fib_frontend.c revision e2666f84958adb3a034b98e99699b55705117e01
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 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(__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 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.flowi4_mark = mark; 206 fl4.daddr = src; 207 fl4.saddr = dst; 208 fl4.flowi4_tos = tos; 209 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 210 211 no_addr = rpf = accept_local = 0; 212 in_dev = __in_dev_get_rcu(dev); 213 if (in_dev) { 214 no_addr = in_dev->ifa_list == NULL; 215 rpf = IN_DEV_RPFILTER(in_dev); 216 accept_local = IN_DEV_ACCEPT_LOCAL(in_dev); 217 if (mark && !IN_DEV_SRC_VMARK(in_dev)) 218 fl4.flowi4_mark = 0; 219 } 220 221 if (in_dev == NULL) 222 goto e_inval; 223 224 net = dev_net(dev); 225 if (fib_lookup(net, &fl4, &res)) 226 goto last_resort; 227 if (res.type != RTN_UNICAST) { 228 if (res.type != RTN_LOCAL || !accept_local) 229 goto e_inval; 230 } 231 *spec_dst = FIB_RES_PREFSRC(net, res); 232 fib_combine_itag(itag, &res); 233 dev_match = false; 234 235#ifdef CONFIG_IP_ROUTE_MULTIPATH 236 for (ret = 0; ret < res.fi->fib_nhs; ret++) { 237 struct fib_nh *nh = &res.fi->fib_nh[ret]; 238 239 if (nh->nh_dev == dev) { 240 dev_match = true; 241 break; 242 } 243 } 244#else 245 if (FIB_RES_DEV(res) == dev) 246 dev_match = true; 247#endif 248 if (dev_match) { 249 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 250 return ret; 251 } 252 if (no_addr) 253 goto last_resort; 254 if (rpf == 1) 255 goto e_rpf; 256 fl4.flowi4_oif = dev->ifindex; 257 258 ret = 0; 259 if (fib_lookup(net, &fl4, &res) == 0) { 260 if (res.type == RTN_UNICAST) { 261 *spec_dst = FIB_RES_PREFSRC(net, res); 262 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 263 } 264 } 265 return ret; 266 267last_resort: 268 if (rpf) 269 goto e_rpf; 270 *spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE); 271 *itag = 0; 272 return 0; 273 274e_inval: 275 return -EINVAL; 276e_rpf: 277 return -EXDEV; 278} 279 280static inline __be32 sk_extract_addr(struct sockaddr *addr) 281{ 282 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 283} 284 285static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 286{ 287 struct nlattr *nla; 288 289 nla = (struct nlattr *) ((char *) mx + len); 290 nla->nla_type = type; 291 nla->nla_len = nla_attr_size(4); 292 *(u32 *) nla_data(nla) = value; 293 294 return len + nla_total_size(4); 295} 296 297static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 298 struct fib_config *cfg) 299{ 300 __be32 addr; 301 int plen; 302 303 memset(cfg, 0, sizeof(*cfg)); 304 cfg->fc_nlinfo.nl_net = net; 305 306 if (rt->rt_dst.sa_family != AF_INET) 307 return -EAFNOSUPPORT; 308 309 /* 310 * Check mask for validity: 311 * a) it must be contiguous. 312 * b) destination must have all host bits clear. 313 * c) if application forgot to set correct family (AF_INET), 314 * reject request unless it is absolutely clear i.e. 315 * both family and mask are zero. 316 */ 317 plen = 32; 318 addr = sk_extract_addr(&rt->rt_dst); 319 if (!