14 */
  15
  16#include <linux/module.h>
  17#include <asm/uaccess.h>
  18#include <asm/system.h>
  19#include <linux/bitops.h>
  20#include <linux/capability.h>
  21#include <linux/types.h>
  22#include <linux/kernel.h>
  23#include <linux/mm.h>
  24#include <linux/string.h>
  25#include <linux/socket.h>
  26#include <linux/sockios.h>
  27#include <linux/errno.h>
  28#include <linux/in.h>
  29#include <linux/inet.h>
  30#include <linux/inetdevice.h>
  31#include <linux/netdevice.h>
  32#include <linux/if_addr.h>
  33#include <linux/if_arp.h>
  34#include <linux/skbuff.h>
 
  35#include <linux/init.h>
  36#include <linux/list.h>
  37#include <linux/slab.h>
  38
  39#include <net/ip.h>
  40#include <net/protocol.h>
  41#include <net/route.h>
  42#include <net/tcp.h>
  43#include <net/sock.h>
  44#include <net/arp.h>
  45#include <net/ip_fib.h>
 
  46#include <net/rtnetlink.h>
  47#include <net/xfrm.h>
 
 
 
  48
  49#ifndef CONFIG_IP_MULTIPLE_TABLES
  50
  51static int __net_init fib4_rules_init(struct net *net)
  52{
  53	struct fib_table *local_table, *main_table;
  54
  55	local_table = fib_trie_table(RT_TABLE_LOCAL);
  56	if (local_table == NULL)
  57		return -ENOMEM;
  58
  59	main_table  = fib_trie_table(RT_TABLE_MAIN);
  60	if (main_table == NULL)
  61		goto fail;
  62
  63	hlist_add_head_rcu(&local_table->tb_hlist,
  64				&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
  65	hlist_add_head_rcu(&main_table->tb_hlist,
  66				&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
  67	return 0;
  68
  69fail:
  70	kfree(local_table);
  71	return -ENOMEM;
  72}
  73#else
  74
  75struct fib_table *fib_new_table(struct net *net, u32 id)
  76{
  77	struct fib_table *tb;
  78	unsigned int h;
  79
  80	if (id == 0)
  81		id = RT_TABLE_MAIN;
  82	tb = fib_get_table(net, id);
  83	if (tb)
  84		return tb;
  85
  86	tb = fib_trie_table(id);
 
 
 
  87	if (!tb)
  88		return NULL;
 
 
 
 
 
 
 
 
 
 
 
 
  89	h = id & (FIB_TABLE_HASHSZ - 1);
  90	hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
  91	return tb;
  92}
 
  93
 
  94struct fib_table *fib_get_table(struct net *net, u32 id)
  95{
  96	struct fib_table *tb;
  97	struct hlist_node *node;
  98	struct hlist_head *head;
  99	unsigned int h;
 100
 101	if (id == 0)
 102		id = RT_TABLE_MAIN;
 103	h = id & (FIB_TABLE_HASHSZ - 1);
 104
 105	rcu_read_lock();
 106	head = &net->ipv4.fib_table_hash[h];
 107	hlist_for_each_entry_rcu(tb, node, head, tb_hlist) {
 108		if (tb->tb_id == id) {
 109			rcu_read_unlock();
 110			return tb;
 111		}
 112	}
 113	rcu_read_unlock();
 114	return NULL;
 115}
 116#endif /* CONFIG_IP_MULTIPLE_TABLES */
 117
 118static void fib_flush(struct net *net)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 119{
 120	int flushed = 0;
 121	struct fib_table *tb;
 122	struct hlist_node *node;
 123	struct hlist_head *head;
 124	unsigned int h;
 125
 126	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
 127		head = &net->ipv4.fib_table_hash[h];
 128		hlist_for_each_entry(tb, node, head, tb_hlist)
 129			flushed += fib_table_flush(tb);
 
 
 
 130	}
 131
 132	if (flushed)
 133		rt_cache_flush(net, -1);
 134}
 135
 136/*
 137 * Find address type as if only "dev" was present in the system. If
 138 * on_dev is NULL then all interfaces are taken into consideration.
 139 */
 140static inline unsigned __inet_dev_addr_type(struct net *net,
 141					    const struct net_device *dev,
 142					    __be32 addr)
 143{
 144	struct flowi4		fl4 = { .daddr = addr };
 145	struct fib_result	res;
 146	unsigned ret = RTN_BROADCAST;
 147	struct fib_table *local_table;
 148
 149	if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
 150		return RTN_BROADCAST;
 151	if (ipv4_is_multicast(addr))
 152		return RTN_MULTICAST;
 153
 154#ifdef CONFIG_IP_MULTIPLE_TABLES
 155	res.r = NULL;
 156#endif
 157
 158	local_table = fib_get_table(net, RT_TABLE_LOCAL);
 159	if (local_table) {
 160		ret = RTN_UNICAST;
 161		rcu_read_lock();
 162		if (!fib_table_lookup(local_table, &fl4, &res, FIB_LOOKUP_NOREF)) {
 163			if (!dev || dev == res.fi->fib_dev)
 
