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; 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 ? : LOOPBACK_IFINDEX; 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 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0; 262 263 net = dev_net(dev); 264 if (fib_lookup(net, &fl4, &res)) 265 goto last_resort; 266 if (res.type != RTN_UNICAST && 267 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev))) 268 goto e_inval; 269 if (!rpf && !fib_num_tclassid_users(dev_net(dev)) && 270 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) 271 goto last_resort; 272 fib_combine_itag(itag, &res); 273 dev_match = false; 274 275 #ifdef CONFIG_IP_ROUTE_MULTIPATH 276 for (ret = 0; ret < res.fi->fib_nhs; ret++) { 277 struct fib_nh *nh = &res.fi->fib_nh[ret]; 278 279 if (nh->nh_dev == dev) { 280 dev_match = true; 281 break; 282 } 283 } 284 #else 285 if (FIB_RES_DEV(res) == dev) 286 dev_match = true; 287 #endif 288 if (dev_match) { 289 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 290 return ret; 291 } 292 if (no_addr) 293 goto last_resort; 294 if (rpf == 1) 295 goto e_rpf; 296 fl4.flowi4_oif = dev->ifindex; 297 298 ret = 0; 299 if (fib_lookup(net, &fl4, &res) == 0) { 300 if (res.type == RTN_UNICAST) 301 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 302 } 303 return ret; 304 305 last_resort: 306 if (rpf) 307 goto e_rpf; 308 *itag = 0; 309 return 0; 310 311 e_inval: 312 return -EINVAL; 313 e_rpf: 314 return -EXDEV; 315 } 316 317 /* Ignore rp_filter for packets protected by IPsec. */ 318 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 319 u8 tos, int oif, struct net_device *dev, 320 struct in_device *idev, u32 *itag) 321 { 322 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev); 323 324 if (!r && !fib_num_tclassid_users(dev_net(dev)) && 325 IN_DEV_ACCEPT_LOCAL(idev) && 326 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) { 327 *itag = 0; 328 return 0; 329 } 330 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag); 331 } 332 333 static inline __be32 sk_extract_addr(struct sockaddr *addr) 334 { 335 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 336 } 337 338 static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 339 { 340 struct nlattr *nla; 341 342 nla = (struct nlattr *) ((char *) mx + len); 343 nla->nla_type = type; 344 nla->nla_len = nla_attr_size(4); 345 *(u32 *) nla_data(nla) = value; 346 347 return len + nla_total_size(4); 348 } 349 350 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 351 struct fib_config *cfg) 352 { 353 __be32 addr; 354 int plen; 355 356 memset(cfg, 0, sizeof(*cfg)); 357 cfg->fc_nlinfo.nl_net = net; 358 359 if (rt->rt_dst.sa_family != AF_INET) 360 return -EAFNOSUPPORT; 361 362 /* 363 * Check mask for validity: 364 * a) it must be contiguous. 365 * b) destination must have all host bits clear. 366 * c) if application forgot to set correct family (AF_INET), 367 * reject request unless it is absolutely clear i.e. 368 * both family and mask are zero. 369 */ 370 plen = 32; 371 addr = sk_extract_addr(&rt->rt_dst); 372 if (!