1015 lines
23 KiB
C
1015 lines
23 KiB
C
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/workqueue.h>
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#include <linux/rtnetlink.h>
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#include <linux/cache.h>
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#include <linux/slab.h>
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#include <linux/list.h>
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#include <linux/delay.h>
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#include <linux/sched.h>
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#include <linux/idr.h>
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#include <linux/rculist.h>
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#include <linux/nsproxy.h>
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#include <linux/fs.h>
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#include <linux/proc_ns.h>
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#include <linux/file.h>
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#include <linux/export.h>
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#include <linux/user_namespace.h>
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#include <linux/net_namespace.h>
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#include <net/sock.h>
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#include <net/netlink.h>
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#include <net/net_namespace.h>
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#include <net/netns/generic.h>
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/*
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* Our network namespace constructor/destructor lists
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*/
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static LIST_HEAD(pernet_list);
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static struct list_head *first_device = &pernet_list;
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DEFINE_MUTEX(net_mutex);
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LIST_HEAD(net_namespace_list);
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EXPORT_SYMBOL_GPL(net_namespace_list);
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struct net init_net = {
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.dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head),
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};
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EXPORT_SYMBOL(init_net);
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static bool init_net_initialized;
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#define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */
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static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
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static struct net_generic *net_alloc_generic(void)
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{
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struct net_generic *ng;
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size_t generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]);
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ng = kzalloc(generic_size, GFP_KERNEL);
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if (ng)
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ng->len = max_gen_ptrs;
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return ng;
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}
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static int net_assign_generic(struct net *net, int id, void *data)
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{
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struct net_generic *ng, *old_ng;
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BUG_ON(!mutex_is_locked(&net_mutex));
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BUG_ON(id == 0);
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old_ng = rcu_dereference_protected(net->gen,
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lockdep_is_held(&net_mutex));
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ng = old_ng;
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if (old_ng->len >= id)
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goto assign;
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ng = net_alloc_generic();
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if (ng == NULL)
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return -ENOMEM;
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/*
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* Some synchronisation notes:
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*
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* The net_generic explores the net->gen array inside rcu
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* read section. Besides once set the net->gen->ptr[x]
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* pointer never changes (see rules in netns/generic.h).
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*
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* That said, we simply duplicate this array and schedule
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* the old copy for kfree after a grace period.
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*/
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memcpy(&ng->ptr, &old_ng->ptr, old_ng->len * sizeof(void*));
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rcu_assign_pointer(net->gen, ng);
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kfree_rcu(old_ng, rcu);
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assign:
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ng->ptr[id - 1] = data;
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return 0;
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}
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static int ops_init(const struct pernet_operations *ops, struct net *net)
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{
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int err = -ENOMEM;
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void *data = NULL;
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if (ops->id && ops->size) {
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data = kzalloc(ops->size, GFP_KERNEL);
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if (!data)
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goto out;
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err = net_assign_generic(net, *ops->id, data);
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if (err)
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goto cleanup;
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}
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err = 0;
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if (ops->init)
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err = ops->init(net);
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if (!err)
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return 0;
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cleanup:
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kfree(data);
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out:
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return err;
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}
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static void ops_free(const struct pernet_operations *ops, struct net *net)
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{
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if (ops->id && ops->size) {
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int id = *ops->id;
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kfree(net_generic(net, id));
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}
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}
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static void ops_exit_list(const struct pernet_operations *ops,
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struct list_head *net_exit_list)
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{
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struct net *net;
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if (ops->exit) {
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list_for_each_entry(net, net_exit_list, exit_list)
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ops->exit(net);
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}
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if (ops->exit_batch)
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ops->exit_batch(net_exit_list);
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}
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static void ops_free_list(const struct pernet_operations *ops,
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struct list_head *net_exit_list)
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{
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struct net *net;
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if (ops->size && ops->id) {
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list_for_each_entry(net, net_exit_list, exit_list)
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ops_free(ops, net);
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}
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}
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/* should be called with nsid_lock held */
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static int alloc_netid(struct net *net, struct net *peer, int reqid)
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{
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int min = 0, max = 0;
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if (reqid >= 0) {
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min = reqid;
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max = reqid + 1;
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}
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return idr_alloc(&net->netns_ids, peer, min, max, GFP_ATOMIC);
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}
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/* This function is used by idr_for_each(). If net is equal to peer, the
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* function returns the id so that idr_for_each() stops. Because we cannot
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* returns the id 0 (idr_for_each() will not stop), we return the magic value
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* NET_ID_ZERO (-1) for it.
