fib_frontend.c revision 9ffc93f203c18a70623f21950f1dd473c9ec48cd
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 __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 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 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} 1136