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/cache.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 int __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 int 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 __be32 fib_compute_spec_dst(struct sk_buff *skb) 185 { 186 struct net_device *dev = skb->dev; 187 struct in_device *in_dev; 188 struct fib_result res; 189 struct rtable *rt; 190 struct flowi4 fl4; 191 struct net *net; 192 int scope; 193 194 rt = skb_rtable(skb); 195 if (!(rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))) 196 return ip_hdr(skb)->daddr; 197 198 in_dev = __in_dev_get_rcu(dev); 199 BUG_ON(!in_dev); 200 201 net = dev_net(dev); 202 203 scope = RT_SCOPE_UNIVERSE; 204 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) { 205 fl4.flowi4_oif = 0; 206 fl4.flowi4_iif = net->loopback_dev->ifindex; 207 fl4.daddr = ip_hdr(skb)->saddr; 208 fl4.saddr = 0; 209 fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos); 210 fl4.flowi4_scope = scope; 211 fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0; 212 if (!fib_lookup(net, &fl4, &res)) 213 return FIB_RES_PREFSRC(net, res); 214 } else { 215 scope = RT_SCOPE_LINK; 216 } 217 218 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope); 219 } 220 221 #ifdef CONFIG_IP_ROUTE_CLASSID 222 int fib_num_tclassid_users __read_mostly; 223 #endif 224 225 /* Given (packet source, input interface) and optional (dst, oif, tos): 226 * - (main) check, that source is valid i.e. not broadcast or our local 227 * address. 228 * - figure out what "logical" interface this packet arrived 229 * and calculate "specific destination" address. 230 * - check, that packet arrived from expected physical interface. 231 * called with rcu_read_lock() 232 */ 233 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 234 u8 tos, int oif, struct net_device *dev, 235 int rpf, struct in_device *idev, u32 *itag) 236 { 237 int ret, no_addr, accept_local; 238 struct fib_result res; 239 struct flowi4 fl4; 240 struct net *net; 241 bool dev_match; 242 243 fl4.flowi4_oif = 0; 244 fl4.flowi4_iif = oif; 245 fl4.daddr = src; 246 fl4.saddr = dst; 247 fl4.flowi4_tos = tos; 248 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 249 250 no_addr = accept_local = 0; 251 no_addr = idev->ifa_list == NULL; 252 253 accept_local = IN_DEV_ACCEPT_LOCAL(idev); 254 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0; 255 256 net = dev_net(dev); 257 if (fib_lookup(net, &fl4, &res)) 258 goto last_resort; 259 if (res.type != RTN_UNICAST) { 260 if (res.type != RTN_LOCAL || !accept_local) 261 goto e_inval; 262 } 263 fib_combine_itag(itag, &res); 264 dev_match = false; 265 266 #ifdef CONFIG_IP_ROUTE_MULTIPATH 267 for (ret = 0; ret < res.fi->fib_nhs; ret++) { 268 struct fib_nh *nh = &res.fi->fib_nh[ret]; 269 270 if (nh->nh_dev == dev) { 271 dev_match = true; 272 break; 273 } 274 } 275 #else 276 if (FIB_RES_DEV(res) == dev) 277 dev_match = true; 278 #endif 279 if (dev_match) { 280 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 281 return ret; 282 } 283 if (no_addr) 284 goto last_resort; 285 if (rpf == 1) 286 goto e_rpf; 287 fl4.flowi4_oif = dev->ifindex; 288 289 ret = 0; 290 if (fib_lookup(net, &fl4, &res) == 0) { 291 if (res.type == RTN_UNICAST) 292 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 