fib_frontend.c revision 63f3444fb9a54c024d55f1205f8b94e7d2786595
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} 252 253#ifndef CONFIG_IP_NOSIOCRT 254 255static inline __be32 sk_extract_addr(struct sockaddr *addr) 256{ 257 return ((struct sockaddr_in *) addr)->sin_addr.s_addr; 258} 259 260static int put_rtax(struct nlattr *mx, int len, int type, u32 value) 261{ 262 struct nlattr *nla; 263 264 nla = (struct nlattr *) ((char *) mx + len); 265 nla->nla_type = type; 266 nla->nla_len = nla_attr_size(4); 267 *(u32 *) nla_data(nla) = value; 268 269 return len + nla_total_size(4); 270} 271 272static int rtentry_to_fib_config(int cmd, struct rtentry *rt, 273 struct fib_config *cfg) 274{ 275 __be32 addr; 276 int plen; 277 278 memset(cfg, 0, sizeof(*cfg)); 279 280 if (rt->rt_dst.sa_family != AF_INET) 281 return -EAFNOSUPPORT; 282 283 /* 284 * Check mask for validity: 285 * a) it must be contiguous. 286 * b) destination must have all host bits clear. 287 * c) if application forgot to set correct family (AF_INET), 288 * reject request unless it is absolutely clear i.e. 289 * both family and mask are zero. 290 */ 291 plen = 32; 292 addr = sk_extract_addr(&rt->rt_dst); 293 if (!(rt->rt_flags & RTF_HOST)) { 294 __be32 mask = sk_extract_addr(&rt->rt_genmask); 295 296 if (rt->rt_genmask.sa_family != AF_INET) { 297 if (mask || rt->rt_genmask.sa_family) 298 return -EAFNOSUPPORT; 299 } 300 301 if (bad_mask(mask, addr)) 302 return -EINVAL; 303 304 plen = inet_mask_len(mask); 305 } 306 307 cfg->fc_dst_len = plen; 308 cfg->fc_dst = addr; 309 310 if (cmd != SIOCDELRT) { 311 cfg->fc_nlflags = NLM_F_CREATE; 312 cfg->fc_protocol = RTPROT_BOOT; 313 } 314 315 if (rt->rt_metric) 316 cfg->fc_priority = rt->rt_metric - 1; 317 318 if (rt->rt_flags & RTF_REJECT) { 319 cfg->fc_scope = RT_SCOPE_HOST; 320 cfg->fc_type = RTN_UNREACHABLE; 321 return 0; 322 } 323 324 cfg->fc_scope = RT_SCOPE_NOWHERE; 325 cfg->fc_type = RTN_UNICAST; 326 327 if (rt->rt_dev) { 328 char *colon; 329 struct net_device *dev; 330 char devname[IFNAMSIZ]; 331 332 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1)) 333 return -EFAULT; 334 335 devname[IFNAMSIZ-1] = 0; 336 colon = strchr(devname, ':'); 337 if (colon) 338 *colon = 0; 339 dev = __dev_get_by_name(devname); 340 if (!dev) 341 return -ENODEV; 342 cfg->fc_oif = dev->ifindex; 343 if (colon) { 344 struct in_ifaddr *ifa; 345 struct in_device *in_dev = __in_dev_get_rtnl(dev); 346 if (!in_dev) 347 return -ENODEV; 348 *colon = ':'; 349 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) 350 if (strcmp(ifa->ifa_label, devname) == 0) 351 break; 352 if (ifa == NULL) 353 return -ENODEV; 354 cfg->fc_prefsrc = ifa->ifa_local; 355 } 356 } 357 358 addr = sk_extract_addr(&rt->rt_gateway); 359 if (rt->rt_gateway.sa_family == AF_INET && addr) { 360 cfg->fc_gw = addr; 361 if (rt->rt_flags & RTF_GATEWAY && 362 inet_addr_type(addr) == RTN_UNICAST) 363 cfg->fc_scope = RT_SCOPE_UNIVERSE; 364 } 365 366 if (cmd == SIOCDELRT) 367 return 0; 368 369 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw) 370 return -EINVAL; 371 372 if (cfg->fc_scope == RT_SCOPE_NOWHERE) 373 cfg->fc_scope = RT_SCOPE_LINK; 374 375 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { 376 struct nlattr *mx; 377 int len = 0; 378 379 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL); 380 if (mx == NULL) 381 return -ENOMEM; 382 383 if (rt->rt_flags & RTF_MTU) 384 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40); 385 386 if (rt->rt_flags & RTF_WINDOW) 387 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window); 388 389 if (rt->rt_flags & RTF_IRTT) 390 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3); 391 392 cfg->fc_mx = mx; 393 cfg->fc_mx_len = len; 394 } 395 396 return 0; 397} 398 399/* 400 * Handle IP routing ioctl calls. These are used to manipulate the routing tables 401 */ 402 403int ip_rt_ioctl(unsigned int cmd, void __user *arg) 404{ 405 struct fib_config cfg; 406 struct rtentry rt; 407 int err; 408 409 switch (cmd) { 410 case SIOCADDRT: /* Add a route */ 411 case SIOCDELRT: /* Delete a route */ 412 if (!capable(CAP_NET_ADMIN)) 413 return -EPERM; 414 415 if (copy_from_user(&rt, arg, sizeof(rt))) 416 return -EFAULT; 417 418 rtnl_lock(); 419 err = rtentry_to_fib_config(cmd, &rt, &cfg); 420 if (err == 0) { 421 struct fib_table *tb; 422 423 if (cmd == SIOCDELRT) { 424 tb = fib_get_table(cfg.fc_table); 425 if (tb) 426 err = tb->tb_delete(tb, &cfg); 427 else 428 err = -ESRCH; 429 } else { 430 tb = fib_new_table(cfg.fc_table); 431 if (tb) 432 err = tb->tb_insert(tb, &cfg); 433 else 434 err = -ENOBUFS; 435 } 436 437 /* allocated by rtentry_to_fib_config() */ 438 kfree(cfg.fc_mx); 439 } 440 rtnl_unlock(); 441 return err; 442 } 443 return -EINVAL; 444} 445 446#else 447 448int ip_rt_ioctl(unsigned int cmd, void *arg) 449{ 450 return -EINVAL; 451} 452 453#endif 454 455struct nla_policy rtm_ipv4_policy[RTA_MAX+1] __read_mostly = { 456 [RTA_DST] = { .type = NLA_U32 }, 457 [RTA_SRC] = { .type = NLA_U32 }, 458 [RTA_IIF] = { .type = NLA_U32 }, 459 [RTA_OIF] = { .type = NLA_U32 }, 460 [RTA_GATEWAY] = { .type = NLA_U32 }, 461 [RTA_PRIORITY] = { .type = NLA_U32 }, 462 [RTA_PREFSRC] = { .type = NLA_U32 }, 463 [RTA_METRICS] = { .type = NLA_NESTED }, 464 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 465 [RTA_PROTOINFO] = { .type = NLA_U32 }, 466 [RTA_FLOW] = { .type = NLA_U32 }, 467 [RTA_MP_ALGO] = { .type = NLA_U32 }, 468}; 469 470static int rtm_to_fib_config(struct sk_buff *skb, struct nlmsghdr *nlh, 471 struct fib_config *cfg) 472{ 473 struct nlattr *attr; 474 int err, remaining; 475 struct rtmsg *rtm; 476 477 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy); 478 if (err < 0) 479 goto errout; 480 481 memset(cfg, 0, sizeof(*cfg)); 482 483 rtm = nlmsg_data(nlh); 484 cfg->fc_dst_len = rtm->rtm_dst_len; 485 cfg->fc_tos = rtm->rtm_tos; 486 cfg->fc_table = rtm->rtm_table; 487 cfg->fc_protocol = rtm->rtm_protocol; 488 cfg->fc_scope = rtm->rtm_scope; 489 cfg->fc_type = rtm->rtm_type; 490 cfg->fc_flags = rtm->rtm_flags; 491 cfg->fc_nlflags = nlh->nlmsg_flags; 492 493 cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid; 494 cfg->fc_nlinfo.nlh = nlh; 495 496 if (cfg->fc_type > RTN_MAX) { 497 err = -EINVAL; 498 goto errout; 499 } 500 501 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { 502 switch (attr->nla_type) { 503 case RTA_DST: 504 cfg->fc_dst = nla_get_be32(attr); 505 break; 506 case RTA_OIF: 507 cfg->fc_oif = nla_get_u32(attr); 508 break; 509 case RTA_GATEWAY: 510 cfg->fc_gw = nla_get_be32(attr); 511 break; 512 case RTA_PRIORITY: 513 cfg->fc_priority = nla_get_u32(attr); 514 break; 515 case RTA_PREFSRC: 516 cfg->fc_prefsrc = nla_get_be32(attr); 517 break; 518 case RTA_METRICS: 519 cfg->fc_mx = nla_data(attr); 520 cfg->fc_mx_len = nla_len(attr); 521 break; 522 case RTA_MULTIPATH: 523 cfg->fc_mp = nla_data(attr); 524 cfg->fc_mp_len = nla_len(attr); 525 break; 526 case RTA_FLOW: 527 cfg->fc_flow = nla_get_u32(attr); 528 break; 529 