fib_frontend.c revision 226b0b4a51d1cc09928e569b121ca0abe2839169
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 * Version: $Id: fib_frontend.c,v 1.26 2001/10/31 21:55:54 davem Exp $ 9 * 10 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License 14 * as published by the Free Software Foundation; either version 15 * 2 of the License, or (at your option) any later version. 16 */ 17 18#include <linux/module.h> 19#include <asm/uaccess.h> 20#include <asm/system.h> 21#include <linux/bitops.h> 22#include <linux/capability.h> 23#include <linux/types.h> 24#include <linux/kernel.h> 25#include <linux/mm.h> 26#include <linux/string.h> 27#include <linux/socket.h> 28#include <linux/sockios.h> 29#include <linux/errno.h> 30#include <linux/in.h> 31#include <linux/inet.h> 32#include <linux/inetdevice.h> 33#include <linux/netdevice.h> 34#include <linux/if_addr.h> 35#include <linux/if_arp.h> 36#include <linux/skbuff.h> 37#include <linux/init.h> 38#include <linux/list.h> 39 40#include <net/ip.h> 41#include <net/protocol.h> 42#include <net/route.h> 43#include <net/tcp.h> 44#include <net/sock.h> 45#include <net/icmp.h> 46#include <net/arp.h> 47#include <net/ip_fib.h> 48#include <net/rtnetlink.h> 49 50#define FFprint(a...) printk(KERN_DEBUG a) 51 52#ifndef CONFIG_IP_MULTIPLE_TABLES 53 54static int __net_init fib4_rules_init(struct net *net) 55{ 56 struct fib_table *local_table, *main_table; 57 58 local_table = fib_hash_init(RT_TABLE_LOCAL); 59 if (local_table == NULL) 60 return -ENOMEM; 61 62 main_table = fib_hash_init(RT_TABLE_MAIN); 63 if (main_table == NULL) 64 goto fail; 65 66 hlist_add_head_rcu(&local_table->tb_hlist, 67 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]); 68 hlist_add_head_rcu(&main_table->tb_hlist, 69 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]); 70 return 0; 71 72fail: 73 kfree(local_table); 74 return -ENOMEM; 75} 76#else 77 78struct fib_table *fib_new_table(struct net *net, u32 id) 79{ 80 struct fib_table *tb; 81 unsigned int h; 82 83 if (id == 0) 84 id = RT_TABLE_MAIN; 85 tb = fib_get_table(net, id); 86 if (tb) 87 return tb; 88 tb = fib_hash_init(id); 89 if (!tb) 90 return NULL; 91 h = id & (FIB_TABLE_HASHSZ - 1); 92 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]); 93 return tb; 94} 95 96struct fib_table *fib_get_table(struct net *net, u32 id) 97{ 98 struct fib_table *tb; 99 struct hlist_node *node; 100 struct hlist_head *head; 101 unsigned int h; 102 103 if (id == 0) 104 id = RT_TABLE_MAIN; 105 h = id & (FIB_TABLE_HASHSZ - 1); 106 107 rcu_read_lock(); 108 head = &net->ipv4.fib_table_hash[h]; 109 hlist_for_each_entry_rcu(tb, node, head, tb_hlist) { 110 if (tb->tb_id == id) { 111 rcu_read_unlock(); 112 return tb; 113 } 114 } 115 rcu_read_unlock(); 116 return NULL; 117} 118#endif /* CONFIG_IP_MULTIPLE_TABLES */ 119 120static void fib_flush(struct net *net) 121{ 122 int flushed = 0; 123 struct fib_table *tb; 124 struct hlist_node *node; 125 struct hlist_head *head; 126 unsigned int h; 127 128 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 129 head = &net->ipv4.fib_table_hash[h]; 130 hlist_for_each_entry(tb, node, head, tb_hlist) 131 flushed += tb->tb_flush(tb); 132 } 133 134 if (flushed) 135 rt_cache_flush(-1); 136} 137 138/* 139 * Find the first device with a given source address. 