293 } 294 return ret; 295 296 last_resort: 297 if (rpf) 298 goto e_rpf; 299 *itag = 0; 300 return 0; 301 302 e_inval: 303 return -EINVAL; 304 e_rpf: 305 return -EXDEV; 306 } 307 308 /* Ignore rp_filter for packets protected by IPsec. */ 309 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 310 u8 tos, int oif, struct net_device *dev, 311 struct in_device *idev, u32 *itag) 312 { 313 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev); 314 315 if (!r && !fib_num_tclassid_users) { 316 *itag = 0; 317 return 0; 318 } 319 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag); 320 } 321 322 static inline __be32 sk_extract_addr(struct sockaddr *addr) 323 { 324 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 325 } 326 327 static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 328 { 329 struct nlattr *nla; 330 331 nla = (struct nlattr *) ((char *) mx + len); 332 nla->nla_type = type; 333 nla->nla_len = nla_attr_size(4); 334 *(u32 *) nla_data(nla) = value; 335 336 return len + nla_total_size(4); 337 } 338 339 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 340 struct fib_config *cfg) 341 { 342 __be32 addr; 343 int plen; 344 345 memset(cfg, 0, sizeof(*cfg)); 346 cfg->fc_nlinfo.nl_net = net; 347 348 if (rt->rt_dst.sa_family != AF_INET) 349 return -EAFNOSUPPORT; 350 351 /* 352 * Check mask for validity: 353 * a) it must be contiguous. 354 * b) destination must have all host bits clear. 355 * c) if application forgot to set correct family (AF_INET), 356 * reject request unless it is absolutely clear i.e. 357 * both family and mask are zero. 358 */ 359 plen = 32; 360 addr = sk_extract_addr(&rt->rt_dst); 361 if (!(rt->rt_flags & RTF_HOST)) { 362 __be32 mask = sk_extract_addr(&rt->rt_genmask); 363 364 if (rt->rt_genmask.sa_family != AF_INET) { 365 if (mask || rt->rt_genmask.sa_family) 366 return -EAFNOSUPPORT; 367 } 368 369 if (bad_mask(mask, addr)) 370 return -EINVAL; 371 372 plen = inet_mask_len(mask); 373 } 374 375 cfg->fc_dst_len = plen; 376 cfg->fc_dst = addr; 377 378 if (cmd != SIOCDELRT) { 379 cfg->fc_nlflags = NLM_F_CREATE; 380 cfg->fc_protocol = RTPROT_BOOT; 381 } 382 383 if (rt->rt_metric) 384 cfg->fc_priority = rt->rt_metric - 1; 385 386 if (rt->rt_flags & RTF_REJECT) { 387 cfg->fc_scope = RT_SCOPE_HOST; 388 cfg->fc_type = RTN_UNREACHABLE; 389 return 0; 390 } 391 392 cfg->fc_scope = RT_SCOPE_NOWHERE; 393 cfg->fc_type = RTN_UNICAST; 394 395 if (rt->rt_dev) { 396 char *colon; 397 struct net_device *dev; 398 char devname[IFNAMSIZ]; 399 400 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 401 return -EFAULT; 402 403 devname[IFNAMSIZ-1] = 0; 404 colon = strchr(devname, ':'); 405 if (colon) 406 *colon = 0; 407 dev = __dev_get_by_name(net, devname); 408 if (!dev) 409 return -ENODEV; 410 cfg->fc_oif = dev->ifindex; 411 if (colon) { 412 struct in_ifaddr *ifa; 413 struct in_device *in_dev = __in_dev_get_rtnl(dev); 414 if (!in_dev) 415 return -ENODEV; 416 *colon = ':'; 417 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) 418 if (strcmp(ifa->ifa_label, devname) == 0) 419 break; 420 if (ifa == NULL) 421 return -ENODEV; 422 cfg->fc_prefsrc = ifa->ifa_local; 423 } 424 } 425 426 addr = sk_extract_addr(&rt->rt_gateway); 427 if (rt->rt_gateway.sa_family == AF_INET && addr) { 428 cfg->fc_gw = addr; 429 if (rt->rt_flags & RTF_GATEWAY && 430 inet_addr_type(net, addr) == RTN_UNICAST) 431 cfg->fc_scope = RT_SCOPE_UNIVERSE; 432 } 433 434 if (cmd == SIOCDELRT) 435 return 0; 436 437 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw) 438 return -EINVAL; 439 440 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 441 cfg->fc_scope = RT_SCOPE_LINK; 442 443 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 444 struct nlattr *mx; 445 int len = 0; 446 447 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL); 448 if (mx == NULL) 449 return -ENOMEM; 450 451 if (rt->rt_flags & RTF_MTU) 452 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 453 454 if (rt->rt_flags & RTF_WINDOW) 455 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 456 457 if (rt->rt_flags & RTF_IRTT) 458 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 459 460 cfg->fc_mx = mx; 461 cfg->fc_mx_len = len; 462 } 463 464 return 0; 465 } 466 467 /* 468 * Handle IP routing ioctl calls. 469 * These are used to manipulate the routing tables 470 */ 471 int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg) 472 { 473 struct fib_config cfg; 474 struct rtentry rt; 475 int err; 476 477 switch (cmd) { 478 case SIOCADDRT: /* Add a route */ 479 case SIOCDELRT: /* Delete a route */ 480 if (!capable(CAP_NET_ADMIN)) 481 return -EPERM; 482 483 if (copy_from_user(&rt, arg, sizeof(rt))) 484 return -EFAULT; 485 486 rtnl_lock(); 487 err = rtentry_to_fib_config(net, cmd, &rt, &cfg); 488 if (err == 0) { 489 struct fib_table *tb; 490 491 if (cmd == SIOCDELRT) { 492 tb = fib_get_table(net, cfg.fc_table); 493 if (tb) 494 err = fib_table_delete(tb, &cfg); 495 else 496 err = -ESRCH; 497 } else { 498 tb = fib_new_table(net, cfg.fc_table); 499 if (tb) 500 err = fib_table_insert(tb, &cfg); 501 else 502 err = -ENOBUFS; 503 } 504 505 /* allocated by rtentry_to_fib_config() */ 506 kfree(cfg.fc_mx); 507 } 508 rtnl_unlock(); 509 return err; 510 } 511 return -EINVAL; 512 } 513 514 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 515 [RTA_DST] = { .type = NLA_U32 }, 516 [RTA_SRC] = { .type = NLA_U32 }, 517 [RTA_IIF] = { .type = NLA_U32 }, 518 [RTA_OIF] = { .type = NLA_U32 }, 519 [RTA_GATEWAY] = { .type = NLA_U32 }, 520 [RTA_PRIORITY] = { .type = NLA_U32 }, 521 [RTA_PREFSRC] = { .type = NLA_U32 }, 522 [RTA_METRICS] = { .type = NLA_NESTED }, 523 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 524 [RTA_FLOW] = { .type = NLA_U32 }, 525 }; 526 527 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 528 struct nlmsghdr *nlh, struct fib_config *cfg) 529 { 530 struct nlattr *attr; 531 int err, remaining; 532 struct rtmsg *rtm; 533 534 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy); 535 if (err < 0) 536 goto errout; 537 538 memset(cfg, 0, sizeof(*cfg)); 539 540 rtm = nlmsg_data(nlh); 541 cfg->fc_dst_len = rtm->rtm_dst_len; 542 cfg->fc_tos = rtm->rtm_tos; 543 cfg->fc_table = rtm->rtm_table; 544 cfg->fc_protocol = rtm->rtm_protocol; 545 cfg->fc_scope = rtm->rtm_scope; 546 cfg->fc_type = rtm->rtm_type; 547 cfg->fc_flags = rtm->rtm_flags; 548 cfg->fc_nlflags = nlh->nlmsg_flags; 549 550 cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid; 551 cfg->fc_nlinfo.nlh = nlh; 552 cfg->fc_nlinfo.nl_net = net; 553 554 if (cfg->fc_type > RTN_MAX) { 555 err = -EINVAL; 556 