1 // SPDX-License-Identifier: GPL-2.0
3 * NETLINK Generic Netlink Family
5 * Authors: Jamal Hadi Salim
6 * Thomas Graf <tgraf@suug.ch>
7 * Johannes Berg <johannes@sipsolutions.net>
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/errno.h>
14 #include <linux/types.h>
15 #include <linux/socket.h>
16 #include <linux/string.h>
17 #include <linux/skbuff.h>
18 #include <linux/mutex.h>
19 #include <linux/bitmap.h>
20 #include <linux/rwsem.h>
21 #include <linux/idr.h>
23 #include <net/genetlink.h>
25 static DEFINE_MUTEX(genl_mutex
); /* serialization of message processing */
26 static DECLARE_RWSEM(cb_lock
);
28 atomic_t genl_sk_destructing_cnt
= ATOMIC_INIT(0);
29 DECLARE_WAIT_QUEUE_HEAD(genl_sk_destructing_waitq
);
33 mutex_lock(&genl_mutex
);
35 EXPORT_SYMBOL(genl_lock
);
37 void genl_unlock(void)
39 mutex_unlock(&genl_mutex
);
41 EXPORT_SYMBOL(genl_unlock
);
44 bool lockdep_genl_is_held(void)
46 return lockdep_is_held(&genl_mutex
);
48 EXPORT_SYMBOL(lockdep_genl_is_held
);
51 static void genl_lock_all(void)
57 static void genl_unlock_all(void)
63 static DEFINE_IDR(genl_fam_idr
);
66 * Bitmap of multicast groups that are currently in use.
68 * To avoid an allocation at boot of just one unsigned long,
69 * declare it global instead.
70 * Bit 0 is marked as already used since group 0 is invalid.
71 * Bit 1 is marked as already used since the drop-monitor code
72 * abuses the API and thinks it can statically use group 1.
73 * That group will typically conflict with other groups that
74 * any proper users use.
75 * Bit 16 is marked as used since it's used for generic netlink
76 * and the code no longer marks pre-reserved IDs as used.
77 * Bit 17 is marked as already used since the VFS quota code
78 * also abused this API and relied on family == group ID, we
79 * cater to that by giving it a static family and group ID.
80 * Bit 18 is marked as already used since the PMCRAID driver
81 * did the same thing as the VFS quota code (maybe copied?)
83 static unsigned long mc_group_start
= 0x3 | BIT(GENL_ID_CTRL
) |
84 BIT(GENL_ID_VFS_DQUOT
) |
86 static unsigned long *mc_groups
= &mc_group_start
;
87 static unsigned long mc_groups_longs
= 1;
89 static int genl_ctrl_event(int event
, const struct genl_family
*family
,
90 const struct genl_multicast_group
*grp
,
93 static const struct genl_family
*genl_family_find_byid(unsigned int id
)
95 return idr_find(&genl_fam_idr
, id
);
98 static const struct genl_family
*genl_family_find_byname(char *name
)
100 const struct genl_family
*family
;
103 idr_for_each_entry(&genl_fam_idr
, family
, id
)
104 if (strcmp(family
->name
, name
) == 0)
110 static int genl_get_cmd_cnt(const struct genl_family
*family
)
112 return family
->n_ops
+ family
->n_small_ops
;
115 static void genl_op_from_full(const struct genl_family
*family
,
116 unsigned int i
, struct genl_ops
*op
)
118 *op
= family
->ops
[i
];
121 op
->maxattr
= family
->maxattr
;
123 op
->policy
= family
->policy
;
126 static int genl_get_cmd_full(u32 cmd
, const struct genl_family
*family
,
131 for (i
= 0; i
< family
->n_ops
; i
++)
132 if (family
->ops
[i
].cmd
== cmd
) {
133 genl_op_from_full(family
, i
, op
);
140 static void genl_op_from_small(const struct genl_family
*family
,
141 unsigned int i
, struct genl_ops
*op
)
143 memset(op
, 0, sizeof(*op
));
144 op
->doit
= family
->small_ops
[i
].doit
;
145 op
->dumpit
= family
->small_ops
[i
].dumpit
;
146 op
->cmd
= family
->small_ops
[i
].cmd
;
147 op
->internal_flags
= family
->small_ops
[i
].internal_flags
;
148 op
->flags
= family
->small_ops
[i
].flags
;
149 op
->validate
= family
->small_ops
[i
].validate
;
151 op
->maxattr
= family
->maxattr
;
152 op
->policy
= family
->policy
;
155 static int genl_get_cmd_small(u32 cmd
, const struct genl_family
*family
,
160 for (i
= 0; i
< family
->n_small_ops
; i
++)
161 if (family
->small_ops
[i
].cmd
== cmd
) {
162 genl_op_from_small(family
, i
, op
);
169 static int genl_get_cmd(u32 cmd
, const struct genl_family
*family
,
172 if (!genl_get_cmd_full(cmd
, family
, op
))
174 return genl_get_cmd_small(cmd
, family
, op
);
177 static void genl_get_cmd_by_index(unsigned int i
