net/ipv4/devinet.c

   1 /*
   2  *      NET3    IP device support routines.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  *      Derived from the IP parts of dev.c 1.0.19
  10  *              Authors:        Ross Biro
  11  *                              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  12  *                              Mark Evans, <evansmp@uhura.aston.ac.uk>
  13  *
  14  *      Additional Authors:
  15  *              Alan Cox, <gw4pts@gw4pts.ampr.org>
  16  *              Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  17  *
  18  *      Changes:
  19  *              Alexey Kuznetsov:       pa_* fields are replaced with ifaddr
  20  *                                      lists.
  21  *              Cyrus Durgin:           updated for kmod
  22  *              Matthias Andree:        in devinet_ioctl, compare label and
  23  *                                      address (4.4BSD alias style support),
  24  *                                      fall back to comparing just the label
  25  *                                      if no match found.
  26  */
  27
  28
  29 #include <asm/uaccess.h>
  30 #include <asm/system.h>
  31 #include <linux/bitops.h>
  32 #include <linux/capability.h>
  33 #include <linux/module.h>
  34 #include <linux/types.h>
  35 #include <linux/kernel.h>
  36 #include <linux/string.h>
  37 #include <linux/mm.h>
  38 #include <linux/socket.h>
  39 #include <linux/sockios.h>
  40 #include <linux/in.h>
  41 #include <linux/errno.h>
  42 #include <linux/interrupt.h>
  43 #include <linux/if_addr.h>
  44 #include <linux/if_ether.h>
  45 #include <linux/inet.h>
  46 #include <linux/netdevice.h>
  47 #include <linux/etherdevice.h>
  48 #include <linux/skbuff.h>
  49 #include <linux/init.h>
  50 #include <linux/notifier.h>
  51 #include <linux/inetdevice.h>
  52 #include <linux/igmp.h>
  53 #include <linux/slab.h>
  54 #include <linux/hash.h>
  55 #ifdef CONFIG_SYSCTL
  56 #include <linux/sysctl.h>
  57 #endif
  58 #include <linux/kmod.h>
  59
  60 #include <net/arp.h>
  61 #include <net/ip.h>
  62 #include <net/route.h>
  63 #include <net/ip_fib.h>
  64 #include <net/rtnetlink.h>
  65 #include <net/net_namespace.h>
  66
  67 #include "fib_lookup.h"
  68
  69 static struct ipv4_devconf ipv4_devconf = {
  70         .data = {
  71                 [IPV4_DEVCONF_ACCEPT_REDIRECTS - 1] = 1,
  72                 [IPV4_DEVCONF_SEND_REDIRECTS - 1] = 1,
  73                 [IPV4_DEVCONF_SECURE_REDIRECTS - 1] = 1,
  74                 [IPV4_DEVCONF_SHARED_MEDIA - 1] = 1,
  75         },
  76 };
  77
  78 static struct ipv4_devconf ipv4_devconf_dflt = {
  79         .data = {
  80                 [IPV4_DEVCONF_ACCEPT_REDIRECTS - 1] = 1,
  81                 [IPV4_DEVCONF_SEND_REDIRECTS - 1] = 1,
  82                 [IPV4_DEVCONF_SECURE_REDIRECTS - 1] = 1,
  83                 [IPV4_DEVCONF_SHARED_MEDIA - 1] = 1,
  84                 [IPV4_DEVCONF_ACCEPT_SOURCE_ROUTE - 1] = 1,
  85         },
  86 };
  87
  88 #define IPV4_DEVCONF_DFLT(net, attr) \
  89         IPV4_DEVCONF((*net->ipv4.devconf_dflt), attr)
  90
  91 static const struct nla_policy ifa_ipv4_policy[IFA_MAX+1] = {
  92         [IFA_LOCAL]             = { .type = NLA_U32 },
  93         [IFA_ADDRESS]           = { .type = NLA_U32 },
  94         [IFA_BROADCAST]         = { .type = NLA_U32 },
  95         [IFA_LABEL]             = { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
  96 };
  97
  98 /* inet_addr_hash's shifting is dependent upon this IN4_ADDR_HSIZE
  99  * value.  So if you change this define, make appropriate changes to
 100  * inet_addr_hash as well.
 101  */
 102 #define IN4_ADDR_HSIZE  256
 103 static struct hlist_head inet_addr_lst[IN4_ADDR_HSIZE];
 104 static DEFINE_SPINLOCK(inet_addr_hash_lock);
 105
 106 static inline unsigned int inet_addr_hash(struct net *net, __be32 addr)
 107 {
 108         u32 val = (__force u32) addr ^ hash_ptr(net, 8);
 109
 110         return ((val ^ (val >> 8) ^ (val >> 16) ^ (val >> 24)) &
 111                 (IN4_ADDR_HSIZE - 1));
 112 }
 113
 114 static void inet_hash_insert(struct net *net, struct in_ifaddr *ifa)
 115 {
 116         unsigned int hash = inet_addr_hash(net, ifa->ifa_local);
 117
 118         spin_lock(&inet_addr_hash_lock);
 119         hlist_add_head_rcu(&ifa->hash, &inet_addr_lst[hash]);
 120         spin_unlock(&inet_addr_hash_lock);
 121 }
 122
 123 static void inet_hash_remove(struct in_ifaddr *ifa)
 124 {
 125         spin_lock(&inet_addr_hash_lock);
 126         hlist_del_init_rcu(&ifa->hash);
 127         spin_unlock(&inet_addr_hash_lock);
 128 }
 129
 130 /**
 131  * __ip_dev_find - find the first device with a given source address.
 132  * @net: the net namespace
 133  * @addr: the source address
 134  * @devref: if true, take a reference on the found device
 135  *
 136  * If a caller uses devref=false, it should be protected by RCU, or RTNL
 137  */
 138 struct net_device *__ip_dev_find(struct net *net, __be32 addr, bool devref)
 139 {
 140         unsigned int hash = inet_addr_hash(net, addr);
 141         struct net_device *result = NULL;
 142         struct in_ifaddr *ifa;
 143         struct hlist_node *node;
 144
 145         rcu_read_lock();
 146         hlist_for_each_entry_rcu(ifa, node, &inet_addr_lst[hash], hash) {
 147                 struct net_device *dev = ifa->ifa_dev->dev;
 148
 149                 if (!net_eq(dev_net(dev), net))
 150                         continue;
 151                 if (ifa->ifa_local == addr) {
 152                         result = dev;
 153                         break;
 154                 }
 155         }
 156         if (!result) {
 157                 struct flowi4 fl4 = { .daddr = addr };
 158                 struct fib_result res = { 0 };
 159                 struct fib_table *local;
 160
 161                 /* Fallback to FIB local table so that communication
 162                  * over loopback subnets work.