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*/
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#define NET_ID_ZERO -1
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static int net_eq_idr(int id, void *net, void *peer)
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{
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if (net_eq(net, peer))
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return id ? : NET_ID_ZERO;
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return 0;
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}
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/* Should be called with nsid_lock held. If a new id is assigned, the bool alloc
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* is set to true, thus the caller knows that the new id must be notified via
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* rtnl.
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*/
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static int __peernet2id_alloc(struct net *net, struct net *peer, bool *alloc)
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{
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int id = idr_for_each(&net->netns_ids, net_eq_idr, peer);
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bool alloc_it = *alloc;
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*alloc = false;
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/* Magic value for id 0. */
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if (id == NET_ID_ZERO)
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return 0;
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if (id > 0)
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return id;
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if (alloc_it) {
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id = alloc_netid(net, peer, -1);
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*alloc = true;
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return id >= 0 ? id : NETNSA_NSID_NOT_ASSIGNED;
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}
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return NETNSA_NSID_NOT_ASSIGNED;
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}
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/* should be called with nsid_lock held */
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static int __peernet2id(struct net *net, struct net *peer)
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{
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bool no = false;
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return __peernet2id_alloc(net, peer, &no);
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}
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static void rtnl_net_notifyid(struct net *net, int cmd, int id);
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/* This function returns the id of a peer netns. If no id is assigned, one will
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* be allocated and returned.
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*/
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int peernet2id_alloc(struct net *net, struct net *peer)
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{
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bool alloc;
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int id;
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spin_lock_bh(&net->nsid_lock);
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alloc = atomic_read(&peer->count) == 0 ? false : true;
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id = __peernet2id_alloc(net, peer, &alloc);
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spin_unlock_bh(&net->nsid_lock);
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if (alloc && id >= 0)
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rtnl_net_notifyid(net, RTM_NEWNSID, id);
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return id;
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}
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/* This function returns, if assigned, the id of a peer netns. */
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int peernet2id(struct net *net, struct net *peer)
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{
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int id;
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spin_lock_bh(&net->nsid_lock);
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id = __peernet2id(net, peer);
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spin_unlock_bh(&net->nsid_lock);
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return id;
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}
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EXPORT_SYMBOL(peernet2id);
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/* This function returns true is the peer netns has an id assigned into the
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* current netns.
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*/
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bool peernet_has_id(struct net *net, struct net *peer)
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{
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return peernet2id(net, peer) >= 0;
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}
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struct net *get_net_ns_by_id(struct net *net, int id)
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{
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struct net *peer;
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if (id < 0)
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return NULL;
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rcu_read_lock();
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spin_lock_bh(&net->nsid_lock);
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peer = idr_find(&net->netns_ids, id);
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if (peer)
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get_net(peer);
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spin_unlock_bh(&net->nsid_lock);
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rcu_read_unlock();
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return peer;
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}
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/*
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* setup_net runs the initializers for the network namespace object.
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*/
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static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
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{
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/* Must be called with net_mutex held */
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const struct pernet_operations *ops, *saved_ops;
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int error = 0;
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LIST_HEAD(net_exit_list);
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atomic_set(&net->count, 1);
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atomic_set(&net->passive, 1);
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net->dev_base_seq = 1;
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net->user_ns = user_ns;
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idr_init(&net->netns_ids);
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spin_lock_init(&net->nsid_lock);
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list_for_each_entry(ops, &pernet_list, list) {
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error = ops_init(ops, net);
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if (error < 0)
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goto out_undo;
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}
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out:
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return error;
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out_undo:
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/* Walk through the list backwards calling the exit functions
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* for the pernet modules whose init functions did not fail.