,
178 const struct genl_family
*family
,
181 if (i
< family
->n_ops
)
182 genl_op_from_full(family
, i
, op
);
183 else if (i
< family
->n_ops
+ family
->n_small_ops
)
184 genl_op_from_small(family
, i
- family
->n_ops
, op
);
189 static int genl_allocate_reserve_groups(int n_groups
, int *first_id
)
191 unsigned long *new_groups
;
199 id
= find_first_zero_bit(mc_groups
,
203 id
= find_next_zero_bit(mc_groups
,
204 mc_groups_longs
* BITS_PER_LONG
,
209 i
< min_t(int, id
+ n_groups
,
210 mc_groups_longs
* BITS_PER_LONG
);
212 if (test_bit(i
, mc_groups
)) {
219 if (id
+ n_groups
> mc_groups_longs
* BITS_PER_LONG
) {
220 unsigned long new_longs
= mc_groups_longs
+
221 BITS_TO_LONGS(n_groups
);
222 size_t nlen
= new_longs
* sizeof(unsigned long);
224 if (mc_groups
== &mc_group_start
) {
225 new_groups
= kzalloc(nlen
, GFP_KERNEL
);
228 mc_groups
= new_groups
;
229 *mc_groups
= mc_group_start
;
231 new_groups
= krealloc(mc_groups
, nlen
,
235 mc_groups
= new_groups
;
236 for (i
= 0; i
< BITS_TO_LONGS(n_groups
); i
++)
237 mc_groups
[mc_groups_longs
+ i
] = 0;
239 mc_groups_longs
= new_longs
;
243 for (i
= id
; i
< id
+ n_groups
; i
++)
244 set_bit(i
, mc_groups
);
249 static struct genl_family genl_ctrl
;
251 static int genl_validate_assign_mc_groups(struct genl_family
*family
)
254 int n_groups
= family
->n_mcgrps
;
256 bool groups_allocated
= false;
261 for (i
= 0; i
< n_groups
; i
++) {
262 const struct genl_multicast_group
*grp
= &family
->mcgrps
[i
];
264 if (WARN_ON(grp
->name
[0] == '\0'))
266 if (WARN_ON(memchr(grp
->name
, '\0', GENL_NAMSIZ
) == NULL
))
270 /* special-case our own group and hacks */
271 if (family
== &genl_ctrl
) {
272 first_id
= GENL_ID_CTRL
;
273 BUG_ON(n_groups
!= 1);
274 } else if (strcmp(family
->name
, "NET_DM") == 0) {
276 BUG_ON(n_groups
!= 1);
277 } else if (family
->id
== GENL_ID_VFS_DQUOT
) {
278 first_id
= GENL_ID_VFS_DQUOT
;
279 BUG_ON(n_groups
!= 1);
280 } else if (family
->id
== GENL_ID_PMCRAID
) {
281 first_id
= GENL_ID_PMCRAID
;
282 BUG_ON(n_groups
!= 1);
284 groups_allocated
= true;
285 err
= genl_allocate_reserve_groups(n_groups
, &first_id
);
290 family
->mcgrp_offset
= first_id
;
292 /* if still initializing, can't and don't need to realloc bitmaps */
293 if (!init_net
.genl_sock
)
296 if (family
->netnsok
) {
299 netlink_table_grab();
301 for_each_net_rcu(net
) {
302 err
= __netlink_change_ngroups(net
->genl_sock
,
303 mc_groups_longs
* BITS_PER_LONG
);
306 * No need to roll back, can only fail if
307 * memory allocation fails and then the
308 * number of _possible_ groups has been
309 * increased on some sockets which is ok.
315 netlink_table_ungrab();
317 err
= netlink_change_ngroups(init_net
.genl_sock
,
318 mc_groups_longs
* BITS_PER_LONG
);
321 if (groups_allocated
&& err
) {
322 for (i
= 0; i
< family
->n_mcgrps
; i
++)
323 clear_bit(family
->mcgrp_offset
+ i
, mc_groups
);
329 static void genl_unregister_mc_groups(const struct genl_family
*family
)
334 netlink_table_grab();
336 for_each_net_rcu(net
) {
337 for (i
= 0; i
< family
->n_mcgrps
; i
++)
338 __netlink_clear_multicast_users(
339 net
->genl_sock
, family
->mcgrp_offset
+ i
);
342 netlink_table_ungrab();
344 for (i
= 0; i
< family
->n_mcgrps
; i
++) {
345 int grp_id
= family
->mcgrp_offset
+ i
;
348 clear_bit(grp_id
, mc_groups
);
349 genl_ctrl_event(CTRL_CMD_DELMCAST_GRP
, family
,
350 &family
->mcgrps
[i
], grp_id
);
354 static int genl_validate_ops(const struct genl_family
*family
)
358 if (WARN_ON(family
->n_ops
&& !family
->ops
) ||
359 WARN_ON(family
->n_small_ops
&& !family
->small_ops
))
362 for (i
= 0; i
< genl_get_cmd_cnt(family
); i
++) {
365 genl_get_cmd_by_index(i
, family
, &op
);
366 if (op
.dumpit
== NULL
&& op
.doit
== NULL
)
368 for (j
= i
+ 1; j
< genl_get_cmd_cnt(family
); j
++) {
371 genl_get_cmd_by_index(j
, family
, &op2
);
372 if (op
.cmd
== op2
.cmd
)
381 * genl_register_family - register a generic netlink family
382 * @family: generic netlink family
384 * Registers the specified family after validating it first. Only one
385 * family may be registered with the same family name or identifier.
