fib_frontend.c revision 9e56e3800ea42e78b7c816bdd2d87d047be80541
1/* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * IPv4 Forwarding Information Base: FIB frontend. 7 * 8 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16#include <linux/module.h> 17#include <asm/uaccess.h> 18#include <linux/bitops.h> 19#include <linux/capability.h> 20#include <linux/types.h> 21#include <linux/kernel.h> 22#include <linux/mm.h> 23#include <linux/string.h> 24#include <linux/socket.h> 25#include <linux/sockios.h> 26#include <linux/errno.h> 27#include <linux/in.h> 28#include <linux/inet.h> 29#include <linux/inetdevice.h> 30#include <linux/netdevice.h> 31#include <linux/if_addr.h> 32#include <linux/if_arp.h> 33#include <linux/skbuff.h> 34#include <linux/init.h> 35#include <linux/list.h> 36#include <linux/slab.h> 37 38#include <net/ip.h> 39#include <net/protocol.h> 40#include <net/route.h> 41#include <net/tcp.h> 42#include <net/sock.h> 43#include <net/arp.h> 44#include <net/ip_fib.h> 45#include <net/rtnetlink.h> 46#include <net/xfrm.h> 47 48#ifndef CONFIG_IP_MULTIPLE_TABLES 49 50static int __net_init fib4_rules_init(struct net *net) 51{ 52 struct fib_table *local_table, *main_table; 53 54 local_table = fib_trie_table(RT_TABLE_LOCAL); 55 if (local_table == NULL) 56 return -ENOMEM; 57 58 main_table = fib_trie_table(RT_TABLE_MAIN); 59 if (main_table == NULL) 60 goto fail; 61 62 hlist_add_head_rcu(&local_table->tb_hlist, 63 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]); 64 hlist_add_head_rcu(&main_table->tb_hlist, 65 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]); 66 return 0; 67 68fail: 69 kfree(local_table); 70 return -ENOMEM; 71} 72#else 73 74struct fib_table *fib_new_table(struct net *net, u32 id) 75{ 76 struct fib_table *tb; 77 unsigned int h; 78 79 if (id == 0) 80 id = RT_TABLE_MAIN; 81 tb = fib_get_table(net, id); 82 if (tb) 83 return tb; 84 85 tb = fib_trie_table(id); 86 if (!tb) 87 return NULL; 88 h = id & (FIB_TABLE_HASHSZ - 1); 89 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]); 90 return tb; 91} 92 93struct fib_table *fib_get_table(struct net *net, u32 id) 94{ 95 struct fib_table *tb; 96 struct hlist_node *node; 97 struct hlist_head *head; 98 unsigned int h; 99 100 if (id == 0) 101 id = RT_TABLE_MAIN; 102 h = id & (FIB_TABLE_HASHSZ - 1); 103 104 rcu_read_lock(); 105 head = &net->ipv4.fib_table_hash[h]; 106 hlist_for_each_entry_rcu(tb, node, head, tb_hlist) { 107 if (tb->tb_id == id) { 108 rcu_read_unlock(); 109 return tb; 110 } 111 } 112 rcu_read_unlock(); 113 return NULL; 114} 115#endif /* CONFIG_IP_MULTIPLE_TABLES */ 116 117static void fib_flush(struct net *net) 118{ 119 int flushed = 0; 120 struct fib_table *tb; 121 struct hlist_node *node; 122 struct hlist_head *head; 123 unsigned int h; 124 125 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 126 head = &net->ipv4.fib_table_hash[h]; 127 hlist_for_each_entry(tb, node, head, tb_hlist) 128 flushed += fib_table_flush(tb); 129 } 130 131 if (flushed) 132 rt_cache_flush(net, -1); 133} 134 135/* 136 * Find address type as if only "dev" was present in the system. If 137 * on_dev is NULL then all interfaces are taken into consideration. 