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![Michal Kubecek](/assets/img/avatar_default.png)
Unlike do requests, dump genetlink requests now perform strict validation
by default even if the genetlink family does not set policy and maxtype
because it does validation and parsing on its own (e.g. because it wants to
allow different message format for different commands). While the null
policy will be ignored, maxtype (which would be zero) is still checked so
that any attribute will fail validation.
The solution is to only call __nla_validate() from genl_family_rcv_msg()
if family->maxtype is set.
Fixes: ef6243acb4
("genetlink: optionally validate strictly/dumps")
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
1173 lines
26 KiB
C
1173 lines
26 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* NETLINK Generic Netlink Family
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*
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* Authors: Jamal Hadi Salim
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* Thomas Graf <tgraf@suug.ch>
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* Johannes Berg <johannes@sipsolutions.net>
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/socket.h>
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#include <linux/string.h>
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#include <linux/skbuff.h>
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#include <linux/mutex.h>
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#include <linux/bitmap.h>
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#include <linux/rwsem.h>
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#include <linux/idr.h>
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#include <net/sock.h>
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#include <net/genetlink.h>
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static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
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static DECLARE_RWSEM(cb_lock);
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atomic_t genl_sk_destructing_cnt = ATOMIC_INIT(0);
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DECLARE_WAIT_QUEUE_HEAD(genl_sk_destructing_waitq);
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void genl_lock(void)
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{
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mutex_lock(&genl_mutex);
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}
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EXPORT_SYMBOL(genl_lock);
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void genl_unlock(void)
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{
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mutex_unlock(&genl_mutex);
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}
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EXPORT_SYMBOL(genl_unlock);
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#ifdef CONFIG_LOCKDEP
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bool lockdep_genl_is_held(void)
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{
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return lockdep_is_held(&genl_mutex);
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}
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EXPORT_SYMBOL(lockdep_genl_is_held);
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#endif
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static void genl_lock_all(void)
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{
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down_write(&cb_lock);
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genl_lock();
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}
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static void genl_unlock_all(void)
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{
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genl_unlock();
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up_write(&cb_lock);
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}
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static DEFINE_IDR(genl_fam_idr);
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/*
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* Bitmap of multicast groups that are currently in use.
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*
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* To avoid an allocation at boot of just one unsigned long,
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* declare it global instead.
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* Bit 0 is marked as already used since group 0 is invalid.
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* Bit 1 is marked as already used since the drop-monitor code
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* abuses the API and thinks it can statically use group 1.
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* That group will typically conflict with other groups that
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* any proper users use.
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* Bit 16 is marked as used since it's used for generic netlink
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* and the code no longer marks pre-reserved IDs as used.
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* Bit 17 is marked as already used since the VFS quota code
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* also abused this API and relied on family == group ID, we
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* cater to that by giving it a static family and group ID.
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* Bit 18 is marked as already used since the PMCRAID driver
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* did the same thing as the VFS quota code (maybe copied?)
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*/
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static unsigned long mc_group_start = 0x3 | BIT(GENL_ID_CTRL) |
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BIT(GENL_ID_VFS_DQUOT) |
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BIT(GENL_ID_PMCRAID);
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static unsigned long *mc_groups = &mc_group_start;
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static unsigned long mc_groups_longs = 1;
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static int genl_ctrl_event(int event, const struct genl_family *family,
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const struct genl_multicast_group *grp,
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int grp_id);
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static const struct genl_family *genl_family_find_byid(unsigned int id)
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{
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return idr_find(&genl_fam_idr, id);
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}
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static const struct genl_family *genl_family_find_byname(char *name)
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{
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const struct genl_family *family;
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unsigned int id;
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idr_for_each_entry(&genl_fam_idr, family, id)
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if (strcmp(family->name, name) == 0)
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return family;
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return NULL;
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}
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static const struct genl_ops *genl_get_cmd(u8 cmd,
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const struct genl_family *family)
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{
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int i;
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for (i = 0; i < family->n_ops; i++)
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if (family->ops[i].cmd == cmd)
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return &family->ops[i];
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return NULL;
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}
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static int genl_allocate_reserve_groups(int n_groups, int *first_id)
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{
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unsigned long *new_groups;
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int start = 0;
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int i;
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int id;
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bool fits;
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do {
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if (start == 0)
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id = find_first_zero_bit(mc_groups,
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mc_groups_longs *
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BITS_PER_LONG);
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else
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id = find_next_zero_bit(mc_groups,
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mc_groups_longs * BITS_PER_LONG,
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start);
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fits = true;
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for (i = id;
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i < min_t(int, id + n_groups,
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mc_groups_longs * BITS_PER_LONG);
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i++) {
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if (test_bit(i, mc_groups)) {
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start = i;
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fits = false;
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break;
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}
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}
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if (id + n_groups > mc_groups_longs * BITS_PER_LONG) {
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unsigned long new_longs = mc_groups_longs +
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BITS_TO_LONGS(n_groups);