(rt->rt_flags & RTF_HOST)) { 320 __be32 mask = sk_extract_addr(&rt->rt_genmask); 321 322 if (rt->rt_genmask.sa_family != AF_INET) { 323 if (mask || rt->rt_genmask.sa_family) 324 return -EAFNOSUPPORT; 325 } 326 327 if (bad_mask(mask, addr)) 328 return -EINVAL; 329 330 plen = inet_mask_len(mask); 331 } 332 333 cfg->fc_dst_len = plen; 334 cfg->fc_dst = addr; 335 336 if (cmd != SIOCDELRT) { 337 cfg->fc_nlflags = NLM_F_CREATE; 338 cfg->fc_protocol = RTPROT_BOOT; 339 } 340 341 if (rt->rt_metric) 342 cfg->fc_priority = rt->rt_metric - 1; 343 344 if (rt->rt_flags & RTF_REJECT) { 345 cfg->fc_scope = RT_SCOPE_HOST; 346 cfg->fc_type = RTN_UNREACHABLE; 347 return 0; 348 } 349 350 cfg->fc_scope = RT_SCOPE_NOWHERE; 351 cfg->fc_type = RTN_UNICAST; 352 353 if (rt->rt_dev) { 354 char *colon; 355 struct net_device *dev; 356 char devname[IFNAMSIZ]; 357 358 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 359 return -EFAULT; 360 361 devname[IFNAMSIZ-1] = 0; 362 colon = strchr(devname, ':'); 363 if (colon) 364 *colon = 0; 365 dev = __dev_get_by_name(net, devname); 366 if (!dev) 367 return -ENODEV; 368 cfg->fc_oif = dev->ifindex; 369 if (colon) { 370 struct in_ifaddr *ifa; 371 struct in_device *in_dev = __in_dev_get_rtnl(dev); 372 if (!in_dev) 373 return -ENODEV; 374 *colon = ':'; 375 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) 376 if (strcmp(ifa->ifa_label, devname) == 0) 377 break; 378 if (ifa == NULL) 379 return -ENODEV; 380 cfg->fc_prefsrc = ifa->ifa_local; 381 } 382 } 383 384 addr = sk_extract_addr(&rt->rt_gateway); 385 if (rt->rt_gateway.sa_family == AF_INET && addr) { 386 cfg->fc_gw = addr; 387 if (rt->rt_flags & RTF_GATEWAY && 388 inet_addr_type(net, addr) == RTN_UNICAST) 389 cfg->fc_scope = RT_SCOPE_UNIVERSE; 390 } 391 392 if (cmd == SIOCDELRT) 393 return 0; 394 395 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw) 396 return -EINVAL; 397 398 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 399 cfg->fc_scope = RT_SCOPE_LINK; 400 401 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 402 struct nlattr *mx; 403 int len = 0; 404 405 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL); 406 if (mx == NULL) 407 return -ENOMEM; 408 409 if (rt->rt_flags & RTF_MTU) 410 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 411 412 if (rt->rt_flags & RTF_WINDOW) 413 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 414 415 if (rt->rt_flags & RTF_IRTT) 416 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 417 418 cfg->fc_mx = mx; 419 cfg->fc_mx_len = len; 420 } 421 422 return 0; 423} 424 425/* 426 * Handle IP routing ioctl calls. 427 * These are used to manipulate the routing tables 428 */ 429int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg) 430{ 431 struct fib_config cfg; 432 struct rtentry rt; 433 int err; 434 435 switch (cmd) { 436 case SIOCADDRT: /* Add a route */ 437 case SIOCDELRT: /* Delete a route */ 438 if (!capable(CAP_NET_ADMIN)) 439 return -EPERM; 440 441 if (copy_from_user(&rt, arg, sizeof(rt))) 442 return -EFAULT; 443 444 rtnl_lock(); 445 err = rtentry_to_fib_config(net, cmd, &rt, &cfg); 446 if (err == 0) { 447 struct fib_table *tb; 448 449 if (cmd == SIOCDELRT) { 450 tb = fib_get_table(net, cfg.fc_table); 451 if (tb) 452 err = fib_table_delete(tb, &cfg); 453 else 454 err = -ESRCH; 455 } else { 456 tb = fib_new_table(net, cfg.fc_table); 457 if (tb) 458 err = fib_table_insert(tb, &cfg); 459 else 460 err = -ENOBUFS; 461 } 462 463 /* allocated by rtentry_to_fib_config() */ 464 kfree(cfg.fc_mx); 465 } 466 rtnl_unlock(); 467 return err; 468 } 469 return -EINVAL; 470} 471 472const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 473 [RTA_DST] = { .type = NLA_U32 }, 474 [RTA_SRC] = { .type = NLA_U32 }, 475 [RTA_IIF] = { .type = NLA_U32 }, 476 [RTA_OIF] = { .type = NLA_U32 }, 477 [RTA_GATEWAY] = { .type = NLA_U32 }, 478 [RTA_PRIORITY] = { .type = NLA_U32 }, 479 [RTA_PREFSRC] = { .type = NLA_U32 }, 480 [RTA_METRICS] = { .type = NLA_NESTED }, 481 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 482 [RTA_FLOW] = { .type = NLA_U32 }, 483}; 484 485static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 486 struct nlmsghdr *nlh, struct fib_config *cfg) 487{ 488 struct nlattr *attr; 489 int err, remaining; 490 struct rtmsg *rtm; 491 492 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy); 493 if (err < 0) 494 goto errout; 495 496 memset(cfg, 0, sizeof(*cfg)); 497 498 rtm = nlmsg_data(nlh); 499 cfg->fc_dst_len = rtm->rtm_dst_len; 500 cfg->fc_tos = rtm->rtm_tos; 501 cfg->fc_table = rtm->rtm_table; 502 cfg->fc_protocol = rtm->rtm_protocol; 503 cfg->fc_scope = rtm->rtm_scope; 504 cfg->fc_type = rtm->rtm_type; 505 cfg->fc_flags = rtm->rtm_flags; 506 cfg->fc_nlflags = nlh->nlmsg_flags; 507 508 cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid; 509 cfg->fc_nlinfo.nlh = nlh; 510 cfg->fc_nlinfo.nl_net = net; 511 512 if (cfg->fc_type > RTN_MAX) { 513 err = -EINVAL; 514 goto errout; 515 } 516 517 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 518 switch (nla_type(attr)) { 519 case RTA_DST: 520 cfg->fc_dst = nla_get_be32(attr); 521 break; 522 case RTA_OIF: 523 cfg->fc_oif = nla_get_u32(attr); 524 break; 525 case RTA_GATEWAY: 526 cfg->fc_gw = nla_get_be32(attr); 527 break; 528 case RTA_PRIORITY: 529 cfg->fc_priority = nla_get_u32(attr); 530 break; 531 case RTA_PREFSRC: 532 cfg->fc_prefsrc = nla_get_be32(attr); 533 break; 534 case RTA_METRICS: 535 cfg->fc_mx = nla_data(attr); 536 cfg->fc_mx_len = nla_len(attr); 537 break; 538 case RTA_MULTIPATH: 539 cfg->fc_mp = nla_data(attr); 540 cfg->fc_mp_len = nla_len(attr); 541 break; 542 case RTA_FLOW: 543 cfg->fc_flow = nla_get_u32(attr); 544 break; 545 case RTA_TABLE: 546 cfg->fc_table = nla_get_u32(attr); 547 break; 548 } 549 } 550 551 return 0; 552errout: 553 return err; 554} 555 556static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 557{ 558 struct net *net = sock_net(skb->sk); 559 struct fib_config cfg; 560 struct fib_table *tb; 561 int err; 562 563 err = rtm_to_fib_config(net, skb, nlh, &cfg); 564 if (err < 0) 565 goto errout; 566 567 tb = fib_get_table(net, cfg.fc_table); 568 if (tb == NULL) { 569 err = -ESRCH; 570 goto errout; 571 } 572 573 err = fib_table_delete(tb, &cfg); 574errout: 575 return err; 576} 577 578static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 579{ 580 struct net *net = sock_net(skb->sk); 581 struct fib_config cfg; 582 struct fib_table *tb; 583 int err; 584 585 err = rtm_to_fib_config(net, skb, nlh, &cfg); 586 if (err < 0) 587 goto errout; 588 589 tb = fib_new_table(net, cfg.fc_table); 590 if (tb == NULL) { 591 err = -ENOBUFS; 592 goto errout; 593 } 594 595 err = fib_table_insert(tb, &cfg); 596errout: 597 return err; 598} 599 600static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 601{ 602 struct net *net = sock_net(skb->sk); 603 unsigned int h, s_h; 604 unsigned int e = 0, s_e; 605 struct fib_table *tb; 606 struct hlist_node *node; 607 struct hlist_head *head; 608 int dumped = 0; 609 610 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) && 611 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED) 612 return ip_rt_dump(skb, cb); 613 614 s_h = cb->args[0]; 615 s_e = cb->args[1]; 616 617 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 618 e = 0; 619 head = &net->ipv4.fib_table_hash[h]; 620 hlist_for_each_entry(tb, node, head, tb_hlist) { 621 if (e < s_e) 622 goto next; 623 if (dumped) 624 memset(&cb->args[2], 0, sizeof(cb->args) - 625 2 * sizeof(cb->args[0])); 626 if (fib_table_dump(tb, skb, cb) < 0) 627 goto out; 628 dumped = 1; 629next: 630 e++; 631 } 632 } 633out: 634 cb->args[1] = e; 635 cb->args[0] = h; 636 637 return skb->len; 638} 639 640/* Prepare and feed intra-kernel routing request. 