(rt->rt_flags & RTF_HOST)) { 373 __be32 mask = sk_extract_addr(&rt->rt_genmask); 374 375 if (rt->rt_genmask.sa_family != AF_INET) { 376 if (mask || rt->rt_genmask.sa_family) 377 return -EAFNOSUPPORT; 378 } 379 380 if (bad_mask(mask, addr)) 381 return -EINVAL; 382 383 plen = inet_mask_len(mask); 384 } 385 386 cfg->fc_dst_len = plen; 387 cfg->fc_dst = addr; 388 389 if (cmd != SIOCDELRT) { 390 cfg->fc_nlflags = NLM_F_CREATE; 391 cfg->fc_protocol = RTPROT_BOOT; 392 } 393 394 if (rt->rt_metric) 395 cfg->fc_priority = rt->rt_metric - 1; 396 397 if (rt->rt_flags & RTF_REJECT) { 398 cfg->fc_scope = RT_SCOPE_HOST; 399 cfg->fc_type = RTN_UNREACHABLE; 400 return 0; 401 } 402 403 cfg->fc_scope = RT_SCOPE_NOWHERE; 404 cfg->fc_type = RTN_UNICAST; 405 406 if (rt->rt_dev) { 407 char *colon; 408 struct net_device *dev; 409 char devname[IFNAMSIZ]; 410 411 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 412 return -EFAULT; 413 414 devname[IFNAMSIZ-1] = 0; 415 colon = strchr(devname, ':'); 416 if (colon) 417 *colon = 0; 418 dev = __dev_get_by_name(net, devname); 419 if (!dev) 420 return -ENODEV; 421 cfg->fc_oif = dev->ifindex; 422 if (colon) { 423 struct in_ifaddr *ifa; 424 struct in_device *in_dev = __in_dev_get_rtnl(dev); 425 if (!in_dev) 426 return -ENODEV; 427 *colon = ':'; 428 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) 429 if (strcmp(ifa->ifa_label, devname) == 0) 430 break; 431 if (ifa == NULL) 432 return -ENODEV; 433 cfg->fc_prefsrc = ifa->ifa_local; 434 } 435 } 436 437 addr = sk_extract_addr(&rt->rt_gateway); 438 if (rt->rt_gateway.sa_family == AF_INET && addr) { 439 cfg->fc_gw = addr; 440 if (rt->rt_flags & RTF_GATEWAY && 441 inet_addr_type(net, addr) == RTN_UNICAST) 442 cfg->fc_scope = RT_SCOPE_UNIVERSE; 443 } 444 445 if (cmd == SIOCDELRT) 446 return 0; 447 448 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw) 449 return -EINVAL; 450 451 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 452 cfg->fc_scope = RT_SCOPE_LINK; 453 454 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 455 struct nlattr *mx; 456 int len = 0; 457 458 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL); 459 if (mx == NULL) 460 return -ENOMEM; 461 462 if (rt->rt_flags & RTF_MTU) 463 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 464 465 if (rt->rt_flags & RTF_WINDOW) 466 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 467 468 if (rt->rt_flags & RTF_IRTT) 469 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 470 471 cfg->fc_mx = mx; 472 cfg->fc_mx_len = len; 473 } 474 475 return 0; 476 } 477 478 /* 479 * Handle IP routing ioctl calls. 480 * These are used to manipulate the routing tables 481 */ 482 int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg) 483 { 484 struct fib_config cfg; 485 struct rtentry rt; 486 int err; 487 488 switch (cmd) { 489 case SIOCADDRT: /* Add a route */ 490 case SIOCDELRT: /* Delete a route */ 491 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 492 return -EPERM; 493 494 if (copy_from_user(&rt, arg, sizeof(rt))) 495 return -EFAULT; 496 497 rtnl_lock(); 498 err = rtentry_to_fib_config(net, cmd, &rt, &cfg); 499 if (err == 0) { 500 struct fib_table *tb; 501 502 if (cmd == SIOCDELRT) { 503 tb = fib_get_table(net, cfg.fc_table); 504 if (tb) 505 err = fib_table_delete(tb, &cfg); 506 else 507 err = -ESRCH; 508 } else { 509 tb = fib_new_table(net, cfg.fc_table); 510 if (tb) 511 err = fib_table_insert(tb, &cfg); 512 else 513 err = -ENOBUFS; 514 } 515 516 /* allocated by rtentry_to_fib_config() */ 517 kfree(cfg.fc_mx); 518 } 519 rtnl_unlock(); 520 return err; 521 } 522 return -EINVAL; 523 } 524 525 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 526 [RTA_DST] = { .type = NLA_U32 }, 527 [RTA_SRC] = { .type = NLA_U32 }, 528 [RTA_IIF] = { .type = NLA_U32 }, 529 [RTA_OIF] = { .type = NLA_U32 }, 530 [RTA_GATEWAY] = { .type = NLA_U32 }, 531 [RTA_PRIORITY] = { .type = NLA_U32 }, 532 [RTA_PREFSRC] = { .type = NLA_U32 }, 533 [RTA_METRICS] = { .type = NLA_NESTED }, 534 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 535 [RTA_FLOW] = { .type = NLA_U32 }, 536 }; 537 538 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 539 struct nlmsghdr *nlh, struct fib_config *cfg) 540 { 541 struct nlattr *attr; 542 int err, remaining; 543 struct rtmsg *rtm; 544 545 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy); 546 if (err < 0) 547 goto errout; 548 549 memset(cfg, 0, sizeof(*cfg)); 550 551 rtm = nlmsg_data(nlh); 552 cfg->fc_dst_len = rtm->rtm_dst_len; 553 cfg->fc_tos = rtm->rtm_tos; 554 cfg->fc_table = rtm->rtm_table; 555 cfg->fc_protocol = rtm->rtm_protocol; 556 cfg->fc_scope = rtm->rtm_scope; 557 cfg->fc_type = rtm->rtm_type; 558 cfg->fc_flags = rtm->rtm_flags; 559 cfg->fc_nlflags = nlh->nlmsg_flags; 560 561 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; 562 cfg->fc_nlinfo.nlh = nlh; 563 cfg->fc_nlinfo.nl_net = net; 564 565 if (cfg->fc_type > RTN_MAX) { 566 err = -EINVAL; 567 goto errout; 568 } 569 570 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 571 switch (nla_type(attr)) { 572 case RTA_DST: 573 cfg->fc_dst = nla_get_be32(attr); 574 break; 575 case RTA_OIF: 576 cfg->fc_oif = nla_get_u32(attr); 577 break; 578 case RTA_GATEWAY: 579 cfg->fc_gw = nla_get_be32(attr); 580 break; 581 case RTA_PRIORITY: 582 cfg->fc_priority = nla_get_u32(attr); 583 break; 584 case RTA_PREFSRC: 585 cfg->fc_prefsrc = nla_get_be32(attr); 586 break; 587 case RTA_METRICS: 588 cfg->fc_mx = nla_data(attr); 589 cfg->fc_mx_len = nla_len(attr); 590 break; 591 case RTA_MULTIPATH: 592 cfg->fc_mp = nla_data(attr); 593 cfg->fc_mp_len = nla_len(attr); 594 break; 595 case RTA_FLOW: 596 cfg->fc_flow = nla_get_u32(attr); 597 break; 598 case RTA_TABLE: 599 cfg->fc_table = nla_get_u32(attr); 600 break; 601 } 602 } 603 604 return 0; 605 errout: 606 return err; 607 } 608 609 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh) 610 { 611 struct net *net = sock_net(skb->sk); 612 struct fib_config cfg; 613 struct fib_table *tb; 614 int err; 615 616 err = rtm_to_fib_config(net, skb, nlh, &cfg); 617 if (err < 0) 618 goto errout; 619 620 tb = fib_get_table(net, cfg.fc_table); 621 if (tb == NULL) { 622 err = -ESRCH; 623 goto errout; 624 } 625 626 err = fib_table_delete(tb, &cfg); 627 errout: 628 return err; 629 } 630 631 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh) 632 { 633 struct net *net = sock_net(skb->sk); 634 struct fib_config cfg; 635 struct fib_table *tb; 636 int err; 637 638 err = rtm_to_fib_config(net, skb, nlh, &cfg); 639 if (err < 0) 640 goto errout; 641 642 tb = fib_new_table(net, cfg.fc_table); 643 if (tb == NULL) { 644 err = -ENOBUFS; 645 goto errout; 646 } 647 648 err = fib_table_insert(tb, &cfg); 649 errout: 650 return err; 651 } 652 653 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 654 { 655 struct net *net = sock_net(skb->sk); 656 unsigned int h, s_h; 657 unsigned int e = 0, s_e; 658 struct fib_table *tb; 659 struct hlist_head *head; 660 int dumped = 0; 661 662 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) && 663 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED) 664 return skb->len; 665 666 s_h = cb->args[0]; 667 s_e = cb->args[1]; 668 669 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 670 e = 0; 671 head = &net->ipv4.fib_table_hash[h]; 672 hlist_for_each_entry(tb, head, tb_hlist) { 673 if (e < s_e) 674 goto next; 675 if (dumped) 676 memset(&cb->args[2], 0, sizeof(cb->args) - 677 2 * sizeof(cb->args[0])); 678 if (fib_table_dump(tb, skb, cb) < 0) 679 goto out; 680 dumped = 1; 681 next: 682 e++; 683 } 684 } 685 out: 686 cb->args[1] = e; 687 cb->args[0] = h; 688 689 return skb->len; 690 } 691 692 /* Prepare and feed intra-kernel routing request. 