138 */ 139static inline unsigned int __inet_dev_addr_type(struct net *net, 140 const struct net_device *dev, 141 __be32 addr) 142{ 143 struct flowi4 fl4 = { .daddr = addr }; 144 struct fib_result res; 145 unsigned int ret = RTN_BROADCAST; 146 struct fib_table *local_table; 147 148 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr)) 149 return RTN_BROADCAST; 150 if (ipv4_is_multicast(addr)) 151 return RTN_MULTICAST; 152 153#ifdef CONFIG_IP_MULTIPLE_TABLES 154 res.r = NULL; 155#endif 156 157 local_table = fib_get_table(net, RT_TABLE_LOCAL); 158 if (local_table) { 159 ret = RTN_UNICAST; 160 rcu_read_lock(); 161 if (!fib_table_lookup(local_table, &fl4, &res, FIB_LOOKUP_NOREF)) { 162 if (!dev || dev == res.fi->fib_dev) 163 ret = res.type; 164 } 165 rcu_read_unlock(); 166 } 167 return ret; 168} 169 170unsigned int inet_addr_type(struct net *net, __be32 addr) 171{ 172 return __inet_dev_addr_type(net, NULL, addr); 173} 174EXPORT_SYMBOL(inet_addr_type); 175 176unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, 177 __be32 addr) 178{ 179 return __inet_dev_addr_type(net, dev, addr); 180} 181EXPORT_SYMBOL(inet_dev_addr_type); 182 183__be32 fib_compute_spec_dst(struct sk_buff *skb) 184{ 185 struct net_device *dev = skb->dev; 186 struct in_device *in_dev; 187 struct fib_result res; 188 struct rtable *rt; 189 struct flowi4 fl4; 190 struct net *net; 191 int scope; 192 193 rt = skb_rtable(skb); 194 if (!(rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))) 195 return ip_hdr(skb)->daddr; 196 197 in_dev = __in_dev_get_rcu(dev); 198 BUG_ON(!in_dev); 199 200 net = dev_net(dev); 201 202 scope = RT_SCOPE_UNIVERSE; 203 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) { 204 fl4.flowi4_oif = 0; 205 fl4.flowi4_iif = net->loopback_dev->ifindex; 206 fl4.daddr = ip_hdr(skb)->saddr; 207 fl4.saddr = 0; 208 fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos); 209 fl4.flowi4_scope = scope; 210 fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0; 211 if (!fib_lookup(net, &fl4, &res)) 212 return FIB_RES_PREFSRC(net, res); 213 } else { 214 scope = RT_SCOPE_LINK; 215 } 216 217 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope); 218} 219 220/* Given (packet source, input interface) and optional (dst, oif, tos): 221 * - (main) check, that source is valid i.e. not broadcast or our local 222 * address. 223 * - figure out what "logical" interface this packet arrived 224 * and calculate "specific destination" address. 225 * - check, that packet arrived from expected physical interface. 226 * called with rcu_read_lock() 227 */ 228int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, u8 tos, 229 int oif, struct net_device *dev, struct in_device *idev, 230 u32 *itag) 231{ 232 int ret, no_addr, rpf, accept_local; 233 struct fib_result res; 234 struct flowi4 fl4; 235 struct net *net; 236 bool dev_match; 237 238 fl4.flowi4_oif = 0; 239 fl4.flowi4_iif = oif; 240 fl4.daddr = src; 241 fl4.saddr = dst; 242 fl4.flowi4_tos = tos; 243 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 244 245 no_addr = rpf = accept_local = 0; 246 no_addr = idev->ifa_list == NULL; 247 248 /* Ignore rp_filter for packets protected by IPsec. */ 249 rpf = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev); 250 251 accept_local = IN_DEV_ACCEPT_LOCAL(idev); 252 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0; 253 254 net = dev_net(dev); 255 if (fib_lookup(net, &fl4, &res)) 256 goto last_resort; 257 if (res.type != RTN_UNICAST) { 258 if (res.type != RTN_LOCAL || !accept_local) 259 goto e_inval; 260 } 261 fib_combine_itag(itag, &res); 262 dev_match = false; 263 264#ifdef CONFIG_IP_ROUTE_MULTIPATH 265 for (ret = 0; ret < res.fi->fib_nhs; ret++) { 266 struct fib_nh *nh = &res.fi->fib_nh[ret]; 267 268 if (nh->nh_dev == dev) { 269 dev_match = true; 270 break; 271 } 272 } 273#else 274 if (FIB_RES_DEV(res) == dev) 275 dev_match = true; 276#endif 277 if (dev_match) { 278 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 279 return ret; 280 } 281 if (no_addr) 282 goto last_resort; 283 if (rpf == 1) 284 goto e_rpf; 285 fl4.flowi4_oif = dev->ifindex; 286 287 ret = 0; 288 if (fib_lookup(net, &fl4, &res) == 0) { 289 if (res.type == RTN_UNICAST) 290 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 291 } 292 return ret; 293 