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size_t nlen = new_longs * sizeof(unsigned long);
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if (mc_groups == &mc_group_start) {
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new_groups = kzalloc(nlen, GFP_KERNEL);
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if (!new_groups)
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return -ENOMEM;
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mc_groups = new_groups;
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*mc_groups = mc_group_start;
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} else {
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new_groups = krealloc(mc_groups, nlen,
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GFP_KERNEL);
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if (!new_groups)
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return -ENOMEM;
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mc_groups = new_groups;
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for (i = 0; i < BITS_TO_LONGS(n_groups); i++)
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mc_groups[mc_groups_longs + i] = 0;
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}
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mc_groups_longs = new_longs;
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}
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} while (!fits);
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for (i = id; i < id + n_groups; i++)
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set_bit(i, mc_groups);
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*first_id = id;
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return 0;
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}
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static struct genl_family genl_ctrl;
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static int genl_validate_assign_mc_groups(struct genl_family *family)
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{
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int first_id;
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int n_groups = family->n_mcgrps;
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int err = 0, i;
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bool groups_allocated = false;
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if (!n_groups)
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return 0;
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for (i = 0; i < n_groups; i++) {
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const struct genl_multicast_group *grp = &family->mcgrps[i];
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if (WARN_ON(grp->name[0] == '\0'))
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return -EINVAL;
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if (WARN_ON(memchr(grp->name, '\0', GENL_NAMSIZ) == NULL))
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return -EINVAL;
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}
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/* special-case our own group and hacks */
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if (family == &genl_ctrl) {
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first_id = GENL_ID_CTRL;
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BUG_ON(n_groups != 1);
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} else if (strcmp(family->name, "NET_DM") == 0) {
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first_id = 1;
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BUG_ON(n_groups != 1);
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} else if (family->id == GENL_ID_VFS_DQUOT) {
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first_id = GENL_ID_VFS_DQUOT;
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BUG_ON(n_groups != 1);
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} else if (family->id == GENL_ID_PMCRAID) {
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first_id = GENL_ID_PMCRAID;
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BUG_ON(n_groups != 1);
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} else {
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groups_allocated = true;
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err = genl_allocate_reserve_groups(n_groups, &first_id);
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if (err)
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return err;
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}
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family->mcgrp_offset = first_id;
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/* if still initializing, can't and don't need to to realloc bitmaps */
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if (!init_net.genl_sock)
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return 0;
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if (family->netnsok) {
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struct net *net;
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netlink_table_grab();
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rcu_read_lock();
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for_each_net_rcu(net) {
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err = __netlink_change_ngroups(net->genl_sock,
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mc_groups_longs * BITS_PER_LONG);
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if (err) {
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/*
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* No need to roll back, can only fail if
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* memory allocation fails and then the
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* number of _possible_ groups has been
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* increased on some sockets which is ok.
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*/
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break;
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}
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}
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rcu_read_unlock();
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netlink_table_ungrab();
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} else {
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err = netlink_change_ngroups(init_net.genl_sock,
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mc_groups_longs * BITS_PER_LONG);
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}
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if (groups_allocated && err) {
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for (i = 0; i < family->n_mcgrps; i++)
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clear_bit(family->mcgrp_offset + i, mc_groups);
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}
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return err;
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}
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static void genl_unregister_mc_groups(const struct genl_family *family)
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{
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struct net *net;
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int i;
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netlink_table_grab();
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rcu_read_lock();
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for_each_net_rcu(net) {
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for (i = 0; i < family->n_mcgrps; i++)
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__netlink_clear_multicast_users(
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net->genl_sock, family->mcgrp_offset + i);
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}
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rcu_read_unlock();
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netlink_table_ungrab();
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for (i = 0; i < family->n_mcgrps; i++) {
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int grp_id = family->mcgrp_offset + i;
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if (grp_id != 1)
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clear_bit(grp_id, mc_groups);
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genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, family,
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&family->mcgrps[i], grp_id);
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}
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}
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static int genl_validate_ops(const struct genl_family *family)
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{
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const struct genl_ops *ops = family->ops;
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unsigned int n_ops = family->n_ops;
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int i, j;
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if (WARN_ON(n_ops && !ops))
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return -EINVAL;
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if (!n_ops)
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return 0;
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for (i = 0; i < n_ops; i++) {
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if (ops[i].dumpit == NULL && ops[i].doit == NULL)
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return -EINVAL;
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for (j = i + 1; j < n_ops; j++)
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if (ops[i].cmd == ops[j].cmd)
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return -EINVAL;
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}
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return 0;
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}
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/**
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* genl_register_family - register a generic netlink family
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* @family: generic netlink family
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*
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* Registers the specified family after validating it first. Only one
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* family may be registered with the same family name or identifier.
