net/core/rtnetlink.c

   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  *              Routing netlink socket interface: protocol independent part.
   7  *
   8  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   9  *
  10  *              This program is free software; you can redistribute it and/or
  11  *              modify it under the terms of the GNU General Public License
  12  *              as published by the Free Software Foundation; either version
  13  *              2 of the License, or (at your option) any later version.
  14  *
  15  *      Fixes:
  16  *      Vitaly E. Lavrov                RTA_OK arithmetics was wrong.
  17  */
  18
  19 #include <linux/errno.h>
  20 #include <linux/module.h>
  21 #include <linux/types.h>
  22 #include <linux/socket.h>
  23 #include <linux/kernel.h>
  24 #include <linux/timer.h>
  25 #include <linux/string.h>
  26 #include <linux/sockios.h>
  27 #include <linux/net.h>
  28 #include <linux/fcntl.h>
  29 #include <linux/mm.h>
  30 #include <linux/slab.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/capability.h>
  33 #include <linux/skbuff.h>
  34 #include <linux/init.h>
  35 #include <linux/security.h>
  36 #include <linux/mutex.h>
  37 #include <linux/if_addr.h>
  38
  39 #include <asm/uaccess.h>
  40 #include <asm/system.h>
  41 #include <asm/string.h>
  42
  43 #include <linux/inet.h>
  44 #include <linux/netdevice.h>
  45 #include <net/ip.h>
  46 #include <net/protocol.h>
  47 #include <net/arp.h>
  48 #include <net/route.h>
  49 #include <net/udp.h>
  50 #include <net/sock.h>
  51 #include <net/pkt_sched.h>
  52 #include <net/fib_rules.h>
  53 #include <net/netlink.h>
  54 #ifdef CONFIG_NET_WIRELESS_RTNETLINK
  55 #include <linux/wireless.h>
  56 #include <net/iw_handler.h>
  57 #endif  /* CONFIG_NET_WIRELESS_RTNETLINK */
  58
  59 static DEFINE_MUTEX(rtnl_mutex);
  60 static struct sock *rtnl;
  61
  62 void rtnl_lock(void)
  63 {
  64         mutex_lock(&rtnl_mutex);
  65 }
  66
  67 void __rtnl_unlock(void)
  68 {
  69         mutex_unlock(&rtnl_mutex);
  70 }
  71
  72 void rtnl_unlock(void)
  73 {
  74         mutex_unlock(&rtnl_mutex);
  75         if (rtnl && rtnl->sk_receive_queue.qlen)
  76                 rtnl->sk_data_ready(rtnl, 0);
  77         netdev_run_todo();
  78 }
  79
  80 int rtnl_trylock(void)
  81 {
  82         return mutex_trylock(&rtnl_mutex);
  83 }
  84
  85 int rtattr_parse(struct rtattr *tb[], int maxattr, struct rtattr *rta, int len)
  86 {
  87         memset(tb, 0, sizeof(struct rtattr*)*maxattr);
  88
  89         while (RTA_OK(rta, len)) {
  90                 unsigned flavor = rta->rta_type;
  91                 if (flavor && flavor <= maxattr)
  92                         tb[flavor-1] = rta;
  93                 rta = RTA_NEXT(rta, len);
  94         }
  95         return 0;
  96 }
  97
  98 struct rtnetlink_link * rtnetlink_links[NPROTO];
  99
 100 static const int rtm_min[RTM_NR_FAMILIES] =
 101 {
 102         [RTM_FAM(RTM_NEWLINK)]      = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
 103         [RTM_FAM(RTM_NEWADDR)]      = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
 104         [RTM_FAM(RTM_NEWROUTE)]     = NLMSG_LENGTH(sizeof(struct rtmsg)),
 105         [RTM_FAM(RTM_NEWRULE)]      = NLMSG_LENGTH(sizeof(struct fib_rule_hdr)),
 106         [RTM_FAM(RTM_NEWQDISC)]     = NLMSG_LENGTH(sizeof(struct tcmsg)),
 107         [RTM_FAM(RTM_NEWTCLASS)]    = NLMSG_LENGTH(sizeof(struct tcmsg)),
 108         [RTM_FAM(RTM_NEWTFILTER)]   = NLMSG_LENGTH(sizeof(struct tcmsg)),
 109         [RTM_FAM(RTM_NEWACTION)]    = NLMSG_LENGTH(sizeof(struct tcamsg)),
 110         [RTM_FAM(RTM_GETMULTICAST)] = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
 111         [RTM_FAM(RTM_GETANYCAST)]   = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
 112 };
 113
 114 static const int rta_max[RTM_NR_FAMILIES] =
 115 {
 116         [RTM_FAM(RTM_NEWLINK)]      = IFLA_MAX,