 163                  */
 164                 local = fib_get_table(net, RT_TABLE_LOCAL);
 165                 if (local &&
 166                     !fib_table_lookup(local, &fl4, &res, FIB_LOOKUP_NOREF) &&
 167                     res.type == RTN_LOCAL)
 168                         result = FIB_RES_DEV(res);
 169         }
 170         if (result && devref)
 171                 dev_hold(result);
 172         rcu_read_unlock();
 173         return result;
 174 }
 175 EXPORT_SYMBOL(__ip_dev_find);
 176
 177 static void rtmsg_ifa(int event, struct in_ifaddr *, struct nlmsghdr *, u32);
 178
 179 static BLOCKING_NOTIFIER_HEAD(inetaddr_chain);
 180 static void inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
 181                          int destroy);
 182 #ifdef CONFIG_SYSCTL
 183 static void devinet_sysctl_register(struct in_device *idev);
 184 static void devinet_sysctl_unregister(struct in_device *idev);
 185 #else
 186 static inline void devinet_sysctl_register(struct in_device *idev)
 187 {
 188 }
 189 static inline void devinet_sysctl_unregister(struct in_device *idev)
 190 {
 191 }
 192 #endif
 193
 194 /* Locks all the inet devices. */
 195
 196 static struct in_ifaddr *inet_alloc_ifa(void)
 197 {
 198         return kzalloc(sizeof(struct in_ifaddr), GFP_KERNEL);
 199 }
 200
 201 static void inet_rcu_free_ifa(struct rcu_head *head)
 202 {
 203         struct in_ifaddr *ifa = container_of(head, struct in_ifaddr, rcu_head);
 204         if (ifa->ifa_dev)
 205                 in_dev_put(ifa->ifa_dev);
 206         kfree(ifa);
 207 }
 208
 209 static inline void inet_free_ifa(struct in_ifaddr *ifa)
 210 {
 211         call_rcu(&ifa->rcu_head, inet_rcu_free_ifa);
 212 }
 213
 214 void in_dev_finish_destroy(struct in_device *idev)
 215 {
 216         struct net_device *dev = idev->dev;
 217
 218         WARN_ON(idev->ifa_list);
 219         WARN_ON(idev->mc_list);
 220 #ifdef NET_REFCNT_DEBUG
 221         printk(KERN_DEBUG "in_dev_finish_destroy: %p=%s\n",
 222                idev, dev ? dev->name : "NIL");
 223 #endif
 224         dev_put(dev);
 225         if (!idev->dead)
 226                 pr_err("Freeing alive in_device %p\n", idev);
 227         else
 228                 kfree(idev);
 229 }
 230 EXPORT_SYMBOL(in_dev_finish_destroy);
 231
 232 static struct in_device *inetdev_init(struct net_device *dev)
 233 {
 234         struct in_device *in_dev;
 235
 236         ASSERT_RTNL();
 237
 238         in_dev = kzalloc(sizeof(*in_dev), GFP_KERNEL);
 239         if (!in_dev)
 240                 goto out;
 241         memcpy(&in_dev->cnf, dev_net(dev)->ipv4.devconf_dflt,
 242                         sizeof(in_dev->cnf));
 243         in_dev->cnf.sysctl = NULL;
 244         in_dev->dev = dev;
 245         in_dev->arp_parms = neigh_parms_alloc(dev, &arp_tbl);
 246         if (!in_dev->arp_parms)
 247                 goto out_kfree;
 248         if (IPV4_DEVCONF(in_dev->cnf, FORWARDING))
 249                 dev_disable_lro(dev);
 250         /* Reference in_dev->dev */
 251         dev_hold(dev);
 252         /* Account for reference dev->ip_ptr (below) */
 253         in_dev_hold(in_dev);
 254
 255         devinet_sysctl_register(in_dev);
 256         ip_mc_init_dev(in_dev);
 257         if (dev->flags & IFF_UP)
 258                 ip_mc_up(in_dev);
 259
 260         /* we can receive as soon as ip_ptr is set -- do this last */
 261         RCU_INIT_POINTER(dev->ip_ptr, in_dev);
 262 out:
 263         return in_dev;
 264 out_kfree:
 265         kfree(in_dev);
 266         in_dev = NULL;
 267         goto out;
 268 }
 269
 270 static void in_dev_rcu_put(struct rcu_head *head)
 271 {
 272         struct in_device *idev = container_of(head, struct in_device, rcu_head);
 273         in_dev_put(idev);
 274 }
 275
 276 static void inetdev_destroy(struct in_device *in_dev)
 277 {
 278         struct in_ifaddr *ifa;
 279         struct net_device *dev;
 280
 281         ASSERT_RTNL();
 282
 283         dev = in_dev->dev;
 284
 285         in_dev->dead = 1;
 286
 287         ip_mc_destroy_dev(in_dev);
 288
 289         while ((ifa = in_dev->ifa_list) != NULL) {
 290                 inet_del_ifa(in_dev, &in_dev->ifa_list, 0);
 291                 inet_free_ifa(ifa);
 292         }
 293
 294         RCU_INIT_POINTER(dev->ip_ptr, NULL);
 295
 296         devinet_sysctl_unregister(in_dev);
 297         neigh_parms_release(&arp_tbl, in_dev->arp_parms);
 298         arp_ifdown(dev);
 299
 300         call_rcu(&in_dev->rcu_head, in_dev_rcu_put);
 301 }
 302
 303 int inet_addr_onlink(struct in_device *in_dev, __be32 a, __be32 b)
 304 {
 305         rcu_read_lock();
 306         for_primary_ifa(in_dev) {
 307                 if (inet_ifa_match(a, ifa)) {
 308                         if (!b || inet_ifa_match(b, ifa)) {
 309                                 rcu_read_unlock();
 310                                 return 1;
 311                         }
 312                 }
 313         } endfor_ifa(in_dev);
 314         rcu_read_unlock();
 315         return 0;
 316 }
 317
 318 static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
 319                          int destroy, struct nlmsghdr *nlh, u32 pid)
 320 {
 321         struct in_ifaddr *promote = NULL;
 322         struct in_ifaddr *ifa, *ifa1 = *ifap;
 323         struct in_ifaddr *last_prim = in_dev->ifa_list;
 324         struct in_ifaddr *prev_prom = NULL;
 325         int do_promote = IN_DEV_PROMOTE_SECONDARIES(in_dev);
 326
 327         ASSERT_RTNL();
 328
 329         /* 1. Deleting primary ifaddr forces deletion all secondaries
 330          * unless alias promotion is set
 331          **/
 332
 333         if (!(ifa1->ifa_flags & IFA_F_SECONDARY)) {
 334                 struct in_ifaddr **ifap1 = &ifa1->ifa_next;
 335
 336                 while ((ifa = *ifap1) != NULL) {
 337                         if (!(ifa->ifa_flags & IFA_F_SECONDARY) &&
 338                             ifa1->ifa_scope <= ifa->ifa_scope)
 339                                 last_prim = ifa;
 340
 341                         if (!(ifa->ifa_flags & IFA_F_SECONDARY) ||
 342                             ifa1->ifa_mask != ifa->ifa_mask ||
 343                             !inet_ifa_match(ifa1->ifa_address, ifa)) {
 344                                 ifap1 = &ifa->ifa_next;
 345                                 prev_prom = ifa;
 346                                 continue;
 347                         }
 348
 349                         if (!do_promote) {
 350                                 inet_hash_remove(ifa);
 351                                 *ifap1 = ifa->ifa_next;
 352
 353                                 rtmsg_ifa(RTM_DELADDR, ifa, nlh, pid);
 354                                 blocking_notifier_call_chain(&inetaddr_chain,
 355                                                 NETDEV_DOWN, ifa);
 356                                 inet_free_ifa(ifa);
 357                         } else {
 358                                 promote = ifa;
 359                                 break;
 360                         }
 361                 }
 362         }
 363
 364         /* On promotion all secondaries from subnet are changing
 365          * the primary IP, we must remove all their routes silently
 366          * and later to add them back with new prefsrc. Do this
 367          * while all addresses are on the device list.
 368          */
 369         for (ifa = promote; ifa; ifa = ifa->ifa_next) {
 370                 if (ifa1->ifa_mask == ifa->ifa_mask &&
 371                     inet_ifa_match(ifa1->ifa_address, ifa))
 372                         fib_del_ifaddr(ifa, ifa1);
 373         }
 374
 375         /* 2. Unlink it */
 376
 377         *ifap = ifa1->ifa_next;
 378         inet_hash_remove(ifa1);
 379
 380         /* 3. Announce address deletion */
 381
 382         /* Send message first, then call notifier.
 383            At first sight, FIB update triggered by notifier
 384            will refer to already deleted ifaddr, that could confuse
 385            netlink listeners. It is not true: look, gated sees
 386            that route deleted and if it still thinks that ifaddr
 387            is valid, it will try to restore deleted routes... Grr.
 388            So that, this order is correct.
 389          */
 390         rtmsg_ifa(RTM_DELADDR, ifa1, nlh, pid);
 391         blocking_notifier_call_chain(&inetaddr_chain, NETDEV_DOWN, ifa1);
 392
 393         if (promote) {
 394                 struct in_ifaddr *next_sec = promote->ifa_next;
 395
 396                 if (prev_prom) {
 397                         prev_prom->ifa_next = promote->ifa_next;
 398                         promote->ifa_next = last_prim->ifa_next;
 399                         last_prim->ifa_next = promote;
 400                 }
 401
 402                 promote->ifa_flags &= ~IFA_F_SECONDARY;
 403                 rtmsg_ifa(RTM_NEWADDR, promote, nlh, pid);
 404                 blocking_notifier_call_chain(&inetaddr_chain,
 405                                 NETDEV_UP, promote);
 406                 for (ifa = next_sec; ifa; ifa = ifa->ifa_next) {
 407                         if (ifa1->ifa_mask != ifa->ifa_mask ||
 408                             !inet_ifa_match(ifa1->ifa_address, ifa))
 409                                         continue;
 410                         fib_add_ifaddr(ifa);
 411                 }
 412
 413         }
 414         if (destroy)
 415                 inet_free_ifa(ifa1);
 416 }
 417
 418 static void inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
 419                          int destroy)
 420 {
 421         __inet_del_ifa(in_dev, ifap, destroy, NULL, 0);
 422 }
 423
 424 static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh,
 425                              u32 pid)
 426 {
 427         struct in_device *in_dev = ifa->ifa_dev;
 428         struct in_ifaddr *ifa1, **ifap, **last_primary;
 429
 430         ASSERT_RTNL();
 431
 432         if (!ifa->ifa_local) {
 433                 inet_free_ifa(ifa);
 434                 return 0;
 435         }
 436
 437         ifa->ifa_flags &= ~IFA_F_SECONDARY;
 438         last_primary = &in_dev->ifa_list;
 439
 440         for (ifap = &in_dev->ifa_list; (ifa1 = *ifap) != NULL;
 441              ifap = &ifa1->ifa_next) {
 442                 if (!(ifa1->ifa_flags & IFA_F_SECONDARY) &&
 443                     ifa->ifa_scope <= ifa1->ifa_scope)
 444                         last_primary = &ifa1->ifa_next;
 445                 if (ifa1->ifa_mask == ifa->ifa_mask &&
 446                     inet_ifa_match(ifa1->ifa_address, ifa)) {
 447                         if (ifa1->ifa_local == ifa->ifa_local) {
 448                                 inet_free_ifa(ifa);
 449                                 return -EEXIST;
 450                         }
 451                         if (ifa1->ifa_scope != ifa->ifa_scope) {
 452                                 inet_free_ifa(ifa);
 453                                 return -EINVAL;
 454                         }
 455                         ifa->ifa_flags |= IFA_F_SECONDARY;
 456                 }
 457         }
 458
 459         if (!(ifa->ifa_flags & IFA_F_SECONDARY)) {
 460                 net_srandom(ifa->ifa_local);
 461                 ifap = last_primary;
 462         }
 463
 464         ifa->ifa_next = *ifap;
 465         *ifap = ifa;
 466
 467         inet_hash_insert(dev_net(in_dev->dev), ifa);
 468
 469         /* Send message first, then call notifier.