goto errout; 557 } 558 559 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 560 switch (nla_type(attr)) { 561 case RTA_DST: 562 cfg->fc_dst = nla_get_be32(attr); 563 break; 564 case RTA_OIF: 565 cfg->fc_oif = nla_get_u32(attr); 566 break; 567 case RTA_GATEWAY: 568 cfg->fc_gw = nla_get_be32(attr); 569 break; 570 case RTA_PRIORITY: 571 cfg->fc_priority = nla_get_u32(attr); 572 break; 573 case RTA_PREFSRC: 574 cfg->fc_prefsrc = nla_get_be32(attr); 575 break; 576 case RTA_METRICS: 577 cfg->fc_mx = nla_data(attr); 578 cfg->fc_mx_len = nla_len(attr); 579 break; 580 case RTA_MULTIPATH: 581 cfg->fc_mp = nla_data(attr); 582 cfg->fc_mp_len = nla_len(attr); 583 break; 584 case RTA_FLOW: 585 cfg->fc_flow = nla_get_u32(attr); 586 break; 587 case RTA_TABLE: 588 cfg->fc_table = nla_get_u32(attr); 589 break; 590 } 591 } 592 593 return 0; 594 errout: 595 return err; 596 } 597 598 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 599 { 600 struct net *net = sock_net(skb->sk); 601 struct fib_config cfg; 602 struct fib_table *tb; 603 int err; 604 605 err = rtm_to_fib_config(net, skb, nlh, &cfg); 606 if (err < 0) 607 goto errout; 608 609 tb = fib_get_table(net, cfg.fc_table); 610 if (tb == NULL) { 611 err = -ESRCH; 612 goto errout; 613 } 614 615 err = fib_table_delete(tb, &cfg); 616 errout: 617 return err; 618 } 619 620 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 621 { 622 struct net *net = sock_net(skb->sk); 623 struct fib_config cfg; 624 struct fib_table *tb; 625 int err; 626 627 err = rtm_to_fib_config(net, skb, nlh, &cfg); 628 if (err < 0) 629 goto errout; 630 631 tb = fib_new_table(net, cfg.fc_table); 632 if (tb == NULL) { 633 err = -ENOBUFS; 634 goto errout; 635 } 636 637 err = fib_table_insert(tb, &cfg); 638 errout: 639 return err; 640 } 641 642 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 643 { 644 struct net *net = sock_net(skb->sk); 645 unsigned int h, s_h; 646 unsigned int e = 0, s_e; 647 struct fib_table *tb; 648 struct hlist_node *node; 649 struct hlist_head *head; 650 int dumped = 0; 651 652 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) && 653 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED) 654 return ip_rt_dump(skb, cb); 655 656 s_h = cb->args[0]; 657 s_e = cb->args[1]; 658 659 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 660 e = 0; 661 head = &net->ipv4.fib_table_hash[h]; 662 hlist_for_each_entry(tb, node, head, tb_hlist) { 663 if (e < s_e) 664 goto next; 665 if (dumped) 666 memset(&cb->args[2], 0, sizeof(cb->args) - 667 2 * sizeof(cb->args[0])); 668 if (fib_table_dump(tb, skb, cb) < 0) 669 goto out; 670 dumped = 1; 671 next: 672 e++; 673 } 674 } 675 out: 676 cb->args[1] = e; 677 cb->args[0] = h; 678 679 return skb->len; 680 } 681 682 /* Prepare and feed intra-kernel routing request. 683 * Really, it should be netlink message, but :-( netlink 684 * can be not configured, so that we feed it directly 685 * to fib engine. It is legal, because all events occur 686 * only when netlink is already locked. 