SELinux: Add a capabilities bitmap to SELinux policy version 22

Add a new policy capabilities bitmap to SELinux policy version 22.  This bitmap
will enable the security server to query the policy to determine which features
it supports.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 85 insertions, 4 deletions

diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 397fd4955fe1..a85740530afc 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -2,6 +2,11 @@
  *
  *      Added conditional policy language extensions
  *
+ *  Updated: Hewlett-Packard <paul.moore@hp.com>
+ *
+ *      Added support for the policy capability bitmap
+ *
+ * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
  * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
  *      This program is free software; you can redistribute it and/or modify
@@ -35,6 +40,11 @@
 #include "objsec.h"
 #include "conditional.h"
 
+/* Policy capability filenames */
+static char *policycap_names[] = {
+        "network_peer_controls"
+};
+
 unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
 
 #ifdef CONFIG_SECURITY_SELINUX_ENABLE_SECMARK_DEFAULT
@@ -72,6 +82,9 @@ static int *bool_pending_values = NULL;
 static struct dentry *class_dir = NULL;
 static unsigned long last_class_ino;
 
+/* global data for policy capabilities */
+static struct dentry *policycap_dir = NULL;
+
 extern void selnl_notify_setenforce(int val);
 
 /* Check whether a task is allowed to use a security operation. */
@@ -111,10 +124,11 @@ enum sel_inos {
 
 static unsigned long sel_last_ino = SEL_INO_NEXT - 1;
 
-#define SEL_INITCON_INO_OFFSET  0x01000000
-#define SEL_BOOL_INO_OFFSET     0x02000000
-#define SEL_CLASS_INO_OFFSET    0x04000000
-#define SEL_INO_MASK            0x00ffffff
+#define SEL_INITCON_INO_OFFSET          0x01000000
+#define SEL_BOOL_INO_OFFSET             0x02000000
+#define SEL_CLASS_INO_OFFSET            0x04000000
+#define SEL_POLICYCAP_INO_OFFSET        0x08000000
+#define SEL_INO_MASK                    0x00ffffff
 
 #define TMPBUFLEN       12
 static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
@@ -263,6 +277,7 @@ static const struct file_operations sel_policyvers_ops = {
 /* declaration for sel_write_load */
 static int sel_make_bools(void);
 static int sel_make_classes(void);
+static int sel_make_policycap(void);
 
 /* declaration for sel_make_class_dirs */
 static int sel_make_dir(struct inode *dir, struct dentry *dentry,
@@ -323,6 +338,12 @@ static ssize_t sel_write_load(struct file * file, const char __user * buf,
         }
 
         ret = sel_make_classes();
+        if (ret) {
+                length = ret;
+                goto out1;
+        }
+
+        ret = sel_make_policycap();
         if (ret)
                 length = ret;
         else
@@ -1399,6 +1420,24 @@ static const struct file_operations sel_perm_ops = {
         .read           = sel_read_perm,
 };
 
+static ssize_t sel_read_policycap(struct file *file, char __user *buf,
+                                  size_t count, loff_t *ppos)
+{
+        int value;
+        char tmpbuf[TMPBUFLEN];
+        ssize_t length;
+        unsigned long i_ino = file->f_path.dentry->d_inode->i_ino;
+
+        value = security_policycap_supported(i_ino & SEL_INO_MASK);
+        length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
+
+        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
+}
+
+static const struct file_operations sel_policycap_ops = {
+        .read           = sel_read_policycap,
+};
+
 static int sel_make_perm_files(char *objclass, int classvalue,
                                 struct dentry *dir)
 {
@@ -1545,6 +1584,36 @@ out:
         return rc;
 }
 
+static int sel_make_policycap(void)
+{
+        unsigned int iter;
+        struct dentry *dentry = NULL;
+        struct inode *inode = NULL;
+
+        sel_remove_entries(policycap_dir);
+
+        for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
+                if (iter < ARRAY_SIZE(policycap_names))
+                        dentry = d_alloc_name(policycap_dir,
+                                              policycap_names[iter]);
+                else
+                        dentry = d_alloc_name(policycap_dir, "unknown");
+
+                if (dentry == NULL)
+                        return -ENOMEM;
+
+                inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
+                if (inode == NULL)
+                        return -ENOMEM;
+
+                inode->i_fop = &sel_policycap_ops;
+                inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
+                d_add(dentry, inode);
+        }
+
+        return 0;
+}
+
 static int sel_make_dir(struct inode *dir, struct dentry *dentry,
                         unsigned long *ino)
 {
@@ -1673,6 +1742,18 @@ static int sel_fill_super(struct super_block * sb, void * data, int silent)
 
         class_dir = dentry;
 
+        dentry = d_alloc_name(sb->s_root, "policy_capabilities");
+        if (!dentry) {
+                ret = -ENOMEM;
+                goto err;
+        }
+
+        ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
+        if (ret)
+                goto err;
+
+        policycap_dir = dentry;
+
 out:
         return ret;
 err: