// SPDX-License-Identifier: GPL-2.0-only#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/workqueue.h>#include <linux/rtnetlink.h>#include <linux/cache.h>#include <linux/slab.h>#include <linux/list.h>#include <linux/delay.h>#include <linux/sched.h>#include <linux/idr.h>#include <linux/rculist.h>#include <linux/nsproxy.h>#include <linux/fs.h>#include <linux/proc_ns.h>#include <linux/file.h>#include <linux/export.h>#include <linux/user_namespace.h>#include <linux/net_namespace.h>#include <linux/sched/task.h>#include <linux/uidgid.h>#include <linux/proc_fs.h>#include <linux/nstree.h> #include <net/aligned_data.h>#include <net/sock.h>#include <net/netlink.h>#include <net/net_namespace.h>#include <net/netns/generic.h> /* * Our network namespace constructor/destructor lists */ static LIST_HEAD(pernet_list);static struct list_head *first_device = &pernet_list; LIST_HEAD(net_namespace_list);EXPORT_SYMBOL_GPL(net_namespace_list); /* Protects net_namespace_list. Nests iside rtnl_lock() */DECLARE_RWSEM(net_rwsem);EXPORT_SYMBOL_GPL(net_rwsem); #ifdef CONFIG_KEYSstatic struct key_tag init_net_key_domain = { .usage = REFCOUNT_INIT(1) };#endif struct net init_net;EXPORT_SYMBOL(init_net); static bool init_net_initialized;/* * pernet_ops_rwsem: protects: pernet_list, net_generic_ids, * init_net_initialized and first_device pointer. * This is internal net namespace object. Please, don't use it * outside. */DECLARE_RWSEM(pernet_ops_rwsem); #define MIN_PERNET_OPS_ID \ ((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *)) #define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */ static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS; static struct net_generic *net_alloc_generic(void){ unsigned int gen_ptrs = READ_ONCE(max_gen_ptrs); unsigned int generic_size; struct net_generic *ng; generic_size = offsetof(struct net_generic, ptr[gen_ptrs]); ng = kzalloc(generic_size, GFP_KERNEL); if (ng) ng->s.len = gen_ptrs; return ng;} static int net_assign_generic(struct net *net, unsigned int id, void *data){ struct net_generic *ng, *old_ng; BUG_ON(id < MIN_PERNET_OPS_ID); old_ng = rcu_dereference_protected(net->gen, lockdep_is_held(&pernet_ops_rwsem)); if (old_ng->s.len > id) { old_ng->ptr[id] = data; return 0; } ng = net_alloc_generic(); if (!ng) return -ENOMEM; /* * Some synchronisation notes: * * The net_generic explores the net->gen array inside rcu * read section. Besides once set the net->gen->ptr[x] * pointer never changes (see rules in netns/generic.h). * * That said, we simply duplicate this array and schedule * the old copy for kfree after a grace period. */ memcpy(&ng->ptr[MIN_PERNET_OPS_ID], &old_ng->ptr[MIN_PERNET_OPS_ID], (old_ng->s.len - MIN_PERNET_OPS_ID) * sizeof(void *)); ng->ptr[id] = data; rcu_assign_pointer(net->gen, ng); kfree_rcu(old_ng, s.rcu); return 0;} static int ops_init(const struct pernet_operations *ops, struct net *net){ struct net_generic *ng; int err = -ENOMEM; void *data = NULL; if (ops->id) { data = kzalloc(ops->size, GFP_KERNEL); if (!data) goto out; err = net_assign_generic(net, *ops->id, data); if (err) goto cleanup; } err = 0; if (ops->init) err = ops->init(net); if (!err) return 0; if (ops->id) { ng = rcu_dereference_protected(net->gen, lockdep_is_held(&pernet_ops_rwsem)); ng->ptr[*ops->id] = NULL; } cleanup: kfree(data); out: return err;} static void ops_pre_exit_list(const struct pernet_operations *ops, struct list_head *net_exit_list){ struct net *net; if (ops->pre_exit) { list_for_each_entry(net, net_exit_list, exit_list) ops->pre_exit(net); }} static void ops_exit_rtnl_list(const struct list_head *ops_list, const struct pernet_operations *ops, struct list_head *net_exit_list){ const struct pernet_operations *saved_ops = ops; LIST_HEAD(dev_kill_list); struct net *net; rtnl_lock(); list_for_each_entry(net, net_exit_list, exit_list) { __rtnl_net_lock(net); ops = saved_ops; list_for_each_entry_continue_reverse(ops, ops_list, list) { if (ops->exit_rtnl) ops->exit_rtnl(net, &dev_kill_list); } unregister_netdevice_queue_many_net(net, &dev_kill_list); __rtnl_net_unlock(net); } unregister_netdevice_many(&dev_kill_list); rtnl_unlock();} static void ops_exit_list(const struct pernet_operations *ops, struct list_head *net_exit_list){ if (ops->exit) { struct net *net; list_for_each_entry(net, net_exit_list, exit_list) { ops->exit(net); cond_resched(); } } if (ops->exit_batch) ops->exit_batch(net_exit_list);} static void ops_free_list(const struct pernet_operations *ops, struct list_head *net_exit_list){ struct net *net; if (ops->id) { list_for_each_entry(net, net_exit_list, exit_list) kfree(net_generic(net, *ops->id)); }} static void ops_undo_list(const struct list_head *ops_list, const struct pernet_operations *ops, struct list_head *net_exit_list, bool expedite_rcu){ const struct pernet_operations *saved_ops; bool hold_rtnl = false; if (!ops) ops = list_entry(ops_list, typeof(*ops), list); saved_ops = ops; list_for_each_entry_continue_reverse(ops, ops_list, list) { hold_rtnl |= !!ops->exit_rtnl; ops_pre_exit_list(ops, net_exit_list); } /* Another CPU might be rcu-iterating the list, wait for it. * This needs to be before calling the exit() notifiers, so the * rcu_barrier() after ops_undo_list() isn't sufficient alone. * Also the pre_exit() and exit() methods need this barrier. */ if (expedite_rcu) synchronize_rcu_expedited(); else synchronize_rcu(); if (hold_rtnl) ops_exit_rtnl_list(ops_list, saved_ops, net_exit_list); ops = saved_ops; list_for_each_entry_continue_reverse(ops, ops_list, list) ops_exit_list(ops, net_exit_list); ops = saved_ops; list_for_each_entry_continue_reverse(ops, ops_list, list) ops_free_list(ops, net_exit_list);} static void ops_undo_single(struct pernet_operations *ops, struct list_head *net_exit_list){ LIST_HEAD(ops_list); list_add(&ops->list, &ops_list); ops_undo_list(&ops_list, NULL, net_exit_list, false); list_del(&ops->list);} /* should be called with nsid_lock held */static int alloc_netid(struct net *net, struct net *peer, int reqid){ int min = 0, max = 0; if (reqid >= 0) { min = reqid; max = reqid + 1; } return idr_alloc(&net->netns_ids, peer, min, max, GFP_ATOMIC);} /* This function is used by idr_for_each(). If net is equal to peer, the * function returns the id so that idr_for_each() stops. Because we cannot * returns the id 0 (idr_for_each() will not stop), we return the magic value * NET_ID_ZERO (-1) for it. */#define NET_ID_ZERO -1static int net_eq_idr(int id, void *net, void *peer){ if (net_eq(net, peer)) return id ? : NET_ID_ZERO; return 0;} /* Must be called from RCU-critical section or with nsid_lock held */static int __peernet2id(const struct net *net, struct net *peer){ int id = idr_for_each(&net->netns_ids, net_eq_idr, peer); /* Magic value for id 0. */ if (id == NET_ID_ZERO) return 0; if (id > 0) return id; return NETNSA_NSID_NOT_ASSIGNED;} static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid, struct nlmsghdr *nlh, gfp_t gfp);/* This function returns the id of a peer netns. If no id is assigned, one will * be allocated and returned. */int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp){ int id; if (!check_net(net)) return NETNSA_NSID_NOT_ASSIGNED; spin_lock(&net->nsid_lock); id = __peernet2id(net, peer); if (id >= 0) { spin_unlock(&net->nsid_lock); return id; } /* When peer is obtained from RCU lists, we may race with * its cleanup. Check whether it's alive, and this guarantees * we never hash a peer back to net->netns_ids, after it has * just been idr_remove()'d from there in cleanup_net(). */ if (!maybe_get_net(peer)) { spin_unlock(&net->nsid_lock); return