fib_frontend.c revision e06e7c615877026544ad7f8b309d1a3706410383
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 * Version: $Id: fib_frontend.c,v 1.26 2001/10/31 21:55:54 davem Exp $ 9 * 10 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License 14 * as published by the Free Software Foundation; either version 15 * 2 of the License, or (at your option) any later version. 16 */ 17 18#include <linux/module.h> 19#include <asm/uaccess.h> 20#include <asm/system.h> 21#include <linux/bitops.h> 22#include <linux/capability.h> 23#include <linux/types.h> 24#include <linux/kernel.h> 25#include <linux/mm.h> 26#include <linux/string.h> 27#include <linux/socket.h> 28#include <linux/sockios.h> 29#include <linux/errno.h> 30#include <linux/in.h> 31#include <linux/inet.h> 32#include <linux/inetdevice.h> 33#include <linux/netdevice.h> 34#include <linux/if_addr.h> 35#include <linux/if_arp.h> 36#include <linux/skbuff.h> 37#include <linux/init.h> 38#include <linux/list.h> 39 40#include <net/ip.h> 41#include <net/protocol.h> 42#include <net/route.h> 43#include <net/tcp.h> 44#include <net/sock.h> 45#include <net/icmp.h> 46#include <net/arp.h> 47#include <net/ip_fib.h> 48#include <net/rtnetlink.h> 49 50#define FFprint(a...) printk(KERN_DEBUG a) 51 52#ifndef CONFIG_IP_MULTIPLE_TABLES 53 54struct fib_table *ip_fib_local_table; 55struct fib_table *ip_fib_main_table; 56 57#define FIB_TABLE_HASHSZ 1 58static struct hlist_head fib_table_hash[FIB_TABLE_HASHSZ]; 59 60#else 61 62#define FIB_TABLE_HASHSZ 256 63static struct hlist_head fib_table_hash[FIB_TABLE_HASHSZ]; 64 65struct fib_table *fib_new_table(u32 id) 66{ 67 struct fib_table *tb; 68 unsigned int h; 69 70 if (id == 0) 71 id = RT_TABLE_MAIN; 72 tb = fib_get_table(id); 73 if (tb) 74 return tb; 75 tb = fib_hash_init(id); 76 if (!tb) 77 return NULL; 78 h = id & (FIB_TABLE_HASHSZ - 1); 79 hlist_add_head_rcu(&tb->tb_hlist, &fib_table_hash[h]); 80 return tb; 81} 82 83struct fib_table *fib_get_table(u32 id) 84{ 85 struct fib_table *tb; 86 struct hlist_node *node; 87 unsigned int h; 88 89 if (id == 0) 90 id = RT_TABLE_MAIN; 91 h = id & (FIB_TABLE_HASHSZ - 1); 92 rcu_read_lock(); 93 hlist_for_each_entry_rcu(tb, node, &fib_table_hash[h], tb_hlist) { 94 if (tb->tb_id == id) { 95 rcu_read_unlock(); 96 return tb; 97 } 98 } 99 rcu_read_unlock(); 100 return NULL; 101} 102#endif /* CONFIG_IP_MULTIPLE_TABLES */ 103 104static void fib_flush(void) 105{ 106 int flushed = 0; 107 struct fib_table *tb; 108 struct hlist_node *node; 109 unsigned int h; 110 111 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 112 hlist_for_each_entry(tb, node, &fib_table_hash[h], tb_hlist) 113 flushed += tb->tb_flush(tb); 114 } 115 116 if (flushed) 117 rt_cache_flush(-1); 118} 119 120/* 121 * Find the first device with a given source address. 