fib_frontend.c revision 9435eb1cf0b76b323019cebf8d16762a50a12a19
1/* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * IPv4 Forwarding Information Base: FIB frontend. 7 * 8 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16#include <linux/module.h> 17#include <asm/uaccess.h> 18#include <asm/system.h> 19#include <linux/bitops.h> 20#include <linux/capability.h> 21#include <linux/types.h> 22#include <linux/kernel.h> 23#include <linux/mm.h> 24#include <linux/string.h> 25#include <linux/socket.h> 26#include <linux/sockios.h> 27#include <linux/errno.h> 28#include <linux/in.h> 29#include <linux/inet.h> 30#include <linux/inetdevice.h> 31#include <linux/netdevice.h> 32#include <linux/if_addr.h> 33#include <linux/if_arp.h> 34#include <linux/skbuff.h> 35#include <linux/init.h> 36#include <linux/list.h> 37#include <linux/slab.h> 38 39#include <net/ip.h> 40#include <net/protocol.h> 41#include <net/route.h> 42#include <net/tcp.h> 43#include <net/sock.h> 44#include <net/arp.h> 45#include <net/ip_fib.h> 46#include <net/rtnetlink.h> 47 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 flowi fl = { .fl4_dst = 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, &fl, &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(__be32 src, __be32 dst, u8 tos, int oif, 192 struct net_device *dev, __be32 *spec_dst, 193 u32 *itag, u32 mark) 194{ 195 struct in_device *in_dev; 196 struct flowi fl = { 197 .fl4_dst = src, 198 .fl4_src = dst, 199 .fl4_tos = tos, 200 .mark = mark, 201 .iif = oif 202 }; 203 struct fib_result res; 204 int no_addr, rpf, accept_local; 205 bool dev_match; 206 int ret; 207 struct net *net; 208 209 no_addr = rpf = accept_local = 0; 210 in_dev = __in_dev_get_rcu(dev); 211 if (in_dev) { 212 no_addr = in_dev->ifa_list == NULL; 213 rpf = IN_DEV_RPFILTER(in_dev); 214 accept_local = IN_DEV_ACCEPT_LOCAL(in_dev); 215 if (mark && !IN_DEV_SRC_VMARK(in_dev)) 216 fl.mark = 0; 217 } 218 219 if (in_dev == NULL) 220 goto e_inval; 221 222 net = dev_net(dev); 223 if (fib_lookup(net, &fl, &res)) 224 goto last_resort; 225 if (res.type != RTN_UNICAST) { 226 if (res.type != RTN_LOCAL || !accept_local) 227 goto e_inval; 228 } 229 *spec_dst = FIB_RES_PREFSRC(res); 230 fib_combine_itag(itag, &res); 231 dev_match = false; 232 233#ifdef CONFIG_IP_ROUTE_MULTIPATH 234 for (ret = 0; ret < res.fi->fib_nhs; ret++) { 235 struct fib_nh *nh = &res.fi->fib_nh[ret]; 236 237 if (nh->nh_dev == dev) { 238 dev_match = true; 239 break; 240 } 241 } 242#else 243 if (FIB_RES_DEV(res) == dev) 244 dev_match = true; 245#endif 246 if (dev_match) { 247 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 248 return ret; 249 } 250 if (no_addr) 251 goto last_resort; 252 if (rpf == 1) 253 goto e_rpf; 254 fl.oif = dev->ifindex; 255 256 ret = 0; 257 if (fib_lookup(net, &fl, &res) == 0) { 258 if (res.type == RTN_UNICAST) { 259 *spec_dst = FIB_RES_PREFSRC(res); 260 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 261 } 262 } 263 return ret; 264 265last_resort: 266 if (rpf) 267 goto e_rpf; 268 *spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE); 269 *itag = 0; 270 return 0; 271 272e_inval: 273 return -EINVAL; 274e_rpf: 275 return -EXDEV; 276} 277 278static inline __be32 sk_extract_addr(struct sockaddr *addr) 279{ 280 