641 * Really, it should be netlink message, but :-( netlink 642 * can be not configured, so that we feed it directly 643 * to fib engine. It is legal, because all events occur 644 * only when netlink is already locked. 645 */ 646static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa) 647{ 648 struct net *net = dev_net(ifa->ifa_dev->dev); 649 struct fib_table *tb; 650 struct fib_config cfg = { 651 .fc_protocol = RTPROT_KERNEL, 652 .fc_type = type, 653 .fc_dst = dst, 654 .fc_dst_len = dst_len, 655 .fc_prefsrc = ifa->ifa_local, 656 .fc_oif = ifa->ifa_dev->dev->ifindex, 657 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 658 .fc_nlinfo = { 659 .nl_net = net, 660 }, 661 }; 662 663 if (type == RTN_UNICAST) 664 tb = fib_new_table(net, RT_TABLE_MAIN); 665 else 666 tb = fib_new_table(net, RT_TABLE_LOCAL); 667 668 if (tb == NULL) 669 return; 670 671 cfg.fc_table = tb->tb_id; 672 673 if (type != RTN_LOCAL) 674 cfg.fc_scope = RT_SCOPE_LINK; 675 else 676 cfg.fc_scope = RT_SCOPE_HOST; 677 678 if (cmd == RTM_NEWROUTE) 679 fib_table_insert(tb, &cfg); 680 else 681 fib_table_delete(tb, &cfg); 682} 683 684void fib_add_ifaddr(struct in_ifaddr *ifa) 685{ 686 struct in_device *in_dev = ifa->ifa_dev; 687 struct net_device *dev = in_dev->dev; 688 struct in_ifaddr *prim = ifa; 689 __be32 mask = ifa->ifa_mask; 690 __be32 addr = ifa->ifa_local; 691 __be32 prefix = ifa->ifa_address & mask; 692 693 if (ifa->ifa_flags & IFA_F_SECONDARY) { 694 prim = inet_ifa_byprefix(in_dev, prefix, mask); 695 if (prim == NULL) { 696 printk(KERN_WARNING "fib_add_ifaddr: bug: prim == NULL\n"); 697 return; 698 } 699 } 700 701 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim); 702 703 if (!(dev->flags & IFF_UP)) 704 return; 705 706 /* Add broadcast address, if it is explicitly assigned. */ 707 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 708 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 709 710 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 711 (prefix != addr || ifa->ifa_prefixlen < 32)) { 712 fib_magic(RTM_NEWROUTE, 713 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 714 prefix, ifa->ifa_prefixlen, prim); 715 716 /* Add network specific broadcasts, when it takes a sense */ 717 if (ifa->ifa_prefixlen < 31) { 718 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim); 719 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 720 32, prim); 721 } 722 } 723} 724 725/* Delete primary or secondary address. 726 * Optionally, on secondary address promotion consider the addresses 727 * from subnet iprim as deleted, even if they are in device list. 728 * In this case the secondary ifa can be in device list. 729 */ 730void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 731{ 732 struct in_device *in_dev = ifa->ifa_dev; 733 struct net_device *dev = in_dev->dev; 734 struct in_ifaddr *ifa1; 735 struct in_ifaddr *prim = ifa, *prim1 = NULL; 736 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 737 __be32 any = ifa->ifa_address & ifa->ifa_mask; 738#define LOCAL_OK 1 739#define BRD_OK 2 740#define BRD0_OK 4 741#define BRD1_OK 8 742 unsigned ok = 0; 743 