122 */ 123 124struct net_device * ip_dev_find(__be32 addr) 125{ 126 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = addr } } }; 127 struct fib_result res; 128 struct net_device *dev = NULL; 129 130#ifdef CONFIG_IP_MULTIPLE_TABLES 131 res.r = NULL; 132#endif 133 134 if (!ip_fib_local_table || 135 ip_fib_local_table->tb_lookup(ip_fib_local_table, &fl, &res)) 136 return NULL; 137 if (res.type != RTN_LOCAL) 138 goto out; 139 dev = FIB_RES_DEV(res); 140 141 if (dev) 142 dev_hold(dev); 143out: 144 fib_res_put(&res); 145 return dev; 146} 147 148unsigned inet_addr_type(__be32 addr) 149{ 150 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = addr } } }; 151 struct fib_result res; 152 unsigned ret = RTN_BROADCAST; 153 154 if (ZERONET(addr) || BADCLASS(addr)) 155 return RTN_BROADCAST; 156 if (MULTICAST(addr)) 157 return RTN_MULTICAST; 158 159#ifdef CONFIG_IP_MULTIPLE_TABLES 160 res.r = NULL; 161#endif 162 163 if (ip_fib_local_table) { 164 ret = RTN_UNICAST; 165 if (!ip_fib_local_table->tb_lookup(ip_fib_local_table, 166 &fl, &res)) { 167 ret = res.type; 168 fib_res_put(&res); 169 } 170 } 171 return ret; 172} 173 174/* Given (packet source, input interface) and optional (dst, oif, tos): 175 - (main) check, that source is valid i.e. not broadcast or our local 176 address. 177 - figure out what "logical" interface this packet arrived 178 and calculate "specific destination" address. 179 - check, that packet arrived from expected physical interface. 180 */ 181 182int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif, 183 struct net_device *dev, __be32 *spec_dst, u32 *itag) 184{ 185 struct in_device *in_dev; 186 struct flowi fl = { .nl_u = { .ip4_u = 187 { .daddr = src, 188 .saddr = dst, 189 .tos = tos } }, 190 .iif = oif }; 191 struct fib_result res; 192 int no_addr, rpf; 193 int ret; 194 195 no_addr = rpf = 0; 196 rcu_read_lock(); 197 in_dev = __in_dev_get_rcu(dev); 198 if (in_dev) { 199 no_addr = in_dev->ifa_list == NULL; 200 rpf = IN_DEV_RPFILTER(in_dev); 201 } 202 rcu_read_unlock(); 203 204 if (in_dev == NULL) 205 goto e_inval; 206 207 if (fib_lookup(&fl, &res)) 208 goto last_resort; 209 if (res.type != RTN_UNICAST) 210 goto e_inval_res; 211 *spec_dst = FIB_RES_PREFSRC(res); 212 fib_combine_itag(itag, &res); 213#ifdef CONFIG_IP_ROUTE_MULTIPATH 214 if (FIB_RES_DEV(res) == dev || res.fi->fib_nhs > 1) 215#else 216 if (FIB_RES_DEV(res) == dev) 217#endif 218 { 219 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 220 fib_res_put(&res); 221 return ret; 222 } 223 fib_res_put(&res); 224 if (no_addr) 225 goto last_resort; 226 if (rpf) 227 goto e_inval; 228 fl.oif = dev->ifindex; 229 230 ret = 0; 231 if (fib_lookup(&fl, &res) == 0) { 232 if (res.type == RTN_UNICAST) { 233 *spec_dst = FIB_RES_PREFSRC(res); 234 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST; 235 } 236 fib_res_put(&res); 237 } 238 return ret; 239 240last_resort: 241 if (rpf) 242 goto e_inval; 243 *spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE); 244 *itag = 0; 245 return 0; 246 247e_inval_res: 248 fib_res_put(&res); 249e_inval: 250 return -EINVAL; 251} 252 253static inline __be32 sk_extract_addr(struct sockaddr *addr) 254{ 255 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 256} 257 258static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 259{ 260 struct nlattr *nla; 261 262 nla = (struct nlattr *) ((char *) mx + len); 263 nla->nla_type = type; 264 nla->nla_len = nla_attr_size(4); 265 *(u32 *) nla_data(nla) = value; 266 267 return len + nla_total_size(4); 268} 269 270static int rtentry_to_fib_config(int cmd, struct rtentry *rt, 271 struct fib_config *cfg) 272{ 273 __be32 addr; 274 int plen; 275 276 memset(cfg, 0, sizeof(*cfg)); 277 278 if (rt->rt_dst.sa_family != AF_INET) 279 return -EAFNOSUPPORT; 280 281 /* 282 * Check mask for validity: 283 * a) it must be contiguous. 