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v5.4
   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
  74static bool fib4_has_custom_rules(struct net *net)
  75{
  76	return false;
  77}
  78#else
  79
  80struct fib_table *fib_new_table(struct net *net, u32 id)
  81{
  82	struct fib_table *tb, *alias = NULL;
  83	unsigned int h;
  84
  85	if (id == 0)
  86		id = RT_TABLE_MAIN;
  87	tb = fib_get_table(net, id);
  88	if (tb)
  89		return tb;
  90
  91	if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules)
  92		alias = fib_new_table(net, RT_TABLE_MAIN);
  93
  94	tb = fib_trie_table(id, alias);
  95	if (!tb)
  96		return NULL;
  97
  98	switch (id) {
 
 
 
 
  99	case RT_TABLE_MAIN:
 100		rcu_assign_pointer(net->ipv4.fib_main, tb);
 101		break;
 
 102	case RT_TABLE_DEFAULT:
 103		rcu_assign_pointer(net->ipv4.fib_default, tb);
 104		break;
 
 105	default:
 106		break;
 107	}
 108
 109	h = id & (FIB_TABLE_HASHSZ - 1);
 110	hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
 111	return tb;
 112}
 113EXPORT_SYMBOL_GPL(fib_new_table);
 114
 115/* caller must hold either rtnl or rcu read lock */
 116struct fib_table *fib_get_table(struct net *net, u32 id)
 117{
 118	struct fib_table *tb;
 119	struct hlist_head *head;
 120	unsigned int h;
 121
 122	if (id == 0)
 123		id = RT_TABLE_MAIN;
 124	h = id & (FIB_TABLE_HASHSZ - 1);
 125
 
 126	head = &net->ipv4.fib_table_hash[h];
 127	hlist_for_each_entry_rcu(tb, head, tb_hlist,
 128				 lockdep_rtnl_is_held()) {
 129		if (tb->tb_id == id)
 130			return tb;
 
 131	}
 
 132	return NULL;
 133}
 134
 135static bool fib4_has_custom_rules(struct net *net)
 136{
 137	return net->ipv4.fib_has_custom_rules;
 138}
 139#endif /* CONFIG_IP_MULTIPLE_TABLES */
 140
 141static void fib_replace_table(struct net *net, struct fib_table *old,
 142			      struct fib_table *new)
 143{
 144#ifdef CONFIG_IP_MULTIPLE_TABLES
 145	switch (new->tb_id) {
 146	case RT_TABLE_MAIN:
 147		rcu_assign_pointer(net->ipv4.fib_main, new);
 148		break;
 149	case RT_TABLE_DEFAULT:
 150		rcu_assign_pointer(net->ipv4.fib_default, new);
 151		break;
 152	default:
 153		break;
 154	}
 155
 156#endif
 157	/* replace the old table in the hlist */
 158	hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
 159}
 160
 161int fib_unmerge(struct net *net)
 162{
 163	struct fib_table *old, *new, *main_table;
 164
 165	/* attempt to fetch local table if it has been allocated */
 166	old = fib_get_table(net, RT_TABLE_LOCAL);
 167	if (!old)
 168		return 0;
 169
 170	new = fib_trie_unmerge(old);
 171	if (!new)
 172		return -ENOMEM;
 173
 174	/* table is already unmerged */
 175	if (new == old)
 176		return 0;
 177
 178	/* replace merged table with clean table */
 179	fib_replace_table(net, old, new);
 180	fib_free_table(old);
 181
 182	/* attempt to fetch main table if it has been allocated */
 183	main_table = fib_get_table(net, RT_TABLE_MAIN);
 184	if (!main_table)
 185		return 0;
 186
 187	/* flush local entries from main table */
 188	fib_table_flush_external(main_table);
 189
 190	return 0;
 191}
 192
 193void fib_flush(struct net *net)
 194{
 195	int flushed = 0;
 
 
 196	unsigned int h;
 197
 198	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
 199		struct hlist_head *head = &net->ipv4.fib_table_hash[h];
 200		struct hlist_node *tmp;
 201		struct fib_table *tb;
 202
 203		hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
 204			flushed += fib_table_flush(net, tb, false);
 205	}
 206
 207	if (flushed)
 208		rt_cache_flush(net);
 209}
 210
 211/*
 212 * Find address type as if only "dev" was present in the system. If
 213 * on_dev is NULL then all interfaces are taken into consideration.
 214 */
 215static inline unsigned int __inet_dev_addr_type(struct net *net,
 216						const struct net_device *dev,
 217						__be32 addr, u32 tb_id)
 218{
 219	struct flowi4		fl4 = { .daddr = addr };
 220	struct fib_result	res;
 221	unsigned int ret = RTN_BROADCAST;
 222	struct fib_table *table;
 223
 224	if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
 225		return RTN_BROADCAST;
 226	if (ipv4_is_multicast(addr))
 227		return RTN_MULTICAST;
 228
 229	rcu_read_lock();
 230
 231	table = fib_get_table(net, tb_id);
 232	if (table) {
 233		ret = RTN_UNICAST;
 234		if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
 235			struct fib_nh_common *nhc = fib_info_nhc(res.fi, 0);
 236
 237			if (!dev || dev == nhc->nhc_dev)
 238				ret = res.type;
 239		}
 
 240	}
 241
 242	rcu_read_unlock();
 243	return ret;
 244}
 245
 246unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
 247{
 248	return __inet_dev_addr_type(net, NULL, addr, tb_id);
 249}
 250EXPORT_SYMBOL(inet_addr_type_table);
 251
 252unsigned int inet_addr_type(struct net *net, __be32 addr)
 253{
 254	return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
 255}
 256EXPORT_SYMBOL(inet_addr_type);
 257
 258unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
 259				__be32 addr)
 260{
 261	u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
 262
 263	return __inet_dev_addr_type(net, dev, addr, rt_table);
 264}
 265EXPORT_SYMBOL(inet_dev_addr_type);
 266
 267/* inet_addr_type with dev == NULL but using the table from a dev
 268 * if one is associated
 269 */
 270unsigned int inet_addr_type_dev_table(struct net *net,
 271				      const struct net_device *dev,
 272				      __be32 addr)
 273{
 274	u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
 275
 276	return __inet_dev_addr_type(net, NULL, addr, rt_table);
 277}
 278EXPORT_SYMBOL(inet_addr_type_dev_table);
 279
 280__be32 fib_compute_spec_dst(struct sk_buff *skb)
 281{
 282	struct net_device *dev = skb->dev;
 283	struct in_device *in_dev;
 284	struct fib_result res;
 285	struct rtable *rt;
 
 286	struct net *net;
 287	int scope;
 288
 289	rt = skb_rtable(skb);
 290	if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
 291	    RTCF_LOCAL)
 292		return ip_hdr(skb)->daddr;
 293
 294	in_dev = __in_dev_get_rcu(dev);
 
 295
 296	net = dev_net(dev);
 297
 298	scope = RT_SCOPE_UNIVERSE;
 299	if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
 300		bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev);
 301		struct flowi4 fl4 = {
 302			.flowi4_iif = LOOPBACK_IFINDEX,
 303			.flowi4_oif = l3mdev_master_ifindex_rcu(dev),
 304			.daddr = ip_hdr(skb)->saddr,
 305			.flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
 306			.flowi4_scope = scope,
 307			.flowi4_mark = vmark ? skb->mark : 0,
 308		};
 309		if (!fib_lookup(net, &fl4, &res, 0))
 310			return fib_result_prefsrc(net, &res);
 311	} else {
 312		scope = RT_SCOPE_LINK;
 313	}
 314
 315	return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
 316}
 317
 318bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev)
 319{
 320	bool dev_match = false;
 321#ifdef CONFIG_IP_ROUTE_MULTIPATH
 322	int ret;
 323
 324	for (ret = 0; ret < fib_info_num_path(fi); ret++) {
 325		const struct fib_nh_common *nhc = fib_info_nhc(fi, ret);
 326
 327		if (nhc->nhc_dev == dev) {
 328			dev_match = true;
 329			break;
 330		} else if (l3mdev_master_ifindex_rcu(nhc->nhc_dev) == dev->ifindex) {
 331			dev_match = true;
 332			break;
 333		}
 334	}
 335#else
 336	if (fib_info_nhc(fi, 0)->nhc_dev == dev)
 337		dev_match = true;
 338#endif
 339
 340	return dev_match;
 341}
 342EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev);
 343
 344/* Given (packet source, input interface) and optional (dst, oif, tos):
 345 * - (main) check, that source is valid i.e. not broadcast or our local
 346 *   address.
 347 * - figure out what "logical" interface this packet arrived
 348 *   and calculate "specific destination" address.
 349 * - check, that packet arrived from expected physical interface.
 350 * called with rcu_read_lock()
 351 */
 352static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 353				 u8 tos, int oif, struct net_device *dev,
 354				 int rpf, struct in_device *idev, u32 *itag)
 355{
 356	struct net *net = dev_net(dev);
 357	struct flow_keys flkeys;
 358	int ret, no_addr;
 359	struct fib_result res;
 360	struct flowi4 fl4;
 
 361	bool dev_match;
 362
 363	fl4.flowi4_oif = 0;
 364	fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
 365	if (!fl4.flowi4_iif)
 366		fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
 367	fl4.daddr = src;
 368	fl4.saddr = dst;
 369	fl4.flowi4_tos = tos;
 370	fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
 371	fl4.flowi4_tun_key.tun_id = 0;
 372	fl4.flowi4_flags = 0;
 373	fl4.flowi4_uid = sock_net_uid(net, NULL);
 374
 375	no_addr = idev->ifa_list == NULL;
 376
 
 377	fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
 378	if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) {
 379		fl4.flowi4_proto = 0;
 380		fl4.fl4_sport = 0;
 381		fl4.fl4_dport = 0;
 382	}
 383
 384	if (fib_lookup(net, &fl4, &res, 0))
 
 385		goto last_resort;
 386	if (res.type != RTN_UNICAST &&
 387	    (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
 388		goto e_inval;
 
 389	fib_combine_itag(itag, &res);
 
 390
 391	dev_match = fib_info_nh_uses_dev(res.fi, dev);
 392	/* This is not common, loopback packets retain skb_dst so normally they
 393	 * would not even hit this slow path.
 394	 */
 395	dev_match = dev_match || (res.type == RTN_LOCAL &&
 396				  dev == net->loopback_dev);
 
 
 
 
 
 
 