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*/
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list_add(&net->exit_list, &net_exit_list);
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saved_ops = ops;
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list_for_each_entry_continue_reverse(ops, &pernet_list, list)
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ops_exit_list(ops, &net_exit_list);
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ops = saved_ops;
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list_for_each_entry_continue_reverse(ops, &pernet_list, list)
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ops_free_list(ops, &net_exit_list);
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rcu_barrier();
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goto out;
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}
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#ifdef CONFIG_NET_NS
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static struct kmem_cache *net_cachep;
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static struct workqueue_struct *netns_wq;
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static struct net *net_alloc(void)
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{
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struct net *net = NULL;
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struct net_generic *ng;
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ng = net_alloc_generic();
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if (!ng)
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goto out;
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net = kmem_cache_zalloc(net_cachep, GFP_KERNEL);
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if (!net)
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goto out_free;
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rcu_assign_pointer(net->gen, ng);
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out:
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return net;
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out_free:
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kfree(ng);
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goto out;
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}
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static void net_free(struct net *net)
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{
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kfree(rcu_access_pointer(net->gen));
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kmem_cache_free(net_cachep, net);
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}
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void net_drop_ns(void *p)
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{
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struct net *ns = p;
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if (ns && atomic_dec_and_test(&ns->passive))
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net_free(ns);
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}
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struct net *copy_net_ns(unsigned long flags,
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struct user_namespace *user_ns, struct net *old_net)
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{
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struct net *net;
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int rv;
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if (!(flags & CLONE_NEWNET))
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return get_net(old_net);
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net = net_alloc();
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if (!net)
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return ERR_PTR(-ENOMEM);
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get_user_ns(user_ns);
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mutex_lock(&net_mutex);
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rv = setup_net(net, user_ns);
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if (rv == 0) {
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rtnl_lock();
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list_add_tail_rcu(&net->list, &net_namespace_list);
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rtnl_unlock();
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}
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mutex_unlock(&net_mutex);
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if (rv < 0) {
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put_user_ns(user_ns);
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net_drop_ns(net);
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return ERR_PTR(rv);
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}
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return net;
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}
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static DEFINE_SPINLOCK(cleanup_list_lock);
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static LIST_HEAD(cleanup_list); /* Must hold cleanup_list_lock to touch */
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static void cleanup_net(struct work_struct *work)
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{
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const struct pernet_operations *ops;
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struct net *net, *tmp;
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struct list_head net_kill_list;
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LIST_HEAD(net_exit_list);
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/* Atomically snapshot the list of namespaces to cleanup */
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spin_lock_irq(&cleanup_list_lock);
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list_replace_init(&cleanup_list, &net_kill_list);
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spin_unlock_irq(&cleanup_list_lock);
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mutex_lock(&net_mutex);
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/* Don't let anyone else find us. */
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rtnl_lock();
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list_for_each_entry(net, &net_kill_list, cleanup_list) {
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list_del_rcu(&net->list);
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list_add_tail(&net->exit_list, &net_exit_list);
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for_each_net(tmp) {
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int id;
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spin_lock_bh(&tmp->nsid_lock);
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id = __peernet2id(tmp, net);
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if (id >= 0)
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idr_remove(&tmp->netns_ids, id);
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spin_unlock_bh(&tmp->nsid_lock);
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if (id >= 0)
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rtnl_net_notifyid(tmp, RTM_DELNSID, id);
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}
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spin_lock_bh(&net->nsid_lock);
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idr_destroy(&net->netns_ids);
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spin_unlock_bh(&net->nsid_lock);
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}
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rtnl_unlock();
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/*
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* Another CPU might be rcu-iterating the list, wait for it.