 117         [RTM_FAM(RTM_NEWADDR)]      = IFA_MAX,
 118         [RTM_FAM(RTM_NEWROUTE)]     = RTA_MAX,
 119         [RTM_FAM(RTM_NEWRULE)]      = FRA_MAX,
 120         [RTM_FAM(RTM_NEWQDISC)]     = TCA_MAX,
 121         [RTM_FAM(RTM_NEWTCLASS)]    = TCA_MAX,
 122         [RTM_FAM(RTM_NEWTFILTER)]   = TCA_MAX,
 123         [RTM_FAM(RTM_NEWACTION)]    = TCAA_MAX,
 124 };
 125
 126 void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
 127 {
 128         struct rtattr *rta;
 129         int size = RTA_LENGTH(attrlen);
 130
 131         rta = (struct rtattr*)skb_put(skb, RTA_ALIGN(size));
 132         rta->rta_type = attrtype;
 133         rta->rta_len = size;
 134         memcpy(RTA_DATA(rta), data, attrlen);
 135         memset(RTA_DATA(rta) + attrlen, 0, RTA_ALIGN(size) - size);
 136 }
 137
 138 size_t rtattr_strlcpy(char *dest, const struct rtattr *rta, size_t size)
 139 {
 140         size_t ret = RTA_PAYLOAD(rta);
 141         char *src = RTA_DATA(rta);
 142
 143         if (ret > 0 && src[ret - 1] == '\0')
 144                 ret--;
 145         if (size > 0) {
 146                 size_t len = (ret >= size) ? size - 1 : ret;
 147                 memset(dest, 0, size);
 148                 memcpy(dest, src, len);
 149         }
 150         return ret;
 151 }
 152
 153 int rtnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo)
 154 {
 155         int err = 0;
 156
 157         NETLINK_CB(skb).dst_group = group;
 158         if (echo)
 159                 atomic_inc(&skb->users);
 160         netlink_broadcast(rtnl, skb, pid, group, GFP_KERNEL);
 161         if (echo)
 162                 err = netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
 163         return err;
 164 }
 165
 166 int rtnl_unicast(struct sk_buff *skb, u32 pid)
 167 {
 168         return nlmsg_unicast(rtnl, skb, pid);
 169 }
 170
 171 int rtnl_notify(struct sk_buff *skb, u32 pid, u32 group,
 172                 struct nlmsghdr *nlh, gfp_t flags)
 173 {
 174         int report = 0;
 175
 176         if (nlh)
 177                 report = nlmsg_report(nlh);
 178
 179         return nlmsg_notify(rtnl, skb, pid, group, report, flags);
 180 }
 181
 182 void rtnl_set_sk_err(u32 group, int error)
 183 {
 184         netlink_set_err(rtnl, 0, group, error);
 185 }
 186
 187 int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics)
 188 {
 189         struct nlattr *mx;
 190         int i, valid = 0;
 191
 192         mx = nla_nest_start(skb, RTA_METRICS);
 193         if (mx == NULL)
 194                 return -ENOBUFS;
 195
 196         for (i = 0; i < RTAX_MAX; i++) {
 197                 if (metrics[i]) {
 198                         valid++;
 199                         NLA_PUT_U32(skb, i+1, metrics[i]);
 200                 }
 201         }
 202
 203         if (!valid) {
 204                 nla_nest_cancel(skb, mx);
 205                 return 0;
 206         }
 207
 208         return nla_nest_end(skb, mx);
 209
 210 nla_put_failure:
 211         return nla_nest_cancel(skb, mx);
 212 }
 213
 214 int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id,
 215                        u32 ts, u32 tsage, long expires, u32 error)
 216 {
 217         struct rta_cacheinfo ci = {
 218                 .rta_lastuse = jiffies_to_clock_t(jiffies - dst->lastuse),
 219                 .rta_used = dst->__use,
 220                 .rta_clntref = atomic_read(&(dst->__refcnt)),
 221                 .rta_error = error,
 222                 .rta_id =  id,
 223                 .rta_ts = ts,
 224                 .rta_tsage = tsage,
 225         };
 226
 227         if (expires)
 228                 ci.rta_expires = jiffies_to_clock_t(expires);
 229
 230         return nla_put(skb, RTA_CACHEINFO, sizeof(ci), &ci);
 231 }
 232
 233 EXPORT_SYMBOL_GPL(rtnl_put_cacheinfo);
 234
 235 static void set_operstate(struct net_device *dev, unsigned char transition)
 236 {
 237         unsigned char operstate = dev->operstate;
 238
 239         switch(transition) {
 240         case IF_OPER_UP:
 241                 if ((operstate == IF_OPER_DORMANT ||
 242                      operstate == IF_OPER_UNKNOWN) &&
 243                     !netif_dormant(dev))
 244                         operstate = IF_OPER_UP;
 245                 break;
 246
 247         case IF_OPER_DORMANT:
 248                 if (operstate == IF_OPER_UP ||
 249                     operstate == IF_OPER_UNKNOWN)
 250                         operstate = IF_OPER_DORMANT;
 251                 break;
 252         };
 253
 254         if (dev->operstate != operstate) {
 255                 write_lock_bh(&dev_base_lock);
 256                 dev->operstate = operstate;
 257                 write_unlock_bh(&dev_base_lock);
 258                 netdev_state_change(dev);
 259         }
 260 }
 261
 262 static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
 263                                  struct net_device_stats *b)
 264 {
 265         a->rx_packets = b->rx_packets;
 266         a->tx_packets = b->tx_packets;
 267         a->rx_bytes = b->rx_bytes;
 268         a->tx_bytes = b->tx_bytes;
 269         a->rx_errors = b->rx_errors;
 270         a->tx_errors = b->tx_errors;
 271         a->rx_dropped = b->rx_dropped;
 272         a->tx_dropped = b->tx_dropped;
 273
 274         a->multicast = b->multicast;
 275         a->collisions = b->collisions;
 276
 277         a->rx_length_errors = b->rx_length_errors;
 278         a->rx_over_errors = b->rx_over_errors;
 279         a->rx_crc_errors = b->rx_crc_errors;
 280         a->rx_frame_errors = b->rx_frame_errors;
 281         a->rx_fifo_errors = b->rx_fifo_errors;
 282         a->rx_missed_errors = b->rx_missed_errors;
 283
 284         a->tx_aborted_errors = b->tx_aborted_errors;
 285         a->tx_carrier_errors = b->tx_carrier_errors;
 286         a->tx_fifo_errors = b->tx_fifo_errors;
 287         a->tx_heartbeat_errors = b->tx_heartbeat_errors;
 288         a->tx_window_errors = b->tx_window_errors;
 289
 290         a->rx_compressed = b->rx_compressed;
 291         a->tx_compressed = b->tx_compressed;
 292 };
 293
 294 static inline size_t if_nlmsg_size(int iwbuflen)
 295 {
 296         return NLMSG_ALIGN(sizeof(struct ifinfomsg))
 297                + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
 298                + nla_total_size(IFNAMSIZ) /* IFLA_QDISC */
 299                + nla_total_size(sizeof(struct rtnl_link_ifmap))
 300                + nla_total_size(sizeof(struct rtnl_link_stats))
 301                + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
 302                + nla_total_size(MAX_ADDR_LEN) /* IFLA_BROADCAST */
 303                + nla_total_size(4) /* IFLA_TXQLEN */
 304                + nla_total_size(4) /* IFLA_WEIGHT */
 305                + nla_total_size(4) /* IFLA_MTU */
 306                + nla_total_size(4) /* IFLA_LINK */
 307                + nla_total_size(4) /* IFLA_MASTER */
 308                + nla_total_size(1) /* IFLA_OPERSTATE */
 309                + nla_total_size(1) /* IFLA_LINKMODE */
 310                + nla_total_size(iwbuflen);
 311 }
 312
 313 static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
 314                             void *iwbuf, int iwbuflen, int type, u32 pid,
 315                             u32 seq, u32 change, unsigned int flags)
 316 {
 317         struct ifinfomsg *ifm;
 318         struct nlmsghdr *nlh;
 319
 320         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ifm), flags);
 321         if (nlh == NULL)
 322                 return -EMSGSIZE;
 323
 324         ifm = nlmsg_data(nlh);
 325         ifm->ifi_family = AF_UNSPEC;
 326         ifm->__ifi_pad = 0;
 327         ifm->ifi_type = dev->type;
 328         ifm->ifi_index = dev->ifindex;
 329         ifm->ifi_flags = dev_get_flags(dev);
 330         ifm->ifi_change = change;
 331
 332         NLA_PUT_STRING(skb, IFLA_IFNAME, dev->name);
 333         NLA_PUT_U32(skb, IFLA_TXQLEN, dev->tx_queue_len);