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 281} 282 283static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 284{ 285 struct nlattr *nla; 286 287 nla = (struct nlattr *) ((char *) mx + len); 288 nla->nla_type = type; 289 nla->nla_len = nla_attr_size(4); 290 *(u32 *) nla_data(nla) = value; 291 292 return len + nla_total_size(4); 293} 294 295static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 296 struct fib_config *cfg) 297{ 298 __be32 addr; 299 int plen; 300 301 memset(cfg, 0, sizeof(*cfg)); 302 cfg->fc_nlinfo.nl_net = net; 303 304 if (rt->rt_dst.sa_family != AF_INET) 305 return -EAFNOSUPPORT; 306 307 /* 308 * Check mask for validity: 309 * a) it must be contiguous. 310 * b) destination must have all host bits clear. 311 * c) if application forgot to set correct family (AF_INET), 312 * reject request unless it is absolutely clear i.e. 313 * both family and mask are zero. 314 */ 315 plen = 32; 316 addr = sk_extract_addr(&rt->rt_dst); 317 if (!(rt->rt_flags & RTF_HOST)) { 318 __be32 mask = sk_extract_addr(&rt->rt_genmask); 319 320 if (rt->rt_genmask.sa_family != AF_INET) { 321 if (mask || rt->rt_genmask.sa_family) 322 return -EAFNOSUPPORT; 323 } 324 325 if (bad_mask(mask, addr)) 326 return -EINVAL; 327 328 plen = inet_mask_len(mask); 329 } 330 331 cfg->fc_dst_len = plen; 332 cfg->fc_dst = addr; 333 334 if (cmd != SIOCDELRT) { 335 cfg->fc_nlflags = NLM_F_CREATE; 336 cfg->fc_protocol = RTPROT_BOOT; 337 } 338 339 if (rt->rt_metric) 340 cfg->fc_priority = rt->rt_metric - 1; 341 342 if (rt->rt_flags & RTF_REJECT) { 343 cfg->fc_scope = RT_SCOPE_HOST; 344 cfg->fc_type = RTN_UNREACHABLE; 345 return 0; 346 } 347 348 cfg->fc_scope = RT_SCOPE_NOWHERE; 349 cfg->fc_type = RTN_UNICAST; 350 351 if (rt->rt_dev) { 352 char *colon; 353 struct net_device *dev; 354 char devname[IFNAMSIZ]; 355 356 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 357 return -EFAULT; 358 359 devname[IFNAMSIZ-1] = 0; 360 colon = strchr(devname, ':'); 361 if (colon) 362 *colon = 0; 363 dev = __dev_get_by_name(net, devname); 364 if (!dev) 365 return -ENODEV; 366 cfg->fc_oif = dev->ifindex; 367 if (colon) { 368 struct in_ifaddr *ifa; 369 struct in_device *in_dev = __in_dev_get_rtnl(dev); 370 if (!in_dev) 371 return -ENODEV; 372 *colon = ':'; 373 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) 374 if (strcmp(ifa->ifa_label, devname) == 0) 375 break; 376 if (ifa == NULL) 377 return -ENODEV; 378 cfg->fc_prefsrc = ifa->ifa_local; 379 } 380 } 381 382 addr = sk_extract_addr(&rt->rt_gateway); 383 if (rt->rt_gateway.sa_family == AF_INET && addr) { 384 cfg->fc_gw = addr; 385 if (rt->rt_flags & RTF_GATEWAY && 386 inet_addr_type(net, addr) == RTN_UNICAST) 387 cfg->fc_scope = RT_SCOPE_UNIVERSE; 388 } 389 390 if (cmd == SIOCDELRT) 391 return 0; 392 393 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw) 394 return -EINVAL; 395 396 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 397 cfg->fc_scope = RT_SCOPE_LINK; 398 399 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 400 struct nlattr *mx; 401 int len = 0; 402 403 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL); 404 if (mx == NULL) 405 return -ENOMEM; 406 407 if (rt->rt_flags & RTF_MTU) 408 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 409 410 if (rt->rt_flags & RTF_WINDOW) 411 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 412 413 if (rt->rt_flags & RTF_IRTT) 414 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 415 416 cfg->fc_mx = mx; 417 cfg->fc_mx_len = len; 418 } 419 420 return 0; 421} 422 423/* 424 * Handle IP routing ioctl calls. 