fib_frontend.c revision 9f00d9776bc5beb92e8bfc884a7e96ddc5589e2e
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 51static 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 69fail: 70 kfree(local_table); 71 return -ENOMEM; 72} 73#else 74 75struct 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 112struct fib_table *fib_get_table(struct net *net, u32 id) 113{ 114 struct fib_table *tb; 115 struct hlist_node *node; 116 struct hlist_head *head; 117 unsigned int h; 118 119 if (id == 0) 120 id = RT_TABLE_MAIN; 121 h = id & (FIB_TABLE_HASHSZ - 1); 122 123 rcu_read_lock(); 124 head = &net->ipv4.fib_table_hash[h]; 125 hlist_for_each_entry_rcu(tb, node, head, tb_hlist) { 126 if (tb->tb_id == id) { 127 rcu_read_unlock(); 128 return tb; 129 } 130 } 131 rcu_read_unlock(); 132 return NULL; 133} 134#endif /* CONFIG_IP_MULTIPLE_TABLES */ 135 136static void fib_flush(struct net *net) 137{ 138 int flushed = 0; 139 struct fib_table *tb; 140 struct hlist_node *node; 141 struct hlist_head *head; 142 unsigned int h; 143 144 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 145 head = &net->ipv4.fib_table_hash[h]; 146 hlist_for_each_entry(tb, node, head, tb_hlist) 147 flushed += fib_table_flush(tb); 148 } 149 150 if (flushed) 151 rt_cache_flush(net); 152} 153 154/* 155 * Find address type as if only "dev" was present in the system. If 156 * on_dev is NULL then all interfaces are taken into consideration. 157 */ 158static inline unsigned int __inet_dev_addr_type(struct net *net, 159 const struct net_device *dev, 160 __be32 addr) 161{ 162 struct flowi4 fl4 = { .daddr = addr }; 163 struct fib_result res; 164 unsigned int ret = RTN_BROADCAST; 165 struct fib_table *local_table; 166 167 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr)) 168 return RTN_BROADCAST; 169 if (ipv4_is_multicast(addr)) 170 return RTN_MULTICAST; 171 172 local_table = fib_get_table(net, RT_TABLE_LOCAL); 173 if (local_table) { 174 ret = RTN_UNICAST; 175 rcu_read_lock(); 176 if (!fib_table_lookup(local_table, &fl4, &res, FIB_LOOKUP_NOREF)) { 177 if (!dev || dev == res.fi->fib_dev) 178 ret = res.type; 179 } 180 rcu_read_unlock(); 181 } 182 return ret; 183} 184 185unsigned int inet_addr_type(struct net *net, __be32 addr) 186{ 187 return __inet_dev_addr_type(net, NULL, addr); 188} 189EXPORT_SYMBOL(inet_addr_type); 190 191unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, 192 __be32 addr) 193{ 194 return __inet_dev_addr_type(net, dev, addr); 195} 196EXPORT_SYMBOL(inet_dev_addr_type); 197 198__be32 fib_compute_spec_dst(struct sk_buff *skb) 199{ 200 struct net_device *dev = skb->dev; 201 struct in_device *in_dev; 202 struct fib_result res; 203 struct rtable *rt; 204 struct flowi4 fl4; 205 struct net *net; 206 int scope; 207 208 rt = skb_rtable(skb); 209 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) == 210 RTCF_LOCAL) 211 return ip_hdr(skb)->daddr; 212 213 in_dev = __in_dev_get_rcu(dev); 214 BUG_ON(!in_dev); 215 216 net = dev_net(dev); 217 218 scope = RT_SCOPE_UNIVERSE; 219 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) { 220 fl4.flowi4_oif = 0; 221 fl4.flowi4_iif = LOOPBACK_IFINDEX; 222 fl4.daddr = ip_hdr(skb)->saddr; 223 fl4.saddr = 0; 224 fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos); 225 fl4.flowi4_scope = scope; 226 fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0; 227 if (!fib_lookup(net, &fl4, &res)) 228 return FIB_RES_PREFSRC(net, res); 229 } else { 230 scope = RT_SCOPE_LINK; 231 } 232 233 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope); 234} 235 236/* Given (packet source, input interface) and optional (dst, oif, tos): 237 * - (main) check, that source is valid i.e. not broadcast or our local 238 * address. 