693 * Really, it should be netlink message, but :-( netlink 694 * can be not configured, so that we feed it directly 695 * to fib engine. It is legal, because all events occur 696 * only when netlink is already locked. 697 */ 698 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa) 699 { 700 struct net *net = dev_net(ifa->ifa_dev->dev); 701 struct fib_table *tb; 702 struct fib_config cfg = { 703 .fc_protocol = RTPROT_KERNEL, 704 .fc_type = type, 705 .fc_dst = dst, 706 .fc_dst_len = dst_len, 707 .fc_prefsrc = ifa->ifa_local, 708 .fc_oif = ifa->ifa_dev->dev->ifindex, 709 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 710 .fc_nlinfo = { 711 .nl_net = net, 712 }, 713 }; 714 715 if (type == RTN_UNICAST) 716 tb = fib_new_table(net, RT_TABLE_MAIN); 717 else 718 tb = fib_new_table(net, RT_TABLE_LOCAL); 719 720 if (tb == NULL) 721 return; 722 723 cfg.fc_table = tb->tb_id; 724 725 if (type != RTN_LOCAL) 726 cfg.fc_scope = RT_SCOPE_LINK; 727 else 728 cfg.fc_scope = RT_SCOPE_HOST; 729 730 if (cmd == RTM_NEWROUTE) 731 fib_table_insert(tb, &cfg); 732 else 733 fib_table_delete(tb, &cfg); 734 } 735 736 void fib_add_ifaddr(struct in_ifaddr *ifa) 737 { 738 struct in_device *in_dev = ifa->ifa_dev; 739 struct net_device *dev = in_dev->dev; 740 struct in_ifaddr *prim = ifa; 741 __be32 mask = ifa->ifa_mask; 742 __be32 addr = ifa->ifa_local; 743 __be32 prefix = ifa->ifa_address & mask; 744 745 if (ifa->ifa_flags & IFA_F_SECONDARY) { 746 prim = inet_ifa_byprefix(in_dev, prefix, mask); 747 if (prim == NULL) { 748 pr_warn("%s: bug: prim == NULL\n", __func__); 749 return; 750 } 751 } 752 753 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim); 754 755 if (!(dev->flags & IFF_UP)) 756 return; 757 758 /* Add broadcast address, if it is explicitly assigned. */ 759 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 760 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 761 762 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 763 (prefix != addr || ifa->ifa_prefixlen < 32)) { 764 fib_magic(RTM_NEWROUTE, 765 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 766 prefix, ifa->ifa_prefixlen, prim); 767 768 /* Add network specific broadcasts, when it takes a sense */ 769 if (ifa->ifa_prefixlen < 31) { 770 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim); 771 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 772 32, prim); 773 } 774 } 775 } 776 777 /* Delete primary or secondary address. 778 * Optionally, on secondary address promotion consider the addresses 779 * from subnet iprim as deleted, even if they are in device list. 780 * In this case the secondary ifa can be in device list. 781 */ 782 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) 783 { 784 struct in_device *in_dev = ifa->ifa_dev; 785 struct net_device *dev = in_dev->dev; 786 struct in_ifaddr *ifa1; 787 struct in_ifaddr *prim = ifa, *prim1 = NULL; 788 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 789 __be32 any = ifa->ifa_address & ifa->ifa_mask; 790 #define LOCAL_OK 1 791 #define BRD_OK 