387 * The family's ops, multicast groups and module pointer must already
390 * Return 0 on success or a negative error code.
392 int genl_register_family(struct genl_family
*family
)
395 int start
= GENL_START_ALLOC
, end
= GENL_MAX_ID
;
397 err
= genl_validate_ops(family
);
403 if (genl_family_find_byname(family
->name
)) {
409 * Sadly, a few cases need to be special-cased
410 * due to them having previously abused the API
411 * and having used their family ID also as their
412 * multicast group ID, so we use reserved IDs
413 * for both to be sure we can do that mapping.
415 if (family
== &genl_ctrl
) {
416 /* and this needs to be special for initial family lookups */
417 start
= end
= GENL_ID_CTRL
;
418 } else if (strcmp(family
->name
, "pmcraid") == 0) {
419 start
= end
= GENL_ID_PMCRAID
;
420 } else if (strcmp(family
->name
, "VFS_DQUOT") == 0) {
421 start
= end
= GENL_ID_VFS_DQUOT
;
424 family
->id
= idr_alloc_cyclic(&genl_fam_idr
, family
,
425 start
, end
+ 1, GFP_KERNEL
);
426 if (family
->id
< 0) {
431 err
= genl_validate_assign_mc_groups(family
);
437 /* send all events */
438 genl_ctrl_event(CTRL_CMD_NEWFAMILY
, family
, NULL
, 0);
439 for (i
= 0; i
< family
->n_mcgrps
; i
++)
440 genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP
, family
,
441 &family
->mcgrps
[i
], family
->mcgrp_offset
+ i
);
446 idr_remove(&genl_fam_idr
, family
->id
);
451 EXPORT_SYMBOL(genl_register_family
);
454 * genl_unregister_family - unregister generic netlink family
455 * @family: generic netlink family
457 * Unregisters the specified family.
459 * Returns 0 on success or a negative error code.
461 int genl_unregister_family(const struct genl_family
*family
)
465 if (!genl_family_find_byid(family
->id
)) {
470 genl_unregister_mc_groups(family
);
472 idr_remove(&genl_fam_idr
, family
->id
);
475 wait_event(genl_sk_destructing_waitq
,
476 atomic_read(&genl_sk_destructing_cnt
) == 0);
479 genl_ctrl_event(CTRL_CMD_DELFAMILY
, family
, NULL
, 0);
483 EXPORT_SYMBOL(genl_unregister_family
);
486 * genlmsg_put - Add generic netlink header to netlink message
487 * @skb: socket buffer holding the message
488 * @portid: netlink portid the message is addressed to
489 * @seq: sequence number (usually the one of the sender)
490 * @family: generic netlink family
491 * @flags: netlink message flags
492 * @cmd: generic netlink command
494 * Returns pointer to user specific header
496 void *genlmsg_put(struct sk_buff
*skb
, u32 portid
, u32 seq
,
497 const struct genl_family
*family
, int flags
, u8 cmd
)
499 struct nlmsghdr
*nlh
;
500 struct genlmsghdr
*hdr
;
502 nlh
= nlmsg_put(skb
, portid
, seq
, family
->id
, GENL_HDRLEN
+
503 family
->hdrsize
, flags
);
507 hdr
= nlmsg_data(nlh
);
509 hdr
->version
= family
->version
;
512 return (char *) hdr
+ GENL_HDRLEN
;
514 EXPORT_SYMBOL(genlmsg_put
);
516 static struct genl_dumpit_info
*genl_dumpit_info_alloc(void)
518 return kmalloc(sizeof(struct genl_dumpit_info
), GFP_KERNEL
);
521 static void genl_dumpit_info_free(const struct genl_dumpit_info
*info
)
526 static struct nlattr
**
527 genl_family_rcv_msg_attrs_parse(const struct genl_family
*family
,
528 struct nlmsghdr
*nlh
,
529 struct netlink_ext_ack
*extack
,
530 const struct genl_ops
*ops
,
532 enum genl_validate_flags no_strict_flag
)
534 enum netlink_validation validate
= ops
->validate
& no_strict_flag
?