687 */ 688 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa) 689 { 690 struct net *net = dev_net(ifa->ifa_dev->dev); 691 struct fib_table *tb; 692 struct fib_config cfg = { 693 .fc_protocol = RTPROT_KERNEL, 694 .fc_type = type, 695 .fc_dst = dst, 696 .fc_dst_len = dst_len, 697 .fc_prefsrc = ifa->ifa_local, 698 .fc_oif = ifa->ifa_dev->dev->ifindex, 699 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 700 .fc_nlinfo = { 701 .nl_net = net, 702 }, 703 }; 704 705 if (type == RTN_UNICAST) 706 tb = fib_new_table(net, RT_TABLE_MAIN); 707 else 708 tb = fib_new_table(net, RT_TABLE_LOCAL); 709 710 if (tb == NULL) 711 return; 712 713 cfg.fc_table = tb->tb_id; 714 715 if (type != RTN_LOCAL) 716 cfg.fc_scope = RT_SCOPE_LINK; 717 else 718 cfg.fc_scope = RT_SCOPE_HOST; 719 720 if (cmd == RTM_NEWROUTE) 721 fib_table_insert(tb, &cfg); 722 else 723 fib_table_delete(tb, &cfg); 724 } 725 726 void fib_add_ifaddr(struct in_ifaddr *ifa) 727 { 728 struct in_device *in_dev = ifa->ifa_dev; 729 struct net_device *dev = in_dev->dev; 730 struct in_ifaddr *prim = ifa; 731 __be32 mask = ifa->ifa_mask; 732 __be32 addr = ifa->ifa_local; 733 __be32 prefix = ifa->ifa_address & mask; 734 735 if (ifa->ifa_flags & IFA_F_SECONDARY) { 736 prim = inet_ifa_byprefix(in_dev, prefix, mask); 737 if (prim == NULL) { 738 pr_warn("%s: bug: prim == NULL\n", __func__); 739 return; 740 } 741 } 742 743 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim); 744 745 if (!(dev->flags & IFF_UP)) 746 return; 747 748 /* Add broadcast address, if it is explicitly assigned. */ 749 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 750 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 751 752 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 753 (prefix != addr || ifa->ifa_prefixlen < 32)) { 754 fib_magic(RTM_NEWROUTE, 755 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 756 prefix, ifa->ifa_prefixlen, prim); 757 758 /* Add network specific broadcasts, when it takes a sense */ 759 if (ifa->ifa_prefixlen < 31) { 760 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim); 761 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 762 32, prim); 763 } 764 } 765 } 766 767 /* Delete primary or secondary address. 768 * Optionally, on secondary address promotion consider the addresses 769 * from subnet iprim as deleted, even if they are in device list. 770 * In this case the secondary ifa can be in device list. 771 */ 772 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 773 { 774 struct in_device *in_dev = ifa->ifa_dev; 775 struct net_device *dev = in_dev->dev; 776 struct in_ifaddr *ifa1; 777 struct in_ifaddr *prim = ifa, *prim1 = NULL; 778 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 779 __be32 any = ifa->ifa_address & ifa->ifa_mask; 780 #define LOCAL_OK 1 781 #define BRD_OK 2 782 #define BRD0_OK 4 783 #define BRD1_OK 8 784 unsigned int ok = 0; 785 int subnet = 0; /* Primary network */ 786 int gone = 1; /* Address is missing */ 787 int same_prefsrc = 0; /* Another primary with same IP */ 788 789 if (ifa->ifa_flags & IFA_F_SECONDARY) { 790 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 791 if (prim == NULL) { 792 pr_warn("%s: bug: prim == NULL\n", __func__); 793 return; 794 } 795 if (iprim && iprim != prim) { 796 pr_warn("%s: bug: iprim != prim\n", __func__); 797 return; 798 } 799 } else if (!ipv4_is_zeronet(any) && 800 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 801 fib_magic(RTM_DELROUTE, 802 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 803 any, ifa->ifa_prefixlen, prim); 804 subnet = 1; 805 } 