941 lines
21 KiB
C
941 lines
21 KiB
C
/*
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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 <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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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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#define GENL_FAM_TAB_SIZE 16
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#define GENL_FAM_TAB_MASK (GENL_FAM_TAB_SIZE - 1)
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static struct list_head family_ht[GENL_FAM_TAB_SIZE];
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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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*/
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static unsigned long mc_group_start = 0x1;
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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, void *data);
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static inline unsigned int genl_family_hash(unsigned int id)
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{
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return id & GENL_FAM_TAB_MASK;
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}
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static inline struct list_head *genl_family_chain(unsigned int id)
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{
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return &family_ht[genl_family_hash(id)];
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}
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static struct genl_family *genl_family_find_byid(unsigned int id)
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{
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struct genl_family *f;
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list_for_each_entry(f, genl_family_chain(id), family_list)
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if (f->id == id)
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return f;
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return NULL;
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}
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static struct genl_family *genl_family_find_byname(char *name)
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{
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struct genl_family *f;
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int i;
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for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
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list_for_each_entry(f, genl_family_chain(i), family_list)
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if (strcmp(f->name, name) == 0)
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return f;
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return NULL;
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}
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static struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family)
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{
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struct genl_ops *ops;
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list_for_each_entry(ops, &family->ops_list, ops_list)
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if (ops->cmd == cmd)
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return ops;
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return NULL;
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}
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/* Of course we are going to have problems once we hit
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* 2^16 alive types, but that can only happen by year 2K
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*/
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static inline u16 genl_generate_id(void)
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{
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static u16 id_gen_idx = GENL_MIN_ID;
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int i;
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for (i = 0; i <= GENL_MAX_ID - GENL_MIN_ID; i++) {
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if (!genl_family_find_byid(id_gen_idx))
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return id_gen_idx;
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if (++id_gen_idx > GENL_MAX_ID)
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id_gen_idx = GENL_MIN_ID;
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}
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return 0;
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}
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static struct genl_multicast_group notify_grp;
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/**
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* genl_register_mc_group - register a multicast group
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*
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* Registers the specified multicast group and notifies userspace
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* about the new group.
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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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* @family: The generic netlink family the group shall be registered for.
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* @grp: The group to register, must have a name.
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*/
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int genl_register_mc_group(struct genl_family *family,
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struct genl_multicast_group *grp)
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{
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int id;
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unsigned long *new_groups;
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int err = 0;
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BUG_ON(grp->name[0] == '\0');
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genl_lock();
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/* special-case our own group */
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if (grp == ¬ify_grp)
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id = GENL_ID_CTRL;
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else
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id = find_first_zero_bit(mc_groups,
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mc_groups_longs * BITS_PER_LONG);
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if (id >= mc_groups_longs * BITS_PER_LONG) {
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size_t nlen = (mc_groups_longs + 1) * 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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err = -ENOMEM;
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goto out;
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}
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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, GFP_KERNEL);
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if (!new_groups) {
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err = -ENOMEM;
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goto out;
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}
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mc_groups = new_groups;
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mc_groups[mc_groups_longs] = 0;
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}
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mc_groups_longs++;
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}
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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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rcu_read_unlock();
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netlink_table_ungrab();
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goto out;
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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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if (err)
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goto out;
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}
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grp->id = id;
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set_bit(id, mc_groups);
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list_add_tail(&grp->list, &family->mcast_groups);
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grp->family = family;
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genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, grp);
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out:
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genl_unlock();
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return err;
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}
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EXPORT_SYMBOL(genl_register_mc_group);
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static void __genl_unregister_mc_group(struct genl_family *family,
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struct genl_multicast_group *grp)
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{
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struct net *net;
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BUG_ON(grp->family != family);
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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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__netlink_clear_multicast_users(net->genl_sock, grp->id);
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rcu_read_unlock();
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netlink_table_ungrab();
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clear_bit(grp->id, mc_groups);
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list_del(&grp->list);
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genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, grp);
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grp->id = 0;
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grp->family = NULL;
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}
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/**
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* genl_unregister_mc_group - unregister a multicast group
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*
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* Unregisters the specified multicast group and notifies userspace
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* about it. All current listeners on the group are removed.
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*
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* Note: It is not necessary to unregister all multicast groups before
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* unregistering the family, unregistering the family will cause
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* all assigned multicast groups to be unregistered automatically.
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*
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* @family: Generic netlink family the group belongs to.
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* @grp: The group to unregister, must have been registered successfully
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* previously.
