1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * IPv4 Forwarding Information Base: FIB frontend. 7 * 8 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16 #include <linux/module.h> 17 #include <asm/uaccess.h> 18 #include <asm/system.h> 19 #include <linux/bitops.h> 20 #include <linux/capability.h> 21 #include <linux/types.h> 22 #include <linux/kernel.h> 23 #include <linux/mm.h> 24 #include <linux/string.h> 25 #include <linux/socket.h> 26 #include <linux/sockios.h> 27 #include <linux/errno.h> 28 #include <linux/in.h> 29 #include <linux/inet.h> 30 #include <linux/inetdevice.h> 31 #include <linux/netdevice.h> 32 #include <linux/if_addr.h> 33 #include <linux/if_arp.h> 34 #include <linux/skbuff.h> 35 #include <linux/init.h> 36 #include <linux/list.h> 37 #include <linux/slab.h> 38 39 #include <net/ip.h> 40 #include <net/protocol.h> 41 #include <net/route.h> 42 #include <net/tcp.h> 43 #include <net/sock.h> 44 #include <net/arp.h> 45 #include <net/ip_fib.h> 46 #include <net/rtnetlink.h> 47 48 #ifndef CONFIG_IP_MULTIPLE_TABLES 49 50 static int __net_init fib4_rules_init(struct net *net) 51 { 52 struct fib_table *local_table, *main_table; 53 54 local_table = fib_hash_table(RT_TABLE_LOCAL); 55 if (local_table == NULL) 56 return -ENOMEM; 57 58 main_table = fib_hash_table(RT_TABLE_MAIN); 59 if (main_table == NULL) 60 goto fail; 61 62 hlist_add_head_rcu(&local_table->tb_hlist, 63 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]); 64 hlist_add_head_rcu(&main_table->tb_hlist, 65 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]); 66 return 0; 67 68 fail: 69 kfree(local_table); 70 return -ENOMEM; 71 } 72 #else 73 74 struct fib_table *fib_new_table(struct net *net, u32 id) 75 { 76 struct fib_table *tb; 77 unsigned int h; 78 79 if (id == 0) 80 id = RT_TABLE_MAIN; 81 tb = fib_get_table(net, id); 82 if (tb) 83 return tb; 84 85 tb = fib_hash_table(id); 86 if (!tb) 87 return NULL; 88 h = id & (FIB_TABLE_HASHSZ - 1); 89 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]); 90 return tb; 91 } 92 93 struct fib_table *fib_get_table(struct net *net, u32 id) 94 { 95 struct fib_table *tb; 96 struct hlist_node *node; 97 struct hlist_head *head; 98 unsigned int h; 99 100 if (id == 0) 101 id = RT_TABLE_MAIN; 102 h = id & (FIB_TABLE_HASHSZ - 1); 103 104 rcu_read_lock(); 105 head = &net->ipv4.fib_table_hash[h]; 106 hlist_for_each_entry_rcu(tb, node, head, tb_hlist) { 107 if (tb->tb_id == id) { 108 rcu_read_unlock(); 109 return tb; 110 } 111 } 112 rcu_read_unlock(); 113 return NULL; 114 } 115 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 116 117 void fib_select_default(struct net *net, 118 const struct flowi *flp, struct fib_result *res) 119 { 120 struct fib_table *tb; 121 int table = RT_TABLE_MAIN; 122 #ifdef CONFIG_IP_MULTIPLE_TABLES 123 if (res->r == NULL || res->r->action != FR_ACT_TO_TBL) 124 return; 125 table = res->r->table; 126 #endif 127 tb = fib_get_table(net, table); 128 if (FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) 129 fib_table_select_default(tb, flp, res); 130 } 131 132 static void fib_flush(struct net *net) 133 { 134 int flushed = 0; 135 struct fib_table *tb; 136 struct hlist_node *node; 137 struct hlist_head *head; 138 unsigned int h; 139 140 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 141 head = &net->ipv4.fib_table_hash[h]; 142 hlist_for_each_entry(tb, node, head, tb_hlist) 143 flushed += fib_table_flush(tb); 144 } 145 146 if (flushed) 147 rt_cache_flush(net, -1); 148 } 149 150 /** 151 * __ip_dev_find - find the first device with a given source address. 