425 * These are used to manipulate the routing tables 426 */ 427int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg) 428{ 429 struct fib_config cfg; 430 struct rtentry rt; 431 int err; 432 433 switch (cmd) { 434 case SIOCADDRT: /* Add a route */ 435 case SIOCDELRT: /* Delete a route */ 436 if (!capable(CAP_NET_ADMIN)) 437 return -EPERM; 438 439 if (copy_from_user(&rt, arg, sizeof(rt))) 440 return -EFAULT; 441 442 rtnl_lock(); 443 err = rtentry_to_fib_config(net, cmd, &rt, &cfg); 444 if (err == 0) { 445 struct fib_table *tb; 446 447 if (cmd == SIOCDELRT) { 448 tb = fib_get_table(net, cfg.fc_table); 449 if (tb) 450 err = fib_table_delete(tb, &cfg); 451 else 452 err = -ESRCH; 453 } else { 454 tb = fib_new_table(net, cfg.fc_table); 455 if (tb) 456 err = fib_table_insert(tb, &cfg); 457 else 458 err = -ENOBUFS; 459 } 460 461 /* allocated by rtentry_to_fib_config() */ 462 kfree(cfg.fc_mx); 463 } 464 rtnl_unlock(); 465 return err; 466 } 467 return -EINVAL; 468} 469 470const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 471 [RTA_DST] = { .type = NLA_U32 }, 472 [RTA_SRC] = { .type = NLA_U32 }, 473 [RTA_IIF] = { .type = NLA_U32 }, 474 [RTA_OIF] = { .type = NLA_U32 }, 475 [RTA_GATEWAY] = { .type = NLA_U32 }, 476 [RTA_PRIORITY] = { .type = NLA_U32 }, 477 [RTA_PREFSRC] = { .type = NLA_U32 }, 478 [RTA_METRICS] = { .type = NLA_NESTED }, 479 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 480 [RTA_FLOW] = { .type = NLA_U32 }, 481}; 482 483static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 484 struct nlmsghdr *nlh, struct fib_config *cfg) 485{ 486 struct nlattr *attr; 487 int err, remaining; 488 struct rtmsg *rtm; 489 490 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy); 491 if (err < 0) 492 goto errout; 493 494 memset(cfg, 0, sizeof(*cfg)); 495 496 rtm = nlmsg_data(nlh); 497 cfg->fc_dst_len = rtm->rtm_dst_len; 498 cfg->fc_tos = rtm->rtm_tos; 499 cfg->fc_table = rtm->rtm_table; 500 cfg->fc_protocol = rtm->rtm_protocol; 501 cfg->fc_scope = rtm->rtm_scope; 502 cfg->fc_type = rtm->rtm_type; 503 cfg->fc_flags = rtm->rtm_flags; 504 cfg->fc_nlflags = nlh->nlmsg_flags; 505 506 cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid; 507 cfg->fc_nlinfo.nlh = nlh; 508 cfg->fc_nlinfo.nl_net = net; 509 510 if (cfg->fc_type > RTN_MAX) { 511 err = -EINVAL; 512 goto errout; 513 } 514 515 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 516 switch (nla_type(attr)) { 517 case RTA_DST: 518 cfg->fc_dst = nla_get_be32(attr); 519 break; 520 case RTA_OIF: 521 cfg->fc_oif = nla_get_u32(attr); 522 break; 523 case RTA_GATEWAY: 524 cfg->fc_gw = nla_get_be32(attr); 525 break; 526 case RTA_PRIORITY: 527 cfg->fc_priority = nla_get_u32(attr); 528 break; 529 case RTA_PREFSRC: 530 cfg->fc_prefsrc = nla_get_be32(attr); 531 break; 532 case RTA_METRICS: 533 cfg->fc_mx = nla_data(attr); 534 cfg->fc_mx_len = nla_len(attr); 535 break; 536 case RTA_MULTIPATH: 537 cfg->fc_mp = nla_data(attr); 