datapath/linux-2.4/compat-2.4/genetlink.c

   1 /*
   2  * NETLINK      Generic Netlink Family
   3  *
   4  *              Authors:        Jamal Hadi Salim
   5  *                              Thomas Graf <tgraf@suug.ch>
   6  *                              Johannes Berg <johannes@sipsolutions.net>
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/kernel.h>
  11 #include <linux/errno.h>
  12 #include <linux/types.h>
  13 #include <linux/socket.h>
  14 #include <linux/string.h>
  15 #include <linux/skbuff.h>
  16 #include <asm/semaphore.h>
  17 #include <net/sock.h>
  18 #include <net/genetlink.h>
  19
  20 #include "compat24.h"
  21
  22 struct sock *genl_sock = NULL;
  23
  24 static DECLARE_MUTEX(genl_mutex); /* serialization of message processing */
  25
  26 static void genl_lock(void)
  27 {
  28         down(&genl_mutex);
  29 }
  30
  31 static int genl_trylock(void)
  32 {
  33         return down_trylock(&genl_mutex);
  34 }
  35
  36 static void genl_unlock(void)
  37 {
  38         up(&genl_mutex);
  39
  40         if (genl_sock && genl_sock->receive_queue.qlen)
  41                 genl_sock->data_ready(genl_sock, 0);
  42 }
  43
  44 #define GENL_FAM_TAB_SIZE       16
  45 #define GENL_FAM_TAB_MASK       (GENL_FAM_TAB_SIZE - 1)
  46
  47 static struct list_head family_ht[GENL_FAM_TAB_SIZE];
  48 /*
  49  * Bitmap of multicast groups that are currently in use.
  50  *
  51  * To avoid an allocation at boot of just one unsigned long,
  52  * declare it global instead.
  53  * Bit 0 is marked as already used since group 0 is invalid.
  54  */
  55 static unsigned long mc_group_start = 0x1;
  56 static unsigned long *mc_groups = &mc_group_start;
  57 static unsigned long mc_groups_longs = 1;
  58
  59 static int genl_ctrl_event(int event, void *data);
  60
  61 static inline unsigned int genl_family_hash(unsigned int id)
  62 {
  63         return id & GENL_FAM_TAB_MASK;
  64 }
  65
  66 static inline struct list_head *genl_family_chain(unsigned int id)
  67 {
  68         return &family_ht[genl_family_hash(id)];
  69 }
  70
  71 static struct genl_family *genl_family_find_byid(unsigned int id)
  72 {
  73         struct genl_family *f;
  74
  75         list_for_each_entry(f, genl_family_chain(id), family_list)
  76                 if (f->id == id)
  77                         return f;
  78
  79         return NULL;
  80 }
  81
  82 static struct genl_family *genl_family_find_byname(char *name)
  83 {
  84         struct genl_family *f;
  85         int i;
  86
  87         for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
  88                 list_for_each_entry(f, genl_family_chain(i), family_list)
  89                         if (strcmp(f->name, name) == 0)
  90                                 return f;
  91
  92         return NULL;
  93 }
  94
  95 static struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family)
  96 {
  97         struct genl_ops *ops;
  98
  99         list_for_each_entry(ops, &family->ops_list, ops_list)
 100                 if (ops->cmd == cmd)
 101                         return ops;
 102
 103         return NULL;
 104 }
 105
 106 /* Of course we are going to have problems once we hit
 107  * 2^16 alive types, but that can only happen by year 2K
 108 */
 109 static inline u16 genl_generate_id(void)
 110 {
 111         static u16 id_gen_idx;
 112         int overflowed = 0;
 113
 114         do {
 115                 if (id_gen_idx == 0)
 116                         id_gen_idx = GENL_MIN_ID;
 117
 118                 if (++id_gen_idx > GENL_MAX_ID) {
 119                         if (!overflowed) {
 120                                 overflowed = 1;
 121                                 id_gen_idx = 0;
 122                                 continue;
 123                         } else
 124                                 return 0;
 125                 }
 126
 127         } while (genl_family_find_byid(id_gen_idx));
 128
 129         return id_gen_idx;
 130 }
 131
 132 static struct genl_multicast_group notify_grp;
 133
 134 /**
 135  * genl_register_mc_group - register a multicast group
 136  *
 137  * Registers the specified multicast group and notifies userspace
 138  * about the new group.
 139  *
 140  * Returns 0 on success or a negative error code.
 141  *
 142  * @family: The generic netlink family the group shall be registered for.