 164				ret = res.type;
 165		}
 166		rcu_read_unlock();
 167	}
 
 
 168	return ret;
 169}
 170
 
 
 
 
 
 
 171unsigned int inet_addr_type(struct net *net, __be32 addr)
 172{
 173	return __inet_dev_addr_type(net, NULL, addr);
 174}
 175EXPORT_SYMBOL(inet_addr_type);
 176
 177unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
 178				__be32 addr)
 179{
 180	return __inet_dev_addr_type(net, dev, addr);
 
 
 181}
 182EXPORT_SYMBOL(inet_dev_addr_type);
 183
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 184/* Given (packet source, input interface) and optional (dst, oif, tos):
 185 * - (main) check, that source is valid i.e. not broadcast or our local
 186 *   address.
 187 * - figure out what "logical" interface this packet arrived
 188 *   and calculate "specific destination" address.
 189 * - check, that packet arrived from expected physical interface.
 190 * called with rcu_read_lock()
 191 */
 192int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, u8 tos,
 193			int oif, struct net_device *dev, __be32 *spec_dst,
 194			u32 *itag)
 195{
 196	struct in_device *in_dev;
 
 
 
 197	struct flowi4 fl4;
 198	struct fib_result res;
 199	int no_addr, rpf, accept_local;
 200	bool dev_match;
 201	int ret;
 202	struct net *net;
 203
 204	fl4.flowi4_oif = 0;
 205	fl4.flowi4_iif = oif;
 
 
 206	fl4.daddr = src;
 207	fl4.saddr = dst;
 208	fl4.flowi4_tos = tos;
 209	fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
 210
 211	no_addr = rpf = accept_local = 0;
 212	in_dev = __in_dev_get_rcu(dev);
 213	if (in_dev) {
 214		no_addr = in_dev->ifa_list == NULL;
 215
 216		/* Ignore rp_filter for packets protected by IPsec. */
 217		rpf = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(in_dev);
 218
 219		accept_local = IN_DEV_ACCEPT_LOCAL(in_dev);
 220		fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0;
 
 
 
 221	}
 222
 223	if (in_dev == NULL)
 
 
 
