2 * NETLINK Generic Netlink Family
4 * Authors: Jamal Hadi Salim
5 * Thomas Graf <tgraf@suug.ch>
6 * Johannes Berg <johannes@sipsolutions.net>
9 #include <linux/module.h>
10 #include <linux/kernel.h>
11 #include <linux/slab.h>
12 #include <linux/errno.h>
13 #include <linux/types.h>
14 #include <linux/socket.h>
15 #include <linux/string.h>
16 #include <linux/skbuff.h>
17 #include <linux/mutex.h>
18 #include <linux/bitmap.h>
19 #include <linux/rwsem.h>
20 #include <linux/idr.h>
22 #include <net/genetlink.h>
24 static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
25 static DECLARE_RWSEM(cb_lock);
27 atomic_t genl_sk_destructing_cnt = ATOMIC_INIT(0);
28 DECLARE_WAIT_QUEUE_HEAD(genl_sk_destructing_waitq);
32 mutex_lock(&genl_mutex);
34 EXPORT_SYMBOL(genl_lock);
36 void genl_unlock(void)
38 mutex_unlock(&genl_mutex);
40 EXPORT_SYMBOL(genl_unlock);
43 bool lockdep_genl_is_held(void)
45 return lockdep_is_held(&genl_mutex);
47 EXPORT_SYMBOL(lockdep_genl_is_held);
50 static void genl_lock_all(void)
56 static void genl_unlock_all(void)
62 static DEFINE_IDR(genl_fam_idr);
65 * Bitmap of multicast groups that are currently in use.
67 * To avoid an allocation at boot of just one unsigned long,
68 * declare it global instead.
69 * Bit 0 is marked as already used since group 0 is invalid.
70 * Bit 1 is marked as already used since the drop-monitor code
71 * abuses the API and thinks it can statically use group 1.
72 * That group will typically conflict with other groups that
73 * any proper users use.
74 * Bit 16 is marked as used since it's used for generic netlink
75 * and the code no longer marks pre-reserved IDs as used.
76 * Bit 17 is marked as already used since the VFS quota code
77 * also abused this API and relied on family == group ID, we
78 * cater to that by giving it a static family and group ID.
79 * Bit 18 is marked as already used since the PMCRAID driver
80 * did the same thing as the VFS quota code (maybe copied?)
82 static unsigned long mc_group_start = 0x3 | BIT(GENL_ID_CTRL) |
83 BIT(GENL_ID_VFS_DQUOT) |
85 static unsigned long *mc_groups = &mc_group_start;
86 static unsigned long mc_groups_longs = 1;
88 static int genl_ctrl_event(int event, const struct genl_family *family,
89 const struct genl_multicast_group *grp,
92 static const struct genl_family *genl_family_find_byid(unsigned int id)
94 return idr_find(&genl_fam_idr, id);
97 static const struct genl_family *genl_family_find_byname(char *name)
99 const struct genl_family *family;
102 idr_for_each_entry(&genl_fam_idr, family, id)
103 if (strcmp(family->name, name) == 0)
109 static const struct genl_ops *genl_get_cmd(u8 cmd,
110 const struct genl_family *family)
114 for (i = 0; i < family->n_ops; i++)
115 if (family->ops[i].cmd == cmd)
116 return &family->ops[i];
121 static int genl_allocate_reserve_groups(int n_groups, int *first_id)
123 unsigned long *new_groups;
131 id = find_first_zero_bit(mc_groups,
135 id = find_next_zero_bit(mc_groups,
136 mc_groups_longs * BITS_PER_LONG,
141 i < min_t(int, id + n_groups,
142 mc_groups_longs * BITS_PER_LONG);
144 if (test_bit(i, mc_groups)) {
151 if (id + n_groups > mc_groups_longs * BITS_PER_LONG) {
152 unsigned long new_longs = mc_groups_longs +
153 BITS_TO_LONGS(n_groups);
154 size_t nlen = new_longs * sizeof(unsigned long);
156 if (mc_groups == &mc_group_start) {
157 new_groups = kzalloc(nlen, GFP_KERNEL);
160 mc_groups = new_groups;
161 *mc_groups = mc_group_start;
163 new_groups = krealloc(mc_groups, nlen,
167 mc_groups = new_groups;
