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-rw-r--r--net/core/net_namespace.c1412
1 files changed, 1412 insertions, 0 deletions
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
new file mode 100644
index 000000000..e05dd4f32
--- /dev/null
+++ b/net/core/net_namespace.c
@@ -0,0 +1,1412 @@
+// 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/cookie.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 = {
+ .count = REFCOUNT_INIT(1),
+ .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head),
+#ifdef CONFIG_KEYS
+ .key_domain = &init_net_key_domain,
+#endif
+};
+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);
+EXPORT_SYMBOL_GPL(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;
+
+DEFINE_COOKIE(net_cookie);
+
+u64 __net_gen_cookie(struct net *net)
+{
+ while (1) {
+ u64 res = atomic64_read(&net->net_cookie);
+
+ if (res)
+ return res;
+ res = gen_cookie_next(&net_cookie);
+ atomic64_cmpxchg(&net->net_cookie, 0, res);
+ }
+}
+
+static struct net_generic *net_alloc_generic(void)
+{
+ struct net_generic *ng;
+ unsigned int generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]);
+
+ ng = kzalloc(generic_size, GFP_KERNEL);
+ if (ng)
+ ng->s.len = max_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 == NULL)
+ 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 && ops->size) {
+ 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 && ops->size) {
+ 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_free(const struct pernet_operations *ops, struct net *net)
+{
+ if (ops->id && ops->size) {
+ kfree(net_generic(net, *ops->id));
+ }
+}
+
+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_list(const struct pernet_operations *ops,
+ struct list_head *net_exit_list)
+{
+ struct net *net;
+ if (ops->exit) {
+ 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->size && ops->id) {
+ list_for_each_entry(net, net_exit_list, exit_list)
+ ops_free(ops, net);
+ }
+}
+
+/* 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 (refcount_read(&net->count) == 0)
+ return NETNSA_NSID_NOT_ASSIGNED;
+
+ spin_lock_bh(&net->nsid_lock);
+ id = __peernet2id(net, peer);
+ if (id >= 0) {
+ spin_unlock_bh(&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_bh(&net->nsid_lock);
+ return NETNSA_NSID_NOT_ASSIGNED;
+ }
+
+ id = alloc_netid(net, peer, -1);
+ spin_unlock_bh(&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;
+}
+
+/*
+ * setup_net runs the initializers for the network namespace object.
+ */
+static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
+{
+ /* Must be called with pernet_ops_rwsem held */
+ const struct pernet_operations *ops, *saved_ops;
+ int error = 0;
+ LIST_HEAD(net_exit_list);
+
+ refcount_set(&net->count, 1);
+ refcount_set(&net->passive, 1);
+ get_random_bytes(&net->hash_mix, sizeof(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);
+
+ 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);
+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);
+ saved_ops = ops;
+ list_for_each_entry_continue_reverse(ops, &pernet_list, list)
+ ops_pre_exit_list(ops, &net_exit_list);
+
+ synchronize_rcu();
+
+ ops = saved_ops;
+ list_for_each_entry_continue_reverse(ops, &pernet_list, list)
+ ops_exit_list(ops, &net_exit_list);
+
+ ops = saved_ops;
+ list_for_each_entry_continue_reverse(ops, &pernet_list, list)
+ ops_free_list(ops, &net_exit_list);
+
+ rcu_barrier();
+ goto out;
+}
+
+static int __net_init net_defaults_init_net(struct net *net)
+{
+ net->core.sysctl_somaxconn = SOMAXCONN;
+ return 0;
+}
+
+static struct pernet_operations net_defaults_ops = {
+ .init = net_defaults_init_net,
+};
+
+static __init int net_defaults_init(void)
+{
