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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}
v3.5.6
 
   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/init.h>
  35#include <linux/list.h>
  36#include <linux/slab.h>
  37
  38#include <net/ip.h>
  39#include <net/protocol.h>
  40#include <net/route.h>
  41#include <net/tcp.h>
  42#include <net/sock.h>
  43#include <net/arp.h>
  44#include <net/ip_fib.h>
 
  45#include <net/rtnetlink.h>
  46#include <net/xfrm.h>
 
 
 
  47
  48#ifndef CONFIG_IP_MULTIPLE_TABLES
  49
  50static int __net_init fib4_rules_init(struct net *net)
  51{
  52	struct fib_table *local_table, *main_table;
  53
  54	local_table = fib_trie_table(RT_TABLE_LOCAL);
  55	if (local_table == NULL)
  56		return -ENOMEM;
  57
  58	main_table  = fib_trie_table(RT_TABLE_MAIN);
  59	if (main_table == NULL)
  60		goto fail;
  61
  62	hlist_add_head_rcu(&local_table->tb_hlist,
  63				&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
  64	hlist_add_head_rcu(&main_table->tb_hlist,
  65				&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
  66	return 0;
  67
  68fail:
  69	kfree(local_table);
  70	return -ENOMEM;
  71}
 
 
 
 
 
  72#else
  73
  74struct fib_table *fib_new_table(struct net *net, u32 id)
  75{
  76	struct fib_table *tb;
  77	unsigned int h;
  78
  79	if (id == 0)
  80		id = RT_TABLE_MAIN;
  81	tb = fib_get_table(net, id);
  82	if (tb)
  83		return tb;
  84
  85	tb = fib_trie_table(id);
 
 
 
  86	if (!tb)
  87		return NULL;
 
 
 
 
 
 
 
 
 
 
 
 
  88	h = id & (FIB_TABLE_HASHSZ - 1);
  89	hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
  90	return tb;
  91}
 
  92
 
  93struct fib_table *fib_get_table(struct net *net, u32 id)
  94{
  95	struct fib_table *tb;
  96	struct hlist_node *node;
  97	struct hlist_head *head;
  98	unsigned int h;
  99
 100	if (id == 0)
 101		id = RT_TABLE_MAIN;
 102	h = id & (FIB_TABLE_HASHSZ - 1);
 103
 104	rcu_read_lock();
 105	head = &net->ipv4.fib_table_hash[h];
 106	hlist_for_each_entry_rcu(tb, node, head, tb_hlist) {
 107		if (tb->tb_id == id) {
 108			rcu_read_unlock();
 109			return tb;
 110		}
 111	}
 112	rcu_read_unlock();
 113	return NULL;
 114}
 
 
 
 
 
 115#endif /* CONFIG_IP_MULTIPLE_TABLES */
 116
 117static void fib_flush(struct net *net)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 118{
 119	int flushed = 0;
 120	struct fib_table *tb;
 121	struct hlist_node *node;
 122	struct hlist_head *head;
 123	unsigned int h;
 124
 125	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
 126		head = &net->ipv4.fib_table_hash[h];
 127		hlist_for_each_entry(tb, node, head, tb_hlist)
 128			flushed += fib_table_flush(tb);
 
 
 
 129	}
 130
 131	if (flushed)
 132		rt_cache_flush(net, -1);
 133}
 134
 135/*
 136 * Find address type as if only "dev" was present in the system. If
 137 * on_dev is NULL then all interfaces are taken into consideration.
 138 */
 139static inline unsigned int __inet_dev_addr_type(struct net *net,
 140						const struct net_device *dev,
 141						__be32 addr)
 142{
 143	struct flowi4		fl4 = { .daddr = addr };
 144	struct fib_result	res;
 145	unsigned int ret = RTN_BROADCAST;
 146	struct fib_table *local_table;
 147
 148	if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
 149		return RTN_BROADCAST;
 150	if (ipv4_is_multicast(addr))
 151		return RTN_MULTICAST;
 152
 153#ifdef CONFIG_IP_MULTIPLE_TABLES
 154	res.r = NULL;
 155#endif
 156
 157	local_table = fib_get_table(net, RT_TABLE_LOCAL);
 158	if (local_table) {
 159		ret = RTN_UNICAST;
 160		rcu_read_lock();
 161		if (!fib_table_lookup(local_table, &fl4, &res, FIB_LOOKUP_NOREF)) {
 162			if (!dev || dev == res.fi->fib_dev)
 
 163				ret = res.type;
 164		}
 165		rcu_read_unlock();
 166	}
 
 
 167	return ret;
 168}
 169
 
 
 
 
 
 
 170unsigned int inet_addr_type(struct net *net, __be32 addr)
 171{
 172	return __inet_dev_addr_type(net, NULL, addr);
 173}
 174EXPORT_SYMBOL(inet_addr_type);
 175
 176unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
 177				__be32 addr)
 178{
 179	return __inet_dev_addr_type(net, dev, addr);
 
 
 180}
 181EXPORT_SYMBOL(inet_dev_addr_type);
 182
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 183/* Given (packet source, input interface) and optional (dst, oif, tos):
 184 * - (main) check, that source is valid i.e. not broadcast or our local
 185 *   address.
 186 * - figure out what "logical" interface this packet arrived
 187 *   and calculate "specific destination" address.
 188 * - check, that packet arrived from expected physical interface.
 189 * called with rcu_read_lock()
 190 */
 191int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, u8 tos,
 192			int oif, struct net_device *dev, __be32 *spec_dst,
 193			u32 *itag)
 194{
 195	struct in_device *in_dev;
 
 
 
 196	struct flowi4 fl4;
 197	struct fib_result res;
 198	int no_addr, rpf, accept_local;
 199	bool dev_match;
 200	int ret;
 201	struct net *net;
 202
 203	fl4.flowi4_oif = 0;
 204	fl4.flowi4_iif = oif;
 
 
 205	fl4.daddr = src;
 206	fl4.saddr = dst;
 207	fl4.flowi4_tos = tos;
 208	fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
 
 
 
 209
 210	no_addr = rpf = accept_local = 0;
 211	in_dev = __in_dev_get_rcu(dev);
 212	if (in_dev) {
 213		no_addr = in_dev->ifa_list == NULL;
 214
 215		/* Ignore rp_filter for packets protected by IPsec. */
 216		rpf = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(in_dev);
 217
 218		accept_local = IN_DEV_ACCEPT_LOCAL(in_dev);
 219		fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0;
 
 
 
 220	}
 221
 222	if (in_dev == NULL)
 
 
 
 223		goto e_inval;
 224
 225	net = dev_net(dev);
 226	if (fib_lookup(net, &fl4, &res))
 227		goto last_resort;
 228	if (res.type != RTN_UNICAST) {
 229		if (res.type != RTN_LOCAL || !accept_local)
 230			goto e_inval;
 231	}
 232	*spec_dst = FIB_RES_PREFSRC(net, res);
 233	fib_combine_itag(itag, &res);
 234	dev_match = false;
 235
 236#ifdef CONFIG_IP_ROUTE_MULTIPATH
 237	for (ret = 0; ret < res.fi->fib_nhs; ret++) {
 238		struct fib_nh *nh = &res.fi->fib_nh[ret];
 239
 240		if (nh->nh_dev == dev) {
 241			dev_match = true;
 242			break;
 243		}
 244	}
 245#else
 246	if (FIB_RES_DEV(res) == dev)
 247		dev_match = true;
 248#endif
 249	if (dev_match) {
 250		ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
 251		return ret;
 252	}
 253	if (no_addr)
 254		goto last_resort;
 255	if (rpf == 1)
 256		goto e_rpf;
 257	fl4.flowi4_oif = dev->ifindex;
 258
 259	ret = 0;
 260	if (fib_lookup(net, &fl4, &res) == 0) {
 261		if (res.type == RTN_UNICAST) {
 262			*spec_dst = FIB_RES_PREFSRC(net, res);
 263			ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
 264		}
 265	}
 266	return ret;
 267
 268last_resort:
 269	if (rpf)
 270		goto e_rpf;
 271	*spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
 272	*itag = 0;
 273	return 0;
 274
 275e_inval:
 276	return -EINVAL;
 277e_rpf:
 278	return -EXDEV;
 279}
 280
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 281static inline __be32 sk_extract_addr(struct sockaddr *addr)
 282{
 283	return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
 284}
 285
 286static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
 287{
 288	struct nlattr *nla;
 289
 290	nla = (struct nlattr *) ((char *) mx + len);
 291	nla->nla_type = type;
 292	nla->nla_len = nla_attr_size(4);
 293	*(u32 *) nla_data(nla) = value;
 294
 295	return len + nla_total_size(4);
 296}
 297
 298static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
 299				 struct fib_config *cfg)
 300{
 301	__be32 addr;
 302	int plen;
 303
 304	memset(cfg, 0, sizeof(*cfg));
 305	cfg->fc_nlinfo.nl_net = net;
 306
 307	if (rt->rt_dst.sa_family != AF_INET)
 308		return -EAFNOSUPPORT;
 309
 310	/*
 311	 * Check mask for validity:
 312	 * a) it must be contiguous.
 313	 * b) destination must have all host bits clear.
 314	 * c) if application forgot to set correct family (AF_INET),
 315	 *    reject request unless it is absolutely clear i.e.
 316	 *    both family and mask are zero.
 317	 */
 318	plen = 32;
 319	addr = sk_extract_addr(&rt->rt_dst);
 320	if (!(rt->rt_flags & RTF_HOST)) {
 321		__be32 mask = sk_extract_addr(&rt->rt_genmask);
 322
 323		if (rt->rt_genmask.sa_family != AF_INET) {
 324			if (mask || rt->rt_genmask.sa_family)
 325				return -EAFNOSUPPORT;
 326		}
 327
 328		if (bad_mask(mask, addr))
 329			return -EINVAL;
 330
 331		plen = inet_mask_len(mask);
 332	}
 333
 334	cfg->fc_dst_len = plen;
 335	cfg->fc_dst = addr;
 336
 337	if (cmd != SIOCDELRT) {
 338		cfg->fc_nlflags = NLM_F_CREATE;
 339		cfg->fc_protocol = RTPROT_BOOT;
 340	}
 341
 342	if (rt->rt_metric)
 343		cfg->fc_priority = rt->rt_metric - 1;
 344
 345	if (rt->rt_flags & RTF_REJECT) {
 346		cfg->fc_scope = RT_SCOPE_HOST;
 347		cfg->fc_type = RTN_UNREACHABLE;
 348		return 0;
 349	}
 350
 351	cfg->fc_scope = RT_SCOPE_NOWHERE;
 352	cfg->fc_type = RTN_UNICAST;
 353
 354	if (rt->rt_dev) {
 355		char *colon;
 356		struct net_device *dev;
 357		char devname[IFNAMSIZ];
 358
 359		if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
 360			return -EFAULT;
 361
 362		devname[IFNAMSIZ-1] = 0;
 363		colon = strchr(devname, ':');
 364		if (colon)
 365			*colon = 0;
 366		dev = __dev_get_by_name(net, devname);
 367		if (!dev)
 368			return -ENODEV;
 369		cfg->fc_oif = dev->ifindex;
 
 370		if (colon) {
 371			struct in_ifaddr *ifa;
 372			struct in_device *in_dev = __in_dev_get_rtnl(dev);
 
 
 373			if (!in_dev)
 374				return -ENODEV;
 
 375			*colon = ':';
 376			for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
 
 
 377				if (strcmp(ifa->ifa_label, devname) == 0)
 378					break;
 379			if (ifa == NULL)
 
 
 
 380				return -ENODEV;
 381			cfg->fc_prefsrc = ifa->ifa_local;
 382		}
 383	}
 384
 385	addr = sk_extract_addr(&rt->rt_gateway);
 386	if (rt->rt_gateway.sa_family == AF_INET && addr) {
 387		cfg->fc_gw = addr;
 
 
 
 
 388		if (rt->rt_flags & RTF_GATEWAY &&
 389		    inet_addr_type(net, addr) == RTN_UNICAST)
 390			cfg->fc_scope = RT_SCOPE_UNIVERSE;
 391	}
 392
 393	if (cmd == SIOCDELRT)
 394		return 0;
 395
 396	if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
 397		return -EINVAL;
 398
 399	if (cfg->fc_scope == RT_SCOPE_NOWHERE)
 400		cfg->fc_scope = RT_SCOPE_LINK;
 401
 402	if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
 403		struct nlattr *mx;
 404		int len = 0;
 405
 406		mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
 407		if (mx == NULL)
 408			return -ENOMEM;
 409
 410		if (rt->rt_flags & RTF_MTU)
 411			len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
 412
 413		if (rt->rt_flags & RTF_WINDOW)
 414			len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
 415
 416		if (rt->rt_flags & RTF_IRTT)
 417			len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
 418
 419		cfg->fc_mx = mx;
 420		cfg->fc_mx_len = len;
 421	}
 422
 423	return 0;
 424}
 425
 426/*
 427 * Handle IP routing ioctl calls.
 428 * These are used to manipulate the routing tables
 429 */
 430int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 431{
 432	struct fib_config cfg;
 433	struct rtentry rt;
 434	int err;
 435
 436	switch (cmd) {
 437	case SIOCADDRT:		/* Add a route */
 438	case SIOCDELRT:		/* Delete a route */
 439		if (!capable(CAP_NET_ADMIN))
 440			return -EPERM;
 441
 442		if (copy_from_user(&rt, arg, sizeof(rt)))
 443			return -EFAULT;
 444
 445		rtnl_lock();
 446		err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
 447		if (err == 0) {
 448			struct fib_table *tb;
 449
 450			if (cmd == SIOCDELRT) {
 451				tb = fib_get_table(net, cfg.fc_table);
 452				if (tb)
 453					err = fib_table_delete(tb, &cfg);
 
 454				else
 455					err = -ESRCH;
 456			} else {
 457				tb = fib_new_table(net, cfg.fc_table);
 458				if (tb)
 459					err = fib_table_insert(tb, &cfg);
 
 460				else
 461					err = -ENOBUFS;
 462			}
 463
 464			/* allocated by rtentry_to_fib_config() */
 465			kfree(cfg.fc_mx);
 466		}
 467		rtnl_unlock();
 468		return err;
 469	}
 470	return -EINVAL;
 471}
 472
 473const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
 
 474	[RTA_DST]		= { .type = NLA_U32 },
 475	[RTA_SRC]		= { .type = NLA_U32 },
 476	[RTA_IIF]		= { .type = NLA_U32 },
 477	[RTA_OIF]		= { .type = NLA_U32 },
 478	[RTA_GATEWAY]		= { .type = NLA_U32 },
 479	[RTA_PRIORITY]		= { .type = NLA_U32 },
 480	[RTA_PREFSRC]		= { .type = NLA_U32 },
 481	[RTA_METRICS]		= { .type = NLA_NESTED },
 482	[RTA_MULTIPATH]		= { .len = sizeof(struct rtnexthop) },
 483	[RTA_FLOW]		= { .type = NLA_U32 },
 
 
 
 
 
 
 
 
 
 484};
 485
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 486static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
 487			     struct nlmsghdr *nlh, struct fib_config *cfg)
 
 488{
 
 489	struct nlattr *attr;
 490	int err, remaining;
 491	struct rtmsg *rtm;
 492
 493	err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
 
 494	if (err < 0)
 495		goto errout;
 496
 497	memset(cfg, 0, sizeof(*cfg));
 498
 499	rtm = nlmsg_data(nlh);
 500	cfg->fc_dst_len = rtm->rtm_dst_len;
 501	cfg->fc_tos = rtm->rtm_tos;
 502	cfg->fc_table = rtm->rtm_table;
 503	cfg->fc_protocol = rtm->rtm_protocol;
 504	cfg->fc_scope = rtm->rtm_scope;
 505	cfg->fc_type = rtm->rtm_type;
 506	cfg->fc_flags = rtm->rtm_flags;
 507	cfg->fc_nlflags = nlh->nlmsg_flags;
 508
 509	cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid;
 510	cfg->fc_nlinfo.nlh = nlh;
 511	cfg->fc_nlinfo.nl_net = net;
 512
 513	if (cfg->fc_type > RTN_MAX) {
 
 514		err = -EINVAL;
 515		goto errout;
 516	}
 517
 518	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
 519		switch (nla_type(attr)) {
 520		case RTA_DST:
 521			cfg->fc_dst = nla_get_be32(attr);
 522			break;
 523		case RTA_OIF:
 524			cfg->fc_oif = nla_get_u32(attr);
 525			break;
 526		case RTA_GATEWAY:
 527			cfg->fc_gw = nla_get_be32(attr);
 
 
 
 
 
 
 
 
 
 528			break;
 529		case RTA_PRIORITY:
 530			cfg->fc_priority = nla_get_u32(attr);
 531			break;
 532		case RTA_PREFSRC:
 533			cfg->fc_prefsrc = nla_get_be32(attr);
 534			break;
 535		case RTA_METRICS:
 536			cfg->fc_mx = nla_data(attr);
 537			cfg->fc_mx_len = nla_len(attr);
 538			break;
 539		case RTA_MULTIPATH:
 
 
 
 
 
 540			cfg->fc_mp = nla_data(attr);
 541			cfg->fc_mp_len = nla_len(attr);
 542			break;
 543		case RTA_FLOW:
 544			cfg->fc_flow = nla_get_u32(attr);
 545			break;
 546		case RTA_TABLE:
 547			cfg->fc_table = nla_get_u32(attr);
 548			break;
 
 
 
 
 
 
 
 
 
 
 
 
 
 549		}
 550	}
 551
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 552	return 0;
 553errout:
 554	return err;
 555}
 556
 557static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 
 558{
 559	struct net *net = sock_net(skb->sk);
 560	struct fib_config cfg;
 561	struct fib_table *tb;
 562	int err;
 563
 564	err = rtm_to_fib_config(net, skb, nlh, &cfg);
 565	if (err < 0)
 566		goto errout;
 567
 
 
 
 
 