 224		goto e_inval;
 225
 226	net = dev_net(dev);
 227	if (fib_lookup(net, &fl4, &res))
 228		goto last_resort;
 229	if (res.type != RTN_UNICAST) {
 230		if (res.type != RTN_LOCAL || !accept_local)
 231			goto e_inval;
 232	}
 233	*spec_dst = FIB_RES_PREFSRC(net, res);
 234	fib_combine_itag(itag, &res);
 235	dev_match = false;
 236
 237#ifdef CONFIG_IP_ROUTE_MULTIPATH
 238	for (ret = 0; ret < res.fi->fib_nhs; ret++) {
 239		struct fib_nh *nh = &res.fi->fib_nh[ret];
 240
 241		if (nh->nh_dev == dev) {
 242			dev_match = true;
 243			break;
 244		}
 245	}
 246#else
 247	if (FIB_RES_DEV(res) == dev)
 248		dev_match = true;
 249#endif
 250	if (dev_match) {
 251		ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
 252		return ret;
 253	}
 254	if (no_addr)
 255		goto last_resort;
 256	if (rpf == 1)
 257		goto e_rpf;
 258	fl4.flowi4_oif = dev->ifindex;
 259
 260	ret = 0;
 261	if (fib_lookup(net, &fl4, &res) == 0) {
 262		if (res.type == RTN_UNICAST) {
 263			*spec_dst = FIB_RES_PREFSRC(net, res);
 264			ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
 265		}
 266	}
 267	return ret;
 268
 269last_resort:
 270	if (rpf)
 271		goto e_rpf;
 272	*spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
 273	*itag = 0;
 274	return 0;
 275
 276e_inval:
 277	return -EINVAL;
 278e_rpf:
 279	return -EXDEV;
 280}
 281
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 282static inline __be32 sk_extract_addr(struct sockaddr *addr)
 283{
 284	return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
 285}
 286
 287static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
 288{
 289	struct nlattr *nla;
 290
 291	nla = (struct nlattr *) ((char *) mx + len);
 292	nla->nla_type = type;
 293	nla->nla_len = nla_attr_size(4);
 294	*(u32 *) nla_data(nla) = value;
 295
 296	return len + nla_total_size(4);
 297}
 298
 299static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
 300				 struct fib_config *cfg)
 301{
 302	__be32 addr;
 303	int plen;
 304
 305	memset(cfg, 0, sizeof(*cfg));
 306	cfg->fc_nlinfo.nl_net = net;
 307
 308	if (rt->rt_dst.sa_family != AF_INET)
 309		return -EAFNOSUPPORT;
 310
 311	/*
 312	 * Check mask for validity:
 313	 * a) it must be contiguous.
 314	 * b) destination must have all host bits clear.
 315	 * c) if application forgot to set correct family (AF_INET),
 316	 *    reject request unless it is absolutely clear i.e.
 317	 *    both family and mask are zero.
 318	 */
 319	plen = 32;
 320	addr = sk_extract_addr(&rt->rt_dst);
 321	if (!(rt->rt_flags & RTF_HOST)) {
 322		__be32 mask = sk_extract_addr(&rt->rt_genmask);
 323
 324		if (rt->rt_genmask.sa_family != AF_INET) {
 325			if (mask || rt->rt_genmask.sa_family)
 326				return -EAFNOSUPPORT;
 327		}
 328
 329		if (bad_mask(mask, addr))
 330			return -EINVAL;
 331
 332		plen = inet_mask_len(mask);
 333	}
 334
 335	cfg->fc_dst_len = plen;
 336	cfg->fc_dst = addr;
 337
 338	if (cmd != SIOCDELRT) {
 339		cfg->fc_nlflags = NLM_F_CREATE;
 340		cfg->fc_protocol = RTPROT_BOOT;
 341	}
 342
 343	if (rt->rt_metric)
 344		cfg->fc_priority = rt->rt_metric - 1;
 345
 346	if (rt->rt_flags & RTF_REJECT) {
 347		cfg->fc_scope = RT_SCOPE_HOST;
 348		cfg->fc_type = RTN_UNREACHABLE;
 349		return 0;
 350	}
 351
 352	cfg->fc_scope = RT_SCOPE_NOWHERE;
 353	cfg->fc_type = RTN_UNICAST;
 354
 355	if (rt->rt_dev) {
 356		char *colon;
 357		struct net_device *dev;
 358		char devname[IFNAMSIZ];
 359
 360		if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
 361			return -EFAULT;
 362
 363		devname[IFNAMSIZ-1] = 0;
 364		colon = strchr(devname, ':');
 365		if (colon)
 366			*colon = 0;
 367		dev = __dev_get_by_name(net, devname);
 368		if (!dev)
 369			return -ENODEV;
 370		cfg->fc_oif = dev->ifindex;
 
 371		if (colon) {
 372			struct in_ifaddr *ifa;
 373			struct in_device *in_dev = __in_dev_get_rtnl(dev);
 
 
 374			if (!in_dev)
 375				return -ENODEV;
 
 376			*colon = ':';
 377			for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
 
 
 378				if (strcmp(ifa->ifa_label, devname) == 0)
 379					break;
 380			if (ifa == NULL)
 
 
 
 381				return -ENODEV;
 382			cfg->fc_prefsrc = ifa->ifa_local;
 383		}
 384	}
 385
 386	addr = sk_extract_addr(&rt->rt_gateway);
 387	if (rt->rt_gateway.sa_family == AF_INET && addr) {
 388		cfg->fc_gw = addr;
 
 
 
 
 389		if (rt->rt_flags & RTF_GATEWAY &&
 390		    inet_addr_type(net, addr) == RTN_UNICAST)
 391			cfg->fc_scope = RT_SCOPE_UNIVERSE;
 392	}
 393
 394	if (cmd == SIOCDELRT)
 395		return 0;
 396
 397	if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
 398		return -EINVAL;
 399
 400	if (cfg->fc_scope == RT_SCOPE_NOWHERE)
 401		cfg->fc_scope = RT_SCOPE_LINK;
 402
 403	if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
 404		struct nlattr *mx;
 405		int len = 0;
 406
 407		mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
 408		if (mx == NULL)
 409			return -ENOMEM;
 410
 411		if (rt->rt_flags & RTF_MTU)
 412			len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
 413
 414		if (rt->rt_flags & RTF_WINDOW)
 415			len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
 416
 417		if (rt->rt_flags & RTF_IRTT)
 418			len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
 419
 420		cfg->fc_mx = mx;
 421		cfg->fc_mx_len = len;
 422	}
 423
 424	return 0;
 425}
 426
 427/*
 428 * Handle IP routing ioctl calls.
 429 * These are used to manipulate the routing tables
 430 */
 431int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 432{
 433	struct fib_config cfg;
 434	struct rtentry rt;
 435	int err;
 436
 437	switch (cmd) {
 438	case SIOCADDRT:		/* Add a route */
 439	case SIOCDELRT:		/* Delete a route */
 440		if (!capable(CAP_NET_ADMIN))
 441			return -EPERM;
 442
 443		if (copy_from_user(&rt, arg, sizeof(rt)))
 444			return -EFAULT;
 445
 446		rtnl_lock();
 447		err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
 448		if (err == 0) {
 449			struct fib_table *tb;
 450
 451			if (cmd == SIOCDELRT) {
 452				tb = fib_get_table(net, cfg.fc_table);
 453				if (tb)
 454					err = fib_table_delete(tb, &cfg);
 