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*/
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void genl_unregister_mc_group(struct genl_family *family,
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struct genl_multicast_group *grp)
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{
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genl_lock();
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__genl_unregister_mc_group(family, grp);
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genl_unlock();
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}
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EXPORT_SYMBOL(genl_unregister_mc_group);
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static void genl_unregister_mc_groups(struct genl_family *family)
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{
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struct genl_multicast_group *grp, *tmp;
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list_for_each_entry_safe(grp, tmp, &family->mcast_groups, list)
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__genl_unregister_mc_group(family, grp);
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}
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/**
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* genl_register_ops - register generic netlink operations
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* @family: generic netlink family
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* @ops: operations to be registered
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*
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* Registers the specified operations and assigns them to the specified
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* family. Either a doit or dumpit callback must be specified or the
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* operation will fail. Only one operation structure per command
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* identifier may be registered.
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*
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* See include/net/genetlink.h for more documenation on the operations
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* structure.
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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_register_ops(struct genl_family *family, struct genl_ops *ops)
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{
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int err = -EINVAL;
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if (ops->dumpit == NULL && ops->doit == NULL)
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goto errout;
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if (genl_get_cmd(ops->cmd, family)) {
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err = -EEXIST;
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goto errout;
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}
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if (ops->dumpit)
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ops->flags |= GENL_CMD_CAP_DUMP;
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if (ops->doit)
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ops->flags |= GENL_CMD_CAP_DO;
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if (ops->policy)
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ops->flags |= GENL_CMD_CAP_HASPOL;
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genl_lock();
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list_add_tail(&ops->ops_list, &family->ops_list);
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genl_unlock();
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genl_ctrl_event(CTRL_CMD_NEWOPS, ops);
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err = 0;
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errout:
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return err;
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}
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EXPORT_SYMBOL(genl_register_ops);
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/**
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* genl_unregister_ops - unregister generic netlink operations
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* @family: generic netlink family
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* @ops: operations to be unregistered
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*
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* Unregisters the specified operations and unassigns them from the
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* specified family. The operation blocks until the current message
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* processing has finished and doesn't start again until the
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* unregister process has finished.
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*
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* Note: It is not necessary to unregister all operations before
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* unregistering the family, unregistering the family will cause
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* all assigned operations to be unregistered automatically.
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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_ops(struct genl_family *family, struct genl_ops *ops)
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{
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struct genl_ops *rc;
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genl_lock();
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list_for_each_entry(rc, &family->ops_list, ops_list) {
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if (rc == ops) {
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list_del(&ops->ops_list);
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genl_unlock();
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genl_ctrl_event(CTRL_CMD_DELOPS, ops);
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return 0;
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}
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}
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genl_unlock();
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return -ENOENT;
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}
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EXPORT_SYMBOL(genl_unregister_ops);
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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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* The family id may equal GENL_ID_GENERATE causing an unique id to
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* be automatically generated and 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 = -EINVAL;
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if (family->id && family->id < GENL_MIN_ID)
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goto errout;
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if (family->id > GENL_MAX_ID)
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goto errout;
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INIT_LIST_HEAD(&family->ops_list);
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INIT_LIST_HEAD(&family->mcast_groups);
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genl_lock();
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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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if (family->id == GENL_ID_GENERATE) {
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u16 newid = genl_generate_id();
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if (!newid) {
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err = -ENOMEM;
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goto errout_locked;
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}
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family->id = newid;
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} else if (genl_family_find_byid(family->id)) {
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err = -EEXIST;
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goto errout_locked;
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}
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if (family->maxattr) {
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family->attrbuf = kmalloc((family->maxattr+1) *
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sizeof(struct nlattr *), 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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list_add_tail(&family->family_list, genl_family_chain(family->id));
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genl_unlock();
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genl_ctrl_event(CTRL_CMD_NEWFAMILY, family);
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return 0;
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errout_locked:
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genl_unlock();
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errout:
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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_register_family_with_ops - register a generic netlink family
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* @family: generic netlink family
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* @ops: operations to be registered
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* @n_ops: number of elements to register
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*
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* Registers the specified family and operations from the specified table.
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* Only one family may be registered with the same family name or identifier.
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*
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* The family id may equal GENL_ID_GENERATE causing an unique id to
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* be automatically generated and assigned.
|
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*
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* Either a doit or dumpit callback must be specified for every registered
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* operation or the function will fail. Only one operation structure per
|
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* command identifier may be registered.