 
 568	tb = fib_get_table(net, cfg.fc_table);
 569	if (tb == NULL) {
 
 570		err = -ESRCH;
 571		goto errout;
 572	}
 573
 574	err = fib_table_delete(tb, &cfg);
 575errout:
 576	return err;
 577}
 578
 579static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 
 580{
 581	struct net *net = sock_net(skb->sk);
 582	struct fib_config cfg;
 583	struct fib_table *tb;
 584	int err;
 585
 586	err = rtm_to_fib_config(net, skb, nlh, &cfg);
 587	if (err < 0)
 588		goto errout;
 589
 590	tb = fib_new_table(net, cfg.fc_table);
 591	if (tb == NULL) {
 592		err = -ENOBUFS;
 593		goto errout;
 594	}
 595
 596	err = fib_table_insert(tb, &cfg);
 
 
 597errout:
 598	return err;
 599}
 600
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 601static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 602{
 
 
 
 603	struct net *net = sock_net(skb->sk);
 604	unsigned int h, s_h;
 605	unsigned int e = 0, s_e;
 606	struct fib_table *tb;
 607	struct hlist_node *node;
 608	struct hlist_head *head;
 609	int dumped = 0;
 610
 611	if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
 612	    ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
 613		return ip_rt_dump(skb, cb);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 614
 615	s_h = cb->args[0];
 616	s_e = cb->args[1];
 617
 
 
 618	for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
 619		e = 0;
 620		head = &net->ipv4.fib_table_hash[h];
 621		hlist_for_each_entry(tb, node, head, tb_hlist) {
 622			if (e < s_e)
 623				goto next;
 624			if (dumped)
 625				memset(&cb->args[2], 0, sizeof(cb->args) -
 626						 2 * sizeof(cb->args[0]));
 627			if (fib_table_dump(tb, skb, cb) < 0)
 628				goto out;
 
 
 
 
 
 629			dumped = 1;
 630next:
 631			e++;
 632		}
 633	}
 634out:
 
 
 
 
 635	cb->args[1] = e;
 636	cb->args[0] = h;
 637
 638	return skb->len;
 639}
 640
 641/* Prepare and feed intra-kernel routing request.
 642 * Really, it should be netlink message, but :-( netlink
 643 * can be not configured, so that we feed it directly
 644 * to fib engine. It is legal, because all events occur
 645 * only when netlink is already locked.
 646 */
 647static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
 
 648{
 649	struct net *net = dev_net(ifa->ifa_dev->dev);
 
 650	struct fib_table *tb;
 651	struct fib_config cfg = {
 652		.fc_protocol = RTPROT_KERNEL,
 653		.fc_type = type,
 654		.fc_dst = dst,
 655		.fc_dst_len = dst_len,
 
 656		.fc_prefsrc = ifa->ifa_local,
 657		.fc_oif = ifa->ifa_dev->dev->ifindex,
 658		.fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
 659		.fc_nlinfo = {
 660			.nl_net = net,
 661		},
 662	};
 663
 664	if (type == RTN_UNICAST)
 665		tb = fib_new_table(net, RT_TABLE_MAIN);
 666	else
 667		tb = fib_new_table(net, RT_TABLE_LOCAL);
 668
 669	if (tb == NULL)
 
 670		return;
 671
 672	cfg.fc_table = tb->tb_id;
 673
 674	if (type != RTN_LOCAL)
 675		cfg.fc_scope = RT_SCOPE_LINK;
 676	else
 677		cfg.fc_scope = RT_SCOPE_HOST;
 678
 679	if (cmd == RTM_NEWROUTE)
 680		fib_table_insert(tb, &cfg);
 681	else
 682		fib_table_delete(tb, &cfg);
 683}
 684
 685void fib_add_ifaddr(struct in_ifaddr *ifa)
 686{
 687	struct in_device *in_dev = ifa->ifa_dev;
 688	struct net_device *dev = in_dev->dev;
 689	struct in_ifaddr *prim = ifa;
 690	__be32 mask = ifa->ifa_mask;
 691	__be32 addr = ifa->ifa_local;
 692	__be32 prefix = ifa->ifa_address & mask;
 693
 694	if (ifa->ifa_flags & IFA_F_SECONDARY) {
 695		prim = inet_ifa_byprefix(in_dev, prefix, mask);
 696		if (prim == NULL) {
 697			pr_warn("%s: bug: prim == NULL\n", __func__);
 698			return;
 699		}
 700	}
 701
 702	fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
 703
 704	if (!(dev->flags & IFF_UP))
 705		return;
 706
 707	/* Add broadcast address, if it is explicitly assigned. */
 708	if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
 709		fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
 
 710
 711	if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
 712	    (prefix != addr || ifa->ifa_prefixlen < 32)) {
 713		fib_magic(RTM_NEWROUTE,
 714			  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
 715			  prefix, ifa->ifa_prefixlen, prim);
 
 
 716
 717		/* Add network specific broadcasts, when it takes a sense */
 718		if (ifa->ifa_prefixlen < 31) {
 719			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
 