 455				else
 456					err = -ESRCH;
 457			} else {
 458				tb = fib_new_table(net, cfg.fc_table);
 459				if (tb)
 460					err = fib_table_insert(tb, &cfg);
 
 461				else
 462					err = -ENOBUFS;
 463			}
 464
 465			/* allocated by rtentry_to_fib_config() */
 466			kfree(cfg.fc_mx);
 467		}
 468		rtnl_unlock();
 469		return err;
 470	}
 471	return -EINVAL;
 472}
 473
 474const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
 
 475	[RTA_DST]		= { .type = NLA_U32 },
 476	[RTA_SRC]		= { .type = NLA_U32 },
 477	[RTA_IIF]		= { .type = NLA_U32 },
 478	[RTA_OIF]		= { .type = NLA_U32 },
 479	[RTA_GATEWAY]		= { .type = NLA_U32 },
 480	[RTA_PRIORITY]		= { .type = NLA_U32 },
 481	[RTA_PREFSRC]		= { .type = NLA_U32 },
 482	[RTA_METRICS]		= { .type = NLA_NESTED },
 483	[RTA_MULTIPATH]		= { .len = sizeof(struct rtnexthop) },
 484	[RTA_FLOW]		= { .type = NLA_U32 },
 
 
 
 
 
 
 
 
 
 485};
 486
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 487static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
 488			     struct nlmsghdr *nlh, struct fib_config *cfg)
 
 489{
 
 490	struct nlattr *attr;
 491	int err, remaining;
 492	struct rtmsg *rtm;
 493
 494	err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
 
 495	if (err < 0)
 496		goto errout;
 497
 498	memset(cfg, 0, sizeof(*cfg));
 499
 500	rtm = nlmsg_data(nlh);
 501	cfg->fc_dst_len = rtm->rtm_dst_len;
 502	cfg->fc_tos = rtm->rtm_tos;
 503	cfg->fc_table = rtm->rtm_table;
 504	cfg->fc_protocol = rtm->rtm_protocol;
 505	cfg->fc_scope = rtm->rtm_scope;
 506	cfg->fc_type = rtm->rtm_type;
 507	cfg->fc_flags = rtm->rtm_flags;
 508	cfg->fc_nlflags = nlh->nlmsg_flags;
 509
 510	cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid;
 511	cfg->fc_nlinfo.nlh = nlh;
 512	cfg->fc_nlinfo.nl_net = net;
 513
 514	if (cfg->fc_type > RTN_MAX) {
 
 515		err = -EINVAL;
 516		goto errout;
 517	}
 518
 519	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
 520		switch (nla_type(attr)) {
 521		case RTA_DST:
 522			cfg->fc_dst = nla_get_be32(attr);
 523			break;
 524		case RTA_OIF:
 525			cfg->fc_oif = nla_get_u32(attr);
 526			break;
 527		case RTA_GATEWAY:
 528			cfg->fc_gw = nla_get_be32(attr);
 
 
 
 
 
 
 
 
 
 529			break;
 530		case RTA_PRIORITY:
 531			cfg->fc_priority = nla_get_u32(attr);
 532			break;
 533		case RTA_PREFSRC:
 534			cfg->fc_prefsrc = nla_get_be32(attr);
 535			break;
 536		case RTA_METRICS:
 537			cfg->fc_mx = nla_data(attr);
 538			cfg->fc_mx_len = nla_len(attr);
 539			break;
 540		case RTA_MULTIPATH:
 
 
 
 
 
 541			cfg->fc_mp = nla_data(attr);
 542			cfg->fc_mp_len = nla_len(attr);
 543			break;
 544		case RTA_FLOW:
 545			cfg->fc_flow = nla_get_u32(attr);
 546			break;
 547		case RTA_TABLE:
 548			cfg->fc_table = nla_get_u32(attr);
 549			break;
 
 
 
 
 
 
 
 
 
 
 
 
 
 550		}
 551	}
 552
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 553	return 0;
 554errout:
 555	return err;
 556}
 557
 558static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 
 559{
 560	struct net *net = sock_net(skb->sk);
 561	struct fib_config cfg;
 562	struct fib_table *tb;
 563	int err;
 564
 565	err = rtm_to_fib_config(net, skb, nlh, &cfg);
 566	if (err < 0)
 567		goto errout;
 568
 
 
 
 
 
