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);
368 err = genl_validate_assign_mc_groups(family);
374 /* send all events */
375 genl_ctrl_event(CTRL_CMD_NEWFAMILY, family, NULL, 0);
376 for (i = 0; i < family->n_mcgrps; i++)
377 genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, family,
378 &family->mcgrps[i], family->mcgrp_offset + i);
383 idr_remove(&genl_fam_idr, family->id);
388 EXPORT_SYMBOL(genl_register_family);
391 * genl_unregister_family - unregister generic netlink family
392 * @family: generic netlink family
394 * Unregisters the specified family.
396 * Returns 0 on success or a negative error code.
398 int genl_unregister_family(const struct genl_family *family)
402 if (genl_family_find_byid(family->id)) {
407 genl_unregister_mc_groups(family);
409 idr_remove(&genl_fam_idr, family->id);
412 wait_event(genl_sk_destructing_waitq,
413 atomic_read(&genl_sk_destructing_cnt) == 0);
416 kfree(family->attrbuf);
418 genl_ctrl_event(CTRL_CMD_DELFAMILY, family, NULL, 0);
422 EXPORT_SYMBOL(genl_unregister_family);
425 * genlmsg_put - Add generic netlink header to netlink message
426 * @skb: socket buffer holding the message
427 * @portid: netlink portid the message is addressed to
428 * @seq: sequence number (usually the one of the sender)
429 * @family: generic netlink family
430 * @flags: netlink message flags
431 * @cmd: generic netlink command
433 * Returns pointer to user specific header
435 void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
436 const struct genl_family *family, int flags, u8 cmd)
438 struct nlmsghdr *nlh;
439 struct genlmsghdr *hdr;
441 nlh = nlmsg_put(skb, portid, seq, family->id, GENL_HDRLEN +
442 family->hdrsize, flags);
446 hdr = nlmsg_data(nlh);
448 hdr->version = family->version;
451 return (char *) hdr + GENL_HDRLEN;
453 EXPORT_SYMBOL(genlmsg_put);
455 static int genl_lock_start(struct netlink_callback *cb)
457 /* our ops are always const - netlink API doesn't propagate that */
458 const struct genl_ops *ops = cb->data;
469 static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
471 /* our ops are always const - netlink API doesn't propagate that */
472 const struct genl_ops *ops = cb->data;
476 rc = ops->dumpit(skb, cb);
481 static int genl_lock_done(struct netlink_callback *cb)
483 /* our ops are always const - netlink API doesn't propagate that */
484 const struct genl_ops *ops = cb->data;
495 static int genl_family_rcv_msg(const struct genl_family *family,
497 struct nlmsghdr *nlh)
499 const struct genl_ops *ops;
500 struct net *net = sock_net(skb->sk);
501 struct genl_info info;
502 struct genlmsghdr *hdr = nlmsg_data(nlh);
503 struct nlattr **attrbuf;
506 /* this family doesn't exist in this netns */
507 if (!family->netnsok && !net_eq(net, &init_net))
510 hdrlen = GENL_HDRLEN + family->hdrsize;
511 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
514 ops = genl_get_cmd(hdr->cmd, family);
518 if ((ops->flags & GENL_ADMIN_PERM) &&
519 !netlink_capable(skb, CAP_NET_ADMIN))
522 if ((ops->flags & GENL_UNS_ADMIN_PERM) &&
523 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
526 if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {
529 if (ops->dumpit == NULL)
532 if (!family->parallel_ops) {
533 struct netlink_dump_control c = {
534 .module = family->module,
535 /* we have const, but the netlink API doesn't */
537 .start = genl_lock_start,
538 .dump = genl_lock_dumpit,
539 .done = genl_lock_done,
543 rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c);
547 struct netlink_dump_control c = {
548 .module = family->module,
554 rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c);
560 if (ops->doit == NULL)
563 if (family->maxattr && family->parallel_ops) {
564 attrbuf = kmalloc((family->maxattr+1) *
565 sizeof(struct nlattr *), GFP_KERNEL);
569 attrbuf = family->attrbuf;
572 err = nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr,
578 info.snd_seq = nlh->nlmsg_seq;
579 info.snd_portid = NETLINK_CB(skb).portid;
581 info.genlhdr = nlmsg_data(nlh);
582 info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
583 info.attrs = attrbuf;
584 genl_info_net_set(&info, net);
585 memset(&info.user_ptr, 0, sizeof(info.user_ptr));
587 if (family->pre_doit) {
588 err = family->pre_doit(ops, skb, &info);
593 err = ops->doit(skb, &info);
595 if (family->post_doit)
596 family->post_doit(ops, skb, &info);
599 if (family->parallel_ops)
605 static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
607 const struct genl_family *family;
610 family = genl_family_find_byid(nlh->nlmsg_type);
614 if (!family->parallel_ops)
617 err = genl_family_rcv_msg(family, skb, nlh);
619 if (!family->parallel_ops)
