2.6.25-rc7

 security

 selinux

diff --git a/security/selinux/netif.c b/security/selinux/netif.c
index e87ab94..013d311 100644
--- a/security/selinux/netif.c
+++ b/security/selinux/netif.c
@@ -7,6 +7,8 @@
  * 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.moore@hp.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,
@@ -29,14 +31,6 @@
 #define SEL_NETIF_HASH_SIZE   64
 #define SEL_NETIF_HASH_MAX   1024
 
-#undef DEBUG
-
-#ifdef DEBUG
-#define DEBUGP printk
-#else
-#define DEBUGP(format, args...)
-#endif
-
 struct sel_netif
 {
    struct list_head list;
@@ -49,174 +43,226 @@ static LIST_HEAD(sel_netif_list);
 static DEFINE_SPINLOCK(sel_netif_lock);
 static struct list_head sel_netif_hash[SEL_NETIF_HASH_SIZE];
 
-static inline u32 sel_netif_hasfn(struct net_device *dev)
+/**
+ * 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 (dev->ifindex & (SEL_NETIF_HASH_SIZE - 1));
+   return (ifindex & (SEL_NETIF_HASH_SIZE - 1));
 }
 
-/*
- * All of the devices should normally fit in the hash, so we optimize
- * for that case.
+/**
+ * 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(struct net_device *dev)
+static inline struct sel_netif *sel_netif_find(int ifindex)
 {
-   struct list_head *pos;
-   int idx = sel_netif_hasfn(dev);
+   int idx = sel_netif_hashfn(ifindex);
+   struct sel_netif *netif;
 
-   __list_for_each_rcu(pos, &sel_netif_hash[idx]) {
-      struct sel_netif *netif = list_entry(pos,
-                                           struct sel_netif, list);
-      if (likely(netif->nsec.dev == dev))
+   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, ret = 0;
+   int idx;
    
-   if (sel_netif_total >= SEL_NETIF_HASH_MAX) {
-      ret = -ENOSPC;
-      goto out;
-   }
+   if (sel_netif_total >= SEL_NETIF_HASH_MAX)
+      return -ENOSPC;
    
-   idx = sel_netif_hasfn(netif->nsec.dev);
+   idx = sel_netif_hashfn(netif->nsec.ifindex);
    list_add_rcu(&netif->list, &sel_netif_hash[idx]);
    sel_netif_total++;
-out:
-   return ret;
+
+   return 0;
 }
 
+/**
+ * sel_netif_free - Frees an interface entry
+ * @p: the entry's RCU field
+ *
+ * Description:
+ * This function is designed to be used as a callback to the call_rcu()
+ * function so that memory allocated to a hash table interface entry can be
+ * released safely.
+ *
+ */
 static void sel_netif_free(struct rcu_head *p)
 {
    struct sel_netif *netif = container_of(p, struct sel_netif, rcu_head);
-
-   DEBUGP("%s: %s\n", __FUNCTION__, netif->nsec.dev->name);
    kfree(netif);
 }
 
+/**
+ * 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)
 {
-   DEBUGP("%s: %s\n", __FUNCTION__, netif->nsec.dev->name);
-
    list_del_rcu(&netif->list);
    sel_netif_total--;
    call_rcu(&netif->rcu_head, sel_netif_free);
 }
 
-static struct sel_netif *sel_netif_lookup(struct net_device *dev)
+/**
+ * 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, *new;
-   struct netif_security_struct *nsec;
-
-   netif = sel_netif_find(dev);
-   if (likely(netif != NULL))
-      goto out;
-   
-   new = kzalloc(sizeof(*new), GFP_ATOMIC);
-   if (!new) {
-      netif = ERR_PTR(-ENOMEM);
-      goto out;
+   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;
    }
-   
-   nsec = &new->nsec;
 