 
 569	tb = fib_get_table(net, cfg.fc_table);
 570	if (tb == NULL) {
 
 571		err = -ESRCH;
 572		goto errout;
 573	}
 574
 575	err = fib_table_delete(tb, &cfg);
 576errout:
 577	return err;
 578}
 579
 580static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 
 581{
 582	struct net *net = sock_net(skb->sk);
 583	struct fib_config cfg;
 584	struct fib_table *tb;
 585	int err;
 586
 587	err = rtm_to_fib_config(net, skb, nlh, &cfg);
 588	if (err < 0)
 589		goto errout;
 590
 591	tb = fib_new_table(net, cfg.fc_table);
 592	if (tb == NULL) {
 593		err = -ENOBUFS;
 594		goto errout;
 595	}
 596
 597	err = fib_table_insert(tb, &cfg);
 
 
 598errout:
 599	return err;
 600}
 601
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 602static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 603{
 
 
 
 604	struct net *net = sock_net(skb->sk);
 605	unsigned int h, s_h;
 606	unsigned int e = 0, s_e;
 607	struct fib_table *tb;
 608	struct hlist_node *node;
 609	struct hlist_head *head;
 610	int dumped = 0;
 611
 612	if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
 613	    ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
 614		return ip_rt_dump(skb, cb);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 615
 616	s_h = cb->args[0];
 617	s_e = cb->args[1];
 618
 
 
 619	for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
 620		e = 0;
 621		head = &net->ipv4.fib_table_hash[h];
 622		hlist_for_each_entry(tb, node, head, tb_hlist) {
 623			if (e < s_e)
 624				goto next;
 625			if (dumped)
 626				memset(&cb->args[2], 0, sizeof(cb->args) -
 627						 2 * sizeof(cb->args[0]));
 628			if (fib_table_dump(tb, skb, cb) < 0)
 629				goto out;
 
 
 
 
 
 630			dumped = 1;
 631next:
 632			e++;
 633		}
 634	}
 635out:
 
 
 
 
 636	cb->args[1] = e;
 637	cb->args[0] = h;
 638
 639	return skb->len;
 640}
 641
 642/* Prepare and feed intra-kernel routing request.
 643 * Really, it should be netlink message, but :-( netlink
 644 * can be not configured, so that we feed it directly
 645 * to fib engine. It is legal, because all events occur
 646 * only when netlink is already locked.
 647 */
 648static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
 
 649{
 650	struct net *net = dev_net(ifa->ifa_dev->dev);
 
 651	struct fib_table *tb;
 652	struct fib_config cfg = {
 653		.fc_protocol = RTPROT_KERNEL,
 654		.fc_type = type,
 655		.fc_dst = dst,
 656		.fc_dst_len = dst_len,
 
 657		.fc_prefsrc = ifa->ifa_local,
 658		.fc_oif = ifa->ifa_dev->dev->ifindex,
 659		.fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
 660		.fc_nlinfo = {
 661			.nl_net = net,
 662		},
 663	};
 664
 665	if (type == RTN_UNICAST)
 666		tb = fib_new_table(net, RT_TABLE_MAIN);
 667	else
 668		tb = fib_new_table(net, RT_TABLE_LOCAL);
 669
 670	if (tb == NULL)
 
 671		return;
 672
 673	cfg.fc_table = tb->tb_id;
 674
 675	if (type != RTN_LOCAL)
 676		cfg.fc_scope = RT_SCOPE_LINK;
 677	else
 678		cfg.fc_scope = RT_SCOPE_HOST;
 679
 680	if (cmd == RTM_NEWROUTE)
 681		fib_table_insert(tb, &cfg);
 682	else
 683		fib_table_delete(tb, &cfg);
 684}
 685
 686void fib_add_ifaddr(struct in_ifaddr *ifa)
 687{
 688	struct in_device *in_dev = ifa->ifa_dev;
 689	struct net_device *dev = in_dev->dev;
 690	struct in_ifaddr *prim = ifa;
 691	__be32 mask = ifa->ifa_mask;
 692	__be32 addr = ifa->ifa_local;
 693	__be32 prefix = ifa->ifa_address & mask;
 694
 695	if (ifa->ifa_flags & IFA_F_SECONDARY) {
 696		prim = inet_ifa_byprefix(in_dev, prefix, mask);
 697		if (prim == NULL) {
 698			printk(KERN_WARNING "fib_add_ifaddr: bug: prim == NULL\n");
 699			return;
 700		}
 701	}
 702
 703	fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
 704
 705	if (!(dev->flags & IFF_UP))
 706		return;
 707
 708	/* Add broadcast address, if it is explicitly assigned. */
 709	if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
 710		fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
 
 711
 712	if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
 713	    (prefix != addr || ifa->ifa_prefixlen < 32)) {
 714		fib_magic(RTM_NEWROUTE,
 715			  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
 716			  prefix, ifa->ifa_prefixlen, prim);
 