294last_resort: 295 if (rpf) 296 goto e_rpf; 297 *itag = 0; 298 return 0; 299 300e_inval: 301 return -EINVAL; 302e_rpf: 303 return -EXDEV; 304} 305 306static inline __be32 sk_extract_addr(struct sockaddr *addr) 307{ 308 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 309} 310 311static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 312{ 313 struct nlattr *nla; 314 315 nla = (struct nlattr *) ((char *) mx + len); 316 nla->nla_type = type; 317 nla->nla_len = nla_attr_size(4); 318 *(u32 *) nla_data(nla) = value; 319 320 return len + nla_total_size(4); 321} 322 323static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 324 struct fib_config *cfg) 325{ 326 __be32 addr; 327 int plen; 328 329 memset(cfg, 0, sizeof(*cfg)); 330 cfg->fc_nlinfo.nl_net = net; 331 332 if (rt->rt_dst.sa_family != AF_INET) 333 return -EAFNOSUPPORT; 334 335 /* 336 * Check mask for validity: 337 * a) it must be contiguous. 338 * b) destination must have all host bits clear. 339 * c) if application forgot to set correct family (AF_INET), 340 * reject request unless it is absolutely clear i.e. 341 * both family and mask are zero. 342 */ 343 plen = 32; 344 addr = sk_extract_addr(&rt->rt_dst); 345 if (!(rt->rt_flags & RTF_HOST)) { 346 __be32 mask = sk_extract_addr(&rt->rt_genmask); 347 348 if (rt->rt_genmask.sa_family != AF_INET) { 349 if (mask || rt->rt_genmask.sa_family) 350 return -EAFNOSUPPORT; 351 } 352 353 if (bad_mask(mask, addr)) 354 return -EINVAL; 355 356 plen = inet_mask_len(mask); 357 } 358 359 cfg->fc_dst_len = plen; 360 cfg->fc_dst = addr; 361 362 if (cmd != SIOCDELRT) { 363 cfg->fc_nlflags = NLM_F_CREATE; 364 cfg->fc_protocol = RTPROT_BOOT; 365 } 366 367 if (rt->rt_metric) 368 cfg->fc_priority = rt->rt_metric - 1; 369 370 if (rt->rt_flags & RTF_REJECT) { 371 cfg->fc_scope = RT_SCOPE_HOST; 372 cfg->fc_type = RTN_UNREACHABLE; 373 return 0; 374 } 375 376 cfg->fc_scope = RT_SCOPE_NOWHERE; 377 cfg->fc_type = RTN_UNICAST; 378 379 if (rt->rt_dev) { 380 char *colon; 381 struct net_device *dev; 382 char devname[IFNAMSIZ]; 383 384 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 385 return -EFAULT; 386 387 devname[IFNAMSIZ-1] = 0; 388 colon = strchr(devname, ':'); 389 if (colon) 390 *colon = 0; 391 dev = __dev_get_by_name(net, devname); 392 if (!dev) 393 return -ENODEV; 394 cfg->fc_oif = dev->ifindex; 395 if (colon) { 396 struct in_ifaddr *ifa; 397 struct in_device *in_dev = __in_dev_get_rtnl(dev); 398 if (!in_dev) 399 return -ENODEV; 400 *colon = ':'; 401 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) 402 if (strcmp(ifa->ifa_label, devname) == 0) 403 break; 404 if (ifa == NULL) 405 return -ENODEV; 406 cfg->fc_prefsrc = ifa->ifa_local; 407 } 408 } 409 410 addr = sk_extract_addr(&rt->rt_gateway); 411 if (rt->rt_gateway.sa_family == AF_INET && addr) { 412 cfg->fc_gw = addr; 413 if (rt->rt_flags & RTF_GATEWAY && 414 inet_addr_type(net, addr) == RTN_UNICAST) 415 cfg->fc_scope = RT_SCOPE_UNIVERSE; 416 } 417 418 if (cmd == SIOCDELRT) 419 return 0; 420 421 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw) 422 return -EINVAL; 423 424 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 425 cfg->fc_scope = RT_SCOPE_LINK; 426 427 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 428 struct nlattr *mx; 429 int len = 0; 430 431 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL); 432 if (mx == NULL) 433 return -ENOMEM; 434 435 if (rt->rt_flags & RTF_MTU) 436 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 437 438 if (rt->rt_flags & RTF_WINDOW) 439 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 440 441 if (rt->rt_flags & RTF_IRTT) 442 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 443 444 cfg->fc_mx = mx; 445 cfg->fc_mx_len = len; 446 } 447 448 return 0; 449} 450 451/* 452 * Handle IP routing ioctl calls. 