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