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1028 lines
23 KiB
1028 lines
23 KiB
#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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/* |
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* Our network namespace constructor/destructor lists |
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*/ |
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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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|
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LIST_HEAD(net_namespace_list); |
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EXPORT_SYMBOL_GPL(net_namespace_list); |
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|
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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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|
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#define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */ |
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|
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static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS; |
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|
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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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|
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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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|
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return ng; |
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} |
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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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|
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BUG_ON(!mutex_is_locked(&net_mutex)); |
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BUG_ON(id == 0); |
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|
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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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|
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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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/* |
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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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|
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memcpy(&ng->ptr, &old_ng->ptr, old_ng->len * sizeof(void*)); |
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|
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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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|
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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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|
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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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|
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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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|
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out: |
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return err; |
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} |
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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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|
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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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|
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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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|
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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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|
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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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|
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return idr_alloc(&net->netns_ids, peer, min, max, GFP_ATOMIC); |
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} |
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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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|
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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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|
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*alloc = false; |
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|
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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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|
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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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|
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return NETNSA_NSID_NOT_ASSIGNED; |
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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 __peernet2id(struct net *net, struct net *peer) |
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{ |
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bool no = false; |
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|
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return __peernet2id_alloc(net, peer, &no); |
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} |
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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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unsigned long flags; |
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bool alloc; |
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int id; |
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|
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if (atomic_read(&net->count) == 0) |
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return NETNSA_NSID_NOT_ASSIGNED; |
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spin_lock_irqsave(&net->nsid_lock, flags); |
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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_irqrestore(&net->nsid_lock, flags); |
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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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EXPORT_SYMBOL(peernet2id_alloc); |
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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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unsigned long flags; |
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int id; |
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|
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spin_lock_irqsave(&net->nsid_lock, flags); |
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id = __peernet2id(net, peer); |
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spin_unlock_irqrestore(&net->nsid_lock, flags); |
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return id; |
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} |
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|
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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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|
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struct net *get_net_ns_by_id(struct net *net, int id) |
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{ |
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unsigned long flags; |
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struct net *peer; |
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|
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if (id < 0) |
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return NULL; |
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|
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rcu_read_lock(); |
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spin_lock_irqsave(&net->nsid_lock, flags); |
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peer = idr_find(&net->netns_ids, id); |
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if (peer) |
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peer = maybe_get_net(peer); |
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spin_unlock_irqrestore(&net->nsid_lock, flags); |
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rcu_read_unlock(); |
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|
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return peer; |
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} |