538 cfg->fc_mp_len = nla_len(attr); 539 break; 540 case RTA_FLOW: 541 cfg->fc_flow = nla_get_u32(attr); 542 break; 543 case RTA_TABLE: 544 cfg->fc_table = nla_get_u32(attr); 545 break; 546 } 547 } 548 549 return 0; 550errout: 551 return err; 552} 553 554static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 555{ 556 struct net *net = sock_net(skb->sk); 557 struct fib_config cfg; 558 struct fib_table *tb; 559 int err; 560 561 err = rtm_to_fib_config(net, skb, nlh, &cfg); 562 if (err < 0) 563 goto errout; 564 565 tb = fib_get_table(net, cfg.fc_table); 566 if (tb == NULL) { 567 err = -ESRCH; 568 goto errout; 569 } 570 571 err = fib_table_delete(tb, &cfg); 572errout: 573 return err; 574} 575 576static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 577{ 578 struct net *net = sock_net(skb->sk); 579 struct fib_config cfg; 580 struct fib_table *tb; 581 int err; 582 583 err = rtm_to_fib_config(net, skb, nlh, &cfg); 584 if (err < 0) 585 goto errout; 586 587 tb = fib_new_table(net, cfg.fc_table); 588 if (tb == NULL) { 589 err = -ENOBUFS; 590 goto errout; 591 } 592 593 err = fib_table_insert(tb, &cfg); 594errout: 595 return err; 596} 597 598static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 599{ 600 struct net *net = sock_net(skb->sk); 601 unsigned int h, s_h; 602 unsigned int e = 0, s_e; 603 struct fib_table *tb; 604 struct hlist_node *node; 605 struct hlist_head *head; 606 int dumped = 0; 607 608 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) && 609 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED) 610 return ip_rt_dump(skb, cb); 611 612 s_h = cb->args[0]; 613 s_e = cb->args[1]; 614 615 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 616 e = 0; 617 head = &net->ipv4.fib_table_hash[h]; 618 hlist_for_each_entry(tb, node, head, tb_hlist) { 619 if (e < s_e) 620 goto next; 621 if (dumped) 622 memset(&cb->args[2], 0, sizeof(cb->args) - 623 2 * sizeof(cb->args[0])); 624 if (fib_table_dump(tb, skb, cb) < 0) 625 goto out; 626 dumped = 1; 627next: 628 e++; 629 } 630 } 631out: 632 cb->args[1] = e; 633 cb->args[0] = h; 634 635 return skb->len; 636} 637 638/* Prepare and feed intra-kernel routing request. 639 * Really, it should be netlink message, but :-( netlink 640 * can be not configured, so that we feed it directly 641 * to fib engine. It is legal, because all events occur 642 * only when netlink is already locked. 643 */ 644static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa) 645{ 646 struct net *net = dev_net(ifa->ifa_dev->dev); 647 struct fib_table *tb; 648 struct fib_config cfg = { 649 .fc_protocol = RTPROT_KERNEL, 650 .fc_type = type, 651 .fc_dst = dst, 652 .fc_dst_len = dst_len, 653 .fc_prefsrc = ifa->ifa_local, 654 .fc_oif = ifa->ifa_dev->dev->ifindex, 655 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 656 .fc_nlinfo = { 657 .nl_net = net, 658 }, 659 }; 660 661 if (type == RTN_UNICAST) 662 tb = fib_new_table(net, RT_TABLE_MAIN); 663 else 664 tb = fib_new_table(net, RT_TABLE_LOCAL); 665 666 if (tb == NULL) 667 return; 668 669 cfg.fc_table = tb->tb_id; 670 671 if (type != RTN_LOCAL) 672 cfg.fc_scope = RT_SCOPE_LINK; 673 else 674 cfg.fc_scope = RT_SCOPE_HOST; 675 676 if (cmd == RTM_NEWROUTE) 677 fib_table_insert(tb, &cfg); 678 else 679 