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![Eric Dumazet](/assets/img/avatar_default.png)
While testing a patch that will follow later ("net: add netns refcount tracker to struct nsproxy") I found that devtmpfs_init() was called before init_net was initialized. This is a bug, because devtmpfs_setup() calls ksys_unshare(CLONE_NEWNS); This has the effect of increasing init_net refcount, which will be later overwritten to 1, as part of setup_net(&init_net) We had too many prior patches [1] trying to work around the root cause. Really, make sure init_net is in BSS section, and that net_ns_init() is called earlier at boot time. Note that another patch ("vfs: add netns refcount tracker to struct fs_context") also will need net_ns_init() being called before vfs_caches_init() As a bonus, this patch saves around 4KB in .data section. [1]f8c46cb390
("netns: do not call pernet ops for not yet set up init_net namespace")b5082df801
("net: Initialise init_net.count to 1")734b65417b
("net: Statically initialize init_net.dev_base_head") v2: fixed a build error reported by kernel build bots (CONFIG_NET=n) Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1381 lines
32 KiB
C
1381 lines
32 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#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 <linux/sched/task.h>
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#include <linux/uidgid.h>
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#include <linux/cookie.h>
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#include <net/sock.h>
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#include <net/netlink.h>
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#include <net/net_namespace.h>
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#include <net/netns/generic.h>
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/*
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* Our network namespace constructor/destructor lists
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*/
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static LIST_HEAD(pernet_list);
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static struct list_head *first_device = &pernet_list;
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LIST_HEAD(net_namespace_list);
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EXPORT_SYMBOL_GPL(net_namespace_list);
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/* Protects net_namespace_list. Nests iside rtnl_lock() */
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DECLARE_RWSEM(net_rwsem);
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EXPORT_SYMBOL_GPL(net_rwsem);
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#ifdef CONFIG_KEYS
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static struct key_tag init_net_key_domain = { .usage = REFCOUNT_INIT(1) };
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#endif
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struct net init_net;
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EXPORT_SYMBOL(init_net);
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static bool init_net_initialized;
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/*
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* pernet_ops_rwsem: protects: pernet_list, net_generic_ids,
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* init_net_initialized and first_device pointer.
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* This is internal net namespace object. Please, don't use it
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* outside.
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*/
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DECLARE_RWSEM(pernet_ops_rwsem);
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EXPORT_SYMBOL_GPL(pernet_ops_rwsem);
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#define MIN_PERNET_OPS_ID \
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((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *))
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#define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */
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static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
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DEFINE_COOKIE(net_cookie);
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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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unsigned int generic_size = offsetof(struct net_generic, ptr[max_gen_ptrs]);
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ng = kzalloc(generic_size, GFP_KERNEL);
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if (ng)
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ng->s.len = max_gen_ptrs;
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return ng;
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}
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static int net_assign_generic(struct net *net, unsigned int id, void *data)
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{
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struct net_generic *ng, *old_ng;
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BUG_ON(id < MIN_PERNET_OPS_ID);
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old_ng = rcu_dereference_protected(net->gen,
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lockdep_is_held(&pernet_ops_rwsem));
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if (old_ng->s.len > id) {
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old_ng->ptr[id] = data;
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return 0;
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}
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ng = net_alloc_generic();
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if (!ng)
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return -ENOMEM;
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/*
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* Some synchronisation notes:
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*
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* The net_generic explores the net->gen array inside rcu
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* read section. Besides once set the net->gen->ptr[x]
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* pointer never changes (see rules in netns/generic.h).
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*
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* That said, we simply duplicate this array and schedule
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* the old copy for kfree after a grace period.