 397	if (dev_match) {
 398		ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
 399		return ret;
 400	}
 401	if (no_addr)
 402		goto last_resort;
 403	if (rpf == 1)
 404		goto e_rpf;
 405	fl4.flowi4_oif = dev->ifindex;
 406
 407	ret = 0;
 408	if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
 409		if (res.type == RTN_UNICAST)
 410			ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
 411	}
 412	return ret;
 413
 414last_resort:
 415	if (rpf)
 416		goto e_rpf;
 417	*itag = 0;
 418	return 0;
 419
 420e_inval:
 421	return -EINVAL;
 422e_rpf:
 423	return -EXDEV;
 424}
 425
 426/* Ignore rp_filter for packets protected by IPsec. */
 427int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 428			u8 tos, int oif, struct net_device *dev,
 429			struct in_device *idev, u32 *itag)
 430{
 431	int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
 432	struct net *net = dev_net(dev);
 433
 434	if (!r && !fib_num_tclassid_users(net) &&
 435	    (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
 436		if (IN_DEV_ACCEPT_LOCAL(idev))
 437			goto ok;
 438		/* with custom local routes in place, checking local addresses
 439		 * only will be too optimistic, with custom rules, checking
 440		 * local addresses only can be too strict, e.g. due to vrf
 441		 */
 442		if (net->ipv4.fib_has_custom_local_routes ||
 443		    fib4_has_custom_rules(net))
 444			goto full_check;
 445		if (inet_lookup_ifaddr_rcu(net, src))
 446			return -EINVAL;
 447
 448ok:
 449		*itag = 0;
 450		return 0;
 451	}
 452
 453full_check:
 454	return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
 455}
 456
 457static inline __be32 sk_extract_addr(struct sockaddr *addr)
 458{
 459	return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
 460}
 461
 462static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
 463{
 464	struct nlattr *nla;
 465
 466	nla = (struct nlattr *) ((char *) mx + len);
 467	nla->nla_type = type;
 468	nla->nla_len = nla_attr_size(4);
 469	*(u32 *) nla_data(nla) = value;
 470
 471	return len + nla_total_size(4);
 472}
 473
 474static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
 475				 struct fib_config *cfg)
 476{
 477	__be32 addr;
 478	int plen;
 479
 480	memset(cfg, 0, sizeof(*cfg));
 481	cfg->fc_nlinfo.nl_net = net;
 482
 483	if (rt->rt_dst.sa_family != AF_INET)
 484		return -EAFNOSUPPORT;
 485
 486	/*
 487	 * Check mask for validity:
 488	 * a) it must be contiguous.
 489	 * b) destination must have all host bits clear.
 490	 * c) if application forgot to set correct family (AF_INET),
 491	 *    reject request unless it is absolutely clear i.e.
 492	 *    both family and mask are zero.
 493	 */
 494	plen = 32;
 495	addr = sk_extract_addr(&rt->rt_dst);
 496	if (!(rt->rt_flags & RTF_HOST)) {
 497		__be32 mask = sk_extract_addr(&rt->rt_genmask);
 498
 499		if (rt->rt_genmask.sa_family != AF_INET) {
 500			if (mask || rt->rt_genmask.sa_family)
 501				return -EAFNOSUPPORT;
 502		}
 503
 504		if (bad_mask(mask, addr))
 505			return -EINVAL;
 506
 507		plen = inet_mask_len(mask);
 508	}
 509
 510	cfg->fc_dst_len = plen;
 511	cfg->fc_dst = addr;
 512
 513	if (cmd != SIOCDELRT) {
 514		cfg->fc_nlflags = NLM_F_CREATE;
 515		cfg->fc_protocol = RTPROT_BOOT;
 516	}
 517
 518	if (rt->rt_metric)
 519		cfg->fc_priority = rt->rt_metric - 1;
 520
 521	if (rt->rt_flags & RTF_REJECT) {
 522		cfg->fc_scope = RT_SCOPE_HOST;
 523		cfg->fc_type = RTN_UNREACHABLE;
 524		return 0;
 525	}
 526
 527	cfg->fc_scope = RT_SCOPE_NOWHERE;
 528	cfg->fc_type = RTN_UNICAST;
 529
 530	if (rt->rt_dev) {
 531		char *colon;
 532		struct net_device *dev;
 533		char devname[IFNAMSIZ];
 534
 535		if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
 536			return -EFAULT;
 537
 538		devname[IFNAMSIZ-1] = 0;
 539		colon = strchr(devname, ':');
 540		if (colon)
 541			*colon = 0;
 542		dev = __dev_get_by_name(net, devname);
 543		if (!dev)
 544			return -ENODEV;
 545		cfg->fc_oif = dev->ifindex;
 546		cfg->fc_table = l3mdev_fib_table(dev);
 547		if (colon) {
 548			const struct in_ifaddr *ifa;
 549			struct in_device *in_dev;
 550
 551			in_dev = __in_dev_get_rtnl(dev);
 552			if (!in_dev)
 553				return -ENODEV;
 554
 555			*colon = ':';
 556
 557			rcu_read_lock();
 558			in_dev_for_each_ifa_rcu(ifa, in_dev) {
 559				if (strcmp(ifa->ifa_label, devname) == 0)
 560					break;
 561			}
 562			rcu_read_unlock();
 563
 564			if (!ifa)
 565				return -ENODEV;
 566			cfg->fc_prefsrc = ifa->ifa_local;
 567		}
 568	}
 569
 570	addr = sk_extract_addr(&rt->rt_gateway);
 571	if (rt->rt_gateway.sa_family == AF_INET && addr) {
 572		unsigned int addr_type;
 573
 574		cfg->fc_gw4 = addr;
 575		cfg->fc_gw_family = AF_INET;
 576		addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
 577		if (rt->rt_flags & RTF_GATEWAY &&
 578		    addr_type == RTN_UNICAST)
 579			cfg->fc_scope = RT_SCOPE_UNIVERSE;
 580	}
 581
 582	if (cmd == SIOCDELRT)
 583		return 0;
 584
 585	if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family)
 586		return -EINVAL;
 587
 588	if (cfg->fc_scope == RT_SCOPE_NOWHERE)
 589		cfg->fc_scope = RT_SCOPE_LINK;
 590
 591	if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
 592		struct nlattr *mx;
 593		int len = 0;
 594
 595		mx = kcalloc(3, nla_total_size(4), GFP_KERNEL);
 596		if (!mx)
 597			return -ENOMEM;
 598
 599		if (rt->rt_flags & RTF_MTU)
 600			len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
 601
 602		if (rt->rt_flags & RTF_WINDOW)
 603			len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
 604
 605		if (rt->rt_flags & RTF_IRTT)
 606			len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
 607
 608		cfg->fc_mx = mx;
 609		cfg->fc_mx_len = len;
 610	}
 611
 612	return 0;
 613}
 614
 615/*
 616 * Handle IP routing ioctl calls.
 617 * These are used to manipulate the routing tables
 618 */
 619int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
 620{
 621	struct fib_config cfg;
 
 622	int err;
 623
 624	switch (cmd) {
 625	case SIOCADDRT:		/* Add a route */
 626	case SIOCDELRT:		/* Delete a route */
 627		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 628			return -EPERM;
 629
 
 
 