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* This needs to be before calling the exit() notifiers, so
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* the rcu_barrier() below isn't sufficient alone.
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*/
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synchronize_rcu();
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/* Run all of the network namespace exit methods */
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list_for_each_entry_reverse(ops, &pernet_list, list)
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ops_exit_list(ops, &net_exit_list);
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/* Free the net generic variables */
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list_for_each_entry_reverse(ops, &pernet_list, list)
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ops_free_list(ops, &net_exit_list);
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mutex_unlock(&net_mutex);
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/* Ensure there are no outstanding rcu callbacks using this
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* network namespace.
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*/
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rcu_barrier();
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/* Finally it is safe to free my network namespace structure */
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list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
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list_del_init(&net->exit_list);
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put_user_ns(net->user_ns);
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net_drop_ns(net);
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}
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}
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static DECLARE_WORK(net_cleanup_work, cleanup_net);
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void __put_net(struct net *net)
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{
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/* Cleanup the network namespace in process context */
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unsigned long flags;
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spin_lock_irqsave(&cleanup_list_lock, flags);
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list_add(&net->cleanup_list, &cleanup_list);
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spin_unlock_irqrestore(&cleanup_list_lock, flags);
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queue_work(netns_wq, &net_cleanup_work);
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}
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EXPORT_SYMBOL_GPL(__put_net);
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struct net *get_net_ns_by_fd(int fd)
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{
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struct file *file;
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struct ns_common *ns;
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struct net *net;
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file = proc_ns_fget(fd);
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if (IS_ERR(file))
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return ERR_CAST(file);
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|
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ns = get_proc_ns(file_inode(file));
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if (ns->ops == &netns_operations)
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net = get_net(container_of(ns, struct net, ns));
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else
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net = ERR_PTR(-EINVAL);
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fput(file);
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return net;
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}
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|
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#else
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struct net *get_net_ns_by_fd(int fd)
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{
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return ERR_PTR(-EINVAL);