case RTA_MP_ALGO: 530 cfg->fc_mp_alg = nla_get_u32(attr); 531 break; 532 case RTA_TABLE: 533 cfg->fc_table = nla_get_u32(attr); 534 break; 535 } 536 } 537 538 return 0; 539errout: 540 return err; 541} 542 543static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 544{ 545 struct fib_config cfg; 546 struct fib_table *tb; 547 int err; 548 549 err = rtm_to_fib_config(skb, nlh, &cfg); 550 if (err < 0) 551 goto errout; 552 553 tb = fib_get_table(cfg.fc_table); 554 if (tb == NULL) { 555 err = -ESRCH; 556 goto errout; 557 } 558 559 err = tb->tb_delete(tb, &cfg); 560errout: 561 return err; 562} 563 564static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 565{ 566 struct fib_config cfg; 567 struct fib_table *tb; 568 int err; 569 570 err = rtm_to_fib_config(skb, nlh, &cfg); 571 if (err < 0) 572 goto errout; 573 574 tb = fib_new_table(cfg.fc_table); 575 if (tb == NULL) { 576 err = -ENOBUFS; 577 goto errout; 578 } 579 580 err = tb->tb_insert(tb, &cfg); 581errout: 582 return err; 583} 584 585static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 586{ 587 unsigned int h, s_h; 588 unsigned int e = 0, s_e; 589 struct fib_table *tb; 590 struct hlist_node *node; 591 int dumped = 0; 592 593 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) && 594 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED) 595 return ip_rt_dump(skb, cb); 596 597 s_h = cb->args[0]; 598 s_e = cb->args[1]; 599 600 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { 601 e = 0; 602 hlist_for_each_entry(tb, node, &fib_table_hash[h], tb_hlist) { 603 if (e < s_e) 604 goto next; 605 if (dumped) 606 memset(&cb->args[2], 0, sizeof(cb->args) - 607 2 * sizeof(cb->args[0])); 608 if (tb->tb_dump(tb, skb, cb) < 0) 609 goto out; 610 dumped = 1; 611next: 612 e++; 613 } 614 } 615out: 616 cb->args[1] = e; 617 cb->args[0] = h; 618 619 return skb->len; 620} 621 622/* Prepare and feed intra-kernel routing request. 623 Really, it should be netlink message, but :-( netlink 624 can be not configured, so that we feed it directly 625 to fib engine. It is legal, because all events occur 626 only when netlink is already locked. 627 */ 628 629static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa) 630{ 631 struct fib_table *tb; 632 struct fib_config cfg = { 633 .fc_protocol = RTPROT_KERNEL, 634 .fc_type = type, 635 .fc_dst = dst, 636 .fc_dst_len = dst_len, 637 .fc_prefsrc = ifa->ifa_local, 638 .fc_oif = ifa->ifa_dev->dev->ifindex, 639 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, 640 }; 641 642 if (type == RTN_UNICAST) 643 tb = fib_new_table(RT_TABLE_MAIN); 644 else 645 tb = fib_new_table(RT_TABLE_LOCAL); 646 647 if (tb == NULL) 648 return; 649 650 cfg.fc_table = tb->tb_id; 651 652 if (type != RTN_LOCAL) 653 cfg.fc_scope = RT_SCOPE_LINK; 654 else 655 cfg.fc_scope = RT_SCOPE_HOST; 656 657 if (cmd == RTM_NEWROUTE) 658 tb->tb_insert(tb, &cfg); 659 else 660 tb->tb_delete(tb, &cfg); 661} 662 663void fib_add_ifaddr(struct in_ifaddr *ifa) 664{ 665 struct in_device *in_dev = ifa->ifa_dev; 666 struct net_device *dev = in_dev->dev; 667 struct in_ifaddr *prim = ifa; 668 __be32 mask = ifa->ifa_mask; 669 __be32 addr = ifa->ifa_local; 670 __be32 prefix = ifa->ifa_address&mask; 671 672 if (ifa->ifa_flags&IFA_F_SECONDARY) { 673 prim = inet_ifa_byprefix(in_dev, prefix, mask); 674 if (prim == NULL) { 675 printk(KERN_DEBUG "fib_add_ifaddr: bug: prim == NULL\n"); 676 return; 677 } 678 } 679 680 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim); 681 682 if (!