284 * b) destination must have all host bits clear. 285 * c) if application forgot to set correct family (AF_INET), 286 * reject request unless it is absolutely clear i.e. 287 * both family and mask are zero. 288 */ 289 plen = 32; 290 addr = sk_extract_addr(&rt->rt_dst); 291 if (!(rt->rt_flags & RTF_HOST)) { 292 __be32 mask = sk_extract_addr(&rt->rt_genmask); 293 294 if (rt->rt_genmask.sa_family != AF_INET) { 295 if (mask || rt->rt_genmask.sa_family) 296 return -EAFNOSUPPORT; 297 } 298 299 if (bad_mask(mask, addr)) 300 return -EINVAL; 301 302 plen = inet_mask_len(mask); 303 } 304 305 cfg->fc_dst_len = plen; 306 cfg->fc_dst = addr; 307 308 if (cmd != SIOCDELRT) { 309 cfg->fc_nlflags = NLM_F_CREATE; 310 cfg->fc_protocol = RTPROT_BOOT; 311 } 312 313 if (rt->rt_metric) 314 cfg->fc_priority = rt->rt_metric - 1; 315 316 if (rt->rt_flags & RTF_REJECT) { 317 cfg->fc_scope = RT_SCOPE_HOST; 318 cfg->fc_type = RTN_UNREACHABLE; 319 return 0; 320 } 321 322 cfg->fc_scope = RT_SCOPE_NOWHERE; 323 cfg->fc_type = RTN_UNICAST; 324 325 if (rt->rt_dev) { 326 char *colon; 327 struct net_device *dev; 328 char devname[IFNAMSIZ]; 329 330 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 331 return -EFAULT; 332 333 devname[IFNAMSIZ-1] = 0; 334 colon = strchr(devname, ':'); 335 if (colon) 336 *colon = 0; 337 dev = __dev_get_by_name(devname); 338 if (!dev) 339 return -ENODEV; 340 cfg->fc_oif = dev->ifindex; 341 if (colon) { 342 struct in_ifaddr *ifa; 343 struct in_device *in_dev = __in_dev_get_rtnl(dev); 344 if (!in_dev) 345 return -ENODEV; 346 *colon = ':'; 347 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) 348 if (strcmp(ifa->ifa_label, devname) == 0) 349 break; 350 if (ifa == NULL) 351 return -ENODEV; 352 cfg->fc_prefsrc = ifa->ifa_local; 353 } 354 } 355 356 addr = sk_extract_addr(&rt->rt_gateway); 357 if (rt->rt_gateway.sa_family == AF_INET && addr) { 358 cfg->fc_gw = addr; 359 if (rt->rt_flags & RTF_GATEWAY && 360 inet_addr_type(addr) == RTN_UNICAST) 361 cfg->fc_scope = RT_SCOPE_UNIVERSE; 362 } 363 364 if (cmd == SIOCDELRT) 365 return 0; 366 367 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw) 368 return -EINVAL; 369 370 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 371 cfg->fc_scope = RT_SCOPE_LINK; 372 373 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 374 struct nlattr *mx; 375 int len = 0; 376 377 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL); 378 if (mx == NULL) 379 return -ENOMEM; 380 381 if (rt->rt_flags & RTF_MTU) 382 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 383 384 if (rt->rt_flags & RTF_WINDOW) 385 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 386 387 if (rt->rt_flags & RTF_IRTT) 388 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 389 390 cfg->fc_mx = mx; 391 cfg->fc_mx_len = len; 392 } 393 394 return 0; 395} 396 397/* 398 * Handle IP routing ioctl calls. These are used to manipulate the routing tables 399 */ 400 401int ip_rt_ioctl(unsigned int cmd, void __user *arg) 402{ 403 struct fib_config cfg; 404 struct rtentry rt; 405 int err; 406 407 switch (cmd) { 408 case SIOCADDRT: /* Add a route */ 409 case SIOCDELRT: /* Delete a route */ 410 if (!capable(CAP_NET_ADMIN)) 411 return -EPERM; 412 