 630		rtnl_lock();
 631		err = rtentry_to_fib_config(net, cmd, rt, &cfg);
 632		if (err == 0) {
 633			struct fib_table *tb;
 634
 635			if (cmd == SIOCDELRT) {
 636				tb = fib_get_table(net, cfg.fc_table);
 637				if (tb)
 638					err = fib_table_delete(net, tb, &cfg,
 639							       NULL);
 640				else
 641					err = -ESRCH;
 642			} else {
 643				tb = fib_new_table(net, cfg.fc_table);
 644				if (tb)
 645					err = fib_table_insert(net, tb,
 646							       &cfg, NULL);
 647				else
 648					err = -ENOBUFS;
 649			}
 650
 651			/* allocated by rtentry_to_fib_config() */
 652			kfree(cfg.fc_mx);
 653		}
 654		rtnl_unlock();
 655		return err;
 656	}
 657	return -EINVAL;
 658}
 659
 660const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
 661	[RTA_UNSPEC]		= { .strict_start_type = RTA_DPORT + 1 },
 662	[RTA_DST]		= { .type = NLA_U32 },
 663	[RTA_SRC]		= { .type = NLA_U32 },
 664	[RTA_IIF]		= { .type = NLA_U32 },
 665	[RTA_OIF]		= { .type = NLA_U32 },
 666	[RTA_GATEWAY]		= { .type = NLA_U32 },
 667	[RTA_PRIORITY]		= { .type = NLA_U32 },
 668	[RTA_PREFSRC]		= { .type = NLA_U32 },
 669	[RTA_METRICS]		= { .type = NLA_NESTED },
 670	[RTA_MULTIPATH]		= { .len = sizeof(struct rtnexthop) },
 671	[RTA_FLOW]		= { .type = NLA_U32 },
 672	[RTA_ENCAP_TYPE]	= { .type = NLA_U16 },
 673	[RTA_ENCAP]		= { .type = NLA_NESTED },
 674	[RTA_UID]		= { .type = NLA_U32 },
 675	[RTA_MARK]		= { .type = NLA_U32 },
 676	[RTA_TABLE]		= { .type = NLA_U32 },
 677	[RTA_IP_PROTO]		= { .type = NLA_U8 },
 678	[RTA_SPORT]		= { .type = NLA_U16 },
 679	[RTA_DPORT]		= { .type = NLA_U16 },
 680	[RTA_NH_ID]		= { .type = NLA_U32 },
 681};
 682
 683int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
 684		    struct netlink_ext_ack *extack)
 685{
 686	struct rtvia *via;
 687	int alen;
 688
 689	if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
 690		NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA");
 691		return -EINVAL;
 692	}
 693
 694	via = nla_data(nla);
 695	alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr);
 696
 697	switch (via->rtvia_family) {
 698	case AF_INET:
 699		if (alen != sizeof(__be32)) {
 700			NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA");
 701			return -EINVAL;
 702		}
 703		cfg->fc_gw_family = AF_INET;
 704		cfg->fc_gw4 = *((__be32 *)via->rtvia_addr);
 705		break;
 706	case AF_INET6:
 707#ifdef CONFIG_IPV6
 708		if (alen != sizeof(struct in6_addr)) {
 709			NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA");
 710			return -EINVAL;
 711		}
 712		cfg->fc_gw_family = AF_INET6;
 713		cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr);
 714#else
 715		NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
 716		return -EINVAL;
 717#endif
 718		break;
 719	default:
 720		NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA");
 721		return -EINVAL;
 722	}
 723
 724	return 0;
 725}
 726
 727static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
 728			     struct nlmsghdr *nlh, struct fib_config *cfg,
 729			     struct netlink_ext_ack *extack)
 730{
 731	bool has_gw = false, has_via = false;
 732	struct nlattr *attr;
 733	int err, remaining;
 734	struct rtmsg *rtm;
 735
 736	err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
 737					rtm_ipv4_policy, extack);
 738	if (err < 0)
 739		goto errout;
 740
 741	memset(cfg, 0, sizeof(*cfg));
 742
 743	rtm = nlmsg_data(nlh);
 744	cfg->fc_dst_len = rtm->rtm_dst_len;
 745	cfg->fc_tos = rtm->rtm_tos;
 746	cfg->fc_table = rtm->rtm_table;
 747	cfg->fc_protocol = rtm->rtm_protocol;
 748	cfg->fc_scope = rtm->rtm_scope;
 749	cfg->fc_type = rtm->rtm_type;
 750	cfg->fc_flags = rtm->rtm_flags;
 751	cfg->fc_nlflags = nlh->nlmsg_flags;
 752
 753	cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
 754	cfg->fc_nlinfo.nlh = nlh;
 755	cfg->fc_nlinfo.nl_net = net;
 756
 757	if (cfg->fc_type > RTN_MAX) {
 758		NL_SET_ERR_MSG(extack, "Invalid route type");
 759		err = -EINVAL;
 760		goto errout;
 761	}
 762
 763	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
 764		switch (nla_type(attr)) {
 765		case RTA_DST:
 766			cfg->fc_dst = nla_get_be32(attr);
 767			break;
 768		case RTA_OIF:
 769			cfg->fc_oif = nla_get_u32(attr);
 770			break;
 771		case RTA_GATEWAY:
 772			has_gw = true;
 773			cfg->fc_gw4 = nla_get_be32(attr);
 774			if (cfg->fc_gw4)
 775				cfg->fc_gw_family = AF_INET;
 776			break;
 777		case RTA_VIA:
 778			has_via = true;
 779			err = fib_gw_from_via(cfg, attr, extack);
 780			if (err)
 781				goto errout;
 782			break;
 783		case RTA_PRIORITY:
 784			cfg->fc_priority = nla_get_u32(attr);
 785			break;
 786		case RTA_PREFSRC:
 787			cfg->fc_prefsrc = nla_get_be32(attr);
 788			break;
 789		case RTA_METRICS:
 790			cfg->fc_mx = nla_data(attr);
 791			cfg->fc_mx_len = nla_len(attr);
 792			break;
 793		case RTA_MULTIPATH:
 794			err = lwtunnel_valid_encap_type_attr(nla_data(attr),
 795							     nla_len(attr),
 796							     extack);
 797			if (err < 0)
 798				goto errout;
 799			cfg->fc_mp = nla_data(attr);
 800			cfg->fc_mp_len = nla_len(attr);
 801			break;
 802		case RTA_FLOW:
 803			cfg->fc_flow = nla_get_u32(attr);
 804			break;
 805		case RTA_TABLE:
 806			cfg->fc_table = nla_get_u32(attr);
 807			break;
 808		case RTA_ENCAP:
 809			cfg->fc_encap = attr;
 810			break;
 811		case RTA_ENCAP_TYPE:
 812			cfg->fc_encap_type = nla_get_u16(attr);
 813			err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
 814							extack);
 815			if (err < 0)
 816				goto errout;
 817			break;
 818		case RTA_NH_ID:
 819			cfg->fc_nh_id = nla_get_u32(attr);
 820			break;
 821		}
 822	}
 823
 824	if (cfg->fc_nh_id) {
 825		if (cfg->fc_oif || cfg->fc_gw_family ||
 826		    cfg->fc_encap || cfg->fc_mp) {
 827			NL_SET_ERR_MSG(extack,
 828				       "Nexthop specification and nexthop id are mutually exclusive");
 829			return -EINVAL;
 830		}
 831	}
 832
 833	if (has_gw && has_via) {
 834		NL_SET_ERR_MSG(extack,
 835			       "Nexthop configuration can not contain both GATEWAY and VIA");
 836		goto errout;
 837	}
 838
 839	return 0;
 840errout:
 841	return err;
 842}
 843
 844static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
 845			     struct netlink_ext_ack *extack)
 846{
 847	struct net *net = sock_net(skb->sk);
 848	struct fib_config cfg;
 849	struct fib_table *tb;
 850	int err;
 851
 852	err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
 853	if (err < 0)
 854		goto errout;
 855
 856	if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) {
 857		NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
 858		err = -EINVAL;
 859		goto errout;
 860	}
 861
 862	tb = fib_get_table(net, cfg.fc_table);
 863	if (!tb) {
 864		NL_SET_ERR_MSG(extack, "FIB table does not exist");
 865		err = -ESRCH;
 866		goto errout;
 867	}
 868
 869	err = fib_table_delete(net, tb, &cfg, extack);
 870errout:
 871	return err;
 872}
 873
 874static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
 875			     struct netlink_ext_ack *extack)
 876{
 877	struct net *net = sock_net(skb->sk);
 878	struct fib_config cfg;
 879	struct fib_table *tb;
 880	int err;
 881
 882	err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
 883	if (err < 0)
 884		goto errout;
 885
 886	tb = fib_new_table(net, cfg.fc_table);
 887	if (!tb) {
 888		err = -ENOBUFS;
 889		goto errout;
 890	}
 891
 892	err = fib_table_insert(net, tb, &cfg, extack);
 893	if (!err && cfg.fc_type == RTN_LOCAL)
 894		net->ipv4.fib_has_custom_local_routes = true;
 895errout:
 896	return err;
 897}
 898
 899int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
 900			  struct fib_dump_filter *filter,
 901			  struct netlink_callback *cb)
 902{
 903	struct netlink_ext_ack *extack = cb->extack;
 904	struct nlattr *tb[RTA_MAX + 1];
 905	struct rtmsg *rtm;
 906	int err, i;
 907
 908	ASSERT_RTNL();
 909
 910	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
 911		NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request");
 912		return -EINVAL;
 913	}
 914
 915	rtm = nlmsg_data(nlh);
 916	if (rtm->rtm_dst_len || rtm->rtm_src_len  || rtm->rtm_tos   ||
 917	    rtm->rtm_scope) {
 918		NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request");
 919		return -EINVAL;
 920	}
 921
 922	if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) {
 923		NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request");
 924		return -EINVAL;
 925	}
 926	if (rtm->rtm_flags & RTM_F_CLONED)
 927		filter->dump_routes = false;
 928	else
 929		filter->dump_exceptions = false;
 930
 931	filter->dump_all_families = (rtm->rtm_family == AF_UNSPEC);
 932	filter->flags    = rtm->rtm_flags;
 933	filter->protocol = rtm->rtm_protocol;
 934	filter->rt_type  = rtm->rtm_type;
 935	filter->table_id = rtm->rtm_table;
 936
 937	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
 938					    rtm_ipv4_policy, extack);
 939	if (err < 0)
 940		return err;
 941
 942	for (i = 0; i <= RTA_MAX; ++i) {
 943		int ifindex;
 944
 945		if (!tb[i])
 946			continue;
 947
 948		switch (i) {
 949		case RTA_TABLE:
 950			filter->table_id = nla_get_u32(tb[i]);
 951			break;
 952		case RTA_OIF:
 953			ifindex = nla_get_u32(tb[i]);
 954			filter->dev = __dev_get_by_index(net, ifindex);
 955			if (!filter->dev)
 956				return -ENODEV;
 957			break;
 958		default:
 959			NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
 960			return -EINVAL;
 961		}
 962	}
 963
 964	if (filter->flags || filter->protocol || filter->rt_type ||
 965	    filter->table_id || filter->dev) {
 966		filter->filter_set = 1;
 967		cb->answer_flags = NLM_F_DUMP_FILTERED;
 968	}
 969
 970	return 0;
 971}
 972EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req);
 973
 974static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 975{
 976	struct fib_dump_filter filter = { .dump_routes = true,
 977					  .dump_exceptions = true };
 978	const struct nlmsghdr *nlh = cb->nlh;
 979	struct net *net = sock_net(skb->sk);
 980	unsigned int h, s_h;
 981	unsigned int e = 0, s_e;
 982	struct fib_table *tb;
 983	struct hlist_head *head;
 984	int dumped = 0, err;
 985
 986	if (cb->strict_check) {
 987		err = ip_valid_fib_dump_req(net, nlh, &filter, cb);
 988		if (err < 0)
 989			return err;
 990	} else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
 991		struct rtmsg *rtm = nlmsg_data(nlh);
 992
 993		filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED);
 994	}
 995
 996	/* ipv4 does not use prefix flag */
 997	if (filter.flags & RTM_F_PREFIX)
 998		return skb->len;
 999
1000	if (filter.table_id) {
1001		tb = fib_get_table(net, filter.table_id);
1002		if (!tb) {
1003			if (filter.dump_all_families)
1004				return skb->len;
1005
1006			NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist");
1007			return -ENOENT;
1008		}
1009
1010		err = fib_table_dump(tb, skb, cb, &filter);
1011		return skb->len ? : err;
1012	}
1013
1014	s_h = cb->args[0];
1015	s_e = cb->args[1];
1016
1017	rcu_read_lock();
1018
1019	for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
1020		e = 0;
1021		head = &net->ipv4.fib_table_hash[h];
1022		hlist_for_each_entry_rcu(tb, head, tb_hlist) {
1023			if (e < s_e)
1024				goto next;
1025			if (dumped)
1026				memset(&cb->args[2], 0, sizeof(cb->args) -
1027						 2 * sizeof(cb->args[0]));
1028			err = fib_table_dump(tb, skb, cb, &filter);
1029			if (err < 0) {
1030				if (likely(skb->len))
1031					goto out;
1032
1033				goto out_err;
1034			}
1035			dumped = 1;
1036next:
1037			e++;
1038		}
1039	}
1040out:
1041	err = skb->len;
1042out_err:
1043	rcu_read_unlock();
1044
1045	cb->args[1] = e;
1046	cb->args[0] = h;
1047
1048	return err;
1049}
1050
1051/* Prepare and feed intra-kernel routing request.
1052 * Really, it should be netlink message, but :-( netlink
1053 * can be not configured, so that we feed it directly
1054 * to fib engine. It is legal, because all events occur
1055 * only when netlink is already locked.
1056 */
1057static void fib_magic(int cmd, int type, __be32 dst, int dst_len,
1058		      struct in_ifaddr *ifa, u32 rt_priority)
1059{
1060	struct net *net = dev_net(ifa->ifa_dev->dev);
1061	u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
1062	struct fib_table *tb;
1063	struct fib_config cfg = {
1064		.fc_protocol = RTPROT_KERNEL,
1065		.fc_type = type,
1066		.fc_dst = dst,
1067		.fc_dst_len = dst_len,
1068		.fc_priority = rt_priority,
1069		.fc_prefsrc = ifa->ifa_local,
1070		.fc_oif = ifa->ifa_dev->dev->ifindex,
1071		.fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
1072		.fc_nlinfo = {
1073			.nl_net = net,
1074		},
1075	};
1076
1077	if (!tb_id)
1078		tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
 