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}
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#endif
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EXPORT_SYMBOL_GPL(get_net_ns_by_fd);
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struct net *get_net_ns_by_pid(pid_t pid)
|
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{
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struct task_struct *tsk;
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struct net *net;
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|
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/* Lookup the network namespace */
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net = ERR_PTR(-ESRCH);
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rcu_read_lock();
|
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tsk = find_task_by_vpid(pid);
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if (tsk) {
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struct nsproxy *nsproxy;
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task_lock(tsk);
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nsproxy = tsk->nsproxy;
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if (nsproxy)
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net = get_net(nsproxy->net_ns);
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task_unlock(tsk);
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}
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rcu_read_unlock();
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return net;
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}
|
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EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
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|
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static __net_init int net_ns_net_init(struct net *net)
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{
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#ifdef CONFIG_NET_NS
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net->ns.ops = &netns_operations;
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#endif
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return ns_alloc_inum(&net->ns);
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}
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|
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static __net_exit void net_ns_net_exit(struct net *net)
|
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{
|
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ns_free_inum(&net->ns);
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}
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|
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static struct pernet_operations __net_initdata net_ns_ops = {
|
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.init = net_ns_net_init,
|
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.exit = net_ns_net_exit,
|
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};
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|
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static const struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
|
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[NETNSA_NONE] = { .type = NLA_UNSPEC },
|
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[NETNSA_NSID] = { .type = NLA_S32 },
|
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[NETNSA_PID] = { .type = NLA_U32 },
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[NETNSA_FD] = { .type = NLA_U32 },
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};
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|
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static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh)
|
|
{
|
|
struct net *net = sock_net(skb->sk);
|
|
struct nlattr *tb[NETNSA_MAX + 1];
|
|
struct net *peer;
|
|
int nsid, err;
|
|
|
|
err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
|
|
rtnl_net_policy);
|
|
if (err < 0)
|
|
return err;
|
|
if (!tb[NETNSA_NSID])
|
|
return -EINVAL;
|
|
nsid = nla_get_s32(tb[NETNSA_NSID]);
|
|
|
|
if (tb[NETNSA_PID])
|
|
peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
|
|
else if (tb[NETNSA_FD])
|
|
peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
|
|
else
|