535 NL_VALIDATE_LIBERAL
:
537 struct nlattr
**attrbuf
;
543 attrbuf
= kmalloc_array(ops
->maxattr
+ 1,
544 sizeof(struct nlattr
*), GFP_KERNEL
);
546 return ERR_PTR(-ENOMEM
);
548 err
= __nlmsg_parse(nlh
, hdrlen
, attrbuf
, ops
->maxattr
, ops
->policy
,
557 static void genl_family_rcv_msg_attrs_free(struct nlattr
**attrbuf
)
562 struct genl_start_context
{
563 const struct genl_family
*family
;
564 struct nlmsghdr
*nlh
;
565 struct netlink_ext_ack
*extack
;
566 const struct genl_ops
*ops
;
570 static int genl_start(struct netlink_callback
*cb
)
572 struct genl_start_context
*ctx
= cb
->data
;
573 const struct genl_ops
*ops
= ctx
->ops
;
574 struct genl_dumpit_info
*info
;
575 struct nlattr
**attrs
= NULL
;
578 if (ops
->validate
& GENL_DONT_VALIDATE_DUMP
)
581 if (ctx
->nlh
->nlmsg_len
< nlmsg_msg_size(ctx
->hdrlen
))
584 attrs
= genl_family_rcv_msg_attrs_parse(ctx
->family
, ctx
->nlh
, ctx
->extack
,
586 GENL_DONT_VALIDATE_DUMP_STRICT
);
588 return PTR_ERR(attrs
);
591 info
= genl_dumpit_info_alloc();
593 genl_family_rcv_msg_attrs_free(attrs
);
596 info
->family
= ctx
->family
;
602 if (!ctx
->family
->parallel_ops
)
605 if (!ctx
->family
->parallel_ops
)
610 genl_family_rcv_msg_attrs_free(info
->attrs
);
611 genl_dumpit_info_free(info
);
617 static int genl_lock_dumpit(struct sk_buff
*skb
, struct netlink_callback
*cb
)
619 const struct genl_ops
*ops
= &genl_dumpit_info(cb
)->op
;
623 rc
= ops
->dumpit(skb
, cb
);
628 static int genl_lock_done(struct netlink_callback
*cb
)
630 const struct genl_dumpit_info
*info
= genl_dumpit_info(cb
);
631 const struct genl_ops
*ops
= &info
->op
;
639 genl_family_rcv_msg_attrs_free(info
->attrs
);
640 genl_dumpit_info_free(info
);
644 static int genl_parallel_done(struct netlink_callback
*cb
)
646 const struct genl_dumpit_info
*info
= genl_dumpit_info(cb
);
647 const struct genl_ops
*ops
= &info
->op
;
652 genl_family_rcv_msg_attrs_free(info
->attrs
);
653 genl_dumpit_info_free(info
);
657 static int genl_family_rcv_msg_dumpit(const struct genl_family
*family
,
659 struct nlmsghdr
*nlh
,
660 struct netlink_ext_ack
*extack
,
661 const struct genl_ops
*ops
,
662 int hdrlen
, struct net
*net
)
664 struct genl_start_context ctx
;
676 if (!family
->parallel_ops
) {
677 struct netlink_dump_control c
= {
678 .module
= family
->module
,
681 .dump
= genl_lock_dumpit
,
682 .done
= genl_lock_done
,
686 err
= __netlink_dump_start(net
->genl_sock
, skb
, nlh
, &c
);
689 struct netlink_dump_control c
= {
690 .module
= family
->module
,
694 .done
= genl_parallel_done
,
697 err
= __netlink_dump_start(net
->genl_sock
, skb
, nlh
, &c
);
703 static int genl_family_rcv_msg_doit(const struct genl_family
*family
,
705 struct nlmsghdr
*nlh
,
706 struct netlink_ext_ack
*extack
,
707 const struct genl_ops
*ops
,
708 int hdrlen
, struct net
*net
)
710 struct nlattr
**attrbuf
;
711 struct genl_info info
;
717 attrbuf
= genl_family_rcv_msg_attrs_parse(family
, nlh
, extack
,
719 GENL_DONT_VALIDATE_STRICT
);
721 return PTR_ERR(attrbuf
);
723 info
.snd_seq
= nlh
->nlmsg_seq
;
724 info
.snd_portid
= NETLINK_CB(skb
).portid
;
726 info
.genlhdr
= nlmsg_data(nlh
);
727 info
.userhdr
= nlmsg_data(nlh
) + GENL_HDRLEN
;
728 info
.attrs
= attrbuf
;
729 info
.extack
= extack
;
730 genl_info_net_set(&info
, net
);
731 memset(&info
.user_ptr
, 0, sizeof(info
.user_ptr
));
733 if (family
->pre_doit
) {
734 err
= family
->pre_doit(ops
, skb
, &info
);
739 err
= ops
->doit(skb
, &info
);
741 if (family
->post_doit
)
742 family
->post_doit(ops
, skb
, &info
);
745 genl_family_rcv_msg_attrs_free(attrbuf