int subnet = 0; /* Primary network */ 744 int gone = 1; /* Address is missing */ 745 int same_prefsrc = 0; /* Another primary with same IP */ 746 747 if (ifa->ifa_flags & IFA_F_SECONDARY) { 748 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 749 if (prim == NULL) { 750 printk(KERN_WARNING "fib_del_ifaddr: bug: prim == NULL\n"); 751 return; 752 } 753 if (iprim && iprim != prim) { 754 printk(KERN_WARNING "fib_del_ifaddr: bug: iprim != prim\n"); 755 return; 756 } 757 } else if (!ipv4_is_zeronet(any) && 758 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 759 fib_magic(RTM_DELROUTE, 760 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 761 any, ifa->ifa_prefixlen, prim); 762 subnet = 1; 763 } 764 765 /* Deletion is more complicated than add. 766 * We should take care of not to delete too much :-) 767 * 768 * Scan address list to be sure that addresses are really gone. 769 */ 770 771 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) { 772 if (ifa1 == ifa) { 773 /* promotion, keep the IP */ 774 gone = 0; 775 continue; 776 } 777 /* Ignore IFAs from our subnet */ 778 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 779 inet_ifa_match(ifa1->ifa_address, iprim)) 780 continue; 781 782 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 783 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 784 /* Another address from our subnet? */ 785 if (ifa1->ifa_mask == prim->ifa_mask && 786 inet_ifa_match(ifa1->ifa_address, prim)) 787 prim1 = prim; 788 else { 789 /* We reached the secondaries, so 790 * same_prefsrc should be determined. 791 */ 792 if (!same_prefsrc) 793 continue; 794 /* Search new prim1 if ifa1 is not 795 * using the current prim1 796 */ 797 if (!prim1 || 798 ifa1->ifa_mask != prim1->ifa_mask || 799 !inet_ifa_match(ifa1->ifa_address, prim1)) 800 prim1 = inet_ifa_byprefix(in_dev, 801 ifa1->ifa_address, 802 ifa1->ifa_mask); 803 if (!prim1) 804 continue; 805 if (prim1->ifa_local != prim->ifa_local) 806 continue; 807 } 808 } else { 809 if (prim->ifa_local != ifa1->ifa_local) 810 continue; 811 prim1 = ifa1; 812 if (prim != prim1) 813 same_prefsrc = 1; 814 } 815 if (ifa->ifa_local == ifa1->ifa_local) 816 ok |= LOCAL_OK; 817 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 818 ok |= BRD_OK; 819 if (brd == ifa1->ifa_broadcast) 820 ok |= BRD1_OK; 821 if (any == ifa1->ifa_broadcast) 822 ok |= BRD0_OK; 823 /* primary has network specific broadcasts */ 824 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 825 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 826 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 827 828 if (!ipv4_is_zeronet(any1)) { 829 if (ifa->ifa_broadcast == brd1 || 830 ifa->ifa_broadcast == any1) 831 ok |= BRD_OK; 832 if (brd == brd1 || brd == any1) 833 ok |= BRD1_OK; 834 if (any == brd1 || any == any1) 835 ok |= BRD0_OK; 836 } 837 } 838 } 839 840 if (!(ok & BRD_OK)) 841 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 842 if (subnet && ifa->ifa_prefixlen < 31) { 843 if (!(ok & BRD1_OK)) 844 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim); 845 if (!(ok & BRD0_OK)) 846 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim); 847 } 848 if (!(ok & LOCAL_OK)) { 849 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim); 850 851 /* Check, that this local address finally disappeared. */ 852 if (gone && 853 inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) { 854 /* And the last, but not the least thing. 855 * We must flush stray FIB entries. 