|
return -EINVAL;
|
|
if (IS_ERR(peer))
|
|
return PTR_ERR(peer);
|
|
|
|
spin_lock_bh(&net->nsid_lock);
|
|
if (__peernet2id(net, peer) >= 0) {
|
|
spin_unlock_bh(&net->nsid_lock);
|
|
err = -EEXIST;
|
|
goto out;
|
|
}
|
|
|
|
err = alloc_netid(net, peer, nsid);
|
|
spin_unlock_bh(&net->nsid_lock);
|
|
if (err >= 0) {
|
|
rtnl_net_notifyid(net, RTM_NEWNSID, err);
|
|
err = 0;
|
|
}
|
|
out:
|
|
put_net(peer);
|
|
return err;
|
|
}
|
|
|
|
static int rtnl_net_get_size(void)
|
|
{
|
|
return NLMSG_ALIGN(sizeof(struct rtgenmsg))
|
|
+ nla_total_size(sizeof(s32)) /* NETNSA_NSID */
|
|
;
|
|
}
|
|
|
|
static int rtnl_net_fill(struct sk_buff *skb, u32 portid, u32 seq, int flags,
|
|
int cmd, struct net *net, int nsid)
|
|
{
|
|
struct nlmsghdr *nlh;
|
|
struct rtgenmsg *rth;
|
|
|
|
nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rth), flags);
|
|
if (!nlh)
|
|
return -EMSGSIZE;
|
|
|
|
rth = nlmsg_data(nlh);
|
|
rth->rtgen_family = AF_UNSPEC;
|
|
|
|
if (nla_put_s32(skb, NETNSA_NSID, nsid))
|
|
goto nla_put_failure;
|
|
|
|
nlmsg_end(skb, nlh);
|
|
return 0;
|
|
|
|
nla_put_failure:
|
|
nlmsg_cancel(skb, nlh);
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh)
|
|
{
|
|
struct net *net = sock_net(skb->sk);
|
|
struct nlattr *tb[NETNSA_MAX + 1];
|
|
struct sk_buff *msg;
|
|
struct net *peer;
|
|
int err, id;
|
|
|
|
err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
|
|
rtnl_net_policy);
|
|
if (err < 0)
|
|
return err;
|
|
if (tb[NETNSA_PID])
|
|
peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
|
|
else if (tb[NETNSA_FD])
|
|
peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
|
|
else
|
|
return -EINVAL;
|
|
|
|
if (IS_ERR(peer))
|
|
return PTR_ERR(peer);
|
|
|
|
msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
|
|
if (!msg) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
id = peernet2id(net, peer);
|
|
err = rtnl_net_fill(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq, 0,
|
|
RTM_NEWNSID, net, id);
|
|
if (err < 0)
|
|
goto err_out;
|
|
|
|
err = rtnl_unicast(msg, net, NETLINK_CB(skb).portid);
|
|
goto out;
|
|
|
|
err_out:
|
|
nlmsg_free(msg);
|
|
out:
|
|
put_net(peer);
|
|
return err;
|
|
}
|
|
|
|
struct rtnl_net_dump_cb {
|
|
struct net *net;
|
|
struct sk_buff *skb;
|
|
struct netlink_callback *cb;
|
|
int idx;
|
|
int s_idx;
|
|
};
|
|
|
|
static int rtnl_net_dumpid_one(int id, void *peer, void *data)
|
|
{
|
|
struct rtnl_net_dump_cb *net_cb = (struct rtnl_net_dump_cb *)data;
|
|
int ret;
|
|
|
|
if (net_cb->idx < net_cb->s_idx)
|
|
goto cont;
|
|
|
|
ret = rtnl_net_fill(net_cb->skb, NETLINK_CB(net_cb->cb->skb).portid,
|
|
net_cb->cb->nlh->nlmsg_seq, NLM_F_MULTI,
|
|
RTM_NEWNSID, net_cb->net, id);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
cont:
|
|
net_cb->idx++;
|
|
return 0;
|
|
}
|
|
|
|
static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
|
|
{
|
|
struct net *net = sock_net(skb->sk);
|
|
struct rtnl_net_dump_cb net_cb = {
|
|
.net = net,
|
|
.skb = skb,
|
|
.cb = cb,
|
|
.idx = 0,
|
|
.s_idx = cb->args[0],
|
|
};
|
|
|
|
spin_lock_bh(&net->nsid_lock);
|
|
idr_for_each(&net->netns_ids, rtnl_net_dumpid_one, &net_cb);
|
|
spin_unlock_bh(&net->nsid_lock);
|
|
|
|
cb->args[0] = net_cb.idx;
|
|
return skb->len;
|
|
}
|
|
|
|
static void rtnl_net_notifyid(struct net *net, int cmd, int id)
|
|
{
|
|
struct sk_buff *msg;
|
|
int err = -ENOMEM;
|
|
|
|
msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
|
|
if (!msg)
|
|
goto out;
|
|
|
|
err = rtnl_net_fill(msg, 0, 0, 0, cmd, net, id);
|
|
if (err < 0)
|
|
goto err_out;
|
|
|
|
rtnl_notify(msg, net, 0, RTNLGRP_NSID, NULL, 0);
|
|
return;
|
|
|
|
err_out:
|
|
nlmsg_free(msg);
|
|
out:
|
|
rtnl_set_sk_err(net, RTNLGRP_NSID, err);
|
|
}
|
|
|
|
static int __init net_ns_init(void)
|
|
{
|
|
struct net_generic *ng;
|
|
|
|
#ifdef CONFIG_NET_NS
|
|
net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
|
|
SMP_CACHE_BYTES,
|
|
SLAB_PANIC, NULL);
|
|
|
|
/* Create workqueue for cleanup */
|
|
netns_wq = create_singlethread_workqueue("netns");
|
|
if (!netns_wq)
|
|
panic("Could not create netns workq");
|
|
#endif
|
|
|
|
ng = net_alloc_generic();
|
|
if (!ng)
|
|
panic("Could not allocate generic netns");
|
|
|
|
rcu_assign_pointer(init_net.gen, ng);
|
|
|
|
mutex_lock(&net_mutex);
|
|
if (setup_net(&init_net, &init_user_ns))
|
|
panic("Could not setup the initial network namespace");
|
|
|
|