);
750 static int genl_family_rcv_msg(const struct genl_family
*family
,
752 struct nlmsghdr
*nlh
,
753 struct netlink_ext_ack
*extack
)
755 struct net
*net
= sock_net(skb
->sk
);
756 struct genlmsghdr
*hdr
= nlmsg_data(nlh
);
760 /* this family doesn't exist in this netns */
761 if (!family
->netnsok
&& !net_eq(net
, &init_net
))
764 hdrlen
= GENL_HDRLEN
+ family
->hdrsize
;
765 if (nlh
->nlmsg_len
< nlmsg_msg_size(hdrlen
))
768 if (genl_get_cmd(hdr
->cmd
, family
, &op
))
771 if ((op
.flags
& GENL_ADMIN_PERM
) &&
772 !netlink_capable(skb
, CAP_NET_ADMIN
))
775 if ((op
.flags
& GENL_UNS_ADMIN_PERM
) &&
776 !netlink_ns_capable(skb
, net
->user_ns
, CAP_NET_ADMIN
))
779 if ((nlh
->nlmsg_flags
& NLM_F_DUMP
) == NLM_F_DUMP
)
780 return genl_family_rcv_msg_dumpit(family
, skb
, nlh
, extack
,
783 return genl_family_rcv_msg_doit(family
, skb
, nlh
, extack
,
787 static int genl_rcv_msg(struct sk_buff
*skb
, struct nlmsghdr
*nlh
,
788 struct netlink_ext_ack
*extack
)
790 const struct genl_family
*family
;
793 family
= genl_family_find_byid(nlh
->nlmsg_type
);
797 if (!family
->parallel_ops
)
800 err
= genl_family_rcv_msg(family
, skb
, nlh
, extack
);
802 if (!family
->parallel_ops
)
808 static void genl_rcv(struct sk_buff
*skb
)
811 netlink_rcv_skb(skb
, &genl_rcv_msg
);
815 /**************************************************************************
817 **************************************************************************/
819 static struct genl_family genl_ctrl
;
821 static int ctrl_fill_info(const struct genl_family
*family
, u32 portid
, u32 seq
,
822 u32 flags
, struct sk_buff
*skb
, u8 cmd
)
826 hdr
= genlmsg_put(skb
, portid
, seq
, &genl_ctrl
, flags
, cmd
);
830 if (nla_put_string(skb
, CTRL_ATTR_FAMILY_NAME
, family
->name
) ||
831 nla_put_u16(skb
, CTRL_ATTR_FAMILY_ID
, family
->id
) ||
832 nla_put_u32(skb
, CTRL_ATTR_VERSION
, family
->version
) ||
833 nla_put_u32(skb
, CTRL_ATTR_HDRSIZE
, family
->hdrsize
) ||
834 nla_put_u32(skb
, CTRL_ATTR_MAXATTR
, family
->maxattr
))
835 goto nla_put_failure
;
837 if (genl_get_cmd_cnt(family
)) {
838 struct nlattr
*nla_ops
;
841 nla_ops
= nla_nest_start_noflag(skb
, CTRL_ATTR_OPS
);
843 goto nla_put_failure
;
845 for (i
= 0; i
< genl_get_cmd_cnt(family
); i
++) {
850 genl_get_cmd_by_index(i
, family
, &op
);
853 op_flags
|= GENL_CMD_CAP_DUMP
;
855 op_flags
|= GENL_CMD_CAP_DO
;
857 op_flags
|= GENL_CMD_CAP_HASPOL
;
859 nest
= nla_nest_start_noflag(skb
, i
+ 1);
861 goto nla_put_failure
;
863 if (nla_put_u32(skb
, CTRL_ATTR_OP_ID
, op
.cmd
) ||
864 nla_put_u32(skb
, CTRL_ATTR_OP_FLAGS
, op_flags
))
865 goto nla_put_failure
;
867 nla_nest_end(skb
, nest
);
870 nla_nest_end(skb
, nla_ops
);
873 if (family
->n_mcgrps
) {
874 struct nlattr
*nla_grps
;
877 nla_grps
= nla_nest_start_noflag(skb
, CTRL_ATTR_MCAST_GROUPS
);
878 if (nla_grps
== NULL
)
879 goto nla_put_failure
;
881 for (i
= 0; i
< family
->n_mcgrps
; i
++) {
883 const struct genl_multicast_group
*grp
;
885 grp
= &family
->mcgrps
[i
];
887 nest
= nla_nest_start_noflag(skb
, i
+ 1);
889 goto nla_put_failure
;
891 if (nla_put_u32(skb
, CTRL_ATTR_MCAST_GRP_ID
,
892 family
->mcgrp_offset
+ i
) ||
893 nla_put_string(skb
, CTRL_ATTR_MCAST_GRP_NAME
,
895 goto nla_put_failure
;
897 nla_nest_end(skb
, nest
);
899 nla_nest_end(skb
, nla_grps
);
902 genlmsg_end(skb
, hdr
);
906 genlmsg_cancel(skb
, hdr
);
910 static int ctrl_fill_mcgrp_info(const struct genl_family
*family
,
911 const struct genl_multicast_group
*grp
,
912 int grp_id
, u32 portid
, u32 seq
, u32 flags
,
913 struct sk_buff