+ if (register_pernet_subsys(&net_defaults_ops))
+ panic("Cannot initialize net default settings");
+
+ return 0;
+}
+
+core_initcall(net_defaults_init);
+
+#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(sizeof(struct key_tag), GFP_KERNEL);
+ 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;
+
+#ifdef CONFIG_KEYS
+out_free_2:
+ kmem_cache_free(net_cachep, net);
+ net = NULL;
+#endif
+out_free:
+ kfree(ng);
+ goto out;
+}
+
+static void net_free(struct net *net)
+{
+ kfree(rcu_access_pointer(net->gen));
+ kmem_cache_free(net_cachep, net);
+}
+
+void net_drop_ns(void *p)
+{
+ struct net *ns = p;
+ if (ns && refcount_dec_and_test(&ns->passive))
+ net_free(ns);
+}
+
+struct net *copy_net_ns(unsigned long flags,
+ struct user_namespace *user_ns, struct net *old_net)
+{
+ struct ucounts *ucounts;
+ struct net *net;
+ int rv;
+
+ if (!(flags & CLONE_NEWNET))
+ return get_net(old_net);
+
+ ucounts = inc_net_namespaces(user_ns);
+ if (!ucounts)
+ return ERR_PTR(-ENOSPC);
+
+ net = net_alloc();
+ if (!net) {
+ rv = -ENOMEM;
+ goto dec_ucounts;
+ }
+ refcount_set(&net->passive, 1);
+ net->ucounts = ucounts;
+ get_user_ns(user_ns);
+
+ rv = down_read_killable(&pernet_ops_rwsem);
+ if (rv < 0)
+ goto put_userns;
+
+ rv = setup_net(net, user_ns);
+
+ up_read(&pernet_ops_rwsem);
+
+ if (rv < 0) {
+put_userns:
+#ifdef CONFIG_KEYS
+ key_remove_domain(net->key_domain);
+#endif
+ put_user_ns(user_ns);
+ net_drop_ns(net);
+dec_ucounts:
+ dec_net_namespaces(ucounts);
+ return ERR_PTR(rv);
+ }
+ return net;
+}
+
+/**
+ * net_ns_get_ownership - get sysfs ownership data for @net
+ * @net: network namespace in question (can be NULL)
+ * @uid: kernel user ID for sysfs objects
+ * @gid: kernel group ID for sysfs objects
+ *
+ * Returns the uid/gid pair of root in the user namespace associated with the
+ * given network namespace.
+ */
+void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid)
+{
+ if (net) {
+ kuid_t ns_root_uid = make_kuid(net->user_ns, 0);
+ kgid_t ns_root_gid = make_kgid(net->user_ns, 0);
+
+ if (uid_valid(ns_root_uid))
+ *uid = ns_root_uid;
+
+ if (gid_valid(ns_root_gid))
+ *gid = ns_root_gid;
+ } else {
+ *uid = GLOBAL_ROOT_UID;
+ *gid = GLOBAL_ROOT_GID;
+ }
+}
+EXPORT_SYMBOL_GPL(net_ns_get_ownership);
+
+static void unhash_nsid(struct net *net, struct net *last)
+{
+ struct net *tmp;
+ /* This function is only called from cleanup_net() work,
+ * and this work is the only process, that may delete
+ * a net from net_namespace_list. So, when the below
+ * is executing, the list may only grow. Thus, we do not
+ * use for_each_net_rcu() or net_rwsem.
+ */
+ for_each_net(tmp) {
+ int id;
+
+ spin_lock_bh(&tmp->nsid_lock);
+ id = __peernet2id(tmp, net);
+ if (id >= 0)
+ idr_remove(&tmp->netns_ids, id);
+ spin_unlock_bh(&tmp->nsid_lock);
+ if (id >= 0)
+ rtnl_net_notifyid(tmp, RTM_DELNSID, id, 0, NULL,
+ GFP_KERNEL);
+ if (tmp == last)
+ break;
+ }
+ spin_lock_bh(&net->nsid_lock);
+ idr_destroy(&net->netns_ids);
+ spin_unlock_bh(&net->nsid_lock);
+}
+
+static LLIST_HEAD(cleanup_list);
+
+static void cleanup_net(struct work_struct *work)
+{
+ const struct pernet_operations *ops;
+ struct net *net, *tmp, *last;
+ struct llist_node *net_kill_list;
+ LIST_HEAD(net_exit_list);
+
+ /* Atomically snapshot the list of namespaces to cleanup */
+ net_kill_list = llist_del_all(&cleanup_list);
+
+ down_read(&pernet_ops_rwsem);
+
+ /* Don't let anyone else find us. */
+ down_write(&net_rwsem);
+ llist_for_each_entry(net, net_kill_list, cleanup_list)
+ list_del_rcu(&net->list);
+ /* Cache last net. After we unlock rtnl, no one new net
+ * added to net_namespace_list can assign nsid pointer
+ * to a net from net_kill_list (see peernet2id_alloc()).