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*
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* The family's ops, multicast groups and module pointer must already
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* be assigned.
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*
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* Return 0 on success or a negative error code.
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*/
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int genl_register_family(struct genl_family *family)
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{
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int err, i;
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int start = GENL_START_ALLOC, end = GENL_MAX_ID;
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err = genl_validate_ops(family);
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if (err)
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return err;
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genl_lock_all();
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if (genl_family_find_byname(family->name)) {
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err = -EEXIST;
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goto errout_locked;
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}
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/*
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* Sadly, a few cases need to be special-cased
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* due to them having previously abused the API
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* and having used their family ID also as their
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* multicast group ID, so we use reserved IDs
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* for both to be sure we can do that mapping.
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*/
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if (family == &genl_ctrl) {
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/* and this needs to be special for initial family lookups */
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start = end = GENL_ID_CTRL;
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} else if (strcmp(family->name, "pmcraid") == 0) {
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start = end = GENL_ID_PMCRAID;
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} else if (strcmp(family->name, "VFS_DQUOT") == 0) {
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start = end = GENL_ID_VFS_DQUOT;
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}
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if (family->maxattr && !family->parallel_ops) {
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family->attrbuf = kmalloc_array(family->maxattr + 1,
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sizeof(struct nlattr *),
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GFP_KERNEL);
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if (family->attrbuf == NULL) {
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err = -ENOMEM;
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goto errout_locked;
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}
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} else
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family->attrbuf = NULL;
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family->id = idr_alloc_cyclic(&genl_fam_idr, family,
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start, end + 1, GFP_KERNEL);
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if (family->id < 0) {
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err = family->id;
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goto errout_free;
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}
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err = genl_validate_assign_mc_groups(family);
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if (err)
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goto errout_remove;
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genl_unlock_all();
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/* send all events */
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genl_ctrl_event(CTRL_CMD_NEWFAMILY, family, NULL, 0);
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for (i = 0; i < family->n_mcgrps; i++)
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genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, family,
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&family->mcgrps[i], family->mcgrp_offset + i);