140 */ 141 142struct net_device * ip_dev_find(__be32 addr) 143{ 144 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = addr } } }; 145 struct fib_result res; 146 struct net_device *dev = NULL; 147 struct fib_table *local_table; 148 149#ifdef CONFIG_IP_MULTIPLE_TABLES 150 res.r = NULL; 151#endif 152 153 local_table = fib_get_table(&init_net, RT_TABLE_LOCAL); 154 if (!local_table || local_table->tb_lookup(local_table, &fl, &res)) 155 return NULL; 156 if (res.type != RTN_LOCAL) 157 goto out; 158 dev = FIB_RES_DEV(res); 159 160 if (dev) 161 dev_hold(dev); 162out: 163 fib_res_put(&res); 164 return dev; 165} 166 167/* 168 * Find address type as if only "dev" was present in the system. If 169 * on_dev is NULL then all interfaces are taken into consideration. 170 */ 171static inline unsigned __inet_dev_addr_type(struct net *net, 172 const struct net_device *dev, 173 __be32 addr) 174{ 175 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = addr } } }; 176 struct fib_result res; 177 unsigned ret = RTN_BROADCAST; 178 struct fib_table *local_table; 179 180 if (ipv4_is_zeronet(addr) || ipv4_is_badclass(addr)) 181 return RTN_BROADCAST; 182 if (ipv4_is_multicast(addr)) 183 return RTN_MULTICAST; 184 185#ifdef CONFIG_IP_MULTIPLE_TABLES 186 res.r = NULL; 187#endif 188 189 local_table = fib_get_table(net, RT_TABLE_LOCAL); 190 if (local_table) { 191 ret = RTN_UNICAST; 192 if (!local_table->tb_lookup(local_table, &fl, &res)) { 193 if (!dev || dev == res.fi->fib_dev) 194 ret = res.type; 195 fib_res_put(&res); 196 } 197 } 198 return ret; 199} 200 201unsigned int inet_addr_type(struct net *net, __be32 addr) 202{ 203 return __inet_dev_addr_type(net, NULL, addr); 204} 205 206unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, 207 __be32 addr) 208{ 209 return __inet_dev_addr_type(net, dev, addr); 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 */ 219 220int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif, 221 struct net_device *dev, __be32 *spec_dst, u32 *itag) 222{ 223 struct in_device *in_dev; 224 struct flowi fl = { .nl_u = { .ip4_u = 225 { .daddr = src, 226 .saddr = dst, 227 .tos = tos } }, 228 .iif = oif }; 229 struct fib_result res; 230 int no_addr, rpf; 231 int ret; 232 233 no_addr = rpf = 0; 234 rcu_read_lock(); 235 in_dev = __in_dev_get_rcu(dev); 236 if (in_dev) { 237 no_addr = in_dev->ifa_list == NULL; 238 rpf = IN_DEV_RPFILTER(in_dev); 239 } 240 rcu_read_unlock(); 241 242 if (in_dev == NULL) 243 goto e_inval; 244 245 if (fib_lookup(&fl, &res)) 246 goto last_resort; 247 if (res.type != RTN_UNICAST) 248 goto e_inval_res; 249 *spec_dst = FIB_RES_PREFSRC(res); 250 fib_combine_itag(itag, &res); 251#ifdef CONFIG_IP_ROUTE_MULTIPATH 252 if (FIB_RES_DEV(res) == dev || res.fi->fib_nhs > 1) 253#else 254 if (FIB_RES_DEV(res) == dev) 255#endif 256 { 257 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 258 fib_res_put(&res); 259 return ret; 260 } 261 fib_res_put(&res); 262 if (no_addr) 263 goto last_resort; 264 if (rpf) 265 goto e_inval; 266 fl.oif = dev->ifindex; 267 268 ret = 0; 269 if (fib_lookup(&fl, &res) == 0) { 270 if (res.type == RTN_UNICAST) { 271 *spec_dst = FIB_RES_PREFSRC(res); 272 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 273 } 274 fib_res_put(&res); 275 } 276 return ret; 277 278last_resort: 279 if (rpf) 280 goto