152 * @net: the net namespace 153 * @addr: the source address 154 * @devref: if true, take a reference on the found device 155 * 156 * If a caller uses devref=false, it should be protected by RCU, or RTNL 157 */ 158 struct net_device *__ip_dev_find(struct net *net, __be32 addr, bool devref) 159 { 160 struct flowi fl = { 161 .fl4_dst = addr, 162 }; 163 struct fib_result res = { 0 }; 164 struct net_device *dev = NULL; 165 struct fib_table *local_table; 166 167 #ifdef CONFIG_IP_MULTIPLE_TABLES 168 res.r = NULL; 169 #endif 170 171 rcu_read_lock(); 172 local_table = fib_get_table(net, RT_TABLE_LOCAL); 173 if (!local_table || 174 fib_table_lookup(local_table, &fl, &res, FIB_LOOKUP_NOREF)) { 175 rcu_read_unlock(); 176 return NULL; 177 } 178 if (res.type != RTN_LOCAL) 179 goto out; 180 dev = FIB_RES_DEV(res); 181 182 if (dev && devref) 183 dev_hold(dev); 184 out: 185 rcu_read_unlock(); 186 return dev; 187 } 188 EXPORT_SYMBOL(__ip_dev_find); 189 190 /* 191 * Find address type as if only "dev" was present in the system. If 192 * on_dev is NULL then all interfaces are taken into consideration. 193 */ 194 static inline unsigned __inet_dev_addr_type(struct net *net, 195 const struct net_device *dev, 196 __be32 addr) 197 { 198 struct flowi fl = { .fl4_dst = addr }; 199 struct fib_result res; 200 unsigned ret = RTN_BROADCAST; 201 struct fib_table *local_table; 202 203 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr)) 204 return RTN_BROADCAST; 205 if (ipv4_is_multicast(addr)) 206 return RTN_MULTICAST; 207 208 #ifdef CONFIG_IP_MULTIPLE_TABLES 209 res.r = NULL; 210 #endif 211 212 local_table = fib_get_table(net, RT_TABLE_LOCAL); 213 if (local_table) { 214 ret = RTN_UNICAST; 215 rcu_read_lock(); 216 if (!fib_table_lookup(local_table, &fl, &res, FIB_LOOKUP_NOREF)) { 217 if (!dev || dev == res.fi->fib_dev) 218 ret = res.type; 219 } 220 rcu_read_unlock(); 221 } 222 return ret; 223 } 224 225 unsigned int inet_addr_type(struct net *net, __be32 addr) 226 { 227 return __inet_dev_addr_type(net, NULL, addr); 228 } 229 EXPORT_SYMBOL(inet_addr_type); 230 231 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, 232 __be32 addr) 233 { 234 return __inet_dev_addr_type(net, dev, addr); 235 } 236 EXPORT_SYMBOL(inet_dev_addr_type); 237 238 /* Given (packet source, input interface) and optional (dst, oif, tos): 239 * - (main) check, that source is valid i.e. not broadcast or our local 240 * address. 241 * - figure out what "logical" interface this packet arrived 242 * and calculate "specific destination" address. 243 * - check, that packet arrived from expected physical interface. 244 * called with rcu_read_lock() 245 */ 246 int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif, 247 struct net_device *dev, __be32 *spec_dst, 248 u32 *itag, u32 mark) 249 { 250 struct in_device *in_dev; 251 struct flowi fl = { 252 .fl4_dst = src, 253 .fl4_src = dst, 254 .fl4_tos = tos, 255 .mark = mark, 256 .iif = oif 257 }; 258 struct fib_result res; 259 int no_addr, rpf, accept_local; 260 bool dev_match; 261 int ret; 262 struct net *net; 263 264 no_addr = rpf = accept_local = 0; 265 in_dev = __in_dev_get_rcu(dev); 266 if (in_dev) { 267 no_addr = in_dev->ifa_list == NULL; 