168 for (i = 0; i < BITS_TO_LONGS(n_groups); i++)
169 mc_groups[mc_groups_longs + i] = 0;
171 mc_groups_longs = new_longs;
175 for (i = id; i < id + n_groups; i++)
176 set_bit(i, mc_groups);
181 static struct genl_family genl_ctrl;
183 static int genl_validate_assign_mc_groups(struct genl_family *family)
186 int n_groups = family->n_mcgrps;
188 bool groups_allocated = false;
193 for (i = 0; i < n_groups; i++) {
194 const struct genl_multicast_group *grp = &family->mcgrps[i];
196 if (WARN_ON(grp->name[0] == '\0'))
198 if (WARN_ON(memchr(grp->name, '\0', GENL_NAMSIZ) == NULL))
202 /* special-case our own group and hacks */
203 if (family == &genl_ctrl) {
204 first_id = GENL_ID_CTRL;
205 BUG_ON(n_groups != 1);
206 } else if (strcmp(family->name, "NET_DM") == 0) {
208 BUG_ON(n_groups != 1);
209 } else if (family->id == GENL_ID_VFS_DQUOT) {
210 first_id = GENL_ID_VFS_DQUOT;
211 BUG_ON(n_groups != 1);
212 } else if (family->id == GENL_ID_PMCRAID) {
213 first_id = GENL_ID_PMCRAID;
214 BUG_ON(n_groups != 1);
216 groups_allocated = true;
217 err = genl_allocate_reserve_groups(n_groups, &first_id);
222 family->mcgrp_offset = first_id;
224 /* if still initializing, can't and don't need to to realloc bitmaps */
225 if (!init_net.genl_sock)
228 if (family->netnsok) {
231 netlink_table_grab();
233 for_each_net_rcu(net) {
234 err = __netlink_change_ngroups(net->genl_sock,
235 mc_groups_longs * BITS_PER_LONG);
238 * No need to roll back, can only fail if
239 * memory allocation fails and then the
240 * number of _possible_ groups has been
241 * increased on some sockets which is ok.
247 netlink_table_ungrab();
249 err = netlink_change_ngroups(init_net.genl_sock,
250 mc_groups_longs * BITS_PER_LONG);
253 if (groups_allocated && err) {
254 for (i = 0; i < family->n_mcgrps; i++)
255 clear_bit(family->mcgrp_offset + i, mc_groups);
261 static void genl_unregister_mc_groups(const struct genl_family *family)
266 netlink_table_grab();
268 for_each_net_rcu(net) {
269 for (i = 0; i < family->n_mcgrps; i++)
270 __netlink_clear_multicast_users(
271 net->genl_sock, family->mcgrp_offset + i);
274 netlink_table_ungrab();
276 for (i = 0; i < family->n_mcgrps; i++) {
277 int grp_id = family->mcgrp_offset + i;
280 clear_bit(grp_id, mc_groups);
281 genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, family,
282 &family->mcgrps[i], grp_id);
286 static int genl_validate_ops(const struct genl_family *family)
288 const struct genl_ops *ops = family->ops;
289 unsigned int n_ops = family->n_ops;
292 if (WARN_ON(n_ops && !ops))
298 for (i = 0; i < n_ops; i++) {
299 if (ops[i].dumpit == NULL && ops[i].doit == NULL)
301 for (j = i + 1; j < n_ops; j++)
302 if (ops[i].cmd == ops[j].cmd)
310 * genl_register_family - register a generic netlink family
311 * @family: generic netlink family
313 * Registers the specified family after validating it first. Only one
314 * family may be registered with the same family name or identifier.
316 * The family's ops, multicast groups and module pointer must already
319 * Return 0 on success or a negative error code.
321 int genl_register_family(struct genl_family *family)
324 int start = GENL_START_ALLOC, end = GENL_MAX_ID;
326 err = genl_validate_ops(family);
332 if (genl_family_find_byname(family->name)) {
338 * Sadly, a few cases need to be special-cased
339 * due to them having previously abused the API
340 * and having used their family ID also as their
341 * multicast group ID, so we use reserved IDs
342 * for both to be sure we can do that mapping.