413 if (copy_from_user(&rt, arg, sizeof(rt))) 414 return -EFAULT; 415 416 rtnl_lock(); 417 err = rtentry_to_fib_config(cmd, &rt, &cfg); 418 if (err == 0) { 419 struct fib_table *tb; 420 421 if (cmd == SIOCDELRT) { 422 tb = fib_get_table(cfg.fc_table); 423 if (tb) 424 err = tb->tb_delete(tb, &cfg); 425 else 426 err = -ESRCH; 427 } else { 428 tb = fib_new_table(cfg.fc_table); 429 if (tb) 430 err = tb->tb_insert(tb, &cfg); 431 else 432 err = -ENOBUFS; 433 } 434 435 /* allocated by rtentry_to_fib_config() */ 436 kfree(cfg.fc_mx); 437 } 438 rtnl_unlock(); 439 return err; 440 } 441 return -EINVAL; 442} 443 444const struct nla_policy rtm_ipv4_policy[RTA_MAX+1] = { 445 [RTA_DST] = { .type = NLA_U32 }, 446 [RTA_SRC] = { .type = NLA_U32 }, 447 [RTA_IIF] = { .type = NLA_U32 }, 448 [RTA_OIF] = { .type = NLA_U32 }, 449 [RTA_GATEWAY] = { .type = NLA_U32 }, 450 [RTA_PRIORITY] = { .type = NLA_U32 }, 451 [RTA_PREFSRC] = { .type = NLA_U32 }, 452 [RTA_METRICS] = { .type = NLA_NESTED }, 453 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 454 [RTA_PROTOINFO] = { .type = NLA_U32 }, 455 [RTA_FLOW] = { .type = NLA_U32 }, 456}; 457 458static int rtm_to_fib_config(struct sk_buff *skb, struct nlmsghdr *nlh, 459 struct fib_config *cfg) 460{ 461 struct nlattr *attr; 462 int err, remaining; 463 struct rtmsg *rtm; 464 465 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy); 466 if (err < 0) 467 goto errout; 468 469 memset(cfg, 0, sizeof(*cfg)); 470 471 rtm = nlmsg_data(nlh); 472 cfg->fc_dst_len = rtm->rtm_dst_len; 473 cfg->fc_tos = rtm->rtm_tos; 474 cfg->fc_table = rtm->rtm_table; 475 cfg->fc_protocol = rtm->rtm_protocol; 476 cfg->fc_scope = rtm->rtm_scope; 477 cfg->fc_type = rtm->rtm_type; 478 cfg->fc_flags = rtm->rtm_flags; 479 cfg->fc_nlflags = nlh->nlmsg_flags; 480 481 cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid; 482 cfg->fc_nlinfo.nlh = nlh; 483 484 if (cfg->fc_type > RTN_MAX) { 485 err = -EINVAL; 486 goto errout; 487 } 488 489 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 490 switch (attr->nla_type) { 491 case RTA_DST: 492 cfg->fc_dst = nla_get_be32(attr); 493 break; 494 case RTA_OIF: 495 cfg->fc_oif = nla_get_u32(attr); 496 break; 497 case RTA_GATEWAY: 498 cfg->fc_gw = nla_get_be32(attr); 499 break; 500 case RTA_PRIORITY: 501 cfg->fc_priority = nla_get_u32(attr); 502 break; 503 case RTA_PREFSRC: 504 cfg->fc_prefsrc = nla_get_be32(attr); 505 break; 506 case RTA_METRICS: 507 cfg->fc_mx = nla_data(attr); 508 cfg->fc_mx_len = nla_len(attr); 509 break; 510 case RTA_MULTIPATH: 511 cfg->fc_mp = nla_data(attr); 512 cfg->fc_mp_len = nla_len(attr); 513 break; 514 case RTA_FLOW: 515 cfg->fc_flow = nla_get_u32(attr); 516 break; 517 case RTA_TABLE: 518 cfg->fc_table = nla_get_u32(attr); 519 break; 520 } 521 } 522 523 return 0; 524errout: 525 return err; 526} 527 528static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 529{ 530 struct fib_config cfg; 531 struct fib_table *tb; 532 int err; 533 534 err = rtm_to_fib_config(skb, nlh, &cfg); 535 if (err < 0) 536 goto errout; 537 538 tb = fib_get_table(cfg.fc_table); 539 if (tb == NULL) { 540 err = -ESRCH; 541 goto errout; 542 } 543 544 err = tb->tb_delete(tb, &cfg); 545errout: 546 return err; 547} 548 549static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 550{ 