 334         NLA_PUT_U32(skb, IFLA_WEIGHT, dev->weight);
 335         NLA_PUT_U8(skb, IFLA_OPERSTATE,
 336                    netif_running(dev) ? dev->operstate : IF_OPER_DOWN);
 337         NLA_PUT_U8(skb, IFLA_LINKMODE, dev->link_mode);
 338         NLA_PUT_U32(skb, IFLA_MTU, dev->mtu);
 339
 340         if (dev->ifindex != dev->iflink)
 341                 NLA_PUT_U32(skb, IFLA_LINK, dev->iflink);
 342
 343         if (dev->master)
 344                 NLA_PUT_U32(skb, IFLA_MASTER, dev->master->ifindex);
 345
 346         if (dev->qdisc_sleeping)
 347                 NLA_PUT_STRING(skb, IFLA_QDISC, dev->qdisc_sleeping->ops->id);
 348
 349         if (1) {
 350                 struct rtnl_link_ifmap map = {
 351                         .mem_start   = dev->mem_start,
 352                         .mem_end     = dev->mem_end,
 353                         .base_addr   = dev->base_addr,
 354                         .irq         = dev->irq,
 355                         .dma         = dev->dma,
 356                         .port        = dev->if_port,
 357                 };
 358                 NLA_PUT(skb, IFLA_MAP, sizeof(map), &map);
 359         }
 360
 361         if (dev->addr_len) {
 362                 NLA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr);
 363                 NLA_PUT(skb, IFLA_BROADCAST, dev->addr_len, dev->broadcast);
 364         }
 365
 366         if (dev->get_stats) {
 367                 struct net_device_stats *stats = dev->get_stats(dev);
 368                 if (stats) {
 369                         struct nlattr *attr;
 370
 371                         attr = nla_reserve(skb, IFLA_STATS,
 372                                            sizeof(struct rtnl_link_stats));
 373                         if (attr == NULL)
 374                                 goto nla_put_failure;
 375
 376                         copy_rtnl_link_stats(nla_data(attr), stats);
 377                 }
 378         }
 379
 380         if (iwbuf)
 381                 NLA_PUT(skb, IFLA_WIRELESS, iwbuflen, iwbuf);
 382
 383         return nlmsg_end(skb, nlh);
 384
 385 nla_put_failure:
 386         nlmsg_cancel(skb, nlh);
 387         return -EMSGSIZE;
 388 }
 389
 390 static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 391 {
 392         int idx;
 393         int s_idx = cb->args[0];
 394         struct net_device *dev;
 395
 396         read_lock(&dev_base_lock);
 397         for (dev=dev_base, idx=0; dev; dev = dev->next, idx++) {
 398                 if (idx < s_idx)
 399                         continue;
 400                 if (rtnl_fill_ifinfo(skb, dev, NULL, 0, RTM_NEWLINK,
 401                                      NETLINK_CB(cb->skb).pid,
 402                                      cb->nlh->nlmsg_seq, 0, NLM_F_MULTI) <= 0)
 403                         break;
 404         }
 405         read_unlock(&dev_base_lock);
 406         cb->args[0] = idx;
 407
 408         return skb->len;
 409 }
 410
 411 static struct nla_policy ifla_policy[IFLA_MAX+1] __read_mostly = {
 412         [IFLA_IFNAME]           = { .type = NLA_STRING, .len = IFNAMSIZ-1 },
 413         [IFLA_MAP]              = { .len = sizeof(struct rtnl_link_ifmap) },
 414         [IFLA_MTU]              = { .type = NLA_U32 },
 415         [IFLA_TXQLEN]           = { .type = NLA_U32 },
 416         [IFLA_WEIGHT]           = { .type = NLA_U32 },
 417         [IFLA_OPERSTATE]        = { .type = NLA_U8 },
 418         [IFLA_LINKMODE]         = { .type = NLA_U8 },
 419 };
 420
 421 static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 422 {
 423         struct ifinfomsg *ifm;
 424         struct net_device *dev;
 425         int err, send_addr_notify = 0, modified = 0;
 426         struct nlattr *tb[IFLA_MAX+1];
 427         char ifname[IFNAMSIZ];
 428
 429         err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
 430         if (err < 0)
 431                 goto errout;
 432
