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