239 * - figure out what "logical" interface this packet arrived 240 * and calculate "specific destination" address. 241 * - check, that packet arrived from expected physical interface. 242 * called with rcu_read_lock() 243 */ 244static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 245 u8 tos, int oif, struct net_device *dev, 246 int rpf, struct in_device *idev, u32 *itag) 247{ 248 int ret, no_addr, accept_local; 249 struct fib_result res; 250 struct flowi4 fl4; 251 struct net *net; 252 bool dev_match; 253 254 fl4.flowi4_oif = 0; 255 fl4.flowi4_iif = oif; 256 fl4.daddr = src; 257 fl4.saddr = dst; 258 fl4.flowi4_tos = tos; 259 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 260 261 no_addr = idev->ifa_list == NULL; 262 263 accept_local = IN_DEV_ACCEPT_LOCAL(idev); 264 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0; 265 266 net = dev_net(dev); 267 if (fib_lookup(net, &fl4, &res)) 268 goto last_resort; 269 if (res.type != RTN_UNICAST) { 270 if (res.type != RTN_LOCAL || !accept_local) 271 goto e_inval; 272 } 273 fib_combine_itag(itag, &res); 274 dev_match = false; 275 276#ifdef CONFIG_IP_ROUTE_MULTIPATH 277 for (ret = 0; ret < res.fi->fib_nhs; ret++) { 278 struct fib_nh *nh = &res.fi->fib_nh[ret]; 279 280 if (nh->nh_dev == dev) { 281 dev_match = true; 282 break; 283 } 284 } 285#else 286 if (FIB_RES_DEV(res) == dev) 287 dev_match = true; 288#endif 289 if (dev_match) { 290 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 291 return ret; 292 } 293 if (no_addr) 294 goto last_resort; 295 if (rpf == 1) 296 goto e_rpf; 297 fl4.flowi4_oif = dev->ifindex; 298 299 ret = 0; 300 if (fib_lookup(net, &fl4, &res) == 0) { 301 if (res.type == RTN_UNICAST) 302 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 303 } 304 return ret; 305 306last_resort: 307 if (rpf) 308 goto e_rpf; 309 *itag = 0; 310 return 0; 311 312e_inval: 313 return -EINVAL; 314e_rpf: 315 return -EXDEV; 316} 317 318/* Ignore rp_filter for packets protected by IPsec. */ 319int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 320 u8 tos, int oif, struct net_device *dev, 321 struct in_device *idev, u32 *itag) 322{ 323 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev); 324 325 if (!r && !fib_num_tclassid_users(dev_net(dev))) { 326 *itag = 0; 327 return 0; 328 } 329 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag); 330} 331 332static inline __be32 sk_extract_addr(struct sockaddr *addr) 333{ 334 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 335} 336 337static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 338{ 339 struct nlattr *nla; 340 341 nla = (struct nlattr *) ((char *) mx + len); 342 nla->nla_type = type; 343 nla->nla_len = nla_attr_size(4); 344 *(u32 *) nla_data(nla) = value; 345 346 return len + nla_total_size(4); 347} 348 349static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, 350 struct fib_config *cfg) 351{ 352 __be32 addr; 353 int plen; 354 355 memset(cfg, 0, sizeof(*cfg)); 356 cfg->fc_nlinfo.nl_net = net; 357 358 if (rt->rt_dst.sa_family != AF_INET) 359 return -EAFNOSUPPORT; 360 361 /* 362 * Check mask for validity: 363 * a) it must be contiguous. 364 * b) destination must have all host bits clear. 365 * c) if application forgot to set correct family (AF_INET), 366 * reject request unless it is absolutely clear i.e. 367 * both family and mask are zero. 368 */ 369 plen = 32; 370 addr = sk_extract_addr(&rt->rt_dst); 371 if (!