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return 0;
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errout_remove:
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idr_remove(&genl_fam_idr, family->id);
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errout_free:
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kfree(family->attrbuf);
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errout_locked:
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genl_unlock_all();
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return err;
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}
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EXPORT_SYMBOL(genl_register_family);
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/**
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* genl_unregister_family - unregister generic netlink family
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* @family: generic netlink family
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*
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* Unregisters the specified family.
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*
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* Returns 0 on success or a negative error code.
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*/
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int genl_unregister_family(const struct genl_family *family)
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{
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genl_lock_all();
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if (!genl_family_find_byid(family->id)) {
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genl_unlock_all();
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return -ENOENT;
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}
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genl_unregister_mc_groups(family);
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idr_remove(&genl_fam_idr, family->id);
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up_write(&cb_lock);
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wait_event(genl_sk_destructing_waitq,
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atomic_read(&genl_sk_destructing_cnt) == 0);
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genl_unlock();
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kfree(family->attrbuf);
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genl_ctrl_event(CTRL_CMD_DELFAMILY, family, NULL, 0);
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return 0;
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}
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EXPORT_SYMBOL(genl_unregister_family);
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|
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/**
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* genlmsg_put - Add generic netlink header to netlink message
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* @skb: socket buffer holding the message
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* @portid: netlink portid the message is addressed to
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* @seq: sequence number (usually the one of the sender)
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* @family: generic netlink family
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* @flags: netlink message flags
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* @cmd: generic netlink command
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*
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* Returns pointer to user specific header
|
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*/
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void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
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const struct genl_family *family, int flags, u8 cmd)
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{
|
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struct nlmsghdr *nlh;
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struct genlmsghdr *hdr;
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nlh = nlmsg_put(skb, portid, seq, family->id, GENL_HDRLEN +
|
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family->hdrsize, flags);
|
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if (nlh == NULL)
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return NULL;
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hdr = nlmsg_data(nlh);
|
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hdr->cmd = cmd;
|
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hdr->version = family->version;
|