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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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|
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atomic_set(&net->count, 1); |
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atomic_set(&net->passive, 1); |
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get_random_bytes(&net->hash_mix, sizeof(u32)); |
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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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|
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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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|
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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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|
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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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|
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rcu_barrier(); |
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goto out; |
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} |
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|
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static int __net_init net_defaults_init_net(struct net *net) |
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{ |
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net->core.sysctl_somaxconn = SOMAXCONN; |
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return 0; |
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} |
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|
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static struct pernet_operations net_defaults_ops = { |
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.init = net_defaults_init_net, |
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}; |
|
|
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static __init int net_defaults_init(void) |
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{ |
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if (register_pernet_subsys(&net_defaults_ops)) |
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panic("Cannot initialize net default settings"); |
|
|
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return 0; |
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} |
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|
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core_initcall(net_defaults_init); |
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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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|
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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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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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{ |
|
struct net *ns = p; |
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if (ns && atomic_dec_and_test(&ns->passive)) |
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net_free(ns); |
|
} |
|
|
|
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); |
|
|
|
net = net_alloc(); |
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if (!net) |
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return ERR_PTR(-ENOMEM); |
|
|
|
get_user_ns(user_ns); |
|
|
|
mutex_lock(&net_mutex); |
|
rv = setup_net(net, user_ns); |
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if (rv == 0) { |
|
rtnl_lock(); |
|
list_add_tail_rcu(&net->list, &net_namespace_list); |
|
rtnl_unlock(); |
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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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} |
|
return net; |
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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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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); |
|
|
|
/* Atomically snapshot the list of namespaces to cleanup */ |
|
spin_lock_irq(&cleanup_list_lock); |
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list_replace_init(&cleanup_list, &net_kill_list); |
|
spin_unlock_irq(&cleanup_list_lock); |
|
|
|
mutex_lock(&net_mutex); |
|
|
|
/* Don't let anyone else find us. */ |
|
rtnl_lock(); |
|
list_for_each_entry(net, &net_kill_list, cleanup_list) { |
|
list_del_rcu(&net->list); |
|
list_add_tail(&net->exit_list, &net_exit_list); |
|
for_each_net(tmp) { |
|
int id; |
|
|
|
spin_lock_irq(&tmp->nsid_lock); |
|
id = __peernet2id(tmp, net); |
|
if (id >= 0) |
|
idr_remove(&tmp->netns_ids, id); |
|
spin_unlock_irq(&tmp->nsid_lock); |
|
if (id >= 0) |
|
rtnl_net_notifyid(tmp, RTM_DELNSID, id); |
|
} |
|
spin_lock_irq(&net->nsid_lock); |
|
idr_destroy(&net->netns_ids); |
|
spin_unlock_irq(&net->nsid_lock); |
|
|
|
} |
|
rtnl_unlock(); |
|
|
|
/* |
|
* Another CPU might be rcu-iterating the list, wait for it. |
|
* This needs to be before calling the exit() notifiers, so |
|
* the rcu_barrier() below isn't sufficient alone. |
|
*/ |
|
synchronize_rcu(); |
|
|
|
/* Run all of the network namespace exit methods */ |
|
list_for_each_entry_reverse(ops, &pernet_list, list) |
|
ops_exit_list(ops, &net_exit_list); |
|
|
|
/* Free the net generic variables */ |
|
list_for_each_entry_reverse(ops, &pernet_list, list) |
|
ops_free_list(ops, &net_exit_list); |
|
|
|
mutex_unlock(&net_mutex); |
|
|
|
/* Ensure there are no outstanding rcu callbacks using this |
|
* network namespace. |
|
*/ |
|
rcu_barrier(); |
|
|
|
/* Finally it is safe to free my network namespace structure */ |
|
list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) { |
|
list_del_init(&net->exit_list); |
|
put_user_ns(net->user_ns); |
|
net_drop_ns(net); |
|
} |
|
} |
|
static DECLARE_WORK(net_cleanup_work, cleanup_net); |
|
|
|
void __put_net(struct net *net) |
|
{ |
|
/* Cleanup the network namespace in process context */ |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&cleanup_list_lock, flags); |
|
list_add(&net->cleanup_list, &cleanup_list); |
|
spin_unlock_irqrestore(&cleanup_list_lock, flags); |
|
|
|
queue_work(netns_wq, &net_cleanup_work); |
|
} |
|
EXPORT_SYMBOL_GPL(__put_net); |
|
|
|
struct net *get_net_ns_by_fd(int fd) |
|
{ |
|
struct file *file; |
|
struct ns_common *ns; |
|
struct net *net; |
|
|
|
file = proc_ns_fget(fd); |
|
if (IS_ERR(file)) |
|
return ERR_CAST(file); |
|
|
|
ns = get_proc_ns(file_inode(file)); |
|
if (ns->ops == &netns_operations) |
|
net = get_net(container_of(ns, struct net, ns)); |
|
else |
|
net = ERR_PTR(-EINVAL); |
|
|
|
fput(file); |
|
return net; |
|
} |
|
|
|
#else |
|
struct net *get_net_ns_by_fd(int fd) |
|
{ |
|
return ERR_PTR(-EINVAL); |
|
} |
|
#endif |
|
EXPORT_SYMBOL_GPL(get_net_ns_by_fd); |
|
|
|
struct net *get_net_ns_by_pid(pid_t pid) |
|
{ |
|
struct task_struct *tsk; |
|
struct net *net; |
|
|
|
/* Lookup the network namespace */ |
|
net = ERR_PTR(-ESRCH); |
|
rcu_read_lock(); |
|
tsk = find_task_by_vpid(pid); |
|
if (tsk) { |
|
struct nsproxy *nsproxy; |
|
task_lock(tsk); |
|
nsproxy = tsk->nsproxy; |
|
if (nsproxy) |
|
net = get_net(nsproxy->net_ns); |
|
task_unlock(tsk); |
|
} |
|
rcu_read_unlock(); |
|
return net; |
|
} |
|
EXPORT_SYMBOL_GPL(get_net_ns_by_pid); |
|
|
|
static __net_init int net_ns_net_init(struct net *net) |
|
{ |
|
#ifdef CONFIG_NET_NS |
|
net->ns.ops = &netns_operations; |
|
#endif |
|
return ns_alloc_inum(&net->ns); |
|
} |
|
|
|
static __net_exit void net_ns_net_exit(struct net *net) |
|
{ |
|
ns_free_inum(&net->ns); |
|
} |
|
|
|
static struct pernet_operations __net_initdata net_ns_ops = { |
|
.init = net_ns_net_init, |
|
.exit = net_ns_net_exit, |
|
}; |
|
|
|
static struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = { |
|
[NETNSA_NONE] = { .type = NLA_UNSPEC }, |
|
[NETNSA_NSID] = { .type = NLA_S32 }, |
|
[NETNSA_PID] = { .type = NLA_U32 }, |
|
[NETNSA_FD] = { .type = NLA_U32 }, |
|
}; |
|
|
|
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]; |
|
unsigned long flags; |
|
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_irqsave(&net->nsid_lock, flags); |
|
if (__peernet2id(net, peer) >= 0) { |
|
spin_unlock_irqrestore(&net->nsid_lock, flags); |
|
err = -EEXIST; |
|
goto out; |
|
} |
|
|
|
err = alloc_netid(net, peer, nsid); |
|
spin_unlock_irqrestore(&net->nsid_lock, flags); |
|
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], |
|
}; |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&net->nsid_lock, flags); |
|
idr_for_each(&net->netns_ids, rtnl_net_dumpid_one, &net_cb); |
|
spin_unlock_irqrestore(&net->nsid_lock, flags); |
|
|
|
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"); |
|
|
|
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) |
|
{ |
|
return ops_init(ops, &init_net); |
|
} |
|
|
|
static void __unregister_pernet_operations(struct pernet_operations *ops) |
|
{ |
|
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
|
|
|