(rt->rt_flags & RTF_HOST)) { 372 __be32 mask = sk_extract_addr(&rt->rt_genmask); 373 374 if (rt->rt_genmask.sa_family != AF_INET) { 375 if (mask || rt->rt_genmask.sa_family) 376 return -EAFNOSUPPORT; 377 } 378 379 if (bad_mask(mask, addr)) 380 return -EINVAL; 381 382 plen = inet_mask_len(mask); 383 } 384 385 cfg->fc_dst_len = plen; 386 cfg->fc_dst = addr; 387 388 if (cmd != SIOCDELRT) { 389 cfg->fc_nlflags = NLM_F_CREATE; 390 cfg->fc_protocol = RTPROT_BOOT; 391 } 392 393 if (rt->rt_metric) 394 cfg->fc_priority = rt->rt_metric - 1; 395 396 if (rt->rt_flags & RTF_REJECT) { 397 cfg->fc_scope = RT_SCOPE_HOST; 398 cfg->fc_type = RTN_UNREACHABLE; 399 return 0; 400 } 401 402 cfg->fc_scope = RT_SCOPE_NOWHERE; 403 cfg->fc_type = RTN_UNICAST; 404 405 if (rt->rt_dev) { 406 char *colon; 407 struct net_device *dev; 408 char devname[IFNAMSIZ]; 409 410 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 411 return -EFAULT; 412 413 devname[IFNAMSIZ-1] = 0; 414 colon = strchr(devname, ':'); 415 if (colon) 416 *colon = 0; 417 dev = __dev_get_by_name(net, devname); 418 if (!dev) 419 return -ENODEV; 420 cfg->fc_oif = dev->ifindex; 421 if (colon) { 422 struct in_ifaddr *ifa; 423 struct in_device *in_dev = __in_dev_get_rtnl(dev); 424 if (!in_dev) 425 return -ENODEV; 426 *colon = ':'; 427 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) 428 if (strcmp(ifa->ifa_label, devname) == 0) 429 break; 430 if (ifa == NULL) 431 return -ENODEV; 432 cfg->fc_prefsrc = ifa->ifa_local; 433 } 434 } 435 436 addr = sk_extract_addr(&rt->rt_gateway); 437 if (rt->rt_gateway.sa_family == AF_INET && addr) { 438 cfg->fc_gw = addr; 439 if (rt->rt_flags & RTF_GATEWAY && 440 inet_addr_type(net, addr) == RTN_UNICAST) 441 cfg->fc_scope = RT_SCOPE_UNIVERSE; 442 } 443 444 if (cmd == SIOCDELRT) 445 return 0; 446 447 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw) 448 return -EINVAL; 449 450 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 451 cfg->fc_scope = RT_SCOPE_LINK; 452 453 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 454 struct nlattr *mx; 455 int len = 0; 456 457 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL); 458 if (mx == NULL) 459 return -ENOMEM; 460 461 if (rt->rt_flags & RTF_MTU) 462 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 463 464 if (rt->rt_flags & RTF_WINDOW) 465 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 466 467 if (rt->rt_flags & RTF_IRTT) 468 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 469 470 cfg->fc_mx = mx; 471 cfg->fc_mx_len = len; 472 } 473 474 return 0; 475} 476 477/* 478 * Handle IP routing ioctl calls. 479 * These are used to manipulate the routing tables 480 */ 481int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg) 482{ 483 struct fib_config cfg; 484 struct rtentry rt; 485 int err; 486 487 switch (cmd) { 488 case SIOCADDRT: /* Add a route */ 489 case SIOCDELRT: /* Delete a route */ 490 if (!capable(CAP_NET_ADMIN)) 491 return -EPERM; 492 493 if (copy_from_user(&rt, arg, sizeof(rt))) 494 return -EFAULT; 495 496 rtnl_lock(); 497 err = rtentry_to_fib_config(net, cmd, &rt, &cfg); 498 if (err == 0) { 499 struct fib_table *tb; 500 501 if (cmd == SIOCDELRT) { 502 tb = fib_get_table(net, cfg.fc_table); 503 if (tb) 504 err = fib_table_delete(tb, &cfg); 505 else 506 err = -ESRCH; 507 } else { 508 tb = fib_new_table(net, cfg.fc_table); 509 if (tb) 510 err = fib_table_insert(tb, &cfg); 511 else 512 err = -ENOBUFS; 513 } 514 515 /* allocated by rtentry_to_fib_config() */ 516 kfree(cfg.fc_mx); 517 } 518 rtnl_unlock(); 519 return err; 520 } 521 return -EINVAL; 522} 523 524const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { 525 [RTA_DST] = { .type = NLA_U32 }, 526 [RTA_SRC] = { .type = NLA_U32 }, 527 [RTA_IIF] = { .type = NLA_U32 }, 528 [RTA_OIF] = { .type = NLA_U32 }, 529 [RTA_GATEWAY] = { .type = NLA_U32 }, 530 [RTA_PRIORITY] = { .type = NLA_U32 }, 531 [RTA_PREFSRC] = { .type = NLA_U32 }, 532 [RTA_METRICS] = { .type = NLA_NESTED }, 533 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 534 [RTA_FLOW] = { .type = NLA_U32 }, 535}; 536 537static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, 538 