+ * So, we skip them in unhash_nsid().
+ *
+ * Note, that unhash_nsid() does not delete nsid links
+ * between net_kill_list's nets, as they've already
+ * deleted from net_namespace_list. But, this would be
+ * useless anyway, as netns_ids are destroyed there.
+ */
+ last = list_last_entry(&net_namespace_list, struct net, list);
+ up_write(&net_rwsem);
+
+ llist_for_each_entry(net, net_kill_list, cleanup_list) {
+ unhash_nsid(net, last);
+ list_add_tail(&net->exit_list, &net_exit_list);
+ }
+
+ /* Run all of the network namespace pre_exit methods */
+ list_for_each_entry_reverse(ops, &pernet_list, list)
+ 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() below isn't sufficient alone.
+ * Also the pre_exit() and exit() methods need this barrier.
+ */
+ 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);
+
+ up_read(&pernet_ops_rwsem);
+
+ /* 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);
+ dec_net_namespaces(net->ucounts);
+#ifdef CONFIG_KEYS
+ key_remove_domain(net->key_domain);
+#endif
+ put_user_ns(net->user_ns);
+ net_drop_ns(net);
+ }
+}
+
+/**
+ * net_ns_barrier - wait until concurrent net_cleanup_work is done
+ *
+ * cleanup_net runs from work queue and will first remove namespaces
+ * from the global list, then run net exit functions.
+ *
+ * Call this in module exit path to make sure that all netns
+ * ->exit ops have been invoked before the function is removed.
+ */
+void net_ns_barrier(void)
+{
+ down_write(&pernet_ops_rwsem);
+ up_write(&pernet_ops_rwsem);
+}
+EXPORT_SYMBOL(net_ns_barrier);
+
+static DECLARE_WORK(net_cleanup_work, cleanup_net);
+
+void __put_net(struct net *net)
+{
+ /* Cleanup the network namespace in process context */
+ if (llist_add(&net->cleanup_list, &cleanup_list))
+ queue_work(netns_wq, &net_cleanup_work);
+}
+EXPORT_SYMBOL_GPL(__put_net);
+
+/**
+ * get_net_ns - increment the refcount of the network namespace
+ * @ns: common namespace (net)
+ *
+ * Returns the net's common namespace.
+ */
+struct ns_common *get_net_ns(struct ns_common *ns)
+{
+ return &get_net(container_of(ns, struct net, ns))->ns;
+}
+EXPORT_SYMBOL_GPL(get_net_ns);
+
+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 const 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 },
+ [NETNSA_TARGET_NSID] = { .type = NLA_S32 },
+};
+
+static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
+{
+ struct net *net = sock_net(skb->sk);
+ struct nlattr *tb[NETNSA_MAX + 1];
+ struct nlattr *nla;
+ struct net *peer;
+ int nsid, err;
+
+ err = nlmsg_parse_deprecated(nlh, sizeof(struct rtgenmsg), tb,
+ NETNSA_MAX, rtnl_net_policy, extack);
+ if (err < 0)
+ return err;
+ if (!tb[NETNSA_NSID]) {
+ NL_SET_ERR_MSG(extack, "nsid is missing");
+ 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]));
+ nla = tb[NETNSA_PID];
+ } else if (tb[NETNSA_FD]) {
+ peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
+ nla = tb[NETNSA_FD];
+ } else {
+ NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
+ return -EINVAL;
+ }
+ if (IS_ERR(peer)) {
+ NL_SET_BAD_ATTR(extack, nla);
+ NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
+ return PTR_ERR(peer);
+ }
+
+ spin_lock_bh(&net->nsid_lock);
+ if (__peernet2id(net, peer) >= 0) {
+ spin_unlock_bh(&net->nsid_lock);
+ err = -EEXIST;