 433         if (tb[IFLA_IFNAME])
 434                 nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
 435         else
 436                 ifname[0] = '\0';
 437
 438         err = -EINVAL;
 439         ifm = nlmsg_data(nlh);
 440         if (ifm->ifi_index >= 0)
 441                 dev = dev_get_by_index(ifm->ifi_index);
 442         else if (tb[IFLA_IFNAME])
 443                 dev = dev_get_by_name(ifname);
 444         else
 445                 goto errout;
 446
 447         if (dev == NULL) {
 448                 err = -ENODEV;
 449                 goto errout;
 450         }
 451
 452         if (tb[IFLA_ADDRESS] &&
 453             nla_len(tb[IFLA_ADDRESS]) < dev->addr_len)
 454                 goto errout_dev;
 455
 456         if (tb[IFLA_BROADCAST] &&
 457             nla_len(tb[IFLA_BROADCAST]) < dev->addr_len)
 458                 goto errout_dev;
 459
 460         if (tb[IFLA_MAP]) {
 461                 struct rtnl_link_ifmap *u_map;
 462                 struct ifmap k_map;
 463
 464                 if (!dev->set_config) {
 465                         err = -EOPNOTSUPP;
 466                         goto errout_dev;
 467                 }
 468
 469                 if (!netif_device_present(dev)) {
 470                         err = -ENODEV;
 471                         goto errout_dev;
 472                 }
 473
 474                 u_map = nla_data(tb[IFLA_MAP]);
 475                 k_map.mem_start = (unsigned long) u_map->mem_start;
 476                 k_map.mem_end = (unsigned long) u_map->mem_end;
 477                 k_map.base_addr = (unsigned short) u_map->base_addr;
 478                 k_map.irq = (unsigned char) u_map->irq;
 479                 k_map.dma = (unsigned char) u_map->dma;
 480                 k_map.port = (unsigned char) u_map->port;
 481
 482                 err = dev->set_config(dev, &k_map);
 483                 if (err < 0)
 484                         goto errout_dev;
 485
 486                 modified = 1;
 487         }
 488
 489         if (tb[IFLA_ADDRESS]) {
 490                 struct sockaddr *sa;
 491                 int len;
 492
 493                 if (!dev->set_mac_address) {
 494                         err = -EOPNOTSUPP;
 495                         goto errout_dev;
 496                 }
 497
 498                 if (!netif_device_present(dev)) {
 499                         err = -ENODEV;
 500                         goto errout_dev;
 501                 }
 502
 503                 len = sizeof(sa_family_t) + dev->addr_len;
 504                 sa = kmalloc(len, GFP_KERNEL);
 505                 if (!sa) {
 506                         err = -ENOMEM;
 507                         goto errout_dev;
 508                 }
 509                 sa->sa_family = dev->type;
 510                 memcpy(sa->sa_data, nla_data(tb[IFLA_ADDRESS]),
 511                        dev->addr_len);
 512                 err = dev->set_mac_address(dev, sa);
 513                 kfree(sa);
 514                 if (err)
 515                         goto errout_dev;
 516                 send_addr_notify = 1;
 517                 modified = 1;
 518         }
 519
 520         if (tb[IFLA_MTU]) {
 521                 err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
 522                 if (err < 0)
 523                         goto errout_dev;
 524                 modified = 1;
 525         }
 526
 527         /*
 528          * Interface selected by interface index but interface
 529          * name provided implies that a name change has been
 530          * requested.
 531          */
 532         if (ifm->ifi_index >= 0 && ifname[0]) {
 533                 err = dev_change_name(dev, ifname);
 534                 if (err < 0)
 535                         goto errout_dev;
 536                 modified = 1;
 537         }
 538
 539 #ifdef CONFIG_NET_WIRELESS_RTNETLINK
 540         if (tb[IFLA_WIRELESS]) {
 541                 /* Call Wireless Extensions.