551 struct fib_config cfg; 552 struct fib_table *tb; 553 int err; 554 555 err = rtm_to_fib_config(skb, nlh, &cfg); 556 if (err < 0) 557 goto errout; 558 559 tb = fib_new_table(cfg.fc_table); 560 if (tb == NULL) { 561 err = -ENOBUFS; 562 goto errout; 563 } 564 565 err = tb->tb_insert(tb, &cfg); 566errout: 567 return err; 568} 569 570static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 571{ 572 unsigned int h, s_h; 573 unsigned int e = 0, s_e; 574 struct fib_table *tb; 575 struct hlist_node *node; 576 int dumped = 0; 577 578 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) && 579 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED) 580 return ip_rt_dump(skb, cb); 581 582 s_h = cb->args[0]; 583 s_e = cb->args[1]; 584 585 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 586 e = 0; 587 hlist_for_each_entry(tb, node, &fib_table_hash[h], tb_hlist) { 588 if (e < s_e) 589 goto next; 590 if (dumped) 591 memset(&cb->args[2], 0, sizeof(cb->args) - 592 2 * sizeof(cb->args[0])); 593 if (tb->tb_dump(tb, skb, cb) < 0) 594 goto out; 595 dumped = 1; 596next: 597 e++; 598 } 599 } 600out: 601 cb->args[1] = e; 602 cb->args[0] = h; 603 604 return skb->len; 605} 606 607/* Prepare and feed intra-kernel routing request. 608 Really, it should be netlink message, but :-( netlink 609 can be not configured, so that we feed it directly 610 to fib engine. It is legal, because all events occur 611 only when netlink is already locked. 612 */ 613 614static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa) 615{ 616 struct fib_table *tb; 617 struct fib_config cfg = { 618 .fc_protocol = RTPROT_KERNEL, 619 .fc_type = type, 620 .fc_dst = dst, 621 .fc_dst_len = dst_len, 622 .fc_prefsrc = ifa->ifa_local, 623 .fc_oif = ifa->ifa_dev->dev->ifindex, 624 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 625 }; 626 627 if (type == RTN_UNICAST) 628 tb = fib_new_table(RT_TABLE_MAIN); 629 else 630 tb = fib_new_table(RT_TABLE_LOCAL); 631 632 if (tb == NULL) 633 return; 634 635 cfg.fc_table = tb->tb_id; 636 637 if (type != RTN_LOCAL) 638 cfg.fc_scope = RT_SCOPE_LINK; 639 else 640 cfg.fc_scope = RT_SCOPE_HOST; 641 642 if (cmd == RTM_NEWROUTE) 643 tb->tb_insert(tb, &cfg); 644 else 645 tb->tb_delete(tb, &cfg); 646} 647 648void fib_add_ifaddr(struct in_ifaddr *ifa) 649{ 650 struct in_device *in_dev = ifa->ifa_dev; 651 struct net_device *dev = in_dev->dev; 652 struct in_ifaddr *prim = ifa; 653 __be32 mask = ifa->ifa_mask; 654 __be32 addr = ifa->ifa_local; 655 __be32 prefix = ifa->ifa_address&mask; 656 657 if (ifa->ifa_flags&IFA_F_SECONDARY) { 658 prim = inet_ifa_byprefix(in_dev, prefix, mask); 659 if (prim == NULL) { 660 printk(KERN_DEBUG "fib_add_ifaddr: bug: prim == NULL\n"); 661 return; 662 } 663 } 664 665 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim); 666 667 if (!(dev->flags&IFF_UP)) 668 return; 669 670 /* Add broadcast address, if it is explicitly assigned. */ 671 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 672 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 673 674 if (!ZERONET(prefix) && !