453 * These are used to manipulate the routing tables 454 */ 455int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg) 456{ 457 struct fib_config cfg; 458 struct rtentry rt; 459 int err; 460 461 switch (cmd) { 462 case SIOCADDRT: /* Add a route */ 463 case SIOCDELRT: /* Delete a route */ 464 if (!capable(CAP_NET_ADMIN)) 465 return -EPERM; 466 467 if (copy_from_user(&rt, arg, sizeof(rt))) 468 return -EFAULT; 469 470 rtnl_lock(); 471 err = rtentry_to_fib_config(net, cmd, &rt, &cfg); 472 if (err == 0) { 473 struct fib_table *tb; 474 475 if (cmd == SIOCDELRT) { 476 tb = fib_get_table(net, cfg.fc_table); 477 if (tb) 478 err = fib_table_delete(tb, &cfg); 479 else 480 err = -ESRCH; 481 } else { 482 tb = fib_new_table(net, cfg.fc_table); 483 if (tb) 484 err = fib_table_insert(tb, &cfg); 485 else 486 err = -ENOBUFS; 487 } 488 489 /* allocated by rtentry_to_fib_config() */ 490 kfree(cfg.fc_mx); 491 } 492 rtnl_unlock(); 493 return err; 494 } 495 return -EINVAL; 496} 497 498const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 499 [RTA_DST] = { .type = NLA_U32 }, 500 [RTA_SRC] = { .type = NLA_U32 }, 501 [RTA_IIF] = { .type = NLA_U32 }, 502 [RTA_OIF] = { .type = NLA_U32 }, 503 [RTA_GATEWAY] = { .type = NLA_U32 }, 504 [RTA_PRIORITY] = { .type = NLA_U32 }, 505 [RTA_PREFSRC] = { .type = NLA_U32 }, 506 [RTA_METRICS] = { .type = NLA_NESTED }, 507 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 508 [RTA_FLOW] = { .type = NLA_U32 }, 509}; 510 511static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 512 struct nlmsghdr *nlh, struct fib_config *cfg) 513{ 514 struct nlattr *attr; 515 int err, remaining; 516 struct rtmsg *rtm; 517 518 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy); 519 if (err < 0) 520 goto errout; 521 522 memset(cfg, 0, sizeof(*cfg)); 523 524 rtm = nlmsg_data(nlh); 525 cfg->fc_dst_len = rtm->rtm_dst_len; 526 cfg->fc_tos = rtm->rtm_tos; 527 cfg->fc_table = rtm->rtm_table; 528 cfg->fc_protocol = rtm->rtm_protocol; 529 cfg->fc_scope = rtm->rtm_scope; 530 cfg->fc_type = rtm->rtm_type; 531 cfg->fc_flags = rtm->rtm_flags; 532 cfg->fc_nlflags = nlh->nlmsg_flags; 533 534 cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid; 535 cfg->fc_nlinfo.nlh = nlh; 536 cfg->fc_nlinfo.nl_net = net; 537 538 if (cfg->fc_type > RTN_MAX) { 539 err = -EINVAL; 540 goto errout; 541 } 542 543 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 544 switch (nla_type(attr)) { 545 case RTA_DST: 546 cfg->fc_dst = nla_get_be32(attr); 547 break; 548 case RTA_OIF: 549 cfg->fc_oif = nla_get_u32(attr); 550 break; 551 case RTA_GATEWAY: 552 cfg->fc_gw = nla_get_be32(attr); 553 break; 554 case RTA_PRIORITY: 555 cfg->fc_priority = nla_get_u32(attr); 556 break; 557 case RTA_PREFSRC: 558 cfg->fc_prefsrc = nla_get_be32(attr); 559 break; 560 case RTA_METRICS: 561 cfg->fc_mx = nla_data(attr); 562 cfg->fc_mx_len = nla_len(attr); 563 break; 564 case RTA_MULTIPATH: 565 cfg->fc_mp = nla_data(attr); 566 cfg->fc_mp_len = nla_len(attr); 567 break; 568 case RTA_FLOW: 569 cfg->fc_flow = nla_get_u32(attr); 570 break; 571 case RTA_TABLE: 572 cfg->fc_table = nla_get_u32(attr); 573 break; 574 } 575 } 576 577 return 0; 578errout: 579 return err; 580} 581 582static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 583{ 584 struct net *net = sock_net(skb->sk); 585 struct fib_config cfg; 586 struct fib_table *tb; 587 int err; 588 589 err = rtm_to_fib_config(net, skb, nlh, &cfg); 590 if (err < 0) 591 goto errout; 592 593 tb = fib_get_table(net, cfg.fc_table); 594 if (tb == NULL) { 595 err = -ESRCH; 596 goto errout; 597 } 598 599 err = fib_table_delete(tb, &cfg); 600errout: 601 return err; 602} 603 