v4.19.13 snapshot.
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
new file mode 100644
index 0000000..9b5fdc5
--- /dev/null
+++ b/include/net/net_namespace.h
@@ -0,0 +1,442 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Operations on the network namespace
+ */
+#ifndef __NET_NET_NAMESPACE_H
+#define __NET_NET_NAMESPACE_H
+
+#include <linux/atomic.h>
+#include <linux/refcount.h>
+#include <linux/workqueue.h>
+#include <linux/list.h>
+#include <linux/sysctl.h>
+#include <linux/uidgid.h>
+
+#include <net/flow.h>
+#include <net/netns/core.h>
+#include <net/netns/mib.h>
+#include <net/netns/unix.h>
+#include <net/netns/packet.h>
+#include <net/netns/ipv4.h>
+#include <net/netns/ipv6.h>
+#include <net/netns/ieee802154_6lowpan.h>
+#include <net/netns/sctp.h>
+#include <net/netns/dccp.h>
+#include <net/netns/netfilter.h>
+#include <net/netns/x_tables.h>
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+#include <net/netns/conntrack.h>
+#endif
+#include <net/netns/nftables.h>
+#include <net/netns/xfrm.h>
+#include <net/netns/mpls.h>
+#include <net/netns/can.h>
+#include <linux/ns_common.h>
+#include <linux/idr.h>
+#include <linux/skbuff.h>
+
+struct user_namespace;
+struct proc_dir_entry;
+struct net_device;
+struct sock;
+struct ctl_table_header;
+struct net_generic;
+struct uevent_sock;
+struct netns_ipvs;
+
+
+#define NETDEV_HASHBITS 8
+#define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
+
+struct net {
+ refcount_t passive; /* To decided when the network
+ * namespace should be freed.
+ */
+ refcount_t count; /* To decided when the network
+ * namespace should be shut down.
+ */
+ spinlock_t rules_mod_lock;
+
+ atomic64_t cookie_gen;
+
+ struct list_head list; /* list of network namespaces */
+ struct list_head exit_list; /* To linked to call pernet exit
+ * methods on dead net (
+ * pernet_ops_rwsem read locked),
+ * or to unregister pernet ops
+ * (pernet_ops_rwsem write locked).
+ */
+ struct llist_node cleanup_list; /* namespaces on death row */
+
+ struct user_namespace *user_ns; /* Owning user namespace */
+ struct ucounts *ucounts;
+ spinlock_t nsid_lock;
+ struct idr netns_ids;
+
+ struct ns_common ns;
+
+ struct proc_dir_entry *proc_net;
+ struct proc_dir_entry *proc_net_stat;
+
+#ifdef CONFIG_SYSCTL
+ struct ctl_table_set sysctls;
+#endif
+
+ struct sock *rtnl; /* rtnetlink socket */
+ struct sock *genl_sock;
+
+ struct uevent_sock *uevent_sock; /* uevent socket */
+
+ struct list_head dev_base_head;
+ struct hlist_head *dev_name_head;
+ struct hlist_head *dev_index_head;
+ unsigned int dev_base_seq; /* protected by rtnl_mutex */
+ int ifindex;
+ unsigned int dev_unreg_count;
+
+ /* core fib_rules */
+ struct list_head rules_ops;
+
+ struct list_head fib_notifier_ops; /* Populated by
+ * register_pernet_subsys()
+ */
+ struct net_device *loopback_dev; /* The loopback */
+ struct netns_core core;
+ struct netns_mib mib;
+ struct netns_packet packet;
+ struct netns_unix unx;
+ struct netns_ipv4 ipv4;
+#if IS_ENABLED(CONFIG_IPV6)
+ struct netns_ipv6 ipv6;
+#endif
+#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
+ struct netns_ieee802154_lowpan ieee802154_lowpan;
+#endif
+#if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
+ struct netns_sctp sctp;
+#endif
+#if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
+ struct netns_dccp dccp;
+#endif
+#ifdef CONFIG_NETFILTER
+ struct netns_nf nf;
+ struct netns_xt xt;
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+ struct netns_ct ct;
+#endif
+#if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
+ struct netns_nftables nft;
+#endif
+#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
+ struct netns_nf_frag nf_frag;
+ struct ctl_table_header *nf_frag_frags_hdr;
+#endif
+ struct sock *nfnl;
+ struct sock *nfnl_stash;
+#if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT)
+ struct list_head nfnl_acct_list;
+#endif
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
+ struct list_head nfct_timeout_list;
+#endif
+#endif