(dev->flags&IFF_UP)) 683 return; 684 685 /* Add broadcast address, if it is explicitly assigned. */ 686 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) 687 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 688 689 if (!ZERONET(prefix) && !(ifa->ifa_flags&IFA_F_SECONDARY) && 690 (prefix != addr || ifa->ifa_prefixlen < 32)) { 691 fib_magic(RTM_NEWROUTE, dev->flags&IFF_LOOPBACK ? RTN_LOCAL : 692 RTN_UNICAST, prefix, ifa->ifa_prefixlen, prim); 693 694 /* Add network specific broadcasts, when it takes a sense */ 695 if (ifa->ifa_prefixlen < 31) { 696 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim); 697 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix|~mask, 32, prim); 698 } 699 } 700} 701 702static void fib_del_ifaddr(struct in_ifaddr *ifa) 703{ 704 struct in_device *in_dev = ifa->ifa_dev; 705 struct net_device *dev = in_dev->dev; 706 struct in_ifaddr *ifa1; 707 struct in_ifaddr *prim = ifa; 708 __be32 brd = ifa->ifa_address|~ifa->ifa_mask; 709 __be32 any = ifa->ifa_address&ifa->ifa_mask; 710#define LOCAL_OK 1 711#define BRD_OK 2 712#define BRD0_OK 4 713#define BRD1_OK 8 714 unsigned ok = 0; 715 716 if (!(ifa->ifa_flags&IFA_F_SECONDARY)) 717 fib_magic(RTM_DELROUTE, dev->flags&IFF_LOOPBACK ? RTN_LOCAL : 718 RTN_UNICAST, any, ifa->ifa_prefixlen, prim); 719 else { 720 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask); 721 if (prim == NULL) { 722 printk(KERN_DEBUG "fib_del_ifaddr: bug: prim == NULL\n"); 723 return; 724 } 725 } 726 727 /* Deletion is more complicated than add. 728 We should take care of not to delete too much :-) 729 730 Scan address list to be sure that addresses are really gone. 731 */ 732 733 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) { 734 if (ifa->ifa_local == ifa1->ifa_local) 735 ok |= LOCAL_OK; 736 if (ifa->ifa_broadcast == ifa1->ifa_broadcast) 737 ok |= BRD_OK; 738 if (brd == ifa1->ifa_broadcast) 739 ok |= BRD1_OK; 740 if (any == ifa1->ifa_broadcast) 741 ok |= BRD0_OK; 742 } 743 744 if (!(ok&BRD_OK)) 745 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim); 746 if (!(ok&BRD1_OK)) 747 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim); 748 if (!(ok&BRD0_OK)) 749 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim); 750 if (!(ok&LOCAL_OK)) { 751 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim); 752 753 /* Check, that this local address finally disappeared. */ 754 if (inet_addr_type(ifa->ifa_local) != RTN_LOCAL) { 755 /* And the last, but not the least thing. 756 We must flush stray FIB entries. 757 758 First of all, we scan fib_info list searching 759 for stray nexthop entries, then ignite fib_flush. 760 */ 761 if (fib_sync_down(ifa->ifa_local, NULL, 0)) 762 fib_flush(); 763 } 764 } 765#undef LOCAL_OK 766#undef BRD_OK 767#undef BRD0_OK 768#undef BRD1_OK 769} 770 771static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb ) 772{ 773 774 struct fib_result res; 775 struct flowi fl = { .mark = frn->fl_mark, 776 .nl_u = { .ip4_u = { .daddr = frn->fl_addr, 777 .tos = frn->fl_tos, 778 .scope = frn->fl_scope } } }; 779 780 frn->err = -ENOENT; 781 if (tb) { 782 local_bh_disable(); 783 784 frn->tb_id = tb->tb_id; 785 frn->err = tb->tb_lookup(tb, &fl, &res); 786 787 if (!frn->err) { 788 frn->prefixlen = res.prefixlen; 789 frn->nh_sel = res.nh_sel; 790 frn->type = res.type; 791 frn->scope = res.scope; 792 fib_res_put(&res); 793 } 794 local_bh_enable(); 795 } 796} 797 798static void nl_fib_input(struct sock *sk, int len) 799{ 800 struct