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hdr->reserved = 0;
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|
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return (char *) hdr + GENL_HDRLEN;
|
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}
|
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EXPORT_SYMBOL(genlmsg_put);
|
|
|
|
static int genl_lock_start(struct netlink_callback *cb)
|
|
{
|
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/* our ops are always const - netlink API doesn't propagate that */
|
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const struct genl_ops *ops = cb->data;
|
|
int rc = 0;
|
|
|
|
if (ops->start) {
|
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genl_lock();
|
|
rc = ops->start(cb);
|
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genl_unlock();
|
|
}
|
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return rc;
|
|
}
|
|
|
|
static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
|
|
{
|
|
/* our ops are always const - netlink API doesn't propagate that */
|
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const struct genl_ops *ops = cb->data;
|
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int rc;
|
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|
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genl_lock();
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rc = ops->dumpit(skb, cb);
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genl_unlock();
|
|
return rc;
|
|
}
|
|
|
|
static int genl_lock_done(struct netlink_callback *cb)
|
|
{
|
|
/* our ops are always const - netlink API doesn't propagate that */
|
|
const struct genl_ops *ops = cb->data;
|
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int rc = 0;
|
|
|
|
if (ops->done) {
|
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genl_lock();
|
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rc = ops->done(cb);
|
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genl_unlock();
|
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}
|
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return rc;
|
|
}
|
|
|
|
static int genl_family_rcv_msg(const struct genl_family *family,
|
|
struct sk_buff *skb,
|
|
struct nlmsghdr *nlh,
|
|
struct netlink_ext_ack *extack)
|
|
{
|
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const struct genl_ops *ops;
|
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struct net *net = sock_net(skb->sk);
|
|
struct genl_info info;
|
|
struct genlmsghdr *hdr = nlmsg_data(nlh);
|
|
struct nlattr **attrbuf;
|
|
int hdrlen, err;
|
|
|
|
/* this family doesn't exist in this netns */
|
|
if (!family->netnsok && !net_eq(net, &init_net))
|
|
return -ENOENT;
|
|
|
|
hdrlen = GENL_HDRLEN + family->hdrsize;
|
|
if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
|
|
return -EINVAL;
|
|
|
|
ops = genl_get_cmd(hdr->cmd, family);
|
|
if (ops == NULL)
|
|
return -EOPNOTSUPP;
|
|
|
|
if ((ops->flags & GENL_ADMIN_PERM) &&
|
|
!netlink_capable(skb, CAP_NET_ADMIN))
|
|
return -EPERM;
|
|
|
|
if ((ops->flags & GENL_UNS_ADMIN_PERM) &&
|
|
!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
|
|
return -EPERM;
|
|
|
|
if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {
|
|
int rc;
|
|
|
|
if (ops->dumpit == NULL)
|
|
return -EOPNOTSUPP;
|
|
|
|
if (!(ops->validate & GENL_DONT_VALIDATE_DUMP)) {
|
|
int hdrlen = GENL_HDRLEN + family->hdrsize;
|
|
|
|
if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
|
|
return -EINVAL;
|
|
|
|
if (family->maxattr) {
|
|
unsigned int validate = NL_VALIDATE_STRICT;
|
|
|
|
if (ops->validate &
|
|
GENL_DONT_VALIDATE_DUMP_STRICT)
|
|
validate = NL_VALIDATE_LIBERAL;
|
|
rc = __nla_validate(nlmsg_attrdata(nlh, hdrlen),
|
|
nlmsg_attrlen(nlh, hdrlen),
|
|
family->maxattr,
|
|
family->policy,
|
|
validate, extack);
|
|
if (rc)
|
|
return rc;
|
|
}
|
|
}
|
|
|
|
if (!family->parallel_ops) {
|
|
struct netlink_dump_control c = {
|
|
.module = family->module,
|
|
/* we have const, but the netlink API doesn't */
|
|
.data = (void *)ops,
|
|
.start = genl_lock_start,
|
|
.dump = genl_lock_dumpit,
|
|
.done = genl_lock_done,
|
|
};
|
|
|
|
genl_unlock();
|
|
rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c);
|
|
genl_lock();
|
|
|
|
} else {
|
|
struct netlink_dump_control c = {
|
|
.module = family->module,
|
|
.start = ops->start,
|
|
.dump = ops->dumpit,
|
|
.done = ops->done,
|
|
};
|
|
|
|
rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c);
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
if (ops->doit == NULL)
|
|
return -EOPNOTSUPP;
|
|
|
|
if (family->maxattr && family->parallel_ops) {
|
|
attrbuf = kmalloc_array(family->maxattr + 1,
|
|
sizeof(struct nlattr *),
|
|
GFP_KERNEL);
|
|
if (attrbuf == NULL)