+#ifdef CONFIG_WEXT_CORE
+ struct sk_buff_head wext_nlevents;
+#endif
+ struct net_generic __rcu *gen;
+
+ /* Note : following structs are cache line aligned */
+#ifdef CONFIG_XFRM
+ struct netns_xfrm xfrm;
+#endif
+#if IS_ENABLED(CONFIG_IP_VS)
+ struct netns_ipvs *ipvs;
+#endif
+#if IS_ENABLED(CONFIG_MPLS)
+ struct netns_mpls mpls;
+#endif
+#if IS_ENABLED(CONFIG_CAN)
+ struct netns_can can;
+#endif
+ struct sock *diag_nlsk;
+ atomic_t fnhe_genid;
+} __randomize_layout;
+
+#include <linux/seq_file_net.h>
+
+/* Init's network namespace */
+extern struct net init_net;
+
+#ifdef CONFIG_NET_NS
+struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
+ struct net *old_net);
+
+void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
+
+void net_ns_barrier(void);
+#else /* CONFIG_NET_NS */
+#include <linux/sched.h>
+#include <linux/nsproxy.h>
+static inline struct net *copy_net_ns(unsigned long flags,
+ struct user_namespace *user_ns, struct net *old_net)
+{
+ if (flags & CLONE_NEWNET)
+ return ERR_PTR(-EINVAL);
+ return old_net;
+}
+
+static inline void net_ns_get_ownership(const struct net *net,
+ kuid_t *uid, kgid_t *gid)
+{
+ *uid = GLOBAL_ROOT_UID;
+ *gid = GLOBAL_ROOT_GID;
+}
+
+static inline void net_ns_barrier(void) {}
+#endif /* CONFIG_NET_NS */
+
+
+extern struct list_head net_namespace_list;
+
+struct net *get_net_ns_by_pid(pid_t pid);
+struct net *get_net_ns_by_fd(int fd);
+
+#ifdef CONFIG_SYSCTL
+void ipx_register_sysctl(void);
+void ipx_unregister_sysctl(void);
+#else
+#define ipx_register_sysctl()
+#define ipx_unregister_sysctl()
+#endif
+
+#ifdef CONFIG_NET_NS
+void __put_net(struct net *net);
+
+static inline struct net *get_net(struct net *net)
+{
+ refcount_inc(&net->count);
+ return net;
+}
+
+static inline struct net *maybe_get_net(struct net *net)
+{
+ /* Used when we know struct net exists but we
+ * aren't guaranteed a previous reference count
+ * exists. If the reference count is zero this
+ * function fails and returns NULL.
+ */
+ if (!refcount_inc_not_zero(&net->count))
+ net = NULL;
+ return net;
+}
+
+static inline void put_net(struct net *net)
+{
+ if (refcount_dec_and_test(&net->count))
+ __put_net(net);
+}
+
+static inline
+int net_eq(const struct net *net1, const struct net *net2)
+{
+ return net1 == net2;
+}
+
+static inline int check_net(const struct net *net)
+{
+ return refcount_read(&net->count) != 0;
+}
+
+void net_drop_ns(void *);
+
+#else
+
+static inline struct net *get_net(struct net *net)
+{
+ return net;
+}
+
+static inline void put_net(struct net *net)
+{
+}
+
+static inline struct net *maybe_get_net(struct net *net)
+{
+ return net;
+}
+
+static inline
+int net_eq(const struct net *net1, const struct net *net2)
+{
+ return 1;
+}
+
+static inline int check_net(const struct net *net)
+{
+ return 1;
+}
+
+#define net_drop_ns NULL
+#endif
+
+
+typedef struct {
+#ifdef CONFIG_NET_NS
+ struct net *net;
+#endif
+} possible_net_t;
+
+static inline void write_pnet(possible_net_t *pnet, struct net *net)
+{
+#ifdef CONFIG_NET_NS
+ pnet->net = net;
+#endif
+}
+
+static inline struct net *read_pnet(const possible_net_t *pnet)
+{
+#ifdef CONFIG_NET_NS
+ return pnet->net;
+#else
+ return &init_net;
+#endif
+}
+
+/* Protected by net_rwsem */
+#define for_each_net(VAR) \
+ list_for_each_entry(VAR, &net_namespace_list, list)
+
+#define for_each_net_rcu(VAR) \
+ list_for_each_entry_rcu(VAR, &net_namespace_list, list)
+
+#ifdef CONFIG_NET_NS
+#define __net_init
+#define __net_exit
+#define __net_initdata
+#define __net_initconst
+#else
+#define __net_init __init
+#define __net_exit __ref
+#define __net_initdata __initdata
+#define __net_initconst __initconst
+#endif
+
+int peernet2id_alloc(struct net *net, struct net *peer);
+int peernet2id(struct net *net, struct net *peer);
+bool peernet_has_id(struct net *net, struct net *peer);
+struct net *get_net_ns_by_id(struct net *net, int id);
+
+struct pernet_operations {
+ struct list_head list;
+ /*
+ * Below methods are called without any exclusive locks.