 720			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
 721				  32, prim);
 722		}
 723	}
 724}
 725
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 726/* Delete primary or secondary address.
 727 * Optionally, on secondary address promotion consider the addresses
 728 * from subnet iprim as deleted, even if they are in device list.
 729 * In this case the secondary ifa can be in device list.
 730 */
 731void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
 732{
 733	struct in_device *in_dev = ifa->ifa_dev;
 734	struct net_device *dev = in_dev->dev;
 735	struct in_ifaddr *ifa1;
 736	struct in_ifaddr *prim = ifa, *prim1 = NULL;
 737	__be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
 738	__be32 any = ifa->ifa_address & ifa->ifa_mask;
 739#define LOCAL_OK	1
 740#define BRD_OK		2
 741#define BRD0_OK		4
 742#define BRD1_OK		8
 743	unsigned int ok = 0;
 744	int subnet = 0;		/* Primary network */
 745	int gone = 1;		/* Address is missing */
 746	int same_prefsrc = 0;	/* Another primary with same IP */
 747
 748	if (ifa->ifa_flags & IFA_F_SECONDARY) {
 749		prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
 750		if (prim == NULL) {
 751			pr_warn("%s: bug: prim == NULL\n", __func__);
 
 
 
 
 752			return;
 753		}
 754		if (iprim && iprim != prim) {
 755			pr_warn("%s: bug: iprim != prim\n", __func__);
 756			return;
 757		}
 758	} else if (!ipv4_is_zeronet(any) &&
 759		   (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
 760		fib_magic(RTM_DELROUTE,
 761			  dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
 762			  any, ifa->ifa_prefixlen, prim);
 
 763		subnet = 1;
 764	}
 765
 
 
 
 766	/* Deletion is more complicated than add.
 767	 * We should take care of not to delete too much :-)
 768	 *
 769	 * Scan address list to be sure that addresses are really gone.
 770	 */
 771
 772	for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
 773		if (ifa1 == ifa) {
 774			/* promotion, keep the IP */
 775			gone = 0;
 776			continue;
 777		}
 778		/* Ignore IFAs from our subnet */
 779		if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
 780		    inet_ifa_match(ifa1->ifa_address, iprim))
 781			continue;
 782
 783		/* Ignore ifa1 if it uses different primary IP (prefsrc) */
 784		if (ifa1->ifa_flags & IFA_F_SECONDARY) {
 785			/* Another address from our subnet? */
 786			if (ifa1->ifa_mask == prim->ifa_mask &&
 787			    inet_ifa_match(ifa1->ifa_address, prim))
 788				prim1 = prim;
 789			else {
 790				/* We reached the secondaries, so
 791				 * same_prefsrc should be determined.
 792				 */
 793				if (!same_prefsrc)
 794					continue;
 795				/* Search new prim1 if ifa1 is not
 796				 * using the current prim1
 797				 */
 798				if (!prim1 ||
 799				    ifa1->ifa_mask != prim1->ifa_mask ||
 800				    !inet_ifa_match(ifa1->ifa_address, prim1))
 801					prim1 = inet_ifa_byprefix(in_dev,
 802							ifa1->ifa_address,
 803							ifa1->ifa_mask);
 804				if (!prim1)
 805					continue;
 806				if (prim1->ifa_local != prim->ifa_local)
 807					continue;
 808			}
 809		} else {
 810			if (prim->ifa_local != ifa1->ifa_local)
 811				continue;
 812			prim1 = ifa1;
 813			if (prim != prim1)
 814				same_prefsrc = 1;
 815		}
 816		if (ifa->ifa_local == ifa1->ifa_local)
 817			ok |= LOCAL_OK;
 818		if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
 819			ok |= BRD_OK;
 820		if (brd == ifa1->ifa_broadcast)
 821			ok |= BRD1_OK;
 822		if (any == ifa1->ifa_broadcast)
 823			ok |= BRD0_OK;
 824		/* primary has network specific broadcasts */
 825		if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
 826			__be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
 827			__be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
 828
 829			if (!ipv4_is_zeronet(any1)) {
 830				if (ifa->ifa_broadcast == brd1 ||
 831				    ifa->ifa_broadcast == any1)
 832					ok |= BRD_OK;
 833				if (brd == brd1 || brd == any1)
 834					ok |= BRD1_OK;
 835				if (any == brd1 || any == any1)
 836					ok |= BRD0_OK;
 837			}
 838		}
 839	}
 
 840
 
 841	if (!(ok & BRD_OK))
 842		fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
 
 843	if (subnet && ifa->ifa_prefixlen < 31) {
 844		if (!(ok & BRD1_OK))
 845			fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
 
 846		if (!(ok & BRD0_OK))
 847			fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
 
