fib_frontend.c revision 41347dcdd81988b8e60853257b2875285cc17a4e
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__be32 fib_compute_spec_dst(struct sk_buff *skb) 184{ 185 struct net_device *dev = skb->dev; 186 struct in_device *in_dev; 187 struct fib_result res; 188 struct flowi4 fl4; 189 struct net *net; 190 191 if (skb->pkt_type != PACKET_BROADCAST && 192 skb->pkt_type != PACKET_MULTICAST) 193 return ip_hdr(skb)->daddr; 194 195 in_dev = __in_dev_get_rcu(dev); 196 BUG_ON(!in_dev); 197 fl4.flowi4_oif = 0; 198 fl4.flowi4_iif = 0; 199 fl4.daddr = ip_hdr(skb)->saddr; 200 fl4.saddr = ip_hdr(skb)->daddr; 201 fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos); 202 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 203 fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0; 204 205 net = dev_net(dev); 206 if (!fib_lookup(net, &fl4, &res)) 207 return FIB_RES_PREFSRC(net, res); 208 else 209 return inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE); 210} 211 212/* Given (packet source, input interface) and optional (dst, oif, tos): 213 * - (main) check, that source is valid i.e. not broadcast or our local 214 * address. 215 * - figure out what "logical" interface this packet arrived 216 * and calculate "specific destination" address. 217 * - check, that packet arrived from expected physical interface. 218 * called with rcu_read_lock() 219 */ 220int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, u8 tos, 221 int oif, struct net_device *dev, u32 *itag) 222{ 223 struct in_device *in_dev; 224 struct flowi4 fl4; 225 struct fib_result res; 226 int no_addr, rpf, accept_local; 227 bool dev_match; 228 int ret; 229 struct net *net; 230 231 fl4.flowi4_oif = 0; 232 fl4.flowi4_iif = oif; 233 fl4.daddr = src; 234 fl4.saddr = dst; 235 fl4.flowi4_tos = tos; 236 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 237 238 no_addr = rpf = accept_local = 0; 239 in_dev = __in_dev_get_rcu(dev); 240 if (in_dev) { 241 no_addr = in_dev->ifa_list == NULL; 242 243 /* Ignore rp_filter for packets protected by IPsec. */ 244 rpf = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(in_dev); 245 246 accept_local = IN_DEV_ACCEPT_LOCAL(in_dev); 247 fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0; 248 } 249 250 if (in_dev == NULL) 251 goto e_inval; 252 253 net = dev_net(dev); 254 if (fib_lookup(net, &fl4, &res)) 255 goto last_resort; 256 if (res.type != RTN_UNICAST) { 257 if (res.type != RTN_LOCAL || !accept_local) 258 goto e_inval; 259 } 260 fib_combine_itag(itag, &res); 261 dev_match = false; 262 263#ifdef CONFIG_IP_ROUTE_MULTIPATH 264 for (ret = 0; ret < res.fi->fib_nhs; ret++) { 265 struct fib_nh *nh = &res.fi->fib_nh[ret]; 266 267 if (nh->nh_dev == dev) { 268 dev_match = true; 269 break; 270 } 271 } 272#else 273 if (FIB_RES_DEV(res) == dev) 274 dev_match = true; 275#endif 276 if (dev_match) { 277 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 278 return ret; 279 } 280 if (no_addr) 281 goto last_resort; 282 if (rpf == 1) 283 goto e_rpf; 284 fl4.flowi4_oif = dev->ifindex; 285 286 ret = 0; 287 if (fib_lookup(net, &fl4, &res) == 0) { 288 if (res.type == RTN_UNICAST) 289 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 290 } 291 return ret; 292 293last_resort: 294 if (rpf) 295 goto e_rpf; 296 *itag = 0; 297 return 0; 298 299e_inval: 300 return -EINVAL; 301e_rpf: 302 return -EXDEV; 303} 304 305static inline __be32 sk_extract_addr(struct sockaddr *addr) 306{ 307 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 308} 309 310static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 311{ 312 struct nlattr *nla; 313 314 nla = (struct nlattr *) ((char *) mx + len); 315 nla->nla_type = type; 316 nla->nla_len = nla_attr_size(4); 317 *(u32 *) nla_data(nla) = value; 318 319 return len + nla_total_size(4); 320} 321 322static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 323 struct fib_config *cfg) 324{ 325 __be32 addr; 326 int plen; 327 328 memset(cfg, 0, sizeof(*cfg)); 329 cfg->fc_nlinfo.nl_net = net; 330 331 if (rt->rt_dst.sa_family != AF_INET) 332 return -EAFNOSUPPORT; 333 334 /* 335 * Check mask for validity: 336 * a) it must be contiguous. 