|
|
return -ENOMEM;
|
|
} else
|
|
attrbuf = family->attrbuf;
|
|
|
|
if (attrbuf) {
|
|
enum netlink_validation validate = NL_VALIDATE_STRICT;
|
|
|
|
if (ops->validate & GENL_DONT_VALIDATE_STRICT)
|
|
validate = NL_VALIDATE_LIBERAL;
|
|
|
|
err = __nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr,
|
|
family->policy, validate, extack);
|
|
if (err < 0)
|
|
goto out;
|
|
}
|
|
|
|
info.snd_seq = nlh->nlmsg_seq;
|
|
info.snd_portid = NETLINK_CB(skb).portid;
|
|
info.nlhdr = nlh;
|
|
info.genlhdr = nlmsg_data(nlh);
|
|
info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
|
|
info.attrs = attrbuf;
|
|
info.extack = extack;
|
|
genl_info_net_set(&info, net);
|
|
memset(&info.user_ptr, 0, sizeof(info.user_ptr));
|
|
|
|
if (family->pre_doit) {
|
|
err = family->pre_doit(ops, skb, &info);
|
|
if (err)
|
|
goto out;
|
|
}
|
|
|
|
err = ops->doit(skb, &info);
|
|
|
|
if (family->post_doit)
|
|
family->post_doit(ops, skb, &info);
|
|
|
|
out:
|
|
if (family->parallel_ops)
|
|
kfree(attrbuf);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
|
|
struct netlink_ext_ack *extack)
|
|
{
|
|
const struct genl_family *family;
|
|
int err;
|
|
|
|
family = genl_family_find_byid(nlh->nlmsg_type);
|
|
if (family == NULL)
|
|
return -ENOENT;
|
|
|
|
if (!family->parallel_ops)
|
|
genl_lock();
|
|
|
|
err = genl_family_rcv_msg(family, skb, nlh, extack);
|
|
|
|
if (!family->parallel_ops)
|
|
genl_unlock();
|
|
|
|
return err;
|
|
}
|
|
|
|
static void genl_rcv(struct sk_buff *skb)
|
|
{
|
|
down_read(&cb_lock);
|
|
netlink_rcv_skb(skb, &genl_rcv_msg);
|
|
up_read(&cb_lock);
|
|
}
|
|
|
|
/**************************************************************************
|
|
* Controller
|
|
**************************************************************************/
|
|
|
|
static struct genl_family genl_ctrl;
|
|
|
|
static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq,
|
|
u32 flags, struct sk_buff *skb, u8 cmd)
|
|
{
|
|
void *hdr;
|
|
|
|
hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
|
|
if (hdr == NULL)
|
|
return -1;
|
|
|
|
if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
|
|
nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id) ||
|
|
nla_put_u32(skb, CTRL_ATTR_VERSION, family->version) ||
|
|
nla_put_u32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize) ||
|
|
nla_put_u32(skb, CTRL_ATTR_MAXATTR, family->maxattr))
|
|
goto nla_put_failure;
|
|
|
|
if (family->n_ops) {
|
|
struct nlattr *nla_ops;
|
|
int i;
|
|
|
|
nla_ops = nla_nest_start_noflag(skb, CTRL_ATTR_OPS);
|
|
if (nla_ops == NULL)
|
|
goto nla_put_failure;
|
|
|
|
for (i = 0; i < family->n_ops; i++) {
|
|
struct nlattr *nest;
|
|
const struct genl_ops *ops = &family->ops[i];
|
|
u32 op_flags = ops->flags;
|
|
|
|
if (ops->dumpit)
|
|
op_flags |= GENL_CMD_CAP_DUMP;
|
|
if (ops->doit)
|
|
op_flags |= GENL_CMD_CAP_DO;
|
|
if (family->policy)
|
|
op_flags |= GENL_CMD_CAP_HASPOL;
|
|
|
|
nest = nla_nest_start_noflag(skb, i + 1);
|
|
if (nest == NULL)
|
|
goto nla_put_failure;
|
|
|
|
if (nla_put_u32(skb, CTRL_ATTR_OP_ID, ops->cmd) ||
|
|
nla_put_u32(skb, CTRL_ATTR_OP_FLAGS, op_flags))
|
|
goto nla_put_failure;
|
|
|
|
nla_nest_end(skb, nest);
|
|
}
|
|
|
|
nla_nest_end(skb, nla_ops);
|
|
}
|
|
|
|
if (family->n_mcgrps) {
|
|
struct nlattr *nla_grps;
|
|
int i;
|
|
|
|
nla_grps = nla_nest_start_noflag(skb, CTRL_ATTR_MCAST_GROUPS);
|
|
if (nla_grps == NULL)
|
|
goto nla_put_failure;
|
|
|
|
for (i = 0; i < family->n_mcgrps; i++) {
|
|
struct nlattr *nest;
|
|
const struct genl_multicast_group *grp;
|
|
|
|
grp = &family->mcgrps[i];
|
|
|
|
nest = nla_nest_start_noflag(skb, i + 1);
|
|
if (nest == NULL)
|
|
goto nla_put_failure;
|
|
|
|
if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID,
|
|
family->mcgrp_offset + i) ||
|
|
nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
|
|
grp->name))
|
|
goto nla_put_failure;
|
|
|
|
nla_nest_end(skb, nest);
|
|
}
|
|
nla_nest_end(skb, nla_grps);
|
|
}
|
|
|
|
genlmsg_end(skb, hdr);
|
|
return 0;
|
|
|
|
nla_put_failure:
|
|
genlmsg_cancel(skb, hdr);
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
static int ctrl_fill_mcgrp_info(const struct genl_family *family,
|
|
const struct genl_multicast_group *grp,
|
|
int grp_id, u32 portid, u32 seq, u32 flags,
|
|
struct sk_buff *skb, u8 cmd)
|
|
{
|
|
void *hdr;
|
|
struct nlattr *nla_grps;
|
|
struct nlattr *nest;
|
|
|
|
hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
|
|
if (hdr == NULL)
|
|
return -1;
|
|
|
|
if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
|
|
nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id))
|
|
goto nla_put_failure;
|
|
|
|
nla_grps = nla_nest_start_noflag(skb, CTRL_ATTR_MCAST_GROUPS);
|
|
if (nla_grps == NULL)
|
|