+ NL_SET_BAD_ATTR(extack, nla);
+ NL_SET_ERR_MSG(extack,
+ "Peer netns already has a nsid assigned");
+ goto out;
+ }
+
+ err = alloc_netid(net, peer, nsid);
+ spin_unlock_bh(&net->nsid_lock);
+ if (err >= 0) {
+ rtnl_net_notifyid(net, RTM_NEWNSID, err, NETLINK_CB(skb).portid,
+ nlh, GFP_KERNEL);
+ err = 0;
+ } else if (err == -ENOSPC && nsid >= 0) {
+ err = -EEXIST;
+ NL_SET_BAD_ATTR(extack, tb[NETNSA_NSID]);
+ NL_SET_ERR_MSG(extack, "The specified nsid is already used");
+ }
+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 */
+ + nla_total_size(sizeof(s32)) /* NETNSA_CURRENT_NSID */
+ ;
+}
+
+struct net_fill_args {
+ u32 portid;
+ u32 seq;
+ int flags;
+ int cmd;
+ int nsid;
+ bool add_ref;
+ int ref_nsid;
+};
+
+static int rtnl_net_fill(struct sk_buff *skb, struct net_fill_args *args)
+{
+ struct nlmsghdr *nlh;
+ struct rtgenmsg *rth;
+
+ nlh = nlmsg_put(skb, args->portid, args->seq, args->cmd, sizeof(*rth),
+ args->flags);
+ if (!nlh)
+ return -EMSGSIZE;
+
+ rth = nlmsg_data(nlh);
+ rth->rtgen_family = AF_UNSPEC;
+
+ if (nla_put_s32(skb, NETNSA_NSID, args->nsid))
+ goto nla_put_failure;
+
+ if (args->add_ref &&
+ nla_put_s32(skb, NETNSA_CURRENT_NSID, args->ref_nsid))
+ goto nla_put_failure;
+
+ nlmsg_end(skb, nlh);
+ return 0;
+
+nla_put_failure:
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
+}
+
+static int rtnl_net_valid_getid_req(struct sk_buff *skb,
+ const struct nlmsghdr *nlh,
+ struct nlattr **tb,
+ struct netlink_ext_ack *extack)
+{
+ int i, err;
+
+ if (!netlink_strict_get_check(skb))
+ return nlmsg_parse_deprecated(nlh, sizeof(struct rtgenmsg),
+ tb, NETNSA_MAX, rtnl_net_policy,
+ extack);
+
+ err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct rtgenmsg), tb,
+ NETNSA_MAX, rtnl_net_policy,
+ extack);
+ if (err)
+ return err;
+
+ for (i = 0; i <= NETNSA_MAX; i++) {
+ if (!tb[i])
+ continue;
+
+ switch (i) {
+ case NETNSA_PID:
+ case NETNSA_FD:
+ case NETNSA_NSID:
+ case NETNSA_TARGET_NSID:
+ break;
+ default:
+ NL_SET_ERR_MSG(extack, "Unsupported attribute in peer netns getid request");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
+{
+ struct net *net = sock_net(skb->sk);
+ struct nlattr *tb[NETNSA_MAX + 1];
+ struct net_fill_args fillargs = {
+ .portid = NETLINK_CB(skb).portid,
+ .seq = nlh->nlmsg_seq,
+ .cmd = RTM_NEWNSID,
+ };
+ struct net *peer, *target = net;
+ struct nlattr *nla;
+ struct sk_buff *msg;
+ int err;
+
+ err = rtnl_net_valid_getid_req(skb, nlh, tb, extack);
+ if (err < 0)
+ return err;
+ if (tb[NETNSA_PID]) {
+ peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
+ nla = tb[NETNSA_PID];
+ } else if (tb[NETNSA_FD]) {
+ peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
+ nla = tb[NETNSA_FD];
+ } else if (tb[NETNSA_NSID]) {
+ peer = get_net_ns_by_id(net, nla_get_s32(tb[NETNSA_NSID]));
+ if (!peer)
+ peer = ERR_PTR(-ENOENT);
+ nla = tb[NETNSA_NSID];
+ } else {
+ NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
+ return -EINVAL;
+ }
+
+ if (IS_ERR(peer)) {
+ NL_SET_BAD_ATTR(extack, nla);
+ NL_SET_ERR_MSG(extack, "Peer netns reference is invalid");
+ return PTR_ERR(peer);
+ }
+
+ if (tb[NETNSA_TARGET_NSID]) {
+ int id = nla_get_s32(tb[NETNSA_TARGET_NSID]);
+
+ target = rtnl_get_net_ns_capable(NETLINK_CB(skb).sk, id);
+ if (IS_ERR(target)) {