856 * 857 * First of all, we scan fib_info list searching 858 * for stray nexthop entries, then ignite fib_flush. 859 */ 860 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local)) 861 fib_flush(dev_net(dev)); 862 } 863 } 864#undef LOCAL_OK 865#undef BRD_OK 866#undef BRD0_OK 867#undef BRD1_OK 868} 869 870static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb) 871{ 872 873 struct fib_result res; 874 struct flowi4 fl4 = { 875 .flowi4_mark = frn->fl_mark, 876 .daddr = frn->fl_addr, 877 .flowi4_tos = frn->fl_tos, 878 .flowi4_scope = frn->fl_scope, 879 }; 880 881#ifdef CONFIG_IP_MULTIPLE_TABLES 882 res.r = NULL; 883#endif 884 885 frn->err = -ENOENT; 886 if (tb) { 887 local_bh_disable(); 888 889 frn->tb_id = tb->tb_id; 890 rcu_read_lock(); 891 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 892 893 if (!frn->err) { 894 frn->prefixlen = res.prefixlen; 895 frn->nh_sel = res.nh_sel; 896 frn->type = res.type; 897 frn->scope = res.scope; 898 } 899 rcu_read_unlock(); 900 local_bh_enable(); 901 } 902} 903 904static void nl_fib_input(struct sk_buff *skb) 905{ 906 struct net *net; 907 struct fib_result_nl *frn; 908 struct nlmsghdr *nlh; 909 struct fib_table *tb; 910 u32 pid; 911 912 net = sock_net(skb->sk); 913 nlh = nlmsg_hdr(skb); 914 if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len || 915 nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn))) 916 return; 917 918 skb = skb_clone(skb, GFP_KERNEL); 919 if (skb == NULL) 920 return; 921 nlh = nlmsg_hdr(skb); 922 923 frn = (struct fib_result_nl *) NLMSG_DATA(nlh); 924 tb = fib_get_table(net, frn->tb_id_in); 925 926 nl_fib_lookup(frn, tb); 927 928 pid = NETLINK_CB(skb).pid; /* pid of sending process */ 929 NETLINK_CB(skb).pid = 0; /* from kernel */ 930 NETLINK_CB(skb).dst_group = 0; /* unicast */ 931 netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT); 932} 933 934static int __net_init nl_fib_lookup_init(struct net *net) 935{ 936 struct sock *sk; 937 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0, 938 nl_fib_input, NULL, THIS_MODULE); 939 if (sk == NULL) 940 return -EAFNOSUPPORT; 941 net->ipv4.fibnl = sk; 942 return 0; 943} 944 945static void nl_fib_lookup_exit(struct net *net) 946{ 947 netlink_kernel_release(net->ipv4.fibnl); 948 net->ipv4.fibnl = NULL; 949} 950 951static void fib_disable_ip(struct net_device *dev, int force, int delay) 952{ 953 if (fib_sync_down_dev(dev, force)) 954 fib_flush(dev_net(dev)); 955 rt_cache_flush(dev_net(dev), delay); 956 arp_ifdown(dev); 957} 958 959static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 960{ 961 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 962 struct net_device *dev = ifa->ifa_dev->dev; 963 struct net *net = dev_net(dev); 964 965 switch (event) { 966 case NETDEV_UP: 967 fib_add_ifaddr(ifa); 968#ifdef CONFIG_IP_ROUTE_MULTIPATH 969 fib_sync_up(dev); 970#endif 971 atomic_inc(&net->ipv4.dev_addr_genid); 972 rt_cache_flush(dev_net(dev), -1); 973 break; 974 case NETDEV_DOWN: 975 fib_del_ifaddr(ifa, NULL); 976 atomic_inc(&net->ipv4.dev_addr_genid); 977 if (ifa->ifa_dev->ifa_list == NULL) { 978 /* Last address was deleted from this interface. 