 470            Notifier will trigger FIB update, so that
 471            listeners of netlink will know about new ifaddr */
 472         rtmsg_ifa(RTM_NEWADDR, ifa, nlh, pid);
 473         blocking_notifier_call_chain(&inetaddr_chain, NETDEV_UP, ifa);
 474
 475         return 0;
 476 }
 477
 478 static int inet_insert_ifa(struct in_ifaddr *ifa)
 479 {
 480         return __inet_insert_ifa(ifa, NULL, 0);
 481 }
 482
 483 static int inet_set_ifa(struct net_device *dev, struct in_ifaddr *ifa)
 484 {
 485         struct in_device *in_dev = __in_dev_get_rtnl(dev);
 486
 487         ASSERT_RTNL();
 488
 489         if (!in_dev) {
 490                 inet_free_ifa(ifa);
 491                 return -ENOBUFS;
 492         }
 493         ipv4_devconf_setall(in_dev);
 494         if (ifa->ifa_dev != in_dev) {
 495                 WARN_ON(ifa->ifa_dev);
 496                 in_dev_hold(in_dev);
 497                 ifa->ifa_dev = in_dev;
 498         }
 499         if (ipv4_is_loopback(ifa->ifa_local))
 500                 ifa->ifa_scope = RT_SCOPE_HOST;
 501         return inet_insert_ifa(ifa);
 502 }
 503
 504 /* Caller must hold RCU or RTNL :
 505  * We dont take a reference on found in_device
 506  */
 507 struct in_device *inetdev_by_index(struct net *net, int ifindex)
 508 {
 509         struct net_device *dev;
 510         struct in_device *in_dev = NULL;
 511
 512         rcu_read_lock();
 513         dev = dev_get_by_index_rcu(net, ifindex);
 514         if (dev)
 515                 in_dev = rcu_dereference_rtnl(dev->ip_ptr);
 516         rcu_read_unlock();
 517         return in_dev;
 518 }
 519 EXPORT_SYMBOL(inetdev_by_index);
 520
 521 /* Called only from RTNL semaphored context. No locks. */
 522
 523 struct in_ifaddr *inet_ifa_byprefix(struct in_device *in_dev, __be32 prefix,
 524                                     __be32 mask)
 525 {
 526         ASSERT_RTNL();
 527
 528         for_primary_ifa(in_dev) {
 529                 if (ifa->ifa_mask == mask && inet_ifa_match(prefix, ifa))
 530                         return ifa;
 531         } endfor_ifa(in_dev);
 532         return NULL;
 533 }
 534
 535 static int inet_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 536 {
 537         struct net *net = sock_net(skb->sk);
 538         struct nlattr *tb[IFA_MAX+1];
 539         struct in_device *in_dev;
 540         struct ifaddrmsg *ifm;
 541         struct in_ifaddr *ifa, **ifap;
 542         int err = -EINVAL;
 543
 544         ASSERT_RTNL();
 545
 546         err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv4_policy);
 547         if (err < 0)
 548                 goto errout;
 549
 550         ifm = nlmsg_data(nlh);
 551         in_dev = inetdev_by_index(net, ifm->ifa_index);
 552         if (in_dev == NULL) {
 553                 err = -ENODEV;
 554                 goto errout;
 555         }
 556
 557         for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
 558              ifap = &ifa->ifa_next) {
 559                 if (tb[IFA_LOCAL] &&
 560                     ifa->ifa_local != nla_get_be32(tb[IFA_LOCAL]))
 561                         continue;
 562
 563                 if (tb[IFA_LABEL] && nla_strcmp(tb[IFA_LABEL], ifa->ifa_label))
 564                         continue;
 565
 566                 if (tb[IFA_ADDRESS] &&
 567                     (ifm->ifa_prefixlen != ifa->ifa_prefixlen ||
 568                     !inet_ifa_match(nla_get_be32(tb[IFA_ADDRESS]), ifa)))
 569                         continue;
 570
 571                 __inet_del_ifa(in_dev, ifap, 1, nlh, NETLINK_CB(skb).pid);
 572                 return 0;
 573         }
 574
 575         err = -EADDRNOTAVAIL;
 576 errout:
 577         return err;
 578 }
 579
 580 static struct in_ifaddr *rtm_to_ifaddr(struct net *net, struct nlmsghdr *nlh)
 581 {
 582         struct nlattr *tb[IFA_MAX+1];
 583         struct in_ifaddr *ifa;
 584         struct ifaddrmsg *ifm;
 585         struct net_device *dev;
 586         struct in_device *in_dev;
 587         int err;
 588
 589         err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv4_policy);
 590         if (err < 0)
 591                 goto errout;
 592
 593         ifm = nlmsg_data(nlh);
 594         err = -EINVAL;
 595         if (ifm->ifa_prefixlen > 32 || tb[IFA_LOCAL] == NULL)
 596                 goto errout;
 597
 598         dev = __dev_get_by_index(net, ifm->ifa_index);
 599         err = -ENODEV;
 600         if (dev == NULL)
 601                 goto errout;
 602
 603         in_dev = __in_dev_get_rtnl(dev);
 604         err = -ENOBUFS;
 605         if (in_dev == NULL)
 606                 goto errout;
 607
 608         ifa = inet_alloc_ifa();
 609         if (ifa == NULL)
 610                 /*
 611                  * A potential indev allocation can be left alive, it stays
 612                  * assigned to its device and is destroy with it.
 613                  */
 614                 goto errout;
 615
 616         ipv4_devconf_setall(in_dev);
 617         in_dev_hold(in_dev);
 618
 619         if (tb[IFA_ADDRESS] == NULL)
 620                 tb[IFA_ADDRESS] = tb[IFA_LOCAL];
 621
 622         INIT_HLIST_NODE(&ifa->hash);
 623         ifa->ifa_prefixlen = ifm->ifa_prefixlen;
 624         ifa->ifa_mask = inet_make_mask(ifm->ifa_prefixlen);
 625         ifa->ifa_flags = ifm->ifa_flags;
 626         ifa->ifa_scope = ifm->ifa_scope;
 627         ifa->ifa_dev = in_dev;
 628
 629         ifa->ifa_local = nla_get_be32(tb[IFA_LOCAL]);
 630         ifa->ifa_address = nla_get_be32(tb[IFA_ADDRESS]);
 631
 632         if (tb[IFA_BROADCAST])
 633                 ifa->ifa_broadcast = nla_get_be32(tb[IFA_BROADCAST]);
 634
 635         if (tb[IFA_LABEL])
 636                 nla_strlcpy(ifa->ifa_label, tb[IFA_LABEL], IFNAMSIZ);
 637         else
 638                 memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
 639
 640         return ifa;
 641
 642 errout:
 643         return ERR_PTR(err);
 644 }
 645
 646 static int inet_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 647 {
 648         struct net *net = sock_net(skb->sk);
 649         struct in_ifaddr *ifa;
 650
 651         ASSERT_RTNL();
 652
 653         ifa = rtm_to_ifaddr(net, nlh);
 654         if (IS_ERR(ifa))
 655                 return PTR_ERR(ifa);
 656
 657         return __inet_insert_ifa(ifa, nlh, NETLINK_CB(skb).pid);
 658 }
 659
 660 /*
 661  *      Determine a default network mask, based on the IP address.
 662  */
 663
 664 static inline int inet_abc_len(__be32 addr)
 665 {
 666         int rc = -1;    /* Something else, probably a multicast. */
 667
 668         if (ipv4_is_zeronet(addr))
 669                 rc = 0;
 670         else {
 671                 __u32 haddr = ntohl(addr);
 672
 673                 if (IN_CLASSA(haddr))
 674                         rc = 8;
 675                 else if (IN_CLASSB(haddr))
 676                         rc = 16;
 677                 else if (IN_CLASSC(haddr))
 678                         rc = 24;
 679         }
 680
 681         return rc;
 682 }
 683
 684
 685 int devinet_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 686 {
 687         struct ifreq ifr;
 688         struct sockaddr_in sin_orig;
 689         struct sockaddr_in *sin = (struct sockaddr_in *)&ifr.ifr_addr;
 690         struct in_device *in_dev;
 691         struct in_ifaddr **ifap = NULL;
 692         struct in_ifaddr *ifa = NULL;
 693         struct net_device *dev;
 694         char *colon;
 695         int ret = -EFAULT;
 696         int tryaddrmatch = 0;
 697
 698         /*
 699          *      Fetch the caller's info block into kernel space
 700          */
 701
 702         if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
 703                 goto out;
 704         ifr.ifr_name[IFNAMSIZ - 1] = 0;
 705
 706         /* save original address for comparison */
 707         memcpy(&sin_orig, sin, sizeof(*sin));
 708
 709         colon = strchr(ifr.ifr_name, ':');
 710         if (colon)
 711                 *colon = 0;
 712
 713         dev_load(net, ifr.ifr_name);
 714
 715         switch (cmd) {
 716         case SIOCGIFADDR:       /* Get interface address */
 717         case SIOCGIFBRDADDR:    /* Get the broadcast address */
 718         case SIOCGIFDSTADDR:    /* Get the destination address */
 719         case SIOCGIFNETMASK:    /* Get the netmask for the interface */
 720                 /* Note that these ioctls will not sleep,
 721                    so that we do not impose a lock.