 143  * @grp: The group to register, must have a name.
 144  */
 145 int genl_register_mc_group(struct genl_family *family,
 146                            struct genl_multicast_group *grp)
 147 {
 148         int id;
 149
 150         BUG_ON(grp->name[0] == '\0');
 151
 152         genl_lock();
 153
 154         /* special-case our own group */
 155         if (grp == &notify_grp)
 156                 id = GENL_ID_CTRL;
 157         else
 158                 id = find_first_zero_bit(mc_groups,
 159                                          mc_groups_longs * BITS_PER_LONG);
 160
 161
 162         if (id >= mc_groups_longs * BITS_PER_LONG) {
 163                 genl_unlock();
 164                 return -ENOMEM;
 165         }
 166
 167         grp->id = id;
 168         set_bit(id, mc_groups);
 169         list_add_tail(&grp->list, &family->mcast_groups);
 170         grp->family = family;
 171
 172         genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, grp);
 173         genl_unlock();
 174         return 0;
 175 }
 176 EXPORT_SYMBOL(genl_register_mc_group);
 177
 178 static void __genl_unregister_mc_group(struct genl_family *family,
 179                                        struct genl_multicast_group *grp)
 180 {
 181         BUG_ON(grp->family != family);
 182
 183         /* We should clear this multicast group from any subscribers, but 2.4
 184          * doesn't have the proper interface to do it, and we'd need a patch to
 185          * implement it. */
 186         /*netlink_clear_multicast_users(genl_sock, grp->id);*/
 187         clear_bit(grp->id, mc_groups);
 188         list_del(&grp->list);
 189         genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, grp);
 190         grp->id = 0;
 191         grp->family = NULL;
 192 }
 193
 194 /**
 195  * genl_unregister_mc_group - unregister a multicast group
 196  *
 197  * Unregisters the specified multicast group and notifies userspace
 198  * about it. All current listeners on the group are removed.
 199  *
 200  * Note: It is not necessary to unregister all multicast groups before
 201  *       unregistering the family, unregistering the family will cause
 202  *       all assigned multicast groups to be unregistered automatically.
 203  *
 204  * @family: Generic netlink family the group belongs to.
 205  * @grp: The group to unregister, must have been registered successfully
 206  *       previously.
 207  */
 208 void genl_unregister_mc_group(struct genl_family *family,
 209                               struct genl_multicast_group *grp)
 210 {
 211         genl_lock();
 212         __genl_unregister_mc_group(family, grp);
 213         genl_unlock();
 214 }
 215 EXPORT_SYMBOL(genl_unregister_mc_group);
 216
 217 static void genl_unregister_mc_groups(struct genl_family *family)
 218 {
 219         struct genl_multicast_group *grp, *tmp;
 220
 221         genl_lock();
 222         list_for_each_entry_safe(grp, tmp, &family->mcast_groups, list)
 223                 __genl_unregister_mc_group(family, grp);
 224         genl_unlock();
 225 }
 226
 227 /**
 228  * genl_register_ops - register generic netlink operations
 229  * @family: generic netlink family
 230  * @ops: operations to be registered
 231  *
 232  * Registers the specified operations and assigns them to the specified
 233  * family. Either a doit or dumpit callback must be specified or the
 234  * operation will fail. Only one operation structure per command
 235  * identifier may be registered.
 236  *
 237  * See include/net/genetlink.h for more documenation on the operations
 238  * structure.
 239  *
 240  * Returns 0 on success or a negative error code.
 241  */
 242 int genl_register_ops(struct genl_family *family, struct genl_ops *ops)
 243 {
 244         int err = -EINVAL;
 245
 246         if (ops->dumpit == NULL && ops->doit == NULL)
 247                 goto errout;
 248
 249         if (genl_get_cmd(ops->cmd, family)) {
 250                 err = -EEXIST;
 251                 goto errout;
 252         }
 253
 254         if (ops->dumpit)
 255                 ops->flags |= GENL_CMD_CAP_DUMP;
 256         if (ops->doit)
 257                 ops->flags |= GENL_CMD_CAP_DO;
 258         if (ops->policy)
 259                 ops->flags |= GENL_CMD_CAP_HASPOL;
 260
 261         genl_lock();
 262         list_add_tail(&ops->ops_list, &family->ops_list);
 263         genl_unlock();
 264
 265         genl_ctrl_event(CTRL_CMD_NEWOPS, ops);
 266         err = 0;
 267 errout:
 268         return err;
 269 }
 270
 271 /**
 272  * genl_unregister_ops - unregister generic netlink operations
 273  * @family: generic netlink family
 274  * @ops: operations to be unregistered
 275  *
 276  * Unregisters the specified operations and unassigns them from the
 277  * specified family. The operation blocks until the current message
 278  * processing has finished and doesn't start again until the
 279  * unregister process has finished.