604static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 605{ 606 struct net *net = sock_net(skb->sk); 607 struct fib_config cfg; 608 struct fib_table *tb; 609 int err; 610 611 err = rtm_to_fib_config(net, skb, nlh, &cfg); 612 if (err < 0) 613 goto errout; 614 615 tb = fib_new_table(net, cfg.fc_table); 616 if (tb == NULL) { 617 err = -ENOBUFS; 618 goto errout; 619 } 620 621 err = fib_table_insert(tb, &cfg); 622errout: 623 return err; 624} 625 626static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 627{ 628 struct net *net = sock_net(skb->sk); 629 unsigned int h, s_h; 630 unsigned int e = 0, s_e; 631 struct fib_table *tb; 632 struct hlist_node *node; 633 struct hlist_head *head; 634 int dumped = 0; 635 636 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) && 637 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED) 638 return ip_rt_dump(skb, cb); 639 640 s_h = cb->args[0]; 641 s_e = cb->args[1]; 642 643 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 644 e = 0; 645 head = &net->ipv4.fib_table_hash[h]; 646 hlist_for_each_entry(tb, node, head, tb_hlist) { 647 if (e < s_e) 648 goto next; 649 if (dumped) 650 memset(&cb->args[2], 0, sizeof(cb->args) - 651 2 * sizeof(cb->args[0])); 652 if (fib_table_dump(tb, skb, cb) < 0) 653 goto out; 654 dumped = 1; 655next: 656 e++; 657 } 658 } 659out: 660 cb->args[1] = e; 661 cb->args[0] = h; 662 663 return skb->len; 664} 665 666/* Prepare and feed intra-kernel routing request. 667 * Really, it should be netlink message, but :-( netlink 668 * can be not configured, so that we feed it directly 669 * to fib engine. It is legal, because all events occur 670 * only when netlink is already locked. 671 */ 672static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa) 673{ 674 struct net *net = dev_net(ifa->ifa_dev->dev); 675 struct fib_table *tb; 676 struct fib_config cfg = { 677 .fc_protocol = RTPROT_KERNEL, 678 .fc_type = type, 679 .fc_dst = dst, 680 .fc_dst_len = dst_len, 681 .fc_prefsrc = ifa->ifa_local, 682 .fc_oif = ifa->ifa_dev->dev->ifindex, 683 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 684 .fc_nlinfo = { 685 .nl_net = net, 686 }, 687 }; 688 689 if (type == RTN_UNICAST) 690 tb = fib_new_table(net, RT_TABLE_MAIN); 691 else 692 tb = fib_new_table(net, RT_TABLE_LOCAL); 693 694 if (tb == NULL) 695 return; 696 697 cfg.fc_table = tb->tb_id; 698 699 if (type != RTN_LOCAL) 700 cfg.fc_scope = RT_SCOPE_LINK; 701 else 702 cfg.fc_scope = RT_SCOPE_HOST; 703 704 if (cmd == RTM_NEWROUTE) 705 fib_table_insert(tb, &cfg); 706 else 707 fib_table_delete(tb, &cfg); 708} 709 710void fib_add_ifaddr(struct in_ifaddr *ifa) 711{ 712 struct in_device *in_dev = ifa->ifa_dev; 713 struct net_device *dev = in_dev->dev; 714 struct in_ifaddr *prim = ifa; 715 __be32 mask = ifa->ifa_mask; 716 __be32 addr = ifa->ifa_local; 717 __be32 prefix = ifa->ifa_address & mask; 718 719 if (ifa->ifa_flags & IFA_F_SECONDARY) { 720 prim = inet_ifa_byprefix(in_dev, prefix, mask); 721 if (prim == NULL) { 722 pr_warn("%s: bug: prim == NULL\n", __func__); 723 return; 724 } 725 } 726 727 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim); 728 729 if (!(dev->flags & IFF_UP)) 730 return; 731 732 /* Add broadcast address, if it is explicitly assigned. */ 733 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 734 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 735 736 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 737 (prefix != addr || ifa->ifa_prefixlen < 32)) { 738 fib_magic(RTM_NEWROUTE, 739 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 740 prefix, ifa->ifa_prefixlen, prim); 741 742 /* Add network specific broadcasts, when it takes a sense */ 743 if (ifa->ifa_prefixlen < 31) { 744 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim); 745 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 746 32, prim); 747 } 748 } 749} 750 751/* Delete primary or secondary address. 