sk_buff *skb = NULL; 801 struct nlmsghdr *nlh = NULL; 802 struct fib_result_nl *frn; 803 u32 pid; 804 struct fib_table *tb; 805 806 skb = skb_dequeue(&sk->sk_receive_queue); 807 if (skb == NULL) 808 return; 809 810 nlh = nlmsg_hdr(skb); 811 if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len || 812 nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn))) { 813 kfree_skb(skb); 814 return; 815 } 816 817 frn = (struct fib_result_nl *) NLMSG_DATA(nlh); 818 tb = fib_get_table(frn->tb_id_in); 819 820 nl_fib_lookup(frn, tb); 821 822 pid = NETLINK_CB(skb).pid; /* pid of sending process */ 823 NETLINK_CB(skb).pid = 0; /* from kernel */ 824 NETLINK_CB(skb).dst_group = 0; /* unicast */ 825 netlink_unicast(sk, skb, pid, MSG_DONTWAIT); 826} 827 828static void nl_fib_lookup_init(void) 829{ 830 netlink_kernel_create(NETLINK_FIB_LOOKUP, 0, nl_fib_input, THIS_MODULE); 831} 832 833static void fib_disable_ip(struct net_device *dev, int force) 834{ 835 if (fib_sync_down(0, dev, force)) 836 fib_flush(); 837 rt_cache_flush(0); 838 arp_ifdown(dev); 839} 840 841static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) 842{ 843 struct in_ifaddr *ifa = (struct in_ifaddr*)ptr; 844 845 switch (event) { 846 case NETDEV_UP: 847 fib_add_ifaddr(ifa); 848#ifdef CONFIG_IP_ROUTE_MULTIPATH 849 fib_sync_up(ifa->ifa_dev->dev); 850#endif 851 rt_cache_flush(-1); 852 break; 853 case NETDEV_DOWN: 854 fib_del_ifaddr(ifa); 855 if (ifa->ifa_dev->ifa_list == NULL) { 856 /* Last address was deleted from this interface. 857 Disable IP. 858 */ 859 fib_disable_ip(ifa->ifa_dev->dev, 1); 860 } else { 861 rt_cache_flush(-1); 862 } 863 break; 864 } 865 return NOTIFY_DONE; 866} 867 868static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 869{ 870 struct net_device *dev = ptr; 871 struct in_device *in_dev = __in_dev_get_rtnl(dev); 872 873 if (event == NETDEV_UNREGISTER) { 874 fib_disable_ip(dev, 2); 875 return NOTIFY_DONE; 876 } 877 878 if (!in_dev) 879 return NOTIFY_DONE; 880 881 switch (event) { 882 case NETDEV_UP: 883 for_ifa(in_dev) { 884 fib_add_ifaddr(ifa); 885 } endfor_ifa(in_dev); 886#ifdef CONFIG_IP_ROUTE_MULTIPATH 887 fib_sync_up(dev); 888#endif 889 rt_cache_flush(-1); 890 break; 891 case NETDEV_DOWN: 892 fib_disable_ip(dev, 0); 893 break; 894 case NETDEV_CHANGEMTU: 895 case NETDEV_CHANGE: 896 rt_cache_flush(0); 897 break; 898 } 899 return NOTIFY_DONE; 900} 901 902static struct notifier_block fib_inetaddr_notifier = { 903 .notifier_call =fib_inetaddr_event, 904}; 905 906static struct notifier_block fib_netdev_notifier = { 907 .notifier_call =fib_netdev_event, 908}; 909 910void __init ip_fib_init(void) 911{ 912 unsigned int i; 913 914 for (i = 0; i < FIB_TABLE_HASHSZ; i++) 915 INIT_HLIST_HEAD(&fib_table_hash[i]); 916#ifndef CONFIG_IP_MULTIPLE_TABLES 917 ip_fib_local_table = fib_hash_init(RT_TABLE_LOCAL); 918 hlist_add_head_rcu(&ip_fib_local_table->tb_hlist, &fib_table_hash[0]); 919 ip_fib_main_table = fib_hash_init(RT_TABLE_MAIN); 920 hlist_add_head_rcu(&ip_fib_main_table->tb_hlist, &fib_table_hash[0]); 921#else 922 fib4_rules_init(); 923#endif 924 925 register_netdevice_notifier(&fib_netdev_notifier); 926 register_inetaddr_notifier(&fib_inetaddr_notifier); 927 nl_fib_lookup_init(); 928 929 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL); 930 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL); 931 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib); 932} 933 934EXPORT_SYMBOL(inet_addr_type); 935EXPORT_SYMBOL(ip_dev_find); 936