![Pravin B Shelar](/assets/img/avatar_default.png)
netlink dump operations take module as parameter to hold reference for entire netlink dump duration. Currently it holds ref only on genl module which is not correct when we use ops registered to genl from another module. Following patch adds module pointer to genl_ops so that netlink can hold ref count on it. CC: Jesse Gross <jesse@nicira.com> CC: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1107 lines
25 KiB
C
1107 lines
25 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 <linux/rwsem.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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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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int 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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#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 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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BUG_ON(memchr(grp->name, '\0', GENL_NAMSIZ) == NULL);
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genl_lock_all();
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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_all();
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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_all();
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__genl_unregister_mc_group(family, grp);
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genl_unlock_all();
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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_all();
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list_add_tail(&ops->ops_list, &family->ops_list);
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genl_unlock_all();
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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_all();
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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_all();
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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_all();
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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_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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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 && !family->parallel_ops) {
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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_all();
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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_all();
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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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*/
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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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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);
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if (err)
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goto err_out;
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}
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return 0;
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err_out:
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genl_unregister_family(family);
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return err;
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}
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EXPORT_SYMBOL(__genl_register_family_with_ops);
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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(struct genl_family *family)
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{
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struct genl_family *rc;
|
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genl_lock_all();
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genl_unregister_mc_groups(family);
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list_for_each_entry(rc, genl_family_chain(family->id), family_list) {
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if (family->id != rc->id || strcmp(rc->name, family->name))
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continue;
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list_del(&rc->family_list);
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INIT_LIST_HEAD(&family->ops_list);
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genl_unlock_all();
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kfree(family->attrbuf);
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genl_ctrl_event(CTRL_CMD_DELFAMILY, family);
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return 0;
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}
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genl_unlock_all();
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return -ENOENT;
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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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*/
|
|
void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
|
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struct genl_family *family, int flags, u8 cmd)
|
|
{
|
|
struct nlmsghdr *nlh;
|
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struct genlmsghdr *hdr;
|
|
|
|
nlh = nlmsg_put(skb, portid, seq, family->id, GENL_HDRLEN +
|
|
family->hdrsize, flags);
|
|
if (nlh == NULL)
|
|
return NULL;
|
|
|
|
hdr = nlmsg_data(nlh);
|
|
hdr->cmd = cmd;
|
|
hdr->version = family->version;
|
|
hdr->reserved = 0;
|
|
|
|
return (char *) hdr + GENL_HDRLEN;
|
|
}
|
|
EXPORT_SYMBOL(genlmsg_put);
|
|
|
|
static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
|
|
{
|
|
struct genl_ops *ops = cb->data;
|
|
int rc;
|
|
|
|
genl_lock();
|
|
rc = ops->dumpit(skb, cb);
|
|
genl_unlock();
|
|
return rc;
|
|
}
|
|
|
|
static int genl_lock_done(struct netlink_callback *cb)
|
|
{
|
|
struct genl_ops *ops = cb->data;
|
|
int rc = 0;
|
|
|
|
if (ops->done) {
|
|
genl_lock();
|
|
rc = ops->done(cb);
|
|
genl_unlock();
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
static int genl_family_rcv_msg(struct genl_family *family,
|
|
struct sk_buff *skb,
|
|
struct nlmsghdr *nlh)
|
|
{
|
|
struct genl_ops *ops;
|
|
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) &&
|
|
!capable(CAP_NET_ADMIN))
|
|
return -EPERM;
|
|
|
|
if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {
|
|
int rc;
|
|
|
|
if (ops->dumpit == NULL)
|
|
return -EOPNOTSUPP;
|
|
|
|
if (!family->parallel_ops) {
|
|
struct netlink_dump_control c = {
|
|
.module = family->module,
|
|
.data = ops,
|
|
.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,
|
|
.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((family->maxattr+1) *
|
|
sizeof(struct nlattr *), GFP_KERNEL);
|
|
if (attrbuf == NULL)
|
|
return -ENOMEM;
|
|
} else
|
|
attrbuf = family->attrbuf;
|
|
|
|
if (attrbuf) {
|
|
err = nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr,
|
|
ops->policy);
|
|
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;
|
|
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 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);
|
|
|
|
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 = {
|
|
.id = GENL_ID_CTRL,
|
|
.name = "nlctrl",
|
|
.version = 0x2,
|
|
.maxattr = CTRL_ATTR_MAX,
|
|
.netnsok = true,
|
|
};
|
|
|
|
static int ctrl_fill_info(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 (!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;
|
|
|
|
if (nla_put_u32(skb, CTRL_ATTR_OP_ID, ops->cmd) ||
|
|
nla_put_u32(skb, CTRL_ATTR_OP_FLAGS, ops->flags))
|
|
goto nla_put_failure;
|
|
|
|
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;
|
|
|
|
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);
|
|
}
|
|
|
|
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 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, grp->family->name) ||
|
|
nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, grp->family->id))
|
|
goto nla_put_failure;
|
|
|
|
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;
|
|
|
|
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);
|
|
|
|
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).portid,
|
|
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 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(struct genl_multicast_group *grp,
|
|
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(grp, 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;
|
|
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, 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)
|
|
{
|
|
struct netlink_kernel_cfg cfg = {
|
|
.input = genl_rcv,
|
|
.flags = NL_CFG_F_NONROOT_RECV,
|
|
};
|
|
|
|
/* 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 i, err;
|
|
|
|
for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
|
|
INIT_LIST_HEAD(&family_ht[i]);
|
|
|
|
err = genl_register_family_with_ops(&genl_ctrl, &genl_ctrl_ops, 1);
|
|
if (err < 0)
|
|
goto problem;
|
|
|
|
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 portid, 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,
|
|
portid, group, flags);
|
|
if (err)
|
|
goto error;
|
|
}
|
|
|
|
prev = net;
|
|
}
|
|
|
|
return nlmsg_multicast(prev->genl_sock, skb, portid, group, flags);
|
|
error:
|
|
kfree_skb(skb);
|
|
return err;
|
|
}
|
|
|
|
int genlmsg_multicast_allns(struct sk_buff *skb, u32 portid, unsigned int group,
|
|
gfp_t flags)
|
|
{
|
|
return genlmsg_mcast(skb, portid, group, flags);
|
|
}
|
|
EXPORT_SYMBOL(genlmsg_multicast_allns);
|
|
|
|
void genl_notify(struct sk_buff *skb, struct net *net, u32 portid, u32 group,
|
|
struct nlmsghdr *nlh, gfp_t flags)
|
|
{
|
|
struct sock *sk = net->genl_sock;
|
|
int report = 0;
|
|
|
|
if (nlh)
|
|
report = nlmsg_report(nlh);
|
|
|
|
nlmsg_notify(sk, skb, portid, group, report, flags);
|
|
}
|
|
EXPORT_SYMBOL(genl_notify);
|