 
1079
1080	tb = fib_new_table(net, tb_id);
1081	if (!tb)
1082		return;
1083
1084	cfg.fc_table = tb->tb_id;
1085
1086	if (type != RTN_LOCAL)
1087		cfg.fc_scope = RT_SCOPE_LINK;
1088	else
1089		cfg.fc_scope = RT_SCOPE_HOST;
1090
1091	if (cmd == RTM_NEWROUTE)
1092		fib_table_insert(net, tb, &cfg, NULL);
1093	else
1094		fib_table_delete(net, tb, &cfg, NULL);
1095}
1096
1097void fib_add_ifaddr(struct in_ifaddr *ifa)
1098{
1099	struct in_device *in_dev = ifa->ifa_dev;
1100	struct net_device *dev = in_dev->dev;
1101	struct in_ifaddr *prim = ifa;
1102	__be32 mask = ifa->ifa_mask;
1103	__be32 addr = ifa->ifa_local;
1104	__be32 prefix = ifa->ifa_address & mask;
1105
1106	if (ifa->ifa_flags & IFA_F_SECONDARY) {
1107		prim = inet_ifa_byprefix(in_dev, prefix, mask);
1108		if (!prim) {
1109			pr_warn("%s: bug: prim == NULL\n", __func__);
1110			return;
1111		}
1112	}
1113
1114	fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0);
1115
1116	if (!(dev->flags & IFF_UP))
1117		return;
1118
1119	/* Add broadcast address, if it is explicitly assigned. */
1120	if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
1121		fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1122			  prim, 0);
1123
1124	if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
1125	    (prefix != addr || ifa->ifa_prefixlen < 32)) {
1126		if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1127			fib_magic(RTM_NEWROUTE,
1128				  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1129				  prefix, ifa->ifa_prefixlen, prim,
1130				  ifa->ifa_rt_priority);
1131
1132		/* Add network specific broadcasts, when it takes a sense */
1133		if (ifa->ifa_prefixlen < 31) {
1134			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32,
1135				  prim, 0);
1136			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
1137				  32, prim, 0);
1138		}
1139	}
1140}
1141
1142void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric)
1143{
1144	__be32 prefix = ifa->ifa_address & ifa->ifa_mask;
1145	struct in_device *in_dev = ifa->ifa_dev;
1146	struct net_device *dev = in_dev->dev;
1147
1148	if (!(dev->flags & IFF_UP) ||
1149	    ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) ||
1150	    ipv4_is_zeronet(prefix) ||
1151	    (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32))
1152		return;
1153
1154	/* add the new */
1155	fib_magic(RTM_NEWROUTE,
1156		  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1157		  prefix, ifa->ifa_prefixlen, ifa, new_metric);
1158
1159	/* delete the old */
1160	fib_magic(RTM_DELROUTE,
1161		  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1162		  prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority);
1163}
1164
1165/* Delete primary or secondary address.
1166 * Optionally, on secondary address promotion consider the addresses
1167 * from subnet iprim as deleted, even if they are in device list.
1168 * In this case the secondary ifa can be in device list.
1169 */
1170void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
1171{
1172	struct in_device *in_dev = ifa->ifa_dev;
1173	struct net_device *dev = in_dev->dev;
1174	struct in_ifaddr *ifa1;
1175	struct in_ifaddr *prim = ifa, *prim1 = NULL;
1176	__be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
1177	__be32 any = ifa->ifa_address & ifa->ifa_mask;
1178#define LOCAL_OK	1
1179#define BRD_OK		2
1180#define BRD0_OK		4
1181#define BRD1_OK		8
1182	unsigned int ok = 0;
1183	int subnet = 0;		/* Primary network */
1184	int gone = 1;		/* Address is missing */
1185	int same_prefsrc = 0;	/* Another primary with same IP */
1186
1187	if (ifa->ifa_flags & IFA_F_SECONDARY) {
1188		prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
1189		if (!prim) {
1190			/* if the device has been deleted, we don't perform
1191			 * address promotion
1192			 */
1193			if (!in_dev->dead)
1194				pr_warn("%s: bug: prim == NULL\n", __func__);
1195			return;
1196		}
1197		if (iprim && iprim != prim) {
1198			pr_warn("%s: bug: iprim != prim\n", __func__);
1199			return;
1200		}
1201	} else if (!ipv4_is_zeronet(any) &&
1202		   (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
1203		if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1204			fib_magic(RTM_DELROUTE,
1205				  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1206				  any, ifa->ifa_prefixlen, prim, 0);
1207		subnet = 1;
1208	}
1209
1210	if (in_dev->dead)
1211		goto no_promotions;
1212
1213	/* Deletion is more complicated than add.
1214	 * We should take care of not to delete too much :-)
1215	 *
1216	 * Scan address list to be sure that addresses are really gone.
1217	 */
1218	rcu_read_lock();
1219	in_dev_for_each_ifa_rcu(ifa1, in_dev) {
1220		if (ifa1 == ifa) {
1221			/* promotion, keep the IP */
1222			gone = 0;
1223			continue;
1224		}
1225		/* Ignore IFAs from our subnet */
1226		if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
1227		    inet_ifa_match(ifa1->ifa_address, iprim))
1228			continue;
1229
1230		/* Ignore ifa1 if it uses different primary IP (prefsrc) */
1231		if (ifa1->ifa_flags & IFA_F_SECONDARY) {
1232			/* Another address from our subnet? */
1233			if (ifa1->ifa_mask == prim->ifa_mask &&
1234			    inet_ifa_match(ifa1->ifa_address, prim))
1235				prim1 = prim;
1236			else {
1237				/* We reached the secondaries, so
1238				 * same_prefsrc should be determined.
1239				 */
1240				if (!same_prefsrc)
1241					continue;
1242				/* Search new prim1 if ifa1 is not
1243				 * using the current prim1
1244				 */
1245				if (!prim1 ||
1246				    ifa1->ifa_mask != prim1->ifa_mask ||
1247				    !inet_ifa_match(ifa1->ifa_address, prim1))
1248					prim1 = inet_ifa_byprefix(in_dev,
1249							ifa1->ifa_address,
1250							ifa1->ifa_mask);
1251				if (!prim1)
1252					continue;
1253				if (prim1->ifa_local != prim->ifa_local)
1254					continue;
1255			}
1256		} else {
1257			if (prim->ifa_local != ifa1->ifa_local)
1258				continue;
1259			prim1 = ifa1;
1260			if (prim != prim1)
1261				same_prefsrc = 1;
1262		}
1263		if (ifa->ifa_local == ifa1->ifa_local)
1264			ok |= LOCAL_OK;
1265		if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1266			ok |= BRD_OK;
1267		if (brd == ifa1->ifa_broadcast)
1268			ok |= BRD1_OK;
1269		if (any == ifa1->ifa_broadcast)
1270			ok |= BRD0_OK;
1271		/* primary has network specific broadcasts */
1272		if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1273			__be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1274			__be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1275
1276			if (!ipv4_is_zeronet(any1)) {
1277				if (ifa->ifa_broadcast == brd1 ||
1278				    ifa->ifa_broadcast == any1)
1279					ok |= BRD_OK;
1280				if (brd == brd1 || brd == any1)
1281					ok |= BRD1_OK;
1282				if (any == brd1 || any == any1)
1283					ok |= BRD0_OK;
1284			}
1285		}
1286	}
1287	rcu_read_unlock();
1288
1289no_promotions:
1290	if (!(ok & BRD_OK))
1291		fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1292			  prim, 0);
1293	if (subnet && ifa->ifa_prefixlen < 31) {
1294		if (!(ok & BRD1_OK))
1295			fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32,
1296				  prim, 0);
1297		if (!(ok & BRD0_OK))
1298			fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32,
1299				  prim, 0);
1300	}
1301	if (!(ok & LOCAL_OK)) {
1302		unsigned int addr_type;
1303
1304		fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0);
1305
1306		/* Check, that this local address finally disappeared. */
1307		addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1308						     ifa->ifa_local);
1309		if (gone && addr_type != RTN_LOCAL) {
1310			/* And the last, but not the least thing.
1311			 * We must flush stray FIB entries.
1312			 *
1313			 * First of all, we scan fib_info list searching
1314			 * for stray nexthop entries, then ignite fib_flush.
1315			 */
1316			if (fib_sync_down_addr(dev, ifa->ifa_local))
1317				fib_flush(dev_net(dev));
1318		}
1319	}
1320#undef LOCAL_OK
1321#undef BRD_OK
1322#undef BRD0_OK
1323#undef BRD1_OK
1324}
1325
1326static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1327{
1328
1329	struct fib_result       res;
1330	struct flowi4           fl4 = {
1331		.flowi4_mark = frn->fl_mark,
1332		.daddr = frn->fl_addr,
1333		.flowi4_tos = frn->fl_tos,
1334		.flowi4_scope = frn->fl_scope,
1335	};
1336	struct fib_table *tb;
1337
1338	rcu_read_lock();
1339
1340	tb = fib_get_table(net, frn->tb_id_in);
1341
1342	frn->err = -ENOENT;
1343	if (tb) {
1344		local_bh_disable();
1345
1346		frn->tb_id = tb->tb_id;
1347		frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1348
1349		if (!frn->err) {
1350			frn->prefixlen = res.prefixlen;
1351			frn->nh_sel = res.nh_sel;
1352			frn->type = res.type;
1353			frn->scope = res.scope;
1354		}
1355		local_bh_enable();
1356	}
1357
1358	rcu_read_unlock();
1359}
1360
1361static void nl_fib_input(struct sk_buff *skb)
1362{
1363	struct net *net;
1364	struct fib_result_nl *frn;
1365	struct nlmsghdr *nlh;
 
1366	u32 portid;
1367
1368	net = sock_net(skb->sk);
1369	nlh = nlmsg_hdr(skb);
1370	if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1371	    skb->len < nlh->nlmsg_len ||
1372	    nlmsg_len(nlh) < sizeof(*frn))
1373		return;
1374
1375	skb = netlink_skb_clone(skb, GFP_KERNEL);
1376	if (!skb)
1377		return;
1378	nlh = nlmsg_hdr(skb);
1379
1380	frn = (struct fib_result_nl *) nlmsg_data(nlh);
1381	nl_fib_lookup(net, frn);
 