337 * b) destination must have all host bits clear. 338 * c) if application forgot to set correct family (AF_INET), 339 * reject request unless it is absolutely clear i.e. 340 * both family and mask are zero. 341 */ 342 plen = 32; 343 addr = sk_extract_addr(&rt->rt_dst); 344 if (!(rt->rt_flags & RTF_HOST)) { 345 __be32 mask = sk_extract_addr(&rt->rt_genmask); 346 347 if (rt->rt_genmask.sa_family != AF_INET) { 348 if (mask || rt->rt_genmask.sa_family) 349 return -EAFNOSUPPORT; 350 } 351 352 if (bad_mask(mask, addr)) 353 return -EINVAL; 354 355 plen = inet_mask_len(mask); 356 } 357 358 cfg->fc_dst_len = plen; 359 cfg->fc_dst = addr; 360 361 if (cmd != SIOCDELRT) { 362 cfg->fc_nlflags = NLM_F_CREATE; 363 cfg->fc_protocol = RTPROT_BOOT; 364 } 365 366 if (rt->rt_metric) 367 cfg->fc_priority = rt->rt_metric - 1; 368 369 if (rt->rt_flags & RTF_REJECT) { 370 cfg->fc_scope = RT_SCOPE_HOST; 371 cfg->fc_type = RTN_UNREACHABLE; 372 return 0; 373 } 374 375 cfg->fc_scope = RT_SCOPE_NOWHERE; 376 cfg->fc_type = RTN_UNICAST; 377 378 if (rt->rt_dev) { 379 char *colon; 380 struct net_device *dev; 381 char devname[IFNAMSIZ]; 382 383 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 384 return -EFAULT; 385 386 devname[IFNAMSIZ-1] = 0; 387 colon = strchr(devname, ':'); 388 if (colon) 389 *colon = 0; 390 dev = __dev_get_by_name(net, devname); 391 if (!dev) 392 return -ENODEV; 393 cfg->fc_oif = dev->ifindex; 394 if (colon) { 395 struct in_ifaddr *ifa; 396 struct in_device *in_dev = __in_dev_get_rtnl(dev); 397 if (!in_dev) 398 return -ENODEV; 399 *colon = ':'; 400 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) 401 if (strcmp(ifa->ifa_label, devname) == 0) 402 break; 403 if (ifa == NULL) 404 return -ENODEV; 405 cfg->fc_prefsrc = ifa->ifa_local; 406 } 407 } 408 409 addr = sk_extract_addr(&rt->rt_gateway); 410 if (rt->rt_gateway.sa_family == AF_INET && addr) { 411 cfg->fc_gw = addr; 412 if (rt->rt_flags & RTF_GATEWAY && 413 inet_addr_type(net, addr) == RTN_UNICAST) 414 cfg->fc_scope = RT_SCOPE_UNIVERSE; 415 } 416 417 if (cmd == SIOCDELRT) 418 return 0; 419 420 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw) 421 return -EINVAL; 422 423 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 424 cfg->fc_scope = RT_SCOPE_LINK; 425 426 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 427 struct nlattr *mx; 428 int len = 0; 429 430 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL); 431 if (mx == NULL) 432 return -ENOMEM; 433 434 if (rt->rt_flags & RTF_MTU) 435 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 436 437 if (rt->rt_flags & RTF_WINDOW) 438 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 439 440 if (rt->rt_flags & RTF_IRTT) 441 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 442 443 cfg->fc_mx = mx; 444 cfg->fc_mx_len = len; 445 } 446 447 return 0; 448} 449 450/* 451 * Handle IP routing ioctl calls. 