268 rpf = IN_DEV_RPFILTER(in_dev); 269 accept_local = IN_DEV_ACCEPT_LOCAL(in_dev); 270 if (mark && !IN_DEV_SRC_VMARK(in_dev)) 271 fl.mark = 0; 272 } 273 274 if (in_dev == NULL) 275 goto e_inval; 276 277 net = dev_net(dev); 278 if (fib_lookup(net, &fl, &res)) 279 goto last_resort; 280 if (res.type != RTN_UNICAST) { 281 if (res.type != RTN_LOCAL || !accept_local) 282 goto e_inval; 283 } 284 *spec_dst = FIB_RES_PREFSRC(res); 285 fib_combine_itag(itag, &res); 286 dev_match = false; 287 288 #ifdef CONFIG_IP_ROUTE_MULTIPATH 289 for (ret = 0; ret < res.fi->fib_nhs; ret++) { 290 struct fib_nh *nh = &res.fi->fib_nh[ret]; 291 292 if (nh->nh_dev == dev) { 293 dev_match = true; 294 break; 295 } 296 } 297 #else 298 if (FIB_RES_DEV(res) == dev) 299 dev_match = true; 300 #endif 301 if (dev_match) { 302 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 303 return ret; 304 } 305 if (no_addr) 306 goto last_resort; 307 if (rpf == 1) 308 goto e_rpf; 309 fl.oif = dev->ifindex; 310 311 ret = 0; 312 if (fib_lookup(net, &fl, &res) == 0) { 313 if (res.type == RTN_UNICAST) { 314 *spec_dst = FIB_RES_PREFSRC(res); 315 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 316 } 317 } 318 return ret; 319 320 last_resort: 321 if (rpf) 322 goto e_rpf; 323 *spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE); 324 *itag = 0; 325 return 0; 326 327 e_inval: 328 return -EINVAL; 329 e_rpf: 330 return -EXDEV; 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 (!capable(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.pid = NETLINK_CB(skb).pid; 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, void *arg) 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, void *arg) 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_node *node; 660 struct hlist_head *head; 661 int dumped = 0; 662 663 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) && 664 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED) 665 return ip_rt_dump(skb, cb); 666 667 s_h = cb->args[0]; 668 s_e = cb->args[1]; 669 670 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 671 e = 0; 672 head = &net->ipv4.fib_table_hash[h]; 673 hlist_for_each_entry(tb, node, head, tb_hlist) { 674 if (e < s_e) 675 goto next; 676 if (dumped) 677 memset(&cb->args[2], 0, sizeof(cb->args) - 678 2 * sizeof(cb->args[0])); 679 if (fib_table_dump(tb, skb, cb) < 0) 680 goto out; 681 dumped = 1; 682 next: 683 e++; 684 } 685 } 686 out: 687 cb->args[1] = e; 688 cb->args[0] = h; 689 690 return skb->len; 691 } 692 693 /* Prepare and feed intra-kernel routing request. 694 * Really, it should be netlink message, but :-( netlink 695 * can be not configured, so that we feed it directly 696 * to fib engine. It is legal, because all events occur 697 * only when netlink is already locked. 698 */ 699 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa) 700 { 701 struct net *net = dev_net(ifa->ifa_dev->dev); 702 struct fib_table *tb; 703 struct fib_config cfg = { 704 .fc_protocol = RTPROT_KERNEL, 705 .fc_type = type, 706 .fc_dst = dst, 707 .fc_dst_len = dst_len, 708 .fc_prefsrc = ifa->ifa_local, 709 .fc_oif = ifa->ifa_dev->dev->ifindex, 710 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 711 .fc_nlinfo = { 712 .nl_net = net, 713 }, 714 }; 715 716 if (type == RTN_UNICAST) 717 tb = fib_new_table(net, RT_TABLE_MAIN); 718 else 719 tb = fib_new_table(net, RT_TABLE_LOCAL); 720 721 if (tb == NULL) 722 return; 723 724 cfg.fc_table = tb->tb_id; 725 726 if (type != RTN_LOCAL) 727 cfg.fc_scope = RT_SCOPE_LINK; 728 else 729 cfg.fc_scope = RT_SCOPE_HOST; 730 731 if (cmd == RTM_NEWROUTE) 732 fib_table_insert(tb, &cfg); 733 else 734 fib_table_delete(tb, &cfg); 735 } 736 737 void fib_add_ifaddr(struct in_ifaddr *ifa) 738 { 739 struct in_device *in_dev = ifa->ifa_dev; 740 struct net_device *dev = in_dev->dev; 741 struct in_ifaddr *prim = ifa; 742 __be32 mask = ifa->ifa_mask; 743 __be32 addr = ifa->ifa_local; 744 __be32 prefix = ifa->ifa_address & mask; 745 746 if (ifa->ifa_flags & IFA_F_SECONDARY) { 747 prim = inet_ifa_byprefix(in_dev, prefix, mask); 748 if (prim == NULL) { 749 printk(KERN_WARNING "fib_add_ifaddr: bug: prim == NULL\n"); 750 return; 751 } 752 } 753 754 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim); 755 756 if (!(dev->flags & IFF_UP)) 757 return; 758 759 /* Add broadcast address, if it is explicitly assigned. */ 760 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 761 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 762 763 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && 764 (prefix != addr || ifa->ifa_prefixlen < 32)) { 765 fib_magic(RTM_NEWROUTE, 766 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 767 prefix, ifa->ifa_prefixlen, prim); 768 769 /* Add network specific broadcasts, when it takes a sense */ 770 if (ifa->ifa_prefixlen < 31) { 771 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim); 772 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask, 773 32, prim); 774 } 775 } 776 } 777 778 static void fib_del_ifaddr(struct in_ifaddr *ifa) 779 { 780 struct in_device *in_dev = ifa->ifa_dev; 781 struct net_device *dev = in_dev->dev; 782 struct in_ifaddr *ifa1; 783 struct in_ifaddr *prim = ifa; 784 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; 785 __be32 any = ifa->ifa_address & ifa->ifa_mask; 786 #define LOCAL_OK 1 787 #define BRD_OK 2 788 #define BRD0_OK 4 789 #define BRD1_OK 8 790 unsigned ok = 0; 791 792 if (!(ifa->ifa_flags & IFA_F_SECONDARY)) 793 fib_magic(RTM_DELROUTE, 794 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, 795 any, ifa->ifa_prefixlen, prim); 796 else { 797 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 798 if (prim == NULL) { 799 printk(KERN_WARNING "fib_del_ifaddr: bug: prim == NULL\n"); 800 return; 801 } 802 } 803 804 /* Deletion is more complicated than add. 805 * We should take care of not to delete too much :-) 806 * 807 * Scan address list to be sure that addresses are really gone. 808 */ 809 810 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) { 811 if (ifa->ifa_local == ifa1->ifa_local) 812 ok |= LOCAL_OK; 813 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 814 ok |= BRD_OK; 815 if (brd == ifa1->ifa_broadcast) 816 ok |= BRD1_OK; 817 if (any == ifa1->ifa_broadcast) 818 ok |= BRD0_OK; 819 } 820 821 if (!(ok & BRD_OK)) 822 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 823 if (!(ok & BRD1_OK)) 824 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim); 825 if (!(ok & BRD0_OK)) 826 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim); 827 if (!(ok & LOCAL_OK)) { 828 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim); 829 830 /* Check, that this local address finally disappeared. */ 831 if (inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) { 832 /* And the last, but not the least thing. 