 
1382
1383	portid = NETLINK_CB(skb).portid;      /* netlink portid */
1384	NETLINK_CB(skb).portid = 0;        /* from kernel */
1385	NETLINK_CB(skb).dst_group = 0;  /* unicast */
1386	netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1387}
1388
1389static int __net_init nl_fib_lookup_init(struct net *net)
1390{
1391	struct sock *sk;
1392	struct netlink_kernel_cfg cfg = {
1393		.input	= nl_fib_input,
1394	};
1395
1396	sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1397	if (!sk)
1398		return -EAFNOSUPPORT;
1399	net->ipv4.fibnl = sk;
1400	return 0;
1401}
1402
1403static void nl_fib_lookup_exit(struct net *net)
1404{
1405	netlink_kernel_release(net->ipv4.fibnl);
1406	net->ipv4.fibnl = NULL;
1407}
1408
1409static void fib_disable_ip(struct net_device *dev, unsigned long event,
1410			   bool force)
1411{
1412	if (fib_sync_down_dev(dev, event, force))
1413		fib_flush(dev_net(dev));
1414	else
1415		rt_cache_flush(dev_net(dev));
1416	arp_ifdown(dev);
1417}
1418
1419static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1420{
1421	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1422	struct net_device *dev = ifa->ifa_dev->dev;
1423	struct net *net = dev_net(dev);
1424
1425	switch (event) {
1426	case NETDEV_UP:
1427		fib_add_ifaddr(ifa);
1428#ifdef CONFIG_IP_ROUTE_MULTIPATH
1429		fib_sync_up(dev, RTNH_F_DEAD);
1430#endif
1431		atomic_inc(&net->ipv4.dev_addr_genid);
1432		rt_cache_flush(dev_net(dev));
1433		break;
1434	case NETDEV_DOWN:
1435		fib_del_ifaddr(ifa, NULL);
1436		atomic_inc(&net->ipv4.dev_addr_genid);
1437		if (!ifa->ifa_dev->ifa_list) {
1438			/* Last address was deleted from this interface.
1439			 * Disable IP.
1440			 */
1441			fib_disable_ip(dev, event, true);
1442		} else {
1443			rt_cache_flush(dev_net(dev));
1444		}
1445		break;
1446	}
1447	return NOTIFY_DONE;
1448}
1449
1450static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1451{
1452	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1453	struct netdev_notifier_changeupper_info *upper_info = ptr;
1454	struct netdev_notifier_info_ext *info_ext = ptr;
1455	struct in_device *in_dev;
1456	struct net *net = dev_net(dev);
1457	struct in_ifaddr *ifa;
1458	unsigned int flags;
1459
1460	if (event == NETDEV_UNREGISTER) {
1461		fib_disable_ip(dev, event, true);
1462		rt_flush_dev(dev);
1463		return NOTIFY_DONE;
1464	}
1465
1466	in_dev = __in_dev_get_rtnl(dev);
1467	if (!in_dev)
1468		return NOTIFY_DONE;
1469
1470	switch (event) {
1471	case NETDEV_UP:
1472		in_dev_for_each_ifa_rtnl(ifa, in_dev) {
1473			fib_add_ifaddr(ifa);
1474		}
1475#ifdef CONFIG_IP_ROUTE_MULTIPATH
1476		fib_sync_up(dev, RTNH_F_DEAD);
1477#endif
1478		atomic_inc(&net->ipv4.dev_addr_genid);
1479		rt_cache_flush(net);
1480		break;
1481	case NETDEV_DOWN:
1482		fib_disable_ip(dev, event, false);
1483		break;
1484	case NETDEV_CHANGE:
1485		flags = dev_get_flags(dev);
1486		if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1487			fib_sync_up(dev, RTNH_F_LINKDOWN);
1488		else
1489			fib_sync_down_dev(dev, event, false);
1490		rt_cache_flush(net);
1491		break;
1492	case NETDEV_CHANGEMTU:
1493		fib_sync_mtu(dev, info_ext->ext.mtu);
1494		rt_cache_flush(net);
1495		break;
1496	case NETDEV_CHANGEUPPER:
1497		upper_info = ptr;
1498		/* flush all routes if dev is linked to or unlinked from
1499		 * an L3 master device (e.g., VRF)
1500		 */
1501		if (upper_info->upper_dev &&
1502		    netif_is_l3_master(upper_info->upper_dev))
1503			fib_disable_ip(dev, NETDEV_DOWN, true);
1504		break;
1505	}
1506	return NOTIFY_DONE;
1507}
1508
1509static struct notifier_block fib_inetaddr_notifier = {
1510	.notifier_call = fib_inetaddr_event,
1511};
1512
1513static struct notifier_block fib_netdev_notifier = {
1514	.notifier_call = fib_netdev_event,
1515};
1516
1517static int __net_init ip_fib_net_init(struct net *net)
1518{
1519	int err;
1520	size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1521
1522	err = fib4_notifier_init(net);
1523	if (err)
1524		return err;
1525
1526	/* Avoid false sharing : Use at least a full cache line */
1527	size = max_t(size_t, size, L1_CACHE_BYTES);
1528
1529	net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1530	if (!net->ipv4.fib_table_hash) {
1531		err = -ENOMEM;
1532		goto err_table_hash_alloc;
1533	}
1534
1535	err = fib4_rules_init(net);
1536	if (err < 0)
1537		goto err_rules_init;
1538	return 0;
1539
1540err_rules_init:
1541	kfree(net->ipv4.fib_table_hash);
1542err_table_hash_alloc:
1543	fib4_notifier_exit(net);
1544	return err;
1545}
1546
1547static void ip_fib_net_exit(struct net *net)
1548{
1549	int i;
1550
1551	rtnl_lock();
1552#ifdef CONFIG_IP_MULTIPLE_TABLES
1553	RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1554	RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1555#endif
1556	/* Destroy the tables in reverse order to guarantee that the
1557	 * local table, ID 255, is destroyed before the main table, ID
1558	 * 254. This is necessary as the local table may contain
1559	 * references to data contained in the main table.
1560	 */
1561	for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1562		struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1563		struct hlist_node *tmp;
1564		struct fib_table *tb;
 
 
1565
 
1566		hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1567			hlist_del(&tb->tb_hlist);
1568			fib_table_flush(net, tb, true);
1569			fib_free_table(tb);
1570		}
1571	}
1572
1573#ifdef CONFIG_IP_MULTIPLE_TABLES
1574	fib4_rules_exit(net);
1575#endif
1576	rtnl_unlock();
1577	kfree(net->ipv4.fib_table_hash);
1578	fib4_notifier_exit(net);
1579}
1580
1581static int __net_init fib_net_init(struct net *net)
1582{
1583	int error;
1584
1585#ifdef CONFIG_IP_ROUTE_CLASSID
1586	net->ipv4.fib_num_tclassid_users = 0;
1587#endif
1588	error = ip_fib_net_init(net);
1589	if (error < 0)
1590		goto out;
1591	error = nl_fib_lookup_init(net);
1592	if (error < 0)
1593		goto out_nlfl;
1594	error = fib_proc_init(net);
1595	if (error < 0)
1596		goto out_proc;
1597out:
1598	return error;
1599
1600out_proc:
1601	nl_fib_lookup_exit(net);
1602out_nlfl:
1603	ip_fib_net_exit(net);
1604	goto out;
1605}
1606
1607static void __net_exit fib_net_exit(struct net *net)
1608{
1609	fib_proc_exit(net);
1610	nl_fib_lookup_exit(net);
1611	ip_fib_net_exit(net);
1612}
1613
1614static struct pernet_operations fib_net_ops = {
1615	.init = fib_net_init,
1616	.exit = fib_net_exit,
1617};
1618
1619void __init ip_fib_init(void)
1620{
1621	fib_trie_init();
 
 
1622
1623	register_pernet_subsys(&fib_net_ops);
1624
1625	register_netdevice_notifier(&fib_netdev_notifier);
1626	register_inetaddr_notifier(&fib_inetaddr_notifier);
1627
1628	rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0);
1629	rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0);
1630	rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0);
1631}
v3.15
 
   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 <linux/bitops.h>
  19#include <linux/capability.h>
  20#include <linux/types.h>
  21#include <linux/kernel.h>
  22#include <linux/mm.h>
  23#include <linux/string.h>
  24#include <linux/socket.h>
  25#include <linux/sockios.h>
  26#include <linux/errno.h>
  27#include <linux/in.h>
  28#include <linux/inet.h>
  29#include <linux/inetdevice.h>
  30#include <linux/netdevice.h>
  31#include <linux/if_addr.h>
  32#include <linux/if_arp.h>
  33#include <linux/skbuff.h>
  34#include <linux/cache.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
  90	switch (id) {
  91	case RT_TABLE_LOCAL:
  92		net->ipv4.fib_local = tb;
  93		break;
  94
  95	case RT_TABLE_MAIN:
  96		net->ipv4.fib_main = tb;
  97		break;
  98
  99	case RT_TABLE_DEFAULT:
 100		net->ipv4.fib_default = tb;
 101		break;
 102
 103	default:
 104		break;
 105	}
 106
 107	h = id & (FIB_TABLE_HASHSZ - 1);
 108	hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
 109	return tb;
 110}
 
 111
 
 112struct fib_table *fib_get_table(struct net *net, u32 id)
 113{
 114	struct fib_table *tb;
 115	struct hlist_head *head;
 116	unsigned int h;
 117
 118	if (id == 0)
 119		id = RT_TABLE_MAIN;
 120	h = id & (FIB_TABLE_HASHSZ - 1);
 121
 122	rcu_read_lock();
 123	head = &net->ipv4.fib_table_hash[h];
 124	hlist_for_each_entry_rcu(tb, head, tb_hlist) {
 125		if (tb->tb_id == id) {
 126			rcu_read_unlock();
 127			return tb;
 128		}
 129	}
 130	rcu_read_unlock();
 131	return NULL;
 132}
 
 
 
 
 
 133#endif /* CONFIG_IP_MULTIPLE_TABLES */
 134
 135static void fib_flush(struct net *net)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 136{
 137	int flushed = 0;
 138	struct fib_table *tb;
 139	struct hlist_head *head;
 140	unsigned int h;
 141
 142	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
 143		head = &net->ipv4.fib_table_hash[h];
 144		hlist_for_each_entry(tb, head, tb_hlist)
 145			flushed += fib_table_flush(tb);
 
 
 
 146	}
 147
 148	if (flushed)
 149		rt_cache_flush(net);
 150}
 151
 152/*
 153 * Find address type as if only "dev" was present in the system. If
 154 * on_dev is NULL then all interfaces are taken into consideration.
 155 */
 156static inline unsigned int __inet_dev_addr_type(struct net *net,
 157						const struct net_device *dev,
 158						__be32 addr)
 159{
 160	struct flowi4		fl4 = { .daddr = addr };
 161	struct fib_result	res;
 162	unsigned int ret = RTN_BROADCAST;
 163	struct fib_table *local_table;
 164
 165	if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
 166		return RTN_BROADCAST;
 167	if (ipv4_is_multicast(addr))
 168		return RTN_MULTICAST;
 169
 170	local_table = fib_get_table(net, RT_TABLE_LOCAL);
 171	if (local_table) {
 
 
 172		ret = RTN_UNICAST;
 173		rcu_read_lock();
 174		if (!fib_table_lookup(local_table, &fl4, &res, FIB_LOOKUP_NOREF)) {
 175			if (!dev || dev == res.fi->fib_dev)
 
 176				ret = res.type;
 177		}
 178		rcu_read_unlock();
 179	}
 
 
 180	return ret;
 181}
 182
 
 
 
 
 
 
 183unsigned int inet_addr_type(struct net *net, __be32 addr)
 184{
 185	return __inet_dev_addr_type(net, NULL, addr);
 186}
 187EXPORT_SYMBOL(inet_addr_type);
 188
 189unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
 190				__be32 addr)
 191{
 192	return __inet_dev_addr_type(net, dev, addr);
 