452 * These are used to manipulate the routing tables 453 */ 454int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg) 455{ 456 struct fib_config cfg; 457 struct rtentry rt; 458 int err; 459 460 switch (cmd) { 461 case SIOCADDRT: /* Add a route */ 462 case SIOCDELRT: /* Delete a route */ 463 if (!capable(CAP_NET_ADMIN)) 464 return -EPERM; 465 466 if (copy_from_user(&rt, arg, sizeof(rt))) 467 return -EFAULT; 468 469 rtnl_lock(); 470 err = rtentry_to_fib_config(net, cmd, &rt, &cfg); 471 if (err == 0) { 472 struct fib_table *tb; 473 474 if (cmd == SIOCDELRT) { 475 tb = fib_get_table(net, cfg.fc_table); 476 if (tb) 477 err = fib_table_delete(tb, &cfg); 478 else 479 err = -ESRCH; 480 } else { 481 tb = fib_new_table(net, cfg.fc_table); 482 if (tb) 483 err = fib_table_insert(tb, &cfg); 484 else 485 err = -ENOBUFS; 486 } 487 488 /* allocated by rtentry_to_fib_config() */ 489 kfree(cfg.fc_mx); 490 } 491 rtnl_unlock(); 492 return err; 493 } 494 return -EINVAL; 495} 496 497const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 498 [RTA_DST] = { .type = NLA_U32 }, 499 [RTA_SRC] = { .type = NLA_U32 }, 500 [RTA_IIF] = { .type = NLA_U32 }, 501 [RTA_OIF] = { .type = NLA_U32 }, 502 [RTA_GATEWAY] = { .type = NLA_U32 }, 503 [RTA_PRIORITY] = { .type = NLA_U32 }, 504 [RTA_PREFSRC] = { .type = NLA_U32 }, 505 [RTA_METRICS] = { .type = NLA_NESTED }, 506 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 507 [RTA_FLOW] = { .type = NLA_U32 }, 508}; 509 510static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 511 struct nlmsghdr *nlh, struct fib_config *cfg) 512{ 513 struct nlattr *attr; 514 int err, remaining; 515 struct rtmsg *rtm; 516 517 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy); 518 if (err < 0) 519 goto errout; 520 521 memset(cfg, 0, sizeof(*cfg)); 522 523 rtm = nlmsg_data(nlh); 524 cfg->fc_dst_len = rtm->rtm_dst_len; 525 cfg->fc_tos = rtm->rtm_tos; 526 cfg->fc_table = rtm->rtm_table; 527 cfg->fc_protocol = rtm->rtm_protocol; 528 cfg->fc_scope = rtm->rtm_scope; 529 cfg->fc_type = rtm->rtm_type; 530 cfg->fc_flags = rtm->rtm_flags; 531 cfg->fc_nlflags = nlh->nlmsg_flags; 532 533 cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid; 534 cfg->fc_nlinfo.nlh = nlh; 535 cfg->fc_nlinfo.nl_net = net; 536 537 if (cfg->fc_type > RTN_MAX) { 538 err = -EINVAL; 539 goto errout; 540 } 541 542 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 543 switch (nla_type(attr)) { 544 case RTA_DST: 545 cfg->fc_dst = nla_get_be32(attr); 546 break; 547 case RTA_OIF: 548 cfg->fc_oif = nla_get_u32(attr); 549 break; 550 case RTA_GATEWAY: 551 cfg->fc_gw = nla_get_be32(attr); 552 break; 553 case RTA_PRIORITY: 554 cfg->fc_priority = nla_get_u32(attr); 555 break; 556 case RTA_PREFSRC: 557 cfg->fc_prefsrc = nla_get_be32(attr); 558 break; 559 case RTA_METRICS: 560 cfg->fc_mx = nla_data(attr); 561 cfg->fc_mx_len = nla_len(attr); 562 break; 563 case RTA_MULTIPATH: 564 cfg->fc_mp = nla_data(attr); 565 cfg->fc_mp_len = nla_len(attr); 566 break; 567 case RTA_FLOW: 568 cfg->fc_flow = nla_get_u32(attr); 569 break; 570 case RTA_TABLE: 571 cfg->fc_table = nla_get_u32(attr); 572 break; 573 } 574 } 575 576 return 0; 577errout: 578 return err; 579} 580 581static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 582{ 583 struct net *net = sock_net(skb->sk); 584 struct fib_config cfg; 585 struct fib_table *tb; 586 int err; 587 588 err = rtm_to_fib_config(net, skb, nlh, &cfg); 589 if (err < 0) 590 goto errout; 591 592 tb = fib_get_table(net, cfg.fc_table); 593 if (tb == NULL) { 594 err = -ESRCH; 595 goto errout; 596 } 597 598 err = fib_table_delete(tb, &cfg); 599errout: 600 return err; 601} 602 603static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 604{ 605 struct net *net = sock_net(skb->sk); 606 struct fib_config cfg; 607 struct fib_table *tb; 608 int err; 609 610 err = rtm_to_fib_config(net, skb, nlh, &cfg); 611 if (err < 0) 612 goto errout; 613 614 tb = fib_new_table(net, cfg.fc_table); 615 if (tb == NULL) { 616 err = -ENOBUFS; 617 goto errout; 618 } 619 620 err = fib_table_insert(tb, &cfg); 621errout: 622 return err; 623} 624 625static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 626{ 627 struct net *net = sock_net(skb->sk); 628 unsigned int h, s_h; 629 unsigned int e = 0, s_e; 630 struct fib_table *tb; 631 struct hlist_node *node; 632 struct hlist_head *head; 633 int dumped = 0; 634 635 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) && 636 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED) 637 return ip_rt_dump(skb, cb); 638 639 s_h = cb->args[0]; 640 s_e = cb->args[1]; 641 642 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 643 e = 0; 644 head = &net->ipv4.fib_table_hash[h]; 645 hlist_for_each_entry(tb, node, head, tb_hlist) { 646 if (e < s_e) 647 goto next; 648 if (dumped) 649 memset(&cb->args[2], 0, sizeof(cb->args) - 650 2 * sizeof(cb->args[0])); 651 if (fib_table_dump(tb, skb, cb) < 0) 652 goto out; 653 dumped = 1; 654next: 655 e++; 656 } 657 } 658out: 659 cb->args[1] = e; 660 cb->args[0] = h; 661 662 return skb->len; 663} 664 665/* Prepare and feed intra-kernel routing request. 666 * Really, it should be netlink message, but :-( netlink 667 * can be not configured, so that we feed it directly 668 * to fib engine. It is legal, because all events occur 669 * only when netlink is already locked. 670 */ 671static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa) 672{ 673 struct net *net = dev_net(ifa->ifa_dev->dev); 674 struct fib_table *tb; 675 struct fib_config cfg = { 676 .fc_protocol = RTPROT_KERNEL, 677 .fc_type = type, 678 .fc_dst = dst, 679 .fc_dst_len = dst_len, 680 .fc_prefsrc = ifa->ifa_local, 681 .fc_oif = ifa->ifa_dev->dev->ifindex, 682 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 683 .fc_nlinfo = { 684 .nl_net = net, 685 }, 686 }; 687 688 if (type == RTN_UNICAST) 689 tb = fib_new_table(net, RT_TABLE_MAIN); 690 else 691 tb = fib_new_table(net, RT_TABLE_LOCAL); 692 693 if (tb == NULL) 694 return; 695 696 cfg.fc_table = tb->tb_id; 697 698 if (type != RTN_LOCAL) 699 cfg.fc_scope = RT_SCOPE_LINK; 700 else 701 cfg.fc_scope = RT_SCOPE_HOST; 702 703 if (cmd == RTM_NEWROUTE) 704 fib_table_insert(tb, &cfg); 705 else 706 fib_table_delete(tb, &cfg); 707} 708 709void fib_add_ifaddr(struct in_ifaddr *ifa) 710{ 711 struct in_device *in_dev = ifa->ifa_dev; 712 struct net_device *dev = in_dev->dev; 713 struct in_ifaddr *prim = ifa; 714 __be32 mask = ifa->ifa_mask; 715 __be32 addr = ifa->ifa_local; 716 __be32 prefix = ifa->ifa_address & mask; 717 718 if (ifa->ifa_flags & IFA_F_SECONDARY) { 719 prim = inet_ifa_byprefix(in_dev, prefix, mask); 720 if (prim == NULL) { 721 pr_warn("%s: bug: prim == NULL\n", __func__); 722 return; 723 } 724 } 725 726 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim); 727 728 if (!(dev->flags & IFF_UP)) 729 return; 730 731 /* Add broadcast address, if it is explicitly assigned. */ 732 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 733 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 734 735 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 736 (prefix != addr || ifa->ifa_prefixlen < 32)) { 737 fib_magic(RTM_NEWROUTE, 738 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 739 prefix, ifa->ifa_prefixlen, prim); 740 741 /* Add network specific broadcasts, when it takes a sense */ 742 if (ifa->ifa_prefixlen < 31) { 743 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim); 744 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 745 32, prim); 746 } 747 } 748} 749 750/* Delete primary or secondary address. 