 848	}
 849	if (!(ok & LOCAL_OK)) {
 850		fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
 
 
 851
 852		/* Check, that this local address finally disappeared. */
 853		if (gone &&
 854		    inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) {
 
 855			/* And the last, but not the least thing.
 856			 * We must flush stray FIB entries.
 857			 *
 858			 * First of all, we scan fib_info list searching
 859			 * for stray nexthop entries, then ignite fib_flush.
 860			 */
 861			if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
 862				fib_flush(dev_net(dev));
 863		}
 864	}
 865#undef LOCAL_OK
 866#undef BRD_OK
 867#undef BRD0_OK
 868#undef BRD1_OK
 869}
 870
 871static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb)
 872{
 873
 874	struct fib_result       res;
 875	struct flowi4           fl4 = {
 876		.flowi4_mark = frn->fl_mark,
 877		.daddr = frn->fl_addr,
 878		.flowi4_tos = frn->fl_tos,
 879		.flowi4_scope = frn->fl_scope,
 880	};
 
 
 
 881
 882#ifdef CONFIG_IP_MULTIPLE_TABLES
 883	res.r = NULL;
 884#endif
 885
 886	frn->err = -ENOENT;
 887	if (tb) {
 888		local_bh_disable();
 889
 890		frn->tb_id = tb->tb_id;
 891		rcu_read_lock();
 892		frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
 893
 894		if (!frn->err) {
 895			frn->prefixlen = res.prefixlen;
 896			frn->nh_sel = res.nh_sel;
 897			frn->type = res.type;
 898			frn->scope = res.scope;
 899		}
 900		rcu_read_unlock();
 901		local_bh_enable();
 902	}
 
 
 903}
 904
 905static void nl_fib_input(struct sk_buff *skb)
 906{
 907	struct net *net;
 908	struct fib_result_nl *frn;
 909	struct nlmsghdr *nlh;
 910	struct fib_table *tb;
 911	u32 pid;
 912
 913	net = sock_net(skb->sk);
 914	nlh = nlmsg_hdr(skb);
 915	if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len ||
 916	    nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn)))
 
 917		return;
 918
 919	skb = skb_clone(skb, GFP_KERNEL);
 920	if (skb == NULL)
 921		return;
 922	nlh = nlmsg_hdr(skb);
 923
 924	frn = (struct fib_result_nl *) NLMSG_DATA(nlh);
 925	tb = fib_get_table(net, frn->tb_id_in);
 926
 927	nl_fib_lookup(frn, tb);
 928
 929	pid = NETLINK_CB(skb).pid;      /* pid of sending process */
 930	NETLINK_CB(skb).pid = 0;        /* from kernel */
 931	NETLINK_CB(skb).dst_group = 0;  /* unicast */
 932	netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT);
 933}
 934
 935static int __net_init nl_fib_lookup_init(struct net *net)
 936{
 937	struct sock *sk;
 938	sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0,
 939				   nl_fib_input, NULL, THIS_MODULE);
 940	if (sk == NULL)
 
 
 
 941		return -EAFNOSUPPORT;
 942	net->ipv4.fibnl = sk;
 943	return 0;
 944}
 945
 946static void nl_fib_lookup_exit(struct net *net)
 947{
 948	netlink_kernel_release(net->ipv4.fibnl);
 949	net->ipv4.fibnl = NULL;
 950}
 951
 952static void fib_disable_ip(struct net_device *dev, int force, int delay)
 
 953{
 954	if (fib_sync_down_dev(dev, force))
 955		fib_flush(dev_net(dev));
 956	rt_cache_flush(dev_net(dev), delay);
 
 957	arp_ifdown(dev);
 958}
 959
 960static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
 961{
 962	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
 963	struct net_device *dev = ifa->ifa_dev->dev;
 964	struct net *net = dev_net(dev);
 965
 966	switch (event) {
 967	case NETDEV_UP:
 968		fib_add_ifaddr(ifa);
 969#ifdef CONFIG_IP_ROUTE_MULTIPATH
 970		fib_sync_up(dev);
 971#endif
 972		atomic_inc(&net->ipv4.dev_addr_genid);
 973		rt_cache_flush(dev_net(dev), -1);
 974		break;
 975	case NETDEV_DOWN:
 976		fib_del_ifaddr(ifa, NULL);
 977		atomic_inc(&net->ipv4.dev_addr_genid);
 978		if (ifa->ifa_dev->ifa_list == NULL) {
 979			/* Last address was deleted from this interface.
 980			 * Disable IP.
 981			 */
 982			fib_disable_ip(dev, 1, 0);
 983		} else {
 984			rt_cache_flush(dev_net(dev), -1);
 985		}
 986		break;
 987	}
 988	return NOTIFY_DONE;
 989}
 990
 991static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
 992{
 993	struct net_device *dev = ptr;
 994	struct in_device *in_dev = __in_dev_get_rtnl(dev);
 