init_net_initialized = true;
|
|
|
|
rtnl_lock();
|
|
list_add_tail_rcu(&init_net.list, &net_namespace_list);
|
|
rtnl_unlock();
|
|
|
|
mutex_unlock(&net_mutex);
|
|
|
|
register_pernet_subsys(&net_ns_ops);
|
|
|
|
rtnl_register(PF_UNSPEC, RTM_NEWNSID, rtnl_net_newid, NULL, NULL);
|
|
rtnl_register(PF_UNSPEC, RTM_GETNSID, rtnl_net_getid, rtnl_net_dumpid,
|
|
NULL);
|
|
|
|
return 0;
|
|
}
|
|
|
|
pure_initcall(net_ns_init);
|
|
|
|
#ifdef CONFIG_NET_NS
|
|
static int __register_pernet_operations(struct list_head *list,
|
|
struct pernet_operations *ops)
|
|
{
|
|
struct net *net;
|
|
int error;
|
|
LIST_HEAD(net_exit_list);
|
|
|
|
list_add_tail(&ops->list, list);
|
|
if (ops->init || (ops->id && ops->size)) {
|
|
for_each_net(net) {
|
|
error = ops_init(ops, net);
|
|
if (error)
|
|
goto out_undo;
|
|
list_add_tail(&net->exit_list, &net_exit_list);
|
|
}
|
|
}
|
|
return 0;
|
|
|
|
out_undo:
|
|
/* If I have an error cleanup all namespaces I initialized */
|
|
list_del(&ops->list);
|
|
ops_exit_list(ops, &net_exit_list);
|
|
ops_free_list(ops, &net_exit_list);
|
|
return error;
|
|
}
|
|
|
|
static void __unregister_pernet_operations(struct pernet_operations *ops)
|
|
{
|
|
struct net *net;
|
|
LIST_HEAD(net_exit_list);
|
|
|
|
list_del(&ops->list);
|
|
for_each_net(net)
|
|
list_add_tail(&net->exit_list, &net_exit_list);
|
|
ops_exit_list(ops, &net_exit_list);
|
|
ops_free_list(ops, &net_exit_list);
|
|
}
|
|
|
|
#else
|
|
|
|
static int __register_pernet_operations(struct list_head *list,
|
|
struct pernet_operations *ops)
|
|
{
|
|
if (!init_net_initialized) {
|
|
list_add_tail(&ops->list, list);
|
|
return 0;
|
|
}
|
|
|
|
return ops_init(ops, &init_net);
|
|
}
|
|
|
|
static void __unregister_pernet_operations(struct pernet_operations *ops)
|
|
{
|
|
if (!init_net_initialized) {
|
|
list_del(&ops->list);
|
|
} else {
|
|
LIST_HEAD(net_exit_list);
|
|
list_add(&init_net.exit_list, &net_exit_list);
|
|
ops_exit_list(ops, &net_exit_list);
|
|
ops_free_list(ops, &net_exit_list);
|
|
}
|
|
}
|
|
|
|
#endif /* CONFIG_NET_NS */
|
|
|
|
static DEFINE_IDA(net_generic_ids);
|
|
|
|
static int register_pernet_operations(struct list_head *list,
|
|
struct pernet_operations *ops)
|
|
{
|
|
int error;
|
|
|
|
if (ops->id) {
|
|
again:
|
|
error = ida_get_new_above(&net_generic_ids, 1, ops->id);
|
|
if (error < 0) {
|
|
if (error == -EAGAIN) {
|
|
ida_pre_get(&net_generic_ids, GFP_KERNEL);
|
|
goto again;
|
|
}
|
|
return error;
|
|
}
|
|
max_gen_ptrs = max_t(unsigned int, max_gen_ptrs, *ops->id);
|
|
}
|
|
error = __register_pernet_operations(list, ops);
|
|
if (error) {
|
|
rcu_barrier();
|
|
if (ops->id)
|
|
ida_remove(&net_generic_ids, *ops->id);
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
static void unregister_pernet_operations(struct pernet_operations *ops)
|
|
{
|
|
|
|
__unregister_pernet_operations(ops);
|
|
rcu_barrier();
|
|
if (ops->id)
|
|
ida_remove(&net_generic_ids, *ops->id);
|
|
}
|
|
|
|
/**
|
|
* register_pernet_subsys - register a network namespace subsystem
|
|
* @ops: pernet operations structure for the subsystem
|
|
*
|
|
* Register a subsystem which has init and exit functions
|
|
* that are called when network namespaces are created and
|
|
* destroyed respectively.
|
|
*
|
|
* When registered all network namespace init functions are
|
|
* called for every existing network namespace. Allowing kernel
|
|
* modules to have a race free view of the set of network namespaces.
|
|
*
|
|
* When a new network namespace is created all of the init
|
|
* methods are called in the order in which they were registered.
|
|
*
|
|
* When a network namespace is destroyed all of the exit methods
|
|
* are called in the reverse of the order with which they were
|
|
* registered.
|
|
*/
|
|
int register_pernet_subsys(struct pernet_operations *ops)
|
|
{
|
|
int error;
|
|
mutex_lock(&net_mutex);
|
|
error = register_pernet_operations(first_device, ops);
|
|
mutex_unlock(&net_mutex);
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(register_pernet_subsys);
|
|
|
|
/**
|
|
* unregister_pernet_subsys - unregister a network namespace subsystem
|
|
* @ops: pernet operations structure to manipulate
|
|
*
|
|
* Remove the pernet operations structure from the list to be
|
|
* used when network namespaces are created or destroyed. In
|
|
* addition run the exit method for all existing network
|
|
* namespaces.