752 * Optionally, on secondary address promotion consider the addresses 753 * from subnet iprim as deleted, even if they are in device list. 754 * In this case the secondary ifa can be in device list. 755 */ 756void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 757{ 758 struct in_device *in_dev = ifa->ifa_dev; 759 struct net_device *dev = in_dev->dev; 760 struct in_ifaddr *ifa1; 761 struct in_ifaddr *prim = ifa, *prim1 = NULL; 762 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 763 __be32 any = ifa->ifa_address & ifa->ifa_mask; 764#define LOCAL_OK 1 765#define BRD_OK 2 766#define BRD0_OK 4 767#define BRD1_OK 8 768 unsigned int ok = 0; 769 int subnet = 0; /* Primary network */ 770 int gone = 1; /* Address is missing */ 771 int same_prefsrc = 0; /* Another primary with same IP */ 772 773 if (ifa->ifa_flags & IFA_F_SECONDARY) { 774 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 775 if (prim == NULL) { 776 pr_warn("%s: bug: prim == NULL\n", __func__); 777 return; 778 } 779 if (iprim && iprim != prim) { 780 pr_warn("%s: bug: iprim != prim\n", __func__); 781 return; 782 } 783 } else if (!ipv4_is_zeronet(any) && 784 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 785 fib_magic(RTM_DELROUTE, 786 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 787 any, ifa->ifa_prefixlen, prim); 788 subnet = 1; 789 } 790 791 /* Deletion is more complicated than add. 792 * We should take care of not to delete too much :-) 793 * 794 * Scan address list to be sure that addresses are really gone. 795 */ 796 797 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) { 798 if (ifa1 == ifa) { 799 /* promotion, keep the IP */ 800 gone = 0; 801 continue; 802 } 803 /* Ignore IFAs from our subnet */ 804 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 805 inet_ifa_match(ifa1->ifa_address, iprim)) 806 continue; 807 808 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 809 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 810 /* Another address from our subnet? */ 811 if (ifa1->ifa_mask == prim->ifa_mask && 812 inet_ifa_match(ifa1->ifa_address, prim)) 813 prim1 = prim; 814 else { 815 /* We reached the secondaries, so 816 * same_prefsrc should be determined. 817 */ 818 if (!same_prefsrc) 819 continue; 820 /* Search new prim1 if ifa1 is not 821 * using the current prim1 822 */ 823 if (!prim1 || 824 ifa1->ifa_mask != prim1->ifa_mask || 825 !inet_ifa_match(ifa1->ifa_address, prim1)) 826 prim1 = inet_ifa_byprefix(in_dev, 827 ifa1->ifa_address, 828 ifa1->ifa_mask); 829 if (!prim1) 830 continue; 831 if (prim1->ifa_local != prim->ifa_local) 832 continue; 833 } 834 } else { 835 if (prim->ifa_local != ifa1->ifa_local) 836 continue; 837 prim1 = ifa1; 838 if (prim != prim1) 839 same_prefsrc = 1; 840 } 841 if (ifa->ifa_local == ifa1->ifa_local) 842 ok |= LOCAL_OK; 843 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 844 ok |= BRD_OK; 845 if (brd == ifa1->ifa_broadcast) 846 ok |= BRD1_OK; 847 if (any == ifa1->ifa_broadcast) 848 ok |= BRD0_OK; 849 /* primary has network specific broadcasts */ 850 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 851 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 852 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 853 854 if (!ipv4_is_zeronet(any1)) { 855 if (ifa->ifa_broadcast == brd1 || 856 ifa->ifa_broadcast == any1) 857 ok |= BRD_OK; 858 if (brd == brd1 || brd == any1) 859 ok |= BRD1_OK; 860 if (any == brd1 || any == any1) 861 ok |= BRD0_OK; 862 } 863 } 864 } 865 866 if (!(ok & BRD_OK)) 867 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 868 if (subnet && ifa->ifa_prefixlen < 31) { 869 if (!