979 * Disable IP. 980 */ 981 fib_disable_ip(dev, 1, 0); 982 } else { 983 rt_cache_flush(dev_net(dev), -1); 984 } 985 break; 986 } 987 return NOTIFY_DONE; 988} 989 990static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 991{ 992 struct net_device *dev = ptr; 993 struct in_device *in_dev = __in_dev_get_rtnl(dev); 994 struct net *net = dev_net(dev); 995 996 if (event == NETDEV_UNREGISTER) { 997 fib_disable_ip(dev, 2, -1); 998 return NOTIFY_DONE; 999 } 1000 1001 if (!in_dev) 1002 return NOTIFY_DONE; 1003 1004 switch (event) { 1005 case NETDEV_UP: 1006 for_ifa(in_dev) { 1007 fib_add_ifaddr(ifa); 1008 } endfor_ifa(in_dev); 1009#ifdef CONFIG_IP_ROUTE_MULTIPATH 1010 fib_sync_up(dev); 1011#endif 1012 atomic_inc(&net->ipv4.dev_addr_genid); 1013 rt_cache_flush(dev_net(dev), -1); 1014 break; 1015 case NETDEV_DOWN: 1016 fib_disable_ip(dev, 0, 0); 1017 break; 1018 case NETDEV_CHANGEMTU: 1019 case NETDEV_CHANGE: 1020 rt_cache_flush(dev_net(dev), 0); 1021 break; 1022 case NETDEV_UNREGISTER_BATCH: 1023 /* The batch unregister is only called on the first 1024 * device in the list of devices being unregistered. 1025 * Therefore we should not pass dev_net(dev) in here. 1026 */ 1027 rt_cache_flush_batch(NULL); 1028 break; 1029 } 1030 return NOTIFY_DONE; 1031} 1032 1033static struct notifier_block fib_inetaddr_notifier = { 1034 .notifier_call = fib_inetaddr_event, 1035}; 1036 1037static struct notifier_block fib_netdev_notifier = { 1038 .notifier_call = fib_netdev_event, 1039}; 1040 1041static int __net_init ip_fib_net_init(struct net *net) 1042{ 1043 int err; 1044 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1045 1046 /* Avoid false sharing : Use at least a full cache line */ 1047 size = max_t(size_t, size, L1_CACHE_BYTES); 1048 1049 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1050 if (net->ipv4.fib_table_hash == NULL) 1051 return -ENOMEM; 1052 1053 err = fib4_rules_init(net); 1054 if (err < 0) 1055 goto fail; 1056 return 0; 1057 1058fail: 1059 kfree(net->ipv4.fib_table_hash); 1060 return err; 1061} 1062 1063static void ip_fib_net_exit(struct net *net) 1064{ 1065 unsigned int i; 1066 1067#ifdef CONFIG_IP_MULTIPLE_TABLES 1068 fib4_rules_exit(net); 1069#endif 1070 1071 rtnl_lock(); 1072 for (i = 0; i < FIB_TABLE_HASHSZ; i++) { 1073 struct fib_table *tb; 1074 struct hlist_head *head; 1075 struct hlist_node *node, *tmp; 1076 1077 head = &net->ipv4.fib_table_hash[i]; 1078 hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) { 1079 hlist_del(node); 1080 fib_table_flush(tb); 1081 fib_free_table(tb); 1082 } 1083 } 1084 rtnl_unlock(); 1085 kfree(net->ipv4.fib_table_hash); 1086} 1087 1088static int __net_init fib_net_init(struct net *net) 1089{ 1090 int error; 1091 1092 error = ip_fib_net_init(net); 1093 if (error < 0) 1094 goto out; 1095 error = nl_fib_lookup_init(net); 1096 if (error < 0) 1097 goto out_nlfl; 1098 error = fib_proc_init(net); 1099 if (error < 0) 1100 goto out_proc; 1101out: 1102 return error; 1103 1104out_proc: 1105 nl_fib_lookup_exit(net); 1106out_nlfl: 1107 ip_fib_net_exit(net); 1108 goto out; 1109} 1110 1111static void __net_exit fib_net_exit(struct net *net) 1112{ 1113 fib_proc_exit(net); 1114 nl_fib_lookup_exit(net); 1115 ip_fib_net_exit(net); 1116} 1117 1118static struct pernet_operations fib_net_ops = { 1119 .init = fib_net_init, 1120 .exit = fib_net_exit, 1121}; 1122 1123void __init ip_fib_init(void) 1124{ 1125 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL); 1126 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL); 1127 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib); 1128 1129 register_pernet_subsys(&fib_net_ops); 1130 register_netdevice_notifier(&fib_netdev_notifier); 1131 register_inetaddr_notifier(&fib_inetaddr_notifier); 1132 1133 fib_trie_init(); 1134} 1135