806 807 /* Deletion is more complicated than add. 808 * We should take care of not to delete too much :-) 809 * 810 * Scan address list to be sure that addresses are really gone. 811 */ 812 813 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) { 814 if (ifa1 == ifa) { 815 /* promotion, keep the IP */ 816 gone = 0; 817 continue; 818 } 819 /* Ignore IFAs from our subnet */ 820 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 821 inet_ifa_match(ifa1->ifa_address, iprim)) 822 continue; 823 824 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 825 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 826 /* Another address from our subnet? */ 827 if (ifa1->ifa_mask == prim->ifa_mask && 828 inet_ifa_match(ifa1->ifa_address, prim)) 829 prim1 = prim; 830 else { 831 /* We reached the secondaries, so 832 * same_prefsrc should be determined. 833 */ 834 if (!same_prefsrc) 835 continue; 836 /* Search new prim1 if ifa1 is not 837 * using the current prim1 838 */ 839 if (!prim1 || 840 ifa1->ifa_mask != prim1->ifa_mask || 841 !inet_ifa_match(ifa1->ifa_address, prim1)) 842 prim1 = inet_ifa_byprefix(in_dev, 843 ifa1->ifa_address, 844 ifa1->ifa_mask); 845 if (!prim1) 846 continue; 847 if (prim1->ifa_local != prim->ifa_local) 848 continue; 849 } 850 } else { 851 if (prim->ifa_local != ifa1->ifa_local) 852 continue; 853 prim1 = ifa1; 854 if (prim != prim1) 855 same_prefsrc = 1; 856 } 857 if (ifa->ifa_local == ifa1->ifa_local) 858 ok |= LOCAL_OK; 859 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 860 ok |= BRD_OK; 861 if (brd == ifa1->ifa_broadcast) 862 ok |= BRD1_OK; 863 if (any == ifa1->ifa_broadcast) 864 ok |= BRD0_OK; 865 /* primary has network specific broadcasts */ 866 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 867 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 868 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 869 870 if (!ipv4_is_zeronet(any1)) { 871 if (ifa->ifa_broadcast == brd1 || 872 ifa->ifa_broadcast == any1) 873 ok |= BRD_OK; 874 if (brd == brd1 || brd == any1) 875 ok |= BRD1_OK; 876 if (any == brd1 || any == any1) 877 ok |= BRD0_OK; 878 } 879 } 880 } 881 882 if (!(ok & BRD_OK)) 883 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 884 if (subnet && ifa->ifa_prefixlen < 31) { 885 if (!(ok & BRD1_OK)) 886 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim); 887 if (!(ok & BRD0_OK)) 888 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim); 889 } 890 if (!(ok & LOCAL_OK)) { 891 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim); 892 893 /* Check, that this local address finally disappeared. */ 894 if (gone && 895 inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) { 896 /* And the last, but not the least thing. 897 * We must flush stray FIB entries. 898 * 899 * First of all, we scan fib_info list searching 900 * for stray nexthop entries, then ignite fib_flush. 