 542                  * Various stuff checked in there... */
 543                 err = wireless_rtnetlink_set(dev, nla_data(tb[IFLA_WIRELESS]),
 544                                              nla_len(tb[IFLA_WIRELESS]));
 545                 if (err < 0)
 546                         goto errout_dev;
 547         }
 548 #endif  /* CONFIG_NET_WIRELESS_RTNETLINK */
 549
 550         if (tb[IFLA_BROADCAST]) {
 551                 nla_memcpy(dev->broadcast, tb[IFLA_BROADCAST], dev->addr_len);
 552                 send_addr_notify = 1;
 553         }
 554
 555
 556         if (ifm->ifi_flags)
 557                 dev_change_flags(dev, ifm->ifi_flags);
 558
 559         if (tb[IFLA_TXQLEN])
 560                 dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
 561
 562         if (tb[IFLA_WEIGHT])
 563                 dev->weight = nla_get_u32(tb[IFLA_WEIGHT]);
 564
 565         if (tb[IFLA_OPERSTATE])
 566                 set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
 567
 568         if (tb[IFLA_LINKMODE]) {
 569                 write_lock_bh(&dev_base_lock);
 570                 dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
 571                 write_unlock_bh(&dev_base_lock);
 572         }
 573
 574         err = 0;
 575
 576 errout_dev:
 577         if (err < 0 && modified && net_ratelimit())
 578                 printk(KERN_WARNING "A link change request failed with "
 579                        "some changes comitted already. Interface %s may "
 580                        "have been left with an inconsistent configuration, "
 581                        "please check.\n", dev->name);
 582
 583         if (send_addr_notify)
 584                 call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
 585
 586         dev_put(dev);
 587 errout:
 588         return err;
 589 }
 590
 591 static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 592 {
 593         struct ifinfomsg *ifm;
 594         struct nlattr *tb[IFLA_MAX+1];
 595         struct net_device *dev = NULL;
 596         struct sk_buff *nskb;
 597         char *iw_buf = NULL, *iw = NULL;
 598         int iw_buf_len = 0;
 599         int err;
 600
 601         err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
 602         if (err < 0)
 603                 return err;
 604
 605         ifm = nlmsg_data(nlh);
 606         if (ifm->ifi_index >= 0) {
 607                 dev = dev_get_by_index(ifm->ifi_index);
 608                 if (dev == NULL)
 609                         return -ENODEV;
 610         } else
 611                 return -EINVAL;
 612
 613
 614 #ifdef CONFIG_NET_WIRELESS_RTNETLINK
 615         if (tb[IFLA_WIRELESS]) {
 616                 /* Call Wireless Extensions. We need to know the size before
 617                  * we can alloc. Various stuff checked in there... */
 618                 err = wireless_rtnetlink_get(dev, nla_data(tb[IFLA_WIRELESS]),
 619                                              nla_len(tb[IFLA_WIRELESS]),
 620                                              &iw_buf, &iw_buf_len);
 621                 if (err < 0)
 622                         goto errout;
 623
 624                 /* Payload is at an offset in buffer */
 625                 iw = iw_buf + IW_EV_POINT_OFF;
 626         }
 627 #endif  /* CONFIG_NET_WIRELESS_RTNETLINK */
 628
 629         nskb = nlmsg_new(if_nlmsg_size(iw_buf_len), GFP_KERNEL);
 630         if (nskb == NULL) {
 631                 err = -ENOBUFS;
 632                 goto errout;
 633         }
 634
 635         err = rtnl_fill_ifinfo(nskb, dev, iw, iw_buf_len, RTM_NEWLINK,
 636                                NETLINK_CB(skb).pid, nlh->nlmsg_seq, 0, 0);
 637         if (err < 0) {
 638                 /* -EMSGSIZE implies BUG in if_nlmsg_size */
 639                 WARN_ON(err == -EMSGSIZE);
 640                 kfree_skb(nskb);
 641                 goto errout;
 642         }
 643         err = rtnl_unicast(nskb, NETLINK_CB(skb).pid);
 644 errout:
 645         kfree(iw_buf);
 646         dev_put(dev);
 647
 648         return err;
 649 }
 650
 651 static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
 652 {
 653         int idx;
 654         int s_idx = cb->family;
 655
 656         if (s_idx == 0)
 657                 s_idx = 1;
 658         for (idx=1; idx<NPROTO; idx++) {
 659                 int type = cb->nlh->nlmsg_type-RTM_BASE;
 660                 if (idx < s_idx || idx == PF_PACKET)