(ifa->ifa_flags&IFA_F_SECONDARY) && 675 (prefix != addr || ifa->ifa_prefixlen < 32)) { 676 fib_magic(RTM_NEWROUTE, dev->flags&IFF_LOOPBACK ? RTN_LOCAL : 677 RTN_UNICAST, prefix, ifa->ifa_prefixlen, prim); 678 679 /* Add network specific broadcasts, when it takes a sense */ 680 if (ifa->ifa_prefixlen < 31) { 681 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim); 682 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix|~mask, 32, prim); 683 } 684 } 685} 686 687static void fib_del_ifaddr(struct in_ifaddr *ifa) 688{ 689 struct in_device *in_dev = ifa->ifa_dev; 690 struct net_device *dev = in_dev->dev; 691 struct in_ifaddr *ifa1; 692 struct in_ifaddr *prim = ifa; 693 __be32 brd = ifa->ifa_address|~ifa->ifa_mask; 694 __be32 any = ifa->ifa_address&ifa->ifa_mask; 695#define LOCAL_OK 1 696#define BRD_OK 2 697#define BRD0_OK 4 698#define BRD1_OK 8 699 unsigned ok = 0; 700 701 if (!(ifa->ifa_flags&IFA_F_SECONDARY)) 702 fib_magic(RTM_DELROUTE, dev->flags&IFF_LOOPBACK ? RTN_LOCAL : 703 RTN_UNICAST, any, ifa->ifa_prefixlen, prim); 704 else { 705 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 706 if (prim == NULL) { 707 printk(KERN_DEBUG "fib_del_ifaddr: bug: prim == NULL\n"); 708 return; 709 } 710 } 711 712 /* Deletion is more complicated than add. 713 We should take care of not to delete too much :-) 714 715 Scan address list to be sure that addresses are really gone. 716 */ 717 718 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) { 719 if (ifa->ifa_local == ifa1->ifa_local) 720 ok |= LOCAL_OK; 721 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 722 ok |= BRD_OK; 723 if (brd == ifa1->ifa_broadcast) 724 ok |= BRD1_OK; 725 if (any == ifa1->ifa_broadcast) 726 ok |= BRD0_OK; 727 } 728 729 if (!(ok&BRD_OK)) 730 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 731 if (!(ok&BRD1_OK)) 732 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim); 733 if (!(ok&BRD0_OK)) 734 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim); 735 if (!(ok&LOCAL_OK)) { 736 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim); 737 738 /* Check, that this local address finally disappeared. */ 739 if (inet_addr_type(ifa->ifa_local) != RTN_LOCAL) { 740 /* And the last, but not the least thing. 741 We must flush stray FIB entries. 742 743 First of all, we scan fib_info list searching 744 for stray nexthop entries, then ignite fib_flush. 745 */ 746 if (fib_sync_down(ifa->ifa_local, NULL, 0)) 747 fib_flush(); 748 } 749 } 750#undef LOCAL_OK 751#undef BRD_OK 752#undef BRD0_OK 753#undef BRD1_OK 754} 755 756static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb ) 757{ 758 759 struct fib_result res; 760 struct flowi fl = { .mark = frn->fl_mark, 761 .nl_u = { .ip4_u = { .daddr = frn->fl_addr, 762 .tos = frn->fl_tos, 763 .scope = frn->fl_scope } } }; 764 765#ifdef CONFIG_IP_MULTIPLE_TABLES 766 res.r = NULL; 767#endif 768 769 frn->err = -ENOENT; 770 if (tb) { 771 local_bh_disable(); 772 773 frn->tb_id = tb->tb_id; 774 frn->err = tb->tb_lookup(tb, &fl, &res); 775 776 if (!frn->err) { 777 frn->prefixlen = res.prefixlen; 778 frn->nh_sel = res.nh_sel; 779 frn->type = res.type; 780 frn->scope = res.scope; 781 fib_res_put(&res); 782 } 783 local_bh_enable(); 784 } 785} 786 787static void nl_fib_input(struct sock *sk, int len) 788{ 789 struct sk_buff *skb = NULL; 790 struct nlmsghdr *nlh = NULL; 791 struct fib_result_nl *frn; 792 u32 pid; 793 struct fib_table *tb; 794 795 skb = skb_dequeue(&sk->sk_receive_queue); 796 if (skb == NULL) 797 return; 798 