NETNSA_NSID_NOT_ASSIGNED; } id = alloc_netid(net, peer, -1); spin_unlock(&net->nsid_lock); put_net(peer); if (id < 0) return NETNSA_NSID_NOT_ASSIGNED; rtnl_net_notifyid(net, RTM_NEWNSID, id, 0, NULL, gfp); return id;}EXPORT_SYMBOL_GPL(peernet2id_alloc); /* This function returns, if assigned, the id of a peer netns. */int peernet2id(const struct net *net, struct net *peer){ int id; rcu_read_lock(); id = __peernet2id(net, peer); rcu_read_unlock(); return id;}EXPORT_SYMBOL(peernet2id); /* This function returns true is the peer netns has an id assigned into the * current netns. */bool peernet_has_id(const struct net *net, struct net *peer){ return peernet2id(net, peer) >= 0;} struct net *get_net_ns_by_id(const struct net *net, int id){ struct net *peer; if (id < 0) return NULL; rcu_read_lock(); peer = idr_find(&net->netns_ids, id); if (peer) peer = maybe_get_net(peer); rcu_read_unlock(); return peer;}EXPORT_SYMBOL_GPL(get_net_ns_by_id); static __net_init void preinit_net_sysctl(struct net *net){ net->core.sysctl_somaxconn = SOMAXCONN; /* Limits per socket sk_omem_alloc usage. * TCP zerocopy regular usage needs 128 KB. */ net->core.sysctl_optmem_max = 128 * 1024; net->core.sysctl_txrehash = SOCK_TXREHASH_ENABLED; net->core.sysctl_tstamp_allow_data = 1; net->core.sysctl_txq_reselection = msecs_to_jiffies(1000);} /* init code that must occur even if setup_net() is not called. */static __net_init void preinit_net(struct net *net, struct user_namespace *user_ns){ refcount_set(&net->passive, 1); ref_tracker_dir_init(&net->refcnt_tracker, 128, "net_refcnt"); ref_tracker_dir_init(&net->notrefcnt_tracker, 128, "net_notrefcnt"); net->hash_mix = get_random_u32(); net->dev_base_seq = 1; net->user_ns = user_ns; idr_init(&net->netns_ids); spin_lock_init(&net->nsid_lock); mutex_init(&net->ipv4.ra_mutex); #ifdef CONFIG_DEBUG_NET_SMALL_RTNL mutex_init(&net->rtnl_mutex); lock_set_cmp_fn(&net->rtnl_mutex, rtnl_net_lock_cmp_fn, NULL); INIT_WORK(&net->rtnl_work, rtnl_net_work_func); INIT_LIST_HEAD(&net->dev_unreg_head); spin_lock_init(&net->dev_unreg_lock);#endif INIT_LIST_HEAD(&net->ptype_all); INIT_LIST_HEAD(&net->ptype_specific); preinit_net_sysctl(net);} /* * setup_net runs the initializers for the network namespace object. */static __net_init int setup_net(struct net *net){ /* Must be called with pernet_ops_rwsem held */ const struct pernet_operations *ops; LIST_HEAD(net_exit_list); int error = 0; net->net_cookie = ns_tree_gen_id(net); list_for_each_entry(ops, &pernet_list, list) { error = ops_init(ops, net); if (error < 0) goto out_undo; } down_write(&net_rwsem); list_add_tail_rcu(&net->list, &net_namespace_list); up_write(&net_rwsem); ns_tree_add_raw(net);out: return error; out_undo: /* Walk through the list backwards calling the exit functions * for the pernet modules whose init functions did not fail. */ list_add(&net->exit_list, &net_exit_list); ops_undo_list(&pernet_list, ops, &net_exit_list, false); rcu_barrier(); goto out;} #ifdef CONFIG_NET_NSstatic struct ucounts *inc_net_namespaces(struct user_namespace *ns){ return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES);} static void dec_net_namespaces(struct ucounts *ucounts){ dec_ucount(ucounts, UCOUNT_NET_NAMESPACES);} static struct kmem_cache *net_cachep __ro_after_init;static struct workqueue_struct *netns_wq; static struct net *net_alloc(void){ struct net *net = NULL; struct net_generic *ng; ng = net_alloc_generic(); if (!ng) goto out; net = kmem_cache_zalloc(net_cachep, GFP_KERNEL); if (!net) goto out_free; #ifdef CONFIG_KEYS net->key_domain = kzalloc_obj(struct key_tag); if (!net->key_domain) goto out_free_2; refcount_set(&net->key_domain->usage, 1);#endif rcu_assign_pointer(net->gen, ng);out: return net;Lines 1–500 of 1560. 