344 if (family == &genl_ctrl) {
345 /* and this needs to be special for initial family lookups */
346 start = end = GENL_ID_CTRL;
347 } else if (strcmp(family->name, "pmcraid") == 0) {
348 start = end = GENL_ID_PMCRAID;
349 } else if (strcmp(family->name, "VFS_DQUOT") == 0) {
350 start = end = GENL_ID_VFS_DQUOT;
353 if (family->maxattr && !family->parallel_ops) {
354 family->attrbuf = kmalloc((family->maxattr+1) *
355 sizeof(struct nlattr *), GFP_KERNEL);
356 if (family->attrbuf == NULL) {
361 family->attrbuf = NULL;
363 family->id = idr_alloc(&genl_fam_idr, family,
364 start, end + 1, GFP_KERNEL);
365 if (family->id < 0) {
370 err = genl_validate_assign_mc_groups(family);
376 /* send all events */
377 genl_ctrl_event(CTRL_CMD_NEWFAMILY, family, NULL, 0);
378 for (i = 0; i < family->n_mcgrps; i++)
379 genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, family,
380 &family->mcgrps[i], family->mcgrp_offset + i);
385 idr_remove(&genl_fam_idr, family->id);
386 kfree(family->attrbuf);
391 EXPORT_SYMBOL(genl_register_family);
394 * genl_unregister_family - unregister generic netlink family
395 * @family: generic netlink family
397 * Unregisters the specified family.
399 * Returns 0 on success or a negative error code.
401 int genl_unregister_family(const struct genl_family *family)
405 if (!genl_family_find_byid(family->id)) {
410 genl_unregister_mc_groups(family);
412 idr_remove(&genl_fam_idr, family->id);
415 wait_event(genl_sk_destructing_waitq,
416 atomic_read(&genl_sk_destructing_cnt) == 0);
419 kfree(family->attrbuf);
421 genl_ctrl_event(CTRL_CMD_DELFAMILY, family, NULL, 0);
425 EXPORT_SYMBOL(genl_unregister_family);
428 * genlmsg_put - Add generic netlink header to netlink message
429 * @skb: socket buffer holding the message
430 * @portid: netlink portid the message is addressed to
431 * @seq: sequence number (usually the one of the sender)
432 * @family: generic netlink family
433 * @flags: netlink message flags
434 * @cmd: generic netlink command
436 * Returns pointer to user specific header
438 void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
439 const struct genl_family *family, int flags, u8 cmd)
441 struct nlmsghdr *nlh;
442 struct genlmsghdr *hdr;
444 nlh = nlmsg_put(skb, portid, seq, family->id, GENL_HDRLEN +
445 family->hdrsize, flags);
449 hdr = nlmsg_data(nlh);
451 hdr->version = family->version;
454 return (char *) hdr + GENL_HDRLEN;
456 EXPORT_SYMBOL(genlmsg_put);
458 static int genl_lock_start(struct netlink_callback *cb)
460 /* our ops are always const - netlink API doesn't propagate that */
461 const struct genl_ops *ops = cb->data;
472 static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
474 /* our ops are always const - netlink API doesn't propagate that */
475 const struct genl_ops *ops = cb->data;
479 rc = ops->dumpit(skb, cb);
484 static int genl_lock_done(struct netlink_callback *cb)
486 /* our ops are always const - netlink API doesn't propagate that */
487 const struct genl_ops *ops = cb->data;
498 static int genl_family_rcv_msg(const struct genl_family *family,
500 struct nlmsghdr *nlh,
501 struct netlink_ext_ack *extack)
503 const struct genl_ops *ops;
504 struct net *net = sock_net(skb->sk);
505 struct genl_info info;
506 struct genlmsghdr *hdr = nlmsg_data(nlh);
507 struct nlattr **attrbuf;
510 /* this family doesn't exist in this netns */
511 if (!family->netnsok && !net_eq(net, &init_net))
514 hdrlen = GENL_HDRLEN + family->hdrsize;
515 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
518 ops = genl_get_cmd(hdr->cmd, family);
522 if ((ops->flags & GENL_ADMIN_PERM) &&
523 !netlink_capable(skb, CAP_NET_ADMIN))
526 if ((ops->flags & GENL_UNS_ADMIN_PERM) &&