 
 193}
 194EXPORT_SYMBOL(inet_dev_addr_type);
 195
 
 
 
 
 
 
 
 
 
 
 
 
 
 196__be32 fib_compute_spec_dst(struct sk_buff *skb)
 197{
 198	struct net_device *dev = skb->dev;
 199	struct in_device *in_dev;
 200	struct fib_result res;
 201	struct rtable *rt;
 202	struct flowi4 fl4;
 203	struct net *net;
 204	int scope;
 205
 206	rt = skb_rtable(skb);
 207	if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
 208	    RTCF_LOCAL)
 209		return ip_hdr(skb)->daddr;
 210
 211	in_dev = __in_dev_get_rcu(dev);
 212	BUG_ON(!in_dev);
 213
 214	net = dev_net(dev);
 215
 216	scope = RT_SCOPE_UNIVERSE;
 217	if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
 218		fl4.flowi4_oif = 0;
 219		fl4.flowi4_iif = LOOPBACK_IFINDEX;
 220		fl4.daddr = ip_hdr(skb)->saddr;
 221		fl4.saddr = 0;
 222		fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos);
 223		fl4.flowi4_scope = scope;
 224		fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0;
 225		if (!fib_lookup(net, &fl4, &res))
 226			return FIB_RES_PREFSRC(net, res);
 
 
 227	} else {
 228		scope = RT_SCOPE_LINK;
 229	}
 230
 231	return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
 232}
 233
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 234/* Given (packet source, input interface) and optional (dst, oif, tos):
 235 * - (main) check, that source is valid i.e. not broadcast or our local
 236 *   address.
 237 * - figure out what "logical" interface this packet arrived
 238 *   and calculate "specific destination" address.
 239 * - check, that packet arrived from expected physical interface.
 240 * called with rcu_read_lock()
 241 */
 242static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 243				 u8 tos, int oif, struct net_device *dev,
 244				 int rpf, struct in_device *idev, u32 *itag)
 245{
 246	int ret, no_addr, accept_local;
 
 
 247	struct fib_result res;
 248	struct flowi4 fl4;
 249	struct net *net;
 250	bool dev_match;
 251
 252	fl4.flowi4_oif = 0;
 253	fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
 
 
 254	fl4.daddr = src;
 255	fl4.saddr = dst;
 256	fl4.flowi4_tos = tos;
 257	fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
 
 
 
 258
 259	no_addr = idev->ifa_list == NULL;
 260
 261	accept_local = IN_DEV_ACCEPT_LOCAL(idev);
 262	fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
 
 
 
 
 
 263
 264	net = dev_net(dev);
 265	if (fib_lookup(net, &fl4, &res))
 266		goto last_resort;
 267	if (res.type != RTN_UNICAST) {
 268		if (res.type != RTN_LOCAL || !accept_local)
 269			goto e_inval;
 270	}
 271	fib_combine_itag(itag, &res);
 272	dev_match = false;
 273
 274#ifdef CONFIG_IP_ROUTE_MULTIPATH
 275	for (ret = 0; ret < res.fi->fib_nhs; ret++) {
 276		struct fib_nh *nh = &res.fi->fib_nh[ret];
 277
 278		if (nh->nh_dev == dev) {
 279			dev_match = true;
 280			break;
 281		}
 282	}
 283#else
 284	if (FIB_RES_DEV(res) == dev)
 285		dev_match = true;
 286#endif
 287	if (dev_match) {
 288		ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
 289		return ret;
 290	}
 291	if (no_addr)
 292		goto last_resort;
 293	if (rpf == 1)
 294		goto e_rpf;
 295	fl4.flowi4_oif = dev->ifindex;
 296
 297	ret = 0;
 298	if (fib_lookup(net, &fl4, &res) == 0) {
 299		if (res.type == RTN_UNICAST)
 300			ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
 301	}
 302	return ret;
 303
 304last_resort:
 305	if (rpf)
 306		goto e_rpf;
 307	*itag = 0;
 308	return 0;
 309
 310e_inval:
 311	return -EINVAL;
 312e_rpf:
 313	return -EXDEV;
 314}
 315
 316/* Ignore rp_filter for packets protected by IPsec. */
 317int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 318			u8 tos, int oif, struct net_device *dev,
 319			struct in_device *idev, u32 *itag)
 320{
 321	int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
 
 322
 323	if (!r && !fib_num_tclassid_users(dev_net(dev)) &&
 324	    (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 325		*itag = 0;
 326		return 0;
 327	}
 
 
 328	return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
 329}
 330
 331static inline __be32 sk_extract_addr(struct sockaddr *addr)
 332{
 333	return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
 334}
 335
 336static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
 337{
 338	struct nlattr *nla;
 339
 340	nla = (struct nlattr *) ((char *) mx + len);
 341	nla->nla_type = type;
 342	nla->nla_len = nla_attr_size(4);
 343	*(u32 *) nla_data(nla) = value;
 344
 345	return len + nla_total_size(4);
 346}
 347
 348static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
 349				 struct fib_config *cfg)
 350{
 351	__be32 addr;
 352	int plen;
 353
 354	memset(cfg, 0, sizeof(*cfg));
 355	cfg->fc_nlinfo.nl_net = net;
 356
 357	if (rt->rt_dst.sa_family != AF_INET)
 358		return -EAFNOSUPPORT;
 359
 360	/*
 361	 * Check mask for validity:
 362	 * a) it must be contiguous.
 363	 * b) destination must have all host bits clear.
 364	 * c) if application forgot to set correct family (AF_INET),
 365	 *    reject request unless it is absolutely clear i.e.
 366	 *    both family and mask are zero.
 367	 */
 368	plen = 32;
 369	addr = sk_extract_addr(&rt->rt_dst);
 370	if (!(rt->rt_flags & RTF_HOST)) {
 371		__be32 mask = sk_extract_addr(&rt->rt_genmask);
 372
 373		if (rt->rt_genmask.sa_family != AF_INET) {
 374			if (mask || rt->rt_genmask.sa_family)
 375				return -EAFNOSUPPORT;
 376		}
 377
 378		if (bad_mask(mask, addr))
 379			return -EINVAL;
 380
 381		plen = inet_mask_len(mask);
 382	}
 383
 384	cfg->fc_dst_len = plen;
 385	cfg->fc_dst = addr;
 386
 387	if (cmd != SIOCDELRT) {
 388		cfg->fc_nlflags = NLM_F_CREATE;
 389		cfg->fc_protocol = RTPROT_BOOT;
 390	}
 391
 392	if (rt->rt_metric)
 393		cfg->fc_priority = rt->rt_metric - 1;
 394
 395	if (rt->rt_flags & RTF_REJECT) {
 396		cfg->fc_scope = RT_SCOPE_HOST;
 397		cfg->fc_type = RTN_UNREACHABLE;
 398		return 0;
 399	}
 400
 401	cfg->fc_scope = RT_SCOPE_NOWHERE;
 402	cfg->fc_type = RTN_UNICAST;
 403
 404	if (rt->rt_dev) {
 405		char *colon;
 406		struct net_device *dev;
 407		char devname[IFNAMSIZ];
 408
 409		if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
 410			return -EFAULT;
 411
 412		devname[IFNAMSIZ-1] = 0;
 413		colon = strchr(devname, ':');
 414		if (colon)
 415			*colon = 0;
 416		dev = __dev_get_by_name(net, devname);
 417		if (!dev)
 418			return -ENODEV;
 419		cfg->fc_oif = dev->ifindex;
 
 420		if (colon) {
 421			struct in_ifaddr *ifa;
 422			struct in_device *in_dev = __in_dev_get_rtnl(dev);
 
 
 423			if (!in_dev)
 424				return -ENODEV;
 
 425			*colon = ':';
 426			for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
 
 
 427				if (strcmp(ifa->ifa_label, devname) == 0)
 428					break;
 429			if (ifa == NULL)
 
 
 
 430				return -ENODEV;
 431			cfg->fc_prefsrc = ifa->ifa_local;
 432		}
 433	}
 434
 435	addr = sk_extract_addr(&rt->rt_gateway);
 436	if (rt->rt_gateway.sa_family == AF_INET && addr) {
 437		cfg->fc_gw = addr;
 
 
 
 
 438		if (rt->rt_flags & RTF_GATEWAY &&
 439		    inet_addr_type(net, addr) == RTN_UNICAST)
 440			cfg->fc_scope = RT_SCOPE_UNIVERSE;
 441	}
 442
 443	if (cmd == SIOCDELRT)
 444		return 0;
 445
 446	if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
 447		return -EINVAL;
 448
 449	if (cfg->fc_scope == RT_SCOPE_NOWHERE)
 450		cfg->fc_scope = RT_SCOPE_LINK;
 451
 452	if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
 453		struct nlattr *mx;
 454		int len = 0;
 455
 456		mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
 457		if (mx == NULL)
 458			return -ENOMEM;
 459
 460		if (rt->rt_flags & RTF_MTU)
 461			len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
 462
 463		if (rt->rt_flags & RTF_WINDOW)
 464			len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
 465
 466		if (rt->rt_flags & RTF_IRTT)
 467			len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
 468
 469		cfg->fc_mx = mx;
 470		cfg->fc_mx_len = len;
 471	}
 472
 473	return 0;
 474}
 475
 476/*
 477 * Handle IP routing ioctl calls.
 478 * These are used to manipulate the routing tables
 479 */
 480int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 481{
 482	struct fib_config cfg;
 483	struct rtentry rt;
 484	int err;
 485
 486	switch (cmd) {
 487	case SIOCADDRT:		/* Add a route */
 488	case SIOCDELRT:		/* Delete a route */
 489		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 490			return -EPERM;
 491
 492		if (copy_from_user(&rt, arg, sizeof(rt)))
 493			return -EFAULT;
 494
 495		rtnl_lock();
 496		err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
 497		if (err == 0) {
 498			struct fib_table *tb;
 499
 500			if (cmd == SIOCDELRT) {
 501				tb = fib_get_table(net, cfg.fc_table);
 502				if (tb)
 503					err = fib_table_delete(tb, &cfg);
 
 504				else
 505					err = -ESRCH;
 506			} else {
 507				tb = fib_new_table(net, cfg.fc_table);
 508				if (tb)
 509					err = fib_table_insert(tb, &cfg);
 
 510				else
 511					err = -ENOBUFS;
 512			}
 513
 514			/* allocated by rtentry_to_fib_config() */
 515			kfree(cfg.fc_mx);
 516		}
 517		rtnl_unlock();
 518		return err;
 519	}
 520	return -EINVAL;
 521}
 522
 523const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
 
 524	[RTA_DST]		= { .type = NLA_U32 },
 525	[RTA_SRC]		= { .type = NLA_U32 },
 526	[RTA_IIF]		= { .type = NLA_U32 },
 527	[RTA_OIF]		= { .type = NLA_U32 },
 528	[RTA_GATEWAY]		= { .type = NLA_U32 },
 529	[RTA_PRIORITY]		= { .type = NLA_U32 },
 530	[RTA_PREFSRC]		= { .type = NLA_U32 },
 531	[RTA_METRICS]		= { .type = NLA_NESTED },
 532	[RTA_MULTIPATH]		= { .len = sizeof(struct rtnexthop) },
 533	[RTA_FLOW]		= { .type = NLA_U32 },
 