e_inval; 281 *spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE); 282 *itag = 0; 283 return 0; 284 285e_inval_res: 286 fib_res_put(&res); 287e_inval: 288 return -EINVAL; 289} 290 291static inline __be32 sk_extract_addr(struct sockaddr *addr) 292{ 293 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 294} 295 296static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 297{ 298 struct nlattr *nla; 299 300 nla = (struct nlattr *) ((char *) mx + len); 301 nla->nla_type = type; 302 nla->nla_len = nla_attr_size(4); 303 *(u32 *) nla_data(nla) = value; 304 305 return len + nla_total_size(4); 306} 307 308static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 309 struct fib_config *cfg) 310{ 311 __be32 addr; 312 int plen; 313 314 memset(cfg, 0, sizeof(*cfg)); 315 cfg->fc_nlinfo.nl_net = net; 316 317 if (rt->rt_dst.sa_family != AF_INET) 318 return -EAFNOSUPPORT; 319 320 /* 321 * Check mask for validity: 322 * a) it must be contiguous. 323 * b) destination must have all host bits clear. 324 * c) if application forgot to set correct family (AF_INET), 325 * reject request unless it is absolutely clear i.e. 326 * both family and mask are zero. 327 */ 328 plen = 32; 329 addr = sk_extract_addr(&rt->rt_dst); 330 if (!(rt->rt_flags & RTF_HOST)) { 331 __be32 mask = sk_extract_addr(&rt->rt_genmask); 332 333 if (rt->rt_genmask.sa_family != AF_INET) { 334 if (mask || rt->rt_genmask.sa_family) 335 return -EAFNOSUPPORT; 336 } 337 338 if (bad_mask(mask, addr)) 339 return -EINVAL; 340 341 plen = inet_mask_len(mask); 342 } 343 344 cfg->fc_dst_len = plen; 345 cfg->fc_dst = addr; 346 347 if (cmd != SIOCDELRT) { 348 cfg->fc_nlflags = NLM_F_CREATE; 349 cfg->fc_protocol = RTPROT_BOOT; 350 } 351 352 if (rt->rt_metric) 353 cfg->fc_priority = rt->rt_metric - 1; 354 355 if (rt->rt_flags & RTF_REJECT) { 356 cfg->fc_scope = RT_SCOPE_HOST; 357 cfg->fc_type = RTN_UNREACHABLE; 358 return 0; 359 } 360 361 cfg->fc_scope = RT_SCOPE_NOWHERE; 362 cfg->fc_type = RTN_UNICAST; 363 364 if (rt->rt_dev) { 365 char *colon; 366 struct net_device *dev; 367 char devname[IFNAMSIZ]; 368 369 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 370 return -EFAULT; 371 372 devname[IFNAMSIZ-1] = 0; 373 colon = strchr(devname, ':'); 374 if (colon) 375 *colon = 0; 376 dev = __dev_get_by_name(net, devname); 377 if (!dev) 378 return -ENODEV; 379 cfg->fc_oif = dev->ifindex; 380 if (colon) { 381 struct in_ifaddr *ifa; 382 struct in_device *in_dev = __in_dev_get_rtnl(dev); 383 if (!in_dev) 384 return -ENODEV; 385 *colon = ':'; 386 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) 387 if (strcmp(ifa->ifa_label, devname) == 0) 388 break; 389 if (ifa == NULL) 390 return -ENODEV; 391 cfg->fc_prefsrc = ifa->ifa_local; 392 } 393 } 394 395 addr = sk_extract_addr(&rt->rt_gateway); 396 if (rt->rt_gateway.sa_family == AF_INET && addr) { 397 cfg->fc_gw = addr; 398 if (rt->rt_flags & RTF_GATEWAY && 399 inet_addr_type(net, addr) == RTN_UNICAST) 400 cfg->fc_scope = RT_SCOPE_UNIVERSE; 401 } 402 403 if (cmd == SIOCDELRT) 404 return 0; 405 406 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw) 407 return -EINVAL; 408 409 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 410 cfg->fc_scope = RT_SCOPE_LINK; 411 412 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 413 struct nlattr *mx; 414 int len = 0; 415 416 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL); 417 if (mx == NULL) 418 return -ENOMEM; 419 420 if (rt->rt_flags & RTF_MTU) 421 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 422 423 if (rt->rt_flags & RTF_WINDOW) 424 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 425 426 if (rt->rt_flags & RTF_IRTT) 427 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 428 429 cfg->fc_mx = mx; 430 cfg->fc_mx_len = len; 431 } 432 433 return 0; 434} 435 436/* 437 * Handle IP routing ioctl calls. These are used to manipulate the routing tables 438 */ 439 440int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg) 441{ 442 struct fib_config cfg; 443 struct rtentry rt; 444 int err; 445 446 switch (cmd) { 447 case SIOCADDRT: /* Add a route */ 448 case SIOCDELRT: /* Delete a route */ 449 if (!capable(CAP_NET_ADMIN)) 450 return -EPERM; 451 452 if (copy_from_user(&rt, arg, sizeof(rt))) 453 return -EFAULT; 454 455 rtnl_lock(); 456 err = rtentry_to_fib_config(net, cmd, &rt, &cfg); 457 if (err == 0) { 458 struct fib_table *tb; 459 460 if (cmd == SIOCDELRT) { 461 tb = fib_get_table(net, cfg.fc_table); 462 if (tb) 463 err = tb->tb_delete(tb, &cfg); 464 else 465 err = -ESRCH; 466 } else { 467 tb = fib_new_table(net, cfg.fc_table); 468 if (tb) 469 err = tb->tb_insert(tb, &cfg); 470 else 471 err = -ENOBUFS; 472 } 473 474 /* allocated by rtentry_to_fib_config() */ 475 kfree(cfg.fc_mx); 476 } 477 rtnl_unlock(); 478 return err; 479 } 480 return -EINVAL; 481} 482 483const struct nla_policy rtm_ipv4_policy[RTA_MAX+1] = { 484 [RTA_DST] = { .type = NLA_U32 }, 485 [RTA_SRC] = { .type = NLA_U32 }, 486 [RTA_IIF] = { .type = NLA_U32 }, 487 [RTA_OIF] = { .type = NLA_U32 }, 488 [RTA_GATEWAY] = { .type = NLA_U32 }, 489 [RTA_PRIORITY] = { .type = NLA_U32 }, 490 [RTA_PREFSRC] = { .type = NLA_U32 }, 491 [RTA_METRICS] = { .type = NLA_NESTED }, 492 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 493 [RTA_PROTOINFO] = { .type = NLA_U32 }, 494 [RTA_FLOW] = { .type = NLA_U32 }, 495}; 496 497static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 498 struct nlmsghdr *nlh, struct fib_config *cfg) 499{ 500 struct nlattr *attr; 501 int err, remaining; 502 struct rtmsg *rtm; 503 504 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy); 505 if (err < 0) 506 goto errout; 507 508 memset(cfg, 0, sizeof(*cfg)); 509 510 rtm = nlmsg_data(nlh); 511 cfg->fc_dst_len = rtm->rtm_dst_len; 512 cfg->fc_tos = rtm->rtm_tos; 513 cfg->fc_table = rtm->rtm_table; 514 cfg->fc_protocol = rtm->rtm_protocol; 515 cfg->fc_scope = rtm->rtm_scope; 516 cfg->fc_type = rtm->rtm_type; 517 cfg->fc_flags = rtm->rtm_flags; 518 cfg->fc_nlflags = nlh->nlmsg_flags; 519 520 cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid; 521 cfg->fc_nlinfo.nlh = nlh; 522 cfg->fc_nlinfo.nl_net = net; 523 524 if (cfg->fc_type > RTN_MAX) { 525 err = -EINVAL; 526 goto errout; 527 } 528 529 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 530 switch (nla_type(attr)) { 531 case RTA_DST: 532 cfg->fc_dst = nla_get_be32(attr); 533 break; 534 case RTA_OIF: 535 cfg->fc_oif = nla_get_u32(attr); 536 break; 537 case RTA_GATEWAY: 538 cfg->fc_gw = nla_get_be32(attr); 539 break; 540 case RTA_PRIORITY: 541 cfg->fc_priority = nla_get_u32(attr); 542 break; 543 case RTA_PREFSRC: 