527 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
530 if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {
533 if (ops->dumpit == NULL)
536 if (!family->parallel_ops) {
537 struct netlink_dump_control c = {
538 .module = family->module,
539 /* we have const, but the netlink API doesn't */
541 .start = genl_lock_start,
542 .dump = genl_lock_dumpit,
543 .done = genl_lock_done,
547 rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c);
551 struct netlink_dump_control c = {
552 .module = family->module,
558 rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c);
564 if (ops->doit == NULL)
567 if (family->maxattr && family->parallel_ops) {
568 attrbuf = kmalloc((family->maxattr+1) *
569 sizeof(struct nlattr *), GFP_KERNEL);
573 attrbuf = family->attrbuf;
576 err = nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr,
577 ops->policy, extack);
582 info.snd_seq = nlh->nlmsg_seq;
583 info.snd_portid = NETLINK_CB(skb).portid;
585 info.genlhdr = nlmsg_data(nlh);
586 info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
587 info.attrs = attrbuf;
588 info.extack = extack;
589 genl_info_net_set(&info, net);
590 memset(&info.user_ptr, 0, sizeof(info.user_ptr));
592 if (family->pre_doit) {
593 err = family->pre_doit(ops, skb, &info);
598 err = ops->doit(skb, &info);
600 if (family->post_doit)
601 family->post_doit(ops, skb, &info);
604 if (family->parallel_ops)
610 static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
611 struct netlink_ext_ack *extack)
613 const struct genl_family *family;
616 family = genl_family_find_byid(nlh->nlmsg_type);
620 if (!family->parallel_ops)
623 err = genl_family_rcv_msg(family, skb, nlh, extack);
625 if (!family->parallel_ops)
631 static void genl_rcv(struct sk_buff *skb)
634 netlink_rcv_skb(skb, &genl_rcv_msg);
638 /**************************************************************************
640 **************************************************************************/
642 static struct genl_family genl_ctrl;
644 static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq,
645 u32 flags, struct sk_buff *skb, u8 cmd)
649 hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
653 if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
654 nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id) ||
655 nla_put_u32(skb, CTRL_ATTR_VERSION, family->version) ||
656 nla_put_u32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize) ||
657 nla_put_u32(skb, CTRL_ATTR_MAXATTR, family->maxattr))
658 goto nla_put_failure;
661 struct nlattr *nla_ops;
664 nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
666 goto nla_put_failure;
668 for (i = 0; i < family->n_ops; i++) {
670 const struct genl_ops *ops = &family->ops[i];
671 u32 op_flags = ops->flags;
674 op_flags |= GENL_CMD_CAP_DUMP;
676 op_flags |= GENL_CMD_CAP_DO;
678 op_flags |= GENL_CMD_CAP_HASPOL;
680 nest = nla_nest_start(skb, i + 1);
682 goto nla_put_failure;
684 if (nla_put_u32(skb, CTRL_ATTR_OP_ID, ops->cmd) ||
685 nla_put_u32(skb, CTRL_ATTR_OP_FLAGS, op_flags))
686 goto nla_put_failure;
688 nla_nest_end(skb, nest);
691 nla_nest_end(skb, nla_ops);
694 if (family->n_mcgrps) {
695 struct nlattr *nla_grps;
698 nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
699 if (nla_grps == NULL)
700 goto nla_put_failure;
702 for (i = 0; i < family->n_mcgrps; i++) {
704 const struct genl_multicast_group *grp;
706 grp = &family->mcgrps[i];
708 nest = nla_nest_start(skb, i + 1);
710 goto nla_put_failure;
712 if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID,
713 family->mcgrp_offset + i) ||
714 nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
716 goto nla_put_failure;