625 static void genl_rcv(struct sk_buff *skb)
628 netlink_rcv_skb(skb, &genl_rcv_msg);
632 /**************************************************************************
634 **************************************************************************/
636 static struct genl_family genl_ctrl;
638 static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq,
639 u32 flags, struct sk_buff *skb, u8 cmd)
643 hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
647 if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
648 nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id) ||
649 nla_put_u32(skb, CTRL_ATTR_VERSION, family->version) ||
650 nla_put_u32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize) ||
651 nla_put_u32(skb, CTRL_ATTR_MAXATTR, family->maxattr))
652 goto nla_put_failure;
655 struct nlattr *nla_ops;
658 nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
660 goto nla_put_failure;
662 for (i = 0; i < family->n_ops; i++) {
664 const struct genl_ops *ops = &family->ops[i];
665 u32 op_flags = ops->flags;
668 op_flags |= GENL_CMD_CAP_DUMP;
670 op_flags |= GENL_CMD_CAP_DO;
672 op_flags |= GENL_CMD_CAP_HASPOL;
674 nest = nla_nest_start(skb, i + 1);
676 goto nla_put_failure;
678 if (nla_put_u32(skb, CTRL_ATTR_OP_ID, ops->cmd) ||
679 nla_put_u32(skb, CTRL_ATTR_OP_FLAGS, op_flags))
680 goto nla_put_failure;
682 nla_nest_end(skb, nest);
685 nla_nest_end(skb, nla_ops);
688 if (family->n_mcgrps) {
689 struct nlattr *nla_grps;
692 nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
693 if (nla_grps == NULL)
694 goto nla_put_failure;
696 for (i = 0; i < family->n_mcgrps; i++) {
698 const struct genl_multicast_group *grp;
700 grp = &family->mcgrps[i];
702 nest = nla_nest_start(skb, i + 1);
704 goto nla_put_failure;
706 if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID,
707 family->mcgrp_offset + i) ||
708 nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
710 goto nla_put_failure;
712 nla_nest_end(skb, nest);
714 nla_nest_end(skb, nla_grps);
717 genlmsg_end(skb, hdr);
721 genlmsg_cancel(skb, hdr);
725 static int ctrl_fill_mcgrp_info(const struct genl_family *family,
726 const struct genl_multicast_group *grp,
727 int grp_id, u32 portid, u32 seq, u32 flags,
728 struct sk_buff *skb, u8 cmd)
731 struct nlattr *nla_grps;
734 hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
738 if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
739 nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id))
740 goto nla_put_failure;
742 nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
743 if (nla_grps == NULL)
744 goto nla_put_failure;
746 nest = nla_nest_start(skb, 1);
748 goto nla_put_failure;
750 if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID, grp_id) ||
751 nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
753 goto nla_put_failure;
755 nla_nest_end(skb, nest);
756 nla_nest_end(skb, nla_grps);
758 genlmsg_end(skb, hdr);
762 genlmsg_cancel(skb, hdr);
766 static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
769 struct genl_family *rt;
770 struct net *net = sock_net(skb->sk);
771 int fams_to_skip = cb->args[0];
774 idr_for_each_entry(&genl_fam_idr, rt, id) {
775 if (!rt->netnsok && !net_eq(net, &init_net))
778 if (n++ < fams_to_skip)
781 if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).portid,
782 cb->nlh->nlmsg_seq, NLM_F_MULTI,
783 skb, CTRL_CMD_NEWFAMILY) < 0)
791 static struct sk_buff *ctrl_build_family_msg(const struct genl_family *family,
792 u32 portid, int seq, u8 cmd)
797 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
799 return ERR_PTR(-ENOBUFS);
801 err = ctrl_fill_info(family, portid, seq, 0, skb, cmd);
810 static struct sk_buff *
811 ctrl_build_mcgrp_msg(const struct genl_family *family,
812 const struct genl_multicast_group *grp,
813 int grp_id, u32 portid, int seq, u8 cmd)
818 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
820 return ERR_PTR(-ENOBUFS);
822 err = ctrl_fill_mcgrp_info(family, grp, grp_id, portid,
832 static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = {
833 [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 },
834 [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING,
835 .len = GENL_NAMSIZ - 1 },
838 static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
841 const struct genl_family *res = NULL;
844 if (info->attrs[CTRL_ATTR_FAMILY_ID]) {
845 u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]);
846 res = genl_family_find_byid(id);
850 if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
853 name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
854 res = genl_family_find_byname(name);
855 #ifdef CONFIG_MODULES