 
 
 
 
 
 
 
 
 534};
 535
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 536static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
 537			     struct nlmsghdr *nlh, struct fib_config *cfg)
 
 538{
 
 539	struct nlattr *attr;
 540	int err, remaining;
 541	struct rtmsg *rtm;
 542
 543	err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
 
 544	if (err < 0)
 545		goto errout;
 546
 547	memset(cfg, 0, sizeof(*cfg));
 548
 549	rtm = nlmsg_data(nlh);
 550	cfg->fc_dst_len = rtm->rtm_dst_len;
 551	cfg->fc_tos = rtm->rtm_tos;
 552	cfg->fc_table = rtm->rtm_table;
 553	cfg->fc_protocol = rtm->rtm_protocol;
 554	cfg->fc_scope = rtm->rtm_scope;
 555	cfg->fc_type = rtm->rtm_type;
 556	cfg->fc_flags = rtm->rtm_flags;
 557	cfg->fc_nlflags = nlh->nlmsg_flags;
 558
 559	cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
 560	cfg->fc_nlinfo.nlh = nlh;
 561	cfg->fc_nlinfo.nl_net = net;
 562
 563	if (cfg->fc_type > RTN_MAX) {
 
 564		err = -EINVAL;
 565		goto errout;
 566	}
 567
 568	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
 569		switch (nla_type(attr)) {
 570		case RTA_DST:
 571			cfg->fc_dst = nla_get_be32(attr);
 572			break;
 573		case RTA_OIF:
 574			cfg->fc_oif = nla_get_u32(attr);
 575			break;
 576		case RTA_GATEWAY:
 577			cfg->fc_gw = nla_get_be32(attr);
 
 
 
 
 
 
 
 
 
 578			break;
 579		case RTA_PRIORITY:
 580			cfg->fc_priority = nla_get_u32(attr);
 581			break;
 582		case RTA_PREFSRC:
 583			cfg->fc_prefsrc = nla_get_be32(attr);
 584			break;
 585		case RTA_METRICS:
 586			cfg->fc_mx = nla_data(attr);
 587			cfg->fc_mx_len = nla_len(attr);
 588			break;
 589		case RTA_MULTIPATH:
 
 
 
 
 
 590			cfg->fc_mp = nla_data(attr);
 591			cfg->fc_mp_len = nla_len(attr);
 592			break;
 593		case RTA_FLOW:
 594			cfg->fc_flow = nla_get_u32(attr);
 595			break;
 596		case RTA_TABLE:
 597			cfg->fc_table = nla_get_u32(attr);
 598			break;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 599		}
 600	}
 601
 
 
 
 
 
 
 602	return 0;
 603errout:
 604	return err;
 605}
 606
 607static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
 
 608{
 609	struct net *net = sock_net(skb->sk);
 610	struct fib_config cfg;
 611	struct fib_table *tb;
 612	int err;
 613
 614	err = rtm_to_fib_config(net, skb, nlh, &cfg);
 615	if (err < 0)
 616		goto errout;
 617
 
 
 
 
 
 
 618	tb = fib_get_table(net, cfg.fc_table);
 619	if (tb == NULL) {
 
 620		err = -ESRCH;
 621		goto errout;
 622	}
 623
 624	err = fib_table_delete(tb, &cfg);
 625errout:
 626	return err;
 627}
 628
 629static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
 
 630{
 631	struct net *net = sock_net(skb->sk);
 632	struct fib_config cfg;
 633	struct fib_table *tb;
 634	int err;
 635
 636	err = rtm_to_fib_config(net, skb, nlh, &cfg);
 637	if (err < 0)
 638		goto errout;
 639
 640	tb = fib_new_table(net, cfg.fc_table);
 641	if (tb == NULL) {
 642		err = -ENOBUFS;
 643		goto errout;
 644	}
 645
 646	err = fib_table_insert(tb, &cfg);
 
 
 647errout:
 648	return err;
 649}
 650
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 651static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 652{
 
 
 
 653	struct net *net = sock_net(skb->sk);
 654	unsigned int h, s_h;
 655	unsigned int e = 0, s_e;
 656	struct fib_table *tb;
 657	struct hlist_head *head;
 658	int dumped = 0;
 659
 660	if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
 661	    ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
 
 
 
 
 
 
 
 
 
 
 662		return skb->len;
 663
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 664	s_h = cb->args[0];
 665	s_e = cb->args[1];
 666
 
 
 667	for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
 668		e = 0;
 669		head = &net->ipv4.fib_table_hash[h];
 670		hlist_for_each_entry(tb, head, tb_hlist) {
 671			if (e < s_e)
 672				goto next;
 673			if (dumped)
 674				memset(&cb->args[2], 0, sizeof(cb->args) -
 675						 2 * sizeof(cb->args[0]));
 676			if (fib_table_dump(tb, skb, cb) < 0)
 677				goto out;
 
 
 
 
 
 678			dumped = 1;
 679next:
 680			e++;
 681		}
 682	}
 683out:
 
 
 
 
 684	cb->args[1] = e;
 685	cb->args[0] = h;
 686
 687	return skb->len;
 688}
 689
 690/* Prepare and feed intra-kernel routing request.
 691 * Really, it should be netlink message, but :-( netlink
 692 * can be not configured, so that we feed it directly
 693 * to fib engine. It is legal, because all events occur
 694 * only when netlink is already locked.
 695 */
 696static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
 
 697{
 698	struct net *net = dev_net(ifa->ifa_dev->dev);
 
 699	struct fib_table *tb;
 700	struct fib_config cfg = {
 701		.fc_protocol = RTPROT_KERNEL,
 702		.fc_type = type,
 703		.fc_dst = dst,
 704		.fc_dst_len = dst_len,
 
 705		.fc_prefsrc = ifa->ifa_local,
 706		.fc_oif = ifa->ifa_dev->dev->ifindex,
 707		.fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
 708		.fc_nlinfo = {
 709			.nl_net = net,
 710		},
 711	};
 712
 713	if (type == RTN_UNICAST)
 714		tb = fib_new_table(net, RT_TABLE_MAIN);
 715	else
 716		tb = fib_new_table(net, RT_TABLE_LOCAL);
 717
 718	if (tb == NULL)
 
 719		return;
 720
 721	cfg.fc_table = tb->tb_id;
 722
 723	if (type != RTN_LOCAL)
 724		cfg.fc_scope = RT_SCOPE_LINK;
 725	else
 726		cfg.fc_scope = RT_SCOPE_HOST;
 727
 728	if (cmd == RTM_NEWROUTE)
 729		fib_table_insert(tb, &cfg);
 730	else
 731		fib_table_delete(tb, &cfg);
 732}
 733
 734void fib_add_ifaddr(struct in_ifaddr *ifa)
 735{
 736	struct in_device *in_dev = ifa->ifa_dev;
 737	struct net_device *dev = in_dev->dev;
 738	struct in_ifaddr *prim = ifa;
 739	__be32 mask = ifa->ifa_mask;
 740	__be32 addr = ifa->ifa_local;
 741	__be32 prefix = ifa->ifa_address & mask;
 742
 743	if (ifa->ifa_flags & IFA_F_SECONDARY) {
 744		prim = inet_ifa_byprefix(in_dev, prefix, mask);
 745		if (prim == NULL) {
 746			pr_warn("%s: bug: prim == NULL\n", __func__);
 747			return;
 748		}
 749	}
 750
 751	fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
 752
 753	if (!(dev->flags & IFF_UP))
 754		return;
 755
 756	/* Add broadcast address, if it is explicitly assigned. */
 757	if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
 758		fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
 
 759
 760	if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
 761	    (prefix != addr || ifa->ifa_prefixlen < 32)) {
 762		fib_magic(RTM_NEWROUTE,
 763			  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
 764			  prefix, ifa->ifa_prefixlen, prim);
 
 
 765
 766		/* Add network specific broadcasts, when it takes a sense */
 767		if (ifa->ifa_prefixlen < 31) {
 768			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
 
 769			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
 770				  32, prim);
 771		}
 772	}
 773}
 774
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 775/* Delete primary or secondary address.
 776 * Optionally, on secondary address promotion consider the addresses
 777 * from subnet iprim as deleted, even if they are in device list.
 778 * In this case the secondary ifa can be in device list.
 779 */
 780void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
 781{
 782	struct in_device *in_dev = ifa->ifa_dev;
 783	struct net_device *dev = in_dev->dev;
 784	struct in_ifaddr *ifa1;
 785	struct in_ifaddr *prim = ifa, *prim1 = NULL;
 786	__be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
 787	__be32 any = ifa->ifa_address & ifa->ifa_mask;
 788#define LOCAL_OK	1
 789#define BRD_OK		2
 790#define BRD0_OK		4
 791#define BRD1_OK		8
 792	unsigned int ok = 0;
 793	int subnet = 0;		/* Primary network */
 794	int gone = 1;		/* Address is missing */
 795	int same_prefsrc = 0;	/* Another primary with same IP */
 796
 797	if (ifa->ifa_flags & IFA_F_SECONDARY) {
 798		prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
 799		if (prim == NULL) {
 800			pr_warn("%s: bug: prim == NULL\n", __func__);
 
 
 
 
 801			return;
 802		}
 803		if (iprim && iprim != prim) {
 804			pr_warn("%s: bug: iprim != prim\n", __func__);
 805			return;
 806		}
 807	} else if (!ipv4_is_zeronet(any) &&
 808		   (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
 809		fib_magic(RTM_DELROUTE,
 810			  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
 811			  any, ifa->ifa_prefixlen, prim);
 
 812		subnet = 1;
 813	}
 814
 
 
 