 722                    One day we will be forced to put shlock here (I mean SMP)
 723                  */
 724                 tryaddrmatch = (sin_orig.sin_family == AF_INET);
 725                 memset(sin, 0, sizeof(*sin));
 726                 sin->sin_family = AF_INET;
 727                 break;
 728
 729         case SIOCSIFFLAGS:
 730                 ret = -EACCES;
 731                 if (!capable(CAP_NET_ADMIN))
 732                         goto out;
 733                 break;
 734         case SIOCSIFADDR:       /* Set interface address (and family) */
 735         case SIOCSIFBRDADDR:    /* Set the broadcast address */
 736         case SIOCSIFDSTADDR:    /* Set the destination address */
 737         case SIOCSIFNETMASK:    /* Set the netmask for the interface */
 738                 ret = -EACCES;
 739                 if (!capable(CAP_NET_ADMIN))
 740                         goto out;
 741                 ret = -EINVAL;
 742                 if (sin->sin_family != AF_INET)
 743                         goto out;
 744                 break;
 745         default:
 746                 ret = -EINVAL;
 747                 goto out;
 748         }
 749
 750         rtnl_lock();
 751
 752         ret = -ENODEV;
 753         dev = __dev_get_by_name(net, ifr.ifr_name);
 754         if (!dev)
 755                 goto done;
 756
 757         if (colon)
 758                 *colon = ':';
 759
 760         in_dev = __in_dev_get_rtnl(dev);
 761         if (in_dev) {
 762                 if (tryaddrmatch) {
 763                         /* Matthias Andree */
 764                         /* compare label and address (4.4BSD style) */
 765                         /* note: we only do this for a limited set of ioctls
 766                            and only if the original address family was AF_INET.
 767                            This is checked above. */
 768                         for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
 769                              ifap = &ifa->ifa_next) {
 770                                 if (!strcmp(ifr.ifr_name, ifa->ifa_label) &&
 771                                     sin_orig.sin_addr.s_addr ==
 772                                                         ifa->ifa_local) {
 773                                         break; /* found */
 774                                 }
 775                         }
 776                 }
 777                 /* we didn't get a match, maybe the application is
 778                    4.3BSD-style and passed in junk so we fall back to
 779                    comparing just the label */
 780                 if (!ifa) {
 781                         for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
 782                              ifap = &ifa->ifa_next)
 783                                 if (!strcmp(ifr.ifr_name, ifa->ifa_label))
 784                                         break;
 785                 }
 786         }
 787
 788         ret = -EADDRNOTAVAIL;
 789         if (!ifa && cmd != SIOCSIFADDR && cmd != SIOCSIFFLAGS)
 790                 goto done;
 791
 792         switch (cmd) {
 793         case SIOCGIFADDR:       /* Get interface address */
 794                 sin->sin_addr.s_addr = ifa->ifa_local;
 795                 goto rarok;
 796
 797         case SIOCGIFBRDADDR:    /* Get the broadcast address */
 798                 sin->sin_addr.s_addr = ifa->ifa_broadcast;
 799                 goto rarok;
 800
 801         case SIOCGIFDSTADDR:    /* Get the destination address */
 802                 sin->sin_addr.s_addr = ifa->ifa_address;
 803                 goto rarok;
 804
 805         case SIOCGIFNETMASK:    /* Get the netmask for the interface */
 806                 sin->sin_addr.s_addr = ifa->ifa_mask;
 807                 goto rarok;
 808
 809         case SIOCSIFFLAGS:
 810                 if (colon) {
 811                         ret = -EADDRNOTAVAIL;
 812                         if (!ifa)
 813                                 break;
 814                         ret = 0;
 815                         if (!(ifr.ifr_flags & IFF_UP))
 816                                 inet_del_ifa(in_dev, ifap, 1);
 817                         break;
 818                 }
 819                 ret = dev_change_flags(dev, ifr.ifr_flags);
 820                 break;
 821
 822         case SIOCSIFADDR:       /* Set interface address (and family) */
 823                 ret = -EINVAL;
 824                 if (inet_abc_len(sin->sin_addr.s_addr) < 0)
 825                         break;
 826
 827                 if (!ifa) {
 828                         ret = -ENOBUFS;
 829                         ifa = inet_alloc_ifa();
 830                         INIT_HLIST_NODE(&ifa->hash);
 831                         if (!ifa)
 832                                 break;
 833                         if (colon)
 834                                 memcpy(ifa->ifa_label, ifr.ifr_name, IFNAMSIZ);
 835                         else
 836                                 memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
 837                 } else {
 838                         ret = 0;
 839                         if (ifa->ifa_local == sin->sin_addr.s_addr)
 840                                 break;
 841                         inet_del_ifa(in_dev, ifap, 0);
 842                         ifa->ifa_broadcast = 0;
 843                         ifa->ifa_scope = 0;
 844                 }
 845
 846                 ifa->ifa_address = ifa->ifa_local = sin->sin_addr.s_addr;
 847
 848                 if (!(dev->flags & IFF_POINTOPOINT)) {
 849                         ifa->ifa_prefixlen = inet_abc_len(ifa->ifa_address);
 850                         ifa->ifa_mask = inet_make_mask(ifa->ifa_prefixlen);
 851                         if ((dev->flags & IFF_BROADCAST) &&
 852                             ifa->ifa_prefixlen < 31)
 853                                 ifa->ifa_broadcast = ifa->ifa_address |
 854                                                      ~ifa->ifa_mask;
 855                 } else {
 856                         ifa->ifa_prefixlen = 32;
 857                         ifa->ifa_mask = inet_make_mask(32);
 858                 }
 859                 ret = inet_set_ifa(dev, ifa);
 860                 break;
 861
 862         case SIOCSIFBRDADDR:    /* Set the broadcast address */
 863                 ret = 0;
 864                 if (ifa->ifa_broadcast != sin->sin_addr.s_addr) {
 865                         inet_del_ifa(in_dev, ifap, 0);
 866                         ifa->ifa_broadcast = sin->sin_addr.s_addr;
 867                         inet_insert_ifa(ifa);
 868                 }
 869                 break;
 870
 871         case SIOCSIFDSTADDR:    /* Set the destination address */
 872                 ret = 0;
 873                 if (ifa->ifa_address == sin->sin_addr.s_addr)
 874                         break;
 875                 ret = -EINVAL;
 876                 if (inet_abc_len(sin->sin_addr.s_addr) < 0)
 877                         break;
 878                 ret = 0;
 879                 inet_del_ifa(in_dev, ifap, 0);
 880                 ifa->ifa_address = sin->sin_addr.s_addr;
 881                 inet_insert_ifa(ifa);
 882                 break;
 883
 884         case SIOCSIFNETMASK:    /* Set the netmask for the interface */
 885
 886                 /*
 887                  *      The mask we set must be legal.
 888                  */
 889                 ret = -EINVAL;
 890                 if (bad_mask(sin->sin_addr.s_addr, 0))
 891                         break;
 892                 ret = 0;
 893                 if (ifa->ifa_mask != sin->sin_addr.s_addr) {
 894                         __be32 old_mask = ifa->ifa_mask;
 895                         inet_del_ifa(in_dev, ifap, 0);
 896                         ifa->ifa_mask = sin->sin_addr.s_addr;
 897                         ifa->ifa_prefixlen = inet_mask_len(ifa->ifa_mask);
 898
 899                         /* See if current broadcast address matches
 900                          * with current netmask, then recalculate
 901                          * the broadcast address. Otherwise it's a
 902                          * funny address, so don't touch it since
 903                          * the user seems to know what (s)he's doing...