fib_table_delete(tb, &cfg); 680} 681 682void fib_add_ifaddr(struct in_ifaddr *ifa) 683{ 684 struct in_device *in_dev = ifa->ifa_dev; 685 struct net_device *dev = in_dev->dev; 686 struct in_ifaddr *prim = ifa; 687 __be32 mask = ifa->ifa_mask; 688 __be32 addr = ifa->ifa_local; 689 __be32 prefix = ifa->ifa_address & mask; 690 691 if (ifa->ifa_flags & IFA_F_SECONDARY) { 692 prim = inet_ifa_byprefix(in_dev, prefix, mask); 693 if (prim == NULL) { 694 printk(KERN_WARNING "fib_add_ifaddr: bug: prim == NULL\n"); 695 return; 696 } 697 } 698 699 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim); 700 701 if (!(dev->flags & IFF_UP)) 702 return; 703 704 /* Add broadcast address, if it is explicitly assigned. */ 705 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 706 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 707 708 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 709 (prefix != addr || ifa->ifa_prefixlen < 32)) { 710 fib_magic(RTM_NEWROUTE, 711 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 712 prefix, ifa->ifa_prefixlen, prim); 713 714 /* Add network specific broadcasts, when it takes a sense */ 715 if (ifa->ifa_prefixlen < 31) { 716 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim); 717 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 718 32, prim); 719 } 720 } 721} 722 723static void fib_del_ifaddr(struct in_ifaddr *ifa) 724{ 725 struct in_device *in_dev = ifa->ifa_dev; 726 struct net_device *dev = in_dev->dev; 727 struct in_ifaddr *ifa1; 728 struct in_ifaddr *prim = ifa; 729 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 730 __be32 any = ifa->ifa_address & ifa->ifa_mask; 731#define LOCAL_OK 1 732#define BRD_OK 2 733#define BRD0_OK 4 734#define BRD1_OK 8 735 unsigned ok = 0; 736 737 if (!(ifa->ifa_flags & IFA_F_SECONDARY)) 738 fib_magic(RTM_DELROUTE, 739 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 740 any, ifa->ifa_prefixlen, prim); 741 else { 742 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 743 if (prim == NULL) { 744 printk(KERN_WARNING "fib_del_ifaddr: bug: prim == NULL\n"); 745 return; 746 } 747 } 748 749 /* Deletion is more complicated than add. 750 * We should take care of not to delete too much :-) 751 * 752 * Scan address list to be sure that addresses are really gone. 753 */ 754 755 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) { 756 if (ifa->ifa_local == ifa1->ifa_local) 757 ok |= LOCAL_OK; 758 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 759 ok |= BRD_OK; 760 if (brd == ifa1->ifa_broadcast) 761 ok |= BRD1_OK; 762 if (any == ifa1->ifa_broadcast) 763 ok |= BRD0_OK; 764 } 765 766 if (!(ok & BRD_OK)) 767 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 768 if (!(ok & BRD1_OK)) 769 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim); 770 if (!(ok & BRD0_OK)) 771 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim); 772 if (!(ok & LOCAL_OK)) { 773 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim); 774 775 /* Check, that this local address finally disappeared. */ 776 if (inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) { 777 /* And the last, but not the least thing. 778 * We must flush stray FIB entries. 779 * 780 * First of all, we scan fib_info list searching 781 * for stray nexthop entries, then ignite fib_flush. 