 280  *
 281  * Note: It is not necessary to unregister all operations before
 282  *       unregistering the family, unregistering the family will cause
 283  *       all assigned operations to be unregistered automatically.
 284  *
 285  * Returns 0 on success or a negative error code.
 286  */
 287 int genl_unregister_ops(struct genl_family *family, struct genl_ops *ops)
 288 {
 289         struct genl_ops *rc;
 290
 291         genl_lock();
 292         list_for_each_entry(rc, &family->ops_list, ops_list) {
 293                 if (rc == ops) {
 294                         list_del(&ops->ops_list);
 295                         genl_unlock();
 296                         genl_ctrl_event(CTRL_CMD_DELOPS, ops);
 297                         return 0;
 298                 }
 299         }
 300         genl_unlock();
 301
 302         return -ENOENT;
 303 }
 304
 305 /**
 306  * genl_register_family - register a generic netlink family
 307  * @family: generic netlink family
 308  *
 309  * Registers the specified family after validating it first. Only one
 310  * family may be registered with the same family name or identifier.
 311  * The family id may equal GENL_ID_GENERATE causing an unique id to
 312  * be automatically generated and assigned.
 313  *
 314  * Return 0 on success or a negative error code.
 315  */
 316 int genl_register_family(struct genl_family *family)
 317 {
 318         int err = -EINVAL;
 319
 320         if (family->id && family->id < GENL_MIN_ID)
 321                 goto errout;
 322
 323         if (family->id > GENL_MAX_ID)
 324                 goto errout;
 325
 326         INIT_LIST_HEAD(&family->ops_list);
 327         INIT_LIST_HEAD(&family->mcast_groups);
 328
 329         genl_lock();
 330
 331         if (genl_family_find_byname(family->name)) {
 332                 err = -EEXIST;
 333                 goto errout_locked;
 334         }
 335
 336         if (genl_family_find_byid(family->id)) {
 337                 err = -EEXIST;
 338                 goto errout_locked;
 339         }
 340
 341         if (family->id == GENL_ID_GENERATE) {
 342                 u16 newid = genl_generate_id();
 343
 344                 if (!newid) {
 345                         err = -ENOMEM;
 346                         goto errout_locked;
 347                 }
 348
 349                 family->id = newid;
 350         }
 351
 352         if (family->maxattr) {
 353                 family->attrbuf = kmalloc((family->maxattr+1) *
 354                                         sizeof(struct nlattr *), GFP_KERNEL);
 355                 if (family->attrbuf == NULL) {
 356                         err = -ENOMEM;
 357                         goto errout_locked;
 358                 }
 359         } else
 360                 family->attrbuf = NULL;
 361
 362         list_add_tail(&family->family_list, genl_family_chain(family->id));
 363         MOD_INC_USE_COUNT;
 364         genl_unlock();
 365
 366         genl_ctrl_event(CTRL_CMD_NEWFAMILY, family);
 367
 368         return 0;
 369
 370 errout_locked:
 371         genl_unlock();
 372 errout:
 373         return err;
 374 }
 375
 376 /**
 377  * genl_unregister_family - unregister generic netlink family
 378  * @family: generic netlink family
 379  *
 380  * Unregisters the specified family.
 381  *
 382  * Returns 0 on success or a negative error code.