+ * More than one net may be constructed and destructed
+ * in parallel on several cpus. Every pernet_operations
+ * have to keep in mind all other pernet_operations and
+ * to introduce a locking, if they share common resources.
+ *
+ * The only time they are called with exclusive lock is
+ * from register_pernet_subsys(), unregister_pernet_subsys()
+ * register_pernet_device() and unregister_pernet_device().
+ *
+ * Exit methods using blocking RCU primitives, such as
+ * synchronize_rcu(), should be implemented via exit_batch.
+ * Then, destruction of a group of net requires single
+ * synchronize_rcu() related to these pernet_operations,
+ * instead of separate synchronize_rcu() for every net.
+ * Please, avoid synchronize_rcu() at all, where it's possible.
+ */
+ int (*init)(struct net *net);
+ void (*exit)(struct net *net);
+ void (*exit_batch)(struct list_head *net_exit_list);
+ unsigned int *id;
+ size_t size;
+};
+
+/*
+ * Use these carefully. If you implement a network device and it
+ * needs per network namespace operations use device pernet operations,
+ * otherwise use pernet subsys operations.
+ *
+ * Network interfaces need to be removed from a dying netns _before_
+ * subsys notifiers can be called, as most of the network code cleanup
+ * (which is done from subsys notifiers) runs with the assumption that
+ * dev_remove_pack has been called so no new packets will arrive during
+ * and after the cleanup functions have been called. dev_remove_pack
+ * is not per namespace so instead the guarantee of no more packets
+ * arriving in a network namespace is provided by ensuring that all
+ * network devices and all sockets have left the network namespace
+ * before the cleanup methods are called.
+ *
+ * For the longest time the ipv4 icmp code was registered as a pernet
+ * device which caused kernel oops, and panics during network
+ * namespace cleanup. So please don't get this wrong.
+ */
+int register_pernet_subsys(struct pernet_operations *);
+void unregister_pernet_subsys(struct pernet_operations *);
+int register_pernet_device(struct pernet_operations *);
+void unregister_pernet_device(struct pernet_operations *);
+
+struct ctl_table;
+struct ctl_table_header;
+
+#ifdef CONFIG_SYSCTL
+int net_sysctl_init(void);
+struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
+ struct ctl_table *table);
+void unregister_net_sysctl_table(struct ctl_table_header *header);
+#else
+static inline int net_sysctl_init(void) { return 0; }
+static inline struct ctl_table_header *register_net_sysctl(struct net *net,
+ const char *path, struct ctl_table *table)
+{
+ return NULL;
+}
+static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
+{
+}
+#endif
+
+static inline int rt_genid_ipv4(struct net *net)
+{
+ return atomic_read(&net->ipv4.rt_genid);
+}
+
+static inline void rt_genid_bump_ipv4(struct net *net)
+{
+ atomic_inc(&net->ipv4.rt_genid);
+}
+
+extern void (*__fib6_flush_trees)(struct net *net);
+static inline void rt_genid_bump_ipv6(struct net *net)
+{
+ if (__fib6_flush_trees)
+ __fib6_flush_trees(net);
+}
+
+#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
+static inline struct netns_ieee802154_lowpan *
+net_ieee802154_lowpan(struct net *net)
+{
+ return &net->ieee802154_lowpan;
+}
+#endif
+
+/* For callers who don't really care about whether it's IPv4 or IPv6 */
+static inline void rt_genid_bump_all(struct net *net)
+{
+ rt_genid_bump_ipv4(net);
+ rt_genid_bump_ipv6(net);
+}
+
+static inline int fnhe_genid(struct net *net)
+{
+ return atomic_read(&net->fnhe_genid);
+}
+
+static inline void fnhe_genid_bump(struct net *net)
+{
+ atomic_inc(&net->fnhe_genid);
+}
+
+#endif /* __NET_NET_NAMESPACE_H */