 
 995	struct net *net = dev_net(dev);
 
 
 996
 997	if (event == NETDEV_UNREGISTER) {
 998		fib_disable_ip(dev, 2, -1);
 
 999		return NOTIFY_DONE;
1000	}
1001
 
1002	if (!in_dev)
1003		return NOTIFY_DONE;
1004
1005	switch (event) {
1006	case NETDEV_UP:
1007		for_ifa(in_dev) {
1008			fib_add_ifaddr(ifa);
1009		} endfor_ifa(in_dev);
1010#ifdef CONFIG_IP_ROUTE_MULTIPATH
1011		fib_sync_up(dev);
1012#endif
1013		atomic_inc(&net->ipv4.dev_addr_genid);
1014		rt_cache_flush(dev_net(dev), -1);
1015		break;
1016	case NETDEV_DOWN:
1017		fib_disable_ip(dev, 0, 0);
 
 
 
 
 
 
 
 
1018		break;
1019	case NETDEV_CHANGEMTU:
1020	case NETDEV_CHANGE:
1021		rt_cache_flush(dev_net(dev), 0);
1022		break;
1023	case NETDEV_UNREGISTER_BATCH:
1024		/* The batch unregister is only called on the first
1025		 * device in the list of devices being unregistered.
1026		 * Therefore we should not pass dev_net(dev) in here.
1027		 */
1028		rt_cache_flush_batch(NULL);
 
 
1029		break;
1030	}
1031	return NOTIFY_DONE;
1032}
1033
1034static struct notifier_block fib_inetaddr_notifier = {
1035	.notifier_call = fib_inetaddr_event,
1036};
1037
1038static struct notifier_block fib_netdev_notifier = {
1039	.notifier_call = fib_netdev_event,
1040};
1041
1042static int __net_init ip_fib_net_init(struct net *net)
1043{
1044	int err;
1045	size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1046
 
 
 
 
1047	/* Avoid false sharing : Use at least a full cache line */
1048	size = max_t(size_t, size, L1_CACHE_BYTES);
1049
1050	net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1051	if (net->ipv4.fib_table_hash == NULL)
1052		return -ENOMEM;
 
 
1053
1054	err = fib4_rules_init(net);
1055	if (err < 0)
1056		goto fail;
1057	return 0;
1058
1059fail:
1060	kfree(net->ipv4.fib_table_hash);
 
 
1061	return err;
1062}
1063
1064static void ip_fib_net_exit(struct net *net)
1065{
1066	unsigned int i;
1067
 
1068#ifdef CONFIG_IP_MULTIPLE_TABLES
1069	fib4_rules_exit(net);
 
1070#endif
1071
1072	rtnl_lock();
1073	for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
 
 
 
 
 
1074		struct fib_table *tb;
1075		struct hlist_head *head;
1076		struct hlist_node *node, *tmp;
1077
1078		head = &net->ipv4.fib_table_hash[i];
1079		hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) {
1080			hlist_del(node);
1081			fib_table_flush(tb);
1082			fib_free_table(tb);
1083		}
1084	}
 
 
 
 
1085	rtnl_unlock();
1086	kfree(net->ipv4.fib_table_hash);
 
1087}
1088
1089static int __net_init fib_net_init(struct net *net)
1090{
1091	int error;
1092
 
 
 
1093	error = ip_fib_net_init(net);
1094	if (error < 0)
1095		goto out;
1096	error = nl_fib_lookup_init(net);
1097	if (error < 0)
1098		goto out_nlfl;
1099	error = fib_proc_init(net);
1100	if (error < 0)
1101		goto out_proc;
1102out:
1103	return error;
1104
1105out_proc:
1106	nl_fib_lookup_exit(net);
1107out_nlfl:
1108	ip_fib_net_exit(net);
1109	goto out;
1110}
1111
1112static void __net_exit fib_net_exit(struct net *net)
1113{
1114	fib_proc_exit(net);
1115	nl_fib_lookup_exit(net);
1116	ip_fib_net_exit(net);
1117}
1118
1119static struct pernet_operations fib_net_ops = {
1120	.init = fib_net_init,
1121	.exit = fib_net_exit,
1122};
1123
1124void __init ip_fib_init(void)
1125{
1126	rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1127	rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1128	rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1129
1130	register_pernet_subsys(&fib_net_ops);
 
1131	register_netdevice_notifier(&fib_netdev_notifier);
1132	register_inetaddr_notifier(&fib_inetaddr_notifier);
1133
1134	fib_trie_init();
 
 
1135}