901 */ 902 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local)) 903 fib_flush(dev_net(dev)); 904 } 905 } 906 #undef LOCAL_OK 907 #undef BRD_OK 908 #undef BRD0_OK 909 #undef BRD1_OK 910 } 911 912 static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb) 913 { 914 915 struct fib_result res; 916 struct flowi4 fl4 = { 917 .flowi4_mark = frn->fl_mark, 918 .daddr = frn->fl_addr, 919 .flowi4_tos = frn->fl_tos, 920 .flowi4_scope = frn->fl_scope, 921 }; 922 923 #ifdef CONFIG_IP_MULTIPLE_TABLES 924 res.r = NULL; 925 #endif 926 927 frn->err = -ENOENT; 928 if (tb) { 929 local_bh_disable(); 930 931 frn->tb_id = tb->tb_id; 932 rcu_read_lock(); 933 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 934 935 if (!frn->err) { 936 frn->prefixlen = res.prefixlen; 937 frn->nh_sel = res.nh_sel; 938 frn->type = res.type; 939 frn->scope = res.scope; 940 } 941 rcu_read_unlock(); 942 local_bh_enable(); 943 } 944 } 945 946 static void nl_fib_input(struct sk_buff *skb) 947 { 948 struct net *net; 949 struct fib_result_nl *frn; 950 struct nlmsghdr *nlh; 951 struct fib_table *tb; 952 u32 pid; 953 954 net = sock_net(skb->sk); 955 nlh = nlmsg_hdr(skb); 956 if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len || 957 nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn))) 958 return; 959 960 skb = skb_clone(skb, GFP_KERNEL); 961 if (skb == NULL) 962 return; 963 nlh = nlmsg_hdr(skb); 964 965 frn = (struct fib_result_nl *) NLMSG_DATA(nlh); 966 tb = fib_get_table(net, frn->tb_id_in); 967 968 nl_fib_lookup(frn, tb); 969 970 pid = NETLINK_CB(skb).pid; /* pid of sending process */ 971 NETLINK_CB(skb).pid = 0; /* from kernel */ 972 NETLINK_CB(skb).dst_group = 0; /* unicast */ 973 netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT); 974 } 975 976 static int __net_init nl_fib_lookup_init(struct net *net) 977 { 978 struct sock *sk; 979 struct netlink_kernel_cfg cfg = { 980 .input = nl_fib_input, 981 }; 982 983 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, THIS_MODULE, &cfg); 984 if (sk == NULL) 985 return -EAFNOSUPPORT; 986 net->ipv4.fibnl = sk; 987 return 0; 988 } 989 990 static void nl_fib_lookup_exit(struct net *net) 991 { 992 netlink_kernel_release(net->ipv4.fibnl); 993 net->ipv4.fibnl = NULL; 994 } 995 996 static void fib_disable_ip(struct net_device *dev, int force, int delay) 997 { 998 if (fib_sync_down_dev(dev, force)) 999 fib_flush(dev_net(dev)); 1000 rt_cache_flush(dev_net(dev), delay); 1001 arp_ifdown(dev); 1002 } 1003 1004 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 1005 { 1006 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 1007 struct net_device *dev = ifa->ifa_dev->dev; 1008 struct net *net = dev_net(dev); 1009 1010 switch (event) { 1011 case NETDEV_UP: 1012 fib_add_ifaddr(ifa); 1013 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1014 fib_sync_up(dev); 1015 #endif 1016 atomic_inc(&net->ipv4.dev_addr_genid); 1017 rt_cache_flush(dev_net(dev), -1); 1018 break; 1019 case NETDEV_DOWN: 1020 fib_del_ifaddr(ifa, NULL); 1021 atomic_inc(&net->ipv4.dev_addr_genid); 1022 if (ifa->ifa_dev->ifa_list == NULL) { 1023 /* Last address was deleted from this interface. 1024 * Disable IP. 1025 */ 1026 fib_disable_ip(dev, 1, 0); 1027 } else { 1028 rt_cache_flush(dev_net(dev), -1); 1029 } 1030 break; 1031 } 1032 return NOTIFY_DONE; 1033 } 1034 1035 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1036 { 1037 struct net_device *dev = ptr; 1038 struct in_device *in_dev = __in_dev_get_rtnl(dev); 1039 struct net *net = dev_net(dev); 1040 1041 if (event == NETDEV_UNREGISTER) { 1042 fib_disable_ip(dev, 2, -1); 1043 return NOTIFY_DONE; 1044 } 1045 1046 if (!in_dev) 1047 return NOTIFY_DONE; 1048 1049 switch (event) { 1050 