2 792 #define BRD0_OK 4 793 #define BRD1_OK 8 794 unsigned int ok = 0; 795 int subnet = 0; /* Primary network */ 796 int gone = 1; /* Address is missing */ 797 int same_prefsrc = 0; /* Another primary with same IP */ 798 799 if (ifa->ifa_flags & IFA_F_SECONDARY) { 800 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 801 if (prim == NULL) { 802 pr_warn("%s: bug: prim == NULL\n", __func__); 803 return; 804 } 805 if (iprim && iprim != prim) { 806 pr_warn("%s: bug: iprim != prim\n", __func__); 807 return; 808 } 809 } else if (!ipv4_is_zeronet(any) && 810 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { 811 fib_magic(RTM_DELROUTE, 812 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 813 any, ifa->ifa_prefixlen, prim); 814 subnet = 1; 815 } 816 817 /* Deletion is more complicated than add. 818 * We should take care of not to delete too much :-) 819 * 820 * Scan address list to be sure that addresses are really gone. 821 */ 822 823 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) { 824 if (ifa1 == ifa) { 825 /* promotion, keep the IP */ 826 gone = 0; 827 continue; 828 } 829 /* Ignore IFAs from our subnet */ 830 if (iprim && ifa1->ifa_mask == iprim->ifa_mask && 831 inet_ifa_match(ifa1->ifa_address, iprim)) 832 continue; 833 834 /* Ignore ifa1 if it uses different primary IP (prefsrc) */ 835 if (ifa1->ifa_flags & IFA_F_SECONDARY) { 836 /* Another address from our subnet? */ 837 if (ifa1->ifa_mask == prim->ifa_mask && 838 inet_ifa_match(ifa1->ifa_address, prim)) 839 prim1 = prim; 840 else { 841 /* We reached the secondaries, so 842 * same_prefsrc should be determined. 843 */ 844 if (!same_prefsrc) 845 continue; 846 /* Search new prim1 if ifa1 is not 847 * using the current prim1 848 */ 849 if (!prim1 || 850 ifa1->ifa_mask != prim1->ifa_mask || 851 !inet_ifa_match(ifa1->ifa_address, prim1)) 852 prim1 = inet_ifa_byprefix(in_dev, 853 ifa1->ifa_address, 854 ifa1->ifa_mask); 855 if (!prim1) 856 continue; 857 if (prim1->ifa_local != prim->ifa_local) 858 continue; 859 } 860 } else { 861 if (prim->ifa_local != ifa1->ifa_local) 862 continue; 863 prim1 = ifa1; 864 if (prim != prim1) 865 same_prefsrc = 1; 866 } 867 if (ifa->ifa_local == ifa1->ifa_local) 868 ok |= LOCAL_OK; 869 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 870 ok |= BRD_OK; 871 if (brd == ifa1->ifa_broadcast) 872 ok |= BRD1_OK; 873 if (any == ifa1->ifa_broadcast) 874 ok |= BRD0_OK; 875 /* primary has network specific broadcasts */ 876 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { 877 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; 878 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; 879 880 if (!ipv4_is_zeronet(any1)) { 881 if (ifa->ifa_broadcast == brd1 || 882 ifa->ifa_broadcast == any1) 883 ok |= BRD_OK; 884 if (brd == brd1 || brd == any1) 885 ok |= BRD1_OK; 886 if (any == brd1 || any == any1) 887 ok |= BRD0_OK; 888 } 889 } 890 } 891 892 if (!(ok & BRD_OK)) 893 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 894 if (subnet && ifa->ifa_prefixlen < 31) { 895 if (!(ok & BRD1_OK)) 896 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim); 897 if (!(ok & BRD0_OK)) 898 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim); 899 } 900 if (!(ok & LOCAL_OK)) { 901 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim); 902 903 /* Check, that this local address finally disappeared. */ 904 if (gone && 905 inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) { 906 /* And the last, but not the least thing. 