 
 717
 718		/* Add network specific broadcasts, when it takes a sense */
 719		if (ifa->ifa_prefixlen < 31) {
 720			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
 721			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
 722				  32, prim);
 723		}
 724	}
 725}
 726
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 727/* Delete primary or secondary address.
 728 * Optionally, on secondary address promotion consider the addresses
 729 * from subnet iprim as deleted, even if they are in device list.
 730 * In this case the secondary ifa can be in device list.
 731 */
 732void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
 733{
 734	struct in_device *in_dev = ifa->ifa_dev;
 735	struct net_device *dev = in_dev->dev;
 736	struct in_ifaddr *ifa1;
 737	struct in_ifaddr *prim = ifa, *prim1 = NULL;
 738	__be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
 739	__be32 any = ifa->ifa_address & ifa->ifa_mask;
 740#define LOCAL_OK	1
 741#define BRD_OK		2
 742#define BRD0_OK		4
 743#define BRD1_OK		8
 744	unsigned ok = 0;
 745	int subnet = 0;		/* Primary network */
 746	int gone = 1;		/* Address is missing */
 747	int same_prefsrc = 0;	/* Another primary with same IP */
 748
 749	if (ifa->ifa_flags & IFA_F_SECONDARY) {
 750		prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
 751		if (prim == NULL) {
 752			printk(KERN_WARNING "fib_del_ifaddr: bug: prim == NULL\n");
 
 
 
 
 753			return;
 754		}
 755		if (iprim && iprim != prim) {
 756			printk(KERN_WARNING "fib_del_ifaddr: bug: iprim != prim\n");
 757			return;
 758		}
 759	} else if (!ipv4_is_zeronet(any) &&
 760		   (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
 761		fib_magic(RTM_DELROUTE,
 762			  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
 763			  any, ifa->ifa_prefixlen, prim);
 
 764		subnet = 1;
 765	}
 766
 
 
 
 767	/* Deletion is more complicated than add.
 768	 * We should take care of not to delete too much :-)
 769	 *
 770	 * Scan address list to be sure that addresses are really gone.
 771	 */
 772
 773	for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
 774		if (ifa1 == ifa) {
 775			/* promotion, keep the IP */
 776			gone = 0;
 777			continue;
 778		}
 779		/* Ignore IFAs from our subnet */
 780		if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
 781		    inet_ifa_match(ifa1->ifa_address, iprim))
 782			continue;
 783
 784		/* Ignore ifa1 if it uses different primary IP (prefsrc) */
 785		if (ifa1->ifa_flags & IFA_F_SECONDARY) {
 786			/* Another address from our subnet? */
 787			if (ifa1->ifa_mask == prim->ifa_mask &&
 788			    inet_ifa_match(ifa1->ifa_address, prim))
 789				prim1 = prim;
 790			else {
 791				/* We reached the secondaries, so
 792				 * same_prefsrc should be determined.
 793				 */
 794				if (!same_prefsrc)
 795					continue;
 796				/* Search new prim1 if ifa1 is not
 797				 * using the current prim1
 798				 */
 799				if (!prim1 ||
 800				    ifa1->ifa_mask != prim1->ifa_mask ||
 801				    !inet_ifa_match(ifa1->ifa_address, prim1))
 802					prim1 = inet_ifa_byprefix(in_dev,
 803							ifa1->ifa_address,
 804							ifa1->ifa_mask);
 805				if (!prim1)
 806					continue;
 807				if (prim1->ifa_local != prim->ifa_local)
 808					continue;
 809			}
 810		} else {
 811			if (prim->ifa_local != ifa1->ifa_local)
 812				continue;
 813			prim1 = ifa1;
 814			if (prim != prim1)
 815				same_prefsrc = 1;
 816		}
 817		if (ifa->ifa_local == ifa1->ifa_local)
 818			ok |= LOCAL_OK;
 819		if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
 820			ok |= BRD_OK;
 821		if (brd == ifa1->ifa_broadcast)
 822			ok |= BRD1_OK;
 823		if (any == ifa1->ifa_broadcast)
 824			ok |= BRD0_OK;
 825		/* primary has network specific broadcasts */
 826		if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
 827			__be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
 828			__be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
 829
 830			if (!ipv4_is_zeronet(any1)) {
 831				if (ifa->ifa_broadcast == brd1 ||
 832				    ifa->ifa_broadcast == any1)
 833					ok |= BRD_OK;
 834				if (brd == brd1 || brd == any1)
 835					ok |= BRD1_OK;
 836				if (any == brd1 || any == any1)
 837					ok |= BRD0_OK;
 838			}
 839		}
 840	}
 
 841
 
 842	if (!(ok & BRD_OK))
 843		fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
 