(ok & BRD1_OK)) 870 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim); 871 if (!(ok & BRD0_OK)) 872 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim); 873 } 874 if (!(ok & LOCAL_OK)) { 875 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim); 876 877 /* Check, that this local address finally disappeared. */ 878 if (gone && 879 inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) { 880 /* And the last, but not the least thing. 881 * We must flush stray FIB entries. 882 * 883 * First of all, we scan fib_info list searching 884 * for stray nexthop entries, then ignite fib_flush. 885 */ 886 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local)) 887 fib_flush(dev_net(dev)); 888 } 889 } 890#undef LOCAL_OK 891#undef BRD_OK 892#undef BRD0_OK 893#undef BRD1_OK 894} 895 896static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb) 897{ 898 899 struct fib_result res; 900 struct flowi4 fl4 = { 901 .flowi4_mark = frn->fl_mark, 902 .daddr = frn->fl_addr, 903 .flowi4_tos = frn->fl_tos, 904 .flowi4_scope = frn->fl_scope, 905 }; 906 907#ifdef CONFIG_IP_MULTIPLE_TABLES 908 res.r = NULL; 909#endif 910 911 frn->err = -ENOENT; 912 if (tb) { 913 local_bh_disable(); 914 915 frn->tb_id = tb->tb_id; 916 rcu_read_lock(); 917 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 918 919 if (!frn->err) { 920 frn->prefixlen = res.prefixlen; 921 frn->nh_sel = res.nh_sel; 922 frn->type = res.type; 923 frn->scope = res.scope; 924 } 925 rcu_read_unlock(); 926 local_bh_enable(); 927 } 928} 929 930static void nl_fib_input(struct sk_buff *skb) 931{ 932 struct net *net; 933 struct fib_result_nl *frn; 934 struct nlmsghdr *nlh; 935 struct fib_table *tb; 936 u32 pid; 937 938 net = sock_net(skb->sk); 939 nlh = nlmsg_hdr(skb); 940 if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len || 941 nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn))) 942 return; 943 944 skb = skb_clone(skb, GFP_KERNEL); 945 if (skb == NULL) 946 return; 947 nlh = nlmsg_hdr(skb); 948 949 frn = (struct fib_result_nl *) NLMSG_DATA(nlh); 950 tb = fib_get_table(net, frn->tb_id_in); 951 952 nl_fib_lookup(frn, tb); 953 954 pid = NETLINK_CB(skb).pid; /* pid of sending process */ 955 NETLINK_CB(skb).pid = 0; /* from kernel */ 956 NETLINK_CB(skb).dst_group = 0; /* unicast */ 957 netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT); 958} 959 960static int __net_init nl_fib_lookup_init(struct net *net) 961{ 962 struct sock *sk; 963 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0, 964 nl_fib_input, NULL, THIS_MODULE); 965 if (sk == NULL) 966 return -EAFNOSUPPORT; 967 net->ipv4.fibnl = sk; 968 return 0; 969} 970 971static void nl_fib_lookup_exit(struct net *net) 972{ 973 netlink_kernel_release(net->ipv4.fibnl); 974 net->ipv4.fibnl = NULL; 975} 976 977static void fib_disable_ip(struct net_device *dev, int force, int delay) 978{ 979 if (fib_sync_down_dev(dev, force)) 980 fib_flush(dev_net(dev)); 981 rt_cache_flush(dev_net(dev), delay); 982 arp_ifdown(dev); 983} 984 985static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 986{ 987 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 988 struct net_device *dev = ifa->ifa_dev->dev; 989 struct net *net = dev_net(dev); 990 991 switch (event) { 992 case NETDEV_UP: 993 fib_add_ifaddr(ifa); 994#ifdef CONFIG_IP_ROUTE_MULTIPATH 995 fib_sync_up(dev); 996#endif 997 atomic_inc(&net->ipv4.dev_addr_genid); 998 rt_cache_flush(dev_net(dev), -1); 999 break; 1000 case NETDEV_DOWN: 1001 fib_del_ifaddr(ifa, NULL); 1002 atomic_inc(&net->ipv4.dev_addr_genid); 1003 if (ifa->ifa_dev->ifa_list == NULL) { 1004 /* Last address was deleted from this interface. 