 661                         continue;
 662                 if (rtnetlink_links[idx] == NULL ||
 663                     rtnetlink_links[idx][type].dumpit == NULL)
 664                         continue;
 665                 if (idx > s_idx)
 666                         memset(&cb->args[0], 0, sizeof(cb->args));
 667                 if (rtnetlink_links[idx][type].dumpit(skb, cb))
 668                         break;
 669         }
 670         cb->family = idx;
 671
 672         return skb->len;
 673 }
 674
 675 void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change)
 676 {
 677         struct sk_buff *skb;
 678         int err = -ENOBUFS;
 679
 680         skb = nlmsg_new(if_nlmsg_size(0), GFP_KERNEL);
 681         if (skb == NULL)
 682                 goto errout;
 683
 684         err = rtnl_fill_ifinfo(skb, dev, NULL, 0, type, 0, 0, change, 0);
 685         if (err < 0) {
 686                 /* -EMSGSIZE implies BUG in if_nlmsg_size() */
 687                 WARN_ON(err == -EMSGSIZE);
 688                 kfree_skb(skb);
 689                 goto errout;
 690         }
 691         err = rtnl_notify(skb, 0, RTNLGRP_LINK, NULL, GFP_KERNEL);
 692 errout:
 693         if (err < 0)
 694                 rtnl_set_sk_err(RTNLGRP_LINK, err);
 695 }
 696
 697 /* Protected by RTNL sempahore.  */
 698 static struct rtattr **rta_buf;
 699 static int rtattr_max;
 700
 701 /* Process one rtnetlink message. */
 702
 703 static __inline__ int
 704 rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp)
 705 {
 706         struct rtnetlink_link *link;
 707         struct rtnetlink_link *link_tab;
 708         int sz_idx, kind;
 709         int min_len;
 710         int family;
 711         int type;
 712         int err;
 713
 714         /* Only requests are handled by kernel now */
 715         if (!(nlh->nlmsg_flags&NLM_F_REQUEST))
 716                 return 0;
 717
 718         type = nlh->nlmsg_type;
 719
 720         /* A control message: ignore them */
 721         if (type < RTM_BASE)
 722                 return 0;
 723
 724         /* Unknown message: reply with EINVAL */
 725         if (type > RTM_MAX)
 726                 goto err_inval;
 727
 728         type -= RTM_BASE;
 729
 730         /* All the messages must have at least 1 byte length */
 731         if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct rtgenmsg)))
 732                 return 0;
 733
 734         family = ((struct rtgenmsg*)NLMSG_DATA(nlh))->rtgen_family;
 735         if (family >= NPROTO) {
 736                 *errp = -EAFNOSUPPORT;
 737                 return -1;
 738         }
 739
 740         link_tab = rtnetlink_links[family];
 741         if (link_tab == NULL)
 742                 link_tab = rtnetlink_links[PF_UNSPEC];
 743         link = &link_tab[type];
 744
 745         sz_idx = type>>2;
 746         kind = type&3;
 747
 748         if (kind != 2 && security_netlink_recv(skb, CAP_NET_ADMIN)) {
 749                 *errp = -EPERM;
 750                 return -1;
 751         }
 752
 753         if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
 754                 if (link->dumpit == NULL)
 755                         link = &(rtnetlink_links[PF_UNSPEC][type]);
 756
 757                 if (link->dumpit == NULL)
 758                         goto err_inval;
 759
 760                 if ((*errp = netlink_dump_start(rtnl, skb, nlh,
 761                                                 link->dumpit, NULL)) != 0) {
 762                         return -1;
 763                 }
 764
 765                 netlink_queue_skip(nlh, skb);
 766                 return -1;
 767         }
 768
 769         memset(rta_buf, 0, (rtattr_max * sizeof(struct rtattr *)));
 770
 771         min_len = rtm_min[sz_idx];
 772         if (nlh->nlmsg_len < min_len)
 773                 goto err_inval;
 774
 775         if (nlh->nlmsg_len > min_len) {
 776                 int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
 777                 struct rtattr *attr = (void*)nlh + NLMSG_ALIGN(min_len);
 778
 779                 while (RTA_OK(attr, attrlen)) {
 780                         unsigned flavor = attr->rta_type;
 781                         if (flavor) {
 782                                 if (flavor > rta_max[sz_idx])
 783                                         goto err_inval;
 784                                 rta_buf[flavor-1] = attr;