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*
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* See include/net/genetlink.h for more documenation on the operations
|
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* structure.
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*
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* This is equivalent to calling genl_register_family() followed by
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* genl_register_ops() for every operation entry in the table taking
|
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* care to unregister the family on error path.
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*
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* Return 0 on success or a negative error code.
|
|
*/
|
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int genl_register_family_with_ops(struct genl_family *family,
|
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struct genl_ops *ops, size_t n_ops)
|
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{
|
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int err, i;
|
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|
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err = genl_register_family(family);
|
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if (err)
|
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return err;
|
|
|
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for (i = 0; i < n_ops; ++i, ++ops) {
|
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err = genl_register_ops(family, ops);
|
|
if (err)
|
|
goto err_out;
|
|
}
|
|
return 0;
|
|
err_out:
|
|
genl_unregister_family(family);
|
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return err;
|
|
}
|
|
EXPORT_SYMBOL(genl_register_family_with_ops);
|
|
|
|
/**
|
|
* genl_unregister_family - unregister generic netlink family
|
|
* @family: generic netlink family
|
|
*
|
|
* Unregisters the specified family.
|
|
*
|
|
* Returns 0 on success or a negative error code.
|
|
*/
|
|
int genl_unregister_family(struct genl_family *family)
|
|
{
|
|
struct genl_family *rc;
|
|
|
|
genl_lock();
|
|
|
|
genl_unregister_mc_groups(family);
|
|
|
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list_for_each_entry(rc, genl_family_chain(family->id), family_list) {
|
|
if (family->id != rc->id || strcmp(rc->name, family->name))
|
|
continue;
|
|
|
|
list_del(&rc->family_list);
|
|
INIT_LIST_HEAD(&family->ops_list);
|
|
genl_unlock();
|
|
|
|
kfree(family->attrbuf);
|
|
genl_ctrl_event(CTRL_CMD_DELFAMILY, family);
|
|
return 0;
|
|
}
|
|
|
|
genl_unlock();
|
|
|
|
return -ENOENT;
|
|
}
|
|
EXPORT_SYMBOL(genl_unregister_family);
|
|
|
|
static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
|
|
{
|
|
struct genl_ops *ops;
|
|
struct genl_family *family;
|
|
struct net *net = sock_net(skb->sk);
|
|
struct genl_info info;
|
|
struct genlmsghdr *hdr = nlmsg_data(nlh);
|
|
int hdrlen, err;
|
|
|
|
family = genl_family_find_byid(nlh->nlmsg_type);
|
|
if (family == NULL)
|
|
return -ENOENT;
|
|
|
|
/* 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) &&
|
|
security_netlink_recv(skb, CAP_NET_ADMIN))
|
|
return -EPERM;
|
|
|
|
if (nlh->nlmsg_flags & NLM_F_DUMP) {
|
|
if (ops->dumpit == NULL)
|
|
return -EOPNOTSUPP;
|
|
|
|
genl_unlock();
|
|
err = netlink_dump_start(net->genl_sock, skb, nlh,
|
|
ops->dumpit, ops->done);
|
|
genl_lock();
|
|
return err;
|
|
}
|
|
|
|
if (ops->doit == NULL)
|
|
return -EOPNOTSUPP;
|
|
|
|
if (family->attrbuf) {
|
|
err = nlmsg_parse(nlh, hdrlen, family->attrbuf, family->maxattr,
|
|
ops->policy);
|
|
if (err < 0)
|
|
return err;
|
|
}
|
|
|
|
info.snd_seq = nlh->nlmsg_seq;
|
|
info.snd_pid = NETLINK_CB(skb).pid;
|
|
info.nlhdr = nlh;