907 * We must flush stray FIB entries. 908 * 909 * First of all, we scan fib_info list searching 910 * for stray nexthop entries, then ignite fib_flush. 911 */ 912 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local)) 913 fib_flush(dev_net(dev)); 914 } 915 } 916 #undef LOCAL_OK 917 #undef BRD_OK 918 #undef BRD0_OK 919 #undef BRD1_OK 920 } 921 922 static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb) 923 { 924 925 struct fib_result res; 926 struct flowi4 fl4 = { 927 .flowi4_mark = frn->fl_mark, 928 .daddr = frn->fl_addr, 929 .flowi4_tos = frn->fl_tos, 930 .flowi4_scope = frn->fl_scope, 931 }; 932 933 frn->err = -ENOENT; 934 if (tb) { 935 local_bh_disable(); 936 937 frn->tb_id = tb->tb_id; 938 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 939 940 if (!frn->err) { 941 frn->prefixlen = res.prefixlen; 942 frn->nh_sel = res.nh_sel; 943 frn->type = res.type; 944 frn->scope = res.scope; 945 } 946 local_bh_enable(); 947 } 948 } 949 950 static void nl_fib_input(struct sk_buff *skb) 951 { 952 struct net *net; 953 struct fib_result_nl *frn; 954 struct nlmsghdr *nlh; 955 struct fib_table *tb; 956 u32 portid; 957 958 net = sock_net(skb->sk); 959 nlh = nlmsg_hdr(skb); 960 if (skb->len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len || 961 nlmsg_len(nlh) < sizeof(*frn)) 962 return; 963 964 skb = netlink_skb_clone(skb, GFP_KERNEL); 965 if (skb == NULL) 966 return; 967 nlh = nlmsg_hdr(skb); 968 969 frn = (struct fib_result_nl *) nlmsg_data(nlh); 970 tb = fib_get_table(net, frn->tb_id_in); 971 972 nl_fib_lookup(frn, tb); 973 974 portid = NETLINK_CB(skb).portid; /* netlink portid */ 975 NETLINK_CB(skb).portid = 0; /* from kernel */ 976 NETLINK_CB(skb).dst_group = 0; /* unicast */ 977 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT); 978 } 979 980 static int __net_init nl_fib_lookup_init(struct net *net) 981 { 982 struct sock *sk; 983 struct netlink_kernel_cfg cfg = { 984 .input = nl_fib_input, 985 }; 986 987 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg); 988 if (sk == NULL) 989 return -EAFNOSUPPORT; 990 net->ipv4.fibnl = sk; 991 return 0; 992 } 993 994 static void nl_fib_lookup_exit(struct net *net) 995 { 996 netlink_kernel_release(net->ipv4.fibnl); 997 net->ipv4.fibnl = NULL; 998 } 999 1000 static void fib_disable_ip(struct net_device *dev, int force) 1001 { 1002 if (fib_sync_down_dev(dev, force)) 1003 fib_flush(dev_net(dev)); 1004 rt_cache_flush(dev_net(dev)); 1005 arp_ifdown(dev); 1006 } 1007 1008 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 1009 { 1010 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 1011 struct net_device *dev = ifa->ifa_dev->dev; 1012 struct net *net = dev_net(dev); 1013 1014 switch (event) { 1015 case NETDEV_UP: 1016 fib_add_ifaddr(ifa); 1017 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1018 fib_sync_up(dev); 1019 #endif 1020 atomic_inc(&net->ipv4.dev_addr_genid); 1021 rt_cache_flush(dev_net(dev)); 1022 break; 1023 case NETDEV_DOWN: 1024 fib_del_ifaddr(ifa, NULL); 1025 atomic_inc(&net->ipv4.dev_addr_genid); 1026 if (ifa->ifa_dev->ifa_list == NULL) { 1027 /* Last address was deleted from this interface. 