 815	/* Deletion is more complicated than add.
 816	 * We should take care of not to delete too much :-)
 817	 *
 818	 * Scan address list to be sure that addresses are really gone.
 819	 */
 820
 821	for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
 822		if (ifa1 == ifa) {
 823			/* promotion, keep the IP */
 824			gone = 0;
 825			continue;
 826		}
 827		/* Ignore IFAs from our subnet */
 828		if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
 829		    inet_ifa_match(ifa1->ifa_address, iprim))
 830			continue;
 831
 832		/* Ignore ifa1 if it uses different primary IP (prefsrc) */
 833		if (ifa1->ifa_flags & IFA_F_SECONDARY) {
 834			/* Another address from our subnet? */
 835			if (ifa1->ifa_mask == prim->ifa_mask &&
 836			    inet_ifa_match(ifa1->ifa_address, prim))
 837				prim1 = prim;
 838			else {
 839				/* We reached the secondaries, so
 840				 * same_prefsrc should be determined.
 841				 */
 842				if (!same_prefsrc)
 843					continue;
 844				/* Search new prim1 if ifa1 is not
 845				 * using the current prim1
 846				 */
 847				if (!prim1 ||
 848				    ifa1->ifa_mask != prim1->ifa_mask ||
 849				    !inet_ifa_match(ifa1->ifa_address, prim1))
 850					prim1 = inet_ifa_byprefix(in_dev,
 851							ifa1->ifa_address,
 852							ifa1->ifa_mask);
 853				if (!prim1)
 854					continue;
 855				if (prim1->ifa_local != prim->ifa_local)
 856					continue;
 857			}
 858		} else {
 859			if (prim->ifa_local != ifa1->ifa_local)
 860				continue;
 861			prim1 = ifa1;
 862			if (prim != prim1)
 863				same_prefsrc = 1;
 864		}
 865		if (ifa->ifa_local == ifa1->ifa_local)
 866			ok |= LOCAL_OK;
 867		if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
 868			ok |= BRD_OK;
 869		if (brd == ifa1->ifa_broadcast)
 870			ok |= BRD1_OK;
 871		if (any == ifa1->ifa_broadcast)
 872			ok |= BRD0_OK;
 873		/* primary has network specific broadcasts */
 874		if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
 875			__be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
 876			__be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
 877
 878			if (!ipv4_is_zeronet(any1)) {
 879				if (ifa->ifa_broadcast == brd1 ||
 880				    ifa->ifa_broadcast == any1)
 881					ok |= BRD_OK;
 882				if (brd == brd1 || brd == any1)
 883					ok |= BRD1_OK;
 884				if (any == brd1 || any == any1)
 885					ok |= BRD0_OK;
 886			}
 887		}
 888	}
 
 889
 
 890	if (!(ok & BRD_OK))
 891		fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
 
 892	if (subnet && ifa->ifa_prefixlen < 31) {
 893		if (!(ok & BRD1_OK))
 894			fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
 
 895		if (!(ok & BRD0_OK))
 896			fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
 
 897	}
 898	if (!(ok & LOCAL_OK)) {
 899		fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
 
 
 900
 901		/* Check, that this local address finally disappeared. */
 902		if (gone &&
 903		    inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) {
 
 904			/* And the last, but not the least thing.
 905			 * We must flush stray FIB entries.
 906			 *
 907			 * First of all, we scan fib_info list searching
 908			 * for stray nexthop entries, then ignite fib_flush.
 909			 */
 910			if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
 911				fib_flush(dev_net(dev));
 912		}
 913	}
 914#undef LOCAL_OK
 915#undef BRD_OK
 916#undef BRD0_OK
 917#undef BRD1_OK
 918}
 919
 920static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb)
 921{
 922
 923	struct fib_result       res;
 924	struct flowi4           fl4 = {
 925		.flowi4_mark = frn->fl_mark,
 926		.daddr = frn->fl_addr,
 927		.flowi4_tos = frn->fl_tos,
 928		.flowi4_scope = frn->fl_scope,
 929	};
 
 
 
 
 
 930
 931	frn->err = -ENOENT;
 932	if (tb) {
 933		local_bh_disable();
 934
 935		frn->tb_id = tb->tb_id;
 936		frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
 937
 938		if (!frn->err) {
 939			frn->prefixlen = res.prefixlen;
 940			frn->nh_sel = res.nh_sel;
 941			frn->type = res.type;
 942			frn->scope = res.scope;
 943		}
 944		local_bh_enable();
 945	}
 
 
 946}
 947
 948static void nl_fib_input(struct sk_buff *skb)
 949{
 950	struct net *net;
 951	struct fib_result_nl *frn;
 952	struct nlmsghdr *nlh;
 953	struct fib_table *tb;
 954	u32 portid;
 955
 956	net = sock_net(skb->sk);
 957	nlh = nlmsg_hdr(skb);
 958	if (skb->len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len ||
 
 959	    nlmsg_len(nlh) < sizeof(*frn))
 960		return;
 961
 962	skb = netlink_skb_clone(skb, GFP_KERNEL);
 963	if (skb == NULL)
 964		return;
 965	nlh = nlmsg_hdr(skb);
 966
 967	frn = (struct fib_result_nl *) nlmsg_data(nlh);
 968	tb = fib_get_table(net, frn->tb_id_in);
 969
 970	nl_fib_lookup(frn, tb);
 971
 972	portid = NETLINK_CB(skb).portid;      /* netlink portid */
 973	NETLINK_CB(skb).portid = 0;        /* from kernel */
 974	NETLINK_CB(skb).dst_group = 0;  /* unicast */
 975	netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
 976}
 977
 978static int __net_init nl_fib_lookup_init(struct net *net)
 979{
 980	struct sock *sk;
 981	struct netlink_kernel_cfg cfg = {
 982		.input	= nl_fib_input,
 983	};
 984
 985	sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
 986	if (sk == NULL)
 987		return -EAFNOSUPPORT;
 988	net->ipv4.fibnl = sk;
 989	return 0;
 990}
 991
 992static void nl_fib_lookup_exit(struct net *net)
 993{
 994	netlink_kernel_release(net->ipv4.fibnl);
 995	net->ipv4.fibnl = NULL;
 996}
 997
 998static void fib_disable_ip(struct net_device *dev, int force)
 
 999{
1000	if (fib_sync_down_dev(dev, force))
1001		fib_flush(dev_net(dev));
1002	rt_cache_flush(dev_net(dev));
 
1003	arp_ifdown(dev);
1004}
1005
1006static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1007{
1008	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1009	struct net_device *dev = ifa->ifa_dev->dev;
1010	struct net *net = dev_net(dev);
1011
1012	switch (event) {
1013	case NETDEV_UP:
1014		fib_add_ifaddr(ifa);
1015#ifdef CONFIG_IP_ROUTE_MULTIPATH
1016		fib_sync_up(dev);
1017#endif
1018		atomic_inc(&net->ipv4.dev_addr_genid);
1019		rt_cache_flush(dev_net(dev));
1020		break;
1021	case NETDEV_DOWN:
1022		fib_del_ifaddr(ifa, NULL);
1023		atomic_inc(&net->ipv4.dev_addr_genid);
1024		if (ifa->ifa_dev->ifa_list == NULL) {
1025			/* Last address was deleted from this interface.
1026			 * Disable IP.
1027			 */
1028			fib_disable_ip(dev, 1);
1029		} else {
1030			rt_cache_flush(dev_net(dev));
1031		}
1032		break;
1033	}
1034	return NOTIFY_DONE;
1035}
1036
1037static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1038{
1039	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 
 
1040	struct in_device *in_dev;
1041	struct net *net = dev_net(dev);
 
 
1042
1043	if (event == NETDEV_UNREGISTER) {
1044		fib_disable_ip(dev, 2);
1045		rt_flush_dev(dev);
1046		return NOTIFY_DONE;
1047	}
1048
1049	in_dev = __in_dev_get_rtnl(dev);
1050	if (!in_dev)
1051		return NOTIFY_DONE;
1052
1053	switch (event) {
1054	case NETDEV_UP:
1055		for_ifa(in_dev) {
1056			fib_add_ifaddr(ifa);
1057		} endfor_ifa(in_dev);
1058#ifdef CONFIG_IP_ROUTE_MULTIPATH
1059		fib_sync_up(dev);
1060#endif
1061		atomic_inc(&net->ipv4.dev_addr_genid);
1062		rt_cache_flush(net);
1063		break;
1064	case NETDEV_DOWN:
1065		fib_disable_ip(dev, 0);
 
 
 
 
 
 
 
 
1066		break;
1067	case NETDEV_CHANGEMTU:
1068	case NETDEV_CHANGE:
1069		rt_cache_flush(net);
1070		break;
 
 
 
 
 
 
 
 
 
1071	}
1072	return NOTIFY_DONE;
1073}
1074
1075static struct notifier_block fib_inetaddr_notifier = {
1076	.notifier_call = fib_inetaddr_event,
1077};
1078
1079static struct notifier_block fib_netdev_notifier = {
1080	.notifier_call = fib_netdev_event,
1081};
1082
1083static int __net_init ip_fib_net_init(struct net *net)
1084{
1085	int err;
1086	size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1087
 
 
 
 
1088	/* Avoid false sharing : Use at least a full cache line */
1089	size = max_t(size_t, size, L1_CACHE_BYTES);
1090
1091	net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1092	if (net->ipv4.fib_table_hash == NULL)
1093		return -ENOMEM;
 
 
1094
1095	err = fib4_rules_init(net);
1096	if (err < 0)
1097		goto fail;
1098	return 0;
1099
1100fail:
1101	kfree(net->ipv4.fib_table_hash);
 
 
1102	return err;
1103}
1104
1105static void ip_fib_net_exit(struct net *net)
1106{
1107	unsigned int i;
1108
 
1109#ifdef CONFIG_IP_MULTIPLE_TABLES
1110	fib4_rules_exit(net);
 
1111#endif
1112
1113	rtnl_lock();
1114	for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
 
 
 
 
 
1115		struct fib_table *tb;
1116		struct hlist_head *head;
1117		struct hlist_node *tmp;
1118
1119		head = &net->ipv4.fib_table_hash[i];
1120		hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1121			hlist_del(&tb->tb_hlist);
1122			fib_table_flush(tb);
1123			fib_free_table(tb);
1124		}
1125	}
 
 
 
 
1126	rtnl_unlock();
1127	kfree(net->ipv4.fib_table_hash);
 
1128}
1129
1130static int __net_init fib_net_init(struct net *net)
1131{
1132	int error;
1133
1134#ifdef CONFIG_IP_ROUTE_CLASSID
1135	net->ipv4.fib_num_tclassid_users = 0;
1136#endif
1137	error = ip_fib_net_init(net);
1138	if (error < 0)
1139		goto out;
1140	error = nl_fib_lookup_init(net);
1141	if (error < 0)
1142		goto out_nlfl;
1143	error = fib_proc_init(net);
1144	if (error < 0)
1145		goto out_proc;
1146out:
1147	return error;
1148
1149out_proc:
1150	nl_fib_lookup_exit(net);
1151out_nlfl:
1152	ip_fib_net_exit(net);
1153	goto out;
1154}
1155
1156static void __net_exit fib_net_exit(struct net *net)
1157{
1158	fib_proc_exit(net);
1159	nl_fib_lookup_exit(net);
1160	ip_fib_net_exit(net);
1161}
1162
1163static struct pernet_operations fib_net_ops = {
1164	.init = fib_net_init,
1165	.exit = fib_net_exit,
1166};
1167
1168void __init ip_fib_init(void)
1169{
1170	rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1171	rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1172	rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1173
1174	register_pernet_subsys(&fib_net_ops);
 
1175	register_netdevice_notifier(&fib_netdev_notifier);
1176	register_inetaddr_notifier(&fib_inetaddr_notifier);
1177
1178	fib_trie_init();
 
 
1179}