833 * We must flush stray FIB entries. 834 * 835 * First of all, we scan fib_info list searching 836 * for stray nexthop entries, then ignite fib_flush. 837 */ 838 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local)) 839 fib_flush(dev_net(dev)); 840 } 841 } 842 #undef LOCAL_OK 843 #undef BRD_OK 844 #undef BRD0_OK 845 #undef BRD1_OK 846 } 847 848 static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb) 849 { 850 851 struct fib_result res; 852 struct flowi fl = { 853 .mark = frn->fl_mark, 854 .fl4_dst = frn->fl_addr, 855 .fl4_tos = frn->fl_tos, 856 .fl4_scope = frn->fl_scope, 857 }; 858 859 #ifdef CONFIG_IP_MULTIPLE_TABLES 860 res.r = NULL; 861 #endif 862 863 frn->err = -ENOENT; 864 if (tb) { 865 local_bh_disable(); 866 867 frn->tb_id = tb->tb_id; 868 rcu_read_lock(); 869 frn->err = fib_table_lookup(tb, &fl, &res, FIB_LOOKUP_NOREF); 870 871 if (!frn->err) { 872 frn->prefixlen = res.prefixlen; 873 frn->nh_sel = res.nh_sel; 874 frn->type = res.type; 875 frn->scope = res.scope; 876 } 877 rcu_read_unlock(); 878 local_bh_enable(); 879 } 880 } 881 882 static void nl_fib_input(struct sk_buff *skb) 883 { 884 struct net *net; 885 struct fib_result_nl *frn; 886 struct nlmsghdr *nlh; 887 struct fib_table *tb; 888 u32 pid; 889 890 net = sock_net(skb->sk); 891 nlh = nlmsg_hdr(skb); 892 if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len || 893 nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn))) 894 return; 895 896 skb = skb_clone(skb, GFP_KERNEL); 897 if (skb == NULL) 898 return; 899 nlh = nlmsg_hdr(skb); 900 901 frn = (struct fib_result_nl *) NLMSG_DATA(nlh); 902 tb = fib_get_table(net, frn->tb_id_in); 903 904 nl_fib_lookup(frn, tb); 905 906 pid = NETLINK_CB(skb).pid; /* pid of sending process */ 907 NETLINK_CB(skb).pid = 0; /* from kernel */ 908 NETLINK_CB(skb).dst_group = 0; /* unicast */ 909 netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT); 910 } 911 912 static int __net_init nl_fib_lookup_init(struct net *net) 913 { 914 struct sock *sk; 915 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0, 916 nl_fib_input, NULL, THIS_MODULE); 917 if (sk == NULL) 918 return -EAFNOSUPPORT; 919 net->ipv4.fibnl = sk; 920 return 0; 921 } 922 923 static void nl_fib_lookup_exit(struct net *net) 924 { 925 netlink_kernel_release(net->ipv4.fibnl); 926 net->ipv4.fibnl = NULL; 927 } 928 929 static void fib_disable_ip(struct net_device *dev, int force, int delay) 930 { 931 if (fib_sync_down_dev(dev, force)) 932 fib_flush(dev_net(dev)); 933 rt_cache_flush(dev_net(dev), delay); 934 arp_ifdown(dev); 935 } 936 937 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 938 { 939 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 940 struct net_device *dev = ifa->ifa_dev->dev; 941 942 switch (event) { 943 case NETDEV_UP: 944 fib_add_ifaddr(ifa); 945 #ifdef CONFIG_IP_ROUTE_MULTIPATH 946 fib_sync_up(dev); 947 #endif 948 rt_cache_flush(dev_net(dev), -1); 949 break; 950 case NETDEV_DOWN: 951 fib_del_ifaddr(ifa); 952 if (ifa->ifa_dev->ifa_list == NULL) { 953 /* Last address was deleted from this interface. 