|
|
info.genlhdr = nlmsg_data(nlh);
|
|
info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
|
|
info.attrs = family->attrbuf;
|
|
genl_info_net_set(&info, net);
|
|
|
|
return ops->doit(skb, &info);
|
|
}
|
|
|
|
static void genl_rcv(struct sk_buff *skb)
|
|
{
|
|
genl_lock();
|
|
netlink_rcv_skb(skb, &genl_rcv_msg);
|
|
genl_unlock();
|
|
}
|
|
|
|
/**************************************************************************
|
|
* Controller
|
|
**************************************************************************/
|
|
|
|
static struct genl_family genl_ctrl = {
|
|
.id = GENL_ID_CTRL,
|
|
.name = "nlctrl",
|
|
.version = 0x2,
|
|
.maxattr = CTRL_ATTR_MAX,
|
|
.netnsok = true,
|
|
};
|
|
|
|
static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq,
|
|
u32 flags, struct sk_buff *skb, u8 cmd)
|
|
{
|
|
void *hdr;
|
|
|
|
hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
|
|
if (hdr == NULL)
|
|
return -1;
|
|
|
|
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);
|
|
|
|
if (!list_empty(&family->ops_list)) {
|
|
struct nlattr *nla_ops;
|
|
struct genl_ops *ops;
|
|
int idx = 1;
|
|
|
|
nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
|
|
if (nla_ops == NULL)
|
|
goto nla_put_failure;
|
|
|
|
list_for_each_entry(ops, &family->ops_list, ops_list) {
|
|
struct nlattr *nest;
|
|
|
|
nest = nla_nest_start(skb, idx++);
|
|
if (nest == NULL)
|
|
goto nla_put_failure;
|
|
|
|
NLA_PUT_U32(skb, CTRL_ATTR_OP_ID, ops->cmd);
|
|
NLA_PUT_U32(skb, CTRL_ATTR_OP_FLAGS, ops->flags);
|
|
|
|
nla_nest_end(skb, nest);
|
|
}
|
|
|
|
nla_nest_end(skb, nla_ops);
|
|
}
|
|
|
|
if (!list_empty(&family->mcast_groups)) {
|
|
struct genl_multicast_group *grp;
|
|
struct nlattr *nla_grps;
|
|
int idx = 1;
|
|
|
|
nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
|
|
if (nla_grps == NULL)
|
|
goto nla_put_failure;
|
|
|
|
list_for_each_entry(grp, &family->mcast_groups, list) {
|
|
struct nlattr *nest;
|
|
|
|
nest = nla_nest_start(skb, idx++);
|
|
if (nest == NULL)
|
|
goto nla_put_failure;
|
|
|
|
NLA_PUT_U32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id);
|
|
NLA_PUT_STRING(skb, CTRL_ATTR_MCAST_GRP_NAME,
|
|
grp->name);
|
|
|
|
nla_nest_end(skb, nest);
|
|
}
|
|
nla_nest_end(skb, nla_grps);
|
|
}
|
|
|
|
return genlmsg_end(skb, hdr);
|
|
|
|
nla_put_failure:
|
|
genlmsg_cancel(skb, hdr);
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
static int ctrl_fill_mcgrp_info(struct genl_multicast_group *grp, u32 pid,
|
|
u32 seq, u32 flags, struct sk_buff *skb,
|
|
u8 cmd)
|
|
{
|
|
void *hdr;
|
|
struct nlattr *nla_grps;
|
|
struct nlattr *nest;
|
|
|
|
hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
|
|
if (hdr == NULL)
|
|
return -1;
|
|
|
|
NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, grp->family->name);
|
|
NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, grp->family->id);
|
|
|
|
nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
|
|
if (nla_grps == NULL)
|
|
goto nla_put_failure;
|
|
|
|
nest = nla_nest_start(skb, 1);
|
|
if (nest == NULL)
|
|
goto nla_put_failure;
|
|
|
|
NLA_PUT_U32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id);
|
|
NLA_PUT_STRING(skb, CTRL_ATTR_MCAST_GRP_NAME,
|
|
grp->name);
|
|
|
|
nla_nest_end(skb, nest);
|
|
nla_nest_end(skb, nla_grps);
|
|
|
|
return genlmsg_end(skb, hdr);
|
|
|
|
nla_put_failure:
|
|
genlmsg_cancel(skb, hdr);
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
|
|
{
|
|
|
|
int i, n = 0;
|
|
struct genl_family *rt;
|
|
struct net *net = sock_net(skb->sk);
|
|
int chains_to_skip = cb->args[0];
|
|
int fams_to_skip = cb->args[1];
|
|
|
|
for (i = chains_to_skip; i < GENL_FAM_TAB_SIZE; i++) {
|
|
n = 0;
|
|
list_for_each_entry(rt, genl_family_chain(i), family_list) {
|
|
if (!rt->netnsok && !net_eq(net, &init_net))
