v4.19.13 snapshot.
diff --git a/security/selinux/netif.c b/security/selinux/netif.c
new file mode 100644
index 0000000..8c738c1
--- /dev/null
+++ b/security/selinux/netif.c
@@ -0,0 +1,289 @@
+/*
+ * Network interface table.
+ *
+ * Network interfaces (devices) do not have a security field, so we
+ * maintain a table associating each interface with a SID.
+ *
+ * Author: James Morris <jmorris@redhat.com>
+ *
+ * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
+ * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
+ * Paul Moore <paul@paul-moore.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2,
+ * as published by the Free Software Foundation.
+ */
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/stddef.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/notifier.h>
+#include <linux/netdevice.h>
+#include <linux/rcupdate.h>
+#include <net/net_namespace.h>
+
+#include "security.h"
+#include "objsec.h"
+#include "netif.h"
+
+#define SEL_NETIF_HASH_SIZE 64
+#define SEL_NETIF_HASH_MAX 1024
+
+struct sel_netif {
+ struct list_head list;
+ struct netif_security_struct nsec;
+ struct rcu_head rcu_head;
+};
+
+static u32 sel_netif_total;
+static LIST_HEAD(sel_netif_list);
+static DEFINE_SPINLOCK(sel_netif_lock);
+static struct list_head sel_netif_hash[SEL_NETIF_HASH_SIZE];
+
+/**
+ * sel_netif_hashfn - Hashing function for the interface table
+ * @ns: the network namespace
+ * @ifindex: the network interface
+ *
+ * Description:
+ * This is the hashing function for the network interface table, it returns the
+ * bucket number for the given interface.
+ *
+ */
+static inline u32 sel_netif_hashfn(const struct net *ns, int ifindex)
+{
+ return (((uintptr_t)ns + ifindex) & (SEL_NETIF_HASH_SIZE - 1));
+}
+
+/**
+ * sel_netif_find - Search for an interface record
+ * @ns: the network namespace
+ * @ifindex: the network interface
+ *
+ * Description:
+ * Search the network interface table and return the record matching @ifindex.
+ * If an entry can not be found in the table return NULL.
+ *
+ */
+static inline struct sel_netif *sel_netif_find(const struct net *ns,
+ int ifindex)
+{
+ int idx = sel_netif_hashfn(ns, ifindex);
+ struct sel_netif *netif;
+
+ list_for_each_entry_rcu(netif, &sel_netif_hash[idx], list)
+ if (net_eq(netif->nsec.ns, ns) &&
+ netif->nsec.ifindex == ifindex)
+ return netif;
+
+ return NULL;
+}
+
+/**
+ * sel_netif_insert - Insert a new interface into the table
+ * @netif: the new interface record
+ *
+ * Description:
+ * Add a new interface record to the network interface hash table. Returns
+ * zero on success, negative values on failure.
+ *
+ */
+static int sel_netif_insert(struct sel_netif *netif)
+{
+ int idx;
+
+ if (sel_netif_total >= SEL_NETIF_HASH_MAX)
+ return -ENOSPC;
+
+ idx = sel_netif_hashfn(netif->nsec.ns, netif->nsec.ifindex);
+ list_add_rcu(&netif->list, &sel_netif_hash[idx]);
+ sel_netif_total++;
+
+ return 0;
+}
+
+/**
+ * sel_netif_destroy - Remove an interface record from the table
+ * @netif: the existing interface record
+ *
+ * Description:
+ * Remove an existing interface record from the network interface table.
+ *
+ */
+static void sel_netif_destroy(struct sel_netif *netif)
+{
+ list_del_rcu(&netif->list);
+ sel_netif_total--;
+ kfree_rcu(netif, rcu_head);
+}
+
+/**
+ * sel_netif_sid_slow - Lookup the SID of a network interface using the policy
+ * @ns: the network namespace
+ * @ifindex: the network interface
+ * @sid: interface SID
+ *
+ * Description:
+ * This function determines the SID of a network interface by quering the
+ * security policy. The result is added to the network interface table to
+ * speedup future queries. Returns zero on success, negative values on
+ * failure.