799 nlh = nlmsg_hdr(skb); 800 if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len || 801 nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn))) { 802 kfree_skb(skb); 803 return; 804 } 805 806 frn = (struct fib_result_nl *) NLMSG_DATA(nlh); 807 tb = fib_get_table(frn->tb_id_in); 808 809 nl_fib_lookup(frn, tb); 810 811 pid = NETLINK_CB(skb).pid; /* pid of sending process */ 812 NETLINK_CB(skb).pid = 0; /* from kernel */ 813 NETLINK_CB(skb).dst_group = 0; /* unicast */ 814 netlink_unicast(sk, skb, pid, MSG_DONTWAIT); 815} 816 817static void nl_fib_lookup_init(void) 818{ 819 netlink_kernel_create(NETLINK_FIB_LOOKUP, 0, nl_fib_input, NULL, 820 THIS_MODULE); 821} 822 823static void fib_disable_ip(struct net_device *dev, int force) 824{ 825 if (fib_sync_down(0, dev, force)) 826 fib_flush(); 827 rt_cache_flush(0); 828 arp_ifdown(dev); 829} 830 831static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 832{ 833 struct in_ifaddr *ifa = (struct in_ifaddr*)ptr; 834 835 switch (event) { 836 case NETDEV_UP: 837 fib_add_ifaddr(ifa); 838#ifdef CONFIG_IP_ROUTE_MULTIPATH 839 fib_sync_up(ifa->ifa_dev->dev); 840#endif 841 rt_cache_flush(-1); 842 break; 843 case NETDEV_DOWN: 844 fib_del_ifaddr(ifa); 845 if (ifa->ifa_dev->ifa_list == NULL) { 846 /* Last address was deleted from this interface. 847 Disable IP. 848 */ 849 fib_disable_ip(ifa->ifa_dev->dev, 1); 850 } else { 851 rt_cache_flush(-1); 852 } 853 break; 854 } 855 return NOTIFY_DONE; 856} 857 858static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 859{ 860 struct net_device *dev = ptr; 861 struct in_device *in_dev = __in_dev_get_rtnl(dev); 862 863 if (event == NETDEV_UNREGISTER) { 864 fib_disable_ip(dev, 2); 865 return NOTIFY_DONE; 866 } 867 868 if (!in_dev) 869 return NOTIFY_DONE; 870 871 switch (event) { 872 case NETDEV_UP: 873 for_ifa(in_dev) { 874 fib_add_ifaddr(ifa); 875 } endfor_ifa(in_dev); 876#ifdef CONFIG_IP_ROUTE_MULTIPATH 877 fib_sync_up(dev); 878#endif 879 rt_cache_flush(-1); 880 break; 881 case NETDEV_DOWN: 882 fib_disable_ip(dev, 0); 883 break; 884 case NETDEV_CHANGEMTU: 885 case NETDEV_CHANGE: 886 rt_cache_flush(0); 887 break; 888 } 889 return NOTIFY_DONE; 890} 891 892static struct notifier_block fib_inetaddr_notifier = { 893 .notifier_call =fib_inetaddr_event, 894}; 895 896static struct notifier_block fib_netdev_notifier = { 897 .notifier_call =fib_netdev_event, 898}; 899 900void __init ip_fib_init(void) 901{ 902 unsigned int i; 903 904 for (i = 0; i < FIB_TABLE_HASHSZ; i++) 905 INIT_HLIST_HEAD(&fib_table_hash[i]); 906#ifndef CONFIG_IP_MULTIPLE_TABLES 907 ip_fib_local_table = fib_hash_init(RT_TABLE_LOCAL); 908 hlist_add_head_rcu(&ip_fib_local_table->tb_hlist, &fib_table_hash[0]); 909 ip_fib_main_table = fib_hash_init(RT_TABLE_MAIN); 910 hlist_add_head_rcu(&ip_fib_main_table->tb_hlist, &fib_table_hash[0]); 911#else 912 fib4_rules_init(); 913#endif 914 915 register_netdevice_notifier(&fib_netdev_notifier); 916 register_inetaddr_notifier(&fib_inetaddr_notifier); 917 nl_fib_lookup_init(); 918 919 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL); 920 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL); 921 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib); 922} 923 924EXPORT_SYMBOL(inet_addr_type); 925EXPORT_SYMBOL(ip_dev_find); 926