 904                          */
 905                         if ((dev->flags & IFF_BROADCAST) &&
 906                             (ifa->ifa_prefixlen < 31) &&
 907                             (ifa->ifa_broadcast ==
 908                              (ifa->ifa_local|~old_mask))) {
 909                                 ifa->ifa_broadcast = (ifa->ifa_local |
 910                                                       ~sin->sin_addr.s_addr);
 911                         }
 912                         inet_insert_ifa(ifa);
 913                 }
 914                 break;
 915         }
 916 done:
 917         rtnl_unlock();
 918 out:
 919         return ret;
 920 rarok:
 921         rtnl_unlock();
 922         ret = copy_to_user(arg, &ifr, sizeof(struct ifreq)) ? -EFAULT : 0;
 923         goto out;
 924 }
 925
 926 static int inet_gifconf(struct net_device *dev, char __user *buf, int len)
 927 {
 928         struct in_device *in_dev = __in_dev_get_rtnl(dev);
 929         struct in_ifaddr *ifa;
 930         struct ifreq ifr;
 931         int done = 0;
 932
 933         if (!in_dev)
 934                 goto out;
 935
 936         for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
 937                 if (!buf) {
 938                         done += sizeof(ifr);
 939                         continue;
 940                 }
 941                 if (len < (int) sizeof(ifr))
 942                         break;
 943                 memset(&ifr, 0, sizeof(struct ifreq));
 944                 if (ifa->ifa_label)
 945                         strcpy(ifr.ifr_name, ifa->ifa_label);
 946                 else
 947                         strcpy(ifr.ifr_name, dev->name);
 948
 949                 (*(struct sockaddr_in *)&ifr.ifr_addr).sin_family = AF_INET;
 950                 (*(struct sockaddr_in *)&ifr.ifr_addr).sin_addr.s_addr =
 951                                                                 ifa->ifa_local;
 952
 953                 if (copy_to_user(buf, &ifr, sizeof(struct ifreq))) {
 954                         done = -EFAULT;
 955                         break;
 956                 }
 957                 buf  += sizeof(struct ifreq);
 958                 len  -= sizeof(struct ifreq);
 959                 done += sizeof(struct ifreq);
 960         }
 961 out:
 962         return done;
 963 }
 964
 965 __be32 inet_select_addr(const struct net_device *dev, __be32 dst, int scope)
 966 {
 967         __be32 addr = 0;
 968         struct in_device *in_dev;
 969         struct net *net = dev_net(dev);
 970
 971         rcu_read_lock();
 972         in_dev = __in_dev_get_rcu(dev);
 973         if (!in_dev)
 974                 goto no_in_dev;
 975
 976         for_primary_ifa(in_dev) {
 977                 if (ifa->ifa_scope > scope)
 978                         continue;
 979                 if (!dst || inet_ifa_match(dst, ifa)) {
 980                         addr = ifa->ifa_local;
 981                         break;
 982                 }
 983                 if (!addr)
 984                         addr = ifa->ifa_local;
 985         } endfor_ifa(in_dev);
 986
 987         if (addr)
 988                 goto out_unlock;
 989 no_in_dev:
 990
 991         /* Not loopback addresses on loopback should be preferred
 992            in this case. It is importnat that lo is the first interface
 993            in dev_base list.
 994          */
 995         for_each_netdev_rcu(net, dev) {
 996                 in_dev = __in_dev_get_rcu(dev);
 997                 if (!in_dev)
 998                         continue;
 999
1000                 for_primary_ifa(in_dev) {
1001                         if (ifa->ifa_scope != RT_SCOPE_LINK &&
1002                             ifa->ifa_scope <= scope) {
1003                                 addr = ifa->ifa_local;
1004                                 goto out_unlock;
1005                         }
1006                 } endfor_ifa(in_dev);
1007         }
1008 out_unlock:
1009         rcu_read_unlock();
1010         return addr;
1011 }
1012 EXPORT_SYMBOL(inet_select_addr);
1013
1014 static __be32 confirm_addr_indev(struct in_device *in_dev, __be32 dst,
1015                               __be32 local, int scope)
1016 {
1017         int same = 0;
1018         __be32 addr = 0;
1019
1020         for_ifa(in_dev) {
1021                 if (!addr &&
1022                     (local == ifa->ifa_local || !local) &&
1023                     ifa->ifa_scope <= scope) {
1024                         addr = ifa->ifa_local;
1025                         if (same)
1026                                 break;
1027                 }
1028                 if (!same) {
1029                         same = (!local || inet_ifa_match(local, ifa)) &&
1030                                 (!dst || inet_ifa_match(dst, ifa));
1031                         if (same && addr) {
1032                                 if (local || !dst)
1033                                         break;
1034                                 /* Is the selected addr into dst subnet? */
1035                                 if (inet_ifa_match(addr, ifa))
1036                                         break;
1037                                 /* No, then can we use new local src? */
1038                                 if (ifa->ifa_scope <= scope) {
1039                                         addr = ifa->ifa_local;
1040                                         break;
1041                                 }
1042                                 /* search for large dst subnet for addr */
1043                                 same = 0;
1044                         }
1045                 }
1046         } endfor_ifa(in_dev);
1047
1048         return same ? addr : 0;
1049 }
1050
1051 /*
1052  * Confirm that local IP address exists using wildcards:
1053  * - in_dev: only on this interface, 0=any interface
1054  * - dst: only in the same subnet as dst, 0=any dst
1055  * - local: address, 0=autoselect the local address
1056  * - scope: maximum allowed scope value for the local address
1057  */
1058 __be32 inet_confirm_addr(struct in_device *in_dev,
1059                          __be32 dst, __be32 local, int scope)
1060 {
1061         __be32 addr = 0;
1062         struct net_device *dev;
1063         struct net *net;
1064
1065         if (scope != RT_SCOPE_LINK)
1066                 return confirm_addr_indev(in_dev, dst, local, scope);
1067
1068         net = dev_net(in_dev->dev);
1069         rcu_read_lock();
1070         for_each_netdev_rcu(net, dev) {
1071                 in_dev = __in_dev_get_rcu(dev);
1072                 if (in_dev) {
1073                         addr = confirm_addr_indev(in_dev, dst, local, scope);
1074                         if (addr)
1075                                 break;
1076                 }
1077         }
1078         rcu_read_unlock();
1079
1080         return addr;
1081 }
1082
1083 /*
1084  *      Device notifier
1085  */
1086
1087 int register_inetaddr_notifier(struct notifier_block *nb)
1088 {
1089         return blocking_notifier_chain_register(&inetaddr_chain, nb);
1090 }
1091 EXPORT_SYMBOL(register_inetaddr_notifier);
1092
1093 int unregister_inetaddr_notifier(struct notifier_block *nb)
1094 {
1095         return blocking_notifier_chain_unregister(&inetaddr_chain, nb);
1096 }
1097 EXPORT_SYMBOL(unregister_inetaddr_notifier);
1098
1099 /* Rename ifa_labels for a device name change. Make some effort to preserve
1100  * existing alias numbering and to create unique labels if possible.
1101 */
1102 static void inetdev_changename(struct net_device *dev, struct in_device *in_dev)
1103 {
1104         struct in_ifaddr *ifa;
1105         int named = 0;
1106
1107         for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
1108                 char old[IFNAMSIZ], *dot;
1109
1110                 memcpy(old, ifa->ifa_label, IFNAMSIZ);
1111                 memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
1112                 if (named++ == 0)
1113                         goto skip;
1114                 dot = strchr(old, ':');
1115                 if (dot == NULL) {
1116                         sprintf(old, ":%d", named);
1117                         dot = old;
1118                 }
1119                 if (strlen(dot) + strlen(dev->name) < IFNAMSIZ)
1120                         strcat(ifa->ifa_label, dot);
1121                 else
1122                         strcpy(ifa->ifa_label + (IFNAMSIZ - strlen(dot) - 1), dot);
1123 skip:
1124                 rtmsg_ifa(RTM_NEWADDR, ifa, NULL, 0);
1125         }
1126 }
1127
1128 static inline bool inetdev_valid_mtu(unsigned mtu)
1129 {
1130         return mtu >= 68;
1131 }
1132
1133 static void inetdev_send_gratuitous_arp(struct net_device *dev,
1134                                         struct in_device *in_dev)
1135
1136 {
1137         struct in_ifaddr *ifa;
1138
1139         for (ifa = in_dev->ifa_list; ifa;
1140              ifa = ifa->ifa_next) {
1141                 arp_send(ARPOP_REQUEST, ETH_P_ARP,
1142                          ifa->ifa_local, dev,
1143                          ifa->ifa_local, NULL,
1144                          dev->dev_addr, NULL);
1145         }
1146 }
1147
1148 /* Called only under RTNL semaphore */
1149
1150 static int inetdev_event(struct notifier_block *this, unsigned long event,
1151                          void *ptr)
1152 {
1153         struct net_device *dev = ptr;
1154         struct in_device *in_dev = __in_dev_get_rtnl(dev);
1155
1156         ASSERT_RTNL();
1157
1158         if (!in_dev) {
1159                 if (event == NETDEV_REGISTER) {
1160                         in_dev = inetdev_init(dev);
1161                         if (!in_dev)
1162                                 return notifier_from_errno(-ENOMEM);
1163                         if (dev->flags & IFF_LOOPBACK) {
1164                                 IN_DEV_CONF_SET(in_dev, NOXFRM, 1);
1165                                 IN_DEV_CONF_SET(in_dev, NOPOLICY, 1);
1166                         }
1167                 } else if (event == NETDEV_CHANGEMTU) {
1168                         /* Re-enabling IP */
1169                         if (inetdev_valid_mtu(dev->mtu))
1170                                 in_dev = inetdev_init(dev);
1171                 }
1172                 goto out;
1173         }
1174
1175         switch (event) {
1176         case NETDEV_REGISTER:
1177                 printk(KERN_DEBUG "inetdev_event: bug\n");
1178                 RCU_INIT_POINTER(dev->ip_ptr, NULL);
1179                 break;
1180         case NETDEV_UP:
1181                 if (!inetdev_valid_mtu(dev->mtu))
1182                         break;
1183                 if (dev->flags & IFF_LOOPBACK) {
1184                         struct in_ifaddr *ifa = inet_alloc_ifa();
1185
1186                         if (ifa) {
1187                                 INIT_HLIST_NODE(&ifa->hash);
1188                                 ifa->ifa_local =
1189                                   ifa->ifa_address = htonl(INADDR_LOOPBACK);
1190                                 ifa->ifa_prefixlen = 8;
1191                                 ifa->ifa_mask = inet_make_mask(8);
1192                                 in_dev_hold(in_dev);
1193                                 ifa->ifa_dev = in_dev;
1194                                 ifa->ifa_scope = RT_SCOPE_HOST;
1195                                 memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
1196                                 inet_insert_ifa(ifa);
1197                         }
1198                 }
1199                 ip_mc_up(in_dev);
1200                 /* fall through */
1201         case NETDEV_CHANGEADDR:
1202                 if (!IN_DEV_ARP_NOTIFY(in_dev))
1203                         break;
1204                 /* fall through */
1205         case NETDEV_NOTIFY_PEERS:
1206                 /* Send gratuitous ARP to notify of link change */
1207                 inetdev_send_gratuitous_arp(dev, in_dev);
1208                 break;
1209         case NETDEV_DOWN:
1210                 ip_mc_down(in_dev);
1211                 break;
1212         case NETDEV_PRE_TYPE_CHANGE:
1213                 ip_mc_unmap(in_dev);
1214                 break;
1215         case NETDEV_POST_TYPE_CHANGE:
1216                 ip_mc_remap(in_dev);
1217                 break;
1218         case NETDEV_CHANGEMTU:
1219                 if (inetdev_valid_mtu(dev->mtu))
1220                         break;
1221                 /* disable IP when MTU is not enough */
1222         case NETDEV_UNREGISTER:
1223                 inetdev_destroy(in_dev);
1224                 break;
1225         case NETDEV_CHANGENAME:
1226                 /* Do not notify about label change, this event is
1227                  * not interesting to applications using netlink.