+ *
+ */
+static int sel_netif_sid_slow(struct net *ns, int ifindex, u32 *sid)
+{
+ int ret;
+ struct sel_netif *netif;
+ struct sel_netif *new = NULL;
+ struct net_device *dev;
+
+ /* NOTE: we always use init's network namespace since we don't
+ * currently support containers */
+
+ dev = dev_get_by_index(ns, ifindex);
+ if (unlikely(dev == NULL)) {
+ pr_warn("SELinux: failure in %s(), invalid network interface (%d)\n",
+ __func__, ifindex);
+ return -ENOENT;
+ }
+
+ spin_lock_bh(&sel_netif_lock);
+ netif = sel_netif_find(ns, ifindex);
+ if (netif != NULL) {
+ *sid = netif->nsec.sid;
+ ret = 0;
+ goto out;
+ }
+ new = kzalloc(sizeof(*new), GFP_ATOMIC);
+ if (new == NULL) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ ret = security_netif_sid(&selinux_state, dev->name, &new->nsec.sid);
+ if (ret != 0)
+ goto out;
+ new->nsec.ns = ns;
+ new->nsec.ifindex = ifindex;
+ ret = sel_netif_insert(new);
+ if (ret != 0)
+ goto out;
+ *sid = new->nsec.sid;
+
+out:
+ spin_unlock_bh(&sel_netif_lock);
+ dev_put(dev);
+ if (unlikely(ret)) {
+ pr_warn("SELinux: failure in %s(), unable to determine network interface label (%d)\n",
+ __func__, ifindex);
+ kfree(new);
+ }
+ return ret;
+}
+
+/**
+ * sel_netif_sid - Lookup the SID of a network interface
+ * @ns: the network namespace
+ * @ifindex: the network interface
+ * @sid: interface SID
+ *
+ * Description:
+ * This function determines the SID of a network interface using the fastest
+ * method possible. First the interface table is queried, but if an entry
+ * can't be found then the policy is queried and the result is added to the
+ * table to speedup future queries. Returns zero on success, negative values
+ * on failure.
+ *
+ */
+int sel_netif_sid(struct net *ns, int ifindex, u32 *sid)
+{
+ struct sel_netif *netif;
+
+ rcu_read_lock();
+ netif = sel_netif_find(ns, ifindex);
+ if (likely(netif != NULL)) {
+ *sid = netif->nsec.sid;
+ rcu_read_unlock();
+ return 0;
+ }
+ rcu_read_unlock();
+
+ return sel_netif_sid_slow(ns, ifindex, sid);
+}
+
+/**
+ * sel_netif_kill - Remove an entry from the network interface table
+ * @ns: the network namespace
+ * @ifindex: the network interface
+ *
+ * Description:
+ * This function removes the entry matching @ifindex from the network interface
+ * table if it exists.
+ *
+ */
+static void sel_netif_kill(const struct net *ns, int ifindex)
+{
+ struct sel_netif *netif;
+
+ rcu_read_lock();
+ spin_lock_bh(&sel_netif_lock);
+ netif = sel_netif_find(ns, ifindex);
+ if (netif)
+ sel_netif_destroy(netif);
+ spin_unlock_bh(&sel_netif_lock);
+ rcu_read_unlock();
+}
+
+/**
+ * sel_netif_flush - Flush the entire network interface table
+ *
+ * Description:
+ * Remove all entries from the network interface table.
+ *
+ */
+void sel_netif_flush(void)
+{
+ int idx;
+ struct sel_netif *netif;
+
+ spin_lock_bh(&sel_netif_lock);
+ for (idx = 0; idx < SEL_NETIF_HASH_SIZE; idx++)
+ list_for_each_entry(netif, &sel_netif_hash[idx], list)
+ sel_netif_destroy(netif);
+ spin_unlock_bh(&sel_netif_lock);
+}
+
+static int sel_netif_netdev_notifier_handler(struct notifier_block *this,
+ unsigned long event, void *ptr)
+{
+ struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+ if (event == NETDEV_DOWN)
+ sel_netif_kill(dev_net(dev), dev->ifindex);
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block sel_netif_netdev_notifier = {
+ .notifier_call = sel_netif_netdev_notifier_handler,
+};
+
+static __init int sel_netif_init(void)
+{
+ int i;
+
+ if (!selinux_enabled)
+ return 0;
+
+ for (i = 0; i < SEL_NETIF_HASH_SIZE; i++)
+ INIT_LIST_HEAD(&sel_netif_hash[i]);
+
+ register_netdevice_notifier(&sel_netif_netdev_notifier);
+
+ return 0;
+}
+
+__initcall(sel_netif_init);
+