 844	if (subnet && ifa->ifa_prefixlen < 31) {
 845		if (!(ok & BRD1_OK))
 846			fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
 
 847		if (!(ok & BRD0_OK))
 848			fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
 
 849	}
 850	if (!(ok & LOCAL_OK)) {
 851		fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
 
 
 852
 853		/* Check, that this local address finally disappeared. */
 854		if (gone &&
 855		    inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) {
 
 856			/* And the last, but not the least thing.
 857			 * We must flush stray FIB entries.
 858			 *
 859			 * First of all, we scan fib_info list searching
 860			 * for stray nexthop entries, then ignite fib_flush.
 861			 */
 862			if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
 863				fib_flush(dev_net(dev));
 864		}
 865	}
 866#undef LOCAL_OK
 867#undef BRD_OK
 868#undef BRD0_OK
 869#undef BRD1_OK
 870}
 871
 872static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb)
 873{
 874
 875	struct fib_result       res;
 876	struct flowi4           fl4 = {
 877		.flowi4_mark = frn->fl_mark,
 878		.daddr = frn->fl_addr,
 879		.flowi4_tos = frn->fl_tos,
 880		.flowi4_scope = frn->fl_scope,
 881	};
 
 882
 883#ifdef CONFIG_IP_MULTIPLE_TABLES
 884	res.r = NULL;
 885#endif
 886
 887	frn->err = -ENOENT;
 888	if (tb) {
 889		local_bh_disable();
 890
 891		frn->tb_id = tb->tb_id;
 892		rcu_read_lock();
 893		frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
 894
 895		if (!frn->err) {
 896			frn->prefixlen = res.prefixlen;
 897			frn->nh_sel = res.nh_sel;
 898			frn->type = res.type;
 899			frn->scope = res.scope;
 900		}
 901		rcu_read_unlock();
 902		local_bh_enable();
 903	}
 
 
 904}
 905
 906static void nl_fib_input(struct sk_buff *skb)
 907{
 908	struct net *net;
 909	struct fib_result_nl *frn;
 910	struct nlmsghdr *nlh;
 911	struct fib_table *tb;
 912	u32 pid;
 913
 914	net = sock_net(skb->sk);
 915	nlh = nlmsg_hdr(skb);
 916	if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len ||
 917	    nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn)))
 
 918		return;
 919
 920	skb = skb_clone(skb, GFP_KERNEL);
 921	if (skb == NULL)
 922		return;
 923	nlh = nlmsg_hdr(skb);
 924
 925	frn = (struct fib_result_nl *) NLMSG_DATA(nlh);
 926	tb = fib_get_table(net, frn->tb_id_in);
 927
 928	nl_fib_lookup(frn, tb);
 929
 930	pid = NETLINK_CB(skb).pid;      /* pid of sending process */
 931	NETLINK_CB(skb).pid = 0;        /* from kernel */
 932	NETLINK_CB(skb).dst_group = 0;  /* unicast */
 933	netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT);
 934}
 935
 936static int __net_init nl_fib_lookup_init(struct net *net)
 937{
 938	struct sock *sk;
 939	sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0,
 940				   nl_fib_input, NULL, THIS_MODULE);
 941	if (sk == NULL)
 
 
 
 942		return -EAFNOSUPPORT;
 943	net->ipv4.fibnl = sk;
 944	return 0;
 945}
 946
 947static void nl_fib_lookup_exit(struct net *net)
 948{
 949	netlink_kernel_release(net->ipv4.fibnl);
 950	net->ipv4.fibnl = NULL;
 951}
 952
 953static void fib_disable_ip(struct net_device *dev, int force, int delay)
 
 954{
 955	if (fib_sync_down_dev(dev, force))
 956		fib_flush(dev_net(dev));
 957	rt_cache_flush(dev_net(dev), delay);
 
 958	arp_ifdown(dev);
 959}
 960
 961static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
 962{
 963	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
 964	struct net_device *dev = ifa->ifa_dev->dev;
 965	struct net *net = dev_net(dev);
 966
 967	switch (event) {
 968	case NETDEV_UP:
 969		fib_add_ifaddr(ifa);
 970#ifdef CONFIG_IP_ROUTE_MULTIPATH
 971		fib_sync_up(dev);
 972#endif
 973		atomic_inc(&net->ipv4.dev_addr_genid);
 974		rt_cache_flush(dev_net(dev), -1);
 975		break;
 976	case NETDEV_DOWN:
 977		fib_del_ifaddr(ifa, NULL);
 978		atomic_inc(&net->ipv4.dev_addr_genid);
 979		if (ifa->ifa_dev->ifa_list == NULL) {
 980			/* Last address was deleted from this interface.
 981			 * Disable IP.
 982			 */
 983			fib_disable_ip(dev, 1, 0);
 984		} else {
 985			rt_cache_flush(dev_net(dev), -1);
 986		}
 987		break;
 988	}
 989	return NOTIFY_DONE;
 990}
 991
 992static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
 993{
 994	struct net_device *dev = ptr;
 995	struct in_device *in_dev = __in_dev_get_rtnl(dev);
 