 383  */
 384 int genl_unregister_family(struct genl_family *family)
 385 {
 386         struct genl_family *rc;
 387
 388         genl_unregister_mc_groups(family);
 389
 390         genl_lock();
 391
 392         list_for_each_entry(rc, genl_family_chain(family->id), family_list) {
 393                 if (family->id != rc->id || strcmp(rc->name, family->name))
 394                         continue;
 395
 396                 list_del(&rc->family_list);
 397                 INIT_LIST_HEAD(&family->ops_list);
 398                 genl_unlock();
 399
 400                 kfree(family->attrbuf);
 401                 genl_ctrl_event(CTRL_CMD_DELFAMILY, family);
 402                 return 0;
 403         }
 404
 405         MOD_DEC_USE_COUNT;
 406         genl_unlock();
 407
 408         return -ENOENT;
 409 }
 410
 411 static int null_done_func(struct netlink_callback *cb)
 412 {
 413         return 0;
 414 }
 415
 416 static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 417 {
 418         struct genl_ops *ops;
 419         struct genl_family *family;
 420         struct genl_info info;
 421         struct genlmsghdr *hdr = nlmsg_data(nlh);
 422         int hdrlen, err;
 423
 424         family = genl_family_find_byid(nlh->nlmsg_type);
 425         if (family == NULL)
 426                 return -ENOENT;
 427
 428         hdrlen = GENL_HDRLEN + family->hdrsize;
 429         if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
 430                 return -EINVAL;
 431
 432         ops = genl_get_cmd(hdr->cmd, family);
 433         if (ops == NULL)
 434                 return -EOPNOTSUPP;
 435
 436         if ((ops->flags & GENL_ADMIN_PERM) && !capable(CAP_NET_ADMIN))
 437                 return -EPERM;
 438
 439         if (nlh->nlmsg_flags & NLM_F_DUMP) {
 440                 if (ops->dumpit == NULL)
 441                         return -EOPNOTSUPP;
 442
 443                 return netlink_dump_start(genl_sock, skb, nlh,
 444                                           ops->dumpit,
 445                                           ops->done ?: null_done_func);
 446         }
 447
 448         if (ops->doit == NULL)
 449                 return -EOPNOTSUPP;
 450
 451         if (family->attrbuf) {
 452                 err = nlmsg_parse(nlh, hdrlen, family->attrbuf, family->maxattr,
 453                                   ops->policy);
 454                 if (err < 0)
 455                         return err;
 456         }
 457
 458         info.snd_seq = nlh->nlmsg_seq;
 459         info.snd_pid = NETLINK_CB(skb).pid;
 460         info.nlhdr = nlh;
 461         info.genlhdr = nlmsg_data(nlh);
 462         info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
 463         info.attrs = family->attrbuf;
 464
 465         return ops->doit(skb, &info);
 466 }
 467
 468 static void genl_rcv(struct sock *sk, int len)
 469 {
 470         unsigned int qlen = 0;
 471
 472         do {
 473                 if (genl_trylock())
 474                         return;
 475                 netlink_run_queue(sk, &qlen, genl_rcv_msg);
 476                 genl_unlock();
 477         } while (qlen && genl_sock && genl_sock->receive_queue.qlen);
 478 }
 479
 480 /**************************************************************************
 481  * Controller
 482  **************************************************************************/
 483
 484 static struct genl_family genl_ctrl = {
 485         .id = GENL_ID_CTRL,
 486         .name = "nlctrl",
 487         .version = 0x2,
 488         .maxattr = CTRL_ATTR_MAX,
 489 };
 490
 491 static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq,
 492                           u32 flags, struct sk_buff *skb, u8 cmd)
 493 {
 494         void *hdr;
 495
 496         hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
 497         if (hdr == NULL)
 498                 return -1;
 499
 500         NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, family->name);
 501         NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, family->id);
 502         NLA_PUT_U32(skb, CTRL_ATTR_VERSION, family->version);
 503         NLA_PUT_U32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize);
 504         NLA_PUT_U32(skb, CTRL_ATTR_MAXATTR, family->maxattr);
 505
 506         if (!list_empty(&family->ops_list)) {
 507                 struct nlattr *nla_ops;
 508                 struct genl_ops *ops;
 509                 int idx = 1;
 510
 511                 nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
 512                 if (nla_ops == NULL)
 513                         goto nla_put_failure;
 514
 515                 list_for_each_entry(ops, &family->ops_list, ops_list) {
 516                         struct nlattr *nest;
 517
 518                         nest = nla_nest_start(skb, idx++);
 519                         if (nest == NULL)