718 nla_nest_end(skb, nest);
720 nla_nest_end(skb, nla_grps);
723 genlmsg_end(skb, hdr);
727 genlmsg_cancel(skb, hdr);
731 static int ctrl_fill_mcgrp_info(const struct genl_family *family,
732 const struct genl_multicast_group *grp,
733 int grp_id, u32 portid, u32 seq, u32 flags,
734 struct sk_buff *skb, u8 cmd)
737 struct nlattr *nla_grps;
740 hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
744 if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
745 nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id))
746 goto nla_put_failure;
748 nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
749 if (nla_grps == NULL)
750 goto nla_put_failure;
752 nest = nla_nest_start(skb, 1);
754 goto nla_put_failure;
756 if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID, grp_id) ||
757 nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
759 goto nla_put_failure;
761 nla_nest_end(skb, nest);
762 nla_nest_end(skb, nla_grps);
764 genlmsg_end(skb, hdr);
768 genlmsg_cancel(skb, hdr);
772 static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
775 struct genl_family *rt;
776 struct net *net = sock_net(skb->sk);
777 int fams_to_skip = cb->args[0];
780 idr_for_each_entry(&genl_fam_idr, rt, id) {
781 if (!rt->netnsok && !net_eq(net, &init_net))
784 if (n++ < fams_to_skip)
787 if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).portid,
788 cb->nlh->nlmsg_seq, NLM_F_MULTI,
789 skb, CTRL_CMD_NEWFAMILY) < 0) {
799 static struct sk_buff *ctrl_build_family_msg(const struct genl_family *family,
800 u32 portid, int seq, u8 cmd)
805 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
807 return ERR_PTR(-ENOBUFS);
809 err = ctrl_fill_info(family, portid, seq, 0, skb, cmd);
818 static struct sk_buff *
819 ctrl_build_mcgrp_msg(const struct genl_family *family,
820 const struct genl_multicast_group *grp,
821 int grp_id, u32 portid, int seq, u8 cmd)
826 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
828 return ERR_PTR(-ENOBUFS);
830 err = ctrl_fill_mcgrp_info(family, grp, grp_id, portid,
840 static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = {
841 [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 },
842 [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING,
843 .len = GENL_NAMSIZ - 1 },
846 static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
849 const struct genl_family *res = NULL;
852 if (info->attrs[CTRL_ATTR_FAMILY_ID]) {
853 u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]);
854 res = genl_family_find_byid(id);
858 if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
861 name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
862 res = genl_family_find_byname(name);
863 #ifdef CONFIG_MODULES
867 request_module("net-pf-%d-proto-%d-family-%s",
868 PF_NETLINK, NETLINK_GENERIC, name);
871 res = genl_family_find_byname(name);
880 if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) {
881 /* family doesn't exist here */
885 msg = ctrl_build_family_msg(res, info->snd_portid, info->snd_seq,
890 return genlmsg_reply(msg, info);
893 static int genl_ctrl_event(int event, const struct genl_family *family,
894 const struct genl_multicast_group *grp,
899 /* genl is still initialising */
900 if (!init_net.genl_sock)
904 case CTRL_CMD_NEWFAMILY:
905 case CTRL_CMD_DELFAMILY:
907 msg = ctrl_build_family_msg(family, 0, 0, event);
909 case CTRL_CMD_NEWMCAST_GRP:
910 case CTRL_CMD_DELMCAST_GRP:
912 msg = ctrl_build_mcgrp_msg(family, grp, grp_id, 0, 0, event);
921 if (!family->netnsok) {
922 genlmsg_multicast_netns(&genl_ctrl, &init_net, msg, 0,
926 genlmsg_multicast_allns(&genl_ctrl, msg, 0,
934 static const struct genl_ops genl_ctrl_ops[] = {
936 .cmd = CTRL_CMD_GETFAMILY,