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*/
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memcpy(&ng->ptr[MIN_PERNET_OPS_ID], &old_ng->ptr[MIN_PERNET_OPS_ID],
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(old_ng->s.len - MIN_PERNET_OPS_ID) * sizeof(void *));
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ng->ptr[id] = data;
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rcu_assign_pointer(net->gen, ng);
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kfree_rcu(old_ng, s.rcu);
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return 0;
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}
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static int ops_init(const struct pernet_operations *ops, struct net *net)
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{
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int err = -ENOMEM;
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void *data = NULL;
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if (ops->id && ops->size) {
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data = kzalloc(ops->size, GFP_KERNEL);
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if (!data)
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goto out;
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err = net_assign_generic(net, *ops->id, data);
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if (err)
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goto cleanup;
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}
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err = 0;
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if (ops->init)
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err = ops->init(net);
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if (!err)
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return 0;
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cleanup:
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kfree(data);
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out:
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return err;
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}
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static void ops_pre_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->pre_exit) {
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list_for_each_entry(net, net_exit_list, exit_list)
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ops->pre_exit(net);
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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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cond_resched();
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}
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}
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if (ops->exit_batch)
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ops->exit_batch(net_exit_list);
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}
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static void ops_free_list(const struct pernet_operations *ops,
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struct list_head *net_exit_list)
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{
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struct net *net;
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if (ops->size && ops->id) {
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list_for_each_entry(net, net_exit_list, exit_list)
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kfree(net_generic(net, *ops->id));
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}
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}
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/* should be called with nsid_lock held */
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static int alloc_netid(struct net *net, struct net *peer, int reqid)
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{
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int min = 0, max = 0;
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if (reqid >= 0) {
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min = reqid;
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max = reqid + 1;
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}
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return idr_alloc(&net->netns_ids, peer, min, max, GFP_ATOMIC);
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}
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/* This function is used by idr_for_each(). If net is equal to peer, the
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* function returns the id so that idr_for_each() stops. Because we cannot
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* returns the id 0 (idr_for_each() will not stop), we return the magic value
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* NET_ID_ZERO (-1) for it.
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*/
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#define NET_ID_ZERO -1
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static int net_eq_idr(int id, void *net, void *peer)
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{
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if (net_eq(net, peer))
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return id ? : NET_ID_ZERO;
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return 0;
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}
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/* Must be called from RCU-critical section or with nsid_lock held */
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static int __peernet2id(const struct net *net, struct net *peer)
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{
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int id = idr_for_each(&net->netns_ids, net_eq_idr, peer);
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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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return NETNSA_NSID_NOT_ASSIGNED;
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}
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static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
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struct nlmsghdr *nlh, gfp_t gfp);
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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, gfp_t gfp)
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{
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int id;
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if (refcount_read(&net->ns.count) == 0)
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return NETNSA_NSID_NOT_ASSIGNED;
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spin_lock_bh(&net->nsid_lock);
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id = __peernet2id(net, peer);
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if (id >= 0) {
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spin_unlock_bh(&net->nsid_lock);
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return id;
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}
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/* When peer is obtained from RCU lists, we may race with
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* its cleanup. Check whether it's alive, and this guarantees
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* we never hash a peer back to net->netns_ids, after it has
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* just been idr_remove()'d from there in cleanup_net().
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*/
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if (!maybe_get_net(peer)) {
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spin_unlock_bh(&net->nsid_lock);
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return NETNSA_NSID_NOT_ASSIGNED;
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}
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id = alloc_netid(net, peer, -1);
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spin_unlock_bh(&net->nsid_lock);
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put_net(peer);
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if (id < 0)
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return NETNSA_NSID_NOT_ASSIGNED;
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rtnl_net_notifyid(net, RTM_NEWNSID, id, 0, NULL, gfp);
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return id;
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}
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EXPORT_SYMBOL_GPL(peernet2id_alloc);
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/* This function returns, if assigned, the id of a peer netns. */
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int peernet2id(const struct net *net, struct net *peer)
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{
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int id;
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rcu_read_lock();
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id = __peernet2id(net, peer);
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rcu_read_unlock();
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return id;
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}
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EXPORT_SYMBOL(peernet2id);
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/* This function returns true is the peer netns has an id assigned into the
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* current netns.
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*/
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bool peernet_has_id(const struct net *net, struct net *peer)
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{
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return peernet2id(net, peer) >= 0;
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}
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struct net *get_net_ns_by_id(const struct net *net, int id)
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{
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struct net *peer;
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if (id < 0)
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return NULL;
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rcu_read_lock();
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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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rcu_read_unlock();
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return peer;
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}
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EXPORT_SYMBOL_GPL(get_net_ns_by_id);
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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 pernet_ops_rwsem 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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refcount_set(&net->ns.count, 1);
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ref_tracker_dir_init(&net->refcnt_tracker, 128);
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refcount_set(&net->passive, 1);
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get_random_bytes(&net->hash_mix, sizeof(u32));
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preempt_disable();
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net->net_cookie = gen_cookie_next(&net_cookie);
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preempt_enable();
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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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mutex_init(&net->ipv4.ra_mutex);
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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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down_write(&net_rwsem);
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list_add_tail_rcu(&net->list, &net_namespace_list);
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up_write(&net_rwsem);
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out:
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return error;
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out_undo:
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/* Walk through the list backwards calling the exit functions
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* for the pernet modules whose init functions did not fail.