751 * Optionally, on secondary address promotion consider the addresses 752 * from subnet iprim as deleted, even if they are in device list. 753 * In this case the secondary ifa can be in device list. 754 */ 755void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 756{ 757 struct in_device *in_dev = ifa->ifa_dev; 758 struct net_device *dev = in_dev->dev; 759 struct in_ifaddr *ifa1; 760 struct in_ifaddr *prim = ifa, *prim1 = NULL; 761 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 762 __be32 any = ifa->ifa_address & ifa->ifa_mask; 763#define LOCAL_OK 1 764#define BRD_OK 2 765#define BRD0_OK 4 766#define BRD1_OK 8 767 unsigned int ok = 0; 768 int subnet = 0; /* Primary network */ 769 int gone = 1; /* Address is missing */ 770 int same_prefsrc = 0; /* Another primary with same IP */ 771 772 if (ifa->ifa_flags & IFA_F_SECONDARY) { 773 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 774 if (prim == NULL) { 775 pr_warn("%s: bug: prim == NULL\n", __func__); 776 return; 777 } 778 if (iprim && iprim != prim) { 779 pr_warn("%s: bug: iprim != prim\n", __func__); 780 return; 781 } 782 } else if (!ipv4_is_zeronet(any) && 783 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 784 fib_magic(RTM_DELROUTE, 785 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 786 any, ifa->ifa_prefixlen, prim); 787 subnet = 1; 788 } 789 790 /* Deletion is more complicated than add. 791 * We should take care of not to delete too much :-) 792 * 793 * Scan address list to be sure that addresses are really gone. 794 */ 795 796 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) { 797 if (ifa1 == ifa) { 798 /* promotion, keep the IP */ 799 gone = 0; 800 continue; 801 } 802 /* Ignore IFAs from our subnet */ 803 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 804 inet_ifa_match(ifa1->ifa_address, iprim)) 805 continue; 806 807 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 808 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 809 /* Another address from our subnet? */ 810 if (ifa1->ifa_mask == prim->ifa_mask && 811 inet_ifa_match(ifa1->ifa_address, prim)) 812 prim1 = prim; 813 else { 814 /* We reached the secondaries, so 815 * same_prefsrc should be determined. 816 */ 817 if (!same_prefsrc) 818 continue; 819 /* Search new prim1 if ifa1 is not 820 * using the current prim1 821 */ 822 if (!prim1 || 823 ifa1->ifa_mask != prim1->ifa_mask || 824 !inet_ifa_match(ifa1->ifa_address, prim1)) 825 prim1 = inet_ifa_byprefix(in_dev, 826 ifa1->ifa_address, 827 ifa1->ifa_mask); 828 if (!prim1) 829 continue; 830 if (prim1->ifa_local != prim->ifa_local) 831 continue; 832 } 833 } else { 834 if (prim->ifa_local != ifa1->ifa_local) 835 continue; 836 prim1 = ifa1; 837 if (prim != prim1) 838 same_prefsrc = 1; 839 } 840 if (ifa->ifa_local == ifa1->ifa_local) 841 ok |= LOCAL_OK; 842 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 843 ok |= BRD_OK; 844 if (brd == ifa1->ifa_broadcast) 845 ok |= BRD1_OK; 846 if (any == ifa1->ifa_broadcast) 847 ok |= BRD0_OK; 848 /* primary has network specific broadcasts */ 849 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 850 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 851 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 852 853 if (!ipv4_is_zeronet(any1)) { 854 if (ifa->ifa_broadcast == brd1 || 855 ifa->ifa_broadcast == any1) 856 ok |= BRD_OK; 857 if (brd == brd1 || brd == any1) 858 ok |= BRD1_OK; 859 if (any == brd1 || any == any1) 860 ok |= BRD0_OK; 861 } 862 } 863 } 864 865 if (!(ok & BRD_OK)) 866 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 867 if (subnet && ifa->ifa_prefixlen < 31) { 868 if (!(ok & BRD1_OK)) 869 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim); 870 if (!