544 cfg->fc_prefsrc = nla_get_be32(attr); 545 break; 546 case RTA_METRICS: 547 cfg->fc_mx = nla_data(attr); 548 cfg->fc_mx_len = nla_len(attr); 549 break; 550 case RTA_MULTIPATH: 551 cfg->fc_mp = nla_data(attr); 552 cfg->fc_mp_len = nla_len(attr); 553 break; 554 case RTA_FLOW: 555 cfg->fc_flow = nla_get_u32(attr); 556 break; 557 case RTA_TABLE: 558 cfg->fc_table = nla_get_u32(attr); 559 break; 560 } 561 } 562 563 return 0; 564errout: 565 return err; 566} 567 568static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 569{ 570 struct net *net = skb->sk->sk_net; 571 struct fib_config cfg; 572 struct fib_table *tb; 573 int err; 574 575 if (net != &init_net) 576 return -EINVAL; 577 578 err = rtm_to_fib_config(net, skb, nlh, &cfg); 579 if (err < 0) 580 goto errout; 581 582 tb = fib_get_table(net, cfg.fc_table); 583 if (tb == NULL) { 584 err = -ESRCH; 585 goto errout; 586 } 587 588 err = tb->tb_delete(tb, &cfg); 589errout: 590 return err; 591} 592 593static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 594{ 595 struct net *net = skb->sk->sk_net; 596 struct fib_config cfg; 597 struct fib_table *tb; 598 int err; 599 600 if (net != &init_net) 601 return -EINVAL; 602 603 err = rtm_to_fib_config(net, skb, nlh, &cfg); 604 if (err < 0) 605 goto errout; 606 607 tb = fib_new_table(net, cfg.fc_table); 608 if (tb == NULL) { 609 err = -ENOBUFS; 610 goto errout; 611 } 612 613 err = tb->tb_insert(tb, &cfg); 614errout: 615 return err; 616} 617 618static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 619{ 620 struct net *net = skb->sk->sk_net; 621 unsigned int h, s_h; 622 unsigned int e = 0, s_e; 623 struct fib_table *tb; 624 struct hlist_node *node; 625 struct hlist_head *head; 626 int dumped = 0; 627 628 if (net != &init_net) 629 return 0; 630 631 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) && 632 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED) 633 return ip_rt_dump(skb, cb); 634 635 s_h = cb->args[0]; 636 s_e = cb->args[1]; 637 638 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 639 e = 0; 640 head = &net->ipv4.fib_table_hash[h]; 641 hlist_for_each_entry(tb, node, head, tb_hlist) { 642 if (e < s_e) 643 goto next; 644 if (dumped) 645 memset(&cb->args[2], 0, sizeof(cb->args) - 646 2 * sizeof(cb->args[0])); 647 if (tb->tb_dump(tb, skb, cb) < 0) 648 goto out; 649 dumped = 1; 650next: 651 e++; 652 } 653 } 654out: 655 cb->args[1] = e; 656 cb->args[0] = h; 657 658 return skb->len; 659} 660 661/* Prepare and feed intra-kernel routing request. 662 Really, it should be netlink message, but :-( netlink 663 can be not configured, so that we feed it directly 664 to fib engine. It is legal, because all events occur 665 only when netlink is already locked. 666 */ 667 668static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa) 669{ 670 struct net *net = ifa->ifa_dev->dev->nd_net; 671 struct fib_table *tb; 672 struct fib_config cfg = { 673 .fc_protocol = RTPROT_KERNEL, 674 .fc_type = type, 675 .fc_dst = dst, 676 .fc_dst_len = dst_len, 677 .fc_prefsrc = ifa->ifa_local, 678 .fc_oif = ifa->ifa_dev->dev->ifindex, 679 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 680 .fc_nlinfo = { 681 .nl_net = net, 682 }, 683 }; 684 685 if (type == RTN_UNICAST) 686 tb = fib_new_table(net, RT_TABLE_MAIN); 687 else 688 tb = fib_new_table(net, RT_TABLE_LOCAL); 689 690 if (tb == NULL) 691 return; 692 693 cfg.fc_table = tb->tb_id; 694 695 if (type != RTN_LOCAL) 696 cfg.fc_scope = RT_SCOPE_LINK; 697 else 698 cfg.fc_scope = RT_SCOPE_HOST; 699 700 if (cmd == RTM_NEWROUTE) 701 tb->tb_insert(tb, &cfg); 702 else 703 tb->tb_delete(tb, &cfg); 704} 705 706void fib_add_ifaddr(struct in_ifaddr *ifa) 707{ 708 struct in_device *in_dev = ifa->ifa_dev; 709 struct net_device *dev = in_dev->dev; 710 struct in_ifaddr *prim = ifa; 711 __be32 mask = ifa->ifa_mask; 712 __be32 addr = ifa->ifa_local; 713 __be32 prefix = ifa->ifa_address&mask; 714 715 if (ifa->ifa_flags&IFA_F_SECONDARY) { 716 prim = inet_ifa_byprefix(in_dev, prefix, mask); 717 if (prim == NULL) { 718 printk(KERN_DEBUG "fib_add_ifaddr: bug: prim == NULL\n"); 719 return; 720 } 721 } 722 723 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim); 724 725 if (!(dev->flags&IFF_UP)) 726 return; 727 728 /* Add broadcast address, if it is explicitly assigned. */ 729 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 730 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 731 732 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags&IFA_F_SECONDARY) && 733 (prefix != addr || ifa->ifa_prefixlen < 32)) { 734 fib_magic(RTM_NEWROUTE, dev->flags&IFF_LOOPBACK ? RTN_LOCAL : 735 RTN_UNICAST, prefix, ifa->ifa_prefixlen, prim); 736 737 /* Add network specific broadcasts, when it takes a sense */ 738 if (ifa->ifa_prefixlen < 31) { 739 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim); 740 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix|~mask, 32, prim); 741 } 742 } 743} 744 745static void fib_del_ifaddr(struct in_ifaddr *ifa) 746{ 747 struct in_device *in_dev = ifa->ifa_dev; 748 struct net_device *dev = in_dev->dev; 749 struct in_ifaddr *ifa1; 750 struct in_ifaddr *prim = ifa; 751 __be32 brd = ifa->ifa_address|~ifa->ifa_mask; 752 __be32 any = ifa->ifa_address&ifa->ifa_mask; 753#define LOCAL_OK 1 754#define BRD_OK 2 755#define BRD0_OK 4 756#define BRD1_OK 8 757 unsigned ok = 0; 758 759 if (!(ifa->ifa_flags&IFA_F_SECONDARY)) 760 fib_magic(RTM_DELROUTE, dev->flags&IFF_LOOPBACK ? RTN_LOCAL : 761 RTN_UNICAST, any, ifa->ifa_prefixlen, prim); 762 else { 763 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 764 if (prim == NULL) { 765 printk(KERN_DEBUG "fib_del_ifaddr: bug: prim == NULL\n"); 766 return; 767 } 768 } 769 770 /* Deletion is more complicated than add. 771 We should take care of not to delete too much :-) 772 773 Scan address list to be sure that addresses are really gone. 774 */ 775 776 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) { 777 if (ifa->ifa_local == ifa1->ifa_local) 778 ok |= LOCAL_OK; 779 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 780 ok |= BRD_OK; 781 if (brd == ifa1->ifa_broadcast) 782 ok |= BRD1_OK; 783 if (any == ifa1->ifa_broadcast) 784 ok |= BRD0_OK; 785 } 786 787 if (!(ok&BRD_OK)) 788 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 789 if (!(ok&BRD1_OK)) 790 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim); 791 if (!(ok&BRD0_OK)) 792 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim); 793 if (!(ok&LOCAL_OK)) { 794 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim); 795 796 /* Check, that this local address finally disappeared. */ 797 if (inet_addr_type(dev->nd_net, ifa->ifa_local) != RTN_LOCAL) { 798 /* And the last, but not the least thing. 