*skb
, u8 cmd
)
916 struct nlattr
*nla_grps
;
919 hdr
= genlmsg_put(skb
, portid
, seq
, &genl_ctrl
, flags
, cmd
);
923 if (nla_put_string(skb
, CTRL_ATTR_FAMILY_NAME
, family
->name
) ||
924 nla_put_u16(skb
, CTRL_ATTR_FAMILY_ID
, family
->id
))
925 goto nla_put_failure
;
927 nla_grps
= nla_nest_start_noflag(skb
, CTRL_ATTR_MCAST_GROUPS
);
928 if (nla_grps
== NULL
)
929 goto nla_put_failure
;
931 nest
= nla_nest_start_noflag(skb
, 1);
933 goto nla_put_failure
;
935 if (nla_put_u32(skb
, CTRL_ATTR_MCAST_GRP_ID
, grp_id
) ||
936 nla_put_string(skb
, CTRL_ATTR_MCAST_GRP_NAME
,
938 goto nla_put_failure
;
940 nla_nest_end(skb
, nest
);
941 nla_nest_end(skb
, nla_grps
);
943 genlmsg_end(skb
, hdr
);
947 genlmsg_cancel(skb
, hdr
);
951 static int ctrl_dumpfamily(struct sk_buff
*skb
, struct netlink_callback
*cb
)
954 struct genl_family
*rt
;
955 struct net
*net
= sock_net(skb
->sk
);
956 int fams_to_skip
= cb
->args
[0];
959 idr_for_each_entry(&genl_fam_idr
, rt
, id
) {
960 if (!rt
->netnsok
&& !net_eq(net
, &init_net
))
963 if (n
++ < fams_to_skip
)
966 if (ctrl_fill_info(rt
, NETLINK_CB(cb
->skb
).portid
,
967 cb
->nlh
->nlmsg_seq
, NLM_F_MULTI
,
968 skb
, CTRL_CMD_NEWFAMILY
) < 0) {
978 static struct sk_buff
*ctrl_build_family_msg(const struct genl_family
*family
,
979 u32 portid
, int seq
, u8 cmd
)
984 skb
= nlmsg_new(NLMSG_DEFAULT_SIZE
, GFP_KERNEL
);
986 return ERR_PTR(-ENOBUFS
);
988 err
= ctrl_fill_info(family
, portid
, seq
, 0, skb
, cmd
);
997 static struct sk_buff
*
998 ctrl_build_mcgrp_msg(const struct genl_family
*family
,
999 const struct genl_multicast_group
*grp
,
1000 int grp_id
, u32 portid
, int seq
, u8 cmd
)
1002 struct sk_buff
*skb
;
1005 skb
= nlmsg_new(NLMSG_DEFAULT_SIZE
, GFP_KERNEL
);
1007 return ERR_PTR(-ENOBUFS
);
1009 err
= ctrl_fill_mcgrp_info(family
, grp
, grp_id
, portid
,
1013 return ERR_PTR(err
);
1019 static const struct nla_policy ctrl_policy_family
[] = {
1020 [CTRL_ATTR_FAMILY_ID
] = { .type
= NLA_U16
},
1021 [CTRL_ATTR_FAMILY_NAME
] = { .type
= NLA_NUL_STRING
,
1022 .len
= GENL_NAMSIZ
- 1 },
1025 static int ctrl_getfamily(struct sk_buff
*skb
, struct genl_info
*info
)
1027 struct sk_buff
*msg
;
1028 const struct genl_family
*res
= NULL
;
1031 if (info
->attrs
[CTRL_ATTR_FAMILY_ID
]) {
1032 u16 id
= nla_get_u16(info
->attrs
[CTRL_ATTR_FAMILY_ID
]);
1033 res
= genl_family_find_byid(id
);
1037 if (info
->attrs
[CTRL_ATTR_FAMILY_NAME
]) {
1040 name
= nla_data(info
->attrs
[CTRL_ATTR_FAMILY_NAME
]);
1041 res
= genl_family_find_byname(name
);
1042 #ifdef CONFIG_MODULES
1046 request_module("net-pf-%d-proto-%d-family-%s",
1047 PF_NETLINK
, NETLINK_GENERIC
, name
);
1048 down_read(&cb_lock
);
1050 res
= genl_family_find_byname(name
);
1059 if (!res
->netnsok
&& !net_eq(genl_info_net(info
), &init_net
)) {
1060 /* family doesn't exist here */
1064 msg
= ctrl_build_family_msg(res
, info
->snd_portid
, info
->snd_seq
,
1065 CTRL_CMD_NEWFAMILY
);
1067 return PTR_ERR(msg
);
1069 return genlmsg_reply(msg
, info
);
1072 static int genl_ctrl_event(int event
, const struct genl_family
*family
,
1073 const struct genl_multicast_group
*grp
,
1076 struct sk_buff
*msg
;
1078 /* genl is still initialising */
1079 if (!init_net
.genl_sock
)
1083 case CTRL_CMD_NEWFAMILY
:
1084 case CTRL_CMD_DELFAMILY
:
1086 msg
= ctrl_build_family_msg(family
, 0, 0, event
);
1088 case CTRL_CMD_NEWMCAST_GRP
:
1089 case CTRL_CMD_DELMCAST_GRP
:
1091 msg
= ctrl_build_mcgrp_msg(family
, grp
, grp_id
, 0, 0, event
);
1098 return PTR_ERR(msg
);
1100 if (!family
->netnsok
) {
1101 genlmsg_multicast_netns(&genl_ctrl
