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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /security/selinux/netif.c | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
download | FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.gz FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.bz2 FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.zip |
Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'security/selinux/netif.c')
-rw-r--r-- | security/selinux/netif.c | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/security/selinux/netif.c b/security/selinux/netif.c new file mode 100644 index 00000000..326f22cb --- /dev/null +++ b/security/selinux/netif.c @@ -0,0 +1,304 @@ +/* + * 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 + * @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(int ifindex) +{ + return (ifindex & (SEL_NETIF_HASH_SIZE - 1)); +} + +/** + * sel_netif_find - Search for an interface record + * @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(int ifindex) +{ + int idx = sel_netif_hashfn(ifindex); + struct sel_netif *netif; + + list_for_each_entry_rcu(netif, &sel_netif_hash[idx], list) + /* all of the devices should normally fit in the hash, so we + * optimize for that case */ + if (likely(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.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 + * @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(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(&init_net, ifindex); + if (unlikely(dev == NULL)) { + printk(KERN_WARNING + "SELinux: failure in sel_netif_sid_slow()," + " invalid network interface (%d)\n", ifindex); + return -ENOENT; + } + + spin_lock_bh(&sel_netif_lock); + netif = sel_netif_find(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(dev->name, &new->nsec.sid); + if (ret != 0) + goto out; + 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)) { + printk(KERN_WARNING + "SELinux: failure in sel_netif_sid_slow()," + " unable to determine network interface label (%d)\n", + ifindex); + kfree(new); + } + return ret; +} + +/** + * sel_netif_sid - Lookup the SID of a network interface + * @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(int ifindex, u32 *sid) +{ + struct sel_netif *netif; + + rcu_read_lock(); + netif = sel_netif_find(ifindex); + if (likely(netif != NULL)) { + *sid = netif->nsec.sid; + rcu_read_unlock(); + return 0; + } + rcu_read_unlock(); + + return sel_netif_sid_slow(ifindex, sid); +} + +/** + * sel_netif_kill - Remove an entry from the network interface table + * @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(int ifindex) +{ + struct sel_netif *netif; + + rcu_read_lock(); + spin_lock_bh(&sel_netif_lock); + netif = sel_netif_find(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. + * + */ +static 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_avc_callback(u32 event, u32 ssid, u32 tsid, + u16 class, u32 perms, u32 *retained) +{ + if (event == AVC_CALLBACK_RESET) { + sel_netif_flush(); + synchronize_net(); + } + return 0; +} + +static int sel_netif_netdev_notifier_handler(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct net_device *dev = ptr; + + if (dev_net(dev) != &init_net) + return NOTIFY_DONE; + + if (event == NETDEV_DOWN) + sel_netif_kill(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, err; + + 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); + + err = avc_add_callback(sel_netif_avc_callback, AVC_CALLBACK_RESET, + SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0); + if (err) + panic("avc_add_callback() failed, error %d\n", err); + + return err; +} + +__initcall(sel_netif_init); + |