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// SPDX-License-Identifier: GPL-2.0-only #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/workqueue.h> #include <linux/rtnetlink.h> #include <linux/cache.h> #include <linux/slab.h> #include <linux/list.h> #include <linux/delay.h> #include <linux/sched.h> #include <linux/idr.h> #include <linux/rculist.h> #include <linux/nsproxy.h> #include <linux/fs.h> #include <linux/proc_ns.h> #include <linux/file.h> #include <linux/export.h> #include <linux/user_namespace.h> #include <linux/net_namespace.h> #include <linux/sched/task.h> #include <linux/uidgid.h> #include <linux/proc_fs.h> #include <linux/nstree.h> #include <net/aligned_data.h> #include <net/sock.h> #include <net/netlink.h> #include <net/net_namespace.h> #include <net/netns/generic.h> /* * Our network namespace constructor/destructor lists */ static LIST_HEAD(pernet_list); static struct list_head *first_device = &pernet_list; LIST_HEAD(net_namespace_list); EXPORT_SYMBOL_GPL(net_namespace_list); /* Protects net_namespace_list. Nests iside rtnl_lock() */ DECLARE_RWSEM(net_rwsem); EXPORT_SYMBOL_GPL(net_rwsem); #ifdef CONFIG_KEYS static struct key_tag init_net_key_domain = { .usage = REFCOUNT_INIT(1) }; #endif struct net init_net; EXPORT_SYMBOL(init_net); static bool init_net_initialized; /* * pernet_ops_rwsem: protects: pernet_list, net_generic_ids, * init_net_initialized and first_device pointer. * This is internal net namespace object. Please, don't use it * outside. */ DECLARE_RWSEM(pernet_ops_rwsem); #define MIN_PERNET_OPS_ID \ ((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *)) #define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */ static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS; static struct net_generic *net_alloc_generic(void) { unsigned int gen_ptrs = READ_ONCE(max_gen_ptrs); unsigned int generic_size; struct net_generic *ng; generic_size = offsetof(struct net_generic, ptr[gen_ptrs]); ng = kzalloc(generic_size, GFP_KERNEL); if (ng) ng->s.len = gen_ptrs; return ng; } static int net_assign_generic(struct net *net, unsigned int id, void *data) { struct net_generic *ng, *old_ng; BUG_ON(id < MIN_PERNET_OPS_ID); old_ng = rcu_dereference_protected(net->gen, lockdep_is_held(&pernet_ops_rwsem)); if (old_ng->s.len > id) { old_ng->ptr[id] = data; return 0; } ng = net_alloc_generic(); if (!ng) return -ENOMEM; /* * Some synchronisation notes: * * The net_generic explores the net->gen array inside rcu * read section. Besides once set the net->gen->ptr[x] * pointer never changes (see rules in netns/generic.h). * * That said, we simply duplicate this array and schedule * the old copy for kfree after a grace period. */ memcpy(&ng->ptr[MIN_PERNET_OPS_ID], &old_ng->ptr[MIN_PERNET_OPS_ID], (old_ng->s.len - MIN_PERNET_OPS_ID) * sizeof(void *)); ng->ptr[id] = data; rcu_assign_pointer(net->gen, ng); kfree_rcu(old_ng, s.rcu); return 0; } static int ops_init(const struct pernet_operations *ops, struct net *net) { struct net_generic *ng; int err = -ENOMEM; void *data = NULL; if (ops->id) { data = kzalloc(ops->size, GFP_KERNEL); if (!data) goto out; err = net_assign_generic(net, *ops->id, data); if (err) goto cleanup; } err = 0; if (ops->init) err = ops->init(net); if (!err) return 0; if (ops->id) { ng = rcu_dereference_protected(net->gen, lockdep_is_held(&pernet_ops_rwsem)); ng->ptr[*ops->id] = NULL; } cleanup: kfree(data); out: return err; } static void ops_pre_exit_list(const struct pernet_operations *ops, struct list_head *net_exit_list) { struct net *net; if (ops->pre_exit) { list_for_each_entry(net, net_exit_list, exit_list) ops->pre_exit(net); } } static void ops_exit_rtnl_list(const struct list_head *ops_list, const struct pernet_operations *ops, struct list_head *net_exit_list) { const struct pernet_operations *saved_ops = ops; LIST_HEAD(dev_kill_list); struct net *net; rtnl_lock(); list_for_each_entry(net, net_exit_list, exit_list) { __rtnl_net_lock(net); ops = saved_ops; list_for_each_entry_continue_reverse(ops, ops_list, list) { if (ops->exit_rtnl) ops->exit_rtnl(net, &dev_kill_list); } unregister_netdevice_queue_many_net(net, &dev_kill_list); __rtnl_net_unlock(net); } unregister_netdevice_many(&dev_kill_list); rtnl_unlock(); } static void ops_exit_list(const struct pernet_operations *ops, struct list_head *net_exit_list) { if (ops->exit) { struct net *net; list_for_each_entry(net, net_exit_list, exit_list) { ops->exit(net); cond_resched(); } } if (ops->exit_batch) ops->exit_batch(net_exit_list); } static void ops_free_list(const struct pernet_operations *ops, struct list_head *net_exit_list) { struct net *net; if (ops->id) { list_for_each_entry(net, net_exit_list, exit_list) kfree(net_generic(net, *ops->id)); } } static void ops_undo_list(const struct list_head *ops_list, const struct pernet_operations *ops, struct list_head *net_exit_list, bool expedite_rcu) { const struct pernet_operations *saved_ops; bool hold_rtnl = false; if (!ops) ops = list_entry(ops_list, typeof(*ops), list); saved_ops = ops; list_for_each_entry_continue_reverse(ops, ops_list, list) { hold_rtnl |= !!ops->exit_rtnl; ops_pre_exit_list(ops, net_exit_list); } /* Another CPU might be rcu-iterating the list, wait for it. * This needs to be before calling the exit() notifiers, so the * rcu_barrier() after ops_undo_list() isn't sufficient alone. * Also the pre_exit() and exit() methods need this barrier. */ if (expedite_rcu) synchronize_rcu_expedited(); else synchronize_rcu(); if (hold_rtnl) ops_exit_rtnl_list(ops_list, saved_ops, net_exit_list); ops = saved_ops; list_for_each_entry_continue_reverse(ops, ops_list, list) ops_exit_list(ops, net_exit_list); ops = saved_ops; list_for_each_entry_continue_reverse(ops, ops_list, list) ops_free_list(ops, net_exit_list); } static void ops_undo_single(struct pernet_operations *ops, struct list_head *net_exit_list) { LIST_HEAD(ops_list); list_add(&ops->list, &ops_list); ops_undo_list(&ops_list, NULL, net_exit_list, false); list_del(&ops->list); } /* should be called with nsid_lock held */ static int alloc_netid(struct net *net, struct net *peer, int reqid) { int min = 0, max = 0; if (reqid >= 0) { min = reqid; max = reqid + 1; } return idr_alloc(&net->netns_ids, peer, min, max, GFP_ATOMIC); } /* This function is used by idr_for_each(). If net is equal to peer, the * function returns the id so that idr_for_each() stops. Because we cannot * returns the id 0 (idr_for_each() will not stop), we return the magic value * NET_ID_ZERO (-1) for it. */ #define NET_ID_ZERO -1 static int net_eq_idr(int id, void *net, void *peer) { if (net_eq(net, peer)) return id ? : NET_ID_ZERO; return 0; } /* Must be called from RCU-critical section or with nsid_lock held */ static int __peernet2id(const struct net *net, struct net *peer) { int id = idr_for_each(&net->netns_ids, net_eq_idr, peer); /* Magic value for id 0. */ if (id == NET_ID_ZERO) return 0; if (id > 0) return id; return NETNSA_NSID_NOT_ASSIGNED; } static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid, struct nlmsghdr *nlh, gfp_t gfp); /* This function returns the id of a peer netns. If no id is assigned, one will * be allocated and returned. */ int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp) { int id; if (!check_net(net)) return NETNSA_NSID_NOT_ASSIGNED; spin_lock(&net->nsid_lock); id = __peernet2id(net, peer); if (id >= 0) { spin_unlock(&net->nsid_lock); return id; } /* When peer is obtained from RCU lists, we may race with * its cleanup. Check whether it's alive, and this guarantees * we never hash a peer back to net->netns_ids, after it has * just been idr_remove()'d from there in cleanup_net(). */ if (!maybe_get_net(peer)) { spin_unlock(&net->nsid_lock); return NETNSA_NSID_NOT_ASSIGNED; } id = alloc_netid(net, peer, -1); spin_unlock(&net->nsid_lock); put_net(peer); if (id < 0) return NETNSA_NSID_NOT_ASSIGNED; rtnl_net_notifyid(net, RTM_NEWNSID, id, 0, NULL, gfp); return id; } EXPORT_SYMBOL_GPL(peernet2id_alloc); /* This function returns, if assigned, the id of a peer netns. */ int peernet2id(const struct net *net, struct net *peer) { int id; rcu_read_lock(); id = __peernet2id(net, peer); rcu_read_unlock(); return id; } EXPORT_SYMBOL(peernet2id); /* This function returns true is the peer netns has an id assigned into the * current netns. */ bool peernet_has_id(const struct net *net, struct net *peer) { return peernet2id(net, peer) >= 0; } struct net *get_net_ns_by_id(const struct net *net, int id) { struct net *peer; if (id < 0) return NULL; rcu_read_lock(); peer = idr_find(&net->netns_ids, id); if (peer) peer = maybe_get_net(peer); rcu_read_unlock(); return peer; } EXPORT_SYMBOL_GPL(get_net_ns_by_id); static __net_init void preinit_net_sysctl(struct net *net) { net->core.sysctl_somaxconn = SOMAXCONN; /* Limits per socket sk_omem_alloc usage. * TCP zerocopy regular usage needs 128 KB. */ net->core.sysctl_optmem_max = 128 * 1024; net->core.sysctl_txrehash = SOCK_TXREHASH_ENABLED; net->core.sysctl_tstamp_allow_data = 1; net->core.sysctl_txq_reselection = msecs_to_jiffies(1000); } /* init code that must occur even if setup_net() is not called. */ static __net_init void preinit_net(struct net *net, struct user_namespace *user_ns) { refcount_set(&net->passive, 1); ref_tracker_dir_init(&net->refcnt_tracker, 128, "net_refcnt"); ref_tracker_dir_init(&net->notrefcnt_tracker, 128, "net_notrefcnt"); net->hash_mix = get_random_u32(); net->dev_base_seq = 1; net->user_ns = user_ns; idr_init(&net->netns_ids); spin_lock_init(&net->nsid_lock); mutex_init(&net->ipv4.ra_mutex); #ifdef CONFIG_DEBUG_NET_SMALL_RTNL mutex_init(&net->rtnl_mutex); lock_set_cmp_fn(&net->rtnl_mutex, rtnl_net_lock_cmp_fn, NULL); INIT_WORK(&net->rtnl_work, rtnl_net_work_func); INIT_LIST_HEAD(&net->dev_unreg_head); spin_lock_init(&net->dev_unreg_lock); #endif INIT_LIST_HEAD(&net->ptype_all); INIT_LIST_HEAD(&net->ptype_specific); preinit_net_sysctl(net); } /* * setup_net runs the initializers for the network namespace object. */ static __net_init int setup_net(struct net *net) { /* Must be called with pernet_ops_rwsem held */ const struct pernet_operations *ops; LIST_HEAD(net_exit_list); int error = 0; net->net_cookie = ns_tree_gen_id(net); list_for_each_entry(ops, &pernet_list, list) { error = ops_init(ops, net); if (error < 0) goto out_undo; } down_write(&net_rwsem); list_add_tail_rcu(&net->list, &net_namespace_list); up_write(&net_rwsem); ns_tree_add_raw(net); out: return error; out_undo: /* Walk through the list backwards calling the exit functions * for the pernet modules whose init functions did not fail. */ list_add(&net->exit_list, &net_exit_list); ops_undo_list(&pernet_list, ops, &net_exit_list, false); rcu_barrier(); goto out; } #ifdef CONFIG_NET_NS static struct ucounts *inc_net_namespaces(struct user_namespace *ns) { return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES); } static void dec_net_namespaces(struct ucounts *ucounts) { dec_ucount(ucounts, UCOUNT_NET_NAMESPACES); } static struct kmem_cache *net_cachep __ro_after_init; static struct workqueue_struct *netns_wq; static struct net *net_alloc(void) { struct net *net = NULL; struct net_generic *ng; ng = net_alloc_generic(); if (!ng) goto out; net = kmem_cache_zalloc(net_cachep, GFP_KERNEL); if (!net) goto out_free; #ifdef CONFIG_KEYS net->key_domain = kzalloc_obj(struct key_tag); if (!net->key_domain) goto out_free_2; refcount_set(&net->key_domain->usage, 1); #endif rcu_assign_pointer(net->gen, ng); out: return net;