782 */ 783 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local)) 784 fib_flush(dev_net(dev)); 785 } 786 } 787#undef LOCAL_OK 788#undef BRD_OK 789#undef BRD0_OK 790#undef BRD1_OK 791} 792 793static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb) 794{ 795 796 struct fib_result res; 797 struct flowi fl = { 798 .mark = frn->fl_mark, 799 .fl4_dst = frn->fl_addr, 800 .fl4_tos = frn->fl_tos, 801 .fl4_scope = frn->fl_scope, 802 }; 803 804#ifdef CONFIG_IP_MULTIPLE_TABLES 805 res.r = NULL; 806#endif 807 808 frn->err = -ENOENT; 809 if (tb) { 810 local_bh_disable(); 811 812 frn->tb_id = tb->tb_id; 813 rcu_read_lock(); 814 frn->err = fib_table_lookup(tb, &fl, &res, FIB_LOOKUP_NOREF); 815 816 if (!frn->err) { 817 frn->prefixlen = res.prefixlen; 818 frn->nh_sel = res.nh_sel; 819 frn->type = res.type; 820 frn->scope = res.scope; 821 } 822 rcu_read_unlock(); 823 local_bh_enable(); 824 } 825} 826 827static void nl_fib_input(struct sk_buff *skb) 828{ 829 struct net *net; 830 struct fib_result_nl *frn; 831 struct nlmsghdr *nlh; 832 struct fib_table *tb; 833 u32 pid; 834 835 net = sock_net(skb->sk); 836 nlh = nlmsg_hdr(skb); 837 if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len || 838 nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn))) 839 return; 840 841 skb = skb_clone(skb, GFP_KERNEL); 842 if (skb == NULL) 843 return; 844 nlh = nlmsg_hdr(skb); 845 846 frn = (struct fib_result_nl *) NLMSG_DATA(nlh); 847 tb = fib_get_table(net, frn->tb_id_in); 848 849 nl_fib_lookup(frn, tb); 850 851 pid = NETLINK_CB(skb).pid; /* pid of sending process */ 852 NETLINK_CB(skb).pid = 0; /* from kernel */ 853 NETLINK_CB(skb).dst_group = 0; /* unicast */ 854 netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT); 855} 856 857static int __net_init nl_fib_lookup_init(struct net *net) 858{ 859 struct sock *sk; 860 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0, 861 nl_fib_input, NULL, THIS_MODULE); 862 if (sk == NULL) 863 return -EAFNOSUPPORT; 864 net->ipv4.fibnl = sk; 865 return 0; 866} 867 868static void nl_fib_lookup_exit(struct net *net) 869{ 870 netlink_kernel_release(net->ipv4.fibnl); 871 net->ipv4.fibnl = NULL; 872} 873 874static void fib_disable_ip(struct net_device *dev, int force, int delay) 875{ 876 if (fib_sync_down_dev(dev, force)) 877 fib_flush(dev_net(dev)); 878 rt_cache_flush(dev_net(dev), delay); 879 arp_ifdown(dev); 880} 881 882static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 883{ 884 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 885 struct net_device *dev = ifa->ifa_dev->dev; 886 887 switch (event) { 888 case NETDEV_UP: 889 fib_add_ifaddr(ifa); 890#ifdef CONFIG_IP_ROUTE_MULTIPATH 891 fib_sync_up(dev); 892#endif 893 rt_cache_flush(dev_net(dev), -1); 894 break; 895 case NETDEV_DOWN: 896 fib_del_ifaddr(ifa); 897 if (ifa->ifa_dev->ifa_list == NULL) { 898 /* Last address was deleted from this interface. 