1228                  */
1229                 inetdev_changename(dev, in_dev);
1230
1231                 devinet_sysctl_unregister(in_dev);
1232                 devinet_sysctl_register(in_dev);
1233                 break;
1234         }
1235 out:
1236         return NOTIFY_DONE;
1237 }
1238
1239 static struct notifier_block ip_netdev_notifier = {
1240         .notifier_call = inetdev_event,
1241 };
1242
1243 static inline size_t inet_nlmsg_size(void)
1244 {
1245         return NLMSG_ALIGN(sizeof(struct ifaddrmsg))
1246                + nla_total_size(4) /* IFA_ADDRESS */
1247                + nla_total_size(4) /* IFA_LOCAL */
1248                + nla_total_size(4) /* IFA_BROADCAST */
1249                + nla_total_size(IFNAMSIZ); /* IFA_LABEL */
1250 }
1251
1252 static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa,
1253                             u32 pid, u32 seq, int event, unsigned int flags)
1254 {
1255         struct ifaddrmsg *ifm;
1256         struct nlmsghdr  *nlh;
1257
1258         nlh = nlmsg_put(skb, pid, seq, event, sizeof(*ifm), flags);
1259         if (nlh == NULL)
1260                 return -EMSGSIZE;
1261
1262         ifm = nlmsg_data(nlh);
1263         ifm->ifa_family = AF_INET;
1264         ifm->ifa_prefixlen = ifa->ifa_prefixlen;
1265         ifm->ifa_flags = ifa->ifa_flags|IFA_F_PERMANENT;
1266         ifm->ifa_scope = ifa->ifa_scope;
1267         ifm->ifa_index = ifa->ifa_dev->dev->ifindex;
1268
1269         if (ifa->ifa_address)
1270                 NLA_PUT_BE32(skb, IFA_ADDRESS, ifa->ifa_address);
1271
1272         if (ifa->ifa_local)
1273                 NLA_PUT_BE32(skb, IFA_LOCAL, ifa->ifa_local);
1274
1275         if (ifa->ifa_broadcast)
1276                 NLA_PUT_BE32(skb, IFA_BROADCAST, ifa->ifa_broadcast);
1277
1278         if (ifa->ifa_label[0])
1279                 NLA_PUT_STRING(skb, IFA_LABEL, ifa->ifa_label);
1280
1281         return nlmsg_end(skb, nlh);
1282
1283 nla_put_failure:
1284         nlmsg_cancel(skb, nlh);
1285         return -EMSGSIZE;
1286 }
1287
1288 static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
1289 {
1290         struct net *net = sock_net(skb->sk);
1291         int h, s_h;
1292         int idx, s_idx;
1293         int ip_idx, s_ip_idx;
1294         struct net_device *dev;
1295         struct in_device *in_dev;
1296         struct in_ifaddr *ifa;
1297         struct hlist_head *head;
1298         struct hlist_node *node;
1299
1300         s_h = cb->args[0];
1301         s_idx = idx = cb->args[1];
1302         s_ip_idx = ip_idx = cb->args[2];
1303
1304         for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
1305                 idx = 0;
1306                 head = &net->dev_index_head[h];
1307                 rcu_read_lock();
1308                 hlist_for_each_entry_rcu(dev, node, head, index_hlist) {
1309                         if (idx < s_idx)
1310                                 goto cont;
1311                         if (h > s_h || idx > s_idx)
1312                                 s_ip_idx = 0;
1313                         in_dev = __in_dev_get_rcu(dev);
1314                         if (!in_dev)
1315                                 goto cont;
1316
1317                         for (ifa = in_dev->ifa_list, ip_idx = 0; ifa;
1318                              ifa = ifa->ifa_next, ip_idx++) {
1319                                 if (ip_idx < s_ip_idx)
1320                                         continue;
1321                                 if (inet_fill_ifaddr(skb, ifa,
1322                                              NETLINK_CB(cb->skb).pid,
1323                                              cb->nlh->nlmsg_seq,
1324                                              RTM_NEWADDR, NLM_F_MULTI) <= 0) {
1325                                         rcu_read_unlock();
1326                                         goto done;
1327                                 }
1328                         }
1329 cont:
1330                         idx++;
1331                 }
1332                 rcu_read_unlock();
1333         }
1334
1335 done:
1336         cb->args[0] = h;
1337         cb->args[1] = idx;
1338         cb->args[2] = ip_idx;
1339
1340         return skb->len;
1341 }
1342
1343 static void rtmsg_ifa(int event, struct in_ifaddr *ifa, struct nlmsghdr *nlh,
1344                       u32 pid)
1345 {
1346         struct sk_buff *skb;
1347         u32 seq = nlh ? nlh->nlmsg_seq : 0;
1348         int err = -ENOBUFS;
1349         struct net *net;
1350
1351         net = dev_net(ifa->ifa_dev->dev);
1352         skb = nlmsg_new(inet_nlmsg_size(), GFP_KERNEL);
1353         if (skb == NULL)
1354                 goto errout;
1355
1356         err = inet_fill_ifaddr(skb, ifa, pid, seq, event, 0);
1357         if (err < 0) {
1358                 /* -EMSGSIZE implies BUG in inet_nlmsg_size() */
1359                 WARN_ON(err == -EMSGSIZE);
1360                 kfree_skb(skb);
1361                 goto errout;
1362         }
1363         rtnl_notify(skb, net, pid, RTNLGRP_IPV4_IFADDR, nlh, GFP_KERNEL);
1364         return;
1365 errout:
1366         if (err < 0)
1367                 rtnl_set_sk_err(net, RTNLGRP_IPV4_IFADDR, err);
1368 }
1369
1370 static size_t inet_get_link_af_size(const struct net_device *dev)
1371 {
1372         struct in_device *in_dev = rcu_dereference_rtnl(dev->ip_ptr);
1373
1374         if (!in_dev)
1375                 return 0;
1376
1377         return nla_total_size(IPV4_DEVCONF_MAX * 4); /* IFLA_INET_CONF */
1378 }
1379
1380 static int inet_fill_link_af(struct sk_buff *skb, const struct net_device *dev)
1381 {
1382         struct in_device *in_dev = rcu_dereference_rtnl(dev->ip_ptr);
1383         struct nlattr *nla;
1384         int i;
1385
1386         if (!in_dev)
1387                 return -ENODATA;
1388
1389         nla = nla_reserve(skb, IFLA_INET_CONF, IPV4_DEVCONF_MAX * 4);
1390         if (nla == NULL)
1391                 return -EMSGSIZE;
1392
1393         for (i = 0; i < IPV4_DEVCONF_MAX; i++)
1394                 ((u32 *) nla_data(nla))[i] = in_dev->cnf.data[i];
1395
1396         return 0;
1397 }
1398
1399 static const struct nla_policy inet_af_policy[IFLA_INET_MAX+1] = {
1400         [IFLA_INET_CONF]        = { .type = NLA_NESTED },
1401 };
1402
1403 static int inet_validate_link_af(const struct net_device *dev,
1404                                  const struct nlattr *nla)
1405 {
1406         struct nlattr *a, *tb[IFLA_INET_MAX+1];
1407         int err, rem;
1408
1409         if (dev && !__in_dev_get_rtnl(dev))
1410                 return -EAFNOSUPPORT;
1411
1412         err = nla_parse_nested(tb, IFLA_INET_MAX, nla, inet_af_policy);
1413         if (err < 0)
1414                 return err;
1415
1416         if (tb[IFLA_INET_CONF]) {
1417                 nla_for_each_nested(a, tb[IFLA_INET_CONF], rem) {
1418                         int cfgid = nla_type(a);
1419
1420                         if (nla_len(a) < 4)
1421                                 return -EINVAL;
1422
1423                         if (cfgid <= 0 || cfgid > IPV4_DEVCONF_MAX)
1424                                 return -EINVAL;
1425                 }
1426         }
1427
1428         return 0;
1429 }
1430
1431 static int inet_set_link_af(struct net_device *dev, const struct nlattr *nla)
1432 {
1433         struct in_device *in_dev = __in_dev_get_rtnl(dev);
1434         struct nlattr *a, *tb[IFLA_INET_MAX+1];
1435         int rem;
1436
1437         if (!in_dev)
1438                 return -EAFNOSUPPORT;
1439
1440         if (nla_parse_nested(tb, IFLA_INET_MAX, nla, NULL) < 0)
1441                 BUG();
1442
1443         if (tb[IFLA_INET_CONF]) {
1444                 nla_for_each_nested(a, tb[IFLA_INET_CONF], rem)
1445                         ipv4_devconf_set(in_dev, nla_type(a), nla_get_u32(a));
1446         }
1447
1448         return 0;
1449 }
1450
1451 #ifdef CONFIG_SYSCTL
1452
1453 static void devinet_copy_dflt_conf(struct net *net, int i)
1454 {
1455         struct net_device *dev;
1456
1457         rcu_read_lock();
1458         for_each_netdev_rcu(net, dev) {
1459                 struct in_device *in_dev;
1460
1461                 in_dev = __in_dev_get_rcu(dev);
1462                 if (in_dev && !test_bit(i, in_dev->cnf.state))