|
|
*/
|
|
void unregister_pernet_subsys(struct pernet_operations *ops)
|
|
{
|
|
mutex_lock(&net_mutex);
|
|
unregister_pernet_operations(ops);
|
|
mutex_unlock(&net_mutex);
|
|
}
|
|
EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
|
|
|
|
/**
|
|
* register_pernet_device - register a network namespace device
|
|
* @ops: pernet operations structure for the subsystem
|
|
*
|
|
* Register a device which has init and exit functions
|
|
* that are called when network namespaces are created and
|
|
* destroyed respectively.
|
|
*
|
|
* When registered all network namespace init functions are
|
|
* called for every existing network namespace. Allowing kernel
|
|
* modules to have a race free view of the set of network namespaces.
|
|
*
|
|
* When a new network namespace is created all of the init
|
|
* methods are called in the order in which they were registered.
|
|
*
|
|
* When a network namespace is destroyed all of the exit methods
|
|
* are called in the reverse of the order with which they were
|
|
* registered.
|
|
*/
|
|
int register_pernet_device(struct pernet_operations *ops)
|
|
{
|
|
int error;
|
|
mutex_lock(&net_mutex);
|
|
error = register_pernet_operations(&pernet_list, ops);
|
|
if (!error && (first_device == &pernet_list))
|
|
first_device = &ops->list;
|
|
mutex_unlock(&net_mutex);
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(register_pernet_device);
|
|
|
|
/**
|
|
* unregister_pernet_device - unregister a network namespace netdevice
|
|
* @ops: pernet operations structure to manipulate
|
|
*
|
|
* Remove the pernet operations structure from the list to be
|
|
* used when network namespaces are created or destroyed. In
|
|
* addition run the exit method for all existing network
|
|
* namespaces.
|
|
*/
|
|
void unregister_pernet_device(struct pernet_operations *ops)
|
|
{
|
|
mutex_lock(&net_mutex);
|
|
if (&ops->list == first_device)
|
|
first_device = first_device->next;
|
|
unregister_pernet_operations(ops);
|
|
mutex_unlock(&net_mutex);
|
|
}
|
|
EXPORT_SYMBOL_GPL(unregister_pernet_device);
|
|
|
|
#ifdef CONFIG_NET_NS
|
|
static struct ns_common *netns_get(struct task_struct *task)
|
|
{
|
|
struct net *net = NULL;
|
|
struct nsproxy *nsproxy;
|
|
|
|
task_lock(task);
|
|
nsproxy = task->nsproxy;
|
|
if (nsproxy)
|
|
net = get_net(nsproxy->net_ns);
|
|
task_unlock(task);
|
|
|
|
return net ? &net->ns : NULL;
|
|
}
|
|
|
|
static inline struct net *to_net_ns(struct ns_common *ns)
|
|
{
|
|
return container_of(ns, struct net, ns);
|
|
}
|
|
|
|
static void netns_put(struct ns_common *ns)
|
|
{
|
|
put_net(to_net_ns(ns));
|
|
}
|
|
|
|
static int netns_install(struct nsproxy *nsproxy, struct ns_common *ns)
|
|
{
|
|
struct net *net = to_net_ns(ns);
|
|
|
|
if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) ||
|
|
!ns_capable(current_user_ns(), CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
|
|
put_net(nsproxy->net_ns);
|
|
nsproxy->net_ns = get_net(net);
|
|
return 0;
|
|
}
|
|
|
|
const struct proc_ns_operations netns_operations = {
|
|
.name = "net",
|
|
.type = CLONE_NEWNET,
|
|
.get = netns_get,
|
|
.put = netns_put,
|
|
.install = netns_install,
|
|
};
|
|
#endif
|