 520                                 goto nla_put_failure;
 521
 522                         NLA_PUT_U32(skb, CTRL_ATTR_OP_ID, ops->cmd);
 523                         NLA_PUT_U32(skb, CTRL_ATTR_OP_FLAGS, ops->flags);
 524
 525                         nla_nest_end(skb, nest);
 526                 }
 527
 528                 nla_nest_end(skb, nla_ops);
 529         }
 530
 531         if (!list_empty(&family->mcast_groups)) {
 532                 struct genl_multicast_group *grp;
 533                 struct nlattr *nla_grps;
 534                 int idx = 1;
 535
 536                 nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
 537                 if (nla_grps == NULL)
 538                         goto nla_put_failure;
 539
 540                 list_for_each_entry(grp, &family->mcast_groups, list) {
 541                         struct nlattr *nest;
 542
 543                         nest = nla_nest_start(skb, idx++);
 544                         if (nest == NULL)
 545                                 goto nla_put_failure;
 546
 547                         NLA_PUT_U32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id);
 548                         NLA_PUT_STRING(skb, CTRL_ATTR_MCAST_GRP_NAME,
 549                                        grp->name);
 550
 551                         nla_nest_end(skb, nest);
 552                 }
 553                 nla_nest_end(skb, nla_grps);
 554         }
 555
 556         return genlmsg_end(skb, hdr);
 557
 558 nla_put_failure:
 559         return genlmsg_cancel(skb, hdr);
 560 }
 561
 562 static int ctrl_fill_mcgrp_info(struct genl_multicast_group *grp, u32 pid,
 563                                 u32 seq, u32 flags, struct sk_buff *skb,
 564                                 u8 cmd)
 565 {
 566         void *hdr;
 567         struct nlattr *nla_grps;
 568         struct nlattr *nest;
 569
 570         hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
 571         if (hdr == NULL)
 572                 return -1;
 573
 574         NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, grp->family->name);
 575         NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, grp->family->id);
 576
 577         nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
 578         if (nla_grps == NULL)
 579                 goto nla_put_failure;
 580
 581         nest = nla_nest_start(skb, 1);
 582         if (nest == NULL)
 583                 goto nla_put_failure;
 584
 585         NLA_PUT_U32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id);
 586         NLA_PUT_STRING(skb, CTRL_ATTR_MCAST_GRP_NAME,
 587                        grp->name);
 588
 589         nla_nest_end(skb, nest);
 590         nla_nest_end(skb, nla_grps);
 591
 592         return genlmsg_end(skb, hdr);
 593
 594 nla_put_failure:
 595         return genlmsg_cancel(skb, hdr);
 596 }
 597
 598 static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
 599 {
 600
 601         int i, n = 0;
 602         struct genl_family *rt;
 603         int chains_to_skip = cb->args[0];
 604         int fams_to_skip = cb->args[1];
 605
 606         if (chains_to_skip != 0)
 607                 genl_lock();
 608
 609         for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
 610                 if (i < chains_to_skip)
 611                         continue;
 612                 n = 0;
 613                 list_for_each_entry(rt, genl_family_chain(i), family_list) {
 614                         if (++n < fams_to_skip)
 615                                 continue;
 616                         if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).pid,
 617                                            cb->nlh->nlmsg_seq, NLM_F_MULTI,
 618                                            skb, CTRL_CMD_NEWFAMILY) < 0)
 619                                 goto errout;
 620                 }
 621
 622                 fams_to_skip = 0;
 623         }
 624
 625 errout:
 626         if (chains_to_skip != 0)
 627                 genl_unlock();
 628
 629         cb->args[0] = i;
 630         cb->args[1] = n;
 631
 632         return skb->len;
 633 }
 634
 635 static struct sk_buff *ctrl_build_family_msg(struct genl_family *family,
 636                                              u32 pid, int seq, u8 cmd)
 637 {
 638         struct sk_buff *skb;
 639         int err;
 640
 641         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 642         if (skb == NULL)
 643                 return ERR_PTR(-ENOBUFS);
 644
 645         err = ctrl_fill_info(family, pid, seq, 0, skb, cmd);
 646         if (err < 0) {
 647                 nlmsg_free(skb);
 648                 return ERR_PTR(err);
 649         }
 650
 651         return skb;
 652 }
 653
 654 static struct sk_buff *ctrl_build_mcgrp_msg(struct genl_multicast_group *grp,
 655                                             u32 pid, int seq, u8 cmd)
 656 {
 657         struct sk_buff *skb;