, &init_net
, msg
, 0,
1105 genlmsg_multicast_allns(&genl_ctrl
, msg
, 0,
1113 struct ctrl_dump_policy_ctx
{
1114 struct netlink_policy_dump_state
*state
;
1115 const struct genl_family
*rt
;
1123 static const struct nla_policy ctrl_policy_policy
[] = {
1124 [CTRL_ATTR_FAMILY_ID
] = { .type
= NLA_U16
},
1125 [CTRL_ATTR_FAMILY_NAME
] = { .type
= NLA_NUL_STRING
,
1126 .len
= GENL_NAMSIZ
- 1 },
1127 [CTRL_ATTR_OP
] = { .type
= NLA_U32
},
1130 static int ctrl_dumppolicy_start(struct netlink_callback
*cb
)
1132 const struct genl_dumpit_info
*info
= genl_dumpit_info(cb
);
1133 struct ctrl_dump_policy_ctx
*ctx
= (void *)cb
->ctx
;
1134 struct nlattr
**tb
= info
->attrs
;
1135 const struct genl_family
*rt
;
1139 BUILD_BUG_ON(sizeof(*ctx
) > sizeof(cb
->ctx
));
1141 if (!tb
[CTRL_ATTR_FAMILY_ID
] && !tb
[CTRL_ATTR_FAMILY_NAME
])
1144 if (tb
[CTRL_ATTR_FAMILY_ID
]) {
1145 ctx
->fam_id
= nla_get_u16(tb
[CTRL_ATTR_FAMILY_ID
]);
1147 rt
= genl_family_find_byname(
1148 nla_data(tb
[CTRL_ATTR_FAMILY_NAME
]));
1151 ctx
->fam_id
= rt
->id
;
1154 rt
= genl_family_find_byid(ctx
->fam_id
);
1160 if (tb
[CTRL_ATTR_OP
]) {
1161 ctx
->single_op
= true;
1162 ctx
->op
= nla_get_u32(tb
[CTRL_ATTR_OP
]);
1164 err
= genl_get_cmd(ctx
->op
, rt
, &op
);
1166 NL_SET_BAD_ATTR(cb
->extack
, tb
[CTRL_ATTR_OP
]);
1173 return netlink_policy_dump_add_policy(&ctx
->state
, op
.policy
,
1177 for (i
= 0; i
< genl_get_cmd_cnt(rt
); i
++) {
1178 genl_get_cmd_by_index(i
, rt
, &op
);
1181 err
= netlink_policy_dump_add_policy(&ctx
->state
,
1194 static void *ctrl_dumppolicy_prep(struct sk_buff
*skb
,
1195 struct netlink_callback
*cb
)
1197 struct ctrl_dump_policy_ctx
*ctx
= (void *)cb
->ctx
;
1200 hdr
= genlmsg_put(skb
, NETLINK_CB(cb
->skb
).portid
,
1201 cb
->nlh
->nlmsg_seq
, &genl_ctrl
,
1202 NLM_F_MULTI
, CTRL_CMD_GETPOLICY
);
1206 if (nla_put_u16(skb
, CTRL_ATTR_FAMILY_ID
, ctx
->fam_id
))
1212 static int ctrl_dumppolicy_put_op(struct sk_buff
*skb
,
1213 struct netlink_callback
*cb
,
1214 struct genl_ops
*op
)
1216 struct ctrl_dump_policy_ctx
*ctx
= (void *)cb
->ctx
;
1217 struct nlattr
*nest_pol
, *nest_op
;
1221 /* skip if we have nothing to show */
1225 (!op
->dumpit
|| op
->validate
& GENL_DONT_VALIDATE_DUMP
))
1228 hdr
= ctrl_dumppolicy_prep(skb
, cb
);
1232 nest_pol
= nla_nest_start(skb
, CTRL_ATTR_OP_POLICY
);
1236 nest_op
= nla_nest_start(skb
, op
->cmd
);
1240 /* for now both do/dump are always the same */
1241 idx
= netlink_policy_dump_get_policy_idx(ctx
->state
,
1245 if (op
->doit
&& nla_put_u32(skb
, CTRL_ATTR_POLICY_DO
, idx
))
1248 if (op
->dumpit
&& !(op
->validate
& GENL_DONT_VALIDATE_DUMP
) &&
1249 nla_put_u32(skb
, CTRL_ATTR_POLICY_DUMP
, idx
))
1252 nla_nest_end(skb
, nest_op
);
1253 nla_nest_end(skb
, nest_pol
);
1254 genlmsg_end(skb
, hdr
);
1258 genlmsg_cancel(skb
, hdr
);
1262 static int ctrl_dumppolicy(struct sk_buff
*skb
, struct netlink_callback
*cb
)
1264 struct ctrl_dump_policy_ctx
*ctx
= (void *)cb
->ctx
;
1267 if (!ctx
->policies
) {
1268 while (ctx
->opidx
< genl_get_cmd_cnt(ctx
->rt
)) {
1271 if (ctx
->single_op
) {
1274 err
= genl_get_cmd(ctx
->op
, ctx
->rt
, &op
);
1278 /* break out of the loop after this one */
1279 ctx
->opidx
= genl_get_cmd_cnt(ctx
->rt
);
1281 genl_get_cmd_by_index(ctx
->opidx
, ctx
->rt
, &op
);
1284 if (ctrl_dumppolicy_put_op(skb
, cb
, &op
))
1290 /* completed with the per-op policy index list */
1291 ctx
->policies
= true;
1294 while (netlink_policy_dump_loop(ctx
->state
)) {
1295 struct nlattr
*nest
;
1297 hdr
= ctrl_dumppolicy_prep(skb
, cb
);