(ok & BRD0_OK)) 871 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim); 872 } 873 if (!(ok & LOCAL_OK)) { 874 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim); 875 876 /* Check, that this local address finally disappeared. */ 877 if (gone && 878 inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) { 879 /* And the last, but not the least thing. 880 * We must flush stray FIB entries. 881 * 882 * First of all, we scan fib_info list searching 883 * for stray nexthop entries, then ignite fib_flush. 884 */ 885 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local)) 886 fib_flush(dev_net(dev)); 887 } 888 } 889#undef LOCAL_OK 890#undef BRD_OK 891#undef BRD0_OK 892#undef BRD1_OK 893} 894 895static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb) 896{ 897 898 struct fib_result res; 899 struct flowi4 fl4 = { 900 .flowi4_mark = frn->fl_mark, 901 .daddr = frn->fl_addr, 902 .flowi4_tos = frn->fl_tos, 903 .flowi4_scope = frn->fl_scope, 904 }; 905 906#ifdef CONFIG_IP_MULTIPLE_TABLES 907 res.r = NULL; 908#endif 909 910 frn->err = -ENOENT; 911 if (tb) { 912 local_bh_disable(); 913 914 frn->tb_id = tb->tb_id; 915 rcu_read_lock(); 916 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 917 918 if (!frn->err) { 919 frn->prefixlen = res.prefixlen; 920 frn->nh_sel = res.nh_sel; 921 frn->type = res.type; 922 frn->scope = res.scope; 923 } 924 rcu_read_unlock(); 925 local_bh_enable(); 926 } 927} 928 929static void nl_fib_input(struct sk_buff *skb) 930{ 931 struct net *net; 932 struct fib_result_nl *frn; 933 struct nlmsghdr *nlh; 934 struct fib_table *tb; 935 u32 pid; 936 937 net = sock_net(skb->sk); 938 nlh = nlmsg_hdr(skb); 939 if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len || 940 nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn))) 941 return; 942 943 skb = skb_clone(skb, GFP_KERNEL); 944 if (skb == NULL) 945 return; 946 nlh = nlmsg_hdr(skb); 947 948 frn = (struct fib_result_nl *) NLMSG_DATA(nlh); 949 tb = fib_get_table(net, frn->tb_id_in); 950 951 nl_fib_lookup(frn, tb); 952 953 pid = NETLINK_CB(skb).pid; /* pid of sending process */ 954 NETLINK_CB(skb).pid = 0; /* from kernel */ 955 NETLINK_CB(skb).dst_group = 0; /* unicast */ 956 netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT); 957} 958 959static int __net_init nl_fib_lookup_init(struct net *net) 960{ 961 struct sock *sk; 962 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0, 963 nl_fib_input, NULL, THIS_MODULE); 964 if (sk == NULL) 965 return -EAFNOSUPPORT; 966 net->ipv4.fibnl = sk; 967 return 0; 968} 969 970static void nl_fib_lookup_exit(struct net *net) 971{ 972 netlink_kernel_release(net->ipv4.fibnl); 973 net->ipv4.fibnl = NULL; 974} 975 976static void fib_disable_ip(struct net_device *dev, int force, int delay) 977{ 978 if (fib_sync_down_dev(dev, force)) 979 fib_flush(dev_net(dev)); 980 rt_cache_flush(dev_net(dev), delay); 981 arp_ifdown(dev); 982} 983 984static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 985{ 986 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 987 struct net_device *dev = ifa->ifa_dev->dev; 988 struct net *net = dev_net(dev); 989 990 switch (event) { 991 case NETDEV_UP: 992 fib_add_ifaddr(ifa); 993#ifdef CONFIG_IP_ROUTE_MULTIPATH 994 fib_sync_up(dev); 995#endif 996 atomic_inc(&net->ipv4.dev_addr_genid); 997 rt_cache_flush(dev_net(dev), -1); 998 break; 999 case NETDEV_DOWN: 1000 fib_del_ifaddr(ifa, NULL); 1001 atomic_inc(&net->ipv4.dev_addr_genid); 1002 if (ifa->ifa_dev->ifa_list == NULL) { 1003 /* Last address was deleted from this interface. 