 658         int err;
 659
 660         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 661         if (skb == NULL)
 662                 return ERR_PTR(-ENOBUFS);
 663
 664         err = ctrl_fill_mcgrp_info(grp, pid, seq, 0, skb, cmd);
 665         if (err < 0) {
 666                 nlmsg_free(skb);
 667                 return ERR_PTR(err);
 668         }
 669
 670         return skb;
 671 }
 672
 673 static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = {
 674         [CTRL_ATTR_FAMILY_ID]   = { .type = NLA_U16 },
 675         [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING,
 676                                     .len = GENL_NAMSIZ - 1 },
 677 };
 678
 679 static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
 680 {
 681         struct sk_buff *msg;
 682         struct genl_family *res = NULL;
 683         int err = -EINVAL;
 684
 685         if (info->attrs[CTRL_ATTR_FAMILY_ID]) {
 686                 u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]);
 687                 res = genl_family_find_byid(id);
 688         }
 689
 690         if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
 691                 char *name;
 692
 693                 name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
 694                 res = genl_family_find_byname(name);
 695         }
 696
 697         if (res == NULL) {
 698                 err = -ENOENT;
 699                 goto errout;
 700         }
 701
 702         msg = ctrl_build_family_msg(res, info->snd_pid, info->snd_seq,
 703                                     CTRL_CMD_NEWFAMILY);
 704         if (IS_ERR(msg)) {
 705                 err = PTR_ERR(msg);
 706                 goto errout;
 707         }
 708
 709         err = genlmsg_reply(msg, info);
 710 errout:
 711         return err;
 712 }
 713
 714 static int genl_ctrl_event(int event, void *data)
 715 {
 716         struct sk_buff *msg;
 717
 718         if (genl_sock == NULL)
 719                 return 0;
 720
 721         switch (event) {
 722         case CTRL_CMD_NEWFAMILY:
 723         case CTRL_CMD_DELFAMILY:
 724                 msg = ctrl_build_family_msg(data, 0, 0, event);
 725                 if (IS_ERR(msg))
 726                         return PTR_ERR(msg);
 727
 728                 genlmsg_multicast(msg, 0, GENL_ID_CTRL, GFP_KERNEL);
 729                 break;
 730         case CTRL_CMD_NEWMCAST_GRP:
 731         case CTRL_CMD_DELMCAST_GRP:
 732                 msg = ctrl_build_mcgrp_msg(data, 0, 0, event);
 733                 if (IS_ERR(msg))
 734                         return PTR_ERR(msg);
 735
 736                 genlmsg_multicast(msg, 0, GENL_ID_CTRL, GFP_KERNEL);
 737                 break;
 738         }
 739
 740         return 0;
 741 }
 742
 743 static struct genl_ops genl_ctrl_ops = {
 744         .cmd            = CTRL_CMD_GETFAMILY,
 745         .doit           = ctrl_getfamily,
 746         .dumpit         = ctrl_dumpfamily,
 747         .policy         = ctrl_policy,
 748 };
 749
 750 static struct genl_multicast_group notify_grp = {
 751         .name           = "notify",
 752 };
 753
 754 int __init genl_init(void)
 755 {
 756         int i, err;
 757
 758         for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
 759                 INIT_LIST_HEAD(&family_ht[i]);
 760
 761         err = genl_register_family(&genl_ctrl);
 762         if (err < 0)
 763                 goto errout;
 764
 765         err = genl_register_ops(&genl_ctrl, &genl_ctrl_ops);
 766         if (err < 0)
 767                 goto errout_register;
 768
 769         netlink_set_nonroot(NETLINK_GENERIC, NL_NONROOT_RECV);
 770         genl_sock = netlink_kernel_create(NETLINK_GENERIC, genl_rcv);
 771         if (genl_sock == NULL)
 772                 panic("GENL: Cannot initialize generic netlink\n");
 773
 774         err = genl_register_mc_group(&genl_ctrl, &notify_grp);
 775         if (err < 0)
 776                 goto errout_register;
 777
 778         return 0;
 779
 780 errout_register:
 781         genl_unregister_family(&genl_ctrl);
 782 errout:
 783         panic("GENL: Cannot register controller: %d\n", err);
 784 }
 785
 786 void __exit genl_exit(void)
 787 {
 788         int err;
 789
 790         err = genl_unregister_ops(&genl_ctrl, &genl_ctrl_ops);
 791         if (err) {
 792                 printk("GENL: cannot unregister ops (%d)\n", err);
 793                 return;
 794         }
 795
 796         err = genl_unregister_family(&genl_ctrl);
 797         if (err) {
 798                 printk("GENL: cannot unregister family (%d)\n", err);
 799                 return;
 800         }
 801
 802 }
 803
 804 EXPORT_SYMBOL(genl_sock);
 805 EXPORT_SYMBOL(genl_register_ops);
 806 EXPORT_SYMBOL(genl_unregister_ops);
 807 EXPORT_SYMBOL(genl_register_family);
 808 EXPORT_SYMBOL(genl_unregister_family);
 809
 810 MODULE_LICENSE("GPL");