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*/
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list_add(&net->exit_list, &net_exit_list);
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saved_ops = ops;
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list_for_each_entry_continue_reverse(ops, &pernet_list, list)
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ops_pre_exit_list(ops, &net_exit_list);
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synchronize_rcu();
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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_exit_list(ops, &net_exit_list);
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ops = saved_ops;
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list_for_each_entry_continue_reverse(ops, &pernet_list, list)
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ops_free_list(ops, &net_exit_list);
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rcu_barrier();
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goto out;
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}
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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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net->core.sysctl_txrehash = SOCK_TXREHASH_ENABLED;
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return 0;
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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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core_initcall(net_defaults_init);
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#ifdef CONFIG_NET_NS
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static struct ucounts *inc_net_namespaces(struct user_namespace *ns)
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{
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return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES);
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}
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static void dec_net_namespaces(struct ucounts *ucounts)
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{
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dec_ucount(ucounts, UCOUNT_NET_NAMESPACES);
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}
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static struct kmem_cache *net_cachep __ro_after_init;
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static struct workqueue_struct *netns_wq;
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static struct net *net_alloc(void)
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{
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struct net *net = NULL;
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struct net_generic *ng;
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ng = net_alloc_generic();
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if (!ng)
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goto out;
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net = kmem_cache_zalloc(net_cachep, GFP_KERNEL);
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if (!net)
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goto out_free;
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#ifdef CONFIG_KEYS
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net->key_domain = kzalloc(sizeof(struct key_tag), GFP_KERNEL);
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if (!net->key_domain)
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goto out_free_2;
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refcount_set(&net->key_domain->usage, 1);
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#endif
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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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#ifdef CONFIG_KEYS
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out_free_2:
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kmem_cache_free(net_cachep, net);
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net = NULL;
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#endif
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out_free:
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kfree(ng);
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goto out;
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}
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static void net_free(struct net *net)
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{
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if (refcount_dec_and_test(&net->passive)) {
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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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}
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void net_drop_ns(void *p)
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{
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struct net *net = (struct net *)p;
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if (net)
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net_free(net);
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}
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struct net *copy_net_ns(unsigned long flags,
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struct user_namespace *user_ns, struct net *old_net)
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{
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struct ucounts *ucounts;
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struct net *net;
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int rv;
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if (!(flags & CLONE_NEWNET))
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return get_net(old_net);
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ucounts = inc_net_namespaces(user_ns);
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if (!ucounts)
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return ERR_PTR(-ENOSPC);
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net = net_alloc();
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if (!net) {
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rv = -ENOMEM;
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goto dec_ucounts;
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}
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refcount_set(&net->passive, 1);
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net->ucounts = ucounts;
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get_user_ns(user_ns);
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rv = down_read_killable(&pernet_ops_rwsem);
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if (rv < 0)
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goto put_userns;
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|
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rv = setup_net(net, user_ns);
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|
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up_read(&pernet_ops_rwsem);
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|
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if (rv < 0) {
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put_userns:
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|
#ifdef CONFIG_KEYS
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key_remove_domain(net->key_domain);
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#endif
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put_user_ns(user_ns);
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net_free(net);
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dec_ucounts:
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|
dec_net_namespaces(ucounts);
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return ERR_PTR(rv);
|
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}
|
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return net;
|
|
}
|
|
|
|
/**
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* net_ns_get_ownership - get sysfs ownership data for @net
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|
* @net: network namespace in question (can be NULL)
|
|
* @uid: kernel user ID for sysfs objects
|
|
* @gid: kernel group ID for sysfs objects
|
|
*
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|
* 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)
|
|
{
|
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if (net) {
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kuid_t ns_root_uid = make_kuid(net->user_ns, 0);
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kgid_t ns_root_gid = make_kgid(net->user_ns, 0);
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|
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if (uid_valid(ns_root_uid))
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*uid = ns_root_uid;
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|
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if (gid_valid(ns_root_gid))
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*gid = ns_root_gid;
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} else {
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*uid = GLOBAL_ROOT_UID;
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|
*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_free(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)
|
|
{
|
|
ref_tracker_dir_exit(&net->refcnt_tracker);
|
|
/* 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;
|
|
}
|
|
EXPORT_SYMBOL_GPL(get_net_ns_by_fd);
|
|
#endif
|
|
|
|
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);
|
|
}
|
|
|
|
void __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);
|
|
|
|
#ifdef CONFIG_KEYS
|
|
init_net.key_domain = &init_net_key_domain;
|
|
#endif
|
|
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);
|
|
}
|
|
|
|
static void free_exit_list(struct pernet_operations *ops, struct list_head *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);
|
|
}
|
|
|
|
#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);
|
|
free_exit_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);
|
|
|
|
free_exit_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);
|
|
free_exit_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
|