+ NL_SET_BAD_ATTR(extack, tb[NETNSA_TARGET_NSID]);
+ NL_SET_ERR_MSG(extack,
+ "Target netns reference is invalid");
+ err = PTR_ERR(target);
+ goto out;
+ }
+ fillargs.add_ref = true;
+ fillargs.ref_nsid = peernet2id(net, peer);
+ }
+
+ msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
+ if (!msg) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ fillargs.nsid = peernet2id(target, peer);
+ err = rtnl_net_fill(msg, &fillargs);
+ if (err < 0)
+ goto err_out;
+
+ err = rtnl_unicast(msg, net, NETLINK_CB(skb).portid);
+ goto out;
+
+err_out:
+ nlmsg_free(msg);
+out:
+ if (fillargs.add_ref)
+ put_net(target);
+ put_net(peer);
+ return err;
+}
+
+struct rtnl_net_dump_cb {
+ struct net *tgt_net;
+ struct net *ref_net;
+ struct sk_buff *skb;
+ struct net_fill_args fillargs;
+ int idx;
+ int s_idx;
+};
+
+/* Runs in RCU-critical section. */
+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;
+
+ net_cb->fillargs.nsid = id;
+ if (net_cb->fillargs.add_ref)
+ net_cb->fillargs.ref_nsid = __peernet2id(net_cb->ref_net, peer);
+ ret = rtnl_net_fill(net_cb->skb, &net_cb->fillargs);
+ if (ret < 0)
+ return ret;
+
+cont:
+ net_cb->idx++;
+ return 0;
+}
+
+static int rtnl_valid_dump_net_req(const struct nlmsghdr *nlh, struct sock *sk,
+ struct rtnl_net_dump_cb *net_cb,
+ struct netlink_callback *cb)
+{
+ struct netlink_ext_ack *extack = cb->extack;
+ struct nlattr *tb[NETNSA_MAX + 1];
+ int err, i;
+
+ err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct rtgenmsg), tb,
+ NETNSA_MAX, rtnl_net_policy,
+ extack);
+ if (err < 0)
+ return err;
+
+ for (i = 0; i <= NETNSA_MAX; i++) {
+ if (!tb[i])
+ continue;
+
+ if (i == NETNSA_TARGET_NSID) {
+ struct net *net;
+
+ net = rtnl_get_net_ns_capable(sk, nla_get_s32(tb[i]));
+ if (IS_ERR(net)) {
+ NL_SET_BAD_ATTR(extack, tb[i]);
+ NL_SET_ERR_MSG(extack,
+ "Invalid target network namespace id");
+ return PTR_ERR(net);
+ }
+ net_cb->fillargs.add_ref = true;
+ net_cb->ref_net = net_cb->tgt_net;
+ net_cb->tgt_net = net;
+ } else {
+ NL_SET_BAD_ATTR(extack, tb[i]);
+ NL_SET_ERR_MSG(extack,
+ "Unsupported attribute in dump request");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct rtnl_net_dump_cb net_cb = {
+ .tgt_net = sock_net(skb->sk),
+ .skb = skb,
+ .fillargs = {
+ .portid = NETLINK_CB(cb->skb).portid,
+ .seq = cb->nlh->nlmsg_seq,
+ .flags = NLM_F_MULTI,
+ .cmd = RTM_NEWNSID,
+ },
+ .idx = 0,
+ .s_idx = cb->args[0],
+ };
+ int err = 0;
+
+ if (cb->strict_check) {
+ err = rtnl_valid_dump_net_req(cb->nlh, skb->sk, &net_cb, cb);
+ if (err < 0)
+ goto end;
+ }
+
+ rcu_read_lock();
+ idr_for_each(&net_cb.tgt_net->netns_ids, rtnl_net_dumpid_one, &net_cb);
+ rcu_read_unlock();
+
+ cb->args[0] = net_cb.idx;
+end:
+ if (net_cb.fillargs.add_ref)
+ put_net(net_cb.tgt_net);
+ return err < 0 ? err : skb->len;
+}
+
+static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
+ struct nlmsghdr *nlh, gfp_t gfp)
+{
+ struct net_fill_args fillargs = {
+ .portid = portid,
+ .seq = nlh ? nlh->nlmsg_seq : 0,
+ .cmd = cmd,
+ .nsid = id,
+ };
+ struct sk_buff *msg;
+ int err = -ENOMEM;
+
+ msg = nlmsg_new(rtnl_net_get_size(), gfp);
+ if (!msg)
+ goto out;
+
+ err = rtnl_net_fill(msg, &fillargs);
+ if (err < 0)
+ goto err_out;
+
+ rtnl_notify(msg, net, portid, RTNLGRP_NSID, nlh, gfp);