954 * Disable IP. 955 */ 956 fib_disable_ip(dev, 1, 0); 957 } else { 958 rt_cache_flush(dev_net(dev), -1); 959 } 960 break; 961 } 962 return NOTIFY_DONE; 963 } 964 965 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 966 { 967 struct net_device *dev = ptr; 968 struct in_device *in_dev = __in_dev_get_rtnl(dev); 969 970 if (event == NETDEV_UNREGISTER) { 971 fib_disable_ip(dev, 2, -1); 972 return NOTIFY_DONE; 973 } 974 975 if (!in_dev) 976 return NOTIFY_DONE; 977 978 switch (event) { 979 case NETDEV_UP: 980 for_ifa(in_dev) { 981 fib_add_ifaddr(ifa); 982 } endfor_ifa(in_dev); 983 #ifdef CONFIG_IP_ROUTE_MULTIPATH 984 fib_sync_up(dev); 985 #endif 986 rt_cache_flush(dev_net(dev), -1); 987 break; 988 case NETDEV_DOWN: 989 fib_disable_ip(dev, 0, 0); 990 break; 991 case NETDEV_CHANGEMTU: 992 case NETDEV_CHANGE: 993 rt_cache_flush(dev_net(dev), 0); 994 break; 995 case NETDEV_UNREGISTER_BATCH: 996 /* The batch unregister is only called on the first 997 * device in the list of devices being unregistered. 998 * Therefore we should not pass dev_net(dev) in here. 999 */ 1000 rt_cache_flush_batch(NULL); 1001 break; 1002 } 1003 return NOTIFY_DONE; 1004 } 1005 1006 static struct notifier_block fib_inetaddr_notifier = { 1007 .notifier_call = fib_inetaddr_event, 1008 }; 1009 1010 static struct notifier_block fib_netdev_notifier = { 1011 .notifier_call = fib_netdev_event, 1012 }; 1013 1014 static int __net_init ip_fib_net_init(struct net *net) 1015 { 1016 int err; 1017 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; 1018 1019 /* Avoid false sharing : Use at least a full cache line */ 1020 size = max_t(size_t, size, L1_CACHE_BYTES); 1021 1022 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); 1023 if (net->ipv4.fib_table_hash == NULL) 1024 return -ENOMEM; 1025 1026 err = fib4_rules_init(net); 1027 if (err < 0) 1028 goto fail; 1029 return 0; 1030 1031 fail: 1032 kfree(net->ipv4.fib_table_hash); 1033 return err; 1034 } 1035 1036 static void ip_fib_net_exit(struct net *net) 1037 { 1038 unsigned int i; 1039 1040 #ifdef CONFIG_IP_MULTIPLE_TABLES 1041 fib4_rules_exit(net); 1042 #endif 1043 1044 for (i = 0; i < FIB_TABLE_HASHSZ; i++) { 1045 struct fib_table *tb; 1046 struct hlist_head *head; 1047 struct hlist_node *node, *tmp; 1048 1049 head = &net->ipv4.fib_table_hash[i]; 1050 hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) { 1051 hlist_del(node); 1052 fib_table_flush(tb); 1053 fib_free_table(tb); 1054 } 1055 } 1056 kfree(net->ipv4.fib_table_hash); 1057 } 1058 1059 static int __net_init fib_net_init(struct net *net) 1060 { 1061 int error; 1062 1063 error = ip_fib_net_init(net); 1064 if (error < 0) 1065 goto out; 1066 error = nl_fib_lookup_init(net); 1067 if (error < 0) 1068 goto out_nlfl; 1069 error = fib_proc_init(net); 1070 if (error < 0) 1071 goto out_proc; 1072 out: 1073 return error; 1074 1075 out_proc: 1076 nl_fib_lookup_exit(net); 1077 out_nlfl: 1078 ip_fib_net_exit(net); 1079 goto out; 1080 } 1081 1082 static void __net_exit fib_net_exit(struct net *net) 1083 { 1084 fib_proc_exit(net); 1085 nl_fib_lookup_exit(net); 1086 ip_fib_net_exit(net); 1087 } 1088 1089 static struct pernet_operations fib_net_ops = { 1090 .init = fib_net_init, 1091 .exit = fib_net_exit, 1092 }; 1093 1094 void __init ip_fib_init(void) 1095 { 1096 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL); 1097 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL); 1098 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib); 1099 1100 register_pernet_subsys(&fib_net_ops); 1101 register_netdevice_notifier(&fib_netdev_notifier); 1102 register_inetaddr_notifier(&fib_inetaddr_notifier); 1103 1104 fib_hash_init(); 1105 } 1106