struct nlmsghdr *nlh, struct fib_config *cfg) 539{ 540 struct nlattr *attr; 541 int err, remaining; 542 struct rtmsg *rtm; 543 544 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy); 545 if (err < 0) 546 goto errout; 547 548 memset(cfg, 0, sizeof(*cfg)); 549 550 rtm = nlmsg_data(nlh); 551 cfg->fc_dst_len = rtm->rtm_dst_len; 552 cfg->fc_tos = rtm->rtm_tos; 553 cfg->fc_table = rtm->rtm_table; 554 cfg->fc_protocol = rtm->rtm_protocol; 555 cfg->fc_scope = rtm->rtm_scope; 556 cfg->fc_type = rtm->rtm_type; 557 cfg->fc_flags = rtm->rtm_flags; 558 cfg->fc_nlflags = nlh->nlmsg_flags; 559 560 cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid; 561 cfg->fc_nlinfo.nlh = nlh; 562 cfg->fc_nlinfo.nl_net = net; 563 564 if (cfg->fc_type > RTN_MAX) { 565 err = -EINVAL; 566 goto errout; 567 } 568 569 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 570 switch (nla_type(attr)) { 571 case RTA_DST: 572 cfg->fc_dst = nla_get_be32(attr); 573 break; 574 case RTA_OIF: 575 cfg->fc_oif = nla_get_u32(attr); 576 break; 577 case RTA_GATEWAY: 578 cfg->fc_gw = nla_get_be32(attr); 579 break; 580 case RTA_PRIORITY: 581 cfg->fc_priority = nla_get_u32(attr); 582 break; 583 case RTA_PREFSRC: 584 cfg->fc_prefsrc = nla_get_be32(attr); 585 break; 586 case RTA_METRICS: 587 cfg->fc_mx = nla_data(attr); 588 cfg->fc_mx_len = nla_len(attr); 589 break; 590 case RTA_MULTIPATH: 591 cfg->fc_mp = nla_data(attr); 592 cfg->fc_mp_len = nla_len(attr); 593 break; 594 case RTA_FLOW: 595 cfg->fc_flow = nla_get_u32(attr); 596 break; 597 case RTA_TABLE: 598 cfg->fc_table = nla_get_u32(attr); 599 break; 600 } 601 } 602 603 return 0; 604errout: 605 return err; 606} 607 608static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 609{ 610 struct net *net = sock_net(skb->sk); 611 struct fib_config cfg; 612 struct fib_table *tb; 613 int err; 614 615 err = rtm_to_fib_config(net, skb, nlh, &cfg); 616 if (err < 0) 617 goto errout; 618 619 tb = fib_get_table(net, cfg.fc_table); 620 if (tb == NULL) { 621 err = -ESRCH; 622 goto errout; 623 } 624 625 err = fib_table_delete(tb, &cfg); 626errout: 627 return err; 628} 629 630static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 631{ 632 struct net *net = sock_net(skb->sk); 633 struct fib_config cfg; 634 struct fib_table *tb; 635 int err; 636 637 err = rtm_to_fib_config(net, skb, nlh, &cfg); 638 if (err < 0) 639 goto errout; 640 641 tb = fib_new_table(net, cfg.fc_table); 642 if (tb == NULL) { 643 err = -ENOBUFS; 644 goto errout; 645 } 646 647 err = fib_table_insert(tb, &cfg); 648errout: 649 return err; 650} 651 652static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 653{ 654 struct net *net = sock_net(skb->sk); 655 unsigned int h, s_h; 656 unsigned int e = 0, s_e; 657 struct fib_table *tb; 658 struct hlist_node *node; 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 ip_rt_dump(skb, cb); 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, node, 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; 681next: 682 e++; 683 } 684 } 685out: 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 */ 698static 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 736void 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 */ 782void 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 922static 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 rcu_read_lock(); 939 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 940 941 if (!frn->err) { 942 frn->prefixlen = res.prefixlen; 943 frn->nh_sel = res.nh_sel; 944 frn->type = res.type; 945 frn->scope = res.scope; 946 } 947 rcu_read_unlock(); 948 local_bh_enable(); 949 } 950} 951 952static void nl_fib_input(struct sk_buff *skb) 953{ 954 struct net *net; 955 struct fib_result_nl *frn; 956 struct nlmsghdr *nlh; 957 struct