1004 * Disable IP. 1005 */ 1006 fib_disable_ip(dev, 1, 0); 1007 } else { 1008 rt_cache_flush(dev_net(dev), -1); 1009 } 1010 break; 1011 } 1012 return NOTIFY_DONE; 1013} 1014 1015static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1016{ 1017 struct net_device *dev = ptr; 1018 struct in_device *in_dev = __in_dev_get_rtnl(dev); 1019 struct net *net = dev_net(dev); 1020 1021 if (event == NETDEV_UNREGISTER) { 1022 fib_disable_ip(dev, 2, -1); 1023 return NOTIFY_DONE; 1024 } 1025 1026 if (!in_dev) 1027 return NOTIFY_DONE; 1028 1029 switch (event) { 1030 case NETDEV_UP: 1031 for_ifa(in_dev) { 1032 fib_add_ifaddr(ifa); 1033 } endfor_ifa(in_dev); 1034#ifdef CONFIG_IP_ROUTE_MULTIPATH 1035 fib_sync_up(dev); 1036#endif 1037 atomic_inc(&net->ipv4.dev_addr_genid); 1038 rt_cache_flush(dev_net(dev), -1); 1039 break; 1040 case NETDEV_DOWN: 1041 fib_disable_ip(dev, 0, 0); 1042 break; 1043 case NETDEV_CHANGEMTU: 1044 case NETDEV_CHANGE: 1045 rt_cache_flush(dev_net(dev), 0); 1046 break; 1047 case NETDEV_UNREGISTER_BATCH: 1048 /* The batch unregister is only called on the first 1049 * device in the list of devices being unregistered. 1050 * Therefore we should not pass dev_net(dev) in here. 1051 */ 1052 rt_cache_flush_batch(NULL); 1053 break; 1054 } 1055 return NOTIFY_DONE; 1056} 1057 1058static struct notifier_block fib_inetaddr_notifier = { 1059 .notifier_call = fib_inetaddr_event, 1060}; 1061 1062static struct notifier_block fib_netdev_notifier = { 1063 .notifier_call = fib_netdev_event, 1064}; 1065 1066static int __net_init ip_fib_net_init(struct net *net) 1067{ 1068 int err; 1069 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1070 1071 /* Avoid false sharing : Use at least a full cache line */ 1072 size = max_t(size_t, size, L1_CACHE_BYTES); 1073 1074 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1075 if (net->ipv4.fib_table_hash == NULL) 1076 return -ENOMEM; 1077 1078 err = fib4_rules_init(net); 1079 if (err < 0) 1080 goto fail; 1081 return 0; 1082 1083fail: 1084 kfree(net->ipv4.fib_table_hash); 1085 return err; 1086} 1087 1088static void ip_fib_net_exit(struct net *net) 1089{ 1090 unsigned int i; 1091 1092#ifdef CONFIG_IP_MULTIPLE_TABLES 1093 fib4_rules_exit(net); 1094#endif 1095 1096 rtnl_lock(); 1097 for (i = 0; i < FIB_TABLE_HASHSZ; i++) { 1098 struct fib_table *tb; 1099 struct hlist_head *head; 1100 struct hlist_node *node, *tmp; 1101 1102 head = &net->ipv4.fib_table_hash[i]; 1103 hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) { 1104 hlist_del(node); 1105 fib_table_flush(tb); 1106 fib_free_table(tb); 1107 } 1108 } 1109 rtnl_unlock(); 1110 kfree(net->ipv4.fib_table_hash); 1111} 1112 1113static int __net_init fib_net_init(struct net *net) 1114{ 1115 int error; 1116 1117 error = ip_fib_net_init(net); 1118 if (error < 0) 1119 goto out; 1120 error = nl_fib_lookup_init(net); 1121 if (error < 0) 1122 goto out_nlfl; 1123 error = fib_proc_init(net); 1124 if (error < 0) 1125 goto out_proc; 1126out: 1127 return error; 1128 1129out_proc: 1130 nl_fib_lookup_exit(net); 1131out_nlfl: 1132 ip_fib_net_exit(net); 1133 goto out; 1134} 1135 1136static void __net_exit fib_net_exit(struct net *net) 1137{ 1138 fib_proc_exit(net); 1139 nl_fib_lookup_exit(net); 1140 ip_fib_net_exit(net); 1141} 1142 1143static struct pernet_operations fib_net_ops = { 1144 .init = fib_net_init, 1145 .exit = fib_net_exit, 1146}; 1147 1148void __init ip_fib_init(void) 1149{ 1150 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL); 1151 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL); 1152 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL); 1153 1154 register_pernet_subsys(&fib_net_ops); 1155 register_netdevice_notifier(&fib_netdev_notifier); 1156 register_inetaddr_notifier(&fib_inetaddr_notifier); 1157 1158 fib_trie_init(); 1159} 1160