1028 * Disable IP. 1029 */ 1030 fib_disable_ip(dev, 1); 1031 } else { 1032 rt_cache_flush(dev_net(dev)); 1033 } 1034 break; 1035 } 1036 return NOTIFY_DONE; 1037 } 1038 1039 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1040 { 1041 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1042 struct in_device *in_dev; 1043 struct net *net = dev_net(dev); 1044 1045 if (event == NETDEV_UNREGISTER) { 1046 fib_disable_ip(dev, 2); 1047 rt_flush_dev(dev); 1048 return NOTIFY_DONE; 1049 } 1050 1051 in_dev = __in_dev_get_rtnl(dev); 1052 if (!in_dev) 1053 return NOTIFY_DONE; 1054 1055 switch (event) { 1056 case NETDEV_UP: 1057 for_ifa(in_dev) { 1058 fib_add_ifaddr(ifa); 1059 } endfor_ifa(in_dev); 1060 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1061 fib_sync_up(dev); 1062 #endif 1063 atomic_inc(&net->ipv4.dev_addr_genid); 1064 rt_cache_flush(net); 1065 break; 1066 case NETDEV_DOWN: 1067 fib_disable_ip(dev, 0); 1068 break; 1069 case NETDEV_CHANGEMTU: 1070 case NETDEV_CHANGE: 1071 rt_cache_flush(net); 1072 break; 1073 } 1074 return NOTIFY_DONE; 1075 } 1076 1077 static struct notifier_block fib_inetaddr_notifier = { 1078 .notifier_call = fib_inetaddr_event, 1079 }; 1080 1081 static struct notifier_block fib_netdev_notifier = { 1082 .notifier_call = fib_netdev_event, 1083 }; 1084 1085 static int __net_init ip_fib_net_init(struct net *net) 1086 { 1087 int err; 1088 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1089 1090 /* Avoid false sharing : Use at least a full cache line */ 1091 size = max_t(size_t, size, L1_CACHE_BYTES); 1092 1093 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1094 if (net->ipv4.fib_table_hash == NULL) 1095 return -ENOMEM; 1096 1097 err = fib4_rules_init(net); 1098 if (err < 0) 1099 goto fail; 1100 return 0; 1101 1102 fail: 1103 kfree(net->ipv4.fib_table_hash); 1104 return err; 1105 } 1106 1107 static void ip_fib_net_exit(struct net *net) 1108 { 1109 unsigned int i; 1110 1111 #ifdef CONFIG_IP_MULTIPLE_TABLES 1112 fib4_rules_exit(net); 1113 #endif 1114 1115 rtnl_lock(); 1116 for (i = 0; i < FIB_TABLE_HASHSZ; i++) { 1117 struct fib_table *tb; 1118 struct hlist_head *head; 1119 struct hlist_node *tmp; 1120 1121 head = &net->ipv4.fib_table_hash[i]; 1122 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { 1123 hlist_del(&tb->tb_hlist); 1124 fib_table_flush(tb); 1125 fib_free_table(tb); 1126 } 1127 } 1128 rtnl_unlock(); 1129 kfree(net->ipv4.fib_table_hash); 1130 } 1131 1132 static int __net_init fib_net_init(struct net *net) 1133 { 1134 int error; 1135 1136 #ifdef CONFIG_IP_ROUTE_CLASSID 1137 net->ipv4.fib_num_tclassid_users = 0; 1138 #endif 1139 error = ip_fib_net_init(net); 1140 if (error < 0) 1141 goto out; 1142 error = nl_fib_lookup_init(net); 1143 if (error < 0) 1144 goto out_nlfl; 1145 error = fib_proc_init(net); 1146 if (error < 0) 1147 goto out_proc; 1148 out: 1149 return error; 1150 1151 out_proc: 1152 nl_fib_lookup_exit(net); 1153 out_nlfl: 1154 ip_fib_net_exit(net); 1155 goto out; 1156 } 1157 1158 static void __net_exit fib_net_exit(struct net *net) 1159 { 1160 fib_proc_exit(net); 1161 nl_fib_lookup_exit(net); 1162 ip_fib_net_exit(net); 1163 } 1164 1165 static struct pernet_operations fib_net_ops = { 1166 .init = fib_net_init, 1167 .exit = fib_net_exit, 1168 }; 1169 1170 void __init ip_fib_init(void) 1171 { 1172 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL); 1173 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL); 1174 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL); 1175 1176 register_pernet_subsys(&fib_net_ops); 1177 register_netdevice_notifier(&fib_netdev_notifier); 1178 register_inetaddr_notifier(&fib_inetaddr_notifier); 1179 1180 fib_trie_init(); 1181 } 1182