fib_table *tb; 958 u32 pid; 959 960 net = sock_net(skb->sk); 961 nlh = nlmsg_hdr(skb); 962 if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len || 963 nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn))) 964 return; 965 966 skb = skb_clone(skb, GFP_KERNEL); 967 if (skb == NULL) 968 return; 969 nlh = nlmsg_hdr(skb); 970 971 frn = (struct fib_result_nl *) NLMSG_DATA(nlh); 972 tb = fib_get_table(net, frn->tb_id_in); 973 974 nl_fib_lookup(frn, tb); 975 976 pid = NETLINK_CB(skb).pid; /* pid of sending process */ 977 NETLINK_CB(skb).pid = 0; /* from kernel */ 978 NETLINK_CB(skb).dst_group = 0; /* unicast */ 979 netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT); 980} 981 982static int __net_init nl_fib_lookup_init(struct net *net) 983{ 984 struct sock *sk; 985 struct netlink_kernel_cfg cfg = { 986 .input = nl_fib_input, 987 }; 988 989 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg); 990 if (sk == NULL) 991 return -EAFNOSUPPORT; 992 net->ipv4.fibnl = sk; 993 return 0; 994} 995 996static void nl_fib_lookup_exit(struct net *net) 997{ 998 netlink_kernel_release(net->ipv4.fibnl); 999 net->ipv4.fibnl = NULL; 1000} 1001 1002static void fib_disable_ip(struct net_device *dev, int force) 1003{ 1004 if (fib_sync_down_dev(dev, force)) 1005 fib_flush(dev_net(dev)); 1006 rt_cache_flush(dev_net(dev)); 1007 arp_ifdown(dev); 1008} 1009 1010static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 1011{ 1012 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 1013 struct net_device *dev = ifa->ifa_dev->dev; 1014 struct net *net = dev_net(dev); 1015 1016 switch (event) { 1017 case NETDEV_UP: 1018 fib_add_ifaddr(ifa); 1019#ifdef CONFIG_IP_ROUTE_MULTIPATH 1020 fib_sync_up(dev); 1021#endif 1022 atomic_inc(&net->ipv4.dev_addr_genid); 1023 rt_cache_flush(dev_net(dev)); 1024 break; 1025 case NETDEV_DOWN: 1026 fib_del_ifaddr(ifa, NULL); 1027 atomic_inc(&net->ipv4.dev_addr_genid); 1028 if (ifa->ifa_dev->ifa_list == NULL) { 1029 /* Last address was deleted from this interface. 1030 * Disable IP. 1031 */ 1032 fib_disable_ip(dev, 1); 1033 } else { 1034 rt_cache_flush(dev_net(dev)); 1035 } 1036 break; 1037 } 1038 return NOTIFY_DONE; 1039} 1040 1041static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1042{ 1043 struct net_device *dev = ptr; 1044 struct in_device *in_dev; 1045 struct net *net = dev_net(dev); 1046 1047 if (event == NETDEV_UNREGISTER) { 1048 fib_disable_ip(dev, 2); 1049 rt_flush_dev(dev); 1050 return NOTIFY_DONE; 1051 } 1052 1053 in_dev = __in_dev_get_rtnl(dev); 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 1077static struct notifier_block fib_inetaddr_notifier = { 1078 .notifier_call = fib_inetaddr_event, 1079}; 1080 1081static struct notifier_block fib_netdev_notifier = { 1082 .notifier_call = fib_netdev_event, 1083}; 1084 1085static 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 1102fail: 1103 kfree(net->ipv4.fib_table_hash); 1104 return err; 1105} 1106 1107static 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 *node, *tmp; 1120 1121 head = &net->ipv4.fib_table_hash[i]; 1122 hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) { 1123 hlist_del(node); 1124 fib_table_flush(tb); 1125 fib_free_table(tb); 1126 } 1127 } 1128 rtnl_unlock(); 1129 kfree(net->ipv4.fib_table_hash); 1130} 1131 1132static 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; 1148out: 1149 return error; 1150 1151out_proc: 1152 nl_fib_lookup_exit(net); 1153out_nlfl: 1154 ip_fib_net_exit(net); 1155 goto out; 1156} 1157 1158static 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 1165static struct pernet_operations fib_net_ops = { 1166 .init = fib_net_init, 1167 .exit = fib_net_exit, 1168}; 1169 1170void __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