799 We must flush stray FIB entries. 800 801 First of all, we scan fib_info list searching 802 for stray nexthop entries, then ignite fib_flush. 803 */ 804 if (fib_sync_down(ifa->ifa_local, NULL, 0)) 805 fib_flush(dev->nd_net); 806 } 807 } 808#undef LOCAL_OK 809#undef BRD_OK 810#undef BRD0_OK 811#undef BRD1_OK 812} 813 814static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb ) 815{ 816 817 struct fib_result res; 818 struct flowi fl = { .mark = frn->fl_mark, 819 .nl_u = { .ip4_u = { .daddr = frn->fl_addr, 820 .tos = frn->fl_tos, 821 .scope = frn->fl_scope } } }; 822 823#ifdef CONFIG_IP_MULTIPLE_TABLES 824 res.r = NULL; 825#endif 826 827 frn->err = -ENOENT; 828 if (tb) { 829 local_bh_disable(); 830 831 frn->tb_id = tb->tb_id; 832 frn->err = tb->tb_lookup(tb, &fl, &res); 833 834 if (!frn->err) { 835 frn->prefixlen = res.prefixlen; 836 frn->nh_sel = res.nh_sel; 837 frn->type = res.type; 838 frn->scope = res.scope; 839 fib_res_put(&res); 840 } 841 local_bh_enable(); 842 } 843} 844 845static void nl_fib_input(struct sk_buff *skb) 846{ 847 struct net *net; 848 struct fib_result_nl *frn; 849 struct nlmsghdr *nlh; 850 struct fib_table *tb; 851 u32 pid; 852 853 net = skb->sk->sk_net; 854 nlh = nlmsg_hdr(skb); 855 if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len || 856 nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn))) 857 return; 858 859 skb = skb_clone(skb, GFP_KERNEL); 860 if (skb == NULL) 861 return; 862 nlh = nlmsg_hdr(skb); 863 864 frn = (struct fib_result_nl *) NLMSG_DATA(nlh); 865 tb = fib_get_table(net, frn->tb_id_in); 866 867 nl_fib_lookup(frn, tb); 868 869 pid = NETLINK_CB(skb).pid; /* pid of sending process */ 870 NETLINK_CB(skb).pid = 0; /* from kernel */ 871 NETLINK_CB(skb).dst_group = 0; /* unicast */ 872 netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT); 873} 874 875static int nl_fib_lookup_init(struct net *net) 876{ 877 struct sock *sk; 878 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0, 879 nl_fib_input, NULL, THIS_MODULE); 880 if (sk == NULL) 881 return -EAFNOSUPPORT; 882 /* Don't hold an extra reference on the namespace */ 883 put_net(sk->sk_net); 884 net->ipv4.fibnl = sk; 885 return 0; 886} 887 888static void nl_fib_lookup_exit(struct net *net) 889{ 890 /* At the last minute lie and say this is a socket for the 891 * initial network namespace. So the socket will be safe to free. 892 */ 893 net->ipv4.fibnl->sk_net = get_net(&init_net); 894 sock_put(net->ipv4.fibnl); 895} 896 897static void fib_disable_ip(struct net_device *dev, int force) 898{ 899 if (fib_sync_down(0, dev, force)) 900 fib_flush(dev->nd_net); 901 rt_cache_flush(0); 902 arp_ifdown(dev); 903} 904 905static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 906{ 907 struct in_ifaddr *ifa = (struct in_ifaddr*)ptr; 908 909 switch (event) { 910 case NETDEV_UP: 911 fib_add_ifaddr(ifa); 912#ifdef CONFIG_IP_ROUTE_MULTIPATH 913 fib_sync_up(ifa->ifa_dev->dev); 914#endif 915 rt_cache_flush(-1); 916 break; 917 case NETDEV_DOWN: 918 fib_del_ifaddr(ifa); 919 if (ifa->ifa_dev->ifa_list == NULL) { 920 /* Last address was deleted from this interface. 