 
 996	struct net *net = dev_net(dev);
 
 
 997
 998	if (event == NETDEV_UNREGISTER) {
 999		fib_disable_ip(dev, 2, -1);
 
1000		return NOTIFY_DONE;
1001	}
1002
 
1003	if (!in_dev)
1004		return NOTIFY_DONE;
1005
1006	switch (event) {
1007	case NETDEV_UP:
1008		for_ifa(in_dev) {
1009			fib_add_ifaddr(ifa);
1010		} endfor_ifa(in_dev);
1011#ifdef CONFIG_IP_ROUTE_MULTIPATH
1012		fib_sync_up(dev);
1013#endif
1014		atomic_inc(&net->ipv4.dev_addr_genid);
1015		rt_cache_flush(dev_net(dev), -1);
1016		break;
1017	case NETDEV_DOWN:
1018		fib_disable_ip(dev, 0, 0);
 
 
 
 
 
 
 
 
1019		break;
1020	case NETDEV_CHANGEMTU:
1021	case NETDEV_CHANGE:
1022		rt_cache_flush(dev_net(dev), 0);
1023		break;
1024	case NETDEV_UNREGISTER_BATCH:
1025		/* The batch unregister is only called on the first
1026		 * device in the list of devices being unregistered.
1027		 * Therefore we should not pass dev_net(dev) in here.
1028		 */
1029		rt_cache_flush_batch(NULL);
 
 
1030		break;
1031	}
1032	return NOTIFY_DONE;
1033}
1034
1035static struct notifier_block fib_inetaddr_notifier = {
1036	.notifier_call = fib_inetaddr_event,
1037};
1038
1039static struct notifier_block fib_netdev_notifier = {
1040	.notifier_call = fib_netdev_event,
1041};
1042
1043static int __net_init ip_fib_net_init(struct net *net)
1044{
1045	int err;
1046	size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1047
 
 
 
 
 
 
 
 
 
 
1048	/* Avoid false sharing : Use at least a full cache line */
1049	size = max_t(size_t, size, L1_CACHE_BYTES);
1050
1051	net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1052	if (net->ipv4.fib_table_hash == NULL)
1053		return -ENOMEM;
 
 
1054
1055	err = fib4_rules_init(net);
1056	if (err < 0)
1057		goto fail;
1058	return 0;
1059
1060fail:
1061	kfree(net->ipv4.fib_table_hash);
 
 
1062	return err;
1063}
1064
1065static void ip_fib_net_exit(struct net *net)
1066{
1067	unsigned int i;
1068
 
1069#ifdef CONFIG_IP_MULTIPLE_TABLES
1070	fib4_rules_exit(net);
 
1071#endif
1072
1073	rtnl_lock();
1074	for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
 
 
 
 
 
1075		struct fib_table *tb;
1076		struct hlist_head *head;
1077		struct hlist_node *node, *tmp;
1078
1079		head = &net->ipv4.fib_table_hash[i];
1080		hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) {
1081			hlist_del(node);
1082			fib_table_flush(tb);
1083			fib_free_table(tb);
1084		}
1085	}
 
 
 
 
1086	rtnl_unlock();
1087	kfree(net->ipv4.fib_table_hash);
 
1088}
1089
1090static int __net_init fib_net_init(struct net *net)
1091{
1092	int error;
1093
 
 
 
1094	error = ip_fib_net_init(net);
1095	if (error < 0)
1096		goto out;
1097	error = nl_fib_lookup_init(net);
1098	if (error < 0)
1099		goto out_nlfl;
1100	error = fib_proc_init(net);
1101	if (error < 0)
1102		goto out_proc;
1103out:
1104	return error;
1105
1106out_proc:
1107	nl_fib_lookup_exit(net);
1108out_nlfl:
1109	ip_fib_net_exit(net);
1110	goto out;
1111}
1112
1113static void __net_exit fib_net_exit(struct net *net)
1114{
1115	fib_proc_exit(net);
1116	nl_fib_lookup_exit(net);
1117	ip_fib_net_exit(net);
1118}
1119
1120static struct pernet_operations fib_net_ops = {
1121	.init = fib_net_init,
1122	.exit = fib_net_exit,
1123};
1124
1125void __init ip_fib_init(void)
1126{
1127	rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1128	rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1129	rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1130
1131	register_pernet_subsys(&fib_net_ops);
 
1132	register_netdevice_notifier(&fib_netdev_notifier);
1133	register_inetaddr_notifier(&fib_inetaddr_notifier);
1134
1135	fib_trie_init();
 
 
1136}