-   ret = security_netif_sid(dev->name, &nsec->if_sid, &nsec->msg_sid);
-   if (ret < 0) {
-      kfree(new);
-      netif = ERR_PTR(ret);
+   spin_lock_bh(&sel_netif_lock);
+   netif = sel_netif_find(ifindex);
+   if (netif != NULL) {
+      *sid = netif->nsec.sid;
+      ret = 0;
       goto out;
    }
-
-   nsec->dev = dev;
-   
-   spin_lock_bh(&sel_netif_lock);
-   
-   netif = sel_netif_find(dev);
-   if (netif) {
-      spin_unlock_bh(&sel_netif_lock);
-      kfree(new);
+   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);
-   spin_unlock_bh(&sel_netif_lock);
-   
-   if (ret) {
-      kfree(new);
-      netif = ERR_PTR(ret);
+   if (ret != 0)
       goto out;
-   }
+   *sid = new->nsec.sid;
 
-   netif = new;
-   
-   DEBUGP("new: ifindex=%u name=%s if_sid=%u msg_sid=%u\n", dev->ifindex, dev->name,
-           nsec->if_sid, nsec->msg_sid);
 out:
-   return netif;
-}
-
-static void sel_netif_assign_sids(u32 if_sid_in, u32 msg_sid_in, u32 *if_sid_out, u32 *msg_sid_out)
-{
-   if (if_sid_out)
-      *if_sid_out = if_sid_in;
-   if (msg_sid_out)
-      *msg_sid_out = msg_sid_in;
-}
-
-static int sel_netif_sids_slow(struct net_device *dev, u32 *if_sid, u32 *msg_sid)
-{
-   int ret = 0;
-   u32 tmp_if_sid, tmp_msg_sid;
-   
-   ret = security_netif_sid(dev->name, &tmp_if_sid, &tmp_msg_sid);
-   if (!ret)
-      sel_netif_assign_sids(tmp_if_sid, tmp_msg_sid, if_sid, msg_sid);
+   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;
 }
 
-int sel_netif_sids(struct net_device *dev, u32 *if_sid, u32 *msg_sid)
+/**
+ * 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)
 {
-   int ret = 0;
    struct sel_netif *netif;
 
    rcu_read_lock();
-   netif = sel_netif_lookup(dev);
-   if (IS_ERR(netif)) {
+   netif = sel_netif_find(ifindex);
+   if (likely(netif != NULL)) {
+      *sid = netif->nsec.sid;
       rcu_read_unlock();
-      ret = sel_netif_sids_slow(dev, if_sid, msg_sid);
-      goto out;
+      return 0;
    }
-   sel_netif_assign_sids(netif->nsec.if_sid, netif->nsec.msg_sid, if_sid, msg_sid);
    rcu_read_unlock();
-out:
-   return ret;
+
+   return sel_netif_sid_slow(ifindex, sid);
 }
 
-static void sel_netif_kill(struct net_device *dev)
+/**
+ * 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;
 
    spin_lock_bh(&sel_netif_lock);
-   netif = sel_netif_find(dev);
+   netif = sel_netif_find(ifindex);
    if (netif)
       sel_netif_destroy(netif);
    spin_unlock_bh(&sel_netif_lock);
 }
 
+/**
+ * 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++) {
-      struct sel_netif *netif;
-      
+   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);
 }
 
@@ -239,7 +285,7 @@ static int sel_netif_netdev_notifier_handler(struct notifier_block *this,
       return NOTIFY_DONE;
 
    if (event == NETDEV_DOWN)
-      sel_netif_kill(dev);
+      sel_netif_kill(dev->ifindex);
 
    return NOTIFY_DONE;
 }
@@ -250,10 +296,10 @@ static struct notifier_block sel_netif_netdev_notifier = {
 
 static __init int sel_netif_init(void)
 {
-   int i, err = 0;
+   int i, err;
    
    if (!selinux_enabled)
-      goto out;
+      return 0;
 
    for (i = 0; i < SEL_NETIF_HASH_SIZE; i++)
       INIT_LIST_HEAD(&sel_netif_hash[i]);
@@ -265,7 +311,6 @@ static __init int sel_netif_init(void)
    if (err)
       panic("avc_add_callback() failed, error %d\n", err);
 
-out:
    return err;
 }