921 Disable IP. 922 */ 923 fib_disable_ip(ifa->ifa_dev->dev, 1); 924 } else { 925 rt_cache_flush(-1); 926 } 927 break; 928 } 929 return NOTIFY_DONE; 930} 931 932static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 933{ 934 struct net_device *dev = ptr; 935 struct in_device *in_dev = __in_dev_get_rtnl(dev); 936 937 if (dev->nd_net != &init_net) 938 return NOTIFY_DONE; 939 940 if (event == NETDEV_UNREGISTER) { 941 fib_disable_ip(dev, 2); 942 return NOTIFY_DONE; 943 } 944 945 if (!in_dev) 946 return NOTIFY_DONE; 947 948 switch (event) { 949 case NETDEV_UP: 950 for_ifa(in_dev) { 951 fib_add_ifaddr(ifa); 952 } endfor_ifa(in_dev); 953#ifdef CONFIG_IP_ROUTE_MULTIPATH 954 fib_sync_up(dev); 955#endif 956 rt_cache_flush(-1); 957 break; 958 case NETDEV_DOWN: 959 fib_disable_ip(dev, 0); 960 break; 961 case NETDEV_CHANGEMTU: 962 case NETDEV_CHANGE: 963 rt_cache_flush(0); 964 break; 965 } 966 return NOTIFY_DONE; 967} 968 969static struct notifier_block fib_inetaddr_notifier = { 970 .notifier_call =fib_inetaddr_event, 971}; 972 973static struct notifier_block fib_netdev_notifier = { 974 .notifier_call =fib_netdev_event, 975}; 976 977static int __net_init ip_fib_net_init(struct net *net) 978{ 979 unsigned int i; 980 981 net->ipv4.fib_table_hash = kzalloc( 982 sizeof(struct hlist_head)*FIB_TABLE_HASHSZ, GFP_KERNEL); 983 if (net->ipv4.fib_table_hash == NULL) 984 return -ENOMEM; 985 986 for (i = 0; i < FIB_TABLE_HASHSZ; i++) 987 INIT_HLIST_HEAD(&net->ipv4.fib_table_hash[i]); 988 989 return fib4_rules_init(net); 990} 991 992static void __net_exit ip_fib_net_exit(struct net *net) 993{ 994 unsigned int i; 995 996#ifdef CONFIG_IP_MULTIPLE_TABLES 997 fib4_rules_exit(net); 998#endif 999 1000 for (i = 0; i < FIB_TABLE_HASHSZ; i++) { 1001 struct fib_table *tb; 1002 struct hlist_head *head; 1003 struct hlist_node *node, *tmp; 1004 1005 head = &net->ipv4.fib_table_hash[i]; 1006 hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) { 1007 hlist_del(node); 1008 tb->tb_flush(tb); 1009 kfree(tb); 1010 } 1011 } 1012 kfree(net->ipv4.fib_table_hash); 1013} 1014 1015static int __net_init fib_net_init(struct net *net) 1016{ 1017 int error; 1018 1019 error = 0; 1020 if (net != &init_net) 1021 goto out; 1022 1023 error = ip_fib_net_init(net); 1024 if (error < 0) 1025 goto out; 1026 error = nl_fib_lookup_init(net); 1027 if (error < 0) 1028 goto out_nlfl; 1029 error = fib_proc_init(net); 1030 if (error < 0) 1031 goto out_proc; 1032out: 1033 return error; 1034 1035out_proc: 1036 nl_fib_lookup_exit(net); 1037out_nlfl: 1038 ip_fib_net_exit(net); 1039 goto out; 1040} 1041 1042static void __net_exit fib_net_exit(struct net *net) 1043{ 1044 fib_proc_exit(net); 1045 nl_fib_lookup_exit(net); 1046 ip_fib_net_exit(net); 1047} 1048 1049static struct pernet_operations fib_net_ops = { 1050 .init = fib_net_init, 1051 .exit = fib_net_exit, 1052}; 1053 1054void __init ip_fib_init(void) 1055{ 1056 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL); 1057 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL); 1058 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib); 1059 1060 register_pernet_subsys(&fib_net_ops); 1061 register_netdevice_notifier(&fib_netdev_notifier); 1062 register_inetaddr_notifier(&fib_inetaddr_notifier); 1063} 1064 1065EXPORT_SYMBOL(inet_addr_type); 1066EXPORT_SYMBOL(inet_dev_addr_type); 1067EXPORT_SYMBOL(ip_dev_find); 1068