859 request_module("net-pf-%d-proto-%d-family-%s",
860 PF_NETLINK, NETLINK_GENERIC, name);
863 res = genl_family_find_byname(name);
872 if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) {
873 /* family doesn't exist here */
877 msg = ctrl_build_family_msg(res, info->snd_portid, info->snd_seq,
882 return genlmsg_reply(msg, info);
885 static int genl_ctrl_event(int event, const struct genl_family *family,
886 const struct genl_multicast_group *grp,
891 /* genl is still initialising */
892 if (!init_net.genl_sock)
896 case CTRL_CMD_NEWFAMILY:
897 case CTRL_CMD_DELFAMILY:
899 msg = ctrl_build_family_msg(family, 0, 0, event);
901 case CTRL_CMD_NEWMCAST_GRP:
902 case CTRL_CMD_DELMCAST_GRP:
904 msg = ctrl_build_mcgrp_msg(family, grp, grp_id, 0, 0, event);
913 if (!family->netnsok) {
914 genlmsg_multicast_netns(&genl_ctrl, &init_net, msg, 0,
918 genlmsg_multicast_allns(&genl_ctrl, msg, 0,
926 static const struct genl_ops genl_ctrl_ops[] = {
928 .cmd = CTRL_CMD_GETFAMILY,
929 .doit = ctrl_getfamily,
930 .dumpit = ctrl_dumpfamily,
931 .policy = ctrl_policy,
935 static const struct genl_multicast_group genl_ctrl_groups[] = {
936 { .name = "notify", },
939 static struct genl_family genl_ctrl __ro_after_init = {
940 .module = THIS_MODULE,
941 .ops = genl_ctrl_ops,
942 .n_ops = ARRAY_SIZE(genl_ctrl_ops),
943 .mcgrps = genl_ctrl_groups,
944 .n_mcgrps = ARRAY_SIZE(genl_ctrl_groups),
948 .maxattr = CTRL_ATTR_MAX,
952 static int genl_bind(struct net *net, int group)
954 struct genl_family *f;
960 idr_for_each_entry(&genl_fam_idr, f, id) {
961 if (group >= f->mcgrp_offset &&
962 group < f->mcgrp_offset + f->n_mcgrps) {
963 int fam_grp = group - f->mcgrp_offset;
965 if (!f->netnsok && net != &init_net)
967 else if (f->mcast_bind)
968 err = f->mcast_bind(net, fam_grp);
979 static void genl_unbind(struct net *net, int group)
981 struct genl_family *f;
986 idr_for_each_entry(&genl_fam_idr, f, id) {
987 if (group >= f->mcgrp_offset &&
988 group < f->mcgrp_offset + f->n_mcgrps) {
989 int fam_grp = group - f->mcgrp_offset;
992 f->mcast_unbind(net, fam_grp);
999 static int __net_init genl_pernet_init(struct net *net)
1001 struct netlink_kernel_cfg cfg = {
1003 .flags = NL_CFG_F_NONROOT_RECV,
1005 .unbind = genl_unbind,
1008 /* we'll bump the group number right afterwards */
1009 net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, &cfg);
1011 if (!net->genl_sock && net_eq(net, &init_net))
1012 panic("GENL: Cannot initialize generic netlink\n");
1014 if (!net->genl_sock)
1020 static void __net_exit genl_pernet_exit(struct net *net)
1022 netlink_kernel_release(net->genl_sock);
1023 net->genl_sock = NULL;
1026 static struct pernet_operations genl_pernet_ops = {
1027 .init = genl_pernet_init,
1028 .exit = genl_pernet_exit,
1031 static int __init genl_init(void)
1035 err = genl_register_family(&genl_ctrl);
1039 err = register_pernet_subsys(&genl_pernet_ops);
1046 panic("GENL: Cannot register controller: %d\n", err);
1049 subsys_initcall(genl_init);
1052 * genl_family_attrbuf - return family's attrbuf
1053 * @family: the family
1055 * Return the family's attrbuf, while validating that it's
1056 * actually valid to access it.
1058 * You cannot use this function with a family that has parallel_ops
1059 * and you can only use it within (pre/post) doit/dumpit callbacks.
1061 struct nlattr **genl_family_attrbuf(const struct genl_family *family)
1063 if (!WARN_ON(family->parallel_ops))
1064 lockdep_assert_held(&genl_mutex);
1066 return family->attrbuf;
1068 EXPORT_SYMBOL(genl_family_attrbuf);
1070 static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group,
1073 struct sk_buff *tmp;
1074 struct net *net, *prev = NULL;
1077 for_each_net_rcu(net) {
1079 tmp = skb_clone(skb, flags);
1084 err = nlmsg_multicast(prev->genl_sock, tmp,
1085 portid, group, flags);
1093 return nlmsg_multicast(prev->genl_sock, skb, portid, group, flags);
1099 int genlmsg_multicast_allns(const struct genl_family *family,
1100 struct sk_buff *skb, u32 portid,
1101 unsigned int group, gfp_t flags)
1103 if (WARN_ON_ONCE(group >= family->n_mcgrps))
1105 group = family->mcgrp_offset + group;
1106 return genlmsg_mcast(skb, portid, group, flags);
1108 EXPORT_SYMBOL(genlmsg_multicast_allns);
1110 void genl_notify(const struct genl_family *family, struct sk_buff *skb,
1111 struct genl_info *info, u32 group, gfp_t flags)
1113 struct net *net = genl_info_net(info);
1114 struct sock *sk = net->genl_sock;
1118 report = nlmsg_report(info->nlhdr);
1120 if (WARN_ON_ONCE(group >= family->n_mcgrps))
1122 group = family->mcgrp_offset + group;
1123 nlmsg_notify(sk, skb, info->snd_portid, group, report, flags);
1125 EXPORT_SYMBOL(genl_notify);