goto nla_put_failure;
|
|
|
|
nest = nla_nest_start_noflag(skb, 1);
|
|
if (nest == NULL)
|
|
goto nla_put_failure;
|
|
|
|
if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID, grp_id) ||
|
|
nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
|
|
grp->name))
|
|
goto nla_put_failure;
|
|
|
|
nla_nest_end(skb, nest);
|
|
nla_nest_end(skb, nla_grps);
|
|
|
|
genlmsg_end(skb, hdr);
|
|
return 0;
|
|
|
|
nla_put_failure:
|
|
genlmsg_cancel(skb, hdr);
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
|
|
{
|
|
int n = 0;
|
|
struct genl_family *rt;
|
|
struct net *net = sock_net(skb->sk);
|
|
int fams_to_skip = cb->args[0];
|
|
unsigned int id;
|
|
|
|
idr_for_each_entry(&genl_fam_idr, rt, id) {
|
|
if (!rt->netnsok && !net_eq(net, &init_net))
|
|
continue;
|
|
|
|
if (n++ < fams_to_skip)
|
|
continue;
|
|
|
|
if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).portid,
|
|
cb->nlh->nlmsg_seq, NLM_F_MULTI,
|
|
skb, CTRL_CMD_NEWFAMILY) < 0) {
|
|
n--;
|
|
break;
|
|
}
|
|
}
|
|
|
|
cb->args[0] = n;
|
|
return skb->len;
|
|
}
|
|
|
|
static struct sk_buff *ctrl_build_family_msg(const struct genl_family *family,
|
|
u32 portid, int seq, u8 cmd)
|
|
{
|
|
struct sk_buff *skb;
|
|
int err;
|
|
|
|
skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
|
|
if (skb == NULL)
|
|
return ERR_PTR(-ENOBUFS);
|
|
|
|
err = ctrl_fill_info(family, portid, seq, 0, skb, cmd);
|
|
if (err < 0) {
|
|
nlmsg_free(skb);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
return skb;
|
|
}
|
|
|
|
static struct sk_buff *
|
|
ctrl_build_mcgrp_msg(const struct genl_family *family,
|
|
const struct genl_multicast_group *grp,
|
|
int grp_id, u32 portid, int seq, u8 cmd)
|
|
{
|
|
struct sk_buff *skb;
|
|
int err;
|
|
|
|
skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
|
|
if (skb == NULL)
|
|
return ERR_PTR(-ENOBUFS);
|
|
|
|
err = ctrl_fill_mcgrp_info(family, grp, grp_id, portid,
|
|
seq, 0, skb, cmd);
|
|
if (err < 0) {
|
|
nlmsg_free(skb);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
return skb;
|
|
}
|
|
|
|
static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = {
|
|
[CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 },
|
|
[CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING,
|
|
.len = GENL_NAMSIZ - 1 },
|
|
};
|
|
|
|
static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
|
|
{
|
|
struct sk_buff *msg;
|
|
const struct genl_family *res = NULL;
|
|
int err = -EINVAL;
|
|
|
|
if (info->attrs[CTRL_ATTR_FAMILY_ID]) {
|
|
u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]);
|
|
res = genl_family_find_byid(id);
|
|
err = -ENOENT;
|
|
}
|
|
|
|
if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
|
|
char *name;
|
|
|
|
name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
|
|
res = genl_family_find_byname(name);
|
|
#ifdef CONFIG_MODULES
|
|
if (res == NULL) {
|
|
genl_unlock();
|
|
up_read(&cb_lock);
|
|
request_module("net-pf-%d-proto-%d-family-%s",
|
|
PF_NETLINK, NETLINK_GENERIC, name);
|
|
down_read(&cb_lock);
|
|
genl_lock();
|
|
res = genl_family_find_byname(name);
|
|
}
|
|
#endif
|
|
err = -ENOENT;
|
|
}
|
|
|
|
if (res == NULL)
|
|
return err;
|
|
|
|
if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) {
|
|
/* family doesn't exist here */
|
|
return -ENOENT;
|
|
}
|
|
|
|
msg = ctrl_build_family_msg(res, info->snd_portid, info->snd_seq,
|
|
CTRL_CMD_NEWFAMILY);
|
|
if (IS_ERR(msg))
|
|
return PTR_ERR(msg);
|
|
|
|
return genlmsg_reply(msg, info);
|
|
}
|
|
|
|
static int genl_ctrl_event(int event, const struct genl_family *family,
|
|
const struct genl_multicast_group *grp,
|
|
int grp_id)
|
|
{
|
|
struct sk_buff *msg;
|
|
|
|
/* genl is still initialising */
|
|
if (!init_net.genl_sock)
|
|
return 0;
|
|
|
|
switch (event) {
|
|
case CTRL_CMD_NEWFAMILY:
|
|
case CTRL_CMD_DELFAMILY:
|
|
WARN_ON(grp);
|
|
msg = ctrl_build_family_msg(family, 0, 0, event);
|
|
break;
|
|
case CTRL_CMD_NEWMCAST_GRP:
|
|
case CTRL_CMD_DELMCAST_GRP:
|
|
BUG_ON(!grp);
|
|
msg = ctrl_build_mcgrp_msg(family, grp, grp_id, 0, 0, event);
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (IS_ERR(msg))
|
|
return PTR_ERR(msg);
|
|
|
|
if (!family->netnsok) {
|
|
genlmsg_multicast_netns(&genl_ctrl, &init_net, msg, 0,
|
|
0, GFP_KERNEL);
|
|
} else {
|
|
rcu_read_lock();
|
|
genlmsg_multicast_allns(&genl_ctrl, msg, 0,
|
|
0, GFP_ATOMIC);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct genl_ops genl_ctrl_ops[] = {
|
|
{
|
|
.cmd = CTRL_CMD_GETFAMILY,
|
|
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
|
|
.doit = ctrl_getfamily,
|
|
.dumpit = ctrl_dumpfamily,
|
|
},
|
|
};
|
|
|
|
static const struct genl_multicast_group genl_ctrl_groups[] = {
|
|
{ .name = "notify", },
|
|
};
|
|
|
|
static struct genl_family genl_ctrl __ro_after_init = {