1005 * Disable IP. 1006 */ 1007 fib_disable_ip(dev, 1, 0); 1008 } else { 1009 rt_cache_flush(dev_net(dev), -1); 1010 } 1011 break; 1012 } 1013 return NOTIFY_DONE; 1014} 1015 1016static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1017{ 1018 struct net_device *dev = ptr; 1019 struct in_device *in_dev = __in_dev_get_rtnl(dev); 1020 struct net *net = dev_net(dev); 1021 1022 if (event == NETDEV_UNREGISTER) { 1023 fib_disable_ip(dev, 2, -1); 1024 return NOTIFY_DONE; 1025 } 1026 1027 if (!in_dev) 1028 return NOTIFY_DONE; 1029 1030 switch (event) { 1031 case NETDEV_UP: 1032 for_ifa(in_dev) { 1033 fib_add_ifaddr(ifa); 1034 } endfor_ifa(in_dev); 1035#ifdef CONFIG_IP_ROUTE_MULTIPATH 1036 fib_sync_up(dev); 1037#endif 1038 atomic_inc(&net->ipv4.dev_addr_genid); 1039 rt_cache_flush(dev_net(dev), -1); 1040 break; 1041 case NETDEV_DOWN: 1042 fib_disable_ip(dev, 0, 0); 1043 break; 1044 case NETDEV_CHANGEMTU: 1045 case NETDEV_CHANGE: 1046 rt_cache_flush(dev_net(dev), 0); 1047 break; 1048 case NETDEV_UNREGISTER_BATCH: 1049 /* The batch unregister is only called on the first 1050 * device in the list of devices being unregistered. 1051 * Therefore we should not pass dev_net(dev) in here. 1052 */ 1053 rt_cache_flush_batch(NULL); 1054 break; 1055 } 1056 return NOTIFY_DONE; 1057} 1058 1059static struct notifier_block fib_inetaddr_notifier = { 1060 .notifier_call = fib_inetaddr_event, 1061}; 1062 1063static struct notifier_block fib_netdev_notifier = { 1064 .notifier_call = fib_netdev_event, 1065}; 1066 1067static int __net_init ip_fib_net_init(struct net *net) 1068{ 1069 int err; 1070 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1071 1072 /* Avoid false sharing : Use at least a full cache line */ 1073 size = max_t(size_t, size, L1_CACHE_BYTES); 1074 1075 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1076 if (net->ipv4.fib_table_hash == NULL) 1077 return -ENOMEM; 1078 1079 err = fib4_rules_init(net); 1080 if (err < 0) 1081 goto fail; 1082 return 0; 1083 1084fail: 1085 kfree(net->ipv4.fib_table_hash); 1086 return err; 1087} 1088 1089static void ip_fib_net_exit(struct net *net) 1090{ 1091 unsigned int i; 1092 1093#ifdef CONFIG_IP_MULTIPLE_TABLES 1094 fib4_rules_exit(net); 1095#endif 1096 1097 rtnl_lock(); 1098 for (i = 0; i < FIB_TABLE_HASHSZ; i++) { 1099 struct fib_table *tb; 1100 struct hlist_head *head; 1101 struct hlist_node *node, *tmp; 1102 1103 head = &net->ipv4.fib_table_hash[i]; 1104 hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) { 1105 hlist_del(node); 1106 fib_table_flush(tb); 1107 fib_free_table(tb); 1108 } 1109 } 1110 rtnl_unlock(); 1111 kfree(net->ipv4.fib_table_hash); 1112} 1113 1114static int __net_init fib_net_init(struct net *net) 1115{ 1116 int error; 1117 1118 error = ip_fib_net_init(net); 1119 if (error < 0) 1120 goto out; 1121 error = nl_fib_lookup_init(net); 1122 if (error < 0) 1123 goto out_nlfl; 1124 error = fib_proc_init(net); 1125 if (error < 0) 1126 goto out_proc; 1127out: 1128 return error; 1129 1130out_proc: 1131 nl_fib_lookup_exit(net); 1132out_nlfl: 1133 ip_fib_net_exit(net); 1134 goto out; 1135} 1136 1137static void __net_exit fib_net_exit(struct net *net) 1138{ 1139 fib_proc_exit(net); 1140 nl_fib_lookup_exit(net); 1141 ip_fib_net_exit(net); 1142} 1143 1144static struct pernet_operations fib_net_ops = { 1145 .init = fib_net_init, 1146 .exit = fib_net_exit, 1147}; 1148 1149void __init ip_fib_init(void) 1150{ 1151 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL); 1152 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL); 1153 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL); 1154 1155 register_pernet_subsys(&fib_net_ops); 1156 register_netdevice_notifier(&fib_netdev_notifier); 1157 register_inetaddr_notifier(&fib_inetaddr_notifier); 1158 1159 fib_trie_init(); 1160} 1161