899 * Disable IP. 900 */ 901 fib_disable_ip(dev, 1, 0); 902 } else { 903 rt_cache_flush(dev_net(dev), -1); 904 } 905 break; 906 } 907 return NOTIFY_DONE; 908} 909 910static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 911{ 912 struct net_device *dev = ptr; 913 struct in_device *in_dev = __in_dev_get_rtnl(dev); 914 915 if (event == NETDEV_UNREGISTER) { 916 fib_disable_ip(dev, 2, -1); 917 return NOTIFY_DONE; 918 } 919 920 if (!in_dev) 921 return NOTIFY_DONE; 922 923 switch (event) { 924 case NETDEV_UP: 925 for_ifa(in_dev) { 926 fib_add_ifaddr(ifa); 927 } endfor_ifa(in_dev); 928#ifdef CONFIG_IP_ROUTE_MULTIPATH 929 fib_sync_up(dev); 930#endif 931 rt_cache_flush(dev_net(dev), -1); 932 break; 933 case NETDEV_DOWN: 934 fib_disable_ip(dev, 0, 0); 935 break; 936 case NETDEV_CHANGEMTU: 937 case NETDEV_CHANGE: 938 rt_cache_flush(dev_net(dev), 0); 939 break; 940 case NETDEV_UNREGISTER_BATCH: 941 /* The batch unregister is only called on the first 942 * device in the list of devices being unregistered. 943 * Therefore we should not pass dev_net(dev) in here. 944 */ 945 rt_cache_flush_batch(NULL); 946 break; 947 } 948 return NOTIFY_DONE; 949} 950 951static struct notifier_block fib_inetaddr_notifier = { 952 .notifier_call = fib_inetaddr_event, 953}; 954 955static struct notifier_block fib_netdev_notifier = { 956 .notifier_call = fib_netdev_event, 957}; 958 959static int __net_init ip_fib_net_init(struct net *net) 960{ 961 int err; 962 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 963 964 /* Avoid false sharing : Use at least a full cache line */ 965 size = max_t(size_t, size, L1_CACHE_BYTES); 966 967 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 968 if (net->ipv4.fib_table_hash == NULL) 969 return -ENOMEM; 970 971 err = fib4_rules_init(net); 972 if (err < 0) 973 goto fail; 974 return 0; 975 976fail: 977 kfree(net->ipv4.fib_table_hash); 978 return err; 979} 980 981static void ip_fib_net_exit(struct net *net) 982{ 983 unsigned int i; 984 985#ifdef CONFIG_IP_MULTIPLE_TABLES 986 fib4_rules_exit(net); 987#endif 988 989 for (i = 0; i < FIB_TABLE_HASHSZ; i++) { 990 struct fib_table *tb; 991 struct hlist_head *head; 992 struct hlist_node *node, *tmp; 993 994 head = &net->ipv4.fib_table_hash[i]; 995 hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) { 996 hlist_del(node); 997 fib_table_flush(tb); 998 fib_free_table(tb); 999 } 1000 } 1001 kfree(net->ipv4.fib_table_hash); 1002} 1003 1004static int __net_init fib_net_init(struct net *net) 1005{ 1006 int error; 1007 1008 error = ip_fib_net_init(net); 1009 if (error < 0) 1010 goto out; 1011 error = nl_fib_lookup_init(net); 1012 if (error < 0) 1013 goto out_nlfl; 1014 error = fib_proc_init(net); 1015 if (error < 0) 1016 goto out_proc; 1017out: 1018 return error; 1019 1020out_proc: 1021 nl_fib_lookup_exit(net); 1022out_nlfl: 1023 ip_fib_net_exit(net); 1024 goto out; 1025} 1026 1027static void __net_exit fib_net_exit(struct net *net) 1028{ 1029 fib_proc_exit(net); 1030 nl_fib_lookup_exit(net); 1031 ip_fib_net_exit(net); 1032} 1033 1034static struct pernet_operations fib_net_ops = { 1035 .init = fib_net_init, 1036 .exit = fib_net_exit, 1037}; 1038 1039void __init ip_fib_init(void) 1040{ 1041 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL); 1042 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL); 1043 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib); 1044 1045 register_pernet_subsys(&fib_net_ops); 1046 register_netdevice_notifier(&fib_netdev_notifier); 1047 register_inetaddr_notifier(&fib_inetaddr_notifier); 1048 1049 fib_trie_init(); 1050} 1051