1463                         in_dev->cnf.data[i] = net->ipv4.devconf_dflt->data[i];
1464         }
1465         rcu_read_unlock();
1466 }
1467
1468 /* called with RTNL locked */
1469 static void inet_forward_change(struct net *net)
1470 {
1471         struct net_device *dev;
1472         int on = IPV4_DEVCONF_ALL(net, FORWARDING);
1473
1474         IPV4_DEVCONF_ALL(net, ACCEPT_REDIRECTS) = !on;
1475         IPV4_DEVCONF_DFLT(net, FORWARDING) = on;
1476
1477         for_each_netdev(net, dev) {
1478                 struct in_device *in_dev;
1479                 if (on)
1480                         dev_disable_lro(dev);
1481                 rcu_read_lock();
1482                 in_dev = __in_dev_get_rcu(dev);
1483                 if (in_dev)
1484                         IN_DEV_CONF_SET(in_dev, FORWARDING, on);
1485                 rcu_read_unlock();
1486         }
1487 }
1488
1489 static int devinet_conf_proc(ctl_table *ctl, int write,
1490                              void __user *buffer,
1491                              size_t *lenp, loff_t *ppos)
1492 {
1493         int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1494
1495         if (write) {
1496                 struct ipv4_devconf *cnf = ctl->extra1;
1497                 struct net *net = ctl->extra2;
1498                 int i = (int *)ctl->data - cnf->data;
1499
1500                 set_bit(i, cnf->state);
1501
1502                 if (cnf == net->ipv4.devconf_dflt)
1503                         devinet_copy_dflt_conf(net, i);
1504         }
1505
1506         return ret;
1507 }
1508
1509 static int devinet_sysctl_forward(ctl_table *ctl, int write,
1510                                   void __user *buffer,
1511                                   size_t *lenp, loff_t *ppos)
1512 {
1513         int *valp = ctl->data;
1514         int val = *valp;
1515         loff_t pos = *ppos;
1516         int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1517
1518         if (write && *valp != val) {
1519                 struct net *net = ctl->extra2;
1520
1521                 if (valp != &IPV4_DEVCONF_DFLT(net, FORWARDING)) {
1522                         if (!rtnl_trylock()) {
1523                                 /* Restore the original values before restarting */
1524                                 *valp = val;
1525                                 *ppos = pos;
1526                                 return restart_syscall();
1527                         }
1528                         if (valp == &IPV4_DEVCONF_ALL(net, FORWARDING)) {
1529                                 inet_forward_change(net);
1530                         } else if (*valp) {
1531                                 struct ipv4_devconf *cnf = ctl->extra1;
1532                                 struct in_device *idev =
1533                                         container_of(cnf, struct in_device, cnf);
1534                                 dev_disable_lro(idev->dev);
1535                         }
1536                         rtnl_unlock();
1537                         rt_cache_flush(net, 0);
1538                 }
1539         }
1540
1541         return ret;
1542 }
1543
1544 static int ipv4_doint_and_flush(ctl_table *ctl, int write,
1545                                 void __user *buffer,
1546                                 size_t *lenp, loff_t *ppos)
1547 {
1548         int *valp = ctl->data;
1549         int val = *valp;
1550         int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1551         struct net *net = ctl->extra2;
1552
1553         if (write && *valp != val)
1554                 rt_cache_flush(net, 0);
1555
1556         return ret;
1557 }
1558
1559 #define DEVINET_SYSCTL_ENTRY(attr, name, mval, proc) \
1560         { \
1561                 .procname       = name, \
1562                 .data           = ipv4_devconf.data + \
1563                                   IPV4_DEVCONF_ ## attr - 1, \
1564                 .maxlen         = sizeof(int), \
1565                 .mode           = mval, \
1566                 .proc_handler   = proc, \
1567                 .extra1         = &ipv4_devconf, \
1568         }
1569
1570 #define DEVINET_SYSCTL_RW_ENTRY(attr, name) \
1571         DEVINET_SYSCTL_ENTRY(attr, name, 0644, devinet_conf_proc)
1572
1573 #define DEVINET_SYSCTL_RO_ENTRY(attr, name) \
1574         DEVINET_SYSCTL_ENTRY(attr, name, 0444, devinet_conf_proc)
1575
1576 #define DEVINET_SYSCTL_COMPLEX_ENTRY(attr, name, proc) \
1577         DEVINET_SYSCTL_ENTRY(attr, name, 0644, proc)
1578
1579 #define DEVINET_SYSCTL_FLUSHING_ENTRY(attr, name) \
1580         DEVINET_SYSCTL_COMPLEX_ENTRY(attr, name, ipv4_doint_and_flush)
1581
1582 static struct devinet_sysctl_table {
1583         struct ctl_table_header *sysctl_header;
1584         struct ctl_table devinet_vars[__IPV4_DEVCONF_MAX];
1585         char *dev_name;
1586 } devinet_sysctl = {
1587         .devinet_vars = {
1588                 DEVINET_SYSCTL_COMPLEX_ENTRY(FORWARDING, "forwarding",
1589                                              devinet_sysctl_forward),
1590                 DEVINET_SYSCTL_RO_ENTRY(MC_FORWARDING, "mc_forwarding"),
1591
1592                 DEVINET_SYSCTL_RW_ENTRY(ACCEPT_REDIRECTS, "accept_redirects"),
1593                 DEVINET_SYSCTL_RW_ENTRY(SECURE_REDIRECTS, "secure_redirects"),
1594                 DEVINET_SYSCTL_RW_ENTRY(SHARED_MEDIA, "shared_media"),
1595                 DEVINET_SYSCTL_RW_ENTRY(RP_FILTER, "rp_filter"),
1596                 DEVINET_SYSCTL_RW_ENTRY(SEND_REDIRECTS, "send_redirects"),
1597                 DEVINET_SYSCTL_RW_ENTRY(ACCEPT_SOURCE_ROUTE,
1598                                         "accept_source_route"),
1599                 DEVINET_SYSCTL_RW_ENTRY(ACCEPT_LOCAL, "accept_local"),
1600                 DEVINET_SYSCTL_RW_ENTRY(SRC_VMARK, "src_valid_mark"),
1601                 DEVINET_SYSCTL_RW_ENTRY(PROXY_ARP, "proxy_arp"),
1602                 DEVINET_SYSCTL_RW_ENTRY(MEDIUM_ID, "medium_id"),
1603                 DEVINET_SYSCTL_RW_ENTRY(BOOTP_RELAY, "bootp_relay"),
1604                 DEVINET_SYSCTL_RW_ENTRY(LOG_MARTIANS, "log_martians"),
1605                 DEVINET_SYSCTL_RW_ENTRY(TAG, "tag"),
1606                 DEVINET_SYSCTL_RW_ENTRY(ARPFILTER, "arp_filter"),
1607                 DEVINET_SYSCTL_RW_ENTRY(ARP_ANNOUNCE, "arp_announce"),
1608                 DEVINET_SYSCTL_RW_ENTRY(ARP_IGNORE, "arp_ignore"),
1609                 DEVINET_SYSCTL_RW_ENTRY(ARP_ACCEPT, "arp_accept"),
1610                 DEVINET_SYSCTL_RW_ENTRY(ARP_NOTIFY, "arp_notify"),
1611                 DEVINET_SYSCTL_RW_ENTRY(PROXY_ARP_PVLAN, "proxy_arp_pvlan"),
1612
1613                 DEVINET_SYSCTL_FLUSHING_ENTRY(NOXFRM, "disable_xfrm"),
1614                 DEVINET_SYSCTL_FLUSHING_ENTRY(NOPOLICY, "disable_policy"),
1615                 DEVINET_SYSCTL_FLUSHING_ENTRY(FORCE_IGMP_VERSION,
1616                                               "force_igmp_version"),
1617                 DEVINET_SYSCTL_FLUSHING_ENTRY(PROMOTE_SECONDARIES,
1618                                               "promote_secondaries"),
1619         },
1620 };
1621
1622 static int __devinet_sysctl_register(struct net *net, char *dev_name,
1623                                         struct ipv4_devconf *p)
1624 {
1625         int i;
1626         struct devinet_sysctl_table *t;
1627
1628 #define DEVINET_CTL_PATH_DEV    3
1629
1630         struct ctl_path devinet_ctl_path[] = {
1631                 { .procname = "net",  },
1632                 { .procname = "ipv4", },
1633                 { .procname = "conf", },
1634                 { /* to be set */ },
1635                 { },
1636         };
1637
1638         t = kmemdup(&devinet_sysctl, sizeof(*t), GFP_KERNEL);
1639         if (!t)
1640                 goto out;
1641
1642         for (i = 0; i < ARRAY_SIZE(t->devinet_vars) - 1; i++) {
1643                 t->devinet_vars[i].data += (char *)p - (char *)&ipv4_devconf;
1644                 t->devinet_vars[i].extra1 = p;
1645                 t->devinet_vars[i].extra2 = net;
1646         }
1647
1648         /*
1649          * Make a copy of dev_name, because '.procname' is regarded as const
1650          * by sysctl and we wouldn't want anyone to change it under our feet
1651          * (see SIOCSIFNAME).