937 .doit = ctrl_getfamily,
938 .dumpit = ctrl_dumpfamily,
939 .policy = ctrl_policy,
943 static const struct genl_multicast_group genl_ctrl_groups[] = {
944 { .name = "notify", },
947 static struct genl_family genl_ctrl __ro_after_init = {
948 .module = THIS_MODULE,
949 .ops = genl_ctrl_ops,
950 .n_ops = ARRAY_SIZE(genl_ctrl_ops),
951 .mcgrps = genl_ctrl_groups,
952 .n_mcgrps = ARRAY_SIZE(genl_ctrl_groups),
956 .maxattr = CTRL_ATTR_MAX,
960 static int genl_bind(struct net *net, int group)
962 struct genl_family *f;
968 idr_for_each_entry(&genl_fam_idr, f, id) {
969 if (group >= f->mcgrp_offset &&
970 group < f->mcgrp_offset + f->n_mcgrps) {
971 int fam_grp = group - f->mcgrp_offset;
973 if (!f->netnsok && net != &init_net)
975 else if (f->mcast_bind)
976 err = f->mcast_bind(net, fam_grp);
987 static void genl_unbind(struct net *net, int group)
989 struct genl_family *f;
994 idr_for_each_entry(&genl_fam_idr, f, id) {
995 if (group >= f->mcgrp_offset &&
996 group < f->mcgrp_offset + f->n_mcgrps) {
997 int fam_grp = group - f->mcgrp_offset;
1000 f->mcast_unbind(net, fam_grp);
1007 static int __net_init genl_pernet_init(struct net *net)
1009 struct netlink_kernel_cfg cfg = {
1011 .flags = NL_CFG_F_NONROOT_RECV,
1013 .unbind = genl_unbind,
1016 /* we'll bump the group number right afterwards */
1017 net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, &cfg);
1019 if (!net->genl_sock && net_eq(net, &init_net))
1020 panic("GENL: Cannot initialize generic netlink\n");
1022 if (!net->genl_sock)
1028 static void __net_exit genl_pernet_exit(struct net *net)
1030 netlink_kernel_release(net->genl_sock);
1031 net->genl_sock = NULL;
1034 static struct pernet_operations genl_pernet_ops = {
1035 .init = genl_pernet_init,
1036 .exit = genl_pernet_exit,
1039 static int __init genl_init(void)
1043 err = genl_register_family(&genl_ctrl);
1047 err = register_pernet_subsys(&genl_pernet_ops);
1054 panic("GENL: Cannot register controller: %d\n", err);
1057 subsys_initcall(genl_init);
1060 * genl_family_attrbuf - return family's attrbuf
1061 * @family: the family
1063 * Return the family's attrbuf, while validating that it's
1064 * actually valid to access it.
1066 * You cannot use this function with a family that has parallel_ops
1067 * and you can only use it within (pre/post) doit/dumpit callbacks.
1069 struct nlattr **genl_family_attrbuf(const struct genl_family *family)
1071 if (!WARN_ON(family->parallel_ops))
1072 lockdep_assert_held(&genl_mutex);
1074 return family->attrbuf;
1076 EXPORT_SYMBOL(genl_family_attrbuf);
1078 static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group,
1081 struct sk_buff *tmp;
1082 struct net *net, *prev = NULL;
1085 for_each_net_rcu(net) {
1087 tmp = skb_clone(skb, flags);
1092 err = nlmsg_multicast(prev->genl_sock, tmp,
1093 portid, group, flags);
1101 return nlmsg_multicast(prev->genl_sock, skb, portid, group, flags);
1107 int genlmsg_multicast_allns(const struct genl_family *family,
1108 struct sk_buff *skb, u32 portid,
1109 unsigned int group, gfp_t flags)
1111 if (WARN_ON_ONCE(group >= family->n_mcgrps))
1113 group = family->mcgrp_offset + group;
1114 return genlmsg_mcast(skb, portid, group, flags);
1116 EXPORT_SYMBOL(genlmsg_multicast_allns);
1118 void genl_notify(const struct genl_family *family, struct sk_buff *skb,
1119 struct genl_info *info, u32 group, gfp_t flags)
1121 struct net *net = genl_info_net(info);
1122 struct sock *sk = net->genl_sock;
1126 report = nlmsg_report(info->nlhdr);
1128 if (WARN_ON_ONCE(group >= family->n_mcgrps))
1130 group = family->mcgrp_offset + group;
1131 nlmsg_notify(sk, skb, info->snd_portid, group, report, flags);
1133 EXPORT_SYMBOL(genl_notify);