+ 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|SLAB_ACCOUNT, 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);
+
+ preempt_disable();
+ __net_gen_cookie(&init_net);
+ preempt_enable();
+
+ down_write(&pernet_ops_rwsem);
+ if (setup_net(&init_net, &init_user_ns))
+ panic("Could not setup the initial network namespace");
+
+ init_net_initialized = true;
+ up_write(&pernet_ops_rwsem);
+
+ if (register_pernet_subsys(&net_ns_ops))
+ panic("Could not register network namespace subsystems");
+
+ rtnl_register(PF_UNSPEC, RTM_NEWNSID, rtnl_net_newid, NULL,
+ RTNL_FLAG_DOIT_UNLOCKED);
+ rtnl_register(PF_UNSPEC, RTM_GETNSID, rtnl_net_getid, rtnl_net_dumpid,
+ RTNL_FLAG_DOIT_UNLOCKED);
+
+ 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)) {
+ /* We held write locked pernet_ops_rwsem, and parallel
+ * setup_net() and cleanup_net() are not possible.
+ */
+ 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_pre_exit_list(ops, &net_exit_list);
+ synchronize_rcu();
+ 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);
+ /* See comment in __register_pernet_operations() */
+ for_each_net(net)
+ list_add_tail(&net->exit_list, &net_exit_list);
+ ops_pre_exit_list(ops, &net_exit_list);
+ synchronize_rcu();
+ 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_pre_exit_list(ops, &net_exit_list);
+ synchronize_rcu();
+ 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) {
+ error = ida_alloc_min(&net_generic_ids, MIN_PERNET_OPS_ID,
+ GFP_KERNEL);
+ if (error < 0)
+ return error;
+ *ops->id = error;
+ max_gen_ptrs = max(max_gen_ptrs, *ops->id + 1);
+ }
+ error = __register_pernet_operations(list, ops);
+ if (error) {
+ rcu_barrier();
+ if (ops->id)
+ ida_free(&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_free(&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;
+ down_write(&pernet_ops_rwsem);
+ error = register_pernet_operations(first_device, ops);
+ up_write(&pernet_ops_rwsem);
+ 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)
+{
+ down_write(&pernet_ops_rwsem);
+ unregister_pernet_operations(ops);
+ up_write(&pernet_ops_rwsem);
+}
+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;
+ down_write(&pernet_ops_rwsem);
+ error = register_pernet_operations(&pernet_list, ops);
+ if (!error && (first_device == &pernet_list))
+ first_device = &ops->list;
+ up_write(&pernet_ops_rwsem);
+ 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)
+{
+ down_write(&pernet_ops_rwsem);
+ if (&ops->list == first_device)
+ first_device = first_device->next;
+ unregister_pernet_operations(ops);
+ up_write(&pernet_ops_rwsem);
+}
+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 nsset *nsset, struct ns_common *ns)
+{
+ struct nsproxy *nsproxy = nsset->nsproxy;
+ struct net *net = to_net_ns(ns);
+
+ if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) ||
+ !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN))
+ return -EPERM;
+
+ put_net(nsproxy->net_ns);
+ nsproxy->net_ns = get_net(net);
+ return 0;
+}
+
+static struct user_namespace *netns_owner(struct ns_common *ns)
+{
+ return to_net_ns(ns)->user_ns;
+}
+
+const struct proc_ns_operations netns_operations = {
+ .name = "net",
+ .type = CLONE_NEWNET,
+ .get = netns_get,
+ .put = netns_put,
+ .install = netns_install,
+ .owner = netns_owner,
+};
+#endif