1652          */
1653         t->dev_name = kstrdup(dev_name, GFP_KERNEL);
1654         if (!t->dev_name)
1655                 goto free;
1656
1657         devinet_ctl_path[DEVINET_CTL_PATH_DEV].procname = t->dev_name;
1658
1659         t->sysctl_header = register_net_sysctl_table(net, devinet_ctl_path,
1660                         t->devinet_vars);
1661         if (!t->sysctl_header)
1662                 goto free_procname;
1663
1664         p->sysctl = t;
1665         return 0;
1666
1667 free_procname:
1668         kfree(t->dev_name);
1669 free:
1670         kfree(t);
1671 out:
1672         return -ENOBUFS;
1673 }
1674
1675 static void __devinet_sysctl_unregister(struct ipv4_devconf *cnf)
1676 {
1677         struct devinet_sysctl_table *t = cnf->sysctl;
1678
1679         if (t == NULL)
1680                 return;
1681
1682         cnf->sysctl = NULL;
1683         unregister_net_sysctl_table(t->sysctl_header);
1684         kfree(t->dev_name);
1685         kfree(t);
1686 }
1687
1688 static void devinet_sysctl_register(struct in_device *idev)
1689 {
1690         neigh_sysctl_register(idev->dev, idev->arp_parms, "ipv4", NULL);
1691         __devinet_sysctl_register(dev_net(idev->dev), idev->dev->name,
1692                                         &idev->cnf);
1693 }
1694
1695 static void devinet_sysctl_unregister(struct in_device *idev)
1696 {
1697         __devinet_sysctl_unregister(&idev->cnf);
1698         neigh_sysctl_unregister(idev->arp_parms);
1699 }
1700
1701 static struct ctl_table ctl_forward_entry[] = {
1702         {
1703                 .procname       = "ip_forward",
1704                 .data           = &ipv4_devconf.data[
1705                                         IPV4_DEVCONF_FORWARDING - 1],
1706                 .maxlen         = sizeof(int),
1707                 .mode           = 0644,
1708                 .proc_handler   = devinet_sysctl_forward,
1709                 .extra1         = &ipv4_devconf,
1710                 .extra2         = &init_net,
1711         },
1712         { },
1713 };
1714
1715 static __net_initdata struct ctl_path net_ipv4_path[] = {
1716         { .procname = "net", },
1717         { .procname = "ipv4", },
1718         { },
1719 };
1720 #endif
1721
1722 static __net_init int devinet_init_net(struct net *net)
1723 {
1724         int err;
1725         struct ipv4_devconf *all, *dflt;
1726 #ifdef CONFIG_SYSCTL
1727         struct ctl_table *tbl = ctl_forward_entry;
1728         struct ctl_table_header *forw_hdr;
1729 #endif
1730
1731         err = -ENOMEM;
1732         all = &ipv4_devconf;
1733         dflt = &ipv4_devconf_dflt;
1734
1735         if (!net_eq(net, &init_net)) {
1736                 all = kmemdup(all, sizeof(ipv4_devconf), GFP_KERNEL);
1737                 if (all == NULL)
1738                         goto err_alloc_all;
1739
1740                 dflt = kmemdup(dflt, sizeof(ipv4_devconf_dflt), GFP_KERNEL);
1741                 if (dflt == NULL)
1742                         goto err_alloc_dflt;
1743
1744 #ifdef CONFIG_SYSCTL
1745                 tbl = kmemdup(tbl, sizeof(ctl_forward_entry), GFP_KERNEL);
1746                 if (tbl == NULL)
1747                         goto err_alloc_ctl;
1748
1749                 tbl[0].data = &all->data[IPV4_DEVCONF_FORWARDING - 1];
1750                 tbl[0].extra1 = all;
1751                 tbl[0].extra2 = net;
1752 #endif
1753         }
1754
1755 #ifdef CONFIG_SYSCTL
1756         err = __devinet_sysctl_register(net, "all", all);
1757         if (err < 0)
1758                 goto err_reg_all;
1759
1760         err = __devinet_sysctl_register(net, "default", dflt);
1761         if (err < 0)
1762                 goto err_reg_dflt;
1763
1764         err = -ENOMEM;
1765         forw_hdr = register_net_sysctl_table(net, net_ipv4_path, tbl);
1766         if (forw_hdr == NULL)
1767                 goto err_reg_ctl;
1768         net->ipv4.forw_hdr = forw_hdr;
1769 #endif
1770
1771         net->ipv4.devconf_all = all;
1772         net->ipv4.devconf_dflt = dflt;
1773         return 0;
1774
1775 #ifdef CONFIG_SYSCTL
1776 err_reg_ctl:
1777         __devinet_sysctl_unregister(dflt);
1778 err_reg_dflt:
1779         __devinet_sysctl_unregister(all);
1780 err_reg_all:
1781         if (tbl != ctl_forward_entry)
1782                 kfree(tbl);
1783 err_alloc_ctl:
1784 #endif
1785         if (dflt != &ipv4_devconf_dflt)
1786                 kfree(dflt);
1787 err_alloc_dflt:
1788         if (all != &ipv4_devconf)
1789                 kfree(all);
1790 err_alloc_all:
1791         return err;
1792 }
1793
1794 static __net_exit void devinet_exit_net(struct net *net)
1795 {
1796 #ifdef CONFIG_SYSCTL
1797         struct ctl_table *tbl;
1798
1799         tbl = net->ipv4.forw_hdr->ctl_table_arg;
1800         unregister_net_sysctl_table(net->ipv4.forw_hdr);
1801         __devinet_sysctl_unregister(net->ipv4.devconf_dflt);
1802         __devinet_sysctl_unregister(net->ipv4.devconf_all);
1803         kfree(tbl);
1804 #endif
1805         kfree(net->ipv4.devconf_dflt);
1806         kfree(net->ipv4.devconf_all);
1807 }
1808
1809 static __net_initdata struct pernet_operations devinet_ops = {
1810         .init = devinet_init_net,
1811         .exit = devinet_exit_net,
1812 };
1813
1814 static struct rtnl_af_ops inet_af_ops = {
1815         .family           = AF_INET,
1816         .fill_link_af     = inet_fill_link_af,
1817         .get_link_af_size = inet_get_link_af_size,
1818         .validate_link_af = inet_validate_link_af,
1819         .set_link_af      = inet_set_link_af,
1820 };
1821
1822 void __init devinet_init(void)
1823 {
1824         int i;
1825
1826         for (i = 0; i < IN4_ADDR_HSIZE; i++)
1827                 INIT_HLIST_HEAD(&inet_addr_lst[i]);
1828
1829         register_pernet_subsys(&devinet_ops);
1830
1831         register_gifconf(PF_INET, inet_gifconf);
1832         register_netdevice_notifier(&ip_netdev_notifier);
1833
1834         rtnl_af_register(&inet_af_ops);
1835
1836         rtnl_register(PF_INET, RTM_NEWADDR, inet_rtm_newaddr, NULL, NULL);
1837         rtnl_register(PF_INET, RTM_DELADDR, inet_rtm_deladdr, NULL, NULL);
1838         rtnl_register(PF_INET, RTM_GETADDR, NULL, inet_dump_ifaddr, NULL);
1839 }
1840