1299 goto nla_put_failure
;
1301 nest
= nla_nest_start(skb
, CTRL_ATTR_POLICY
);
1303 goto nla_put_failure
;
1305 if (netlink_policy_dump_write(skb
, ctx
->state
))
1306 goto nla_put_failure
;
1308 nla_nest_end(skb
, nest
);
1310 genlmsg_end(skb
, hdr
);
1316 genlmsg_cancel(skb
, hdr
);
1320 static int ctrl_dumppolicy_done(struct netlink_callback
*cb
)
1322 struct ctrl_dump_policy_ctx
*ctx
= (void *)cb
->ctx
;
1324 netlink_policy_dump_free(ctx
->state
);
1328 static const struct genl_ops genl_ctrl_ops
[] = {
1330 .cmd
= CTRL_CMD_GETFAMILY
,
1331 .validate
= GENL_DONT_VALIDATE_STRICT
| GENL_DONT_VALIDATE_DUMP
,
1332 .policy
= ctrl_policy_family
,
1333 .maxattr
= ARRAY_SIZE(ctrl_policy_family
) - 1,
1334 .doit
= ctrl_getfamily
,
1335 .dumpit
= ctrl_dumpfamily
,
1338 .cmd
= CTRL_CMD_GETPOLICY
,
1339 .policy
= ctrl_policy_policy
,
1340 .maxattr
= ARRAY_SIZE(ctrl_policy_policy
) - 1,
1341 .start
= ctrl_dumppolicy_start
,
1342 .dumpit
= ctrl_dumppolicy
,
1343 .done
= ctrl_dumppolicy_done
,
1347 static const struct genl_multicast_group genl_ctrl_groups
[] = {
1348 { .name
= "notify", },
1351 static struct genl_family genl_ctrl __ro_after_init
= {
1352 .module
= THIS_MODULE
,
1353 .ops
= genl_ctrl_ops
,
1354 .n_ops
= ARRAY_SIZE(genl_ctrl_ops
),
1355 .mcgrps
= genl_ctrl_groups
,
1356 .n_mcgrps
= ARRAY_SIZE(genl_ctrl_groups
),
1363 static int __net_init
genl_pernet_init(struct net
*net
)
1365 struct netlink_kernel_cfg cfg
= {
1367 .flags
= NL_CFG_F_NONROOT_RECV
,
1370 /* we'll bump the group number right afterwards */
1371 net
->genl_sock
= netlink_kernel_create(net
, NETLINK_GENERIC
, &cfg
);
1373 if (!net
->genl_sock
&& net_eq(net
, &init_net
))
1374 panic("GENL: Cannot initialize generic netlink\n");
1376 if (!net
->genl_sock
)
1382 static void __net_exit
genl_pernet_exit(struct net
*net
)
1384 netlink_kernel_release(net
->genl_sock
);
1385 net
->genl_sock
= NULL
;
1388 static struct pernet_operations genl_pernet_ops
= {
1389 .init
= genl_pernet_init
,
1390 .exit
= genl_pernet_exit
,
1393 static int __init
genl_init(void)
1397 err
= genl_register_family(&genl_ctrl
);
1401 err
= register_pernet_subsys(&genl_pernet_ops
);
1408 panic("GENL: Cannot register controller: %d\n", err
);
1411 core_initcall(genl_init
);
1413 static int genlmsg_mcast(struct sk_buff
*skb
, u32 portid
, unsigned long group
,
1416 struct sk_buff
*tmp
;
1417 struct net
*net
, *prev
= NULL
;
1418 bool delivered
= false;
1421 for_each_net_rcu(net
) {
1423 tmp
= skb_clone(skb
, flags
);
1428 err
= nlmsg_multicast(prev
->genl_sock
, tmp
,
1429 portid
, group
, flags
);
1432 else if (err
!= -ESRCH
)
1439 err
= nlmsg_multicast(prev
->genl_sock
, skb
, portid
, group
, flags
);
1442 else if (err
!= -ESRCH
)
1444 return delivered
? 0 : -ESRCH
;
1450 int genlmsg_multicast_allns(const struct genl_family
*family
,
1451 struct sk_buff
*skb
, u32 portid
,
1452 unsigned int group
, gfp_t flags
)
1454 if (WARN_ON_ONCE(group
>= family
->n_mcgrps
))
1456 group
= family
->mcgrp_offset
+ group
;
1457 return genlmsg_mcast(skb
, portid
, group
, flags
);
1459 EXPORT_SYMBOL(genlmsg_multicast_allns
);
1461 void genl_notify(const struct genl_family
*family
, struct sk_buff
*skb
,
1462 struct genl_info
*info
, u32 group
, gfp_t flags
)
1464 struct net
*net
= genl_info_net(info
);
1465 struct sock
*sk
= net
->genl_sock
;
1469 report
= nlmsg_report(info
->nlhdr
);
1471 if (WARN_ON_ONCE(group
>= family
->n_mcgrps
))
1473 group
= family
->mcgrp_offset
+ group
;
1474 nlmsg_notify(sk
, skb
, info
->snd_portid
, group
, report
, flags
);
1476 EXPORT_SYMBOL(genl_notify
);