case NETDEV_UP: 1051 for_ifa(in_dev) { 1052 fib_add_ifaddr(ifa); 1053 } endfor_ifa(in_dev); 1054 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1055 fib_sync_up(dev); 1056 #endif 1057 atomic_inc(&net->ipv4.dev_addr_genid); 1058 rt_cache_flush(dev_net(dev), -1); 1059 break; 1060 case NETDEV_DOWN: 1061 fib_disable_ip(dev, 0, 0); 1062 break; 1063 case NETDEV_CHANGEMTU: 1064 case NETDEV_CHANGE: 1065 rt_cache_flush(dev_net(dev), 0); 1066 break; 1067 case NETDEV_UNREGISTER_BATCH: 1068 /* The batch unregister is only called on the first 1069 * device in the list of devices being unregistered. 1070 * Therefore we should not pass dev_net(dev) in here. 1071 */ 1072 rt_cache_flush_batch(NULL); 1073 break; 1074 } 1075 return NOTIFY_DONE; 1076 } 1077 1078 static struct notifier_block fib_inetaddr_notifier = { 1079 .notifier_call = fib_inetaddr_event, 1080 }; 1081 1082 static struct notifier_block fib_netdev_notifier = { 1083 .notifier_call = fib_netdev_event, 1084 }; 1085 1086 static int __net_init ip_fib_net_init(struct net *net) 1087 { 1088 int err; 1089 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1090 1091 /* Avoid false sharing : Use at least a full cache line */ 1092 size = max_t(size_t, size, L1_CACHE_BYTES); 1093 1094 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1095 if (net->ipv4.fib_table_hash == NULL) 1096 return -ENOMEM; 1097 1098 err = fib4_rules_init(net); 1099 if (err < 0) 1100 goto fail; 1101 return 0; 1102 1103 fail: 1104 kfree(net->ipv4.fib_table_hash); 1105 return err; 1106 } 1107 1108 static void ip_fib_net_exit(struct net *net) 1109 { 1110 unsigned int i; 1111 1112 #ifdef CONFIG_IP_MULTIPLE_TABLES 1113 fib4_rules_exit(net); 1114 #endif 1115 1116 rtnl_lock(); 1117 for (i = 0; i < FIB_TABLE_HASHSZ; i++) { 1118 struct fib_table *tb; 1119 struct hlist_head *head; 1120 struct hlist_node *node, *tmp; 1121 1122 head = &net->ipv4.fib_table_hash[i]; 1123 hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) { 1124 hlist_del(node); 1125 fib_table_flush(tb); 1126 fib_free_table(tb); 1127 } 1128 } 1129 rtnl_unlock(); 1130 kfree(net->ipv4.fib_table_hash); 1131 } 1132 1133 static int __net_init fib_net_init(struct net *net) 1134 { 1135 int error; 1136 1137 error = ip_fib_net_init(net); 1138 if (error < 0) 1139 goto out; 1140 error = nl_fib_lookup_init(net); 1141 if (error < 0) 1142 goto out_nlfl; 1143 error = fib_proc_init(net); 1144 if (error < 0) 1145 goto out_proc; 1146 out: 1147 return error; 1148 1149 out_proc: 1150 nl_fib_lookup_exit(net); 1151 out_nlfl: 1152 ip_fib_net_exit(net); 1153 goto out; 1154 } 1155 1156 static void __net_exit fib_net_exit(struct net *net) 1157 { 1158 fib_proc_exit(net); 1159 nl_fib_lookup_exit(net); 1160 ip_fib_net_exit(net); 1161 } 1162 1163 static struct pernet_operations fib_net_ops = { 1164 .init = fib_net_init, 1165 .exit = fib_net_exit, 1166 }; 1167 1168 void __init ip_fib_init(void) 1169 { 1170 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL); 1171 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL); 1172 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL); 1173 1174 register_pernet_subsys(&fib_net_ops); 1175 register_netdevice_notifier(&fib_netdev_notifier); 1176 register_inetaddr_notifier(&fib_inetaddr_notifier); 1177 1178 fib_trie_init(); 1179 } 1180