|
|
.module = THIS_MODULE,
|
|
.ops = genl_ctrl_ops,
|
|
.n_ops = ARRAY_SIZE(genl_ctrl_ops),
|
|
.mcgrps = genl_ctrl_groups,
|
|
.n_mcgrps = ARRAY_SIZE(genl_ctrl_groups),
|
|
.id = GENL_ID_CTRL,
|
|
.name = "nlctrl",
|
|
.version = 0x2,
|
|
.maxattr = CTRL_ATTR_MAX,
|
|
.policy = ctrl_policy,
|
|
.netnsok = true,
|
|
};
|
|
|
|
static int genl_bind(struct net *net, int group)
|
|
{
|
|
struct genl_family *f;
|
|
int err = -ENOENT;
|
|
unsigned int id;
|
|
|
|
down_read(&cb_lock);
|
|
|
|
idr_for_each_entry(&genl_fam_idr, f, id) {
|
|
if (group >= f->mcgrp_offset &&
|
|
group < f->mcgrp_offset + f->n_mcgrps) {
|
|
int fam_grp = group - f->mcgrp_offset;
|
|
|
|
if (!f->netnsok && net != &init_net)
|
|
err = -ENOENT;
|
|
else if (f->mcast_bind)
|
|
err = f->mcast_bind(net, fam_grp);
|
|
else
|
|
err = 0;
|
|
break;
|
|
}
|
|
}
|
|
up_read(&cb_lock);
|
|
|
|
return err;
|
|
}
|
|
|
|
static void genl_unbind(struct net *net, int group)
|
|
{
|
|
struct genl_family *f;
|
|
unsigned int id;
|
|
|
|
down_read(&cb_lock);
|
|
|
|
idr_for_each_entry(&genl_fam_idr, f, id) {
|
|
if (group >= f->mcgrp_offset &&
|
|
group < f->mcgrp_offset + f->n_mcgrps) {
|
|
int fam_grp = group - f->mcgrp_offset;
|
|
|
|
if (f->mcast_unbind)
|
|
f->mcast_unbind(net, fam_grp);
|
|
break;
|
|
}
|
|
}
|
|
up_read(&cb_lock);
|
|
}
|
|
|
|
static int __net_init genl_pernet_init(struct net *net)
|
|
{
|
|
struct netlink_kernel_cfg cfg = {
|
|
.input = genl_rcv,
|
|
.flags = NL_CFG_F_NONROOT_RECV,
|
|
.bind = genl_bind,
|
|
.unbind = genl_unbind,
|
|
};
|
|
|
|
/* we'll bump the group number right afterwards */
|
|
net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, &cfg);
|
|
|
|
if (!net->genl_sock && net_eq(net, &init_net))
|
|
panic("GENL: Cannot initialize generic netlink\n");
|
|
|
|
if (!net->genl_sock)
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __net_exit genl_pernet_exit(struct net *net)
|
|
{
|
|
netlink_kernel_release(net->genl_sock);
|
|
net->genl_sock = NULL;
|
|
}
|
|
|
|
static struct pernet_operations genl_pernet_ops = {
|
|
.init = genl_pernet_init,
|
|
.exit = genl_pernet_exit,
|
|
};
|
|
|
|
static int __init genl_init(void)
|
|
{
|
|
int err;
|
|
|
|
err = genl_register_family(&genl_ctrl);
|
|
if (err < 0)
|
|
goto problem;
|
|
|
|
err = register_pernet_subsys(&genl_pernet_ops);
|
|
if (err)
|
|
goto problem;
|
|
|
|
return 0;
|
|
|
|
problem:
|
|
panic("GENL: Cannot register controller: %d\n", err);
|
|
}
|
|
|
|
subsys_initcall(genl_init);
|
|
|
|
/**
|
|
* genl_family_attrbuf - return family's attrbuf
|
|
* @family: the family
|
|
*
|
|
* Return the family's attrbuf, while validating that it's
|
|
* actually valid to access it.
|
|
*
|
|
* You cannot use this function with a family that has parallel_ops
|
|
* and you can only use it within (pre/post) doit/dumpit callbacks.
|
|
*/
|
|
struct nlattr **genl_family_attrbuf(const struct genl_family *family)
|
|
{
|
|
if (!WARN_ON(family->parallel_ops))
|
|
lockdep_assert_held(&genl_mutex);
|
|
|
|
return family->attrbuf;
|
|
}
|
|
EXPORT_SYMBOL(genl_family_attrbuf);
|
|
|
|
static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group,
|
|
gfp_t flags)
|
|
{
|
|
struct sk_buff *tmp;
|
|
struct net *net, *prev = NULL;
|
|
bool delivered = false;
|
|
int err;
|
|
|
|
for_each_net_rcu(net) {
|
|
if (prev) {
|
|
tmp = skb_clone(skb, flags);
|
|
if (!tmp) {
|
|
err = -ENOMEM;
|
|
goto error;
|
|
}
|
|
err = nlmsg_multicast(prev->genl_sock, tmp,
|
|
portid, group, flags);
|
|
if (!err)
|
|
delivered = true;
|
|
else if (err != -ESRCH)
|
|
goto error;
|
|
}
|
|
|
|
prev = net;
|
|
}
|
|
|
|
err = nlmsg_multicast(prev->genl_sock, skb, portid, group, flags);
|
|
if (!err)
|
|
delivered = true;
|
|
else if (err != -ESRCH)
|
|
return err;
|
|
return delivered ? 0 : -ESRCH;
|
|
error:
|
|
kfree_skb(skb);
|
|
return err;
|
|
}
|
|
|
|
int genlmsg_multicast_allns(const struct genl_family *family,
|
|
struct sk_buff *skb, u32 portid,
|
|
unsigned int group, gfp_t flags)
|
|
{
|
|
if (WARN_ON_ONCE(group >= family->n_mcgrps))
|
|
return -EINVAL;
|
|
group = family->mcgrp_offset + group;
|
|
return genlmsg_mcast(skb, portid, group, flags);
|
|
}
|
|
EXPORT_SYMBOL(genlmsg_multicast_allns);
|
|
|
|
void genl_notify(const struct genl_family *family, struct sk_buff *skb,
|
|
struct genl_info *info, u32 group, gfp_t flags)
|
|
{
|
|
struct net *net = genl_info_net(info);
|
|
struct sock *sk = net->genl_sock;
|
|
int report = 0;
|
|
|
|
if (info->nlhdr)
|
|
report = nlmsg_report(info->nlhdr);
|
|
|
|
if (WARN_ON_ONCE(group >= family->n_mcgrps))
|
|
return;
|
|
group = family->mcgrp_offset + group;
|
|
nlmsg_notify(sk, skb, info->snd_portid, group, report, flags);
|
|
}
|
|
EXPORT_SYMBOL(genl_notify);
|