 785                         }
 786                         attr = RTA_NEXT(attr, attrlen);
 787                 }
 788         }
 789
 790         if (link->doit == NULL)
 791                 link = &(rtnetlink_links[PF_UNSPEC][type]);
 792         if (link->doit == NULL)
 793                 goto err_inval;
 794         err = link->doit(skb, nlh, (void *)&rta_buf[0]);
 795
 796         *errp = err;
 797         return err;
 798
 799 err_inval:
 800         *errp = -EINVAL;
 801         return -1;
 802 }
 803
 804 static void rtnetlink_rcv(struct sock *sk, int len)
 805 {
 806         unsigned int qlen = 0;
 807
 808         do {
 809                 mutex_lock(&rtnl_mutex);
 810                 netlink_run_queue(sk, &qlen, &rtnetlink_rcv_msg);
 811                 mutex_unlock(&rtnl_mutex);
 812
 813                 netdev_run_todo();
 814         } while (qlen);
 815 }
 816
 817 static struct rtnetlink_link link_rtnetlink_table[RTM_NR_MSGTYPES] =
 818 {
 819         [RTM_GETLINK     - RTM_BASE] = { .doit   = rtnl_getlink,
 820                                          .dumpit = rtnl_dump_ifinfo      },
 821         [RTM_SETLINK     - RTM_BASE] = { .doit   = rtnl_setlink          },
 822         [RTM_GETADDR     - RTM_BASE] = { .dumpit = rtnl_dump_all         },
 823         [RTM_GETROUTE    - RTM_BASE] = { .dumpit = rtnl_dump_all         },
 824         [RTM_NEWNEIGH    - RTM_BASE] = { .doit   = neigh_add             },
 825         [RTM_DELNEIGH    - RTM_BASE] = { .doit   = neigh_delete          },
 826         [RTM_GETNEIGH    - RTM_BASE] = { .dumpit = neigh_dump_info       },
 827 #ifdef CONFIG_FIB_RULES
 828         [RTM_NEWRULE     - RTM_BASE] = { .doit   = fib_nl_newrule        },
 829         [RTM_DELRULE     - RTM_BASE] = { .doit   = fib_nl_delrule        },
 830 #endif
 831         [RTM_GETRULE     - RTM_BASE] = { .dumpit = rtnl_dump_all         },
 832         [RTM_GETNEIGHTBL - RTM_BASE] = { .dumpit = neightbl_dump_info    },
 833         [RTM_SETNEIGHTBL - RTM_BASE] = { .doit   = neightbl_set          },
 834 };
 835
 836 static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr)
 837 {
 838         struct net_device *dev = ptr;
 839         switch (event) {
 840         case NETDEV_UNREGISTER:
 841                 rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
 842                 break;
 843         case NETDEV_REGISTER:
 844                 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
 845                 break;
 846         case NETDEV_UP:
 847         case NETDEV_DOWN:
 848                 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
 849                 break;
 850         case NETDEV_CHANGE:
 851         case NETDEV_GOING_DOWN:
 852                 break;
 853         default:
 854                 rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
 855                 break;
 856         }
 857         return NOTIFY_DONE;
 858 }
 859
 860 static struct notifier_block rtnetlink_dev_notifier = {
 861         .notifier_call  = rtnetlink_event,
 862 };
 863
 864 void __init rtnetlink_init(void)
 865 {
 866         int i;
 867
 868         rtattr_max = 0;
 869         for (i = 0; i < ARRAY_SIZE(rta_max); i++)
 870                 if (rta_max[i] > rtattr_max)
 871                         rtattr_max = rta_max[i];
 872         rta_buf = kmalloc(rtattr_max * sizeof(struct rtattr *), GFP_KERNEL);
 873         if (!rta_buf)
 874                 panic("rtnetlink_init: cannot allocate rta_buf\n");
 875
 876         rtnl = netlink_kernel_create(NETLINK_ROUTE, RTNLGRP_MAX, rtnetlink_rcv,
 877                                      THIS_MODULE);
 878         if (rtnl == NULL)
 879                 panic("rtnetlink_init: cannot initialize rtnetlink\n");
 880         netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
 881         register_netdevice_notifier(&rtnetlink_dev_notifier);
 882         rtnetlink_links[PF_UNSPEC] = link_rtnetlink_table;
 883         rtnetlink_links[PF_PACKET] = link_rtnetlink_table;
 884 }
 885
 886 EXPORT_SYMBOL(__rta_fill);
 887 EXPORT_SYMBOL(rtattr_strlcpy);
 888 EXPORT_SYMBOL(rtattr_parse);
 889 EXPORT_SYMBOL(rtnetlink_links);
 890 EXPORT_SYMBOL(rtnetlink_put_metrics);
 891 EXPORT_SYMBOL(rtnl_lock);
 892 EXPORT_SYMBOL(rtnl_trylock);
 893 EXPORT_SYMBOL(rtnl_unlock);
 894 EXPORT_SYMBOL(rtnl_unicast);
 895 EXPORT_SYMBOL(rtnl_notify);
 896 EXPORT_SYMBOL(rtnl_set_sk_err);