|
|
continue;
|
|
if (++n < fams_to_skip)
|
|
continue;
|
|
if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).pid,
|
|
cb->nlh->nlmsg_seq, NLM_F_MULTI,
|
|
skb, CTRL_CMD_NEWFAMILY) < 0)
|
|
goto errout;
|
|
}
|
|
|
|
fams_to_skip = 0;
|
|
}
|
|
|
|
errout:
|
|
cb->args[0] = i;
|
|
cb->args[1] = n;
|
|
|
|
return skb->len;
|
|
}
|
|
|
|
static struct sk_buff *ctrl_build_family_msg(struct genl_family *family,
|
|
u32 pid, 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, pid, seq, 0, skb, cmd);
|
|
if (err < 0) {
|
|
nlmsg_free(skb);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
return skb;
|
|
}
|
|
|
|
static struct sk_buff *ctrl_build_mcgrp_msg(struct genl_multicast_group *grp,
|
|
u32 pid, 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(grp, pid, 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;
|
|
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);
|
|
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_pid, 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, void *data)
|
|
{
|
|
struct sk_buff *msg;
|
|
struct genl_family *family;
|
|
struct genl_multicast_group *grp;
|
|
|
|
/* genl is still initialising */
|
|
if (!init_net.genl_sock)
|
|
return 0;
|
|
|
|
switch (event) {
|
|
case CTRL_CMD_NEWFAMILY:
|
|
case CTRL_CMD_DELFAMILY:
|
|
family = data;
|
|
msg = ctrl_build_family_msg(family, 0, 0, event);
|
|
break;
|
|
case CTRL_CMD_NEWMCAST_GRP:
|
|
case CTRL_CMD_DELMCAST_GRP:
|
|
grp = data;
|
|
family = grp->family;
|
|
msg = ctrl_build_mcgrp_msg(data, 0, 0, event);
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (IS_ERR(msg))
|
|
return PTR_ERR(msg);
|
|
|
|
if (!family->netnsok) {
|
|
genlmsg_multicast_netns(&init_net, msg, 0,
|
|
GENL_ID_CTRL, GFP_KERNEL);
|
|
} else {
|
|
rcu_read_lock();
|
|
genlmsg_multicast_allns(msg, 0, GENL_ID_CTRL, GFP_ATOMIC);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct genl_ops genl_ctrl_ops = {
|
|
.cmd = CTRL_CMD_GETFAMILY,
|
|
.doit = ctrl_getfamily,
|
|
.dumpit = ctrl_dumpfamily,
|
|
.policy = ctrl_policy,
|
|
};
|
|
|
|
static struct genl_multicast_group notify_grp = {
|
|
.name = "notify",
|
|
};
|
|
|
|
static int __net_init genl_pernet_init(struct net *net)
|
|
{
|
|
/* we'll bump the group number right afterwards */
|
|
net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, 0,
|
|
genl_rcv, &genl_mutex,
|
|
THIS_MODULE);
|
|
|
|
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 i, err;
|
|
|
|
for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
|
|
INIT_LIST_HEAD(&family_ht[i]);
|
|
|
|
err = genl_register_family(&genl_ctrl);
|
|
if (err < 0)
|
|
goto problem;
|
|
|
|
err = genl_register_ops(&genl_ctrl, &genl_ctrl_ops);
|
|
if (err < 0)
|
|
goto problem;
|
|
|
|
netlink_set_nonroot(NETLINK_GENERIC, NL_NONROOT_RECV);
|
|
|
|
err = register_pernet_subsys(&genl_pernet_ops);
|
|
if (err)
|
|
goto problem;
|
|
|
|
err = genl_register_mc_group(&genl_ctrl, ¬ify_grp);
|
|
if (err < 0)
|
|
goto problem;
|
|
|
|
return 0;
|
|
|
|
problem:
|
|
panic("GENL: Cannot register controller: %d\n", err);
|
|
}
|
|
|
|
subsys_initcall(genl_init);
|
|
|
|
static int genlmsg_mcast(struct sk_buff *skb, u32 pid, unsigned long group,
|
|
gfp_t flags)
|
|
{
|
|
struct sk_buff *tmp;
|
|
struct net *net, *prev = NULL;
|
|
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,
|
|
pid, group, flags);
|
|
if (err)
|
|
goto error;
|
|
}
|
|
|
|
prev = net;
|
|
}
|
|
|
|
return nlmsg_multicast(prev->genl_sock, skb, pid, group, flags);
|
|
error:
|
|
kfree_skb(skb);
|
|
return err;
|
|
}
|
|
|
|
int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid, unsigned int group,
|
|
gfp_t flags)
|
|
{
|
|
return genlmsg_mcast(skb, pid, group, flags);
|
|
}
|
|
EXPORT_SYMBOL(genlmsg_multicast_allns);
|